Voice and Video
Voice and video in libPurple is being worked on using Farstream (formerly Farsight). There are a few parts to this implementation. Firstly, basic API support needs to be added to libPurple. Then Pidgin and Finch need to be able to initiate, participate in, and terminate the voice and video sessions. After these two requirements are met, each protocol will require both the signaling to be implemented (such as SIP or Jingle) and the proper Farstream plugins.
Farstream has rawudp, iceudp, and multicast transmitter plugins and an MSN webcam plugin. Basic voice and video support for libPurple, Pidgin, and Finch (voice support only) have been added to the im.pidgin.pidgin development branch. XMPP/GTalk/Gmail is working, but not complete. None of the other protocols have had much work done.
Protocol Specific Information
XMPP/GTalk
XMPP, GTalk, and Gmail use RTP. XMPP uses Jingle. GTalk and Gmail use their own flavor of Jingle. XMPP uses rawudp and XMPP, GTalk, and Gmail use the libnice Farstream transmitter plugin.
Voice and video support for XMPP/GTalk was worked on for a Summer of Code project
MSN
MSN has several different voice and video types:
- MSN Audio Conference (WLM 2009)
- MSN Video Conference (WLM 2009. Includes audio. Allows the h263 codec)
- MSN Audio Conference (pre-WLM 2009. Sometimes works with WLM2009)
- MSN Video Conference (pre-WLM 2009. Sometimes works with WLM2009. Includes audio. Only uses the wmv3 codec for which there is no open source encoder/GStreamer element)
- MSN Webcam
A Farsight2 plugin for MSN Webcam has been released.
http://imfreedom.org/wiki/MSN:AV has more information about the protocol.
Oscar (AIM, iChat, ICQ)
All Oscar protocols use RTP and SIP.
Yahoo
Yahoo voice uses straight SIP. It binds to the SIP server upon login and sends INVITEs as necessary.
Yahoo webcam uses the JPEG2000 codec with proprietary transport and signalling. The old Farsight Yahoo plugin will need to be ported to the new Farstream API.
Sametime
Sametime seems to support at least voice chat http://publib.boulder.ibm.com/infocenter/sametime/v8r0/index.jsp?topic=/com.ibm.help.sametime.standard.doc/st_adm_avserv_aboutvoicechat_r.html
Gadu-gadu
This is a placeholder for information regarding GG voice An announcement that might be of interest: http://www.finanznachrichten.de/nachrichten-2008-10/12104971-global-ip-solutions-ab-gadu-gadu-launches-new-version-of-instant-messenger-with-excellent-voice-powered-by-gips-004.htm
Building with Voice and Video
Please be familiar with compiling and installing code from source. Please also submit any bugs you find to Trac (TipsForBugReports).
Make sure you are using the latest release of Pidgin.
Farsight 2 0.0.9 and libNice 0.0.7 are the minimum versions required, but the newest versions you can get are best. Make sure to check Farsight2's README and make sure you have all of the dependencies for it. gst-plugins-base is also required for the gstreamer-interfaces-0.10 interface. Some distros call it libgstreamer-plugins-base0.10-dev. If everything in order, the configure script should output this line:
Build with voice and video.... yes
For help with building, see Installing Pidgin. Please carefully read through that section and any extra information for the distribution you're using.
Codec Configuration
If a certain codec isn't working for you, you need to create an "fs-codec.conf" file in your purple config directory. See this for the specification: fs-codec-list-from-keyfile
So, for example, if you want to disable the MPV codec you'd put this in the fs-codec.conf file:
[video/mpv] id=-1
