Dual Mpeg Video Sample Compression System

Along with the constant development of electronic technology and communication technology, people make demands of better multimedia information. Video compression transmission technology comes into existence to meet the requirement of high-speed and high-quality multimedia information. From the earlier H.261 to recent MPEG-4 and H.264, video transmission technology breaks through the bottleneck of bandwith. People can receive sharp video program with lower bit-rates. Nowadays, video compression transmission technology is widely used in every corner of our life, such as digital television brocasting, digital battlefield, video monitoring, distance education, visualize conference, etc. Video sampling and compression board performs video A/D converting and compression encoding.This paper mainly researches the hardware designing of sampling and compression board and software programming of system controller. The main content is as following:1.According to the system specification, a hardware structure is designed, and several chips are chosen as function module of this board. MB86391 performs MPEG-2 compression. A FPGA EP1C6T144C8 made by ALTERA is used as a multiplexer, and A MCU P89LPC932 works as a controller of this system. With this system, two analog video signal can be transformed to one MPEG-2 Transport Stream(TS), and output through Asynchronous Serial Interface(ASI).2.Particularly, this paper illustrates the design of control module of this board. The program is developed in the environment of Keil C51. Through SPI(Serial Peripheral Interface) and I2C bus MB86391 and TV5150, CY22393 are controlled. We use Philips'P89LPC932 MCU to implement the function of change output bit stream on four levels and self-adaption to input video format.3.During the process of layouting PCB, we seriously considered the design of analog and digital mix-signal section and high speed signal section. Finally, we use BTA-P100 bit stream analyzer checks some important parameters of this board which include the speed of bit stream, PSI(Program Specific Information) and PCR(Program Clock Reference).The test result makes it clear that the scheme integrating encoder and multiplexer not only saves the space of equipment but also has some advantages on several parameters comparing with separate design. It provides reference to the future improvement.