Cookie Cutter / Keyframing Problem

RNLVideo wrote on 3/4/2005, 9:00 AM
I'm editing a piece where a vehicle is going through an intersection and I need it to appear as if it's running a red light. I have a transition from the "red light shot" to a panning shot of the vehicle going through - but there is a yellow light visible on the corner of the intersection.

Simple enough (I thought). I applied a cookie cutter (circle) to the track, keyframed out the yellow light and put a duplicate track beneath. With pan / zoom, I moved the bottom track so it looks like an unlit stop light bulb. Looks great on the timeline.

When I render (tried .avi and .wmv), I'm able to see the yellow light again. The when I pause the video, my mask is there, but if's offset slightly. Checked the timeline again - looks great.

I'm thining that this is an interlace issue of some sort where one field is getting the mask right and the other isn't. I think I can fix it by enlarging my mask (to a point), but I'm perplexed as to why it shows up great on the timeline but not in the rendered video. Any ideas?



Spot|DSE wrote on 3/4/2005, 9:37 AM
Any chance you're dropping frames while in preview mode, and therefore missing it? Does it show up if you pre-render it?
You also might try using a Bezier mask rather than the Cookie Cutter, if you want to have a cleaner, more specific masked area.
Orcatek wrote on 3/4/2005, 9:50 AM
I had a similar problem and tech support said it was because the output was a than the project. Ie the project was DV at 720 wide while the output was wmv at 640 wide.

I really didn't like that, but I eventually just worked around it.

RNLVideo wrote on 3/4/2005, 2:33 PM
Spot - I'm sure it's not dropping frames; I also went through the entire section one frame at a time on the timeline and it looks perfect.

It's not an issue with project size either - I rendered out to a 720X480 AVI file and the problem persists.

I'll have to give it a shot with the Bezier mask and see if it still occurs. The interlacing issue (or more specifically the possibility that the mask isn't getting applied correctly on either the upper or lower) still seems like a possibility to me though. The shot is a real quick pan; the yellow light goes across the screen in 28 frames. I'm sure I can work around it but I'd still be interested to know what the problem is.