Speex dev - Jan 2010 - Fwd: Re: Fixed Point on wideband-mode: Single Frame loss on 2000 Hz sine causes "freak off"

Hi again,

I tested lower cumul_gain limit values. In fact, I reduced the value to 240000,
230000, 220000, ..., 20000, 10000, 5000, 2000, 1000, 500.  (quality 7,
complexity 2)

For input signal 2000 Hz, the values 190000, 130000, 60000, and 1000 look o.k.,
all others don't. For 500, the (zoomed out) waveform shows some kind of
amplitude ripple -- i think, this value is definetely too low.
I tested the good values for 2200 Hz input, too. Only the value 1000 looks more
or less o.k. (no huge instability, but some kind of visible "artifact"
inside the fade in after the frame loss), for the other values the codec is not
stable.

So, this does not seem to be a solution. Any further ideas what to test?

best regards,
Frank


Jean-Marc Valin <jean-marc.valin at usherbrooke.ca> hat am 14. Januar 2010
um 13:15 geschrieben:
> What happens if you change that line:
>
> if (cumul_gain > 262144)
>
> to use a smaller value? What value works OK (if any)?
>
> One more thing, when things go wrong, do they eventually go back to
> normal or does the codec never recover? It's unavoidable that the audio
> goes bad for a short period of time because of the long-term predictor.
>
>         Jean-Marc
> 
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Did you run the encoder with the fixed-point debug option?

	Jean-Marc

On 2010-01-14 11:11, Frank Lorenz wrote:
> Hi again,
>
> I tested lower cumul_gain limit values. In fact, I reduced the value to
240000, 230000, 220000, ..., 20000, 10000, 5000, 2000, 1000, 500.  (quality 7,
complexity 2)
>
> For input signal 2000 Hz, the values 190000, 130000, 60000, and 1000 look
o.k., all others don't. For 500, the (zoomed out) waveform shows some kind
of amplitude ripple -- i think, this value is definetely too low.
> I tested the good values for 2200 Hz input, too. Only the value 1000 looks
more or less o.k. (no huge instability, but some kind of visible
"artifact" inside the fade in after the frame loss), for the other
values the codec is not stable.
>
> So, this does not seem to be a solution. Any further ideas what to test?
>
> best regards,
> Frank
>
>
> Jean-Marc Valin<jean-marc.valin at usherbrooke.ca>  hat am 14. Januar
2010 um 13:15 geschrieben:
>
>> What happens if you change that line:
>>
>> if (cumul_gain>  262144)
>>
>> to use a smaller value? What value works OK (if any)?
>>
>> One more thing, when things go wrong, do they eventually go back to
>> normal or does the codec never recover? It's unavoidable that the
audio
>> goes bad for a short period of time because of the long-term predictor.
>>
>>          Jean-Marc
>>
> ______________________________________________________
> GRATIS f?r alle WEB.DE-Nutzer: Die maxdome Movie-FLAT!
> Jetzt freischalten unter http://movieflat.web.de
>
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>
>