]> Raphaël G. Git Repositories - youtubedl/blobdiff - youtube_dl/extractor/youtube.py
Prepare for upload.
[youtubedl] / youtube_dl / extractor / youtube.py
index d45545ee490867d8f2e89d5c36e038364281a72d..6071d72452655f0db74c104ec257cfbe434ad137 100644 (file)
@@ -1,19 +1,18 @@
 # coding: utf-8
 
-import collections
-import errno
-import io
+from __future__ import unicode_literals
+
+
 import itertools
 import json
 import os.path
 import re
-import struct
 import traceback
-import zlib
 
 from .common import InfoExtractor, SearchInfoExtractor
 from .subtitles import SubtitlesInfoExtractor
 from ..jsinterp import JSInterpreter
+from ..swfinterp import SWFInterpreter
 from ..utils import (
     compat_chr,
     compat_parse_qs,
@@ -23,22 +22,21 @@ from ..utils import (
     compat_str,
 
     clean_html,
-    get_cachedir,
     get_element_by_id,
     get_element_by_attribute,
     ExtractorError,
     int_or_none,
-    PagedList,
+    OnDemandPagedList,
     unescapeHTML,
     unified_strdate,
     orderedSet,
-    write_json_file,
     uppercase_escape,
 )
 
 class YoutubeBaseInfoExtractor(InfoExtractor):
     """Provide base functions for Youtube extractors"""
     _LOGIN_URL = 'https://accounts.google.com/ServiceLogin'
+    _TWOFACTOR_URL = 'https://accounts.google.com/SecondFactor'
     _LANG_URL = r'https://www.youtube.com/?hl=en&persist_hl=1&gl=US&persist_gl=1&opt_out_ackd=1'
     _AGE_URL = 'https://www.youtube.com/verify_age?next_url=/&gl=US&hl=en'
     _NETRC_MACHINE = 'youtube'
@@ -48,48 +46,57 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
     def _set_language(self):
         return bool(self._download_webpage(
             self._LANG_URL, None,
-            note=u'Setting language', errnote='unable to set language',
+            note='Setting language', errnote='unable to set language',
             fatal=False))
 
     def _login(self):
+        """
+        Attempt to log in to YouTube.
+        True is returned if successful or skipped.
+        False is returned if login failed.
+
+        If _LOGIN_REQUIRED is set and no authentication was provided, an error is raised.
+        """
         (username, password) = self._get_login_info()
         # No authentication to be performed
         if username is None:
             if self._LOGIN_REQUIRED:
-                raise ExtractorError(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,
-            note=u'Downloading login page',
-            errnote=u'unable to fetch login page', fatal=False)
+            note='Downloading login page',
+            errnote='unable to fetch login page', fatal=False)
         if login_page is False:
             return
 
         galx = self._search_regex(r'(?s)<input.+?name="GALX".+?value="(.+?)"',
-                                  login_page, u'Login GALX parameter')
+                                  login_page, 'Login GALX parameter')
 
         # Log in
         login_form_strs = {
-                u'continue': u'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
-                u'Email': username,
-                u'GALX': galx,
-                u'Passwd': password,
-                u'PersistentCookie': u'yes',
-                u'_utf8': u'霱',
-                u'bgresponse': u'js_disabled',
-                u'checkConnection': u'',
-                u'checkedDomains': u'youtube',
-                u'dnConn': u'',
-                u'pstMsg': u'0',
-                u'rmShown': u'1',
-                u'secTok': u'',
-                u'signIn': u'Sign in',
-                u'timeStmp': u'',
-                u'service': u'youtube',
-                u'uilel': u'3',
-                u'hl': u'en_US',
+                'continue': 'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
+                'Email': username,
+                'GALX': galx,
+                'Passwd': password,
+
+                'PersistentCookie': 'yes',
+                '_utf8': '霱',
+                'bgresponse': 'js_disabled',
+                'checkConnection': '',
+                'checkedDomains': 'youtube',
+                'dnConn': '',
+                'pstMsg': '0',
+                'rmShown': '1',
+                'secTok': '',
+                'signIn': 'Sign in',
+                'timeStmp': '',
+                'service': 'youtube',
+                'uilel': '3',
+                'hl': 'en_US',
         }
+
         # Convert to UTF-8 *before* urlencode because Python 2.x's urlencode
         # chokes on unicode
         login_form = dict((k.encode('utf-8'), v.encode('utf-8')) for k,v in login_form_strs.items())
@@ -98,11 +105,73 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
         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 re.search(r'id="errormsg_0_Passwd"', login_results) is not None:
+            raise ExtractorError('Please use your account password and a two-factor code instead of an application-specific password.', expected=True)
+
+        # Two-Factor
+        # TODO add SMS and phone call support - these require making a request and then prompting the user
+
+        if re.search(r'(?i)<form[^>]* id="gaia_secondfactorform"', login_results) is not None:
+            tfa_code = self._get_tfa_info()
+
+            if tfa_code is None:
+                self._downloader.report_warning('Two-factor authentication required. Provide it with --twofactor <code>')
+                self._downloader.report_warning('(Note that only TOTP (Google Authenticator App) codes work at this time.)')
+                return False
+
+            # Unlike the first login form, secTok and timeStmp are both required for the TFA form
+
+            match = re.search(r'id="secTok"\n\s+value=\'(.+)\'/>', login_results, re.M | re.U)
+            if match is None:
+                self._downloader.report_warning('Failed to get secTok - did the page structure change?')
+            secTok = match.group(1)
+            match = re.search(r'id="timeStmp"\n\s+value=\'(.+)\'/>', login_results, re.M | re.U)
+            if match is None:
+                self._downloader.report_warning('Failed to get timeStmp - did the page structure change?')
+            timeStmp = match.group(1)
+
+            tfa_form_strs = {
+                'continue': 'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
+                'smsToken': '',
+                'smsUserPin': tfa_code,
+                'smsVerifyPin': 'Verify',
+
+                'PersistentCookie': 'yes',
+                'checkConnection': '',
+                'checkedDomains': 'youtube',
+                'pstMsg': '1',
+                'secTok': secTok,
+                'timeStmp': timeStmp,
+                'service': 'youtube',
+                'hl': 'en_US',
+            }
+            tfa_form = dict((k.encode('utf-8'), v.encode('utf-8')) for k,v in tfa_form_strs.items())
+            tfa_data = compat_urllib_parse.urlencode(tfa_form).encode('ascii')
+
+            tfa_req = compat_urllib_request.Request(self._TWOFACTOR_URL, tfa_data)
+            tfa_results = self._download_webpage(
+                tfa_req, None,
+                note='Submitting TFA code', errnote='unable to submit tfa', fatal=False)
+
+            if tfa_results is False:
+                return False
+
+            if re.search(r'(?i)<form[^>]* id="gaia_secondfactorform"', tfa_results) is not None:
+                self._downloader.report_warning('Two-factor code expired. Please try again, or use a one-use backup code instead.')
+                return False
+            if re.search(r'(?i)<form[^>]* id="gaia_loginform"', tfa_results) is not None:
+                self._downloader.report_warning('unable to log in - did the page structure change?')
+                return False
+            if re.search(r'smsauth-interstitial-reviewsettings', tfa_results) is not None:
+                self._downloader.report_warning('Your Google account has a security notice. Please log in on your web browser, resolve the notice, and try again.')
+                return False
+
         if re.search(r'(?i)<form[^>]* id="gaia_loginform"', login_results) is not None:
-            self._downloader.report_warning(u'unable to log in: bad username or password')
+            self._downloader.report_warning('unable to log in: bad username or password')
             return False
         return True
 
