gtk4: Add DMABuf VideoMeta clip support (and VideoCropMeta?)
Following up on gstreamer!7355 (comment 2647344): we need something akin to https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/6833/diffs?commit_id=d91d0f1c0a23dc682ebcf7a06bde0540e3e8225a for certain HW video decoders, otherwise we sometimes show areas with undefined content.
While on it we could also implement support for the VideoCropMeta
- that could come in handy in various situations, one being zoom support in Snapshot.
One rather extreme example, once in Showtime using gtk4paintablesink
:
compared with the gtk demo player using gtkgstsink
with the commit linked above: