[theora-dev] coprocessor

John Kintree jkintree at swbell.net
Thu Feb 14 17:52:56 PST 2008

Hi, Andrey.  Thanks for that clarification.  Perhaps you are 
the most qualified person to present the idea to Walter Bender, 
or maybe to Mary Lou Jepsen.  

When using the Record activity of the XO laptop, the quality 
of the unprocessed video image is pretty good.  After clicking 
the Record button within that activity, and saving a video clip, 
the quality of the clip when played from storage instead of 
directly from the camera is not nearly as good.  

IMHO, if it could be done for about $20 per laptop in large 
quantities, the improved quality of the recorded video as well 
as the reduced need for bandwidth and storage would make 
adding the FPGA and DDR SDRAM to the next generation XO 
laptop well worth it.  

Having lots of people producing good quality video in native 
ogg theora format would also be a big boost to establishing a 
royalty-free, open source codec as an industry standard.
John Kintree

On Thursday 14 February 2008 05:33 pm, Andrey Filippov wrote:
> John,
> Theora compressor in FPGA need also a DDR SDRAM chip (not too expensive in
> volume) and fast connection to the CPU/DMA/whatever to be able to transfer
> compressed data.
> And of course I love the idea of adding FPGA+SDRAM to the system, but it
> should be not just Theora encoder, but perform variety of other functions
> to make it efficient.
> Andrey
> On Thu, Feb 14, 2008 at 1:17 PM, John Kintree <jkintree at swbell.net> wrote:
> > On Thursday 14 February 2008 06:16 am, xiphmont at xiph.org wrote:
> > > Could it possibly make sense?  Yes, but that would depend on the
> > > details of the coprocessor.  Do you have any specific parameters for
> > > the coprocessor in mind?
> >
> > In March of 2005, Andrey Filippov reported that he had used a
> > Xilinx Spartan 3 FPGA with theora to design a network camera
> > that could compress the image from a 1280x1024 sensor at 30 fps.
> > http://www.linuxdevices.com/articles/AT3888835064.html
> >
> > According to the Xilinx web site, the Spartan-3E (XC3S1200E)
> > with 1.2M system gates can be purchased for under US$9.00
> > in quantites of 500K.
> >
> > http://www.xilinx.com/products/silicon_solutions/fpgas/spartan_series/spa
> >rtan3e_fpgas/index.htm
> >
> > Those price/performance parameters were what I had in mind.  It
> > just seems like doing the compression right behind the sensor
> > is the way to go.  With a 640x480 sensor, maybe that kind of FPGA
> > could also handle the audio compression?
> > Regards,
> > John Kintree
> > _______________________________________________
> > theora-dev mailing list
> > theora-dev at xiph.org
> > http://lists.xiph.org/mailman/listinfo/theora-dev

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