Optimization Method Of H.264Intra Prediction Research

H.264/AVC is the newest video coding standard of the ITU-T VCEG and the ISO MPEG. H.264/AVC not only has a excellent compression performance, but also has a good network compatibility, which is Widely used in the digital TV, video communication and network streaming media, etc. Although H.264/AVC has used many efficient algorithms to optimize coding, the time complexity of coding is still high, which limits the practical application of H.264.Intra prediction is a core technology of H.264video compression coding standard, it is used to eliminate the space redundancy. H.264uses Rate-distortion optimized cost function to choose the best prediction mode, which cases the effect is good, but the time complexity is high. This paper proposes a fast intra prediction algorithm which is based on narrowing the prediction range, This algorithm uses macroblock type anticipation and the fast mode selection of4x4block to narrow the prediction range, which can reduce the time complexity of intra prediction. The experiment result shows that the algorithm can greatly reduce the encoding time while the PSNR is slightly degraded and the increasing of bitrate can be ignored.The Graphics Processing Unit (GPU) has strong data processing and parallel processing ability, In order to do more effectively computing on GPU, NVIDIA proposes Compute Unified Device Architecture (CUD A). This paper uses the CUD A parallel platform, which let the intra prediction process on GPU, but the rest still process on CPU. At the same time, it uses CUDA’s two levels parallel model to improve the parallel degree. The experiment result shows that the parallelization algorithm can greatly reduce the process time of intra prediction, the accelerate effect is more and more obvious with the improvement of video resolution.This paper makes a systematic analysis about the optimization methods of H.264intra prediction, and proposes a fast intra prediction algorithm and a intra prediction parallelization method. The optimization methods of H.264intra prediction can effectively improve the coding speed, which are helpful for the real-time application of H.264.