[Freeswitch-users] echo cancelation

[Steve Underwood]

On 04/23/2015 08:12 PM, Sergey Safarov wrote:
> 1)How would you propose to do that with a fixed rate type of echo
> canceler, like OSLEC?
> If application can be used only with PCM/8000 call it wil be helpful 
> for me.
> For other rates OSLEC source code changes may be  requered.
In VoIP you don't really have exactly 8000 samples per second. You might 
have 7999 in one direction and 8001 in the other. OSLEC can't tolerate 
that. It needs the two directions be using EXACTLY the same sample rate.
> 2) Do you also believe in unicorns? ...
> Please accept my apologies. Now I understand what said Steve Underwood
>
> 3) The OSLEC echo canceler is blocked by licence conditions.
> I find it difficult to understand why the FS can use GPL Linux kernel, 
> but can not use one of his GPL drivers (not propritory firmware driver).
The kernel is not a part of Freeswitch. The licencing of one piece of 
software has not bearing on the licencing of some other piece of 
software it communicates with.
>
> 4) The OSLEC echo canceler is a great addition to the PSTN interfaces -
> DADHI and FreeTDM - but has no use elsewhere.
> Could you help me to see how OSLEC uses DAHDI or FreeTDM api. Why 
> other application cannot use OSLEC without DAHDI?
>
> Sergey.
>
Regards,
Steve