面向4K的HEVC视频编码及其在高清网络摄像机上应用的研究

发布时间：2018-06-28 01:40

本文选题：4K + HEVC　；参考：《浙江大学》2016年硕士论文

【摘要】：现有的H.264视频编码标准可以有效压缩高清视频(1920×1080),但难以提供更高的压缩比。4K超高清视频(4096x2160)由于图像质量大幅提高,视频数据和传输速率极大增加,对视频编解码技术、硬件处理水平、软件系统架构以及传输方式等都提出了更高的要求。本文主要研究HEVC视频编码标准的帧内预测和码率控制部分,并提出了优化改进算法,此外,高清网络摄像机系统软硬件的高效设计也是本文工作的重点。帧内预测快速算法是提高HEVC编码效率的关键之一,本文提出基于图像纹理特征的块划分优化算法,通过定义FMAD来表征图像复杂度；提出基于哈达玛变换的帧内模式选择快速算法,详细阐述了通过纹理角来减少候选预测模式数量的算法流程,实验结果表明优化后编码性能均有明显提高。码率控制目的在于更好的匹配编码输出与传输信道,进而提供更加优质的视频服务和体验,本文研究了基于R-lambda模型的码率控制算法,并在比特分配策略上做了优化改进工作,提出并实现基于SATD的自适应比特分配过程,明显提高码率控制的质量。本文还完成了高清网络摄像机IPC系统的总体设计方案,从图像传输角度阐述了系统硬件设计和电路连接原理,成功搭建了系统硬件平台；编写了系统服务端和客户端软件,并进行系统功能和稳定性测试,综合效果满足实际需求；最后研究并应用x265项目,在本文软硬件平台上验证了不同模式下码率控制的实际效果。本文结合4K超高清视频和HEVC视频编码的特点,提出基于纹理复杂度和沃尔什-哈达玛变换的优化算法,显著提升了编码性能；针对现有R-lambda模型中存在的问题,提出了一种改进的码率控制策略,设计并实现了具有较高通用性和稳定性的IPC软硬件整套系统,用实际测试证实了码率控制性能的提升,具有较高的理论意义和应用价值。
[Abstract]:The existing H.264 video coding standard can effectively compress high-definition video (1920 脳 1080), but it is difficult to provide a higher compression ratio .4K ultra-high definition video (4096x2160). The hardware processing level, the software system structure and the transmission mode all put forward the higher request. This paper mainly studies the part of intra prediction and rate control of HEVC video coding standard, and proposes an optimized improved algorithm. In addition, the efficient design of hardware and software of high definition network camera system is also the focus of this paper. Fast intra prediction algorithm is one of the keys to improve the coding efficiency of HEVC. A block partition optimization algorithm based on image texture features is proposed in this paper. FMAD is defined to characterize the complexity of the image. A fast algorithm for intra-frame mode selection based on Hadamard transform is proposed. The algorithm flow of reducing the number of candidate prediction patterns by texture angle is described in detail. The experimental results show that the coding performance is improved obviously after optimization. The purpose of rate control is to match the coding output and transmission channel better, and then to provide better video service and experience. This paper studies the rate control algorithm based on R-lambda model, and optimizes and improves the bit allocation strategy. An adaptive bit allocation process based on SATD is proposed and implemented to improve the quality of bit rate control. This paper also completed the overall design scheme of the high-definition network camera IPC system, elaborated the system hardware design and the circuit connection principle from the view of image transmission, successfully built the system hardware platform, compiled the system server end and the client side software, The system function and stability are tested to meet the practical requirements. Finally, the x265 project is studied and applied to verify the actual effect of rate control in different modes on the hardware and software platform of this paper. Considering the characteristics of 4K ultra high definition video coding and HEVC video coding, this paper proposes an optimized algorithm based on texture complexity and Walsh Hadamard transform, which improves the coding performance significantly, aiming at the problems existing in the existing R-lambda model. An improved rate control strategy is proposed, and an IPC software and hardware system with high generality and stability is designed and implemented. The improvement of the rate control performance is proved by practical tests, which has high theoretical significance and application value.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN948.41;TN919.81

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