With Low-pass Filtering Of Video Bit Rate Conversion

At present, digital TV is paid more and more attention in the world because of the high level video, Hi-Si audio and plenty of programs. And the market value of digital TV is multiplied. Because of the different context of program and channel, most of the bit-stream rates of programs video are different. When one TV station relays other's program, or when we convert program from HFC to VOD, TCP/IP system, it is need to convert the bit-stream rate which could not meet the need of local channel. The traditional method was stated firstly and it's shortcoming was pointed out. At the same time, popular new methods and their latest situation were described. We put forward a new method of bit-stream rate of video - Low Pass Filter and rate control algorithm. This method is easy to be realized and to meet the need of real time comparing with those popular ones, so it has more practical value. This paper discussed the method in detail. It's technical principle was stated first. And a new MPEG-2 video rate control algorithm was put forward referring the character of this method. This algorithm was realized by Philips Trimedia DSP TM1300 firstly. On the basis of analyzing hardware and software, we stated pSOS system simply. The schedule of this algorithm was presented. Because Trimedia DSP TM1300 has relative more complex hardware structure and parallel process mechanism, we described it's software development environment. Then the software schedule and the reference key function of this algorithm were discussed. In recent years, FPGA was paid more and more attention because of it's short development cycle, development fee. We also realize this bit-stream rate by FPGA. The schedule of this algorithm was presented. Because the realization depends mainly on software, we gave the statement of software in more detail. The structure of software was analyzed firstly and the respective module was discussed in detail. We emphasized the signal of every port. In the end, the results were put forward, including the picture of primitive video sequence, realization of Philips Trimedia DSP TM1300 and Xilinx FPGA, and these results was discussed.