@@ -116,24 +185,25 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
 
         self._download_webpage(
             req, None,
-            note=u'Confirming age', errnote=u'Unable to confirm age')
-        return True
+            note='Confirming age', errnote='Unable to confirm age',
+            fatal=False)
 
     def _real_initialize(self):
         if self._downloader is None:
             return
-        if not self._set_language():
-            return
+        if self._get_login_info()[0] is not None:
+            if not self._set_language():
+                return
         if not self._login():
             return
         self._confirm_age()
 
 
 class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
-    IE_DESC = u'YouTube.com'
+    IE_DESC = 'YouTube.com'
     _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/|
@@ -142,7 +212,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                             youtube\.googleapis\.com/)                        # the various hostnames, with wildcard subdomains
                          (?:.*?\#/)?                                          # handle anchor (#/) redirect urls
                          (?:                                                  # the various things that can precede the ID:
-                             (?:(?:v|embed|e)/)                               # v/ or embed/ or e/
+                             (?:(?:v|embed|e)/(?!videoseries))                # v/ or embed/ or e/
                              |(?:                                             # or the v= param in all its forms
                                  (?:(?:watch|movie)(?:_popup)?(?:\.php)?/?)?  # preceding watch(_popup|.php) or nothing (like /?v=xxxx)
                                  (?:\?|\#!?)                                  # the params delimiter ? or # or #!
@@ -151,10 +221,11 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                              )
                          ))
                          |youtu\.be/                                          # just youtu.be/xxxx
-                         |https?://(?:www\.)?cleanvideosearch\.com/media/action/yt/watch\?videoId=
+                         |(?: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
+                     (?!.*?&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=([^&]+)'
@@ -216,6 +287,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         '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},
@@ -224,191 +296,188 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         '247': {'ext': 'webm', 'height': 720, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
         '248': {'ext': 'webm', 'height': 1080, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
         '271': {'ext': 'webm', 'height': 1440, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '272': {'ext': 'webm', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
+        '302': {'ext': 'webm', 'height': 720, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'VP9'},
+        '303': {'ext': 'webm', 'height': 1080, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'VP9'},
 
         # Dash webm audio
-        '171': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH audio', 'abr': 48, '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 mov
+        '298': {'ext': 'mov', 'height': 720, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'h264'},
+        '299': {'ext': 'mov', 'height': 1080, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'fps': 60, 'vcodec': 'h264'},
+        '266': {'ext': 'mov', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40, 'vcodec': 'h264'},
+
         # RTMP (unnamed)
         '_rtmp': {'protocol': 'rtmp'},
     }
 
-    IE_NAME = u'youtube'
+    IE_NAME = 'youtube'
     _TESTS = [
         {
-            u"url":  u"http://www.youtube.com/watch?v=BaW_jenozKc",
-            u"file":  u"BaW_jenozKc.mp4",
-            u"info_dict": {
-                u"title": u"youtube-dl test video \"'/\\ä↭𝕐",
-                u"uploader": u"Philipp Hagemeister",
-                u"uploader_id": u"phihag",
-                u"upload_date": u"20121002",
-                u"description": u"test chars:  \"'/\\ä↭𝕐\ntest URL: https://github.com/rg3/youtube-dl/issues/1892\n\nThis is a test video for youtube-dl.\n\nFor more information, contact phihag@phihag.de .",
-                u"categories": [u'Science & Technology'],
+            '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:fea86fda2d5a5784273df5c7cc994d9f",
-                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'
             },
-            u"params": {
-                u"youtube_include_dash_manifest": True,
-                u"format": "141",
+            'params': {
+                'youtube_include_dash_manifest': True,
+                'format': '141',
             },
         },
         # DASH manifest with encrypted signature
         {
-            u'url': u'https://www.youtube.com/watch?v=IB3lcPjvWLA',
-            u'info_dict': {
-                u'id': u'IB3lcPjvWLA',
-                u'ext': u'm4a',
-                u'title': u'Afrojack - The Spark ft. Spree Wilson',
-                u'description': u'md5:9717375db5a9a3992be4668bbf3bc0a8',
-                u'uploader': u'AfrojackVEVO',
-                u'uploader_id': u'AfrojackVEVO',
-                u'upload_date': u'20131011',
+            'url': 'https://www.youtube.com/watch?v=IB3lcPjvWLA',
+            'info_dict': {
+                'id': 'IB3lcPjvWLA',
+                'ext': 'm4a',
+                'title': 'Afrojack - The Spark ft. Spree Wilson',
+                'description': 'md5:9717375db5a9a3992be4668bbf3bc0a8',
+                'uploader': 'AfrojackVEVO',
+                'uploader_id': 'AfrojackVEVO',
+                'upload_date': '20131011',
             },
-            u"params": {
-                u'youtube_include_dash_manifest': True,
-                u'format': '141',
+            'params': {
+                'youtube_include_dash_manifest': True,
+                'format': '141',
             },
         },
     ]
 
-
-    @classmethod
-    def suitable(cls, url):
-        """Receives a URL and returns True if suitable for this IE."""
-        if YoutubePlaylistIE.suitable(url): return False
-        return re.match(cls._VALID_URL, url) is not None
-
     def __init__(self, *args, **kwargs):
         super(YoutubeIE, self).__init__(*args, **kwargs)
         self._player_cache = {}
 
     def report_video_info_webpage_download(self, video_id):
         """Report attempt to download video info webpage."""
-        self.to_screen(u'%s: Downloading video info webpage' % video_id)
+        self.to_screen('%s: Downloading video info webpage' % video_id)
 
     def report_information_extraction(self, video_id):
         """Report attempt to extract video information."""
-        self.to_screen(u'%s: Extracting video information' % video_id)
+        self.to_screen('%s: Extracting video information' % video_id)
 
     def report_unavailable_format(self, video_id, format):
         """Report extracted video URL."""
-        self.to_screen(u'%s: Format %s not available' % (video_id, format))
+        self.to_screen('%s: Format %s not available' % (video_id, format))
 
     def report_rtmp_download(self):
         """Indicate the download will use the RTMP protocol."""
-        self.to_screen(u'RTMP download detected')
-
-    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
-        func_id = '%s_%s_%d' % (player_type, player_id, slen)
+        func_id = '%s_%s_%s' % (
+            player_type, player_id, self._signature_cache_id(example_sig))
         assert os.path.basename(func_id) == func_id
-        cache_dir = get_cachedir(self._downloader.params)
 
-        cache_enabled = cache_dir is not None
-        if cache_enabled:
-            cache_fn = os.path.join(os.path.expanduser(cache_dir),
-                                    u'youtube-sigfuncs',
-                                    func_id + '.json')
-            try:
-                with io.open(cache_fn, 'r', encoding='utf-8') as cachef:
-                    cache_spec = json.load(cachef)
-                return lambda s: u''.join(s[i] for i in cache_spec)
-            except IOError:
-                pass  # No cache available
+        cache_spec = self._downloader.cache.load('youtube-sigfuncs', func_id)
+        if cache_spec is not None:
+            return lambda s: ''.join(s[i] for i in cache_spec)
 
         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,
-                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
 
