]> Raphaël G. Git Repositories - youtubedl/blobdiff - youtube_dl/extractor/youtube.py
debian/control: Add recommends on aria2 | wget | curl to use external downloaders.
[youtubedl] / youtube_dl / extractor / youtube.py
index a8103684301eef0711fdb1f28bd15dcb40c6430b..e4b26b84fe5cf65dfdcedc5d9fd9bf2b67e17f35 100644 (file)
 # coding: utf-8
 
 # coding: utf-8
 
-import collections
-import errno
-import io
+from __future__ import unicode_literals
+
+
 import itertools
 import json
 import os.path
 import re
 import itertools
 import json
 import os.path
 import re
-import string
-import struct
+import time
 import traceback
 import traceback
-import zlib
 
 from .common import InfoExtractor, SearchInfoExtractor
 from .subtitles import SubtitlesInfoExtractor
 
 from .common import InfoExtractor, SearchInfoExtractor
 from .subtitles import SubtitlesInfoExtractor
-from ..utils import (
+from ..jsinterp import JSInterpreter
+from ..swfinterp import SWFInterpreter
+from ..compat import (
     compat_chr,
     compat_parse_qs,
     compat_urllib_parse,
     compat_urllib_request,
     compat_urlparse,
     compat_str,
     compat_chr,
     compat_parse_qs,
     compat_urllib_parse,
     compat_urllib_request,
     compat_urlparse,
     compat_str,
-
+)
+from ..utils import (
     clean_html,
     clean_html,
-    get_cachedir,
-    get_element_by_id,
-    get_element_by_attribute,
     ExtractorError,
     ExtractorError,
+    get_element_by_attribute,
+    get_element_by_id,
     int_or_none,
     int_or_none,
-    PagedList,
-    RegexNotFoundError,
+    OnDemandPagedList,
+    orderedSet,
     unescapeHTML,
     unified_strdate,
     unescapeHTML,
     unified_strdate,
-    orderedSet,
-    write_json_file,
     uppercase_escape,
 )
 
     uppercase_escape,
 )
 
+
 class YoutubeBaseInfoExtractor(InfoExtractor):
     """Provide base functions for Youtube extractors"""
     _LOGIN_URL = 'https://accounts.google.com/ServiceLogin'
 class YoutubeBaseInfoExtractor(InfoExtractor):
     """Provide base functions for Youtube extractors"""
     _LOGIN_URL = 'https://accounts.google.com/ServiceLogin'
-    _LANG_URL = r'https://www.youtube.com/?hl=en&persist_hl=1&gl=US&persist_gl=1&opt_out_ackd=1'
-    _AGE_URL = 'https://www.youtube.com/verify_age?next_url=/&gl=US&hl=en'
+    _TWOFACTOR_URL = 'https://accounts.google.com/SecondFactor'
     _NETRC_MACHINE = 'youtube'
     # If True it will raise an error if no login info is provided
     _LOGIN_REQUIRED = False
 
     def _set_language(self):
     _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=u'Setting language', errnote='unable to set language',
-            fatal=False))
+        self._set_cookie(
+            '.youtube.com', 'PREF', 'f1=50000000&hl=en',
+            # YouTube sets the expire time to about two months
+            expire_time=time.time() + 2 * 30 * 24 * 3600)
 
     def _login(self):
 
     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:
         (username, password) = self._get_login_info()
         # No authentication to be performed
         if username is None:
             if self._LOGIN_REQUIRED:
-                raise ExtractorError(u'No login info available, needed for using %s.' % self.IE_NAME, expected=True)
-            return False
+                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,
 
         login_page = self._download_webpage(
             self._LOGIN_URL, None,
-            note=u'Downloading login page',
-            errnote=u'unable to fetch login page', fatal=False)
+            note='Downloading login page',
+            errnote='unable to fetch login page', fatal=False)
         if login_page is False:
             return
 
         galx = self._search_regex(r'(?s)<input.+?name="GALX".+?value="(.+?)"',
         if login_page is False:
             return
 
         galx = self._search_regex(r'(?s)<input.+?name="GALX".+?value="(.+?)"',
-                                  login_page, u'Login GALX parameter')
+                                  login_page, 'Login GALX parameter')
 
         # Log in
         login_form_strs = {
 
         # Log in
         login_form_strs = {
-                u'continue': u'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
-                u'Email': username,
-                u'GALX': galx,
-                u'Passwd': password,
-                u'PersistentCookie': u'yes',
-                u'_utf8': u'霱',
-                u'bgresponse': u'js_disabled',
-                u'checkConnection': u'',
-                u'checkedDomains': u'youtube',
-                u'dnConn': u'',
-                u'pstMsg': u'0',
-                u'rmShown': u'1',
-                u'secTok': u'',
-                u'signIn': u'Sign in',
-                u'timeStmp': u'',
-                u'service': u'youtube',
-                u'uilel': u'3',
-                u'hl': u'en_US',
+            '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
         # 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_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,
         login_data = compat_urllib_parse.urlencode(login_form).encode('ascii')
 
         req = compat_urllib_request.Request(self._LOGIN_URL, login_data)
         login_results = self._download_webpage(
             req, None,
-            note=u'Logging in', errnote=u'unable to log in', fatal=False)
+            note='Logging in', errnote='unable to log in', fatal=False)
         if login_results is False:
             return False
         if login_results is False:
             return False
-        if re.search(r'(?i)<form[^>]* id="gaia_loginform"', login_results) is not None:
-            self._downloader.report_warning(u'unable to log in: bad username or password')
-            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'))
+        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
 
 
-        self._download_webpage(
-            req, None,
-            note=u'Confirming age', errnote=u'Unable to confirm age')
+        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 _real_initialize(self):
         if self._downloader is None:
             return
         return True
 
     def _real_initialize(self):
         if self._downloader is None:
             return
-        if not self._set_language():
-            return
+        self._set_language()
         if not self._login():
             return
         if not self._login():
             return
-        self._confirm_age()
 
 
 class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
 
 
 class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
-    IE_DESC = u'YouTube.com'
+    IE_DESC = 'YouTube.com'
     _VALID_URL = r"""(?x)^
                      (
     _VALID_URL = r"""(?x)^
                      (
-                         (?:https?://|//)?                                    # http(s):// or protocol-independent URL (optional)
+                         (?: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/|
                          (?:(?:(?:(?:\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:
                             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
                              |(?:                                             # or the v= param in all its forms
-                                 (?:(?:watch|movie)(?:_popup)?(?:\.php)?)?    # preceding watch(_popup|.php) or nothing (like /?v=xxxx)
+                                 (?:(?:watch|movie)(?:_popup)?(?:\.php)?/?)?  # preceding watch(_popup|.php) or nothing (like /?v=xxxx)
                                  (?:\?|\#!?)                                  # the params delimiter ? or # or #!
                                  (?:.*?&)?                                    # any other preceding param (like /?s=tuff&v=xxxx)
                                  v=
                              )
                          ))
                          |youtu\.be/                                          # just youtu.be/xxxx
                                  (?:\?|\#!?)                                  # the params delimiter ? or # or #!
                                  (?:.*?&)?                                    # any other preceding param (like /?s=tuff&v=xxxx)
                                  v=
                              )
                          ))
                          |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_-]{11})                                      # here is it! the YouTube video ID
                          )
                      )?                                                       # all until now is optional -> you can pass the naked 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
                      $"""
     _NEXT_URL_RE = r'[\?&]next_url=([^&]+)'
                      (?(1).+)?                                                # if we found the ID, everything can follow
                      $"""
     _NEXT_URL_RE = r'[\?&]next_url=([^&]+)'
@@ -176,223 +233,348 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
 
 
         # 3d videos
 
 
         # 3d videos
-        '82': {'ext': 'mp4', 'height': 360, 'resolution': '360p', 'format_note': '3D', 'preference': -20},
-        '83': {'ext': 'mp4', 'height': 480, 'resolution': '480p', 'format_note': '3D', 'preference': -20},
-        '84': {'ext': 'mp4', 'height': 720, 'resolution': '720p', 'format_note': '3D', 'preference': -20},
-        '85': {'ext': 'mp4', 'height': 1080, 'resolution': '1080p', 'format_note': '3D', 'preference': -20},
-        '100': {'ext': 'webm', 'height': 360, 'resolution': '360p', 'format_note': '3D', 'preference': -20},
-        '101': {'ext': 'webm', 'height': 480, 'resolution': '480p', 'format_note': '3D', 'preference': -20},
-        '102': {'ext': 'webm', 'height': 720, 'resolution': '720p', 'format_note': '3D', 'preference': -20},
+        '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
 
         # Apple HTTP Live Streaming
-        '92': {'ext': 'mp4', 'height': 240, 'resolution': '240p', 'format_note': 'HLS', 'preference': -10},
-        '93': {'ext': 'mp4', 'height': 360, 'resolution': '360p', 'format_note': 'HLS', 'preference': -10},
-        '94': {'ext': 'mp4', 'height': 480, 'resolution': '480p', 'format_note': 'HLS', 'preference': -10},
-        '95': {'ext': 'mp4', 'height': 720, 'resolution': '720p', 'format_note': 'HLS', 'preference': -10},
-        '96': {'ext': 'mp4', 'height': 1080, 'resolution': '1080p', 'format_note': 'HLS', 'preference': -10},
-        '132': {'ext': 'mp4', 'height': 240, 'resolution': '240p', 'format_note': 'HLS', 'preference': -10},
-        '151': {'ext': 'mp4', 'height': 72, 'resolution': '72p', 'format_note': 'HLS', 'preference': -10},
+        '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
 
         # DASH mp4 video
-        '133': {'ext': 'mp4', 'height': 240, 'resolution': '240p', 'format_note': 'DASH video', 'preference': -40},
-        '134': {'ext': 'mp4', 'height': 360, 'resolution': '360p', 'format_note': 'DASH video', 'preference': -40},
-        '135': {'ext': 'mp4', 'height': 480, 'resolution': '480p', 'format_note': 'DASH video', 'preference': -40},
-        '136': {'ext': 'mp4', 'height': 720, 'resolution': '720p', 'format_note': 'DASH video', 'preference': -40},
-        '137': {'ext': 'mp4', 'height': 1080, 'resolution': '1080p', 'format_note': 'DASH video', 'preference': -40},
-        '138': {'ext': 'mp4', 'height': 1081, 'resolution': '>1080p', 'format_note': 'DASH video', 'preference': -40},
-        '160': {'ext': 'mp4', 'height': 192, 'resolution': '192p', 'format_note': 'DASH video', 'preference': -40},
-        '264': {'ext': 'mp4', 'height': 1080, 'resolution': '1080p', 'format_note': 'DASH video', 'preference': -40},
+        '133': {'ext': 'mp4', 'height': 240, 'format_note': 'DASH video', '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', 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},  # Height can vary (https://github.com/rg3/youtube-dl/issues/4559)
+        '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},
+        '298': {'ext': 'mp4', 'height': 720, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'h264'},
+        '299': {'ext': 'mp4', 'height': 1080, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'h264'},
+        '266': {'ext': 'mp4', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'vcodec': 'h264'},
 
         # Dash mp4 audio
 
         # Dash mp4 audio
-        '139': {'ext': 'm4a', 'format_note': 'DASH audio', 'vcodec': 'none', 'abr': 48, 'preference': -50},
-        '140': {'ext': 'm4a', 'format_note': 'DASH audio', 'vcodec': 'none', 'abr': 128, 'preference': -50},
-        '141': {'ext': 'm4a', 'format_note': 'DASH audio', 'vcodec': 'none', 'abr': 256, 'preference': -50},
+        '139': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'vcodec': 'none', 'abr': 48, 'preference': -50, 'container': 'm4a_dash'},
+        '140': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'vcodec': 'none', 'abr': 128, 'preference': -50, 'container': 'm4a_dash'},
+        '141': {'ext': 'm4a', 'format_note': 'DASH audio', 'acodec': 'aac', 'vcodec': 'none', 'abr': 256, 'preference': -50, 'container': 'm4a_dash'},
 
         # Dash webm
 
         # Dash webm
-        '167': {'ext': 'webm', 'height': 360, 'width': 640, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
-        '168': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
-        '169': {'ext': 'webm', 'height': 720, 'width': 1280, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
-        '170': {'ext': 'webm', 'height': 1080, 'width': 1920, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
-        '218': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
-        '219': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
-        '242': {'ext': 'webm', 'height': 240, 'resolution': '240p', 'format_note': 'DASH webm', 'preference': -40},
-        '243': {'ext': 'webm', 'height': 360, 'resolution': '360p', 'format_note': 'DASH webm', 'preference': -40},
-        '244': {'ext': 'webm', 'height': 480, 'resolution': '480p', 'format_note': 'DASH webm', 'preference': -40},
-        '245': {'ext': 'webm', 'height': 480, 'resolution': '480p', 'format_note': 'DASH webm', 'preference': -40},
-        '246': {'ext': 'webm', 'height': 480, 'resolution': '480p', 'format_note': 'DASH webm', 'preference': -40},
-        '247': {'ext': 'webm', 'height': 720, 'resolution': '720p', 'format_note': 'DASH webm', 'preference': -40},
-        '248': {'ext': 'webm', 'height': 1080, 'resolution': '1080p', 'format_note': 'DASH webm', 'preference': -40},
+        '167': {'ext': 'webm', 'height': 360, 'width': 640, 'format_note': 'DASH video', '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'},
+        '308': {'ext': 'webm', 'height': 1440, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'VP9'},
+        '313': {'ext': 'webm', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'vcodec': 'VP9'},
+        '315': {'ext': 'webm', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'VP9'},
 
