]> Raphaël G. Git Repositories - youtubedl/blobdiff - youtube_dl/extractor/youtube.py
Prepare for upload.
[youtubedl] / youtube_dl / extractor / youtube.py
index c7922c533343ca162c922659d34dc867d6839864..6071d72452655f0db74c104ec257cfbe434ad137 100644 (file)
 # coding: utf-8
 
+from __future__ import unicode_literals
+
+
+import itertools
 import json
-import netrc
+import os.path
 import re
-import socket
+import traceback
 
 from .common import InfoExtractor, SearchInfoExtractor
+from .subtitles import SubtitlesInfoExtractor
+from ..jsinterp import JSInterpreter
+from ..swfinterp import SWFInterpreter
 from ..utils import (
-    compat_http_client,
+    compat_chr,
     compat_parse_qs,
-    compat_urllib_error,
     compat_urllib_parse,
     compat_urllib_request,
+    compat_urlparse,
     compat_str,
 
     clean_html,
     get_element_by_id,
+    get_element_by_attribute,
     ExtractorError,
+    int_or_none,
+    OnDemandPagedList,
     unescapeHTML,
     unified_strdate,
+    orderedSet,
+    uppercase_escape,
 )
 
+class YoutubeBaseInfoExtractor(InfoExtractor):
+    """Provide base functions for Youtube extractors"""
+    _LOGIN_URL = 'https://accounts.google.com/ServiceLogin'
+    _TWOFACTOR_URL = 'https://accounts.google.com/SecondFactor'
+    _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'
+    _NETRC_MACHINE = 'youtube'
+    # If True it will raise an error if no login info is provided
+    _LOGIN_REQUIRED = False
+
+    def _set_language(self):
+        return bool(self._download_webpage(
+            self._LANG_URL, None,
+            note='Setting language', errnote='unable to set language',
+            fatal=False))
+
+    def _login(self):
+        """
+        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('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='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, 'Login GALX parameter')
+
+        # Log in
+        login_form_strs = {
+                'continue': 'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
+                'Email': username,
+                'GALX': galx,
+                'Passwd': password,
+
+                'PersistentCookie': 'yes',
+                '_utf8': '霱',
+                'bgresponse': 'js_disabled',
+                'checkConnection': '',
+                'checkedDomains': 'youtube',
+                'dnConn': '',
+                'pstMsg': '0',
+                'rmShown': '1',
+                'secTok': '',
+                'signIn': 'Sign in',
+                'timeStmp': '',
+                'service': 'youtube',
+                'uilel': '3',
+                'hl': '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='Logging in', errnote='unable to log in', fatal=False)
+        if login_results is False:
+            return False
+
+        if re.search(r'id="errormsg_0_Passwd"', login_results) is not None:
+            raise ExtractorError('Please use your account password and a two-factor code instead of an application-specific password.', expected=True)
+
+        # Two-Factor
+        # TODO add SMS and phone call support - these require making a request and then prompting the user
+
+        if re.search(r'(?i)<form[^>]* id="gaia_secondfactorform"', login_results) is not None:
+            tfa_code = self._get_tfa_info()
+
+            if tfa_code is None:
+                self._downloader.report_warning('Two-factor authentication required. Provide it with --twofactor <code>')
+                self._downloader.report_warning('(Note that only TOTP (Google Authenticator App) codes work at this time.)')
+                return False
+
+            # Unlike the first login form, secTok and timeStmp are both required for the TFA form
+
+            match = re.search(r'id="secTok"\n\s+value=\'(.+)\'/>', login_results, re.M | re.U)
+            if match is None:
+                self._downloader.report_warning('Failed to get secTok - did the page structure change?')
+            secTok = match.group(1)
+            match = re.search(r'id="timeStmp"\n\s+value=\'(.+)\'/>', login_results, re.M | re.U)
+            if match is None:
+                self._downloader.report_warning('Failed to get timeStmp - did the page structure change?')
+            timeStmp = match.group(1)
+
+            tfa_form_strs = {
+                'continue': 'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
+                'smsToken': '',
+                'smsUserPin': tfa_code,
+                'smsVerifyPin': 'Verify',
+
+                'PersistentCookie': 'yes',
+                'checkConnection': '',
+                'checkedDomains': 'youtube',
+                'pstMsg': '1',
+                'secTok': secTok,
+                'timeStmp': timeStmp,
+                'service': 'youtube',
+                'hl': 'en_US',
+            }
+            tfa_form = dict((k.encode('utf-8'), v.encode('utf-8')) for k,v in tfa_form_strs.items())
+            tfa_data = compat_urllib_parse.urlencode(tfa_form).encode('ascii')
+
+            tfa_req = compat_urllib_request.Request(self._TWOFACTOR_URL, tfa_data)
+            tfa_results = self._download_webpage(
+                tfa_req, None,
+                note='Submitting TFA code', errnote='unable to submit tfa', fatal=False)
+
+            if tfa_results is False:
+                return False
+
+            if re.search(r'(?i)<form[^>]* id="gaia_secondfactorform"', tfa_results) is not None:
+                self._downloader.report_warning('Two-factor code expired. Please try again, or use a one-use backup code instead.')
+                return False
+            if re.search(r'(?i)<form[^>]* id="gaia_loginform"', tfa_results) is not None:
+                self._downloader.report_warning('unable to log in - did the page structure change?')
+                return False
+            if re.search(r'smsauth-interstitial-reviewsettings', tfa_results) is not None:
+                self._downloader.report_warning('Your Google account has a security notice. Please log in on your web browser, resolve the notice, and try again.')
+                return False
+
+        if re.search(r'(?i)<form[^>]* id="gaia_loginform"', login_results) is not None:
+            self._downloader.report_warning('unable to log in: bad username or password')
+            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'))
+
+        self._download_webpage(
+            req, None,
+            note='Confirming age', errnote='Unable to confirm age',
+            fatal=False)
+
+    def _real_initialize(self):
+        if self._downloader is None:
+            return
+        if self._get_login_info()[0] is not None:
+            if not self._set_language():
+                return
+        if not self._login():
+            return
+        self._confirm_age()
 
-class YoutubeIE(InfoExtractor):
-    """Information extractor for youtube.com."""
 
