ffmpeg non-regression tests

[ymartin59]

As SynoCommunity maintainer, I am interested in a set of videos files in various formats/containers (mp4, mkv...) covering audio and video decoders (at least those known to have troubles) so that we can build automated non-regression tests on our DSM systems and confirm hardware acceleration is enabled.

Of course, those videos should be copyright-free and we expect them to be as light as possible (~ max 20 MiB) and runs at least 2 minutes to compare CPU usage.