MPEG-4 AVC协处理器的ASIC设计

音频视频同步、内容保护和强大的系统解决方案是采用MPEG-4 AVC时需要考虑的主要因素。MPEG-4先进视频解码(AVC)已在广泛的消费与专业应用领域迅速成为主导视频编解码器,这些应用包括广播、高清DVD、安全系统和视频会议设备。采用这种强大的编码标准,即H.264的新应用正在不断推出并走向市场。因此,设计师在开发基于MPEG-4 AVC的产品时充分理解这些选择十分重要。     

新一代视频编码标准H．264／AVC的特点及应用

1H.264/AVC的诞生过程及其背景作为最新一代的视频编码标准,H.264/AVC是国际电信标准化部门(ITU-T)和规定MPEG标准的国际标准化组织/国际电工协会(ISO/IEC)共同制订的一种基于块的活动图像编码方式的国际标准格式,也被成为MPEG-4AVC或者MPEG-4Part10。H.264/AVC的诞生,是为了满     

一种新的视频编解码H.264/AVC

H.264/AVC(先进的视频编码)已经被作为下一代高清晰度DVD的标准,这种编解码技术的普及正日益增长。最新报告显示,业内相当多的公司声称已制定出采用H.264/AVC标准的计划并推出了供展示的产品样品。 目前正在将由ITU-T与MPEG(移动图象专家组)联合开发的此项视频压缩标准(全称为H.264或MPEG-4pt.10/AVC)应用到产品中的公司包括:美国苹果公司、日本索尼公司、英国电信、法国电信、英特尔公司、摩托罗拉、诺基亚、     

H.264中DCT/IDCT/Hadamard变换多时钟方式的FPGA实现

DCT/IDCT/Hadamard变换被广泛应用于多种视频编码标准中,而H.264/MPEG-4AVC作为新一代的视频压缩标准,它具有在相同图像质量下比其他视频压缩标准拥有更高的压缩率的特性[1],因此对于H.264/MPEG-4AVC中的DCT/IDCT/Hadamard变换的研究就有着十分重要的意义。对于H.264/MPEG-4AVC中变换算法进行分析,并且提出一种可用的高效的硬件实现电路结构,此电路结构能够并行计算4输入像素数据。     

处理能力与性价平衡将考验机顶盒设计

随着北美IPTV的不断升温,日前北京传视数码(TransVideo)科技有限公司推出了两款全业务H.264IPTV机顶盒解决方案.DMD2000 plus和DMD3000 plus机顶盒可在500Kbps～3Mbps低带宽下实现FullD1(DVD)清晰的视频质量,同时具备可扩展的硬件和开放的软件架构的特征,支持包括H.264/MPEG-4 AVC在内的多种编码格式,并具有多种网络接口.     

H.264/AVC在3G移动通信中的应用

H.264/AVC是目前最新,也是性能最优异的国际视频压缩编码标准。在相同的视频质量下,H.264/AVC可以比MPEG-4(SP)节省大约一半的带宽,同时还具有更好的网络适应性和传输健壮性,在3G移动通信系统带宽资源紧张、通信环境恶劣的情况下,H.264/AVC应该是目前最合适的选择。从压缩效率、网络适应性和健壮性3个方面分析了H.264/AVC的新技术,并讨论了它们在3G移动通信中的应用。     

4.音视频摄录/播放设备H.264将成为视频压缩的主角兼容性问题尚未完全解决

用于消费电子设备、可用MPEG-4 AVC/H.264(以下简称为H.264)方式对HDTV视频进行实时压缩的芯片面世成为对摄像机及录像机等音/视频设备领域影响最大的新闻.     

H.264解码解决方案实例介绍

随着互联网电视IPTV如火如荼的展开,H.264视频压缩国际标准逐渐被大家所熟悉.H.264是由国际电信标准化部门(ITU-T)和制定MPEG的国际标准化组织(ISO)国际电工协会(IEC)共同制订的一种视频编码国际标准格式.H.264同时又称为MPEG-4 AVC("活动图像专家组4的高级视频编码"),或MPEG-4 Part10.     

H.264标准中的分层技术

H.264/AVC标准是当前国际上最新的图像编码标准。被ITU-T命名为H.264。ISO/IEC则把此标准叫做国际标准14496-10(MPEG-4的第10部分)高级图像编码(AVC)。本对标准中关键技术(分层技术)从定义、分类、流格式方面及其实现作了比较系统的介绍。     

新闻荟萃播出平台常见故障的处理方法

1新闻荟萃播出平台的组成新闻荟萃播出平台(又名多画面导航系统、马赛克播出系统)由MPEG-2标清编码器、H.264/AVC标清编码器、H.264/AVC高清编码器、DVB复用器、DVB复用加扰器、独立加扰器、QAM调制器、数字媒体综合处理平台、IPQAM、SI注入服务器、主备SI服务器、主备硬盘播出矩阵、主备DVB播放器、终端显示器和键盘等外围设备组成,所有核心设备都有热备份自动切换功能。     

Fast Interframe mode decision algorithm based on mode mapping and MB activity for MPEG-2 to H.264/AVC transcoding

