MPEG, sometimes called MPG, 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.
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AC3 is an audio format designed by Dolby Digital to offer surround sound listening. This format is available on most Blu-ray and DVD media files and is played using a Dolby Digital DVD Player. Interestingly, AC3 can be output in up to six speakers of a home stereo system. On a computer, AC3 can be opened on VLC Media Player, Apple QuickTime Player, and Windows Media Player.
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