         # Dash webm audio
 
         # Dash webm audio
-        '171': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH webm audio', 'abr': 48, 'preference': -50},
-        '172': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH webm audio', 'abr': 256, 'preference': -50},
+        '171': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'abr': 128, 'preference': -50},
+        '172': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'abr': 256, 'preference': -50},
+
+        # Dash webm audio with opus inside
+        '249': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'acodec': 'opus', 'abr': 50, 'preference': -50},
+        '250': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'acodec': 'opus', 'abr': 70, 'preference': -50},
+        '251': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'acodec': 'opus', 'abr': 160, 'preference': -50},
 
         # RTMP (unnamed)
         '_rtmp': {'protocol': 'rtmp'},
     }
 
 
         # RTMP (unnamed)
         '_rtmp': {'protocol': 'rtmp'},
     }
 
-    IE_NAME = u'youtube'
+    IE_NAME = 'youtube'
     _TESTS = [
         {
     _TESTS = [
         {
-            u"url":  u"http://www.youtube.com/watch?v=BaW_jenozKc",
-            u"file":  u"BaW_jenozKc.mp4",
-            u"info_dict": {
-                u"title": u"youtube-dl test video \"'/\\ä↭𝕐",
-                u"uploader": u"Philipp Hagemeister",
-                u"uploader_id": u"phihag",
-                u"upload_date": u"20121002",
-                u"description": u"test chars:  \"'/\\ä↭𝕐\ntest URL: https://github.com/rg3/youtube-dl/issues/1892\n\nThis is a test video for youtube-dl.\n\nFor more information, contact phihag@phihag.de ."
+            'url': '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,
             }
         },
         {
             }
         },
         {
-            u"url":  u"http://www.youtube.com/watch?v=UxxajLWwzqY",
-            u"file":  u"UxxajLWwzqY.mp4",
-            u"note": u"Test generic use_cipher_signature video (#897)",
-            u"info_dict": {
-                u"upload_date": u"20120506",
-                u"title": u"Icona Pop - I Love It (feat. Charli XCX) [OFFICIAL VIDEO]",
-                u"description": u"md5:5b292926389560516e384ac437c0ec07",
-                u"uploader": u"Icona Pop",
-                u"uploader_id": u"IconaPop"
+            'url': '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',
             }
         },
         {
             }
         },
         {
-            u"url":  u"https://www.youtube.com/watch?v=07FYdnEawAQ",
-            u"file":  u"07FYdnEawAQ.mp4",
-            u"note": u"Test VEVO video with age protection (#956)",
-            u"info_dict": {
-                u"upload_date": u"20130703",
-                u"title": u"Justin Timberlake - Tunnel Vision (Explicit)",
-                u"description": u"md5:64249768eec3bc4276236606ea996373",
-                u"uploader": u"justintimberlakeVEVO",
-                u"uploader_id": u"justintimberlakeVEVO"
+            'url': 'https://www.youtube.com/watch?v=07FYdnEawAQ',
+            'note': 'Test VEVO video with age protection (#956)',
+            'info_dict': {
+                'id': '07FYdnEawAQ',
+                'ext': 'mp4',
+                'upload_date': '20130703',
+                'title': 'Justin Timberlake - Tunnel Vision (Explicit)',
+                'description': 'md5:64249768eec3bc4276236606ea996373',
+                'uploader': 'justintimberlakeVEVO',
+                'uploader_id': 'justintimberlakeVEVO',
             }
         },
         {
             }
         },
         {
-            u"url":  u"//www.YouTube.com/watch?v=yZIXLfi8CZQ",
-            u"file":  u"yZIXLfi8CZQ.mp4",
-            u"note": u"Embed-only video (#1746)",
-            u"info_dict": {
-                u"upload_date": u"20120608",
-                u"title": u"Principal Sexually Assaults A Teacher - Episode 117 - 8th June 2012",
-                u"description": u"md5:09b78bd971f1e3e289601dfba15ca4f7",
-                u"uploader": u"SET India",
-                u"uploader_id": u"setindia"
+            'url': '//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'
             }
         },
         {
             }
         },
         {
-            u"url": u"http://www.youtube.com/watch?v=a9LDPn-MO4I",
-            u"file": u"a9LDPn-MO4I.m4a",
-            u"note": u"256k DASH audio (format 141) via DASH manifest",
-            u"info_dict": {
-                u"upload_date": "20121002",
-                u"uploader_id": "8KVIDEO",
-                u"description": "No description available.",
-                u"uploader": "8KVIDEO",
-                u"title": "UHDTV TEST 8K VIDEO.mp4"
+            '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, Spree Wilson - The Spark ft. Spree Wilson',
+                'description': 'md5:12e7067fa6735a77bdcbb58cb1187d2d',
+                'uploader': 'AfrojackVEVO',
+                'uploader_id': 'AfrojackVEVO',
+                'upload_date': '20131011',
+            },
+            'params': {
+                'youtube_include_dash_manifest': True,
+                'format': '141',
+            },
+        },
+        # JS player signature function name containing $
+        {
+            'url': 'https://www.youtube.com/watch?v=nfWlot6h_JM',
+            'info_dict': {
+                'id': 'nfWlot6h_JM',
+                'ext': 'm4a',
+                'title': 'Taylor Swift - Shake It Off',
+                'description': 'md5:2acfda1b285bdd478ccec22f9918199d',
+                'uploader': 'TaylorSwiftVEVO',
+                'uploader_id': 'TaylorSwiftVEVO',
+                'upload_date': '20140818',
+            },
+            'params': {
+                'youtube_include_dash_manifest': True,
+                'format': '141',
+            },
+        },
+        # Controversy video
+        {
+            'url': 'https://www.youtube.com/watch?v=T4XJQO3qol8',
+            'info_dict': {
+                'id': 'T4XJQO3qol8',
+                'ext': 'mp4',
+                'upload_date': '20100909',
+                'uploader': 'The Amazing Atheist',
+                'uploader_id': 'TheAmazingAtheist',
+                'title': 'Burning Everyone\'s Koran',
+                'description': 'SUBSCRIBE: http://www.youtube.com/saturninefilms\n\nEven Obama has taken a stand against freedom on this issue: http://www.huffingtonpost.com/2010/09/09/obama-gma-interview-quran_n_710282.html',
+            }
+        },
+        # Normal age-gate video (No vevo, embed allowed)
+        {
+            'url': 'http://youtube.com/watch?v=HtVdAasjOgU',
+            'info_dict': {
+                'id': 'HtVdAasjOgU',
+                'ext': 'mp4',
+                'title': 'The Witcher 3: Wild Hunt - The Sword Of Destiny Trailer',
+                'description': 're:(?s).{100,}About the Game\n.*?The Witcher 3: Wild Hunt.{100,}',
+                'uploader': 'The Witcher',
+                'uploader_id': 'WitcherGame',
+                'upload_date': '20140605',
+            },
+        },
+        # Age-gate video with encrypted signature
+        {
+            'url': 'http://www.youtube.com/watch?v=6kLq3WMV1nU',
+            'info_dict': {
+                'id': '6kLq3WMV1nU',
+                'ext': 'mp4',
+                'title': 'Dedication To My Ex (Miss That) (Lyric Video)',
+                'description': 'md5:33765bb339e1b47e7e72b5490139bb41',
+                'uploader': 'LloydVEVO',
+                'uploader_id': 'LloydVEVO',
+                'upload_date': '20110629',
+            },
+        },
+        # video_info is None (https://github.com/rg3/youtube-dl/issues/4421)
+        {
+            'url': '__2ABJjxzNo',
+            'info_dict': {
+                'id': '__2ABJjxzNo',
+                'ext': 'mp4',
+                'upload_date': '20100430',
+                'uploader_id': 'deadmau5',
+                'description': 'md5:12c56784b8032162bb936a5f76d55360',
+                'uploader': 'deadmau5',
+                'title': 'Deadmau5 - Some Chords (HD)',
             },
             },
-            u"params": {
-                u"youtube_include_dash_manifest": True,
-                u"format": "141",
+            'expected_warnings': [
+                'DASH manifest missing',
+            ]
+        },
+        # Olympics (https://github.com/rg3/youtube-dl/issues/4431)
+        {
+            'url': 'lqQg6PlCWgI',
+            'info_dict': {
+                'id': 'lqQg6PlCWgI',
+                'ext': 'mp4',
+                'upload_date': '20120731',
+                'uploader_id': 'olympic',
+                'description': 'HO09  - Women -  GER-AUS - Hockey - 31 July 2012 - London 2012 Olympic Games',
+                'uploader': 'Olympics',
+                'title': 'Hockey - Women -  GER-AUS - London 2012 Olympic Games',
             },
             },
+            'params': {
+                'skip_download': 'requires avconv',
+            }
         },
         },
+        # Non-square pixels
+        {
+            'url': 'https://www.youtube.com/watch?v=_b-2C3KPAM0',
+            'info_dict': {
+                'id': '_b-2C3KPAM0',
+                'ext': 'mp4',
+                'stretched_ratio': 16 / 9.,
+                'upload_date': '20110310',
+                'uploader_id': 'AllenMeow',
+                'description': 'made by Wacom from Korea | 字幕&加油添醋 by TY\'s Allen | 感謝heylisa00cavey1001同學熱情提供梗及翻譯',
+                'uploader': '孫艾倫',
+                'title': '[A-made] 變態妍字幕版 太妍 我就是這樣的人',
+            },
+        }
     ]
 
     ]
 
-
-    @classmethod
-    def suitable(cls, url):
-        """Receives a URL and returns True if suitable for this IE."""
-        if YoutubePlaylistIE.suitable(url): return False
-        return re.match(cls._VALID_URL, url) is not None
-
     def __init__(self, *args, **kwargs):
         super(YoutubeIE, self).__init__(*args, **kwargs)
         self._player_cache = {}
 
     def report_video_info_webpage_download(self, video_id):
         """Report attempt to download video info webpage."""
     def __init__(self, *args, **kwargs):
         super(YoutubeIE, self).__init__(*args, **kwargs)
         self._player_cache = {}
 
     def report_video_info_webpage_download(self, video_id):
         """Report attempt to download video info webpage."""
-        self.to_screen(u'%s: Downloading video info webpage' % video_id)
+        self.to_screen('%s: Downloading video info webpage' % video_id)
 
     def report_information_extraction(self, video_id):
         """Report attempt to extract video information."""
 
     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."""
 
     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."""
 
     def report_rtmp_download(self):
         """Indicate the download will use the RTMP protocol."""
-        self.to_screen(u'RTMP download detected')
-
-    def _extract_signature_function(self, video_id, player_url, slen):
-        id_m = re.match(r'.*-(?P<id>[a-zA-Z0-9_-]+)\.(?P<ext>[a-z]+)$',
-                        player_url)
+        self.to_screen('RTMP download detected')
+
+    def _signature_cache_id(self, example_sig):
+        """ Return a string representation of a signature """
+        return '.'.join(compat_str(len(part)) for part in example_sig.split('.'))
+
+    def _extract_signature_function(self, video_id, player_url, example_sig):
+        id_m = re.match(
+            r'.*?-(?P<id>[a-zA-Z0-9_-]+)(?:/watch_as3|/html5player)?\.(?P<ext>[a-z]+)$',
+            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
         player_type = id_m.group('ext')
         player_id = id_m.group('id')
 
         # Read from filesystem cache
-        func_id = '%s_%s_%d' % (player_type, player_id, slen)
+        func_id = '%s_%s_%s' % (
+            player_type, player_id, self._signature_cache_id(example_sig))
         assert os.path.basename(func_id) == func_id
         assert os.path.basename(func_id) == func_id
-        cache_dir = get_cachedir(self._downloader.params)
 
 
-        cache_enabled = cache_dir is not None
-        if cache_enabled:
-            cache_fn = os.path.join(os.path.expanduser(cache_dir),
-                                    u'youtube-sigfuncs',
-                                    func_id + '.json')
-            try:
-                with io.open(cache_fn, 'r', encoding='utf-8') as cachef:
-                    cache_spec = json.load(cachef)
-                return lambda s: u''.join(s[i] for i in cache_spec)
-            except IOError:
-                pass  # No cache available
+        cache_spec = self._downloader.cache.load('youtube-sigfuncs', func_id)
+        if cache_spec is not None:
+            return lambda s: ''.join(s[i] for i in cache_spec)
 
         if player_type == 'js':
             code = self._download_webpage(
                 player_url, video_id,
 
         if player_type == 'js':
             code = self._download_webpage(
                 player_url, video_id,
-                note=u'Downloading %s player %s' % (player_type, player_id),
-                errnote=u'Download of %s failed' % player_url)
+                note='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,
             res = self._parse_sig_js(code)
         elif player_type == 'swf':
             urlh = self._request_webpage(
                 player_url, video_id,
-                note=u'Downloading %s player %s' % (player_type, player_id),
-                errnote=u'Download of %s failed' % player_url)
+                note='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:
             assert False, 'Invalid player type %r' % player_type
 
             code = urlh.read()
             res = self._parse_sig_swf(code)
         else:
             assert False, 'Invalid player type %r' % player_type
 
