dvsource-dvgrab - collects parameters from command line and config files, connects stdout to dvswitch, shells out to dvgrab which sends dv stream to stdout, thus dvswitch.

dvsource-file - connects to dvswitch, reads from a file, sends to dvswitch.

v4l2 device (like a webcam):

modprobe vivi (virtual v4l driver, everyone has it, good for testing)

ffmpeg -f video4linux2 -s 1024x768 -i /dev/video0 -target ntsc-dv -y - | dvsource-file /dev/stdin

Something doesn't work right: what I get in/out of dvswitch is slow, somewhere frames are getting buffered. guessing it is because the web cam is 16fps. guessing it is a problem with ffmpeg. will try trunk sometime soon.

grabbing X11 screen:

ffmpeg -f x11grab -s 1024x768 -r 29 -i :0.0 -target ntsc-dv -y - | dvsource-file /dev/stdin

vnc

Run a vnc server on the presenters laptop. disable mouse and keybord - just need to view the screen, not control the box.

Run a vnc client on another box. client outputs a video stream that gets converted to dv and sent to dvswitch. The parts exist, someone needs to assemble them.