[extractor/slideslive] Fix slides and chapters/duration (#6024)

* Fix slides/thumbnails extraction
* Extract duration to fix issues w/ `--embed-chapters`, `--split-chapters`
* Add `InfoExtractor._extract_mpd_vod_duration` method
* Expand applicability of `InfoExtractor._parse_m3u8_vod_duration` method
Authored by: bashonly

1 files changed, 11 insertions, 1 deletions

diff --git a/yt_dlp/extractor/common.py b/yt_dlp/extractor/common.py
index e37595ffd..f80536470 100644
--- a/yt_dlp/extractor/common.py
+++ b/yt_dlp/extractor/common.py
@@ -2180,13 +2180,23 @@ class InfoExtractor:
         return self._parse_m3u8_vod_duration(m3u8_vod or '', video_id)
 
     def _parse_m3u8_vod_duration(self, m3u8_vod, video_id):
-        if '#EXT-X-PLAYLIST-TYPE:VOD' not in m3u8_vod:
+        if '#EXT-X-ENDLIST' not in m3u8_vod:
             return None
 
         return int(sum(
             float(line[len('#EXTINF:'):].split(',')[0])
             for line in m3u8_vod.splitlines() if line.startswith('#EXTINF:'))) or None
 
+    def _extract_mpd_vod_duration(
+            self, mpd_url, video_id, note=None, errnote=None, data=None, headers={}, query={}):
+
+        mpd_doc = self._download_xml(
+            mpd_url, video_id,
+            note='Downloading MPD VOD manifest' if note is None else note,
+            errnote='Failed to download VOD manifest' if errnote is None else errnote,
+            fatal=False, data=data, headers=headers, query=query) or {}
+        return int_or_none(parse_duration(mpd_doc.get('mediaPresentationDuration')))
+
     @staticmethod
     def _xpath_ns(path, namespace=None):
         if not namespace: