17.08.2014 12:38, Tanu Kaskinen wrote:
Patch review status updated:
http://www.freedesktop.org/wiki/Software/PulseAudio/PatchStatus/
...
Resampler quality testing
From: poljar (Damir Jelić)
Submission date: 2013-08-26(?)
In a github branch:
https://github.com/poljar/pulseaudio/commits/resampler_quality
Review: does not answer the question "is this distortion audible?" and
provides no way to evaluate quality of non-PulseAudio resamplers.
So I have decided to redo all of this using a different approach. The
new work is based on a psychoacoustical model in order to correct the
first objection, and is supposed to judge any resampler according to its
output as a wav file (including Windows output recorded by KVM) when
given a linear sine sweep. I have already implemented the model, can
answer the "is this distortion audible" question given the spectrum of
the signal and the distortion, but have not used this yet to analyze the
resampler output. Damir also provided useful contributions. So this is
definitely no longer "Waiting for Review".
As this successor is now a side project that does not share code with
PulseAudio and does not even use PulseAudio, I don't expect it to
produce a PulseAudio patch. If Damir agrees, let's remove it from the page.
I think I will have some announceable results in about a week and full
results in about a month, and would like to talk about this (maybe
unofficially) at Audio mini conference 2014.
Resampler implementations
From: poljar (Damir Jelić)
Submission date: 2013-09-06(?)
Reviewed: 2013-11-29
In a github branch:
https://github.com/poljar/pulseaudio/commits/resampler_implementations_v2
Status update:
http://article.gmane.org/gmane.comp.audio.pulseaudio.general/18991
Performance tests (mono):
http://poljar.blogspot.com/2013/08/vol-2-resampling-methods.html
Performance tests (stereo & 5.1): TBD
Bandwidth & Aliasing tests: TBD, with explanatory material at
http://poljar.blogspot.com/2013/10/epilogue-fourier-analysis-and-testing.html
Features (such as variable-rate support, input & output formats,
optimizations for particular combinations of sample rates, compatibility with
rewinds): TBD
Duplicate of this one, and all TBDs still apply to the new submission
(please copy):
resamplers
3 patches
From: Damir Jelić / Peter Meerwald
Submission date: 2014-08-04
On the mailing list:
http://thread.gmane.org/gmane.comp.audio.pulseaudio.general/20739
These have been reviewed by Arun and Alexander, and it's a bit unclear what
will happen next. The first patch appears to be (mostly?) ready to be merged,
the two other patches probably need at least some additional justification.
Yes, the first patch should be merged, with or without taking my
speex_is_fixed_point objection into account. I would have to apply the
other two patches locally in order to do the quality evaluation, but
don't want them to be upstreamed yet, until we have tools to judge them.
Hopefully this clears the "what's next" question.
--
Alexander E. Patrakov
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