“The extensions mpa and mpv are just to be more explicit of what they contain. mp4 is the generic.” Reddit · r/handbrake · 6 years ago
While there is no widespread technical "review" for a specific file named , its file extension and naming convention suggest it is an iTunes video file . M4V is a container format developed by Apple that is nearly identical to MP4 but often includes FairPlay DRM copy protection to prevent unauthorized sharing. Technical Overview of M4V Files RockBlackDoll.m4v
If the file is unprotected, it can often be renamed to .mp4 and played on most standard media players without any quality loss. “The extensions mpa and mpv are just to