]> jfr.im git - yt-dlp.git/blobdiff - yt_dlp/extractor/common.py
[extractor] Improve json+ld extraction
[yt-dlp.git] / yt_dlp / extractor / common.py
index 3b2bda0e752d871f69459a89fc3bf8546e4cb261..d36f025ab823a5675ad1e428dd4ddc94925efc46 100644 (file)
@@ -1,60 +1,59 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 import base64
-import datetime
+import collections
+import getpass
 import hashlib
+import http.client
+import http.cookiejar
+import http.cookies
+import inspect
+import itertools
 import json
+import math
 import netrc
 import os
 import random
 import re
 import sys
 import time
-import math
-
-from ..compat import (
-    compat_cookiejar_Cookie,
-    compat_cookies_SimpleCookie,
-    compat_etree_Element,
-    compat_etree_fromstring,
-    compat_getpass,
-    compat_integer_types,
-    compat_http_client,
-    compat_os_name,
-    compat_str,
-    compat_urllib_error,
-    compat_urllib_parse_unquote,
-    compat_urllib_parse_urlencode,
-    compat_urllib_request,
-    compat_urlparse,
-    compat_xml_parse_error,
-)
+import types
+import urllib.parse
+import urllib.request
+import xml.etree.ElementTree
+
+from ..compat import functools  # isort: split
+from ..compat import compat_etree_fromstring, compat_expanduser, compat_os_name
+from ..cookies import LenientSimpleCookie
 from ..downloader import FileDownloader
-from ..downloader.f4m import (
-    get_base_url,
-    remove_encrypted_media,
-)
+from ..downloader.f4m import get_base_url, remove_encrypted_media
 from ..utils import (
+    IDENTITY,
+    JSON_LD_RE,
     NO_DEFAULT,
+    ExtractorError,
+    GeoRestrictedError,
+    GeoUtils,
+    LenientJSONDecoder,
+    RegexNotFoundError,
+    RetryManager,
+    UnsupportedError,
     age_restricted,
     base_url,
     bug_reports_message,
+    classproperty,
     clean_html,
-    compiled_regex_type,
     determine_ext,
     determine_protocol,
     dict_get,
+    encode_data_uri,
     error_to_compat_str,
-    ExtractorError,
     extract_attributes,
+    filter_dict,
     fix_xml_ampersands,
     float_or_none,
-    GeoRestrictedError,
-    GeoUtils,
+    format_field,
     int_or_none,
+    join_nonempty,
     js_to_json,
-    JSON_LD_RE,
     mimetype2ext,
     network_exceptions,
     orderedSet,
     parse_iso8601,
     parse_m3u8_attributes,
     parse_resolution,
-    RegexNotFoundError,
-    sanitized_Request,
     sanitize_filename,
+    sanitize_url,
+    sanitized_Request,
     str_or_none,
     str_to_int,
     strip_or_none,
+    traverse_obj,
+    try_call,
+    try_get,
     unescapeHTML,
     unified_strdate,
     unified_timestamp,
     update_Request,
     update_url_query,
-    urljoin,
     url_basename,
     url_or_none,
+    urljoin,
+    variadic,
     xpath_element,
     xpath_text,
     xpath_with_ns,
 )
 
 
-class InfoExtractor(object):
+class InfoExtractor:
     """Information Extractor class.
 
     Information extractors are the classes that, given a URL, extract
@@ -102,7 +105,9 @@ class InfoExtractor(object):
     For a video, the dictionaries must include the following fields:
 
     id:             Video identifier.
-    title:          Video title, unescaped.
+    title:          Video title, unescaped. Set to an empty string if video has
+                    no title as opposed to "None" which signifies that the
+                    extractor failed to obtain a title
 
     Additionally, it must contain either a formats entry or a url one:
 
@@ -130,6 +135,8 @@ class InfoExtractor(object):
                                    for HDS - URL of the F4M manifest,
                                    for DASH - URL of the MPD manifest,
                                    for MSS - URL of the ISM manifest.
+                    * manifest_stream_number  (For internal use only)
+                                 The index of the stream in the manifest file
                     * ext        Will be calculated from URL if missing
                     * format     A human-readable description of the format
                                  ("mp4 container with h264/opus").
@@ -143,10 +150,13 @@ class InfoExtractor(object):
                     * width      Width of the video, if known
                     * height     Height of the video, if known
                     * resolution Textual description of width and height
+                    * dynamic_range The dynamic range of the video. One of:
+                                 "SDR" (None), "HDR10", "HDR10+, "HDR12", "HLG, "DV"
                     * tbr        Average bitrate of audio and video in KBit/s
                     * abr        Average audio bitrate in KBit/s
                     * acodec     Name of the audio codec in use
                     * asr        Audio sampling rate in Hertz
+                    * audio_channels  Number of audio channels
                     * vbr        Average video bitrate in KBit/s
                     * fps        Frame rate
                     * vcodec     Name of the video codec in use
@@ -155,9 +165,8 @@ class InfoExtractor(object):
                     * filesize_approx  An estimate for the number of bytes
                     * player_url SWF Player URL (used for rtmpdump).
                     * protocol   The protocol that will be used for the actual
-                                 download, lower-case.
-                                 "http", "https", "rtsp", "rtmp", "rtmp_ffmpeg", "rtmpe",
-                                 "m3u8", "m3u8_native" or "http_dash_segments".
+                                 download, lower-case. One of "http", "https" or
+                                 one of the protocols defined in downloader.PROTOCOL_MAP
                     * fragment_base_url
                                  Base URL for fragments. Each fragment's path
                                  value (if present) will be relative to
@@ -173,6 +182,8 @@ class InfoExtractor(object):
                                             fragment_base_url
                                  * "duration" (optional, int or float)
                                  * "filesize" (optional, int)
+                    * is_from_start  Is a live format that can be downloaded
+                                from the start. Boolean
                     * preference Order number of this format. If this field is
                                  present and not None, the formats get sorted
                                  by this field, regardless of all other values.
@@ -201,8 +212,14 @@ class InfoExtractor(object):
                                  width : height ratio as float.
                     * no_resume  The server does not support resuming the
                                  (HTTP or RTMP) download. Boolean.
-                    * downloader_options  A dictionary of downloader options as
-                                 described in FileDownloader
+                    * has_drm    The format has DRM and cannot be downloaded. Boolean
+                    * downloader_options  A dictionary of downloader options
+                                 (For internal use only)
+                                 * http_chunk_size Chunk size for HTTP downloads
+                                 * ffmpeg_args     Extra arguments for ffmpeg downloader
+                    RTMP formats can also have the additional fields: page_url,
+                    app, play_path, tc_url, flash_version, rtmp_live, rtmp_conn,
+                    rtmp_protocol, rtmp_real_time
 
     url:            Final video URL.
     ext:            Video filename extension.
@@ -211,6 +228,7 @@ class InfoExtractor(object):
 
     The following fields are optional:
 
+    direct:         True if a direct video file was given (must only be set by GenericIE)
     alt_title:      A secondary title of the video.
     display_id      An alternative identifier for the video, not necessarily
                     unique, but available before title. Typically, id is
@@ -225,16 +243,22 @@ class InfoExtractor(object):
                         * "resolution" (optional, string "{width}x{height}",
                                         deprecated)
                         * "filesize" (optional, int)
+                        * "http_headers" (dict) - HTTP headers for the request
     thumbnail:      Full URL to a video thumbnail image.
     description:    Full video description.
     uploader:       Full name of the video uploader.
     license:        License name the video is licensed under.
     creator:        The creator of the video.
-    release_timestamp: UNIX timestamp of the moment the video was released.
-    release_date:   The date (YYYYMMDD) when the video was released.
     timestamp:      UNIX timestamp of the moment the video was uploaded
-    upload_date:    Video upload date (YYYYMMDD).
-                    If not explicitly set, calculated from timestamp.
+    upload_date:    Video upload date in UTC (YYYYMMDD).
+                    If not explicitly set, calculated from timestamp
+    release_timestamp: UNIX timestamp of the moment the video was released.
+                    If it is not clear whether to use timestamp or this, use the former
+    release_date:   The date (YYYYMMDD) when the video was released in UTC.
+                    If not explicitly set, calculated from release_timestamp
+    modified_timestamp: UNIX timestamp of the moment the video was last modified.
+    modified_date:   The date (YYYYMMDD) when the video was last modified in UTC.
+                    If not explicitly set, calculated from modified_timestamp
     uploader_id:    Nickname or id of the video uploader.
     uploader_url:   Full URL to a personal webpage of the video uploader.
     channel:        Full name of the channel the video is uploaded on.
@@ -242,6 +266,7 @@ class InfoExtractor(object):
                     fields. This depends on a particular extractor.
     channel_id:     Id of the channel.
     channel_url:    Full URL to a channel webpage.
+    channel_follower_count: Number of followers of the channel.
     location:       Physical location where the video was filmed.
     subtitles:      The available subtitles as a dictionary in the format
                     {tag: subformats}. "tag" is usually a language code, and
@@ -252,6 +277,8 @@ class InfoExtractor(object):
                         * "url": A URL pointing to the subtitles file
                     It can optionally also have:
                         * "name": Name or description of the subtitles
+                        * "http_headers": A dictionary of additional HTTP headers
+                                  to add to the request.
                     "ext" will be calculated from URL if missing
     automatic_captions: Like 'subtitles'; contains automatically generated
                     captions instead of normal subtitles
@@ -287,10 +314,14 @@ class InfoExtractor(object):
     categories:     A list of categories that the video falls in, for example
                     ["Sports", "Berlin"]
     tags:           A list of tags assigned to the video, e.g. ["sweden", "pop music"]
+    cast:           A list of the video cast
     is_live:        True, False, or None (=unknown). Whether this video is a
                     live stream that goes on instead of a fixed-length video.
     was_live:       True, False, or None (=unknown). Whether this video was
                     originally a live stream.
+    live_status:    None (=unknown), 'is_live', 'is_upcoming', 'was_live', 'not_live',
+                    or 'post_live' (was live, but VOD is not yet processed)
+                    If absent, automatically set from is_live, was_live
     start_time:     Time in seconds where the reproduction should start, as
                     specified in the URL.
     end_time:       Time in seconds where the reproduction should end, as
@@ -302,11 +333,12 @@ class InfoExtractor(object):
     playable_in_embed: Whether this video is allowed to play in embedded
                     players on other sites. Can be True (=always allowed),
                     False (=never allowed), None (=unknown), or a string
-                    specifying the criteria for embedability (Eg: 'whitelist')
+                    specifying the criteria for embedability; e.g. 'whitelist'
     availability:   Under what condition the video is available. One of
                     'private', 'premium_only', 'subscriber_only', 'needs_auth',
                     'unlisted' or 'public'. Use 'InfoExtractor._availability'
                     to set it
+    _old_archive_ids: A list of old archive ids needed for backward compatibility
     __post_extractor: A function to be called just before the metadata is
                     written to either disk, logger or console. The function
                     must return a dict which will be added to the info_dict.
@@ -327,6 +359,7 @@ class InfoExtractor(object):
     series, programme or podcast:
 
     series:         Title of the series or programme the video episode belongs to.
+    series_id:      Id of the series or programme the video episode belongs to, as a unicode string.
     season:         Title of the season the video episode belongs to.
     season_number:  Number of the season the video episode belongs to, as an integer.
     season_id:      Id of the season the video episode belongs to, as a unicode string.
@@ -353,6 +386,16 @@ class InfoExtractor(object):
     disc_number:    Number of the disc or other physical medium the track belongs to,
                     as an integer.
     release_year:   Year (YYYY) when the album was released.
+    composer:       Composer of the piece
+
+    The following fields should only be set for clips that should be cut from the original video:
+
+    section_start:  Start time of the section in seconds
+    section_end:    End time of the section in seconds
+
+    The following fields should only be set for storyboards:
+    rows:           Number of rows in each storyboard fragment, as an integer
+    columns:        Number of columns in each storyboard fragment, as an integer
 
     Unless mentioned otherwise, the fields should be Unicode strings.
 
@@ -363,9 +406,14 @@ class InfoExtractor(object):
     There must be a key "entries", which is a list, an iterable, or a PagedList
     object, each element of which is a valid dictionary by this specification.
 
-    Additionally, playlists can have "id", "title", and any other relevent
+    Additionally, playlists can have "id", "title", and any other relevant
     attributes with the same semantics as videos (see above).
 
+    It can also have the following optional fields:
+
+    playlist_count: The total number of videos in a playlist. If not given,
+                    YoutubeDL tries to calculate it from "entries"
+
 
     _type "multi_video" indicates that there are multiple videos that
     form a single show, for examples multiple acts of an opera or TV episode.
@@ -391,9 +439,33 @@ class InfoExtractor(object):
     title, description etc.
 
 
-    Subclasses of this one should re-define the _real_initialize() and
-    _real_extract() methods and define a _VALID_URL regexp.
-    Probably, they should also be added to the list of extractors.
+    Subclasses of this should also be added to the list of extractors and
+    should define a _VALID_URL regexp and, re-define the _real_extract() and
+    (optionally) _real_initialize() methods.
+
+    Subclasses may also override suitable() if necessary, but ensure the function
+    signature is preserved and that this function imports everything it needs
+    (except other extractors), so that lazy_extractors works correctly.
+
+    Subclasses can define a list of _EMBED_REGEX, which will be searched for in
+    the HTML of Generic webpages. It may also override _extract_embed_urls
+    or _extract_from_webpage as necessary. While these are normally classmethods,
+    _extract_from_webpage is allowed to be an instance method.
+
+    _extract_from_webpage may raise self.StopExtraction() to stop further
+    processing of the webpage and obtain exclusive rights to it. This is useful
+    when the extractor cannot reliably be matched using just the URL,
+    e.g. invidious/peertube instances
+
+    Embed-only extractors can be defined by setting _VALID_URL = False.
+
+    To support username + password (or netrc) login, the extractor must define a
+    _NETRC_MACHINE and re-define _perform_login(username, password) and
+    (optionally) _initialize_pre_login() methods. The _perform_login method will
+    be called between _initialize_pre_login and _real_initialize if credentials
+    are passed by the user. In cases where it is necessary to have the login
+    process as part of the extraction rather than initialization, _perform_login
+    can be left undefined.
 
     _GEO_BYPASS attribute may be set to False in order to disable
     geo restriction bypass mechanisms for a particular extractor.
@@ -410,7 +482,10 @@ class InfoExtractor(object):
     will be used by geo restriction bypass mechanism similarly
     to _GEO_COUNTRIES.
 
-    Finally, the _WORKING attribute should be set to False for broken IEs
+    The _ENABLED attribute should be set to False for IEs that
+    are disabled by default and must be explicitly enabled.
+
+    The _WORKING attribute should be set to False for broken IEs
     in order to warn the users and skip the tests.
     """
 
@@ -421,44 +496,86 @@ class InfoExtractor(object):
     _GEO_COUNTRIES = None
     _GEO_IP_BLOCKS = None
     _WORKING = True
+    _ENABLED = True
+    _NETRC_MACHINE = None
+    IE_DESC = None
+    SEARCH_KEY = None
+    _VALID_URL = None
+    _EMBED_REGEX = []
+
+    def _login_hint(self, method=NO_DEFAULT, netrc=None):
+        password_hint = f'--username and --password, or --netrc ({netrc or self._NETRC_MACHINE}) to provide account credentials'
+        return {
+            None: '',
+            'any': f'Use --cookies, --cookies-from-browser, {password_hint}',
+            'password': f'Use {password_hint}',
+            'cookies': (
+                'Use --cookies-from-browser or --cookies for the authentication. '
+                'See  https://github.com/yt-dlp/yt-dlp/wiki/FAQ#how-do-i-pass-cookies-to-yt-dlp  for how to manually pass cookies'),
+        }[method if method is not NO_DEFAULT else 'any' if self.supports_login() else 'cookies']
 
     def __init__(self, downloader=None):
-        """Constructor. Receives an optional downloader."""
+        """Constructor. Receives an optional downloader (a YoutubeDL instance).
+        If a downloader is not passed during initialization,
+        it must be set using "set_downloader()" before "extract()" is called"""
         self._ready = False
         self._x_forwarded_for_ip = None
+        self._printed_messages = set()
         self.set_downloader(downloader)
 
     @classmethod
-    def suitable(cls, url):
-        """Receives a URL and returns True if suitable for this IE."""
-
+    def _match_valid_url(cls, url):
+        if cls._VALID_URL is False:
+            return None
         # This does not use has/getattr intentionally - we want to know whether
         # we have cached the regexp for *this* class, whereas getattr would also
         # match the superclass
         if '_VALID_URL_RE' not in cls.__dict__:
             cls._VALID_URL_RE = re.compile(cls._VALID_URL)
-        return cls._VALID_URL_RE.match(url) is not None
+        return cls._VALID_URL_RE.match(url)
+
+    @classmethod
+    def suitable(cls, url):
+        """Receives a URL and returns True if suitable for this IE."""
+        # This function must import everything it needs (except other extractors),
+        # so that lazy_extractors works correctly
+        return cls._match_valid_url(url) is not None
 
     @classmethod
     def _match_id(cls, url):
-        if '_VALID_URL_RE' not in cls.__dict__:
-            cls._VALID_URL_RE = re.compile(cls._VALID_URL)
-        m = cls._VALID_URL_RE.match(url)
-        assert m
-        return compat_str(m.group('id'))
+        return cls._match_valid_url(url).group('id')
+
+    @classmethod
+    def get_temp_id(cls, url):
+        try:
+            return cls._match_id(url)
+        except (IndexError, AttributeError):
+            return None
 
     @classmethod
     def working(cls):
         """Getter method for _WORKING."""
         return cls._WORKING
 
+    @classmethod
+    def supports_login(cls):
+        return bool(cls._NETRC_MACHINE)
+
     def initialize(self):
         """Initializes an instance (authentication, etc)."""
+        self._printed_messages = set()
         self._initialize_geo_bypass({
             'countries': self._GEO_COUNTRIES,
             'ip_blocks': self._GEO_IP_BLOCKS,
         })
         if not self._ready:
+            self._initialize_pre_login()
+            if self.supports_login():
+                username, password = self._get_login_info()
+                if username:
+                    self._perform_login(username, password)
+            elif self.get_param('username') and False not in (self.IE_DESC, self._NETRC_MACHINE):
+                self.report_warning(f'Login with password is not supported for this website. {self._login_hint("cookies")}')
             self._real_initialize()
             self._ready = True
 
@@ -524,8 +641,7 @@ def _initialize_geo_bypass(self, geo_bypass_context):
 
             if ip_block:
                 self._x_forwarded_for_ip = GeoUtils.random_ipv4(ip_block)
-                self._downloader.write_debug(
-                    '[debug] Using fake IP %s as X-Forwarded-For' % self._x_forwarded_for_ip)
+                self.write_debug(f'Using fake IP {self._x_forwarded_for_ip} as X-Forwarded-For')
                 return
 
