[Asterisk-video] how to configure app_conference

[Borja SIXTO]

Hi Hihai,

I have added the DSP and silence detector.
But now, I cannot make a nice video switching...

I would like to control cleanly the video switching.
Actually it is strange.

I need to know how do you select the video member 
(conf->current_video_source_id).
The video source should be unselected if any one in the conference is 
speaking and the source is in audio silence.
If not, the last speaker is selected waiting for some one who will start 
to speech.

An other interesting function will be :  use "#" to get the focus.
If I would like to speak, I press the "#" in order to get the focus and 
start speaking.

What do you think about ?

Regards,


Tech from i6net


Mihai Balea a écrit :
> Hi Borja,
>
> Having full VAD in appconference is actually a feature I am interested 
> in -- I just didn't have the time to do it.
> It should actually be quite simple to implement - if you want to go 
> ahead and attempt to do it, I would be more than happy to merge in 
> your patch.
>
> Here are a few pointers that might help you understand what needs to 
> be done:
> - the place you want to look at is member.[ch]
> - if you look at create_member(), you will notice that members marked 
> as 't' (telephone) have a speex preprocessor instance associated with 
> them.  As the code stands right now, members coming in via a zaptel 
> connection cannot do DTX (obviously), so appconference does VAD, AGC 
> and noise reduction by itself.
> - however, if a member is marked as 't', it will not be considered as 
> a candidate for video switching (again, for obvious reasons - no video 
> on zaptel connections).
>
> So what would probably need to be done is define another dialplan 
> flag, that would make appconference initialize a DSP engine for that 
> member. It would be similar to 't', but due to backwards compatibility 
> issues, we cannot really use 't' for this purpose.  Once that is done, 
> appconference _should_ be aware of voice activity from members that do 
> not do DTX and _should_ be able to include this information in the 
> VAD-based video switching logic.  It will obviously need to be tested 
> and there is a good chance that some other parts of the code will need 
> to be tweaked.
>
> Hope this helps.  Let me know if you have any questions.  I have also 
> copied the appconference dev list on this, and I suggest that we move 
> this discussion there, since it is appconference-specific and doesn't 
> really relate to asterisk video in general.
>
> Mihai
>
> On May 15, 2008, at 6:48 AM, Borja SIXTO wrote:
>
>> Hi Mihai,
>>
>> For the 3G handsets we cannot configure this mode for example (Some
>> phones generate always an audio stream).
>> So I think it will be great to be able to enable the full VAD with a
>> specific application option.
>> I will read again the source code.
>>
>> Thanks,
>>
>>
>> Tech from i6net
>>
>>
>> Mihai Balea a écrit :
>>>
>>> On May 15, 2008, at 3:53 AM, Borja SIXTO wrote:
>>>>
>>>> The voice conference works well, but I didn't able to use the video
>>>> switching based on VAD or DTMF.
>>>
>>> Just a quick note here, since this is one of the more confusing
>>> aspects of appconference:
>>> To get VAD-based video switching  working, your clients need to use
>>> DTX (i.e. stop sending audio packets when there is no voice
>>> activity).  While it is possible to implement a full VAD solution in
>>> appconference (the relevant code is there), VAD is quite
>>> CPU-intensive, so there are advantages to offloading this to the 
>>> clients.
>>>
>>> Mihai
>>> ------------------------------------------------------------------------ 
>>>
>>>
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>
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