Rate control techniques for video transmission

The primary goal of rate control is to regulate coded video quality. The design of a rate control system requires careful attention to the following issues: target rate calculation, source and channel modeling, video coding, rate-distortion estimation, bit allocation, frame skipping, real-time implementation, transmission environment and performance evaluation. New and emerging applications, such as Internet video streaming, wireless channel transmission, MPEG-4 VO (Video Object) coding and SNR FGS (Fine-Granular Scalability) coding, require robust and efficient rate control techniques. More recently rate control techniques and methods in those areas have been receiving increasing attention. This paper presents the general framework and fundamental demands for a rate control system, introduces various existing algorithms for CBR (Constant Bit Rate) and VBR (Variable Bit Rate) video, summarizes and compares some of well-known methods. The paper also introduces current research activities and proposes several research topics at the forefront of this challenging field.