文档介绍：华中科技大学
硕士学位论文
MPEG-4流式播放的设计与实现
姓名:郑亮
申请学位级别:硕士
专业:软件工程
指导教师:覃中平
20051028
摘要
随着计算机网络以及多媒体技术的飞速发展,结合计算机网络和多媒体技术的
VOD(Video On Demand,视频点播)等也得到了迅猛的发展。视频点播系统具有较
高的实际应用价值和非常广阔的发展前景。在该类系统的实现中,涉及编码标准、传
输控制等多个方面,尤其是网络传输协议的实现及终端质量控制是整个系统的重要环
节之一。
实时传输协议(Real-time Transport Protocol)是流媒体传输普遍采用的协议,RTP 本
身并不能为按顺序传送数据包提供可靠的传送机制,也不提供流量控制或拥塞控制,
它依靠实时传输控制协议 RTCP(Real-time Transport Control Protocol)提供这些服务。
RTCP 可以监视网络上的传输服务质量,并提供质量控制和会话识别功能。更重要的
是 RTCP 严格控制带宽,提高媒体流的传输效率,在用户较多的情况下具有优势。实
时流协议(Real-Time Streaming Protocol)为用户和服务器之间提供交互命令,控制媒体
流的传输。
本文在流式传输的特性基础上,结合具体开发项目,采用 socket 编程及多线程技
术,完成了基于嵌入式 Linux 系统下的 MPEG-4 流式播放软件各模块的实现:通过
RTSP 协议交互播放控制信息,采用 RTP/RTCP 传输多媒体数据及质量反馈,终端系
统的多级缓冲机制实现流式播放的 QoS 控制。在实际的应用环境中取得了较好的播
放效果,为下一步的研究打下良好的基础。

关键词:流媒体 RTSP RTP RTCP MPEG-4 多级缓冲多线程

I
Abstract
With the rapid development works and multi-media technology, the
VOD(Video On Demond) system, which is bination works and
multi-media technology, is used more and more widely. It also has extensive applications
and a bright future. In the implementation of this kind of systems, it involves to encoding
standards, transport control and so on, especially, the transport protocol and
QoS(Quality of Service) of terminal are important parts of the VOD system.
RTP(Real-time Transport Protocol) is adopted work transfer of streaming media.
RTP itself does not provide any mechanism to ensure delivery or provide other QoS
guarantees, but relies on RTCP(Real-time Transport Control Protocol) to achieve these.
RTCP can be used to monitor the state of data transferring, and provide the control of
service quantity and session identification function. It is also used to do bandwidth control
which is useful if there are many participants using the system. RTSP(Real-Time Streaming
Protocol) provide the control of the session and mand to interact with the server.
This paper is based on the characteristics of streaming transfer, combines with the