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Update README.md
[youtubedl] / youtube_dl / extractor / youtube.py
index a8103684301eef0711fdb1f28bd15dcb40c6430b..02f3ab61aef7be11e68f7f16985823b9d908e70e 100644 (file)
 # coding: utf-8
 
-import collections
-import errno
-import io
+from __future__ import unicode_literals
+
+
 import itertools
 import json
 import os.path
+import random
 import re
-import string
-import struct
+import time
 import traceback
-import zlib
 
 from .common import InfoExtractor, SearchInfoExtractor
-from .subtitles import SubtitlesInfoExtractor
-from ..utils import (
+from ..jsinterp import JSInterpreter
+from ..swfinterp import SWFInterpreter
+from ..compat import (
     compat_chr,
+    compat_HTTPError,
+    compat_kwargs,
     compat_parse_qs,
-    compat_urllib_parse,
-    compat_urllib_request,
+    compat_urllib_parse_unquote,
+    compat_urllib_parse_unquote_plus,
+    compat_urllib_parse_urlencode,
+    compat_urllib_parse_urlparse,
     compat_urlparse,
     compat_str,
-
+)
+from ..utils import (
+    bool_or_none,
     clean_html,
-    get_cachedir,
-    get_element_by_id,
-    get_element_by_attribute,
+    error_to_compat_str,
+    extract_attributes,
     ExtractorError,
+    float_or_none,
+    get_element_by_attribute,
+    get_element_by_id,
     int_or_none,
-    PagedList,
-    RegexNotFoundError,
+    mimetype2ext,
+    orderedSet,
+    parse_codecs,
+    parse_duration,
+    remove_quotes,
+    remove_start,
+    smuggle_url,
+    str_or_none,
+    str_to_int,
+    try_get,
     unescapeHTML,
     unified_strdate,
-    orderedSet,
-    write_json_file,
+    unsmuggle_url,
     uppercase_escape,
+    url_or_none,
+    urlencode_postdata,
 )
 
+
 class YoutubeBaseInfoExtractor(InfoExtractor):
     """Provide base functions for Youtube extractors"""
     _LOGIN_URL = 'https://accounts.google.com/ServiceLogin'
-    _LANG_URL = r'https://www.youtube.com/?hl=en&persist_hl=1&gl=US&persist_gl=1&opt_out_ackd=1'
-    _AGE_URL = 'https://www.youtube.com/verify_age?next_url=/&gl=US&hl=en'
+    _TWOFACTOR_URL = 'https://accounts.google.com/signin/challenge'
+
+    _LOOKUP_URL = 'https://accounts.google.com/_/signin/sl/lookup'
+    _CHALLENGE_URL = 'https://accounts.google.com/_/signin/sl/challenge'
+    _TFA_URL = 'https://accounts.google.com/_/signin/challenge?hl=en&TL={0}'
+
     _NETRC_MACHINE = 'youtube'
     # If True it will raise an error if no login info is provided
     _LOGIN_REQUIRED = False
 
+    _PLAYLIST_ID_RE = r'(?:PL|LL|EC|UU|FL|RD|UL|TL|PU|OLAK5uy_)[0-9A-Za-z-_]{10,}'
+
+    _YOUTUBE_CLIENT_HEADERS = {
+        'x-youtube-client-name': '1',
+        'x-youtube-client-version': '1.20200609.04.02',
+    }
+
     def _set_language(self):
-        return bool(self._download_webpage(
-            self._LANG_URL, None,
-            note=u'Setting language', errnote='unable to set language',
-            fatal=False))
+        self._set_cookie(
+            '.youtube.com', 'PREF', 'f1=50000000&f6=8&hl=en',
+            # YouTube sets the expire time to about two months
+            expire_time=time.time() + 2 * 30 * 24 * 3600)
+
+    def _ids_to_results(self, ids):
+        return [
+            self.url_result(vid_id, 'Youtube', video_id=vid_id)
+            for vid_id in ids]
 
     def _login(self):
-        (username, password) = self._get_login_info()
+        """
+        Attempt to log in to YouTube.
+        True is returned if successful or skipped.
+        False is returned if login failed.
+
+        If _LOGIN_REQUIRED is set and no authentication was provided, an error is raised.
+        """
+        username, password = self._get_login_info()
         # No authentication to be performed
         if username is None:
-            if self._LOGIN_REQUIRED:
-                raise ExtractorError(u'No login info available, needed for using %s.' % self.IE_NAME, expected=True)
-            return False
+            if self._LOGIN_REQUIRED and self._downloader.params.get('cookiefile') is None:
+                raise ExtractorError('No login info available, needed for using %s.' % self.IE_NAME, expected=True)
+            return True
 
         login_page = self._download_webpage(
             self._LOGIN_URL, None,
-            note=u'Downloading login page',
-            errnote=u'unable to fetch login page', fatal=False)
+            note='Downloading login page',
+            errnote='unable to fetch login page', fatal=False)
         if login_page is False:
             return
 
-        galx = self._search_regex(r'(?s)<input.+?name="GALX".+?value="(.+?)"',
-                                  login_page, u'Login GALX parameter')
-
-        # Log in
-        login_form_strs = {
-                u'continue': u'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
-                u'Email': username,
-                u'GALX': galx,
-                u'Passwd': password,
-                u'PersistentCookie': u'yes',
-                u'_utf8': u'霱',
-                u'bgresponse': u'js_disabled',
-                u'checkConnection': u'',
-                u'checkedDomains': u'youtube',
-                u'dnConn': u'',
-                u'pstMsg': u'0',
-                u'rmShown': u'1',
-                u'secTok': u'',
-                u'signIn': u'Sign in',
-                u'timeStmp': u'',
-                u'service': u'youtube',
-                u'uilel': u'3',
-                u'hl': u'en_US',
-        }
-        # Convert to UTF-8 *before* urlencode because Python 2.x's urlencode
-        # chokes on unicode
-        login_form = dict((k.encode('utf-8'), v.encode('utf-8')) for k,v in login_form_strs.items())
-        login_data = compat_urllib_parse.urlencode(login_form).encode('ascii')
-
-        req = compat_urllib_request.Request(self._LOGIN_URL, login_data)
-        login_results = self._download_webpage(
-            req, None,
-            note=u'Logging in', errnote=u'unable to log in', fatal=False)
-        if login_results is False:
+        login_form = self._hidden_inputs(login_page)
+
+        def req(url, f_req, note, errnote):
+            data = login_form.copy()
+            data.update({
+                'pstMsg': 1,
+                'checkConnection': 'youtube',
+                'checkedDomains': 'youtube',
+                'hl': 'en',
+                'deviceinfo': '[null,null,null,[],null,"US",null,null,[],"GlifWebSignIn",null,[null,null,[]]]',
+                'f.req': json.dumps(f_req),
+                'flowName': 'GlifWebSignIn',
+                'flowEntry': 'ServiceLogin',
+                # TODO: reverse actual botguard identifier generation algo
+                'bgRequest': '["identifier",""]',
+            })
+            return self._download_json(
+                url, None, note=note, errnote=errnote,
+                transform_source=lambda s: re.sub(r'^[^[]*', '', s),
+                fatal=False,
+                data=urlencode_postdata(data), headers={
+                    'Content-Type': 'application/x-www-form-urlencoded;charset=utf-8',
+                    'Google-Accounts-XSRF': 1,
+                })
+
+        def warn(message):
+            self._downloader.report_warning(message)
+
+        lookup_req = [
+            username,
+            None, [], None, 'US', None, None, 2, False, True,
+            [
+                None, None,
+                [2, 1, None, 1,
+                 'https://accounts.google.com/ServiceLogin?passive=true&continue=https%3A%2F%2Fwww.youtube.com%2Fsignin%3Fnext%3D%252F%26action_handle_signin%3Dtrue%26hl%3Den%26app%3Ddesktop%26feature%3Dsign_in_button&hl=en&service=youtube&uilel=3&requestPath=%2FServiceLogin&Page=PasswordSeparationSignIn',
+                 None, [], 4],
+                1, [None, None, []], None, None, None, True
+            ],
+            username,
+        ]
+
+        lookup_results = req(
+            self._LOOKUP_URL, lookup_req,
+            'Looking up account info', 'Unable to look up account info')
+
+        if lookup_results is False:
             return False
-        if re.search(r'(?i)<form[^>]* id="gaia_loginform"', login_results) is not None:
-            self._downloader.report_warning(u'unable to log in: bad username or password')
+
+        user_hash = try_get(lookup_results, lambda x: x[0][2], compat_str)
+        if not user_hash:
+            warn('Unable to extract user hash')
             return False
-        return True
 
-    def _confirm_age(self):
-        age_form = {
-            'next_url': '/',
-            'action_confirm': 'Confirm',
-        }
-        req = compat_urllib_request.Request(self._AGE_URL,
-            compat_urllib_parse.urlencode(age_form).encode('ascii'))
+        challenge_req = [
+            user_hash,
+            None, 1, None, [1, None, None, None, [password, None, True]],
+            [
+                None, None, [2, 1, None, 1, 'https://accounts.google.com/ServiceLogin?passive=true&continue=https%3A%2F%2Fwww.youtube.com%2Fsignin%3Fnext%3D%252F%26action_handle_signin%3Dtrue%26hl%3Den%26app%3Ddesktop%26feature%3Dsign_in_button&hl=en&service=youtube&uilel=3&requestPath=%2FServiceLogin&Page=PasswordSeparationSignIn', None, [], 4],
+                1, [None, None, []], None, None, None, True
+            ]]
+
+        challenge_results = req(
+            self._CHALLENGE_URL, challenge_req,
+            'Logging in', 'Unable to log in')
+
+        if challenge_results is False:
+            return
+
+        login_res = try_get(challenge_results, lambda x: x[0][5], list)
+        if login_res:
+            login_msg = try_get(login_res, lambda x: x[5], compat_str)
+            warn(
+                'Unable to login: %s' % 'Invalid password'
+                if login_msg == 'INCORRECT_ANSWER_ENTERED' else login_msg)
+            return False
+
+        res = try_get(challenge_results, lambda x: x[0][-1], list)
+        if not res:
+            warn('Unable to extract result entry')
+            return False
+
+        login_challenge = try_get(res, lambda x: x[0][0], list)
+        if login_challenge:
+            challenge_str = try_get(login_challenge, lambda x: x[2], compat_str)
+            if challenge_str == 'TWO_STEP_VERIFICATION':
+                # SEND_SUCCESS - TFA code has been successfully sent to phone
+                # QUOTA_EXCEEDED - reached the limit of TFA codes
+                status = try_get(login_challenge, lambda x: x[5], compat_str)
+                if status == 'QUOTA_EXCEEDED':
+                    warn('Exceeded the limit of TFA codes, try later')
+                    return False
+
+                tl = try_get(challenge_results, lambda x: x[1][2], compat_str)
+                if not tl:
+                    warn('Unable to extract TL')
+                    return False
+
+                tfa_code = self._get_tfa_info('2-step verification code')
+
+                if not tfa_code:
+                    warn(
+                        'Two-factor authentication required. Provide it either interactively or with --twofactor <code>'
+                        '(Note that only TOTP (Google Authenticator App) codes work at this time.)')
+                    return False
+
+                tfa_code = remove_start(tfa_code, 'G-')
+
+                tfa_req = [
+                    user_hash, None, 2, None,
+                    [
+                        9, None, None, None, None, None, None, None,
+                        [None, tfa_code, True, 2]
+                    ]]
+
+                tfa_results = req(
+                    self._TFA_URL.format(tl), tfa_req,
+                    'Submitting TFA code', 'Unable to submit TFA code')
+
+                if tfa_results is False:
+                    return False
+
+                tfa_res = try_get(tfa_results, lambda x: x[0][5], list)
+                if tfa_res:
+                    tfa_msg = try_get(tfa_res, lambda x: x[5], compat_str)
+                    warn(
+                        'Unable to finish TFA: %s' % 'Invalid TFA code'
+                        if tfa_msg == 'INCORRECT_ANSWER_ENTERED' else tfa_msg)
+                    return False
+
+                check_cookie_url = try_get(
+                    tfa_results, lambda x: x[0][-1][2], compat_str)
+            else:
+                CHALLENGES = {
+                    'LOGIN_CHALLENGE': "This device isn't recognized. For your security, Google wants to make sure it's really you.",
+                    'USERNAME_RECOVERY': 'Please provide additional information to aid in the recovery process.',
+                    'REAUTH': "There is something unusual about your activity. For your security, Google wants to make sure it's really you.",
+                }
+                challenge = CHALLENGES.get(
+                    challenge_str,
+                    '%s returned error %s.' % (self.IE_NAME, challenge_str))
+                warn('%s\nGo to https://accounts.google.com/, login and solve a challenge.' % challenge)
+                return False
+        else:
+            check_cookie_url = try_get(res, lambda x: x[2], compat_str)
+
+        if not check_cookie_url:
+            warn('Unable to extract CheckCookie URL')
+            return False
+
+        check_cookie_results = self._download_webpage(
+            check_cookie_url, None, 'Checking cookie', fatal=False)
+
+        if check_cookie_results is False:
+            return False
+
+        if 'https://myaccount.google.com/' not in check_cookie_results:
+            warn('Unable to log in')
+            return False
 
-        self._download_webpage(
-            req, None,
-            note=u'Confirming age', errnote=u'Unable to confirm age')
         return True
 
+    def _download_webpage_handle(self, *args, **kwargs):
+        query = kwargs.get('query', {}).copy()
+        query['disable_polymer'] = 'true'
+        kwargs['query'] = query
+        return super(YoutubeBaseInfoExtractor, self)._download_webpage_handle(
+            *args, **compat_kwargs(kwargs))
+
     def _real_initialize(self):
         if self._downloader is None:
             return
-        if not self._set_language():
-            return
+        self._set_language()
         if not self._login():
             return
-        self._confirm_age()
 
 
-class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
-    IE_DESC = u'YouTube.com'
+class YoutubeEntryListBaseInfoExtractor(YoutubeBaseInfoExtractor):
+    # Extract entries from page with "Load more" button
+    def _entries(self, page, playlist_id):
+        more_widget_html = content_html = page
+        for page_num in itertools.count(1):
+            for entry in self._process_page(content_html):
+                yield entry
+
+            mobj = re.search(r'data-uix-load-more-href="/?(?P<more>[^"]+)"', more_widget_html)
+            if not mobj:
+                break
+
+            count = 0
+            retries = 3
+            while count <= retries:
+                try:
+                    # Downloading page may result in intermittent 5xx HTTP error
+                    # that is usually worked around with a retry
+                    more = self._download_json(
+                        'https://www.youtube.com/%s' % mobj.group('more'), playlist_id,
+                        'Downloading page #%s%s'
+                        % (page_num, ' (retry #%d)' % count if count else ''),
+                        transform_source=uppercase_escape,
+                        headers=self._YOUTUBE_CLIENT_HEADERS)
+                    break
+                except ExtractorError as e:
+                    if isinstance(e.cause, compat_HTTPError) and e.cause.code in (500, 503):
+                        count += 1
+                        if count <= retries:
+                            continue
+                    raise
+
+            content_html = more['content_html']
+            if not content_html.strip():
+                # Some webpages show a "Load more" button but they don't
+                # have more videos
+                break
+            more_widget_html = more['load_more_widget_html']
+
+
+class YoutubePlaylistBaseInfoExtractor(YoutubeEntryListBaseInfoExtractor):
+    def _process_page(self, content):
+        for video_id, video_title in self.extract_videos_from_page(content):
+            yield self.url_result(video_id, 'Youtube', video_id, video_title)
+
+    def extract_videos_from_page_impl(self, video_re, page, ids_in_page, titles_in_page):
+        for mobj in re.finditer(video_re, page):
+            # The link with index 0 is not the first video of the playlist (not sure if still actual)
+            if 'index' in mobj.groupdict() and mobj.group('id') == '0':
+                continue
+            video_id = mobj.group('id')
+            video_title = unescapeHTML(
+                mobj.group('title')) if 'title' in mobj.groupdict() else None
+            if video_title:
+                video_title = video_title.strip()
+            if video_title == '► Play all':
+                video_title = None
+            try:
+                idx = ids_in_page.index(video_id)
+                if video_title and not titles_in_page[idx]:
+                    titles_in_page[idx] = video_title
+            except ValueError:
+                ids_in_page.append(video_id)
+                titles_in_page.append(video_title)
+
+    def extract_videos_from_page(self, page):
+        ids_in_page = []
+        titles_in_page = []
+        self.extract_videos_from_page_impl(
+            self._VIDEO_RE, page, ids_in_page, titles_in_page)
+        return zip(ids_in_page, titles_in_page)
+
+
+class YoutubePlaylistsBaseInfoExtractor(YoutubeEntryListBaseInfoExtractor):
+    def _process_page(self, content):
+        for playlist_id in orderedSet(re.findall(
+                r'<h3[^>]+class="[^"]*yt-lockup-title[^"]*"[^>]*><a[^>]+href="/?playlist\?list=([0-9A-Za-z-_]{10,})"',
+                content)):
+            yield self.url_result(
+                'https://www.youtube.com/playlist?list=%s' % playlist_id, 'YoutubePlaylist')
+
+    def _real_extract(self, url):
+        playlist_id = self._match_id(url)
+        webpage = self._download_webpage(url, playlist_id)
+        title = self._og_search_title(webpage, fatal=False)
+        return self.playlist_result(self._entries(webpage, playlist_id), playlist_id, title)
+
+
+class YoutubeIE(YoutubeBaseInfoExtractor):
+    IE_DESC = 'YouTube.com'
     _VALID_URL = r"""(?x)^
                      (
-                         (?:https?://|//)?                                    # http(s):// or protocol-independent URL (optional)
-                         (?:(?:(?:(?:\w+\.)?[yY][oO][uU][tT][uU][bB][eE](?:-nocookie)?\.com/|
+                         (?:https?://|//)                                    # http(s):// or protocol-independent URL
+                         (?:(?:(?:(?:\w+\.)?[yY][oO][uU][tT][uU][bB][eE](?:-nocookie|kids)?\.com/|
                             (?:www\.)?deturl\.com/www\.youtube\.com/|
                             (?:www\.)?pwnyoutube\.com/|
+                            (?:www\.)?hooktube\.com/|
+                            (?:www\.)?yourepeat\.com/|
                             tube\.majestyc\.net/|
+                            # Invidious instances taken from https://github.com/omarroth/invidious/wiki/Invidious-Instances
+                            (?:(?:www|dev)\.)?invidio\.us/|
+                            (?:(?:www|no)\.)?invidiou\.sh/|
+                            (?:(?:www|fi|de)\.)?invidious\.snopyta\.org/|
+                            (?:www\.)?invidious\.kabi\.tk/|
+                            (?:www\.)?invidious\.13ad\.de/|
+                            (?:www\.)?invidious\.mastodon\.host/|
+                            (?:www\.)?invidious\.nixnet\.xyz/|
+                            (?:www\.)?invidious\.drycat\.fr/|
+                            (?:www\.)?tube\.poal\.co/|
+                            (?:www\.)?vid\.wxzm\.sx/|
+                            (?:www\.)?yewtu\.be/|
+                            (?:www\.)?yt\.elukerio\.org/|
+                            (?:www\.)?yt\.lelux\.fi/|
+                            (?:www\.)?invidious\.ggc-project\.de/|
+                            (?:www\.)?yt\.maisputain\.ovh/|
+                            (?:www\.)?invidious\.13ad\.de/|
+                            (?:www\.)?invidious\.toot\.koeln/|
+                            (?:www\.)?invidious\.fdn\.fr/|
+                            (?:www\.)?watch\.nettohikari\.com/|
+                            (?:www\.)?kgg2m7yk5aybusll\.onion/|
+                            (?:www\.)?qklhadlycap4cnod\.onion/|
+                            (?:www\.)?axqzx4s6s54s32yentfqojs3x5i7faxza6xo3ehd4bzzsg2ii4fv2iid\.onion/|
+                            (?:www\.)?c7hqkpkpemu6e7emz5b4vyz7idjgdvgaaa3dyimmeojqbgpea3xqjoid\.onion/|
+                            (?:www\.)?fz253lmuao3strwbfbmx46yu7acac2jz27iwtorgmbqlkurlclmancad\.onion/|
+                            (?:www\.)?invidious\.l4qlywnpwqsluw65ts7md3khrivpirse744un3x7mlskqauz5pyuzgqd\.onion/|
+                            (?:www\.)?owxfohz4kjyv25fvlqilyxast7inivgiktls3th44jhk3ej3i7ya\.b32\.i2p/|
+                            (?:www\.)?4l2dgddgsrkf2ous66i6seeyi6etzfgrue332grh2n7madpwopotugyd\.onion/|
                             youtube\.googleapis\.com/)                        # the various hostnames, with wildcard subdomains
                          (?:.*?\#/)?                                          # handle anchor (#/) redirect urls
                          (?:                                                  # the various things that can precede the ID:
-                             (?:(?:v|embed|e)/)                               # v/ or embed/ or e/
+                             (?:(?:v|embed|e)/(?!videoseries))                # v/ or embed/ or e/
                              |(?:                                             # or the v= param in all its forms
-                                 (?:(?:watch|movie)(?:_popup)?(?:\.php)?)?    # preceding watch(_popup|.php) or nothing (like /?v=xxxx)
+                                 (?:(?:watch|movie)(?:_popup)?(?:\.php)?/?)?  # preceding watch(_popup|.php) or nothing (like /?v=xxxx)
                                  (?:\?|\#!?)                                  # the params delimiter ? or # or #!
-                                 (?:.*?&)?                                    # any other preceding param (like /?s=tuff&v=xxxx)
+                                 (?:.*?[&;])??                                # any other preceding param (like /?s=tuff&v=xxxx or ?s=tuff&amp;v=V36LpHqtcDY)
                                  v=
                              )
                          ))
-                         |youtu\.be/                                          # just youtu.be/xxxx
+                         |(?:
+                            youtu\.be|                                        # just youtu.be/xxxx
+                            vid\.plus|                                        # or vid.plus/xxxx
+                            zwearz\.com/watch|                                # or zwearz.com/watch/xxxx
+                         )/
+                         |(?:www\.)?cleanvideosearch\.com/media/action/yt/watch\?videoId=
                          )
                      )?                                                       # all until now is optional -> you can pass the naked ID
                      ([0-9A-Za-z_-]{11})                                      # here is it! the YouTube video ID
+                     (?!.*?\blist=
+                        (?:
+                            %(playlist_id)s|                                  # combined list/video URLs are handled by the playlist IE
+                            WL                                                # WL are handled by the watch later IE
+                        )
+                     )
                      (?(1).+)?                                                # if we found the ID, everything can follow
-                     $"""
+                     $""" % {'playlist_id': YoutubeBaseInfoExtractor._PLAYLIST_ID_RE}
     _NEXT_URL_RE = r'[\?&]next_url=([^&]+)'
+    _PLAYER_INFO_RE = (
+        r'/(?P<id>[a-zA-Z0-9_-]{8,})/player_ias\.vflset(?:/[a-zA-Z]{2,3}_[a-zA-Z]{2,3})?/base\.(?P<ext>[a-z]+)$',
+        r'\b(?P<id>vfl[a-zA-Z0-9_-]+)\b.*?\.(?P<ext>[a-z]+)$',
+    )
     _formats = {
-        '5': {'ext': 'flv', 'width': 400, 'height': 240},
-        '6': {'ext': 'flv', 'width': 450, 'height': 270},
-        '13': {'ext': '3gp'},
-        '17': {'ext': '3gp', 'width': 176, 'height': 144},
-        '18': {'ext': 'mp4', 'width': 640, 'height': 360},
-        '22': {'ext': 'mp4', 'width': 1280, 'height': 720},
-        '34': {'ext': 'flv', 'width': 640, 'height': 360},
-        '35': {'ext': 'flv', 'width': 854, 'height': 480},
-        '36': {'ext': '3gp', 'width': 320, 'height': 240},
-        '37': {'ext': 'mp4', 'width': 1920, 'height': 1080},
-        '38': {'ext': 'mp4', 'width': 4096, 'height': 3072},
-        '43': {'ext': 'webm', 'width': 640, 'height': 360},
-        '44': {'ext': 'webm', 'width': 854, 'height': 480},
-        '45': {'ext': 'webm', 'width': 1280, 'height': 720},
-        '46': {'ext': 'webm', 'width': 1920, 'height': 1080},
-
-
-        # 3d videos
-        '82': {'ext': 'mp4', 'height': 360, 'resolution': '360p', 'format_note': '3D', 'preference': -20},
-        '83': {'ext': 'mp4', 'height': 480, 'resolution': '480p', 'format_note': '3D', 'preference': -20},
-        '84': {'ext': 'mp4', 'height': 720, 'resolution': '720p', 'format_note': '3D', 'preference': -20},
-        '85': {'ext': 'mp4', 'height': 1080, 'resolution': '1080p', 'format_note': '3D', 'preference': -20},
-        '100': {'ext': 'webm', 'height': 360, 'resolution': '360p', 'format_note': '3D', 'preference': -20},
-        '101': {'ext': 'webm', 'height': 480, 'resolution': '480p', 'format_note': '3D', 'preference': -20},
-        '102': {'ext': 'webm', 'height': 720, 'resolution': '720p', 'format_note': '3D', 'preference': -20},
+        '5': {'ext': 'flv', 'width': 400, 'height': 240, 'acodec': 'mp3', 'abr': 64, 'vcodec': 'h263'},
+        '6': {'ext': 'flv', 'width': 450, 'height': 270, 'acodec': 'mp3', 'abr': 64, 'vcodec': 'h263'},
+        '13': {'ext': '3gp', 'acodec': 'aac', 'vcodec': 'mp4v'},
+        '17': {'ext': '3gp', 'width': 176, 'height': 144, 'acodec': 'aac', 'abr': 24, 'vcodec': 'mp4v'},
+        '18': {'ext': 'mp4', 'width': 640, 'height': 360, 'acodec': 'aac', 'abr': 96, 'vcodec': 'h264'},
+        '22': {'ext': 'mp4', 'width': 1280, 'height': 720, 'acodec': 'aac', 'abr': 192, 'vcodec': 'h264'},
+        '34': {'ext': 'flv', 'width': 640, 'height': 360, 'acodec': 'aac', 'abr': 128, 'vcodec': 'h264'},
+        '35': {'ext': 'flv', 'width': 854, 'height': 480, 'acodec': 'aac', 'abr': 128, 'vcodec': 'h264'},
+        # itag 36 videos are either 320x180 (BaW_jenozKc) or 320x240 (__2ABJjxzNo), abr varies as well
+        '36': {'ext': '3gp', 'width': 320, 'acodec': 'aac', 'vcodec': 'mp4v'},
+        '37': {'ext': 'mp4', 'width': 1920, 'height': 1080, 'acodec': 'aac', 'abr': 192, 'vcodec': 'h264'},
+        '38': {'ext': 'mp4', 'width': 4096, 'height': 3072, 'acodec': 'aac', 'abr': 192, 'vcodec': 'h264'},
+        '43': {'ext': 'webm', 'width': 640, 'height': 360, 'acodec': 'vorbis', 'abr': 128, 'vcodec': 'vp8'},
+        '44': {'ext': 'webm', 'width': 854, 'height': 480, 'acodec': 'vorbis', 'abr': 128, 'vcodec': 'vp8'},
+        '45': {'ext': 'webm', 'width': 1280, 'height': 720, 'acodec': 'vorbis', 'abr': 192, 'vcodec': 'vp8'},
+        '46': {'ext': 'webm', 'width': 1920, 'height': 1080, 'acodec': 'vorbis', 'abr': 192, 'vcodec': 'vp8'},
+        '59': {'ext': 'mp4', 'width': 854, 'height': 480, 'acodec': 'aac', 'abr': 128, 'vcodec': 'h264'},
+        '78': {'ext': 'mp4', 'width': 854, 'height': 480, 'acodec': 'aac', 'abr': 128, 'vcodec': 'h264'},
+
+
+        # 3D videos
+        '82': {'ext': 'mp4', 'height': 360, 'format_note': '3D', 'acodec': 'aac', 'abr': 128, 'vcodec': 'h264', 'preference': -20},
+        '83': {'ext': 'mp4', 'height': 480, 'format_note': '3D', 'acodec': 'aac', 'abr': 128, 'vcodec': 'h264', 'preference': -20},
+        '84': {'ext': 'mp4', 'height': 720, 'format_note': '3D', 'acodec': 'aac', 'abr': 192, 'vcodec': 'h264', 'preference': -20},
+        '85': {'ext': 'mp4', 'height': 1080, 'format_note': '3D', 'acodec': 'aac', 'abr': 192, 'vcodec': 'h264', 'preference': -20},
+        '100': {'ext': 'webm', 'height': 360, 'format_note': '3D', 'acodec': 'vorbis', 'abr': 128, 'vcodec': 'vp8', 'preference': -20},
+        '101': {'ext': 'webm', 'height': 480, 'format_note': '3D', 'acodec': 'vorbis', 'abr': 192, 'vcodec': 'vp8', 'preference': -20},
+        '102': {'ext': 'webm', 'height': 720, 'format_note': '3D', 'acodec': 'vorbis', 'abr': 192, 'vcodec': 'vp8', 'preference': -20},
 
