Not all M4V files are protected. Tools like HandBrake often use ".m4v" as a default extension for standard MP4 videos to ensure compatibility with Apple features like chapter markers and AC3 audio. How to Open "4501731.m4v"
Many M4V files are protected by Apple’s FairPlay Digital Rights Management (DRM) , which restricts playback to authorized devices and accounts. 4501731.m4v
Depending on whether the file is copy-protected, you have several options for viewing it: [Updated] What is M4V File Format & How to Play M4V Video Not all M4V files are protected