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Re: [pulseaudio-discuss] Preferred resampler method on armhf.


On Thu, Nov 20, 2014 at 8:30 AM, Sjoerd Simons <sjoerd@xxxxxxxx> wrote:
> On Thu, 2014-11-20 at 11:58 +0100, David Henningsson wrote:
>> On 2014-11-20 08:40, Alexander E. Patrakov wrote:
>> > 20.11.2014 12:35, David Henningsson wrote:
>> >> Crossposting to Debian and upstream lists.
>> >>
>> >> Apparently Debian has a patch that uses fixed point by default on armhf,
>> >> so I'm just echoing Luke's question here: Has anybody performed any
>> >> testing or benchmarks across armhf hardware, w r t fixed point vs
>> >> floating point resampling with speex and PulseAudio?
>> >
>> > That patch has been superseded by this commit:
>> >
>> > http://cgit.freedesktop.org/pulseaudio/pulseaudio/commit/?id=ac984f59d36ef555bc5b0df9af1cd48193d0d14f
>> >
>> >
>> > So, if you prefer a fixed-point resampler on armhf (or, for that matter,
>> > on any other architecture), just compile speex with --enable-fixed-point
>> > there.
>> Well, this is a more of an "upstream default" question rather than a
>> "why don't you recompile speex" question, and one where it might make
>> sense to come up with something reasonable across the board; either by
>> upstreaming "fixed point by default for armhf", or by Debian to drop its
>> patch.
>> It does not look likely to me that PulseAudio upstream and Debian would
>> correspond to so different machine/user scenarios so that a Debian
>> specific patch would make sense here.
> Well with the patch mentioned here, i would probably drop that patch
> from Debian in any case as pulse would just follow speex (which is the
> right thing anyway).. Which makes the upstream choice in pulse a bit
> moot?
> That said i'd still be interesting on seeing speex resampling benchmark
> numbers on a wider set of recentish boards.

In debian the speex maintainer has refused to enable floating point on
armhf [1][2], claiming benchmarks show that fixed point is better even
on armhf. I have not seen those benchmarks, so if it is possible to
corroborate or dispel this information it would be great. On ubuntu I
understand speex is built with floating point.

I only have a raspberry pi to try things on, but I'd be glad to run a
benchmark there if that is of any use.

[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=736752
[2] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=700602


Felipe Sateler

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