alpha mix

pelang's icon

hi,

i try to mix up to 8 videos which have additional alpha channel (videocollage).

- is there a "faster" codec which supports additional alpha cannel than "animation" for jitter ?

- can i use openGL for mixing (jit.gl.slab) ?

- is it possible to mix more than 2 streams with jit.alphablend at the same time ? if not is there another way ?

many thanks in advance

Pe

Wesley Smith's icon

Slabs are definitely a good way to go for this. With slabs and
jit.gl.videoplane, the alpha channel doesn't have to be contained in
the same texture as the video RGB data. Here's a simple
multitexturing videoplane example, but you could easily do more
flexible stuff with a custom shader:

Max Patch
Copy patch and select New From Clipboard in Max.

pelang's icon

hi wesley,

thank you a lot to point me in the right direction...

it works fine with the "apply decal" funtkion for jit.gl.texture

any codecs recommends that hold a alphacannel ?

Max Patch
Copy patch and select New From Clipboard in Max.

Rob Ramirez's icon

animation

joshua goldberg's icon

and multiple-frame png and gif.

On Aug 14, 2008, at 10:58 PM, Robert Ramirez wrote:

>
> animation

ricopoorchico's icon

Hello,

I'm also doing a video collage project, however I would like to mix 1280 x 720 video with alpha channels (animation codec), AND have the ability to sample either video AND adjust the layer order.

Max Patch
Copy patch and select New From Clipboard in Max.

In the patch pasted below, I used the jit.gl.texture tricks that were mentioned above, but I'm getting white pixels around the edges of the video layers. Any ideas on what I could do to get rid of these?

Also, since I am using video which already has an alpha channel, am I barred from using the uyvy colormode/shader?
i.e. [jit.gl.slab blah @file cc.uyvy2rgba.jxs @dimscale 2 1]

Is there anything else I should try for optimization?