-        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
 
-    def _print_sig_code(self, func, slen):
+    def _print_sig_code(self, func, example_sig):
         def gen_sig_code(idxs):
             def _genslice(start, end, step):
-                starts = u'' if start == 0 else str(start)
-                ends = (u':%d' % (end+step)) if end + step >= 0 else u':'
-                steps = u'' if step == 1 else (u':%d' % step)
-                return u's[%s%s%s]' % (starts, ends, steps)
+                starts = '' if start == 0 else str(start)
+                ends = (':%d' % (end+step)) if end + step >= 0 else ':'
+                steps = '' if step == 1 else (':%d' % step)
+                return 's[%s%s%s]' % (starts, ends, steps)
 
             step = None
             start = '(Never used)'  # Quelch pyflakes warnings - start will be
@@ -425,510 +494,61 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                     start = prev
                     continue
                 else:
-                    yield u's[%d]' % prev
+                    yield 's[%d]' % prev
             if step is None:
-                yield u's[%d]' % i
+                yield 's[%d]' % i
             else:
                 yield _genslice(start, i, step)
 
-        test_string = u''.join(map(compat_chr, range(slen)))
+        test_string = ''.join(map(compat_chr, range(len(example_sig))))
         cache_res = func(test_string)
         cache_spec = [ord(c) for c in cache_res]
-        expr_code = u' + '.join(gen_sig_code(cache_spec))
-        code = u'if len(s) == %d:\n    return %s\n' % (slen, expr_code)
-        self.to_screen(u'Extracted signature function:\n' + code)
+        expr_code = ' + '.join(gen_sig_code(cache_spec))
+        signature_id_tuple = '(%s)' % (
+            ', '.join(compat_str(len(p)) for p in example_sig.split('.')))
+        code = ('if tuple(len(p) for p in s.split(\'.\')) == %s:\n'
+                '    return %s\n') % (signature_id_tuple, expr_code)
+        self.to_screen('Extracted signature function:\n' + code)
 