         # Apple HTTP Live Streaming
-        '92': {'ext': 'mp4', 'height': 240, 'resolution': '240p', 'format_note': 'HLS', 'preference': -10},
-        '93': {'ext': 'mp4', 'height': 360, 'resolution': '360p', 'format_note': 'HLS', 'preference': -10},
-        '94': {'ext': 'mp4', 'height': 480, 'resolution': '480p', 'format_note': 'HLS', 'preference': -10},
-        '95': {'ext': 'mp4', 'height': 720, 'resolution': '720p', 'format_note': 'HLS', 'preference': -10},
-        '96': {'ext': 'mp4', 'height': 1080, 'resolution': '1080p', 'format_note': 'HLS', 'preference': -10},
-        '132': {'ext': 'mp4', 'height': 240, 'resolution': '240p', 'format_note': 'HLS', 'preference': -10},
-        '151': {'ext': 'mp4', 'height': 72, 'resolution': '72p', 'format_note': 'HLS', 'preference': -10},
+        '91': {'ext': 'mp4', 'height': 144, 'format_note': 'HLS', 'acodec': 'aac', 'abr': 48, 'vcodec': 'h264', 'preference': -10},
+        '92': {'ext': 'mp4', 'height': 240, 'format_note': 'HLS', 'acodec': 'aac', 'abr': 48, 'vcodec': 'h264', 'preference': -10},
+        '93': {'ext': 'mp4', 'height': 360, 'format_note': 'HLS', 'acodec': 'aac', 'abr': 128, 'vcodec': 'h264', 'preference': -10},
+        '94': {'ext': 'mp4', 'height': 480, 'format_note': 'HLS', 'acodec': 'aac', 'abr': 128, 'vcodec': 'h264', 'preference': -10},
+        '95': {'ext': 'mp4', 'height': 720, 'format_note': 'HLS', 'acodec': 'aac', 'abr': 256, 'vcodec': 'h264', 'preference': -10},
+        '96': {'ext': 'mp4', 'height': 1080, 'format_note': 'HLS', 'acodec': 'aac', 'abr': 256, 'vcodec': 'h264', 'preference': -10},
+        '132': {'ext': 'mp4', 'height': 240, 'format_note': 'HLS', 'acodec': 'aac', 'abr': 48, 'vcodec': 'h264', 'preference': -10},
+        '151': {'ext': 'mp4', 'height': 72, 'format_note': 'HLS', 'acodec': 'aac', 'abr': 24, 'vcodec': 'h264', 'preference': -10},
 
         # DASH mp4 video
-        '133': {'ext': 'mp4', 'height': 240, 'resolution': '240p', 'format_note': 'DASH video', 'preference': -40},
-        '134': {'ext': 'mp4', 'height': 360, 'resolution': '360p', 'format_note': 'DASH video', 'preference': -40},
-        '135': {'ext': 'mp4', 'height': 480, 'resolution': '480p', 'format_note': 'DASH video', 'preference': -40},
-        '136': {'ext': 'mp4', 'height': 720, 'resolution': '720p', 'format_note': 'DASH video', 'preference': -40},
-        '137': {'ext': 'mp4', 'height': 1080, 'resolution': '1080p', 'format_note': 'DASH video', 'preference': -40},
-        '138': {'ext': 'mp4', 'height': 1081, 'resolution': '>1080p', 'format_note': 'DASH video', 'preference': -40},
-        '160': {'ext': 'mp4', 'height': 192, 'resolution': '192p', 'format_note': 'DASH video', 'preference': -40},
-        '264': {'ext': 'mp4', 'height': 1080, 'resolution': '1080p', 'format_note': 'DASH video', 'preference': -40},
+        '133': {'ext': 'mp4', 'height': 240, 'format_note': 'DASH video', 'vcodec': 'h264'},
+        '134': {'ext': 'mp4', 'height': 360, 'format_note': 'DASH video', 'vcodec': 'h264'},
+        '135': {'ext': 'mp4', 'height': 480, 'format_note': 'DASH video', 'vcodec': 'h264'},
+        '136': {'ext': 'mp4', 'height': 720, 'format_note': 'DASH video', 'vcodec': 'h264'},
+        '137': {'ext': 'mp4', 'height': 1080, 'format_note': 'DASH video', 'vcodec': 'h264'},
+        '138': {'ext': 'mp4', 'format_note': 'DASH video', 'vcodec': 'h264'},  # Height can vary (https://github.com/ytdl-org/youtube-dl/issues/4559)
+        '160': {'ext': 'mp4', 'height': 144, 'format_note': 'DASH video', 'vcodec': 'h264'},
+        '212': {'ext': 'mp4', 'height': 480, 'format_note': 'DASH video', 'vcodec': 'h264'},
+        '264': {'ext': 'mp4', 'height': 1440, 'format_note': 'DASH video', 'vcodec': 'h264'},
+        '298': {'ext': 'mp4', 'height': 720, 'format_note': 'DASH video', 'vcodec': 'h264', 'fps': 60},
+        '299': {'ext': 'mp4', 'height': 1080, 'format_note': 'DASH video', 'vcodec': 'h264', 'fps': 60},
+        '266': {'ext': 'mp4', 'height': 2160, 'format_note': 'DASH video', 'vcodec': 'h264'},
 
         # Dash mp4 audio
-        '139': {'ext': 'm4a', 'format_note': 'DASH audio', 'vcodec': 'none', 'abr': 48, 'preference': -50},
-        '140': {'ext': 'm4a', 'format_note': 'DASH audio', 'vcodec': 'none', 'abr': 128, 'preference': -50},
-        '141': {'ext': 'm4a', 'format_note': 'DASH audio', 'vcodec': 'none', 'abr': 256, 'preference': -50},
+        '139': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'abr': 48, 'container': 'm4a_dash'},
+        '140': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'abr': 128, 'container': 'm4a_dash'},
+        '141': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'abr': 256, 'container': 'm4a_dash'},
+        '256': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'container': 'm4a_dash'},
+        '258': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'container': 'm4a_dash'},
+        '325': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'dtse', 'container': 'm4a_dash'},
+        '328': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'ec-3', 'container': 'm4a_dash'},
 
         # Dash webm
-        '167': {'ext': 'webm', 'height': 360, 'width': 640, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
-        '168': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
-        '169': {'ext': 'webm', 'height': 720, 'width': 1280, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
-        '170': {'ext': 'webm', 'height': 1080, 'width': 1920, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
-        '218': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
-        '219': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
-        '242': {'ext': 'webm', 'height': 240, 'resolution': '240p', 'format_note': 'DASH webm', 'preference': -40},
-        '243': {'ext': 'webm', 'height': 360, 'resolution': '360p', 'format_note': 'DASH webm', 'preference': -40},
-        '244': {'ext': 'webm', 'height': 480, 'resolution': '480p', 'format_note': 'DASH webm', 'preference': -40},
-        '245': {'ext': 'webm', 'height': 480, 'resolution': '480p', 'format_note': 'DASH webm', 'preference': -40},
-        '246': {'ext': 'webm', 'height': 480, 'resolution': '480p', 'format_note': 'DASH webm', 'preference': -40},
-        '247': {'ext': 'webm', 'height': 720, 'resolution': '720p', 'format_note': 'DASH webm', 'preference': -40},
-        '248': {'ext': 'webm', 'height': 1080, 'resolution': '1080p', 'format_note': 'DASH webm', 'preference': -40},
+        '167': {'ext': 'webm', 'height': 360, 'width': 640, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'vp8'},
+        '168': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'vp8'},
+        '169': {'ext': 'webm', 'height': 720, 'width': 1280, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'vp8'},
+        '170': {'ext': 'webm', 'height': 1080, 'width': 1920, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'vp8'},
+        '218': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'vp8'},
+        '219': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'vp8'},
+        '278': {'ext': 'webm', 'height': 144, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'vp9'},
+        '242': {'ext': 'webm', 'height': 240, 'format_note': 'DASH video', 'vcodec': 'vp9'},
+        '243': {'ext': 'webm', 'height': 360, 'format_note': 'DASH video', 'vcodec': 'vp9'},
+        '244': {'ext': 'webm', 'height': 480, 'format_note': 'DASH video', 'vcodec': 'vp9'},
+        '245': {'ext': 'webm', 'height': 480, 'format_note': 'DASH video', 'vcodec': 'vp9'},
+        '246': {'ext': 'webm', 'height': 480, 'format_note': 'DASH video', 'vcodec': 'vp9'},
+        '247': {'ext': 'webm', 'height': 720, 'format_note': 'DASH video', 'vcodec': 'vp9'},
+        '248': {'ext': 'webm', 'height': 1080, 'format_note': 'DASH video', 'vcodec': 'vp9'},
+        '271': {'ext': 'webm', 'height': 1440, 'format_note': 'DASH video', 'vcodec': 'vp9'},
+        # itag 272 videos are either 3840x2160 (e.g. RtoitU2A-3E) or 7680x4320 (sLprVF6d7Ug)
+        '272': {'ext': 'webm', 'height': 2160, 'format_note': 'DASH video', 'vcodec': 'vp9'},
+        '302': {'ext': 'webm', 'height': 720, 'format_note': 'DASH video', 'vcodec': 'vp9', 'fps': 60},
+        '303': {'ext': 'webm', 'height': 1080, 'format_note': 'DASH video', 'vcodec': 'vp9', 'fps': 60},
+        '308': {'ext': 'webm', 'height': 1440, 'format_note': 'DASH video', 'vcodec': 'vp9', 'fps': 60},
+        '313': {'ext': 'webm', 'height': 2160, 'format_note': 'DASH video', 'vcodec': 'vp9'},
+        '315': {'ext': 'webm', 'height': 2160, 'format_note': 'DASH video', 'vcodec': 'vp9', 'fps': 60},
 
         # Dash webm audio
-        '171': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH webm audio', 'abr': 48, 'preference': -50},
-        '172': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH webm audio', 'abr': 256, 'preference': -50},
+        '171': {'ext': 'webm', 'acodec': 'vorbis', 'format_note': 'DASH audio', 'abr': 128},
+        '172': {'ext': 'webm', 'acodec': 'vorbis', 'format_note': 'DASH audio', 'abr': 256},
+
+        # Dash webm audio with opus inside
+        '249': {'ext': 'webm', 'format_note': 'DASH audio', 'acodec': 'opus', 'abr': 50},
+        '250': {'ext': 'webm', 'format_note': 'DASH audio', 'acodec': 'opus', 'abr': 70},
+        '251': {'ext': 'webm', 'format_note': 'DASH audio', 'acodec': 'opus', 'abr': 160},
 
         # RTMP (unnamed)
         '_rtmp': {'protocol': 'rtmp'},
+
+        # av01 video only formats sometimes served with "unknown" codecs
+        '394': {'acodec': 'none', 'vcodec': 'av01.0.05M.08'},
+        '395': {'acodec': 'none', 'vcodec': 'av01.0.05M.08'},
+        '396': {'acodec': 'none', 'vcodec': 'av01.0.05M.08'},
+        '397': {'acodec': 'none', 'vcodec': 'av01.0.05M.08'},
     }
+    _SUBTITLE_FORMATS = ('srv1', 'srv2', 'srv3', 'ttml', 'vtt')
+
+    _GEO_BYPASS = False
 
