视频编码中容错率失真优化技术研究(2)
Secondly, a joint source-channel rate-distortion optimization method is proposed. Thetraditional rate-distortion function is extended in terms of the above end-to-end distortion model, in which the coding parameters such as quantization stepsize and motion vectors are jointly considered for the overall rate-distortion optimization. The Lagrange method is employed due to its wide adoption. Intuitively, the Lagrange multiplier should be related to the channel conditions. Thanks to the proposed distortion model, for the first time, the Lagrange multiplier in packet-loss environment is derived in theory. Based on the derived end-to-end distortion and the new Lagrange multiplier, a generalized joint source-channel rate-distortion estimation framework is developed. Experimental results show that the proposed method can achieve high efficiency while it has much lower computational cost.
Thirdly, a rate-distortion optimized hybrid error-resilient video coding approach is proposed, in which the various error-resilient coding tools are jointly optimized. The typical error-resilient tools are statistically analyzed in terms of the relationship between the source of redundancies and the final quality at the decoder side. The statistics show that it is less efficient in the control of error propagation by separately optimizing these coding tools. Accordingly, jointly using these coding tools leads to a further optimization problem. Thanks to generalized framework of the proposed end-to-end distortion model, it is feasible to consider the influence of error concealment at the encoder side. In particular, the flexible macroblock order (FMO)and data partitioning tools are jointly optimized with the help of the extended end-to-end distortion model.
Keywords video compression, error resilient coding, video transmission, rate-distortion optimization, end-to-end distortion estimation
目 次
1引言 1
1.1视频编码系统简介 1
1.2视频传输的差错控制方法 2
1.2.1系统传输层的差错控制 2
1.2.2视频容错编码技术 3
1.2.3错误隐藏技术 3
1.3国内外研究现状及我的工作 4
1.4论文结构安排 5
2.视频容错率失真优化理论 6
2.1率失真理论的基本概念 6
2.2在混合编码器中实现基于率失真优化的编码控制 6
2.2.1 运动矢量选择 7
2.2.2 编码模式决策 7
2.2.3 码率控制 7
2.2.4 以上三者的结合 8
2.3有噪和无噪环境下率失真特性的比较 8
2.4本章小结 9
3.基于错误累积失真跟踪的端到端失真估计 10
3.1 错误累积的影响与分析 10
3.1.1帧内预测的错误累积分析 10
3.1.2 帧间预测的错误积累分析 10
3.1.3 去块效应滤波器的错误积累分析 10
3.2本章小结 11
4基于联合信源-信道率失真优化的编码控制 12
4.1基于联合信源-信道率失真优化的编码控制算法 12
4.1.1 基于联合信源-信道率失真优化的运动矢量选择和编码模式决策 12
4.1.2 联合运动矢量、编码模式决策和码率控制的编码优化 13
4.2 实验结果分析 13
4.2.1 拉格朗日参数的影响 14
4.2.2 码率控制的影响 14
4.3本章小结 14
结 论 16
致 谢 17
参考文献18
1 引言
1.1 视频编码系统简介