Mpeg-4

sorry if this is in the wrong place, but how do i change an MPEG-4 audio file into an MPEG Layer 3 Audio file? because i need to add data on some songs for my psp e.g. track artist, album title etc. i know i can do it on an MPEG-4 but it won't show up. any help would be grateful!

First of all, what type of MPEG4 audio file is it? Is the file-extension ".aac", ".mp4" or ".m4a"?

Some devices may only support reading tags if the audio is in the rigth type of container. If it has the ".mp4" or ".m4a" extension you could try to convert it to an ".acc" (or do the opposite if it's already an acc). Converting an MPEG4 audio file between raw acc and mp4/m4a doesn't make the quality of the file worse.

If changing the container doesn't work, you could try rewriting the tags with another application like Foobar2000.

I don't think converting it to an MP3 would be a good idea since you would lose some quality even if you used a high bitrate. The best option would be to figure out why the PSP won't display the tags.