一、引言 随着人类社会信息化程度的提高以及计算机软硬件技术的发展,网络技术和多媒体技术成为两个正在飞速发展的领域,采用多媒体通信技术的电话会议系统及可视会议系统也得到了很快发展。在通信中,多媒体信号的带宽要求比较高,话音和图像的实时性要求也较强。解决这些问题,通常是从两个方面入 I. INTRODUCTION With the improvement of informatization of human society and the development of computer software and hardware technology, network technology and multimedia technology have become two rapidly developing fields. Teleconferencing systems and video conferencing systems using multimedia communication technology have also been developed Develop rapidly. In communication, multimedia signal bandwidth requirements are relatively high, real-time voice and image requirements are also stronger. Solve these problems, usually from two aspects into