[extractor/youtube] Support changing extraction language (#4470)

Adds `--extractor-args youtube:lang=<supported lang code>` extractor arg to prefer translated fields (e.g. title and description) of that language, if available, for all YouTube extractors. See README or error message for list of supported language codes.

Closes https://github.com/yt-dlp/yt-dlp/issues/387

Authored by: coletdjnz

2 files changed, 287 insertions, 76 deletions

diff --git a/README.md b/README.md
index 77e597ba0..62c83e721 100644
--- a/README.md
+++ b/README.md
@@ -1705,6 +1705,8 @@ The following extractors use this feature:
     * E.g. `all,all,1000,10` will get a maximum of 1000 replies total, with up to 10 replies per thread. `1000,all,100` will get a maximum of 1000 comments, with a maximum of 100 replies total
 * `innertube_host`: Innertube API host to use for all API requests; e.g. `studio.youtube.com`, `youtubei.googleapis.com`. Note that cookies exported from one subdomain will not work on others
 * `innertube_key`: Innertube API key to use for all API requests
+* `lang`: Supported content language code to prefer translated metadata of this language (case-sensitive). By default, video primary language metadata is preferred, with a fallback to `en` translated.
+  * See youtube.py for list of supported content language codes.
 
 #### youtubetab (YouTube playlists, channels, feeds, etc.)
 * `skip`: One or more of `webpage` (skip initial webpage download), `authcheck` (allow the download of playlists requiring authentication when no initial webpage is downloaded. This may cause unwanted behavior, see [#1122](https://github.com/yt-dlp/yt-dlp/pull/1122) for more details)
diff --git a/yt_dlp/extractor/youtube.py b/yt_dlp/extractor/youtube.py
index 6c4e995b8..ac1a5f210 100644
--- a/yt_dlp/extractor/youtube.py
+++ b/yt_dlp/extractor/youtube.py
@@ -2,6 +2,7 @@ import base64
 import calendar
 import copy
 import datetime
+import enum
 import hashlib
 import itertools
 import json
@@ -275,6 +276,15 @@ def build_innertube_clients():
 build_innertube_clients()
 
 
+class BadgeType(enum.Enum):
+    AVAILABILITY_UNLISTED = enum.auto()
+    AVAILABILITY_PRIVATE = enum.auto()
+    AVAILABILITY_PUBLIC = enum.auto()
+    AVAILABILITY_PREMIUM = enum.auto()
+    AVAILABILITY_SUBSCRIPTION = enum.auto()
+    LIVE_NOW = enum.auto()
+
+
 class YoutubeBaseInfoExtractor(InfoExtractor):
     """Provide base functions for Youtube extractors"""
 
@@ -367,6 +377,36 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
         r'(?:www\.)?piped\.privacy\.com\.de',
     )
 
