M4A is a filename extension for AAC container format and is developed by Apple Inc. M4A music is bought on the iTunes Store and does not come with DRM protection. In terms of quality, M4A is better than MP3 because it is lossless but still compressed. This means that it occupies less storage space and doesn’t lose quality over time.
iTunes Apple QuickTime Player VLC Windows Media Player
Xvid is a cross-platform video codec for compressing video files. It can compress a video file at a more than 200:1 ratio. This, in return, makes it easier and quicker to transmit video files over the internet. Also, compressed videos take up less storage space. It compresses data using the MPEG-4 standard.
Roxio Toast 18 Eltima Elmedia Player Windows Media Player (Xvid codec) Apple QuickTime Player (Xvid codec)