Multimedia Visual Telephone System
2009
This chapter concentrates on multimedia visual telephone systems. The related standards, such as ISO MPEG-4 and ITU-T H.324, are explored briefly, and the goal of these standards is explained, respectively. The basic function of an H.324 terminal for multimedia communications is described, and related standards for a video and speech codec are covered. The differences between H.261 and H.263, which serves as the video standard for H.324, are pointed out, and the new advanced coding modes for H.263 are described. Both objective and subjective results are provided to show the excellent performance of the H.263 coding method. Finally, future developments of the multimedia visual telephone systems are also discussed.