QUOTE(MystikTK @ Mar 8 2006, 06:31 AM)
OGG > Apple Lossles > M4A, Quality Loss
Only one of those describe the audio codec, so its hard to say.
If the Ogg files are encoded lossless (FLAC), then you will have no aditional loss when you transcode to Apple Lossless. But if they are encoded lossy (Vorbis), your Apple lossless files will only have the audio quality of the vorbis file but be noticable bigger in size.
Since you posted this is the AAC forum I suppose you want to transcode the files to AAC.
Then I have these final comments:
* If Ogg FLAC, go for it (you will have no additional loss, than going from a PCM files).
* If Ogg Vorbis, you have to ABX and see if you can live with the quality loss (cause you had loss when you encoded to Vorbis, and you will have aditional loss when you transcode to AAC).
Good luck!