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1.
视频压缩技术取得了日新月异的发展.运动图像专家组和视频编码专家组给出一种更好的视频压缩标准,确定为MPEG-4标准的第十部分,即H.264/AVC.H.264/AVC作为新一代视频压缩标准,具有超高压缩率.详细分析了H.264中量化算法,并用Verilog硬件描述语言编程实现量化功能,利用Modelsim进行仿真,得到正确的结果.分析了量化模块所消耗的硬件资源,提出用FPGA实现H.264量化的算法,使H.264能够用硬件的方法实现.  相似文献   

2.
H.264/AVC视频编码新技术   总被引:2,自引:0,他引:2  
H.264/AVC是国际电联ITU-T的视频编码专家组VCEG和国际标准化组织ISO/IEC的活动图像专家组MPEG联合制定的视频编码新标准,其目的是为了获得更好的图像压缩效果和更好地适应不同的网络环境。本文从编码效率和网络适应性方面讨论了H.264/AVC中所采用的新技术。  相似文献   

3.
数字视频技术在通信和广播领域获得了日益广泛的应用,视频信息和多媒体信息在网络中的处理和传输成为当前我国信息化中的热点技术。运动图像专家组和视频编码专家组给出一种更好的标准,确定为MPEG-4标准的第十部分,即H.264/AVC。简述H.264的研究意义及DCT的原理。为了减少运算量,分析H.264中如何对宏块的整数变换,详述H.264的编码变换的方法,给出整数变换方法与传统的DCT的区别和联系,并给出H.264的整数变换方法的快速算法即蝶形算法,这与传统的DCT变换是不同的。  相似文献   

4.
H.264/AVC是一种由ITU-T视频编码专家组合ISO/IEC JTC1动态图像专家组联合提出的高度压缩视频编码器标准。然而H.264/AVC编码器较高的运算复杂度提高了多屏共享系统的延迟时间。H.264/AVC由多种开源的实现,其中X264因简单高效而得到广泛的应用。在此对多频共享系统的关键技术进行实现,分析X264编码器提供的运动估计算法并且提出一种优化的算法。实验表明,新的算法提高了编码的速度、减少了系统延迟时间,同时视频质量几乎没有产生损失。  相似文献   

5.
费伟  朱善安 《移动通信》2007,31(5):55-58
面向无线视频通信的相关视频编码技术是当前的研究热点,联合视频组正在研究开发的H.264/AVC扩展可伸缩编码可在空间、时间及质量上实现完全可伸缩,其视频码流能更好地适应无线网络环境及用户终端的多样性,克服无线网络易错、时变和带限的特点,提供更好的服务质量。文章详细地阐述了基于H.264/AVC扩展的可伸缩编码的关键技术及原理,并描述了其在无线视频通信中的应用及相关技术。  相似文献   

6.
一、引言 H.264/AVC是ITU—T和MPEG联合发展和制定的新一代视频编码国际标准.与以往的H.263、MPEG-4等标准类似,H.264/AVC同样采用了基于块运动补偿和变换编码的混合编码框架.区别在于H.264吸收并应用了许多视频通信领域新的理论和技术成果,如帧内预测、多参考帧、可变块划分模式、1/4像素精度运动估计、cABAC熵编码等。  相似文献   

7.
为提高H.264/AVC标准在带宽资源严重受限时的压缩效率,采用空时域相结合的编码思路,提出了一种基于运动检测的自适应抽帧方法,并结合空域下采样与重建研究了一种改进的H.264/AVC压缩性能优化框架。在编码端,原视频先空域下采样以减少空间分辨率,然后根据视频运动特征,采用不同抽帧模式自适应地降低帧率,再经H.264/AVC编码,有效降低了编码码率。在解码端,解码视频则采用与抽帧模式相对应的运动估计与补偿插帧方法重建出抽取帧,再利用超分辨率重建技术将视频恢复到原空间分辨率。实验结果表明,所提方法在低码率段的视频压缩性能优于H.264/AVC标准编解码及相关文献方法。  相似文献   

8.
随着经济的发展和技术的进步,市场对高性能视频业务的需求不断膨胀,原有的压缩视频标准已经不能够满足要求,新的压缩视频技术将拥有广阔的市场空间。H.264/AVC是目前由ITU-T的视频编码专家组(VCEG)及ISO/IEC的活动图像专家组(MPEG)大力发展研究的,适应于低码率传输的新一代压缩视频标准。2003年3月由两  相似文献   

9.
H.264/AVC是ITU-T VCEG(视频编码专家组)和ISO/IEC MPEG(运动图像专家组)最新的视频标准,与现有的任何标准相比,在同样保真度条件下,节省码率50%以上,适合各种媒体传输和存储,可交互式和非交互式应用,将成为新一代的视频编码标准。应用前景广泛,有很大的经济效益。本文介绍该标准的历史背景,技术要点,应用状况等。  相似文献   

10.
成就最新视频编码标准H.264/AVC优异编码性能的代价是其计算复杂度的大幅增加,编码速度的急剧下降.为了克服H.264/AVC标准中重要且耗时的运动估计编码技术实时性差的缺陷,针对其最新采用的UMHexagonS算法的计算冗余,利用宏块的运动特征,制定了自适应的运动估计策略和搜索点分配准则.仿真实验结果表明,本文提出的运动估计编码方案与UMHexagonS算法相比,平均节省约23%的运动估计编码时间,在有效提高编码速度的前提下,保持了H.264/AVC低码率、高质量的编码优势.  相似文献   

