采用可分级视频编码和基于MPEG-21的视频适配

MPEG-21 Based Adaptation for Scalable Video Streaming

开发了一个基于可分级视频编码和MPEG-21视频适配的视频流系统,其主要特征是支持无线通信.该系统能使无线设备在不破坏当前通信连接的同时在不同无线网络中漫游.采用的视频流编码方法可以自适应调整由于垂直切换带来的无线连接特性的巨大变化.提出了一种基于概念的证明方法——分布式数字项适配(DIA),通过服务器和代理商之间的合作使系统适配更多复杂的情况.实例说明,该设计系统成功地实现了执行垂直切换而并不断开网络连接的视频应用.

In this article,we describe a ubiquitous MPEG-21 based scalable video streaming system.Its main feature is to support seamless communication.The system enables wireless devices to roam among different wireless networks without breaking the ongoing connections.The method of video coding can adaptively adjust to match the significant change of wireless link characteristics due to vertical handoff.A proof-of-concept solution distributed DIA is proposed,for more complex adaptation scenarios through cooperations among the server and proxies.The system designed in the paper is illustrated successfully to achieved the implementation of the vertical handoff without disconnecting the ongoing connections.