MPEG digital video-coding standards

The efficient digital representation of image and video signals has been the subject of considerable research over the past 20 years. Digital video-coding technology has developed into a mature field and products have been developed that are targeted for a wide range of emerging applications, such as video on demand, digital TV/HDTV broadcasting, and multimedia image/video database services. With the increased commercial interest in video communications, the need for international image- and video-compression standards arose. To meet this need, the Moving Picture Experts Group (MPEG) was formed to develop coding standards. MPEG-1 and MPEG-2 video-coding standards have attracted much attention worldwide, with an increasing number of very large scale integration (VLSI) and software implementations of these standards becoming commercially available. MPEG-4, the most recent MPEG standard that is still under development, is targeted for future content-based multimedia applications. We provide an overview of the MPEG video-coding algorithms and standards and their role in video communications. We review the basic concepts and techniques that are relevant in the context of the MPEG video-compression standards and outline MPEG-1 and MPEG-2 video-coding algorithms. The specific properties of the standards related to their applications are presented, and the basic elements of the forthcoming MPEG-4 standard are also described. We also discuss the performance of the standards and their success in the market place     

The role of VLSI in multimedia

The opportunity to develop multimedia applications based on compressed video is the result of progress in three areas: standards, networking, and VLSI. Current video coding standards and their underlying algorithms use a variety of techniques to isolate and remove redundancies in the image sequence. Some of these techniques place severe demands on the underlying VLSI technology. Manufacturers of VLSI codecs have chosen a number of different architectural approaches. The advantages and disadvantages of each are discussed in the context of various applications with examples taken from existing or soon to be announced products. The AT&T AVP4000 chip set is described in some detail. Major design challenges included CAD tools for simulation and verification, packaging and the control of power dissipation     

视频编码系统模拟软件包的设计研究

视频编码国际标准的算法具有安全的开放性，因此，软件模拟是视频编码系统设计中十分重要的环节，本文采用面向对象技术，利用速成原型建模，设计了可模拟多个视频编码标准的软件包，该模拟软件包满足编码系统中扩充性的要求，适于研究不同压压缩算法，并模拟视频编码系统的执行，为构造实时编码系统提供正确的设计数据和适用的算法。     

International standards in radio communication

A REVIEW is given of some of the international technical standards activities and Recommendations of the International Radio Consultative Committee (CCIR) for radio communications. A new Recommendation for the digital coding of television signals provides a basis for a single world standard for video signals in broadcasting studios, recording, and exchange of programs. Work is underway on high-definition television and a standard for satellite direct broadcasting downlink. Fixed satellite earth-station antenna standards (developed earlier), and performance criteria for satellite links in the integrated services digital network are being improved. Digital microwave radio relay standards include allowable bit error ratio, channel arrangements, and baseband interconnection. Mobile service Recommendations include system standards for VHF/UHF automated radiotelephony, a future global maritime distress and safety system, and radio paging codes and formats. Standards for the use of ARQ in HF and maritime communications, and the use of Universal Coordinated Time (UTC) in international telecommunications, are based on CCIR Recommendations.     

Distributed Monoview and Multiview Video Coding

Growing percentage of the world population now uses image and video coding technologies on a regular basis. These technologies are behind the success and quick deployment of services and products such as digital pictures, digital television, DVDs, and Internet video communications. Today's digital video coding paradigm represented by the ITU-T and MPEG standards mainly relies on a hybrid of block- based transform and interframe predictive coding approaches. In this coding framework, the encoder architecture has the task to exploit both the temporal and spatial redundancies present in the video sequence, which is a rather complex exercise. As a consequence, all standard video encoders have a much higher computational complexity than the decoder (typically five to ten times more complex), mainly due to the temporal correlation exploitation tools, notably the motion estimation process. This type of architecture is well-suited for applications where the video is encoded once and decoded many times, i.e., one-to-many topologies, such as broadcasting or video-on-demand, where the cost of the decoder is more critical than the cost of the encoder.     

云平台上AVS视频转码系统的设计与实现

随着网络与宽带技术的飞速发展,数字视频呈现出海量化与多样化的特征.AVS作为我国自主音视频标准,编码效率优于同期国际标准,在保证图像质量的同时,便于视频数据的存储与传输.为了将数字视频进行高效的AVS转码,提出并实现了一种云平台上的AVS转码系统,该系统采用音视频分离方法将其他格式视频文件快速转码成AVS格式,并避免了转码文件中音视频内容间不同步问题,实验结果证明了方案的有效性.     

