[SATLUG] Video conferencing with DV camcorder & firewire

John Choate jdchoate at gmail.com
Tue May 27 17:17:09 CDT 2008


On Tuesday 27 May 2008 14:29:39 Jeremy Mann wrote:
> On Tue, May 27, 2008 at 2:40 AM, John Choate <jdchoate at gmail.com> wrote:
> > I got an assignment to get video conferencing set up for a small school
> > system. To get started I have a Sony Handycam DV camcorder.
> > I have loaded the raw1394 module as well as dc1394... I also
> > have /dev/video1394 available as well.
> > What I have been able to accomplish so far is recording raw video & audio
> > to a file using dvgrab. I have tried getting vlc to grab live video &
> > audio from the camera with no luck at all.
> >
> > I would like to be able to stream live video from the camera as well as
> > to capture to a file, hopefully encoding to other than raw.
> > If I can get this working, the plan will be to set up multiple cameras so
> > a teacher can have their lecture streamed to off-site classrooms as well
> > as take questions from students at the same time.
> >
> > I have never done anything like this before, so I will require
> > some 'hand-holding'. Does anyone have experience with this?
>
> John, yes it can be done but you will be limited with by the amount of
> bandwidth required. The Access Grid (which we use a lot here at the
> HSC) does support DV cameras, but it requires 35mbits of bandwidth at
> its native resolution of 720x480 but there's no way to change the
> resolution.
>
> The same goes for a standard Firewire camera like iChat or a iRez, but
> those require a seperate kernel module that makes the /dev/raw1394
> device show up as a V4L device. I played with this years ago so I'm
> not too sure about it development lately.
>
> What I would suggest? Ditch the DV camera and get some USB cameras and
> use the Access Grid. I would be happy to demo it and show you how to
> set it up for your situation.
>
>
> --
> Jeremy Mann
> jeremy at biochem.uthscsa.edu
>
> University of Texas Health Science Center
> Bioinformatics Core Facility
> http://www.bioinformatics.uthscsa.edu
> Phone: (210) 567-2672

Thanks for the reply and info. We've decided not to stream live, but rather to 
record the instructor and stream those videos, after encoding to a sane 
resolution and format. This way the instructor can preview what they end up 
broadcasting.

I was able to have some success with dvgrav and then streaming with vlc. But 
after experimenting, it seems best to reencode the video... abandoning the 
raw dv or raw avi at 720x480. I'll try some more tomorrow, but now my brain 
is tired.
:)




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