H.264 Video Coding Algorithm Rearch And DSP Implementation

H.264 video coding standard is jointly developed by Video Coding Experts Group and Moving Picture Experts Group. Under the same reconstruction video quality, H.264 has 50% and 20% bit-stream, compared with H.263 and MPEG-4 respectively. H.264 improves the ability to support the network application and the video stream application. But the superior performace of H.264 is achieved at the expense of high complexity,and this is the obstacle for embedded applications with H.264. Therefor, the reserch on the implement and optimization of H.264 based on the related video chip is signification application of video technology on embeded system.The main task of this thesis is to study H.264 key technology of video coding and its implement on TMS320DM642. First, encoding principle of H.264 is analysed in detail, and describes some technology introduced by H.264. Such as intra prediction, inter prediction, transform encoding, loop-filter, entropy encoding. Second, using the open code X264 as a reference model, the thesis studied H.264 encoding flow, including encoding main flow, frame encoding flow and macroblock encoding flow, and the influence of different parameters on the coding efficiency. On this basis, prediction module with high computational complexity is perfered to be optimized: an algorithm of fast INTRA mode decision and an algorithm of fast INTER mode decision are proposed, and their availability is demonstrated by means of table. Further more, making full use of the resources of th DM642, H.264 coder was transplantated and optimized on DM642 after three development stages including code modification, performance optimization and linear assembly.The experiments show that under the condition that SNR and bit-stream are in little change, the effect of optimization based on DM642 is quite obvious: coding time is reduced and the required storage capacity is also significantly reduced.