-    _VALID_URL = r"""^
+class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
+    IE_DESC = 'YouTube.com'
+    _VALID_URL = r"""(?x)^
                      (
-                         (?:https?://)?                                       # http(s):// (optional)
-                         (?:youtu\.be/|(?:\w+\.)?youtube(?:-nocookie)?\.com/|
-                            tube\.majestyc\.net/)                             # the various hostnames, with wildcard subdomains
+                         (?:https?://|//)                                    # http(s):// or protocol-independent URL
+                         (?:(?:(?:(?:\w+\.)?[yY][oO][uU][tT][uU][bB][eE](?:-nocookie)?\.com/|
+                            (?:www\.)?deturl\.com/www\.youtube\.com/|
+                            (?:www\.)?pwnyoutube\.com/|
+                            (?:www\.)?yourepeat\.com/|
+                            tube\.majestyc\.net/|
+                            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(?:_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)
                                  v=
                              )
-                         )?                                                   # optional -> youtube.com/xxxx is OK
+                         ))
+                         |youtu\.be/                                          # just youtu.be/xxxx
+                         |(?:www\.)?cleanvideosearch\.com/media/action/yt/watch\?videoId=
+                         )
                      )?                                                       # all until now is optional -> you can pass the naked ID
-                     ([0-9A-Za-z_-]+)                                         # here is it! the YouTube video ID
+                     ([0-9A-Za-z_-]{11})                                      # here is it! the YouTube video ID
+                     (?!.*?&list=)                                            # combined list/video URLs are handled by the playlist IE
                      (?(1).+)?                                                # if we found the ID, everything can follow
                      $"""
-    _LANG_URL = r'https://www.youtube.com/?hl=en&persist_hl=1&gl=US&persist_gl=1&opt_out_ackd=1'
-    _LOGIN_URL = 'https://accounts.google.com/ServiceLogin'
-    _AGE_URL = 'http://www.youtube.com/verify_age?next_url=/&gl=US&hl=en'
     _NEXT_URL_RE = r'[\?&]next_url=([^&]+)'
-    _NETRC_MACHINE = 'youtube'
-    # Listed in order of quality
-    _available_formats = ['38', '37', '46', '22', '45', '35', '44', '34', '18', '43', '6', '5', '17', '13']
-    _available_formats_prefer_free = ['38', '46', '37', '45', '22', '44', '35', '43', '34', '18', '6', '5', '17', '13']
-    _video_extensions = {
-        '13': '3gp',
-        '17': 'mp4',
-        '18': 'mp4',
-        '22': 'mp4',
-        '37': 'mp4',
-        '38': 'mp4',
-        '43': 'webm',
-        '44': 'webm',
-        '45': 'webm',
-        '46': 'webm',
-    }
-    _video_dimensions = {
-        '5': '240x400',
-        '6': '???',
-        '13': '???',
-        '17': '144x176',
-        '18': '360x640',
-        '22': '720x1280',
-        '34': '360x640',
-        '35': '480x854',
-        '37': '1080x1920',
-        '38': '3072x4096',
-        '43': '360x640',
-        '44': '480x854',
-        '45': '720x1280',
-        '46': '1080x1920',
+    _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, 'format_note': '3D', 'preference': -20},
+        '83': {'ext': 'mp4', 'height': 480, 'format_note': '3D', 'preference': -20},
+        '84': {'ext': 'mp4', 'height': 720, 'format_note': '3D', 'preference': -20},
+        '85': {'ext': 'mp4', 'height': 1080, 'format_note': '3D', 'preference': -20},
+        '100': {'ext': 'webm', 'height': 360, 'format_note': '3D', 'preference': -20},
+        '101': {'ext': 'webm', 'height': 480, 'format_note': '3D', 'preference': -20},
+        '102': {'ext': 'webm', 'height': 720, 'format_note': '3D', 'preference': -20},
+
+        # Apple HTTP Live Streaming
+        '92': {'ext': 'mp4', 'height': 240, 'format_note': 'HLS', 'preference': -10},
+        '93': {'ext': 'mp4', 'height': 360, 'format_note': 'HLS', 'preference': -10},
+        '94': {'ext': 'mp4', 'height': 480, 'format_note': 'HLS', 'preference': -10},
+        '95': {'ext': 'mp4', 'height': 720, 'format_note': 'HLS', 'preference': -10},
+        '96': {'ext': 'mp4', 'height': 1080, 'format_note': 'HLS', 'preference': -10},
+        '132': {'ext': 'mp4', 'height': 240, 'format_note': 'HLS', 'preference': -10},
+        '151': {'ext': 'mp4', 'height': 72, 'format_note': 'HLS', 'preference': -10},
+
+        # DASH mp4 video
+        '133': {'ext': 'mp4', 'height': 240, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '134': {'ext': 'mp4', 'height': 360, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '135': {'ext': 'mp4', 'height': 480, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '136': {'ext': 'mp4', 'height': 720, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '137': {'ext': 'mp4', 'height': 1080, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '138': {'ext': 'mp4', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '160': {'ext': 'mp4', 'height': 144, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '264': {'ext': 'mp4', 'height': 1440, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+
+        # 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},
+
+        # Dash webm
+        '167': {'ext': 'webm', 'height': 360, 'width': 640, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'preference': -40},
+        '168': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'preference': -40},
+        '169': {'ext': 'webm', 'height': 720, 'width': 1280, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'preference': -40},
+        '170': {'ext': 'webm', 'height': 1080, 'width': 1920, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'preference': -40},
+        '218': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'preference': -40},
+        '219': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'preference': -40},
+        '278': {'ext': 'webm', 'height': 144, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'container': 'webm', 'vcodec': 'VP9'},
+        '242': {'ext': 'webm', 'height': 240, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '243': {'ext': 'webm', 'height': 360, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '244': {'ext': 'webm', 'height': 480, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '245': {'ext': 'webm', 'height': 480, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '246': {'ext': 'webm', 'height': 480, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '247': {'ext': 'webm', 'height': 720, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '248': {'ext': 'webm', 'height': 1080, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '271': {'ext': 'webm', 'height': 1440, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '272': {'ext': 'webm', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '302': {'ext': 'webm', 'height': 720, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'VP9'},
+        '303': {'ext': 'webm', 'height': 1080, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'VP9'},
+
+        # Dash webm audio
+        '171': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'abr': 128, 'preference': -50},
+        '172': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'abr': 256, 'preference': -50},
+
+        # Dash mov
+        '298': {'ext': 'mov', 'height': 720, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'h264'},
+        '299': {'ext': 'mov', 'height': 1080, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'h264'},
+        '266': {'ext': 'mov', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'vcodec': 'h264'},
+
+        # RTMP (unnamed)
+        '_rtmp': {'protocol': 'rtmp'},
     }
-    IE_NAME = u'youtube'
 
