Ba3162e2sdede.mkv.mp4 -

: If it is actually an MP4 file, rename it to ba3162e2sdede.mp4 . If you have many such files, you can use PowerToys PowerRename to bulk edit the strings.

Best for PC use and archival; less compatible with some TVs/phones. ba3162e2sdede.mkv.mp4

: If your MKV uses codecs like H.264 or H.265, you can "remux" it into an MP4 container. This is a lossless process that just changes the "wrapper" without re-encoding the video. : If it is actually an MP4 file, rename it to ba3162e2sdede