V12 Quantize To Frame issue

Guy S. wrote on 11/20/2012, 11:24 AM
Quantize To Frames is checked but the video is cutting between frames. Classic case of operator error and I'm posting in case it happens to others:

- Started a new project with my normal default settings of 720-60p
- After video clips were placed on the timeline I noticed poor playback performance and decided to use the "Match Media Settings" function to check my settings
- Vegas switched the project to match my clips: 1080-60i (29.97fps)
- Afterward I noticed that many of the clips previously placed on the timeline are no longer quantized to their frame boundaries and I'm having to fix this edit-by-edit

I always (well obviously not *always*) shoot at 720p and how my camera changed to 1080i is a mystery. My best guess is loose nut behind the viewfinder.

Comments

musicvid10 wrote on 11/20/2012, 2:26 PM
One has to have QTF and Snapping enabled before placing media on the timeline in order for this to work pre-emptively. Otherwise, one must drag the clips by hand individually until they snap to frame boundaries.

It has always been this way, at least back to V2.
Guy S. wrote on 11/20/2012, 4:30 PM
I did check and noticed that QTF was indeed on - that's why I surmised that changing the project properties caused the issue.

I have since noticed what appears to be a short 2-3 frame dissolve between clips at many edit points - there is zero overlap between clips and the clips are quantized to the nearest frame. Playing with the project properties (upper field/lower field/prog scan, 23.976/29.97/59.940) affects whether this apparent dissolve happens to the clip on the left or right side of the edit point.
Chienworks wrote on 11/20/2012, 5:39 PM
Since quantize to frames is aligning things with, well, frames, changing the frame rate in project properties will mess up the alignment because what use to be frame boundaries no longer are and there are now new frame boundaries where they didn't exist before. Remember that QTF is based in project frames, not media frames.

I would have expected that 60p and 60i would line up the same as they should both resolve to 29.97002997002997..., but perhaps 60p has a bug and doesn't do the math exactly right.
Guy S. wrote on 11/20/2012, 7:49 PM
<< I would have expected that 60p and 60i would line up the same as they should both resolve to 29.97002997002997..., but perhaps 60p has a bug and doesn't do the math exactly right.>>

Thanks for the explanation. I would have thought that things would line up, too.

What's interesting is that I got the phantom dissolve even after manually readjusting the clips so that each one was quantized to the nearest frame. It was only in a couple of cases, the majority of my cuts were just fine.
farss wrote on 11/20/2012, 8:33 PM
"What's interesting is that I got the phantom dissolve even after manually readjusting the clips so that each one was quantized to the nearest frame."

That happene when the event is not an integer number of frames long, once you've got QTF on and the frame rate correct you have to trim the event to an integer number of frames to clear the issue with it.

Bob.
Tim L wrote on 11/20/2012, 9:37 PM
"I would have expected that 60p and 60i would line up the same as they should both resolve to 29.97002997002997.."

Won't the 60p project use 59.94 (double NTSC) frame boundaries? Starting with that and then cutting the frame rate in half (to 29.97) would mean that some of the original clips could be placed on half-frame boundaries (in the 29.97 project), and events could be "X and a half" frames long.
NickHope wrote on 11/20/2012, 10:54 PM
Setting this internal preference is a lifesaver for detecting and fixing unquantized clips. Hold <SHIFT> when clicking "preferences" to access internal preferences.

Guy S. wrote on 11/21/2012, 8:20 AM
<<Setting this internal preference is a lifesaver for detecting and fixing unquantized clips.>>

Great find, thanks! If you're ever in San Diego I owe you a beer.
Erni wrote on 11/22/2012, 8:02 AM
Thanks Nick!!!

Erni