Asterisk and Video telephony
----------------------------

Asterisk supports video telephony in the core infrastructure. Internally, it's one audio stream
and one video stream in the same call. Some channel drivers and applications has video support,
but not all.

Codecs and formats
------------------
Asterisk supports the following video codecs and file formats. There's no video
transcoding so you have to make sure that both ends support the same video format.

		Codec	Format
		-----	----------
		H.263	read/write
		H.264	read/write
		H.261	-		Passthrough only

Note that the file produced by Asterisk video format drivers is in no generic
video format. Gstreamer has support for producing these files and converting from
various video files to Asterisk video+audio files.

Note that H.264 is not enabled by default. You need to add that in the channel
configuration file.

Channel drivers
---------------
SIP		The SIP channel driver (chan_sip.so) has support for video
IAX2		Supports video calls (over trunks too)
Local		Forwards video calls as a proxy channel
Agent		Forwards video calls as a proxy channel

Applications
------------
This is not yet a complete list. These dialplan applications are known to handle video:

voicemail	Video voicemail storage (does not attach video to e-mail)
record		Records audio and video files (give audio format as argument)
playback	Plays a video while being instructed to play audio
echo		Echos audio and video back to the user

There is a development group working on enhancing video support for Asterisk. 
If you want to participate, join the asterisk-video mailing list on http://lists.digium.com

---
Updates to this file are more than welcome!