+    # extracted from account/account_menu ep
+    # XXX: These are the supported YouTube UI and API languages,
+    # which is slightly different from languages supported for translation in YouTube studio
+    _SUPPORTED_LANG_CODES = [
+        'af', 'az', 'id', 'ms', 'bs', 'ca', 'cs', 'da', 'de', 'et', 'en-IN', 'en-GB', 'en', 'es',
+        'es-419', 'es-US', 'eu', 'fil', 'fr', 'fr-CA', 'gl', 'hr', 'zu', 'is', 'it', 'sw', 'lv',
+        'lt', 'hu', 'nl', 'no', 'uz', 'pl', 'pt-PT', 'pt', 'ro', 'sq', 'sk', 'sl', 'sr-Latn', 'fi',
+        'sv', 'vi', 'tr', 'be', 'bg', 'ky', 'kk', 'mk', 'mn', 'ru', 'sr', 'uk', 'el', 'hy', 'iw',
+        'ur', 'ar', 'fa', 'ne', 'mr', 'hi', 'as', 'bn', 'pa', 'gu', 'or', 'ta', 'te', 'kn', 'ml',
+        'si', 'th', 'lo', 'my', 'ka', 'am', 'km', 'zh-CN', 'zh-TW', 'zh-HK', 'ja', 'ko'
+    ]
+
+    @functools.cached_property
+    def _preferred_lang(self):
+        """
+        Returns a language code supported by YouTube for the user preferred language.
+        Returns None if no preferred language set.
+        """
+        preferred_lang = self._configuration_arg('lang', ie_key='Youtube', casesense=True, default=[''])[0]
+        if not preferred_lang:
+            return
+        if preferred_lang not in self._SUPPORTED_LANG_CODES:
+            raise ExtractorError(
+                f'Unsupported language code: {preferred_lang}. Supported language codes (case-sensitive): {join_nonempty(*self._SUPPORTED_LANG_CODES, delim=", ")}.',
+                expected=True)
+        elif preferred_lang != 'en':
+            self.report_warning(
+                f'Preferring "{preferred_lang}" translated fields. Note that some metadata extraction may fail or be incorrect.')
+        return preferred_lang
+
     def _initialize_consent(self):
         cookies = self._get_cookies('https://www.youtube.com/')
         if cookies.get('__Secure-3PSID'):
@@ -391,7 +431,7 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
                 pref = dict(urllib.parse.parse_qsl(pref_cookie.value))
             except ValueError:
                 self.report_warning('Failed to parse user PREF cookie' + bug_reports_message())
-        pref.update({'hl': 'en', 'tz': 'UTC'})
+        pref.update({'hl': self._preferred_lang or 'en', 'tz': 'UTC'})
         self._set_cookie('.youtube.com', name='PREF', value=urllib.parse.urlencode(pref))
 
     def _real_initialize(self):
@@ -439,7 +479,7 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
             (ytcfg, self._get_default_ytcfg(default_client)), 'INNERTUBE_CONTEXT', expected_type=dict)
         # Enforce language and tz for extraction
         client_context = traverse_obj(context, 'client', expected_type=dict, default={})
-        client_context.update({'hl': 'en', 'timeZone': 'UTC', 'utcOffsetMinutes': 0})
+        client_context.update({'hl': self._preferred_lang or 'en', 'timeZone': 'UTC', 'utcOffsetMinutes': 0})
         return context
 
     _SAPISID = None
@@ -678,14 +718,50 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
         return self._report_alerts(self._extract_alerts(data), *args, **kwargs)
 
     def _extract_badges(self, renderer: dict):
-        badges = set()
-        for badge in try_get(renderer, lambda x: x['badges'], list) or []:
-            label = try_get(badge, lambda x: x['metadataBadgeRenderer']['label'], str)
-            if label:
-                badges.add(label.lower())
+        privacy_icon_map = {
+            'PRIVACY_UNLISTED': BadgeType.AVAILABILITY_UNLISTED,
+            'PRIVACY_PRIVATE': BadgeType.AVAILABILITY_PRIVATE,
+            'PRIVACY_PUBLIC': BadgeType.AVAILABILITY_PUBLIC
+        }
+
+        badge_style_map = {
+            'BADGE_STYLE_TYPE_MEMBERS_ONLY': BadgeType.AVAILABILITY_SUBSCRIPTION,
+            'BADGE_STYLE_TYPE_PREMIUM': BadgeType.AVAILABILITY_PREMIUM,
+            'BADGE_STYLE_TYPE_LIVE_NOW': BadgeType.LIVE_NOW
+        }
+
+        label_map = {
+            'unlisted': BadgeType.AVAILABILITY_UNLISTED,
+            'private': BadgeType.AVAILABILITY_PRIVATE,
+            'members only': BadgeType.AVAILABILITY_SUBSCRIPTION,
+            'live': BadgeType.LIVE_NOW,
+            'premium': BadgeType.AVAILABILITY_PREMIUM
+        }
+
+        badges = []
+        for badge in traverse_obj(renderer, ('badges', ..., 'metadataBadgeRenderer'), default=[]):
+            badge_type = (
+                privacy_icon_map.get(traverse_obj(badge, ('icon', 'iconType'), expected_type=str))
+                or badge_style_map.get(traverse_obj(badge, 'style'))
+            )
+            if badge_type:
+                badges.append({'type': badge_type})
+                continue
+
+            # fallback, won't work in some languages
+            label = traverse_obj(badge, 'label', expected_type=str, default='')
+            for match, label_badge_type in label_map.items():
+                if match in label.lower():
+                    badges.append({'type': badge_type})
+                    continue
+
         return badges
 
