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IEEE International Symposium on Circuits and Systems (ISCAS)

作者： Tsung-Han Tsai Chuh-Chu Yen Department of Electrical Engineering National Central University Taiwan

ISBN: (纸本)0780374487

MP3 is the popular audio coding standard. But now, a new higher quality audio coding standard Advanced audio coding (AAC) is proposed and widely used. The quantization/re-quantization is essential in both MP3 and AAC. This paper proposes a new high accuracy estimation algorithm for MP3 and MEPG-4 AAC audio coding. The algorithm can be applied not only for re-quantization process in decoder, but also for quantization in encoder. According to the floating-point behavior description, the proposed algorithm can achieve the lowest error result measured in quantization/re-quantization. Furthermore, in order to maintain the high quality with limited data precision, finite word length for fixed-point effects are investigated. Our algorithm has the low complexity advantages of multiplication-free and low memory requirements which will be more suitable in VLSI design for audio encoder/decoder.

关键词： Quantization Digital audio players MPEG 4 Standard audio coding Table lookup Decoding Costs Hardware Very large scale integration Algorithm design and analysis

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Dynamic algorithm transforms for reconfigurable real-time audio coding processor

Dynamic algorithm transforms for reconfigurable real-time au...

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International Conference on Parallel Computing in Electrical Engineering (PARLEC)

作者： A. Petrovsky Computer Science Department Belaruasian State University of Informatics and Radioelectronics Minsk Republic of Belarus

In this paper, dynamic algorithm transforms (DAT) for reconfigurable real-time processor for audio coding based on the adaptive wavelet packet decomposition are presented. The DAT technique is used to constrain a minimum cost subband decomposition of wavelet transform by maximizing the minimum masking threshold (which is limited by the perceptual entropy) in every subband for the given embedded processor architecture and temporal resolution.

关键词： Heuristic algorithms audio coding Signal processing algorithms Wavelet transforms Wavelet packets Real time systems Digital signal processing Signal processing Electronic mail Entropy

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Fast and lossless implementation of the forward and inverse MDCT computation in MPEG audio coding

Fast and lossless implementation of the forward and inverse ...

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IEEE International Symposium on Circuits and Systems (ISCAS)

作者： T. Krishnan S. Oraintara Department of Electrical Engineering University of Texas at Arlington Arlington TX USA Department of Electrical Engineering University of Texas at Arlington Arlington TX

The modified discrete cosine transform (MDCT) is a lapped transform used in transform coding schemes as an analysis/synthesis filter bank based on the concept of time domain aliasing cancellation. We propose to implement the MDCT using the lifting scheme for its lossless implementation with integer coefficients. The lifting scheme requires that the MDCT structure be composed of orthonormal matrices. In this paper we obtain the orthonormal factorization of the rotations and the DCT/DST blocks of the MDCT. The new MDCT structure obtained is then implemented using the lifting scheme. This renders the MDCT impervious to quantization errors making it a lossless scheme, in the sense that any quantization error introduced by the forward transform is removed by the inverse transform. A performance comparison of the proposed implementation and the current technique is presented.

关键词： audio coding Discrete cosine transforms Discrete transforms Transform coding Filter bank Time domain analysis Quantization Frequency Batteries Multimedia communication

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Hybrid natural and structured audio coding for 3D scenes

Hybrid natural and structured audio coding for 3D scenes

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IEEE International Conference on Multimedia and Expo (ICME)

作者： S. Battista G. Zoia A. Simeonov Ruo-hua Zhou bSoft Ltd. Italy Swiss Federal Institute of Technology Switzerland

Natural and structured audio representations can be characterized by the lack or presence of a model describing the sound, respectively; combination of the two approaches can lead to efficient and improved storage and transmission of both speech and music, mixing less efficient but general technologies with more compact and specialized models. Integration of natural audio tracks with structured sound and 3D spatial processing is a challenging effort, especially when the audio, scene requires high quality and precise synchronization with video and graphic information, as it is the case in professional multimedia and virtual reality frameworks. In this paper natural and structured sound are surveyed and a new player is presented, which supports all the mentioned technologies in a normative context.

关键词： audio coding Layout Virtual reality Space technology Pulse modulation Phase change materials Speech Music Graphics Headphones

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Sampling rate scalable lossless audio coding

Sampling rate scalable lossless audio coding

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IEEE Workshop on Speech coding Proceedings

作者： T. Moriya A. Jin T. Mori K. Ikeda T. Kaneko NTT Cyber Space Laboratories NTT Corporation Musashino Japan

This paper proposes a lossless audio coding scheme with hierarchical sampling rate scalability. A single bit stream contains hierarchical information that can generate waveforms ranging from a 96 kHz with 24 bit amplitude resolution through lower sampling/resolution lossless waveforms to highly compressed lossy ones created using an MPEG-4 audio coder. This bit stream structure enables a dynamic rate control and a hierarchical multicasting based on a simple priority control of the IP packet. These functions will be useful for high quality archiving, broadband streaming for various types of networks and terminal equipments.

关键词： Sampling methods audio coding Bit rate Streaming media MPEG 4 Standard Laboratories Scalability Optical distortion Optical fiber networks Signal resolution

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Compression enhancement of video motion of mouth region using joint audio and video coding 5

Compression enhancement of video motion of mouth region usin...

