检索结果-内蒙古大学图书馆

Motion estimation for high performance transcoding

IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 1998年第3期44卷 649-658页

作者： Youn, J Sun, MT Lin, CW Univ Washington Dept Elect Engn Informat Proc Lab Seattle WA 98195 USA ITRI Comp & Commun Res Labs Mito Ibaraki 310 Japan

Traditionally, the re-use of motion vectors extracted from incoming video bit-stream during transcoding has been widely accepted. However, this simple re-use scheme introduces significant quality degradation in many applications including the situation when the frame-rate conversion is needed. In this paper, we analyzed the quantization errors that cause the extracted motion vectors to be non-optimal and we performed simulations to show the quality degradation due to the inaccurate motion vectors during transcoding. To improve the video quality, we proposed an adaptive motion vector refinement. With a highly reduced computational complexity, the proposed adaptive motion vector refinement achieves significant quality improvement in comparison to the conventional motion vector re-use scheme. In addition, the adaptive motion vector refinement is almost as good as performing a new full-scale motion estimation.

关键词： Motion estimation transcoding Degradation Motion analysis Error analysis Performance analysis Quantization Computational modeling Analytical models Computational complexity

来源：评论

学校读者我要写书评

暂无评论

AMTM - An adaptive multimedia transport model

AMTM - An adaptive multimedia transport model

引用

Conference on International Multimedia Management Systems

作者： Liao, CY Shi, YC Xu, GY Tsinghua Univ Dept Comp Sci & Technol Beijing 100084 Peoples R China

ISBN: (纸本)0819438758

With the rapid development of computer network, there appear so many new applications and multimedia data that the chasm, which between the singularity of data sources and the variation of network, terminal devices and users, grows wider and wider. In this paper, we propose a novel algorithm, known as Adaptive Multimedia Transport Model (AMTM), and implement an adaptive supporting platform for multimedia delivery, which can dynamically transcode the multimedia data to accustom them to the variation as said above without data redundancy, so it will become more convenient to develop new applications with the automatic adaptability.

关键词： AMTM transcoding adaptive delivery supporting platform multimedia network

来源：评论

学校读者我要写书评

暂无评论

transcoding DV into MPEG-2 in the DCT domain

Transcoding DV into MPEG-2 in the DCT domain

引用

Meeting on Visual Communications and Image Processing

作者： Kim, D Youn, B Choe, Y Yonsei Univ Sch Elect & Mech Engn Seoul 120749 South Korea

ISBN: (纸本)0819431249

transcoding Digital Video (DV) for Digital Video Cassette Recorder (DVCR) into MPEG-2 intra coding is performed in the DCT domain to reduce conversion steps. Multiplying matrix by transformed data is used for 4:1:1-to-4:2:0 chroma format conversion and 2-4-8 DCT mode to 8-8 DCT mode conversion for parallel processing. M_quant of MPEG-2 rate control is computed in the DCT domain. For MPEG-2 inter coding, fast motion estimations taking advantage of data in the DCT domain are studied for transcoding. Among them, ME with overlapped search range shows better PSNR performance than ME without overlapping.

关键词： transcoding MPEG-2 digital video cassette recorder motion estimation discrete cosine transform

来源：评论

学校读者我要写书评

暂无评论

Implementations of error resilient transcoders for MPEG-2 video over HIPERLAN

引用

Conference on Visual Communications and Image Processing

作者： Cain, GJ Redmill, DW Bull, DR Victoria Univ Melbourne Vic Australia

ISBN: (纸本)0819437034

Digital video broadcasts (DVB) can be redistributed over a local area network using the packet based HIPERLAN (High Performance Radio Local Area Network) protocol. An example of the application of this technology is wireless communication within the home environment. This paper addresses the problem of transmitting MPEG-2 video over HIPERLAN and describes error resilient video transcoding as a means of handling channel errors. The implementation of two transcoding techniques on both PC and DSP platforms are discussed.

关键词： HIPERLAN MPEG-2 transcoding error resilience

来源：评论

学校读者我要写书评

暂无评论

transcoding of MPEG video using lattice vector quantization

Transcoding of MPEG video using lattice vector quantization

引用

IEEE International Conference on Image Processing

作者： L. Lois S. Bozoki Department of Mobile and Broadband Communications Hungarian Telecommunications Company Limited Department of Telecommunications Technical University of Budapest Hungary

We propose a new transcoding method for MPEG video bit-streams. In our implementation, instead of using scalar quantization in the transcoder, a lattice vector quantizer (LVQ) is applied to exceed the MPEG compression capabilities while providing acceptable quality. In this way, the transcoded video is not MPEG-compatible anymore, hence a low cost user interface is needed prior to the MPEG decoding. However, the decoded pictures have higher subjective quality compared to those transcoded by an MPEG-compatible transcoder at the same bit-rate. Due to the LVQ the quantization noise is more uniform on the pictures, and less artifacts are visible around the edges. Beside this, a slight improvement in the PSNR was also experienced by using certain LVQ parameters.

关键词： transcoding Lattices Vector quantization Decoding Transform coding Video on demand Video compression User interfaces PSNR Streaming media

来源：评论

学校读者我要写书评

暂无评论

transcoding Internet content for heterogeneous client devices

Transcoding Internet content for heterogeneous client device...

