.mp4 video files for HW video acceleration tests

[mikhail-nikolskiy]

Files generated from source video input.mp4 by the following command

for c in libxvid mpeg2video mjpeg libx265 libx264 libvpx-vp9 libaom-av1; do ffmpeg -i input.mp4 -strict experimental -c:v $c -pix_fmt yuv420p -b:v 2M sample_322x242_15frames.yuv420p.$c.mp4; done

on ffmpeg version 4.2.4 and Ubuntu 20.04.

Small (but enough) resolution 320x240 plus 2 additional pixels to test behavior on width/height not aligned by 16.