||Audio Video Interleave File
||iTunes Video File
||AVI is a Windows-based multimedia file container format. As the most popular video format, AVI files can contain both audio and video data in a file wrapper that allows synchronous audio-with-video playback.
||M4V is a file container format used by Apple's iTunes application. The M4V file format is a video file format developed by Apple and is very close to MP4 format. Apple uses M4V files to encode TV episodes, movies, and music videos in the iTunes Store.
||Well compatible with most Windows-based media players and devices;
||Default format used by iTunes; fit for iPhone, iPad, etc.
||Not work very well on Mac/iOS-based devices
||Most M4V files are DRM-protected, so you need to make them DRM-free first
|Help You Choose
||Both AVI and M4V are popular video formats that can be played almost anywhere. As to video quality, it's hard to tell which is better as with the same source video content. Thus, you can choose either format as per your need.
|Programs that open AVI/M4V files