-    @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, re.VERBOSE) is not None
-
-    def report_lang(self):
-        """Report attempt to set language."""
-        self.to_screen(u'Setting language')
-
-    def report_login(self):
-        """Report attempt to log in."""
-        self.to_screen(u'Logging in')
-
-    def report_video_webpage_download(self, video_id):
-        """Report attempt to download video webpage."""
-        self.to_screen(u'%s: Downloading video webpage' % video_id)
+    IE_NAME = 'youtube'
+    _TESTS = [
+        {
+            'url': 'http://www.youtube.com/watch?v=BaW_jenozKc',
+            'info_dict': {
+                'id': 'BaW_jenozKc',
+                'ext': 'mp4',
+                'title': 'youtube-dl test video "\'/\\ä↭𝕐',
+                'uploader': 'Philipp Hagemeister',
+                'uploader_id': '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'],
+                'like_count': int,
+                'dislike_count': int,
+            }
+        },
+        {
+            'url': 'http://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]',
+                'description': 'md5:fea86fda2d5a5784273df5c7cc994d9f',
+                'uploader': 'Icona Pop',
+                'uploader_id': 'IconaPop',
+            }
+        },
+        {
+            '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 (Explicit)',
+                'description': 'md5:64249768eec3bc4276236606ea996373',
+                'uploader': 'justintimberlakeVEVO',
+                'uploader_id': 'justintimberlakeVEVO',
+            }
+        },
+        {
+            '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'
+            }
+        },
+        {
+            'url': 'http://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',
+                'description': '',
+                'uploader': '8KVIDEO',
+                'title': 'UHDTV TEST 8K VIDEO.mp4'
+            },
+            'params': {
+                'youtube_include_dash_manifest': True,
+                'format': '141',
+            },
+        },
+        # DASH manifest with encrypted signature
+        {
+            'url': 'https://www.youtube.com/watch?v=IB3lcPjvWLA',
+            'info_dict': {
+                'id': 'IB3lcPjvWLA',
+                'ext': 'm4a',
+                'title': 'Afrojack - The Spark ft. Spree Wilson',
+                'description': 'md5:9717375db5a9a3992be4668bbf3bc0a8',
+                'uploader': 'AfrojackVEVO',
+                'uploader_id': 'AfrojackVEVO',
+                'upload_date': '20131011',
+            },
+            'params': {
+                'youtube_include_dash_manifest': True,
+                'format': '141',
+            },
+        },
+    ]
+
+    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)
-
-    def report_video_subtitles_download(self, video_id):
-        """Report attempt to download video info webpage."""
-        self.to_screen(u'%s: Checking available subtitles' % video_id)
-
-    def report_video_subtitles_request(self, video_id, sub_lang, format):
-        """Report attempt to download video info webpage."""
-        self.to_screen(u'%s: Downloading video subtitles for %s.%s' % (video_id, sub_lang, format))
-
-    def report_video_subtitles_available(self, video_id, sub_lang_list):
-        """Report available subtitles."""
-        sub_lang = ",".join(list(sub_lang_list.keys()))
-        self.to_screen(u'%s: Available subtitles for video: %s' % (video_id, sub_lang))
+        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')
-
-    def _decrypt_signature(self, s):
-        """Decrypt the key the two subkeys must have a length of 43"""
-
-        if len(s) == 88:
-            return s[48] + s[81:67:-1] + s[82] + s[66:62:-1] + s[85] + s[61:48:-1] + s[67] + s[47:12:-1] + s[3] + s[11:3:-1] + s[2] + s[12]
-        elif len(s) == 87:
-            return s[62] + s[82:62:-1] + s[83] + s[61:52:-1] + s[0] + s[51:2:-1]
-        elif len(s) == 86:
-            return s[2:63] + s[82] + s[64:82] + s[63]
-        elif len(s) == 85:
-            return s[76] + s[82:76:-1] + s[83] + s[75:60:-1] + s[0] + s[59:50:-1] + s[1] + s[49:2:-1]
-        elif len(s) == 84:
-            return s[83:36:-1] + s[2] + s[35:26:-1] + s[3] + s[25:3:-1] + s[26]
-        elif len(s) == 83:
-            return s[52] + s[81:55:-1] + s[2] + s[54:52:-1] + s[82] + s[51:36:-1] + s[55] + s[35:2:-1] + s[36]
-        elif len(s) == 82:
-            return s[36] + s[79:67:-1] + s[81] + s[66:40:-1] + s[33] + s[39:36:-1] + s[40] + s[35] + s[0] + s[67] + s[32:0:-1] + s[34]
-
+        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('.'))
+
+    def _extract_signature_function(self, video_id, player_url, example_sig):
+        id_m = re.match(
+            r'.*-(?P<id>[a-zA-Z0-9_-]+)(?:/watch_as3|/html5player)?\.(?P<ext>[a-z]+)$',
+            player_url)
+        if not id_m:
+            raise ExtractorError('Cannot identify player %r' % player_url)
+        player_type = id_m.group('ext')
+        player_id = id_m.group('id')
+
+        # Read from filesystem cache
+        func_id = '%s_%s_%s' % (
+            player_type, player_id, self._signature_cache_id(example_sig))
+        assert os.path.basename(func_id) == func_id
+
+        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)
+
+        if player_type == 'js':
+            code = self._download_webpage(
+                player_url, video_id,
+                note='Downloading %s player %s' % (player_type, player_id),
+                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='Downloading %s player %s' % (player_type, player_id),
+                errnote='Download of %s failed' % player_url)
+            code = urlh.read()
+            res = self._parse_sig_swf(code)
         else:
-            raise ExtractorError(u'Unable to decrypt signature, subkeys length %d not supported; retrying might work' % (len(s)))
-
-    def _get_available_subtitles(self, video_id):
-        self.report_video_subtitles_download(video_id)
-        request = compat_urllib_request.Request('http://video.google.com/timedtext?hl=en&type=list&v=%s' % video_id)
+            assert False, 'Invalid player type %r' % player_type
+
+        if cache_spec is None:
+            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, example_sig):
+        def gen_sig_code(idxs):
+            def _genslice(start, end, step):
+                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
+            for i, prev in zip(idxs[1:], idxs[:-1]):
+                if step is not None:
+                    if i - prev == step:
+                        continue
+                    yield _genslice(start, prev, step)
+                    step = None
+                    continue
+                if i - prev in [-1, 1]:
+                    step = i - prev
+                    start = prev
+                    continue
+                else:
+                    yield 's[%d]' % prev
+            if step is None:
+                yield 's[%d]' % i
+            else:
+                yield _genslice(start, i, step)
+
+        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 = ' + '.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,
+             'Initial JS player signature function name')
+
+        jsi = JSInterpreter(jscode)
+        initial_function = jsi.extract_function(funcname)
+        return lambda s: initial_function([s])
+
+    def _parse_sig_swf(self, file_contents):
+        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 None:
+            raise ExtractorError('Cannot decrypt signature without player_url')
+
+        if player_url.startswith('//'):
+            player_url = 'https:' + player_url
         try:
-            sub_list = compat_urllib_request.urlopen(request).read().decode('utf-8')
-        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
-            return (u'unable to download video subtitles: %s' % compat_str(err), None)
-        sub_lang_list = re.findall(r'name="([^"]*)"[^>]+lang_code="([\w\-]+)"', sub_list)
-        sub_lang_list = dict((l[1], l[0]) for l in sub_lang_list)
+            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):
+        try:
+            sub_list = self._download_webpage(
+                '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('unable to download video subtitles: %s' % 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]
+            if lang in sub_lang_list:
+                continue
+            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 = 'https://www.youtube.com/api/timedtext?' + params
+            sub_lang_list[lang] = url
         if not sub_lang_list:
-            return (u'video doesn\'t have subtitles', None)
+            self._downloader.report_warning('video doesn\'t have subtitles')
+            return {}
         return sub_lang_list
 
-    def _list_available_subtitles(self, video_id):
-        sub_lang_list = self._get_available_subtitles(video_id)
-        self.report_video_subtitles_available(video_id, sub_lang_list)
-
-    def _request_subtitle(self, sub_lang, sub_name, video_id, format):
-        """
-        Return tuple:
-        (error_message, sub_lang, sub)
-        """
-        self.report_video_subtitles_request(video_id, sub_lang, format)
-        params = compat_urllib_parse.urlencode({
-            'lang': sub_lang,
-            'name': sub_name,
-            'v': video_id,
-            'fmt': format,
-        })
-        url = 'http://www.youtube.com/api/timedtext?' + params
-        try:
-            sub = compat_urllib_request.urlopen(url).read().decode('utf-8')
-        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
-            return (u'unable to download video subtitles: %s' % compat_str(err), None, None)
-        if not sub:
-            return (u'Did not fetch video subtitles', None, None)
-        return (None, sub_lang, sub)
-
-    def _request_automatic_caption(self, video_id, webpage):
+    def _get_available_automatic_caption(self, video_id, webpage):
         """We need the webpage for getting the captions url, pass it as an
            argument to speed up the process."""
-        sub_lang = self._downloader.params.get('subtitleslang') or 'en'
-        sub_format = self._downloader.params.get('subtitlesformat')
-        self.to_screen(u'%s: Looking for automatic captions' % video_id)
+        sub_format = self._downloader.params.get('subtitlesformat', 'srt')
+        self.to_screen('%s: Looking for automatic captions' % video_id)
         mobj = re.search(r';ytplayer.config = ({.*?});', webpage)
-        err_msg = u'Couldn\'t find automatic captions for "%s"' % sub_lang
+        err_msg = 'Couldn\'t find automatic captions for %s' % video_id
         if mobj is None:
-            return [(err_msg, None, None)]
+            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']
-            params = compat_urllib_parse.urlencode({
-                'lang': 'en',
-                'tlang': sub_lang,
-                'fmt': sub_format,
-                'ts': timestamp,
-                'kind': 'asr',
+            # We get the available subtitles
+            list_params = compat_urllib_parse.urlencode({
+                'type': 'list',
+                'tlangs': 1,
+                'asrs': 1,
             })
-            subtitles_url = caption_url + '&' + params
-            sub = self._download_webpage(subtitles_url, video_id, u'Downloading automatic captions')
-            return [(None, sub_lang, sub)]
-        except KeyError:
-            return [(err_msg, None, None)]
-
-    def _extract_subtitle(self, video_id):
-        """
-        Return a list with a tuple:
-        [(error_message, sub_lang, sub)]
-        """
-        sub_lang_list = self._get_available_subtitles(video_id)
-        sub_format = self._downloader.params.get('subtitlesformat')
-        if  isinstance(sub_lang_list,tuple): #There was some error, it didn't get the available subtitles
-            return [(sub_lang_list[0], None, None)]
-        if self._downloader.params.get('subtitleslang', False):
-            sub_lang = self._downloader.params.get('subtitleslang')
-        elif 'en' in sub_lang_list:
-            sub_lang = 'en'
-        else:
-            sub_lang = list(sub_lang_list.keys())[0]
-        if not sub_lang in sub_lang_list:
-            return [(u'no closed captions found in the specified language "%s"' % sub_lang, None, None)]
-
-        subtitle = self._request_subtitle(sub_lang, sub_lang_list[sub_lang].encode('utf-8'), video_id, sub_format)
-        return [subtitle]
-
-    def _extract_all_subtitles(self, video_id):
-        sub_lang_list = self._get_available_subtitles(video_id)
-        sub_format = self._downloader.params.get('subtitlesformat')
-        if  isinstance(sub_lang_list,tuple): #There was some error, it didn't get the available subtitles
-            return [(sub_lang_list[0], None, None)]
-        subtitles = []
-        for sub_lang in sub_lang_list:
-            subtitle = self._request_subtitle(sub_lang, sub_lang_list[sub_lang].encode('utf-8'), video_id, sub_format)
-            subtitles.append(subtitle)
-        return subtitles
-
-    def _print_formats(self, formats):
-        print('Available formats:')
-        for x in formats:
-            print('%s\t:\t%s\t[%s]' %(x, self._video_extensions.get(x, 'flv'), self._video_dimensions.get(x, '???')))
+            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('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',
+                })
+                sub_lang_list[sub_lang] = caption_url + '&' + params
+            return 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):
+            self._downloader.report_warning(err_msg)
+            return {}
 
