[AG-TECH] AG video node using berkley mjpeg work

Bob Riddle bdr at internet2.edu
Wed Nov 14 19:43:05 CST 2001


I built a "small" AG node for the purpose of testing the Berkeley mjpeg
video capture with the AG video capture and display machine.  In
summary, I ran the openmash vic on the display machine while in the
Venues Test Room and was able to display an expected H.261 video stream
along with a mjpeg stream. 

Here's the setup:
Display machine - Win2k, dual P500 processors, latest AG software loaded
Video machine - RedHat 7.1, dual P500 processors, latest AG linux apps,
1 WinTV card, 1 LML33 mjpeg card, latest version of MAtthew Delco's code
(http://bmrc.berkeley.edu/~delco/rtptv)

I ran the display machine as any AG operator would expect.  When I got
to the "Test Room", I cancelled the AG vic program and started the
openmash vic using the mcast address (233.2.171.38/42002).  I then
started the mjpeg video capture program using the same mcast address and
asking fro 10 mbps.  Then I started the AG vrm-eventlistener.

Observations:  

If I started the vrm-eventlistener before I started the mjpeg capture
program, the display machine never saw the mjpeg stream.  I don't
understand why this is true.

If I set the mjpeg capture rate greater than 10 mbps the display machine
never saw the mjpeg stream.  I don't understand why this is true.

On the Display machine (Win2K), when I expanded the mjpeg vic window,
the reported frame rate dropped from 30 fps to about 15-17 fps.  The
data rate reported also dropped from 10 mbps to about 6-7 mbps. 
However, the picture was great looking.  I checked the CPU with task
manager & one processor was tapped out completely.  My belief is if I
had a faster processor, I could have sustained higher frame rates.

I'll be glad when the openmash vic has the autoplace function.  I wish I
understood how to replace the AG vic with the openmash vic so that I'm
not required to start this vic manually.  

Any helpful suggestions will be appreciated!



More information about the ag-tech mailing list