OGV is a digital video container format related to the encoding technology of the OGG Vorbis video. It can save multiple related video stream codecs like the DivX and Theora. It is these codecs that allow OGV files to open on varying media players.
MPLayer Classic VLC Media Player Jriver Media Center MPUI
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.
VLC Media Player Apple QuickTime Player Windows Media Player