[AG-TECH] Recording using hardware encoder card

[Christoph Willing]

On 01/07/2010, at 7:43 AM, Richard Palmer wrote:

> Dear List,
>
> 	We're setting up a room node with 4 cameras and we'd like to be able
> 	to record the AG sessions (and also just local events) we're running.
> 	As I understand it, programmes such as AGVCR record a AG session  
> using
> 	the encoded video stream,


Richard,

More precisely, AGVCR records the network packets containing the media  
streams


> which may be (far) lower in quality
> 	than the source material.

and if sites are sending the default h.261 video, then the recordings  
are probably much lower than the captured source (assuming the capture  
cards are PAL/NTSC capable)


> Is there any way to record the local stream
> 	at the highest quality (i.e. as it comes into the capture server)
> 	within AG ?.

Well, if everyone (or just you, if you only want recordings of local  
streams) would transmit large size H264 streams (full PAL/NTSC), then  
your AGVCR recording would contain the high(est) quality video you're  
after.

The downside to this method is the CPU load if you're encoding  
multiple local streams.


> 	If not, would it be possible to use a card such as the Picolo U4
> 	H.264 ? (http://www.euresys.com/Products/picolo/PicoloU4H264.asp), as
> 	that (claims) to allow access to both the encoded and raw version
> 	of each video channel. Presumably AG could use one stream and the		 
> other stream could go straight to disc. Or is it not that simple ?.

Someone might have to come up with some glue code so that vic can  
recognise the card - it depends how the card is accessed from software.


Along similar lines, see:
     http://linux.slashdot.org/story/10/06/17/1929230/Bluecherry-Releases-GPLd-MPEG-4-Driver
and
     http://www.bluecherrydvr.com/2010/06/16/bluecherry-releases-its-version-2-driver-gpl/

We have a normal 4 channel bluecherry card and its worked very well  
for us. Thats a good omen for this new bluecherry mpeg card and  price  
of ~200USD seems pretty reasonable. I didn't see a price for the Picolo.


chris


Christoph Willing                       +61 7 3365 8316
QCIF Access Grid Manager
University of Queensland