MPG, sometimes called MPEG, is a video file format popular for distributing content over the internet. It is the sister format to MP4 and MP3 because they share the same developer – Moving Picture Expert Group. MPG format uses either MPEG-2 or MPEG-1 compression, depending on the circumstance. Opening it is usually easy on any OS platform.
Windows Media Player, VLC Media Player Apple QuickTime Player, Cyberlink PowerDVD 17
AU is an audio format standard in early web pages NEXT systems. It is also called u-law or Sparc-audio format. Typically, AU files can store audio data and annotation blocks. Initially, it was a headerless audio format, but newer versions have a header, thanks to the six unsigned 32.bit words.