so, patches are in, thanks, but then complete fix for Arch (and termux) also includes thirdparty/Makefile changes around libtiff and libjpeg-turbo support inside it .... can you run those on older distro just in case?
"Disable libjpeg support in libtiff, fix build"
"Fix libtiff to link with local libjpeg-turbo, reenable libjpeg there"
My understanding is that ffmpeg-5.1.patch999 is already part of ffmpeg-6.0 so does not have to be carried -- I looked at the 6.0 mathops.h and it appears to be there. If I am wrong, please let me know.
f_acontrast seems to work on 5.1 with those patches too ...