-    def _real_initialize(self):
-        if self._downloader is None:
-            return
-
-        username = None
-        password = None
-        downloader_params = self._downloader.params
-
-        # Attempt to use provided username and password or .netrc data
-        if downloader_params.get('username', None) is not None:
-            username = downloader_params['username']
-            password = downloader_params['password']
-        elif downloader_params.get('usenetrc', False):
-            try:
-                info = netrc.netrc().authenticators(self._NETRC_MACHINE)
-                if info is not None:
-                    username = info[0]
-                    password = info[2]
-                else:
-                    raise netrc.NetrcParseError('No authenticators for %s' % self._NETRC_MACHINE)
-            except (IOError, netrc.NetrcParseError) as err:
-                self._downloader.report_warning(u'parsing .netrc: %s' % compat_str(err))
-                return
-
-        # Set language
-        request = compat_urllib_request.Request(self._LANG_URL)
-        try:
-            self.report_lang()
-            compat_urllib_request.urlopen(request).read()
-        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
-            self._downloader.report_warning(u'unable to set language: %s' % compat_str(err))
-            return
-
-        # No authentication to be performed
-        if username is None:
-            return
-
-        request = compat_urllib_request.Request(self._LOGIN_URL)
-        try:
-            login_page = compat_urllib_request.urlopen(request).read().decode('utf-8')
-        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
-            self._downloader.report_warning(u'unable to fetch login page: %s' % compat_str(err))
-            return
-
-        galx = None
-        dsh = None
-        match = re.search(re.compile(r'<input.+?name="GALX".+?value="(.+?)"', re.DOTALL), login_page)
-        if match:
-          galx = match.group(1)
-
-        match = re.search(re.compile(r'<input.+?name="dsh".+?value="(.+?)"', re.DOTALL), login_page)
-        if match:
-          dsh = match.group(1)
-
-        # 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'dsh': dsh,
-                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')
-        request = compat_urllib_request.Request(self._LOGIN_URL, login_data)
-        try:
-            self.report_login()
-            login_results = compat_urllib_request.urlopen(request).read().decode('utf-8')
-            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')
-                return
-        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
-            self._downloader.report_warning(u'unable to log in: %s' % compat_str(err))
-            return
-
-        # Confirm age
-        age_form = {
-                'next_url':     '/',
-                'action_confirm':   'Confirm',
-                }
-        request = compat_urllib_request.Request(self._AGE_URL, compat_urllib_parse.urlencode(age_form))
-        try:
-            self.report_age_confirmation()
-            compat_urllib_request.urlopen(request).read().decode('utf-8')
-        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
-            raise ExtractorError(u'Unable to confirm age: %s' % compat_str(err))
-
-    def _extract_id(self, url):
-        mobj = re.match(self._VALID_URL, url, re.VERBOSE)
+    @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, '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='Searching for annotations.', errnote='Unable to download video annotations.')
+
     def _real_extract(self, url):
+        proto = (
+            'http' if self._downloader.params.get('prefer_insecure', False)
+            else 'https')
+
         # 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('/')
-        video_id = self._extract_id(url)
+            url = proto + '://www.youtube.com/' + compat_urllib_parse.unquote(mobj.group(1)).lstrip('/')
+        video_id = self.extract_id(url)
 
         # Get video webpage
-        self.report_video_webpage_download(video_id)
-        url = 'https://www.youtube.com/watch?v=%s&gl=US&hl=en&has_verified=1' % video_id
-        request = compat_urllib_request.Request(url)
-        try:
-            video_webpage_bytes = compat_urllib_request.urlopen(request).read()
-        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
-            raise ExtractorError(u'Unable to download video webpage: %s' % compat_str(err))
-
-        video_webpage = video_webpage_bytes.decode('utf-8', 'ignore')
+        url = proto + '://www.youtube.com/watch?v=%s&gl=US&hl=en&has_verified=1' % video_id
+        pref_cookies = [
+            c for c in self._downloader.cookiejar
+            if c.domain == '.youtube.com' and c.name == 'PREF']
+        for pc in pref_cookies:
+            if 'hl=' in pc.value:
+                pc.value = re.sub(r'hl=[^&]+', 'hl=en', pc.value)
+            else:
+                if pc.value:
+                    pc.value += '&'
+                pc.value += 'hl=en'
+        video_webpage = self._download_webpage(url, video_id)
 
         # Attempt to extract SWF player URL
-        mobj = re.search(r'swfConfig.*?"(http:\\/\\/.*?watch.*?-.*?\.swf)"', video_webpage)
+        mobj = re.search(r'swfConfig.*?"(https?:\\/\\/.*?watch.*?-.*?\.swf)"', video_webpage)
         if mobj is not None:
             player_url = re.sub(r'\\(.)', r'\1', mobj.group(1))
         else:
@@ -390,31 +685,58 @@ class YoutubeIE(InfoExtractor):
 
         # Get video info
         self.report_video_info_webpage_download(video_id)
-        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))
+        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,
+                'eurl': 'https://youtube.googleapis.com/v/' + video_id,
+                'sts': self._search_regex(
+                    r'"sts"\s*:\s*(\d+)', video_webpage, 'sts'),
+            })
+            video_info_url = proto + '://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)
-            if 'token' in video_info:
-                break
+        else:
+            age_gate = False
+            for el_type in ['&el=embedded', '&el=detailpage', '&el=vevo', '']:
+                video_info_url = (proto + '://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])
+                raise ExtractorError(
+                    'YouTube said: %s' % video_info['reason'][0],
+                    expected=True, video_id=video_id)
             else:
-                raise ExtractorError(u'"token" parameter not in video info for unknown reason')
+                raise ExtractorError(
+                    '"token" parameter not in video info for unknown reason',
+                    video_id=video_id)
+
+        if 'view_count' in video_info:
+            view_count = int(video_info['view_count'][0])
+        else:
+            view_count = None
 
         # 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')
+            raise ExtractorError('"rental" videos not supported')
 
         # Start extracting information
         self.report_information_extraction(video_id)
 
         # uploader
         if 'author' not in video_info:
-            raise ExtractorError(u'Unable to extract uploader name')
+            raise ExtractorError('Unable to extract uploader name')
         video_uploader = compat_urllib_parse.unquote_plus(video_info['author'][0])
 
         # uploader_id
@@ -423,246 +745,503 @@ class YoutubeIE(InfoExtractor):
         if mobj is not None:
             video_uploader_id = mobj.group(1)
         else:
-            self._downloader.report_warning(u'unable to extract uploader nickname')
+            self._downloader.report_warning('unable to extract uploader nickname')
 
         # title
-        if 'title' not in video_info:
-            raise ExtractorError(u'Unable to extract video title')
-        video_title = compat_urllib_parse.unquote_plus(video_info['title'][0])
+        if 'title' in video_info:
+            video_title = video_info['title'][0]
+        else:
+            self._downloader.report_warning('Unable to extract video title')
+            video_title = '_'
 
         # thumbnail image
-        if 'thumbnail_url' not in video_info:
-            self._downloader.report_warning(u'unable to extract video thumbnail')
-            video_thumbnail = ''
+        # 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('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])
 
         # upload date
         upload_date = None
-        mobj = re.search(r'id="eow-date.*?>(.*?)</span>', video_webpage, re.DOTALL)
+        mobj = re.search(r'(?s)id="eow-date.*?>(.*?)</span>', video_webpage)
+        if mobj is None:
+            mobj = re.search(
+                r'(?s)id="watch-uploader-info".*?>.*?(?:Published|Uploaded|Streamed live) on (.*?)</strong>',
+                video_webpage)
         if mobj is not None:
             upload_date = ' '.join(re.sub(r'[/,-]', r' ', mobj.group(1)).split())
             upload_date = unified_strdate(upload_date)
 
