capture resolution: source or destination?

[feh]

When determining what resolution to capture at, should the quality of the source media be the determining factor, or the destination?

Ie: I've got a VHS tape of average quality. From what I've read, 320x240 is sufficient for this data.

But, I'm going to archive it to DVD-R, and I've generally heard you want 640x480 for that medium.

So which resolution do I capture at? Thanks.

[Gazorgan]

Saying VHS is 320x240 is s subjective thing, it's analog, not digital. Try capturing in 648x480 and downcoverting as needed when encoding.

[macleod]

tying into gazorgan's post, I second his recommendation. If you are looking for the best you can do capture/convert, you want to capture at the HIGHEST resolution and bit rate you can and then convert down to the final resolution you want to view on your TV. There was a post within the last week or so that talked about this. The poster actually did what a lot of people have speculated about, which is to take the same footage (VHS)and cap it at at a few different resolutions and a few different bit rates and then convert down to (I believe it was CVD) the final resolution. His research contradicted what a lot of people have said (capping above 352x240 is a waste of time) as the higher resolution he captured at, the better the final product looked.

As far as DVD-R and what resolution, you probably don't want to cap at 640x480 as that is not a DVD resolutution (assuming you are playing this on a TV). I believe DVD resolution is 720x480. From my personal triumphs on resolutions, I would do 352x480 (heard it called half d-1) at 4-5Kps. What you could do is try your own test using CD's first. Get you source and cap a few minutes of fast motion, etc.) at the highest you can without unnacceptable frame rate drops at a few different kps's (depending on if your dvd player supports them) and burn it on a few CD's and see how it looks.

[feh]

Is there a FAQ that covers resolution and what happens at each phase of the process (ie. VHS -> AVI -> MPEG2 -> burn DVD)?

As an example, what happens if I capture at 480x480? When that gets converted to MPEG2 is it still 480x480, or are things sampled/duplicated to create 720x480? And if my tv displays 640x480, what purpose does the higher resolution of DVD provide?

I'm just trying to learn as much as I can, so I don't waste a bunch of time experimenting.

Thanks.

[Vejita-sama]

Take a look at:

http://www.doom9.org/aspectratios.htm

There are two things at work. The DAR (display aspect ratio) and the resolution. In theory it's possible to have the same DAR at any resolution. But in practice this just doesn't work out.

There are three DARs that we normally deal with

1:1 Computer
4:3 Normal TV
16:9 HDTV/Movies

Now a standard TV ONLY displays 4:3. So what resolutions will give you 4:3 DAR? Long story short 720,480,352 x 480,240 are the only resolutions that work.