mp3 vs. mp4

[coonsanders]

hi gang

can anybody tell me what is the difference between mp3 and mp4??

coonsanders

[Spazmogen]

.mp3 is an audio compression format.
.mp4 is a video compression format.

[bicomputational]

Actually, .mp4 isn't only a video codec. Apple uses .mp4 as the compression
format for their itunes store. By common usage though if an .mp4 file is audio only, its referred to as an .m4a file. So all .m4a files are .mp4 files, but not all .mp4 files are .m4a files - some are video files. As an audio
compression format, most tests I've seen (and my experience too) show that .mp4 files are more accurate than .mp3 files at the same bitrate. Listen to tracks from the itunes store, which are 128 .mp4 files, and compare them to .mp3 files made with any encoder at 128 and I think you will hear the difference. Once you get above about 192 I don't hear much difference. See this Wiki link http://en.wikipedia.org/wiki/MPEG-4_Part_14. (Sorry, that link doesn't take you to exactly where you need to go - just search .mp4 on wiki)