+        m_cat_container = self._search_regex(
+            r'(?s)<h4[^>]*>\s*Category\s*</h4>\s*<ul[^>]*>(.*?)</ul>',
+            video_webpage, 'categories', fatal=False)
+        if m_cat_container:
+            category = self._html_search_regex(
+                r'(?s)<a[^<]+>(.*?)</a>', m_cat_container, 'category',
+                default=None)
+            video_categories = None if category is None else [category]
+        else:
+            video_categories = None
+
         # description
         video_description = get_element_by_id("eow-description", video_webpage)
         if video_description:
+            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>
+            ''', r'\1', 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))
             else:
-                video_description = u''
+                video_description = ''
+
+        def _extract_count(count_name):
+            count = self._search_regex(
+                r'id="watch-%s"[^>]*>.*?([\d,]+)\s*</span>' % re.escape(count_name),
+                video_webpage, count_name, default=None)
+            if count is not None:
+                return int(count.replace(',', ''))
+            return None
+        like_count = _extract_count('like')
+        dislike_count = _extract_count('dislike')
 
         # subtitles
-        video_subtitles = None
-
-        if self._downloader.params.get('writesubtitles', False):
-            video_subtitles = self._extract_subtitle(video_id)
-            if video_subtitles:
-                (sub_error, sub_lang, sub) = video_subtitles[0]
-                if sub_error:
-                    self._downloader.report_warning(sub_error)
-        
-        if self._downloader.params.get('writeautomaticsub', False):
-            video_subtitles = self._request_automatic_caption(video_id, video_webpage)
-            (sub_error, sub_lang, sub) = video_subtitles[0]
-            if sub_error:
-                self._downloader.report_warning(sub_error)
-
-        if self._downloader.params.get('allsubtitles', False):
-            video_subtitles = self._extract_all_subtitles(video_id)
-            for video_subtitle in video_subtitles:
-                (sub_error, sub_lang, sub) = video_subtitle
-                if sub_error:
-                    self._downloader.report_warning(sub_error)
+        video_subtitles = self.extract_subtitles(video_id, video_webpage)
 
         if self._downloader.params.get('listsubtitles', False):
-            self._list_available_subtitles(video_id)
+            self._list_available_subtitles(video_id, video_webpage)
             return
 
         if 'length_seconds' not in video_info:
-            self._downloader.report_warning(u'unable to extract video duration')
-            video_duration = ''
+            self._downloader.report_warning('unable to extract video duration')
+            video_duration = None
         else:
-            video_duration = compat_urllib_parse.unquote_plus(video_info['length_seconds'][0])
+            video_duration = int(compat_urllib_parse.unquote_plus(video_info['length_seconds'][0]))
 
-        # Decide which formats to download
-        req_format = self._downloader.params.get('format', None)
+        # annotations
+        video_annotations = None
+        if self._downloader.params.get('writeannotations', False):
+                video_annotations = self._extract_annotations(video_id)
 
+        # Decide which formats to download
         try:
-            mobj = re.search(r';ytplayer.config = ({.*?});', video_webpage)
+            mobj = re.search(r';ytplayer\.config\s*=\s*({.*?});', video_webpage)
             if not mobj:
                 raise ValueError('Could not find vevo ID')
-            info = json.loads(mobj.group(1))
-            args = info['args']
+            json_code = uppercase_escape(mobj.group(1))
+            ytplayer_config = json.loads(json_code)
+            args = ytplayer_config['args']
             # Easy way to know if the 's' value is in url_encoded_fmt_stream_map
             # this signatures are encrypted
-            m_s = re.search(r'[&,]s=', args['url_encoded_fmt_stream_map'])
+            if 'url_encoded_fmt_stream_map' not in args:
+                raise ValueError('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)
+                self.to_screen('%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', ''))
+            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
+
         if 'conn' in video_info and video_info['conn'][0].startswith('rtmp'):
             self.report_rtmp_download()
-            video_url_list = [(None, video_info['conn'][0])]
-        elif 'url_encoded_fmt_stream_map' in video_info and len(video_info['url_encoded_fmt_stream_map']) >= 1:
+            formats = [{
+                'format_id': '_rtmp',
+                'protocol': 'rtmp',
+                '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]
+            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 video_info['url_encoded_fmt_stream_map'][0].split(','):
+            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]
-                    if 'sig' in url_data:
-                        url += '&signature=' + url_data['sig'][0]
-                    elif 's' in url_data:
-                        if self._downloader.params.get('verbose'):
-                            s = url_data['s'][0]
-                            player = self._search_regex(r'html5player-(.+?)\.js', video_webpage,
-                                'html5 player', fatal=False)
-                            self.to_screen('encrypted signature length %d (%d.%d), itag %s, html5 player %s' %
-                                (len(s), len(s.split('.')[0]), len(s.split('.')[1]), url_data['itag'][0], player))
-                        signature = self._decrypt_signature(url_data['s'][0])
-                        url += '&signature=' + signature
-                    if 'ratebypass' not in url:
-                        url += '&ratebypass=yes'
-                    url_map[url_data['itag'][0]] = url
-
-            format_limit = self._downloader.params.get('format_limit', None)
-            available_formats = self._available_formats_prefer_free if self._downloader.params.get('prefer_free_formats', False) else self._available_formats
-            if format_limit is not None and format_limit in available_formats:
-                format_list = available_formats[available_formats.index(format_limit):]
-            else:
-                format_list = available_formats
-            existing_formats = [x for x in format_list if x in url_map]
-            if len(existing_formats) == 0:
-                raise ExtractorError(u'no known formats available for video')
-            if self._downloader.params.get('listformats', None):
-                self._print_formats(existing_formats)
-                return
-            if req_format is None or req_format == 'best':
-                video_url_list = [(existing_formats[0], url_map[existing_formats[0]])] # Best quality
-            elif req_format == 'worst':
-                video_url_list = [(existing_formats[len(existing_formats)-1], url_map[existing_formats[len(existing_formats)-1]])] # worst quality
-            elif req_format in ('-1', 'all'):
-                video_url_list = [(f, url_map[f]) for f in existing_formats] # All formats
-            else:
-                # Specific formats. We pick the first in a slash-delimeted sequence.
-                # For example, if '1/2/3/4' is requested and '2' and '4' are available, we pick '2'.
-                req_formats = req_format.split('/')
-                video_url_list = None
-                for rf in req_formats:
-                    if rf in url_map:
-                        video_url_list = [(rf, url_map[rf])]
-                        break
-                if video_url_list is None:
-                    raise ExtractorError(u'requested format not available')
+                if 'itag' not in url_data or 'url' not in url_data:
+                    continue
+                format_id = url_data['itag'][0]
+                url = url_data['url'][0]
+
+                if 'sig' in url_data:
+                    url += '&signature=' + url_data['sig'][0]
+                elif 's' in url_data:
+                    encrypted_sig = url_data['s'][0]
+
+                    if not age_gate:
+                        jsplayer_url_json = self._search_regex(
+                            r'"assets":.+?"js":\s*("[^"]+")',
+                            video_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 self._downloader.params.get('verbose'):
+                        if player_url is None:
+                            player_version = 'unknown'
+                            player_desc = 'unknown'
+                        else:
+                            if player_url.endswith('swf'):
+                                player_version = self._search_regex(
+                                    r'-(.+?)(?:/watch_as3)?\.swf$', player_url,
+                                    'flash player', fatal=False)
+                                player_desc = 'flash player %s' % player_version
+                            else:
+                                player_version = self._search_regex(
+                                    r'html5player-([^/]+?)(?:/html5player)?\.js',
+                                    player_url,
+                                    'html5 player', fatal=False)
+                                player_desc = 'html5 player %s' % 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[format_id] = 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)
         else:
-            raise ExtractorError(u'no conn or url_encoded_fmt_stream_map information found in video info')
-
-        results = []
-        for format_param, video_real_url in video_url_list:
-            # Extension
-            video_extension = self._video_extensions.get(format_param, 'flv')
-
-            video_format = '{0} - {1}'.format(format_param if format_param else video_extension,
-                                              self._video_dimensions.get(format_param, '???'))
-
-            results.append({
-                'id':       video_id,
-                'url':      video_real_url,
-                'uploader': video_uploader,
-                'uploader_id': video_uploader_id,
-                'upload_date':  upload_date,
-                'title':    video_title,
-                'ext':      video_extension,
-                'format':   video_format,
-                'thumbnail':    video_thumbnail,
-                'description':  video_description,
-                'player_url':   player_url,
-                'subtitles':    video_subtitles,
-                'duration':     video_duration
-            })
-        return results
+            raise ExtractorError('no conn, hlsvp or url_encoded_fmt_stream_map information found in video info')
 
