MPEG-4 multimedia for our time

The MPEG-4 standard explores every possibility of the digital environment. Recorded images and sounds co-exist with their computer-generated counterparts, a new language for sound promises compact-disk quality at extremely low data rates; and the multimedia content could even adjust itself to suit the transmission rate and quality. Possibly the greatest of the advances made by MPEG-4 is that viewers and listeners need no longer be passive. The height of “interactivity” in audiovisual systems today is the users ability merely to stop or start a video in progress. MPEG-4 is completely different: it allows the user to interact with objects within the scene, whether they derive from so-called real sources, such as moving video, or from synthetic sources, such as computer-aided design output or computer-generated cartoons. Authors of content can give users the power to modify scenes by deleting, adding, or repositioning objects, or to alter the behavior of the objects. Perhaps the most immediate need for MPEG-4 is defensive. It supplies tools with which to create uniform (and top-quality) audio and video encoders and decoders on the Internet, preempting what may become an unmanageable tangle of proprietary formats. In addition to the Internet, the standard is also designed for low bit-rate communications devices, which are usually wireless     

MPEG-4 video object-based rate allocation with variable temporalrates

In object-based coding, bit allocation is performed at the object level and temporal rates of different objects may vary. The proposed algorithm deals with these two issues when coding multiple video objects (MVOs). The proposed algorithm is able to successfully achieve the target bit rate, effectively code arbitrarily shaped MVOs with different temporal rates, and maintain a stable buffer level     

Error concealment for shape in MPEG-4 object-based video coding.

In asynchronus transfer mode networks, cell loss or channel errors can cause data to be dropped in the channel. When digital images/videos are transmitted over these networks, one must be able to reconstruct the missing data so that the impact of the errors is minimized. In this paper, we present an error-concealment technique for shape in MPEG-4 object-based video coding. This method, which is based on using global motion estimation and compensation techniques for boundary recovery, consists of three steps: (1) boundary extraction from shape; (2) boundary patching using global motion compensation; and (3) boundary filling to reconstruct the shape of the damaged video object planes. Global motion parameters are inserted as part of the USER_DATA field in the compressed stream and are utilized in reconstructing the damaged boundaries of compressed video object planes.     

The delivery layer in MPEG-4

The MPEG-4 specifications have provided substantial progress in many areas of multimedia technology. Following MPEG tradition, MPEG-4 focuses on media coding. However, a couple of innovative aspects other than media coding characterise MPEG-4 with respect to its predecessors: the ability to code an audio-visual scene, and the ability to abstract from the delivery technology. This paper focuses its attention on this later aspect, which is covered by part 6 of the MPEG-4 specification: DMIF (Delivery Multimedia Integration Framework). The paper explains the motivations that have driven the delivery technology abstraction, analyses the details of the DMIF architecture, and highlights the practical impact on the “bits-on-the-wire” and on conformance issues. It is important not to forget, throughout this paper, that the whole focus of this work is on real-time delivery of multimedia content.     

基于因特网的MPEG-4视频流技术

从力求视频流服务质量最好的角度，介绍和讨论基于因特网的MPEG-4视频流技术分压缩编码方法、QOS控制和传输结构体系。     

MPEG-4: a multimedia compression standard for interactiveapplications and services

The Moving Pictures Experts Group (MPEG), which produced the MPEG-1 and MPEG-2 video and audio compression standards, is developing the MPEG-4 standard. MPEG-4 targets interactive multimedia applications and will become a standard in 1999. As well as an increased compression efficiency, MPEG-4 will also offer content-based functionality, i.e. the possibility of accessing and manipulating individual objects in the picture. Furthermore, MPEG-4 will offer possibilities for efficient video storage and for transmission over poor audio and video channels at bit rates between 5 kbit/s and 4 Mbit/s. This paper gives an overview of the state of the art of MPEG-4 development, concentrating especially on video content-based functionality, which is so important for interactive applications     

MPEG-4多媒体移动通信系统的一种有效复用结构

介绍了一种基于MPEG－4标准的移动多媒体的两层复用结构。第一层对有相似服务质量（QoS）要求的基本数据流进行打包，形成具有较少QoS要求的数据流；第二层为每个数据流提供相应的防误码措施，形成可在易误码链路进行传输的单一数据流，达到既满足各个基本数据流防误码的要求,又使复用开销最小。     

