[OpenSIPStack] Silence Detection

[Whit T. <de...@wh...>]

Hey Ilian,

Thanks for exposing these methods in ATLSIP!

Has there been any more work on the adaptive Silence Detection? The
threshold of 3 is pretty stable, but I have end-users who complain that all
calls are extremely 'one-sided' meaning that once one side of the call
begins talking, the other person can't easily interrupt them. Logically that
makes sense, but the end users I have love to interrupt each other so its
rather annoying for them to wait till the other person is finished. 

Has anyone else deployed ATLSIP to real world end users?

If so, what has your experience been like? I'd love to see what kind of
settings (Silence, CN etc) others are using in the field.


Regards,
Whit





-----Original Message-----
From: ope...@li...
[mailto:ope...@li...] On Behalf Of Ilian
Jeri C. Pinzon
Sent: Friday, June 29, 2007 6:58 AM
To: ope...@li...
Subject: Re: [OpenSIPStack] Problem with OnOutgoingCallConnected

The attachment was not sent. Probably filtered by the server. Anyway, here
it is:

===========================================================================

Hi all,

I have exposed the setting of silence detection mode and audio jitter 
delay in ATLSIP and SoftPhoneInterface.

Here are the methods:

DisableSilenceDetection()
- Disables silence detection. Disables CNG as well.

EnableFixedSilenceDetection( ULONG threshold )
- Enables fixed silence detection. Any sound level below the threshold 
is treated as silence (and CN is generated as a result). Don't use too 
high threshold values or you'll only hear comfort noise. Try threshold=3 
as suggested by Whit in another thread.

EnableFixedSilenceDetectionEx( ULONG threshold , ULONG signalDeadband, 
ULONG silenceDeadband  )
- An extended version of the previous method. Don't tinker with this 
unless you know what you're doing. For reference on how signalDeadband 
and silenceDeadband are used, look in OpalSilenceDetector::ReceivedPacket().

EnableAdaptiveSilenceDetection( ULONG adaptivePeriod )
- Enables an adaptive silence detection. Supposedly this enables the 
threshold to *adapt* to the current sound level every adaptivePeriod 
milliseconds. However, its silence detection doesn't seem to be very 
effective (at least in my machine). I'll look into this further to see 
what's wrong. This mode with adaptivePeriod=4800 is the default mode for 
ATLSIP.

EnableAdaptiveSilenceDetectionEx( ULONG adaptivePeriod, ULONG 
signalDeadband, ULONG silenceDeadband  )
- An extended version of the previous method. Don't tinker with this 
unless you know what you're doing. For reference on how signalDeadband 
and silenceDeadband are used, look in OpalSilenceDetector::ReceivedPacket().

SetAudioJitterDelay( ULONG minDelay, ULONG maxDelay )
- Sets audio jitter delay settings.


Regards,
Ilian



Ilian Jeri C. Pinzon wrote:
> ATLSIP's default silence detection is still faulty. You can try 
> setting the silence detection to fixed mode. Somebody said in another 
> thread that a threshold of 3 will do the trick. You may have to tweak 
> this value though.
>
> Attached is the thread containing the functions to call for setting 
> the silence detection mode.
>
> - Ilian
>
> tomach wrote:
>> Hello!
>>
>> Ok thank you very much! Till now everythign works correct :) Now some 
>> more advanced test...about quality of voice etc...
>>
>> It started to work correctly (From Tag was ok) after I build it as 
>> debug and reregistered again :) Now everythign works correct:)
>>
>> I still have like last question, do you have comfort noise generator? 
>> Because now its totally silence if somoebdy do not talk at all... and 
>> it could be uncomcofortable for subscirbers...
>>
>> Best Regards,
>> Tom
>>