     def _parse_sig_js(self, jscode):
         funcname = self._search_regex(
             r'signature=([$a-zA-Z]+)', jscode,
-             u'Initial JS player signature function name')
+             '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):
-        if file_contents[1:3] != b'WS':
-            raise ExtractorError(
-                u'Not an SWF file; header is %r' % file_contents[:3])
-        if file_contents[:1] == b'C':
-            content = zlib.decompress(file_contents[8:])
-        else:
-            raise NotImplementedError(u'Unsupported compression format %r' %
-                                      file_contents[:1])
-
-        def extract_tags(content):
-            pos = 0
-            while pos < len(content):
-                header16 = struct.unpack('<H', content[pos:pos+2])[0]
-                pos += 2
-                tag_code = header16 >> 6
-                tag_len = header16 & 0x3f
-                if tag_len == 0x3f:
-                    tag_len = struct.unpack('<I', content[pos:pos+4])[0]
-                    pos += 4
-                assert pos+tag_len <= len(content)
-                yield (tag_code, content[pos:pos+tag_len])
-                pos += tag_len
-
-        code_tag = next(tag
-                        for tag_code, tag in extract_tags(content)
-                        if tag_code == 82)
-        p = code_tag.index(b'\0', 4) + 1
-        code_reader = io.BytesIO(code_tag[p:])
-
-        # Parse ABC (AVM2 ByteCode)
-        def read_int(reader=None):
-            if reader is None:
-                reader = code_reader
-            res = 0
-            shift = 0
-            for _ in range(5):
-                buf = reader.read(1)
-                assert len(buf) == 1
-                b = struct.unpack('<B', buf)[0]
-                res = res | ((b & 0x7f) << shift)
-                if b & 0x80 == 0:
-                    break
-                shift += 7
-            return res
-
-        def u30(reader=None):
-            res = read_int(reader)
-            assert res & 0xf0000000 == 0
-            return res
-        u32 = read_int
-
-        def s32(reader=None):
-            v = read_int(reader)
-            if v & 0x80000000 != 0:
-                v = - ((v ^ 0xffffffff) + 1)
-            return v
-
-        def read_string(reader=None):
-            if reader is None:
-                reader = code_reader
-            slen = u30(reader)
-            resb = reader.read(slen)
-            assert len(resb) == slen
-            return resb.decode('utf-8')
-
-        def read_bytes(count, reader=None):
-            if reader is None:
-                reader = code_reader
-            resb = reader.read(count)
-            assert len(resb) == count
-            return resb
-
-        def read_byte(reader=None):
-            resb = read_bytes(1, reader=reader)
-            res = struct.unpack('<B', resb)[0]
-            return res
-
-        # minor_version + major_version
-        read_bytes(2 + 2)
-
-        # Constant pool
-        int_count = u30()
-        for _c in range(1, int_count):
-            s32()
-        uint_count = u30()
-        for _c in range(1, uint_count):
-            u32()
-        double_count = u30()
-        read_bytes((double_count-1) * 8)
-        string_count = u30()
-        constant_strings = [u'']
-        for _c in range(1, string_count):
-            s = read_string()
-            constant_strings.append(s)
-        namespace_count = u30()
-        for _c in range(1, namespace_count):
-            read_bytes(1)  # kind
-            u30()  # name
-        ns_set_count = u30()
-        for _c in range(1, ns_set_count):
-            count = u30()
-            for _c2 in range(count):
-                u30()
-        multiname_count = u30()
-        MULTINAME_SIZES = {
-            0x07: 2,  # QName
-            0x0d: 2,  # QNameA
-            0x0f: 1,  # RTQName
-            0x10: 1,  # RTQNameA
-            0x11: 0,  # RTQNameL
-            0x12: 0,  # RTQNameLA
-            0x09: 2,  # Multiname
-            0x0e: 2,  # MultinameA
-            0x1b: 1,  # MultinameL
-            0x1c: 1,  # MultinameLA
-        }
-        multinames = [u'']
-        for _c in range(1, multiname_count):
-            kind = u30()
-            assert kind in MULTINAME_SIZES, u'Invalid multiname kind %r' % kind
-            if kind == 0x07:
-                u30()  # namespace_idx
-                name_idx = u30()
-                multinames.append(constant_strings[name_idx])
-            else:
-                multinames.append('[MULTINAME kind: %d]' % kind)
-                for _c2 in range(MULTINAME_SIZES[kind]):
-                    u30()
-
-        # Methods
-        method_count = u30()
-        MethodInfo = collections.namedtuple(
-            'MethodInfo',
-            ['NEED_ARGUMENTS', 'NEED_REST'])
-        method_infos = []
-        for method_id in range(method_count):
-            param_count = u30()
-            u30()  # return type
-            for _ in range(param_count):
-                u30()  # param type
-            u30()  # name index (always 0 for youtube)
-            flags = read_byte()
-            if flags & 0x08 != 0:
-                # Options present
-                option_count = u30()
-                for c in range(option_count):
-                    u30()  # val
-                    read_bytes(1)  # kind
-            if flags & 0x80 != 0:
-                # Param names present
-                for _ in range(param_count):
-                    u30()  # param name
-            mi = MethodInfo(flags & 0x01 != 0, flags & 0x04 != 0)
-            method_infos.append(mi)
-
-        # Metadata
-        metadata_count = u30()
-        for _c in range(metadata_count):
-            u30()  # name
-            item_count = u30()
-            for _c2 in range(item_count):
-                u30()  # key
-                u30()  # value
-
-        def parse_traits_info():
-            trait_name_idx = u30()
-            kind_full = read_byte()
-            kind = kind_full & 0x0f
-            attrs = kind_full >> 4
-            methods = {}
-            if kind in [0x00, 0x06]:  # Slot or Const
-                u30()  # Slot id
-                u30()  # type_name_idx
-                vindex = u30()
-                if vindex != 0:
-                    read_byte()  # vkind
-            elif kind in [0x01, 0x02, 0x03]:  # Method / Getter / Setter
-                u30()  # disp_id
-                method_idx = u30()
-                methods[multinames[trait_name_idx]] = method_idx
-            elif kind == 0x04:  # Class
-                u30()  # slot_id
-                u30()  # classi
-            elif kind == 0x05:  # Function
-                u30()  # slot_id
-                function_idx = u30()
-                methods[function_idx] = multinames[trait_name_idx]
-            else:
-                raise ExtractorError(u'Unsupported trait kind %d' % kind)
-
-            if attrs & 0x4 != 0:  # Metadata present
-                metadata_count = u30()
-                for _c3 in range(metadata_count):
-                    u30()  # metadata index
-
-            return methods
-
-        # Classes
-        TARGET_CLASSNAME = u'SignatureDecipher'
-        searched_idx = multinames.index(TARGET_CLASSNAME)
-        searched_class_id = None
-        class_count = u30()
-        for class_id in range(class_count):
-            name_idx = u30()
-            if name_idx == searched_idx:
-                # We found the class we're looking for!
-                searched_class_id = class_id
-            u30()  # super_name idx
-            flags = read_byte()
-            if flags & 0x08 != 0:  # Protected namespace is present
-                u30()  # protected_ns_idx
-            intrf_count = u30()
-            for _c2 in range(intrf_count):
-                u30()
-            u30()  # iinit
-            trait_count = u30()
-            for _c2 in range(trait_count):
-                parse_traits_info()
-
-        if searched_class_id is None:
-            raise ExtractorError(u'Target class %r not found' %
-                                 TARGET_CLASSNAME)
-
-        method_names = {}
-        method_idxs = {}
-        for class_id in range(class_count):
-            u30()  # cinit
-            trait_count = u30()
-            for _c2 in range(trait_count):
-                trait_methods = parse_traits_info()
-                if class_id == searched_class_id:
-                    method_names.update(trait_methods.items())
-                    method_idxs.update(dict(
-                        (idx, name)
-                        for name, idx in trait_methods.items()))
-
-        # Scripts
-        script_count = u30()
-        for _c in range(script_count):
-            u30()  # init
-            trait_count = u30()
-            for _c2 in range(trait_count):
-                parse_traits_info()
-
-        # Method bodies
-        method_body_count = u30()
-        Method = collections.namedtuple('Method', ['code', 'local_count'])
-        methods = {}
-        for _c in range(method_body_count):
-            method_idx = u30()
-            u30()  # max_stack
-            local_count = u30()
-            u30()  # init_scope_depth
-            u30()  # max_scope_depth
-            code_length = u30()
-            code = read_bytes(code_length)
-            if method_idx in method_idxs:
-                m = Method(code, local_count)
-                methods[method_idxs[method_idx]] = m
-            exception_count = u30()
-            for _c2 in range(exception_count):
-                u30()  # from
-                u30()  # to
-                u30()  # target
-                u30()  # exc_type
-                u30()  # var_name
-            trait_count = u30()
-            for _c2 in range(trait_count):
-                parse_traits_info()
-
-        assert p + code_reader.tell() == len(code_tag)
-        assert len(methods) == len(method_idxs)
-
-        method_pyfunctions = {}
-
-        def extract_function(func_name):
-            if func_name in method_pyfunctions:
-                return method_pyfunctions[func_name]
-            if func_name not in methods:
-                raise ExtractorError(u'Cannot find function %r' % func_name)
-            m = methods[func_name]
-
-            def resfunc(args):
-                registers = ['(this)'] + list(args) + [None] * m.local_count
-                stack = []
-                coder = io.BytesIO(m.code)
-                while True:
-                    opcode = struct.unpack('!B', coder.read(1))[0]
-                    if opcode == 36:  # pushbyte
-                        v = struct.unpack('!B', coder.read(1))[0]
-                        stack.append(v)
-                    elif opcode == 44:  # pushstring
-                        idx = u30(coder)
-                        stack.append(constant_strings[idx])
-                    elif opcode == 48:  # pushscope
-                        # We don't implement the scope register, so we'll just
-                        # ignore the popped value
-                        stack.pop()
-                    elif opcode == 70:  # callproperty
-                        index = u30(coder)
-                        mname = multinames[index]
-                        arg_count = u30(coder)
-                        args = list(reversed(
-                            [stack.pop() for _ in range(arg_count)]))
-                        obj = stack.pop()
-                        if mname == u'split':
-                            assert len(args) == 1
-                            assert isinstance(args[0], compat_str)
-                            assert isinstance(obj, compat_str)
-                            if args[0] == u'':
-                                res = list(obj)
-                            else:
-                                res = obj.split(args[0])
-                            stack.append(res)
-                        elif mname == u'slice':
-                            assert len(args) == 1
-                            assert isinstance(args[0], int)
-                            assert isinstance(obj, list)
-                            res = obj[args[0]:]
-                            stack.append(res)
-                        elif mname == u'join':
-                            assert len(args) == 1
-                            assert isinstance(args[0], compat_str)
-                            assert isinstance(obj, list)
-                            res = args[0].join(obj)
-                            stack.append(res)
-                        elif mname in method_pyfunctions:
-                            stack.append(method_pyfunctions[mname](args))
-                        else:
-                            raise NotImplementedError(
-                                u'Unsupported property %r on %r'
-                                % (mname, obj))
-                    elif opcode == 72:  # returnvalue
-                        res = stack.pop()
-                        return res
-                    elif opcode == 79:  # callpropvoid
-                        index = u30(coder)
-                        mname = multinames[index]
-                        arg_count = u30(coder)
-                        args = list(reversed(
-                            [stack.pop() for _ in range(arg_count)]))
-                        obj = stack.pop()
-                        if mname == u'reverse':
-                            assert isinstance(obj, list)
-                            obj.reverse()
-                        else:
-                            raise NotImplementedError(
-                                u'Unsupported (void) property %r on %r'
-                                % (mname, obj))
-                    elif opcode == 93:  # findpropstrict
-                        index = u30(coder)
-                        mname = multinames[index]
-                        res = extract_function(mname)
-                        stack.append(res)
-                    elif opcode == 97:  # setproperty
-                        index = u30(coder)
-                        value = stack.pop()
-                        idx = stack.pop()
-                        obj = stack.pop()
-                        assert isinstance(obj, list)
-                        assert isinstance(idx, int)
-                        obj[idx] = value
-                    elif opcode == 98:  # getlocal
-                        index = u30(coder)
-                        stack.append(registers[index])
-                    elif opcode == 99:  # setlocal
-                        index = u30(coder)
-                        value = stack.pop()
-                        registers[index] = value
-                    elif opcode == 102:  # getproperty
-                        index = u30(coder)
-                        pname = multinames[index]
-                        if pname == u'length':
-                            obj = stack.pop()
-                            assert isinstance(obj, list)
-                            stack.append(len(obj))
-                        else:  # Assume attribute access
-                            idx = stack.pop()
-                            assert isinstance(idx, int)
-                            obj = stack.pop()
-                            assert isinstance(obj, list)
-                            stack.append(obj[idx])
-                    elif opcode == 128:  # coerce
-                        u30(coder)
-                    elif opcode == 133:  # coerce_s
-                        assert isinstance(stack[-1], (type(None), compat_str))
-                    elif opcode == 164:  # modulo
-                        value2 = stack.pop()
-                        value1 = stack.pop()
-                        res = value1 % value2
-                        stack.append(res)
-                    elif opcode == 208:  # getlocal_0
-                        stack.append(registers[0])
-                    elif opcode == 209:  # getlocal_1
-                        stack.append(registers[1])
-                    elif opcode == 210:  # getlocal_2
-                        stack.append(registers[2])
-                    elif opcode == 211:  # getlocal_3
-                        stack.append(registers[3])
-                    elif opcode == 214:  # setlocal_2
-                        registers[2] = stack.pop()
-                    elif opcode == 215:  # setlocal_3
-                        registers[3] = stack.pop()
-                    else:
-                        raise NotImplementedError(
-                            u'Unsupported opcode %d' % opcode)
-
-            method_pyfunctions[func_name] = resfunc
-            return resfunc
-
-        initial_function = extract_function(u'decipher')
+        swfi = SWFInterpreter(file_contents)
+        TARGET_CLASSNAME = 'SignatureDecipher'
+        searched_class = swfi.extract_class(TARGET_CLASSNAME)
+        initial_function = swfi.extract_function(searched_class, 'decipher')
         return lambda s: initial_function([s])
 
     def _decrypt_signature(self, s, video_id, player_url, age_gate=False):
         """Turn the encrypted s field into a working signature"""
 