-    IE_NAME = u'youtube'
+    IE_NAME = 'youtube'
     _TESTS = [
         {
-            u"url":  u"http://www.youtube.com/watch?v=BaW_jenozKc",
-            u"file":  u"BaW_jenozKc.mp4",
-            u"info_dict": {
-                u"title": u"youtube-dl test video \"'/\\ä↭𝕐",
-                u"uploader": u"Philipp Hagemeister",
-                u"uploader_id": u"phihag",
-                u"upload_date": u"20121002",
-                u"description": u"test chars:  \"'/\\ä↭𝕐\ntest URL: https://github.com/rg3/youtube-dl/issues/1892\n\nThis is a test video for youtube-dl.\n\nFor more information, contact phihag@phihag.de ."
+            'url': 'https://www.youtube.com/watch?v=BaW_jenozKc&t=1s&end=9',
+            'info_dict': {
+                'id': 'BaW_jenozKc',
+                'ext': 'mp4',
+                'title': 'youtube-dl test video "\'/\\ä↭𝕐',
+                'uploader': 'Philipp Hagemeister',
+                'uploader_id': 'phihag',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/phihag',
+                'channel_id': 'UCLqxVugv74EIW3VWh2NOa3Q',
+                'channel_url': r're:https?://(?:www\.)?youtube\.com/channel/UCLqxVugv74EIW3VWh2NOa3Q',
+                'upload_date': '20121002',
+                'description': 'test chars:  "\'/\\ä↭𝕐\ntest URL: https://github.com/rg3/youtube-dl/issues/1892\n\nThis is a test video for youtube-dl.\n\nFor more information, contact phihag@phihag.de .',
+                'categories': ['Science & Technology'],
+                'tags': ['youtube-dl'],
+                'duration': 10,
+                'view_count': int,
+                'like_count': int,
+                'dislike_count': int,
+                'start_time': 1,
+                'end_time': 9,
             }
         },
         {
-            u"url":  u"http://www.youtube.com/watch?v=UxxajLWwzqY",
-            u"file":  u"UxxajLWwzqY.mp4",
-            u"note": u"Test generic use_cipher_signature video (#897)",
-            u"info_dict": {
-                u"upload_date": u"20120506",
-                u"title": u"Icona Pop - I Love It (feat. Charli XCX) [OFFICIAL VIDEO]",
-                u"description": u"md5:5b292926389560516e384ac437c0ec07",
-                u"uploader": u"Icona Pop",
-                u"uploader_id": u"IconaPop"
+            'url': 'https://www.youtube.com/watch?v=UxxajLWwzqY',
+            'note': 'Test generic use_cipher_signature video (#897)',
+            'info_dict': {
+                'id': 'UxxajLWwzqY',
+                'ext': 'mp4',
+                'upload_date': '20120506',
+                'title': 'Icona Pop - I Love It (feat. Charli XCX) [OFFICIAL VIDEO]',
+                'alt_title': 'I Love It (feat. Charli XCX)',
+                'description': 'md5:19a2f98d9032b9311e686ed039564f63',
+                'tags': ['Icona Pop i love it', 'sweden', 'pop music', 'big beat records', 'big beat', 'charli',
+                         'xcx', 'charli xcx', 'girls', 'hbo', 'i love it', "i don't care", 'icona', 'pop',
+                         'iconic ep', 'iconic', 'love', 'it'],
+                'duration': 180,
+                'uploader': 'Icona Pop',
+                'uploader_id': 'IconaPop',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/IconaPop',
+                'creator': 'Icona Pop',
+                'track': 'I Love It (feat. Charli XCX)',
+                'artist': 'Icona Pop',
             }
         },
         {
-            u"url":  u"https://www.youtube.com/watch?v=07FYdnEawAQ",
-            u"file":  u"07FYdnEawAQ.mp4",
-            u"note": u"Test VEVO video with age protection (#956)",
-            u"info_dict": {
-                u"upload_date": u"20130703",
-                u"title": u"Justin Timberlake - Tunnel Vision (Explicit)",
-                u"description": u"md5:64249768eec3bc4276236606ea996373",
-                u"uploader": u"justintimberlakeVEVO",
-                u"uploader_id": u"justintimberlakeVEVO"
+            'url': 'https://www.youtube.com/watch?v=07FYdnEawAQ',
+            'note': 'Test VEVO video with age protection (#956)',
+            'info_dict': {
+                'id': '07FYdnEawAQ',
+                'ext': 'mp4',
+                'upload_date': '20130703',
+                'title': 'Justin Timberlake - Tunnel Vision (Official Music Video) (Explicit)',
+                'alt_title': 'Tunnel Vision',
+                'description': 'md5:07dab3356cde4199048e4c7cd93471e1',
+                'duration': 419,
+                'uploader': 'justintimberlakeVEVO',
+                'uploader_id': 'justintimberlakeVEVO',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/justintimberlakeVEVO',
+                'creator': 'Justin Timberlake',
+                'track': 'Tunnel Vision',
+                'artist': 'Justin Timberlake',
+                'age_limit': 18,
+            }
+        },
+        {
+            'url': '//www.YouTube.com/watch?v=yZIXLfi8CZQ',
+            'note': 'Embed-only video (#1746)',
+            'info_dict': {
+                'id': 'yZIXLfi8CZQ',
+                'ext': 'mp4',
+                'upload_date': '20120608',
+                'title': 'Principal Sexually Assaults A Teacher - Episode 117 - 8th June 2012',
+                'description': 'md5:09b78bd971f1e3e289601dfba15ca4f7',
+                'uploader': 'SET India',
+                'uploader_id': 'setindia',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/setindia',
+                'age_limit': 18,
+            }
+        },
+        {
+            'url': 'https://www.youtube.com/watch?v=BaW_jenozKc&v=UxxajLWwzqY',
+            'note': 'Use the first video ID in the URL',
+            'info_dict': {
+                'id': 'BaW_jenozKc',
+                'ext': 'mp4',
+                'title': 'youtube-dl test video "\'/\\ä↭𝕐',
+                'uploader': 'Philipp Hagemeister',
+                'uploader_id': 'phihag',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/phihag',
+                'upload_date': '20121002',
+                'description': 'test chars:  "\'/\\ä↭𝕐\ntest URL: https://github.com/rg3/youtube-dl/issues/1892\n\nThis is a test video for youtube-dl.\n\nFor more information, contact phihag@phihag.de .',
+                'categories': ['Science & Technology'],
+                'tags': ['youtube-dl'],
+                'duration': 10,
+                'view_count': int,
+                'like_count': int,
+                'dislike_count': int,
+            },
+            'params': {
+                'skip_download': True,
+            },
+        },
+        {
+            'url': 'https://www.youtube.com/watch?v=a9LDPn-MO4I',
+            'note': '256k DASH audio (format 141) via DASH manifest',
+            'info_dict': {
+                'id': 'a9LDPn-MO4I',
+                'ext': 'm4a',
+                'upload_date': '20121002',
+                'uploader_id': '8KVIDEO',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/8KVIDEO',
+                'description': '',
+                'uploader': '8KVIDEO',
+                'title': 'UHDTV TEST 8K VIDEO.mp4'
+            },
+            'params': {
+                'youtube_include_dash_manifest': True,
+                'format': '141',
+            },
+            'skip': 'format 141 not served anymore',
+        },
+        # DASH manifest with encrypted signature
+        {
+            'url': 'https://www.youtube.com/watch?v=IB3lcPjvWLA',
+            'info_dict': {
+                'id': 'IB3lcPjvWLA',
+                'ext': 'm4a',
+                'title': 'Afrojack, Spree Wilson - The Spark (Official Music Video) ft. Spree Wilson',
+                'description': 'md5:8f5e2b82460520b619ccac1f509d43bf',
+                'duration': 244,
+                'uploader': 'AfrojackVEVO',
+                'uploader_id': 'AfrojackVEVO',
+                'upload_date': '20131011',
+            },
+            'params': {
+                'youtube_include_dash_manifest': True,
+                'format': '141/bestaudio[ext=m4a]',
+            },
+        },
+        # JS player signature function name containing $
+        {
+            'url': 'https://www.youtube.com/watch?v=nfWlot6h_JM',
+            'info_dict': {
+                'id': 'nfWlot6h_JM',
+                'ext': 'm4a',
+                'title': 'Taylor Swift - Shake It Off',
+                'description': 'md5:307195cd21ff7fa352270fe884570ef0',
+                'duration': 242,
+                'uploader': 'TaylorSwiftVEVO',
+                'uploader_id': 'TaylorSwiftVEVO',
+                'upload_date': '20140818',
+            },
+            'params': {
+                'youtube_include_dash_manifest': True,
+                'format': '141/bestaudio[ext=m4a]',
+            },
+        },
+        # Controversy video
+        {
+            'url': 'https://www.youtube.com/watch?v=T4XJQO3qol8',
+            'info_dict': {
+                'id': 'T4XJQO3qol8',
+                'ext': 'mp4',
+                'duration': 219,
+                'upload_date': '20100909',
+                'uploader': 'Amazing Atheist',
+                'uploader_id': 'TheAmazingAtheist',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/TheAmazingAtheist',
+                'title': 'Burning Everyone\'s Koran',
+                'description': 'SUBSCRIBE: http://www.youtube.com/saturninefilms\n\nEven Obama has taken a stand against freedom on this issue: http://www.huffingtonpost.com/2010/09/09/obama-gma-interview-quran_n_710282.html',
             }
         },
+        # Normal age-gate video (No vevo, embed allowed)
+        {
+            'url': 'https://youtube.com/watch?v=HtVdAasjOgU',
+            'info_dict': {
+                'id': 'HtVdAasjOgU',
+                'ext': 'mp4',
+                'title': 'The Witcher 3: Wild Hunt - The Sword Of Destiny Trailer',
+                'description': r're:(?s).{100,}About the Game\n.*?The Witcher 3: Wild Hunt.{100,}',
+                'duration': 142,
+                'uploader': 'The Witcher',
+                'uploader_id': 'WitcherGame',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/WitcherGame',
+                'upload_date': '20140605',
+                'age_limit': 18,
+            },
+        },
+        # Age-gate video with encrypted signature
+        {
+            'url': 'https://www.youtube.com/watch?v=6kLq3WMV1nU',
+            'info_dict': {
+                'id': '6kLq3WMV1nU',
+                'ext': 'mp4',
+                'title': 'Dedication To My Ex (Miss That) (Lyric Video)',
+                'description': 'md5:33765bb339e1b47e7e72b5490139bb41',
+                'duration': 246,
+                'uploader': 'LloydVEVO',
+                'uploader_id': 'LloydVEVO',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/LloydVEVO',
+                'upload_date': '20110629',
+                'age_limit': 18,
+            },
+        },
+        # video_info is None (https://github.com/ytdl-org/youtube-dl/issues/4421)
+        # YouTube Red ad is not captured for creator
         {
-            u"url":  u"//www.YouTube.com/watch?v=yZIXLfi8CZQ",
-            u"file":  u"yZIXLfi8CZQ.mp4",
-            u"note": u"Embed-only video (#1746)",
-            u"info_dict": {
-                u"upload_date": u"20120608",
-                u"title": u"Principal Sexually Assaults A Teacher - Episode 117 - 8th June 2012",
-                u"description": u"md5:09b78bd971f1e3e289601dfba15ca4f7",
-                u"uploader": u"SET India",
-                u"uploader_id": u"setindia"
+            'url': '__2ABJjxzNo',
+            'info_dict': {
+                'id': '__2ABJjxzNo',
+                'ext': 'mp4',
+                'duration': 266,
+                'upload_date': '20100430',
+                'uploader_id': 'deadmau5',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/deadmau5',
+                'creator': 'Dada Life, deadmau5',
+                'description': 'md5:12c56784b8032162bb936a5f76d55360',
+                'uploader': 'deadmau5',
+                'title': 'Deadmau5 - Some Chords (HD)',
+                'alt_title': 'This Machine Kills Some Chords',
+            },
+            'expected_warnings': [
+                'DASH manifest missing',
+            ]
+        },
+        # Olympics (https://github.com/ytdl-org/youtube-dl/issues/4431)
+        {
+            'url': 'lqQg6PlCWgI',
+            'info_dict': {
+                'id': 'lqQg6PlCWgI',
+                'ext': 'mp4',
+                'duration': 6085,
+                'upload_date': '20150827',
+                'uploader_id': 'olympic',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/olympic',
+                'description': 'HO09  - Women -  GER-AUS - Hockey - 31 July 2012 - London 2012 Olympic Games',
+                'uploader': 'Olympic',
+                'title': 'Hockey - Women -  GER-AUS - London 2012 Olympic Games',
+            },
+            'params': {
+                'skip_download': 'requires avconv',
             }
         },
+        # Non-square pixels
+        {
+            'url': 'https://www.youtube.com/watch?v=_b-2C3KPAM0',
+            'info_dict': {
+                'id': '_b-2C3KPAM0',
+                'ext': 'mp4',
+                'stretched_ratio': 16 / 9.,
+                'duration': 85,
+                'upload_date': '20110310',
+                'uploader_id': 'AllenMeow',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/AllenMeow',
+                'description': 'made by Wacom from Korea | 字幕&加油添醋 by TY\'s Allen | 感謝heylisa00cavey1001同學熱情提供梗及翻譯',
+                'uploader': '孫ᄋᄅ',
+                'title': '[A-made] 變態妍字幕版 太妍 我就是這樣的人',
+            },
+        },
+        # url_encoded_fmt_stream_map is empty string
+        {
+            'url': 'qEJwOuvDf7I',
+            'info_dict': {
+                'id': 'qEJwOuvDf7I',
+                'ext': 'webm',
+                'title': 'Обсуждение судебной практики по выборам 14 сентября 2014 года в Санкт-Петербурге',
+                'description': '',
+                'upload_date': '20150404',
+                'uploader_id': 'spbelect',
+                'uploader': 'Наблюдатели Петербурга',
+            },
+            'params': {
+                'skip_download': 'requires avconv',
+            },
+            'skip': 'This live event has ended.',
+        },
+        # Extraction from multiple DASH manifests (https://github.com/ytdl-org/youtube-dl/pull/6097)
+        {
+            'url': 'https://www.youtube.com/watch?v=FIl7x6_3R5Y',
+            'info_dict': {
+                'id': 'FIl7x6_3R5Y',
+                'ext': 'webm',
+                'title': 'md5:7b81415841e02ecd4313668cde88737a',
+                'description': 'md5:116377fd2963b81ec4ce64b542173306',
+                'duration': 220,
+                'upload_date': '20150625',
+                'uploader_id': 'dorappi2000',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/dorappi2000',
+                'uploader': 'dorappi2000',
+                'formats': 'mincount:31',
+            },
+            'skip': 'not actual anymore',
+        },
+        # DASH manifest with segment_list
+        {
+            'url': 'https://www.youtube.com/embed/CsmdDsKjzN8',
+            'md5': '8ce563a1d667b599d21064e982ab9e31',
+            'info_dict': {
+                'id': 'CsmdDsKjzN8',
+                'ext': 'mp4',
+                'upload_date': '20150501',  # According to '<meta itemprop="datePublished"', but in other places it's 20150510
+                'uploader': 'Airtek',
+                'description': 'Retransmisión en directo de la XVIII media maratón de Zaragoza.',
+                'uploader_id': 'UCzTzUmjXxxacNnL8I3m4LnQ',
+                'title': 'Retransmisión XVIII Media maratón Zaragoza 2015',
+            },
+            'params': {
+                'youtube_include_dash_manifest': True,
+                'format': '135',  # bestvideo
+            },
+            'skip': 'This live event has ended.',
+        },
+        {
+            # Multifeed videos (multiple cameras), URL is for Main Camera
+            'url': 'https://www.youtube.com/watch?v=jqWvoWXjCVs',
+            'info_dict': {
+                'id': 'jqWvoWXjCVs',
+                'title': 'teamPGP: Rocket League Noob Stream',
+                'description': 'md5:dc7872fb300e143831327f1bae3af010',
+            },
+            'playlist': [{
+                'info_dict': {
+                    'id': 'jqWvoWXjCVs',
+                    'ext': 'mp4',
+                    'title': 'teamPGP: Rocket League Noob Stream (Main Camera)',
+                    'description': 'md5:dc7872fb300e143831327f1bae3af010',
+                    'duration': 7335,
+                    'upload_date': '20150721',
+                    'uploader': 'Beer Games Beer',
+                    'uploader_id': 'beergamesbeer',
+                    'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/beergamesbeer',
+                    'license': 'Standard YouTube License',
+                },
+            }, {
+                'info_dict': {
+                    'id': '6h8e8xoXJzg',
+                    'ext': 'mp4',
+                    'title': 'teamPGP: Rocket League Noob Stream (kreestuh)',
+                    'description': 'md5:dc7872fb300e143831327f1bae3af010',
+                    'duration': 7337,
+                    'upload_date': '20150721',
+                    'uploader': 'Beer Games Beer',
+                    'uploader_id': 'beergamesbeer',
+                    'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/beergamesbeer',
+                    'license': 'Standard YouTube License',
+                },
+            }, {
+                'info_dict': {
+                    'id': 'PUOgX5z9xZw',
+                    'ext': 'mp4',
+                    'title': 'teamPGP: Rocket League Noob Stream (grizzle)',
+                    'description': 'md5:dc7872fb300e143831327f1bae3af010',
+                    'duration': 7337,
+                    'upload_date': '20150721',
+                    'uploader': 'Beer Games Beer',
+                    'uploader_id': 'beergamesbeer',
+                    'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/beergamesbeer',
+                    'license': 'Standard YouTube License',
+                },
+            }, {
+                'info_dict': {
+                    'id': 'teuwxikvS5k',
+                    'ext': 'mp4',
+                    'title': 'teamPGP: Rocket League Noob Stream (zim)',
+                    'description': 'md5:dc7872fb300e143831327f1bae3af010',
+                    'duration': 7334,
+                    'upload_date': '20150721',
+                    'uploader': 'Beer Games Beer',
+                    'uploader_id': 'beergamesbeer',
+                    'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/beergamesbeer',
+                    'license': 'Standard YouTube License',
+                },
+            }],
+            'params': {
+                'skip_download': True,
+            },
+            'skip': 'This video is not available.',
+        },
+        {
+            # Multifeed video with comma in title (see https://github.com/ytdl-org/youtube-dl/issues/8536)
+            'url': 'https://www.youtube.com/watch?v=gVfLd0zydlo',
+            'info_dict': {
+                'id': 'gVfLd0zydlo',
+                'title': 'DevConf.cz 2016 Day 2 Workshops 1 14:00 - 15:30',
+            },
+            'playlist_count': 2,
+            'skip': 'Not multifeed anymore',
+        },
+        {
+            'url': 'https://vid.plus/FlRa-iH7PGw',
+            'only_matching': True,
+        },
+        {
+            'url': 'https://zwearz.com/watch/9lWxNJF-ufM/electra-woman-dyna-girl-official-trailer-grace-helbig.html',
+            'only_matching': True,
+        },
+        {
+            # Title with JS-like syntax "};" (see https://github.com/ytdl-org/youtube-dl/issues/7468)
+            # Also tests cut-off URL expansion in video description (see
+            # https://github.com/ytdl-org/youtube-dl/issues/1892,
+            # https://github.com/ytdl-org/youtube-dl/issues/8164)
+            'url': 'https://www.youtube.com/watch?v=lsguqyKfVQg',
+            'info_dict': {
+                'id': 'lsguqyKfVQg',
+                'ext': 'mp4',
+                'title': '{dark walk}; Loki/AC/Dishonored; collab w/Elflover21',
+                'alt_title': 'Dark Walk - Position Music',
+                'description': 'md5:8085699c11dc3f597ce0410b0dcbb34a',
+                'duration': 133,
+                'upload_date': '20151119',
+                'uploader_id': 'IronSoulElf',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/IronSoulElf',
+                'uploader': 'IronSoulElf',
+                'creator': 'Todd Haberman,  Daniel Law Heath and Aaron Kaplan',
+                'track': 'Dark Walk - Position Music',
+                'artist': 'Todd Haberman,  Daniel Law Heath and Aaron Kaplan',
+                'album': 'Position Music - Production Music Vol. 143 - Dark Walk',
+            },
+            'params': {
+                'skip_download': True,
+            },
+        },
+        {
+            # Tags with '};' (see https://github.com/ytdl-org/youtube-dl/issues/7468)
+            'url': 'https://www.youtube.com/watch?v=Ms7iBXnlUO8',
+            'only_matching': True,
+        },
+        {
+            # Video with yt:stretch=17:0
+            'url': 'https://www.youtube.com/watch?v=Q39EVAstoRM',
+            'info_dict': {
+                'id': 'Q39EVAstoRM',
+                'ext': 'mp4',
+                'title': 'Clash Of Clans#14 Dicas De Ataque Para CV 4',
+                'description': 'md5:ee18a25c350637c8faff806845bddee9',
+                'upload_date': '20151107',
+                'uploader_id': 'UCCr7TALkRbo3EtFzETQF1LA',
+                'uploader': 'CH GAMER DROID',
+            },
+            'params': {
+                'skip_download': True,
+            },
+            'skip': 'This video does not exist.',
+        },
+        {
+            # Video licensed under Creative Commons
+            'url': 'https://www.youtube.com/watch?v=M4gD1WSo5mA',
+            'info_dict': {
+                'id': 'M4gD1WSo5mA',
+                'ext': 'mp4',
+                'title': 'md5:e41008789470fc2533a3252216f1c1d1',
+                'description': 'md5:a677553cf0840649b731a3024aeff4cc',
+                'duration': 721,
+                'upload_date': '20150127',
+                'uploader_id': 'BerkmanCenter',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/BerkmanCenter',
+                'uploader': 'The Berkman Klein Center for Internet & Society',
+                'license': 'Creative Commons Attribution license (reuse allowed)',
+            },
+            'params': {
+                'skip_download': True,
+            },
+        },
+        {
+            # Channel-like uploader_url
+            'url': 'https://www.youtube.com/watch?v=eQcmzGIKrzg',
+            'info_dict': {
+                'id': 'eQcmzGIKrzg',
+                'ext': 'mp4',
+                'title': 'Democratic Socialism and Foreign Policy | Bernie Sanders',
+                'description': 'md5:dda0d780d5a6e120758d1711d062a867',
+                'duration': 4060,
+                'upload_date': '20151119',
+                'uploader': 'Bernie Sanders',
+                'uploader_id': 'UCH1dpzjCEiGAt8CXkryhkZg',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/channel/UCH1dpzjCEiGAt8CXkryhkZg',
+                'license': 'Creative Commons Attribution license (reuse allowed)',
+            },
+            'params': {
+                'skip_download': True,
+            },
+        },
+        {
+            'url': 'https://www.youtube.com/watch?feature=player_embedded&amp;amp;v=V36LpHqtcDY',
+            'only_matching': True,
+        },
+        {
+            # YouTube Red paid video (https://github.com/ytdl-org/youtube-dl/issues/10059)
+            'url': 'https://www.youtube.com/watch?v=i1Ko8UG-Tdo',
+            'only_matching': True,
+        },
+        {
+            # Rental video preview
+            'url': 'https://www.youtube.com/watch?v=yYr8q0y5Jfg',
+            'info_dict': {
+                'id': 'uGpuVWrhIzE',
+                'ext': 'mp4',
+                'title': 'Piku - Trailer',
+                'description': 'md5:c36bd60c3fd6f1954086c083c72092eb',
+                'upload_date': '20150811',
+                'uploader': 'FlixMatrix',
+                'uploader_id': 'FlixMatrixKaravan',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/FlixMatrixKaravan',
+                'license': 'Standard YouTube License',
+            },
+            'params': {
+                'skip_download': True,
+            },
+            'skip': 'This video is not available.',
+        },
+        {
+            # YouTube Red video with episode data
+            'url': 'https://www.youtube.com/watch?v=iqKdEhx-dD4',
+            'info_dict': {
+                'id': 'iqKdEhx-dD4',
+                'ext': 'mp4',
+                'title': 'Isolation - Mind Field (Ep 1)',
+                'description': 'md5:46a29be4ceffa65b92d277b93f463c0f',
+                'duration': 2085,
+                'upload_date': '20170118',
+                'uploader': 'Vsauce',
+                'uploader_id': 'Vsauce',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/Vsauce',
+                'series': 'Mind Field',
+                'season_number': 1,
+                'episode_number': 1,
+            },
+            'params': {
+                'skip_download': True,
+            },
+            'expected_warnings': [
+                'Skipping DASH manifest',
+            ],
+        },
+        {
+            # The following content has been identified by the YouTube community
+            # as inappropriate or offensive to some audiences.
+            'url': 'https://www.youtube.com/watch?v=6SJNVb0GnPI',
+            'info_dict': {
+                'id': '6SJNVb0GnPI',
+                'ext': 'mp4',
+                'title': 'Race Differences in Intelligence',
+                'description': 'md5:5d161533167390427a1f8ee89a1fc6f1',
+                'duration': 965,
+                'upload_date': '20140124',
+                'uploader': 'New Century Foundation',
+                'uploader_id': 'UCEJYpZGqgUob0zVVEaLhvVg',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/channel/UCEJYpZGqgUob0zVVEaLhvVg',
+            },
+            'params': {
+                'skip_download': True,
+            },
+        },
+        {
+            # itag 212
+            'url': '1t24XAntNCY',
+            'only_matching': True,
+        },
+        {
+            # geo restricted to JP
+            'url': 'sJL6WA-aGkQ',
+            'only_matching': True,
+        },
+        {
+            'url': 'https://www.youtube.com/watch?v=MuAGGZNfUkU&list=RDMM',
+            'only_matching': True,
+        },
+        {
+            'url': 'https://invidio.us/watch?v=BaW_jenozKc',
+            'only_matching': True,
+        },
+        {
+            # DRM protected
+            'url': 'https://www.youtube.com/watch?v=s7_qI6_mIXc',
+            'only_matching': True,
+        },
+        {
+            # Video with unsupported adaptive stream type formats
+            'url': 'https://www.youtube.com/watch?v=Z4Vy8R84T1U',
+            'info_dict': {
+                'id': 'Z4Vy8R84T1U',
+                'ext': 'mp4',
+                'title': 'saman SMAN 53 Jakarta(Sancety) opening COFFEE4th at SMAN 53 Jakarta',
+                'description': 'md5:d41d8cd98f00b204e9800998ecf8427e',
+                'duration': 433,
+                'upload_date': '20130923',
+                'uploader': 'Amelia Putri Harwita',
+                'uploader_id': 'UCpOxM49HJxmC1qCalXyB3_Q',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/channel/UCpOxM49HJxmC1qCalXyB3_Q',
+                'formats': 'maxcount:10',
+            },
+            'params': {
+                'skip_download': True,
+                'youtube_include_dash_manifest': False,
+            },
+            'skip': 'not actual anymore',
+        },
+        {
+            # Youtube Music Auto-generated description
+            'url': 'https://music.youtube.com/watch?v=MgNrAu2pzNs',
+            'info_dict': {
+                'id': 'MgNrAu2pzNs',
+                'ext': 'mp4',
+                'title': 'Voyeur Girl',
+                'description': 'md5:7ae382a65843d6df2685993e90a8628f',
+                'upload_date': '20190312',
+                'uploader': 'Stephen - Topic',
+                'uploader_id': 'UC-pWHpBjdGG69N9mM2auIAA',
+                'artist': 'Stephen',
+                'track': 'Voyeur Girl',
+                'album': 'it\'s too much love to know my dear',
+                'release_date': '20190313',
+                'release_year': 2019,
+            },
+            'params': {
+                'skip_download': True,
+            },
+        },
+        {
+            # Youtube Music Auto-generated description
+            # Retrieve 'artist' field from 'Artist:' in video description
+            # when it is present on youtube music video
+            'url': 'https://www.youtube.com/watch?v=k0jLE7tTwjY',
+            'info_dict': {
+                'id': 'k0jLE7tTwjY',
+                'ext': 'mp4',
+                'title': 'Latch Feat. Sam Smith',
+                'description': 'md5:3cb1e8101a7c85fcba9b4fb41b951335',
+                'upload_date': '20150110',
+                'uploader': 'Various Artists - Topic',
+                'uploader_id': 'UCNkEcmYdjrH4RqtNgh7BZ9w',
+                'artist': 'Disclosure',
+                'track': 'Latch Feat. Sam Smith',
+                'album': 'Latch Featuring Sam Smith',
+                'release_date': '20121008',
+                'release_year': 2012,
+            },
+            'params': {
+                'skip_download': True,
+            },
+        },
+        {
+            # Youtube Music Auto-generated description
+            # handle multiple artists on youtube music video
+            'url': 'https://www.youtube.com/watch?v=74qn0eJSjpA',
+            'info_dict': {
+                'id': '74qn0eJSjpA',
+                'ext': 'mp4',
+                'title': 'Eastside',
+                'description': 'md5:290516bb73dcbfab0dcc4efe6c3de5f2',
+                'upload_date': '20180710',
+                'uploader': 'Benny Blanco - Topic',
+                'uploader_id': 'UCzqz_ksRu_WkIzmivMdIS7A',
+                'artist': 'benny blanco, Halsey, Khalid',
+                'track': 'Eastside',
+                'album': 'Eastside',
+                'release_date': '20180713',
+                'release_year': 2018,
+            },
+            'params': {
+                'skip_download': True,
+            },
+        },
+        {
+            # Youtube Music Auto-generated description
+            # handle youtube music video with release_year and no release_date
+            'url': 'https://www.youtube.com/watch?v=-hcAI0g-f5M',
+            'info_dict': {
+                'id': '-hcAI0g-f5M',
+                'ext': 'mp4',
+                'title': 'Put It On Me',
+                'description': 'md5:f6422397c07c4c907c6638e1fee380a5',
+                'upload_date': '20180426',
+                'uploader': 'Matt Maeson - Topic',
+                'uploader_id': 'UCnEkIGqtGcQMLk73Kp-Q5LQ',
+                'artist': 'Matt Maeson',
+                'track': 'Put It On Me',
+                'album': 'The Hearse',
+                'release_date': None,
+                'release_year': 2018,
+            },
+            'params': {
+                'skip_download': True,
+            },
+        },
+        {
+            'url': 'https://www.youtubekids.com/watch?v=3b8nCWDgZ6Q',
+            'only_matching': True,
+        },
+        {
+            # invalid -> valid video id redirection
+            'url': 'DJztXj2GPfl',
+            'info_dict': {
+                'id': 'DJztXj2GPfk',
+                'ext': 'mp4',
+                'title': 'Panjabi MC - Mundian To Bach Ke (The Dictator Soundtrack)',
+                'description': 'md5:bf577a41da97918e94fa9798d9228825',
+                'upload_date': '20090125',
+                'uploader': 'Prochorowka',
+                'uploader_id': 'Prochorowka',
+                'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/Prochorowka',
+                'artist': 'Panjabi MC',
+                'track': 'Beware of the Boys (Mundian to Bach Ke) - Motivo Hi-Lectro Remix',
+                'album': 'Beware of the Boys (Mundian To Bach Ke)',
+            },
+            'params': {
+                'skip_download': True,
+            },
+        },
         {
-            u"url": u"http://www.youtube.com/watch?v=a9LDPn-MO4I",
-            u"file": u"a9LDPn-MO4I.m4a",
-            u"note": u"256k DASH audio (format 141) via DASH manifest",
-            u"info_dict": {
-                u"upload_date": "20121002",
-                u"uploader_id": "8KVIDEO",
-                u"description": "No description available.",
-                u"uploader": "8KVIDEO",
-                u"title": "UHDTV TEST 8K VIDEO.mp4"
+            # empty description results in an empty string
+            'url': 'https://www.youtube.com/watch?v=x41yOUIvK2k',
+            'info_dict': {
+                'id': 'x41yOUIvK2k',
+                'ext': 'mp4',
+                'title': 'IMG 3456',
+                'description': '',
+                'upload_date': '20170613',
+                'uploader_id': 'ElevageOrVert',
+                'uploader': 'ElevageOrVert',
             },
-            u"params": {
-                u"youtube_include_dash_manifest": True,
-                u"format": "141",
+            'params': {
+                'skip_download': True,
             },
         },
     ]
 
-
-    @classmethod
-    def suitable(cls, url):
-        """Receives a URL and returns True if suitable for this IE."""
-        if YoutubePlaylistIE.suitable(url): return False
-        return re.match(cls._VALID_URL, url) is not None
-
     def __init__(self, *args, **kwargs):
         super(YoutubeIE, self).__init__(*args, **kwargs)
         self._player_cache = {}
 
     def report_video_info_webpage_download(self, video_id):
         """Report attempt to download video info webpage."""
-        self.to_screen(u'%s: Downloading video info webpage' % video_id)
+        self.to_screen('%s: Downloading video info webpage' % video_id)
 
     def report_information_extraction(self, video_id):
         """Report attempt to extract video information."""
-        self.to_screen(u'%s: Extracting video information' % video_id)
+        self.to_screen('%s: Extracting video information' % video_id)
 
     def report_unavailable_format(self, video_id, format):
         """Report extracted video URL."""
-        self.to_screen(u'%s: Format %s not available' % (video_id, format))
+        self.to_screen('%s: Format %s not available' % (video_id, format))
 
     def report_rtmp_download(self):
         """Indicate the download will use the RTMP protocol."""
-        self.to_screen(u'RTMP download detected')
+        self.to_screen('RTMP download detected')
+
+    def _signature_cache_id(self, example_sig):
+        """ Return a string representation of a signature """
+        return '.'.join(compat_str(len(part)) for part in example_sig.split('.'))
+
+    @classmethod
+    def _extract_player_info(cls, player_url):
+        for player_re in cls._PLAYER_INFO_RE:
+            id_m = re.search(player_re, player_url)
+            if id_m:
+                break
+        else:
+            raise ExtractorError('Cannot identify player %r' % player_url)
+        return id_m.group('ext'), id_m.group('id')
 
-    def _extract_signature_function(self, video_id, player_url, slen):
-        id_m = re.match(r'.*-(?P<id>[a-zA-Z0-9_-]+)\.(?P<ext>[a-z]+)$',
-                        player_url)
-        player_type = id_m.group('ext')
-        player_id = id_m.group('id')
+    def _extract_signature_function(self, video_id, player_url, example_sig):
+        player_type, player_id = self._extract_player_info(player_url)
 
         # Read from filesystem cache
-        func_id = '%s_%s_%d' % (player_type, player_id, slen)
+        func_id = '%s_%s_%s' % (
+            player_type, player_id, self._signature_cache_id(example_sig))
         assert os.path.basename(func_id) == func_id
-        cache_dir = get_cachedir(self._downloader.params)
 
-        cache_enabled = cache_dir is not None
-        if cache_enabled:
-            cache_fn = os.path.join(os.path.expanduser(cache_dir),
-                                    u'youtube-sigfuncs',
-                                    func_id + '.json')
-            try:
-                with io.open(cache_fn, 'r', encoding='utf-8') as cachef:
-                    cache_spec = json.load(cachef)
-                return lambda s: u''.join(s[i] for i in cache_spec)
-            except IOError:
-                pass  # No cache available
+        cache_spec = self._downloader.cache.load('youtube-sigfuncs', func_id)
+        if cache_spec is not None:
+            return lambda s: ''.join(s[i] for i in cache_spec)
 
+        download_note = (
+            'Downloading player %s' % player_url
+            if self._downloader.params.get('verbose') else
+            'Downloading %s player %s' % (player_type, player_id)
+        )
         if player_type == 'js':
             code = self._download_webpage(
                 player_url, video_id,
-                note=u'Downloading %s player %s' % (player_type, player_id),
-                errnote=u'Download of %s failed' % player_url)
+                note=download_note,
+                errnote='Download of %s failed' % player_url)
             res = self._parse_sig_js(code)
         elif player_type == 'swf':
             urlh = self._request_webpage(
                 player_url, video_id,
-                note=u'Downloading %s player %s' % (player_type, player_id),
-                errnote=u'Download of %s failed' % player_url)
+                note=download_note,
+                errnote='Download of %s failed' % player_url)
             code = urlh.read()
             res = self._parse_sig_swf(code)
         else:
             assert False, 'Invalid player type %r' % player_type
 
-        if cache_enabled:
-            try:
-                test_string = u''.join(map(compat_chr, range(slen)))
-                cache_res = res(test_string)
-                cache_spec = [ord(c) for c in cache_res]
-                try:
-                    os.makedirs(os.path.dirname(cache_fn))
-                except OSError as ose:
-                    if ose.errno != errno.EEXIST:
-                        raise
-                write_json_file(cache_spec, cache_fn)
-            except Exception:
-                tb = traceback.format_exc()
-                self._downloader.report_warning(
-                    u'Writing cache to %r failed: %s' % (cache_fn, tb))
+        test_string = ''.join(map(compat_chr, range(len(example_sig))))
+        cache_res = res(test_string)
+        cache_spec = [ord(c) for c in cache_res]
 
+        self._downloader.cache.store('youtube-sigfuncs', func_id, cache_spec)
         return res
 
-    def _print_sig_code(self, func, slen):
+    def _print_sig_code(self, func, example_sig):
         def gen_sig_code(idxs):
             def _genslice(start, end, step):
-                starts = u'' if start == 0 else str(start)
-                ends = (u':%d' % (end+step)) if end + step >= 0 else u':'
-                steps = u'' if step == 1 else (u':%d' % step)
-                return u's[%s%s%s]' % (starts, ends, steps)
+                starts = '' if start == 0 else str(start)
+                ends = (':%d' % (end + step)) if end + step >= 0 else ':'
+                steps = '' if step == 1 else (':%d' % step)
+                return 's[%s%s%s]' % (starts, ends, steps)
 
             step = None
-            start = '(Never used)'  # Quelch pyflakes warnings - start will be
-                                    # set as soon as step is set
+            # Quelch pyflakes warnings - start will be set when step is set
+            start = '(Never used)'
             for i, prev in zip(idxs[1:], idxs[:-1]):
                 if step is not None:
                     if i - prev == step:
@@ -405,723 +1380,425 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                     start = prev
                     continue
                 else:
-                    yield u's[%d]' % prev
+                    yield 's[%d]' % prev
             if step is None:
-                yield u's[%d]' % i
+                yield 's[%d]' % i
             else:
                 yield _genslice(start, i, step)
 
