Non-buffered rate control for real time video compression

Rate Control (RC) is one of the crucial techniques for video compression and transmission because it controls compression bitrates in order to obtain optimum encoding quality within the available budget of transmission bitrates. In this paper, we conduct a research on developing a new unbuffered real-time rate control for video compression. With the objective to improve the overall rate control performance, we have proposed an effective low-delay rate control algorithm which has two unique features. First, unlike traditional algorithms which adopt buffers in rate control, our algorithm doesn´t use a buffer in rate regulation which can reduce the encoding delay and improve real-time response. Second, a new PID bit controller is proposed to directly control encoding bitrates. In addition, we also developed a simple but effective method for real-time target bit allocation. Numerous experimental results have demonstrated that, when compared with the rate control algorithm adopted in MPEG-4 standard, our proposed algorithm achieves more accurate rate regulation and improves average coding quality.