The Optimization Of AVS Video Encoder Performance And The Implementation On DSP

With the advent of the information age, multi-media technology has infiltrated every corner of life. Video and image are important components of the multimedia information, however, the digitized video signals in the large volume of data is very alarming, which led, the huge volume of video and image data acquisition, storage,and transmission become the biggest bottleneck in the development of multimedia applications. Therefore, the video data compression efficiency is the key technologies to reduce the network bandwidth,and save storage capacity. But video compression algorithm has great complexity of computing,and real-time processing demands on general processors have become very strict, so the various dedicated high-speed digital signal processor (DSP) was widely used.As a common basis of the digital audio and video industry standard,AVS standard is widely used in high-definition and standard-definition digital television,laser disc,multimedia communications of mobile,video conferencing and surveillance,broadband network streaming media, and digital film industries. Compared with other similar standard,AVS has two main advantages: Based on the partial opening and autonomous technology,it has constructed an open standard, which properly resolves the licensing issues;China's increasingly powerful industrial strength and the market provides a good soil. With these two wings, AVS is most likely to become the standard for the second-generation audio-video coding standard in the world. Currently AVS standard group has provided the reference software for enterprise,but the time efficiency of encoder is low and when the RDO function is closed,the image quality is relatively poor. Therefore,further improvement of AVS encoder's time efficiency and image quality is very necessary. Now many enterprises of China hope that the AVS standard applied to the actual products (such as digital television or monitor areas),which would further request that the image quality of AVS encoder is competitive, and real-time encoding can be achieved. Under such circumstances,the performance optimization for AVS encoder and improvement of the time efficiency is of great significance. TI's DM642 development board is specifically for multimedia applications,and its optimizer allows developers to compile code in the form of linear assembler,so as to shorten the development cycle. At the same time its software pipelining operations will greatly enhance the efficiency of the implementation process. It provides a lot of data packing instructions,in order to process more data with one memory visit.The research in TI's DM642 platform to achieve AVS encoder,including the improvement of AVS encoder's performance;With the structural characteristics of DSP and memory limit,to generate a reasonable C code;The transplantation of C code from PC platform to DSP platform; the Optimization of the code on DSP platform. Finally we can produce a AVS encoder which can generate the bit stream decoded by the decoder of AVS reference software successfully, and can achieve the real-time encoding with video of CIF format.