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发表于 2011-10-16 00:41:35
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6. The MPEG-2 Video Compression Standard 171
6.1 Introduction 171
6.2 Picture Types in MPEG-2 173
6.3 The Syntax of MPEG-2 179
6.3.1 Extension Start Code and Extension Data 180
6.3.2 Sequence Layer 181
6.3.3 The Group of Pictures Layer 187
6.3.4 The Picture Layer 188
6.3.5 The Slice Layer 198
6.3.6 The Macroblock Layer 200
6.3.7 The Block Layer 221
6.4 Video Buffer Verifi er 223
6.5 Profi les and Levels 227
6.5.1 Profi les 227
6.5.2 Levels 229
6.6 Summary 229
Problems 229
MATLAB Exercise 6.1: Bidirectional Motion-Compenseted Prediction 233
MATLAB Exercise 6.2: Dual-Prime Motion-Compensated Prediction 233
MATLAB Exercise 6.3: Field and Frame Motion-Compensated
Prediction 234
MATLAB Exercise 6.4: Field and Frame DCT Coding 235
7. Perceptual Audio Coding 237
7.1 The Human Auditory System 238
7.1.1 Outer Ear 239
7.1.2 Middle Ear 239
7.1.3 Inner Ear 240
7.2 Psychoacoustics 244
7.2.1 Sound Pressure Level 244
7.2.2 Auditory Thresholds 244
7.2.3 The Critical Bandwidth and Auditory Filters 246
7.2.4 Auditory Masking 248
7.3 Summary 251
Problems 251
References 252
8. Frequency Analysis and Synthesis 253
8.1 The Sampling Theorem 253
8.2 Digital Filters 255
8.3 Subband Filtering 256
8.3.1 The Analysis Filter Bank 256
8.3.2 The Synthesis Filter Bank 258
8.3.3 Filters for Perfect Reconstruction 259
8.4 Cosine-Modulated Filters 260
8.5 Effi cient Implementation of a Cosine-Modulated Filterbank 265
8.5.1 Analysis Filter 265
8.5.2 Synthesis Filter 270
8.6 Time-Domain Aliasing Cancellation 274
8.7 Summary 280
Problems 280
MATLAB Exercise 8.1 282
MATLAB Exercise 8.2 283
References 284
9. MPEG Audio 285
9.1 MPEG-1 Layer I,II Encoders 287
9.1.1 Analysis Filterbank 288
9.1.2 Scalefactor Calculation 288
9.1.3 Psychoacoustic Model 1 291
9.1.4 Dynamic Bit Allocation 307
9.1.5 Coding of Bit Allocation 310
9.1.6 Quantization and Coding of Subband Samples 311
9.1.7 Formatting 312
9.2 Layer II Encoder 314
9.2.1 Analysis Filterbank 315
9.2.2 Scalefactor Calculation 315
9.2.3 Coding of Scalefactors 315
9.2.4 Dynamic Bit Allocation 317
9.2.5 Coding of Bit Allocation 319
9.2.6 Quantization and Coding of Subband Samples 319
9.2.7 Ancillary Data 321
9.2.8 Formatting 321
9.3 Joint Stereo Coding 322
9.4 MPEG-1 Syntax 323
9.4.1 Audio Sequence Layer 323
9.4.2 Audio Frame 323
9.4.3 Header 324
9.4.4 Error Check 328
9.4.5 Audio Data, Layer I 328
9.4.6 Audio Data, Layer II 328
9.5 MPEG-1 Layer I, II Decoders 328
9.5.1 Bit Allocation Decoding 328
9.5.2 Scalefactor Selection Information Decoding 331
9.5.3 Scalefactor Decoding 331
9.5.4 Requantization of Subband Samples 332
9.5.5 Synthesis Filterbank 333
9.6 MPEG-2 333
9.6.1 Backwards-Compatible MPEG-2 Frame Formatting 333
9.6.2 Matrixing Procedures for Backwards Compatibility 335