-        if cache_enabled:
-            try:
-                test_string = u''.join(map(compat_chr, range(slen)))
-                cache_res = res(test_string)
-                cache_spec = [ord(c) for c in cache_res]
-                try:
-                    os.makedirs(os.path.dirname(cache_fn))
-                except OSError as ose:
-                    if ose.errno != errno.EEXIST:
-                        raise
-                write_json_file(cache_spec, cache_fn)
-            except Exception:
-                tb = traceback.format_exc()
-                self._downloader.report_warning(
-                    u'Writing cache to %r failed: %s' % (cache_fn, tb))
+        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
 
         return res
 
-    def _print_sig_code(self, func, slen):
+    def _print_sig_code(self, func, example_sig):
         def gen_sig_code(idxs):
             def _genslice(start, end, step):
         def gen_sig_code(idxs):
             def _genslice(start, end, step):
-                starts = u'' if start == 0 else str(start)
-                ends = (u':%d' % (end+step)) if end + step >= 0 else u':'
-                steps = u'' if step == 1 else (u':%d' % step)
-                return u's[%s%s%s]' % (starts, ends, steps)
+                starts = '' if start == 0 else str(start)
+                ends = (':%d' % (end + step)) if end + step >= 0 else ':'
+                steps = '' if step == 1 else (':%d' % step)
+                return 's[%s%s%s]' % (starts, ends, steps)
 
             step = None
 
             step = None
-            start = '(Never used)'  # Quelch pyflakes warnings - start will be
-                                    # set as soon as step is set
+            # Quelch pyflakes warnings - start will be set when step is set
+            start = '(Never used)'
             for i, prev in zip(idxs[1:], idxs[:-1]):
                 if step is not None:
                     if i - prev == step:
             for i, prev in zip(idxs[1:], idxs[:-1]):
                 if step is not None:
                     if i - prev == step:
@@ -405,637 +587,86 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                     start = prev
                     continue
                 else:
                     start = prev
                     continue
                 else:
-                    yield u's[%d]' % prev
+                    yield 's[%d]' % prev
             if step is None:
             if step is None:
-                yield u's[%d]' % i
+                yield 's[%d]' % i
             else:
                 yield _genslice(start, i, step)
 
             else:
                 yield _genslice(start, i, step)
 
-        test_string = u''.join(map(compat_chr, range(slen)))
+        test_string = ''.join(map(compat_chr, range(len(example_sig))))
         cache_res = func(test_string)
         cache_spec = [ord(c) for c in cache_res]
         cache_res = func(test_string)
         cache_spec = [ord(c) for c in cache_res]
-        expr_code = u' + '.join(gen_sig_code(cache_spec))
-        code = u'if len(s) == %d:\n    return %s\n' % (slen, expr_code)
-        self.to_screen(u'Extracted signature function:\n' + code)
+        expr_code = ' + '.join(gen_sig_code(cache_spec))
+        signature_id_tuple = '(%s)' % (
+            ', '.join(compat_str(len(p)) for p in example_sig.split('.')))
+        code = ('if tuple(len(p) for p in s.split(\'.\')) == %s:\n'
+                '    return %s\n') % (signature_id_tuple, expr_code)
+        self.to_screen('Extracted signature function:\n' + code)
 
     def _parse_sig_js(self, jscode):
         funcname = self._search_regex(
 
     def _parse_sig_js(self, jscode):
         funcname = self._search_regex(
-            r'signature=([a-zA-Z]+)', jscode,
-            u'Initial JS player signature function name')
-
-        functions = {}
-
-        def argidx(varname):
-            return string.lowercase.index(varname)
-
-        def interpret_statement(stmt, local_vars, allow_recursion=20):
-            if allow_recursion < 0:
-                raise ExtractorError(u'Recursion limit reached')
-
-            if stmt.startswith(u'var '):
-                stmt = stmt[len(u'var '):]
-            ass_m = re.match(r'^(?P<out>[a-z]+)(?:\[(?P<index>[^\]]+)\])?' +
-                             r'=(?P<expr>.*)$', stmt)
-            if ass_m:
-                if ass_m.groupdict().get('index'):
-                    def assign(val):
-                        lvar = local_vars[ass_m.group('out')]
-                        idx = interpret_expression(ass_m.group('index'),
-                                                   local_vars, allow_recursion)
-                        assert isinstance(idx, int)
-                        lvar[idx] = val
-                        return val
-                    expr = ass_m.group('expr')
-                else:
-                    def assign(val):
-                        local_vars[ass_m.group('out')] = val
-                        return val
-                    expr = ass_m.group('expr')
-            elif stmt.startswith(u'return '):
-                assign = lambda v: v
-                expr = stmt[len(u'return '):]
-            else:
-                raise ExtractorError(
-                    u'Cannot determine left side of statement in %r' % stmt)
-
-            v = interpret_expression(expr, local_vars, allow_recursion)
-            return assign(v)
-
-        def interpret_expression(expr, local_vars, allow_recursion):
-            if expr.isdigit():
-                return int(expr)
-
-            if expr.isalpha():
-                return local_vars[expr]
-
-            m = re.match(r'^(?P<in>[a-z]+)\.(?P<member>.*)$', expr)
-            if m:
-                member = m.group('member')
-                val = local_vars[m.group('in')]
-                if member == 'split("")':
-                    return list(val)
-                if member == 'join("")':
-                    return u''.join(val)
-                if member == 'length':
-                    return len(val)
-                if member == 'reverse()':
-                    return val[::-1]
-                slice_m = re.match(r'slice\((?P<idx>.*)\)', member)
-                if slice_m:
-                    idx = interpret_expression(
-                        slice_m.group('idx'), local_vars, allow_recursion-1)
-                    return val[idx:]
-
-            m = re.match(
-                r'^(?P<in>[a-z]+)\[(?P<idx>.+)\]$', expr)
-            if m:
-                val = local_vars[m.group('in')]
-                idx = interpret_expression(m.group('idx'), local_vars,
-                                           allow_recursion-1)
-                return val[idx]
-
-            m = re.match(r'^(?P<a>.+?)(?P<op>[%])(?P<b>.+?)$', expr)
-            if m:
-                a = interpret_expression(m.group('a'),
-                                         local_vars, allow_recursion)
-                b = interpret_expression(m.group('b'),
-                                         local_vars, allow_recursion)
-                return a % b
-
-            m = re.match(
-                r'^(?P<func>[a-zA-Z$]+)\((?P<args>[a-z0-9,]+)\)$', expr)
-            if m:
-                fname = m.group('func')
-                if fname not in functions:
-                    functions[fname] = extract_function(fname)
-                argvals = [int(v) if v.isdigit() else local_vars[v]
-                           for v in m.group('args').split(',')]
-                return functions[fname](argvals)
-            raise ExtractorError(u'Unsupported JS expression %r' % expr)
-
-        def extract_function(funcname):
-            func_m = re.search(
-                r'function ' + re.escape(funcname) +
-                r'\((?P<args>[a-z,]+)\){(?P<code>[^}]+)}',
-                jscode)
-            argnames = func_m.group('args').split(',')
-
-            def resf(args):
-                local_vars = dict(zip(argnames, args))
-                for stmt in func_m.group('code').split(';'):
-                    res = interpret_statement(stmt, local_vars)
-                return res
-            return resf
-
-        initial_function = extract_function(funcname)
+            r'\.sig\|\|([a-zA-Z0-9$]+)\(', 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):
         return lambda s: initial_function([s])
 
