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View Full Version : Possible to circular clip for overlay?


WorBry
17th June 2005, 10:38
When editing my Pal Mini-DV home videos with Ulead VideoStudio 8 I like to include a few clip overlays ("picture-In-Picture") for variety. Whilst the "overlay" function allows the size, position and transparency of the overlayed clip to be adjusted and includes some nice effects (fade-in/out etc), there is no "in-program" facility to crop or mask the clip to produce a circular/eliptical overlay, which would be great for cameo's and the like.

So, you've probably guessed that I'm wondering whether it is possible to create a non-rectangular cropped, or masked, DV clip using AVISynth and VDub? Search results on this forum turned up a few threads that suggest the Layer plug-in, with its masking functions, might be the tool for the job, but I just cannot figure out how to apply it?

If this is possible I'd be really grateful if someone could explain the steps, if possible with a typical AVS script that I could use as a template.

Another approach that I thought might work is to use the Vignette filter effect in Ulead Video Studio. At the sharpest setting, this will at least create a hard-edged circular central image with a user-defined, uniform color surround. I thought I could then take the unedited clip and, using the Fill filter in VDub, create a base (background) clip with a uniform fill of the same color as that of the Vignette surround. By layering the "Vignette" clip over the "Base" clip I thought I might be able to create a circular image with a transparent surround, but again I cannot get my head around the AVS Layer "mask" and "chromakey" functions to acheive the desired result.

Again. any help would be appreciated.

Maybe I'm overcomplicating things, but right now, I just cant "see the wood for the trees" ("masking" pun intentional) :D

Thanks alot.

PS - I know VideoStudio 9 has a new ChromaKey feature, but I'm reluctant to pod out the cash for an upgrade at this point when I only upgraded to VS8 a few months ago.

Didée
17th June 2005, 10:54
To create circular masks, E-Male's GraMaMa (http://forum.doom9.org/showthread.php?p=598958&highlight=%28circular+circle%29+mask#post598958) should do the trick. Once having the basic mask, you can go on with Overlay() or MaskTool's functions.

stickboy
17th June 2005, 11:11
I have an example that shows how to use a grayscale image as an overlay mask:
logo-example.zip (http://www.avisynth.org/stickboy/etc/logo-example.zip)