Speex dev - Jul 2007 - Quality degradation on new versions

Hi,
I have been using speex version 1.0.5 on a text-to-speech program. Recently
I upgraded to version 1.2beta1
and noticed that the waveform the I got after encoding and decoding on the
new versions (beta1,beta2) is much
more different than the original than on version 1.0.5. I also ran a PESQ
comparison test on 700 voice samples
and got better results in the older version  (I used quality 9, and
disabled perceptual enhancement).
Do you know what can cause these changes?
My application requires the waveform after decoding to be as similar in
shape to the original, so if the difference
is the result of some new addition to the encoder i would like to know how
to turn it off.
Thanks,

Aviv

Hi Aviv,

Does the audio sound bad?

You can try turning off the highpass filter (which was not in 1.0.5).  This 
code is from ti/testenc-TI-C5x.c in the source tree:

   /* Turn this off if you want to measure SNR (on by default) */
   tmp=0;
   speex_encoder_ctl(st, SPEEX_SET_HIGHPASS, &tmp);
   speex_decoder_ctl(dec, SPEEX_SET_HIGHPASS, &tmp);

- Jim

----- Original Message ----- 
From: "Aviv Tamar" <AVIVT@il.ibm.com>
To: <speex-dev@xiph.org>
Sent: Thursday, July 12, 2007 10:18 AM
Subject: [Speex-dev] Quality degradation on new versions

>
> Hi,
> I have been using speex version 1.0.5 on a text-to-speech program. 
> Recently
> I upgraded to version 1.2beta1
> and noticed that the waveform the I got after encoding and decoding on the
> new versions (beta1,beta2) is much
> more different than the original than on version 1.0.5. I also ran a PESQ
> comparison test on 700 voice samples
> and got better results in the older version  (I used quality 9, and
> disabled perceptual enhancement).
> Do you know what can cause these changes?
> My application requires the waveform after decoding to be as similar in
> shape to the original, so if the difference
> is the result of some new addition to the encoder i would like to know how
> to turn it off.
> Thanks,
>
> Aviv
>
> _______________________________________________
> Speex-dev mailing list
> Speex-dev@xiph.org
> http://lists.xiph.org/mailman/listinfo/speex-dev
>

Hi Jim,
First of all - thanks, turning the highpass filter off was what I needed,
and the waveforms
match now.
But, when i did the PESQ tests again I found an interesting result :
version 1.0.5 still got
a slightly better average score, but the standard deviation on version 1.2
beta1 was much smaller.
The cause for that is this - on some samples versions 1.0.5 and 1.2beta2
produced a single
noticable 'click' during the speech, while version 1.2beta1 didn't.
Do you have an idea what can cause the click, and how to turn it off?

Aviv


speex-dev-bounces@xiph.org wrote on 12/07/2007 21:26:51:
> Hi Aviv,
>
> Does the audio sound bad?
>
> You can try turning off the highpass filter (which was not in 1.0.5).
This
> code is from ti/testenc-TI-C5x.c in the source tree:
>
>    /* Turn this off if you want to measure SNR (on by default) */
>    tmp=0;
>    speex_encoder_ctl(st, SPEEX_SET_HIGHPASS, &tmp);
>    speex_decoder_ctl(dec, SPEEX_SET_HIGHPASS, &tmp);
>
> - Jim
>
> ----- Original Message -----
> From: "Aviv Tamar" <AVIVT@il.ibm.com>
> To: <speex-dev@xiph.org>
> Sent: Thursday, July 12, 2007 10:18 AM
> Subject: [Speex-dev] Quality degradation on new versions
>
>
> >
> > Hi,
> > I have been using speex version 1.0.5 on a text-to-speech program.
> > Recently
> > I upgraded to version 1.2beta1
> > and noticed that the waveform the I got after encoding and decoding on
the
> > new versions (beta1,beta2) is much
> > more different than the original than on version 1.0.5. I also ran a
PESQ
> > comparison test on 700 voice samples
> > and got better results in the older version  (I used quality 9, and
> > disabled perceptual enhancement).
> > Do you know what can cause these changes?
> > My application requires the waveform after decoding to be as similar
in
> > shape to the original, so if the difference
> > is the result of some new addition to the encoder i would like to know
how
> > to turn it off.
> > Thanks,
> >
> > Aviv
> >
> > _______________________________________________
> > Speex-dev mailing list
> > Speex-dev@xiph.org
> > http://lists.xiph.org/mailman/listinfo/speex-dev
> >
>
>
> _______________________________________________
> Speex-dev mailing list
> Speex-dev@xiph.org
> http://lists.xiph.org/mailman/listinfo/speex-dev