1. when we assigne a coherent matrix size from the source to jit.qt.movie to jit.window like you are mentioning (e.g. 1280 720), but the projector has another resolution we are either loosing DAR (in the case the projectors resolution is bigger or LOOSING SAR, in the case the projectors resolution is smaller. So how to deal with that in order to not distore (scrunch or stretch, pixelize) involontary the video with fullscreen 1?
2. Is there a possibility to assigne scale processing to the a) projector b) external graphiccard like matrox dualhead2go?
1. You will probably want to constrain your video in some way before sending it to a jit.window. One way is to position your incoming video matrix into a larger matrix which has the dimensions of your display. Check out Jitter Tutorial 14 for an overview of matrix positioning. However, this option is not very efficient.
The more efficient method is to use a jit.gl.videoplane and scaling, which we will likely cover in another tutorial. In the meantime, check out the example jit.gl.videoplane-ortho.maxpat in Max5/exaples/jitter-examples/render/ . This covers the basics of this technique pretty well.
2. The Matrox uses whatever pre-existing graphics card you have, so it doesn't really handle any of the processor load.