Статья
  • формат pdf
  • размер 1.15 МБ
  • добавлен 05 августа 2011 г.
Painter T., Spanias A. Perceptual Coding of Digital Audio
Proceedings of the IEEE, 2000, -63 pp.

During the last decade, CD-quality digital audio has essentially replaced analog audio. Emerging digital audio applications for network, wireless, and multimedia computing systems face a series of constraints such as reduced channel bandwidth, limited storage capacity, and low cost. These new applications have created a demand for high-quality digital audio delivery at low bit rates. In response to this need, considerable research has been devoted to the development of algorithms for perceptually transparent coding of high-fidelity (CD-quality) digital audio. As a result, many algorithms have been proposed, and several have now become inteational and/or commercial product standards. This paper reviews algorithms for perceptually transparent coding of CD-quality digital audio, including both research and standardization activities.
This paper is organized as follows. First, psychoacoustic principles are described, with the MPEG psychoacoustic signal analysis model 1 discussed in some detail. Next, filter bank design issues and algorithms are addressed, with a particular emphasis placed on the modified discrete cosine transform, a perfect reconstruction cosine-modulated filter bank that has become of central importance in perceptual audio coding. Then, we review methodologies that achieve perceptually transparent coding of FM- and CD-quality audio signals, including algorithms that manipulate transform components, subband signal decompositions, sinusoidal signal components, and linear prediction parameters, as well as hybrid algorithms that make use of more than one signal model. These discussions concentrate on architectures and applications of those techniques that utilize psychoacoustic models to exploit efficiently masking characteristics of the human receiver. Several algorithms that have become inteational and/or commercial standards receive in-depth treatment, including the ISO/IEC MPEG family (-1, -2, -4), the Lucent Technologies PAC/EPAC/MPAC, the Dolby1 AC-2/AC-3, and the Sony ATRAC/SDDS algorithms. Then, we describe subjective evaluation methodologies in some detail, including the ITU-R BS.1116 recommendation on subjective measurements of small impairments. This paper concludes with a discussion of future research directions.

Introduction.
Generic Perceptual Audio Coding Architecture.
Paper Organization.

Psychoacoustic Principles.
Absolute Threshold of Hearing.
Critical Bands.
Simultaneous Masking, Masking Asymmetry, and the Spread of Masking.
Nonsimultaneous Masking.
Perceptual Entropy.
Example Codec Perceptual Model: ISO 11172-3 (MPEG-1) Psychoacoustic Model 1.

Time-Frequency Analysis: Filter Banks and Transforms.
Filter Banks for Audio Coding: Design Considerations.
Cosine Modulated Pseudo —QMF M-Band Banks.
Cosine Modulated PR M-Band Banks and the MDCT.
Pre-Echo Distortion.
Pre-Echo Control Strategies.

Transform Coders.
Optimum Coding in the Frequency Domain (OCF-1, OCF-2, OCF-3).
Perceptual Transform Coder (PXFM).
Brandenburg–Johnston Hybrid Coder.
CNET Coder.
ASPEC.
DPAC.
DFT Noise Substitution.
DCT with Vector Quantization.
MDCT with Vector Quantization.

Subband Coders.
MASCAM.
MUSICAM.
Wavelet Decompositions.
Adapted Wavelet Packet Decompositions.
Hybrid Harmonic/Wavelet Decompositions.
Signal-Adaptive, Nonuniform Filter Bank (NUFB) Decompositions.
IIR Filter Banks.

Sinusoidal Coders.
Analysis/Synthesis Audio Codec.
Harmonic and Individual Lines Plus Noise Coder.
FM Synthesis.
Hybrid Sinusoidal Coders.

Linear-Prediction-Based Coders.
Multipulse Excitation.
Discrete Wavelet Excitation Coding.
Sinusoidal Excitation Coding.
Frequency Warped LP.

Audio Coding Standards.
ISO/IEC 11172-3 (MPEG-1) and ISO/IEC IS13818-3 (MPEG-2 BC).
ISO/IEC IS13818-7 (MPEG-2 NBC/AAC).
ISO/IEC 14 496-3 (MPEG-4).
Precision Adaptive Subband Coding.
Adaptive Transform Acoustic Coding.
Sony Dynamic Digital Sound (SDDS).
Lucent Technologies Perceptual Audio Coder (PAC), Enhanced PAC (EPAC), and Multichannel PAC (MPAC).
DOLBY AC-2, AC-2A.

Quality Measures for Perceptual Audio Coding.
Subjective Quality Measures.
Confounding Factors in Subjective Evaluations.
Subjective Evaluations of Two-Channel Standardized Codecs.
Subjective Evaluations of 5.1-Channel Standardized Codecs.

Conclusion.
Summary of Applications for Commercial and Inteational Standards.
Summary of Recent Research and Future Research Directions.
Похожие разделы
Смотрите также

Agnieszka Lisowska. Geometrical Wavelets and their Generalization in digital image coding and processing

  • формат pdf
  • размер 1.69 МБ
  • добавлен 10 декабря 2010 г.
Dissertation, Poland, 2005. n this dissertation it has tried to answer two questions: How images can be approximated better, which will lead to improving its coding and processing properties. How the most important information may by extracted from an image in an automatic way. Contents: ntroduction (motivation; problem…). Classical Theory of Wavelets (… Haar wavelet; Mallat algorithm; Family of Wavelets…). Geometrical Wavelets. Generalization of...

