David Beaudry

In a bit of a pickle here. Basically going from new MBP to a Christie Cp2000-s. This is a projector used in movie houses/cinemas (in fact, that's where we are). Connection is mini-display - VGA - DVI (it's what works...some reason it needs an analog DVI connection?!?! But there's a slight problem...the reds are shifted down a pixel or two, greens up a pixel or two. In max, all processing in gl (generally jit.qt.movie >> jit.gl.videoplane >> jit.gl.window). Multiple layers displayed at the same time usually.

So question is: is it possible to shift in software just a single color channel? either within jitter or via some third party option? This apparently cannot be addressed on the projector side (or at least the projectionist claims it can't...but looking into that now).

Hi all,
In a bit of a pickle here. Basically going from new MBP to a Christie Cp2000-s. This is a projector used in movie houses/cinemas (in fact, that's where we are). Connection is mini-display - VGA - DVI (it's what works...some reason it needs an analog DVI connection?!?! But there's a slight problem...the reds are shifted down a pixel or two, greens up a pixel or two. In max, all processing in gl (generally jit.qt.movie >> jit.gl.videoplane >> jit.gl.window). Multiple layers displayed at the same time usually.

emergency-jit-window-color-channel-shift

OK, so following the advice from Mr. Ramirez at the end of this thread:

https://cycling74.com/forums/render-to-texture-question-yes-another-one

I now have my gl context rendered as a texture. Then I use vade's colorseparator shader to shift the reds, green, and blues independently of each other. send the result to a videoplane and voila...software-based convergence!

But I'm not 100% out of the woods. Each window is usually a couple layers (videoplanes) blended together (e.g. text & image over a moving background). Again the process has been generally multiple jit.qt.movie >> multiple jit.gl.videoplane >> jit.gl.window. For the videoplanes @automatic was set to 1, and I specified the layer # to make sure the scene was built with the right order of layers. In order for the above fix to work (render to texture), I had to set the @automatic attribute to 0, but in doing so I seem to have lost the ability to control the order of the layers, i.e. each element gets built when it receives a bang and doesn't seem to pay attention to the @layers attribute. I would love for this not to be the case (where the @layer attribute is ignored, so am hoping I'm missing an obvious flag. Since I'm using "banks" for the images, orchestrating the order of bangs for each element of each scene to build it correctly would be a huge task...so hoping there is another option.

Thanks in advance for any pointers, and please let me know if I am being unclear! I'll spend some time this afternoon getting an example patch uploaded, too.

I'm so close!
OK, so following the advice from Mr. Ramirez at the end of this thread:
https://cycling74.com/forums/render-to-texture-question-yes-another-one
I now have my gl context rendered as a texture. Then I use vade's colorseparator shader to shift the reds, green, and blues independently of each other. send the result to a videoplane and voila...software-based convergence! 

You can render multiple GL objects to a single texture by using a jit.gl.sketch object with "drawobject" messages and setting the @capture of the jit.gl.sketch object. Setting the order of draw messages has the same effect as how you are currently using @layer. Here's a really basic example of that:

You can render multiple GL objects to a single texture by using a jit.gl.sketch object with "drawobject" messages and setting the @capture of the jit.gl.sketch object. Setting the order of draw messages has the same effect as how you are currently using @layer.  Here's a really basic example of that:

So just to confirm, once @automatic is set to 0, @layer attribute is ignored...so the only way to preserve the order is to orchestrate the order of the bangs to each gl object, or the method you outlined above.

Hi Andrew,
Thanks for this.
So just to confirm, once @automatic is set to 0, @layer attribute is ignored...so the only way to preserve the order is to orchestrate the order of the bangs to each gl object, or the method you outlined above.

Just wanted to confirm I understood my options above. Also, is there an advantage/disadvantage wrt GPU overhead to orchestrate bangs to various videoplanes vs. the sketch method mentioned above? I've updated my patch so where it extracts the @layer attribute out of the message I am sending to each "video bank" to determine bang/draw order...now just trying to figure out best method here.

Hi Andrew,
Just wanted to confirm I understood my options above. Also, is there an advantage/disadvantage wrt GPU overhead to orchestrate bangs to various videoplanes vs. the sketch method mentioned above? I've updated my patch so where it extracts the @layer attribute out of the message I am sending to each "video bank" to determine bang/draw order...now just trying to figure out best method here.

EMERGENCY: jit.window color channel shift