Changing Brighness of each Pixel in DVI Input stream?

[TobiTobsen]

Hey at all,
I have a question and I hope you might be able to help me.
Depending on different Input data which I receive from another sytem, I have to change the brightness of an Video Stream which I could receive, for example via DVI input grabber card.
The brightness must be adjustable for nearly each pixel.
I was thinking about using an Alpha mask.

But I never did something like this with vvvv and I am not sure if this could work. What do you think, would that work???

Thanks!

Tobi

[karistouf]

to have an immediate result, there is the pipet way, wich is consumming ressources as CPU and not GPU based. it depends of your input resolution: quads are created and you use pipet to set alpha. each quad becoming a pixel.

a shader approach may be possible with Tex.x coordonates:

http://www.facewound.com/tutorials/shader1/

@facewound site

Texture Coordinate
Tex in our example is a float2. This means it has 2 floats in it. One is x and one is y. x is the across and y is down. They range from 0 to 1. This means that:-
Tex.x = 0 means the far left of the screen (or texture)
Tex.x = 1 means the far right of the screen (or texture)
Tex.x = 0.5 means the exact center of the screen (or texture)
Tex.y = 0 means the very top of the screen (or texture)
Tex.y = 1 means the very bottom of the screen (or texture)
Tex.y = 0.5 means the exact center of the screen (or texture)

[kalle]

simply add/subtract/multiply with another texture in a simple shader.

see quick approach attached

Adjust.zip (3.6 kB)