引用

IEEE International Symposium on Circuits and Systems (ISCAS)

作者： J.R. Smith R. Mohan Chung-Sheng Li IBM Thomas J. Watson Research Center Hawthorne NY USA

There is a growing diversity of client devices that have access to the Internet. However, much of the content on the Internet cannot be handled by the devices that have limited communication, processing, storage and display capabilities. In order to improve the utility of a wide range of client devices, we propose a network-based solution for transcoding Internet content. The system uses an InfoPyramid for representing and transcoding video, images, audio and text. The InfoPyramid manipulates the content along the dimensions of fidelity and modality, and aggregates the methods for content analysis, translation, filtering and selection. The InfoPyramid utilizes a policy engine, which incorporates user and publisher preferences, various transcoding policies, device descriptions, and real-time network constraints in order to adapt the Internet content to the client devices.

关键词： transcoding Internet Personal digital assistants Search engines Markup languages Image coding Milling machines Rivers Displays IP networks

来源：评论

学校读者我要写书评

暂无评论

An integrated source coding and congestion control framework for video streaming in the Internet

An integrated source coding and congestion control framework...

引用

IEEE Annual Joint Conference: INFOCOM, IEEE Computer and Communications Societies

作者： Kang-Won Lee R. Puri Tae-eun Kim K. Ramchandran V. Bharghavan Coordinated Science Laboratory University of Illinois Urbana-Champaign USA Electrical Engineering and Computer Science University of California Berkeley USA

We describe a framework for video transmission over the Internet that features the coordinated operation of an application-layer video source coding algorithm and a transport-layer rate control mechanism. The proposed video coding scheme operates on a progressively encoded video stream and provides graceful resilience to network packet drops. The robustness is enabled through a generalized multiple description (MD) coding strategy, architectured as an adaptive array of packet-erasure correction codes. The video coding algorithm is matched to an efficient and reactive rate control mechanism that minimizes the fluctuation of rate and uses the profile of past losses to adjust the rate in a TCP-friendly manner. While the two constituent algorithms identified above are interesting in their own right, a key feature of this work is the integration of these algorithms in a simple framework that seeks to maximize the expected delivered video quality at the receiver through coordinated adaptation of the two components. We present simple simulation results to illustrate the utility of our approach.

关键词： Source coding Streaming media Internet Video coding Fluctuations transcoding Forward error correction Computer science Resilience Adaptive arrays

来源：评论

学校读者我要写书评

暂无评论

Evaluation of adaptive filtering of MPEG system streams in IP networks

Evaluation of adaptive filtering of MPEG system streams in I...

引用

IEEE International Conference on Multimedia and Expo (ICME)

作者： M. Hemy P. Steenkiste T. Gross School of Computer Science Pittsburgh PA USA Carnegie Mellon University Pittsburgh PA US

Congestion and large differences in available link bandwidth create challenges for the design of applications that want to deliver high quality video over the Internet. We investigate the placement of computation agents within the network to provide filtering to adapt MPEG system streams to the available bandwidth without transcoding. The paper presents an evaluation of our implementation in three different operating environments: a networking testbed in a laboratory environment, a home-user scenario (DSL line with 640 Kbit/sec), and a wide area network covering the Atlantic (server in Europe, client in the US). Our architecture leverages previous work and introduces efficient MPEG system filtering to achieve high quality video over best-effort networks.

关键词： Adaptive filters Streaming media Bandwidth Internet Computer networks Information filtering Information filters transcoding Testing DSL

来源：评论

学校读者我要写书评

暂无评论

Progressive video transmission over a wired-to-wireless network

Progressive video transmission over a wired-to-wireless netw...

引用

IEEE Conference on Vehicular Technology (VTC)

作者： R. Anand C. Podilchuk H. Lou Multimedia Communications Research Laboratory Bell Laboratories Lucent Technologies Inc. Murray Hill NJ USA University of California Berkeley Murray Hill USA

Advances in mobile computing, combined with the increasing demand for multimedia services on mobile terminals have generated much interest in error-resilient video transmission over wireless networks. Much of the work on video transmission has focused on either dealing with packet losses due to congestion found in IP wireline networks or bit errors and packet losses due to the fading channel environment of a wireless network. Many of the applications for multimedia services will involve video transmission over a wired-to-wireless link and an important research topic is error-resilient video which can adapt to the different conditions found in a wired and wireless environment. The current solutions in transmission of multimedia across different networks include some type of transcoder where the source is partially or fully decoded and re-encoded to suit the network conditions. Here we introduce a flexible progressive source/channel coding framework for video which can adapt to the different conditions imposed by wired and wireless channels at the bitstream level, avoiding the often computationally complex step of transcoding between networks that could deteriorate decoded video quality. The framework also allows for graceful degradation of video quality when the network conditions are poor due to congestion or deep fades.

关键词： Mobile computing Computer networks Wireless networks Propagation losses Decoding Multimedia computing Fading Channel coding transcoding Degradation

来源：评论

学校读者我要写书评

暂无评论

The use of software agents as proxies

The use of software agents as proxies

引用

IEEE Symposium on Computers and Communications (ISCC)

作者： B. Thai A. Seneviratne School of Electrical Engineering and Telecommunications University of New South Wales Sydney Australia

Today information can be accessed from the Internet using a variety of devices and via different types of networks. With such diversity, it is impossible for a server on the Internet to contain information for all different types of clients. A possible solution to this problem is to use proxies to alter the content and to provide network enhancements to suit client's individual requirements. The current proxy-based solutions rely on static implementations which have several disadvantages. We believe that it will be possible to overcome these disadvantages by making the proxies transportable and active, i.e. the use of proxy agents. In this paper we present the architecture of such a proxy agent system, and the implementation of a prototype to evaluate its viability.

关键词： Software agents Network servers IP networks Web server Delay transcoding Internet Prototypes Modems Web pages

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：