[pulseaudio-discuss] [PATCH 0/4] Add support for libsoxr resampler

Andrey Semashev andrey.semashev at gmail.com
Wed Mar 11 12:07:54 PDT 2015

On Wednesday 11 March 2015 20:48:11 you wrote:
> On Wed, 2015-03-11 at 20:27 +0200, Tanu Kaskinen wrote:
> > 
> > I'm writing release notes for 7.0, and I'm wondering how to describe the
> > three soxr resampler variants. Alexander says that all variants are
> > perfect quality-wise (no audible distortions). Alexander also says that
> > each variant takes about the same amount of CPU time, but Andrey says
> > that there's 2x difference between mq and vhq. Who's right?
> > 
> > To me it sounds like the hq and vhq variants are redundant, since mq is
> > at least as fast (and on some hardware significantly faster) as the
> > other variants, and there's no meaningful difference in quality.
> I now wrote something to the notes, feel free to comment if you'd like
> to change something:
> http://www.freedesktop.org/wiki/Software/PulseAudio/Notes/7.0/

Technically, "up to 20 ms" is not correct because sometimes the delay may be 
higher. I was careful about that when I updated the man pages.

Regarding hq vs vhq, I think I mentioned it somewhere, vhq does computation 
with more precision bits than hq, so it mostly targeted for high bit depth 
formats. Whether or not the difference is audible and under what conditions is 
an other question. I did some performance measurements, they are given on the 
page I referenced earlier [1].

[1] http://lastique.github.io/src_test/

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