     def _parse_sig_swf(self, file_contents):
-        if file_contents[1:3] != b'WS':
-            raise ExtractorError(
-                u'Not an SWF file; header is %r' % file_contents[:3])
-        if file_contents[:1] == b'C':
-            content = zlib.decompress(file_contents[8:])
-        else:
-            raise NotImplementedError(u'Unsupported compression format %r' %
-                                      file_contents[:1])
-
-        def extract_tags(content):
-            pos = 0
-            while pos < len(content):
-                header16 = struct.unpack('<H', content[pos:pos+2])[0]
-                pos += 2
-                tag_code = header16 >> 6
-                tag_len = header16 & 0x3f
-                if tag_len == 0x3f:
-                    tag_len = struct.unpack('<I', content[pos:pos+4])[0]
-                    pos += 4
-                assert pos+tag_len <= len(content)
-                yield (tag_code, content[pos:pos+tag_len])
-                pos += tag_len
-
-        code_tag = next(tag
-                        for tag_code, tag in extract_tags(content)
-                        if tag_code == 82)
-        p = code_tag.index(b'\0', 4) + 1
-        code_reader = io.BytesIO(code_tag[p:])
-
-        # Parse ABC (AVM2 ByteCode)
-        def read_int(reader=None):
-            if reader is None:
-                reader = code_reader
-            res = 0
-            shift = 0
-            for _ in range(5):
-                buf = reader.read(1)
-                assert len(buf) == 1
-                b = struct.unpack('<B', buf)[0]
-                res = res | ((b & 0x7f) << shift)
-                if b & 0x80 == 0:
-                    break
-                shift += 7
-            return res
-
-        def u30(reader=None):
-            res = read_int(reader)
-            assert res & 0xf0000000 == 0
-            return res
-        u32 = read_int
-
-        def s32(reader=None):
-            v = read_int(reader)
-            if v & 0x80000000 != 0:
-                v = - ((v ^ 0xffffffff) + 1)
-            return v
-
-        def read_string(reader=None):
-            if reader is None:
-                reader = code_reader
-            slen = u30(reader)
-            resb = reader.read(slen)
-            assert len(resb) == slen
-            return resb.decode('utf-8')
-
-        def read_bytes(count, reader=None):
-            if reader is None:
-                reader = code_reader
-            resb = reader.read(count)
-            assert len(resb) == count
-            return resb
-
-        def read_byte(reader=None):
-            resb = read_bytes(1, reader=reader)
-            res = struct.unpack('<B', resb)[0]
-            return res
-
-        # minor_version + major_version
-        read_bytes(2 + 2)
-
-        # Constant pool
-        int_count = u30()
-        for _c in range(1, int_count):
-            s32()
-        uint_count = u30()
-        for _c in range(1, uint_count):
-            u32()
-        double_count = u30()
-        read_bytes((double_count-1) * 8)
-        string_count = u30()
-        constant_strings = [u'']
-        for _c in range(1, string_count):
-            s = read_string()
-            constant_strings.append(s)
-        namespace_count = u30()
-        for _c in range(1, namespace_count):
-            read_bytes(1)  # kind
-            u30()  # name
-        ns_set_count = u30()
-        for _c in range(1, ns_set_count):
-            count = u30()
-            for _c2 in range(count):
-                u30()
-        multiname_count = u30()
-        MULTINAME_SIZES = {
-            0x07: 2,  # QName
-            0x0d: 2,  # QNameA
-            0x0f: 1,  # RTQName
-            0x10: 1,  # RTQNameA
-            0x11: 0,  # RTQNameL
-            0x12: 0,  # RTQNameLA
-            0x09: 2,  # Multiname
-            0x0e: 2,  # MultinameA
-            0x1b: 1,  # MultinameL
-            0x1c: 1,  # MultinameLA
-        }
-        multinames = [u'']
-        for _c in range(1, multiname_count):
-            kind = u30()
-            assert kind in MULTINAME_SIZES, u'Invalid multiname kind %r' % kind
-            if kind == 0x07:
-                u30()  # namespace_idx
-                name_idx = u30()
-                multinames.append(constant_strings[name_idx])
-            else:
-                multinames.append('[MULTINAME kind: %d]' % kind)
-                for _c2 in range(MULTINAME_SIZES[kind]):
-                    u30()
-
-        # Methods
-        method_count = u30()
-        MethodInfo = collections.namedtuple(
-            'MethodInfo',
-            ['NEED_ARGUMENTS', 'NEED_REST'])
-        method_infos = []
-        for method_id in range(method_count):
-            param_count = u30()
-            u30()  # return type
-            for _ in range(param_count):
-                u30()  # param type
-            u30()  # name index (always 0 for youtube)
-            flags = read_byte()
-            if flags & 0x08 != 0:
-                # Options present
-                option_count = u30()
-                for c in range(option_count):
-                    u30()  # val
-                    read_bytes(1)  # kind
-            if flags & 0x80 != 0:
-                # Param names present
-                for _ in range(param_count):
-                    u30()  # param name
-            mi = MethodInfo(flags & 0x01 != 0, flags & 0x04 != 0)
-            method_infos.append(mi)
-
-        # Metadata
-        metadata_count = u30()
-        for _c in range(metadata_count):
-            u30()  # name
-            item_count = u30()
-            for _c2 in range(item_count):
-                u30()  # key
-                u30()  # value
-
-        def parse_traits_info():
-            trait_name_idx = u30()
-            kind_full = read_byte()
-            kind = kind_full & 0x0f
-            attrs = kind_full >> 4
-            methods = {}
-            if kind in [0x00, 0x06]:  # Slot or Const
-                u30()  # Slot id
-                u30()  # type_name_idx
-                vindex = u30()
-                if vindex != 0:
-                    read_byte()  # vkind
-            elif kind in [0x01, 0x02, 0x03]:  # Method / Getter / Setter
-                u30()  # disp_id
-                method_idx = u30()
-                methods[multinames[trait_name_idx]] = method_idx
-            elif kind == 0x04:  # Class
-                u30()  # slot_id
-                u30()  # classi
-            elif kind == 0x05:  # Function
-                u30()  # slot_id
-                function_idx = u30()
-                methods[function_idx] = multinames[trait_name_idx]
-            else:
-                raise ExtractorError(u'Unsupported trait kind %d' % kind)
-
-            if attrs & 0x4 != 0:  # Metadata present
-                metadata_count = u30()
-                for _c3 in range(metadata_count):
-                    u30()  # metadata index
-
-            return methods
-
-        # Classes
-        TARGET_CLASSNAME = u'SignatureDecipher'
-        searched_idx = multinames.index(TARGET_CLASSNAME)
-        searched_class_id = None
-        class_count = u30()
-        for class_id in range(class_count):
-            name_idx = u30()
-            if name_idx == searched_idx:
-                # We found the class we're looking for!
-                searched_class_id = class_id
-            u30()  # super_name idx
-            flags = read_byte()
-            if flags & 0x08 != 0:  # Protected namespace is present
-                u30()  # protected_ns_idx
-            intrf_count = u30()
-            for _c2 in range(intrf_count):
-                u30()
-            u30()  # iinit
-            trait_count = u30()
-            for _c2 in range(trait_count):
-                parse_traits_info()
-
-        if searched_class_id is None:
-            raise ExtractorError(u'Target class %r not found' %
-                                 TARGET_CLASSNAME)
-
-        method_names = {}
-        method_idxs = {}
-        for class_id in range(class_count):
-            u30()  # cinit
-            trait_count = u30()
-            for _c2 in range(trait_count):
-                trait_methods = parse_traits_info()
-                if class_id == searched_class_id:
-                    method_names.update(trait_methods.items())
-                    method_idxs.update(dict(
-                        (idx, name)
-                        for name, idx in trait_methods.items()))
-
-        # Scripts
-        script_count = u30()
-        for _c in range(script_count):
-            u30()  # init
-            trait_count = u30()
-            for _c2 in range(trait_count):
-                parse_traits_info()
-
-        # Method bodies
-        method_body_count = u30()
-        Method = collections.namedtuple('Method', ['code', 'local_count'])
-        methods = {}
-        for _c in range(method_body_count):
-            method_idx = u30()
-            u30()  # max_stack
-            local_count = u30()
-            u30()  # init_scope_depth
-            u30()  # max_scope_depth
-            code_length = u30()
-            code = read_bytes(code_length)
-            if method_idx in method_idxs:
-                m = Method(code, local_count)
-                methods[method_idxs[method_idx]] = m
-            exception_count = u30()
-            for _c2 in range(exception_count):
-                u30()  # from
-                u30()  # to
-                u30()  # target
-                u30()  # exc_type
-                u30()  # var_name
-            trait_count = u30()
-            for _c2 in range(trait_count):
-                parse_traits_info()
-
-        assert p + code_reader.tell() == len(code_tag)
-        assert len(methods) == len(method_idxs)
-
-        method_pyfunctions = {}
-
-        def extract_function(func_name):
-            if func_name in method_pyfunctions:
-                return method_pyfunctions[func_name]
-            if func_name not in methods:
-                raise ExtractorError(u'Cannot find function %r' % func_name)
-            m = methods[func_name]
-
-            def resfunc(args):
-                registers = ['(this)'] + list(args) + [None] * m.local_count
-                stack = []
-                coder = io.BytesIO(m.code)
-                while True:
-                    opcode = struct.unpack('!B', coder.read(1))[0]
-                    if opcode == 36:  # pushbyte
-                        v = struct.unpack('!B', coder.read(1))[0]
-                        stack.append(v)
-                    elif opcode == 44:  # pushstring
-                        idx = u30(coder)
-                        stack.append(constant_strings[idx])
-                    elif opcode == 48:  # pushscope
-                        # We don't implement the scope register, so we'll just
-                        # ignore the popped value
-                        stack.pop()
-                    elif opcode == 70:  # callproperty
-                        index = u30(coder)
-                        mname = multinames[index]
-                        arg_count = u30(coder)
-                        args = list(reversed(
-                            [stack.pop() for _ in range(arg_count)]))
-                        obj = stack.pop()
-                        if mname == u'split':
-                            assert len(args) == 1
-                            assert isinstance(args[0], compat_str)
-                            assert isinstance(obj, compat_str)
-                            if args[0] == u'':
-                                res = list(obj)
-                            else:
-                                res = obj.split(args[0])
-                            stack.append(res)
-                        elif mname == u'slice':
-                            assert len(args) == 1
-                            assert isinstance(args[0], int)
-                            assert isinstance(obj, list)
-                            res = obj[args[0]:]
-                            stack.append(res)
-                        elif mname == u'join':
-                            assert len(args) == 1
-                            assert isinstance(args[0], compat_str)
-                            assert isinstance(obj, list)
-                            res = args[0].join(obj)
-                            stack.append(res)
-                        elif mname in method_pyfunctions:
-                            stack.append(method_pyfunctions[mname](args))
-                        else:
-                            raise NotImplementedError(
-                                u'Unsupported property %r on %r'
-                                % (mname, obj))
-                    elif opcode == 72:  # returnvalue
-                        res = stack.pop()
-                        return res
-                    elif opcode == 79:  # callpropvoid
-                        index = u30(coder)
-                        mname = multinames[index]
-                        arg_count = u30(coder)
-                        args = list(reversed(
-                            [stack.pop() for _ in range(arg_count)]))
-                        obj = stack.pop()
-                        if mname == u'reverse':
-                            assert isinstance(obj, list)
-                            obj.reverse()
-                        else:
-                            raise NotImplementedError(
-                                u'Unsupported (void) property %r on %r'
-                                % (mname, obj))
-                    elif opcode == 93:  # findpropstrict
-                        index = u30(coder)
-                        mname = multinames[index]
-                        res = extract_function(mname)
-                        stack.append(res)
-                    elif opcode == 97:  # setproperty
-                        index = u30(coder)
-                        value = stack.pop()
-                        idx = stack.pop()
-                        obj = stack.pop()
-                        assert isinstance(obj, list)
-                        assert isinstance(idx, int)
-                        obj[idx] = value
-                    elif opcode == 98:  # getlocal
-                        index = u30(coder)
-                        stack.append(registers[index])
-                    elif opcode == 99:  # setlocal
-                        index = u30(coder)
-                        value = stack.pop()
-                        registers[index] = value
-                    elif opcode == 102:  # getproperty
-                        index = u30(coder)
-                        pname = multinames[index]
-                        if pname == u'length':
-                            obj = stack.pop()
-                            assert isinstance(obj, list)
-                            stack.append(len(obj))
-                        else:  # Assume attribute access
-                            idx = stack.pop()
-                            assert isinstance(idx, int)
-                            obj = stack.pop()
-                            assert isinstance(obj, list)
-                            stack.append(obj[idx])
-                    elif opcode == 128:  # coerce
-                        u30(coder)
-                    elif opcode == 133:  # coerce_s
-                        assert isinstance(stack[-1], (type(None), compat_str))
-                    elif opcode == 164:  # modulo
-                        value2 = stack.pop()
-                        value1 = stack.pop()
-                        res = value1 % value2
-                        stack.append(res)
-                    elif opcode == 208:  # getlocal_0
-                        stack.append(registers[0])
-                    elif opcode == 209:  # getlocal_1
-                        stack.append(registers[1])
-                    elif opcode == 210:  # getlocal_2
-                        stack.append(registers[2])
-                    elif opcode == 211:  # getlocal_3
-                        stack.append(registers[3])
-                    elif opcode == 214:  # setlocal_2
-                        registers[2] = stack.pop()
-                    elif opcode == 215:  # setlocal_3
-                        registers[3] = stack.pop()
-                    else:
-                        raise NotImplementedError(
-                            u'Unsupported opcode %d' % opcode)
-
-            method_pyfunctions[func_name] = resfunc
-            return resfunc
-
-        initial_function = extract_function(u'decipher')
+        swfi = SWFInterpreter(file_contents)
+        TARGET_CLASSNAME = 'SignatureDecipher'
+        searched_class = swfi.extract_class(TARGET_CLASSNAME)
+        initial_function = swfi.extract_function(searched_class, 'decipher')
         return lambda s: initial_function([s])
 
     def _decrypt_signature(self, s, video_id, player_url, age_gate=False):
         """Turn the encrypted s field into a working signature"""
 
         return lambda s: initial_function([s])
 
     def _decrypt_signature(self, s, video_id, player_url, age_gate=False):
         """Turn the encrypted s field into a working signature"""
 
-        if player_url is not None:
-            if player_url.startswith(u'//'):
-                player_url = u'https:' + player_url
-            try:
-                player_id = (player_url, len(s))
-                if player_id not in self._player_cache:
-                    func = self._extract_signature_function(
-                        video_id, player_url, len(s)
-                    )
-                    self._player_cache[player_id] = func
-                func = self._player_cache[player_id]
-                if self._downloader.params.get('youtube_print_sig_code'):
-                    self._print_sig_code(func, len(s))
-                return func(s)
-            except Exception:
-                tb = traceback.format_exc()
-                self._downloader.report_warning(
-                    u'Automatic signature extraction failed: ' + tb)
-
-            self._downloader.report_warning(
-                u'Warning: Falling back to static signature algorithm')
-
-        return self._static_decrypt_signature(
-            s, video_id, player_url, age_gate)
-
-    def _static_decrypt_signature(self, s, video_id, player_url, age_gate):
-        if age_gate:
-            # The videos with age protection use another player, so the
-            # algorithms can be different.
-            if len(s) == 86:
-                return s[2:63] + s[82] + s[64:82] + s[63]
-
-        if len(s) == 93:
-            return s[86:29:-1] + s[88] + s[28:5:-1]
-        elif len(s) == 92:
-            return s[25] + s[3:25] + s[0] + s[26:42] + s[79] + s[43:79] + s[91] + s[80:83]
-        elif len(s) == 91:
-            return s[84:27:-1] + s[86] + s[26:5:-1]
-        elif len(s) == 90:
-            return s[25] + s[3:25] + s[2] + s[26:40] + s[77] + s[41:77] + s[89] + s[78:81]
-        elif len(s) == 89:
-            return s[84:78:-1] + s[87] + s[77:60:-1] + s[0] + s[59:3:-1]
-        elif len(s) == 88:
-            return s[7:28] + s[87] + s[29:45] + s[55] + s[46:55] + s[2] + s[56:87] + s[28]
-        elif len(s) == 87:
-            return s[6:27] + s[4] + s[28:39] + s[27] + s[40:59] + s[2] + s[60:]
-        elif len(s) == 86:
-            return s[80:72:-1] + s[16] + s[71:39:-1] + s[72] + s[38:16:-1] + s[82] + s[15::-1]
-        elif len(s) == 85:
-            return s[3:11] + s[0] + s[12:55] + s[84] + s[56:84]
-        elif len(s) == 84:
-            return s[78:70:-1] + s[14] + s[69:37:-1] + s[70] + s[36:14:-1] + s[80] + s[:14][::-1]
-        elif len(s) == 83:
-            return s[80:63:-1] + s[0] + s[62:0:-1] + s[63]
-        elif len(s) == 82:
-            return s[80:37:-1] + s[7] + s[36:7:-1] + s[0] + s[6:0:-1] + s[37]
-        elif len(s) == 81:
-            return s[56] + s[79:56:-1] + s[41] + s[55:41:-1] + s[80] + s[40:34:-1] + s[0] + s[33:29:-1] + s[34] + s[28:9:-1] + s[29] + s[8:0:-1] + s[9]
-        elif len(s) == 80:
-            return s[1:19] + s[0] + s[20:68] + s[19] + s[69:80]
-        elif len(s) == 79:
-            return s[54] + s[77:54:-1] + s[39] + s[53:39:-1] + s[78] + s[38:34:-1] + s[0] + s[33:29:-1] + s[34] + s[28:9:-1] + s[29] + s[8:0:-1] + s[9]
+        if player_url is None:
+            raise ExtractorError('Cannot decrypt signature without player_url')
 
