Based On DM642 Video Encode Algorithm Research

Based on its high compression ratio and better image quality, the new standard of video compression, H.263 has been widely accepted and used in many applications.However, the better capabilities of H.263 are in the cost of the increment of computational complexity. As a result, common used platforms can not satisfy the requirement of the high computational complexity. DSP chips with fast speed and low resource consumption have performed excellently in many fields. With its strong parallel processing ability and signal processing capacity, the C64 series chips of TI corporation is an ideal platform to run H.263 CODEC.Based on the study of H.264 standard testing codes, TMNcodec32 and the hardware structure of the DSP chip, this paper proposed a method to migrate H.263 decoder from VC++ platform to the DM642 platform of the wintech corporation and the techniques of optimization of the migrated program. Some experimental results are presented to verify the effectiveness of the optimization.The video compression standard, H.263 is discussed in some detail and some new features in H.263, i.e. intra prediction, integer transform, entropy encode, compress arithmetic are analyzed at length. After that, we unify DM642 insert the type system the hardware characteristic, from the adjustment encoder software frame flow, the optimized use memory system, the procedure code level optimization and so on several aspects carries on the discussion, optimized and realizes based on the DM642 H.263 software real-time encoder, the oneself initially can achieve the QCIF video frequency the real-time code. In this process, summarized some methods and the skill which developed based on DM642 video frequency compression code software, might for from now on platform software development provide the model based on TI the DM642.Program optimization is the key point in the realization of H.263 CODED. How to accelerate the decoding speed by making maximum use of advantages of C64 processor is the most important issue in this paper. H.263 testing codes pay too much attention to readability, ignoring the realtime requirement as a video CODEC. As a result, time-wasted in some modules are quite a little. To speed up decoding time,some measures of embedded system programming and optimization are used in thispaper. A series of optimization skills such as the adjustment of the structure of codes, the modification of memory assignment, inline assembly and application ofpipeline are adopted in the optimization procedures.Compared the result by the first migrated version of program with the results by the optimized one, the clock cycles of bottleneck functions have significantly decreased. We can get higher quality of picture and faster speed of encode, and we are satisfied with it.