Video capture cards for linux
Robert.Edwards at anu.edu.au
Tue Dec 4 23:45:49 EST 2001
Michael Still wrote:
> Off hand, does anyone know what format VideoCD uses, and is this is a
> cdrecord burning option?
The compressed video format of a Video CD is MPEG-1. The disk format is
"Video CD" (ie. not ISO-9660!). From memory, cdrecord has no problem
burning a Video CD "image" onto a CDR - however, you need to generate
the "image" ("image" here referring to an image of the binary data to go
onto the CD, as opposed to the video "image" it contains!!!). Note that
this is the same as with burning an ISO-9660 CD - cdrecord can't generate
the ISO image either.
> > On a 1.2GHz Athlon I can just capture 640x480, but usually use 320x240
> > since at 90% jpeg quality this looks pretty good and uses heaps less
> > disk space. I used to capture on a PII 350, and I think it could do
> > 320x240, although only just.
> Wow. I hadn't realised how much CPU time the compression takes (I assume
> most of it is taken with compression). Does anyone know what resolution a
> TV runs at?
How long is a piece of string? PAL TV (as used in Australia) is about 575
lines in two fields. Each line is a continuous analogue signal, that can
be digitised at whatever resolution you like. If you like square pixels,
somewhere between 720 and 800 pixels horizontally is usual to maintain the
4 x 3 aspect ratio of a TV screen.
> The next question is now that I know that I can stream this stuff to disc,
> does anyone have a hardware recommendation for streaming it back to the
> TV? I could go the VGA -> TV route, but I am not sure that is the best way
> to go. I am aware that some matrox cards have a TV out -- are they any
I've used an ASUS TNT2 card with TV out for quite a while - it does a
reasonable job with my TV. Cougar sell many video cards with TV out on
> > I'm afraid I haven't tried any non-bttv capture cards, so I can't
> > really provide a comparison, but I'd say I'm fairly happy with bttv -
> > even this few year old card.
> I think I'll go out to the markets and see what I can see.
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