>>698806
That video is encoded as:
H264 - MPEG-4 AVC (part 10)(avc1)

According to this thread: https://www.reddit.com/r/fixthevideoplayer/comments/115aq3k/mp4_upload_rejected_on_firefox/
Firefox has issues with 10-bit AVC (the "part 10" above) but works with 8-bit AVC.

I got the same "mozilla::MediaResult __cdecl mozilla::WMFVideoMFTManager::InitInternal(void): Fail to set the decoder media types." error as the person who created that thread two months ago, which is how I found it.

Firefox devs seem to think 10-bit is "non-standard":

https://bugzilla.mozilla.org/show_bug.cgi?id=1793318