MPEG-7与多媒体信息检索

简要阐述了MPEG-7的概况和多媒体数据的内容和结构，并对应用MPEG-7进行多媒体的信息检索作了一定的探讨。介绍了当前多媒体信息检索的主要技术和今后的主要研究方向。     

多媒体框架标准MPEG-21

1999年提出的作为多媒体框架标准的MPEG—21目前也取得了重大进展，正引起人们的广泛关注。文中即对MPEC一21的目标、基本概念、关键要素、工作规划及应用领域等给予概括阐述。     

MPEG-4: a multimedia standard for the third millennium. 1

MPEG-4 (formally ISO/IEC international standard 14496) defines a multimedia system for the interoperable communication of complex scenes containing audio, video, synthetic audio and graphics material. In this article, we provide a comprehensive overview of the technical elements of the Moving Pictures Expert Group's MPEG-4 multimedia system specification     

MPEG-4: a multimedia standard for the third millennium. 2

MPEG-4 defines a multimedia system for interoperable communication of complex scenes containing audio, video, synthetic audio, and graphics material. In part 1 of this two-part article (Battista et al., 1999) we provided a comprehensive overview of the technical elements. In part 2 we describe an application scenario based on digital satellite television broadcasting, discuss the standard's envisaged evolution, and compare it to other activities in forums addressing multimedia specifications     

Adaptive and personalized multimedia content delivery for disabled users in Internet TV

This paper aims at the delivery of adaptive and personalized multimedia content in interactive Internet Protocol TeleVision (IPTV) environments, using programmable IP services through the MPEG-21 standard, also supporting the features for users with disabilities. Moreover, we propose a system that adapts to users’ preferences using profile separation, not only for individual users but also for user groups as a whole. The system takes advantage of explicit and implicit information through the users’ interaction with the IPTV environment, while the profile reflects groups of similar users, thus dropping the time needed for matching user patterns and profiles when forming a recommendation. The system works in conjunction with a simulation platform acting as an interaction interface between the IPTV architecture and the prospective viewer. Based on this, interactivity in IPTV is faced through metadata and adaptation.     

MPEG-21 event reporting: enabling multimedia e-commerce

To foster multimedia e-commerce, MPEG is developing a new part of the MPEG-21 standard that specifies the creation and delivery of events related to peer usage of digital items. This overview of MPEG's work on event reporting describes the standard's new part and positions it in relation to other efforts.     

Efficient MPEG-4/H/263 video transcoder for interoperability of heterogeneous multimedia networks

As well as some similarities, there are a number of differences between MPEG-4 and the H.263 bitstream syntax. The inclusion of a video transcoder is proposed to achieve interoperability between the two video standards. This novel transcoding algorithm is proved to give highly improved service quality while reducing the complexity and the time delay of conventional cascaded decoding/re-encoding processes.     

因特网环境下MPEG-4视频自适应码率控制方案

介绍了因特网上一种端到端的MPEG-4视频网络传输结构的自适应码率控制方案.结合RTP/RTCP协议,通过终端系统的反馈控制算法,在视频发送端的MPEG-4编码器中由合适的码率调整算法自适应地调整输出码率,从而最大限度地利用网络带宽资源,并且保证视频传输的视觉感知质量.     

MPEG-21: The 21st century multimedia framework

The lack of interoperable (and thus standardized) solutions is stalling the deployment of advanced multimedia packaging and distribution applications although most of the individual technologies are indeed already present. This motivated MPEG (ISO/IEC JTCl SC29 WGI I) in June 2000 to start working on the definition of enabling normative technology for the multimedia applications of the 21st century: MPEG-21 "Multimedia Framework." MPEG-21's approach is to define a framework to support transactions that are interoperable and highly automated, specifically taking into account digital rights management (DRM) requirements and targeting multimedia access and delivery using heterogeneous networks and terminals. This article first outlines the context and background of the MPEG-21 initiative. Then, an overview of MPEG-21 technology is given. Subsequently, it is discussed how MPEG-21 can provide solutions for universal multimedia access (UMA). UMA is also one of the use cases that has led to the creation of a new part in MPEG-21 dealing with digital item adaptation. Finally, this article concludes with an overview of MPEG-21 related activities and an outlook on future developments.     

一种基于因特网的MPEG-4视频流端到端传输方案

在保证网络资源利用率高的条件下如何建立一个使所传图像主观质量最好且有效的MPEG－4传输系统，已成为一个具有挑战性的课题，就此问题提出了一个在因特网上建立MPEG－4视频流的端到端传输方案。