A stable buffer control strategy for MPEG coding

This paper presents a new buffer control strategy that regulates the coded bit stream generated by MPEG video codec so that it can be transmitted robustly. This buffer control strategy is regarded as regulating the compressed bit stream to transmit with (pseudo) constant bit rate (CBR) through a fixed rate channel. It dynamically adjusts the quantizer scale for each frame under the consideration of the steady level of coding quality, the allocated bandwidth of transmission, the level of buffer occupancy, as well as the scene change. In the simulations, this strategy is implemented on MPEG coding algorithm and produces constant rate bit stream no matter what bandwidth is allocated or when the scene change occurs. Besides, the objective quality [in peak signal-to-noise ratio (PSNR)] of the proposed strategy is 1.5 dB more than that of TM5 and is almost the same as the results coded without buffer control. In addition, it always holds the smooth property.