opus - Feb 2018 - opus 1.2.1 regression with --enable-float-approx and --0fast

Hi,
I work on a webRTC application and recently tried updating from opus 1.1.5
to 1.2.1

Afterwards I noticed occasionally weird audio glitches. I finally tracked
down the issue to the opus decoder in my application outputting samples
with the value of -32768.

This behaviour stopped when reverting to opus 1.1.5 or compiling opus 1.2.1
without configuring --enable-float-aprox and --0fast.

The setup is a microphone as audio input into chrome v64 which then sends
opus encoded audio to my application and my application decoding this audio
stream.

I could induce the glitches by breathing/blowing really loudly into the
microphone. I noticed that occasionally this would result in the opus
decoder in my application to keep outputting a stream of -32768 (even if I
stopped) until I talked normally for a bit.

Is it possible that a regression was introduced between 1.1.5 and 1.2.1
when configuring with --enable-float-approx and compiling with --0fast?

Thanks,
-stepan
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Hi Stepan,

I would need more information to be able to investigate further. It's
legal for the decoder to output -32768, so it would be good if you could
explain how this is unexpected. Ideally an audio file with details on
how to reproduce the problem would help.

Optionally, if you could bisect the git repo to see where the problem
started.

Cheers,

	Jean-Marc

On 02/22/2018 07:15 PM, Stepan Salenikovich wrote:
> Hi,
> I work on a webRTC application and recently tried updating from opus
> 1.1.5 to 1.2.1
> 
> Afterwards I noticed occasionally weird audio glitches. I finally
> tracked down the issue to the opus decoder in my application outputting
> samples with the value of -32768.
> 
> This behaviour stopped when reverting to opus 1.1.5 or compiling opus
> 1.2.1 without configuring --enable-float-aprox and --0fast.
> 
> The setup is a microphone as audio input into chrome v64 which then
> sends opus encoded audio to my application and my application decoding
> this audio stream.
> 
> I could induce the glitches by breathing/blowing really loudly into the
> microphone. I noticed that occasionally this would result in the opus
> decoder in my application to keep outputting a stream of -32768 (even if
> I stopped) until I talked normally for a bit.
> 
> Is it possible that a regression was introduced between 1.1.5 and 1.2.1
> when configuring with --enable-float-approx and compiling with --0fast?
> 
> Thanks,
> -stepan
> 
> 
> _______________________________________________
> opus mailing list
> opus at xiph.org
> http://lists.xiph.org/mailman/listinfo/opus
>

On Thu, Feb 22, 2018 at 8:34 PM, Jean-Marc Valin <jmvalin at jmvalin.ca>
wrote:
> Hi Stepan,
>
> I would need more information to be able to investigate further. It's
> legal for the decoder to output -32768, so it would be good if you could
> explain how this is unexpected.

Its unexpected because the decoder continues to output all samples of -32768
even when the microphone input is silence or near silence, so I would
expect the decoded values to be at or near 0.

> Ideally an audio file with details on
> how to reproduce the problem would help.
>
I will try to reproduce with opus_demo or opus-tools.

>
> Optionally, if you could bisect the git repo to see where the problem
> started.
>
> Cheers,
>
>         Jean-Marc
>
> On 02/22/2018 07:15 PM, Stepan Salenikovich wrote:
> > Hi,
> > I work on a webRTC application and recently tried updating from opus
> > 1.1.5 to 1.2.1
> >
> > Afterwards I noticed occasionally weird audio glitches. I finally
> > tracked down the issue to the opus decoder in my application
outputting
> > samples with the value of -32768.
> >
> > This behaviour stopped when reverting to opus 1.1.5 or compiling opus
> > 1.2.1 without configuring --enable-float-aprox and --0fast.
> >
> > The setup is a microphone as audio input into chrome v64 which then
> > sends opus encoded audio to my application and my application decoding
> > this audio stream.
> >
> > I could induce the glitches by breathing/blowing really loudly into
the
> > microphone. I noticed that occasionally this would result in the opus
> > decoder in my application to keep outputting a stream of -32768 (even
if
> > I stopped) until I talked normally for a bit.
> >
> > Is it possible that a regression was introduced between 1.1.5 and
1.2.1
> > when configuring with --enable-float-approx and compiling with
--0fast?
> >
> > Thanks,
> > -stepan
> >
> >
> > _______________________________________________
> > opus mailing list
> > opus at xiph.org
> > http://lists.xiph.org/mailman/listinfo/opus
> >
>
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