I've always had this doubt and i think its time to know it.
Suppose I have a 320cbr mp3, and then I transcode it to V2 or 192cbr... does the archive loses more quality than the one being cut by the fact that it now has less kbps than before ??

Sorry if i can't explain it more clearly, but my english sux.

Thanx.


Edit: I found a better explanation, suppose I rip a track and encode it to two mp3 files, one in 320cbr and the other in V2. Then i transcode the 320cbr file to V2 with, say, dBpowerAMP... does this second V2 file has the same quality as the other V2 file i originally encoded from the wav ?

No

No - the second V2 file has a content wich has been subject to lossy encoding twice, and will be further from the original wav than the first one.

Edit: slooooooow

thanx for the replies, so i see, no matter how you transcode it (from inferior to superior quality and viceversa) the file ends up with a 2-layer lossy compression... is that correct ?

about what it says on wiki:

"Every time you encode with a lossy encoder, the quality will decrease. There's no way to gain quality back even if you transcode your 128kbps MP3 into a 320kbps MP3 (or any other high-quality compression)."

yeah, i knew that, but i had doubts on whats happen when you transcode from 320 to less quality.

When you transcode from X to Y bitrate your resulting file will have a quality that is lower than if you encoded directly to Y bitrate in the first place. And it aplies no mather what is higest, X or Y.

There is an absolute/technical loss in quality, though *many* people seem find that when transcoding from higher bitrates (a transparent source), the output will remain transparent to your ears. This, of course, depends on the encoder and bitrate used.

In my personal experience: I have transcoded a whole bunch of Musepack Q6 files (encoded from wavs) to LAME aps for use in my car, and I can not hear the difference, even when listening on headphones.

Most people on HA will tell you that if you can't hear the difference, or if the outcome is good enough for your application (ie a portable player), then everything is fine and dandy. 'If-it's-good-enough-for-you'

Hope that helps.

ok, thanx for the help guys

If you just want 128k files for your portable player, I think transcoding isn't a bad idea here. The difference in quality from the 320 step won't be big, and you probably don't care for use on a portable anyway.

If you mean to transcode the entire collection AND then delete the 320 source, then no, thats no a good idea.