Re: [Ekiga-list] PTLIB alsa plugin status

[Derek Smithies <derek indranet co nz>]

On Thu, 26 Feb 2009, Alec Leamas wrote:
> But there *are* problems. A well behaved alsa driver should work better 
> aganist pulse, other does. The hw buffer is way to large, 100 ms latency 
> instead of ~50.  No statistics. No rebuffering.  But you have convinced on 
> one, important point: it should be possible to enhance the driver with a set 
> of smaller patches instead of a major rewrite. Such things are always easier.
>
> And I have absolutely no intention to look under the hood in the opal 
> framwork. I just found Andreas' posting, and realized that I had some odd 
> experience in alsa which might be useful. And after looking into this, I 
> still feel that a better alsa interface in Ekiga is really important to get 
> better latency and quality, both of which are crucial in a voip context. Or?
>
> BTW, are you the one which have an overall understanding the complete 
> buffering scheme in Ekiga?

I understand the ptlib and opal side of things quite well.

I had a look at Ekiga, and read about the classes AudioInputCore and 
AudioInputManager. These Audio.... classes are necessary to deal with 
sound device insertion/deletion - such as inserting a USB headset.
My first thought was that the OS (not the app) should deal with device 
insertion/deletion, but Alsa does not.
Pulse is supposed to deal with sound device insertion/deletion.
The ubuntu forums are full of people complaining about pulse.

There is no buffering mechanism in Ekiga that I saw.

Derek.
--
Derek Smithies Ph.D.
IndraNet Technologies Ltd.
Email: derek indranet co nz
ph +64 3 365 6485
Web: http://www.indranet-technologies.com/