Research Of H.264 Video Encoder Based On TMS320DM6446

The flourish of information society promotes the rapidly progress of multimedia technology. As the latest video compression algorithm, H.264 adopted many new features to increase the coding efficiency by 50% without the loss of video quality, but it also brings computing complexity which increases of more than one order of magnitude at the encoder. To achieve the goal of real-time coding, we can reduce the encoder's complexity of H.264 to get the corresponding efficiency.The paper firstly did some researches on the complexity of basic modules. In this progress both computational complexity and coding efficiency should be thought and made to the optimal trade-off in the implementation, and then got the appropriate parameters of actual coding system. Secondly, to reduce the complexity of motion estimation, a study of fast motion estimation algorithm had carried on and an improvement algorithm had proposed which could efficiently decrease the number of search points and get the optimal results. Thirdly, this paper presented an innovative algorithm for detecting all-zero Discrete Cosine Transform (DCT) coefficient blocks prior to DCT and quantization for video coding standard of H.264/AVC. A mathematic model for predetermination was established based on the characteristics of float/integer DCT formula and quantization, the distribution of the residual pixel values, analysis of the false-judgment and miss-judgment of present algorithms. As mentioned, the coding efficiency had improved greatly.After the deep analysis on H.264 encoder, this paper combined the hardware resources in TMS320DM6446 which designed for video processing to perfect the system. In respect of video capturing and preprocessing, we utilized VPSS(Video Processing Subsystem) on Davinci platform and used Codec Engine mechanism to implement H.264 algorithm on DSP-side in respect of encoding. As for video streaming, ARM used UDP protocol to communication with PC client. The Davinci architecture greatly improved the efficiency of time consuming and the D1 format video encoding and transmission speed could realize real-time processing.