hech1 wrote:

You can try to put the AGC (or compressor, which is basically the same 
thing) at the system outputs rather then the inputs. However it will 
require a lot of tweaking to achieve a decent result, especially if you 
are unfamiliar with this stuff. It also depends on the architecture of 
the system.

The goals are the AGC should not pump up the noise (which is very 
annoing), and it should not squash the sound. Also, the AGC should not 
be confused by random clicks or pops, and it should be efficient.


Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com



> Thank you very much Vladimir,
> 
> So what do you suggest instead of the AGC. I found on the Internet other
> techniques like volume compressors but I am not sure. Actually, i don't
> really have experience in signal processing but I want to provide a good
> quality of the conference streams to all participants. Now participants
> are complaining about the variation of the volume when differents speakers
> speak using different equipements.
> 
> Thank you
> 
> 
>>
>>hech1 wrote:
>>
>>
>>>I am working on a VoIP audio conference. I want that all mixed sources
>>>have the same volume before being mixing so that when the speaker
> 
> changes,
> 
>>>participants will keep hearing the same level of volume. 
>>>
>>>Do I need a AGC algorithm?
>>
>>It depends. The AGC may or may not be required. The good AGC is not very
> 
> 
>>simple either. The interaction between the AGC and the EC is another 
>>interesting story. So, if it works OK without the AGC, leave it alone.
>>
>>
>>>All the AGC algorithms that I found on the Internet are about using
> 
> AGC
> 
>>>for a single source, could anybody explain to me how to use AGC for a
>>>conference.
>>
>>Here is the situation: one participant is speaking and the others are 
>>listening. The AGC will raise the noise from each of the participants to
> 
> 
>>the equal level, those noises will be added together, so nobody can hear
> 
> 
>>anything.
>>
>>
>>Vladimir Vassilevsky
>>
>>DSP and Mixed Signal Design Consultant
>>
>>http://www.abvolt.com
>>

Thank you very much Vladimir,

So what do you suggest instead of the AGC. I found on the Internet other
techniques like volume compressors but I am not sure. Actually, i don't
really have experience in signal processing but I want to provide a good
quality of the conference streams to all participants. Now participants
are complaining about the variation of the volume when differents speakers
speak using different equipements.

Thank you

>
>
>hech1 wrote:
>
>> I am working on a VoIP audio conference. I want that all mixed sources
>> have the same volume before being mixing so that when the speaker
changes,
>> participants will keep hearing the same level of volume. 
>> 
>> Do I need a AGC algorithm?
>
>It depends. The AGC may or may not be required. The good AGC is not very

>simple either. The interaction between the AGC and the EC is another 
>interesting story. So, if it works OK without the AGC, leave it alone.
>
>> All the AGC algorithms that I found on the Internet are about using
AGC
>> for a single source, could anybody explain to me how to use AGC for a
>> conference.
>
>Here is the situation: one participant is speaking and the others are 
>listening. The AGC will raise the noise from each of the participants to

>the equal level, those noises will be added together, so nobody can hear

>anything.
>
>
>Vladimir Vassilevsky
>
>DSP and Mixed Signal Design Consultant
>
>http://www.abvolt.com
>



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Is it already listed at http://dsprelated.com/employers.php ?

hech1 wrote:

> I am working on a VoIP audio conference. I want that all mixed sources
> have the same volume before being mixing so that when the speaker changes,
> participants will keep hearing the same level of volume. 
> 
> Do I need a AGC algorithm?

It depends. The AGC may or may not be required. The good AGC is not very 
simple either. The interaction between the AGC and the EC is another 
interesting story. So, if it works OK without the AGC, leave it alone.

> All the AGC algorithms that I found on the Internet are about using AGC
> for a single source, could anybody explain to me how to use AGC for a
> conference.

Here is the situation: one participant is speaking and the others are 
listening. The AGC will raise the noise from each of the participants to 
the equal level, those noises will be added together, so nobody can hear 
anything.


Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com

Hello,
I am working on a VoIP audio conference. I want that all mixed sources
have the same volume before being mixing so that when the speaker changes,
participants will keep hearing the same level of volume. 

Do I need a AGC algorithm?

All the AGC algorithms that I found on the Internet are about using AGC
for a single source, could anybody explain to me how to use AGC for a
conference.

Thank you








_____________________________________
Do you know a company who employs DSP engineers?  
Is it already listed at http://dsprelated.com/employers.php ?