     @staticmethod
+    def _has_badge(badges, badge_type):
+        return bool(traverse_obj(badges, lambda _, v: v['type'] == badge_type))
+
+    @staticmethod
     def _get_text(data, *path_list, max_runs=None):
         for path in path_list or [None]:
             if path is None:
@@ -755,9 +831,9 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
             except ValueError:
                 return None
 
-    def _extract_time_text(self, renderer, *path_list):
-        """@returns (timestamp, time_text)"""
-        text = self._get_text(renderer, *path_list) or ''
+    def _parse_time_text(self, text):
+        if not text:
+            return
         dt = self.extract_relative_time(text)
         timestamp = None
         if isinstance(dt, datetime.datetime):
@@ -770,9 +846,10 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
                         (r'([a-z]+\s*\d{1,2},?\s*20\d{2})', r'(?:.+|^)(?:live|premieres|ed|ing)(?:\s*(?:on|for))?\s*(.+\d)'),
                         text.lower(), 'time text', default=None)))
 
-        if text and timestamp is None:
-            self.report_warning(f"Cannot parse localized time text '{text}'" + bug_reports_message(), only_once=True)
-        return timestamp, text
+        if text and timestamp is None and self._preferred_lang in (None, 'en'):
+            self.report_warning(
+                f'Cannot parse localized time text "{text}"', only_once=True)
+        return timestamp
 
     def _extract_response(self, item_id, query, note='Downloading API JSON', headers=None,
                           ytcfg=None, check_get_keys=None, ep='browse', fatal=True, api_hostname=None,
@@ -848,7 +925,7 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
         channel_id = traverse_obj(
             renderer, ('shortBylineText', 'runs', ..., 'navigationEndpoint', 'browseEndpoint', 'browseId'),
             expected_type=str, get_all=False)
-        timestamp, time_text = self._extract_time_text(renderer, 'publishedTimeText')
+        time_text = self._get_text(renderer, 'publishedTimeText') or ''
         scheduled_timestamp = str_to_int(traverse_obj(renderer, ('upcomingEventData', 'startTime'), get_all=False))
         overlay_style = traverse_obj(
             renderer, ('thumbnailOverlays', ..., 'thumbnailOverlayTimeStatusRenderer', 'style'),
@@ -874,15 +951,21 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
             'uploader': uploader,
             'channel_id': channel_id,
             'thumbnails': thumbnails,
-            'upload_date': (strftime_or_none(timestamp, '%Y%m%d')
+            'upload_date': (strftime_or_none(self._parse_time_text(time_text), '%Y%m%d')
                             if self._configuration_arg('approximate_date', ie_key='youtubetab')
                             else None),
             'live_status': ('is_upcoming' if scheduled_timestamp is not None
                             else 'was_live' if 'streamed' in time_text.lower()
-                            else 'is_live' if overlay_style == 'LIVE' or 'live now' in badges
+                            else 'is_live' if overlay_style == 'LIVE' or self._has_badge(badges, BadgeType.LIVE_NOW)
                             else None),
             'release_timestamp': scheduled_timestamp,
-            'availability': self._availability(needs_premium='premium' in badges, needs_subscription='members only' in badges)
+            'availability':
+                'public' if self._has_badge(badges, BadgeType.AVAILABILITY_PUBLIC)
+                else self._availability(
+                    is_private=self._has_badge(badges, BadgeType.AVAILABILITY_PRIVATE) or None,
+                    needs_premium=self._has_badge(badges, BadgeType.AVAILABILITY_PREMIUM) or None,
+                    needs_subscription=self._has_badge(badges, BadgeType.AVAILABILITY_SUBSCRIPTION) or None,
+                    is_unlisted=self._has_badge(badges, BadgeType.AVAILABILITY_UNLISTED) or None)
         }
 
