Seen in bug 260185. With MSE, fastSeek is broken in that it never seek to the nearest keyframe and performs identical seek as a normal seek. Additionally, in bug 260185, infrastructure has been put in place to make the seek operation asynchronous and to only complete once data has been received by the MediaSource. This is a task that wasn't completed in 260185 for the sake of expediency.
I guess we should use this seek flag, GST_SEEK_FLAG_KEY_UNIT ...
Pull request: https://github.com/WebKit/WebKit/pull/17541
(In reply to Philippe Normand from comment #1) > I guess we should use this seek flag, GST_SEEK_FLAG_KEY_UNIT ... Strangely this broke the media/video-fast-seek.html test... Anyways, I started a patch but couldn't find tests. media/media-source/media-source-fastseek.html is already passing, even with current main, AFAICS.