In this paper, we propose a feasible cross-layer algorithm to improve video quality in wireless communications systems. This algorithm encompasses both the application and the physical layers. In the application layer, the classification of bits is accomplished by the video encoder. In the physical layer, the spatial multiplexing and the diversity gains provided by multiple input multiple output antenna systems with hybrid structure are exploited. Besides that, channel knowledge at the transmitter is used for antenna selection to enhance the performance, which is shown to improve the objective and subjective video quality at the end user.