GStreamer Merge Request https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3867 added improved MSE support in qtdemux, fixing a buffer clipping issue. For these changes to have effect, WebKit needs to use "variant: mse-bytestream" in the caps when supplying buffers to the AppendPipeline.
Pull request: https://github.com/WebKit/WebKit/pull/9768
Committed 260003@main (ce7515d38a3c): <https://commits.webkit.org/260003@main> Reviewed commits have been landed. Closing PR #9768 and removing active labels.
<rdar://problem/105173233>
*** Bug 252266 has been marked as a duplicate of this bug. ***
*** Bug 252199 has been marked as a duplicate of this bug. ***
Shipping in 2.38.5 and GStreamer 1.22.1.