This tutorial contribution covers the use of International Standard IS 13818-1 (MPEG-2 Systems) Transport Stream in Digital TV systems with main emphasis on broadcast systems. The Transport stream was developed by Working Group 11 of ISO/IEC JTC1 as a means for multiplexing and synchronizing multiple video and audio data as well as for transmission in a non-error resilient environment This paper describes some salient features of the Transport Stream and details of how it is used to implement a complete end to end digital TV broadcast service with examples of functionality to support data, channel acquisition, navigation and near video on demand (NVOD) services.
AC-3 is a system for coding up to 3.1 channels of audio into a low bit-rate data stream. High quality may be obtained with compression ratios approaching 12-1 for multichannel audio programs. The high compression ratio is achieved by methods which do not increase decoder memory, and thus cost. The methods employed include: the transmission of a high frequency resolution spectral envelope; and a novel forward/backward adaptive bit allocation algorithm. In order to satisfy practical requirements of an emissions coder, the AC-3 syntax includes a number of features useful to broadcasters and consumers. These features include: loudness uniformity between programs; dynamic range control; and broadcaster control of downmix coefficients. The AC-3 coder has been formally selected for inclusion in the U.S. HDTV broadcast standard, and has been informally selected for several additional applications.
A major advantage of ATM is the ability to support a wide spectrum of video-based and other services using a common network infrastructure. For video-based services, ATM provides the platform for achieving consistent video quality, multiple simultaneous video services, and the ability to select quality within a service.
This paper addresses the network issues including Quality of Service (QOS) that must be provided by ATM network in support of the video-based MPEG2 and JPEG encoded services. State of the art and current commercial availability and future viability of MPEG2 and JPEG codec development are also discussed.
DA VIC (Digital Audio Visual Council) is the defacto standardization organization established in Mar. 1994, based on international consensus for digital audio visual services. After completion of MPEG2 standardization, the broadcasting industry, the communication industry, the computer industry, and consumer electronics industry have started development of concrete services and products. Especially the interactive digital audio visual services, such as Video On Demand(VOD) or Near Video On Demand (NVOD), have become hot topics all over the world. Such interactive digital audio visual services are combined technologies of multi-media coding, digital transmission and computer networking. Therefore more than 150 organizations from all industry sectors have participated in DAVIC and are contributing from their own industrial contexts. DAVIC's basic policy is to use the available technologies specified by the other standards bodies as much as possible. So DA VIC's standardization activities have close relationship with ISO IEC / JTC1 / SC29, ITU-T SG 9, ATMForum, IETF, IMA, DVB, etc.
DAVIC is trying to specify Applications, Reference Models, Security, Usage Information Control, and the interfaces and protocols among the Content Provider, the Server the core network, the access network, and the Set Top Unit (STU).
DAVIC's first goal is to specify DA VIC 1.0 based on CHP1 (Call for Proposal) and CFP2 by Dec. 1995, and the next direction is under preparation for further progress based on CFP3 and CFP4.
In this paper we first introduce some R and D activities to develop the technical standards for digital standard definition TV(SDTV) and high definition TV(HDTV) as well as MPEG related activities in Korea. Then we present the key elements of the technical standards of SDTV and HDTV via satellite, which are based on the MPEG- 2 international standard. We describe design and implementation of a prototype DTV encoding system we developed. We also explain the system architecture and design considerations for the development of the prototype HDTV encoding system with application specific integrated circuit(ASIC)s. Both of these prototype systems will be used to verify the technical standards, which need to be prepared for the introduction of digital video services.
Terrestrial broadcast television in the United States has remained essentially unchanged in the last fifty years except for the addition of color and stereo sound. Today, personal computers are addressing the need for random access of high resolution images and CD quality audio. Furthermore, advances in digital video compression and digital communication technology have cleared the way toward offering high resolution video and audio services to consumers using traditional analog communications channels.