 
-        else:
-            raise ExtractorError(u'Unable to decrypt signature, key length %d not supported; retrying might work' % (len(s)))
+        if player_url.startswith('//'):
+            player_url = 'https:' + player_url
+        try:
+            player_id = (player_url, self._signature_cache_id(s))
+            if player_id not in self._player_cache:
+                func = self._extract_signature_function(
+                    video_id, player_url, s
+                )
+                self._player_cache[player_id] = func
+            func = self._player_cache[player_id]
+            if self._downloader.params.get('youtube_print_sig_code'):
+                self._print_sig_code(func, s)
+            return func(s)
+        except Exception as e:
+            tb = traceback.format_exc()
+            raise ExtractorError(
+                'Signature extraction failed: ' + tb, cause=e)
 
     def _get_available_subtitles(self, video_id, webpage):
         try:
 
     def _get_available_subtitles(self, video_id, webpage):
         try:
-            sub_list = self._download_webpage(
+            subs_doc = self._download_xml(
                 'https://video.google.com/timedtext?hl=en&type=list&v=%s' % video_id,
                 video_id, note=False)
         except ExtractorError as err:
                 'https://video.google.com/timedtext?hl=en&type=list&v=%s' % video_id,
                 video_id, note=False)
         except ExtractorError as err:
-            self._downloader.report_warning(u'unable to download video subtitles: %s' % compat_str(err))
+            self._downloader.report_warning('unable to download video subtitles: %s' % compat_str(err))
             return {}
             return {}
-        lang_list = re.findall(r'name="([^"]*)"[^>]+lang_code="([\w\-]+)"', sub_list)
 
         sub_lang_list = {}
 
         sub_lang_list = {}
-        for l in lang_list:
-            lang = l[1]
+        for track in subs_doc.findall('track'):
+            lang = track.attrib['lang_code']
+            if lang in sub_lang_list:
+                continue
             params = compat_urllib_parse.urlencode({
                 'lang': lang,
                 'v': video_id,
                 'fmt': self._downloader.params.get('subtitlesformat', 'srt'),
             params = compat_urllib_parse.urlencode({
                 'lang': lang,
                 'v': video_id,
                 'fmt': self._downloader.params.get('subtitlesformat', 'srt'),
-                'name': unescapeHTML(l[0]).encode('utf-8'),
+                'name': track.attrib['name'].encode('utf-8'),
             })
             })
-            url = u'https://www.youtube.com/api/timedtext?' + params
+            url = 'https://www.youtube.com/api/timedtext?' + params
             sub_lang_list[lang] = url
         if not sub_lang_list:
             sub_lang_list[lang] = url
         if not sub_lang_list:
-            self._downloader.report_warning(u'video doesn\'t have subtitles')
+            self._downloader.report_warning('video doesn\'t have subtitles')
             return {}
         return sub_lang_list
 
             return {}
         return sub_lang_list
 
@@ -1043,17 +674,17 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         """We need the webpage for getting the captions url, pass it as an
            argument to speed up the process."""
         sub_format = self._downloader.params.get('subtitlesformat', 'srt')
         """We need the webpage for getting the captions url, pass it as an
            argument to speed up the process."""
         sub_format = self._downloader.params.get('subtitlesformat', 'srt')
-        self.to_screen(u'%s: Looking for automatic captions' % video_id)
+        self.to_screen('%s: Looking for automatic captions' % video_id)
         mobj = re.search(r';ytplayer.config = ({.*?});', webpage)
         mobj = re.search(r';ytplayer.config = ({.*?});', webpage)
-        err_msg = u'Couldn\'t find automatic captions for %s' % video_id
+        err_msg = 'Couldn\'t find automatic captions for %s' % video_id
         if mobj is None:
             self._downloader.report_warning(err_msg)
             return {}
         player_config = json.loads(mobj.group(1))
         try:
         if mobj is 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']
+            args = player_config['args']
+            caption_url = args['ttsurl']
+            timestamp = args['timestamp']
             # We get the available subtitles
             list_params = compat_urllib_parse.urlencode({
                 'type': 'list',
             # We get the available subtitles
             list_params = compat_urllib_parse.urlencode({
                 'type': 'list',
@@ -1063,10 +694,11 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             list_url = caption_url + '&' + list_params
             caption_list = self._download_xml(list_url, video_id)
             original_lang_node = caption_list.find('track')
             list_url = caption_url + '&' + list_params
             caption_list = self._download_xml(list_url, video_id)
             original_lang_node = caption_list.find('track')
-            if original_lang_node is None or original_lang_node.attrib.get('kind') != 'asr' :
-                self._downloader.report_warning(u'Video doesn\'t have automatic captions')
+            if original_lang_node is None:
+                self._downloader.report_warning('Video doesn\'t have automatic captions')
                 return {}
             original_lang = original_lang_node.attrib['lang_code']
                 return {}
             original_lang = original_lang_node.attrib['lang_code']
+            caption_kind = original_lang_node.attrib.get('kind', '')
 
             sub_lang_list = {}
             for lang_node in caption_list.findall('target'):
 
             sub_lang_list = {}
             for lang_node in caption_list.findall('target'):
@@ -1076,7 +708,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                     'tlang': sub_lang,
                     'fmt': sub_format,
                     'ts': timestamp,
                     'tlang': sub_lang,
                     'fmt': sub_format,
                     'ts': timestamp,
-                    'kind': 'asr',
+                    'kind': caption_kind,
                 })
                 sub_lang_list[sub_lang] = caption_url + '&' + params
             return sub_lang_list
                 })
                 sub_lang_list[sub_lang] = caption_url + '&' + params
             return sub_lang_list
@@ -1090,18 +722,19 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
     def extract_id(cls, url):
         mobj = re.match(cls._VALID_URL, url, re.VERBOSE)
         if mobj is None:
     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 = {}
         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('#'),
         def _get_urls(_manifest):
             lines = _manifest.split('\n')
             urls = filter(lambda l: l and not l.startswith('#'),
-                            lines)
+                          lines)
             return urls
             return urls
-        manifest = self._download_webpage(manifest_url, video_id, u'Downloading formats manifest')
+        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')
         formats_urls = _get_urls(manifest)
         for format_url in formats_urls:
             itag = self._search_regex(r'itag/(\d+?)/', format_url, 'itag')
@@ -1110,17 +743,62 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
 
     def _extract_annotations(self, video_id):
         url = 'https://www.youtube.com/annotations_invideo?features=1&legacy=1&video_id=%s' % video_id
 
     def _extract_annotations(self, video_id):
         url = 'https://www.youtube.com/annotations_invideo?features=1&legacy=1&video_id=%s' % video_id
-        return self._download_webpage(url, video_id, note=u'Searching for annotations.', errnote=u'Unable to download video annotations.')
+        return self._download_webpage(url, video_id, note='Searching for annotations.', errnote='Unable to download video annotations.')
+
+    def _parse_dash_manifest(
+            self, video_id, dash_manifest_url, player_url, age_gate):
+        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')
+
+        formats = []
+        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')),
+                'height': int_or_none(r.attrib.get('height')),
+                'tbr': int_or_none(r.attrib.get('bandwidth'), 1000),
+                'asr': int_or_none(r.attrib.get('audioSamplingRate')),
+                'filesize': filesize,
+                'fps': int_or_none(r.attrib.get('frameRate')),
+            }
+            try:
+                existing_format = next(
+                    fo for fo in formats
+                    if fo['format_id'] == format_id)
+            except StopIteration:
+                f.update(self._formats.get(format_id, {}).items())
+                formats.append(f)
+            else:
+                existing_format.update(f)
+        return formats
 
     def _real_extract(self, url):
 
     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:
         # Extract original video URL from URL with redirection, like age verification, using next_url parameter
         mobj = re.search(self._NEXT_URL_RE, url)
         if mobj:
-            url = 'https://www.youtube.com/' + compat_urllib_parse.unquote(mobj.group(1)).lstrip('/')
+            url = proto + '://www.youtube.com/' + compat_urllib_parse.unquote(mobj.group(1)).lstrip('/')
         video_id = self.extract_id(url)
 
         # Get video webpage
         video_id = self.extract_id(url)
 
         # Get video webpage
-        url = 'https://www.youtube.com/watch?v=%s&gl=US&hl=en&has_verified=1' % video_id
+        url = proto + '://www.youtube.com/watch?v=%s&gl=US&hl=en&has_verified=1&bpctr=9999999999' % video_id
         video_webpage = self._download_webpage(url, video_id)
 
         # Attempt to extract SWF player URL
         video_webpage = self._download_webpage(url, video_id)
 
         # Attempt to extract SWF player URL
@@ -1131,41 +809,62 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             player_url = None
 
         # Get video info
             player_url = None
 
         # Get video info
-        self.report_video_info_webpage_download(video_id)
+        embed_webpage = None
         if re.search(r'player-age-gate-content">', video_webpage) is not None:
         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
             age_gate = True
             # We simulate the access to the video from www.youtube.com/v/{video_id}
             # this can be viewed without login into Youtube
-            data = compat_urllib_parse.urlencode({'video_id': video_id,
-                                                  'el': 'player_embedded',
-                                                  'gl': 'US',
-                                                  'hl': 'en',
-                                                  'eurl': 'https://youtube.googleapis.com/v/' + video_id,
-                                                  'asv': 3,
-                                                  'sts':'1588',
-                                                  })
-            video_info_url = 'https://www.youtube.com/get_video_info?' + data
-            video_info_webpage = self._download_webpage(video_info_url, video_id,
-                                    note=False,
-                                    errnote='unable to download video info webpage')
+            url = proto + '://www.youtube.com/embed/%s' % video_id
+            embed_webpage = self._download_webpage(url, video_id, 'Downloading embed webpage')
+            data = compat_urllib_parse.urlencode({
+                'video_id': video_id,
+                'eurl': 'https://youtube.googleapis.com/v/' + video_id,
+                'sts': self._search_regex(
+                    r'"sts"\s*:\s*(\d+)', embed_webpage, 'sts', default=''),
+            })
+            video_info_url = proto + '://www.youtube.com/get_video_info?' + data
+            video_info_webpage = self._download_webpage(
+                video_info_url, video_id,
+                note='Refetching age-gated info webpage',
+                errnote='unable to download video info webpage')
             video_info = compat_parse_qs(video_info_webpage)
         else:
             age_gate = False
             video_info = compat_parse_qs(video_info_webpage)
         else:
             age_gate = False
-            for el_type in ['&el=embedded', '&el=detailpage', '&el=vevo', '']:
-                video_info_url = ('https://www.youtube.com/get_video_info?&video_id=%s%s&ps=default&eurl=&gl=US&hl=en'
-                        % (video_id, el_type))
-                video_info_webpage = self._download_webpage(video_info_url, video_id,
-                                        note=False,
-                                        errnote='unable to download video info webpage')
-                video_info = compat_parse_qs(video_info_webpage)
-                if 'token' in video_info:
-                    break
+            try:
+                # Try looking directly into the video webpage
+                mobj = re.search(r';ytplayer\.config\s*=\s*({.*?});', video_webpage)
+                if not mobj:
+                    raise ValueError('Could not find ytplayer.config')  # caught below
+                json_code = uppercase_escape(mobj.group(1))
+                ytplayer_config = json.loads(json_code)
+                args = ytplayer_config['args']
+                # Convert to the same format returned by compat_parse_qs
+                video_info = dict((k, [v]) for k, v in args.items())
+                if 'url_encoded_fmt_stream_map' not in args:
+                    raise ValueError('No stream_map present')  # caught below
+            except ValueError:
+                # We fallback to the get_video_info pages (used by the embed page)
+                self.report_video_info_webpage_download(video_id)
+                for el_type in ['&el=embedded', '&el=detailpage', '&el=vevo', '']:
+                    video_info_url = (
+                        '%s://www.youtube.com/get_video_info?&video_id=%s%s&ps=default&eurl=&gl=US&hl=en'
+                        % (proto, 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:
         if 'token' not in video_info:
             if 'reason' in video_info:
-                raise ExtractorError(u'YouTube said: %s' % video_info['reason'][0], expected=True)
+                raise ExtractorError(
+                    'YouTube said: %s' % video_info['reason'][0],
+                    expected=True, video_id=video_id)
             else:
             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])
 
         if 'view_count' in video_info:
             view_count = int(video_info['view_count'][0])
@@ -1174,14 +873,14 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
 
         # Check for "rental" videos
         if 'ypc_video_rental_bar_text' in video_info and 'author' not in video_info:
 
         # 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:
 
         # 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
         video_uploader = compat_urllib_parse.unquote_plus(video_info['author'][0])
 
         # uploader_id
@@ -1190,14 +889,14 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         if mobj is not None:
             video_uploader_id = mobj.group(1)
         else:
         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' in video_info:
 
         # title
         if 'title' in video_info:
-            video_title = compat_urllib_parse.unquote_plus(video_info['title'][0])
+            video_title = video_info['title'][0]
         else:
         else:
-            self._downloader.report_warning(u'Unable to extract video title')
-            video_title = u'_'
+            self._downloader.report_warning('Unable to extract video title')
+            video_title = '_'
 
         # thumbnail image
         # We try first to get a high quality image:
 
         # thumbnail image
         # We try first to get a high quality image:
@@ -1206,18 +905,33 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         if m_thumb is not None:
             video_thumbnail = m_thumb.group(1)
         elif 'thumbnail_url' not in video_info:
         if m_thumb is not None:
             video_thumbnail = m_thumb.group(1)
         elif 'thumbnail_url' not in video_info:
-            self._downloader.report_warning(u'unable to extract video thumbnail')
+            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
             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)
 