             # Path 2: bypassing based on country code
@@ -544,7 +660,7 @@ def _initialize_geo_bypass(self, geo_bypass_context):
             if country:
                 self._x_forwarded_for_ip = GeoUtils.random_ipv4(country)
                 self._downloader.write_debug(
-                    'Using fake IP %s (%s) as X-Forwarded-For' % (self._x_forwarded_for_ip, country.upper()))
+                    f'Using fake IP {self._x_forwarded_for_ip} ({country.upper()}) as X-Forwarded-For')
 
     def extract(self, url):
         """Extracts URL information and returns it in list of dicts."""
@@ -558,21 +674,32 @@ def extract(self, url):
                         return None
                     if self._x_forwarded_for_ip:
                         ie_result['__x_forwarded_for_ip'] = self._x_forwarded_for_ip
-                    subtitles = ie_result.get('subtitles')
-                    if (subtitles and 'live_chat' in subtitles
-                            and 'no-live-chat' in self.get_param('compat_opts', [])):
-                        del subtitles['live_chat']
+                    subtitles = ie_result.get('subtitles') or {}
+                    if 'no-live-chat' in self.get_param('compat_opts'):
+                        for lang in ('live_chat', 'comments', 'danmaku'):
+                            subtitles.pop(lang, None)
                     return ie_result
                 except GeoRestrictedError as e:
                     if self.__maybe_fake_ip_and_retry(e.countries):
                         continue
                     raise
-        except ExtractorError:
+        except UnsupportedError:
             raise
-        except compat_http_client.IncompleteRead as e:
-            raise ExtractorError('A network error has occurred.', cause=e, expected=True)
+        except ExtractorError as e:
+            kwargs = {
+                'video_id': e.video_id or self.get_temp_id(url),
+                'ie': self.IE_NAME,
+                'tb': e.traceback or sys.exc_info()[2],
+                'expected': e.expected,
+                'cause': e.cause
+            }
+            if hasattr(e, 'countries'):
+                kwargs['countries'] = e.countries
+            raise type(e)(e.orig_msg, **kwargs)
+        except http.client.IncompleteRead as e:
+            raise ExtractorError('A network error has occurred.', cause=e, expected=True, video_id=self.get_temp_id(url))
         except (KeyError, StopIteration) as e:
-            raise ExtractorError('An extractor error has occurred.', cause=e)
+            raise ExtractorError('An extractor error has occurred.', cause=e, video_id=self.get_temp_id(url))
 
     def __maybe_fake_ip_and_retry(self, countries):
         if (not self.get_param('geo_bypass_country', None)
@@ -590,48 +717,67 @@ def __maybe_fake_ip_and_retry(self, countries):
         return False
 
     def set_downloader(self, downloader):
-        """Sets the downloader for this IE."""
+        """Sets a YoutubeDL instance as the downloader for this IE."""
         self._downloader = downloader
 
+    @property
+    def cache(self):
+        return self._downloader.cache
+
+    @property
+    def cookiejar(self):
+        return self._downloader.cookiejar
+
+    def _initialize_pre_login(self):
+        """ Initialization before login. Redefine in subclasses."""
+        pass
+
+    def _perform_login(self, username, password):
+        """ Login with username and password. Redefine in subclasses."""
+        pass
+
     def _real_initialize(self):
         """Real initialization process. Redefine in subclasses."""
         pass
 
     def _real_extract(self, url):
         """Real extraction process. Redefine in subclasses."""
-        pass
+        raise NotImplementedError('This method must be implemented by subclasses')
 
     @classmethod
     def ie_key(cls):
         """A string for getting the InfoExtractor with get_info_extractor"""
-        return compat_str(cls.__name__[:-2])
+        return cls.__name__[:-2]
 
-    @property
-    def IE_NAME(self):
-        return compat_str(type(self).__name__[:-2])
+    @classproperty
+    def IE_NAME(cls):
+        return cls.__name__[:-2]
 
     @staticmethod
     def __can_accept_status_code(err, expected_status):
-        assert isinstance(err, compat_urllib_error.HTTPError)
+        assert isinstance(err, urllib.error.HTTPError)
         if expected_status is None:
             return False
-        if isinstance(expected_status, compat_integer_types):
-            return err.code == expected_status
-        elif isinstance(expected_status, (list, tuple)):
-            return err.code in expected_status
         elif callable(expected_status):
             return expected_status(err.code) is True
         else:
-            assert False
+            return err.code in variadic(expected_status)
+
+    def _create_request(self, url_or_request, data=None, headers=None, query=None):
+        if isinstance(url_or_request, urllib.request.Request):
+            return update_Request(url_or_request, data=data, headers=headers, query=query)
+        if query:
+            url_or_request = update_url_query(url_or_request, query)
+        return sanitized_Request(url_or_request, data, headers or {})
 
-    def _request_webpage(self, url_or_request, video_id, note=None, errnote=None, fatal=True, data=None, headers={}, query={}, expected_status=None):
+    def _request_webpage(self, url_or_request, video_id, note=None, errnote=None, fatal=True, data=None, headers=None, query=None, expected_status=None):
         """
         Return the response handle.
 
         See _download_webpage docstring for arguments specification.
         """
         if not self._downloader._first_webpage_request:
-            sleep_interval = float_or_none(self.get_param('sleep_interval_requests')) or 0
+            sleep_interval = self.get_param('sleep_interval_requests') or 0
             if sleep_interval > 0:
                 self.to_screen('Sleeping %s seconds ...' % sleep_interval)
                 time.sleep(sleep_interval)
@@ -642,9 +788,9 @@ def _request_webpage(self, url_or_request, video_id, note=None, errnote=None, fa
             self.report_download_webpage(video_id)
         elif note is not False:
             if video_id is None:
-                self.to_screen('%s' % (note,))
+                self.to_screen(str(note))
             else:
-                self.to_screen('%s: %s' % (video_id, note))
+                self.to_screen(f'{video_id}: {note}')
 
         # Some sites check X-Forwarded-For HTTP header in order to figure out
         # the origin of the client behind proxy. This allows bypassing geo
@@ -652,21 +798,13 @@ def _request_webpage(self, url_or_request, video_id, note=None, errnote=None, fa
         # geo unrestricted country. We will do so once we encounter any
         # geo restriction error.
         if self._x_forwarded_for_ip:
-            if 'X-Forwarded-For' not in headers:
-                headers['X-Forwarded-For'] = self._x_forwarded_for_ip
+            headers = (headers or {}).copy()
+            headers.setdefault('X-Forwarded-For', self._x_forwarded_for_ip)
 
-        if isinstance(url_or_request, compat_urllib_request.Request):
-            url_or_request = update_Request(
-                url_or_request, data=data, headers=headers, query=query)
-        else:
-            if query:
-                url_or_request = update_url_query(url_or_request, query)
-            if data is not None or headers:
-                url_or_request = sanitized_Request(url_or_request, data, headers)
         try:
-            return self._downloader.urlopen(url_or_request)
+            return self._downloader.urlopen(self._create_request(url_or_request, data, headers, query))
         except network_exceptions as err:
-            if isinstance(err, compat_urllib_error.HTTPError):
+            if isinstance(err, urllib.error.HTTPError):
                 if self.__can_accept_status_code(err, expected_status):
                     # Retain reference to error to prevent file object from
                     # being closed before it can be read. Works around the
@@ -680,21 +818,49 @@ def _request_webpage(self, url_or_request, video_id, note=None, errnote=None, fa
             if errnote is None:
                 errnote = 'Unable to download webpage'
 
-            errmsg = '%s: %s' % (errnote, error_to_compat_str(err))
+            errmsg = f'{errnote}: {error_to_compat_str(err)}'
             if fatal:
-                raise ExtractorError(errmsg, sys.exc_info()[2], cause=err)
+                raise ExtractorError(errmsg, cause=err)
             else:
                 self.report_warning(errmsg)
                 return False
 
-    def _download_webpage_handle(self, url_or_request, video_id, note=None, errnote=None, fatal=True, encoding=None, data=None, headers={}, query={}, expected_status=None):
+    def _download_webpage_handle(self, url_or_request, video_id, note=None, errnote=None, fatal=True,
+                                 encoding=None, data=None, headers={}, query={}, expected_status=None):
         """
         Return a tuple (page content as string, URL handle).
 
-        See _download_webpage docstring for arguments specification.
+        Arguments:
+        url_or_request -- plain text URL as a string or
+            a urllib.request.Request object
+        video_id -- Video/playlist/item identifier (string)
+
+        Keyword arguments:
+        note -- note printed before downloading (string)
+        errnote -- note printed in case of an error (string)
+        fatal -- flag denoting whether error should be considered fatal,
+            i.e. whether it should cause ExtractionError to be raised,
+            otherwise a warning will be reported and extraction continued
+        encoding -- encoding for a page content decoding, guessed automatically
+            when not explicitly specified
+        data -- POST data (bytes)
+        headers -- HTTP headers (dict)
+        query -- URL query (dict)
+        expected_status -- allows to accept failed HTTP requests (non 2xx
+            status code) by explicitly specifying a set of accepted status
+            codes. Can be any of the following entities:
+                - an integer type specifying an exact failed status code to
+                  accept
+                - a list or a tuple of integer types specifying a list of
+                  failed status codes to accept
+                - a callable accepting an actual failed status code and
+                  returning True if it should be accepted
+            Note that this argument does not affect success status codes (2xx)
+            which are always accepted.
         """
+
         # Strip hashes from the URL (#1038)
-        if isinstance(url_or_request, (compat_str, str)):
+        if isinstance(url_or_request, str):
             url_or_request = url_or_request.partition('#')[0]
 
         urlh = self._request_webpage(url_or_request, video_id, note, errnote, fatal, data=data, headers=headers, query=query, expected_status=expected_status)
@@ -749,218 +915,200 @@ def __check_blocked(self, content):
                 'Visit http://blocklist.rkn.gov.ru/ for a block reason.',
                 expected=True)
 
+    def _request_dump_filename(self, url, video_id):
+        basen = f'{video_id}_{url}'
+        trim_length = self.get_param('trim_file_name') or 240
+        if len(basen) > trim_length:
+            h = '___' + hashlib.md5(basen.encode('utf-8')).hexdigest()
+            basen = basen[:trim_length - len(h)] + h
+        filename = sanitize_filename(f'{basen}.dump', restricted=True)
+        # Working around MAX_PATH limitation on Windows (see
+        # http://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx)
+        if compat_os_name == 'nt':
+            absfilepath = os.path.abspath(filename)
+            if len(absfilepath) > 259:
+                filename = fR'\\?\{absfilepath}'
+        return filename
+
+    def __decode_webpage(self, webpage_bytes, encoding, headers):
+        if not encoding:
+            encoding = self._guess_encoding_from_content(headers.get('Content-Type', ''), webpage_bytes)
+        try:
+            return webpage_bytes.decode(encoding, 'replace')
+        except LookupError:
+            return webpage_bytes.decode('utf-8', 'replace')
+
     def _webpage_read_content(self, urlh, url_or_request, video_id, note=None, errnote=None, fatal=True, prefix=None, encoding=None):
-        content_type = urlh.headers.get('Content-Type', '')
         webpage_bytes = urlh.read()
         if prefix is not None:
             webpage_bytes = prefix + webpage_bytes
-        if not encoding:
-            encoding = self._guess_encoding_from_content(content_type, webpage_bytes)
         if self.get_param('dump_intermediate_pages', False):
             self.to_screen('Dumping request to ' + urlh.geturl())
             dump = base64.b64encode(webpage_bytes).decode('ascii')
             self._downloader.to_screen(dump)
-        if self.get_param('write_pages', False):
-            basen = '%s_%s' % (video_id, urlh.geturl())
-            if len(basen) > 240:
-                h = '___' + hashlib.md5(basen.encode('utf-8')).hexdigest()
-                basen = basen[:240 - len(h)] + h
-            raw_filename = basen + '.dump'
-            filename = sanitize_filename(raw_filename, restricted=True)
-            self.to_screen('Saving request to ' + filename)
-            # Working around MAX_PATH limitation on Windows (see
-            # http://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx)
-            if compat_os_name == 'nt':
-                absfilepath = os.path.abspath(filename)
-                if len(absfilepath) > 259:
-                    filename = '\\\\?\\' + absfilepath
+        if self.get_param('write_pages'):
+            filename = self._request_dump_filename(urlh.geturl(), video_id)
+            self.to_screen(f'Saving request to {filename}')
             with open(filename, 'wb') as outf:
                 outf.write(webpage_bytes)
 
-        try:
-            content = webpage_bytes.decode(encoding, 'replace')
-        except LookupError:
-            content = webpage_bytes.decode('utf-8', 'replace')
-
+        content = self.__decode_webpage(webpage_bytes, encoding, urlh.headers)
         self.__check_blocked(content)
 
         return content
 
+    def __print_error(self, errnote, fatal, video_id, err):
+        if fatal:
+            raise ExtractorError(f'{video_id}: {errnote}', cause=err)
+        elif errnote:
+            self.report_warning(f'{video_id}: {errnote}: {err}')
+
+    def _parse_xml(self, xml_string, video_id, transform_source=None, fatal=True, errnote=None):
+        if transform_source:
+            xml_string = transform_source(xml_string)
+        try:
+            return compat_etree_fromstring(xml_string.encode('utf-8'))
+        except xml.etree.ElementTree.ParseError as ve:
+            self.__print_error('Failed to parse XML' if errnote is None else errnote, fatal, video_id, ve)
+
+    def _parse_json(self, json_string, video_id, transform_source=None, fatal=True, errnote=None, **parser_kwargs):
+        try:
+            return json.loads(
+                json_string, cls=LenientJSONDecoder, strict=False, transform_source=transform_source, **parser_kwargs)
+        except ValueError as ve:
+            self.__print_error('Failed to parse JSON' if errnote is None else errnote, fatal, video_id, ve)
+
+    def _parse_socket_response_as_json(self, data, *args, **kwargs):
+        return self._parse_json(data[data.find('{'):data.rfind('}') + 1], *args, **kwargs)
+
+    def __create_download_methods(name, parser, note, errnote, return_value):
+
+        def parse(ie, content, *args, errnote=errnote, **kwargs):
+            if parser is None:
+                return content
+            if errnote is False:
+                kwargs['errnote'] = errnote
+            # parser is fetched by name so subclasses can override it
+            return getattr(ie, parser)(content, *args, **kwargs)
+
+        def download_handle(self, url_or_request, video_id, note=note, errnote=errnote, transform_source=None,
+                            fatal=True, encoding=None, data=None, headers={}, query={}, expected_status=None):
+            res = self._download_webpage_handle(
+                url_or_request, video_id, note=note, errnote=errnote, fatal=fatal, encoding=encoding,
+                data=data, headers=headers, query=query, expected_status=expected_status)
+            if res is False:
+                return res
+            content, urlh = res
+            return parse(self, content, video_id, transform_source=transform_source, fatal=fatal, errnote=errnote), urlh
+
+        def download_content(self, url_or_request, video_id, note=note, errnote=errnote, transform_source=None,
+                             fatal=True, encoding=None, data=None, headers={}, query={}, expected_status=None):
+            if self.get_param('load_pages'):
+                url_or_request = self._create_request(url_or_request, data, headers, query)
+                filename = self._request_dump_filename(url_or_request.full_url, video_id)
+                self.to_screen(f'Loading request from {filename}')
+                try:
+                    with open(filename, 'rb') as dumpf:
+                        webpage_bytes = dumpf.read()
+                except OSError as e:
+                    self.report_warning(f'Unable to load request from disk: {e}')
+                else:
+                    content = self.__decode_webpage(webpage_bytes, encoding, url_or_request.headers)
+                    return parse(self, content, video_id, transform_source=transform_source, fatal=fatal, errnote=errnote)
+            kwargs = {
+                'note': note,
+                'errnote': errnote,
+                'transform_source': transform_source,
+                'fatal': fatal,
+                'encoding': encoding,
+                'data': data,
+                'headers': headers,
+                'query': query,
+                'expected_status': expected_status,
+            }
+            if parser is None:
+                kwargs.pop('transform_source')
+            # The method is fetched by name so subclasses can override _download_..._handle
+            res = getattr(self, download_handle.__name__)(url_or_request, video_id, **kwargs)
+            return res if res is False else res[0]
+
+        def impersonate(func, name, return_value):
+            func.__name__, func.__qualname__ = name, f'InfoExtractor.{name}'
+            func.__doc__ = f'''
+                @param transform_source     Apply this transformation before parsing
+                @returns                    {return_value}
+
+                See _download_webpage_handle docstring for other arguments specification
+            '''
+
+        impersonate(download_handle, f'_download_{name}_handle', f'({return_value}, URL handle)')
+        impersonate(download_content, f'_download_{name}', f'{return_value}')
+        return download_handle, download_content
+
+    _download_xml_handle, _download_xml = __create_download_methods(
+        'xml', '_parse_xml', 'Downloading XML', 'Unable to download XML', 'xml as an xml.etree.ElementTree.Element')
+    _download_json_handle, _download_json = __create_download_methods(
+        'json', '_parse_json', 'Downloading JSON metadata', 'Unable to download JSON metadata', 'JSON object as a dict')
+    _download_socket_json_handle, _download_socket_json = __create_download_methods(
+        'socket_json', '_parse_socket_response_as_json', 'Polling socket', 'Unable to poll socket', 'JSON object as a dict')
+    __download_webpage = __create_download_methods('webpage', None, None, None, 'data of the page as a string')[1]
+
     def _download_webpage(
             self, url_or_request, video_id, note=None, errnote=None,
-            fatal=True, tries=1, timeout=5, encoding=None, data=None,
-            headers={}, query={}, expected_status=None):
+            fatal=True, tries=1, timeout=NO_DEFAULT, *args, **kwargs):
         """
         Return the data of the page as a string.
 
-        Arguments:
-        url_or_request -- plain text URL as a string or
-            a compat_urllib_request.Requestobject
-        video_id -- Video/playlist/item identifier (string)
-
         Keyword arguments:
-        note -- note printed before downloading (string)
-        errnote -- note printed in case of an error (string)
-        fatal -- flag denoting whether error should be considered fatal,
-            i.e. whether it should cause ExtractionError to be raised,
-            otherwise a warning will be reported and extraction continued
         tries -- number of tries
         timeout -- sleep interval between tries
-        encoding -- encoding for a page content decoding, guessed automatically
-            when not explicitly specified
-        data -- POST data (bytes)
-        headers -- HTTP headers (dict)
-        query -- URL query (dict)
-        expected_status -- allows to accept failed HTTP requests (non 2xx
-            status code) by explicitly specifying a set of accepted status
-            codes. Can be any of the following entities:
-                - an integer type specifying an exact failed status code to
-                  accept
-                - a list or a tuple of integer types specifying a list of
-                  failed status codes to accept
-                - a callable accepting an actual failed status code and
-                  returning True if it should be accepted
-            Note that this argument does not affect success status codes (2xx)
-            which are always accepted.
+
+        See _download_webpage_handle docstring for other arguments specification.
         """
 
-        success = False
+        R''' # NB: These are unused; should they be deprecated?
+        if tries != 1:
+            self._downloader.deprecation_warning('tries argument is deprecated in InfoExtractor._download_webpage')
+        if timeout is NO_DEFAULT:
+            timeout = 5
+        else:
+            self._downloader.deprecation_warning('timeout argument is deprecated in InfoExtractor._download_webpage')
+        '''
+
         try_count = 0
-        while success is False:
+        while True:
             try:
-                res = self._download_webpage_handle(
-                    url_or_request, video_id, note, errnote, fatal,
-                    encoding=encoding, data=data, headers=headers, query=query,
-                    expected_status=expected_status)
-                success = True
-            except compat_http_client.IncompleteRead as e:
+                return self.__download_webpage(url_or_request, video_id, note, errnote, None, fatal, *args, **kwargs)
+            except http.client.IncompleteRead as e:
                 try_count += 1
                 if try_count >= tries:
                     raise e
                 self._sleep(timeout, video_id)
-        if res is False:
-            return res
-        else:
-            content, _ = res
-            return content
-
-    def _download_xml_handle(
-            self, url_or_request, video_id, note='Downloading XML',
-            errnote='Unable to download XML', transform_source=None,
-            fatal=True, encoding=None, data=None, headers={}, query={},
-            expected_status=None):
-        """
-        Return a tuple (xml as an compat_etree_Element, URL handle).
 
