“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
Users often find the M4V format confusing due to its similarity to MP4 but restrictive nature on non-Apple devices. RockBlackDoll.m4v
If the file was purchased or rented from the iTunes Store, it likely has DRM, meaning it can only be played on authorized devices. “The extensions mpa and mpv are just to
Tools like HandBrake often default to this extension because it supports specific features like AC3 audio and chapter markers that older Apple players require. Community Perspectives Tools like HandBrake often default to this extension
If you're having trouble playing this specific file, you can try opening it with the VLC media player or using a tool like HandBrake to convert it to a more universal format. What Are M4V Files? | M4V Format Explained - Adobe
If the file is unprotected, it can often be renamed to .mp4 and played on most standard media players without any quality loss.