Re: [Appconference-devel] Adding iLBC support

[孙耀华 <sun...@gm...>]

Hi, Mihai

    Thanks for your advice, I added support of iLBC by using the same way as
G.729a, and after doing that, there was no CLI error message come out, but
when two iLBC client get into the conference, the mixed voice still sounds
choppy.
    There's the same problem when I change to speex codec. I read the code
"member.c", and I found the smoother for speex is disabled, I tried to add a
smoother for iLBC, and modified the code like below, but got no effect.

 switch (member->read_format){
/* these assumptions may be incorrect */
case AST_FORMAT_ULAW:
 case AST_FORMAT_ALAW:
member->smooth_size_in  = 160; //bytes
member->smooth_size_out = 160; //samples
 break;
case AST_FORMAT_GSM:
/*
 member->smooth_size_in  = 33; //bytes
member->smooth_size_out = 160;//samples
 */
break;
case AST_FORMAT_SPEEX:
 break;
 case AST_FORMAT_ILBC:                  // my modifications below: for iLBC
at 30ms
member->smooth_size_in  = 50;  // bytes
 member->smooth_size_out = 240; // samples for 30ms

    Only G.711 works good. Sound mixing is perfect. So I cannot use any
other codec except G.711 right now. I think there must be something wrong,
but I don't know what it is.

Thank you.


2010/1/11 Mihai Balea <mi...@ha...>

>
> On Jan 10, 2010, at 9:11 PM, 孙耀华 wrote:
>
> Hi,
>  Appconference is a great module for replacing meetme, and video
> function is also amazing. But I cannot find out native support for
> iLBC in appconference, and when I use iLBC payload, the voice sound
> very strange. I am sure transcode with iLBC in Asterisk works fine. I
> found G.729a support in Appconference, can I add iLBC support for
> Appconference? how can I do that, and is it possible?
>
>
> Hello
>
> There is no support for ilbc as of now, but it can be added with a minimum
> of effort.
> If you are looking to implement it, I would suggest that you look at the
> way G729 support is implemented and do it in a similar way
>
>
> It is said: "For some reason iLBC codec only accepted frame sizes
> multiple of 50, and since slinear mixing required 240 ( not a multiple
> of 50 ) voice sounded choppy"
> Is it the right reason?
>
>
> That sounds weird. I am not familiar with ilbc, but according to this
>
> http://en.wikipedia.org/wiki/Ilbc
>
> the frame size would be 20 or 30 ms (160 or 240 samples)
>
> Mihai
>