-        See _download_webpage docstring for arguments specification.
-        """
-        res = self._download_webpage_handle(
-            url_or_request, video_id, note, errnote, fatal=fatal,
-            encoding=encoding, data=data, headers=headers, query=query,
-            expected_status=expected_status)
-        if res is False:
-            return res
-        xml_string, urlh = res
-        return self._parse_xml(
-            xml_string, video_id, transform_source=transform_source,
-            fatal=fatal), urlh
-
-    def _download_xml(
-            self, url_or_request, video_id,
-            note='Downloading XML', errnote='Unable to download XML',
-            transform_source=None, fatal=True, encoding=None,
-            data=None, headers={}, query={}, expected_status=None):
-        """
-        Return the xml as an compat_etree_Element.
-
-        See _download_webpage docstring for arguments specification.
-        """
-        res = self._download_xml_handle(
-            url_or_request, video_id, note=note, errnote=errnote,
-            transform_source=transform_source, fatal=fatal, encoding=encoding,
-            data=data, headers=headers, query=query,
-            expected_status=expected_status)
-        return res if res is False else res[0]
-
-    def _parse_xml(self, xml_string, video_id, transform_source=None, fatal=True):
-        if transform_source:
-            xml_string = transform_source(xml_string)
-        try:
-            return compat_etree_fromstring(xml_string.encode('utf-8'))
-        except compat_xml_parse_error as ve:
-            errmsg = '%s: Failed to parse XML ' % video_id
-            if fatal:
-                raise ExtractorError(errmsg, cause=ve)
-            else:
-                self.report_warning(errmsg + str(ve))
-
-    def _download_json_handle(
-            self, url_or_request, video_id, note='Downloading JSON metadata',
-            errnote='Unable to download JSON metadata', transform_source=None,
-            fatal=True, encoding=None, data=None, headers={}, query={},
-            expected_status=None):
-        """
-        Return a tuple (JSON object, URL handle).
-
-        See _download_webpage docstring for arguments specification.
-        """
-        res = self._download_webpage_handle(
-            url_or_request, video_id, note, errnote, fatal=fatal,
-            encoding=encoding, data=data, headers=headers, query=query,
-            expected_status=expected_status)
-        if res is False:
-            return res
-        json_string, urlh = res
-        return self._parse_json(
-            json_string, video_id, transform_source=transform_source,
-            fatal=fatal), urlh
-
-    def _download_json(
-            self, url_or_request, video_id, note='Downloading JSON metadata',
-            errnote='Unable to download JSON metadata', transform_source=None,
-            fatal=True, encoding=None, data=None, headers={}, query={},
-            expected_status=None):
-        """
-        Return the JSON object as a dict.
-
-        See _download_webpage docstring for arguments specification.
-        """
-        res = self._download_json_handle(
-            url_or_request, video_id, note=note, errnote=errnote,
-            transform_source=transform_source, fatal=fatal, encoding=encoding,
-            data=data, headers=headers, query=query,
-            expected_status=expected_status)
-        return res if res is False else res[0]
-
-    def _parse_json(self, json_string, video_id, transform_source=None, fatal=True):
-        if transform_source:
-            json_string = transform_source(json_string)
-        try:
-            return json.loads(json_string)
-        except ValueError as ve:
-            errmsg = '%s: Failed to parse JSON ' % video_id
-            if fatal:
-                raise ExtractorError(errmsg, cause=ve)
-            else:
-                self.report_warning(errmsg + str(ve))
-
-    def report_warning(self, msg, video_id=None, *args, **kwargs):
-        idstr = '' if video_id is None else '%s: ' % video_id
-        self._downloader.report_warning(
-            '[%s] %s%s' % (self.IE_NAME, idstr, msg), *args, **kwargs)
+    def report_warning(self, msg, video_id=None, *args, only_once=False, **kwargs):
+        idstr = format_field(video_id, None, '%s: ')
+        msg = f'[{self.IE_NAME}] {idstr}{msg}'
+        if only_once:
+            if f'WARNING: {msg}' in self._printed_messages:
+                return
+            self._printed_messages.add(f'WARNING: {msg}')
+        self._downloader.report_warning(msg, *args, **kwargs)
 
     def to_screen(self, msg, *args, **kwargs):
         """Print msg to screen, prefixing it with '[ie_name]'"""
-        self._downloader.to_screen('[%s] %s' % (self.IE_NAME, msg), *args, **kwargs)
+        self._downloader.to_screen(f'[{self.IE_NAME}] {msg}', *args, **kwargs)
 
     def write_debug(self, msg, *args, **kwargs):
-        self._downloader.write_debug('[%s] %s' % (self.IE_NAME, msg), *args, **kwargs)
+        self._downloader.write_debug(f'[{self.IE_NAME}] {msg}', *args, **kwargs)
 
     def get_param(self, name, default=None, *args, **kwargs):
         if self._downloader:
             return self._downloader.params.get(name, default, *args, **kwargs)
         return default
 
+    def report_drm(self, video_id, partial=False):
+        self.raise_no_formats('This video is DRM protected', expected=True, video_id=video_id)
+
     def report_extraction(self, id_or_name):
         """Report information extraction."""
         self.to_screen('%s: Extracting information' % id_or_name)
@@ -978,61 +1126,70 @@ def report_login(self):
         self.to_screen('Logging in')
 
     def raise_login_required(
-            self, msg='This video is only available for registered users', metadata_available=False):
-        if metadata_available and self.get_param('ignore_no_formats_error'):
+            self, msg='This video is only available for registered users',
+            metadata_available=False, method=NO_DEFAULT):
+        if metadata_available and (
+                self.get_param('ignore_no_formats_error') or self.get_param('wait_for_video')):
             self.report_warning(msg)
-        raise ExtractorError(
-            '%s. Use --cookies, --username and --password or --netrc to provide account credentials' % msg,
-            expected=True)
+            return
+        msg += format_field(self._login_hint(method), None, '. %s')
+        raise ExtractorError(msg, expected=True)
 
     def raise_geo_restricted(
             self, msg='This video is not available from your location due to geo restriction',
             countries=None, metadata_available=False):
-        if metadata_available and self.get_param('ignore_no_formats_error'):
+        if metadata_available and (
+                self.get_param('ignore_no_formats_error') or self.get_param('wait_for_video')):
             self.report_warning(msg)
         else:
             raise GeoRestrictedError(msg, countries=countries)
 
     def raise_no_formats(self, msg, expected=False, video_id=None):
-        if expected and self.get_param('ignore_no_formats_error'):
+        if expected and (
+                self.get_param('ignore_no_formats_error') or self.get_param('wait_for_video')):
             self.report_warning(msg, video_id)
+        elif isinstance(msg, ExtractorError):
+            raise msg
         else:
             raise ExtractorError(msg, expected=expected, video_id=video_id)
 
     # Methods for following #608
     @staticmethod
-    def url_result(url, ie=None, video_id=None, video_title=None):
+    def url_result(url, ie=None, video_id=None, video_title=None, *, url_transparent=False, **kwargs):
         """Returns a URL that points to a page that should be processed"""
-        # TODO: ie should be the class used for getting the info
-        video_info = {'_type': 'url',
-                      'url': url,
-                      'ie_key': ie}
+        if ie is not None:
+            kwargs['ie_key'] = ie if isinstance(ie, str) else ie.ie_key()
         if video_id is not None:
-            video_info['id'] = video_id
+            kwargs['id'] = video_id
         if video_title is not None:
-            video_info['title'] = video_title
-        return video_info
+            kwargs['title'] = video_title
+        return {
+            **kwargs,
+            '_type': 'url_transparent' if url_transparent else 'url',
+            'url': url,
+        }
 
-    def playlist_from_matches(self, matches, playlist_id=None, playlist_title=None, getter=None, ie=None):
-        urls = orderedSet(
-            self.url_result(self._proto_relative_url(getter(m) if getter else m), ie)
-            for m in matches)
-        return self.playlist_result(
-            urls, playlist_id=playlist_id, playlist_title=playlist_title)
+    @classmethod
+    def playlist_from_matches(cls, matches, playlist_id=None, playlist_title=None,
+                              getter=IDENTITY, ie=None, video_kwargs=None, **kwargs):
+        return cls.playlist_result(
+            (cls.url_result(m, ie, **(video_kwargs or {})) for m in orderedSet(map(getter, matches), lazy=True)),
+            playlist_id, playlist_title, **kwargs)
 
     @staticmethod
-    def playlist_result(entries, playlist_id=None, playlist_title=None, playlist_description=None, **kwargs):
+    def playlist_result(entries, playlist_id=None, playlist_title=None, playlist_description=None, *, multi_video=False, **kwargs):
         """Returns a playlist"""
-        video_info = {'_type': 'playlist',
-                      'entries': entries}
-        video_info.update(kwargs)
         if playlist_id:
-            video_info['id'] = playlist_id
+            kwargs['id'] = playlist_id
         if playlist_title:
-            video_info['title'] = playlist_title
+            kwargs['title'] = playlist_title
         if playlist_description is not None:
-            video_info['description'] = playlist_description
-        return video_info
+            kwargs['description'] = playlist_description
+        return {
+            **kwargs,
+            '_type': 'multi_video' if multi_video else 'playlist',
+            'entries': entries,
+        }
 
     def _search_regex(self, pattern, string, name, default=NO_DEFAULT, fatal=True, flags=0, group=None):
         """
@@ -1041,7 +1198,9 @@ def _search_regex(self, pattern, string, name, default=NO_DEFAULT, fatal=True, f
         In case of failure return a default value or raise a WARNING or a
         RegexNotFoundError, depending on fatal, specifying the field name.
         """
-        if isinstance(pattern, (str, compat_str, compiled_regex_type)):
+        if string is None:
+            mobj = None
+        elif isinstance(pattern, (str, re.Pattern)):
             mobj = re.search(pattern, string, flags)
         else:
             for p in pattern:
@@ -1049,15 +1208,14 @@ def _search_regex(self, pattern, string, name, default=NO_DEFAULT, fatal=True, f
                 if mobj:
                     break
 
-        if not self.get_param('no_color') and compat_os_name != 'nt' and sys.stderr.isatty():
-            _name = '\033[0;34m%s\033[0m' % name
-        else:
-            _name = name
+        _name = self._downloader._format_err(name, self._downloader.Styles.EMPHASIS)
 
         if mobj:
             if group is None:
                 # return the first matching group
                 return next(g for g in mobj.groups() if g is not None)
+            elif isinstance(group, (list, tuple)):
+                return tuple(mobj.group(g) for g in group)
             else:
                 return mobj.group(group)
         elif default is not NO_DEFAULT:
@@ -1068,6 +1226,33 @@ def _search_regex(self, pattern, string, name, default=NO_DEFAULT, fatal=True, f
             self.report_warning('unable to extract %s' % _name + bug_reports_message())
             return None
 
+    def _search_json(self, start_pattern, string, name, video_id, *, end_pattern='',
+                     contains_pattern='(?s:.+)', fatal=True, default=NO_DEFAULT, **kwargs):
+        """Searches string for the JSON object specified by start_pattern"""
+        # NB: end_pattern is only used to reduce the size of the initial match
+        if default is NO_DEFAULT:
+            default, has_default = {}, False
+        else:
+            fatal, has_default = False, True
+
+        json_string = self._search_regex(
+            rf'(?:{start_pattern})\s*(?P<json>{{\s*(?:{contains_pattern})\s*}})\s*(?:{end_pattern})',
+            string, name, group='json', fatal=fatal, default=None if has_default else NO_DEFAULT)
+        if not json_string:
+            return default
+
+        _name = self._downloader._format_err(name, self._downloader.Styles.EMPHASIS)
+        try:
+            return self._parse_json(json_string, video_id, ignore_extra=True, **kwargs)
+        except ExtractorError as e:
+            if fatal:
+                raise ExtractorError(
+                    f'Unable to extract {_name} - Failed to parse JSON', cause=e.cause, video_id=video_id)
+            elif not has_default:
+                self.report_warning(
+                    f'Unable to extract {_name} - Failed to parse JSON: {e}', video_id=video_id)
+        return default
+
     def _html_search_regex(self, pattern, string, name, default=NO_DEFAULT, fatal=True, flags=0, group=None):
         """
         Like _search_regex, but strips HTML tags and unescapes entities.
@@ -1085,14 +1270,17 @@ def _get_netrc_login_info(self, netrc_machine=None):
 
         if self.get_param('usenetrc', False):
             try:
-                info = netrc.netrc().authenticators(netrc_machine)
+                netrc_file = compat_expanduser(self.get_param('netrc_location') or '~')
+                if os.path.isdir(netrc_file):
+                    netrc_file = os.path.join(netrc_file, '.netrc')
+                info = netrc.netrc(file=netrc_file).authenticators(netrc_machine)
                 if info is not None:
                     username = info[0]
                     password = info[2]
                 else:
                     raise netrc.NetrcParseError(
                         'No authenticators for %s' % netrc_machine)
-            except (IOError, netrc.NetrcParseError) as err:
+            except (OSError, netrc.NetrcParseError) as err:
                 self.report_warning(
                     'parsing .netrc: %s' % error_to_compat_str(err))
 
@@ -1129,14 +1317,14 @@ def _get_tfa_info(self, note='two-factor verification code'):
         if tfa is not None:
             return tfa
 
-        return compat_getpass('Type %s and press [Return]: ' % note)
+        return getpass.getpass('Type %s and press [Return]: ' % note)
 
     # Helper functions for extracting OpenGraph info
     @staticmethod
     def _og_regexes(prop):
         content_re = r'content=(?:"([^"]+?)"|\'([^\']+?)\'|\s*([^\s"\'=<>`]+?))'
-        property_re = (r'(?:name|property)=(?:\'og[:-]%(prop)s\'|"og[:-]%(prop)s"|\s*og[:-]%(prop)s\b)'
-                       % {'prop': re.escape(prop)})
+        property_re = (r'(?:name|property)=(?:\'og%(sep)s%(prop)s\'|"og%(sep)s%(prop)s"|\s*og%(sep)s%(prop)s\b)'
+                       % {'prop': re.escape(prop), 'sep': '(?:&#x3A;|[:-])'})
         template = r'<meta[^>]+?%s[^>]+?%s'
         return [
             template % (property_re, content_re),
@@ -1150,8 +1338,7 @@ def _meta_regex(prop):
                     [^>]+?content=(["\'])(?P<content>.*?)\2''' % re.escape(prop)
 
     def _og_search_property(self, prop, html, name=None, **kargs):
-        if not isinstance(prop, (list, tuple)):
-            prop = [prop]
+        prop = variadic(prop)
         if name is None:
             name = 'OpenGraph %s' % prop[0]
         og_regexes = []
@@ -1168,8 +1355,8 @@ def _og_search_thumbnail(self, html, **kargs):
     def _og_search_description(self, html, **kargs):
         return self._og_search_property('description', html, fatal=False, **kargs)
 
-    def _og_search_title(self, html, **kargs):
-        return self._og_search_property('title', html, **kargs)
+    def _og_search_title(self, html, *, fatal=False, **kargs):
+        return self._og_search_property('title', html, fatal=fatal, **kargs)
 
     def _og_search_video_url(self, html, name='video url', secure=True, **kargs):
         regexes = self._og_regexes('video') + self._og_regexes('video:url')
@@ -1180,9 +1367,11 @@ def _og_search_video_url(self, html, name='video url', secure=True, **kargs):
     def _og_search_url(self, html, **kargs):
         return self._og_search_property('url', html, **kargs)
 
+    def _html_extract_title(self, html, name='title', *, fatal=False, **kwargs):
+        return self._html_search_regex(r'(?s)<title\b[^>]*>([^<]+)</title>', html, name, fatal=fatal, **kwargs)
+
     def _html_search_meta(self, name, html, display_name=None, fatal=False, **kwargs):
-        if not isinstance(name, (list, tuple)):
-            name = [name]
+        name = variadic(name)
         if display_name is None:
             display_name = name[0]
         return self._html_search_regex(
@@ -1192,12 +1381,20 @@ def _html_search_meta(self, name, html, display_name=None, fatal=False, **kwargs
     def _dc_search_uploader(self, html):
         return self._html_search_meta('dc.creator', html, 'uploader')
 
-    def _rta_search(self, html):
+    @staticmethod
+    def _rta_search(html):
         # See http://www.rtalabel.org/index.php?content=howtofaq#single
         if re.search(r'(?ix)<meta\s+name="rating"\s+'
                      r'     content="RTA-5042-1996-1400-1577-RTA"',
                      html):
             return 18
+
+        # And then there are the jokers who advertise that they use RTA, but actually don't.
+        AGE_LIMIT_MARKERS = [
+            r'Proudly Labeled <a href="http://www\.rtalabel\.org/" title="Restricted to Adults">RTA</a>',
+        ]
+        if any(re.search(marker, html) for marker in AGE_LIMIT_MARKERS):
+            return 18
         return 0
 
     def _media_rating_search(self, html):
@@ -1236,27 +1433,25 @@ def _twitter_search_player(self, html):
         return self._html_search_meta('twitter:player', html,
                                       'twitter card player')
 
-    def _search_json_ld(self, html, video_id, expected_type=None, **kwargs):
-        json_ld_list = list(re.finditer(JSON_LD_RE, html))
-        default = kwargs.get('default', NO_DEFAULT)
-        # JSON-LD may be malformed and thus `fatal` should be respected.
-        # At the same time `default` may be passed that assumes `fatal=False`
-        # for _search_regex. Let's simulate the same behavior here as well.
-        fatal = kwargs.get('fatal', True) if default == NO_DEFAULT else False
-        json_ld = []
-        for mobj in json_ld_list:
-            json_ld_item = self._parse_json(
-                mobj.group('json_ld'), video_id, fatal=fatal)
-            if not json_ld_item:
-                continue
-            if isinstance(json_ld_item, dict):
-                json_ld.append(json_ld_item)
-            elif isinstance(json_ld_item, (list, tuple)):
-                json_ld.extend(json_ld_item)
-        if json_ld:
-            json_ld = self._json_ld(json_ld, video_id, fatal=fatal, expected_type=expected_type)
-        if json_ld:
-            return json_ld
+    def _yield_json_ld(self, html, video_id, *, fatal=True, default=NO_DEFAULT):
+        """Yield all json ld objects in the html"""
+        if default is not NO_DEFAULT:
+            fatal = False
+        for mobj in re.finditer(JSON_LD_RE, html):
+            json_ld_item = self._parse_json(mobj.group('json_ld'), video_id, fatal=fatal)
+            for json_ld in variadic(json_ld_item):
+                if isinstance(json_ld, dict):
+                    yield json_ld
+
+    def _search_json_ld(self, html, video_id, expected_type=None, *, fatal=True, default=NO_DEFAULT):
+        """Search for a video in any json ld in the html"""
+        if default is not NO_DEFAULT:
+            fatal = False
+        info = self._json_ld(
+            list(self._yield_json_ld(html, video_id, fatal=fatal, default=default)),
+            video_id, fatal=fatal, expected_type=expected_type)
+        if info:
+            return info
         if default is not NO_DEFAULT:
             return default
         elif fatal:
@@ -1266,7 +1461,7 @@ def _search_json_ld(self, html, video_id, expected_type=None, **kwargs):
             return {}
 
     def _json_ld(self, json_ld, video_id, fatal=True, expected_type=None):
-        if isinstance(json_ld, compat_str):
+        if isinstance(json_ld, str):
             json_ld = self._parse_json(json_ld, video_id, fatal=fatal)
         if not json_ld:
             return {}
@@ -1287,6 +1482,10 @@ def _json_ld(self, json_ld, video_id, fatal=True, expected_type=None):
             'ViewAction': 'view',
         }
 
