Media Processor-based Video Decoder Design

With the progress of society and development of industry,people have advanced more and more demand for communication. Especially during the past twenty years,the need of people on communication is converted to multimedia communication because of the fast improvement of the 1C technology and the network. There are some of implement of video communication around us,such as video phone based on PSTN,and monitor system. Video decoder is a essential component of these systems. It,besides video encoder,consist of a video codec terminal.The core of codec is video compression standard. Up to now,there are several video compression standards,such as H.261,H.263,H.263+,H.263++,MPEG1,MPEG2,MPEG4,MJPEG and standard based on Discrete Wavelet Transform (DWT). Which standard to use is decided by the image quality demand of the system and the bandwidth of corresponding channel. H.263 and MPEG-2 are two of the most wildly used standards. H.263 is mainly used in low bitrate and low demand on picture quanlity occasion while MPEG-2 is used in high bitrate and low demand on picture quantity occasion.Based upon the conditions described above,we have designed a video codec system using DSP which can encode and decode H.263 or MPEG-2 video stream. My tast is to design H.263 and MPEG-2 decoder. So the two decoder is the theme of this paper.In the first chapter the background of multimedia and my tast are introduced. In the second chapter I will concisely state the H.263 and MPEG-2 standard respectively. Then the hardware architecture of the system is introduced in Chapter3. Chapter4 and Chapters depict the implement of the H.263 decoder. In Chapter7 a co-operator,VLD,which is very useful in decoding MPEG-2 video stream is introduced. In Chapters I depict how to accomplish the MPEG-2 decoder using VLD on PSOS OS. At last,some advices are proposed to give direction to the following work.