基于MPEG—2的图像压缩系统设计

Design of image compression system based on MPEG—2

针对未压缩的视频图像信号的高传输码率,占用存储空间大进行了研究,提出了一种基于MPEG—2的图像压缩编码系统,实现数字图像的无线传输,并输出传输流。通过视频解码芯片SAA7114H和编码芯片SAA6752H构成压缩模块,分析原始视频图像,经D1格式采集压缩后,分别以不同的速率传输时,视频图像质量变化,表明压缩倍数越高,图像质量越差;由SAA6752芯片引脚采集数据,将采集到的视频流数据转换为十六进制,分析数据结构及排列规律符合传输流特性。该设计方法不仅能保证良好的图像质量,提高视频图像压缩率,且能正确提取传输流。

Aiming at problem of large storage space occupied by high transmission code rate of uncompressed video image signal,a video compression coding system based on MPEG-2 is proposed,realize wireless transmission of digital images,and output transport stream. By video decoder chip SAA7114 H and encoding chip SAA6752 H constitute compression module,analyze original video image,video is captured and compressed by D1 format,respectively,video image quality changes while being transmitting,at different transmission rates,indicating that the higher the compression ratio is,the worse the image quality is; collect data by pins of SAA6752 chip,the captured video stream data is converted to hexadecimal,analyze data structure and arrangement law with the transport stream characteristics. The design method can not only ensure good image quality,increase video compression ratios,but also can extract transport stream correctly.