-        test_string = u''.join(map(compat_chr, range(slen)))
+        test_string = ''.join(map(compat_chr, range(len(example_sig))))
         cache_res = func(test_string)
         cache_spec = [ord(c) for c in cache_res]
-        expr_code = u' + '.join(gen_sig_code(cache_spec))
-        code = u'if len(s) == %d:\n    return %s\n' % (slen, expr_code)
-        self.to_screen(u'Extracted signature function:\n' + code)
+        expr_code = ' + '.join(gen_sig_code(cache_spec))
+        signature_id_tuple = '(%s)' % (
+            ', '.join(compat_str(len(p)) for p in example_sig.split('.')))
+        code = ('if tuple(len(p) for p in s.split(\'.\')) == %s:\n'
+                '    return %s\n') % (signature_id_tuple, expr_code)
+        self.to_screen('Extracted signature function:\n' + code)
 
     def _parse_sig_js(self, jscode):
         funcname = self._search_regex(
-            r'signature=([a-zA-Z]+)', jscode,
-            u'Initial JS player signature function name')
-
-        functions = {}
-
-        def argidx(varname):
-            return string.lowercase.index(varname)
-
-        def interpret_statement(stmt, local_vars, allow_recursion=20):
-            if allow_recursion < 0:
-                raise ExtractorError(u'Recursion limit reached')
-
-            if stmt.startswith(u'var '):
-                stmt = stmt[len(u'var '):]
-            ass_m = re.match(r'^(?P<out>[a-z]+)(?:\[(?P<index>[^\]]+)\])?' +
-                             r'=(?P<expr>.*)$', stmt)
-            if ass_m:
-                if ass_m.groupdict().get('index'):
-                    def assign(val):
-                        lvar = local_vars[ass_m.group('out')]
-                        idx = interpret_expression(ass_m.group('index'),
-                                                   local_vars, allow_recursion)
-                        assert isinstance(idx, int)
-                        lvar[idx] = val
-                        return val
-                    expr = ass_m.group('expr')
-                else:
-                    def assign(val):
-                        local_vars[ass_m.group('out')] = val
-                        return val
-                    expr = ass_m.group('expr')
-            elif stmt.startswith(u'return '):
-                assign = lambda v: v
-                expr = stmt[len(u'return '):]
-            else:
-                raise ExtractorError(
-                    u'Cannot determine left side of statement in %r' % stmt)
-
-            v = interpret_expression(expr, local_vars, allow_recursion)
-            return assign(v)
-
-        def interpret_expression(expr, local_vars, allow_recursion):
-            if expr.isdigit():
-                return int(expr)
-
-            if expr.isalpha():
-                return local_vars[expr]
-
-            m = re.match(r'^(?P<in>[a-z]+)\.(?P<member>.*)$', expr)
-            if m:
-                member = m.group('member')
-                val = local_vars[m.group('in')]
-                if member == 'split("")':
-                    return list(val)
-                if member == 'join("")':
-                    return u''.join(val)
-                if member == 'length':
-                    return len(val)
-                if member == 'reverse()':
-                    return val[::-1]
-                slice_m = re.match(r'slice\((?P<idx>.*)\)', member)
-                if slice_m:
-                    idx = interpret_expression(
-                        slice_m.group('idx'), local_vars, allow_recursion-1)
-                    return val[idx:]
-
-            m = re.match(
-                r'^(?P<in>[a-z]+)\[(?P<idx>.+)\]$', expr)
-            if m:
-                val = local_vars[m.group('in')]
-                idx = interpret_expression(m.group('idx'), local_vars,
-                                           allow_recursion-1)
-                return val[idx]
-
-            m = re.match(r'^(?P<a>.+?)(?P<op>[%])(?P<b>.+?)$', expr)
-            if m:
-                a = interpret_expression(m.group('a'),
-                                         local_vars, allow_recursion)
-                b = interpret_expression(m.group('b'),
-                                         local_vars, allow_recursion)
-                return a % b
-
-            m = re.match(
-                r'^(?P<func>[a-zA-Z$]+)\((?P<args>[a-z0-9,]+)\)$', expr)
-            if m:
-                fname = m.group('func')
-                if fname not in functions:
-                    functions[fname] = extract_function(fname)
-                argvals = [int(v) if v.isdigit() else local_vars[v]
-                           for v in m.group('args').split(',')]
-                return functions[fname](argvals)
-            raise ExtractorError(u'Unsupported JS expression %r' % expr)
-
-        def extract_function(funcname):
-            func_m = re.search(
-                r'function ' + re.escape(funcname) +
-                r'\((?P<args>[a-z,]+)\){(?P<code>[^}]+)}',
-                jscode)
-            argnames = func_m.group('args').split(',')
-
-            def resf(args):
-                local_vars = dict(zip(argnames, args))
-                for stmt in func_m.group('code').split(';'):
-                    res = interpret_statement(stmt, local_vars)
-                return res
-            return resf
-
-        initial_function = extract_function(funcname)
+            (r'\b[cs]\s*&&\s*[adf]\.set\([^,]+\s*,\s*encodeURIComponent\s*\(\s*(?P<sig>[a-zA-Z0-9$]+)\(',
+             r'\b[a-zA-Z0-9]+\s*&&\s*[a-zA-Z0-9]+\.set\([^,]+\s*,\s*encodeURIComponent\s*\(\s*(?P<sig>[a-zA-Z0-9$]+)\(',
+             r'(?:\b|[^a-zA-Z0-9$])(?P<sig>[a-zA-Z0-9$]{2})\s*=\s*function\(\s*a\s*\)\s*{\s*a\s*=\s*a\.split\(\s*""\s*\)',
+             r'(?P<sig>[a-zA-Z0-9$]+)\s*=\s*function\(\s*a\s*\)\s*{\s*a\s*=\s*a\.split\(\s*""\s*\)',
+             # Obsolete patterns
+             r'(["\'])signature\1\s*,\s*(?P<sig>[a-zA-Z0-9$]+)\(',
+             r'\.sig\|\|(?P<sig>[a-zA-Z0-9$]+)\(',
+             r'yt\.akamaized\.net/\)\s*\|\|\s*.*?\s*[cs]\s*&&\s*[adf]\.set\([^,]+\s*,\s*(?:encodeURIComponent\s*\()?\s*(?P<sig>[a-zA-Z0-9$]+)\(',
+             r'\b[cs]\s*&&\s*[adf]\.set\([^,]+\s*,\s*(?P<sig>[a-zA-Z0-9$]+)\(',
+             r'\b[a-zA-Z0-9]+\s*&&\s*[a-zA-Z0-9]+\.set\([^,]+\s*,\s*(?P<sig>[a-zA-Z0-9$]+)\(',
+             r'\bc\s*&&\s*a\.set\([^,]+\s*,\s*\([^)]*\)\s*\(\s*(?P<sig>[a-zA-Z0-9$]+)\(',
+             r'\bc\s*&&\s*[a-zA-Z0-9]+\.set\([^,]+\s*,\s*\([^)]*\)\s*\(\s*(?P<sig>[a-zA-Z0-9$]+)\(',
+             r'\bc\s*&&\s*[a-zA-Z0-9]+\.set\([^,]+\s*,\s*\([^)]*\)\s*\(\s*(?P<sig>[a-zA-Z0-9$]+)\('),
+            jscode, 'Initial JS player signature function name', group='sig')
+
+        jsi = JSInterpreter(jscode)
+        initial_function = jsi.extract_function(funcname)
         return lambda s: initial_function([s])
 
     def _parse_sig_swf(self, file_contents):
-        if file_contents[1:3] != b'WS':
-            raise ExtractorError(
-                u'Not an SWF file; header is %r' % file_contents[:3])
-        if file_contents[:1] == b'C':
-            content = zlib.decompress(file_contents[8:])
-        else:
-            raise NotImplementedError(u'Unsupported compression format %r' %
-                                      file_contents[:1])
-
-        def extract_tags(content):
-            pos = 0
-            while pos < len(content):
-                header16 = struct.unpack('<H', content[pos:pos+2])[0]
-                pos += 2
-                tag_code = header16 >> 6
-                tag_len = header16 & 0x3f
-                if tag_len == 0x3f:
-                    tag_len = struct.unpack('<I', content[pos:pos+4])[0]
-                    pos += 4
-                assert pos+tag_len <= len(content)
-                yield (tag_code, content[pos:pos+tag_len])
-                pos += tag_len
-
-        code_tag = next(tag
-                        for tag_code, tag in extract_tags(content)
-                        if tag_code == 82)
-        p = code_tag.index(b'\0', 4) + 1
-        code_reader = io.BytesIO(code_tag[p:])
-
-        # Parse ABC (AVM2 ByteCode)
-        def read_int(reader=None):
-            if reader is None:
-                reader = code_reader
-            res = 0
-            shift = 0
-            for _ in range(5):
-                buf = reader.read(1)
-                assert len(buf) == 1
-                b = struct.unpack('<B', buf)[0]
-                res = res | ((b & 0x7f) << shift)
-                if b & 0x80 == 0:
-                    break
-                shift += 7
-            return res
-
-        def u30(reader=None):
-            res = read_int(reader)
-            assert res & 0xf0000000 == 0
-            return res
-        u32 = read_int
-
-        def s32(reader=None):
-            v = read_int(reader)
-            if v & 0x80000000 != 0:
-                v = - ((v ^ 0xffffffff) + 1)
-            return v
-
-        def read_string(reader=None):
-            if reader is None:
-                reader = code_reader
-            slen = u30(reader)
-            resb = reader.read(slen)
-            assert len(resb) == slen
-            return resb.decode('utf-8')
-
-        def read_bytes(count, reader=None):
-            if reader is None:
-                reader = code_reader
-            resb = reader.read(count)
-            assert len(resb) == count
-            return resb
-
-        def read_byte(reader=None):
-            resb = read_bytes(1, reader=reader)
-            res = struct.unpack('<B', resb)[0]
-            return res
-
-        # minor_version + major_version
-        read_bytes(2 + 2)
-
-        # Constant pool
-        int_count = u30()
-        for _c in range(1, int_count):
-            s32()
-        uint_count = u30()
-        for _c in range(1, uint_count):
-            u32()
-        double_count = u30()
-        read_bytes((double_count-1) * 8)
-        string_count = u30()
-        constant_strings = [u'']
-        for _c in range(1, string_count):
-            s = read_string()
-            constant_strings.append(s)
-        namespace_count = u30()
-        for _c in range(1, namespace_count):
-            read_bytes(1)  # kind
-            u30()  # name
-        ns_set_count = u30()
-        for _c in range(1, ns_set_count):
-            count = u30()
-            for _c2 in range(count):
-                u30()
-        multiname_count = u30()
-        MULTINAME_SIZES = {
-            0x07: 2,  # QName
-            0x0d: 2,  # QNameA
-            0x0f: 1,  # RTQName
-            0x10: 1,  # RTQNameA
-            0x11: 0,  # RTQNameL
-            0x12: 0,  # RTQNameLA
-            0x09: 2,  # Multiname
-            0x0e: 2,  # MultinameA
-            0x1b: 1,  # MultinameL
-            0x1c: 1,  # MultinameLA
-        }
-        multinames = [u'']
-        for _c in range(1, multiname_count):
-            kind = u30()
-            assert kind in MULTINAME_SIZES, u'Invalid multiname kind %r' % kind
-            if kind == 0x07:
-                u30()  # namespace_idx
-                name_idx = u30()
-                multinames.append(constant_strings[name_idx])
-            else:
-                multinames.append('[MULTINAME kind: %d]' % kind)
-                for _c2 in range(MULTINAME_SIZES[kind]):
-                    u30()
-
-        # Methods
-        method_count = u30()
-        MethodInfo = collections.namedtuple(
-            'MethodInfo',
-            ['NEED_ARGUMENTS', 'NEED_REST'])
-        method_infos = []
-        for method_id in range(method_count):
-            param_count = u30()
-            u30()  # return type
-            for _ in range(param_count):
-                u30()  # param type
-            u30()  # name index (always 0 for youtube)
-            flags = read_byte()
-            if flags & 0x08 != 0:
-                # Options present
-                option_count = u30()
-                for c in range(option_count):
-                    u30()  # val
-                    read_bytes(1)  # kind
-            if flags & 0x80 != 0:
-                # Param names present
-                for _ in range(param_count):
-                    u30()  # param name
-            mi = MethodInfo(flags & 0x01 != 0, flags & 0x04 != 0)
-            method_infos.append(mi)
-
-        # Metadata
-        metadata_count = u30()
-        for _c in range(metadata_count):
-            u30()  # name
-            item_count = u30()
-            for _c2 in range(item_count):
-                u30()  # key
-                u30()  # value
-
-        def parse_traits_info():
-            trait_name_idx = u30()
-            kind_full = read_byte()
-            kind = kind_full & 0x0f
-            attrs = kind_full >> 4
-            methods = {}
-            if kind in [0x00, 0x06]:  # Slot or Const
-                u30()  # Slot id
-                u30()  # type_name_idx
-                vindex = u30()
-                if vindex != 0:
-                    read_byte()  # vkind
-            elif kind in [0x01, 0x02, 0x03]:  # Method / Getter / Setter
-                u30()  # disp_id
-                method_idx = u30()
-                methods[multinames[trait_name_idx]] = method_idx
-            elif kind == 0x04:  # Class
-                u30()  # slot_id
-                u30()  # classi
-            elif kind == 0x05:  # Function
-                u30()  # slot_id
-                function_idx = u30()
-                methods[function_idx] = multinames[trait_name_idx]
-            else:
-                raise ExtractorError(u'Unsupported trait kind %d' % kind)
-
-            if attrs & 0x4 != 0:  # Metadata present
-                metadata_count = u30()
-                for _c3 in range(metadata_count):
-                    u30()  # metadata index
-
-            return methods
-
-        # Classes
-        TARGET_CLASSNAME = u'SignatureDecipher'
-        searched_idx = multinames.index(TARGET_CLASSNAME)
-        searched_class_id = None
-        class_count = u30()
-        for class_id in range(class_count):
-            name_idx = u30()
-            if name_idx == searched_idx:
-                # We found the class we're looking for!
-                searched_class_id = class_id
-            u30()  # super_name idx
-            flags = read_byte()
-            if flags & 0x08 != 0:  # Protected namespace is present
-                u30()  # protected_ns_idx
-            intrf_count = u30()
-            for _c2 in range(intrf_count):
-                u30()
-            u30()  # iinit
-            trait_count = u30()
-            for _c2 in range(trait_count):
-                parse_traits_info()
-
-        if searched_class_id is None:
-            raise ExtractorError(u'Target class %r not found' %
-                                 TARGET_CLASSNAME)
-
-        method_names = {}
-        method_idxs = {}
-        for class_id in range(class_count):
-            u30()  # cinit
-            trait_count = u30()
-            for _c2 in range(trait_count):
-                trait_methods = parse_traits_info()
-                if class_id == searched_class_id:
-                    method_names.update(trait_methods.items())
-                    method_idxs.update(dict(
-                        (idx, name)
-                        for name, idx in trait_methods.items()))
-
-        # Scripts
-        script_count = u30()
-        for _c in range(script_count):
-            u30()  # init
-            trait_count = u30()
-            for _c2 in range(trait_count):
-                parse_traits_info()
-
-        # Method bodies
-        method_body_count = u30()
-        Method = collections.namedtuple('Method', ['code', 'local_count'])
-        methods = {}
-        for _c in range(method_body_count):
-            method_idx = u30()
-            u30()  # max_stack
-            local_count = u30()
-            u30()  # init_scope_depth
-            u30()  # max_scope_depth
-            code_length = u30()
-            code = read_bytes(code_length)
-            if method_idx in method_idxs:
-                m = Method(code, local_count)
-                methods[method_idxs[method_idx]] = m
-            exception_count = u30()
-            for _c2 in range(exception_count):
-                u30()  # from
-                u30()  # to
-                u30()  # target
-                u30()  # exc_type
-                u30()  # var_name
-            trait_count = u30()
-            for _c2 in range(trait_count):
-                parse_traits_info()
-
-        assert p + code_reader.tell() == len(code_tag)
-        assert len(methods) == len(method_idxs)
-
-        method_pyfunctions = {}
-
-        def extract_function(func_name):
-            if func_name in method_pyfunctions:
-                return method_pyfunctions[func_name]
-            if func_name not in methods:
-                raise ExtractorError(u'Cannot find function %r' % func_name)
-            m = methods[func_name]
-
-            def resfunc(args):
-                registers = ['(this)'] + list(args) + [None] * m.local_count
-                stack = []
-                coder = io.BytesIO(m.code)
-                while True:
-                    opcode = struct.unpack('!B', coder.read(1))[0]
-                    if opcode == 36:  # pushbyte
-                        v = struct.unpack('!B', coder.read(1))[0]
-                        stack.append(v)
-                    elif opcode == 44:  # pushstring
-                        idx = u30(coder)
-                        stack.append(constant_strings[idx])
-                    elif opcode == 48:  # pushscope
-                        # We don't implement the scope register, so we'll just
-                        # ignore the popped value
-                        stack.pop()
-                    elif opcode == 70:  # callproperty
-                        index = u30(coder)
-                        mname = multinames[index]
-                        arg_count = u30(coder)
-                        args = list(reversed(
-                            [stack.pop() for _ in range(arg_count)]))
-                        obj = stack.pop()
-                        if mname == u'split':
-                            assert len(args) == 1
-                            assert isinstance(args[0], compat_str)
-                            assert isinstance(obj, compat_str)
-                            if args[0] == u'':
-                                res = list(obj)
-                            else:
-                                res = obj.split(args[0])
-                            stack.append(res)
-                        elif mname == u'slice':
-                            assert len(args) == 1
-                            assert isinstance(args[0], int)
-                            assert isinstance(obj, list)
-                            res = obj[args[0]:]
-                            stack.append(res)
-                        elif mname == u'join':
-                            assert len(args) == 1
-                            assert isinstance(args[0], compat_str)
-                            assert isinstance(obj, list)
-                            res = args[0].join(obj)
-                            stack.append(res)
-                        elif mname in method_pyfunctions:
-                            stack.append(method_pyfunctions[mname](args))
-                        else:
-                            raise NotImplementedError(
-                                u'Unsupported property %r on %r'
-                                % (mname, obj))
-                    elif opcode == 72:  # returnvalue
-                        res = stack.pop()
-                        return res
-                    elif opcode == 79:  # callpropvoid
-                        index = u30(coder)
-                        mname = multinames[index]
-                        arg_count = u30(coder)
-                        args = list(reversed(
-                            [stack.pop() for _ in range(arg_count)]))
-                        obj = stack.pop()
-                        if mname == u'reverse':
-                            assert isinstance(obj, list)
-                            obj.reverse()
-                        else:
-                            raise NotImplementedError(
-                                u'Unsupported (void) property %r on %r'
-                                % (mname, obj))
-                    elif opcode == 93:  # findpropstrict
-                        index = u30(coder)
-                        mname = multinames[index]
-                        res = extract_function(mname)
-                        stack.append(res)
-                    elif opcode == 97:  # setproperty
-                        index = u30(coder)
-                        value = stack.pop()
-                        idx = stack.pop()
-                        obj = stack.pop()
-                        assert isinstance(obj, list)
-                        assert isinstance(idx, int)
-                        obj[idx] = value
-                    elif opcode == 98:  # getlocal
-                        index = u30(coder)
-                        stack.append(registers[index])
-                    elif opcode == 99:  # setlocal
-                        index = u30(coder)
-                        value = stack.pop()
-                        registers[index] = value
-                    elif opcode == 102:  # getproperty
-                        index = u30(coder)
-                        pname = multinames[index]
-                        if pname == u'length':
-                            obj = stack.pop()
-                            assert isinstance(obj, list)
-                            stack.append(len(obj))
-                        else:  # Assume attribute access
-                            idx = stack.pop()
-                            assert isinstance(idx, int)
-                            obj = stack.pop()
-                            assert isinstance(obj, list)
-                            stack.append(obj[idx])
-                    elif opcode == 128:  # coerce
-                        u30(coder)
-                    elif opcode == 133:  # coerce_s
-                        assert isinstance(stack[-1], (type(None), compat_str))
-                    elif opcode == 164:  # modulo
-                        value2 = stack.pop()
-                        value1 = stack.pop()
-                        res = value1 % value2
-                        stack.append(res)
-                    elif opcode == 208:  # getlocal_0
-                        stack.append(registers[0])
-                    elif opcode == 209:  # getlocal_1
-                        stack.append(registers[1])
-                    elif opcode == 210:  # getlocal_2
-                        stack.append(registers[2])
-                    elif opcode == 211:  # getlocal_3
-                        stack.append(registers[3])
-                    elif opcode == 214:  # setlocal_2
-                        registers[2] = stack.pop()
-                    elif opcode == 215:  # setlocal_3
-                        registers[3] = stack.pop()
-                    else:
-                        raise NotImplementedError(
-                            u'Unsupported opcode %d' % opcode)
-
-            method_pyfunctions[func_name] = resfunc
-            return resfunc
-
-        initial_function = extract_function(u'decipher')
+        swfi = SWFInterpreter(file_contents)
+        TARGET_CLASSNAME = 'SignatureDecipher'
+        searched_class = swfi.extract_class(TARGET_CLASSNAME)
+        initial_function = swfi.extract_function(searched_class, 'decipher')
         return lambda s: initial_function([s])
 
     def _decrypt_signature(self, s, video_id, player_url, age_gate=False):
         """Turn the encrypted s field into a working signature"""
 
-        if player_url is not None:
-            if player_url.startswith(u'//'):
-                player_url = u'https:' + player_url
-            try:
-                player_id = (player_url, len(s))
-                if player_id not in self._player_cache:
-                    func = self._extract_signature_function(
-                        video_id, player_url, len(s)
-                    )
-                    self._player_cache[player_id] = func
-                func = self._player_cache[player_id]
-                if self._downloader.params.get('youtube_print_sig_code'):
-                    self._print_sig_code(func, len(s))
-                return func(s)
-            except Exception:
-                tb = traceback.format_exc()
-                self._downloader.report_warning(
-                    u'Automatic signature extraction failed: ' + tb)
-
-            self._downloader.report_warning(
-                u'Warning: Falling back to static signature algorithm')
-
-        return self._static_decrypt_signature(
-            s, video_id, player_url, age_gate)
-
-    def _static_decrypt_signature(self, s, video_id, player_url, age_gate):
-        if age_gate:
-            # The videos with age protection use another player, so the
-            # algorithms can be different.
-            if len(s) == 86:
-                return s[2:63] + s[82] + s[64:82] + s[63]
-
-        if len(s) == 93:
-            return s[86:29:-1] + s[88] + s[28:5:-1]
-        elif len(s) == 92:
-            return s[25] + s[3:25] + s[0] + s[26:42] + s[79] + s[43:79] + s[91] + s[80:83]
-        elif len(s) == 91:
-            return s[84:27:-1] + s[86] + s[26:5:-1]
-        elif len(s) == 90:
-            return s[25] + s[3:25] + s[2] + s[26:40] + s[77] + s[41:77] + s[89] + s[78:81]
-        elif len(s) == 89:
-            return s[84:78:-1] + s[87] + s[77:60:-1] + s[0] + s[59:3:-1]
-        elif len(s) == 88:
-            return s[7:28] + s[87] + s[29:45] + s[55] + s[46:55] + s[2] + s[56:87] + s[28]
-        elif len(s) == 87:
-            return s[6:27] + s[4] + s[28:39] + s[27] + s[40:59] + s[2] + s[60:]
-        elif len(s) == 86:
-            return s[80:72:-1] + s[16] + s[71:39:-1] + s[72] + s[38:16:-1] + s[82] + s[15::-1]
-        elif len(s) == 85:
-            return s[3:11] + s[0] + s[12:55] + s[84] + s[56:84]
-        elif len(s) == 84:
-            return s[78:70:-1] + s[14] + s[69:37:-1] + s[70] + s[36:14:-1] + s[80] + s[:14][::-1]
-        elif len(s) == 83:
-            return s[80:63:-1] + s[0] + s[62:0:-1] + s[63]
-        elif len(s) == 82:
-            return s[80:37:-1] + s[7] + s[36:7:-1] + s[0] + s[6:0:-1] + s[37]
-        elif len(s) == 81:
-            return s[56] + s[79:56:-1] + s[41] + s[55:41:-1] + s[80] + s[40:34:-1] + s[0] + s[33:29:-1] + s[34] + s[28:9:-1] + s[29] + s[8:0:-1] + s[9]
-        elif len(s) == 80:
-            return s[1:19] + s[0] + s[20:68] + s[19] + s[69:80]
-        elif len(s) == 79:
-            return s[54] + s[77:54:-1] + s[39] + s[53:39:-1] + s[78] + s[38:34:-1] + s[0] + s[33:29:-1] + s[34] + s[28:9:-1] + s[29] + s[8:0:-1] + s[9]
+        if player_url is None:
+            raise ExtractorError('Cannot decrypt signature without player_url')
 
-        else:
-            raise ExtractorError(u'Unable to decrypt signature, key length %d not supported; retrying might work' % (len(s)))
+        if player_url.startswith('//'):
+            player_url = 'https:' + player_url
+        elif not re.match(r'https?://', player_url):
+            player_url = compat_urlparse.urljoin(
+                'https://www.youtube.com', player_url)
+        try:
+            player_id = (player_url, self._signature_cache_id(s))
+            if player_id not in self._player_cache:
+                func = self._extract_signature_function(
+                    video_id, player_url, s
+                )
+                self._player_cache[player_id] = func
+            func = self._player_cache[player_id]
+            if self._downloader.params.get('youtube_print_sig_code'):
+                self._print_sig_code(func, s)
+            return func(s)
+        except Exception as e:
+            tb = traceback.format_exc()
+            raise ExtractorError(
+                'Signature extraction failed: ' + tb, cause=e)
 
-    def _get_available_subtitles(self, video_id, webpage):
+    def _get_subtitles(self, video_id, webpage):
         try:
-            sub_list = self._download_webpage(
+            subs_doc = self._download_xml(
                 'https://video.google.com/timedtext?hl=en&type=list&v=%s' % video_id,
                 video_id, note=False)
         except ExtractorError as err:
-            self._downloader.report_warning(u'unable to download video subtitles: %s' % compat_str(err))
+            self._downloader.report_warning('unable to download video subtitles: %s' % error_to_compat_str(err))
             return {}
-        lang_list = re.findall(r'name="([^"]*)"[^>]+lang_code="([\w\-]+)"', sub_list)
 
         sub_lang_list = {}
-        for l in lang_list:
-            lang = l[1]
-            params = compat_urllib_parse.urlencode({
-                'lang': lang,
-                'v': video_id,
-                'fmt': self._downloader.params.get('subtitlesformat', 'srt'),
-                'name': unescapeHTML(l[0]).encode('utf-8'),
-            })
-            url = u'https://www.youtube.com/api/timedtext?' + params
-            sub_lang_list[lang] = url
+        for track in subs_doc.findall('track'):
+            lang = track.attrib['lang_code']
+            if lang in sub_lang_list:
+                continue
+            sub_formats = []
+            for ext in self._SUBTITLE_FORMATS:
+                params = compat_urllib_parse_urlencode({
+                    'lang': lang,
+                    'v': video_id,
+                    'fmt': ext,
+                    'name': track.attrib['name'].encode('utf-8'),
+                })
+                sub_formats.append({
+                    'url': 'https://www.youtube.com/api/timedtext?' + params,
+                    'ext': ext,
+                })
+            sub_lang_list[lang] = sub_formats
         if not sub_lang_list:
-            self._downloader.report_warning(u'video doesn\'t have subtitles')
+            self._downloader.report_warning('video doesn\'t have subtitles')
             return {}
         return sub_lang_list
 
-    def _get_available_automatic_caption(self, video_id, webpage):
+    def _get_ytplayer_config(self, video_id, webpage):
+        patterns = (
+            # User data may contain arbitrary character sequences that may affect
+            # JSON extraction with regex, e.g. when '};' is contained the second
+            # regex won't capture the whole JSON. Yet working around by trying more
+            # concrete regex first keeping in mind proper quoted string handling
+            # to be implemented in future that will replace this workaround (see
+            # https://github.com/ytdl-org/youtube-dl/issues/7468,
+            # https://github.com/ytdl-org/youtube-dl/pull/7599)
+            r';ytplayer\.config\s*=\s*({.+?});ytplayer',
+            r';ytplayer\.config\s*=\s*({.+?});',
+        )
+        config = self._search_regex(
+            patterns, webpage, 'ytplayer.config', default=None)
+        if config:
+            return self._parse_json(
+                uppercase_escape(config), video_id, fatal=False)
+
+    def _get_automatic_captions(self, video_id, webpage):
         """We need the webpage for getting the captions url, pass it as an
            argument to speed up the process."""
-        sub_format = self._downloader.params.get('subtitlesformat', 'srt')
-        self.to_screen(u'%s: Looking for automatic captions' % video_id)
-        mobj = re.search(r';ytplayer.config = ({.*?});', webpage)
-        err_msg = u'Couldn\'t find automatic captions for %s' % video_id
-        if mobj is None:
+        self.to_screen('%s: Looking for automatic captions' % video_id)
+        player_config = self._get_ytplayer_config(video_id, webpage)
+        err_msg = 'Couldn\'t find automatic captions for %s' % video_id
+        if not player_config:
             self._downloader.report_warning(err_msg)
             return {}
-        player_config = json.loads(mobj.group(1))
         try:
-            args = player_config[u'args']
-            caption_url = args[u'ttsurl']
-            timestamp = args[u'timestamp']
-            # We get the available subtitles
-            list_params = compat_urllib_parse.urlencode({
-                'type': 'list',
-                'tlangs': 1,
-                'asrs': 1,
-            })
-            list_url = caption_url + '&' + list_params
-            caption_list = self._download_xml(list_url, video_id)
-            original_lang_node = caption_list.find('track')
-            if original_lang_node is None or original_lang_node.attrib.get('kind') != 'asr' :
-                self._downloader.report_warning(u'Video doesn\'t have automatic captions')
-                return {}
-            original_lang = original_lang_node.attrib['lang_code']
-
-            sub_lang_list = {}
-            for lang_node in caption_list.findall('target'):
-                sub_lang = lang_node.attrib['lang_code']
-                params = compat_urllib_parse.urlencode({
-                    'lang': original_lang,
-                    'tlang': sub_lang,
-                    'fmt': sub_format,
-                    'ts': timestamp,
-                    'kind': 'asr',
+            args = player_config['args']
+            caption_url = args.get('ttsurl')
+            if caption_url:
+                timestamp = args['timestamp']
+                # We get the available subtitles
+                list_params = compat_urllib_parse_urlencode({
+                    'type': 'list',
+                    'tlangs': 1,
+                    'asrs': 1,
                 })
-                sub_lang_list[sub_lang] = caption_url + '&' + params
-            return sub_lang_list
+                list_url = caption_url + '&' + list_params
+                caption_list = self._download_xml(list_url, video_id)
+                original_lang_node = caption_list.find('track')
+                if original_lang_node is None:
+                    self._downloader.report_warning('Video doesn\'t have automatic captions')
+                    return {}
+                original_lang = original_lang_node.attrib['lang_code']
+                caption_kind = original_lang_node.attrib.get('kind', '')
+
+                sub_lang_list = {}
+                for lang_node in caption_list.findall('target'):
+                    sub_lang = lang_node.attrib['lang_code']
+                    sub_formats = []
+                    for ext in self._SUBTITLE_FORMATS:
+                        params = compat_urllib_parse_urlencode({
+                            'lang': original_lang,
+                            'tlang': sub_lang,
+                            'fmt': ext,
+                            'ts': timestamp,
+                            'kind': caption_kind,
+                        })
+                        sub_formats.append({
+                            'url': caption_url + '&' + params,
+                            'ext': ext,
+                        })
+                    sub_lang_list[sub_lang] = sub_formats
+                return sub_lang_list
+
+            def make_captions(sub_url, sub_langs):
+                parsed_sub_url = compat_urllib_parse_urlparse(sub_url)
+                caption_qs = compat_parse_qs(parsed_sub_url.query)
+                captions = {}
+                for sub_lang in sub_langs:
+                    sub_formats = []
+                    for ext in self._SUBTITLE_FORMATS:
+                        caption_qs.update({
+                            'tlang': [sub_lang],
+                            'fmt': [ext],
+                        })
+                        sub_url = compat_urlparse.urlunparse(parsed_sub_url._replace(
+                            query=compat_urllib_parse_urlencode(caption_qs, True)))
+                        sub_formats.append({
+                            'url': sub_url,
+                            'ext': ext,
+                        })
+                    captions[sub_lang] = sub_formats
+                return captions
+
+            # New captions format as of 22.06.2017
+            player_response = args.get('player_response')
+            if player_response and isinstance(player_response, compat_str):
+                player_response = self._parse_json(
+                    player_response, video_id, fatal=False)
+                if player_response:
+                    renderer = player_response['captions']['playerCaptionsTracklistRenderer']
+                    base_url = renderer['captionTracks'][0]['baseUrl']
+                    sub_lang_list = []
+                    for lang in renderer['translationLanguages']:
+                        lang_code = lang.get('languageCode')
+                        if lang_code:
+                            sub_lang_list.append(lang_code)
+                    return make_captions(base_url, sub_lang_list)
+
+            # Some videos don't provide ttsurl but rather caption_tracks and
+            # caption_translation_languages (e.g. 20LmZk1hakA)
+            # Does not used anymore as of 22.06.2017
+            caption_tracks = args['caption_tracks']
+            caption_translation_languages = args['caption_translation_languages']
+            caption_url = compat_parse_qs(caption_tracks.split(',')[0])['u'][0]
+            sub_lang_list = []
+            for lang in caption_translation_languages.split(','):
+                lang_qs = compat_parse_qs(compat_urllib_parse_unquote_plus(lang))
+                sub_lang = lang_qs.get('lc', [None])[0]
+                if sub_lang:
+                    sub_lang_list.append(sub_lang)
+            return make_captions(caption_url, sub_lang_list)
         # An extractor error can be raise by the download process if there are
         # no automatic captions but there are subtitles
-        except (KeyError, ExtractorError):
+        except (KeyError, IndexError, ExtractorError):
             self._downloader.report_warning(err_msg)
             return {}
 