         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', default=None)
+        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:
         # description
         video_description = get_element_by_id("eow-description", video_webpage)
         if video_description:
@@ -1236,17 +950,17 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             if fd_mobj:
                 video_description = unescapeHTML(fd_mobj.group(1))
             else:
             if fd_mobj:
                 video_description = unescapeHTML(fd_mobj.group(1))
             else:
-                video_description = u''
+                video_description = ''
 
 
-        def _extract_count(klass):
+        def _extract_count(count_name):
             count = self._search_regex(
             count = self._search_regex(
-                r'class="%s">([\d,]+)</span>' % re.escape(klass),
-                video_webpage, klass, default=None)
+                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
             if count is not None:
                 return int(count.replace(',', ''))
             return None
-        like_count = _extract_count(u'likes-count')
-        dislike_count = _extract_count(u'dislikes-count')
+        like_count = _extract_count('like')
+        dislike_count = _extract_count('dislike')
 
         # subtitles
         video_subtitles = self.extract_subtitles(video_id, video_webpage)
 
         # subtitles
         video_subtitles = self.extract_subtitles(video_id, video_webpage)
@@ -1256,7 +970,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             return
 
         if 'length_seconds' not in video_info:
             return
 
         if 'length_seconds' not in video_info:
-            self._downloader.report_warning(u'unable to extract video duration')
+            self._downloader.report_warning('unable to extract video duration')
             video_duration = None
         else:
             video_duration = int(compat_urllib_parse.unquote_plus(video_info['length_seconds'][0]))
             video_duration = None
         else:
             video_duration = int(compat_urllib_parse.unquote_plus(video_info['length_seconds'][0]))
@@ -1264,32 +978,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         # annotations
         video_annotations = None
         if self._downloader.params.get('writeannotations', False):
         # 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)
-            if not mobj:
-                raise ValueError('Could not find vevo ID')
-            info = json.loads(mobj.group(1))
-            args = info['args']
-            # Easy way to know if the 's' value is in url_encoded_fmt_stream_map
-            # this signatures are encrypted
-            if 'url_encoded_fmt_stream_map' not in args:
-                raise ValueError(u'No stream_map present')  # caught below
-            re_signature = re.compile(r'[&,]s=')
-            m_s = re_signature.search(args['url_encoded_fmt_stream_map'])
-            if m_s is not None:
-                self.to_screen(u'%s: Encrypted signatures detected.' % video_id)
-                video_info['url_encoded_fmt_stream_map'] = [args['url_encoded_fmt_stream_map']]
-            m_s = re_signature.search(args.get('adaptive_fmts', u''))
-            if m_s is not None:
-                if 'adaptive_fmts' in video_info:
-                    video_info['adaptive_fmts'][0] += ',' + args['adaptive_fmts']
-                else:
-                    video_info['adaptive_fmts'] = [args['adaptive_fmts']]
-        except ValueError:
-            pass
+            video_annotations = self._extract_annotations(video_id)
 
         def _map_to_format_list(urlmap):
             formats = []
 
         def _map_to_format_list(urlmap):
             formats = []
@@ -1312,158 +1001,250 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                 'url': video_info['conn'][0],
                 'player_url': player_url,
             }]
                 'url': video_info['conn'][0],
                 'player_url': player_url,
             }]
-        elif len(video_info.get('url_encoded_fmt_stream_map', [])) >= 1 or len(video_info.get('adaptive_fmts', [])) >= 1:
-            encoded_url_map = video_info.get('url_encoded_fmt_stream_map', [''])[0] + ',' + video_info.get('adaptive_fmts',[''])[0]
+        elif len(video_info.get('url_encoded_fmt_stream_map', [''])[0]) >= 1 or len(video_info.get('adaptive_fmts', [''])[0]) >= 1:
+            encoded_url_map = video_info.get('url_encoded_fmt_stream_map', [''])[0] + ',' + video_info.get('adaptive_fmts', [''])[0]
             if 'rtmpe%3Dyes' in encoded_url_map:
                 raise ExtractorError('rtmpe downloads are not supported, see https://github.com/rg3/youtube-dl/issues/343 for more information.', expected=True)
             url_map = {}
             for url_data_str in encoded_url_map.split(','):
                 url_data = compat_parse_qs(url_data_str)
             if 'rtmpe%3Dyes' in encoded_url_map:
                 raise ExtractorError('rtmpe downloads are not supported, see https://github.com/rg3/youtube-dl/issues/343 for more information.', expected=True)
             url_map = {}
             for url_data_str in encoded_url_map.split(','):
                 url_data = compat_parse_qs(url_data_str)
-                if 'itag' in url_data and 'url' in url_data:
-                    url = url_data['url'][0]
-                    if 'sig' in url_data:
-                        url += '&signature=' + url_data['sig'][0]
-                    elif 's' in url_data:
-                        encrypted_sig = url_data['s'][0]
-                        if self._downloader.params.get('verbose'):
-                            if age_gate:
-                                if player_url is None:
-                                    player_version = 'unknown'
-                                else:
-                                    player_version = self._search_regex(
-                                        r'-(.+)\.swf$', player_url,
-                                        u'flash player', fatal=False)
+                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]
+                    ASSETS_RE = r'"assets":.+?"js":\s*("[^"]+")'
+
+                    jsplayer_url_json = self._search_regex(
+                        ASSETS_RE,
+                        embed_webpage if age_gate else video_webpage,
+                        'JS player URL (1)', default=None)
+                    if not jsplayer_url_json and not age_gate:
+                        # We need the embed website after all
+                        if embed_webpage is None:
+                            embed_url = proto + '://www.youtube.com/embed/%s' % video_id
+                            embed_webpage = self._download_webpage(
+                                embed_url, video_id, 'Downloading embed webpage')
+                        jsplayer_url_json = self._search_regex(
+                            ASSETS_RE, embed_webpage, 'JS player URL')
+
+                    player_url = json.loads(jsplayer_url_json)
+                    if player_url is None:
+                        player_url_json = self._search_regex(
+                            r'ytplayer\.config.*?"url"\s*:\s*("[^"]+")',
+                            video_webpage, 'age gate player URL')
+                        player_url = json.loads(player_url_json)
+
+                    if 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(
                                 player_desc = 'flash player %s' % player_version
                             else:
                                 player_version = self._search_regex(
-                                    r'html5player-(.+?)\.js', video_webpage,
+                                    r'html5player-([^/]+?)(?:/html5player)?\.js',
+                                    player_url,
                                     'html5 player', fatal=False)
                                     'html5 player', fatal=False)
-                                player_desc = u'html5 player %s' % player_version
-
-                            parts_sizes = u'.'.join(compat_str(len(part)) for part in encrypted_sig.split('.'))
-                            self.to_screen(u'encrypted signature length %d (%s), itag %s, %s' %
-                                (len(encrypted_sig), parts_sizes, url_data['itag'][0], player_desc))
-
-                        if not age_gate:
-                            jsplayer_url_json = self._search_regex(
-                                r'"assets":.+?"js":\s*("[^"]+")',
-                                video_webpage, u'JS player URL')
-                            player_url = json.loads(jsplayer_url_json)
-
-                        signature = self._decrypt_signature(
-                            encrypted_sig, video_id, player_url, age_gate)
-                        url += '&signature=' + signature
-                    if 'ratebypass' not in url:
-                        url += '&ratebypass=yes'
-                    url_map[url_data['itag'][0]] = url
+                                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:
             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, hlsvp or url_encoded_fmt_stream_map information found in video info')
+            raise ExtractorError('no conn, hlsvp or url_encoded_fmt_stream_map information found in video info')
 
         # Look for the DASH manifest
 
         # Look for the DASH manifest
-        dash_manifest_url_lst = video_info.get('dashmpd')
-        if (dash_manifest_url_lst and dash_manifest_url_lst[0] and
-                self._downloader.params.get('youtube_include_dash_manifest', False)):
-            try:
-                dash_doc = self._download_xml(
-                    dash_manifest_url_lst[0], video_id,
-                    note=u'Downloading DASH manifest',
-                    errnote=u'Could not download DASH manifest')
-                for r in dash_doc.findall(u'.//{urn:mpeg:DASH:schema:MPD:2011}Representation'):
-                    url_el = r.find('{urn:mpeg:DASH:schema:MPD:2011}BaseURL')
-                    if url_el is None:
-                        continue
-                    format_id = r.attrib['id']
-                    video_url = url_el.text
-                    filesize = int_or_none(url_el.attrib.get('{http://youtube.com/yt/2012/10/10}contentLength'))
-                    f = {
-                        'format_id': format_id,
-                        'url': video_url,
-                        'width': int_or_none(r.attrib.get('width')),
-                        'tbr': int_or_none(r.attrib.get('bandwidth'), 1000),
-                        'asr': int_or_none(r.attrib.get('audioSamplingRate')),
-                        'filesize': filesize,
-                    }
-                    try:
-                        existing_format = next(
-                            fo for fo in formats
-                            if fo['format_id'] == format_id)
-                    except StopIteration:
-                        f.update(self._formats.get(format_id, {}))
-                        formats.append(f)
-                    else:
-                        existing_format.update(f)
-
-            except (ExtractorError, KeyError) as e:
-                self.report_warning(u'Skipping DASH manifest: %s' % e, video_id)
+        if self._downloader.params.get('youtube_include_dash_manifest', True):
+            dash_mpd = video_info.get('dashmpd')
+            if dash_mpd:
+                dash_manifest_url = dash_mpd[0]
+                try:
+                    dash_formats = self._parse_dash_manifest(
+                        video_id, dash_manifest_url, player_url, age_gate)
+                except (ExtractorError, KeyError) as e:
+                    self.report_warning(
+                        'Skipping DASH manifest: %r' % e, video_id)
+                else:
+                    # Hide the formats we found through non-DASH
+                    dash_keys = set(df['format_id'] for df in dash_formats)
+                    for f in formats:
+                        if f['format_id'] in dash_keys:
+                            f['format_id'] = 'nondash-%s' % f['format_id']
+                            f['preference'] = f.get('preference', 0) - 10000
+                    formats.extend(dash_formats)
+
+        # Check for malformed aspect ratio
+        stretched_m = re.search(
+            r'<meta\s+property="og:video:tag".*?content="yt:stretch=(?P<w>[0-9]+):(?P<h>[0-9]+)">',
+            video_webpage)
+        if stretched_m:
+            ratio = float(stretched_m.group('w')) / float(stretched_m.group('h'))
+            for f in formats:
+                if f.get('vcodec') != 'none':
+                    f['stretched_ratio'] = ratio
 
         self._sort_formats(formats)
 
         return {
 
         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,
-            'subtitles':    video_subtitles,
-            'duration':     video_duration,
-            'age_limit':    18 if age_gate else 0,
-            'annotations':  video_annotations,
-            'webpage_url': 'https://www.youtube.com/watch?v=%s' % video_id,
-            'view_count':   view_count,
+            'id': video_id,
+            'uploader': video_uploader,
+            'uploader_id': video_uploader_id,
+            '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,
             'like_count': like_count,
             'dislike_count': dislike_count,
-            'formats':      formats,
+            'formats': formats,
         }
 