Motion Estimation for Video Coding Standards

Motion-compensated estimation is an effective means in reducing the interframe correlation for image sequence coding. Therefore, it is adopted by the international video coding standards, ITU H.261, H.263, ISO MPEG-1 and MPEG-2. This paper provides a comprehensive survey of the motion estimation techniques that are pertinent to video coding standards.There are three popular groups of motion estimation methods: i) block matching methods, ii) differential (gradient) methods, and iii) Fourier methods. However, not all of them are suitable for the block-based motion compensation structure specified by the aforementioned standards. Our focus in this paper is to review those techniques that would fit into the standards. In addition to the basic operations of these techniques, issues discussed are their extensions, their performance limit, their relationships with each other, and the other advantages or disadvantages of these methods. At the end, an example of evaluating block matching algorithms from a system-level VLSI design viewpoint is provided.     

The VC-1 Video Coding Standard

VC-1 is a new video coding standard developed by Microsoft and standardized by the SMPTE. VC-1 is one of the three video compression algorithms standardized for high definition DVD. With high definition DVD players expecting to support MPEG-2, H.264, and VC-1, end users do not have to be concerned about the coding formats. The VC-1 standard offers a competitive quality-complexity tradeoff compared to H.264, especially for high-definition services. With a diverse digital video market, we can expect to see VC-1 co-existing with H.264 in the next generation of broadband and broadcast video services.     

Advances in Scalable Video Coding

Scalable video coding is attractive due to the capability of reconstructing lower resolution or lower quality signals from partial bit streams. This allows for simple solutions in adaptation to network and terminal capabilities. Different modalities of scalability are specified by video coding standards like MPEG-2 and MPEG-4. This paper gives a short overview over these techniques and analyzes in more detail the encoder/decoder drift problem, which is the major reason why scalable coding has been significantly less efficient than single-layer coding in most of these implementations. Only recently, new scalable video coding technology has evolved, which seems to close the gap of compression performance compared to state of the art single-layer video coding. New methods of efficient enhancement layer prediction were developed to improve traditional (motion-compensated hybrid) scalable coders, providing more flexible compromises on the drift problem. As a new technology trend, motion-compensated spatiotemporal wavelet coding has matured which entirely discards the drift and allows most flexible combinations of spatial, temporal, and signal-to-noise ratio (SNR) scalability with fine granularity over a broad range of data rates.     

ADVANCES IN FRACTAL IMAGE AND VIDEO CODING

Fraotal coding is a very promising technique for image compression. However, it has not been widely used because of its high computational complexity, In this paper, techniques for reducing computational complexity of fractal coding are presented. Fractal coding is very effective for images containing sharp edges and smooth textures of large objects but not for small objects and fine details. In this paper, methods to improve overall image quality are presented. Also in this paper, approaches for applying fractal coding to very low bit-rate video as well as VLSI implementations for real-time applications are discussed.     

音视频编码标准AVS

着重描述了AVS的技术特点,包括AVS视频编解码框架、AVS视频编码的核心技术、AVS视频码流层次结构以及AVS图像质量主客观评价。还对视频编码的主要技术指标与国际同类标准MPEG4/AVC进行了比较。以AVS为核心的数字视频产业链＂技术→专利→标准→芯片与软件→整机与系统制造→数字媒体运营与文化产业＂正在形成,AVS同MPEG 4/AVC正在同台竞争下一代视频压缩标准。     

Instruction Set Extensions for MPEG-4 Video

This paper describes instruction set extensions for the acceleration of MPEG-4 algorithms on programmable (RISC-) CPUs. MPEG-4 standardizes audio and video compression schemes for a variety of bit rates and scenarios. As MPEG-4 targets a much broader range of different applications than previously defined hybrid video coding standards like H.263 or MPEG-2, it employs a much higher number of different algorithms and coding modes. Therefore, MPEG-4 implementations will require a more software-oriented approach to be efficient. However, the total computational load for an optimized implementation of an MPEG-4 video codec is expected to exceed the performance levels of today's multimedia signal processors, making further hardware acceleration a necessity. For that purpose, we propose a number of instruction set extensions that add function-specific blocks to the data path of a CPU. These dedicated modules are highly adapted to the most computation-intensive processing schemes of MPEG-4, such as DCT, motion compensation, padding, shape coding, or bitstream parsing. The increased functionality of basic instructions results in a significant speed-up over standard RISC instruction sets, thus making MPEG-4 implementations feasible on programmable processor platforms. Possible target architectures include VLIW multimedia processors, MIMD-style multiprocessors, or coprocessor architectures     

Digital audio coding for visual communications

Current and future visual communications for applications such as broadcasting videotelephony, video- and audiographic-conferencing, and interactive multimedia services assume a substantial audio component. Even text, graphics, fax, still images, email documents, etc. will gain from voice annotation and audio clips. A wide range of speech, wideband speech, and wideband audio coders is available for such applications. In the context of audiovisual communications, the quality of telephone-bandwidth speech is acceptable for some videotelephony and videoconferencing services. Higher bandwidths (wideband speech) may be necessary to improve the intelligibility and naturalness of speech. High quality audio coding including multichannel audio will be necessary in advanced digital TV and multimedia services. This paper explains basic approaches to speech, wideband speech, and audio bit rate compressions in audiovisual communications. These signal classes differ in bandwidth, dynamic range, and in listener expectation of offered quality. It will become obvious that the use of our knowledge of auditory perception helps minimizing perception of coding artifacts and leads to efficient low bit rate coding algorithms which can achieve substantially more compression than was thought possible only a few years ago. The paper concentrates on worldwide source coding standards beneficial for consumers, service providers, and manufacturers     

