I have added x265 update to 4.2 to GIT along with the 3 patches (assuming the current x265_4.0.patch4 is no longer needed?).

However, I did NOT checkin 0002-Add-simple-hevc-alpha-encode-profile-with-hvc1-tag.patch which sort of works because when I mod it with 0003-Fix-h265_alpha-profile.patch and then load the rendering file created with it, it crashes. It is important to know that the ffmpeg-8.1.patch11 and patch12 were in that build too. I did not checkin 0004-Add-two-patches-for-decoding-hevc-alpha.patch because of the crash and I did not have any time to determine cause of crash.

On Fri, May 8, 2026 at 6:34 PM Andrew Randrianasulu <randrianasulu@gmail.com> wrote:

https://bitbucket.org/multicoreware/x265_git/downloads/x265_4.2.tar.gz

Patch (git am) attached

put file in thirdparty/src, patch sources, autogen.sh then build as usual

In theory now for h265.mp4 you can select yuva420/yuva420p10, but I am
not sure it works as intended ...

decoding says alpha present (if I set loglevel=debug in decode.opts)
but other sources including ffprobe from ffmpeg-8.1 detect just
yuvj420p ?

Tested only on Rosa 2016 x86-64 chroot