-class YoutubePlaylistIE(InfoExtractor):
-    """Information Extractor for YouTube playlists."""
+        # Look for the DASH manifest
+        if self._downloader.params.get('youtube_include_dash_manifest', True):
+            try:
+                # The DASH manifest used needs to be the one from the original video_webpage.
+                # The one found in get_video_info seems to be using different signatures.
+                # However, in the case of an age restriction there won't be any embedded dashmpd in the video_webpage.
+                # Luckily, it seems, this case uses some kind of default signature (len == 86), so the
+                # combination of get_video_info and the _static_decrypt_signature() decryption fallback will work here.
+                if age_gate:
+                    dash_manifest_url = video_info.get('dashmpd')[0]
+                else:
+                    dash_manifest_url = ytplayer_config['args']['dashmpd']
+                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
+                dash_manifest_url = re.sub(r'/s/([\w\.]+)', decrypt_sig, dash_manifest_url)
+                dash_doc = self._download_xml(
+                    dash_manifest_url, video_id,
+                    note='Downloading DASH manifest',
+                    errnote='Could not download DASH manifest')
+                for r in dash_doc.findall('.//{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('Skipping DASH manifest: %s' % e, video_id)
+
+        self._sort_formats(formats)
+
+        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,
+            'categories':   video_categories,
+            'subtitles':    video_subtitles,
+            'duration':     video_duration,
+            'age_limit':    18 if age_gate else 0,
+            'annotations':  video_annotations,
+            '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,
+        }
 
-    _VALID_URL = r"""(?:
+class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
+    IE_DESC = 'YouTube.com playlists'
+    _VALID_URL = r"""(?x)(?:
                         (?:https?://)?
                         (?:\w+\.)?
                         youtube\.com/
                         (?:
-                           (?:course|view_play_list|my_playlists|artist|playlist|watch)
+                           (?:course|view_play_list|my_playlists|artist|playlist|watch|embed/videoseries)
                            \? (?:.*?&)*? (?:p|a|list)=
                         |  p/
                         )
-                        ((?:PL|EC|UU)?[0-9A-Za-z-_]{10,})
+                        (
+                            (?:PL|LL|EC|UU|FL|RD)?[0-9A-Za-z-_]{10,}
+                            # Top tracks, they can also include dots 
+                            |(?:MC)[\w\.]*
+                        )
                         .*
                      |
-                        ((?:PL|EC|UU)[0-9A-Za-z-_]{10,})
+                        ((?:PL|LL|EC|UU|FL|RD)[0-9A-Za-z-_]{10,})
                      )"""
-    _TEMPLATE_URL = 'https://gdata.youtube.com/feeds/api/playlists/%s?max-results=%i&start-index=%i&v=2&alt=json&safeSearch=none'
-    _MAX_RESULTS = 50
-    IE_NAME = u'youtube:playlist'
+    _TEMPLATE_URL = 'https://www.youtube.com/playlist?list=%s'
+    _MORE_PAGES_INDICATOR = r'data-link-type="next"'
+    _VIDEO_RE = r'href="\s*/watch\?v=(?P<id>[0-9A-Za-z_-]{11})&amp;[^"]*?index=(?P<index>\d+)'
+    IE_NAME = 'youtube:playlist'
+    _TESTS = [{
+        'url': 'https://www.youtube.com/playlist?list=PLwiyx1dc3P2JR9N8gQaQN_BCvlSlap7re',
+        'info_dict': {
+            'title': 'ytdl test PL',
+        },
+        'playlist_count': 3,
+    }, {
+        'url': 'https://www.youtube.com/playlist?list=PLtPgu7CB4gbZDA7i_euNxn75ISqxwZPYx',
+        'info_dict': {
+            'title': 'YDL_Empty_List',
+        },
+        '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',
+        },
+        'playlist_count': 95,
+    }, {
+        'note': 'issue #673',
+        'url': 'PLBB231211A4F62143',
+        'info_dict': {
+            'title': '[OLD]Team Fortress 2 (Class-based LP)',
+        },
+        'playlist_mincount': 26,
+    }, {
+        'note': 'Large playlist',
+        'url': 'https://www.youtube.com/playlist?list=UUBABnxM4Ar9ten8Mdjj1j0Q',
+        'info_dict': {
+            'title': 'Uploads from Cauchemar',
+        },
+        'playlist_mincount': 799,
+    }, {
+        'url': 'PLtPgu7CB4gbY9oDN3drwC3cMbJggS7dKl',
+        'info_dict': {
+            'title': 'YDL_safe_search',
+        },
+        'playlist_count': 2,
+    }, {
+        'note': 'embedded',
+        'url': 'http://www.youtube.com/embed/videoseries?list=PL6IaIsEjSbf96XFRuNccS_RuEXwNdsoEu',
+        'playlist_count': 4,
+        'info_dict': {
+            'title': 'JODA15',
+        }
+    }, {
+        'note': 'Embedded SWF player',
+        'url': 'http://www.youtube.com/p/YN5VISEtHet5D4NEvfTd0zcgFk84NqFZ?hl=en_US&fs=1&rel=0',
+        'playlist_count': 4,
+        'info_dict': {
+            'title': 'JODA7',
+        }
+    }]
 
-    @classmethod
-    def suitable(cls, url):
-        """Receives a URL and returns True if suitable for this IE."""
-        return re.match(cls._VALID_URL, url, re.VERBOSE) is not None
+    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_mix(self, playlist_id):
+        # The mixes are generated from a 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, 'Downloading Youtube mix')
+        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)
+        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))
+        url_results = self._ids_to_results(ids)
+
+        return self.playlist_result(url_results, playlist_id, title)
 
     def _real_extract(self, url):
         # Extract playlist id
-        mobj = re.match(self._VALID_URL, url, re.VERBOSE)
+        mobj = re.match(self._VALID_URL, url)
         if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
-
-        # Download playlist videos from API
+            raise ExtractorError('Invalid URL: %s' % url)
         playlist_id = mobj.group(1) or mobj.group(2)
-        page_num = 1
-        videos = []
 
-        while True:
-            url = self._TEMPLATE_URL % (playlist_id, self._MAX_RESULTS, self._MAX_RESULTS * (page_num - 1) + 1)
-            page = self._download_webpage(url, playlist_id, u'Downloading page #%s' % page_num)
+        # 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('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('Downloading playlist %s - add --no-playlist to just download video %s' % (playlist_id, video_id))
+
+        if playlist_id.startswith('RD'):
+            # Mixes require a custom extraction process
+            return self._extract_mix(playlist_id)
+        if playlist_id.startswith('TL'):
+            raise ExtractorError('For downloading YouTube.com top lists, use '
+                'the "yttoplist" keyword, for example "youtube-dl \'yttoplist:music:Top Tracks\'"', expected=True)
+
+        url = self._TEMPLATE_URL % playlist_id
+        page = self._download_webpage(url, playlist_id)
+        more_widget_html = content_html = page
+
+        # Check if the playlist exists or is private
+        if re.search(r'<div class="yt-alert-message">[^<]*?(The|This) playlist (does not exist|is private)[^<]*?</div>', page) is not None:
+            raise ExtractorError(
+                'The playlist doesn\'t exist or is private, use --username or '
+                '--netrc to access it.',
+                expected=True)
+
+        # Extract the video ids from the playlist pages
+        ids = []
+
+        for page_num in itertools.count(1):
+            matches = re.finditer(self._VIDEO_RE, content_html)
+            # 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)
+
+            mobj = re.search(r'data-uix-load-more-href="/?(?P<more>[^"]+)"', more_widget_html)
+            if not mobj:
+                break
 
-            try:
-                response = json.loads(page)
-            except ValueError as err:
-                raise ExtractorError(u'Invalid JSON in API response: ' + compat_str(err))
+            more = self._download_json(
+                'https://youtube.com/%s' % mobj.group('more'), playlist_id,
+                'Downloading page #%s' % page_num,
+                transform_source=uppercase_escape)
+            content_html = more['content_html']
+            more_widget_html = more['load_more_widget_html']
 
-            if 'feed' not in response:
-                raise ExtractorError(u'Got a malformed response from YouTube API')
-            playlist_title = response['feed']['title']['$t']
-            if 'entry' not in response['feed']:
-                # Number of videos is a multiple of self._MAX_RESULTS
-                break
+        playlist_title = self._html_search_regex(
+            r'(?s)<h1 class="pl-header-title[^"]*">\s*(.*?)\s*</h1>',
+            page, 'title')
 
