"Natural" capture resolution?digital cable->s-v

[fatcatfan]

I'm sure this must be a FAQ, but the nature of the question makes it difficult to narrow done a search for a previous topic. The keywords just aren't specific enough, I think. anywho, here goes.

I'm getting a new P4 system - very nice - and it will have the ATI AiW Radeon 8500DV. One thing I plan on doing with it is capturing Farscape on the SCI-FI channel when I can't be around to watch it as it airs, or when I just want to be able to watch it over and over... I'll be making SVCDs but I want to do a raw capture to HUFFYUV video and either PCM or APE audio, reencoding to SVCD later.

so the video signal will be coming from the s-video output on my motorola DCT2224 digital cable box. my question (finally!) is what is the "natural" resolution and framerate I should use for the initial capture? the resolution that is an exact match to the signal coming in from the s-video. Is it standard NTSC analog tv resolution? (and what are those dimensions? I've not found a definitive answer yet.) Framerate should be 29.97Hz I'm sure, but the size is what I'm not cartain of.

[BJ_M]

well the maximum it can output is 525 lines but i looked up that model and of course there is a great area of grey on what your broadcaster is acually pumping out any given minute up to the sat .. but in accual fact most of the time they are only doing 440 lines it apears out of the box .. but there is no harm in going over this and its for better quality anyway ..

so cap at 640 x 480 or 720 x 480 (704 x 480)

[fatcatfan]

As you can tell I'm inexperienced with capturing. I've done enough encoding and whatnot to be comfortable with that, but never done any serious capturing.

so... what would be the the difference between capping at 640x480 versus 720x480? Would the video be "stretched" to fit this resolution or would there just be blank areas on the left and right edges?

and thanks for your prompt reply.

[BJ_M]

well for example i use avi_io for cap'ng w/ a reeltime nitro or sgi sdi input or component (personal not work, where we use some the same plus more) and the image would fill the size mentioned .. your tv is underscanned from that pic by 10% (6 % in some, more in others ) so in final encoding you can make image 10% smaller in "clip image" full screen custom size but make the svcd at 480 x 480 or dvd at 720 x 480.
IMO cap at the highest you can and still best color and no drop frames .. so 720 x 480