Researches On MPEG-4 Video Encoding And Optimization Based On DSP

With the widely usage of digital video encoding technology in more and more applications such as in the video surveillance systems and long-distance education systems, the practicability of the video encoding standards is impending. People want to use the least bits expressing video images with certain quality to reduce the needs of transmission bands. There are kinds of methods to achieve it such as the one based on DSP. It is so flexible, extendable, upgradeable and maintainable that can meet the needs of processing particular video formats.This dissertation studies deeply the conventional method to video compression and the present video coding standards, emphatically the MPEG-4 video coding standard, and makes a deep research on the performances of DM642, a digital medial processor by TI incorporated. Based on these studies the dissertation presents the implementation and the optimization of the video encoder of MPEG-4 SP by adopting DM642. Also a universal optimization technique is provided including algorithm optimization, memory distribution, EDMA and TI's function libraries usage and so on. The technique can be applied to a video encoder of MPEG-2, H.263 or MPEG-4. With these methods an MPEG-4 encoder based on DM642 which encodes mother images of CIF can carry out real-time encoding with 40 frames per second with the average PSNR value of above 30dB. Both real-time encoding and high image quality are achieved with this technique, so this technique has the applied value in engineering projects.