M4P (MPEG-4 Protected) is a digital audio file extension for the AAC (Advanced Audio Codec) container format. It uses lossy compression and is an audio-only file. In most cases, M4P files are purchased on Apple iTunes, which means they are DRM-protected. M4A is the unprotected version of M4P.
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