Andrew,

Try https://yadi.sk/i/uWcb_QWohkuZDQ
CinGG_test2-vc2.mkv
sha256sum CinGG_test2-vc2.mkv
01f95e6a4e88c8b7793d134988c96b2295cf90bb6264997535353d1c30c18ff2 CinGG_test2-vc2.mkv

du -h CinGG_test2-vc2.mkv
446M CinGG_test2-vc2.mkv

I wonder if your mplayer or mpv can play it?

Thanks for the file. GG did not get time to look at it today but we downloaded it and he is curious to take a look at it. We do not have mplayer or mpv installed because we try to keep our computer devoid of extras.