Usually a video file with an .mpg file extension is a video that uses the MPEG-1/MEPG-2 video compression standards. It contains video and audio data that are compressed with quality loss for the convenience of deliverability. Most of the time an MPG file that uses the MPEG-1 codec can be accepted and played by most video players, but one that uses the MPEG-2 codec might require specific video codecs to play with certain video players. While AVI is a more common video file. It’s naturally supported by many mobile devices. We have shown you how to convert MPG to MOV. Here we will show you how to convert MPG to AVI on Mac.