-        if player_url is not None:
-            if player_url.startswith(u'//'):
-                player_url = u'https:' + player_url
-            try:
-                player_id = (player_url, len(s))
-                if player_id not in self._player_cache:
-                    func = self._extract_signature_function(
-                        video_id, player_url, len(s)
-                    )
-                    self._player_cache[player_id] = func
-                func = self._player_cache[player_id]
-                if self._downloader.params.get('youtube_print_sig_code'):
-                    self._print_sig_code(func, len(s))
-                return func(s)
-            except Exception:
-                tb = traceback.format_exc()
-                self._downloader.report_warning(
-                    u'Automatic signature extraction failed: ' + tb)
-
-            self._downloader.report_warning(
-                u'Warning: Falling back to static signature algorithm')
-
-        return self._static_decrypt_signature(
-            s, video_id, player_url, age_gate)
-
-    def _static_decrypt_signature(self, s, video_id, player_url, age_gate):
-        if age_gate:
-            # The videos with age protection use another player, so the
-            # algorithms can be different.
-            if len(s) == 86:
-                return s[2:63] + s[82] + s[64:82] + s[63]
-
-        if len(s) == 93:
-            return s[86:29:-1] + s[88] + s[28:5:-1]
-        elif len(s) == 92:
-            return s[25] + s[3:25] + s[0] + s[26:42] + s[79] + s[43:79] + s[91] + s[80:83]
-        elif len(s) == 91:
-            return s[84:27:-1] + s[86] + s[26:5:-1]
-        elif len(s) == 90:
-            return s[25] + s[3:25] + s[2] + s[26:40] + s[77] + s[41:77] + s[89] + s[78:81]
-        elif len(s) == 89:
-            return s[84:78:-1] + s[87] + s[77:60:-1] + s[0] + s[59:3:-1]
-        elif len(s) == 88:
-            return s[7:28] + s[87] + s[29:45] + s[55] + s[46:55] + s[2] + s[56:87] + s[28]
-        elif len(s) == 87:
-            return s[6:27] + s[4] + s[28:39] + s[27] + s[40:59] + s[2] + s[60:]
-        elif len(s) == 86:
-            return s[80:72:-1] + s[16] + s[71:39:-1] + s[72] + s[38:16:-1] + s[82] + s[15::-1]
-        elif len(s) == 85:
-            return s[3:11] + s[0] + s[12:55] + s[84] + s[56:84]
-        elif len(s) == 84:
-            return s[78:70:-1] + s[14] + s[69:37:-1] + s[70] + s[36:14:-1] + s[80] + s[:14][::-1]
-        elif len(s) == 83:
-            return s[80:63:-1] + s[0] + s[62:0:-1] + s[63]
-        elif len(s) == 82:
-            return s[80:37:-1] + s[7] + s[36:7:-1] + s[0] + s[6:0:-1] + s[37]
-        elif len(s) == 81:
-            return s[56] + s[79:56:-1] + s[41] + s[55:41:-1] + s[80] + s[40:34:-1] + s[0] + s[33:29:-1] + s[34] + s[28:9:-1] + s[29] + s[8:0:-1] + s[9]
-        elif len(s) == 80:
-            return s[1:19] + s[0] + s[20:68] + s[19] + s[69:80]
-        elif len(s) == 79:
-            return s[54] + s[77:54:-1] + s[39] + s[53:39:-1] + s[78] + s[38:34:-1] + s[0] + s[33:29:-1] + s[34] + s[28:9:-1] + s[29] + s[8:0:-1] + s[9]
+        if player_url is None:
+            raise ExtractorError('Cannot decrypt signature without player_url')
 
-        else:
-            raise ExtractorError(u'Unable to decrypt signature, key length %d not supported; retrying might work' % (len(s)))
+        if player_url.startswith('//'):
+            player_url = 'https:' + player_url
+        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:
@@ -936,23 +556,25 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                 '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 {}
         lang_list = re.findall(r'name="([^"]*)"[^>]+lang_code="([\w\-]+)"', sub_list)
 
         sub_lang_list = {}
         for l in lang_list:
             lang = l[1]
+            if lang in sub_lang_list:
+                continue
             params = compat_urllib_parse.urlencode({
                 'lang': lang,
                 'v': video_id,
                 'fmt': self._downloader.params.get('subtitlesformat', 'srt'),
                 'name': unescapeHTML(l[0]).encode('utf-8'),
             })
-            url = 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:
-            self._downloader.report_warning(u'video doesn\'t have subtitles')
+            self._downloader.report_warning('video doesn\'t have subtitles')
             return {}
         return sub_lang_list
 
@@ -960,9 +582,9 @@ 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')
-        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)
-        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 {}
@@ -981,7 +603,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             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')
+                self._downloader.report_warning('Video doesn\'t have automatic captions')
                 return {}
             original_lang = original_lang_node.attrib['lang_code']
 
@@ -1007,7 +629,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
     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
 
@@ -1018,7 +640,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             urls = filter(lambda l: l and not l.startswith('#'),
                             lines)
             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')
@@ -1027,12 +649,12 @@ 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
-        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 _real_extract(self, url):
         proto = (
-            u'http' if self._downloader.params.get('prefer_insecure', False)
-            else u'https')
+            '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)
@@ -1042,6 +664,16 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
 
         # Get video webpage
         url = proto + '://www.youtube.com/watch?v=%s&gl=US&hl=en&has_verified=1' % video_id
+        pref_cookies = [
+            c for c in self._downloader.cookiejar
+            if c.domain == '.youtube.com' and c.name == 'PREF']
+        for pc in pref_cookies:
+            if 'hl=' in pc.value:
+                pc.value = re.sub(r'hl=[^&]+', 'hl=en', pc.value)
+            else:
+                if pc.value:
+                    pc.value += '&'
+                pc.value += 'hl=en'
         video_webpage = self._download_webpage(url, video_id)
 
         # Attempt to extract SWF player URL
@@ -1058,14 +690,12 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             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',
-                                                  })
+            data = compat_urllib_parse.urlencode({
+                'video_id': video_id,
+                'eurl': 'https://youtube.googleapis.com/v/' + video_id,
+                'sts': self._search_regex(
+                    r'"sts"\s*:\s*(\d+)', video_webpage, 'sts'),
+            })
             video_info_url = proto + '://www.youtube.com/get_video_info?' + data
             video_info_webpage = self._download_webpage(video_info_url, video_id,
                                     note=False,
@@ -1085,11 +715,11 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         if 'token' not in video_info:
             if 'reason' in video_info:
                 raise ExtractorError(
-                    u'YouTube said: %s' % video_info['reason'][0],
+                    'YouTube said: %s' % video_info['reason'][0],
                     expected=True, video_id=video_id)
             else:
                 raise ExtractorError(
-                    u'"token" parameter not in video info for unknown reason',
+                    '"token" parameter not in video info for unknown reason',
                     video_id=video_id)
 
         if 'view_count' in video_info:
@@ -1099,14 +729,14 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
 