+        def is_type(e, *expected_types):
+            type = variadic(traverse_obj(e, '@type'))
+            return any(x in type for x in expected_types)
+
         def extract_interaction_type(e):
             interaction_type = e.get('interactionType')
             if isinstance(interaction_type, dict):
@@ -1300,9 +1499,7 @@ def extract_interaction_statistic(e):
             if not isinstance(interaction_statistic, list):
                 return
             for is_e in interaction_statistic:
-                if not isinstance(is_e, dict):
-                    continue
-                if is_e.get('@type') != 'InteractionCounter':
+                if not is_type(is_e, 'InteractionCounter'):
                     continue
                 interaction_type = extract_interaction_type(is_e)
                 if not interaction_type:
@@ -1321,35 +1518,69 @@ def extract_interaction_statistic(e):
                     continue
                 info[count_key] = interaction_count
 
+        def extract_chapter_information(e):
+            chapters = [{
+                'title': part.get('name'),
+                'start_time': part.get('startOffset'),
+                'end_time': part.get('endOffset'),
+            } for part in variadic(e.get('hasPart') or []) if part.get('@type') == 'Clip']
+            for idx, (last_c, current_c, next_c) in enumerate(zip(
+                    [{'end_time': 0}] + chapters, chapters, chapters[1:])):
+                current_c['end_time'] = current_c['end_time'] or next_c['start_time']
+                current_c['start_time'] = current_c['start_time'] or last_c['end_time']
+                if None in current_c.values():
+                    self.report_warning(f'Chapter {idx} contains broken data. Not extracting chapters')
+                    return
+            if chapters:
+                chapters[-1]['end_time'] = chapters[-1]['end_time'] or info['duration']
+                info['chapters'] = chapters
+
         def extract_video_object(e):
-            assert e['@type'] == 'VideoObject'
             author = e.get('author')
             info.update({
                 'url': url_or_none(e.get('contentUrl')),
+                'ext': mimetype2ext(e.get('encodingFormat')),
                 'title': unescapeHTML(e.get('name')),
                 'description': unescapeHTML(e.get('description')),
-                'thumbnail': url_or_none(e.get('thumbnailUrl') or e.get('thumbnailURL')),
+                'thumbnails': [{'url': unescapeHTML(url)}
+                               for url in variadic(traverse_obj(e, 'thumbnailUrl', 'thumbnailURL'))
+                               if url_or_none(url)],
                 'duration': parse_duration(e.get('duration')),
                 'timestamp': unified_timestamp(e.get('uploadDate')),
                 # author can be an instance of 'Organization' or 'Person' types.
                 # both types can have 'name' property(inherited from 'Thing' type). [1]
                 # however some websites are using 'Text' type instead.
                 # 1. https://schema.org/VideoObject
-                'uploader': author.get('name') if isinstance(author, dict) else author if isinstance(author, compat_str) else None,
-                'filesize': float_or_none(e.get('contentSize')),
+                'uploader': author.get('name') if isinstance(author, dict) else author if isinstance(author, str) else None,
+                'artist': traverse_obj(e, ('byArtist', 'name'), expected_type=str),
+                'filesize': int_or_none(float_or_none(e.get('contentSize'))),
                 'tbr': int_or_none(e.get('bitrate')),
                 'width': int_or_none(e.get('width')),
                 'height': int_or_none(e.get('height')),
                 'view_count': int_or_none(e.get('interactionCount')),
+                'tags': try_call(lambda: e.get('keywords').split(',')),
             })
+            if is_type(e, 'AudioObject'):
+                info.update({
+                    'vcodec': 'none',
+                    'abr': int_or_none(e.get('bitrate')),
+                })
             extract_interaction_statistic(e)
+            extract_chapter_information(e)
 
-        for e in json_ld:
-            if '@context' in e:
-                item_type = e.get('@type')
-                if expected_type is not None and expected_type != item_type:
+        def traverse_json_ld(json_ld, at_top_level=True):
+            for e in json_ld:
+                if at_top_level and '@context' not in e:
                     continue
-                if item_type in ('TVEpisode', 'Episode'):
+                if at_top_level and set(e.keys()) == {'@context', '@graph'}:
+                    traverse_json_ld(variadic(e['@graph'], allowed_types=(dict,)), at_top_level=False)
+                    break
+                if expected_type is not None and not is_type(e, expected_type):
+                    continue
+                rating = traverse_obj(e, ('aggregateRating', 'ratingValue'), expected_type=float_or_none)
+                if rating is not None:
+                    info['average_rating'] = rating
+                if is_type(e, 'TVEpisode', 'Episode'):
                     episode_name = unescapeHTML(e.get('name'))
                     info.update({
                         'episode': episode_name,
@@ -1359,41 +1590,71 @@ def extract_video_object(e):
                     if not info.get('title') and episode_name:
                         info['title'] = episode_name
                     part_of_season = e.get('partOfSeason')
-                    if isinstance(part_of_season, dict) and part_of_season.get('@type') in ('TVSeason', 'Season', 'CreativeWorkSeason'):
+                    if is_type(part_of_season, 'TVSeason', 'Season', 'CreativeWorkSeason'):
                         info.update({
                             'season': unescapeHTML(part_of_season.get('name')),
                             'season_number': int_or_none(part_of_season.get('seasonNumber')),
                         })
                     part_of_series = e.get('partOfSeries') or e.get('partOfTVSeries')
-                    if isinstance(part_of_series, dict) and part_of_series.get('@type') in ('TVSeries', 'Series', 'CreativeWorkSeries'):
+                    if is_type(part_of_series, 'TVSeries', 'Series', 'CreativeWorkSeries'):
                         info['series'] = unescapeHTML(part_of_series.get('name'))
-                elif item_type == 'Movie':
+                elif is_type(e, 'Movie'):
                     info.update({
                         'title': unescapeHTML(e.get('name')),
                         'description': unescapeHTML(e.get('description')),
                         'duration': parse_duration(e.get('duration')),
                         'timestamp': unified_timestamp(e.get('dateCreated')),
                     })
-                elif item_type in ('Article', 'NewsArticle'):
+                elif is_type(e, 'Article', 'NewsArticle'):
                     info.update({
                         'timestamp': parse_iso8601(e.get('datePublished')),
                         'title': unescapeHTML(e.get('headline')),
-                        'description': unescapeHTML(e.get('articleBody')),
+                        'description': unescapeHTML(e.get('articleBody') or e.get('description')),
                     })
-                elif item_type == 'VideoObject':
+                    if is_type(traverse_obj(e, ('video', 0)), 'VideoObject'):
+                        extract_video_object(e['video'][0])
+                    elif is_type(traverse_obj(e, ('subjectOf', 0)), 'VideoObject'):
+                        extract_video_object(e['subjectOf'][0])
+                elif is_type(e, 'VideoObject', 'AudioObject'):
                     extract_video_object(e)
                     if expected_type is None:
                         continue
                     else:
                         break
                 video = e.get('video')
-                if isinstance(video, dict) and video.get('@type') == 'VideoObject':
+                if is_type(video, 'VideoObject'):
                     extract_video_object(video)
                 if expected_type is None:
                     continue
                 else:
                     break
-        return dict((k, v) for k, v in info.items() if v is not None)
+        traverse_json_ld(json_ld)
+
+        return filter_dict(info)
+
+    def _search_nextjs_data(self, webpage, video_id, *, transform_source=None, fatal=True, **kw):
+        return self._parse_json(
+            self._search_regex(
+                r'(?s)<script[^>]+id=[\'"]__NEXT_DATA__[\'"][^>]*>([^<]+)</script>',
+                webpage, 'next.js data', fatal=fatal, **kw),
+            video_id, transform_source=transform_source, fatal=fatal)
+
+    def _search_nuxt_data(self, webpage, video_id, context_name='__NUXT__', *, fatal=True, traverse=('data', 0)):
+        """Parses Nuxt.js metadata. This works as long as the function __NUXT__ invokes is a pure function"""
+        rectx = re.escape(context_name)
+        FUNCTION_RE = r'\(function\((?P<arg_keys>.*?)\){return\s+(?P<js>{.*?})\s*;?\s*}\((?P<arg_vals>.*?)\)'
+        js, arg_keys, arg_vals = self._search_regex(
+            (rf'<script>\s*window\.{rectx}={FUNCTION_RE}\s*\)\s*;?\s*</script>', rf'{rectx}\(.*?{FUNCTION_RE}'),
+            webpage, context_name, group=('js', 'arg_keys', 'arg_vals'), fatal=fatal)
+
+        args = dict(zip(arg_keys.split(','), arg_vals.split(',')))
+
+        for key, val in args.items():
+            if val in ('undefined', 'void 0'):
+                args[key] = 'null'
+
+        ret = self._parse_json(js, video_id, transform_source=functools.partial(js_to_json, vars=args), fatal=fatal)
+        return traverse_obj(ret, traverse) or {}
 
     @staticmethod
     def _hidden_inputs(html):
@@ -1420,83 +1681,102 @@ def _form_hidden_inputs(self, form_id, html):
     class FormatSort:
         regex = r' *((?P<reverse>\+)?(?P<field>[a-zA-Z0-9_]+)((?P<separator>[~:])(?P<limit>.*?))?)? *$'
 
-        default = ('hidden', 'hasvid', 'ie_pref', 'lang', 'quality',
-                   'res', 'fps', 'codec:vp9.2', 'size', 'br', 'asr',
-                   'proto', 'ext', 'hasaud', 'source', 'format_id')  # These must not be aliases
-        ytdl_default = ('hasaud', 'quality', 'tbr', 'filesize', 'vbr',
+        default = ('hidden', 'aud_or_vid', 'hasvid', 'ie_pref', 'lang', 'quality',
+                   'res', 'fps', 'hdr:12', 'vcodec:vp9.2', 'channels', 'acodec',
+                   'size', 'br', 'asr', 'proto', 'ext', 'hasaud', 'source', 'id')  # These must not be aliases
+        ytdl_default = ('hasaud', 'lang', 'quality', 'tbr', 'filesize', 'vbr',
                         'height', 'width', 'proto', 'vext', 'abr', 'aext',
-                        'fps', 'fs_approx', 'source', 'format_id')
+                        'fps', 'fs_approx', 'source', 'id')
 
         settings = {
             'vcodec': {'type': 'ordered', 'regex': True,
                        'order': ['av0?1', 'vp0?9.2', 'vp0?9', '[hx]265|he?vc?', '[hx]264|avc', 'vp0?8', 'mp4v|h263', 'theora', '', None, 'none']},
             'acodec': {'type': 'ordered', 'regex': True,
-                       'order': ['opus', 'vorbis', 'aac', 'mp?4a?', 'mp3', 'e?a?c-?3', 'dts', '', None, 'none']},
+                       'order': ['[af]lac', 'wav|aiff', 'opus', 'vorbis|ogg', 'aac', 'mp?4a?', 'mp3', 'e-?a?c-?3', 'ac-?3', 'dts', '', None, 'none']},
+            'hdr': {'type': 'ordered', 'regex': True, 'field': 'dynamic_range',
+                    'order': ['dv', '(hdr)?12', r'(hdr)?10\+', '(hdr)?10', 'hlg', '', 'sdr', None]},
             'proto': {'type': 'ordered', 'regex': True, 'field': 'protocol',
-                      'order': ['(ht|f)tps', '(ht|f)tp$', 'm3u8.+', 'm3u8', '.*dash', '', 'mms|rtsp', 'none', 'f4']},
+                      'order': ['(ht|f)tps', '(ht|f)tp$', 'm3u8.*', '.*dash', 'websocket_frag', 'rtmpe?', '', 'mms|rtsp', 'ws|websocket', 'f4']},
             'vext': {'type': 'ordered', 'field': 'video_ext',
                      'order': ('mp4', 'webm', 'flv', '', 'none'),
                      'order_free': ('webm', 'mp4', 'flv', '', 'none')},
             'aext': {'type': 'ordered', 'field': 'audio_ext',
                      'order': ('m4a', 'aac', 'mp3', 'ogg', 'opus', 'webm', '', 'none'),
-                     'order_free': ('opus', 'ogg', 'webm', 'm4a', 'mp3', 'aac', '', 'none')},
+                     'order_free': ('ogg', 'opus', 'webm', 'mp3', 'm4a', 'aac', '', 'none')},
             'hidden': {'visible': False, 'forced': True, 'type': 'extractor', 'max': -1000},
+            'aud_or_vid': {'visible': False, 'forced': True, 'type': 'multiple',
+                           'field': ('vcodec', 'acodec'),
+                           'function': lambda it: int(any(v != 'none' for v in it))},
             'ie_pref': {'priority': True, 'type': 'extractor'},
             'hasvid': {'priority': True, 'field': 'vcodec', 'type': 'boolean', 'not_in_list': ('none',)},
             'hasaud': {'field': 'acodec', 'type': 'boolean', 'not_in_list': ('none',)},
-            'lang': {'priority': True, 'convert': 'ignore', 'field': 'language_preference'},
-            'quality': {'convert': 'float_none', 'default': -1},
+            'lang': {'convert': 'float', 'field': 'language_preference', 'default': -1},
+            'quality': {'convert': 'float', 'default': -1},
             'filesize': {'convert': 'bytes'},
             'fs_approx': {'convert': 'bytes', 'field': 'filesize_approx'},
             'id': {'convert': 'string', 'field': 'format_id'},
             'height': {'convert': 'float_none'},
             'width': {'convert': 'float_none'},
             'fps': {'convert': 'float_none'},
+            'channels': {'convert': 'float_none', 'field': 'audio_channels'},
             'tbr': {'convert': 'float_none'},
             'vbr': {'convert': 'float_none'},
             'abr': {'convert': 'float_none'},
             'asr': {'convert': 'float_none'},
-            'source': {'convert': 'ignore', 'field': 'source_preference'},
+            'source': {'convert': 'float', 'field': 'source_preference', 'default': -1},
 
             'codec': {'type': 'combined', 'field': ('vcodec', 'acodec')},
             'br': {'type': 'combined', 'field': ('tbr', 'vbr', 'abr'), 'same_limit': True},
             'size': {'type': 'combined', 'same_limit': True, 'field': ('filesize', 'fs_approx')},
             'ext': {'type': 'combined', 'field': ('vext', 'aext')},
-            'res': {'type': 'multiple', 'field': ('height', 'width'), 'function': min},
-
-            # Most of these exist only for compatibility reasons
-            'dimension': {'type': 'alias', 'field': 'res'},
-            'resolution': {'type': 'alias', 'field': 'res'},
-            'extension': {'type': 'alias', 'field': 'ext'},
-            'bitrate': {'type': 'alias', 'field': 'br'},
-            'total_bitrate': {'type': 'alias', 'field': 'tbr'},
-            'video_bitrate': {'type': 'alias', 'field': 'vbr'},
-            'audio_bitrate': {'type': 'alias', 'field': 'abr'},
-            'framerate': {'type': 'alias', 'field': 'fps'},
-            'language_preference': {'type': 'alias', 'field': 'lang'},  # not named as 'language' because such a field exists
-            'protocol': {'type': 'alias', 'field': 'proto'},
+            'res': {'type': 'multiple', 'field': ('height', 'width'),
+                    'function': lambda it: (lambda l: min(l) if l else 0)(tuple(filter(None, it)))},
+
+            # Actual field names
+            'format_id': {'type': 'alias', 'field': 'id'},
+            'preference': {'type': 'alias', 'field': 'ie_pref'},
+            'language_preference': {'type': 'alias', 'field': 'lang'},
             'source_preference': {'type': 'alias', 'field': 'source'},
+            'protocol': {'type': 'alias', 'field': 'proto'},
             'filesize_approx': {'type': 'alias', 'field': 'fs_approx'},
-            'filesize_estimate': {'type': 'alias', 'field': 'size'},
-            'samplerate': {'type': 'alias', 'field': 'asr'},
-            'video_ext': {'type': 'alias', 'field': 'vext'},
-            'audio_ext': {'type': 'alias', 'field': 'aext'},
-            'video_codec': {'type': 'alias', 'field': 'vcodec'},
-            'audio_codec': {'type': 'alias', 'field': 'acodec'},
-            'video': {'type': 'alias', 'field': 'hasvid'},
-            'has_video': {'type': 'alias', 'field': 'hasvid'},
-            'audio': {'type': 'alias', 'field': 'hasaud'},
-            'has_audio': {'type': 'alias', 'field': 'hasaud'},
-            'extractor': {'type': 'alias', 'field': 'ie_pref'},
-            'preference': {'type': 'alias', 'field': 'ie_pref'},
-            'extractor_preference': {'type': 'alias', 'field': 'ie_pref'},
-            'format_id': {'type': 'alias', 'field': 'id'},
+            'audio_channels': {'type': 'alias', 'field': 'channels'},
+
+            # Deprecated
+            'dimension': {'type': 'alias', 'field': 'res', 'deprecated': True},
+            'resolution': {'type': 'alias', 'field': 'res', 'deprecated': True},
+            'extension': {'type': 'alias', 'field': 'ext', 'deprecated': True},
+            'bitrate': {'type': 'alias', 'field': 'br', 'deprecated': True},
+            'total_bitrate': {'type': 'alias', 'field': 'tbr', 'deprecated': True},
+            'video_bitrate': {'type': 'alias', 'field': 'vbr', 'deprecated': True},
+            'audio_bitrate': {'type': 'alias', 'field': 'abr', 'deprecated': True},
+            'framerate': {'type': 'alias', 'field': 'fps', 'deprecated': True},
+            'filesize_estimate': {'type': 'alias', 'field': 'size', 'deprecated': True},
+            'samplerate': {'type': 'alias', 'field': 'asr', 'deprecated': True},
+            'video_ext': {'type': 'alias', 'field': 'vext', 'deprecated': True},
+            'audio_ext': {'type': 'alias', 'field': 'aext', 'deprecated': True},
+            'video_codec': {'type': 'alias', 'field': 'vcodec', 'deprecated': True},
+            'audio_codec': {'type': 'alias', 'field': 'acodec', 'deprecated': True},
+            'video': {'type': 'alias', 'field': 'hasvid', 'deprecated': True},
+            'has_video': {'type': 'alias', 'field': 'hasvid', 'deprecated': True},
+            'audio': {'type': 'alias', 'field': 'hasaud', 'deprecated': True},
+            'has_audio': {'type': 'alias', 'field': 'hasaud', 'deprecated': True},
+            'extractor': {'type': 'alias', 'field': 'ie_pref', 'deprecated': True},
+            'extractor_preference': {'type': 'alias', 'field': 'ie_pref', 'deprecated': True},
         }
 
-        _order = []
+        def __init__(self, ie, field_preference):
+            self._order = []
+            self.ydl = ie._downloader
+            self.evaluate_params(self.ydl.params, field_preference)
+            if ie.get_param('verbose'):
+                self.print_verbose_info(self.ydl.write_debug)
 
         def _get_field_setting(self, field, key):
             if field not in self.settings:
+                if key in ('forced', 'priority'):
+                    return False
+                self.ydl.deprecated_feature(f'Using arbitrary fields ({field}) for format sorting is '
+                                            'deprecated and may be removed in a future version')
                 self.settings[field] = {}
             propObj = self.settings[field]
             if key not in propObj:
@@ -1506,7 +1786,7 @@ def _get_field_setting(self, field, key):
                 elif key == 'convert':
                     default = 'order' if type == 'ordered' else 'float_string' if field else 'ignore'
                 else:
-                    default = {'type': 'field', 'visible': True, 'order': [], 'not_in_list': (None,), 'function': max}.get(key, None)
+                    default = {'type': 'field', 'visible': True, 'order': [], 'not_in_list': (None,)}.get(key, None)
                 propObj[key] = default
             return propObj[key]
 
