Simple Q: quantize frames

Serena wrote on 5/23/2005, 5:57 AM
What indicates that "quantize frames" is set? Alt+F8 sets it (and presumably toggles it to "off"). Although on the timeline all my cuts in the current project check out as whole frames, in rendering I'm getting some cuts that are a combination of adjacent fields. Obviously this produces very noticable cuts. My thought is that I haven't got "quantize frames switched on, but I can find nothing that indicates that it is or is not.

It might be important that I'm working with the Cineform intermediate (HDV) and rendering out to widescreen DV (PAL) for transfer to DVD. To prevent nasty raster edges on sloping/moving objects I select "upper field first". This has worked well with Vegas 5, and with Vegas 6 except now I'm getting the occasional mixed field cut.

Advice most welcome!

Comments

farss wrote on 5/23/2005, 6:03 AM
Look under Options, it'll tell you if QTF is on or off, unless you're editing audio you really need to have it ON.

You shouldn't be swapping field order just because of jaggy edges. If the field order is wrong you'll get jerky motion.

Bob.
Spot|DSE wrote on 5/23/2005, 6:03 AM
Put Quantize to Frames on your toolbar, you'll always be able to see if the button is up or down.
Serena wrote on 5/23/2005, 6:14 AM
Thanks Spot -- excellent -- done that.

Farss -- agree -- always intended that quantize be on, but this looked like an obvious possibility. Rendering out with Upper field first produces a fine image in all respects (other than the loss in downconverting to DV). And it's a quick way to get it into a projectable format for evaluation; don't want to use the camera as a player.

Thanks to you both for your quick advice.

Serena
Serena wrote on 5/23/2005, 8:57 PM
Bob,
Well I had managed to turn off "quantize frames" during the project, so I've had to check every cut. Of course this meant also checking the sound FX and so on. I've tried some loop renders to check that the cuts are now clean (they are) and also the business of UFF and LFF in rendering out to PAL DV Widescreen. My earlier tests had shown that UFF was needed when working from HDV (and I think some discussion occured on this site), but your comment re LFF got me reconsidering.
My previous conclusion was arrived at through burning a DVD and viewing the results of UFF and LFF on the big screen. I was quite confident about my conclusion, but I'm giving LFF another try.

Serena
Serena wrote on 5/27/2005, 5:11 AM
Possibly worth giving my results for UFF and LFF in rendering from HDV to SD. When I first got the HDV camera I found that UFF was far superior to LFF when rendering from Vegas using the CF Intermediates, but Bob suggested I could be in error.
Using my current project on sail racing (so a fair amount of quick moving stuff) I did trials rendering to both .avi and to mpeg-2, each set using the default LFF with a repeat with UFF selected instead of the default. I reviewed the .avi files on the desktop 17" screen and burnt the mpeg to DVD for projection as well as review on the computer.
I've reviewed each of these four several times and finally by concentrating on particular sequences. I can't see any differences between UFF and LFF, even on paused frames.
This is a bit of surprise to me and my initial response was to repeat a render to make sure I had indeed changed the default LFF to UFF.
Perhaps someone is going to tell me that the CF Intermediates are progressive so it doesn't matter? I would have expected the difference made by the wrong choice compared to the correct one to be profoundly noticable.
Any comments?
farss wrote on 5/27/2005, 5:55 AM
Serena,
HDV is UFF so when you're viewing it in Vegas your project should be set to UFF otherwise it's going to look pretty jerky. Vegas though isn't dumb, it'll read what the source media is and it'll convert it to the correct thing if you have your render settings correct and if you use a standard template you shouldn't have a problem. That's why it didn't make any difference what you set the project to.
From my intial work going from HDV to SD DVD it does look pretty bl**dy good, for one project we've had a mixture of digibetacam and HDV, pretty hard to tell the difference really, the DB footage was downconverted to DV25 in a J30 so that didn't give it a fair shake, gotta get a SDI card, sigh. What you can start to see though is the difference the optics make, this is to be expected, for the price of the lens on the DB camera you'd buy quite a few Z1s.
One tip if you didn't already know, use Best as to get the best possible result when downconverting.

Bob.
Serena wrote on 5/27/2005, 6:27 AM
Bob, maybe you've hit the nail -- perhaps originally I didn't set UFF for HDV in Vegas and my memory has become confused about the actual events. I always think my memory retains all important details such as this, despite years of contrary experience.

Serena