temp/libcamera: backport swISP RGBA support
Which can have significant performance impact on affected devices, such as the Librem5 or the PinePhone. The patch already landed upstream, however a new release is likely several weeks or months away, making a backport worthwhile.
Additional notes:
- It allows direct import of buffers to the GPU as well as handover to the Wayland compositor, reducing GPU/IO overhead (especially visible with the gstreamer
waylandsink
andgtk4paintablesink
wit WIP patches). - It does not solve low fps issues with the swISP caused by single-threaded CPU debayer algorithm.
- It has no API changes, i.e. fine to backport without rebuilding dependencies - confirmed by a libcamera maintainer.
See also https://gitlab.alpinelinux.org/alpine/aports/-/merge_requests/68171 - unfortunately I had somehow forgotten about the downstream package and only realized after that one got merged :( (but shouldn't hurt to have it in Alpine as well - quite the opposite actually).