Most devices do not output NDI feeds directly. You have to get an SDI to NDI converter, like a BirdDog in order to take the SDI multiviewer and convert it to an NDI source (https://bird-dog.tv/).
The numbers used in the sub-window are the x,y coordinates and the width and height you want to display.
The way I figured out those coordinates are by just playing with the numbers. I knew my multiviewer had 4 windows (2x2), so I divided the total width and height by 2, and added a bit of padding to take into account the bars between the windows. I then figured the top left window was near 0,0, and then added some padding for the bars on the left/top.
So if my total image size is 1080x720, then the top left quadrant is probably at 0,0 and is 540x360 in size. The top right quadrant is probably at 540,0 and is the same size. Etc.
You may have to try several combinations of coordinates and width and heights to dial in the exact position of each window in your multiviewer.
#DashBoard