In 1987, the U.S. Federal Communications Commission (FCC) chartered an advisory committee to recommend an advanced television system for the United States. From 1990 to 1992, the Advanced Television Test Center (ATTC) tested four all-digital systems, one analog High Definition Television (HDTV) system, and one enhancement NTSC system using broadcast and cable television environment simulators. The formation of the HDTV Grand Alliance in May of 1993 resulted from the withdrawal of the only analog HDTV system from the competition and a stalemate between the other four all-digital systems.
The HDTV Grand Alliance system is composed of the best components from previously competing digital systems demonstrated to the FCC. Moving Pictures Experts Group (MPEG-2) syntax is used with novel encoding techniques to deliver a set of video scanning formats for a variety of applications. This paper describes the important features and concepts embodied in the HDTV Grand Alliance system.
This paper describes development and standardization work on HDTV. Technical research and development and standardization are equally important These affect each other and sometimes come into conflict. HDTV provides a good example for considering the relationship between R and D and standardization.
The video coding and distribution approach presented in this paper has two key characteristics that make it ideal for integration of video communication services over common broadband digital networks. The modular multi-resolution nature of the coding scheme provides the necessary flexibility to accommodate future advances in video technology as well as robust distribution over various network environments.
This paper will present an efficient and scalable coding scheme for video communications. The scheme is capable of encoding and decoding video signals in a hierarchical, multilayer fashion to provide video at differing quality grades. Subsequently, the utilization of this approach to enable efficient bandwidth sharing and robust distribution of video signals in multipoint communications is presented. Coding and distribution architectures are discussed which include multi-party communications in a multi-window fashion within ATM environments.
Furthermore, under the limited capabilities typical of wideband/broadband access networks, this architecture accommodates important video-based service applications such as Interactive Distance Learning.
Motion-compensated estimation is an effective means in reducing the interframe correlation for image sequence coding. Therefore, it is adopted by international video coding standards, CCITT H.261 and ISO MPEG-1 and MPEG-2. This paper provides a comprehensive survey of the motion estimation techniques that are pertinent to video coding standards.
Three popular groups of motion estimation methods are presented: 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.
With the advent of ISDN / OSI products conforming to international standards, interconnectivity or interoperability has been attracting users’ attention over the world. By means of interconnectivity testing, domestic or international, interconnectivity of H. 320 terminals through commercial ISDN networks is getting more and more reliable.
Currently, ratio of successful calls is about 90% according to measurements made by HATS Conference (Japan). This means one out of ten (10) calls will be incomplete on the average. To make users very comfortable with H. 320 terminals, higher ratio is expected and it is well within our reach according to the author’s experience.
In order to realize higher reliability and better utility of H.320 terminals, international cooperation throughout the world is strongly desired.
An overview of the new H.324 standard for real-time multimedia teleconferencing is presented. Its main components, H.223, H.245, H.263, and G.723 are briefly reviewed, with emphasis on the improvements of each one over their corresponding H.320 series standards.
The draft international standard ITU-T H.263 is closely related to the well known and widely used ITU-T Recommendation H.261. However, H.263 does provide the same subjective image quality at less than half the bit-rate. In this paper we investigate to what extend single enhancements of H.263 contribute to this performance gain, and consider the trade-off quality vs. complexity. Based on the test sequence “Foreman”, H.263 in its default- and optional codingmodes is compared to H.261 on the basis of rate distortion curves at bit-rates up to 128 kbps. At 64 kbps, the performance gain of H.263 in its default mode compared to H.261 is approximately 2 dB PSNR. This improvement is achieved with only little increase of complexity, and is mainly due to more accurate motion compensation with half-pel accuracy. Considering the trade-off quality vs. complexity, the combination of the optional coding-modes “Advanced prediction mode” and “PB-frames mode” seems to be a good compromise, resulting in an additional performance gain of 1 dB PSNR at 64 kbps. The “Syntax-based arithmetic coding mode” on the other hand, offers only a very small performance gain (0.2 dB PSNR at 64 kbps) for its increased computational complexity. Results from profiling a H.263 software codec are presented in order to support complexity considerations of the optional coding-modes.
