Srange Lines in Video

mjroddy wrote on 9/30/2003, 10:22 AM
This is probably an easy one, but I can't seem to find where I am going wrong.
I have a project that is Standard NTSC 720x480. Video was acquired from a JVC GY DV500. It's a guy ChromaKeyed over a Media Generated cloud background. All looked great on the preview window as well as my external monitor and I thought I was done with it. After rendering the bugger to Windows Media Video V9 (any preset), there is a line of about 5 pixels at the top and bottom that aren't being affected properly. The rebles! Hmm... Hard to describe, but the main place I notice this irritation is on fadeout. Got a 1 second fade by placeing a Generated Media Black Clip on the top track and fading that in. It leaves those bars (or lines) on top and bottom until the lower clip ends. Gads. Does that make sense? One might think that it was due to the Black Clip being the wrong size or aspect ratio, but the bars are throughout the entire project. It's really distracting on fadeout, though.

Any help would be most appreciated. -mjr

Comments

Finster wrote on 9/30/2003, 3:57 PM
"One might think that it was due to the Black Clip being the wrong size..."

I've had this happen too, where an upper track just doesn't quite cover a lower track. Those few lines are outside the viewing area on a TV, but would show up when I made a letterboxed version of a widescreen project.

Sometimes moving things down a track or two might remedy this, if you've got several tracks to chose from, or you could enlarge the upper track video slightly to get full coverage using track motion keyframes. In your case it sounds like you could eliminate the generated media on the upper track entirely and just fade out the lower clips -- put matching fades at the end of each so they fade out simultaneously.
mjroddy wrote on 9/30/2003, 5:03 PM
Thanks for the reply. However, I'm thinking there may be more at work. On the .WVM, I see the same 5 or so pixel line on top and bottom on the entire project. It's just not a problem while there is live video between them.
And, while I could do a fade without the black clip, I have Titles over a cloud background. So if I fade the BKG and the Titles, I find that the titles go transparent (as they fade away) reveiling the BKG as it fades away. Not desirable for what I want to see. I just like a simple fade to black.
But you suggested moving everything down a few levels may fix the problem. Um... does that mean this problem is *shutter* a bug? It certainly isn't a feature. I won't be the first to cry "BUG," bug if moving the clips in this fashion fixes things, that's a very odd problem. But maybe I'm not sure what you mean by "move it down a track or two. Unfortunately, I can't test that right now, because I'm at Work and Vegas is at Home. I'll definately try that when I get home.
Thanks again. -mjr
mjroddy wrote on 10/1/2003, 12:21 AM
Enlarging the track with the generated black seems to have solved the appearance of the problem. The problem exists, of course, but your suggestion made it not apparent.
Nobody yelled at me when I called it a potential bug (but I don't know if anyone is reading this particular thread), but what else would it be called. Every track reads 720 x 480, so one track not fully covering another is an odd thing to happen as far as I can tell.
But there's a workaround, as you pointed out. Thanks for that! I'm happier now. -mjr
Finster wrote on 10/1/2003, 8:36 AM
Like you, I didn't want to be the first to call it a "bug." I haven't done tests to verify the problem, but it sure looks like upper tracks (lower numbered) can be smaller than tracks below them. Are they always smaller? Or just sometimes? Darned if I know...

mjroddy wrote on 10/1/2003, 2:01 PM
Weird. How come we seem to be the only ones chiming on this? I would have expected either, "NO! You're doing something wrong!" (Which is what I was hoping for.) Or, "Yeah! That's a known issue. It'll be fixed in the next update. (I'd settle for that.)
Ah well. Maybe we're alone in this problem. -mjr
Ron Lucas wrote on 10/21/2003, 7:29 PM
I was having this problem too. I got rid of this problem by turning off "Maintain Aspect Ratio" on the event in the timeline. Not sure why, but now it looks fine.

Ron