[youtube] Improve extraction of livestream metadata

Modified from and closes #441
Authored by: pukkandan, krichbanana

yt_dlp/extractor/youtube.py

@@ -43,6 +43,7 @@ from ..utils import (
     parse_codecs,
     parse_count,
     parse_duration,
+    parse_iso8601,
     qualities,
     remove_start,
     smuggle_url,
@@ -2678,17 +2679,10 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             else:
                 self.to_screen('Downloading just video %s because of --no-playlist' % video_id)
 
-        category = get_first(microformats, 'category') or search_meta('genre')
-        channel_id = get_first(video_details, 'channelId') \
-            or get_first(microformats, 'externalChannelId') \
-            or search_meta('channelId')
-        duration = int_or_none(
-            get_first(video_details, 'lengthSeconds')
-            or get_first(microformats, 'lengthSeconds')) \
-            or parse_duration(search_meta('duration'))
+        live_broadcast_details = traverse_obj(microformats, (..., 'liveBroadcastDetails'))
         is_live = get_first(video_details, 'isLive')
-        is_upcoming = get_first(video_details, 'isUpcoming')
-        owner_profile_url = get_first(microformats, 'ownerProfileUrl')
+        if is_live is None:
+            is_live = get_first(live_broadcast_details, 'isLiveNow')
 
         streaming_data = traverse_obj(player_responses, (..., 'streamingData'), default=[])
         formats = list(self._extract_formats(streaming_data, video_id, player_url, is_live))
@@ -2786,6 +2780,29 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             thumb['preference'] = (0 if '.webp' in thumb['url'] else -1) - (2 * i)
         self._remove_duplicate_formats(thumbnails)
 
+        category = get_first(microformats, 'category') or search_meta('genre')
+        channel_id = str_or_none(
+            get_first(video_details, 'channelId')
+            or get_first(microformats, 'externalChannelId')
+            or search_meta('channelId'))
+        duration = int_or_none(
+            get_first(video_details, 'lengthSeconds')
+            or get_first(microformats, 'lengthSeconds')
+            or parse_duration(search_meta('duration'))) or None
+        owner_profile_url = get_first(microformats, 'ownerProfileUrl')
+
+        live_content = get_first(video_details, 'isLiveContent')
+        is_upcoming = get_first(video_details, 'isUpcoming')
+        if is_live is None:
+            if is_upcoming or live_content is False:
+                is_live = False
+        if is_upcoming is None and (live_content or is_live):
+            is_upcoming = False
+        live_starttime = parse_iso8601(get_first(live_broadcast_details, 'startTimestamp'))
+        live_endtime = parse_iso8601(get_first(live_broadcast_details, 'endTimestamp'))
+        if not duration and live_endtime and live_starttime:
+            duration = live_endtime - live_starttime
+
         info = {
             'id': video_id,
             'title': self._live_title(video_title) if is_live else video_title,
@@ -2812,9 +2829,13 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             'webpage_url': webpage_url,
             'categories': [category] if category else None,
             'tags': keywords,
-            'is_live': is_live,
             'playable_in_embed': get_first(playability_statuses, 'playableInEmbed'),
-            'was_live': get_first(video_details, 'isLiveContent'),
+            'is_live': is_live,
+            'was_live': (False if is_live or is_upcoming or live_content is False
+                         else None if is_live is None or is_upcoming is None
+                         else live_content),
+            'live_status': 'is_upcoming' if is_upcoming else None,  # rest will be set by YoutubeDL
+            'release_timestamp': live_starttime,
         }
 
         pctr = get_first(player_responses, ('captions', 'playerCaptionsTracklistRenderer'), expected_type=dict)