Bug 177976 - [MSE][GStreamer] Seek on youtube.com/tv fails after r217185
Summary: [MSE][GStreamer] Seek on youtube.com/tv fails after r217185
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: Media (show other bugs)
Version: WebKit Local Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Enrique Ocaña
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2017-10-05 15:58 PDT by Enrique Ocaña
Modified: 2017-10-06 00:45 PDT (History)
3 users (show)

See Also:


Attachments
Patch (1.45 KB, patch)
2017-10-05 16:07 PDT, Enrique Ocaña
no flags Details | Formatted Diff | Diff

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Description Enrique Ocaña 2017-10-05 15:58:42 PDT
http://trac.webkit.org/changeset/217185 added an extra call to MediaSourcePrivate::waitForSeekCompleted() on MediaSource::seekToTime() that our MediaPlayerPrivateGStreamerMSE (the final receiver) isn't expecting. This is completely breaking the seek behaviour because, unlike MediaPlayerPrivateMediaSourceAVFObjC, the GStreamer MSE player private doesn't have an internal seek state to distinguish the original call from the new one.
Comment 1 Enrique Ocaña 2017-10-05 16:07:05 PDT
Created attachment 322931 [details]
Patch
Comment 2 Jer Noble 2017-10-05 16:31:55 PDT
Sorry about that!  But keep in mind, there are some WebGL conformance tests that require that the <video> element has a decoded frame available as soon as the "seeked" event fires.  The point of the second "waitForSeekCompleted()" was to give the private an opportunity to delay completion of a seek until it's had a chance to decode the frame at the seeded time.  So you may want to look into adding that kind of behavior to the GStreamer back-end.
Comment 3 Enrique Ocaña 2017-10-06 00:19:48 PDT
Thanks for pointing it out. However, by now our priority should be to put MSE in GStreamer on a better shape (lots of w3c tests failing, webm support, still some seek corner cases). Then we can focus on proper interoperation with other parts of webkit (WebGL, as you mention).
Comment 4 WebKit Commit Bot 2017-10-06 00:44:14 PDT
Comment on attachment 322931 [details]
Patch

Clearing flags on attachment: 322931

Committed r222966: <http://trac.webkit.org/changeset/222966>
Comment 5 WebKit Commit Bot 2017-10-06 00:44:15 PDT
All reviewed patches have been landed.  Closing bug.
Comment 6 Radar WebKit Bug Importer 2017-10-06 00:45:15 PDT
<rdar://problem/34851779>