[Cin] ffmpeg 5.1 patches

[Andrea paz]

I tried compiling the latest git (Tue, 26 jul 2022), manually adding
Andrew's latest patches (only the ones in this post, not the previous
ones) in .../thirdparty/src/. I have no compilation errors. During
./autogen.sh I got these messages:

libtoolize: Consider adding 'AC_CONFIG_MACRO_DIRS([m4])' to configure.ac,
libtoolize: and rerunning libtoolize and aclocal.

I did the addition and ran the two commands without getting any
errors. Then I continued the compilation.
CinGG is working, but I don't think it is using ffmpeg5. For example,
the new filters in ffmpeg5/5.1 did not appear.
Did I do something wrong? How can you see if ffmpeg5 is being used?