@@ -1579,7 +1859,10 @@ def add_item(field, reverse, closest, limit_text):
                 if field is None:
                     continue
                 if self._get_field_setting(field, 'type') == 'alias':
-                    field = self._get_field_setting(field, 'field')
+                    alias, field = field, self._get_field_setting(field, 'field')
+                    if self._get_field_setting(alias, 'deprecated'):
+                        self.ydl.deprecated_feature(f'Format sorting alias {alias} is deprecated and may '
+                                                    'be removed in a future version. Please use {field} instead')
                 reverse = match.group('reverse') is not None
                 closest = match.group('separator') == '~'
                 limit_text = match.group('limit')
@@ -1589,7 +1872,7 @@ def add_item(field, reverse, closest, limit_text):
                 has_multiple_limits = has_limit and has_multiple_fields and not self._get_field_setting(field, 'same_limit')
 
                 fields = self._get_field_setting(field, 'field') if has_multiple_fields else (field,)
-                limits = limit_text.split(":") if has_multiple_limits else (limit_text,) if has_limit else tuple()
+                limits = limit_text.split(':') if has_multiple_limits else (limit_text,) if has_limit else tuple()
                 limit_count = len(limits)
                 for (i, f) in enumerate(fields):
                     add_item(f, reverse, closest,
@@ -1646,13 +1929,7 @@ def _calculate_field_preference(self, format, field):
                 type = 'field'  # Only 'field' is allowed in multiple for now
                 actual_fields = self._get_field_setting(field, 'field')
 
-                def wrapped_function(values):
-                    values = tuple(filter(lambda x: x is not None, values))
-                    return (self._get_field_setting(field, 'function')(*values) if len(values) > 1
-                            else values[0] if values
-                            else None)
-
-                value = wrapped_function((get_value(f) for f in actual_fields))
+                value = self._get_field_setting(field, 'function')(get_value(f) for f in actual_fields)
             else:
                 value = get_value(field)
             return self._calculate_field_preference_from_value(format, field, type, value)
@@ -1666,7 +1943,7 @@ def calculate_preference(self, format):
             if not format.get('ext') and 'url' in format:
                 format['ext'] = determine_ext(format['url'])
             if format.get('vcodec') == 'none':
-                format['audio_ext'] = format['ext']
+                format['audio_ext'] = format['ext'] if format.get('acodec') != 'none' else 'none'
                 format['video_ext'] = 'none'
             else:
                 format['video_ext'] = format['ext']
@@ -1679,23 +1956,17 @@ def calculate_preference(self, format):
                 if format.get('vbr') is not None and format.get('abr') is not None:
                     format['tbr'] = format.get('vbr', 0) + format.get('abr', 0)
             else:
-                if format.get('vcodec') != "none" and format.get('vbr') is None:
+                if format.get('vcodec') != 'none' and format.get('vbr') is None:
                     format['vbr'] = format.get('tbr') - format.get('abr', 0)
-                if format.get('acodec') != "none" and format.get('abr') is None:
+                if format.get('acodec') != 'none' and format.get('abr') is None:
                     format['abr'] = format.get('tbr') - format.get('vbr', 0)
 
             return tuple(self._calculate_field_preference(format, field) for field in self._order)
 
     def _sort_formats(self, formats, field_preference=[]):
         if not formats:
-            if self.get_param('ignore_no_formats_error'):
-                return
-            raise ExtractorError('No video formats found')
-        format_sort = self.FormatSort()  # params and to_screen are taken from the downloader
-        format_sort.evaluate_params(self._downloader.params, field_preference)
-        if self.get_param('verbose', False):
-            format_sort.print_verbose_info(self._downloader.write_debug)
-        formats.sort(key=lambda f: format_sort.calculate_preference(f))
+            return
+        formats.sort(key=self.FormatSort(self, field_preference).calculate_preference)
 
     def _check_formats(self, formats, video_id):
         if formats:
@@ -1737,14 +2008,9 @@ def http_scheme(self):
             else 'https:')
 
     def _proto_relative_url(self, url, scheme=None):
-        if url is None:
-            return url
-        if url.startswith('//'):
-            if scheme is None:
-                scheme = self.http_scheme()
-            return scheme + url
-        else:
-            return url
+        scheme = scheme or self.http_scheme()
+        assert scheme.endswith(':')
+        return sanitize_url(url, scheme=scheme[:-1])
 
     def _sleep(self, timeout, video_id, msg_template=None):
         if msg_template is None:
@@ -1756,17 +2022,19 @@ def _sleep(self, timeout, video_id, msg_template=None):
     def _extract_f4m_formats(self, manifest_url, video_id, preference=None, quality=None, f4m_id=None,
                              transform_source=lambda s: fix_xml_ampersands(s).strip(),
                              fatal=True, m3u8_id=None, data=None, headers={}, query={}):
-        manifest = self._download_xml(
+        res = self._download_xml_handle(
             manifest_url, video_id, 'Downloading f4m manifest',
             'Unable to download f4m manifest',
             # Some manifests may be malformed, e.g. prosiebensat1 generated manifests
             # (see https://github.com/ytdl-org/youtube-dl/issues/6215#issuecomment-121704244)
             transform_source=transform_source,
             fatal=fatal, data=data, headers=headers, query=query)
-
-        if manifest is False:
+        if res is False:
             return []
 
+        manifest, urlh = res
+        manifest_url = urlh.geturl()
+
         return self._parse_f4m_formats(
             manifest, manifest_url, video_id, preference=preference, quality=quality, f4m_id=f4m_id,
             transform_source=transform_source, fatal=fatal, m3u8_id=m3u8_id)
@@ -1774,7 +2042,7 @@ def _extract_f4m_formats(self, manifest_url, video_id, preference=None, quality=
     def _parse_f4m_formats(self, manifest, manifest_url, video_id, preference=None, quality=None, f4m_id=None,
                            transform_source=lambda s: fix_xml_ampersands(s).strip(),
                            fatal=True, m3u8_id=None):
-        if not isinstance(manifest, compat_etree_Element) and not fatal:
+        if not isinstance(manifest, xml.etree.ElementTree.Element) and not fatal:
             return []
 
         # currently yt-dlp cannot decode the playerVerificationChallenge as Akamai uses Adobe Alchemy
@@ -1813,7 +2081,7 @@ def _parse_f4m_formats(self, manifest, manifest_url, video_id, preference=None,
             tbr = int_or_none(media_el.attrib.get('bitrate'))
             width = int_or_none(media_el.attrib.get('width'))
             height = int_or_none(media_el.attrib.get('height'))
-            format_id = '-'.join(filter(None, [f4m_id, compat_str(i if tbr is None else tbr)]))
+            format_id = join_nonempty(f4m_id, tbr or i)
             # If <bootstrapInfo> is present, the specified f4m is a
             # stream-level manifest, and only set-level manifests may refer to
             # external resources.  See section 11.4 and section 4 of F4M spec
@@ -1875,7 +2143,7 @@ def _parse_f4m_formats(self, manifest, manifest_url, video_id, preference=None,
 
     def _m3u8_meta_format(self, m3u8_url, ext=None, preference=None, quality=None, m3u8_id=None):
         return {
-            'format_id': '-'.join(filter(None, [m3u8_id, 'meta'])),
+            'format_id': join_nonempty(m3u8_id, 'meta'),
             'url': m3u8_url,
             'ext': ext,
             'protocol': 'm3u8',
@@ -1885,25 +2153,28 @@ def _m3u8_meta_format(self, m3u8_url, ext=None, preference=None, quality=None, m
             'format_note': 'Quality selection URL',
         }
 
+    def _report_ignoring_subs(self, name):
+        self.report_warning(bug_reports_message(
+            f'Ignoring subtitle tracks found in the {name} manifest; '
+            'if any subtitle tracks are missing,'
+        ), only_once=True)
+
     def _extract_m3u8_formats(self, *args, **kwargs):
         fmts, subs = self._extract_m3u8_formats_and_subtitles(*args, **kwargs)
         if subs:
-            self.report_warning(bug_reports_message(
-                "Ignoring subtitle tracks found in the HLS manifest; "
-                "if any subtitle tracks are missing,"
-            ))
+            self._report_ignoring_subs('HLS')
         return fmts
 
     def _extract_m3u8_formats_and_subtitles(
-            self, m3u8_url, video_id, ext=None, entry_protocol='m3u8',
+            self, m3u8_url, video_id, ext=None, entry_protocol='m3u8_native',
             preference=None, quality=None, m3u8_id=None, note=None,
             errnote=None, fatal=True, live=False, data=None, headers={},
             query={}):
 
         res = self._download_webpage_handle(
             m3u8_url, video_id,
-            note=note or 'Downloading m3u8 information',
-            errnote=errnote or 'Failed to download m3u8 information',
+            note='Downloading m3u8 information' if note is None else note,
+            errnote='Failed to download m3u8 information' if errnote is None else errnote,
             fatal=fatal, data=data, headers=headers, query=query)
 
         if res is False:
@@ -1919,28 +2190,35 @@ def _extract_m3u8_formats_and_subtitles(
             headers=headers, query=query, video_id=video_id)
 
     def _parse_m3u8_formats_and_subtitles(
-            self, m3u8_doc, m3u8_url, ext=None, entry_protocol='m3u8',
+            self, m3u8_doc, m3u8_url=None, ext=None, entry_protocol='m3u8_native',
             preference=None, quality=None, m3u8_id=None, live=False, note=None,
             errnote=None, fatal=True, data=None, headers={}, query={},
             video_id=None):
+        formats, subtitles = [], {}
+
+        has_drm = re.search('|'.join([
+            r'#EXT-X-FAXS-CM:',  # Adobe Flash Access
+            r'#EXT-X-(?:SESSION-)?KEY:.*?URI="skd://',  # Apple FairPlay
+        ]), m3u8_doc)
+
+        def format_url(url):
+            return url if re.match(r'^https?://', url) else urllib.parse.urljoin(m3u8_url, url)
+
+        if self.get_param('hls_split_discontinuity', False):
+            def _extract_m3u8_playlist_indices(manifest_url=None, m3u8_doc=None):
+                if not m3u8_doc:
+                    if not manifest_url:
+                        return []
+                    m3u8_doc = self._download_webpage(
+                        manifest_url, video_id, fatal=fatal, data=data, headers=headers,
+                        note=False, errnote='Failed to download m3u8 playlist information')
+                    if m3u8_doc is False:
+                        return []
+                return range(1 + sum(line.startswith('#EXT-X-DISCONTINUITY') for line in m3u8_doc.splitlines()))
 
-        if '#EXT-X-FAXS-CM:' in m3u8_doc:  # Adobe Flash Access
-            return [], {}
-
-        if (not self.get_param('allow_unplayable_formats')
-                and re.search(r'#EXT-X-SESSION-KEY:.*?URI="skd://', m3u8_doc)):  # Apple FairPlay
-            return [], {}
-
-        formats = []
-
-        subtitles = {}
-
-        format_url = lambda u: (
-            u
-            if re.match(r'^https?://', u)
-            else compat_urlparse.urljoin(m3u8_url, u))
-
-        split_discontinuity = self.get_param('hls_split_discontinuity', False)
+        else:
+            def _extract_m3u8_playlist_indices(*args, **kwargs):
+                return [None]
 
         # References:
         # 1. https://tools.ietf.org/html/draft-pantos-http-live-streaming-21
@@ -1958,68 +2236,17 @@ def _parse_m3u8_formats_and_subtitles(
         # media playlist and MUST NOT appear in master playlist thus we can
         # clearly detect media playlist with this criterion.
 
-        def _extract_m3u8_playlist_formats(format_url=None, m3u8_doc=None, video_id=None,
-                                           fatal=True, data=None, headers={}):
-            if not m3u8_doc:
-                if not format_url:
-                    return []
-                res = self._download_webpage_handle(
-                    format_url, video_id,
-                    note=False,
-                    errnote='Failed to download m3u8 playlist information',
-                    fatal=fatal, data=data, headers=headers)
-
-                if res is False:
-                    return []
-
-                m3u8_doc, urlh = res
-                format_url = urlh.geturl()
-
-            playlist_formats = []
-            i = (
-                0
-                if split_discontinuity
-                else None)
-            format_info = {
-                'index': i,
-                'key_data': None,
-                'files': [],
-            }
-            for line in m3u8_doc.splitlines():
-                if not line.startswith('#'):
-                    format_info['files'].append(line)
-                elif split_discontinuity and line.startswith('#EXT-X-DISCONTINUITY'):
-                    i += 1
-                    playlist_formats.append(format_info)
-                    format_info = {
-                        'index': i,
-                        'url': format_url,
-                        'files': [],
-                    }
-            playlist_formats.append(format_info)
-            return playlist_formats
-
         if '#EXT-X-TARGETDURATION' in m3u8_doc:  # media playlist, return as is
-
-            playlist_formats = _extract_m3u8_playlist_formats(m3u8_doc=m3u8_doc)
-
-            for format in playlist_formats:
-                format_id = []
-                if m3u8_id:
-                    format_id.append(m3u8_id)
-                format_index = format.get('index')
-                if format_index:
-                    format_id.append(str(format_index))
-                f = {
-                    'format_id': '-'.join(format_id),
-                    'format_index': format_index,
-                    'url': m3u8_url,
-                    'ext': ext,
-                    'protocol': entry_protocol,
-                    'preference': preference,
-                    'quality': quality,
-                }
-                formats.append(f)
+            formats = [{
+                'format_id': join_nonempty(m3u8_id, idx),
+                'format_index': idx,
+                'url': m3u8_url or encode_data_uri(m3u8_doc.encode('utf-8'), 'application/x-mpegurl'),
+                'ext': ext,
+                'protocol': entry_protocol,
+                'preference': preference,
+                'quality': quality,
+                'has_drm': has_drm,
+            } for idx in _extract_m3u8_playlist_indices(m3u8_doc=m3u8_doc)]
 
             return formats, subtitles
 
@@ -2035,7 +2262,12 @@ def extract_media(x_media_line):
             groups.setdefault(group_id, []).append(media)
             # <https://tools.ietf.org/html/rfc8216#section-4.3.4.1>
             if media_type == 'SUBTITLES':
-                lang = media['LANGUAGE']  # XXX: normalise?
+                # According to RFC 8216 Â§4.3.4.2.1, URI is REQUIRED in the
+                # EXT-X-MEDIA tag if the media type is SUBTITLES.
+                # However, lack of URI has been spotted in the wild.
+                # e.g. NebulaIE; see https://github.com/yt-dlp/yt-dlp/issues/339
+                if not media.get('URI'):
+                    return
                 url = format_url(media['URI'])
                 sub_info = {
                     'url': url,
@@ -2047,37 +2279,26 @@ def extract_media(x_media_line):
                     # <https://tools.ietf.org/html/rfc8216#section-3.1>
                     sub_info['ext'] = 'vtt'
                     sub_info['protocol'] = 'm3u8_native'
+                lang = media.get('LANGUAGE') or 'und'
                 subtitles.setdefault(lang, []).append(sub_info)
             if media_type not in ('VIDEO', 'AUDIO'):
                 return
             media_url = media.get('URI')
             if media_url:
                 manifest_url = format_url(media_url)
-                format_id = []
-                playlist_formats = _extract_m3u8_playlist_formats(manifest_url, video_id=video_id,
-                                                                  fatal=fatal, data=data, headers=headers)
-
-                for format in playlist_formats:
-                    format_index = format.get('index')
-                    for v in (m3u8_id, group_id, name):
-                        if v:
-                            format_id.append(v)
-                    if format_index:
-                        format_id.append(str(format_index))
-                    f = {
-                        'format_id': '-'.join(format_id),
-                        'format_index': format_index,
-                        'url': manifest_url,
-                        'manifest_url': m3u8_url,
-                        'language': media.get('LANGUAGE'),
-                        'ext': ext,
-                        'protocol': entry_protocol,
-                        'preference': preference,
-                        'quality': quality,
-                    }
-                    if media_type == 'AUDIO':
-                        f['vcodec'] = 'none'
-                    formats.append(f)
+                formats.extend({
+                    'format_id': join_nonempty(m3u8_id, group_id, name, idx),
+                    'format_note': name,
+                    'format_index': idx,
+                    'url': manifest_url,
+                    'manifest_url': m3u8_url,
+                    'language': media.get('LANGUAGE'),
+                    'ext': ext,
+                    'protocol': entry_protocol,
+                    'preference': preference,
+                    'quality': quality,
+                    'vcodec': 'none' if media_type == 'AUDIO' else None,
+                } for idx in _extract_m3u8_playlist_indices(manifest_url))
 
         def build_stream_name():
             # Despite specification does not mention NAME attribute for
@@ -2116,25 +2337,17 @@ def build_stream_name():
                     or last_stream_inf.get('BANDWIDTH'), scale=1000)
                 manifest_url = format_url(line.strip())
 
-                playlist_formats = _extract_m3u8_playlist_formats(manifest_url, video_id=video_id,
-                                                                  fatal=fatal, data=data, headers=headers)
-
-                for frmt in playlist_formats:
-                    format_id = []
-                    if m3u8_id:
-                        format_id.append(m3u8_id)
-                    format_index = frmt.get('index')
-                    stream_name = build_stream_name()
+                for idx in _extract_m3u8_playlist_indices(manifest_url):
+                    format_id = [m3u8_id, None, idx]
                     # Bandwidth of live streams may differ over time thus making
                     # format_id unpredictable. So it's better to keep provided
                     # format_id intact.
                     if not live:
-                        format_id.append(stream_name if stream_name else '%d' % (tbr if tbr else len(formats)))
-                    if format_index:
-                        format_id.append(str(format_index))
+                        stream_name = build_stream_name()
+                        format_id[1] = stream_name or '%d' % (tbr or len(formats))
                     f = {
-                        'format_id': '-'.join(format_id),
-                        'format_index': format_index,
+                        'format_id': join_nonempty(*format_id),
+                        'format_index': idx,
                         'url': manifest_url,
                         'manifest_url': m3u8_url,
                         'tbr': tbr,
@@ -2165,7 +2378,7 @@ def build_stream_name():
                     audio_group_id = last_stream_inf.get('AUDIO')
                     # As per [1, 4.3.4.1.1] any EXT-X-STREAM-INF tag which
                     # references a rendition group MUST have a CODECS attribute.
-                    # However, this is not always respected, for example, [2]
+                    # However, this is not always respected. E.g. [2]
                     # contains EXT-X-STREAM-INF tag which references AUDIO
                     # rendition group but does not have CODECS and despite
                     # referencing an audio group it represents a complete
@@ -2197,6 +2410,25 @@ def build_stream_name():
                 last_stream_inf = {}
         return formats, subtitles
 
+    def _extract_m3u8_vod_duration(
+            self, m3u8_vod_url, video_id, note=None, errnote=None, data=None, headers={}, query={}):
+
+        m3u8_vod = self._download_webpage(
+            m3u8_vod_url, video_id,
+            note='Downloading m3u8 VOD manifest' if note is None else note,
+            errnote='Failed to download VOD manifest' if errnote is None else errnote,
+            fatal=False, data=data, headers=headers, query=query)
+
+        return self._parse_m3u8_vod_duration(m3u8_vod or '', video_id)
+
+    def _parse_m3u8_vod_duration(self, m3u8_vod, video_id):
+        if '#EXT-X-PLAYLIST-TYPE:VOD' not in m3u8_vod:
+            return None
+
+        return int(sum(
+            float(line[len('#EXTINF:'):].split(',')[0])
+            for line in m3u8_vod.splitlines() if line.startswith('#EXTINF:'))) or None
+
     @staticmethod
     def _xpath_ns(path, namespace=None):
         if not namespace:
@@ -2209,26 +2441,42 @@ def _xpath_ns(path, namespace=None):
                 out.append('{%s}%s' % (namespace, c))
         return '/'.join(out)
 