11.
新一代运动图像压缩标准H.264/AVC   总被引:3,自引:0,他引:3  
H.264/AVC是ISO/IECMPEG与ITU-TVCEG共同制订的新一代图像编码标准,它具有更高的压缩性能。文章介绍H.264/AVC图像编解码系统的实现过程,并对其采用的新技术进行描述。  相似文献   

12.
Video coding with H.264/AVC: tools, performance, and complexity   总被引:2,自引:0,他引:2  
H.264/AVC, the result of the collaboration between the ISO/IEC Moving Picture Experts Group and the ITU-T Video Coding Experts Group, is the latest standard for video coding. The goals of this standardization effort were enhanced compression efficiency, network friendly video representation for interactive (video telephony) and non-interactive applications (broadcast, streaming, storage, video on demand). H.264/AVC provides gains in compression efficiency of up to 50% over a wide range of bit rates and video resolutions compared to previous standards. Compared to previous standards, the decoder complexity is about four times that of MPEG-2 and two times that of MPEG-4 Visual Simple Profile. This paper provides an overview of the new tools, features and complexity of H.264/AVC.  相似文献   

13.
The high-efficiency video coding(HEVC) standard is the newest video coding standard currently under joint development by ITU-T Video Coding Experts Group(VCEG) and ISO/IEC Moving Picture Experts Group(MPEG).HEVC is the next-generation video coding standard after H.264/AVC.The goals of the HEVC standardization effort are to double the video coding efficiency of existing H.264/AVC while supporting all the recognized potential applications,such as,video telephony,storage,broadcast,streaming,especially for large picture size video(4k × 2k).The HEVC standard will be completed as an ISO/IEC and ITU-T standard in January 2013.In February 2012,the HEVC standardization process reached its committee draft(CD) stage.The ever-improving HEVC standard has demonstrated a significant gain in coding efficiency in rate-distortion efficiency relative to the existing H.264/AVC.This paper provides an overview of the technical features of HEVC close to HEVC CD stage,covering high-level structure,coding units,prediction units,transform units,spatial signal transformation and PCM representation,intra-picture prediction,inter-picture prediction,entropy coding and in-loop filtering.The HEVC coding efficiency performances comparing with H.264/AVC are also provided.  相似文献   

14.
An efficient rate control algorithm is required to transmit coded video sequences without abrupt changes in quality due to the limited channel bandwidth. Thus, in this paper, an efficient rate control method is proposed for the H.264/MPEG (Moving Picture Experts Group)-4 Advanced Video Coding (AVC) baseline profile that meets the above constraint by using a ρ-domain source model. Firstly, a simple target bits determination method that considers the ideal buffer level is proposed, and secondly, a method of adequately determining the Quantization Parameter (QP) is presented using two kinds of linear regression. The experimental results show that the proposed rate control algorithm using the above two methods performs better than other rate control algorithms for H.264/MPEG-4 AVC in terms of the rate estimation error and the standard deviation of the Peak Signal-to- Noise Ratio (PSNR), which provides a measure of the constancy of the video quality throughout the whole video sequence.  相似文献   

15.
H.264视频压缩关键技术及其应用前景   总被引:6,自引:0,他引:6  
ISO/IEC和ITU-T联合制定的H.264标准,标志着视频压缩技术的最新进展.H.264视频编码新标准采用一系列最新的压缩技术,提高了压缩率.该文重点介绍了视频编码新标准H.264的关键模块,并阐述了它在数字电视、高清晰度电视以及移动通信等方面的应用前景.  相似文献   

16.
In video communication systems, the video signals are typically compressed and sent to the decoder through an error-prone transmission channel that may corrupt the compressed signal, causing the degradation of the final decoded video quality. In this context, it is possible to enhance the error resilience of typical predictive video coding schemes using as inspiration principles and tools from an alternative video coding approach, the so-called Distributed Video Coding (DVC), based on the Distributed Source Coding (DSC) theory. Further improvements in the decoded video quality after error-prone transmission may also be obtained by considering the perceptual relevance of the video content, as distortions occurring in different regions of a picture have a different impact on the user's final experience. In this context, this paper proposes a Perceptually Driven Error Protection (PDEP) video coding solution that enhances the error resilience of a state-of-the-art H.264/AVC predictive video codec using DSC principles and perceptual considerations. To increase the H.264/AVC error resilience performance, the main technical novelties brought by the proposed video coding solution are: (i) design of an improved compressed domain perceptual classification mechanism; (ii) design of an improved transcoding tool for the DSC-based protection mechanism; and (iii) integration of a perceptual classification mechanism in an H.264/AVC compliant codec with a DSC-based error protection mechanism. The performance results obtained show that the proposed PDEP video codec provides a better performing alternative to traditional error protection video coding schemes, notably Forward Error Correction (FEC)-based schemes.  相似文献   

17.
介绍了基本的差错掩盖技术以及最近新提出的基于H.264的差错掩盖技术,并对在编码端加入引导信息的决策树法进行了改进,给出了初步的实验结果,最后概括了这些掩盖方法的特点.  相似文献   

18.
In the Advanced Video Coding (AVC) standard, motion estimation (ME) adopts many new features to increase the coding performances such as block matching algorithm (BMA), motion vector prediction (MVP) and variable block size motion estimation (VBSME). However, VBSME is utilized in the MPEG4-AVC/H.264 standard which leads to high computational complexity and data dependency that make the hardware implementation very complex.  相似文献   

19.
介绍了H.264/AVC标准中主要使用的三种新型抗误码技术,即参数集、灵活的宏块排列次序(FMO)和冗佘片技术,并分析了这三种技术的特点并对其应用方法进行了研究.  相似文献   

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