Real-Time Implementation of MPEG-4 Video Encoder on Digital Signal Processors

• Main Authors: Pei-Yun Kuo, 郭沛昀
• Other Authors: David W. Lin
• Format: Others
• Language: en_US
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/93486115281761758283

碩士 === 國立交通大學 === 電子工程系 === 91 === The MPEG-4 standard defined by ISO/IEC MPEG is a very efficient coding standard for multimedia data. In this thesis, we use digital signal processors to implement MPEG-4 video encoding and to achieve the goal of real-time coding. The digital signal processing environment is Innovative Integration’s Quatro62 personal computer card, which houses Texas Instruments’ TMS320C6201 which is a powerful signal processor with strong arithmetic operation capability. In the thesis, we use the public-domain codec MoMusys to establish an MPEG-4 coding and decoding system and modify the architecture to speed up the processing for digital signal processor. First, we do some adjustment to fit the program memory. We remove the rate control, use macros to replace simple functions, change the method of setting control parameters, side-step layers and objects and do others simple modifications for code size reduction. In the MoMuSys, we reduce 77% program memory size and separate the system into two parts, texture coding and main part with motion estimation. In our work, we try to make use of the parallel functional units of the digital signal processor and increase the parallel instructions as much as we can. To speed up the execution, we primarily accelerate DCT/IDCT and motion estimation. For DCT/IDCT, we replace float-point computations by fixed-point computations. For motion estimation, we not only modify the algorithm but also tune the program for the processor to accelerate the computation with parallelized code. This only results in a little performance loss. Employing two digital signal processors working in parallel, we are also to attain an encoding speed of six frames per second. In the thesis, we introduce the MPEG-4 and the environment of DSP (digital signal processor) implementation first. Then we discuss the optimization of the MPEG-4 simple profile video encoder for DSP, and we describe the overall design of the MPEG-4 encoder system, which uses two DSPs working together with the host PC. Finally, we present experimental results on the speed and the rate-distortion performance of the implementation and compare them with results of the original program.