I recent d/l'ed some classical music encoded in mpc insane. Now, if I were to transcode them to mp3 or ogg, how bad would the quality loss be?

To Quote Fred Picker of Zone VI Workshops fame :"try it and see"

I take it you want to trasncode for portable use? Try --alt-preset medium with LAME, or Q3 with vorbis, and do an abx test between those and the original mpc and see how much quality deterioration you can hear.

insane = most likely undetectable

especially if you are going for, say a portable use, ~ <160kbps
--apm
--aps
--ap 128
etc

oh, this brings back some great memories, and some great listening tests!


later

since when aps and apm are below or equal 160kbps?

Maybe he's talking about --alt-preset standard -Y...

This is very unhelpful, should he try to ABX every song he plans on transcoding?

Here you can find some public listening tests.

The chances are you won't notice a quality difference using lame 3.90.3 APS, 128kbps & lower ogg will outperform mp3 in most cases.

MPC q5 to Lame alt-preset-medium works well for portable use. I did some limited testing and haven't abx'd anything yet so MPC q7 - insane won't be any worse!. Never tried this with vorbis but I think that q4-5 would give good results.


In any case for whatever the reason, you should abx first.

right. sorry i did mean aps -Y
(thanx devo)


later

It depends very much on the music. I found that a lot of my music collection is fine from muspack insane down to mp3 standard and ATRAC3 (Minidisc). There are some examples however where it does not work so well.

I posted some transcoding tests I did a while ago from Musepack q10, Vorbis q10 and Lame insane to ATRAC3, and Musepack was by far the best of the three, but I could still find some artifacts in a sample from Blue Monday by New Order. The sample and the tests themselves are here in HA in various threads.

I agree it is not helpful or feasible to ABX every single track. I can only suggest that you try a spread of the tracks and check them out for yourself. Remember too that ABXing is not everything. If you have a close listen to the transcoded tracks in your typical listening environment, you can probably judge whether they are acceptable to you or not, even if they are not perfectly transparent.

I hope this helps.

Den.