-            for entry in response['feed']['entry']:
-                index = entry['yt$position']['$t']
-                if 'media$group' in entry and 'media$player' in entry['media$group']:
-                    videos.append((index, entry['media$group']['media$player']['url']))
+        url_results = self._ids_to_results(ids)
+        return self.playlist_result(url_results, playlist_id, playlist_title)
 
-            if len(response['feed']['entry']) < self._MAX_RESULTS:
-                break
-            page_num += 1
 
-        videos = [v[1] for v in sorted(videos)]
+class YoutubeTopListIE(YoutubePlaylistIE):
+    IE_NAME = 'youtube:toplist'
+    IE_DESC = ('YouTube.com top lists, "yttoplist:{channel}:{list title}"'
+        ' (Example: "yttoplist:music:Top Tracks")')
+    _VALID_URL = r'yttoplist:(?P<chann>.*?):(?P<title>.*?)$'
+    _TESTS = [{
+        'url': 'yttoplist:music:Trending',
+        'playlist_mincount': 5,
+        'skip': 'Only works for logged-in users',
+    }]
 
-        url_results = [self.url_result(url, 'Youtube') for url in videos]
-        return [self.playlist_result(url_results, playlist_id, playlist_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})
+        channel_page = self._download_webpage(
+            'https://www.youtube.com/%s' % channel, title)
+        link = self._html_search_regex(
+            r'''(?x)
+                <a\s+href="([^"]+)".*?>\s*
+                <span\s+class="branded-page-module-title-text">\s*
+                <span[^>]*>.*?%s.*?</span>''' % re.escape(query),
+            channel_page, '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 = '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)
 
 
 class YoutubeChannelIE(InfoExtractor):
-    """Information Extractor for YouTube channels."""
-
+    IE_DESC = 'YouTube.com channels'
     _VALID_URL = r"^(?:https?://)?(?:youtu\.be|(?:\w+\.)?youtube(?:-nocookie)?\.com)/channel/([0-9A-Za-z_-]+)"
-    _TEMPLATE_URL = 'http://www.youtube.com/channel/%s/videos?sort=da&flow=list&view=0&page=%s&gl=US&hl=en'
     _MORE_PAGES_INDICATOR = 'yt-uix-load-more'
-    _MORE_PAGES_URL = 'http://www.youtube.com/channel_ajax?action_load_more_videos=1&flow=list&paging=%s&view=0&sort=da&channel_id=%s'
-    IE_NAME = u'youtube:channel'
+    _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 = 'youtube:channel'
+    _TESTS = [{
+        'note': 'paginated channel',
+        'url': 'https://www.youtube.com/channel/UCKfVa3S1e4PHvxWcwyMMg8w',
+        'playlist_mincount': 91,
+    }]
 
     def extract_videos_from_page(self, page):
         ids_in_page = []
@@ -675,60 +1254,76 @@ class YoutubeChannelIE(InfoExtractor):
         # Extract channel 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)
 
         # Download channel page
         channel_id = mobj.group(1)
         video_ids = []
-        pagenum = 1
-
-        url = self._TEMPLATE_URL % (channel_id, pagenum)
-        page = self._download_webpage(url, channel_id,
-                                      u'Downloading page #%s' % pagenum)
-
-        # Extract video identifiers
-        ids_in_page = self.extract_videos_from_page(page)
-        video_ids.extend(ids_in_page)
-
-        # Download any subsequent channel pages using the json-based channel_ajax query
-        if self._MORE_PAGES_INDICATOR in page:
-            while True:
-                pagenum = pagenum + 1
-
+        url = 'https://www.youtube.com/channel/%s/videos' % channel_id
+        channel_page = self._download_webpage(url, channel_id)
+        autogenerated = re.search(r'''(?x)
+                class="[^"]*?(?:
+                    channel-header-autogenerated-label|
+                    yt-channel-title-autogenerated
+                )[^"]*"''', channel_page) is not None
+
+        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_webpage(url, channel_id,
-                                              u'Downloading page #%s' % pagenum)
-
-                page = json.loads(page)
+                page = self._download_json(
+                    url, channel_id, note='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']:
+    
+                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)))
+        self._downloader.to_screen('[youtube] Channel %s: Found %i videos' % (channel_id, len(video_ids)))
 
-        urls = ['http://www.youtube.com/watch?v=%s' % id for id in video_ids]
-        url_entries = [self.url_result(url, 'Youtube') for url in urls]
-        return [self.playlist_result(url_entries, channel_id)]
+        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)
 
 
 class YoutubeUserIE(InfoExtractor):
-    """Information Extractor for YouTube users."""
-
-    _VALID_URL = r'(?:(?:(?:https?://)?(?:\w+\.)?youtube\.com/user/)|ytuser:)([A-Za-z0-9_-]+)'
-    _TEMPLATE_URL = 'http://gdata.youtube.com/feeds/api/users/%s'
+    IE_DESC = 'YouTube.com user videos (URL or "ytuser" keyword)'
+    _VALID_URL = r'(?:(?:(?:https?://)?(?:\w+\.)?youtube\.com/(?:user/)?(?!(?:attribution_link|watch|results)(?:$|[^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 = 'http://gdata.youtube.com/feeds/api/users/%s/uploads?max-results=%d&start-index=%d'
-    _VIDEO_INDICATOR = r'/watch\?v=(.+?)[\<&]'
-    IE_NAME = u'youtube:user'
+    _GDATA_URL = 'https://gdata.youtube.com/feeds/api/users/%s/uploads?max-results=%d&start-index=%d&alt=json'
+    IE_NAME = 'youtube:user'
+
+    _TESTS = [{
+        'url': 'https://www.youtube.com/user/TheLinuxFoundation',
+        'playlist_mincount': 320,
+        'info_dict': {
+            'title': 'TheLinuxFoundation',
+        }
+    }, {
+        'url': 'ytuser:phihag',
+        '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)
 
     def _real_extract(self, url):
         # Extract username
         mobj = re.match(self._VALID_URL, url)
         if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
+            raise ExtractorError('Invalid URL: %s' % url)
 
         username = mobj.group(1)
 
@@ -737,70 +1332,68 @@ class YoutubeUserIE(InfoExtractor):
         # page by page until there are no video ids - it means we got
         # all of them.
 
-        video_ids = []
-        pagenum = 0
-
-        while True:
+        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))
-
-            # Extract video identifiers
-            ids_in_page = []
-
-            for mobj in re.finditer(self._VIDEO_INDICATOR, page):
-                if mobj.group(1) not in ids_in_page:
-                    ids_in_page.append(mobj.group(1))
-
-            video_ids.extend(ids_in_page)
+            page = self._download_webpage(
+                gdata_url, username,
+                'Downloading video ids from %d to %d' % (
+                    start_index, start_index + self._GDATA_PAGE_SIZE))
 
-            # A little optimization - if current page is not
-            # "full", ie. does not contain PAGE_SIZE video ids then
-            # we can assume that this page is the last one - there
-            # are no more ids on further pages - no need to query
-            # again.
+            try:
+                response = json.loads(page)
+            except ValueError as err:
+                raise ExtractorError('Invalid JSON in API response: ' + compat_str(err))
+            if 'entry' not in response['feed']:
+                return
 
-            if len(ids_in_page) < self._GDATA_PAGE_SIZE:
-                break
+            # 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 = OnDemandPagedList(download_page, self._GDATA_PAGE_SIZE)
 
-            pagenum += 1
+        return self.playlist_result(url_results, playlist_title=username)
 
-        urls = ['http://www.youtube.com/watch?v=%s' % video_id for video_id in video_ids]
-        url_results = [self.url_result(url, 'Youtube') for url in urls]
-        return [self.playlist_result(url_results, playlist_title = username)]
 
 class YoutubeSearchIE(SearchInfoExtractor):
-    """Information Extractor for YouTube search queries."""
+    IE_DESC = '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'
+    IE_NAME = 'youtube:search'
     _SEARCH_KEY = 'ytsearch'
 
