Builds and at least renders png, tga, tiff, and exr sequences with the following additional patches:

0001-Possible-fix-for-ffmpeg-4.4-in-pluginfclient.C.patch
0001-Add-libjpeg-dep-to.libtiff-in-thirdparty-Makefile.patch
0001-Fileext-reading-error-handling-for-bg-render.patch
0001-More-error-handling-in-filepng-sorry.patch

Off the computer now for several hours.

On Tue, Aug 29, 2023 at 10:46 PM Andrew Randrianasulu <randrianasulu@gmail.com> wrote:
Using https://openexr.com/en/latest/HelloWorld.html as example

so for now I have base

commit d51dc1ff2dbd920c6488af4380b8064c9b6a7b4c (origin/master, origin/HEAD)
Author: Good Guy <good1.2guy@gmail.com>
Date:   Tue Aug 29 20:20:10 2023 -0600

    Credit Andrew - rest of fix for Arch (and termux) which includes
thirdparty/Makefile


plus

commit afa6a601fd3228be18aef413061b3d0165344d7c (HEAD -> master)
Author: Andrew Randrianasulu <randrianasulu@gmail.com>
Date:   Wed Aug 30 07:27:57 2023 +0300

    Fileext reading error handling for bg render

commit cac447973db936f7d5594c83521c34f3e5a9c187
Author: Andrew Randrianasulu <randrianasulu@gmail.com>
Date:   Wed Aug 30 05:27:10 2023 +0300

    Add libjpeg dep to.libtiff in thirdparty/Makefile

commit 8297b38e49da0ce73e119138c158e806eb1fb45d
Author: Andrew Randrianasulu <randrianasulu@gmail.com>
Date:   Wed Aug 30 02:48:47 2023 +0300

    Possible fix for ffmpeg 4.4 in pluginfclient.C

====

so, ffmpeg 5.1 based cin seems to work on Slackware 15.0 i586 (with
some self-build packages).

Tested adding ffmpeg video filter to video track, and of course
background render with  on-the-fly compressor switch.

aggrh, in commit message fileert instead of fileexr. I hope this is
not a big problem



will try  my virtual machines next