+    def _mark_watched(self, video_id, video_info, player_response):
+        playback_url = url_or_none(try_get(
+            player_response,
+            lambda x: x['playbackTracking']['videostatsPlaybackUrl']['baseUrl']) or try_get(
+            video_info, lambda x: x['videostats_playback_base_url'][0]))
+        if not playback_url:
+            return
+        parsed_playback_url = compat_urlparse.urlparse(playback_url)
+        qs = compat_urlparse.parse_qs(parsed_playback_url.query)
+
+        # cpn generation algorithm is reverse engineered from base.js.
+        # In fact it works even with dummy cpn.
+        CPN_ALPHABET = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_'
+        cpn = ''.join((CPN_ALPHABET[random.randint(0, 256) & 63] for _ in range(0, 16)))
+
+        qs.update({
+            'ver': ['2'],
+            'cpn': [cpn],
+        })
+        playback_url = compat_urlparse.urlunparse(
+            parsed_playback_url._replace(query=compat_urllib_parse_urlencode(qs, True)))
+
+        self._download_webpage(
+            playback_url, video_id, 'Marking watched',
+            'Unable to mark watched', fatal=False)
+
+    @staticmethod
+    def _extract_urls(webpage):
+        # Embedded YouTube player
+        entries = [
+            unescapeHTML(mobj.group('url'))
+            for mobj in re.finditer(r'''(?x)
+            (?:
+                <iframe[^>]+?src=|
+                data-video-url=|
+                <embed[^>]+?src=|
+                embedSWF\(?:\s*|
+                <object[^>]+data=|
+                new\s+SWFObject\(
+            )
+            (["\'])
+                (?P<url>(?:https?:)?//(?:www\.)?youtube(?:-nocookie)?\.com/
+                (?:embed|v|p)/[0-9A-Za-z_-]{11}.*?)
+            \1''', webpage)]
+
+        # lazyYT YouTube embed
+        entries.extend(list(map(
+            unescapeHTML,
+            re.findall(r'class="lazyYT" data-youtube-id="([^"]+)"', webpage))))
+
+        # Wordpress "YouTube Video Importer" plugin
+        matches = re.findall(r'''(?x)<div[^>]+
+            class=(?P<q1>[\'"])[^\'"]*\byvii_single_video_player\b[^\'"]*(?P=q1)[^>]+
+            data-video_id=(?P<q2>[\'"])([^\'"]+)(?P=q2)''', webpage)
+        entries.extend(m[-1] for m in matches)
+
+        return entries
+
+    @staticmethod
+    def _extract_url(webpage):
+        urls = YoutubeIE._extract_urls(webpage)
+        return urls[0] if urls else None
+
     @classmethod
     def extract_id(cls, url):
         mobj = re.match(cls._VALID_URL, url, re.VERBOSE)
         if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
+            raise ExtractorError('Invalid URL: %s' % url)
         video_id = mobj.group(2)
         return video_id
 
-    def _extract_from_m3u8(self, manifest_url, video_id):
-        url_map = {}
-        def _get_urls(_manifest):
-            lines = _manifest.split('\n')
-            urls = filter(lambda l: l and not l.startswith('#'),
-                            lines)
-            return urls
-        manifest = self._download_webpage(manifest_url, video_id, u'Downloading formats manifest')
-        formats_urls = _get_urls(manifest)
-        for format_url in formats_urls:
-            itag = self._search_regex(r'itag/(\d+?)/', format_url, 'itag')
-            url_map[itag] = format_url
-        return url_map
-
-    def _extract_annotations(self, video_id):
-        url = 'https://www.youtube.com/annotations_invideo?features=1&legacy=1&video_id=%s' % video_id
-        return self._download_webpage(url, video_id, note=u'Searching for annotations.', errnote=u'Unable to download video annotations.')
+    def _extract_chapters_from_json(self, webpage, video_id, duration):
+        if not webpage:
+            return
+        player = self._parse_json(
+            self._search_regex(
+                r'RELATED_PLAYER_ARGS["\']\s*:\s*({.+})\s*,?\s*\n', webpage,
+                'player args', default='{}'),
+            video_id, fatal=False)
+        if not player or not isinstance(player, dict):
+            return
+        watch_next_response = player.get('watch_next_response')
+        if not isinstance(watch_next_response, compat_str):
+            return
+        response = self._parse_json(watch_next_response, video_id, fatal=False)
+        if not response or not isinstance(response, dict):
+            return
+        chapters_list = try_get(
+            response,
+            lambda x: x['playerOverlays']
+                       ['playerOverlayRenderer']
+                       ['decoratedPlayerBarRenderer']
+                       ['decoratedPlayerBarRenderer']
+                       ['playerBar']
+                       ['chapteredPlayerBarRenderer']
+                       ['chapters'],
+            list)
+        if not chapters_list:
+            return
+
+        def chapter_time(chapter):
+            return float_or_none(
+                try_get(
+                    chapter,
+                    lambda x: x['chapterRenderer']['timeRangeStartMillis'],
+                    int),
+                scale=1000)
+        chapters = []
+        for next_num, chapter in enumerate(chapters_list, start=1):
+            start_time = chapter_time(chapter)
+            if start_time is None:
+                continue
+            end_time = (chapter_time(chapters_list[next_num])
+                        if next_num < len(chapters_list) else duration)
+            if end_time is None:
+                continue
+            title = try_get(
+                chapter, lambda x: x['chapterRenderer']['title']['simpleText'],
+                compat_str)
+            chapters.append({
+                'start_time': start_time,
+                'end_time': end_time,
+                'title': title,
+            })
+        return chapters
+
+    @staticmethod
+    def _extract_chapters_from_description(description, duration):
+        if not description:
+            return None
+        chapter_lines = re.findall(
+            r'(?:^|<br\s*/>)([^<]*<a[^>]+onclick=["\']yt\.www\.watch\.player\.seekTo[^>]+>(\d{1,2}:\d{1,2}(?::\d{1,2})?)</a>[^>]*)(?=$|<br\s*/>)',
+            description)
+        if not chapter_lines:
+            return None
+        chapters = []
+        for next_num, (chapter_line, time_point) in enumerate(
+                chapter_lines, start=1):
+            start_time = parse_duration(time_point)
+            if start_time is None:
+                continue
+            if start_time > duration:
+                break
+            end_time = (duration if next_num == len(chapter_lines)
+                        else parse_duration(chapter_lines[next_num][1]))
+            if end_time is None:
+                continue
+            if end_time > duration:
+                end_time = duration
+            if start_time > end_time:
+                break
+            chapter_title = re.sub(
+                r'<a[^>]+>[^<]+</a>', '', chapter_line).strip(' \t-')
+            chapter_title = re.sub(r'\s+', ' ', chapter_title)
+            chapters.append({
+                'start_time': start_time,
+                'end_time': end_time,
+                'title': chapter_title,
+            })
+        return chapters
+
+    def _extract_chapters(self, webpage, description, video_id, duration):
+        return (self._extract_chapters_from_json(webpage, video_id, duration)
+                or self._extract_chapters_from_description(description, duration))
 
     def _real_extract(self, url):
+        url, smuggled_data = unsmuggle_url(url, {})
+
+        proto = (
+            'http' if self._downloader.params.get('prefer_insecure', False)
+            else 'https')
+
+        start_time = None
+        end_time = None
+        parsed_url = compat_urllib_parse_urlparse(url)
+        for component in [parsed_url.fragment, parsed_url.query]:
+            query = compat_parse_qs(component)
+            if start_time is None and 't' in query:
+                start_time = parse_duration(query['t'][0])
+            if start_time is None and 'start' in query:
+                start_time = parse_duration(query['start'][0])
+            if end_time is None and 'end' in query:
+                end_time = parse_duration(query['end'][0])
+
         # Extract original video URL from URL with redirection, like age verification, using next_url parameter
         mobj = re.search(self._NEXT_URL_RE, url)
         if mobj:
-            url = 'https://www.youtube.com/' + compat_urllib_parse.unquote(mobj.group(1)).lstrip('/')
+            url = proto + '://www.youtube.com/' + compat_urllib_parse_unquote(mobj.group(1)).lstrip('/')
         video_id = self.extract_id(url)
 
         # Get video webpage
-        url = 'https://www.youtube.com/watch?v=%s&gl=US&hl=en&has_verified=1' % video_id
-        video_webpage = self._download_webpage(url, video_id)
+        url = proto + '://www.youtube.com/watch?v=%s&gl=US&hl=en&has_verified=1&bpctr=9999999999' % video_id
+        video_webpage, urlh = self._download_webpage_handle(url, video_id)
+
+        qs = compat_parse_qs(compat_urllib_parse_urlparse(urlh.geturl()).query)
+        video_id = qs.get('v', [None])[0] or video_id
 
         # Attempt to extract SWF player URL
         mobj = re.search(r'swfConfig.*?"(https?:\\/\\/.*?watch.*?-.*?\.swf)"', video_webpage)
@@ -1130,179 +1807,212 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         else:
             player_url = None
 
-        # Get video info
-        self.report_video_info_webpage_download(video_id)
-        if re.search(r'player-age-gate-content">', video_webpage) is not None:
-            self.report_age_confirmation()
-            age_gate = True
-            # We simulate the access to the video from www.youtube.com/v/{video_id}
-            # this can be viewed without login into Youtube
-            data = compat_urllib_parse.urlencode({'video_id': video_id,
-                                                  'el': 'player_embedded',
-                                                  'gl': 'US',
-                                                  'hl': 'en',
-                                                  'eurl': 'https://youtube.googleapis.com/v/' + video_id,
-                                                  'asv': 3,
-                                                  'sts':'1588',
-                                                  })
-            video_info_url = 'https://www.youtube.com/get_video_info?' + data
-            video_info_webpage = self._download_webpage(video_info_url, video_id,
-                                    note=False,
-                                    errnote='unable to download video info webpage')
-            video_info = compat_parse_qs(video_info_webpage)
-        else:
-            age_gate = False
-            for el_type in ['&el=embedded', '&el=detailpage', '&el=vevo', '']:
-                video_info_url = ('https://www.youtube.com/get_video_info?&video_id=%s%s&ps=default&eurl=&gl=US&hl=en'
-                        % (video_id, el_type))
-                video_info_webpage = self._download_webpage(video_info_url, video_id,
-                                        note=False,
-                                        errnote='unable to download video info webpage')
-                video_info = compat_parse_qs(video_info_webpage)
-                if 'token' in video_info:
-                    break
-        if 'token' not in video_info:
-            if 'reason' in video_info:
-                raise ExtractorError(u'YouTube said: %s' % video_info['reason'][0], expected=True)
-            else:
-                raise ExtractorError(u'"token" parameter not in video info for unknown reason')
+        dash_mpds = []
 
-        if 'view_count' in video_info:
-            view_count = int(video_info['view_count'][0])
-        else:
-            view_count = None
+        def add_dash_mpd(video_info):
+            dash_mpd = video_info.get('dashmpd')
+            if dash_mpd and dash_mpd[0] not in dash_mpds:
+                dash_mpds.append(dash_mpd[0])
 
-        # Check for "rental" videos
-        if 'ypc_video_rental_bar_text' in video_info and 'author' not in video_info:
-            raise ExtractorError(u'"rental" videos not supported')
+        def add_dash_mpd_pr(pl_response):
+            dash_mpd = url_or_none(try_get(
+                pl_response, lambda x: x['streamingData']['dashManifestUrl'],
+                compat_str))
+            if dash_mpd and dash_mpd not in dash_mpds:
+                dash_mpds.append(dash_mpd)
 
-        # Start extracting information
-        self.report_information_extraction(video_id)
+        is_live = None
+        view_count = None
 
-        # uploader
-        if 'author' not in video_info:
-            raise ExtractorError(u'Unable to extract uploader name')
-        video_uploader = compat_urllib_parse.unquote_plus(video_info['author'][0])
+        def extract_view_count(v_info):
+            return int_or_none(try_get(v_info, lambda x: x['view_count'][0]))
 
-        # uploader_id
-        video_uploader_id = None
-        mobj = re.search(r'<link itemprop="url" href="http://www.youtube.com/(?:user|channel)/([^"]+)">', video_webpage)
-        if mobj is not None:
-            video_uploader_id = mobj.group(1)
-        else:
-            self._downloader.report_warning(u'unable to extract uploader nickname')
+        def extract_player_response(player_response, video_id):
+            pl_response = str_or_none(player_response)
+            if not pl_response:
+                return
+            pl_response = self._parse_json(pl_response, video_id, fatal=False)
+            if isinstance(pl_response, dict):
+                add_dash_mpd_pr(pl_response)
+                return pl_response
+
+        player_response = {}
 
-        # title
-        if 'title' in video_info:
-            video_title = compat_urllib_parse.unquote_plus(video_info['title'][0])
+        # Get video info
+        video_info = {}
+        embed_webpage = None
+        if (self._og_search_property('restrictions:age', video_webpage, default=None) == '18+'
+                or re.search(r'player-age-gate-content">', video_webpage) is not None):
+            age_gate = True
+            # We simulate the access to the video from www.youtube.com/v/{video_id}
+            # this can be viewed without login into Youtube
+            url = proto + '://www.youtube.com/embed/%s' % video_id
+            embed_webpage = self._download_webpage(url, video_id, 'Downloading embed webpage')
+            data = compat_urllib_parse_urlencode({
+                'video_id': video_id,
+                'eurl': 'https://youtube.googleapis.com/v/' + video_id,
+                'sts': self._search_regex(
+                    r'"sts"\s*:\s*(\d+)', embed_webpage, 'sts', default=''),
+            })
+            video_info_url = proto + '://www.youtube.com/get_video_info?' + data
+            try:
+                video_info_webpage = self._download_webpage(
+                    video_info_url, video_id,
+                    note='Refetching age-gated info webpage',
+                    errnote='unable to download video info webpage')
+            except ExtractorError:
+                video_info_webpage = None
+            if video_info_webpage:
+                video_info = compat_parse_qs(video_info_webpage)
+                pl_response = video_info.get('player_response', [None])[0]
+                player_response = extract_player_response(pl_response, video_id)
+                add_dash_mpd(video_info)
+                view_count = extract_view_count(video_info)
         else:
-            self._downloader.report_warning(u'Unable to extract video title')
-            video_title = u'_'
-
-        # thumbnail image
-        # We try first to get a high quality image:
-        m_thumb = re.search(r'<span itemprop="thumbnail".*?href="(.*?)">',
-                            video_webpage, re.DOTALL)
-        if m_thumb is not None:
-            video_thumbnail = m_thumb.group(1)
-        elif 'thumbnail_url' not in video_info:
-            self._downloader.report_warning(u'unable to extract video thumbnail')
-            video_thumbnail = None
-        else:   # don't panic if we can't find it
-            video_thumbnail = compat_urllib_parse.unquote_plus(video_info['thumbnail_url'][0])
+            age_gate = False
+            # Try looking directly into the video webpage
+            ytplayer_config = self._get_ytplayer_config(video_id, video_webpage)
+            if ytplayer_config:
+                args = ytplayer_config['args']
+                if args.get('url_encoded_fmt_stream_map') or args.get('hlsvp'):
+                    # Convert to the same format returned by compat_parse_qs
+                    video_info = dict((k, [v]) for k, v in args.items())
+                    add_dash_mpd(video_info)
+                # Rental video is not rented but preview is available (e.g.
+                # https://www.youtube.com/watch?v=yYr8q0y5Jfg,
+                # https://github.com/ytdl-org/youtube-dl/issues/10532)
+                if not video_info and args.get('ypc_vid'):
+                    return self.url_result(
+                        args['ypc_vid'], YoutubeIE.ie_key(), video_id=args['ypc_vid'])
+                if args.get('livestream') == '1' or args.get('live_playback') == 1:
+                    is_live = True
+                if not player_response:
+                    player_response = extract_player_response(args.get('player_response'), video_id)
+            if not video_info or self._downloader.params.get('youtube_include_dash_manifest', True):
+                add_dash_mpd_pr(player_response)
+
+        def extract_unavailable_message():
+            messages = []
+            for tag, kind in (('h1', 'message'), ('div', 'submessage')):
+                msg = self._html_search_regex(
+                    r'(?s)<{tag}[^>]+id=["\']unavailable-{kind}["\'][^>]*>(.+?)</{tag}>'.format(tag=tag, kind=kind),
+                    video_webpage, 'unavailable %s' % kind, default=None)
+                if msg:
+                    messages.append(msg)
+            if messages:
+                return '\n'.join(messages)
+
+        if not video_info and not player_response:
+            unavailable_message = extract_unavailable_message()
+            if not unavailable_message:
+                unavailable_message = 'Unable to extract video data'
+            raise ExtractorError(
+                'YouTube said: %s' % unavailable_message, expected=True, video_id=video_id)
 
-        # upload date
-        upload_date = None
-        mobj = re.search(r'id="eow-date.*?>(.*?)</span>', video_webpage, re.DOTALL)
-        if mobj is not None:
-            upload_date = ' '.join(re.sub(r'[/,-]', r' ', mobj.group(1)).split())
-            upload_date = unified_strdate(upload_date)
+        if not isinstance(video_info, dict):
+            video_info = {}
+
+        video_details = try_get(
+            player_response, lambda x: x['videoDetails'], dict) or {}
 
-        # description
-        video_description = get_element_by_id("eow-description", video_webpage)
+        microformat = try_get(
+            player_response, lambda x: x['microformat']['playerMicroformatRenderer'], dict) or {}
+
+        video_title = video_info.get('title', [None])[0] or video_details.get('title')
+        if not video_title:
+            self._downloader.report_warning('Unable to extract video title')
+            video_title = '_'
+
+        description_original = video_description = get_element_by_id("eow-description", video_webpage)
         if video_description:
-            video_description = re.sub(r'''(?x)
+
+            def replace_url(m):
+                redir_url = compat_urlparse.urljoin(url, m.group(1))
+                parsed_redir_url = compat_urllib_parse_urlparse(redir_url)
+                if re.search(r'^(?:www\.)?(?:youtube(?:-nocookie)?\.com|youtu\.be)$', parsed_redir_url.netloc) and parsed_redir_url.path == '/redirect':
+                    qs = compat_parse_qs(parsed_redir_url.query)
+                    q = qs.get('q')
+                    if q and q[0]:
+                        return q[0]
+                return redir_url
+
+            description_original = video_description = re.sub(r'''(?x)
                 <a\s+
-                    (?:[a-zA-Z-]+="[^"]+"\s+)*?
-                    title="([^"]+)"\s+
-                    (?:[a-zA-Z-]+="[^"]+"\s+)*?
-                    class="yt-uix-redirect-link"\s*>
-                [^<]+
+                    (?:[a-zA-Z-]+="[^"]*"\s+)*?
+                    (?:title|href)="([^"]+)"\s+
+                    (?:[a-zA-Z-]+="[^"]*"\s+)*?
+                    class="[^"]*"[^>]*>
+                [^<]+\.{3}\s*
                 </a>
-            ''', r'\1', video_description)
+            ''', replace_url, video_description)
             video_description = clean_html(video_description)
         else:
-            fd_mobj = re.search(r'<meta name="description" content="([^"]+)"', video_webpage)
-            if fd_mobj:
-                video_description = unescapeHTML(fd_mobj.group(1))
+            video_description = video_details.get('shortDescription')
+            if video_description is None:
+                video_description = self._html_search_meta('description', video_webpage)
+
+        if not smuggled_data.get('force_singlefeed', False):
+            if not self._downloader.params.get('noplaylist'):
+                multifeed_metadata_list = try_get(
+                    player_response,
+                    lambda x: x['multicamera']['playerLegacyMulticameraRenderer']['metadataList'],
+                    compat_str) or try_get(
+                    video_info, lambda x: x['multifeed_metadata_list'][0], compat_str)
+                if multifeed_metadata_list:
+                    entries = []
+                    feed_ids = []
+                    for feed in multifeed_metadata_list.split(','):
+                        # Unquote should take place before split on comma (,) since textual
+                        # fields may contain comma as well (see
+                        # https://github.com/ytdl-org/youtube-dl/issues/8536)
+                        feed_data = compat_parse_qs(compat_urllib_parse_unquote_plus(feed))
+
+                        def feed_entry(name):
+                            return try_get(feed_data, lambda x: x[name][0], compat_str)
+
+                        feed_id = feed_entry('id')
+                        if not feed_id:
+                            continue
+                        feed_title = feed_entry('title')
+                        title = video_title
+                        if feed_title:
+                            title += ' (%s)' % feed_title
+                        entries.append({
+                            '_type': 'url_transparent',
+                            'ie_key': 'Youtube',
+                            'url': smuggle_url(
+                                '%s://www.youtube.com/watch?v=%s' % (proto, feed_data['id'][0]),
+                                {'force_singlefeed': True}),
+                            'title': title,
+                        })
+                        feed_ids.append(feed_id)
+                    self.to_screen(
+                        'Downloading multifeed video (%s) - add --no-playlist to just download video %s'
+                        % (', '.join(feed_ids), video_id))
+                    return self.playlist_result(entries, video_id, video_title, video_description)
             else:
-                video_description = u''
-
-        def _extract_count(klass):
-            count = self._search_regex(
-                r'class="%s">([\d,]+)</span>' % re.escape(klass),
-                video_webpage, klass, default=None)
-            if count is not None:
-                return int(count.replace(',', ''))
-            return None
-        like_count = _extract_count(u'likes-count')
-        dislike_count = _extract_count(u'dislikes-count')
+                self.to_screen('Downloading just video %s because of --no-playlist' % video_id)
 
-        # subtitles
-        video_subtitles = self.extract_subtitles(video_id, video_webpage)
+        if view_count is None:
+            view_count = extract_view_count(video_info)
+        if view_count is None and video_details:
+            view_count = int_or_none(video_details.get('viewCount'))
+        if view_count is None and microformat:
+            view_count = int_or_none(microformat.get('viewCount'))
 
-        if self._downloader.params.get('listsubtitles', False):
-            self._list_available_subtitles(video_id, video_webpage)
-            return
+        if is_live is None:
+            is_live = bool_or_none(video_details.get('isLive'))
 
-        if 'length_seconds' not in video_info:
-            self._downloader.report_warning(u'unable to extract video duration')
-            video_duration = None
-        else:
-            video_duration = int(compat_urllib_parse.unquote_plus(video_info['length_seconds'][0]))
+        # Check for "rental" videos
+        if 'ypc_video_rental_bar_text' in video_info and 'author' not in video_info:
+            raise ExtractorError('"rental" videos not supported. See https://github.com/ytdl-org/youtube-dl/issues/359 for more information.', expected=True)
 
-        # annotations
-        video_annotations = None
-        if self._downloader.params.get('writeannotations', False):
-                video_annotations = self._extract_annotations(video_id)
+        def _extract_filesize(media_url):
+            return int_or_none(self._search_regex(
+                r'\bclen[=/](\d+)', media_url, 'filesize', default=None))
 
