I am compressing wave files that are currently 44.1 kHz, using:

# lame --resample 44.1 --abr 64 -h foo.wav

These are voice files (hence 64 kbps). I have to force 44.1 using "resample", because with bit rate 64, Lame defaults to 24 kHz.

My question is: Does Lame notice that no change in sample rate is required, and hence not resample, or does it actually resample and thus introduce unnecessary degradation?

Thanks.

there is no need to use 44.1khz for voice files, especially when using 64kbps...

There is no resampling to do, if you are already at the said sample rate. However, maybe you should try lower settings of resample, since the lowpass is probably below 16000 Hz and 32 kHz is probably enough of a sample rate.

I understand that. I posted a question on sampling rates last year, and people here helped me. However, I am forced to do it as I am working with someone else who needs it (has a setup that assumes 44.1).

Shade wrote:

> There is no resampling to do, if you are already at the said sample rate.

If I just do
# lame --abr 64 -h foo.wav
then Lame will resample to a different rate, of its own volition. In order to force Lame to keep the original 44.1 kHz you need to use --resample.

Regardless of what should be happening in an ideal world, if anyone can tell me whether Lame will re-calculate the sampling when I nominally "resample" at the original rate, I would be grateful.

What I meant, was : there is no resampling to do, as the -resample 44 switch will simply prevent resampling to another sample rate. (whew! that's a lot of samples!)

I don't see (mathematically) how you could resample a 44kHz signal to another 44kHz signal... unless it's very poorly implemented (eg. multiply, round, divide), it should always give the same thing.

answering first part: yes
answering second part: no

Got it.

Thanks to all for your help.