[Kdenlive-devel] XML representation for effects.

[Jason Wood]

On Saturday 13 March 2004 20:46, Dan Dennedy wrote:
> P.S. You guys should take a look at the luma transition in Kino's timfx
> plugin for a generic, extensible wipe processor. It applies a time
> varying threshold filter over the luma channel of an image (grayscale
> bitmap) to determine which parts of clip A vs B to use. You can get
> download additional luma maps from http://mlt.sf.net/ Warning: my bar,
> bardoor, and box wipe collections are 16bit PGMs, which can not be read
> by many apps (try 'display' from ImageMagick). I do not recommend the
> partial.tar.bz2 as it was created in Photoshop with dithering enabled,
> which produces dirty edges.

That sounds cool. 

I haven't looked at the code but if your description above is correct, here 
are two thoughts on how to make it a more generic effect :

The first is to make the time-varying threshold variable a simple scalar value 
that relies on something else to keyframe it. A simple linear keyframing from 
0-1 would then provide the current threshold filter effect, but  a non-linear 
keyframing would give more control over the effect.

My second thought - make the grayscale bitmap into a third video input to the 
effect (that can still be a bitmap), then we can have some funky wipes that 
move about while transitioning between the two videos :-)

Cheers,
Jason

-- 
Jason Wood
Homepage : www.uchian.pwp.blueyonder.co.uk