The Golden Age of Imaging

Imaging research, development, and applications are growing at an astounding rate, and image-processing researchers can take credit for having created much of the enabling technologies that have fueled this growth. The development of image and video coding standards, such as JPEG and MPEG, has enabled the web as a center for commerce and entertainment. Ubiquitous technologies, such as Direct TV, DVDs, BlueRay, and TiVo, depend on these standards; streaming Internet video services, like Tunes' recently announced movie rental feature, are well on their way to replacing traditional analog broadcast video. Other consumer products, such as home printers, digital cameras, and mobile video devices, have each been a major disruptive product enabled by fundamental innovation from image-processing researchers.     

MPEG-4视频对象分割技术

随着MPEG-4,MPEG-7的研究发展,其基于内容的编码和面向对象的存取和操纵技术日益得到人们的重视。基于对象的视频图像分割是实现MPEG-4基于内容的编码和交互功能的关键。视频图像分割方法分为自动分割法和半自动分割法两种。结合视频分割的发展趋势,深入介绍了基于对象的视频分割的主要技术及国内外的最新研究算法,包括数学形态学算法以及活动轮廓模型(蛇模型)在该领域的应用,并分析了当前视频分割技术尚存在的问题和研究前景。     

图像通信和图像图形处理芯片的新进展

由于VLSl技术和数字图像、图形处理技术、压缩编码技术的迅速发展,图像通信正得到广泛应用。而对小型化、实时性的要求进一步促进了高速高性能图像、图形处理芯片的开发。本文主要介绍用于实时图像通信、图像图形处理芯片和多媒介处理器的新进展。     

MPEG-2 over ATM for video dial tone networks: issues and strategies

Market growth for PC multimedia and digital video owes largely to the rapid adoption of ISO compression standards by the industry. For video dial tone (VDT) services, the MPEG-2 set of standards have clearly emerged as the preferred coding method for VDT networks. For point-to-point switched video or multimedia connections, ATM has emerged as the technology of choice for switching and transport. This article describes how compressed digital video is transported over a VDT network, what some of the issues are, and how they are being addressed by the industry. It describes a generic VDT reference architecture, and the delivery method of video and multimedia information over such a network     

Analog VLSI Circuits for Competitive Learning Networks

An investigation is made concerning implementations of competitive learning algorithms in analog VLSI circuits and systems. Analog and low power digital circuits for competitive learning are currently important for their applications in computationally-efficient speech and image compression by vector quantization, as required for example in portable multi-media terminals. A summary of competitive learning models is presented to indicate the type of VLSI computations required, and the effects of weight quantization are discussed. Analog circuit representations of computational primitives for learning and evaluation of distortion metrics are discussed. The present state of VLSI implementations of hard and soft competitive learning algorithms are described, as well as those for topological feature maps. Tolerance of learning algorithms to observed analog circuit properties is reported. New results are also presented from simulations of frequency-sensitive and soft competitive learning concerning sensitivity of these algorithms to precision in VLSI learning computations. Applications of these learning algorithms to unsupervised feature extraction and to vector quantization of speech and images are also described.     

Coding of 12-bit video from thermal imaging systems

A number of advanced applications of digital video technology exist which require pixels to be represented with a resolution higher than the 8 bits that is used in most existing video coding standards. These applications include the video generated by many modern thermal imaging systems used in surveillance applications, which has a dynamic range of 12 bits. In this paper, we describe the modifications required to extend existing video coding standards to support surveillance applications, concentrating on applications with pixels whose dynamic range is up to 12 bits. We examine the tools necessary to implement directly a 12-bit coding algorithm, as well as a scalable coding approach using SNR scalability.     

Evaluation architecturale VLSI de systèmes standard de codage ďimages

Image coding systems currently undergoing standardisation within ISO and CCITT are the final outcome of a process of incremental improvements to classical hybrid (transform-predictive) algorithms. The task of VLSI architecture synthesis for these complete systems is made somewhat awkward due to the unstructured, irregular and non-modular nature of these algorithms. An ad hoc methodology for pruning the architectural search space, directed by the goal of minimizing the overall internal memory, leads to a strongly control-flow solution, using a pipeline scheme more efficient than with the original signal-flow graph. A generic image coding processor using a parallel programmable architecture is another solution. It may be inferred that second generation image coding techniques should be designed with massive fine-grain parallelism in view, if they are to take advantage of the full potential of dedicated VLSI implementations.