Implementation Of MPEG-2 Transport Stream Demultiplexer

Digital television refers to the television system that uses of digital technology to encoding and compression moving images and audio signal, broadcasting them for users either via storage or real time method. It has many advantages, such as: may achieve two-way interactive business, anti-interference capability, higher utilization rate of the frequency resources, It can provide high-quality television images and more video services (such as interactive television, distance education, video conferencing, television commercial, video-on-demand, etc.). Digital television is another major technological revolution of the development of the television history.Digital TV (DTV) signals can be divided into terrestrial digital TV, satellite TV and digital cable television by means of transmission. MPEG-2 standard defines the codec technology and data flow transmission agreements. The data flow of MPEG-2 encoded audio and video, be multiplexed into Transport Stream (TS), and the transmitter conducting a number of transport stream multiplexing, then sending out the signal via satellite, cable or terrestrial transmitting station. The end user receiver picks up the DTV signal, demultiplexes it and finally the MPEG-2 decoder presents the decoded audio and viedeo stream to the user. Thus, the transport stream demultiplexing implements the the system layer decoding tasks in the digital television receiver, and plays an important role of the source decoder.This paper presents an implementation of MPEG-2 transport stream demultiplexer, including PID filtering, section filtering and PCR field extraction; The software will required to parse the PSI sections, and the CPU will config the control registers of the demultiplexer to guide the hardware operations. This cooperation scheme of hardware and software aims to achieve a balance between cost and performance. The demultiplexer has an internal data bus of 8-bit width along with a read data pointer of 8-bit width to facilitate the parsing process, and the implementation is designed to lower down the power comsumption and reduce the hardware resources.