HDTV视频解码器中码率缓冲的实现方法

Implementation of bit-rate buffering in HDTV video decoder

对于采用ＭＰＥＧ－２编码格式的视频流，由于视频信源的非平稳特性和不同类型帧采用不同的压缩算法，导致序列中各类型图像帧之间的数据量存在较大差异。而经解码后显示的侦速率是恒定的，这就要求在解码端有一个缓冲器来实现输入码率与输出码率间的过渡。基于此，介绍了ＭＰＥＧ－２标准中对码率缓冲器的有关规定，阐述了高清晰度电视视频解码器对码率缓存的实际要求，提出了一种实现码率缓冲器的方法。

There are three types of frame in MPEG-2 system and each has a compress method difference from others.And,the video signal source is non-stabiles.The sizes of different type of frames have distinguished difference. The input bit rate and the output frame rate of video decoder is fix, so a Rate Buffer is needed to balance this rate difference.In this paper, some rules about rate buffer in MPEG-2 standard are introduced firstly. And then, a design method is given in detail, considering the demand of HDTV video decoder.