-    def _extract_smil_formats(self, smil_url, video_id, fatal=True, f4m_params=None, transform_source=None):
-        smil = self._download_smil(smil_url, video_id, fatal=fatal, transform_source=transform_source)
-
-        if smil is False:
+    def _extract_smil_formats_and_subtitles(self, smil_url, video_id, fatal=True, f4m_params=None, transform_source=None):
+        res = self._download_smil(smil_url, video_id, fatal=fatal, transform_source=transform_source)
+        if res is False:
             assert not fatal
-            return []
+            return [], {}
+
+        smil, urlh = res
+        smil_url = urlh.geturl()
 
         namespace = self._parse_smil_namespace(smil)
 
-        return self._parse_smil_formats(
+        fmts = self._parse_smil_formats(
             smil, smil_url, video_id, namespace=namespace, f4m_params=f4m_params)
+        subs = self._parse_smil_subtitles(
+            smil, namespace=namespace)
+
+        return fmts, subs
+
+    def _extract_smil_formats(self, *args, **kwargs):
+        fmts, subs = self._extract_smil_formats_and_subtitles(*args, **kwargs)
+        if subs:
+            self._report_ignoring_subs('SMIL')
+        return fmts
 
     def _extract_smil_info(self, smil_url, video_id, fatal=True, f4m_params=None):
-        smil = self._download_smil(smil_url, video_id, fatal=fatal)
-        if smil is False:
+        res = self._download_smil(smil_url, video_id, fatal=fatal)
+        if res is False:
             return {}
+
+        smil, urlh = res
+        smil_url = urlh.geturl()
+
         return self._parse_smil(smil, smil_url, video_id, f4m_params=f4m_params)
 
     def _download_smil(self, smil_url, video_id, fatal=True, transform_source=None):
-        return self._download_xml(
+        return self._download_xml_handle(
             smil_url, video_id, 'Downloading SMIL file',
             'Unable to download SMIL file', fatal=fatal, transform_source=transform_source)
 
@@ -2288,14 +2536,15 @@ def _parse_smil_formats(self, smil, smil_url, video_id, namespace=None, f4m_para
         rtmp_count = 0
         http_count = 0
         m3u8_count = 0
+        imgs_count = 0
 
-        srcs = []
+        srcs = set()
         media = smil.findall(self._xpath_ns('.//video', namespace)) + smil.findall(self._xpath_ns('.//audio', namespace))
         for medium in media:
             src = medium.get('src')
             if not src or src in srcs:
                 continue
-            srcs.append(src)
+            srcs.add(src)
 
             bitrate = float_or_none(medium.get('system-bitrate') or medium.get('systemBitrate'), 1000)
             filesize = int_or_none(medium.get('size') or medium.get('fileSize'))
@@ -2326,7 +2575,7 @@ def _parse_smil_formats(self, smil, smil_url, video_id, namespace=None, f4m_para
                     })
                 continue
 
-            src_url = src if src.startswith('http') else compat_urlparse.urljoin(base, src)
+            src_url = src if src.startswith('http') else urllib.parse.urljoin(base, src)
             src_url = src_url.strip()
 
             if proto == 'm3u8' or src_ext == 'm3u8':
@@ -2349,7 +2598,7 @@ def _parse_smil_formats(self, smil, smil_url, video_id, namespace=None, f4m_para
                         'plugin': 'flowplayer-3.2.0.1',
                     }
                 f4m_url += '&' if '?' in f4m_url else '?'
-                f4m_url += compat_urllib_parse_urlencode(f4m_params)
+                f4m_url += urllib.parse.urlencode(f4m_params)
                 formats.extend(self._extract_f4m_formats(f4m_url, video_id, f4m_id='hds', fatal=False))
             elif src_ext == 'mpd':
                 formats.extend(self._extract_mpd_formats(
@@ -2369,6 +2618,24 @@ def _parse_smil_formats(self, smil, smil_url, video_id, namespace=None, f4m_para
                     'height': height,
                 })
 
+        for medium in smil.findall(self._xpath_ns('.//imagestream', namespace)):
+            src = medium.get('src')
+            if not src or src in srcs:
+                continue
+            srcs.add(src)
+
+            imgs_count += 1
+            formats.append({
+                'format_id': 'imagestream-%d' % (imgs_count),
+                'url': src,
+                'ext': mimetype2ext(medium.get('type')),
+                'acodec': 'none',
+                'vcodec': 'none',
+                'width': int_or_none(medium.get('width')),
+                'height': int_or_none(medium.get('height')),
+                'format_note': 'SMIL storyboards',
+            })
+
         return formats
 
     def _parse_smil_subtitles(self, smil, namespace=None, subtitles_lang='en'):
@@ -2388,11 +2655,15 @@ def _parse_smil_subtitles(self, smil, namespace=None, subtitles_lang='en'):
         return subtitles
 
     def _extract_xspf_playlist(self, xspf_url, playlist_id, fatal=True):
-        xspf = self._download_xml(
+        res = self._download_xml_handle(
             xspf_url, playlist_id, 'Downloading xpsf playlist',
             'Unable to download xspf manifest', fatal=fatal)
-        if xspf is False:
+        if res is False:
             return []
+
+        xspf, urlh = res
+        xspf_url = urlh.geturl()
+
         return self._parse_xspf(
             xspf, playlist_id, xspf_url=xspf_url,
             xspf_base_url=base_url(xspf_url))
@@ -2441,10 +2712,7 @@ def _parse_xspf(self, xspf_doc, playlist_id, xspf_url=None, xspf_base_url=None):
     def _extract_mpd_formats(self, *args, **kwargs):
         fmts, subs = self._extract_mpd_formats_and_subtitles(*args, **kwargs)
         if subs:
-            self.report_warning(bug_reports_message(
-                "Ignoring subtitle tracks found in the DASH manifest; "
-                "if any subtitle tracks are missing,"
-            ))
+            self._report_ignoring_subs('DASH')
         return fmts
 
     def _extract_mpd_formats_and_subtitles(
@@ -2452,15 +2720,18 @@ def _extract_mpd_formats_and_subtitles(
             fatal=True, data=None, headers={}, query={}):
         res = self._download_xml_handle(
             mpd_url, video_id,
-            note=note or 'Downloading MPD manifest',
-            errnote=errnote or 'Failed to download MPD manifest',
+            note='Downloading MPD manifest' if note is None else note,
+            errnote='Failed to download MPD manifest' if errnote is None else errnote,
             fatal=fatal, data=data, headers=headers, query=query)
         if res is False:
             return [], {}
         mpd_doc, urlh = res
         if mpd_doc is None:
             return [], {}
-        mpd_base_url = base_url(urlh.geturl())
+
+        # We could have been redirected to a new url when we retrieved our mpd file.
+        mpd_url = urlh.geturl()
+        mpd_base_url = base_url(mpd_url)
 
         return self._parse_mpd_formats_and_subtitles(
             mpd_doc, mpd_id, mpd_base_url, mpd_url)
@@ -2468,10 +2739,7 @@ def _extract_mpd_formats_and_subtitles(
     def _parse_mpd_formats(self, *args, **kwargs):
         fmts, subs = self._parse_mpd_formats_and_subtitles(*args, **kwargs)
         if subs:
-            self.report_warning(bug_reports_message(
-                "Ignoring subtitle tracks found in the DASH manifest; "
-                "if any subtitle tracks are missing,"
-            ))
+            self._report_ignoring_subs('DASH')
         return fmts
 
     def _parse_mpd_formats_and_subtitles(
@@ -2553,11 +2821,9 @@ def extract_Initialization(source):
                         extract_Initialization(segment_template)
             return ms_info
 
-        skip_unplayable = not self.get_param('allow_unplayable_formats')
-
         mpd_duration = parse_duration(mpd_doc.get('mediaPresentationDuration'))
-        formats = []
-        subtitles = {}
+        formats, subtitles = [], {}
+        stream_numbers = collections.defaultdict(int)
         for period in mpd_doc.findall(_add_ns('Period')):
             period_duration = parse_duration(period.get('duration')) or mpd_duration
             period_ms_info = extract_multisegment_info(period, {
@@ -2565,225 +2831,266 @@ def extract_Initialization(source):
                 'timescale': 1,
             })
             for adaptation_set in period.findall(_add_ns('AdaptationSet')):
-                if skip_unplayable and is_drm_protected(adaptation_set):
-                    continue
                 adaption_set_ms_info = extract_multisegment_info(adaptation_set, period_ms_info)
                 for representation in adaptation_set.findall(_add_ns('Representation')):
-                    if skip_unplayable and is_drm_protected(representation):
-                        continue
                     representation_attrib = adaptation_set.attrib.copy()
                     representation_attrib.update(representation.attrib)
                     # According to [1, 5.3.7.2, Table 9, page 41], @mimeType is mandatory
                     mime_type = representation_attrib['mimeType']
                     content_type = representation_attrib.get('contentType', mime_type.split('/')[0])
 
-                    if content_type in ('video', 'audio', 'text'):
-                        base_url = ''
-                        for element in (representation, adaptation_set, period, mpd_doc):
-                            base_url_e = element.find(_add_ns('BaseURL'))
-                            if base_url_e is not None:
-                                base_url = base_url_e.text + base_url
-                                if re.match(r'^https?://', base_url):
-                                    break
-                        if mpd_base_url and not re.match(r'^https?://', base_url):
-                            if not mpd_base_url.endswith('/') and not base_url.startswith('/'):
-                                mpd_base_url += '/'
-                            base_url = mpd_base_url + base_url
-                        representation_id = representation_attrib.get('id')
-                        lang = representation_attrib.get('lang')
-                        url_el = representation.find(_add_ns('BaseURL'))
-                        filesize = int_or_none(url_el.attrib.get('{http://youtube.com/yt/2012/10/10}contentLength') if url_el is not None else None)
-                        bandwidth = int_or_none(representation_attrib.get('bandwidth'))
-                        if content_type in ('video', 'audio'):
-                            f = {
-                                'format_id': '%s-%s' % (mpd_id, representation_id) if mpd_id else representation_id,
-                                'manifest_url': mpd_url,
-                                'ext': mimetype2ext(mime_type),
-                                'width': int_or_none(representation_attrib.get('width')),
-                                'height': int_or_none(representation_attrib.get('height')),
-                                'tbr': float_or_none(bandwidth, 1000),
-                                'asr': int_or_none(representation_attrib.get('audioSamplingRate')),
-                                'fps': int_or_none(representation_attrib.get('frameRate')),
-                                'language': lang if lang not in ('mul', 'und', 'zxx', 'mis') else None,
-                                'format_note': 'DASH %s' % content_type,
-                                'filesize': filesize,
-                                'container': mimetype2ext(mime_type) + '_dash',
-                            }
-                            f.update(parse_codecs(representation_attrib.get('codecs')))
-                        elif content_type == 'text':
-                            f = {
-                                'ext': mimetype2ext(mime_type),
-                                'manifest_url': mpd_url,
-                                'filesize': filesize,
-                            }
-                        representation_ms_info = extract_multisegment_info(representation, adaption_set_ms_info)
-
-                        def prepare_template(template_name, identifiers):
-                            tmpl = representation_ms_info[template_name]
-                            # First of, % characters outside $...$ templates
-                            # must be escaped by doubling for proper processing
-                            # by % operator string formatting used further (see
-                            # https://github.com/ytdl-org/youtube-dl/issues/16867).
-                            t = ''
-                            in_template = False
-                            for c in tmpl:
+                    codec_str = representation_attrib.get('codecs', '')
+                    # Some kind of binary subtitle found in some youtube livestreams
+                    if mime_type == 'application/x-rawcc':
+                        codecs = {'scodec': codec_str}
+                    else:
+                        codecs = parse_codecs(codec_str)
+                    if content_type not in ('video', 'audio', 'text'):
+                        if mime_type == 'image/jpeg':
+                            content_type = mime_type
+                        elif codecs.get('vcodec', 'none') != 'none':
+                            content_type = 'video'
+                        elif codecs.get('acodec', 'none') != 'none':
+                            content_type = 'audio'
+                        elif codecs.get('scodec', 'none') != 'none':
+                            content_type = 'text'
+                        elif mimetype2ext(mime_type) in ('tt', 'dfxp', 'ttml', 'xml', 'json'):
+                            content_type = 'text'
+                        else:
+                            self.report_warning('Unknown MIME type %s in DASH manifest' % mime_type)
+                            continue
+
+                    base_url = ''
+                    for element in (representation, adaptation_set, period, mpd_doc):
+                        base_url_e = element.find(_add_ns('BaseURL'))
+                        if try_call(lambda: base_url_e.text) is not None:
+                            base_url = base_url_e.text + base_url
+                            if re.match(r'^https?://', base_url):
+                                break
+                    if mpd_base_url and base_url.startswith('/'):
+                        base_url = urllib.parse.urljoin(mpd_base_url, base_url)
+                    elif mpd_base_url and not re.match(r'^https?://', base_url):
+                        if not mpd_base_url.endswith('/'):
+                            mpd_base_url += '/'
+                        base_url = mpd_base_url + base_url
+                    representation_id = representation_attrib.get('id')
+                    lang = representation_attrib.get('lang')
+                    url_el = representation.find(_add_ns('BaseURL'))
+                    filesize = int_or_none(url_el.attrib.get('{http://youtube.com/yt/2012/10/10}contentLength') if url_el is not None else None)
+                    bandwidth = int_or_none(representation_attrib.get('bandwidth'))
+                    if representation_id is not None:
+                        format_id = representation_id
+                    else:
+                        format_id = content_type
+                    if mpd_id:
+                        format_id = mpd_id + '-' + format_id
+                    if content_type in ('video', 'audio'):
+                        f = {
+                            'format_id': format_id,
+                            'manifest_url': mpd_url,
+                            'ext': mimetype2ext(mime_type),
+                            'width': int_or_none(representation_attrib.get('width')),
+                            'height': int_or_none(representation_attrib.get('height')),
+                            'tbr': float_or_none(bandwidth, 1000),
+                            'asr': int_or_none(representation_attrib.get('audioSamplingRate')),
+                            'fps': int_or_none(representation_attrib.get('frameRate')),
+                            'language': lang if lang not in ('mul', 'und', 'zxx', 'mis') else None,
+                            'format_note': 'DASH %s' % content_type,
+                            'filesize': filesize,
+                            'container': mimetype2ext(mime_type) + '_dash',
+                            **codecs
+                        }
+                    elif content_type == 'text':
+                        f = {
+                            'ext': mimetype2ext(mime_type),
+                            'manifest_url': mpd_url,
+                            'filesize': filesize,
+                        }
+                    elif content_type == 'image/jpeg':
+                        # See test case in VikiIE
+                        # https://www.viki.com/videos/1175236v-choosing-spouse-by-lottery-episode-1
+                        f = {
+                            'format_id': format_id,
+                            'ext': 'mhtml',
+                            'manifest_url': mpd_url,
+                            'format_note': 'DASH storyboards (jpeg)',
+                            'acodec': 'none',
+                            'vcodec': 'none',
+                        }
+                    if is_drm_protected(adaptation_set) or is_drm_protected(representation):
+                        f['has_drm'] = True
+                    representation_ms_info = extract_multisegment_info(representation, adaption_set_ms_info)
+
+                    def prepare_template(template_name, identifiers):
+                        tmpl = representation_ms_info[template_name]
+                        if representation_id is not None:
+                            tmpl = tmpl.replace('$RepresentationID$', representation_id)
+                        # First of, % characters outside $...$ templates
+                        # must be escaped by doubling for proper processing
+                        # by % operator string formatting used further (see
+                        # https://github.com/ytdl-org/youtube-dl/issues/16867).
+                        t = ''
+                        in_template = False
+                        for c in tmpl:
+                            t += c
+                            if c == '$':
+                                in_template = not in_template
+                            elif c == '%' and not in_template:
                                 t += c
-                                if c == '$':
-                                    in_template = not in_template
-                                elif c == '%' and not in_template:
-                                    t += c
-                            # Next, $...$ templates are translated to their
-                            # %(...) counterparts to be used with % operator
-                            t = t.replace('$RepresentationID$', representation_id)
-                            t = re.sub(r'\$(%s)\$' % '|'.join(identifiers), r'%(\1)d', t)
-                            t = re.sub(r'\$(%s)%%([^$]+)\$' % '|'.join(identifiers), r'%(\1)\2', t)
-                            t.replace('$$', '$')
-                            return t
-
-                        # @initialization is a regular template like @media one
-                        # so it should be handled just the same way (see
-                        # https://github.com/ytdl-org/youtube-dl/issues/11605)
-                        if 'initialization' in representation_ms_info:
-                            initialization_template = prepare_template(
-                                'initialization',
-                                # As per [1, 5.3.9.4.2, Table 15, page 54] $Number$ and
-                                # $Time$ shall not be included for @initialization thus
-                                # only $Bandwidth$ remains
-                                ('Bandwidth', ))
-                            representation_ms_info['initialization_url'] = initialization_template % {
-                                'Bandwidth': bandwidth,
-                            }
+                        # Next, $...$ templates are translated to their
+                        # %(...) counterparts to be used with % operator
+                        t = re.sub(r'\$(%s)\$' % '|'.join(identifiers), r'%(\1)d', t)
+                        t = re.sub(r'\$(%s)%%([^$]+)\$' % '|'.join(identifiers), r'%(\1)\2', t)
+                        t.replace('$$', '$')
+                        return t
+
+                    # @initialization is a regular template like @media one
+                    # so it should be handled just the same way (see
+                    # https://github.com/ytdl-org/youtube-dl/issues/11605)
+                    if 'initialization' in representation_ms_info:
+                        initialization_template = prepare_template(
+                            'initialization',
+                            # As per [1, 5.3.9.4.2, Table 15, page 54] $Number$ and
+                            # $Time$ shall not be included for @initialization thus
+                            # only $Bandwidth$ remains
+                            ('Bandwidth', ))
+                        representation_ms_info['initialization_url'] = initialization_template % {
+                            'Bandwidth': bandwidth,
+                        }
 