-        # Decide which formats to download
-        try:
-            mobj = re.search(r';ytplayer.config = ({.*?});', video_webpage)
-            if not mobj:
-                raise ValueError('Could not find vevo ID')
-            info = json.loads(mobj.group(1))
-            args = info['args']
-            # Easy way to know if the 's' value is in url_encoded_fmt_stream_map
-            # this signatures are encrypted
-            if 'url_encoded_fmt_stream_map' not in args:
-                raise ValueError(u'No stream_map present')  # caught below
-            re_signature = re.compile(r'[&,]s=')
-            m_s = re_signature.search(args['url_encoded_fmt_stream_map'])
-            if m_s is not None:
-                self.to_screen(u'%s: Encrypted signatures detected.' % video_id)
-                video_info['url_encoded_fmt_stream_map'] = [args['url_encoded_fmt_stream_map']]
-            m_s = re_signature.search(args.get('adaptive_fmts', u''))
-            if m_s is not None:
-                if 'adaptive_fmts' in video_info:
-                    video_info['adaptive_fmts'][0] += ',' + args['adaptive_fmts']
-                else:
-                    video_info['adaptive_fmts'] = [args['adaptive_fmts']]
-        except ValueError:
-            pass
-
-        def _map_to_format_list(urlmap):
-            formats = []
-            for itag, video_real_url in urlmap.items():
-                dct = {
-                    'format_id': itag,
-                    'url': video_real_url,
-                    'player_url': player_url,
-                }
-                if itag in self._formats:
-                    dct.update(self._formats[itag])
-                formats.append(dct)
-            return formats
+        streaming_formats = try_get(player_response, lambda x: x['streamingData']['formats'], list) or []
+        streaming_formats.extend(try_get(player_response, lambda x: x['streamingData']['adaptiveFormats'], list) or [])
 
         if 'conn' in video_info and video_info['conn'][0].startswith('rtmp'):
             self.report_rtmp_download()
@@ -1312,271 +2022,981 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                 'url': video_info['conn'][0],
                 'player_url': player_url,
             }]
-        elif len(video_info.get('url_encoded_fmt_stream_map', [])) >= 1 or len(video_info.get('adaptive_fmts', [])) >= 1:
-            encoded_url_map = video_info.get('url_encoded_fmt_stream_map', [''])[0] + ',' + video_info.get('adaptive_fmts',[''])[0]
+        elif not is_live and (streaming_formats or len(video_info.get('url_encoded_fmt_stream_map', [''])[0]) >= 1 or len(video_info.get('adaptive_fmts', [''])[0]) >= 1):
+            encoded_url_map = video_info.get('url_encoded_fmt_stream_map', [''])[0] + ',' + video_info.get('adaptive_fmts', [''])[0]
             if 'rtmpe%3Dyes' in encoded_url_map:
-                raise ExtractorError('rtmpe downloads are not supported, see https://github.com/rg3/youtube-dl/issues/343 for more information.', expected=True)
-            url_map = {}
-            for url_data_str in encoded_url_map.split(','):
-                url_data = compat_parse_qs(url_data_str)
-                if 'itag' in url_data and 'url' in url_data:
-                    url = url_data['url'][0]
+                raise ExtractorError('rtmpe downloads are not supported, see https://github.com/ytdl-org/youtube-dl/issues/343 for more information.', expected=True)
+            formats = []
+            formats_spec = {}
+            fmt_list = video_info.get('fmt_list', [''])[0]
+            if fmt_list:
+                for fmt in fmt_list.split(','):
+                    spec = fmt.split('/')
+                    if len(spec) > 1:
+                        width_height = spec[1].split('x')
+                        if len(width_height) == 2:
+                            formats_spec[spec[0]] = {
+                                'resolution': spec[1],
+                                'width': int_or_none(width_height[0]),
+                                'height': int_or_none(width_height[1]),
+                            }
+            for fmt in streaming_formats:
+                itag = str_or_none(fmt.get('itag'))
+                if not itag:
+                    continue
+                quality = fmt.get('quality')
+                quality_label = fmt.get('qualityLabel') or quality
+                formats_spec[itag] = {
+                    'asr': int_or_none(fmt.get('audioSampleRate')),
+                    'filesize': int_or_none(fmt.get('contentLength')),
+                    'format_note': quality_label,
+                    'fps': int_or_none(fmt.get('fps')),
+                    'height': int_or_none(fmt.get('height')),
+                    # bitrate for itag 43 is always 2147483647
+                    'tbr': float_or_none(fmt.get('averageBitrate') or fmt.get('bitrate'), 1000) if itag != '43' else None,
+                    'width': int_or_none(fmt.get('width')),
+                }
+
+            for fmt in streaming_formats:
+                if fmt.get('drmFamilies') or fmt.get('drm_families'):
+                    continue
+                url = url_or_none(fmt.get('url'))
+
+                if not url:
+                    cipher = fmt.get('cipher') or fmt.get('signatureCipher')
+                    if not cipher:
+                        continue
+                    url_data = compat_parse_qs(cipher)
+                    url = url_or_none(try_get(url_data, lambda x: x['url'][0], compat_str))
+                    if not url:
+                        continue
+                else:
+                    cipher = None
+                    url_data = compat_parse_qs(compat_urllib_parse_urlparse(url).query)
+
+                stream_type = int_or_none(try_get(url_data, lambda x: x['stream_type'][0]))
+                # Unsupported FORMAT_STREAM_TYPE_OTF
+                if stream_type == 3:
+                    continue
+
+                format_id = fmt.get('itag') or url_data['itag'][0]
+                if not format_id:
+                    continue
+                format_id = compat_str(format_id)
+
+                if cipher:
+                    if 's' in url_data or self._downloader.params.get('youtube_include_dash_manifest', True):
+                        ASSETS_RE = r'"assets":.+?"js":\s*("[^"]+")'
+                        jsplayer_url_json = self._search_regex(
+                            ASSETS_RE,
+                            embed_webpage if age_gate else video_webpage,
+                            'JS player URL (1)', default=None)
+                        if not jsplayer_url_json and not age_gate:
+                            # We need the embed website after all
+                            if embed_webpage is None:
+                                embed_url = proto + '://www.youtube.com/embed/%s' % video_id
+                                embed_webpage = self._download_webpage(
+                                    embed_url, video_id, 'Downloading embed webpage')
+                            jsplayer_url_json = self._search_regex(
+                                ASSETS_RE, embed_webpage, 'JS player URL')
+
+                        player_url = json.loads(jsplayer_url_json)
+                        if player_url is None:
+                            player_url_json = self._search_regex(
+                                r'ytplayer\.config.*?"url"\s*:\s*("[^"]+")',
+                                video_webpage, 'age gate player URL')
+                            player_url = json.loads(player_url_json)
+
                     if 'sig' in url_data:
                         url += '&signature=' + url_data['sig'][0]
                     elif 's' in url_data:
                         encrypted_sig = url_data['s'][0]
+
                         if self._downloader.params.get('verbose'):
-                            if age_gate:
-                                if player_url is None:
-                                    player_version = 'unknown'
-                                else:
-                                    player_version = self._search_regex(
-                                        r'-(.+)\.swf$', player_url,
-                                        u'flash player', fatal=False)
-                                player_desc = 'flash player %s' % player_version
+                            if player_url is None:
+                                player_desc = 'unknown'
                             else:
-                                player_version = self._search_regex(
-                                    r'html5player-(.+?)\.js', video_webpage,
-                                    'html5 player', fatal=False)
-                                player_desc = u'html5 player %s' % player_version
-
-                            parts_sizes = u'.'.join(compat_str(len(part)) for part in encrypted_sig.split('.'))
-                            self.to_screen(u'encrypted signature length %d (%s), itag %s, %s' %
-                                (len(encrypted_sig), parts_sizes, url_data['itag'][0], player_desc))
-
-                        if not age_gate:
-                            jsplayer_url_json = self._search_regex(
-                                r'"assets":.+?"js":\s*("[^"]+")',
-                                video_webpage, u'JS player URL')
-                            player_url = json.loads(jsplayer_url_json)
+                                player_type, player_version = self._extract_player_info(player_url)
+                                player_desc = '%s player %s' % ('flash' if player_type == 'swf' else 'html5', player_version)
+                            parts_sizes = self._signature_cache_id(encrypted_sig)
+                            self.to_screen('{%s} signature length %s, %s' %
+                                           (format_id, parts_sizes, player_desc))
 
                         signature = self._decrypt_signature(
                             encrypted_sig, video_id, player_url, age_gate)
-                        url += '&signature=' + signature
-                    if 'ratebypass' not in url:
-                        url += '&ratebypass=yes'
-                    url_map[url_data['itag'][0]] = url
-            formats = _map_to_format_list(url_map)
-        elif video_info.get('hlsvp'):
-            manifest_url = video_info['hlsvp'][0]
-            url_map = self._extract_from_m3u8(manifest_url, video_id)
-            formats = _map_to_format_list(url_map)
+                        sp = try_get(url_data, lambda x: x['sp'][0], compat_str) or 'signature'
+                        url += '&%s=%s' % (sp, signature)
+                if 'ratebypass' not in url:
+                    url += '&ratebypass=yes'
+
+                dct = {
+                    'format_id': format_id,
+                    'url': url,
+                    'player_url': player_url,
+                }
+                if format_id in self._formats:
+                    dct.update(self._formats[format_id])
+                if format_id in formats_spec:
+                    dct.update(formats_spec[format_id])
+
+                # Some itags are not included in DASH manifest thus corresponding formats will
+                # lack metadata (see https://github.com/ytdl-org/youtube-dl/pull/5993).
+                # Trying to extract metadata from url_encoded_fmt_stream_map entry.
+                mobj = re.search(r'^(?P<width>\d+)[xX](?P<height>\d+)$', url_data.get('size', [''])[0])
+                width, height = (int(mobj.group('width')), int(mobj.group('height'))) if mobj else (None, None)
+
+                if width is None:
+                    width = int_or_none(fmt.get('width'))
+                if height is None:
+                    height = int_or_none(fmt.get('height'))
+
+                filesize = int_or_none(url_data.get(
+                    'clen', [None])[0]) or _extract_filesize(url)
+
+                quality = url_data.get('quality', [None])[0] or fmt.get('quality')
+                quality_label = url_data.get('quality_label', [None])[0] or fmt.get('qualityLabel')
+
+                tbr = (float_or_none(url_data.get('bitrate', [None])[0], 1000)
+                       or float_or_none(fmt.get('bitrate'), 1000)) if format_id != '43' else None
+                fps = int_or_none(url_data.get('fps', [None])[0]) or int_or_none(fmt.get('fps'))
+
+                more_fields = {
+                    'filesize': filesize,
+                    'tbr': tbr,
+                    'width': width,
+                    'height': height,
+                    'fps': fps,
+                    'format_note': quality_label or quality,
+                }
+                for key, value in more_fields.items():
+                    if value:
+                        dct[key] = value
+                type_ = url_data.get('type', [None])[0] or fmt.get('mimeType')
+                if type_:
+                    type_split = type_.split(';')
+                    kind_ext = type_split[0].split('/')
+                    if len(kind_ext) == 2:
+                        kind, _ = kind_ext
+                        dct['ext'] = mimetype2ext(type_split[0])
+                        if kind in ('audio', 'video'):
+                            codecs = None
+                            for mobj in re.finditer(
+                                    r'(?P<key>[a-zA-Z_-]+)=(?P<quote>["\']?)(?P<val>.+?)(?P=quote)(?:;|$)', type_):
+                                if mobj.group('key') == 'codecs':
+                                    codecs = mobj.group('val')
+                                    break
+                            if codecs:
+                                dct.update(parse_codecs(codecs))
+                if dct.get('acodec') == 'none' or dct.get('vcodec') == 'none':
+                    dct['downloader_options'] = {
+                        # Youtube throttles chunks >~10M
+                        'http_chunk_size': 10485760,
+                    }
+                formats.append(dct)
+        else:
+            manifest_url = (
+                url_or_none(try_get(
+                    player_response,
+                    lambda x: x['streamingData']['hlsManifestUrl'],
+                    compat_str))
+                or url_or_none(try_get(
+                    video_info, lambda x: x['hlsvp'][0], compat_str)))
+            if manifest_url:
+                formats = []
+                m3u8_formats = self._extract_m3u8_formats(
+                    manifest_url, video_id, 'mp4', fatal=False)
+                for a_format in m3u8_formats:
+                    itag = self._search_regex(
+                        r'/itag/(\d+)/', a_format['url'], 'itag', default=None)
+                    if itag:
+                        a_format['format_id'] = itag
+                        if itag in self._formats:
+                            dct = self._formats[itag].copy()
+                            dct.update(a_format)
+                            a_format = dct
+                    a_format['player_url'] = player_url
+                    # Accept-Encoding header causes failures in live streams on Youtube and Youtube Gaming
+                    a_format.setdefault('http_headers', {})['Youtubedl-no-compression'] = 'True'
+                    formats.append(a_format)
+            else:
+                error_message = extract_unavailable_message()
+                if not error_message:
+                    error_message = clean_html(try_get(
+                        player_response, lambda x: x['playabilityStatus']['reason'],
+                        compat_str))
+                if not error_message:
+                    error_message = clean_html(
+                        try_get(video_info, lambda x: x['reason'][0], compat_str))
+                if error_message:
+                    raise ExtractorError(error_message, expected=True)
+                raise ExtractorError('no conn, hlsvp, hlsManifestUrl or url_encoded_fmt_stream_map information found in video info')
+
+        # uploader
+        video_uploader = try_get(
+            video_info, lambda x: x['author'][0],
+            compat_str) or str_or_none(video_details.get('author'))
+        if video_uploader:
+            video_uploader = compat_urllib_parse_unquote_plus(video_uploader)
+        else:
+            self._downloader.report_warning('unable to extract uploader name')
+
+        # uploader_id
+        video_uploader_id = None
+        video_uploader_url = None
+        mobj = re.search(
+            r'<link itemprop="url" href="(?P<uploader_url>https?://www\.youtube\.com/(?:user|channel)/(?P<uploader_id>[^"]+))">',
+            video_webpage)
+        if mobj is not None:
+            video_uploader_id = mobj.group('uploader_id')
+            video_uploader_url = mobj.group('uploader_url')
+        else:
+            owner_profile_url = url_or_none(microformat.get('ownerProfileUrl'))
+            if owner_profile_url:
+                video_uploader_id = self._search_regex(
+                    r'(?:user|channel)/([^/]+)', owner_profile_url, 'uploader id',
+                    default=None)
+                video_uploader_url = owner_profile_url
+
+        channel_id = (
+            str_or_none(video_details.get('channelId'))
+            or self._html_search_meta(
+                'channelId', video_webpage, 'channel id', default=None)
+            or self._search_regex(
+                r'data-channel-external-id=(["\'])(?P<id>(?:(?!\1).)+)\1',
+                video_webpage, 'channel id', default=None, group='id'))
+        channel_url = 'http://www.youtube.com/channel/%s' % channel_id if channel_id else None
+
+        thumbnails = []
+        thumbnails_list = try_get(
+            video_details, lambda x: x['thumbnail']['thumbnails'], list) or []
+        for t in thumbnails_list:
+            if not isinstance(t, dict):
+                continue
+            thumbnail_url = url_or_none(t.get('url'))
+            if not thumbnail_url:
+                continue
+            thumbnails.append({
+                'url': thumbnail_url,
+                'width': int_or_none(t.get('width')),
+                'height': int_or_none(t.get('height')),
+            })
+
+        if not thumbnails:
+            video_thumbnail = None
+            # We try first to get a high quality image:
+            m_thumb = re.search(r'<span itemprop="thumbnail".*?href="(.*?)">',
+                                video_webpage, re.DOTALL)
+            if m_thumb is not None:
+                video_thumbnail = m_thumb.group(1)
+            thumbnail_url = try_get(video_info, lambda x: x['thumbnail_url'][0], compat_str)
+            if thumbnail_url:
+                video_thumbnail = compat_urllib_parse_unquote_plus(thumbnail_url)
+            if video_thumbnail:
+                thumbnails.append({'url': video_thumbnail})
+
+        # upload date
+        upload_date = self._html_search_meta(
+            'datePublished', video_webpage, 'upload date', default=None)
+        if not upload_date:
+            upload_date = self._search_regex(
+                [r'(?s)id="eow-date.*?>(.*?)</span>',
+                 r'(?:id="watch-uploader-info".*?>.*?|["\']simpleText["\']\s*:\s*["\'])(?:Published|Uploaded|Streamed live|Started) on (.+?)[<"\']'],
+                video_webpage, 'upload date', default=None)
+        if not upload_date:
+            upload_date = microformat.get('publishDate') or microformat.get('uploadDate')
+        upload_date = unified_strdate(upload_date)
+
+        video_license = self._html_search_regex(
+            r'<h4[^>]+class="title"[^>]*>\s*License\s*</h4>\s*<ul[^>]*>\s*<li>(.+?)</li',
+            video_webpage, 'license', default=None)
+
+        m_music = re.search(
+            r'''(?x)
+                <h4[^>]+class="title"[^>]*>\s*Music\s*</h4>\s*
+                <ul[^>]*>\s*
+                <li>(?P<title>.+?)
+                by (?P<creator>.+?)
+                (?:
+                    \(.+?\)|
+                    <a[^>]*
+                        (?:
+                            \bhref=["\']/red[^>]*>|             # drop possible
+                            >\s*Listen ad-free with YouTube Red # YouTube Red ad
+                        )
+                    .*?
+                )?</li
+            ''',
+            video_webpage)
+        if m_music:
+            video_alt_title = remove_quotes(unescapeHTML(m_music.group('title')))
+            video_creator = clean_html(m_music.group('creator'))
+        else:
+            video_alt_title = video_creator = None
+
+        def extract_meta(field):
+            return self._html_search_regex(
+                r'<h4[^>]+class="title"[^>]*>\s*%s\s*</h4>\s*<ul[^>]*>\s*<li>(.+?)</li>\s*' % field,
+                video_webpage, field, default=None)
+
+        track = extract_meta('Song')
+        artist = extract_meta('Artist')
+        album = extract_meta('Album')
+
+        # Youtube Music Auto-generated description
+        release_date = release_year = None
+        if video_description:
+            mobj = re.search(r'(?s)Provided to YouTube by [^\n]+\n+(?P<track>[^·]+)·(?P<artist>[^\n]+)\n+(?P<album>[^\n]+)(?:.+?℗\s*(?P<release_year>\d{4})(?!\d))?(?:.+?Released on\s*:\s*(?P<release_date>\d{4}-\d{2}-\d{2}))?(.+?\nArtist\s*:\s*(?P<clean_artist>[^\n]+))?', video_description)
+            if mobj:
+                if not track:
+                    track = mobj.group('track').strip()
+                if not artist:
+                    artist = mobj.group('clean_artist') or ', '.join(a.strip() for a in mobj.group('artist').split('·'))
+                if not album:
+                    album = mobj.group('album'.strip())
+                release_year = mobj.group('release_year')
+                release_date = mobj.group('release_date')
+                if release_date:
+                    release_date = release_date.replace('-', '')
+                    if not release_year:
+                        release_year = int(release_date[:4])
+                if release_year:
+                    release_year = int(release_year)
+
+        m_episode = re.search(
+            r'<div[^>]+id="watch7-headline"[^>]*>\s*<span[^>]*>.*?>(?P<series>[^<]+)</a></b>\s*S(?P<season>\d+)\s*•\s*E(?P<episode>\d+)</span>',
+            video_webpage)
+        if m_episode:
+            series = unescapeHTML(m_episode.group('series'))
+            season_number = int(m_episode.group('season'))
+            episode_number = int(m_episode.group('episode'))
         else:
-            raise ExtractorError(u'no conn, hlsvp or url_encoded_fmt_stream_map information found in video info')
+            series = season_number = episode_number = None
+
+        m_cat_container = self._search_regex(
+            r'(?s)<h4[^>]*>\s*Category\s*</h4>\s*<ul[^>]*>(.*?)</ul>',
+            video_webpage, 'categories', default=None)
+        category = None
+        if m_cat_container:
+            category = self._html_search_regex(
+                r'(?s)<a[^<]+>(.*?)</a>', m_cat_container, 'category',
+                default=None)
+        if not category:
+            category = try_get(
+                microformat, lambda x: x['category'], compat_str)
+        video_categories = None if category is None else [category]
+
+        video_tags = [
+            unescapeHTML(m.group('content'))
+            for m in re.finditer(self._meta_regex('og:video:tag'), video_webpage)]
+        if not video_tags:
+            video_tags = try_get(video_details, lambda x: x['keywords'], list)
+
+        def _extract_count(count_name):
+            return str_to_int(self._search_regex(
+                r'-%s-button[^>]+><span[^>]+class="yt-uix-button-content"[^>]*>([\d,]+)</span>'
+                % re.escape(count_name),
+                video_webpage, count_name, default=None))
+
+        like_count = _extract_count('like')
+        dislike_count = _extract_count('dislike')
+
+        if view_count is None:
+            view_count = str_to_int(self._search_regex(
+                r'<[^>]+class=["\']watch-view-count[^>]+>\s*([\d,\s]+)', video_webpage,
+                'view count', default=None))
+
+        average_rating = (
+            float_or_none(video_details.get('averageRating'))
+            or try_get(video_info, lambda x: float_or_none(x['avg_rating'][0])))
+
+        # subtitles
+        video_subtitles = self.extract_subtitles(video_id, video_webpage)
+        automatic_captions = self.extract_automatic_captions(video_id, video_webpage)
+
+        video_duration = try_get(
+            video_info, lambda x: int_or_none(x['length_seconds'][0]))
+        if not video_duration:
+            video_duration = int_or_none(video_details.get('lengthSeconds'))
+        if not video_duration:
+            video_duration = parse_duration(self._html_search_meta(
+                'duration', video_webpage, 'video duration'))
+
+        # annotations
+        video_annotations = None
+        if self._downloader.params.get('writeannotations', False):
+            xsrf_token = self._search_regex(
+                r'([\'"])XSRF_TOKEN\1\s*:\s*([\'"])(?P<xsrf_token>[A-Za-z0-9+/=]+)\2',
+                video_webpage, 'xsrf token', group='xsrf_token', fatal=False)
+            invideo_url = try_get(
+                player_response, lambda x: x['annotations'][0]['playerAnnotationsUrlsRenderer']['invideoUrl'], compat_str)
+            if xsrf_token and invideo_url:
+                xsrf_field_name = self._search_regex(
+                    r'([\'"])XSRF_FIELD_NAME\1\s*:\s*([\'"])(?P<xsrf_field_name>\w+)\2',
+                    video_webpage, 'xsrf field name',
+                    group='xsrf_field_name', default='session_token')
+                video_annotations = self._download_webpage(
+                    self._proto_relative_url(invideo_url),
+                    video_id, note='Downloading annotations',
+                    errnote='Unable to download video annotations', fatal=False,
+                    data=urlencode_postdata({xsrf_field_name: xsrf_token}))
+
+        chapters = self._extract_chapters(video_webpage, description_original, video_id, video_duration)
 
         # Look for the DASH manifest
-        dash_manifest_url_lst = video_info.get('dashmpd')
-        if (dash_manifest_url_lst and dash_manifest_url_lst[0] and
-                self._downloader.params.get('youtube_include_dash_manifest', False)):
-            try:
-                dash_doc = self._download_xml(
-                    dash_manifest_url_lst[0], video_id,
-                    note=u'Downloading DASH manifest',
-                    errnote=u'Could not download DASH manifest')
-                for r in dash_doc.findall(u'.//{urn:mpeg:DASH:schema:MPD:2011}Representation'):
-                    url_el = r.find('{urn:mpeg:DASH:schema:MPD:2011}BaseURL')
-                    if url_el is None:
-                        continue
-                    format_id = r.attrib['id']
-                    video_url = url_el.text
-                    filesize = int_or_none(url_el.attrib.get('{http://youtube.com/yt/2012/10/10}contentLength'))
-                    f = {
-                        'format_id': format_id,
-                        'url': video_url,
-                        'width': int_or_none(r.attrib.get('width')),
-                        'tbr': int_or_none(r.attrib.get('bandwidth'), 1000),
-                        'asr': int_or_none(r.attrib.get('audioSamplingRate')),
-                        'filesize': filesize,
-                    }
-                    try:
-                        existing_format = next(
-                            fo for fo in formats
-                            if fo['format_id'] == format_id)
-                    except StopIteration:
-                        f.update(self._formats.get(format_id, {}))
-                        formats.append(f)
-                    else:
-                        existing_format.update(f)
-
-            except (ExtractorError, KeyError) as e:
-                self.report_warning(u'Skipping DASH manifest: %s' % e, video_id)
+        if self._downloader.params.get('youtube_include_dash_manifest', True):
+            dash_mpd_fatal = True
+            for mpd_url in dash_mpds:
+                dash_formats = {}
+                try:
+                    def decrypt_sig(mobj):
+                        s = mobj.group(1)
+                        dec_s = self._decrypt_signature(s, video_id, player_url, age_gate)
+                        return '/signature/%s' % dec_s
+
+                    mpd_url = re.sub(r'/s/([a-fA-F0-9\.]+)', decrypt_sig, mpd_url)
+
+                    for df in self._extract_mpd_formats(
+                            mpd_url, video_id, fatal=dash_mpd_fatal,
+                            formats_dict=self._formats):
+                        if not df.get('filesize'):
+                            df['filesize'] = _extract_filesize(df['url'])
+                        # Do not overwrite DASH format found in some previous DASH manifest
+                        if df['format_id'] not in dash_formats:
+                            dash_formats[df['format_id']] = df
+                        # Additional DASH manifests may end up in HTTP Error 403 therefore
+                        # allow them to fail without bug report message if we already have
+                        # some DASH manifest succeeded. This is temporary workaround to reduce
+                        # burst of bug reports until we figure out the reason and whether it
+                        # can be fixed at all.
+                        dash_mpd_fatal = False
+                except (ExtractorError, KeyError) as e:
+                    self.report_warning(
+                        'Skipping DASH manifest: %r' % e, video_id)
+                if dash_formats:
+                    # Remove the formats we found through non-DASH, they
+                    # contain less info and it can be wrong, because we use
+                    # fixed values (for example the resolution). See
+                    # https://github.com/ytdl-org/youtube-dl/issues/5774 for an
+                    # example.
+                    formats = [f for f in formats if f['format_id'] not in dash_formats.keys()]
+                    formats.extend(dash_formats.values())
+
+        # Check for malformed aspect ratio
+        stretched_m = re.search(
+            r'<meta\s+property="og:video:tag".*?content="yt:stretch=(?P<w>[0-9]+):(?P<h>[0-9]+)">',
+            video_webpage)
+        if stretched_m:
+            w = float(stretched_m.group('w'))
+            h = float(stretched_m.group('h'))
+            # yt:stretch may hold invalid ratio data (e.g. for Q39EVAstoRM ratio is 17:0).
+            # We will only process correct ratios.
+            if w > 0 and h > 0:
+                ratio = w / h
+                for f in formats:
+                    if f.get('vcodec') != 'none':
+                        f['stretched_ratio'] = ratio
+
+        if not formats:
+            if 'reason' in video_info:
+                if 'The uploader has not made this video available in your country.' in video_info['reason']:
+                    regions_allowed = self._html_search_meta(
+                        'regionsAllowed', video_webpage, default=None)
+                    countries = regions_allowed.split(',') if regions_allowed else None
+                    self.raise_geo_restricted(
+                        msg=video_info['reason'][0], countries=countries)
+                reason = video_info['reason'][0]
+                if 'Invalid parameters' in reason:
+                    unavailable_message = extract_unavailable_message()
+                    if unavailable_message:
+                        reason = unavailable_message
+                raise ExtractorError(
+                    'YouTube said: %s' % reason,
+                    expected=True, video_id=video_id)
+            if video_info.get('license_info') or try_get(player_response, lambda x: x['streamingData']['licenseInfos']):
+                raise ExtractorError('This video is DRM protected.', expected=True)
 
         self._sort_formats(formats)
 
+        self.mark_watched(video_id, video_info, player_response)
+
         return {
-            'id':           video_id,
-            'uploader':     video_uploader,
-            'uploader_id':  video_uploader_id,
-            'upload_date':  upload_date,
-            'title':        video_title,
-            'thumbnail':    video_thumbnail,
-            'description':  video_description,
-            'subtitles':    video_subtitles,
-            'duration':     video_duration,
-            'age_limit':    18 if age_gate else 0,
-            'annotations':  video_annotations,
-            'webpage_url': 'https://www.youtube.com/watch?v=%s' % video_id,
-            'view_count':   view_count,
+            'id': video_id,
+            'uploader': video_uploader,
+            'uploader_id': video_uploader_id,
+            'uploader_url': video_uploader_url,
+            'channel_id': channel_id,
+            'channel_url': channel_url,
+            'upload_date': upload_date,
+            'license': video_license,
+            'creator': video_creator or artist,
+            'title': video_title,
+            'alt_title': video_alt_title or track,
+            'thumbnails': thumbnails,
+            'description': video_description,
+            'categories': video_categories,
+            'tags': video_tags,
+            'subtitles': video_subtitles,
+            'automatic_captions': automatic_captions,
+            'duration': video_duration,
+            'age_limit': 18 if age_gate else 0,
+            'annotations': video_annotations,
+            'chapters': chapters,
+            'webpage_url': proto + '://www.youtube.com/watch?v=%s' % video_id,
+            'view_count': view_count,
             'like_count': like_count,
             'dislike_count': dislike_count,
-            'formats':      formats,
+            'average_rating': average_rating,
+            'formats': formats,
+            'is_live': is_live,
+            'start_time': start_time,
+            'end_time': end_time,
+            'series': series,
+            'season_number': season_number,
+            'episode_number': episode_number,
+            'track': track,
+            'artist': artist,
+            'album': album,
+            'release_date': release_date,
+            'release_year': release_year,
         }
 
