[LAU] Best-quality command-line float32-to-16-bit conversion?

[Fons Adriaensen]

On Fri, Apr 23, 2010 at 02:20:00PM -0700, Ken Restivo wrote:

> On Fri, Apr 23, 2010 at 10:58:03PM +0200, Fons Adriaensen wrote:
> > On Fri, Apr 23, 2010 at 10:31:38PM +0200, Julien Claassen wrote:
> > 
> > >   I have Ecasound, sndfile-convert and sox. But from these three I
> > > deem sndfile-convert to be the best. but I seem to remember, that
> > > Fons Adriaensen recently released a tool/library to do the same
> > > task. I believe it is as good as or better than sndfile-convert. I
> > > seem to recall, that there were issues with finetuning dithering,
> > > that sndfile didn't offer. As I said, I'm not 100% syure about that.
> > 
> > That is the 'resample' application, part of the source distribution
> > of zita-resampler. For 16-bit output it offers rectangular, 
> > triangular or Lipschitz noise shaped dithering.
> > 
> 
> Thanks, I'm looking at the different dithering types here:
> 
> http://www.kokkinizita.net/linuxaudio/dithering.html
> 
> And wondering, which is the "best" of them to use?
> 
> Looks to me like the rectangular creates the fewest harmonics. Am I reading this correctly?

No. The only harmonics to be seen are in the first picture,
the one with *no* dithering.

For final delivery (e.g. a CD) the noise-shaped one should
be the best, it will produce the least audible noise. This
doesn't matter is you have a constant high level, it does
for music with a wide dynamic range.

If the signal is an intermediate one in a production process
(but then why would you use 16-bit), the rectangular one is
recommended.

Ciao,

-- 
FA

O tu, che porte, correndo si ?
E guerra e morte !