-                        def location_key(location):
-                            return 'url' if re.match(r'^https?://', location) else 'path'
-
-                        if 'segment_urls' not in representation_ms_info and 'media' in representation_ms_info:
-
-                            media_template = prepare_template('media', ('Number', 'Bandwidth', 'Time'))
-                            media_location_key = location_key(media_template)
-
-                            # As per [1, 5.3.9.4.4, Table 16, page 55] $Number$ and $Time$
-                            # can't be used at the same time
-                            if '%(Number' in media_template and 's' not in representation_ms_info:
-                                segment_duration = None
-                                if 'total_number' not in representation_ms_info and 'segment_duration' in representation_ms_info:
-                                    segment_duration = float_or_none(representation_ms_info['segment_duration'], representation_ms_info['timescale'])
-                                    representation_ms_info['total_number'] = int(math.ceil(float(period_duration) / segment_duration))
-                                representation_ms_info['fragments'] = [{
-                                    media_location_key: media_template % {
-                                        'Number': segment_number,
-                                        'Bandwidth': bandwidth,
-                                    },
-                                    'duration': segment_duration,
-                                } for segment_number in range(
-                                    representation_ms_info['start_number'],
-                                    representation_ms_info['total_number'] + representation_ms_info['start_number'])]
-                            else:
-                                # $Number*$ or $Time$ in media template with S list available
-                                # Example $Number*$: http://www.svtplay.se/klipp/9023742/stopptid-om-bjorn-borg
-                                # Example $Time$: https://play.arkena.com/embed/avp/v2/player/media/b41dda37-d8e7-4d3f-b1b5-9a9db578bdfe/1/129411
-                                representation_ms_info['fragments'] = []
-                                segment_time = 0
-                                segment_d = None
-                                segment_number = representation_ms_info['start_number']
-
-                                def add_segment_url():
-                                    segment_url = media_template % {
-                                        'Time': segment_time,
-                                        'Bandwidth': bandwidth,
-                                        'Number': segment_number,
-                                    }
-                                    representation_ms_info['fragments'].append({
-                                        media_location_key: segment_url,
-                                        'duration': float_or_none(segment_d, representation_ms_info['timescale']),
-                                    })
-
-                                for num, s in enumerate(representation_ms_info['s']):
-                                    segment_time = s.get('t') or segment_time
-                                    segment_d = s['d']
+                    def location_key(location):
+                        return 'url' if re.match(r'^https?://', location) else 'path'
+
+                    if 'segment_urls' not in representation_ms_info and 'media' in representation_ms_info:
+
+                        media_template = prepare_template('media', ('Number', 'Bandwidth', 'Time'))
+                        media_location_key = location_key(media_template)
+
+                        # As per [1, 5.3.9.4.4, Table 16, page 55] $Number$ and $Time$
+                        # can't be used at the same time
+                        if '%(Number' in media_template and 's' not in representation_ms_info:
+                            segment_duration = None
+                            if 'total_number' not in representation_ms_info and 'segment_duration' in representation_ms_info:
+                                segment_duration = float_or_none(representation_ms_info['segment_duration'], representation_ms_info['timescale'])
+                                representation_ms_info['total_number'] = int(math.ceil(
+                                    float_or_none(period_duration, segment_duration, default=0)))
+                            representation_ms_info['fragments'] = [{
+                                media_location_key: media_template % {
+                                    'Number': segment_number,
+                                    'Bandwidth': bandwidth,
+                                },
+                                'duration': segment_duration,
+                            } for segment_number in range(
+                                representation_ms_info['start_number'],
+                                representation_ms_info['total_number'] + representation_ms_info['start_number'])]
+                        else:
+                            # $Number*$ or $Time$ in media template with S list available
+                            # Example $Number*$: http://www.svtplay.se/klipp/9023742/stopptid-om-bjorn-borg
+                            # Example $Time$: https://play.arkena.com/embed/avp/v2/player/media/b41dda37-d8e7-4d3f-b1b5-9a9db578bdfe/1/129411
+                            representation_ms_info['fragments'] = []
+                            segment_time = 0
+                            segment_d = None
+                            segment_number = representation_ms_info['start_number']
+
+                            def add_segment_url():
+                                segment_url = media_template % {
+                                    'Time': segment_time,
+                                    'Bandwidth': bandwidth,
+                                    'Number': segment_number,
+                                }
+                                representation_ms_info['fragments'].append({
+                                    media_location_key: segment_url,
+                                    'duration': float_or_none(segment_d, representation_ms_info['timescale']),
+                                })
+
+                            for num, s in enumerate(representation_ms_info['s']):
+                                segment_time = s.get('t') or segment_time
+                                segment_d = s['d']
+                                add_segment_url()
+                                segment_number += 1
+                                for r in range(s.get('r', 0)):
+                                    segment_time += segment_d
                                     add_segment_url()
                                     segment_number += 1
-                                    for r in range(s.get('r', 0)):
-                                        segment_time += segment_d
-                                        add_segment_url()
-                                        segment_number += 1
-                                    segment_time += segment_d
-                        elif 'segment_urls' in representation_ms_info and 's' in representation_ms_info:
-                            # No media template
-                            # Example: https://www.youtube.com/watch?v=iXZV5uAYMJI
-                            # or any YouTube dashsegments video
-                            fragments = []
-                            segment_index = 0
-                            timescale = representation_ms_info['timescale']
-                            for s in representation_ms_info['s']:
-                                duration = float_or_none(s['d'], timescale)
-                                for r in range(s.get('r', 0) + 1):
-                                    segment_uri = representation_ms_info['segment_urls'][segment_index]
-                                    fragments.append({
-                                        location_key(segment_uri): segment_uri,
-                                        'duration': duration,
-                                    })
-                                    segment_index += 1
-                            representation_ms_info['fragments'] = fragments
-                        elif 'segment_urls' in representation_ms_info:
-                            # Segment URLs with no SegmentTimeline
-                            # Example: https://www.seznam.cz/zpravy/clanek/cesko-zasahne-vitr-o-sile-vichrice-muze-byt-i-zivotu-nebezpecny-39091
-                            # https://github.com/ytdl-org/youtube-dl/pull/14844
-                            fragments = []
-                            segment_duration = float_or_none(
-                                representation_ms_info['segment_duration'],
-                                representation_ms_info['timescale']) if 'segment_duration' in representation_ms_info else None
-                            for segment_url in representation_ms_info['segment_urls']:
-                                fragment = {
-                                    location_key(segment_url): segment_url,
-                                }
-                                if segment_duration:
-                                    fragment['duration'] = segment_duration
-                                fragments.append(fragment)
-                            representation_ms_info['fragments'] = fragments
-                        # If there is a fragments key available then we correctly recognized fragmented media.
-                        # Otherwise we will assume unfragmented media with direct access. Technically, such
-                        # assumption is not necessarily correct since we may simply have no support for
-                        # some forms of fragmented media renditions yet, but for now we'll use this fallback.
-                        if 'fragments' in representation_ms_info:
-                            f.update({
-                                # NB: mpd_url may be empty when MPD manifest is parsed from a string
-                                'url': mpd_url or base_url,
-                                'fragment_base_url': base_url,
-                                'fragments': [],
-                                'protocol': 'http_dash_segments',
-                            })
-                            if 'initialization_url' in representation_ms_info:
-                                initialization_url = representation_ms_info['initialization_url']
-                                if not f.get('url'):
-                                    f['url'] = initialization_url
-                                f['fragments'].append({location_key(initialization_url): initialization_url})
-                            f['fragments'].extend(representation_ms_info['fragments'])
-                        else:
-                            # Assuming direct URL to unfragmented media.
-                            f['url'] = base_url
-                        if content_type in ('video', 'audio'):
-                            formats.append(f)
-                        elif content_type == 'text':
-                            subtitles.setdefault(lang or 'und', []).append(f)
+                                segment_time += segment_d
+                    elif 'segment_urls' in representation_ms_info and 's' in representation_ms_info:
+                        # No media template,
+                        # e.g. https://www.youtube.com/watch?v=iXZV5uAYMJI
+                        # or any YouTube dashsegments video
+                        fragments = []
+                        segment_index = 0
+                        timescale = representation_ms_info['timescale']
+                        for s in representation_ms_info['s']:
+                            duration = float_or_none(s['d'], timescale)
+                            for r in range(s.get('r', 0) + 1):
+                                segment_uri = representation_ms_info['segment_urls'][segment_index]
+                                fragments.append({
+                                    location_key(segment_uri): segment_uri,
+                                    'duration': duration,
+                                })
+                                segment_index += 1
+                        representation_ms_info['fragments'] = fragments
+                    elif 'segment_urls' in representation_ms_info:
+                        # Segment URLs with no SegmentTimeline
+                        # E.g. https://www.seznam.cz/zpravy/clanek/cesko-zasahne-vitr-o-sile-vichrice-muze-byt-i-zivotu-nebezpecny-39091
+                        # https://github.com/ytdl-org/youtube-dl/pull/14844
+                        fragments = []
+                        segment_duration = float_or_none(
+                            representation_ms_info['segment_duration'],
+                            representation_ms_info['timescale']) if 'segment_duration' in representation_ms_info else None
+                        for segment_url in representation_ms_info['segment_urls']:
+                            fragment = {
+                                location_key(segment_url): segment_url,
+                            }
+                            if segment_duration:
+                                fragment['duration'] = segment_duration
+                            fragments.append(fragment)
+                        representation_ms_info['fragments'] = fragments
+                    # If there is a fragments key available then we correctly recognized fragmented media.
+                    # Otherwise we will assume unfragmented media with direct access. Technically, such
+                    # assumption is not necessarily correct since we may simply have no support for
+                    # some forms of fragmented media renditions yet, but for now we'll use this fallback.
+                    if 'fragments' in representation_ms_info:
+                        f.update({
+                            # NB: mpd_url may be empty when MPD manifest is parsed from a string
+                            'url': mpd_url or base_url,
+                            'fragment_base_url': base_url,
+                            'fragments': [],
+                            'protocol': 'http_dash_segments' if mime_type != 'image/jpeg' else 'mhtml',
+                        })
+                        if 'initialization_url' in representation_ms_info:
+                            initialization_url = representation_ms_info['initialization_url']
+                            if not f.get('url'):
+                                f['url'] = initialization_url
+                            f['fragments'].append({location_key(initialization_url): initialization_url})
+                        f['fragments'].extend(representation_ms_info['fragments'])
+                        if not period_duration:
+                            period_duration = try_get(
+                                representation_ms_info,
+                                lambda r: sum(frag['duration'] for frag in r['fragments']), float)
                     else:
-                        self.report_warning('Unknown MIME type %s in DASH manifest' % mime_type)
+                        # Assuming direct URL to unfragmented media.
+                        f['url'] = base_url
+                    if content_type in ('video', 'audio', 'image/jpeg'):
+                        f['manifest_stream_number'] = stream_numbers[f['url']]
+                        stream_numbers[f['url']] += 1
+                        formats.append(f)
+                    elif content_type == 'text':
+                        subtitles.setdefault(lang or 'und', []).append(f)
+
         return formats, subtitles
 
     def _extract_ism_formats(self, *args, **kwargs):
         fmts, subs = self._extract_ism_formats_and_subtitles(*args, **kwargs)
         if subs:
-            self.report_warning(bug_reports_message(
-                "Ignoring subtitle tracks found in the ISM manifest; "
-                "if any subtitle tracks are missing,"
-            ))
+            self._report_ignoring_subs('ISM')
         return fmts
 
     def _extract_ism_formats_and_subtitles(self, ism_url, video_id, ism_id=None, note=None, errnote=None, fatal=True, data=None, headers={}, query={}):
         res = self._download_xml_handle(
             ism_url, video_id,
-            note=note or 'Downloading ISM manifest',
-            errnote=errnote or 'Failed to download ISM manifest',
+            note='Downloading ISM manifest' if note is None else note,
+            errnote='Failed to download ISM manifest' if errnote is None else errnote,
             fatal=fatal, data=data, headers=headers, query=query)
         if res is False:
             return [], {}
@@ -2802,9 +3109,6 @@ def _parse_ism_formats_and_subtitles(self, ism_doc, ism_url, ism_id=None):
         """
         if ism_doc.get('IsLive') == 'TRUE':
             return [], {}
-        if (not self.get_param('allow_unplayable_formats')
-                and ism_doc.find('Protection') is not None):
-            return [], {}
 
         duration = int(ism_doc.attrib['Duration'])
         timescale = int_or_none(ism_doc.get('TimeScale')) or 10000000
@@ -2820,7 +3124,7 @@ def _parse_ism_formats_and_subtitles(self, ism_doc, ism_url, ism_id=None):
             stream_name = stream.get('Name')
             stream_language = stream.get('Language', 'und')
             for track in stream.findall('QualityLevel'):
-                fourcc = track.get('FourCC''AACL' if track.get('AudioTag') == '255' else None)
+                fourcc = track.get('FourCC') or ('AACL' if track.get('AudioTag') == '255' else None)
                 # TODO: add support for WVC1 and WMAP
                 if fourcc not in ('H264', 'AVC1', 'AACL', 'TTML'):
                     self.report_warning('%s is not a supported codec' % fourcc)
@@ -2834,7 +3138,7 @@ def _parse_ism_formats_and_subtitles(self, ism_doc, ism_url, ism_id=None):
                 sampling_rate = int_or_none(track.get('SamplingRate'))
 
                 track_url_pattern = re.sub(r'{[Bb]itrate}', track.attrib['Bitrate'], url_pattern)
-                track_url_pattern = compat_urlparse.urljoin(ism_url, track_url_pattern)
+                track_url_pattern = urllib.parse.urljoin(ism_url, track_url_pattern)
 
                 fragments = []
                 fragment_ctx = {
@@ -2853,18 +3157,11 @@ def _parse_ism_formats_and_subtitles(self, ism_doc, ism_url, ism_id=None):
                         fragment_ctx['duration'] = (next_fragment_time - fragment_ctx['time']) / fragment_repeat
                     for _ in range(fragment_repeat):
                         fragments.append({
-                            'url': re.sub(r'{start[ _]time}', compat_str(fragment_ctx['time']), track_url_pattern),
+                            'url': re.sub(r'{start[ _]time}', str(fragment_ctx['time']), track_url_pattern),
                             'duration': fragment_ctx['duration'] / stream_timescale,
                         })
                         fragment_ctx['time'] += fragment_ctx['duration']
 
-                format_id = []
-                if ism_id:
-                    format_id.append(ism_id)
-                if stream_name:
-                    format_id.append(stream_name)
-                format_id.append(compat_str(tbr))
-
                 if stream_type == 'text':
                     subtitles.setdefault(stream_language, []).append({
                         'ext': 'ismt',
@@ -2883,7 +3180,7 @@ def _parse_ism_formats_and_subtitles(self, ism_doc, ism_url, ism_id=None):
                     })
                 elif stream_type in ('video', 'audio'):
                     formats.append({
-                        'format_id': '-'.join(format_id),
+                        'format_id': join_nonempty(ism_id, stream_name, tbr),
                         'url': ism_url,
                         'manifest_url': ism_url,
                         'ext': 'ismv' if stream_type == 'video' else 'isma',
@@ -2895,6 +3192,7 @@ def _parse_ism_formats_and_subtitles(self, ism_doc, ism_url, ism_id=None):
                         'acodec': 'none' if stream_type == 'video' else fourcc,
                         'protocol': 'ism',
                         'fragments': fragments,
+                        'has_drm': ism_doc.find('Protection') is not None,
                         '_download_params': {
                             'stream_type': stream_type,
                             'duration': duration,
@@ -2912,7 +3210,7 @@ def _parse_ism_formats_and_subtitles(self, ism_doc, ism_url, ism_id=None):
                     })
         return formats, subtitles
 
-    def _parse_html5_media_entries(self, base_url, webpage, video_id, m3u8_id=None, m3u8_entry_protocol='m3u8', mpd_id=None, preference=None, quality=None):
+    def _parse_html5_media_entries(self, base_url, webpage, video_id, m3u8_id=None, m3u8_entry_protocol='m3u8_native', mpd_id=None, preference=None, quality=None):
         def absolute_url(item_url):
             return urljoin(base_url, item_url)
 
@@ -2927,7 +3225,8 @@ def parse_content_type(content_type):
                 return f
             return {}
 
-        def _media_formats(src, cur_media_type, type_info={}):
+        def _media_formats(src, cur_media_type, type_info=None):
+            type_info = type_info or {}
             full_url = absolute_url(src)
             ext = type_info.get('ext') or determine_ext(full_url)
             if ext == 'm3u8':
@@ -2945,12 +3244,13 @@ def _media_formats(src, cur_media_type, type_info={}):
                 formats = [{
                     'url': full_url,
                     'vcodec': 'none' if cur_media_type == 'audio' else None,
+                    'ext': ext,
                 }]
             return is_plain_url, formats
 
         entries = []
         # amp-video and amp-audio are very similar to their HTML5 counterparts
-        # so we wll include them right here (see
+        # so we will include them right here (see
         # https://www.ampproject.org/docs/reference/components/amp-video)
         # For dl8-* tags see https://delight-vr.com/documentation/dl8-video/
         _MEDIA_TAG_NAME_RE = r'(?:(?:amp|dl8(?:-live)?)-)?(video|audio)'
@@ -2960,8 +3260,8 @@ def _media_formats(src, cur_media_type, type_info={}):
         media_tags.extend(re.findall(
             # We only allow video|audio followed by a whitespace or '>'.
             # Allowing more characters may end up in significant slow down (see
-            # https://github.com/ytdl-org/youtube-dl/issues/11979, example URL:
-            # http://www.porntrex.com/maps/videositemap.xml).
+            # https://github.com/ytdl-org/youtube-dl/issues/11979,
+            # e.g. http://www.porntrex.com/maps/videositemap.xml).
             r'(?s)(<(?P<tag>%s)(?:\s+[^>]*)?>)(.*?)</(?P=tag)>' % _MEDIA_TAG_NAME_RE, webpage))
         for media_tag, _, media_type, media_content in media_tags:
             media_info = {
@@ -2969,9 +3269,10 @@ def _media_formats(src, cur_media_type, type_info={}):
                 'subtitles': {},
             }
             media_attributes = extract_attributes(media_tag)
-            src = strip_or_none(media_attributes.get('src'))
+            src = strip_or_none(dict_get(media_attributes, ('src', 'data-video-src', 'data-src', 'data-source')))
             if src:
-                _, formats = _media_formats(src, media_type)
+                f = parse_content_type(media_attributes.get('type'))
+                _, formats = _media_formats(src, media_type, f)
                 media_info['formats'].extend(formats)
             media_info['thumbnail'] = absolute_url(media_attributes.get('poster'))
             if media_content:
@@ -2979,7 +3280,7 @@ def _media_formats(src, cur_media_type, type_info={}):
                     s_attr = extract_attributes(source_tag)
                     # data-video-src and data-src are non standard but seen
                     # several times in the wild
-                    src = strip_or_none(dict_get(s_attr, ('src', 'data-video-src', 'data-src')))
+                    src = strip_or_none(dict_get(s_attr, ('src', 'data-video-src', 'data-src', 'data-source')))
                     if not src:
                         continue
                     f = parse_content_type(s_attr.get('type'))
@@ -3038,10 +3339,7 @@ def _media_formats(src, cur_media_type, type_info={}):
     def _extract_akamai_formats(self, *args, **kwargs):
         fmts, subs = self._extract_akamai_formats_and_subtitles(*args, **kwargs)
         if subs:
-            self.report_warning(bug_reports_message(
-                "Ignoring subtitle tracks found in the manifests; "
-                "if any subtitle tracks are missing,"
-            ))
+            self._report_ignoring_subs('akamai')
         return fmts
 
     def _extract_akamai_formats_and_subtitles(self, manifest_url, video_id, hosts={}):
@@ -3091,7 +3389,7 @@ def _extract_akamai_formats_and_subtitles(self, manifest_url, video_id, hosts={}
                             http_f = f.copy()
                             del http_f['manifest_url']
                             http_url = re.sub(
-                                REPL_REGEX, protocol + r'://%s/\g<1>%s\3' % (http_host, qualities[i]), f['url'])
+                                REPL_REGEX, protocol + fr'://{http_host}/\g<1>{qualities[i]}\3', f['url'])
                             http_f.update({
                                 'format_id': http_f['format_id'].replace('hls-', protocol + '-'),
                                 'url': http_url,
@@ -3103,7 +3401,7 @@ def _extract_akamai_formats_and_subtitles(self, manifest_url, video_id, hosts={}
         return formats, subtitles
 
     def _extract_wowza_formats(self, url, video_id, m3u8_entry_protocol='m3u8_native', skip_protocols=[]):
-        query = compat_urlparse.urlparse(url).query
+        query = urllib.parse.urlparse(url).query
         url = re.sub(r'/(?:manifest|playlist|jwplayer)\.(?:m3u8|f4m|mpd|smil)', '', url)
         mobj = re.search(
             r'(?:(?:http|rtmp|rtsp)(?P<s>s)?:)?(?P<url>//[^?]+)', url)
@@ -3112,7 +3410,7 @@ def _extract_wowza_formats(self, url, video_id, m3u8_entry_protocol='m3u8_native
         formats = []
 
