JOINT VIDEO CODING OF MPEG-2 VIDEO PROGRAMS FOR DIGITAL BROADCASTING SERVICES

In digital broadcasting services such as digital satellite TV, cable T V, and digital terrestrial TV, several video programs are compressed b y MPEG-2 and then simultaneously transmitted over a conventional CBR ( Constant Bit Rate) broadcasting channel, In this environment, picture quality of the aggregated video programs should be kept as equal as po ssible to provide fare video services for all the viewers. In this pap er we propose a joint video coding scheme for ensuring that picture qu ality of all the programs are nearly the same. This objective is achie ved by simultaneously controlling the video encoders to generate the V ER (Variable Bit Rate) compressed video streams. This paper contribute s in two ways, First, we propose a rate-distortion estimation method f or MPEG-2 video, which enables us to predict the amount of bits and th e distortion generated from an encoded picture at a given quantization step size and vice versa. The most attractive features of the propose d estimation method are its accuracy and a computational complexity lo w enough to be applied to real-time video coding applications. Second, this paper presents an efficient and accurate joint video coding sche me using the rate-distortion estimation results. The experimental resu lts show that our coding scheme gives higher and more stable picture q uality and more efficient channel utilization than an independent codi ng scheme that encodes each program independently.