.
WIP on https://github.com/philn/WebKit/tree/eng/258018
We need to make sure our video encoder can ingest DMABufs, whether it is hardware-accelerated (va*enc) or not (x264enc, etc).
Related, https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/3670 pipewiresrc with DMABuf is not yet negotiating with vapostproc/vah264enc.