[Live-devel] Custom RTSP options

[Wouter Verhelst]

Hi,

I'm working on dvswitch[1], where we're changing the architecture from
using a piped dvgrab command that writes directly to a TCP socket to
properly encapsulating DV in RTSP. The liveMedia libraries have been
changed a while back to make that possible (there was no DV
encapsulation previously); thanks for that.

One feature that the current implementation of dvswitch has, but which
the new one doesn't have yet, is support of tally lights[2]. In looking
for how to implement this using the liveMedia library, I found that
there didn't seem to be a possibility.

What I think we'd need is some way to (1) advertise (from the server
side) that a particular RTSP server would understand our custom tally
light command, (2) the possibility to send a tally command from the
client side, and (3) register a callback on the server that gets called
when that custom command has arrived.

Am I mistaken in believing that isn't available? If so, could anyone
point me towards the necessary parts of the code that I should be
looking at? If not, I'll probably look into implementing this myself,
but it'd be nice to get some input on that first, so that I don't end up
writing something which would be refused.

Thanks,

[1] http://dvswitch.alioth.debian.org
[2] In case you haven't heard of them, tally lights are those lights
    shown on most professional TV cameras that tell the camera operator
    (and people in front of the camera) which camera stream is 'live' on
    the broadcast.

-- 
The biometric identification system at the gates of the CIA headquarters
works because there's a guard with a large gun making sure no one is
trying to fool the system.
  http://www.schneier.com/blog/archives/2009/01/biometrics.html