Hello,

I need some recommendation for transcoding (yes, I understand I'll loose
quality and may introduce some artifacts, sigh) files
from
192k WMA CBR
to
AAC
for iPod (iPhone)?
As I have many WMA files (unprotected) in my library and I need to transcode
them to AAC format as iPod cannot play WMA, I'm going to re-rip some of them
I still keep CD's (probably 256k AAC vbr in iTunes). I tried to convert WMA to
AAC in iTunes, at 128k vbr, and it looks like it reduces size and quality seems
to be not as bad as I worried. But I wonder
which bit rate 128k ~ 192k (vbr) may be appropriate for this purpose?
And I wonder if Nero AAC encoder may be a better choice for this? Or
iTunes may be just o.k.?

csp

Experiment with a few tracks, listen carefully to the different encodes and make a decision.

As I've read that NeroAAC now plays fine in iTunes 8 and iPod, you could try newest NeroAAC and -q0.31 (=VBR at around 85 till 110 kpbs). This will save space, and quality should be ok (try yourself, you can set it up higher if you think quality is too low).

The AAC LC mode is recommended for your purposes.

Lower bitrates will use HE-AAC, SBR, PS and so on, which iPods can't decode and so you will get bad quality.

Using iTunes' AAC codec is also ok (maybe more comfortable to use), but with Nero's you can try more settings.

As it's a transcode I'd go for higher bitrates at maybe 150<br<250. Also Nero AAC.
Is space really an issue? At 110 kbps, 1GB must be ~20 hrs of music then, does one need that on a mobile device?

Hi,

Thanks for the info, I mainly listen to classical and jazz music
(with bundle earphone!). I tried a few tracks with iTunes AAC vbr
192k and 128k, but I'm not sure if I can tell the difference, I
may need more tests. But what if the size is not a concern but
keeping quality is? Then, 192k to 192k will be a safe way or
it may not make sense as I'll loose quality so lower than
192k, such as 160k vbr (or -q 0.5 in Nero) may make more sense?

csp

Personally I feel that transcoding to about the same bitrate is the least desirable option. One can justify going to a significantly higher bitrate to minimize the loss of quality when one absolutely has to go to a different format, or to a significantly lower bitrate when one absolutely has to go smaller and there is going to be a loss of quality anyway. But going to a similar bitrate loses quality with no reduction in size, which seems like a complete waste.

Just my two cents.

I don't know if transcoding to the same or even higher bitrate would prevent more quality loss. This should be tested first.

My opinion is transcoding to bigger filesizes is not worth the space, because you'll have less quality anyway.



If the file size doesn't matter but quality in transcoding for your iPod / iTunes:

Just try step-by-step settings (start with -q0.31) and check out if you notice quality loss. If so, try higher settings. (A report from you would be nice if higher bitrate than the source file brings less quality loss )

VBR will be indeed more efficient than "CBR". Just go with -q XX (Nero).