摘要近年来,人们越来越多地使用基于IP 的互联网络和无线网络来传送和接收符合编码标准的视频和音频等多媒体信息。然而,互联网和无线网络不可避免地存在带宽波动、丢包、误码、突发错误、延迟和抖动等状况。传输信道的不可靠性向高效的视频编码和传输提出了挑战,其原因在于,在有噪信道中传输压缩视频流容易产生严重的误差积累,进而影响视觉质量。目前绝大多数网络本身提供了差错控制机制,但应用于视频传输时存在过保护或欠保护的问题,有时还需要反馈信道的支持。针对视频的特点,实现容错的视频编码与传输可以获得更好的服务质量。
本课题主要研究容错视频编码中的率失真优化问题,首先对传输系统的特性进行准确的理论分析,结合信源统计特性、信道特性和解码端的错误隐藏方法推导端到端失真估计函数。在此基础上,研究联合信源信道率失真模型和影响端到端率失真特性的各项因素,以及如何优化控制编码参数以提高端到端的传输效率。62973
毕业论文关键词 视频压缩,容错编码,视频传输,率失真优化,端到端失真估计
毕业设计说明书(论文)外文摘要
Title Study on Fault tolerant Rate-Distortion Optimization Technology in Video coding
Abstract In recent years, people are increasingly using the Internet network based on IP and wireless network to send and receive video and audio coding standards, such as multimedia information.The transmission of compressed video over wireless networks as well as the Internet presents many new challenges due to the problems caused by channel errors. Most of today’s video coding standards are based on a hybrid coding framework. In the error-prone environment, transmitting the hybrid-coded video may suffer from the error propagation and thereby lead to error drifting. While the transmission errors can be controlled in the network layer, the error-resilient source coding can also reduce the network burden and becomes even more efficient, and hence achieve better Quality of Services.
This dissertationtargets at the rate-distortion optimized fault-tolerant video coding. The typical video transmission system is first studied, including the theoretical analysis and modeling of the transmission errors. The end-to-end distortion function is then derived in terms of the source and channel characteristics as well as the employed error concealment method.Based on the end-to-end distortion model, the joint source-channel rate-distortion optimized fault-tolerant coding is proposed, including the selection of coding control parameters.
Keywords video compression,fault tolerant coding, video transmission, rate-distortion optimization, end-to-end distortion estimation
1 绪论 1
1.1 视频编码的概述及标准 1
1.2 视频传输中的主要问题 6
1.3 视频传输差错控制方法 7
2 视频编码基本理论 10
2.1 预测编码 11
2.2 变换编码 15
2.3 熵编码 17
3 率失真优化理论与视频编码 19
3.1 率失真理论的基本概念 19
3.2 视频编码优化的目标和基本方法