How to Keyframe a Mask

farss wrote on 11/1/2003, 4:27 PM

I understand why what I'm trying to do doesn't work but I'm hoping someone can tell me a way to make this work the way I want. Here's what I have:

Track 1: Mask created in PS as PNG, just a thin vertical rectangle with soft edges.

Track2: Copy of track 3 with FX such a blur.
Track3: Original footage.

Track two is linked to track 1 as composite, alpha channel.

All that works as I expect, track 2 only appears where mask lets it through.

Now if I try to use track pan/crop to move the mask using keyframes the wheels fall off because the pan is applied to the OUTPUT of the composite. Looking at that another way, the original position of the mask prior to panning provides the ouput into the pan, result is that potion of track 2 moved across on top of track 3.

I'm doing this to try to mask out a film scratch. I could I worked out use panning on track 1 to make a moving mask then render that out with its alpha channel and then use that AVI as my mask track. This is pretty tedious and if I make a mistake then it's start again.

Question is, is there anyway to make the composite happen based on the panned / keyframed mask? I guess something like the video equivalent of rewire would be handy.

Comments

BillyBoy wrote on 11/1/2003, 5:17 PM

As long as what you're trying to mask is symmetrical in shape I'd skip compositing the tracks and instead try just the cookie cutter approach which I found is pretty straight forward to track with keyframing.

Oops, that may not work, Vegas don't have a rectangular pre set for the cookie cutter.

farss wrote on 11/1/2003, 5:31 PM

First pass I tried using the cookie cutter, but I found it's rather resitricted in what you can do with it. I think even you've mentioed that before.
For example you really are stuck with the defined shapes, what I want is a tall thin rectangle, couldn't see a way to make that happen with CC.

BillyBoy wrote on 11/1/2003, 5:53 PM

Yep I was thinking that after I wrote what I did, which is why I modifed it. I hope that's something that gets attention in version 5.

mfranco wrote on 11/1/2003, 10:46 PM

You could use Generated Media: Color Gradient instead of Cookie Cutter as your mask. If you use the eliptical white to black or transparent to black it works exactly like cookie cutter (better imo).

You can shape and size a rectangle or circle to match just your problem area. It's also pretty straight forward to keyframe a generated media mask. The hard part (for me anyway) is moving those tiny controls with a mouse.

It sounds though like you're trying to cover up the scratch, if you mask it either with CCutter or ColorGradient you'd make that area transparent, and that might look worse then the scratch.

Are you able to zoom into the scene to avoid the scratch? Also if it's bad enough can you edit out and replace the footage and keep the sound track. I've had to do that quite a bit when I've restored video taped shows and the footage was too damaged.

Good luck, Franco

BillyBoy wrote on 11/1/2003, 11:16 PM

"The hard part (for me anyway) is moving those tiny controls with a mouse."

I hear ya.... the work area is rather small.

Why I switched to a trackball years and years ago. One of those personal preference things, but to me I think you get far greater feedback in that in a short time your finger tips seem more attune to tiny movements in part I think because you're not fighting with a mouse chasing it around your desk. With a trackball it just sits there and only the ball moves. It takes a little getting use to, but once you are you'll never go back to a mouse. In fact I can use a trackball almost as well as a pen and tablet when using a graphics program like Photoshop. You can after awhile get that precision of movement.

farss wrote on 11/1/2003, 11:48 PM

I'd agree with both of you, trackballs are far superior. Many years ago I worked on an industrial control system that had a trackball unit beside the keyboard. Bloody trackball was about the size of baseball but was made of solid steel. Not the thing to drop on your foot!

But yeah trackballs, the good ones, are far superior to mice as your hand only has to focus on moving the ball not trying to grip the mouse as well as move it. Even so though it would be nice to be able to zoom in on the workarea in VV (the preview window that is) to get a good look at what you're doing, after all not all of us can afford a precision 21" monitor.

Getting back to what franco had to say though I started out with generated media and that has the same problem. I think when I get back to this project I'l going to have to create a moving mask AVI and then use that. As it's only a labour off love restoring my old 16mm movie form my high school days it's not urgent.

It's actually going to be a lot more work to get it looking really good, it would seem the print that I've got hold of is the answer print which means on every cut you can see the splices as well and there's one sequence with cuts every half second, yuck! Maybe I'll get lucky and someone will find a release print for me to work from.

BTW it was shot with a clockwork camera, 90 secs and the spring ran out. No zoom, just a three lens turret. Ah those were the days, still miss the smell of bromide when editing.

mfranco wrote on 11/2/2003, 12:34 AM

It sounds like a tough but fun project. For what it's worth the ARS-Technica web site has an excellent 3 part tutorial for using virtualdub and avisynth to clean up video. [VDub and AviSynth are free tools that really work well, they just have terrible interfaces.]

There's also a university published pdf on using convolution kernal with a multi-layer technique to clean up damaged film that I found through google. The link escapes me but using the above tools I've been able to clean up some really damaged footage.

OT Question: has anybody ever used a wacom or similar tablet with vegas?

Good luck on your project, I always wanted to work in 16mm.