Research And Vlsi Implementation Of Entropy Coding Algorithm Based On H.264/AVC

H.264/AVC is the newest video coding standard constituted by both ISO/IEC and ITU-T. Comparing to the proposed video standard before, H.264/AVC employs many innovative technologies, such as multiple reference frames, variable block size motion estimation, in-loop deblocking filter and context-based adaptive binary arithmetic coding (CABAC). H.264/AVC can save up to 50% bit rate compared to MPEG-4 under the same video quality. CABAC is considered a significant revolution among these new methods because it is more efficient than traditional entropy coding methods.CABAC combines adaptive techniques, context models and binary arithmetic coding, comparing to CAVLC it can enhance up to 9%~14% data compression efficiency, but the algorithm became more complexity. CABAC adopts look-up table for multiplication and probability estimation, these techniques make it easier for the realization of CABAC encoder and also could enhance the coding rate. However the algorithm is also very complexity, so it is difficult to implement the CABAC encoder for high profile video stream.Firstly, the dissertation summarizes the research process in home and abroad, after analyzing the CABAC encoding algorithm and aiming to the main character of CABAC encoder, we designed the binarization module, context model selected module, probability model initialization and storage module, and arithmetic coding module separately. Each module was modeling and simulation by Verilog HDL, after that build the whole CABAC encoder and finish simulation by testing data picking up from JM86. An ASIC implementation of the CABAC encoder is carried out by SMIC 0.18 um standard cell library of silicon technology. After CABAC encoder got synthesized, we get the netlist, and working frequency is 200MHz. In the end propose an optimized program for the bit stream output and analyze the performance the encoder, this encoder could fits 720P(@30Hz) real-time encoding.