[ie/twitter:broadcast] Support `--wait-for-video` (#8475)

Closes #8473
Authored by: bashonly

yt_dlp/extractor/periscope.py

@@ -4,6 +4,7 @@ from ..utils import (
     parse_iso8601,
     unescapeHTML,
 )
+from ..utils.traversal import traverse_obj
 
 
 class PeriscopeBaseIE(InfoExtractor):
@@ -20,8 +21,6 @@ class PeriscopeBaseIE(InfoExtractor):
         title = broadcast.get('status') or 'Periscope Broadcast'
         uploader = broadcast.get('user_display_name') or broadcast.get('username')
         title = '%s - %s' % (uploader, title) if uploader else title
-        is_live = broadcast.get('state').lower() == 'running'
-
         thumbnails = [{
             'url': broadcast[image],
         } for image in ('image_url', 'image_url_medium', 'image_url_small') if broadcast.get(image)]
@@ -31,12 +30,16 @@ class PeriscopeBaseIE(InfoExtractor):
             'title': title,
             'timestamp': parse_iso8601(broadcast.get('created_at')) or int_or_none(
                 broadcast.get('created_at_ms'), scale=1000),
+            'release_timestamp': int_or_none(broadcast.get('scheduled_start_ms'), scale=1000),
             'uploader': uploader,
             'uploader_id': broadcast.get('user_id') or broadcast.get('username'),
             'thumbnails': thumbnails,
             'view_count': int_or_none(broadcast.get('total_watched')),
             'tags': broadcast.get('tags'),
-            'is_live': is_live,
+            'live_status': {
+                'running': 'is_live',
+                'not_started': 'is_upcoming',
+            }.get(traverse_obj(broadcast, ('state', {str.lower}))) or 'was_live'
         }
 
     @staticmethod

yt_dlp/extractor/twitter.py

@@ -1619,6 +1619,9 @@ class TwitterBroadcastIE(TwitterBaseIE, PeriscopeBaseIE):
         info['title'] = broadcast.get('status') or info.get('title')
         info['uploader_id'] = broadcast.get('twitter_username') or info.get('uploader_id')
         info['uploader_url'] = format_field(broadcast, 'twitter_username', 'https://twitter.com/%s', default=None)
+        if info['live_status'] == 'is_upcoming':
+            return info
+
         media_key = broadcast['media_key']
         source = self._call_api(
             f'live_video_stream/status/{media_key}', media_key)['source']