and we have another winner!

[Christoph Doerbeck]

I forwarded ther questions to the video 4 linux mailing list, and got
the following response...

+-----------------------------------------------+

> >I find the notion of watching TV on my monitor rather appealing,
> >but now that you mention it, what *are* the bandwidth requirements
> >for live video?  

Please note that I am not an expert on such things, but I believe that my
analysis is correct.

The PCI bus in most x68 PCs is 32 bits wide and operates at 33MHz, giving it a
theoretical maximum bandwith of 1.067Gbits/sec, or 133MBytes/sec.  My TV card, 
a
Hauppauge WinTV with the Bt848, operates by writing directly into the video
memory on my display adapter.  If I am watching TV in a 640x480 pixel window
with 32 bit color depth and 29.97 frames/sec, the TV card is writing
295Mbits/sec across the PCI bus, or about 28% of my total PCI bandwidth.  This
leaves 96MBytes/sec for your streaming tape drive, which should be enough for
even a very high-end tape drive.

There may be other issues, such as interrupts/sec, which I cannot address.

Cheers,
Jeffrey

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