Can I use captured SD as HD proxy?

nolonemo wrote on 1/5/2008, 11:10 AM

I've been editing SD video for some time in Vegas (currently Pro 8) on my old IBM laptop, which has just enough power to handle the task. I'm about to get a Canon HV20, and the laptop clearly won't be up to HD.

The HV20 allows you to capture the video from it as either SD or HD. I wonder if I can capture the video from the camera as both SD and HD (i.e., two capture passes), then edit the SD and save the Vegas .veg, then close Vegas, delete the SD media, open the Vegas and the project, whereupon it should tell me it can't find the media and prompt me for the media location, so I could point it to the HD media, to which Vegas would then apply the edits in the .veg, and which I could then render out.

Would this work?

(I know I could use the VASST Gearshift script to render an SD proxy to work on from the captured HD, but I'm guessing that the rendering would take a lot longer than simply capturing the SD in addition to the HD, plus it would cost me 50 bucks.)

Thanks

Comments

Cheno wrote on 1/5/2008, 11:33 AM

Problem you'll have is that capture between SD / HDV is not frame accurate in terms of being identical frames between the two formats. You could do what you're proposing, however you'll end up in each clip most likely when you go to HDV and tweaking.

If you're not wanting to go the Gearshift route (which is pretty painless), I'd capture as HDV, set all your clips up on the timeline and mark them with regions, run the render regions script and downconvert to SD, edit that and then come back to your HD afterwards.

So yes, rendering using a script (or Gearshift) takes longer but it's less headache in the long run because the clips in either format are identical.

cheno

riredale wrote on 1/5/2008, 12:18 PM

Going your route, you need to do two realtime captures, one for m2t and one for avi. Going the GearShift route, you do just the m2t capture, but the laptop will have to build an avi clip for every m2t clip. You'll have quite a bit of rendering time (maybe 1/3 x realtime) but it can be done unattended, and then you can use GearShift to effortlessly jump back and forth. And given what your time is worth, $50 is probably a bargain.

kairosmatt wrote on 1/5/2008, 7:00 PM

I have a related question using 1080 60i footage with advanced pulldown to get 24p.

If I put all the media on one hard drive without pulldown (to get 60i) and then put the same media on another hard drive using pulldown (to get 24p) could I use nolonemo's method to go create two final cuts?-one that is 60i and one that is 24p? I would unplug one hard drive, and when Vegas asks to look for the missing media, point it towards the other one (and then change project settings to the right frame rate).

Would this work, or would it have the same problems with frames not lining up?

kairosmatt

farss wrote on 1/5/2008, 7:52 PM

First problem to be aware of is that as far as I know Vegas doesn't do batch capture of HDV. Even more problematic, when you capture the DV proxies you have to use Vidcap which keeps a logfile so you can recapture. When you go to capture the HDV you have to use Vegas's internal capture which will not read Vidcaps logfile as far as I know. As also stated above, HDV capture isn't frame accurate. These are the reasons Gearshift was developed.
As I've said elsewhere you can pretty much do all this manually. Capture HDV and render to your own proxies of whatever flavour you prefer.

You could I think swap between 24p and 24p60 but why bother. Remove pulldown, do your thing on a 24p T/L. Render once to add pulldown to 60i and once to 24p. I'm no expert on the whole 24p/60i thing but I believe that'd work just fine, assuming it's 24pA in the first place.
One thing to keep in mind too, editing 24p on a 24p timeline is different to editing 24p on a 60i timeline. In the former FXs are rendered as 24p, in the latter case they're rendered as 60i. I've come across this once with 25p/50i and trying to get it all back to 25p for the web was a bit messy.
Bob.

kairosmatt wrote on 1/6/2008, 5:57 AM

Thanks Bob, that makes sense and it does save a ton of hard drive space!

One general question: does adding pulldown to 24p to get to 60i have any quality issues-or is it pretty straight forward?

Thanks

kairosmatt