[Asterisk-Dev] libiax2 OK for production?

[Steve Underwood]

Bruno Hertz wrote:

>On Mon, 2005-01-31 at 18:41 -0500, Steve Kann wrote:
>
>  
>
>>What kind of latency are you talking about here?  There's about 60ms of 
>>latency, on the output side (i.e. to the speakers) in iaxclient proper 
>>that could be removed if we changed the architecture a bit [removing the 
>>buffers in-between decoding and the audio layer], but if you're seeing a 
>>_lot_ of latency, then there's probably some particular issue that can 
>>be resolved.
>>    
>>
>
>About one to two seconds on Fedora Core 3. On my system, it just can't
>compete. Of all clients I tried, linphone, sjphone, cornfed,
>gnomemeeting, ... iaxclient is worst latency wise. So it might be that
>particular issue, but I myself see no easy way pinpointing it.
>
>Reinventing the wheel, not really I guess. Portability is not my
>concern, and as said miniphone already does what I want at a basic
>level. The rest, like codec selection and comfort stuff, is just
>fun hacking I'd say.
>
>Thanks, Bruno.
>  
>
This came up before. iaxcomm itself doesn't give such long delays, but 
some sound card drivers do. My desktop machine give little latency. My 
notebook gives a second or more. I think your sound card is most likely 
the source of this latency. However, the fact you get better results 
with miniphone means it is not a fundamental problem with the card and 
driver (I assume you tried these tests on the same machine, or they are 
meaningless). I believe miniphone and iaxcomm use different ways to 
drive the sound card. Maybe iaxcomm is doing something wrong. Sound 
cards normally work in a high latency mode, which provides lots of 
buffering, and have to be switched to low latency by the application. 
Maybe it isn't done correctly in iaxcomm for all cards, or maybe there 
is some OSS/ALSA conflict. Do you know what sound card hardware you 
have, and which driver?

Regards,
Steve