The Research Of Rate Control For H.264Video Coding

Along with the fast development of wireless communications and Internettechnologies, the requirement of multimedia communications continues to grow. Thevideo is the most pervasive form of the multimedia communications. However, thelimited bandwidth of wireless communication is the bottleneck of achievinghigh-quality multimedia communications in wireless communication systems, which isdifferent from traditional wired world. Because of the contradiction of limitedbandwidth in wireless channel and high data rate requirement of video streams, it’s achallenge task to support video stream as we did in wired communications. Thus, weneed the video compression coding algorithm to reduce the data rate. Especially, the ratecontrol algorithm in video encoder is a key technology, as it adapts the data rate of theoutput video streams to fit the changing wireless channel states.This paper focused on the H.264/AVC video compression encoding/decodingstandard, which has been widely used in industry. Beside a thorough study ofH.264/AVC, this paper analyzed the rate control algorithm of H.264/AVC deeply. Someflaws of current rate control algorithm are discovered in this paper, and we proposed anew rate control algorithm by rectifying those flaws. The proposed algorithm increasesthe performance of H.264/AVC when applied in wireless communication systems. Themain contributions of this paper include following three points:（1） A thorough study of H.264/AVC video compression encoding/decodingstandard is provided, including the main characteristics and working procedures ofH.264/AVC. By analyzing each constituent parts of H.264/AVC encoder, we get thecore idea of H.264/AVC video compression encoding/decoding procedures.（2） With the the above studies on H.264/AVC, we focused on the rate controlalgorithm of H.264/AVC. The2D MAD prediction model and the bit allocationalgorithm are studied in details, which are the core components of the rate controlalgorithm,Some flaws in current rate control algorithm are discovered, and we have alsofound the reason of why those flaws happen. A new rate control algorithm was proposedby rectifying those flaws, which increases the performance effectively.（3） By applying the proposed rate control algorithm in H.264/AVC videocompression encoding/decoding standard, we obtain a new video compression schemefor the wireless communication system. The standard video test sequences are appliedto test the performance of the new scheme. According to the simulation results, theproposed rate control algorithm provides better performance compared with the currentalgorithms. The simulation results confirm the effective performance improvement ofour work.