Allen J.B., Chan W.-Y.G., Voran S. (eds.) Perceptual Models for Speech, Audio, and Music Processing

  • формат pdf
  • размер 7.71 МБ
  • добавлен 20 января 2012 г.
EURASIP Journal on Audio, Speech, and Music Processing, 2007, -92 pp. New understandings of human auditory perception have recently contributed to advances in numerous areas related to audio, speech, and music processing. These include coding, speech and speaker recognition, synthesis, signal separation, signal enhancement, automatic content identification and retrieval, and quality estimation. Researchers continue to seek more detailed, accurat...

Digital Signal Processing Applications Using the ADSP-2100 Family

  • формат pdf
  • размер 6.7 МБ
  • добавлен 21 сентября 2011 г.
This book is about bridging the gap between digital signal processing (Dsp) algorithms and their real-world implementations on state-of-the-art digital signal processors. Each chapter tackles a specific application topic, briefly describing the algorithm and discussing its implementation on the Adsp-2100 family of dsp chips. Introduction. fixed-Point arithmetic. floating-Point arithmetic. function approximation. digital filters. one-Dimensional...

Godsill S.J. and Rayner P.J.W. Digital Audio Restoration - a Statistical Model Based Approach

  • формат pdf
  • размер 2.67 МБ
  • добавлен 14 июля 2011 г.
Издательство Springer, 1998, -346 pp. Алгоритмы устранения дефектов (щелчков, шипений, низкочастотных шумов и т.д.) в аудиозаписях. Until recently, however, digital audio processing has required high-powered computational engines which were only available to large institutions who could afford to use the sophisticated digital remastering technology. With the advent of compact disc and other digital audio formats, followed by the increased acces...

Kahrs M., Brandenburg K. Applications of Digital Signal Processing to Audio and Acoustics

  • формат pdf
  • размер 3.97 МБ
  • добавлен 25 июля 2011 г.
Издательство Kluwer, 2002, -571 pp. With the advent of multimedia, digital signal processing (DSP) of sound has emerged from the shadow of bandwidth-limited speech processing. Today, the main applications of audio DSP are high quality audio coding and the digital generation and manipulation of music signals. They share common research topics including perceptual measurement techniques and analysis/synthesis methods. Smaller but nonetheless very...

Meyer-Baese U. Digital Signal Processing with FPGA

  • формат pdf
  • размер 50.02 МБ
  • добавлен 05 августа 2011 г.
Издательство Springer, 2001, -434 pp. Обработка сигналов при помощи FPGA (Field-programmable gate arrays). Introduction. Computer Arithmetic. FIR Digital Filters. R Digital Filters. Multirate Signal processing. Fourier Transform. Advanced Topics. A Verilog Source Code. B VHDL and Verilog coding.

Najim M. Digital Filters Design for Signal and Image Processing

  • формат pdf
  • размер 4.99 МБ
  • добавлен 05 августа 2011 г.
Издательство ISTE, 2006, -386 pp. Over the last decade, digital signal processing has matured; thus, digital signal processing techniques have played a key role in the expansion of electronic products for everyday use, especially in the field of audio, image and video processing. Nowadays, digital signal is used in MP3 and DVD players, digital cameras, mobile phones, and also in radar processing, biomedical applications, seismic data processing,...

Radhakrishnan S. (ed.) Effective Video Coding for Multimedia Applications

  • формат pdf
  • размер 5.06 МБ
  • добавлен 06 ноября 2011 г.
Издательство InTech, 2011, -266 pp. Information has become one of the most valuable assets in the modern era. Recent technology has introduced the paradigm of digital information and its associated benefits and drawbacks. Within the last 5-10 years, the demand for multimedia applications has increased enormously. Like many other recent developments, the materialization of image and video encoding is due to the contribution from major areas like...

Watkinson J. An Introduction to Digital Audio

  • формат pdf
  • размер 12.9 МБ
  • добавлен 06 ноября 2011 г.
Издательство Focal Press, 1994, -399 pp. When I set out to write The Art of Digital Audio some years ago, it was a goal that the book should, among other things, be a reference work and include details of all major formats and techniques. Progress in digital audio has been phenomenally rapid, with the result that it has been necessary to almost rewrite that book completely. The second edition has inevitably increased in size, and whilst it fulfi...

Yang D.T., Kyriakakis C., Jay Kuo C.-C. High-Fidelity Multichannel Audio Coding

  • формат pdf
  • размер 2.86 МБ
  • добавлен 11 августа 2011 г.
Издательство Hindawi, 2006, -233 pp. Audio is one of the fundamental elements in multimedia signals. Audio signal processing has attracted attention from researchers and engineers for several decades. By exploiting unique features of audio signals and common features of all multimedia signals, researchers and engineers have been able to develop more efficient technologies to compress audio data. Although books on digital audio have been availabl...