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5th IEEE Southwest Symposium on Image Analysis and Interpretation

作者： Mujal, M Kirlin, RL Univ Politecn Cataluna Dept Signal Theory & Commun E-08028 Barcelona Spain

ISBN: (纸本)0769515371

We propose an application that utilizes audio and video data dependencies to achieve additional video compression in low-bit rate encoding systems such as: H.263+ video coding and G.723.1 audio coding standards, The joint correlation of synchronized audio and motion parameters has been proved to exist. A joint performance of Principal Component Analysis (PCA) by Karhunen-Loeve expansions (KL) and Tree-Structured [lector Quantization algorithms (TSVQ) based on Linde-Buzo-Gray (LBG) and Competitive Learning (CL) techniques achieve as much as 60% bit reduction for the motion in the mouth region (1% of the overall output bit rate of a P frame) and provide the same motion-compensated image quality in high picture formats. We show performance evaluations that determine the optimal audio parameters, such as Linear Predictive Coefficients (LPC) or Line Spectrum Pairs (LSP), and determine the nature of the motion parameter in each macroblock of the mouth region when using Advanced Prediction Mode (APM) video coding.

关键词： audio coding Bit rate Encoding Motion analysis Mouth Principal component analysis Region 1 Vector quantization Video coding Video compression

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Underground wireless communications using high-temperature superconducting receivers

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IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 2004年第1期14卷 46-53页

作者： Vasquez, J Rodriguez, V Reagor, D Los Alamos Natl Lab Los Alamos NM 87545 USA

The authors have developed a method for communicating in underground areas with voice. This system utilizes low-frequency electromagnetic radiation and high-temperature superconducting quantum interference devices (SQUIDs) as receivers. The system is primarily,used to communicate in underground areas using through-the-earth electromagnetic waves. The underground areas are typically mines, but the application is not restricted to that purpose. The communication channel is being used to send, voice that has been digitally compressed. Typical rock masses do not allow conventional radio frequency electromagnetic waves to penetrate significant distances. Here, the authors use carrier frequencies of a few kilohertz that penetrate hundreds of meters into rock masses. They are using low-noise broadband superconducting receivers and have established that the signals propagate several hundred meters with modest power levels. audio has been successfully received at distances in excess of 100 in through solid rock.

关键词： audio coding digital communication high-temperature superconductors propagation of radio waves superconducting device noise superconducting quantum interference devices (SQUIDs) underground electromagnetic propagation

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A comparison of integer fast Fourier transforms for lossless coding

A comparison of integer fast Fourier transforms for lossless...

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International Symposium on Communications and Information Technologies (ISCIT)

作者： Y. Yokotani S. Oraintara R. Geiger G. Schuller K.R. Rao Electrical Engineering Department University of Texas Arlington Arlington TX USA Audiu Coding Group Fraunhofer Institute for Digital Media Technology Ilmenau Germany

The lifting scheme-based integer fast Fourier transform (IntFFT), an integer approximation of the FFT, is reversible. When it is used for lossless coding applications, the computational complexity and approximation error increase due to realization of the trivial butterflies by three lifting steps. Since the error appears as a "noise floor" and it limits the lossless coding efficiency, it is desirable to reduce not only the computational complexity but also the noise floor level as much as possible. This survey presents two schemes to realize an improved IntFFT in terms of the number of arithmetic operations and the level of the noise floor. The first scheme is based on employment of two/three lifting step schemes with combined rounding operations, and the second one is the multidimensional lifting (MDL) scheme. The improvement is shown by comparing the number of arithmetic operations and rounding operations to compute the IntFFT and also by comparing levels of the noise floor. In addition, an improvement in lossless coding efficiency due to the reduced noise floor can be predicted by observing the reduced estimated entropy of the IntFFT coefficients.

关键词： Fast Fourier transforms Computational complexity Noise reduction Noise level Arithmetic Approximation error Employment Dairy products Entropy audio coding

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Compression enhancement of video motion of mouth region using joint audio and video coding

Compression enhancement of video motion of mouth region usin...

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IEEE Southwest Symposium on Image Analysis and Interpretation

作者： M. Mujal R.L. Kirlin Department of Signal Theory and Communications Polytechnic University of Catalonia Barcelona Spain Electrical and Computer Engineering University of Victoria Victoria BC Canada

ISBN: (纸本)0769515371

We propose an application that utilises audio and video data dependencies to achieve additional video compression in low-bit rate encoding systems such as: H.263+ video coding and G.723.1 audio coding standards. The joint correlation of synchronized audio and motion parameters has been proved to exist. A joint performance of principal component analysis (PCA) by Karhunen-Loeve expansions (KL) and tree-structured vector quantization algorithms (TSVQ) based on Linde-Buzo-Gray (LBG) and competitive learning (CL) techniques achieve as much as 60% bit reduction for the motion in the mouth region (1% of the overall output bit rate of a P frame) and provide the same motion-compensated image quality in high picture formats. We show performance evaluations that determine the optimal audio parameters, such as linear predictive coefficients (LPC) or line spectrum pairs (LSP), and determine the nature of the motion parameter in each macroblock of the mouth region when using advanced prediction mode (APM) video coding.

关键词： Video compression Mouth Video coding Principal component analysis Motion analysis Encoding audio coding Vector quantization Region 1 Bit rate

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audio object coding for distributed audio data management applications

Audio object coding for distributed audio data management ap...

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International Conference on Communication Systems

作者： K. Melih R. Gonzalez School of Information Technology Griffith University QLD Australia

The now ubiquitous WWW provides ready access to a plethora of MM data. However, the MM information management facilities of the WWW are little better than those that are several decades old. The audio domain in particular has received little attention in this area. The authors have addressed this oversight by developing a structured audio representation based on "audio objects", allowing more useful access than traditional methods. The representation has also been designed for the demands of a networked world where efficient transmission capabilities are a priority. is paper describes how the decomposition of audio into objects can be exploited for compression gain.

关键词： World Wide Web Information management Modems Data mining Feature extraction Information technology Postal services audio coding Multimedia systems Hypertext systems

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