Mpeg4 Video Compression System

The first generation Armored Scout Cars of our army only had the ability of receiving and storing the analog video signal because of the limitation of technologies. At the same time it was composed of too many devices and took up much space, and it was difficult to process the imgage data it stored. With the development of new technologies, many disadvantages can be optimized by digital video technology. Based on the client's requirements, this paper proposes a reform scheme of the 1st Armored Scout Cars utilizing digital video technology.In the hardware system, we capture four channels video signal based on CCIR601, and then combine them into one stream. The combined stream is divided into two outputs: one is used for previewing, the other for compression. The audio processor captures four channels, codes them by the way of PCM, and then sends them to compress. In the system we choose the MPEG-4 standard to compress the video and audio. The compressed data is transported to the control software via PCI bridge.The software system has these main functions as follows: parameters setting, previewing, file storing and playback. We have developed the previewing function by DirectDraw, saved the compressed data with AVI file format, and developed the playback program by DirectShow.After the reform scheme had been proposed, we made PCI card to capture and compress the video/audio data, developed the previewing and playback software based on Microsoft DirectX and achieved the design target on the whole.