摘要
本文简略报道国际活动图像专家组近年对多媒体通信草拟新标准MPEG 4的进展情况。其中音频编码包括语音、音乐 (自然的和合成的 ) ,比特率从 2至 6 4kb /s。视频编码包括甚低比特率 5～ 6 4kb /s和较高比特率 6 4kb /s至 2Mb /s。视频编码可将图像中每一对象分开编码为不同的比特流层 ,又可操纵对象的尺度、位置等 ,具有以内容为基础的交互式功能。除了核心编码器外 ,对输入视频序列的每一帧分成若干个任意形状的“视频对象平面” ,编码成各个分开的“视频对象层”。另外 ,利用“子图形”编码技术 ,将图像的背景以及前景中的每一对象分开编码成视频序列后传输 ,可以改善视像质量。
The paper briefly describes the MPEG 4 standard draft for multimedia communications.It includes audio coding for speech,music,natural and synthetic,with bit rate 2～64kb /s,and video coding for very low bit rate 5～64 kb /s and higher bit rate 64 kb /s～2Mb /s.It mentions the basic concept of the“content based interactive functionality',that in addition to the core coding,each frame of input video sequence is segmented into a number of“video object planes' of arbitrary shape and coded into seperate “video object layers'.Furthermore,there provides sprite coding technology for background scene and various objects in the foreground,in order to improve video quality.
出处
《电信快报》
1998年第6期3-5,共3页
Telecommunications Information
