H.264的视频质量评估及编解码算法的实现

发布时间：2018-01-10 17:27

本文关键词：H.264的视频质量评估及编解码算法的实现　出处：《西安电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着时代的发展和科技的进步,多媒体技术越来越多的渗入到我们的生活中,视频通信业务正在逐步渗入各行各业成为数字通信网络的主要业务之一。在众多的视频业务中,嵌入式视频监控作为当今应用越来越广泛的监控手段,在各行各业的安保系统中起到了举足轻重的作用。本文的提出是为了实现无人看守的视频监控系统方案,由于监控系统的研究重点部分为视频的处理,视频数据具有数据量大、对带宽要求高的特点,因此,要想满足视频数据在特定带宽的信道上实现高质量的传输,我们需要选取高效的压缩算法。国际上对视频压缩标准的研究已经经历了多年的发展。H.264视频编码标准作为当今主流的视频压缩编码标准,在实现对视频的高效压缩、在特定码率信道实现更加优秀视频质量传输方面有很好的表现。本文首先对比了H.264压缩算法相对于其他主流压缩算法的性能优劣,然后确定了采用H.264作为本文压缩算法。选定了视频压缩编码的标准,我们还需要选取一个好的视频质量评定标准用来衡量视频质量的好坏,这对优化视频压缩算法起了重要的作用。视频质量评估分为主观视频质量评估和客观视频质量评估两大类,主观视频质量虽然具有评价符合人眼观察视频质量特性的优点,但是考虑到主观视频质量评估实现环境要求苛刻,因此我们需要开发对易于操作实现、便于测试以及与主观视频质量评价相关性好的客观视频质量评价方法。集合上述条件,本文采用基于结构相似度的客观视频质量方法。首先,本文对SSIM与其他常用客观视频质量评估方法进行了对比,进一步验证了SSIM客观视频质量评估方法能准确评价视频质量的特点。然后,本文采用SSIM客观视频质量评估方法对H.264编码后的视频进行了质量评估,还对不同传输环境下不同算法解码方法解码的视频进行了评估,通过对比进一步验证了H.264适用于本文监控系统方案的特点。H.264编码的形式多种多样,在嵌入式系统中实现H.264编码有很大的优越性。目前嵌入式视频系统中大多采用DSP处理器作为视频处理器。例如:德州仪器推出的DM6446处理器作为一款专门针对多媒体应用的处理器,就是采用ARM+DSP处理架构对视频进行处理。其独特的双核处理架构,对视频信号的处理体现出了强大的优势,对达芬奇平台的开发具有很大的实用价值。本文提出了基于DM6446平台的新开发方案,可以避免使用DM6446平台的codec机制。提高了该平台在算法修改上的灵活性。并利用DM6446平台实现了H.264算法。
[Abstract]:With the development of the times and the progress of science and technology, more and more multimedia technology has penetrated into our life. Video communication service is gradually infiltrating into all walks of life to become one of the main services of digital communication network. In many video services, embedded video surveillance as a more and more widely used monitoring means. It plays an important role in the security system of various industries. The purpose of this paper is to realize the unattended video surveillance system, because the focus of the monitoring system is the processing of video. Video data has the characteristics of large amount of data and high demand for bandwidth. Therefore, to meet the requirements of video data in a specific bandwidth channel to achieve high-quality transmission. We need to select efficient compression algorithms. The international research on video compression standards has experienced many years of development. H. 264 video coding standards as the mainstream video compression standards. In the realization of efficient video compression. The performance of H.264 compression algorithm is compared with that of other mainstream compression algorithms. Then we choose H.264 as our compression algorithm. We select the standard of video compression coding. We also need to select a good video quality evaluation standard to measure the quality of video. This plays an important role in optimizing video compression algorithms. Video quality assessment is divided into subjective video quality assessment and objective video quality evaluation. Although subjective video quality has the advantages of evaluating video quality characteristics of human eye observation, but considering the harsh requirements of subjective video quality evaluation implementation environment, we need to develop easy to implement. Objective video quality evaluation method is easy to test and has good correlation with subjective video quality evaluation. Based on the above conditions, this paper adopts the objective video quality method based on structural similarity. First of all. In this paper, SSIM and other commonly used objective video quality evaluation methods are compared, further verify the SSIM objective video quality evaluation method can accurately evaluate the characteristics of video quality. In this paper, the SSIM objective video quality evaluation method is used to evaluate the quality of H.264 encoded video, and the video decoded by different algorithms and decoding methods under different transmission environment is also evaluated. Through comparison, it is further verified that H.264 is suitable for the monitoring system in this paper. The coding forms of H.264 are various. H.264 coding has great advantages in embedded system. At present, most embedded video systems use DSP processor as video processor. For example:. Texas Instruments introduced the DM6446 processor as a processor dedicated to multimedia applications. ARM DSP processing architecture is used to process video. Its unique dual-core processing architecture, video signal processing shows a strong advantage. It has great practical value for the development of Da Vinci platform. In this paper, a new development scheme based on DM6446 platform is proposed. It can avoid the codec mechanism of DM6446 platform, improve the flexibility of the platform in algorithm modification, and use DM6446 platform to implement H.264 algorithm.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.81

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