[clug] Recording clug talks

Alex Satrapa grail at goldweb.com.au
Thu Mar 22 04:24:55 GMT 2007

On 22/03/2007, at 13:02 , Ben wrote:

> Elphel 333 - open source and 3MP at 15fps or 720p at 24fps.

To capture on-screen action, you really need a screen grabber which  
records from the frame buffer - not an external camera which tries to  
capture the projected output.

> www.elphel.com
> (no auto focus (should be ok for presentations) or mic, but by outputs
> video in ogg theora over 10/100 ethernet).

I'm thinking of the Linux equivalent of Snapz for Mac OS X:  http:// 

As opposed to the painful, nasty hack proposed on Linux.com a few  
days ago:
  - Find window ID for the (single) window you want to capture
  - Arrange for ImageMagick to capture that window to a
    file as fast as it possibly can
  - Perform a bunch of voodoo to convert the thousands of
    images you've captured into a movie at the appropriate
    frame rate and resolution

Another article I've read mentions "xvidcap", "Istanbul",  
"recordmydesktop" and "pyvnc2swf".

But, I fear we are digressing from the original intent which was to  
simply provide a recording of the presentation. A camcorder will  
capture enough information to give people the gist of the message,  
especially if the presenter is aware enough to narrate what they're  
doing rather than relying on eyeballs to follow cursors around the  

> Wouldn't be an issue with the Elphel 333 - I might have to get one.

If you have a laptop with a FireWire port, you can capture video live  
from most Mini-DV cameras. The Elphel is an Ethernet camera, so you'd  
have to have a laptop connected to it anyway (plus a camcorder has a  
batter, the Elphel needs an external power supply).

> I'm happy to help out, but no experience as a camera operator.

You just have to know how to press the stop/start button, and know  
that inserting a tape means gently placing the tape in the holder,  
then pressing the lid closed to trigger the auto-retraction system  
(as opposed to trying to force the tape holder mechanism back into  
the guts of the camera).

Oh... and you also have to understand about not sticking fingers on  
the lens. But that applies to any camera.

> Would Bit Torrent be an option?

Strangely enough, a Bit Torrent tracker/seeder is one of the things I  
want to get running on my NSLU-2. This is exactly the situation that  
Bit Torrent is designed to address (big files, puny bandwidth).

In the end, I have a camcorder available to use, and I am willing to  
volunteer the time to edit the captured footage. If the presenter  
supplies the screencast as well I should be able to edit that in too.

Start off recording *something*, and refine techniques as people come  
up with a better idea of what it means to "record a CLUG talk", and  
how to handle situations where some people present aren't  
particularly keen on having their ugly mug published on the Internet.

Key words to follow up on if you're interested in pursuing the topic  
further: podcasting & screencasting.


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