         # Check for "rental" videos
         if 'ypc_video_rental_bar_text' in video_info and 'author' not in video_info:
-            raise ExtractorError(u'"rental" videos not supported')
+            raise ExtractorError('"rental" videos not supported')
 
         # Start extracting information
         self.report_information_extraction(video_id)
 
         # uploader
         if 'author' not in video_info:
-            raise ExtractorError(u'Unable to extract uploader name')
+            raise ExtractorError('Unable to extract uploader name')
         video_uploader = compat_urllib_parse.unquote_plus(video_info['author'][0])
 
         # uploader_id
@@ -1115,14 +745,14 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         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:
             video_title = video_info['title'][0]
         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:
@@ -1131,7 +761,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         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])
@@ -1147,7 +777,9 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             upload_date = ' '.join(re.sub(r'[/,-]', r' ', mobj.group(1)).split())
             upload_date = unified_strdate(upload_date)
 
-        m_cat_container = get_element_by_id("eow-category", video_webpage)
+        m_cat_container = self._search_regex(
+            r'(?s)<h4[^>]*>\s*Category\s*</h4>\s*<ul[^>]*>(.*?)</ul>',
+            video_webpage, 'categories', fatal=False)
         if m_cat_container:
             category = self._html_search_regex(
                 r'(?s)<a[^<]+>(.*?)</a>', m_cat_container, 'category',
@@ -1174,17 +806,17 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             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(
-                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
-        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)
@@ -1194,7 +826,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             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]))
@@ -1215,13 +847,13 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             # 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
+                raise ValueError('No stream_map present')  # caught below
             re_signature = re.compile(r'[&,]s=')
             m_s = re_signature.search(args['url_encoded_fmt_stream_map'])
             if m_s is not None:
-                self.to_screen(u'%s: Encrypted signatures detected.' % video_id)
+                self.to_screen('%s: Encrypted signatures detected.' % video_id)
                 video_info['url_encoded_fmt_stream_map'] = [args['url_encoded_fmt_stream_map']]
-            m_s = re_signature.search(args.get('adaptive_fmts', u''))
+            m_s = re_signature.search(args.get('adaptive_fmts', ''))
             if m_s is not None:
                 if 'adaptive_fmts' in video_info:
                     video_info['adaptive_fmts'][0] += ',' + args['adaptive_fmts']
@@ -1258,53 +890,64 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             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$', player_url,
-                                        u'flash player', fatal=False)
+                if 'itag' not in url_data or 'url' not in url_data:
+                    continue
+                format_id = url_data['itag'][0]
+                url = url_data['url'][0]
+
+                if 'sig' in url_data:
+                    url += '&signature=' + url_data['sig'][0]
+                elif 's' in url_data:
+                    encrypted_sig = url_data['s'][0]
+
+                    if not age_gate:
+                        jsplayer_url_json = self._search_regex(
+                            r'"assets":.+?"js":\s*("[^"]+")',
+                            video_webpage, 'JS player URL')
+                        player_url = json.loads(jsplayer_url_json)
+                    if player_url is None:
+                        player_url_json = self._search_regex(
+                            r'ytplayer\.config.*?"url"\s*:\s*("[^"]+")',
+                            video_webpage, 'age gate player URL')
+                        player_url = json.loads(player_url_json)
+
+                    if self._downloader.params.get('verbose'):
+                        if player_url is None:
+                            player_version = 'unknown'
+                            player_desc = 'unknown'
+                        else:
+                            if player_url.endswith('swf'):
+                                player_version = self._search_regex(
+                                    r'-(.+?)(?:/watch_as3)?\.swf$', player_url,
+                                    'flash player', fatal=False)
                                 player_desc = 'flash player %s' % player_version
                             else:
                                 player_version = self._search_regex(
-                                    r'html5player-(.+?)\.js', video_webpage,
+                                    r'html5player-([^/]+?)(?:/html5player)?\.js',
+                                    player_url,
                                     '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:
-            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
-        if (self._downloader.params.get('youtube_include_dash_manifest', False)):
+        if self._downloader.params.get('youtube_include_dash_manifest', True):
             try:
                 # The DASH manifest used needs to be the one from the original video_webpage.
                 # The one found in get_video_info seems to be using different signatures.
@@ -1322,9 +965,9 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                 dash_manifest_url = re.sub(r'/s/([\w\.]+)', decrypt_sig, dash_manifest_url)
                 dash_doc = self._download_xml(
                     dash_manifest_url, 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'):
+                    note='Downloading DASH manifest',
+                    errnote='Could not download DASH manifest')
+                for r in dash_doc.findall('.//{urn:mpeg:DASH:schema:MPD:2011}Representation'):
                     url_el = r.find('{urn:mpeg:DASH:schema:MPD:2011}BaseURL')
                     if url_el is None:
                         continue
@@ -1350,7 +993,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                         existing_format.update(f)
 
             except (ExtractorError, KeyError) as e:
-                self.report_warning(u'Skipping DASH manifest: %s' % e, video_id)
+                self.report_warning('Skipping DASH manifest: %s' % e, video_id)
 
         self._sort_formats(formats)
 
@@ -1375,13 +1018,13 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
         }
 
 class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
-    IE_DESC = u'YouTube.com playlists'
+    IE_DESC = 'YouTube.com playlists'
     _VALID_URL = r"""(?x)(?:
                         (?:https?://)?
                         (?:\w+\.)?
                         youtube\.com/
                         (?:
-                           (?:course|view_play_list|my_playlists|artist|playlist|watch)
+                           (?:course|view_play_list|my_playlists|artist|playlist|watch|embed/videoseries)
                            \? (?:.*?&)*? (?:p|a|list)=
                         |  p/
                         )
@@ -1397,27 +1040,86 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
     _TEMPLATE_URL = 'https://www.youtube.com/playlist?list=%s'
     _MORE_PAGES_INDICATOR = r'data-link-type="next"'
     _VIDEO_RE = r'href="\s*/watch\?v=(?P<id>[0-9A-Za-z_-]{11})&amp;[^"]*?index=(?P<index>\d+)'
-    IE_NAME = u'youtube:playlist'
+    IE_NAME = 'youtube:playlist'
+    _TESTS = [{
+        'url': 'https://www.youtube.com/playlist?list=PLwiyx1dc3P2JR9N8gQaQN_BCvlSlap7re',
+        'info_dict': {
+            'title': 'ytdl test PL',
+        },
+        'playlist_count': 3,
+    }, {
+        'url': 'https://www.youtube.com/playlist?list=PLtPgu7CB4gbZDA7i_euNxn75ISqxwZPYx',
+        'info_dict': {
+            'title': 'YDL_Empty_List',
+        },
+        'playlist_count': 0,
+    }, {
+        'note': 'Playlist with deleted videos (#651). As a bonus, the video #51 is also twice in this list.',
+        'url': 'https://www.youtube.com/playlist?list=PLwP_SiAcdui0KVebT0mU9Apz359a4ubsC',
+        'info_dict': {
+            'title': '29C3: Not my department',
+        },
+        'playlist_count': 95,
+    }, {
+        'note': 'issue #673',
+        'url': 'PLBB231211A4F62143',
+        'info_dict': {
+            'title': '[OLD]Team Fortress 2 (Class-based LP)',
+        },
+        'playlist_mincount': 26,
+    }, {
+        'note': 'Large playlist',
+        'url': 'https://www.youtube.com/playlist?list=UUBABnxM4Ar9ten8Mdjj1j0Q',
+        'info_dict': {
+            'title': 'Uploads from Cauchemar',
+        },
+        'playlist_mincount': 799,
+    }, {
+        'url': 'PLtPgu7CB4gbY9oDN3drwC3cMbJggS7dKl',
+        'info_dict': {
+            'title': 'YDL_safe_search',
+        },
+        'playlist_count': 2,
+    }, {
+        'note': 'embedded',
+        'url': 'http://www.youtube.com/embed/videoseries?list=PL6IaIsEjSbf96XFRuNccS_RuEXwNdsoEu',
+        'playlist_count': 4,
+        'info_dict': {
+            'title': 'JODA15',
+        }
+    }, {
+        'note': 'Embedded SWF player',
+        'url': 'http://www.youtube.com/p/YN5VISEtHet5D4NEvfTd0zcgFk84NqFZ?hl=en_US&fs=1&rel=0',
+        'playlist_count': 4,
+        'info_dict': {
+            'title': 'JODA7',
+        }
+    }]
 
