libav provides a fairly comprehensive suite of tests called FATE (http://www.libav.org/fate.html). It should be possible it integrate this as a ptest for libav, and it would be useful to have the ability to easily run this when doing libav recipe upgrades. Note: we'd want to provide an easy way to specify a local mirror of the sample files since those are quite large.
libav has been replaced by ffmpeg but FATE (FFmpeg Automated Testing Environment) is still a nice test suite to support.
FATE for ffmpeg is at https://ffmpeg.org/fate.html.
Note that the test suite data is over 1GB, and the tools cannot easily be installed.
1 GB is a bit large but probably okay for optional ptest.