M4V is a digital video container format developed by Apple Inc. It is pretty similar to the popular MP4 in terms of structure, but M4V files can sometimes be DRM protected. Today, M4V is the primary video format for iTunes Store videos and can multiplex together multiple audio and video data.
Media Player Classic VLC Media Player KMPlayer Zoom Player
AIF (Audio Interchange File/Apple Interchange File Format) is a sound format used on Windows. It comes with a .aif filename extension and .aiff when used on Mac. An AIF file features raw sound data like sample rate, bit depth, and channel (mono/stereo). This file format is also accepted on most CD writers.
File Viewer Plus Apple iTunes QuickTime Player Windows Media Player