Some embodiments provide a method of performing mode selection in a video compression and encoding system. The system includes a first constraining wall and a second constraining wall. The upper piece has an integral steering arm and a pad through which is machined a steering ball taper. Therefore, the total amounts of conductive pins of the electrical connector is reduced, and the complexity of mounting process is able to be simplified when the electrical connector is jointed to a circuit board. The boxes can be easily assembled from substantially flat and rectangular layouts at the point of packaging, either by hand or by using a slightly modified and currently widely used box erection machine, and as easily disassembled for transportation and cleansing at the point of unloading.