 
@@ -2307,6 +2390,61 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
                 'uploader_url': 'http://www.youtube.com/user/nao20010128nao',
             }
         }, {
+            # Prefer primary title+description language metadata by default
+            # Do not prefer translated description if primary is empty
+            'url': 'https://www.youtube.com/watch?v=el3E4MbxRqQ',
+            'info_dict': {
+                'id': 'el3E4MbxRqQ',
+                'ext': 'mp4',
+                'title': 'dlp test video 2 - primary sv no desc',
+                'description': '',
+                'channel': 'cole-dlp-test-acc',
+                'tags': [],
+                'view_count': int,
+                'channel_url': 'https://www.youtube.com/channel/UCiu-3thuViMebBjw_5nWYrA',
+                'like_count': int,
+                'playable_in_embed': True,
+                'availability': 'unlisted',
+                'thumbnail': 'https://i.ytimg.com/vi_webp/el3E4MbxRqQ/maxresdefault.webp',
+                'age_limit': 0,
+                'duration': 5,
+                'uploader_id': 'UCiu-3thuViMebBjw_5nWYrA',
+                'uploader_url': 'http://www.youtube.com/channel/UCiu-3thuViMebBjw_5nWYrA',
+                'live_status': 'not_live',
+                'upload_date': '20220908',
+                'categories': ['People & Blogs'],
+                'uploader': 'cole-dlp-test-acc',
+                'channel_id': 'UCiu-3thuViMebBjw_5nWYrA',
+            },
+            'params': {'skip_download': True}
+        }, {
+            # Extractor argument: prefer translated title+description
+            'url': 'https://www.youtube.com/watch?v=gHKT4uU8Zng',
+            'info_dict': {
+                'id': 'gHKT4uU8Zng',
+                'ext': 'mp4',
+                'channel': 'cole-dlp-test-acc',
+                'tags': [],
+                'duration': 5,
+                'live_status': 'not_live',
+                'channel_id': 'UCiu-3thuViMebBjw_5nWYrA',
+                'upload_date': '20220728',
+                'uploader_id': 'UCiu-3thuViMebBjw_5nWYrA',
+                'view_count': int,
+                'categories': ['People & Blogs'],
+                'thumbnail': 'https://i.ytimg.com/vi_webp/gHKT4uU8Zng/maxresdefault.webp',
+                'title': 'dlp test video title translated (fr)',
+                'availability': 'public',
+                'uploader': 'cole-dlp-test-acc',
+                'age_limit': 0,
+                'description': 'dlp test video description translated (fr)',
+                'playable_in_embed': True,
+                'channel_url': 'https://www.youtube.com/channel/UCiu-3thuViMebBjw_5nWYrA',
+                'uploader_url': 'http://www.youtube.com/channel/UCiu-3thuViMebBjw_5nWYrA',
+            },
+            'params': {'skip_download': True, 'extractor_args': {'youtube': {'lang': ['fr']}}},
+            'expected_warnings': [r'Preferring "fr" translated fields'],
+        }, {
             'note': '6 channel audio',
             'url': 'https://www.youtube.com/watch?v=zgdo7-RRjgo',
             'only_matching': True,
@@ -2907,8 +3045,10 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
 
         text = self._get_text(comment_renderer, 'contentText')
 
-        # note: timestamp is an estimate calculated from the current time and time_text
-        timestamp, time_text = self._extract_time_text(comment_renderer, 'publishedTimeText')
+        # Timestamp is an estimate calculated from the current time and time_text
+        time_text = self._get_text(comment_renderer, 'publishedTimeText') or ''
+        timestamp = self._parse_time_text(time_text)
+
         author = self._get_text(comment_renderer, 'authorText')
         author_id = try_get(comment_renderer,
                             lambda x: x['authorEndpoint']['browseEndpoint']['browseId'], str)
@@ -3554,11 +3694,19 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
         microformats = traverse_obj(
             player_responses, (..., 'microformat', 'playerMicroformatRenderer'),
             expected_type=dict, default=[])
-        video_title = (
-            get_first(video_details, 'title')
-            or self._get_text(microformats, (..., 'title'))
-            or search_meta(['og:title', 'twitter:title', 'title']))
-        video_description = get_first(video_details, 'shortDescription')
+
+        translated_title = self._get_text(microformats, (..., 'title'))
+        video_title = (self._preferred_lang and translated_title
+                       or get_first(video_details, 'title')  # primary
+                       or translated_title
+                       or search_meta(['og:title', 'twitter:title', 'title']))
+        translated_description = self._get_text(microformats, (..., 'description'))
+        original_description = get_first(video_details, 'shortDescription')
+        video_description = (
+            self._preferred_lang and translated_description
+            # If original description is blank, it will be an empty string.
+            # Do not prefer translated description in this case.
+            or original_description if original_description is not None else translated_description)
 
