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

Bob Riddle bdr at internet2.edu
Thu Nov 15 20:14:15 CST 2001


If the openmash vic (on linux) can use the lml33 to capture the video,
then I can probably slide it in place of the AG vic program  - I've been
using the openmash windows vic (5.1.6) on the Win2K machine as the
receiver, so runnin the RTPtv code as a receiver isn't necessary for
what I'm trying to do.

I do know the mjpeg stuff used to work once upon a time in vic, at least
in a version run on a Sun OS machine a few years ago, some guys at
CITI/UM used this for the 1st Internet2 demo to show the video off from
a SEM.

"Lawrence A. Rowe" wrote:
> 
> Bob Riddle wrote:
> >
> > A few more observations:
> >
> > on the Win2k Display machine, you can't just slide the openmash vic.exe
> > (and vic, mash.exe) in teh /ag/agapps/bin directory, even if you rename
> > it to ddvic.exe.  When the DRM manager starts, it expects to find "the"
> > ddvic" in that directory, if not (or if renamed vic.exe) a message box
> > is prodcued telling you its "can't load ddvic".  The same thing happens
> > when you move through the rooms via the web browser.
> >
> > On the linux machine used for video capture, I'm trying to understand
> > better what vrm-eventlistener does upon startup.  It appears to use a
> > "parsed sdp" stream to get the mcast address, but the port isn't
> > mentioned in the stdout messages.  Also, it starts vic with a user
> > script file "-u /tmp/vic-startup.0" which doesn't seem to hang around
> > long enough for me to peek at it.  Anybody know what this script looks
> > like?  I'm trying to figure out why I have to start the mjpeg vserver
> > before the vrm-eventlistener.
> >
> > Anyway, Matthew indicates in his mjpeg pages that vic can be built using
> > the lml33 mjpeg drive.  In fact, Larry Rowe had sent a note some time
> > ago indicating this might be included in future openmash "releases".  So
> > my current thought is to try and get a linux version of the openmash vic
> > slide in place on the AG linux video capture machine and see if it
> > resolves the startup issue by using more "normal" AG video capture
> > software.
> ---
> 
> That's note quite correct.  The LML33 capture interface in OpenMash only
> does raw video capture - that is, it uses the LML33 to capture the frame
> then hands it to the normal software encoding routines.  You can encode
> the captured video as mjpeg and it will be similar to RTPtv streams, but
> probably not identical -- i.e., I don't think we have restart markers in
> the OpenMash code.
> 
> Matt, will RTPtv vclient replay mjpeg streams without restart markers?
>         Larry
> --
> Professor Lawrence A. Rowe          Internet:  Rowe at BMRC.Berkeley.EDU
> Computer Science Division - EECS       Phone: 510-642-5117
> University of California, Berkeley       Fax: 510-642-5615
> Berkeley, CA 94720-1776            URL: http://bmrc.berkeley.edu/~larry



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