Rate control for advance video coding (AVC) standard

Abstract

Rate control plays a very important role in constant bit rate (CBR) coding. AVC standard is jointly developed by ISO and ITU-T, which contains several inter and intra prediction modes. Rate distortion optimization (RDO) based on prerequisite quantization parameters determines the optimal prediction of each macroblock. This makes the current AVC software difficult to adopt the existing rate control techniques. This paper proposes an efficient rate control algorithm at macroblock level for AVC standard by considering both rate control and optimal prediction selection. Firstly, a quantization parameter estimated from neighboring macroblock is used in selecting an initial prediction and calculating the activity. Secondly, the estimated quantization parameter is refined according to the activity and virtual buffer occupancy. At last, the prediction mode is determined with the refined quantization parameter. Experimental results show that the proposed rate control algorithm can accurately achieve the target bit rate. Furthermore, the coding efficiency is similar to or even better than that of variable bit rate (VBR) coding.