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Hydrogenaudio Forums > Lossy Audio Compression > AAC > AAC - Tech
everwicked
Hello everybody

I want to re-encode a bunch of my stuff in AAC but I am not sure what profiles/settings and bitrates to use. Could someone recommend settings/bitrates for the following material? I have Nero.

- HQ Music
- HQ Speech with music
- HQ Speech
- LQ Speech

Thanks!
muaddib
You should also point out how much space you have and how much material you want to place into that space. And also you should mention what quality you want to have.
everwicked
QUOTE(muaddib @ Jul 2 2007, 07:44) *

You should also point out how much space you have and how much material you want to place into that space. And also you should mention what quality you want to have.


Space shouldn't be an issue - I am only interested in preserving the quality of the material. Some of it is low quality and of course would like to provide just the appropriate amount of bitrate so not to waste space. Makes sense?
muaddib
Then you should use the lowest q value (VBR) which is transparent for you. Make some representative selection of the material you want to compress, compress it with some quality value that people in this forum suggest is transparent. Then listen to samples and if they are transparent for you, then you can use that q value or try with lower q.
everwicked
Is there any way to map those to LAME bitrates or quality settings?
kornchild2002
Acording to past listening tests, LAME and Nero AAC are pretty similar so the LAME bitrate gragh could be directly used for comparing Nero AAC bitrates.
muaddib
There is no direct mapping from Lame to AAC quality settings. It is just that at higher bitrates both become good enough, so the average listener can not distinguish them. At lower bitrates AAC is better (Links: http://www.rjamorim.com/test/64test/results.html, http://www.rjamorim.com/test/32kbps/results.html). I also would expect that AAC is noticeably better up to 112kbs for average listener.
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