[linux-audio-dev] How to test resampling quality?

[Steve Harris]

On Wed, Sep 27, 2006 at 11:16:27 +0100, James Courtier-Dutton wrote:
> Hi,
> 
> I was wondering if there are any tools out there to test audio
> resampling quality. I am particularly interested in 44.1kHz to 48kHz
> resampling due to the fact that most sound cards prefer 48kHz.
> 
> At least with up sampling (low rate to higher rate) one does not get
> aliasing.
> 
> I really just want to find some algorithm that I can use to compare
> 44.1kHz audio signal with an 48kHz audio signal, and to see if there has
> been any lose of quality during the up sample.

I'm not sure if it's a good technique, but to test my dithering algorithms
I took high precision FFTs of the input (sine wave IIRC) and output
signals and looked for extranous peaks. You can see the test code in the
tarball: http://plugin.org.uk/libgdither/libgdither-0.6.tar.gz
c.f. http://plugin.org.uk/libgdither/TESTING

- Steve