[mythtv] Merged "ffmpeg cleanup" into devel/ffmpeg-resync branch

[Piotr Oniszczuk]

> Wiadomość napisana przez Peter Bennett <pb.mythtv at gmail.com> w dniu 10.02.2022, o godz. 23:41:
> 
> I have merged Scott Theisen's ffmpeg cleanup into devel/ffmpeg-resync, which was forked from the latest master. I have done some basic testing. Anybody who is interested, please test it so that we can identify bugs if possible before moving it to master.
> 

Peter,

I tested 25b7583221bc49f66d4b82774a2ce99c4aadf5e1 briefly on: v4l2_request & v4l2_m2m platforms with all my mpeg2/h264/hevc/vp8/vp9 samples.

on tested rpi3/rpi4/h6/rk3399/aml_g12b: all good

br