I need to convert some OGG files to MP3 (damn iPod ) and I'm wondering how this will effect the quality?

I know that MP3 to OGG reduces quality, but is it the same in reverse?

I'm using dBpowerAMP with the Blade MP3 Encoder.


Thanks.

Doing any lossy to lossy conversion will result in a quality loss. Whether or not you'd notice it is another thing.

I'm going to disrecommend use of Blade (it's not reputed to be one of the better mp3 encoders at all) and recommend use of LAME as recommended by this forum.

http://www.hydrogenaudio.org/forums/index....showtopic=28124

my guess would be that going from ogg to mp3 would be even more degrading to the quality than mp3 to ogg, but i have not tested that. my first recommendation would, like dreamtactix291 said, to definately use LAME. it is much better quality, and much more flexible, than blade. secondly, try the conversion, and then attempt an abx to see if you can notice the loss in quality. i would recommending using abc-hr or foobar2000. good luck.

edit: the ideal situation would be to rerip with eac into the appropriate sized LAME mp3's. or even better yet, if you have the disk space, rip to a lossless format like wavpack or flac then transcode to lame, so you always have a perfect backup... whatever works best for you.

Thanks for the help, eveyone. I'll most likely just convert from OGG to WAV, since I have the disk space.

My impression gained from various transcoding listening-tests done over the course of time, is that MP3 is one of the worst formats to transcode FROM. Thus, transcoding from Vorbis to MP3 should result in less quality-loss than MP3 to Vorbis. It also depends on with which version of Vorbis the files were encoded and at which quality-setting. Older Vorbis encoders had the high-frequency-noise boost bug way more noticable, than later/current versions.

As for MP3-encoders, definatelly choose LAME - probably v3.97b2.
Blade has been abandonned for a long time and is not competitive with the current up-to-date MP3-encoders. Counting only the latest versions of MP3 encoders, the worst ones are Shine, Blade and iTunes.

As for encoder-settings, if your DAP is properly MP3-compatible(and thus supports VBR), -V4 may be a good choice. In any case, keep your original OGGs and dont delete them.

- Lyx

I didn't think the ipod could play wav, AIFF and Apple lossless yes. Anyhow if you have the space (and seeing how the audio is already lossy) use Lame on 320kbps you will not hear a difference between that and the ogg.

You could convert them to AAC (since it is an ipod)

They support all three of those now:

http://docs.info.apple.com/article.html?artnum=61476

Shoudl I still go with WAV? What difference would AAC (m4a) make? AIFF?

If you have good quality vorbis files (say -q5 and up) you won´t notice much degradation if you encode to MP3 with latest LAME (3.97b2). I do it all the time through foobar for listening on my small flash portable, have a lot of oggs (mostly -q5 or better, encoded with vorbis 1.1 or later). Try -V 4 on LAME´s command line (maybe -V 5 is enough for portable listening, even if transcoded).
I have a couple of small Sennheiser headphones (PX30) for portable use, the resulting files are completely acceptable to my ears.

Hi Megaman,

Have you also transcoded high quality ogg vorbis files (q8 ) to lower quality vorbis files. I was considering doing this to achieve better battery life on my Iaudio U2. In any case, I will have to do some testing to see if q2 is "good enough" with the new version 4.51.

Take care,

Oliver

Hi, never tried transcoding high bitrate vorbis to mid-low bitrate vorbis, but it´s probably ok if it´s for portable use. q2 is maybe too low for my taste, I´d try q3 if I had a vorbis capable DAP, unless I had to listen in quite noisy places.
I guess transcoding from -q8 is almost as encoding from lossless, but you know, lossless is always better than overkill lossy bitrates, at least in theory.
Whenever is possible, I encode from Monkey´s Audio files, but for some albums I don´t care too much I just have a vorbis -q5 or higher copy, hence I need to transcode to listen on my DAP.

Just what I was thinking.