[ie/twitter:broadcast] Support --wait-for-video

Closes #8473
Authored by: bashonly

yt_dlp/extractor/periscope.py

@@ -2,6 +2,7 @@
 from ..utils import (
     int_or_none,
     parse_iso8601,
+    traverse_obj,
     unescapeHTML,
 )
 
@@ -20,22 +21,25 @@ def _parse_broadcast_data(self, broadcast, video_id):
         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_small') if broadcast.get(image)]
 
         return {
             'id': broadcast.get('id') or video_id,
             'title': title,
-            'timestamp': parse_iso8601(broadcast.get('created_at')),
+            '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

@@ -1585,6 +1585,8 @@ def _real_extract(self, url):
         if not broadcast:
             raise ExtractorError('Broadcast no longer exists', expected=True)
         info = self._parse_broadcast_data(broadcast, broadcast_id)
+        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']