[ie/tiktok] Extract via mobile API only if `app_info` is passed (#9938)

Partially addresses #9506
Authored by: bashonly

README.md

@@ -1813,8 +1813,8 @@ The following extractors use this feature:
 * `app_name`: Default app name to use with mobile API calls, e.g. `trill`
 * `app_version`: Default app version to use with mobile API calls - should be set along with `manifest_app_version`, e.g. `34.1.2`
 * `manifest_app_version`: Default numeric app version to use with mobile API calls, e.g. `2023401020`
-* `aid`: Default app ID to use with API calls, e.g. `1180`
-* `app_info`: One or more app info strings in the format of `<iid>/[app_name]/[app_version]/[manifest_app_version]/[aid]`, where `iid` is the unique app install ID. `iid` is the only required value; all other values and their `/` separators can be omitted, e.g. `tiktok:app_info=1234567890123456789` or `tiktok:app_info=123,456/trill///1180,789//34.0.1/340001`
+* `aid`: Default app ID to use with mobile API calls, e.g. `1180`
+* `app_info`: Enable mobile API extraction with one or more app info strings in the format of `<iid>/[app_name]/[app_version]/[manifest_app_version]/[aid]`, where `iid` is the unique app install ID. `iid` is the only required value; all other values and their `/` separators can be omitted, e.g. `tiktok:app_info=1234567890123456789` or `tiktok:app_info=123,456/trill///1180,789//34.0.1/340001`
 
 #### rokfinchannel
 * `tab`: Which tab to download - one of `new`, `top`, `videos`, `podcasts`, `streams`, `stacks`

yt_dlp/extractor/tiktok.py

@@ -45,19 +45,18 @@ class TikTokBaseIE(InfoExtractor):
         # "app id": aweme = 1128, trill = 1180, musical_ly = 1233, universal = 0
         'aid': '0',
     }
-    _KNOWN_APP_INFO = [
-        '7351144126450059040',
-        '7351149742343391009',
-        '7351153174894626592',
-    ]
     _APP_INFO_POOL = None
     _APP_INFO = None
     _APP_USER_AGENT = None
 
+    @property
+    def _KNOWN_APP_INFO(self):
+        return self._configuration_arg('app_info', ie_key=TikTokIE)
+
     @property
     def _API_HOSTNAME(self):
         return self._configuration_arg(
-            'api_hostname', ['api22-normal-c-useast2a.tiktokv.com'], ie_key=TikTokIE)[0]
+            'api_hostname', ['api16-normal-c-useast1a.tiktokv.com'], ie_key=TikTokIE)[0]
 
     def _get_next_app_info(self):
         if self._APP_INFO_POOL is None:
@@ -66,13 +65,10 @@ class TikTokBaseIE(InfoExtractor):
                 for key, default in self._APP_INFO_DEFAULTS.items()
                 if key != 'iid'
             }
-            app_info_list = (
-                self._configuration_arg('app_info', ie_key=TikTokIE)
-                or random.sample(self._KNOWN_APP_INFO, len(self._KNOWN_APP_INFO)))
             self._APP_INFO_POOL = [
                 {**defaults, **dict(
                     (k, v) for k, v in zip(self._APP_INFO_DEFAULTS, app_info.split('/')) if v
-                )} for app_info in app_info_list
+                )} for app_info in self._KNOWN_APP_INFO
             ]
 
         if not self._APP_INFO_POOL:
@@ -757,11 +753,13 @@ class TikTokIE(TikTokBaseIE):
 
     def _real_extract(self, url):
         video_id, user_id = self._match_valid_url(url).group('id', 'user_id')
-        try:
-            return self._extract_aweme_app(video_id)
-        except ExtractorError as e:
-            e.expected = True
-            self.report_warning(f'{e}; trying with webpage')
+
+        if self._KNOWN_APP_INFO:
+            try:
+                return self._extract_aweme_app(video_id)
+            except ExtractorError as e:
+                e.expected = True
+                self.report_warning(f'{e}; trying with webpage')
 
         url = self._create_url(user_id, video_id)
         webpage = self._download_webpage(url, video_id, headers={'User-Agent': 'Mozilla/5.0'})