         multifeed_metadata_list = get_first(
             player_responses,
@@ -3988,7 +4136,8 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             and info.get('live_status') != 'is_upcoming'
             and 'no-youtube-prefer-utc-upload-date' not in self.get_param('compat_opts', [])
         ):
-            upload_date = strftime_or_none(self._extract_time_text(vpir, 'dateText')[0], '%Y%m%d') or upload_date
+            upload_date = strftime_or_none(
+                self._parse_time_text(self._get_text(vpir, 'dateText')), '%Y%m%d') or upload_date
         info['upload_date'] = upload_date
 
         for to, frm in fallbacks.items():
@@ -4000,33 +4149,25 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             if v:
                 info[d_k] = v
 
-        is_private = get_first(video_details, 'isPrivate', expected_type=bool)
-        is_unlisted = get_first(microformats, 'isUnlisted', expected_type=bool)
-        is_membersonly = None
-        is_premium = None
-        if initial_data and is_private is not None:
-            is_membersonly = False
-            is_premium = False
-            contents = try_get(initial_data, lambda x: x['contents']['twoColumnWatchNextResults']['results']['results']['contents'], list) or []
-            badge_labels = set()
-            for content in contents:
-                if not isinstance(content, dict):
-                    continue
-                badge_labels.update(self._extract_badges(content.get('videoPrimaryInfoRenderer')))
-            for badge_label in badge_labels:
-                if badge_label.lower() == 'members only':
-                    is_membersonly = True
-                elif badge_label.lower() == 'premium':
-                    is_premium = True
-                elif badge_label.lower() == 'unlisted':
-                    is_unlisted = True
-
-        info['availability'] = self._availability(
-            is_private=is_private,
-            needs_premium=is_premium,
-            needs_subscription=is_membersonly,
-            needs_auth=info['age_limit'] >= 18,
-            is_unlisted=None if is_private is None else is_unlisted)
+        badges = self._extract_badges(traverse_obj(contents, (..., 'videoPrimaryInfoRenderer'), get_all=False))
+
+        is_private = (self._has_badge(badges, BadgeType.AVAILABILITY_PRIVATE)
+                      or get_first(video_details, 'isPrivate', expected_type=bool))
+
+        info['availability'] = (
+            'public' if self._has_badge(badges, BadgeType.AVAILABILITY_PUBLIC)
+            else self._availability(
+                is_private=is_private,
+                needs_premium=(
+                    self._has_badge(badges, BadgeType.AVAILABILITY_PREMIUM)
+                    or False if initial_data and is_private is not None else None),
+                needs_subscription=(
+                    self._has_badge(badges, BadgeType.AVAILABILITY_SUBSCRIPTION)
+                    or False if initial_data and is_private is not None else None),
+                needs_auth=info['age_limit'] >= 18,
+                is_unlisted=None if is_private is None else (
+                    self._has_badge(badges, BadgeType.AVAILABILITY_UNLISTED)
+                    or get_first(microformats, 'isUnlisted', expected_type=bool))))
 
         info['__post_extractor'] = self.extract_comments(master_ytcfg, video_id, contents, webpage)
 
@@ -4472,7 +4613,7 @@ class YoutubeTabBaseInfoExtractor(YoutubeBaseInfoExtractor):
             playlist_id = item_id
 
         playlist_stats = traverse_obj(primary_sidebar_renderer, 'stats')
-        last_updated_unix, _ = self._extract_time_text(playlist_stats, 2)
+        last_updated_unix = self._parse_time_text(self._get_text(playlist_stats, 2))
         if title is None:
             title = self._get_text(data, ('header', 'hashtagHeaderRenderer', 'hashtag')) or playlist_id
         title += format_field(selected_tab, 'title', ' - %s')
@@ -4566,31 +4707,37 @@ class YoutubeTabBaseInfoExtractor(YoutubeBaseInfoExtractor):
         Note: Unless YouTube tells us explicitly, we do not assume it is public
         @param data: response
         """
-        is_private = is_unlisted = None
         renderer = self._extract_sidebar_info_renderer(data, 'playlistSidebarPrimaryInfoRenderer') or {}
-        badge_labels = self._extract_badges(renderer)
+
+        player_header_privacy = traverse_obj(
+            data, ('header', 'playlistHeaderRenderer', 'privacy'), expected_type=str)
+
+        badges = self._extract_badges(renderer)
 
