Another option, if you want to use all of the screen, is to zoom the image in, which will fill up the entire screen, but cut off the extreme sides of the image. Many times this is the option we use for video heavy content or live video applications. Typically, as long as the camera operators are aware of the 4X3 aspect ratio, they will adjust their shots accordingly to keep the subject toward the center of the shot and away from the extreme side edges.
The second option is to make the picture anamorphic, which squeezes the image to fit the screen. Sometimes this is preferred because it allows the entire image to be on the screen and take up the whole screen without letterboxing. The trade-off here is that it can make your image look squeezed and stretched. Usually these options are presented to the client one by one and we let them make the decision on site. It doesn’t take long for us to show each option using our video processor.
These concepts are also visited when putting video on a vertical LED column or horizontal LED ribbon. The main thing to remember is if the video is not specifically designed for the aspect ratio of the screen, then you will have to make concessions in losing the edges of the picture or squeezing the picture to fit, altering the image.