Tools for Signal Compression

Introduction xi

PART 1. TOOLS FOR SIGNAL COMPRESSION 1

Chapter 1. Scalar Quantization 3

1.1. Introduction 3

1.2. Optimum scalar quantization 4

1.3. Predictive scalar quantization 10

Chapter 2. Vector Quantization 23

2.1. Introduction 23

2.2. Rationale 23

2.3. Optimum codebook generation 26

2.4. Optimum quantizer performance 28

2.5. Using the quantizer 30

2.6. Gain-shape vector quantization 32

Chapter 3. Sub-band Transform Coding 37

3.1. Introduction 37

3.2. Equivalence of filter banks and transforms 38

3.3. Bit allocation 40

3.4. Optimum transform 46

3.5. Performance 48

Chapter 4. Entropy Coding 53

4.1. Introduction 53

4.2. Noiseless coding of discrete, memoryless sources 54

4.3. Noiseless coding of a discrete source with memory 66

4.4. Scalar quantizer with entropy constraint 73

4.5. Capacity of a discrete memoryless channel 79

4.6. Coding a discrete source with a fidelity criterion 83

PART 2. AUDIO SIGNAL APPLICATIONS 89

Chapter 5. Introduction to Audio Signals 91

5.1. Speech signal characteristics 91

5.2. Characteristics of music signals 92

5.3. Standards and recommendations 93

Chapter 6. Speech Coding 101

6.1. PCM and ADPCM coders 101

6.2. The 2.4 bit/s LPC-10 coder 102

6.3. The CELP coder 107

Chapter 7. Audio Coding 123

7.1. Principles of âperceptual codersâ 123

7.2. MPEG-1layer 1 coder 126

7.3. MPEG-2AACcoder 130

7.4. DolbyAC-3 coder 134

7.5. Psychoacoustic model: calculating a masking threshold 135

Chapter 8. Audio Coding: Additional Information 141

8.1. Low bit rate/acceptable quality coders 141

8.2. High bit rate lossless or almost lossless coders 146

Chapter 9. Stereo Coding: A Synthetic Presentation 149

9.1. Basic hypothesis and notation 149

9.2. Determining the inter-channel indices 151

9.3. Downmixing procedure 154

9.4. At the receiver 158

9.5. Draft International Standard 161

PART 3. MATLAB_ PROGRAMS 163

Chapter 10. A Speech Coder 165

10.1. Introduction 165

10.2. Script for the calling function 165

10.3. Script for called functions 170

Chapter 11. A Music Coder 173

11.1. Introduction 173

11.2. Script for the calling function 173

11.3. Script for called functions 176

Bibliography 195

Index 199