         # Personal playlists, when authenticated, have a dropdown visibility selector instead of a badge
-        privacy_dropdown_entries = try_get(
-            renderer, lambda x: x['privacyForm']['dropdownFormFieldRenderer']['dropdown']['dropdownRenderer']['entries'], list) or []
-        for renderer_dict in privacy_dropdown_entries:
-            is_selected = try_get(
-                renderer_dict, lambda x: x['privacyDropdownItemRenderer']['isSelected'], bool) or False
-            if not is_selected:
-                continue
-            label = self._get_text(renderer_dict, ('privacyDropdownItemRenderer', 'label'))
-            if label:
-                badge_labels.add(label.lower())
-                break
+        privacy_setting_icon = traverse_obj(
+            renderer, (
+                'privacyForm', 'dropdownFormFieldRenderer', 'dropdown', 'dropdownRenderer', 'entries',
+                lambda _, v: v['privacyDropdownItemRenderer']['isSelected'], 'privacyDropdownItemRenderer', 'icon', 'iconType'),
+            get_all=False, expected_type=str)
 
-        for badge_label in badge_labels:
-            if badge_label == 'unlisted':
-                is_unlisted = True
-            elif badge_label == 'private':
-                is_private = True
-            elif badge_label == 'public':
-                is_unlisted = is_private = False
-        return self._availability(is_private, False, False, False, is_unlisted)
+        return (
+            'public' if (
+                self._has_badge(badges, BadgeType.AVAILABILITY_PUBLIC)
+                or player_header_privacy == 'PUBLIC'
+                or privacy_setting_icon == 'PRIVACY_PUBLIC')
+            else self._availability(
+                is_private=(
+                    self._has_badge(badges, BadgeType.AVAILABILITY_PRIVATE)
+                    or player_header_privacy == 'PRIVATE' if player_header_privacy is not None
+                    else privacy_setting_icon == 'PRIVACY_PRIVATE' if privacy_setting_icon is not None else None),
+                is_unlisted=(
+                    self._has_badge(badges, BadgeType.AVAILABILITY_UNLISTED)
+                    or player_header_privacy == 'UNLISTED' if player_header_privacy is not None
+                    else privacy_setting_icon == 'PRIVACY_UNLISTED' if privacy_setting_icon is not None else None),
+                needs_subscription=self._has_badge(badges, BadgeType.AVAILABILITY_SUBSCRIPTION) or None,
+                needs_premium=self._has_badge(badges, BadgeType.AVAILABILITY_PREMIUM) or None,
+                needs_auth=False))
 