-    def report_download_page(self, query, pagenum):
-        """Report attempt to download search page with given number."""
-        self._downloader.to_screen(u'[youtube] query "%s": Downloading page %s' % (query, pagenum))
-
     def _get_n_results(self, query, n):
         """Get a specified number of results for a query"""
 
         video_ids = []
         pagenum = 0
         limit = n
-
-        while (50 * pagenum) < limit:
-            self.report_download_page(query, pagenum+1)
-            result_url = self._API_URL % (compat_urllib_parse.quote_plus(query), (50*pagenum)+1)
-            request = compat_urllib_request.Request(result_url)
-            try:
-                data = compat_urllib_request.urlopen(request).read().decode('utf-8')
-            except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
-                raise ExtractorError(u'Unable to download API page: %s' % compat_str(err))
-            api_response = json.loads(data)['data']
-
-            if not 'items' in api_response:
-                raise ExtractorError(u'[youtube] No video results')
+        PAGE_SIZE = 50
+
+        while (PAGE_SIZE * pagenum) < limit:
+            result_url = self._API_URL % (
+                compat_urllib_parse.quote_plus(query.encode('utf-8')),
+                (PAGE_SIZE * pagenum) + 1)
+            data_json = self._download_webpage(
+                result_url, video_id='query "%s"' % query,
+                note='Downloading page %s' % (pagenum + 1),
+                errnote='Unable to download API page')
+            data = json.loads(data_json)
+            api_response = data['data']
+
+            if 'items' not in api_response:
+                raise ExtractorError(
+                    '[youtube] No video results', expected=True)
 
             new_ids = list(video['id'] for video in api_response['items'])
             video_ids += new_ids
@@ -810,5 +1403,237 @@ class YoutubeSearchIE(SearchInfoExtractor):
 
         if len(video_ids) > n:
             video_ids = video_ids[:n]
-        videos = [self.url_result('http://www.youtube.com/watch?v=%s' % id, 'Youtube') for id in video_ids]
+        videos = [self.url_result(video_id, 'Youtube', video_id=video_id)
+                  for video_id in video_ids]
         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 = 'YouTube.com searches, newest videos first'
+
+
+class YoutubeSearchURLIE(InfoExtractor):
+    IE_DESC = 'YouTube.com search URLs'
+    IE_NAME = 'youtube:search_url'
+    _VALID_URL = r'https?://(?:www\.)?youtube\.com/results\?(.*?&)?search_query=(?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',
+        }
+    }]
+
+    def _real_extract(self, url):
+        mobj = re.match(self._VALID_URL, url)
+        query = compat_urllib_parse.unquote_plus(mobj.group('query'))
+
+        webpage = self._download_webpage(url, query)
+        result_code = self._search_regex(
+            r'(?s)<ol class="item-section"(.*?)</ol>', webpage, 'result HTML')
+
+        part_codes = re.findall(
+            r'(?s)<h3 class="yt-lockup-title">(.*?)</h3>', result_code)
+        entries = []
+        for part_code in part_codes:
+            part_title = self._html_search_regex(
+                [r'(?s)title="([^"]+)"', r'>([^<]+)</a>'], part_code, 'item title', fatal=False)
+            part_url_snippet = self._html_search_regex(
+                r'(?s)href="([^"]+)"', part_code, 'item URL')
+            part_url = compat_urlparse.urljoin(
+                'https://www.youtube.com/', part_url_snippet)
+            entries.append({
+                '_type': 'url',
+                'url': part_url,
+                'title': part_title,
+            })
+
+        return {
+            '_type': 'playlist',
+            'entries': entries,
+            'title': query,
+        }
+
+
+class YoutubeShowIE(InfoExtractor):
+    IE_DESC = 'YouTube.com (multi-season) shows'
+    _VALID_URL = r'https?://www\.youtube\.com/show/(?P<id>[^?#]*)'
+    IE_NAME = 'youtube:show'
+    _TESTS = [{
+        'url': 'http://www.youtube.com/show/airdisasters',
+        'playlist_mincount': 3,
+        'info_dict': {
+            'id': 'airdisasters',
+            'title': 'Air Disasters',
+        }
+    }]
+
+    def _real_extract(self, url):
+        mobj = re.match(self._VALID_URL, url)
+        playlist_id = mobj.group('id')
+        webpage = self._download_webpage(
+            url, playlist_id, '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('%s: Found %s seasons' % (playlist_id, len(m_seasons)))
+        entries = [
+            self.url_result(
+                'https://www.youtube.com' + season.group(1), 'YoutubePlaylist')
+            for season in m_seasons
+        ]
+        title = self._og_search_title(webpage, fatal=False)
+
+        return {
+            '_type': 'playlist',
+            'id': playlist_id,
+            'title': title,
+            'entries': entries,
+        }
+
+
+class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
+    """
+    Base class for extractors that fetch info from
+    http://www.youtube.com/feed_ajax
+    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 '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_json(self._FEED_TEMPLATE % paging,
+                                          '%s feed' % self._FEED_NAME,
+                                          'Downloading page %s' % i)
+            feed_html = info.get('feed_html') or info.get('content_html')
+            load_more_widget_html = info.get('load_more_widget_html') or 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)
+            mobj = re.search(
+                r'data-uix-load-more-href="/?[^"]+paging=(?P<paging>\d+)',
+                load_more_widget_html)
+            if mobj is None:
+                break
+            paging = mobj.group('paging')
+        return self.playlist_result(feed_entries, playlist_title=self._PLAYLIST_TITLE)
+
+class YoutubeRecommendedIE(YoutubeFeedsInfoExtractor):
+    IE_DESC = 'YouTube.com recommended videos, "ytrec" keyword (requires authentication)'
+    _VALID_URL = r'https?://www\.youtube\.com/feed/recommended|:ytrec(?:ommended)?'
+    _FEED_NAME = 'recommended'
+    _PLAYLIST_TITLE = 'Youtube Recommended videos'
+
+class YoutubeWatchLaterIE(YoutubeFeedsInfoExtractor):
+    IE_DESC = '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 = 'Youtube Watch Later'
+    _PERSONAL_FEED = True
+
+class YoutubeHistoryIE(YoutubeFeedsInfoExtractor):
+    IE_DESC = 'Youtube watch history, "ythistory" keyword (requires authentication)'
+    _VALID_URL = 'https?://www\.youtube\.com/feed/history|:ythistory'
+    _FEED_NAME = 'history'
+    _PERSONAL_FEED = True
+    _PLAYLIST_TITLE = 'Youtube Watch History'
+
+class YoutubeFavouritesIE(YoutubeBaseInfoExtractor):
+    IE_NAME = 'youtube:favorites'
+    IE_DESC = 'YouTube.com favourite videos, "ytfav" keyword (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, 'favourites playlist id')
+        return self.url_result(playlist_id, 'YoutubePlaylist')
+
+
+class YoutubeSubscriptionsIE(YoutubePlaylistIE):
+    IE_NAME = 'youtube:subscriptions'
+    IE_DESC = 'YouTube.com subscriptions feed, "ytsubs" keyword (requires authentication)'
+    _VALID_URL = r'https?://www\.youtube\.com/feed/subscriptions|:ytsubs(?:criptions)?'
+    _TESTS = []
+
+    def _real_extract(self, url):
+        title = 'Youtube Subscriptions'
+        page = self._download_webpage('https://www.youtube.com/feed/subscriptions', title)
+
+        # 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)
+            new_ids = orderedSet(matches)
+            ids.extend(new_ids)
+
+            mobj = re.search(r'data-uix-load-more-href="/?(?P<more>[^"]+)"', more_widget_html)
+            if not mobj:
+                break
+
+            more = self._download_json(
+                'https://youtube.com/%s' % mobj.group('more'), title,
+                'Downloading page #%s' % page_num,
+                transform_source=uppercase_escape)
+            content_html = more['content_html']
+            more_widget_html = more['load_more_widget_html']
+
+        return {
+            '_type': 'playlist',
+            'title': title,
+            'entries': self._ids_to_results(ids),
+        }
+
+
+class YoutubeTruncatedURLIE(InfoExtractor):
+    IE_NAME = 'youtube:truncated_url'
+    IE_DESC = False  # Do not list
+    _VALID_URL = r'''(?x)
+        (?:https?://)?[^/]+/watch\?(?:
+            feature=[a-z_]+|
+            annotation_id=annotation_[^&]+
+        )?$|
+        (?:https?://)?(?:www\.)?youtube\.com/attribution_link\?a=[^&]+$
+    '''
+
+    _TESTS = [{
+        'url': 'http://www.youtube.com/watch?annotation_id=annotation_3951667041',
+        'only_matching': True,
+    }, {
+        'url': 'http://www.youtube.com/watch?',
+        '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 '
+            '"http://www.youtube.com/watch?feature=foo&v=BaW_jenozKc" '
+            ' or simply  youtube-dl BaW_jenozKc  .',
+            expected=True)