-class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
-    IE_DESC = u'YouTube.com playlists'
+
+class YoutubePlaylistIE(YoutubePlaylistBaseInfoExtractor):
+    IE_DESC = 'YouTube.com playlists'
     _VALID_URL = r"""(?x)(?:
                         (?:https?://)?
                         (?:\w+\.)?
-                        youtube\.com/
                         (?:
-                           (?:course|view_play_list|my_playlists|artist|playlist|watch)
-                           \? (?:.*?&)*? (?:p|a|list)=
-                        |  p/
+                            (?:
+                                youtube(?:kids)?\.com|
+                                invidio\.us
+                            )
+                            /
+                            (?:
+                               (?:course|view_play_list|my_playlists|artist|playlist|watch|embed/(?:videoseries|[0-9A-Za-z_-]{11}))
+                               \? (?:.*?[&;])*? (?:p|a|list)=
+                            |  p/
+                            )|
+                            youtu\.be/[0-9A-Za-z_-]{11}\?.*?\blist=
                         )
                         (
-                            (?:PL|EC|UU|FL|RD)?[0-9A-Za-z-_]{10,}
-                            # Top tracks, they can also include dots 
+                            (?:PL|LL|EC|UU|FL|RD|UL|TL|PU|OLAK5uy_)?[0-9A-Za-z-_]{10,}
+                            # Top tracks, they can also include dots
                             |(?:MC)[\w\.]*
                         )
                         .*
                      |
-                        ((?:PL|EC|UU|FL|RD)[0-9A-Za-z-_]{10,})
-                     )"""
-    _TEMPLATE_URL = 'https://www.youtube.com/playlist?list=%s&page=%s'
-    _MORE_PAGES_INDICATOR = r'data-link-type="next"'
-    _VIDEO_RE = r'href="/watch\?v=(?P<id>[0-9A-Za-z_-]{11})&amp;[^"]*?index=(?P<index>\d+)'
-    IE_NAME = u'youtube:playlist'
+                        (%(playlist_id)s)
+                     )""" % {'playlist_id': YoutubeBaseInfoExtractor._PLAYLIST_ID_RE}
+    _TEMPLATE_URL = 'https://www.youtube.com/playlist?list=%s'
+    _VIDEO_RE_TPL = r'href="\s*/watch\?v=%s(?:&amp;(?:[^"]*?index=(?P<index>\d+))?(?:[^>]+>(?P<title>[^<]+))?)?'
+    _VIDEO_RE = _VIDEO_RE_TPL % r'(?P<id>[0-9A-Za-z_-]{11})'
+    IE_NAME = 'youtube:playlist'
+    _TESTS = [{
+        'url': 'https://www.youtube.com/playlist?list=PL4lCao7KL_QFVb7Iudeipvc2BCavECqzc',
+        'info_dict': {
+            'uploader_id': 'UCmlqkdCBesrv2Lak1mF_MxA',
+            'uploader': 'Sergey M.',
+            'id': 'PL4lCao7KL_QFVb7Iudeipvc2BCavECqzc',
+            'title': 'youtube-dl public playlist',
+        },
+        'playlist_count': 1,
+    }, {
+        'url': 'https://www.youtube.com/playlist?list=PL4lCao7KL_QFodcLWhDpGCYnngnHtQ-Xf',
+        'info_dict': {
+            'uploader_id': 'UCmlqkdCBesrv2Lak1mF_MxA',
+            'uploader': 'Sergey M.',
+            'id': 'PL4lCao7KL_QFodcLWhDpGCYnngnHtQ-Xf',
+            'title': 'youtube-dl empty playlist',
+        },
+        'playlist_count': 0,
+    }, {
+        'note': 'Playlist with deleted videos (#651). As a bonus, the video #51 is also twice in this list.',
+        'url': 'https://www.youtube.com/playlist?list=PLwP_SiAcdui0KVebT0mU9Apz359a4ubsC',
+        'info_dict': {
+            'title': '29C3: Not my department',
+            'id': 'PLwP_SiAcdui0KVebT0mU9Apz359a4ubsC',
+            'uploader': 'Christiaan008',
+            'uploader_id': 'ChRiStIaAn008',
+        },
+        'playlist_count': 96,
+    }, {
+        'note': 'issue #673',
+        'url': 'PLBB231211A4F62143',
+        'info_dict': {
+            'title': '[OLD]Team Fortress 2 (Class-based LP)',
+            'id': 'PLBB231211A4F62143',
+            'uploader': 'Wickydoo',
+            'uploader_id': 'Wickydoo',
+        },
+        'playlist_mincount': 26,
+    }, {
+        'note': 'Large playlist',
+        'url': 'https://www.youtube.com/playlist?list=UUBABnxM4Ar9ten8Mdjj1j0Q',
+        'info_dict': {
+            'title': 'Uploads from Cauchemar',
+            'id': 'UUBABnxM4Ar9ten8Mdjj1j0Q',
+            'uploader': 'Cauchemar',
+            'uploader_id': 'Cauchemar89',
+        },
+        'playlist_mincount': 799,
+    }, {
+        'url': 'PLtPgu7CB4gbY9oDN3drwC3cMbJggS7dKl',
+        'info_dict': {
+            'title': 'YDL_safe_search',
+            'id': 'PLtPgu7CB4gbY9oDN3drwC3cMbJggS7dKl',
+        },
+        'playlist_count': 2,
+        'skip': 'This playlist is private',
+    }, {
+        'note': 'embedded',
+        'url': 'https://www.youtube.com/embed/videoseries?list=PL6IaIsEjSbf96XFRuNccS_RuEXwNdsoEu',
+        'playlist_count': 4,
+        'info_dict': {
+            'title': 'JODA15',
+            'id': 'PL6IaIsEjSbf96XFRuNccS_RuEXwNdsoEu',
+            'uploader': 'milan',
+            'uploader_id': 'UCEI1-PVPcYXjB73Hfelbmaw',
+        }
+    }, {
+        'url': 'http://www.youtube.com/embed/_xDOZElKyNU?list=PLsyOSbh5bs16vubvKePAQ1x3PhKavfBIl',
+        'playlist_mincount': 485,
+        'info_dict': {
+            'title': '2018 Chinese New Singles (11/6 updated)',
+            'id': 'PLsyOSbh5bs16vubvKePAQ1x3PhKavfBIl',
+            'uploader': 'LBK',
+            'uploader_id': 'sdragonfang',
+        }
+    }, {
+        'note': 'Embedded SWF player',
+        'url': 'https://www.youtube.com/p/YN5VISEtHet5D4NEvfTd0zcgFk84NqFZ?hl=en_US&fs=1&rel=0',
+        'playlist_count': 4,
+        'info_dict': {
+            'title': 'JODA7',
+            'id': 'YN5VISEtHet5D4NEvfTd0zcgFk84NqFZ',
+        },
+        'skip': 'This playlist does not exist',
+    }, {
+        'note': 'Buggy playlist: the webpage has a "Load more" button but it doesn\'t have more videos',
+        'url': 'https://www.youtube.com/playlist?list=UUXw-G3eDE9trcvY2sBMM_aA',
+        'info_dict': {
+            'title': 'Uploads from Interstellar Movie',
+            'id': 'UUXw-G3eDE9trcvY2sBMM_aA',
+            'uploader': 'Interstellar Movie',
+            'uploader_id': 'InterstellarMovie1',
+        },
+        'playlist_mincount': 21,
+    }, {
+        # Playlist URL that does not actually serve a playlist
+        'url': 'https://www.youtube.com/watch?v=FqZTN594JQw&list=PLMYEtVRpaqY00V9W81Cwmzp6N6vZqfUKD4',
+        'info_dict': {
+            'id': 'FqZTN594JQw',
+            'ext': 'webm',
+            'title': "Smiley's People 01 detective, Adventure Series, Action",
+            'uploader': 'STREEM',
+            'uploader_id': 'UCyPhqAZgwYWZfxElWVbVJng',
+            'uploader_url': r're:https?://(?:www\.)?youtube\.com/channel/UCyPhqAZgwYWZfxElWVbVJng',
+            'upload_date': '20150526',
+            'license': 'Standard YouTube License',
+            'description': 'md5:507cdcb5a49ac0da37a920ece610be80',
+            'categories': ['People & Blogs'],
+            'tags': list,
+            'view_count': int,
+            'like_count': int,
+            'dislike_count': int,
+        },
+        'params': {
+            'skip_download': True,
+        },
+        'skip': 'This video is not available.',
+        'add_ie': [YoutubeIE.ie_key()],
+    }, {
+        'url': 'https://youtu.be/yeWKywCrFtk?list=PL2qgrgXsNUG5ig9cat4ohreBjYLAPC0J5',
+        'info_dict': {
+            'id': 'yeWKywCrFtk',
+            'ext': 'mp4',
+            'title': 'Small Scale Baler and Braiding Rugs',
+            'uploader': 'Backus-Page House Museum',
+            'uploader_id': 'backuspagemuseum',
+            'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/backuspagemuseum',
+            'upload_date': '20161008',
+            'description': 'md5:800c0c78d5eb128500bffd4f0b4f2e8a',
+            'categories': ['Nonprofits & Activism'],
+            'tags': list,
+            'like_count': int,
+            'dislike_count': int,
+        },
+        'params': {
+            'noplaylist': True,
+            'skip_download': True,
+        },
+    }, {
+        # https://github.com/ytdl-org/youtube-dl/issues/21844
+        'url': 'https://www.youtube.com/playlist?list=PLzH6n4zXuckpfMu_4Ff8E7Z1behQks5ba',
+        'info_dict': {
+            'title': 'Data Analysis with Dr Mike Pound',
+            'id': 'PLzH6n4zXuckpfMu_4Ff8E7Z1behQks5ba',
+            'uploader_id': 'Computerphile',
+            'uploader': 'Computerphile',
+        },
+        'playlist_mincount': 11,
+    }, {
+        'url': 'https://youtu.be/uWyaPkt-VOI?list=PL9D9FC436B881BA21',
+        'only_matching': True,
+    }, {
+        'url': 'TLGGrESM50VT6acwMjAyMjAxNw',
+        'only_matching': True,
+    }, {
+        # music album playlist
+        'url': 'OLAK5uy_m4xAFdmMC5rX3Ji3g93pQe3hqLZw_9LhM',
+        'only_matching': True,
+    }, {
+        'url': 'https://invidio.us/playlist?list=PLDIoUOhQQPlXr63I_vwF9GD8sAKh77dWU',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtubekids.com/watch?v=Agk7R8I8o5U&list=PUZ6jURNr1WQZCNHF0ao-c0g',
+        'only_matching': True,
+    }]
 
     def _real_initialize(self):
         self._login()
 
-    def _ids_to_results(self, ids):
-        return [self.url_result(vid_id, 'Youtube', video_id=vid_id)
-                       for vid_id in ids]
+    def extract_videos_from_page(self, page):
+        ids_in_page = []
+        titles_in_page = []
+
+        for item in re.findall(
+                r'(<[^>]*\bdata-video-id\s*=\s*["\'][0-9A-Za-z_-]{11}[^>]+>)', page):
+            attrs = extract_attributes(item)
+            video_id = attrs['data-video-id']
+            video_title = unescapeHTML(attrs.get('data-title'))
+            if video_title:
+                video_title = video_title.strip()
+            ids_in_page.append(video_id)
+            titles_in_page.append(video_title)
+
+        # Fallback with old _VIDEO_RE
+        self.extract_videos_from_page_impl(
+            self._VIDEO_RE, page, ids_in_page, titles_in_page)
+
+        # Relaxed fallbacks
+        self.extract_videos_from_page_impl(
+            r'href="\s*/watch\?v\s*=\s*(?P<id>[0-9A-Za-z_-]{11})', page,
+            ids_in_page, titles_in_page)
+        self.extract_videos_from_page_impl(
+            r'data-video-ids\s*=\s*["\'](?P<id>[0-9A-Za-z_-]{11})', page,
+            ids_in_page, titles_in_page)
+
+        return zip(ids_in_page, titles_in_page)
 
     def _extract_mix(self, playlist_id):
-        # The mixes are generated from a single video
+        # The mixes are generated from a single video
         # the id of the playlist is just 'RD' + video_id
-        url = 'https://youtube.com/watch?v=%s&list=%s' % (playlist_id[-11:], playlist_id)
-        webpage = self._download_webpage(url, playlist_id, u'Downloading Youtube mix')
-        title_span = (get_element_by_attribute('class', 'title long-title', webpage) or
-            get_element_by_attribute('class', 'title ', webpage))
-        title = clean_html(title_span)
-        video_re = r'data-index="\d+".*?href="/watch\?v=([0-9A-Za-z_-]{11})&amp;[^"]*?list=%s' % re.escape(playlist_id)
-        ids = orderedSet(re.findall(video_re, webpage))
+        ids = []
+        last_id = playlist_id[-11:]
+        for n in itertools.count(1):
+            url = 'https://www.youtube.com/watch?v=%s&list=%s' % (last_id, playlist_id)
+            webpage = self._download_webpage(
+                url, playlist_id, 'Downloading page {0} of Youtube mix'.format(n))
+            new_ids = orderedSet(re.findall(
+                r'''(?xs)data-video-username=".*?".*?
+                           href="/watch\?v=([0-9A-Za-z_-]{11})&amp;[^"]*?list=%s''' % re.escape(playlist_id),
+                webpage))
+            # Fetch new pages until all the videos are repeated, it seems that
+            # there are always 51 unique videos.
+            new_ids = [_id for _id in new_ids if _id not in ids]
+            if not new_ids:
+                break
+            ids.extend(new_ids)
+            last_id = ids[-1]
+
         url_results = self._ids_to_results(ids)
 
+        search_title = lambda class_name: get_element_by_attribute('class', class_name, webpage)
+        title_span = (
+            search_title('playlist-title')
+            or search_title('title long-title')
+            or search_title('title'))
+        title = clean_html(title_span)
+
         return self.playlist_result(url_results, playlist_id, title)
 
+    def _extract_playlist(self, playlist_id):
+        url = self._TEMPLATE_URL % playlist_id
+        page = self._download_webpage(url, playlist_id)
+
+        # the yt-alert-message now has tabindex attribute (see https://github.com/ytdl-org/youtube-dl/issues/11604)
+        for match in re.findall(r'<div class="yt-alert-message"[^>]*>([^<]+)</div>', page):
+            match = match.strip()
+            # Check if the playlist exists or is private
+            mobj = re.match(r'[^<]*(?:The|This) playlist (?P<reason>does not exist|is private)[^<]*', match)
+            if mobj:
+                reason = mobj.group('reason')
+                message = 'This playlist %s' % reason
+                if 'private' in reason:
+                    message += ', use --username or --netrc to access it'
+                message += '.'
+                raise ExtractorError(message, expected=True)
+            elif re.match(r'[^<]*Invalid parameters[^<]*', match):
+                raise ExtractorError(
+                    'Invalid parameters. Maybe URL is incorrect.',
+                    expected=True)
+            elif re.match(r'[^<]*Choose your language[^<]*', match):
+                continue
+            else:
+                self.report_warning('Youtube gives an alert message: ' + match)
+
+        playlist_title = self._html_search_regex(
+            r'(?s)<h1 class="pl-header-title[^"]*"[^>]*>\s*(.*?)\s*</h1>',
+            page, 'title', default=None)
+
+        _UPLOADER_BASE = r'class=["\']pl-header-details[^>]+>\s*<li>\s*<a[^>]+\bhref='
+        uploader = self._html_search_regex(
+            r'%s["\']/(?:user|channel)/[^>]+>([^<]+)' % _UPLOADER_BASE,
+            page, 'uploader', default=None)
+        mobj = re.search(
+            r'%s(["\'])(?P<path>/(?:user|channel)/(?P<uploader_id>.+?))\1' % _UPLOADER_BASE,
+            page)
+        if mobj:
+            uploader_id = mobj.group('uploader_id')
+            uploader_url = compat_urlparse.urljoin(url, mobj.group('path'))
+        else:
+            uploader_id = uploader_url = None
+
+        has_videos = True
+
+        if not playlist_title:
+            try:
+                # Some playlist URLs don't actually serve a playlist (e.g.
+                # https://www.youtube.com/watch?v=FqZTN594JQw&list=PLMYEtVRpaqY00V9W81Cwmzp6N6vZqfUKD4)
+                next(self._entries(page, playlist_id))
+            except StopIteration:
+                has_videos = False
+
+        playlist = self.playlist_result(
+            self._entries(page, playlist_id), playlist_id, playlist_title)
+        playlist.update({
+            'uploader': uploader,
+            'uploader_id': uploader_id,
+            'uploader_url': uploader_url,
+        })
+
+        return has_videos, playlist
+
+    def _check_download_just_video(self, url, playlist_id):
+        # Check if it's a video-specific URL
+        query_dict = compat_urlparse.parse_qs(compat_urlparse.urlparse(url).query)
+        video_id = query_dict.get('v', [None])[0] or self._search_regex(
+            r'(?:(?:^|//)youtu\.be/|youtube\.com/embed/(?!videoseries))([0-9A-Za-z_-]{11})', url,
+            'video id', default=None)
+        if video_id:
+            if self._downloader.params.get('noplaylist'):
+                self.to_screen('Downloading just video %s because of --no-playlist' % video_id)
+                return video_id, self.url_result(video_id, 'Youtube', video_id=video_id)
+            else:
+                self.to_screen('Downloading playlist %s - add --no-playlist to just download video %s' % (playlist_id, video_id))
+                return video_id, None
+        return None, None
+
     def _real_extract(self, url):
         # Extract playlist id
         mobj = re.match(self._VALID_URL, url)
         if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
+            raise ExtractorError('Invalid URL: %s' % url)
         playlist_id = mobj.group(1) or mobj.group(2)
 
-        # Check if it's a video-specific URL
-        query_dict = compat_urlparse.parse_qs(compat_urlparse.urlparse(url).query)
-        if 'v' in query_dict:
-            video_id = query_dict['v'][0]
-            if self._downloader.params.get('noplaylist'):
-                self.to_screen(u'Downloading just video %s because of --no-playlist' % video_id)
-                return self.url_result(video_id, 'Youtube', video_id=video_id)
-            else:
-                self.to_screen(u'Downloading playlist PL%s - add --no-playlist to just download video %s' % (playlist_id, video_id))
+        video_id, video = self._check_download_just_video(url, playlist_id)
+        if video:
+            return video
 
-        if playlist_id.startswith('RD'):
+        if playlist_id.startswith(('RD', 'UL', 'PU')):
             # Mixes require a custom extraction process
             return self._extract_mix(playlist_id)
-        if playlist_id.startswith('TL'):
-            raise ExtractorError(u'For downloading YouTube.com top lists, use '
-                u'the "yttoplist" keyword, for example "youtube-dl \'yttoplist:music:Top Tracks\'"', expected=True)
-
-        # Extract the video ids from the playlist pages
-        ids = []
-
-        for page_num in itertools.count(1):
-            url = self._TEMPLATE_URL % (playlist_id, page_num)
-            page = self._download_webpage(url, playlist_id, u'Downloading page #%s' % page_num)
-            matches = re.finditer(self._VIDEO_RE, page)
-            # We remove the duplicates and the link with index 0
-            # (it's not the first video of the playlist)
-            new_ids = orderedSet(m.group('id') for m in matches if m.group('index') != '0')
-            ids.extend(new_ids)
-
-            if re.search(self._MORE_PAGES_INDICATOR, page) is None:
-                break
-
-        try:
-            playlist_title = self._og_search_title(page)
-        except RegexNotFoundError:
-            self.report_warning(
-                u'Playlist page is missing OpenGraph title, falling back ...',
-                playlist_id)
-            playlist_title = self._html_search_regex(
-                r'<h1 class="pl-header-title">(.*?)</h1>', page, u'title')
-
-        url_results = self._ids_to_results(ids)
-        return self.playlist_result(url_results, playlist_id, playlist_title)
-
-
-class YoutubeTopListIE(YoutubePlaylistIE):
-    IE_NAME = u'youtube:toplist'
-    IE_DESC = (u'YouTube.com top lists, "yttoplist:{channel}:{list title}"'
-        u' (Example: "yttoplist:music:Top Tracks")')
-    _VALID_URL = r'yttoplist:(?P<chann>.*?):(?P<title>.*?)$'
-
-    def _real_extract(self, url):
-        mobj = re.match(self._VALID_URL, url)
-        channel = mobj.group('chann')
-        title = mobj.group('title')
-        query = compat_urllib_parse.urlencode({'title': title})
-        playlist_re = 'href="([^"]+?%s.*?)"' % re.escape(query)
-        channel_page = self._download_webpage('https://www.youtube.com/%s' % channel, title)
-        link = self._html_search_regex(playlist_re, channel_page, u'list')
-        url = compat_urlparse.urljoin('https://www.youtube.com/', link)
-        
-        video_re = r'data-index="\d+".*?data-video-id="([0-9A-Za-z_-]{11})"'
-        ids = []
-        # sometimes the webpage doesn't contain the videos
-        # retry until we get them
-        for i in itertools.count(0):
-            msg = u'Downloading Youtube mix'
-            if i > 0:
-                msg += ', retry #%d' % i
-            webpage = self._download_webpage(url, title, msg)
-            ids = orderedSet(re.findall(video_re, webpage))
-            if ids:
-                break
-        url_results = self._ids_to_results(ids)
-        return self.playlist_result(url_results, playlist_title=title)
 
+        has_videos, playlist = self._extract_playlist(playlist_id)
+        if has_videos or not video_id:
+            return playlist
+
+        # Some playlist URLs don't actually serve a playlist (see
+        # https://github.com/ytdl-org/youtube-dl/issues/10537).
+        # Fallback to plain video extraction if there is a video id
+        # along with playlist id.
+        return self.url_result(video_id, 'Youtube', video_id=video_id)
+
+
+class YoutubeChannelIE(YoutubePlaylistBaseInfoExtractor):
+    IE_DESC = 'YouTube.com channels'
+    _VALID_URL = r'https?://(?:youtu\.be|(?:\w+\.)?youtube(?:-nocookie|kids)?\.com|(?:www\.)?invidio\.us)/channel/(?P<id>[0-9A-Za-z_-]+)'
+    _TEMPLATE_URL = 'https://www.youtube.com/channel/%s/videos'
+    _VIDEO_RE = r'(?:title="(?P<title>[^"]+)"[^>]+)?href="/watch\?v=(?P<id>[0-9A-Za-z_-]+)&?'
+    IE_NAME = 'youtube:channel'
+    _TESTS = [{
+        'note': 'paginated channel',
+        'url': 'https://www.youtube.com/channel/UCKfVa3S1e4PHvxWcwyMMg8w',
+        'playlist_mincount': 91,
+        'info_dict': {
+            'id': 'UUKfVa3S1e4PHvxWcwyMMg8w',
+            'title': 'Uploads from lex will',
+            'uploader': 'lex will',
+            'uploader_id': 'UCKfVa3S1e4PHvxWcwyMMg8w',
+        }
+    }, {
+        'note': 'Age restricted channel',
+        # from https://www.youtube.com/user/DeusExOfficial
+        'url': 'https://www.youtube.com/channel/UCs0ifCMCm1icqRbqhUINa0w',
+        'playlist_mincount': 64,
+        'info_dict': {
+            'id': 'UUs0ifCMCm1icqRbqhUINa0w',
+            'title': 'Uploads from Deus Ex',
+            'uploader': 'Deus Ex',
+            'uploader_id': 'DeusExOfficial',
+        },
+    }, {
+        'url': 'https://invidio.us/channel/UC23qupoDRn9YOAVzeoxjOQA',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtubekids.com/channel/UCyu8StPfZWapR6rfW_JgqcA',
+        'only_matching': True,
+    }]
 
-class YoutubeChannelIE(InfoExtractor):
-    IE_DESC = u'YouTube.com channels'
-    _VALID_URL = r"^(?:https?://)?(?:youtu\.be|(?:\w+\.)?youtube(?:-nocookie)?\.com)/channel/([0-9A-Za-z_-]+)"
-    _MORE_PAGES_INDICATOR = 'yt-uix-load-more'
-    _MORE_PAGES_URL = 'https://www.youtube.com/c4_browse_ajax?action_load_more_videos=1&flow=list&paging=%s&view=0&sort=da&channel_id=%s'
-    IE_NAME = u'youtube:channel'
+    @classmethod
+    def suitable(cls, url):
+        return (False if YoutubePlaylistsIE.suitable(url) or YoutubeLiveIE.suitable(url)
+                else super(YoutubeChannelIE, cls).suitable(url))
 
-    def extract_videos_from_page(self, page):
-        ids_in_page = []
-        for mobj in re.finditer(r'href="/watch\?v=([0-9A-Za-z_-]+)&?', page):
-            if mobj.group(1) not in ids_in_page:
-                ids_in_page.append(mobj.group(1))
-        return ids_in_page
+    def _build_template_url(self, url, channel_id):
+        return self._TEMPLATE_URL % channel_id
 
     def _real_extract(self, url):
-        # Extract channel id
-        mobj = re.match(self._VALID_URL, url)
-        if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
-
-        # Download channel page
-        channel_id = mobj.group(1)
-        video_ids = []
-        url = 'https://www.youtube.com/channel/%s/videos' % channel_id
-        channel_page = self._download_webpage(url, channel_id)
+        channel_id = self._match_id(url)
+
+        url = self._build_template_url(url, channel_id)
+
+        # Channel by page listing is restricted to 35 pages of 30 items, i.e. 1050 videos total (see #5778)
+        # Workaround by extracting as a playlist if managed to obtain channel playlist URL
+        # otherwise fallback on channel by page extraction
+        channel_page = self._download_webpage(
+            url + '?view=57', channel_id,
+            'Downloading channel page', fatal=False)
+        if channel_page is False:
+            channel_playlist_id = False
+        else:
+            channel_playlist_id = self._html_search_meta(
+                'channelId', channel_page, 'channel id', default=None)
+            if not channel_playlist_id:
+                channel_url = self._html_search_meta(
+                    ('al:ios:url', 'twitter:app:url:iphone', 'twitter:app:url:ipad'),
+                    channel_page, 'channel url', default=None)
+                if channel_url:
+                    channel_playlist_id = self._search_regex(
+                        r'vnd\.youtube://user/([0-9A-Za-z_-]+)',
+                        channel_url, 'channel id', default=None)
+        if channel_playlist_id and channel_playlist_id.startswith('UC'):
+            playlist_id = 'UU' + channel_playlist_id[2:]
+            return self.url_result(
+                compat_urlparse.urljoin(url, '/playlist?list=%s' % playlist_id), 'YoutubePlaylist')
+
+        channel_page = self._download_webpage(url, channel_id, 'Downloading page #1')
         autogenerated = re.search(r'''(?x)
                 class="[^"]*?(?:
                     channel-header-autogenerated-label|
@@ -1586,244 +3006,441 @@ class YoutubeChannelIE(InfoExtractor):
         if autogenerated:
             # The videos are contained in a single page
             # the ajax pages can't be used, they are empty
-            video_ids = self.extract_videos_from_page(channel_page)
-        else:
-            # Download all channel pages using the json-based channel_ajax query
-            for pagenum in itertools.count(1):
-                url = self._MORE_PAGES_URL % (pagenum, channel_id)
-                page = self._download_json(
-                    url, channel_id, note=u'Downloading page #%s' % pagenum,
-                    transform_source=uppercase_escape)
-
-                ids_in_page = self.extract_videos_from_page(page['content_html'])
-                video_ids.extend(ids_in_page)
-    
-                if self._MORE_PAGES_INDICATOR not in page['load_more_widget_html']:
-                    break
-
-        self._downloader.to_screen(u'[youtube] Channel %s: Found %i videos' % (channel_id, len(video_ids)))
-
-        url_entries = [self.url_result(video_id, 'Youtube', video_id=video_id)
-                       for video_id in video_ids]
-        return self.playlist_result(url_entries, channel_id)
+            entries = [
+                self.url_result(
+                    video_id, 'Youtube', video_id=video_id,
+                    video_title=video_title)
+                for video_id, video_title in self.extract_videos_from_page(channel_page)]
+            return self.playlist_result(entries, channel_id)
 
