[Asterisk-video] confbridge, h264 and switching

[Matthew Jordan]

----- Original Message -----
> From: "Dmitry Melekhov" <dm at belkam.com>
> To: asterisk-video at lists.digium.com
> Sent: Sunday, April 8, 2012 10:55:53 PM
> Subject: Re: [Asterisk-video] confbridge, h264 and switching
> 
> 06.04.2012 17:53, Matthew Jordan написал:
> > Dmitry:
> >
> > Can you explain what you mean by "it brokes during switching"?
> Hello!
> 
> I mean that without i-frame talking user appears from squares and
> other
> strange shape still showing part of previous talker.

<snip>

Okay, now I understand what you're referring to.

Yes, if the client that has been made the new video source does not
transmit an I-Frame when they are made the video source, the receiving
clients will predict their frames on the previously received frames
from the previous video source.  That would lead to what you're
describing.

Since Asterisk does not interpret or decode the video streams it
receives from the clients, it does not have a mechanism itself to
manipulate the image.  It does, however, notify the client that is
the new video source via a SIP INFO message that it is now the source
of the video.  It is up to the client to know that it should then send
an I-Frame to provide a reference point for the other clients for the
new video images.

A few questions then:
1. What clients are you using?  Do they support RFC 5168 (XML Schema
for Media Control)?
2. If you get a SIP trace or a packet capture, do you see Asterisk
sending the SIP INFO messages when a video update occurs?

Thanks

Matthew Jordan
Digium, Inc. | Software Developer
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at: http://digium.com & http://asterisk.org