         }
 
+
 class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
 class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
-    IE_DESC = u'YouTube.com playlists'
+    IE_DESC = 'YouTube.com playlists'
     _VALID_URL = r"""(?x)(?:
                         (?:https?://)?
                         (?:\w+\.)?
                         youtube\.com/
                         (?:
     _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/
                         )
                         (
                            \? (?:.*?&)*? (?:p|a|list)=
                         |  p/
                         )
                         (
-                            (?:PL|EC|UU|FL|RD)?[0-9A-Za-z-_]{10,}
-                            # Top tracks, they can also include dots 
+                            (?:PL|LL|EC|UU|FL|RD)?[0-9A-Za-z-_]{10,}
+                            # Top tracks, they can also include dots
                             |(?:MC)[\w\.]*
                         )
                         .*
                      |
                             |(?:MC)[\w\.]*
                         )
                         .*
                      |
-                        ((?:PL|EC|UU|FL|RD)[0-9A-Za-z-_]{10,})
+                        ((?:PL|LL|EC|UU|FL|RD)[0-9A-Za-z-_]{10,})
                      )"""
                      )"""
-    _TEMPLATE_URL = 'https://www.youtube.com/playlist?list=%s&page=%s'
-    _MORE_PAGES_INDICATOR = r'data-link-type="next"'
-    _VIDEO_RE = r'href="/watch\?v=(?P<id>[0-9A-Za-z_-]{11})&amp;[^"]*?index=(?P<index>\d+)'
-    IE_NAME = u'youtube:playlist'
+    _TEMPLATE_URL = 'https://www.youtube.com/playlist?list=%s'
+    _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',
+            'id': 'PLwiyx1dc3P2JR9N8gQaQN_BCvlSlap7re',
+        },
+        'playlist_count': 3,
+    }, {
+        'url': 'https://www.youtube.com/playlist?list=PLtPgu7CB4gbZDA7i_euNxn75ISqxwZPYx',
+        'info_dict': {
+            'id': 'PLtPgu7CB4gbZDA7i_euNxn75ISqxwZPYx',
+            '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',
+            'id': 'PLwP_SiAcdui0KVebT0mU9Apz359a4ubsC',
+        },
+        'playlist_count': 95,
+    }, {
+        'note': 'issue #673',
+        'url': 'PLBB231211A4F62143',
+        'info_dict': {
+            'title': '[OLD]Team Fortress 2 (Class-based LP)',
+            'id': 'PLBB231211A4F62143',
+        },
+        'playlist_mincount': 26,
+    }, {
+        'note': 'Large playlist',
+        'url': 'https://www.youtube.com/playlist?list=UUBABnxM4Ar9ten8Mdjj1j0Q',
+        'info_dict': {
+            'title': 'Uploads from Cauchemar',
+            'id': 'UUBABnxM4Ar9ten8Mdjj1j0Q',
+        },
+        'playlist_mincount': 799,
+    }, {
+        'url': 'PLtPgu7CB4gbY9oDN3drwC3cMbJggS7dKl',
+        'info_dict': {
+            'title': 'YDL_safe_search',
+            'id': 'PLtPgu7CB4gbY9oDN3drwC3cMbJggS7dKl',
+        },
+        'playlist_count': 2,
+    }, {
+        'note': 'embedded',
+        'url': 'http://www.youtube.com/embed/videoseries?list=PL6IaIsEjSbf96XFRuNccS_RuEXwNdsoEu',
+        'playlist_count': 4,
+        'info_dict': {
+            'title': 'JODA15',
+            'id': 'PL6IaIsEjSbf96XFRuNccS_RuEXwNdsoEu',
+        }
+    }, {
+        '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',
+            'id': 'YN5VISEtHet5D4NEvfTd0zcgFk84NqFZ',
+        }
+    }, {
+        'note': 'Buggy playlist: the webpage has a "Load more" button but it doesn\'t have more videos',
+        'url': 'https://www.youtube.com/playlist?list=UUXw-G3eDE9trcvY2sBMM_aA',
+        'info_dict': {
+            'title': 'Uploads from Interstellar Movie',
+            'id': 'UUXw-G3eDE9trcvY2sBMM_aA',
+        },
+        'playlist_mincout': 21,
+    }]
 
     def _real_initialize(self):
         self._login()
 
     def _ids_to_results(self, ids):
 
     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]
+        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)
 
     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, u'Downloading Youtube mix')
-        title_span = (get_element_by_attribute('class', 'title long-title', webpage) or
-            get_element_by_attribute('class', 'title ', webpage))
+        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)
         title = clean_html(title_span)
-        video_re = r'data-index="\d+".*?href="/watch\?v=([0-9A-Za-z_-]{11})&amp;[^"]*?list=%s' % re.escape(playlist_id)
-        ids = orderedSet(re.findall(video_re, webpage))
+        ids = 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)
         url_results = self._ids_to_results(ids)
 
         return self.playlist_result(url_results, playlist_id, title)
@@ -1472,7 +1253,7 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
         # Extract playlist id
         mobj = re.match(self._VALID_URL, url)
         if mobj is None:
         # Extract playlist id
         mobj = re.match(self._VALID_URL, url)
         if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
+            raise ExtractorError('Invalid URL: %s' % url)
         playlist_id = mobj.group(1) or mobj.group(2)
 
         # Check if it's a video-specific URL
         playlist_id = mobj.group(1) or mobj.group(2)
 
         # Check if it's a video-specific URL
@@ -1480,84 +1261,71 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
         if 'v' in query_dict:
             video_id = query_dict['v'][0]
             if self._downloader.params.get('noplaylist'):
         if 'v' in query_dict:
             video_id = query_dict['v'][0]
             if self._downloader.params.get('noplaylist'):
-                self.to_screen(u'Downloading just video %s because of --no-playlist' % video_id)
+                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:
                 return self.url_result(video_id, 'Youtube', video_id=video_id)
             else:
-                self.to_screen(u'Downloading playlist PL%s - add --no-playlist to just download video %s' % (playlist_id, video_id))
+                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('RD'):
             # Mixes require a custom extraction process
             return self._extract_mix(playlist_id)
-        if playlist_id.startswith('TL'):
-            raise ExtractorError(u'For downloading YouTube.com top lists, use '
-                u'the "yttoplist" keyword, for example "youtube-dl \'yttoplist:music:Top Tracks\'"', expected=True)
+
+        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):
 
         # Extract the video ids from the playlist pages
         ids = []
 
         for page_num in itertools.count(1):
-            url = self._TEMPLATE_URL % (playlist_id, page_num)
-            page = self._download_webpage(url, playlist_id, u'Downloading page #%s' % page_num)
-            matches = re.finditer(self._VIDEO_RE, page)
+            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)
 
             # We remove the duplicates and the link with index 0
             # (it's not the first video of the playlist)
             new_ids = orderedSet(m.group('id') for m in matches if m.group('index') != '0')
             ids.extend(new_ids)
 
-            if re.search(self._MORE_PAGES_INDICATOR, page) is None:
+            mobj = re.search(r'data-uix-load-more-href="/?(?P<more>[^"]+)"', more_widget_html)
+            if not mobj:
                 break
 
                 break
 
-        try:
-            playlist_title = self._og_search_title(page)
-        except RegexNotFoundError:
-            self.report_warning(
-                u'Playlist page is missing OpenGraph title, falling back ...',
-                playlist_id)
-            playlist_title = self._html_search_regex(
-                r'<h1 class="pl-header-title">(.*?)</h1>', page, u'title')
-
-        url_results = self._ids_to_results(ids)
-        return self.playlist_result(url_results, playlist_id, playlist_title)
-
+            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']
+            if not content_html.strip():
+                # Some webpages show a "Load more" button but they don't
+                # have more videos
+                break
+            more_widget_html = more['load_more_widget_html']
 
 
-class YoutubeTopListIE(YoutubePlaylistIE):
-    IE_NAME = u'youtube:toplist'
-    IE_DESC = (u'YouTube.com top lists, "yttoplist:{channel}:{list title}"'
-        u' (Example: "yttoplist:music:Top Tracks")')
-    _VALID_URL = r'yttoplist:(?P<chann>.*?):(?P<title>.*?)$'
+        playlist_title = self._html_search_regex(
+            r'(?s)<h1 class="pl-header-title[^"]*">\s*(.*?)\s*</h1>',
+            page, 'title')
 
 
-    def _real_extract(self, url):
-        mobj = re.match(self._VALID_URL, url)
-        channel = mobj.group('chann')
-        title = mobj.group('title')
-        query = compat_urllib_parse.urlencode({'title': title})
-        playlist_re = 'href="([^"]+?%s.*?)"' % re.escape(query)
-        channel_page = self._download_webpage('https://www.youtube.com/%s' % channel, title)
-        link = self._html_search_regex(playlist_re, channel_page, u'list')
-        url = compat_urlparse.urljoin('https://www.youtube.com/', link)
-        
-        video_re = r'data-index="\d+".*?data-video-id="([0-9A-Za-z_-]{11})"'
-        ids = []
-        # sometimes the webpage doesn't contain the videos
-        # retry until we get them
-        for i in itertools.count(0):
-            msg = u'Downloading Youtube mix'
-            if i > 0:
-                msg += ', retry #%d' % i
-            webpage = self._download_webpage(url, title, msg)
-            ids = orderedSet(re.findall(video_re, webpage))
-            if ids:
-                break
         url_results = self._ids_to_results(ids)
         url_results = self._ids_to_results(ids)
-        return self.playlist_result(url_results, playlist_title=title)
+        return self.playlist_result(url_results, playlist_id, playlist_title)
 
 
 class YoutubeChannelIE(InfoExtractor):
 
 
 class YoutubeChannelIE(InfoExtractor):
-    IE_DESC = u'YouTube.com channels'
-    _VALID_URL = r"^(?:https?://)?(?:youtu\.be|(?:\w+\.)?youtube(?:-nocookie)?\.com)/channel/([0-9A-Za-z_-]+)"
-    _MORE_PAGES_INDICATOR = 'yt-uix-load-more'
-    _MORE_PAGES_URL = 'https://www.youtube.com/c4_browse_ajax?action_load_more_videos=1&flow=list&paging=%s&view=0&sort=da&channel_id=%s'
-    IE_NAME = u'youtube:channel'
+    IE_DESC = 'YouTube.com channels'
+    _VALID_URL = r'https?://(?:youtu\.be|(?:\w+\.)?youtube(?:-nocookie)?\.com)/channel/(?P<id>[0-9A-Za-z_-]+)'
+    IE_NAME = 'youtube:channel'
+    _TESTS = [{
+        'note': 'paginated channel',
+        'url': 'https://www.youtube.com/channel/UCKfVa3S1e4PHvxWcwyMMg8w',
+        'playlist_mincount': 91,
+        'info_dict': {
+            'id': 'UCKfVa3S1e4PHvxWcwyMMg8w',
+        }
+    }]
 
     def extract_videos_from_page(self, page):
         ids_in_page = []
 
     def extract_videos_from_page(self, page):
         ids_in_page = []
@@ -1567,13 +1335,8 @@ class YoutubeChannelIE(InfoExtractor):
         return ids_in_page
 
     def _real_extract(self, url):
         return ids_in_page
 
     def _real_extract(self, url):
-        # Extract channel id
-        mobj = re.match(self._VALID_URL, url)
-        if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
+        channel_id = self._match_id(url)
 
 
-        # Download channel page
-        channel_id = mobj.group(1)
         video_ids = []
         url = 'https://www.youtube.com/channel/%s/videos' % channel_id
         channel_page = self._download_webpage(url, channel_id)
         video_ids = []
         url = 'https://www.youtube.com/channel/%s/videos' % channel_id
         channel_page = self._download_webpage(url, channel_id)
@@ -1587,50 +1350,67 @@ class YoutubeChannelIE(InfoExtractor):
             # 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)
             # 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
+            entries = [
+                self.url_result(video_id, 'Youtube', video_id=video_id)
+                for video_id in video_ids]
+            return self.playlist_result(entries, channel_id)
+
+        def _entries():
+            more_widget_html = content_html = channel_page
             for pagenum in itertools.count(1):
             for pagenum in itertools.count(1):
-                url = self._MORE_PAGES_URL % (pagenum, channel_id)
-                page = self._download_json(
-                    url, channel_id, note=u'Downloading page #%s' % pagenum,
-                    transform_source=uppercase_escape)
 
 
-                ids_in_page = self.extract_videos_from_page(page['content_html'])
-                video_ids.extend(ids_in_page)
-    
-                if self._MORE_PAGES_INDICATOR not in page['load_more_widget_html']:
+                ids_in_page = self.extract_videos_from_page(content_html)
+                for video_id in ids_in_page:
+                    yield self.url_result(
+                        video_id, 'Youtube', video_id=video_id)
+
+                mobj = re.search(
+                    r'data-uix-load-more-href="/?(?P<more>[^"]+)"',
+                    more_widget_html)
+                if not mobj:
                     break
 
                     break
 
-        self._downloader.to_screen(u'[youtube] Channel %s: Found %i videos' % (channel_id, len(video_ids)))
+                more = self._download_json(
+                    'https://youtube.com/%s' % mobj.group('more'), channel_id,
+                    'Downloading page #%s' % (pagenum + 1),
+                    transform_source=uppercase_escape)
+                content_html = more['content_html']
+                more_widget_html = more['load_more_widget_html']
 
 
-        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)
+        return self.playlist_result(_entries(), channel_id)
 
 
 class YoutubeUserIE(InfoExtractor):
 
 
 class YoutubeUserIE(InfoExtractor):
-    IE_DESC = u'YouTube.com user videos (URL or "ytuser" keyword)'
-    _VALID_URL = r'(?:(?:(?:https?://)?(?:\w+\.)?youtube\.com/(?:user/)?(?!(?:attribution_link|watch)(?:$|[^a-z_A-Z0-9-])))|ytuser:)(?!feed/)([A-Za-z0-9_-]+)'
+    IE_DESC = 'YouTube.com user videos (URL or "ytuser" keyword)'
+    _VALID_URL = r'(?:(?:(?:https?://)?(?:\w+\.)?youtube\.com/(?:user/)?(?!(?:attribution_link|watch|results)(?:$|[^a-z_A-Z0-9-])))|ytuser:)(?!feed/)(?P<id>[A-Za-z0-9_-]+)'
     _TEMPLATE_URL = 'https://gdata.youtube.com/feeds/api/users/%s'
     _GDATA_PAGE_SIZE = 50
     _GDATA_URL = 'https://gdata.youtube.com/feeds/api/users/%s/uploads?max-results=%d&start-index=%d&alt=json'
     _TEMPLATE_URL = 'https://gdata.youtube.com/feeds/api/users/%s'
     _GDATA_PAGE_SIZE = 50
     _GDATA_URL = 'https://gdata.youtube.com/feeds/api/users/%s/uploads?max-results=%d&start-index=%d&alt=json'
-    IE_NAME = u'youtube:user'
+    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)
 
