Re: [Linphone-users] Re: several faq corrections and enhancements

[Liviu Andronic]

On Tue, 15 Mar 2011 14:11:21 +0100, Dragos D <address@hidden> wrote:
> > Here are some more:
>
> - the echo cancellation when using a USB microphone ( for example from a
> webcam) is very poor.
Yes, I think I confirm this. It works fine, though, when headphones are  
used on both sides. (But this is not the same as echo cancellation, I  
presume.)


> - image artifacts when using h.263-1998 or h.264 ( much worse for h.264,  
> but
> my tests are not recent for h.264) .
Yesterday I tried H.264 with speex and sensible bitrate settings with a  
_cable_ internet connection and the result was impressive: no artifacts  
(none!) and very few audio freezes.

When WiFi is used, though, the quality is much more messy. With the same  
settings (and depending on the network quality vagaries) the audio can  
freeze frequently, and the video would quickly display pixelization  
artifacts that dissipate slowly (or sometimes by performing perceptible  
head movements or by "imaginarily" wiping the camera image with the hand,  
in circular motion).


> Dragos
>
> P.S. Skype peer-to-peer connectivity is much better than SIP, but this  
> issue
> is too complex.
What about sipwitch [1][2]? I read about it this morning and although I  
didn't quite understand all the technical details, it seems to allow  
clients to use a Skype-like network.

 GNU SIP Witch is a secure peer-to-peer VoIP server.  Calls can be made
 even behind NAT firewalls, and without needing a service provider.  SIP
 Witch can be used on the desktop to create bottom-up secure calling
 networks as a free software alternative to Skype.  SIP Witch can also
 be used as a stand-alone SIP-based office telephone server, or to
 create secure VoIP networks for an existing IP-PBX such as Asterisk,
 FreeSWITCH, or Yate.

Would this make any sense for Linphone? Cheers
Liviu

[1]  
http://www.mail-archive.com/address@hidden/msg882472.html
[2] http://www.gnu.org/software/sipwitch/


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