M4R is a filename extension for AAC format, which is developed by Apple Inc. It is typically used to save custom iPhone ringtones from Apple iTunes. M4R can only be created from iTunes purchased songs and is usually DRM protected. It can open on iTunes, VLC Media Player, Apple QuickTime Player, and more.
DivX is a video codec brand developed by DivX, LLC. This video codec is mainly compatible with Windows programs, although it can also be embedded on game consoles, alar clocks, car stereo, and more. Today, there are three primary DivX codecs, including MPEG-4 Part 2, HEVC Ultra HD, and H.264/MPEG-4 AVC DivX Plus High Definition video codec.
DVD/Blu-ray Players Alarm Clocks Car Stereo X-Box 360