     @staticmethod
     def _extract_sidebar_info_renderer(data, info_renderer, expected_type=dict):
@@ -4866,6 +5013,7 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'channel_id': 'UCmlqkdCBesrv2Lak1mF_MxA',
             'uploader_url': 'https://www.youtube.com/channel/UCmlqkdCBesrv2Lak1mF_MxA',
             'channel_url': 'https://www.youtube.com/channel/UCmlqkdCBesrv2Lak1mF_MxA',
+            'availability': 'public',
         },
         'playlist_count': 1,
     }, {
@@ -4883,6 +5031,7 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'channel_id': 'UCmlqkdCBesrv2Lak1mF_MxA',
             'channel_url': 'https://www.youtube.com/channel/UCmlqkdCBesrv2Lak1mF_MxA',
             'uploader_url': 'https://www.youtube.com/channel/UCmlqkdCBesrv2Lak1mF_MxA',
+            'availability': 'public',
         },
         'playlist_count': 0,
     }, {
@@ -5029,6 +5178,7 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'channel_id': 'UCEPzS1rYsrkqzSLNp76nrcg',
             'channel_url': 'https://www.youtube.com/c/ChRiStIaAn008',
             'channel': 'Christiaan008',
+            'availability': 'public',
         },
         'playlist_count': 96,
     }, {
@@ -5047,6 +5197,7 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'view_count': int,
             'description': '',
             'channel_id': 'UCBABnxM4Ar9ten8Mdjj1j0Q',
+            'availability': 'public',
         },
         'playlist_mincount': 1123,
         'expected_warnings': [r'[Uu]navailable videos (are|will be) hidden'],
@@ -5070,6 +5221,7 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'channel': 'Interstellar Movie',
             'description': '',
             'modified_date': r're:\d{8}',
+            'availability': 'public',
         },
         'playlist_mincount': 21,
     }, {
@@ -5088,6 +5240,7 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'channel_url': 'https://www.youtube.com/channel/UCTYLiWFZy8xtPwxFwX9rV7Q',
             'channel_id': 'UCTYLiWFZy8xtPwxFwX9rV7Q',
             'modified_date': r're:\d{8}',
+            'availability': 'public',
         },
         'playlist_mincount': 200,
         'expected_warnings': [r'[Uu]navailable videos (are|will be) hidden'],
@@ -5107,6 +5260,7 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'uploader_url': 'https://www.youtube.com/c/blanktv',
             'modified_date': r're:\d{8}',
             'description': '',
+            'availability': 'public',
         },
         'playlist_mincount': 1000,
         'expected_warnings': [r'[Uu]navailable videos (are|will be) hidden'],
@@ -5125,6 +5279,7 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'channel_id': 'UC9-y-6csu5WGm29I7JiwpnA',
             'channel_url': 'https://www.youtube.com/user/Computerphile',
             'channel': 'Computerphile',
+            'availability': 'public',
         },
         'playlist_mincount': 11,
     }, {
@@ -5290,6 +5445,7 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'channel_id': 'UC_aEa8K-EOJ3D6gOs7HcyNg',
             'tags': [],
             'channel': 'NoCopyrightSounds',
+            'availability': 'public',
         },
         'playlist_mincount': 166,
         'expected_warnings': [r'[Uu]navailable videos (are|will be) hidden'],
@@ -5310,6 +5466,7 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'modified_date': r're:\d{8}',
             'uploader_url': 'https://www.youtube.com/channel/UC9ALqqC4aIeG5iDs7i90Bfw',
             'description': '',
+            'availability': 'public',
         },
         'expected_warnings': [
             'The URL does not have a videos tab',
@@ -5410,6 +5567,7 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'channel': 'Royalty Free Music - Topic',
             'view_count': int,
             'uploader_url': 'https://www.youtube.com/channel/UC9ALqqC4aIeG5iDs7i90Bfw',
+            'availability': 'public',
         },
         'expected_warnings': [
             'does not have a videos tab',
@@ -5443,6 +5601,45 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
             'uploader_url': 'https://www.youtube.com/channel/UCKcqXmCcyqnhgpA5P0oHH_Q',
         },
         'playlist_mincount': 2
+    }, {
+        'note': 'translated tab name',
+        'url': 'https://www.youtube.com/channel/UCiu-3thuViMebBjw_5nWYrA/playlists',
+        'info_dict': {
+            'id': 'UCiu-3thuViMebBjw_5nWYrA',
+            'tags': [],
+            'uploader_id': 'UCiu-3thuViMebBjw_5nWYrA',
+            'channel_url': 'https://www.youtube.com/channel/UCiu-3thuViMebBjw_5nWYrA',
+            'description': '',
+            'title': 'cole-dlp-test-acc - 再生リスト',
+            'uploader_url': 'https://www.youtube.com/channel/UCiu-3thuViMebBjw_5nWYrA',
+            'uploader': 'cole-dlp-test-acc',
+            'channel_id': 'UCiu-3thuViMebBjw_5nWYrA',
+            'channel': 'cole-dlp-test-acc',
+        },
+        'playlist_mincount': 1,
+        'params': {'extractor_args': {'youtube': {'lang': ['ja']}}},
+        'expected_warnings': ['Preferring "ja"'],
+    }, {
+        # XXX: this should really check flat playlist entries, but the test suite doesn't support that
+        'note': 'preferred lang set with playlist with translated video titles',
+        'url': 'https://www.youtube.com/playlist?list=PLt5yu3-wZAlQAaPZ5Z-rJoTdbT-45Q7c0',
+        'info_dict': {
+            'id': 'PLt5yu3-wZAlQAaPZ5Z-rJoTdbT-45Q7c0',
+            'tags': [],
+            'view_count': int,
+            'channel_url': 'https://www.youtube.com/channel/UCiu-3thuViMebBjw_5nWYrA',
+            'uploader': 'cole-dlp-test-acc',
+            'uploader_id': 'UCiu-3thuViMebBjw_5nWYrA',
+            'channel': 'cole-dlp-test-acc',
+            'channel_id': 'UCiu-3thuViMebBjw_5nWYrA',
+            'description': 'test',
+            'uploader_url': 'https://www.youtube.com/channel/UCiu-3thuViMebBjw_5nWYrA',
+            'title': 'dlp test playlist',
+            'availability': 'public',
+        },
+        'playlist_mincount': 1,
+        'params': {'extractor_args': {'youtube': {'lang': ['ja']}}},
+        'expected_warnings': ['Preferring "ja"'],
     }]
 
