[Cin] Test rendering whit x265

[Andrea paz]

> Andrea,  in a followup, to your email below.  Does this mean that the patch, ffmpeg_flush_tmp.diff, fixed ffmpeg 4.4 so that it works the same as 4.3?  I > was confused if you had applied this patch or not or had just changed render formats.

It seems to me that this patch is not in randrik14, so I didn't put it
in. Where can I find it? What other randrik14 patches should I put for
ffmpeg-4.4? Sorry for the confusion!