This suggests .
This is the most revealing part. MKV is an open-source, flexible container format. Unlike MP4 (which is optimized for streaming), MKV is the format of choice for . GOMK-46-01.mkv
The -01 suffix suggests this is a render pass . A video editor exported their timeline as GOMK-46-01.mkv (perhaps "Game of MKV, Scene 46, Take 01"). They likely rendered a second version ( -02 ) with corrected color grading. This suggests