Advantage to capture in higher resolution?

[abyss616]

I use a Hauppauge HD-PVR to capture video, edit and process in avisynth/virtualdub and convert to DVD. If the resulting product is in 480p, is there an advantage to capture in 720p and resize to 720x480 in avisynth or should I just capture in 480p and not resize?

[Ghitulescu]

It depends on the capture window of the device itself. If it cannot be set up to SD (I mean using native SD resolution) you'd be better off using the software scaling algorithms (avisynth & co) than with the scaling in the driver/firmware. You have to dig yourself for this info. The safest solution (in case you can't find that info) would be to capture HD at the native resolution.

[pandy]

it is always better to capture in higher resolution - oversampling can improve quality of capture - it is only limited by processing power.

[abyss616]

Thanks for the advice, guys.

[henryho_hk]

Is your source interlaced or progressive?

[abyss616]

Progressive - 720p

[jmac698]

There's a variety of answers to this, I could go on about a theoretical answer but I think you can just try it both ways and judge for yourself.
My theoretical guess, for the record, is that hardware scalers are limited in the number of "taps" they can do in realtime, but beyond a certain value, you can probably hardly notice.

[Ghitulescu]

What is the source of this 720p? maybe there's a way of getting it somehow digitally copied or streamed ...

[jmac698]

It's probably a set top box or also very popular is a video game. No idea about the video game, but not likely possible if it's a ps3. STB is a definite maybe, but either reading the harddrive directly, or using the firewire output, or maybe capture again with a computer digital tuner in clear-QAM or ATSC... (if it ever comes on again)..
You can also buy HDMI capture cards...

[Ghitulescu]

It's probably a set top box or also very popular is a video game.It's highly possible.
You can also buy HDMI capture cards...This won't work as no HDMI card ever would capture HDCP signals.

[henryho_hk]

I presume that you mean 720p@59.94(fps). Then u are converting it to DVD as 480i@59.94fps or 480p@29.97fps (progressive source being encoded as interlaced) in the MPEG2 YV12 colorspace.

[abyss616]

Not sure how we got off on this discussion, but thanks to everyone who's checked in. I've been capturing in 720p and using Lanczos4Resize(720,480) to get it to a DVD-compliant size. The original question was if it was better to start big and let Lanczos resize it for me or to capture in 480 since that was the final size anyway.

[Ghitulescu]

Since you're in the possession of high quality software resizers (no matter which one do you employ, they are better than the generic one in the driver), it's always better to capture at the native resolution of the capturing device. How to find it, it's in the sticky. After capturing, you can resize it at your will.

It it's 1080i, use 1080i, it it's 720p, use 720p. Then resize to 480i. If you capture at 480i you let the scaler within the driver to do this operation for you, sometimes with visible quality losses.