     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)
-        webpage = self._download_webpage(url, playlist_id, u'Downloading Youtube mix')
+        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_span = (
+            search_title('playlist-title') or
+            search_title('title long-title') or
+            search_title('title'))
         title = clean_html(title_span)
-        video_re = r'''(?x)data-video-username=".*?".*?
-                       href="/watch\?v=([0-9A-Za-z_-]{11})&amp;[^"]*?list=%s''' % re.escape(playlist_id)
-        ids = orderedSet(re.findall(video_re, webpage, flags=re.DOTALL))
+        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)
@@ -1426,7 +1128,7 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
         # 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
@@ -1434,17 +1136,17 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
         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:
-                self.to_screen(u'Downloading playlist %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('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)
+            raise ExtractorError('For downloading YouTube.com top lists, use '
+                'the "yttoplist" keyword, for example "youtube-dl \'yttoplist:music:Top Tracks\'"', expected=True)
 
         url = self._TEMPLATE_URL % playlist_id
         page = self._download_webpage(url, playlist_id)
@@ -1453,7 +1155,7 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
         # 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(
-                u'The playlist doesn\'t exist or is private, use --username or '
+                'The playlist doesn\'t exist or is private, use --username or '
                 '--netrc to access it.',
                 expected=True)
 
@@ -1480,26 +1182,36 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
 
         playlist_title = self._html_search_regex(
             r'(?s)<h1 class="pl-header-title[^"]*">\s*(.*?)\s*</h1>',
-            page, u'title')
+            page, 'title')
 
         url_results = self._ids_to_results(ids)
         return self.playlist_result(url_results, playlist_id, playlist_title)
 
 
 class YoutubeTopListIE(YoutubePlaylistIE):
-    IE_NAME = u'youtube:toplist'
-    IE_DESC = (u'YouTube.com top lists, "yttoplist:{channel}:{list title}"'
-        u' (Example: "yttoplist:music:Top Tracks")')
+    IE_NAME = 'youtube:toplist'
+    IE_DESC = ('YouTube.com top lists, "yttoplist:{channel}:{list title}"'
+        ' (Example: "yttoplist:music:Top Tracks")')
     _VALID_URL = r'yttoplist:(?P<chann>.*?):(?P<title>.*?)$'
+    _TESTS = [{
+        'url': 'yttoplist:music:Trending',
+        'playlist_mincount': 5,
+        'skip': 'Only works for logged-in users',
+    }]
 
     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')
+        channel_page = self._download_webpage(
+            'https://www.youtube.com/%s' % channel, title)
+        link = self._html_search_regex(
+            r'''(?x)
+                <a\s+href="([^"]+)".*?>\s*
+                <span\s+class="branded-page-module-title-text">\s*
+                <span[^>]*>.*?%s.*?</span>''' % re.escape(query),
+            channel_page, 'list')
         url = compat_urlparse.urljoin('https://www.youtube.com/', link)
         
         video_re = r'data-index="\d+".*?data-video-id="([0-9A-Za-z_-]{11})"'
@@ -1507,9 +1219,10 @@ class YoutubeTopListIE(YoutubePlaylistIE):
         # sometimes the webpage doesn't contain the videos
         # retry until we get them
         for i in itertools.count(0):
-            msg = u'Downloading Youtube mix'
+            msg = 'Downloading Youtube mix'
             if i > 0:
                 msg += ', retry #%d' % i
+
             webpage = self._download_webpage(url, title, msg)
             ids = orderedSet(re.findall(video_re, webpage))
             if ids:
@@ -1519,11 +1232,16 @@ class YoutubeTopListIE(YoutubePlaylistIE):
 
 
 class YoutubeChannelIE(InfoExtractor):
-    IE_DESC = u'YouTube.com channels'
+    IE_DESC = '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_NAME = 'youtube:channel'
+    _TESTS = [{
+        'note': 'paginated channel',
+        'url': 'https://www.youtube.com/channel/UCKfVa3S1e4PHvxWcwyMMg8w',
+        'playlist_mincount': 91,
+    }]
 
     def extract_videos_from_page(self, page):
         ids_in_page = []
@@ -1536,7 +1254,7 @@ class YoutubeChannelIE(InfoExtractor):
         # Extract channel id
         mobj = re.match(self._VALID_URL, url)
         if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
+            raise ExtractorError('Invalid URL: %s' % url)
 
         # Download channel page
         channel_id = mobj.group(1)
@@ -1558,7 +1276,7 @@ class YoutubeChannelIE(InfoExtractor):
             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,
+                    url, channel_id, note='Downloading page #%s' % pagenum,
                     transform_source=uppercase_escape)
 
                 ids_in_page = self.extract_videos_from_page(page['content_html'])
@@ -1567,7 +1285,7 @@ class YoutubeChannelIE(InfoExtractor):
                 if self._MORE_PAGES_INDICATOR not in page['load_more_widget_html']:
                     break
 
-        self._downloader.to_screen(u'[youtube] Channel %s: Found %i videos' % (channel_id, len(video_ids)))
+        self._downloader.to_screen('[youtube] Channel %s: Found %i videos' % (channel_id, len(video_ids)))
 
         url_entries = [self.url_result(video_id, 'Youtube', video_id=video_id)
                        for video_id in video_ids]
@@ -1575,12 +1293,23 @@ class YoutubeChannelIE(InfoExtractor):
 
 
 class YoutubeUserIE(InfoExtractor):
-    IE_DESC = u'YouTube.com user videos (URL or "ytuser" keyword)'
+    IE_DESC = 'YouTube.com user videos (URL or "ytuser" keyword)'
     _VALID_URL = r'(?:(?:(?:https?://)?(?:\w+\.)?youtube\.com/(?:user/)?(?!(?:attribution_link|watch|results)(?:$|[^a-z_A-Z0-9-])))|ytuser:)(?!feed/)([A-Za-z0-9_-]+)'
     _TEMPLATE_URL = 'https://gdata.youtube.com/feeds/api/users/%s'
     _GDATA_PAGE_SIZE = 50
     _GDATA_URL = '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):
@@ -1594,7 +1323,7 @@ class YoutubeUserIE(InfoExtractor):
         # Extract username
         mobj = re.match(self._VALID_URL, url)
         if mobj is None:
-            raise ExtractorError(u'Invalid URL: %s' % url)
+            raise ExtractorError('Invalid URL: %s' % url)
 
         username = mobj.group(1)
 
@@ -1609,13 +1338,13 @@ class YoutubeUserIE(InfoExtractor):
             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:
-                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
 