-
-class YoutubeUserIE(InfoExtractor):
-    IE_DESC = u'YouTube.com user videos (URL or "ytuser" keyword)'
-    _VALID_URL = r'(?:(?:(?:https?://)?(?:\w+\.)?youtube\.com/(?:user/)?(?!(?:attribution_link|watch)(?:$|[^a-z_A-Z0-9-])))|ytuser:)(?!feed/)([A-Za-z0-9_-]+)'
-    _TEMPLATE_URL = 'https://gdata.youtube.com/feeds/api/users/%s'
-    _GDATA_PAGE_SIZE = 50
-    _GDATA_URL = 'https://gdata.youtube.com/feeds/api/users/%s/uploads?max-results=%d&start-index=%d&alt=json'
-    IE_NAME = u'youtube:user'
+        try:
+            next(self._entries(channel_page, channel_id))
+        except StopIteration:
+            alert_message = self._html_search_regex(
+                r'(?s)<div[^>]+class=(["\']).*?\byt-alert-message\b.*?\1[^>]*>(?P<alert>[^<]+)</div>',
+                channel_page, 'alert', default=None, group='alert')
+            if alert_message:
+                raise ExtractorError('Youtube said: %s' % alert_message, expected=True)
+
+        return self.playlist_result(self._entries(channel_page, channel_id), channel_id)
+
+
+class YoutubeUserIE(YoutubeChannelIE):
+    IE_DESC = 'YouTube.com user videos (URL or "ytuser" keyword)'
+    _VALID_URL = r'(?:(?:https?://(?:\w+\.)?youtube\.com/(?:(?P<user>user|c)/)?(?!(?:attribution_link|watch|results|shared)(?:$|[^a-z_A-Z0-9%-])))|ytuser:)(?!feed/)(?P<id>[A-Za-z0-9_%-]+)'
+    _TEMPLATE_URL = 'https://www.youtube.com/%s/%s/videos'
+    IE_NAME = 'youtube:user'
+
+    _TESTS = [{
+        'url': 'https://www.youtube.com/user/TheLinuxFoundation',
+        'playlist_mincount': 320,
+        'info_dict': {
+            'id': 'UUfX55Sx5hEFjoC3cNs6mCUQ',
+            'title': 'Uploads from The Linux Foundation',
+            'uploader': 'The Linux Foundation',
+            'uploader_id': 'TheLinuxFoundation',
+        }
+    }, {
+        # Only available via https://www.youtube.com/c/12minuteathlete/videos
+        # but not https://www.youtube.com/user/12minuteathlete/videos
+        'url': 'https://www.youtube.com/c/12minuteathlete/videos',
+        'playlist_mincount': 249,
+        'info_dict': {
+            'id': 'UUVjM-zV6_opMDx7WYxnjZiQ',
+            'title': 'Uploads from 12 Minute Athlete',
+            'uploader': '12 Minute Athlete',
+            'uploader_id': 'the12minuteathlete',
+        }
+    }, {
+        'url': 'ytuser:phihag',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/c/gametrailers',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/c/Pawe%C5%82Zadro%C5%BCniak',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/gametrailers',
+        'only_matching': True,
+    }, {
+        # This channel is not available, geo restricted to JP
+        'url': 'https://www.youtube.com/user/kananishinoSMEJ/videos',
+        'only_matching': True,
+    }]
 
     @classmethod
     def suitable(cls, url):
         # Don't return True if the url can be extracted with other youtube
         # extractor, the regex would is too permissive and it would match.
-        other_ies = iter(klass for (name, klass) in globals().items() if name.endswith('IE') and klass is not cls)
-        if any(ie.suitable(url) for ie in other_ies): return False
-        else: return super(YoutubeUserIE, cls).suitable(url)
+        other_yt_ies = iter(klass for (name, klass) in globals().items() if name.startswith('Youtube') and name.endswith('IE') and klass is not cls)
+        if any(ie.suitable(url) for ie in other_yt_ies):
+            return False
+        else:
+            return super(YoutubeUserIE, cls).suitable(url)
 
-    def _real_extract(self, url):
-        # Extract username
+    def _build_template_url(self, url, channel_id):
         mobj = re.match(self._VALID_URL, url)
-        if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
-
-        username = mobj.group(1)
-
-        # Download video ids using YouTube Data API. Result size per
-        # query is limited (currently to 50 videos) so we need to query
-        # page by page until there are no video ids - it means we got
-        # all of them.
-
-        def download_page(pagenum):
-            start_index = pagenum * self._GDATA_PAGE_SIZE + 1
-
-            gdata_url = self._GDATA_URL % (username, self._GDATA_PAGE_SIZE, start_index)
-            page = self._download_webpage(
-                gdata_url, username,
-                u'Downloading video ids from %d to %d' % (
-                    start_index, start_index + self._GDATA_PAGE_SIZE))
+        return self._TEMPLATE_URL % (mobj.group('user') or 'user', mobj.group('id'))
+
+
+class YoutubeLiveIE(YoutubeBaseInfoExtractor):
+    IE_DESC = 'YouTube.com live streams'
+    _VALID_URL = r'(?P<base_url>https?://(?:\w+\.)?youtube\.com/(?:(?:user|channel|c)/)?(?P<id>[^/]+))/live'
+    IE_NAME = 'youtube:live'
+
+    _TESTS = [{
+        'url': 'https://www.youtube.com/user/TheYoungTurks/live',
+        'info_dict': {
+            'id': 'a48o2S1cPoo',
+            'ext': 'mp4',
+            'title': 'The Young Turks - Live Main Show',
+            'uploader': 'The Young Turks',
+            'uploader_id': 'TheYoungTurks',
+            'uploader_url': r're:https?://(?:www\.)?youtube\.com/user/TheYoungTurks',
+            'upload_date': '20150715',
+            'license': 'Standard YouTube License',
+            'description': 'md5:438179573adcdff3c97ebb1ee632b891',
+            'categories': ['News & Politics'],
+            'tags': ['Cenk Uygur (TV Program Creator)', 'The Young Turks (Award-Winning Work)', 'Talk Show (TV Genre)'],
+            'like_count': int,
+            'dislike_count': int,
+        },
+        'params': {
+            'skip_download': True,
+        },
+    }, {
+        'url': 'https://www.youtube.com/channel/UC1yBKRuGpC1tSM73A0ZjYjQ/live',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/c/CommanderVideoHq/live',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/TheYoungTurks/live',
+        'only_matching': True,
+    }]
 
-            try:
-                response = json.loads(page)
-            except ValueError as err:
-                raise ExtractorError(u'Invalid JSON in API response: ' + compat_str(err))
-            if 'entry' not in response['feed']:
-                return
+    def _real_extract(self, url):
+        mobj = re.match(self._VALID_URL, url)
+        channel_id = mobj.group('id')
+        base_url = mobj.group('base_url')
+        webpage = self._download_webpage(url, channel_id, fatal=False)
+        if webpage:
+            page_type = self._og_search_property(
+                'type', webpage, 'page type', default='')
+            video_id = self._html_search_meta(
+                'videoId', webpage, 'video id', default=None)
+            if page_type.startswith('video') and video_id and re.match(
+                    r'^[0-9A-Za-z_-]{11}$', video_id):
+                return self.url_result(video_id, YoutubeIE.ie_key())
+        return self.url_result(base_url)
+
+
+class YoutubePlaylistsIE(YoutubePlaylistsBaseInfoExtractor):
+    IE_DESC = 'YouTube.com user/channel playlists'
+    _VALID_URL = r'https?://(?:\w+\.)?youtube\.com/(?:user|channel|c)/(?P<id>[^/]+)/playlists'
+    IE_NAME = 'youtube:playlists'
+
+    _TESTS = [{
+        'url': 'https://www.youtube.com/user/ThirstForScience/playlists',
+        'playlist_mincount': 4,
+        'info_dict': {
+            'id': 'ThirstForScience',
+            'title': 'ThirstForScience',
+        },
+    }, {
+        # with "Load more" button
+        'url': 'https://www.youtube.com/user/igorkle1/playlists?view=1&sort=dd',
+        'playlist_mincount': 70,
+        'info_dict': {
+            'id': 'igorkle1',
+            'title': 'Игорь Клейнер',
+        },
+    }, {
+        'url': 'https://www.youtube.com/channel/UCiU1dHvZObB2iP6xkJ__Icw/playlists',
+        'playlist_mincount': 17,
+        'info_dict': {
+            'id': 'UCiU1dHvZObB2iP6xkJ__Icw',
+            'title': 'Chem Player',
+        },
+        'skip': 'Blocked',
+    }, {
+        'url': 'https://www.youtube.com/c/ChristophLaimer/playlists',
+        'only_matching': True,
+    }]
 
-            # Extract video identifiers
-            entries = response['feed']['entry']
-            for entry in entries:
-                title = entry['title']['$t']
-                video_id = entry['id']['$t'].split('/')[-1]
-                yield {
-                    '_type': 'url',
-                    'url': video_id,
-                    'ie_key': 'Youtube',
-                    'id': video_id,
-                    'title': title,
-                }
-        url_results = PagedList(download_page, self._GDATA_PAGE_SIZE)
 
-        return self.playlist_result(url_results, playlist_title=username)
+class YoutubeSearchBaseInfoExtractor(YoutubePlaylistBaseInfoExtractor):
+    _VIDEO_RE = r'href="\s*/watch\?v=(?P<id>[0-9A-Za-z_-]{11})(?:[^"]*"[^>]+\btitle="(?P<title>[^"]+))?'
 
 
-class YoutubeSearchIE(SearchInfoExtractor):
-    IE_DESC = u'YouTube.com searches'
-    _API_URL = 'https://gdata.youtube.com/feeds/api/videos?q=%s&start-index=%i&max-results=50&v=2&alt=jsonc'
-    _MAX_RESULTS = 1000
-    IE_NAME = u'youtube:search'
+class YoutubeSearchIE(SearchInfoExtractor, YoutubeSearchBaseInfoExtractor):
+    IE_DESC = 'YouTube.com searches'
+    # there doesn't appear to be a real limit, for example if you search for
+    # 'python' you get more than 8.000.000 results
+    _MAX_RESULTS = float('inf')
+    IE_NAME = 'youtube:search'
     _SEARCH_KEY = 'ytsearch'
+    _EXTRA_QUERY_ARGS = {}
+    _TESTS = []
 
     def _get_n_results(self, query, n):
         """Get a specified number of results for a query"""
 
-        video_ids = []
-        pagenum = 0
+        videos = []
         limit = n
 
-        while (50 * pagenum) < limit:
-            result_url = self._API_URL % (compat_urllib_parse.quote_plus(query), (50*pagenum)+1)
-            data_json = self._download_webpage(
-                result_url, video_id=u'query "%s"' % query,
-                note=u'Downloading page %s' % (pagenum + 1),
-                errnote=u'Unable to download API page')
-            data = json.loads(data_json)
-            api_response = data['data']
-
-            if 'items' not in api_response:
+        url_query = {
+            'search_query': query.encode('utf-8'),
+        }
+        url_query.update(self._EXTRA_QUERY_ARGS)
+        result_url = 'https://www.youtube.com/results?' + compat_urllib_parse_urlencode(url_query)
+
+        for pagenum in itertools.count(1):
+            data = self._download_json(
+                result_url, video_id='query "%s"' % query,
+                note='Downloading page %s' % pagenum,
+                errnote='Unable to download API page',
+                query={'spf': 'navigate'})
+            html_content = data[1]['body']['content']
+
+            if 'class="search-message' in html_content:
                 raise ExtractorError(
-                    u'[youtube] No video results', expected=True)
-
-            new_ids = list(video['id'] for video in api_response['items'])
-            video_ids += new_ids
+                    '[youtube] No video results', expected=True)
 
-            limit = min(n, api_response['totalItems'])
-            pagenum += 1
+            new_videos = list(self._process_page(html_content))
+            videos += new_videos
+            if not new_videos or len(videos) > limit:
+                break
+            next_link = self._html_search_regex(
+                r'href="(/results\?[^"]*\bsp=[^"]+)"[^>]*>\s*<span[^>]+class="[^"]*\byt-uix-button-content\b[^"]*"[^>]*>Next',
+                html_content, 'next link', default=None)
+            if next_link is None:
+                break
+            result_url = compat_urlparse.urljoin('https://www.youtube.com/', next_link)
 
-        if len(video_ids) > n:
-            video_ids = video_ids[:n]
-        videos = [self.url_result(video_id, 'Youtube', video_id=video_id)
-                  for video_id in video_ids]
+        if len(videos) > n:
+            videos = videos[:n]
         return self.playlist_result(videos, query)
 
+
 class YoutubeSearchDateIE(YoutubeSearchIE):
     IE_NAME = YoutubeSearchIE.IE_NAME + ':date'
-    _API_URL = 'https://gdata.youtube.com/feeds/api/videos?q=%s&start-index=%i&max-results=50&v=2&alt=jsonc&orderby=published'
     _SEARCH_KEY = 'ytsearchdate'
-    IE_DESC = u'YouTube.com searches, newest videos first'
-
-class YoutubeShowIE(InfoExtractor):
-    IE_DESC = u'YouTube.com (multi-season) shows'
-    _VALID_URL = r'https?://www\.youtube\.com/show/(.*)'
-    IE_NAME = u'youtube:show'
+    IE_DESC = 'YouTube.com searches, newest videos first'
+    _EXTRA_QUERY_ARGS = {'search_sort': 'video_date_uploaded'}
+
+
+class YoutubeSearchURLIE(YoutubeSearchBaseInfoExtractor):
+    IE_DESC = 'YouTube.com search URLs'
+    IE_NAME = 'youtube:search_url'
+    _VALID_URL = r'https?://(?:www\.)?youtube\.com/results\?(.*?&)?(?:search_query|q)=(?P<query>[^&]+)(?:[&]|$)'
+    _TESTS = [{
+        'url': 'https://www.youtube.com/results?baz=bar&search_query=youtube-dl+test+video&filters=video&lclk=video',
+        'playlist_mincount': 5,
+        'info_dict': {
+            'title': 'youtube-dl test video',
+        }
+    }, {
+        'url': 'https://www.youtube.com/results?q=test&sp=EgQIBBgB',
+        'only_matching': True,
+    }]
 
     def _real_extract(self, url):
         mobj = re.match(self._VALID_URL, url)
-        show_name = mobj.group(1)
-        webpage = self._download_webpage(url, show_name, u'Downloading show webpage')
-        # There's one playlist for each season of the show
-        m_seasons = list(re.finditer(r'href="(/playlist\?list=.*?)"', webpage))
-        self.to_screen(u'%s: Found %s seasons' % (show_name, len(m_seasons)))
-        return [self.url_result('https://www.youtube.com' + season.group(1), 'YoutubePlaylist') for season in m_seasons]
+        query = compat_urllib_parse_unquote_plus(mobj.group('query'))
+        webpage = self._download_webpage(url, query)
+        return self.playlist_result(self._process_page(webpage), playlist_title=query)
+
+
+class YoutubeShowIE(YoutubePlaylistsBaseInfoExtractor):
+    IE_DESC = 'YouTube.com (multi-season) shows'
+    _VALID_URL = r'https?://(?:www\.)?youtube\.com/show/(?P<id>[^?#]*)'
+    IE_NAME = 'youtube:show'
+    _TESTS = [{
+        'url': 'https://www.youtube.com/show/airdisasters',
+        'playlist_mincount': 5,
+        'info_dict': {
+            'id': 'airdisasters',
+            'title': 'Air Disasters',
+        }
+    }]
+
+    def _real_extract(self, url):
+        playlist_id = self._match_id(url)
+        return super(YoutubeShowIE, self)._real_extract(
+            'https://www.youtube.com/show/%s/playlists' % playlist_id)
 
 
 class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
     """
-    Base class for extractors that fetch info from
-    http://www.youtube.com/feed_ajax
+    Base class for feed extractors
     Subclasses must define the _FEED_NAME and _PLAYLIST_TITLE properties.
     """
     _LOGIN_REQUIRED = True
-    # use action_load_personal_feed instead of action_load_system_feed
-    _PERSONAL_FEED = False
-
-    @property
-    def _FEED_TEMPLATE(self):
-        action = 'action_load_system_feed'
-        if self._PERSONAL_FEED:
-            action = 'action_load_personal_feed'
-        return 'https://www.youtube.com/feed_ajax?%s=1&feed_name=%s&paging=%%s' % (action, self._FEED_NAME)
 
     @property
     def IE_NAME(self):
-        return u'youtube:%s' % self._FEED_NAME
+        return 'youtube:%s' % self._FEED_NAME
 
     def _real_initialize(self):
         self._login()
 
-    def _real_extract(self, url):
-        feed_entries = []
-        paging = 0
-        for i in itertools.count(1):
-            info = self._download_webpage(self._FEED_TEMPLATE % paging,
-                                          u'%s feed' % self._FEED_NAME,
-                                          u'Downloading page %s' % i)
-            info = json.loads(info)
-            feed_html = info['feed_html']
-            m_ids = re.finditer(r'"/watch\?v=(.*?)["&]', feed_html)
-            ids = orderedSet(m.group(1) for m in m_ids)
-            feed_entries.extend(
-                self.url_result(video_id, 'Youtube', video_id=video_id)
-                for video_id in ids)
-            if info['paging'] is None:
+    def _entries(self, page):
+        # The extraction process is the same as for playlists, but the regex
+        # for the video ids doesn't contain an index
+        ids = []
+        more_widget_html = content_html = page
+        for page_num in itertools.count(1):
+            matches = re.findall(r'href="\s*/watch\?v=([0-9A-Za-z_-]{11})', content_html)
+
+            # 'recommended' feed has infinite 'load more' and each new portion spins
+            # the same videos in (sometimes) slightly different order, so we'll check
+            # for unicity and break when portion has no new videos
+            new_ids = list(filter(lambda video_id: video_id not in ids, orderedSet(matches)))
+            if not new_ids:
                 break
-            paging = info['paging']
-        return self.playlist_result(feed_entries, playlist_title=self._PLAYLIST_TITLE)
 
-class YoutubeSubscriptionsIE(YoutubeFeedsInfoExtractor):
-    IE_DESC = u'YouTube.com subscriptions feed, "ytsubs" keyword(requires authentication)'
-    _VALID_URL = r'https?://www\.youtube\.com/feed/subscriptions|:ytsubs(?:criptions)?'
-    _FEED_NAME = 'subscriptions'
-    _PLAYLIST_TITLE = u'Youtube Subscriptions'
+            ids.extend(new_ids)
 
-class YoutubeRecommendedIE(YoutubeFeedsInfoExtractor):
-    IE_DESC = u'YouTube.com recommended videos, "ytrec" keyword (requires authentication)'
-    _VALID_URL = r'https?://www\.youtube\.com/feed/recommended|:ytrec(?:ommended)?'
-    _FEED_NAME = 'recommended'
-    _PLAYLIST_TITLE = u'Youtube Recommended videos'
+            for entry in self._ids_to_results(new_ids):
+                yield entry
 
-class YoutubeWatchLaterIE(YoutubeFeedsInfoExtractor):
-    IE_DESC = u'Youtube watch later list, "ytwatchlater" keyword (requires authentication)'
-    _VALID_URL = r'https?://www\.youtube\.com/feed/watch_later|:ytwatchlater'
-    _FEED_NAME = 'watch_later'
-    _PLAYLIST_TITLE = u'Youtube Watch Later'
-    _PERSONAL_FEED = True
+            mobj = re.search(r'data-uix-load-more-href="/?(?P<more>[^"]+)"', more_widget_html)
+            if not mobj:
+                break
+
+            more = self._download_json(
+                'https://www.youtube.com/%s' % mobj.group('more'), self._PLAYLIST_TITLE,
+                'Downloading page #%s' % page_num,
+                transform_source=uppercase_escape,
+                headers=self._YOUTUBE_CLIENT_HEADERS)
+            content_html = more['content_html']
+            more_widget_html = more['load_more_widget_html']
+
+    def _real_extract(self, url):
+        page = self._download_webpage(
+            'https://www.youtube.com/feed/%s' % self._FEED_NAME,
+            self._PLAYLIST_TITLE)
+        return self.playlist_result(
+            self._entries(page), playlist_title=self._PLAYLIST_TITLE)
+
+
+class YoutubeWatchLaterIE(YoutubePlaylistIE):
+    IE_NAME = 'youtube:watchlater'
+    IE_DESC = 'Youtube watch later list, ":ytwatchlater" for short (requires authentication)'
+    _VALID_URL = r'https?://(?:www\.)?youtube\.com/(?:feed/watch_later|(?:playlist|watch)\?(?:.+&)?list=WL)|:ytwatchlater'
+
+    _TESTS = [{
+        'url': 'https://www.youtube.com/playlist?list=WL',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/watch?v=bCNU9TrbiRk&index=1&list=WL',
+        'only_matching': True,
+    }]
+
+    def _real_extract(self, url):
+        _, video = self._check_download_just_video(url, 'WL')
+        if video:
+            return video
+        _, playlist = self._extract_playlist('WL')
+        return playlist
 
-class YoutubeHistoryIE(YoutubeFeedsInfoExtractor):
-    IE_DESC = u'Youtube watch history, "ythistory" keyword (requires authentication)'
-    _VALID_URL = u'https?://www\.youtube\.com/feed/history|:ythistory'
-    _FEED_NAME = 'history'
-    _PERSONAL_FEED = True
-    _PLAYLIST_TITLE = u'Youtube Watch History'
 
 class YoutubeFavouritesIE(YoutubeBaseInfoExtractor):
-    IE_NAME = u'youtube:favorites'
-    IE_DESC = u'YouTube.com favourite videos, "ytfav" keyword (requires authentication)'
-    _VALID_URL = r'https?://www\.youtube\.com/my_favorites|:ytfav(?:ou?rites)?'
+    IE_NAME = 'youtube:favorites'
+    IE_DESC = 'YouTube.com favourite videos, ":ytfav" for short (requires authentication)'
+    _VALID_URL = r'https?://(?:www\.)?youtube\.com/my_favorites|:ytfav(?:ou?rites)?'
     _LOGIN_REQUIRED = True
 
     def _real_extract(self, url):
         webpage = self._download_webpage('https://www.youtube.com/my_favorites', 'Youtube Favourites videos')
-        playlist_id = self._search_regex(r'list=(.+?)["&]', webpage, u'favourites playlist id')
+        playlist_id = self._search_regex(r'list=(.+?)["&]', webpage, 'favourites playlist id')
         return self.url_result(playlist_id, 'YoutubePlaylist')
 
 
+class YoutubeRecommendedIE(YoutubeFeedsInfoExtractor):
+    IE_DESC = 'YouTube.com recommended videos, ":ytrec" for short (requires authentication)'
+    _VALID_URL = r'https?://(?:www\.)?youtube\.com/feed/recommended|:ytrec(?:ommended)?'
+    _FEED_NAME = 'recommended'
+    _PLAYLIST_TITLE = 'Youtube Recommended videos'
+
+
+class YoutubeSubscriptionsIE(YoutubeFeedsInfoExtractor):
+    IE_DESC = 'YouTube.com subscriptions feed, "ytsubs" keyword (requires authentication)'
+    _VALID_URL = r'https?://(?:www\.)?youtube\.com/feed/subscriptions|:ytsubs(?:criptions)?'
+    _FEED_NAME = 'subscriptions'
+    _PLAYLIST_TITLE = 'Youtube Subscriptions'
+
+
+class YoutubeHistoryIE(YoutubeFeedsInfoExtractor):
+    IE_DESC = 'Youtube watch history, ":ythistory" for short (requires authentication)'
+    _VALID_URL = r'https?://(?:www\.)?youtube\.com/feed/history|:ythistory'
+    _FEED_NAME = 'history'
+    _PLAYLIST_TITLE = 'Youtube History'
+
+
 class YoutubeTruncatedURLIE(InfoExtractor):
     IE_NAME = 'youtube:truncated_url'
     IE_DESC = False  # Do not list
     _VALID_URL = r'''(?x)
-        (?:https?://)?[^/]+/watch\?feature=[a-z_]+$|
-        (?:https?://)?(?:www\.)?youtube\.com/attribution_link\?a=[^&]+$
+        (?:https?://)?
+        (?:\w+\.)?[yY][oO][uU][tT][uU][bB][eE](?:-nocookie)?\.com/
+        (?:watch\?(?:
+            feature=[a-z_]+|
+            annotation_id=annotation_[^&]+|
+            x-yt-cl=[0-9]+|
+            hl=[^&]*|
+            t=[0-9]+
+        )?
+        |
+            attribution_link\?a=[^&]+
+        )
+        $
     '''
 
+    _TESTS = [{
+        'url': 'https://www.youtube.com/watch?annotation_id=annotation_3951667041',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/watch?',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/watch?x-yt-cl=84503534',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/watch?feature=foo',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/watch?hl=en-GB',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/watch?t=2372',
+        'only_matching': True,
+    }]
+
+    def _real_extract(self, url):
+        raise ExtractorError(
+            'Did you forget to quote the URL? Remember that & is a meta '
+            'character in most shells, so you want to put the URL in quotes, '
+            'like  youtube-dl '
+            '"https://www.youtube.com/watch?feature=foo&v=BaW_jenozKc" '
+            ' or simply  youtube-dl BaW_jenozKc  .',
+            expected=True)
+
+
+class YoutubeTruncatedIDIE(InfoExtractor):
+    IE_NAME = 'youtube:truncated_id'
+    IE_DESC = False  # Do not list
+    _VALID_URL = r'https?://(?:www\.)?youtube\.com/watch\?v=(?P<id>[0-9A-Za-z_-]{1,10})$'
+
+    _TESTS = [{
+        'url': 'https://www.youtube.com/watch?v=N_708QY7Ob',
+        'only_matching': True,
+    }]
+
     def _real_extract(self, url):
+        video_id = self._match_id(url)
         raise ExtractorError(
-            u'Did you forget to quote the URL? Remember that & is a meta '
-            u'character in most shells, so you want to put the URL in quotes, '
-            u'like  youtube-dl '
-            u'"http://www.youtube.com/watch?feature=foo&v=BaW_jenozKc" '
-            u' or simply  youtube-dl BaW_jenozKc  .',
+            'Incomplete YouTube ID %s. URL %s looks truncated.' % (video_id, url),
             expected=True)