     @classmethod
@@ -5527,10 +5724,20 @@ class YoutubeTabIE(YoutubeTabBaseInfoExtractor):
         tabs = traverse_obj(data, ('contents', 'twoColumnBrowseResultsRenderer', 'tabs'), expected_type=list)
         if tabs:
             selected_tab = self._extract_selected_tab(tabs)
-            selected_tab_name = selected_tab.get('title', '').lower()
+            selected_tab_url = urljoin(
+                url, traverse_obj(selected_tab, ('endpoint', 'commandMetadata', 'webCommandMetadata', 'url')))
+            translated_tab_name = selected_tab.get('title', '').lower()
+
+            # Prefer tab name from tab url as it is always in en,
+            # but only when preferred lang is set as it may not extract reliably in all cases.
+            selected_tab_name = (self._preferred_lang in (None, 'en') and translated_tab_name
+                                 or selected_tab_url and get_mobj(selected_tab_url)['tab'][1:]  # primary
+                                 or translated_tab_name)
+
             if selected_tab_name == 'home':
                 selected_tab_name = 'featured'
             requested_tab_name = mobj['tab'][1:]
+
             if 'no-youtube-channel-redirect' not in compat_opts:
                 if requested_tab_name == 'live':  # Live tab should have redirected to the video
                     raise UserNotLive(video_id=mobj['id'])
@@ -5642,6 +5849,7 @@ class YoutubePlaylistIE(InfoExtractor):
             'channel': 'milan',
             'channel_id': 'UCEI1-PVPcYXjB73Hfelbmaw',
             'uploader_url': 'https://www.youtube.com/channel/UCEI1-PVPcYXjB73Hfelbmaw',
+            'availability': 'public',
         },
         'expected_warnings': [r'[Uu]navailable videos (are|will be) hidden'],
     }, {
@@ -5660,6 +5868,7 @@ class YoutubePlaylistIE(InfoExtractor):
             'uploader_url': 'https://www.youtube.com/c/愛低音的國王',
             'channel_id': 'UC21nz3_MesPLqtDqwdvnoxA',
             'modified_date': r're:\d{8}',
+            'availability': 'public',
         },
         'expected_warnings': [r'[Uu]navailable videos (are|will be) hidden'],
     }, {
@@ -5848,7 +6057,7 @@ class YoutubeNotificationsIE(YoutubeTabBaseInfoExtractor):
         title = self._search_regex(
             rf'{re.escape(channel or "")}[^:]+: (.+)', notification_title,
             'video title', default=None)
-        upload_date = (strftime_or_none(self._extract_time_text(notification, 'sentTimeText')[0], '%Y%m%d')
+        upload_date = (strftime_or_none(self._parse_time_text(self._get_text(notification, 'sentTimeText')), '%Y%m%d')
                        if self._configuration_arg('approximate_date', ie_key=YoutubeTabIE.ie_key())
                        else None)
         return {