Hi, Sorry if this question has been asked before. But I've got some CBR 128 MP3 files, will I gain any advantage by re-converting these to VBR or is it just wasting time?

Transcoding from lossy to lossy not only wastes time but also reduces the quality.
See Transcoding for more details

There would be no gain by converting (do you mean transcoding?) those files. The quality would be at best equal to the original file.

You would need to start from scratch and make higher quality files to get any kind of quality improvement.

I would suggest ripping to a lossless codec like FLAC or Wavpack. This way you can just transcode from the lossless file anytime you wish to have a different lossy file type. The end result would be the same as ripping from the original CD.

Good luck,
JXL

Thanks make sense. I've got a pretty big audio CD collection (1000+) and just got an iPod and thought theres no better time than now to start.

So if I'm ripping from Audio CD's, should I go CD -> lossless -> lossy or straight to lossy

how about both ?
http://www.hydrogenaudio.org/forums/index....58&hl=react

That would work,

Have lossless for archiving
Have lossy for my iPod

MP3Packer may be of interest:

http://www.hydrogenaudio.org/forums/index....showtopic=32379
http://www.hydrogenaudio.org/forums/index....showtopic=40780

However, if you are interested in re-ripping your CDs then I would go lossless if you can afford the space. Well worth doing.

Here is a theoretical question.

If I have 320 kbps CBR MP3s and I convert them to -V0 VBR MP3s, do I lose quality, filesize, or both?

With few words: yes, both.

Of course that's only theortically correct because virtually no one can ABX at that bitrate (ie hear a difference). Just avoid transcoding and you'll be fine (lossless to lossy is ok).

Hi!

In answer to Zealot's question, look a little further up this thread to the MP3Packer reference.

If you were to simply convert the files from 320 CBR to VBR with MP3Packer, you would loose no audio quality, but still achieve a shrinkage in filesize. The process doesn't involve any transcoding at all.

Try it out. It's free, and it's a very nice piece of software.

To give you a rough idea of the space saving to be had, I compressed a typical 3min 30sec late 90's pop song to MP3 in various flavours and noted the filesize :-

320 Kbps CBR MP3, 7.93MB
MP3Packer VBR of above file, 6.83MB
V0 VBR MP3 with 320Kbps max, 5.47MB.

So the MP3Packer file saved about 15% on filesize in this particular instance, with no quality loss.

On the other hand, a V0 VBR MP3 would be smaller still (by around 30%) and seems to be acceptable to even the most 'golden-eared' listeners. Well, those that can tolerate lossy formats anyway.

Experiment, but don't forget to enjoy the music.

Cheers, Slipstreem.

Thanks will give it a go

@Mitch:
You're certainly free to try, but I don't think mp3packer will help you at all. Most encoders can use up 128kbps (except for silent parts), so mp3packer won't be able to "pack" anything.

It may very well help Zealot's (theorhetical) files, as most encoders don't really know what to do with 320kbps all the time. I've gotten one file from 320kbps to 260kbps losslessly, since it was such a simple song.

I also suggest anyone who uses mp3packer run at least a few of the input and output files through Foobar's "bit compare tracks" to make sure they are, in fact, the same. (If not, post a bug on my thread) LAME-encodes are extremely stable, but there's been some other encoders that trip up mp3packer.