         def manifest_url(manifest):
-            m_url = '%s/%s' % (http_base_url, manifest)
+            m_url = f'{http_base_url}/{manifest}'
             if query:
                 m_url += '?%s' % query
             return m_url
@@ -3149,7 +3447,7 @@ def manifest_url(manifest):
             for protocol in ('rtmp', 'rtsp'):
                 if protocol not in skip_protocols:
                     formats.append({
-                        'url': '%s:%s' % (protocol, url_base),
+                        'url': f'{protocol}:{url_base}',
                         'format_id': protocol,
                         'protocol': protocol,
                     })
@@ -3209,7 +3507,7 @@ def _parse_jwplayer_data(self, jwplayer_data, video_id=None, require_title=True,
                     if not isinstance(track, dict):
                         continue
                     track_kind = track.get('kind')
-                    if not track_kind or not isinstance(track_kind, compat_str):
+                    if not track_kind or not isinstance(track_kind, str):
                         continue
                     if track_kind.lower() not in ('captions', 'subtitles'):
                         continue
@@ -3282,7 +3580,7 @@ def _parse_jwplayer_formats(self, jwplayer_sources_data, video_id=None,
                     # Often no height is provided but there is a label in
                     # format like "1080p", "720p SD", or 1080.
                     height = int_or_none(self._search_regex(
-                        r'^(\d{3,4})[pP]?(?:\b|$)', compat_str(source.get('label') or ''),
+                        r'^(\d{3,4})[pP]?(?:\b|$)', str(source.get('label') or ''),
                         'height', default=None))
                 a_format = {
                     'url': source_url,
@@ -3309,17 +3607,13 @@ def _parse_jwplayer_formats(self, jwplayer_sources_data, video_id=None,
         return formats
 
     def _live_title(self, name):
-        """ Generate the title for a live video """
-        now = datetime.datetime.now()
-        now_str = now.strftime('%Y-%m-%d %H:%M')
-        return name + ' ' + now_str
+        self._downloader.deprecation_warning('yt_dlp.InfoExtractor._live_title is deprecated and does not work as expected')
+        return name
 
     def _int(self, v, name, fatal=False, **kwargs):
         res = int_or_none(v, **kwargs)
-        if 'get_attr' in kwargs:
-            print(getattr(v, kwargs['get_attr']))
         if res is None:
-            msg = 'Failed to extract %s: Could not parse value %r' % (name, v)
+            msg = f'Failed to extract {name}: Could not parse value {v!r}'
             if fatal:
                 raise ExtractorError(msg)
             else:
@@ -3329,7 +3623,7 @@ def _int(self, v, name, fatal=False, **kwargs):
     def _float(self, v, name, fatal=False, **kwargs):
         res = float_or_none(v, **kwargs)
         if res is None:
-            msg = 'Failed to extract %s: Could not parse value %r' % (name, v)
+            msg = f'Failed to extract {name}: Could not parse value {v!r}'
             if fatal:
                 raise ExtractorError(msg)
             else:
@@ -3338,17 +3632,15 @@ def _float(self, v, name, fatal=False, **kwargs):
 
     def _set_cookie(self, domain, name, value, expire_time=None, port=None,
                     path='/', secure=False, discard=False, rest={}, **kwargs):
-        cookie = compat_cookiejar_Cookie(
+        cookie = http.cookiejar.Cookie(
             0, name, value, port, port is not None, domain, True,
             domain.startswith('.'), path, True, secure, expire_time,
             discard, None, None, rest)
-        self._downloader.cookiejar.set_cookie(cookie)
+        self.cookiejar.set_cookie(cookie)
 
     def _get_cookies(self, url):
-        """ Return a compat_cookies_SimpleCookie with the cookies for the url """
-        req = sanitized_Request(url)
-        self._downloader.cookiejar.add_cookie_header(req)
-        return compat_cookies_SimpleCookie(req.get_header('Cookie'))
+        """ Return a http.cookies.SimpleCookie with the cookies for the url """
+        return LenientSimpleCookie(self._downloader._calc_cookies(url))
 
     def _apply_first_set_cookie_header(self, url_handle, cookie):
         """
@@ -3367,9 +3659,7 @@ def _apply_first_set_cookie_header(self, url_handle, cookie):
         for header, cookies in url_handle.headers.items():
             if header.lower() != 'set-cookie':
                 continue
-            if sys.version_info[0] >= 3:
-                cookies = cookies.encode('iso-8859-1')
-            cookies = cookies.decode('utf-8')
+            cookies = cookies.encode('iso-8859-1').decode('utf-8')
             cookie_value = re.search(
                 r'%s=(.+?);.*?\b[Dd]omain=(.+?)(?:[,;]|$)' % cookie, cookies)
             if cookie_value:
@@ -3377,34 +3667,62 @@ def _apply_first_set_cookie_header(self, url_handle, cookie):
                 self._set_cookie(domain, cookie, value)
                 break
 
-    def get_testcases(self, include_onlymatching=False):
-        t = getattr(self, '_TEST', None)
+    @classmethod
+    def get_testcases(cls, include_onlymatching=False):
+        t = getattr(cls, '_TEST', None)
         if t:
-            assert not hasattr(self, '_TESTS'), \
-                '%s has _TEST and _TESTS' % type(self).__name__
+            assert not hasattr(cls, '_TESTS'), f'{cls.ie_key()}IE has _TEST and _TESTS'
             tests = [t]
         else:
-            tests = getattr(self, '_TESTS', [])
+            tests = getattr(cls, '_TESTS', [])
         for t in tests:
             if not include_onlymatching and t.get('only_matching', False):
                 continue
-            t['name'] = type(self).__name__[:-len('IE')]
+            t['name'] = cls.ie_key()
             yield t
 
-    def is_suitable(self, age_limit):
-        """ Test whether the extractor is generally suitable for the given
-        age limit (i.e. pornographic sites are not, all others usually are) """
-
-        any_restricted = False
-        for tc in self.get_testcases(include_onlymatching=False):
-            if tc.get('playlist', []):
-                tc = tc['playlist'][0]
-            is_restricted = age_restricted(
-                tc.get('info_dict', {}).get('age_limit'), age_limit)
-            if not is_restricted:
-                return True
-            any_restricted = any_restricted or is_restricted
-        return not any_restricted
+    @classmethod
+    def get_webpage_testcases(cls):
+        tests = getattr(cls, '_WEBPAGE_TESTS', [])
+        for t in tests:
+            t['name'] = cls.ie_key()
+        return tests
+
+    @classproperty
+    def age_limit(cls):
+        """Get age limit from the testcases"""
+        return max(traverse_obj(
+            (*cls.get_testcases(include_onlymatching=False), *cls.get_webpage_testcases()),
+            (..., (('playlist', 0), None), 'info_dict', 'age_limit')) or [0])
+
+    @classmethod
+    def is_suitable(cls, age_limit):
+        """Test whether the extractor is generally suitable for the given age limit"""
+        return not age_restricted(cls.age_limit, age_limit)
+
+    @classmethod
+    def description(cls, *, markdown=True, search_examples=None):
+        """Description of the extractor"""
+        desc = ''
+        if cls._NETRC_MACHINE:
+            if markdown:
+                desc += f' [<abbr title="netrc machine"><em>{cls._NETRC_MACHINE}</em></abbr>]'
+            else:
+                desc += f' [{cls._NETRC_MACHINE}]'
+        if cls.IE_DESC is False:
+            desc += ' [HIDDEN]'
+        elif cls.IE_DESC:
+            desc += f' {cls.IE_DESC}'
+        if cls.SEARCH_KEY:
+            desc += f'; "{cls.SEARCH_KEY}:" prefix'
+            if search_examples:
+                _COUNTS = ('', '5', '10', 'all')
+                desc += f' (e.g. "{cls.SEARCH_KEY}{random.choice(_COUNTS)}:{random.choice(search_examples)}")'
+        if not cls.working():
+            desc += ' (**Currently broken**)' if markdown else ' (Currently broken)'
+
+        name = f' - **{cls.IE_NAME}**' if markdown else cls.IE_NAME
+        return f'{name}:{desc}' if desc else name
 
     def extract_subtitles(self, *args, **kwargs):
         if (self.get_param('writesubtitles', False)
@@ -3415,26 +3733,48 @@ def extract_subtitles(self, *args, **kwargs):
     def _get_subtitles(self, *args, **kwargs):
         raise NotImplementedError('This method must be implemented by subclasses')
 
+    def extract_comments(self, *args, **kwargs):
+        if not self.get_param('getcomments'):
+            return None
+        generator = self._get_comments(*args, **kwargs)
+
+        def extractor():
+            comments = []
+            interrupted = True
+            try:
+                while True:
+                    comments.append(next(generator))
+            except StopIteration:
+                interrupted = False
+            except KeyboardInterrupt:
+                self.to_screen('Interrupted by user')
+            except Exception as e:
+                if self.get_param('ignoreerrors') is not True:
+                    raise
+                self._downloader.report_error(e)
+            comment_count = len(comments)
+            self.to_screen(f'Extracted {comment_count} comments')
+            return {
+                'comments': comments,
+                'comment_count': None if interrupted else comment_count
+            }
+        return extractor
+
+    def _get_comments(self, *args, **kwargs):
+        raise NotImplementedError('This method must be implemented by subclasses')
+
     @staticmethod
     def _merge_subtitle_items(subtitle_list1, subtitle_list2):
-        """ Merge subtitle items for one language. Items with duplicated URLs
+        """ Merge subtitle items for one language. Items with duplicated URLs/data
         will be dropped. """
-        list1_urls = set([item['url'] for item in subtitle_list1])
+        list1_data = {(item.get('url'), item.get('data')) for item in subtitle_list1}
         ret = list(subtitle_list1)
-        ret.extend([item for item in subtitle_list2 if item['url'] not in list1_urls])
+        ret.extend(item for item in subtitle_list2 if (item.get('url'), item.get('data')) not in list1_data)
         return ret
 
     @classmethod
-    def _merge_subtitles(cls, *dicts, **kwargs):
+    def _merge_subtitles(cls, *dicts, target=None):
         """ Merge subtitle dictionaries, language by language. """
-
-        target = (lambda target=None: target)(**kwargs)
-        # The above lambda extracts the keyword argument 'target' from kwargs
-        # while ensuring there are no stray ones. When Python 2 support
-        # is dropped, remove it and change the function signature to:
-        #
-        #     def _merge_subtitles(cls, *dicts, target=None):
-
         if target is None:
             target = {}
         for d in dicts:
@@ -3451,10 +3791,15 @@ def extract_automatic_captions(self, *args, **kwargs):
     def _get_automatic_captions(self, *args, **kwargs):
         raise NotImplementedError('This method must be implemented by subclasses')
 
+    @functools.cached_property
+    def _cookies_passed(self):
+        """Whether cookies have been passed to YoutubeDL"""
+        return self.get_param('cookiefile') is not None or self.get_param('cookiesfrombrowser') is not None
+
     def mark_watched(self, *args, **kwargs):
-        if (self.get_param('mark_watched', False)
-                and (self._get_login_info()[0] is not None
-                     or self.get_param('cookiefile') is not None)):
+        if not self.get_param('mark_watched', False):
+            return
+        if self.supports_login() and self._get_login_info()[0] is not None or self._cookies_passed:
             self._mark_watched(*args, **kwargs)
 
     def _mark_watched(self, *args, **kwargs):
@@ -3467,14 +3812,16 @@ def geo_verification_headers(self):
             headers['Ytdl-request-proxy'] = geo_verification_proxy
         return headers
 
-    def _generic_id(self, url):
-        return compat_urllib_parse_unquote(os.path.splitext(url.rstrip('/').split('/')[-1])[0])
+    @staticmethod
+    def _generic_id(url):
+        return urllib.parse.unquote(os.path.splitext(url.rstrip('/').split('/')[-1])[0])
 
-    def _generic_title(self, url):
-        return compat_urllib_parse_unquote(os.path.splitext(url_basename(url))[0])
+    @staticmethod
+    def _generic_title(url):
+        return urllib.parse.unquote(os.path.splitext(url_basename(url))[0])
 
     @staticmethod
-    def _availability(is_private, needs_premium, needs_subscription, needs_auth, is_unlisted):
+    def _availability(is_private=None, needs_premium=None, needs_subscription=None, needs_auth=None, is_unlisted=None):
         all_known = all(map(
             lambda x: x is not None,
             (is_private, needs_premium, needs_subscription, needs_auth, is_unlisted)))
@@ -3487,29 +3834,111 @@ def _availability(is_private, needs_premium, needs_subscription, needs_auth, is_
             else 'public' if all_known
             else None)
 
+    def _configuration_arg(self, key, default=NO_DEFAULT, *, ie_key=None, casesense=False):
+        '''
+        @returns            A list of values for the extractor argument given by "key"
+                            or "default" if no such key is present
+        @param default      The default value to return when the key is not present (default: [])
+        @param casesense    When false, the values are converted to lower case
+        '''
+        val = traverse_obj(
+            self._downloader.params, ('extractor_args', (ie_key or self.ie_key()).lower(), key))
+        if val is None:
+            return [] if default is NO_DEFAULT else default
+        return list(val) if casesense else [x.lower() for x in val]
+
+    def _yes_playlist(self, playlist_id, video_id, smuggled_data=None, *, playlist_label='playlist', video_label='video'):
+        if not playlist_id or not video_id:
+            return not video_id
+
+        no_playlist = (smuggled_data or {}).get('force_noplaylist')
+        if no_playlist is not None:
+            return not no_playlist
+
+        video_id = '' if video_id is True else f' {video_id}'
+        playlist_id = '' if playlist_id is True else f' {playlist_id}'
+        if self.get_param('noplaylist'):
+            self.to_screen(f'Downloading just the {video_label}{video_id} because of --no-playlist')
+            return False
+        self.to_screen(f'Downloading {playlist_label}{playlist_id} - add --no-playlist to download just the {video_label}{video_id}')
+        return True
+
+    def _error_or_warning(self, err, _count=None, _retries=0, *, fatal=True):
+        RetryManager.report_retry(
+            err, _count or int(fatal), _retries,
+            info=self.to_screen, warn=self.report_warning, error=None if fatal else self.report_warning,
+            sleep_func=self.get_param('retry_sleep_functions', {}).get('extractor'))
+
+    def RetryManager(self, **kwargs):
+        return RetryManager(self.get_param('extractor_retries', 3), self._error_or_warning, **kwargs)
+
+    @classmethod
+    def extract_from_webpage(cls, ydl, url, webpage):
+        ie = (cls if isinstance(cls._extract_from_webpage, types.MethodType)
+              else ydl.get_info_extractor(cls.ie_key()))
+        for info in ie._extract_from_webpage(url, webpage) or []:
+            # url = None since we do not want to set (webpage/original)_url
+            ydl.add_default_extra_info(info, ie, None)
+            yield info
+
+    @classmethod
+    def _extract_from_webpage(cls, url, webpage):
+        for embed_url in orderedSet(
+                cls._extract_embed_urls(url, webpage) or [], lazy=True):
+            yield cls.url_result(embed_url, None if cls._VALID_URL is False else cls)
+
+    @classmethod
+    def _extract_embed_urls(cls, url, webpage):
+        """@returns all the embed urls on the webpage"""
+        if '_EMBED_URL_RE' not in cls.__dict__:
+            assert isinstance(cls._EMBED_REGEX, (list, tuple))
+            for idx, regex in enumerate(cls._EMBED_REGEX):
+                assert regex.count('(?P<url>') == 1, \
+                    f'{cls.__name__}._EMBED_REGEX[{idx}] must have exactly 1 url group\n\t{regex}'
+            cls._EMBED_URL_RE = tuple(map(re.compile, cls._EMBED_REGEX))
+
+        for regex in cls._EMBED_URL_RE:
+            for mobj in regex.finditer(webpage):
+                embed_url = urllib.parse.urljoin(url, unescapeHTML(mobj.group('url')))
+                if cls._VALID_URL is False or cls.suitable(embed_url):
+                    yield embed_url
+
+    class StopExtraction(Exception):
+        pass
+
+    @classmethod
+    def _extract_url(cls, webpage):  # TODO: Remove
+        """Only for compatibility with some older extractors"""
+        return next(iter(cls._extract_embed_urls(None, webpage) or []), None)
+
+    @classmethod
+    def __init_subclass__(cls, *, plugin_name=None, **kwargs):
+        if plugin_name:
+            mro = inspect.getmro(cls)
+            super_class = cls.__wrapped__ = mro[mro.index(cls) + 1]
+            cls.IE_NAME, cls.ie_key = f'{super_class.IE_NAME}+{plugin_name}', super_class.ie_key
+            while getattr(super_class, '__wrapped__', None):
+                super_class = super_class.__wrapped__
+            setattr(sys.modules[super_class.__module__], super_class.__name__, cls)
+
+        return super().__init_subclass__(**kwargs)
+
 
 class SearchInfoExtractor(InfoExtractor):
     """
     Base class for paged search queries extractors.
     They accept URLs in the format _SEARCH_KEY(|all|[0-9]):{query}
-    Instances should define _SEARCH_KEY and _MAX_RESULTS.
+    Instances should define _SEARCH_KEY and optionally _MAX_RESULTS
     """
 
-    @classmethod
-    def _make_valid_url(cls):
-        return r'%s(?P<prefix>|[1-9][0-9]*|all):(?P<query>[\s\S]+)' % cls._SEARCH_KEY
+    _MAX_RESULTS = float('inf')
 
-    @classmethod
-    def suitable(cls, url):
-        return re.match(cls._make_valid_url(), url) is not None
+    @classproperty
+    def _VALID_URL(cls):
+        return r'%s(?P<prefix>|[1-9][0-9]*|all):(?P<query>[\s\S]+)' % cls._SEARCH_KEY
 
     def _real_extract(self, query):
-        mobj = re.match(self._make_valid_url(), query)
-        if mobj is None:
-            raise ExtractorError('Invalid search query "%s"' % query)
-
-        prefix = mobj.group('prefix')
-        query = mobj.group('query')
+        prefix, query = self._match_valid_url(query).group('prefix', 'query')
         if prefix == '':
             return self._get_n_results(query, 1)
         elif prefix == 'all':
@@ -3517,16 +3946,32 @@ def _real_extract(self, query):
         else:
             n = int(prefix)
             if n <= 0:
-                raise ExtractorError('invalid download number %s for query "%s"' % (n, query))
+                raise ExtractorError(f'invalid download number {n} for query "{query}"')
             elif n > self._MAX_RESULTS:
                 self.report_warning('%s returns max %i results (you requested %i)' % (self._SEARCH_KEY, self._MAX_RESULTS, n))
                 n = self._MAX_RESULTS
             return self._get_n_results(query, n)
 
     def _get_n_results(self, query, n):
-        """Get a specified number of results for a query"""
+        """Get a specified number of results for a query.
+        Either this function or _search_results must be overridden by subclasses """
+        return self.playlist_result(
+            itertools.islice(self._search_results(query), 0, None if n == float('inf') else n),
+            query, query)
+
+    def _search_results(self, query):
+        """Returns an iterator of search results"""
         raise NotImplementedError('This method must be implemented by subclasses')
 
-    @property
-    def SEARCH_KEY(self):
-        return self._SEARCH_KEY
+    @classproperty
+    def SEARCH_KEY(cls):
+        return cls._SEARCH_KEY
+
+
+class UnsupportedURLIE(InfoExtractor):
+    _VALID_URL = '.*'
+    _ENABLED = False
+    IE_DESC = False
+
+    def _real_extract(self, url):
+        raise UnsupportedError(url)