Processing while capturing

[TB Player]

All of the guides I have read about capturing VHS video with VDub indicate that one should capture the video then process (color, denoise, etc) the captured video in a separate step. But many of these guides were written several years ago, so I am wondering, now that we are in an age of dual/quad core processors and large amounts of system RAM, if some processing could be carried out at the time of capture (depending of course on how the CPU is handling it)? Is this a possibility, or are there at least some processing functions that will work well at capture time?

[Brad]

As far as I know, the filters available during capture force you to convert to RGB which is a no-no.

[TB Player]

Ah, OK, I hadn't thought of that. Thanks.

[jagabo]

Some filters work in YUV. Converting to RGB isn't a huge problem with VHS captures because the precision losses are far below the noise level -- unless your captured video has levels below Y=16 or above Y=235. And, of course, the conversion takes time, which will make it more likely you'll drop frames. You can always try filtering while capturing. You'll probably find that simple filters (like Levels, RgbAdjust) work ok on fast processors. Slow filters (like Neat Video) probably not.

[fvisagie]

Another aspect to consider is "thou shalt hold thy source sacred" . If you discover some problem with processing in a scene afterwards with this approach, you'll have to repeat everything. If you captured "raw" and processed separately, you'd only have to repeat the latter obviously. Perhaps it makes no difference in your case, but I thought I'd just mention it.

Cheers,
Francois

[TB Player]

Thanks, that makes sense.