[webkit-changes] [WebKit/WebKit] 5d8787: [GStreamer] Don't emit playbackStateChanged() even...

[Enrique Ocaña González]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 5d8787383e48b02ff7d7c92a3ea0ca17f7755f4c
      https://github.com/WebKit/WebKit/commit/5d8787383e48b02ff7d7c92a3ea0ca17f7755f4c
  Author: Enrique Ocaña González <eocanha at igalia.com>
  Date:   2023-02-15 (Wed, 15 Feb 2023)

  Changed paths:
    A LayoutTests/media/video-pause-while-seeking-expected.txt
    A LayoutTests/media/video-pause-while-seeking.html
    M Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp

  Log Message:
  -----------
  [GStreamer] Don't emit playbackStateChanged() event after a seek
https://bugs.webkit.org/show_bug.cgi?id=252063

It is not possible to pause the playback during a seek. Sink elements
lose their states entering ASYNC PAUSED->PAUSED transition. Calling HTML
video.pause() during a seek doesn't result in pipeline state change call
as player reports it's paused already. Forcing gst_element_set_state()
doesn't really help in this case as pipeline enters inconsistent state
after a seek that everything is playing but sinks are paused.

In addition, triggering playbackStateChanged() at seek end causes
HTMLMediaElement::playInternal() that cleans up all signs of previous
pause() call.

Don't emit playbackStateChanged() at seek end so HTML won't force
playInternal() and HTMLMediaElement will call pauseInternal() again
after a seek (from updatePlayState()).

This fixes following scenario:

 video.currentTime = x.xx
 video.play();
 // ensure async duringn a seek (video didn't pause after initial
 // seek had finished)
 setTimeout(()=>{ video.pause(); }, 1}

Original author: Andrzej Surdej (https://github.com/asurdej-comcast)

See: https://github.com/WebPlatformForEmbedded/WPEWebKit/pull/1013

Reviewed by Philippe Normand.

* LayoutTests/media/video-pause-while-seeking-expected.txt: Added.
* LayoutTests/media/video-pause-while-seeking.html: Added.
* Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:
(WebCore::MediaPlayerPrivateGStreamer::updateStates): Don't update playback state during a seek.

Canonical link: https://commits.webkit.org/260314@main