The Design And Implementation And Of H.264 Encoder Based On Davinci Technology

H.264/AVC has become a new generation of international video compression standard for its high coding efficiency and good network compatibility, which is enacted by ITU-T and ISO/IEC Joint Working Group. It has a very broad application prospects in the area of digital media. H.264 algorithm has high encoding efficiency but also high complexity, while the DSP chip is especially suitable for dealing with complex video processing algorithms with its strong processing speed and low consumption of resources through dedicated instructions and architectural design. Davinci technology platform combines the DSP chip with C64x+ processor, providing a strong parallel processing capability. It has presently become an ideal platform in the area of video frequency application for its high computing performance and rich peripheral interface.This paper focused on the research of H.264 video encoding algorithm and the work of the realization and optimization of the algorithm on davinci platform.This paper first introduced the existing international video compression standards, and gived a detailed analysis of the H.264 coding algorithm's principle and core technologies.After that this paper introduced the concept and features of davinci technology in detail, then described architectural characteristics of the DM6446 hardware platform, one of the implementations of Davinci platform, and the development process of davinci with emphasis. In addition, this paper also discussed the memory management of Davinci technology.On the basis of analysising and referencing the three major open-source coding algorithms, this paper proposed the design principle and implementation framwork of our encoder. Motion search, as the component with highest computational complexity in H.264, has a significant impact on the performance of the entire algorithm. An adaptive fast motion estimation algorithm was presented in this paper to improve the efficiency of the search process. The fast motion estimation algorithm firstly decides in advance if the macroblock is skiped, and finds the best one through comparing various prediction center, and then chooses different search methods according to different characteristics of image motion vector. Experimental results showed that the proposed algorithm obviously reduced the number of search points, hence achieved better matching performance.Finally this paper described in detail the transplantation and optimization process of the H.264 video encoding algorithm in davinci platform.By taking full advantage of the DSP hardware capability and using various optimized methods, the performance of original encoding algorithm was improved significantly. This paper finally realized a real-time H.264 encoder in DM6446 hardware platform, which can complete one way real-time image processing with CIF format.