This paper presents a review of the evolving ISO MPEG-4 standard for coding audio and visual information. MPEG-4 is the next generation audio visual coding standard that promises to provide new ways for communication, access and manipulation of audio-visual information. It is being defined to provide a flexible framework and an open set of coding tools for supporting a number of useful functionalities that are not easily supported by the existing compression standards. In this paper the current status of the standard is reviewed and its future directions and potential applications are explored.
Design of a cost-effective microprocessor architecture for MPEG video decoding requires not only the analysis of MPEG algorithms in terms of the raw number of additions or multiplications, but more importantly, a careful study of mapping those algorithms to the target processor architecture at the instruction level. Even though smart compilers can generate fast and compact codes that rival the hand-optimized code on sequential algorithms, a more accurate evaluation of the processor performance on parallel algorithms such as the core functions in the MPEG-2 decoding is achieved by hand-optimizing the tight loop.
In this paper, we analyze the computational requirements of the key MPEG-2 decoding functions from the instruction level. We use a generic sequential processor model with a RISC-like instruction set to map the tight loop of the key functions to machine instructions. We then extend our processor model to instruction-level parallel (ILP) architectures and present the speed improvement of each key function on two different ILP features and as the degree of parallel processing is increased.
In this paper we describe the MPEG2 4:2:2 Profile @ Main Level (abbreviated to 422@ML), and present a study of its characteristics. The MPEG2 422@ML provides a standard based conformance point that addresses, among other applications, the needs of the professional studio and post production environment. In the paper the requirements of such an environment for compressed digital video together with a functional description of the 4:2:2 Profile are given. The 422@ML provides a flexible compression solution that allows edit-ability, supports a wide range of bit rates, and provides good to excellent quality in both intra and inter studio environment. Our experiments show that the 422@ML is very robust in a multi generation environment, provides an efficient coding solution for transmission and storage, and provides transparency or near transparency in stressing operations such as digital video transformations, quality.
Many current as well as emerging applications in areas of entertainment, remote operations, manufacturing industry and medicine can benefit from the depth perception offered by stereoscopic video systems which employ two views of a scene imaged under the constraints imposed by human visual system. Among the many challenges to be overcome for practical realization and widespread use of 3D/stereoscopic systems are good 3D displays and efficient techniques for digital compression of enormous amounts of data while maintaining compatibility with normal video decoding and display systems.
After a brief introduction to the basics of 3D/stereo including issues of depth perception, stereoscopic 3D displays and terminology in stereoscopic imaging and display, we present an overview of tools in the MPEG-2 video standard that are relevant to our discussion on compression of stereoscopic video, which is the main topic of this paper. Next, we outilne the various approaches for compression of stereoscopic video and then focus on compatible stereoscopic video coding using MPEG-2 Temporal scalability concepts. Compatible coding employing two different types of prediction structures become potentially possible, disparity compensated prediction and combined disparity and motion compensated predictions. To further improve coding performance and display quality, preprocessing for reducing mismatch between the two views forming stereoscopic video is considered.
Results of simulations performed on stereoscopic video of normal TV resolution are then reported comparing the performance of two prediction structures with the simulcast solution. It is found that combined disparity and motion compensated prediction offers the best performance. Results indicate that compression of both views of stereoscopic video of normal TV resolution appears feasible in a total of 6 to 8 Mbit/s. We then discuss regarding multi-viewpoint video, a generalization of stereoscopic video. Finally, we describe ongoing efforts within MPEG-2 to define a profile for stereoscopic video coding, as well as, the promise of MPEG-4 in addressing coding of multi-viewpoint video.
MPEG is the very successful standardizing activities which has opened multimedia world. What have been given by the MPEG standards? Impact to industries and standardizing fields are listed in this paper. Among many issues, timely and feasible nature of MPEG and IPR issues are main discussions.