@ Phyllis @ Andrew

Thank you both for replying and clarifying. To save space in email I use "hard snip" as follows

Q2
Is the AppImage static linked and RPM dynamic linked or combined
dynamic/staticvwith regards to libs?

Appimage uses mix of statically-added thirdparty libs embedded in "cin" binary and system's dynamic libs put into self-extracting squashfs archive.

Does it mean that "system's dynamic libs" embedded in the AppImage pick them up from the build-machine?

RPM depends on those dynamic libs from system to be present and compatible between build system and system rpm ran on.

Q4
Where is possibly the ffmpeg binary for the extracted AppImage and
installed RPM?
for own build ffmpeg binary is found in
cinelerra-5.1/thirdparty/ffmpeg-8.0/ffmpeg

it is not packaged/installed.

Ok, in my current, bundled build I used custom
./configure --with-single-user --with-booby --enable-libsvtav1 --with-onevpl --with-vulkan --with-libplacebo --with-libzimg

Then verified with the associated ffmpeg
/home3/cinelerra/cinelerra-5.1/thirdparty/ffmpeg-8.0 # ./ffmpeg -hide_banner -hwaccels

Hardware acceleration methods:
vdpau
cuda
vaapi
qsv
vulkan

This ffmpeg has 25 enabled features plus a lot of thirdparties
/home3/cinelerra/cinelerra-5.1/thirdparty/ffmpeg-8.0 # ./ffmpeg -version
which counts 25 enables

In comparision my system ffmpeg from Packman, on Slowroll has 67 enabled feature, no extra "thirdparties" while ditto multimedia codecs is easy installed with "opi codecs" (OBS Package Installer).
An extra libopenh264 (Cisco's implementation) is installed on openSUSE, enabled in ffmpeg and used by Firefox.

Q5
Who make and maintain the thirdparty ffmpeg and what extra codecs are added?

At this moment it seems that I try to maintain it. I mostly added giant array of pixelformats to yuv4mpeg so cin can show that in GUI. Other patches carrying from earlier versions, dealing with seeking, mpegts muxing for BluRay disks, some gopro-specific cases for hw acceleration and may be something else

So no secrets here :)

Beside for fun, I have played a bit with Google-ai to see what answers are generated to questions in the same genre - for what they are worth or not. Hopefully my shortened urls to save space here will work:

CINELERRA-GG GIT rpm.bld
https://tinyurl.com/2ebt43us

cinelerra.spec vs build script
https://tinyurl.com/35k6493w

what is included and not in Suse Tumbleweed - cinelerra-5.1-_.susetw.x86_64.rpm
https://shorturl.at/EraKS

how to configure cinelerra-gg with unbundled ffmpeg
https://tinyurl.com/4sawurxe

cinelerra configure --enable-ffmpeg
https://shorturl.at/Moi7F

what is cinelerra-gg thirdparty
https://tinyurl.com/3p2xbpx7

see what cinelerra-gg appimage is configured with
https://tinyurl.com/3m8xtrvm

is cinelerra-gg rpm static or dynamic linked
https://tinyurl.com/4w7nxw7j

how to find dynamic linked libs on linux
https://tinyurl.com/ywwkfuyn

should make clean be used after make errors
https://tinyurl.com/2z9j4nzf