Optimization Design Of H.264 Encoder Based On PC

With the coming of IT era, people put forward higher demand on the multimedia service under present condition of communication network. For example, the,higher qulity video phone and video conference; video store and display with higher resolution; video communication in wireless network; etc. But a key technology in all these application is video encode and decode.Multimedia video coding techonogy and corresponding coding standard are developing rapidly these years. The H.264 is outstanding of them. As the latest standard in video codec field, H.264 has such advantage as high compression rate, strong erroe resilience capacity, highly adaptability and so on. In order to gain good coding result, H.264 adopts so many new algorithms that the amount of calculation increase drastically. As a result, its applications in PC environment are restricted. In order to realize H.264 real-time codec, many optimization works have to be done. But these optimization gains should not at the cost of obviously coding performence drop.Basded on the reference software--JM61e of H.264 and through a detailed analysis and capability test of the encoder, we find out the major parts that lead to the high computation. After optimized by corresponding method described in this thesis, the efficiency of the encoder is remarkably improved with little performance loss.The main contents of the thesis are as follow:1. A brief introduction to the technical highlight of the H.264 standard and its development actuality, especially focus on the main technology in video coding layer which the high compression rate of H.264 is achieved based on.2. Sammarized the network adaption of H.264 and its error resilience technology which have greatly improved compared to other compression standard such as H.263.3. Detailedly analyzed the performance and computational complexity of H.264 encoder. Point out the major parts that lead to the high computation. We anvanced a fast block match algorithm based on Rate-Distortion Optimization and a fast intra prediction mode selection strategy based on edge detection. After programming, the result shows greatly improvement of coding efficiency compare to the original algorithm.4. Find the part that fit to optimization by MMX instruction set and realization them (including the SAD calculation and 1/2 pixel interpolation).