     @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)
+        if any(ie.suitable(url) for ie in other_ies):
+            return False
+        else:
+            return super(YoutubeUserIE, cls).suitable(url)
 
     def _real_extract(self, 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)
-
-        username = mobj.group(1)
+        username = self._match_id(url)
 
         # Download video ids using YouTube Data API. Result size per
         # query is limited (currently to 50 videos) so we need to query
 
         # Download video ids using YouTube Data API. Result size per
         # query is limited (currently to 50 videos) so we need to query
@@ -1643,13 +1423,13 @@ class YoutubeUserIE(InfoExtractor):
             gdata_url = self._GDATA_URL % (username, self._GDATA_PAGE_SIZE, start_index)
             page = self._download_webpage(
                 gdata_url, username,
             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' % (
+                'Downloading video ids from %d to %d' % (
                     start_index, start_index + self._GDATA_PAGE_SIZE))
 
             try:
                 response = json.loads(page)
             except ValueError as err:
                     start_index, start_index + self._GDATA_PAGE_SIZE))
 
             try:
                 response = json.loads(page)
             except ValueError as err:
-                raise ExtractorError(u'Invalid JSON in API response: ' + compat_str(err))
+                raise ExtractorError('Invalid JSON in API response: ' + compat_str(err))
             if 'entry' not in response['feed']:
                 return
 
             if 'entry' not in response['feed']:
                 return
 
@@ -1665,16 +1445,16 @@ class YoutubeUserIE(InfoExtractor):
                     'id': video_id,
                     'title': title,
                 }
                     'id': video_id,
                     'title': title,
                 }
-        url_results = PagedList(download_page, self._GDATA_PAGE_SIZE)
+        url_results = OnDemandPagedList(download_page, self._GDATA_PAGE_SIZE)
 
         return self.playlist_result(url_results, playlist_title=username)
 
 
 class YoutubeSearchIE(SearchInfoExtractor):
 
         return self.playlist_result(url_results, playlist_title=username)
 
 
 class YoutubeSearchIE(SearchInfoExtractor):
-    IE_DESC = u'YouTube.com searches'
+    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
     _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 _get_n_results(self, query, n):
     _SEARCH_KEY = 'ytsearch'
 
     def _get_n_results(self, query, n):
@@ -1683,19 +1463,22 @@ class YoutubeSearchIE(SearchInfoExtractor):
         video_ids = []
         pagenum = 0
         limit = n
         video_ids = []
         pagenum = 0
         limit = n
+        PAGE_SIZE = 50
 
 
-        while (50 * pagenum) < limit:
-            result_url = self._API_URL % (compat_urllib_parse.quote_plus(query), (50*pagenum)+1)
+        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(
             data_json = self._download_webpage(
-                result_url, video_id=u'query "%s"' % query,
-                note=u'Downloading page %s' % (pagenum + 1),
-                errnote=u'Unable to download API page')
+                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(
             data = json.loads(data_json)
             api_response = data['data']
 
             if 'items' not in api_response:
                 raise ExtractorError(
-                    u'[youtube] No video results', expected=True)
+                    '[youtube] No video results', expected=True)
 
             new_ids = list(video['id'] for video in api_response['items'])
             video_ids += new_ids
 
             new_ids = list(video['id'] for video in api_response['items'])
             video_ids += new_ids
@@ -1709,25 +1492,91 @@ class YoutubeSearchIE(SearchInfoExtractor):
                   for video_id in video_ids]
         return self.playlist_result(videos, query)
 
                   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'
 class YoutubeSearchDateIE(YoutubeSearchIE):
     IE_NAME = YoutubeSearchIE.IE_NAME + ':date'
     _API_URL = 'https://gdata.youtube.com/feeds/api/videos?q=%s&start-index=%i&max-results=50&v=2&alt=jsonc&orderby=published'
     _SEARCH_KEY = 'ytsearchdate'
-    IE_DESC = u'YouTube.com searches, newest videos first'
+    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):
 
 class YoutubeShowIE(InfoExtractor):
-    IE_DESC = u'YouTube.com (multi-season) shows'
-    _VALID_URL = r'https?://www\.youtube\.com/show/(.*)'
-    IE_NAME = u'youtube:show'
+    IE_DESC = 'YouTube.com (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)
 
     def _real_extract(self, url):
         mobj = re.match(self._VALID_URL, url)
-        show_name = mobj.group(1)
-        webpage = self._download_webpage(url, show_name, u'Downloading show webpage')
+        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))
         # There's one playlist for each season of the show
         m_seasons = list(re.finditer(r'href="(/playlist\?list=.*?)"', webpage))
-        self.to_screen(u'%s: Found %s seasons' % (show_name, len(m_seasons)))
-        return [self.url_result('https://www.youtube.com' + season.group(1), 'YoutubePlaylist') for season in m_seasons]
+        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):
 
 
 class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
@@ -1749,7 +1598,7 @@ class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
 
     @property
     def IE_NAME(self):
 
     @property
     def IE_NAME(self):
-        return u'youtube:%s' % self._FEED_NAME
+        return 'youtube:%s' % self._FEED_NAME
 
     def _real_initialize(self):
         self._login()
 
     def _real_initialize(self):
         self._login()
@@ -1758,72 +1607,157 @@ class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
         feed_entries = []
         paging = 0
         for i in itertools.count(1):
         feed_entries = []
         paging = 0
         for i in itertools.count(1):
-            info = self._download_webpage(self._FEED_TEMPLATE % paging,
-                                          u'%s feed' % self._FEED_NAME,
-                                          u'Downloading page %s' % i)
-            info = json.loads(info)
-            feed_html = info['feed_html']
+            info = self._download_json(
+                self._FEED_TEMPLATE % paging,
+                '%s feed' % self._FEED_NAME,
+                'Downloading page %s' % i,
+                transform_source=uppercase_escape)
+            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)
             m_ids = re.finditer(r'"/watch\?v=(.*?)["&]', feed_html)
             ids = orderedSet(m.group(1) for m in m_ids)
             feed_entries.extend(
                 self.url_result(video_id, 'Youtube', video_id=video_id)
                 for video_id in ids)
-            if info['paging'] is None:
+            mobj = re.search(
+                r'data-uix-load-more-href="/?[^"]+paging=(?P<paging>\d+)',
+                load_more_widget_html)
+            if mobj is None:
                 break
                 break
-            paging = info['paging']
+            paging = mobj.group('paging')
         return self.playlist_result(feed_entries, playlist_title=self._PLAYLIST_TITLE)
 
         return self.playlist_result(feed_entries, playlist_title=self._PLAYLIST_TITLE)
 
-class YoutubeSubscriptionsIE(YoutubeFeedsInfoExtractor):
-    IE_DESC = u'YouTube.com subscriptions feed, "ytsubs" keyword(requires authentication)'
-    _VALID_URL = r'https?://www\.youtube\.com/feed/subscriptions|:ytsubs(?:criptions)?'
-    _FEED_NAME = 'subscriptions'
-    _PLAYLIST_TITLE = u'Youtube Subscriptions'
 
 class YoutubeRecommendedIE(YoutubeFeedsInfoExtractor):
 
 class YoutubeRecommendedIE(YoutubeFeedsInfoExtractor):
-    IE_DESC = u'YouTube.com recommended videos, "ytrec" keyword (requires authentication)'
+    IE_DESC = 'YouTube.com recommended videos, ":ytrec" for short (requires authentication)'
     _VALID_URL = r'https?://www\.youtube\.com/feed/recommended|:ytrec(?:ommended)?'
     _FEED_NAME = 'recommended'
     _VALID_URL = r'https?://www\.youtube\.com/feed/recommended|:ytrec(?:ommended)?'
     _FEED_NAME = 'recommended'
-    _PLAYLIST_TITLE = u'Youtube Recommended videos'
+    _PLAYLIST_TITLE = 'Youtube Recommended videos'
+
 
 class YoutubeWatchLaterIE(YoutubeFeedsInfoExtractor):
 
 class YoutubeWatchLaterIE(YoutubeFeedsInfoExtractor):
-    IE_DESC = u'Youtube watch later list, "ytwatchlater" keyword (requires authentication)'
+    IE_DESC = 'Youtube watch later list, ":ytwatchlater" for short (requires authentication)'
     _VALID_URL = r'https?://www\.youtube\.com/feed/watch_later|:ytwatchlater'
     _FEED_NAME = 'watch_later'
     _VALID_URL = r'https?://www\.youtube\.com/feed/watch_later|:ytwatchlater'
     _FEED_NAME = 'watch_later'
-    _PLAYLIST_TITLE = u'Youtube Watch Later'
+    _PLAYLIST_TITLE = 'Youtube Watch Later'
     _PERSONAL_FEED = True
 
     _PERSONAL_FEED = True
 
+
 class YoutubeHistoryIE(YoutubeFeedsInfoExtractor):
 class YoutubeHistoryIE(YoutubeFeedsInfoExtractor):
-    IE_DESC = u'Youtube watch history, "ythistory" keyword (requires authentication)'
-    _VALID_URL = u'https?://www\.youtube\.com/feed/history|:ythistory'
+    IE_DESC = 'Youtube watch history, ":ythistory" for short (requires authentication)'
+    _VALID_URL = 'https?://www\.youtube\.com/feed/history|:ythistory'
     _FEED_NAME = 'history'
     _PERSONAL_FEED = True
     _FEED_NAME = 'history'
     _PERSONAL_FEED = True
-    _PLAYLIST_TITLE = u'Youtube Watch History'
+    _PLAYLIST_TITLE = 'Youtube Watch History'
+
 
 class YoutubeFavouritesIE(YoutubeBaseInfoExtractor):
 
 class YoutubeFavouritesIE(YoutubeBaseInfoExtractor):
-    IE_NAME = u'youtube:favorites'
-    IE_DESC = u'YouTube.com favourite videos, "ytfav" keyword (requires authentication)'
+    IE_NAME = 'youtube:favorites'
+    IE_DESC = 'YouTube.com favourite videos, ":ytfav" for short (requires authentication)'
     _VALID_URL = r'https?://www\.youtube\.com/my_favorites|:ytfav(?:ou?rites)?'
     _LOGIN_REQUIRED = True
 
     def _real_extract(self, url):
         webpage = self._download_webpage('https://www.youtube.com/my_favorites', 'Youtube Favourites videos')
     _VALID_URL = r'https?://www\.youtube\.com/my_favorites|:ytfav(?:ou?rites)?'
     _LOGIN_REQUIRED = True
 
     def _real_extract(self, url):
         webpage = self._download_webpage('https://www.youtube.com/my_favorites', 'Youtube Favourites videos')
-        playlist_id = self._search_regex(r'list=(.+?)["&]', webpage, u'favourites playlist id')
+        playlist_id = self._search_regex(r'list=(.+?)["&]', webpage, 'favourites playlist id')
         return self.url_result(playlist_id, 'YoutubePlaylist')
 
 
         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)
 class YoutubeTruncatedURLIE(InfoExtractor):
     IE_NAME = 'youtube:truncated_url'
     IE_DESC = False  # Do not list
     _VALID_URL = r'''(?x)
-        (?:https?://)?[^/]+/watch\?feature=[a-z_]+$|
-        (?:https?://)?(?:www\.)?youtube\.com/attribution_link\?a=[^&]+$
+        (?:https?://)?
+        (?:\w+\.)?[yY][oO][uU][tT][uU][bB][eE](?:-nocookie)?\.com/
+        (?:watch\?(?:
+            feature=[a-z_]+|
+            annotation_id=annotation_[^&]+|
+            x-yt-cl=[0-9]+|
+            hl=[^&]*|
+        )?
+        |
+            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,
+    }, {
+        'url': 'https://www.youtube.com/watch?x-yt-cl=84503534',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/watch?feature=foo',
+        'only_matching': True,
+    }, {
+        'url': 'https://www.youtube.com/watch?hl=en-GB',
+        'only_matching': True,
+    }]
+
+    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)
+
+
+class YoutubeTruncatedIDIE(InfoExtractor):
+    IE_NAME = 'youtube:truncated_id'
+    IE_DESC = False  # Do not list
+    _VALID_URL = r'https?://(?:www\.)?youtube\.com/watch\?v=(?P<id>[0-9A-Za-z_-]{1,10})$'
+
+    _TESTS = [{
+        'url': 'https://www.youtube.com/watch?v=N_708QY7Ob',
+        'only_matching': True,
+    }]
+
     def _real_extract(self, url):
     def _real_extract(self, url):
+        video_id = self._match_id(url)
         raise ExtractorError(
         raise ExtractorError(
-            u'Did you forget to quote the URL? Remember that & is a meta '
-            u'character in most shells, so you want to put the URL in quotes, '
-            u'like  youtube-dl '
-            u'"http://www.youtube.com/watch?feature=foo&v=BaW_jenozKc" '
-            u' or simply  youtube-dl BaW_jenozKc  .',
+            'Incomplete YouTube ID %s. URL %s looks truncated.' % (video_id, url),
             expected=True)
             expected=True)