@@ -1631,16 +1360,16 @@ class YoutubeUserIE(InfoExtractor):
                     '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):
-    IE_DESC = u'YouTube.com searches'
-    _API_URL = u'https://gdata.youtube.com/feeds/api/videos?q=%s&start-index=%i&max-results=50&v=2&alt=jsonc'
+    IE_DESC = 'YouTube.com searches'
+    _API_URL = 'https://gdata.youtube.com/feeds/api/videos?q=%s&start-index=%i&max-results=50&v=2&alt=jsonc'
     _MAX_RESULTS = 1000
-    IE_NAME = u'youtube:search'
+    IE_NAME = 'youtube:search'
     _SEARCH_KEY = 'ytsearch'
 
     def _get_n_results(self, query, n):
@@ -1656,15 +1385,15 @@ class YoutubeSearchIE(SearchInfoExtractor):
                 compat_urllib_parse.quote_plus(query.encode('utf-8')),
                 (PAGE_SIZE * pagenum) + 1)
             data_json = self._download_webpage(
-                result_url, video_id=u'query "%s"' % query,
-                note=u'Downloading page %s' % (pagenum + 1),
-                errnote=u'Unable to download API page')
+                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(
-                    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
@@ -1683,13 +1412,20 @@ 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 = u'YouTube.com search URLs'
-    IE_NAME = u'youtube:search_url'
+    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)
@@ -1697,14 +1433,14 @@ class YoutubeSearchURLIE(InfoExtractor):
 
         webpage = self._download_webpage(url, query)
         result_code = self._search_regex(
-            r'(?s)<ol id="search-results"(.*?)</ol>', webpage, u'result HTML')
+            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="([^"]+)"', part_code, 'item title', fatal=False)
+                [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(
@@ -1723,18 +1459,39 @@ class YoutubeSearchURLIE(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)
-        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))
-        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):
@@ -1756,7 +1513,7 @@ class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
 
     @property
     def IE_NAME(self):
-        return u'youtube:%s' % self._FEED_NAME
+        return 'youtube:%s' % self._FEED_NAME
 
     def _real_initialize(self):
         self._login()
@@ -1766,9 +1523,10 @@ class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
         paging = 0
         for i in itertools.count(1):
             info = self._download_json(self._FEED_TEMPLATE % paging,
-                                          u'%s feed' % self._FEED_NAME,
-                                          u'Downloading page %s' % i)
+                                          '%s feed' % self._FEED_NAME,
+                                          'Downloading page %s' % i)
             feed_html = info.get('feed_html') or info.get('content_html')
+            load_more_widget_html = info.get('load_more_widget_html') or feed_html
             m_ids = re.finditer(r'"/watch\?v=(.*?)["&]', feed_html)
             ids = orderedSet(m.group(1) for m in m_ids)
             feed_entries.extend(
@@ -1776,63 +1534,106 @@ class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
                 for video_id in ids)
             mobj = re.search(
                 r'data-uix-load-more-href="/?[^"]+paging=(?P<paging>\d+)',
-                feed_html)
+                load_more_widget_html)
             if mobj is None:
                 break
             paging = mobj.group('paging')
         return self.playlist_result(feed_entries, playlist_title=self._PLAYLIST_TITLE)
 
-class 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):
-    IE_DESC = u'YouTube.com recommended videos, "ytrec" keyword (requires authentication)'
+    IE_DESC = 'YouTube.com recommended videos, "ytrec" keyword (requires authentication)'
     _VALID_URL = r'https?://www\.youtube\.com/feed/recommended|:ytrec(?:ommended)?'
     _FEED_NAME = 'recommended'
-    _PLAYLIST_TITLE = u'Youtube Recommended videos'
+    _PLAYLIST_TITLE = 'Youtube Recommended videos'
 
 class YoutubeWatchLaterIE(YoutubeFeedsInfoExtractor):
-    IE_DESC = u'Youtube watch later list, "ytwatchlater" keyword (requires authentication)'
+    IE_DESC = 'Youtube watch later list, "ytwatchlater" keyword (requires authentication)'
     _VALID_URL = r'https?://www\.youtube\.com/feed/watch_later|:ytwatchlater'
     _FEED_NAME = 'watch_later'
-    _PLAYLIST_TITLE = u'Youtube Watch Later'
+    _PLAYLIST_TITLE = 'Youtube Watch Later'
     _PERSONAL_FEED = True
 
 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" keyword (requires authentication)'
+    _VALID_URL = 'https?://www\.youtube\.com/feed/history|:ythistory'
     _FEED_NAME = 'history'
     _PERSONAL_FEED = True
-    _PLAYLIST_TITLE = u'Youtube Watch History'
+    _PLAYLIST_TITLE = 'Youtube Watch History'
 
 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" keyword (requires authentication)'
     _VALID_URL = r'https?://www\.youtube\.com/my_favorites|:ytfav(?:ou?rites)?'
     _LOGIN_REQUIRED = True
 
     def _real_extract(self, url):
         webpage = self._download_webpage('https://www.youtube.com/my_favorites', 'Youtube Favourites videos')
-        playlist_id = self._search_regex(r'list=(.+?)["&]', webpage, u'favourites playlist id')
+        playlist_id = self._search_regex(r'list=(.+?)["&]', webpage, 'favourites playlist id')
         return self.url_result(playlist_id, 'YoutubePlaylist')
 
 
+class YoutubeSubscriptionsIE(YoutubePlaylistIE):
+    IE_NAME = 'youtube:subscriptions'
+    IE_DESC = 'YouTube.com subscriptions feed, "ytsubs" keyword (requires authentication)'
+    _VALID_URL = r'https?://www\.youtube\.com/feed/subscriptions|:ytsubs(?:criptions)?'
+    _TESTS = []
+
+    def _real_extract(self, url):
+        title = 'Youtube Subscriptions'
+        page = self._download_webpage('https://www.youtube.com/feed/subscriptions', title)
+
+        # The extraction process is the same as for playlists, but the regex
+        # for the video ids doesn't contain an index
+        ids = []
+        more_widget_html = content_html = page
+
+        for page_num in itertools.count(1):
+            matches = re.findall(r'href="\s*/watch\?v=([0-9A-Za-z_-]{11})', content_html)
+            new_ids = orderedSet(matches)
+            ids.extend(new_ids)
+
+            mobj = re.search(r'data-uix-load-more-href="/?(?P<more>[^"]+)"', more_widget_html)
+            if not mobj:
+                break
+
+            more = self._download_json(
+                'https://youtube.com/%s' % mobj.group('more'), title,
+                'Downloading page #%s' % page_num,
+                transform_source=uppercase_escape)
+            content_html = more['content_html']
+            more_widget_html = more['load_more_widget_html']
+
+        return {
+            '_type': 'playlist',
+            'title': title,
+            'entries': self._ids_to_results(ids),
+        }
+
+
 class YoutubeTruncatedURLIE(InfoExtractor):
     IE_NAME = 'youtube:truncated_url'
     IE_DESC = False  # Do not list
     _VALID_URL = r'''(?x)
-        (?:https?://)?[^/]+/watch\?(?:feature=[a-z_]+)?$|
+        (?:https?://)?[^/]+/watch\?(?:
+            feature=[a-z_]+|
+            annotation_id=annotation_[^&]+
+        )?$|
         (?:https?://)?(?:www\.)?youtube\.com/attribution_link\?a=[^&]+$
     '''
 
+    _TESTS = [{
+        'url': 'http://www.youtube.com/watch?annotation_id=annotation_3951667041',
+        'only_matching': True,
+    }, {
+        'url': 'http://www.youtube.com/watch?',
+        'only_matching': True,
+    }]
+
     def _real_extract(self, url):
         raise ExtractorError(
-            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  .',
+            '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)