The first technical step of this project is to control an output signal from a video input. In order to built this patch, I have combined these three tutorials:
The first part of the patch is the camera connection. By using a "getvdevlist" and "getinputlist" objects, I can easily select the proper video feed. You can easily build this patch and understand it better with this tutorial.
Now that I have an input, I needed to generate informations out of it in order to trigger the signal at the end of the patch.