An Experimental High Fidelity Perceptual Audio Coder

Bosse Lincoln

Center for Computer Research in Music and Acoustics (CCRMA)

March 1998

Department of Music, Stanford University
Stanford, California 94305

Detailed Contents (and Navigation)

• Introduction
• Current Implementations
  • Subband Coders
    • MPEG-1, Layer I and II
  • Wavelet Coders
  • Transform Coders
    • MPEG-2 AAC
  
  
• Human Audio Perception: Masking
  • Basics
    • Absolute Threshold of Hearing
    • Implemented Model for ATH
    • Critical Bandwidths
  • Simultaneous Masking
    • Spreading Function
    • Implemented Model for Spreading Function
    • Tonality of Maskers
    • Implemented Model for Tonality
    • Implemented Model for Masking Threshold
    • Addition of Simultaneous Masking
  • Temporal Masking
    • Implemented Model for Post-Masking
    • Implemented Model for Pre-Masking
  • Quantization using the Masking Threshold
  
  
• Audio Coding
  • Transforming
    • Modified Discrete Cosine Transform (MDCT)
    • A Fast MDCT Implementation
    • Karhunen Lòeve Transform (KLT)
  • Quantization and Coding
    • Coefficient Clustering - Frequency Domain
    • Coefficient Clustering - Time Domain
    • Coefficient Quantization
    • Bit Coding
  • Stereo Coding
  
  
• Results and Conclusions
• Bibliography
• About this document ...