Recently the latest video coding standard H.264/AVC is widely used for the mobile and low bitrate video codec in the various multimedia terminals. On the other hand, the MPEG-2 MP@HL codec has become the center of digital video contents since it is the standard codec for the Digital TV (DTV). To provide the bridge between the contents in MPEG-2 and mobile terminals, the transcoding of MPEG-2 contents into H.264/AVC format is an inevitable technology in the digital video market. The main bottleneck in the process lies in the computational complexity. In H.264/AVC, the variable block size (VBS) mode decision (MD) is used in the Interframe for the improved performance in the motion compensated prediction. For the macroblock (MB) which cannot be accurately predicted with one motion vector (MV), it is partitioned into smaller blocks and predicted with different MVs. In addition, SKIP and Intra modes are also permitted in the Interframe MD of H.264/AVC to further ameliorate the encoding performance. With the VBS MD technology, the Inter prediction accuracy can be improved significantly. However, the incidental side-effect is the high computational complexity. In this paper, we propose a fast Interframe MD algorithm for MPEG-2 to H.264/AVC transcoding. The relationships between SKIP and Intra modes are detected at first to map these two kinds of modes directly from MPEG-2 to H.264/AVC. And then the MB activity will be scaled by the residual DCT energy obtained from the MPEG-2 decoding process to estimate the block sizes of the MB mode for H.264/AVC Interframe MD. In our proposed method, the original redundant candidate modes can be eliminated effectively, resulting in the reduction of the computational complexity. It can reduce about 85% Rate-to-Distortion Cost (RDCost) computing and 45% entire processing time compared with the well-known cascaded transcoder while maintaining the video quality.     

Video coding with H.264/AVC: tools, performance, and complexity

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.     

The H.264 Video Coding Standard

The H.264 video coding standard, also known as MPEG AVC, represents the state of the art in video compression. This article provides an overview of the H.264 standard. To help the reader understand the similarities and differences between it and MPEG-2 (and other hybrid video coding standards), the author describes the H.264 features and compare them to functionally similar MPEG-2 features     

A real-time inverse quantised transform for multi-standard with dynamic resolution support

In this paper, a real-time configurable intelligent property (IP) core is presented for image/video decoding process in compatibility with the standard MPEG-4 Visual and the standard H.264/AVC. The inverse quantised discrete cosine and integer transform can be used to perform inverse quantised discrete cosine transform and inverse quantised inverse integer transforms which only required shift and add operations. Meanwhile, COordinate Rotation DIgital Computer iterations and compensation steps are adjustable in order to compensate for the video compression quality regarding various data throughput. The implementations are embedded in publicly available software XVID Codes 1.2.2 for the standard MPEG-4 Visual and the H.264/AVC reference software JM 16.1, where the experimental results show that the balance between the computational complexity and video compression quality is retained. At the end, FPGA synthesised results show that the proposed IP core can bring advantages to low hardware costs and also provide real-time performance for Full HD and 4K–2K video decoding.     

IPTV技术标准与应用前景

介绍IPTV的概念及技术标准,重点介绍主流的3大音视频编解码技术标准MPEG-4,H.264/AVC和AVS及其应用前景。     

A high performance and low complexity sampling-based intra coding method for H.264/AVC

The H.264/AVC video coding standard can achieves higher compression performance than previous video coding standards, such as MPEG-2, MPEG-4, and H.263. Especially, in order to obtain the high coding performance in intra pictures, the H.264/AVC encoder employs various directional spatial prediction modes and the rate-distortion (RD) optimization technique inducing high computational complexity. For further improvement in the coding performance with the low computational complexity, we introduce a sampling-based intra coding method. The proposed method generates two sub-images, which are defined as a sampled sub-image and a prediction error sub-image in this paper, from an original image through horizontal or vertical sampling and prediction processes, and then each sub-image is encoded with different intra prediction modes, quantization parameters, and scanning patterns. Experimental results demonstrate that the proposed method significantly improves the intra coding performance and reduces the encoding complexity with the smaller number of the RD cost calculation process.     

General Architecture for MPEG-2/H.263/H.264/AVC to H.264/AVC Intra Frame Transcoding

The latest international video-coding standard H.264/AVC significantly achieves better coding performance compared to prior video coding standards such as MPEG-2 and H.263, which have been widely used in today’s digital video applications. To provide the interoperability between different coding standards, this paper proposes an efficient architecture for MPEG-2/H.263/H.264/AVC to H.264/AVC intra frame transcoding, using the original information such as discrete cosine transform (DCT) coefficients and coded mode type. Low-frequency components of DCT coefficients and a novel rate distortion cost function are used to select a set of candidate modes for rate distortion optimization (RDO) decision. For H.263 and H.264/AVC, a mode refinement scheme is utilized to eliminate unlikely modes before RDO mode decision, based on coded mode information. The experimental results, conducted on JM12.2 with fast C8MB mode decision, reveal that average 58%, 59% and 60% of computation (re-encoding) time can be saved for MPEG-2, H.263, H.264/AVC to H.264/AVC intra frame transcodings respectively, while preserving good coding performance when compared with complex cascaded pixel domain transcoding (CCPDT); or average 88% (a speed up factor of 8) when compared with CCPDT without considering fast C8MB. The proposed algorithm for H.264/AVC homogeneous transcoding is also compared to the simple cascaded pixel domain transcoding (with original mode reuse). The results of this comparison indicate that the proposed algorithm significantly outperforms the mode reuse algorithm in coding performance, with only slightly higher computation.     

MPEG-4解码器芯片的比较

介绍了目前市场上比较流行的一些MPEG-4编解码芯片，比较了它们的应用前景和特性，并简要介绍了新一代视频编解码标准H．264的芯片产品。