9.7 Summary 335
Problems 336
MATLAB Exercise 9.1 338
MATLAB Exercise 9.2 339
MATLAB Exercise 9.3 340
References 340
10. Dolby AC-3 Audio 341
10.1 Encoder 343
10.1.1 Audio Input Format 344
10.1.2 Transient Detection 345
10.1.3 Forward Transform 346
10.1.4 Channel Coupling 349
10.1.5 Rematrixing 356
10.1.6 Extract Exponents 359
10.1.7 Encode Exponents 363
10.1.8 Bit Allocation 364
10.1.9 Quantize Mantissas 381
10.1.10 Dialog Normalization 386
10.1.11 Dynamic Range Compression 387
10.1.12 Heavy Compression 389
10.1.13 Downmixing 390
10.2 Syntax 397
10.2.1 Syntax Specifi cation 397
10.3 Decoder 410
10.3.1 Decode Exponents 410
10.3.2 Bit Allocation 412
10.3.3 Decode Coeffi cients 413
10.3.4 Decoupling 414
10.3.5 Inverse Transform 414
10.3.6 Overlap and Add 415
10.4 Summary 415
Problems 415
MATLAB Exercise 10.1 419
MATLAB Exercise 10.2 419
MATLAB Exercise 10.3 420
References 420
11. MPEG-2 Systems 421
11.1 Introduction 421
11.2 Service Overview 422
11.3 Multiplexer Structure 425
11.3.1 PES Sublayer 425
11.3.2 Transport Stream Sublayer 428
11.3.3 Program Stream Sublayer 434
11.4 Timing 434
11.4.1 System Time Clock 435
11.4.2 Clock References and Reconstruction of the STC 435
11.4.3 Time Stamps 437
11.5 Buffer Management 437
11.6 Program-Specifi c Information 439
11.6.1 MPEG-2 Descriptors 439
11.6.2 MPEG-2 Tables 453
11.6.3 Overheads Due to PSI 458
11.7 MPEG-2 Decoder Operation 459
11.7.1 Synchronization to Transport Stream 459
11.7.2 PSI Decoding 459
11.7.3 Program Reassembly 459
11.8 Use Of MPEG-2 Systems In Digital Television 463
11.8.1 Use of MPEG-2 Systems in ATSC 463
11.8.2 Use of MPEG-2 Systems in DVB 464
11.8.3 Implementation of PSI in DVB 465
11.9 Conclusion 465
Problems 465
References 469
12. DVB Service Information and ATSC Program and System
Information Protocol 471
12.1 Introduction 471
12.2 Why SI and PSIP? 471
12.3 DVB-SI 472
12.3.1 DVB Common Data Formats 474
12.3.2 DVB Descriptors 476
12.3.3 DVB Tables 492
12.3.4 DVB Delivery Issues 500
12.4 ATSC Program and System Information Protocol 501
12.4.1 Common Data Formats 502
12.4.2 ATSC Descriptors 504
12.4.3 ATSC Tables 508
12.5 DVB SI and ATSC PSIP Interoperability 516
12.5.1 PIDs 517
12.5.2 Use of table_id 517
12.5.3 Use of descriptor_tag 517
12.6 Conclusion 517
Problems 517
MATLAB Exercise 12.1 523
References 524
13. Digital Television Channel Coding and Modulation 525
13.1 Introduction 525
13.2 Generic Concepts 525
13.2.1 Channel Characteristics and Intersymbol Interference 526
13.2.2 Modulation 528
13.2.3 Equalization 532
13.2.4 Randomization 535
13.2.5 Channel Coding Technology 537
13.3 Channel Coding and Modulation for ATSC 545
13.3.1 ATSC 8-VSB Modulation 545
13.3.2 ATSC Data Framing 546
13.3.3 ATSC Concatenated Channel Coder 547
13.3.4 ATSC Channel Capacity 550
13.4 Channel Coding and Modulation for DVB 550
13.4.1 DVB Modulation 550
13.4.2 DVB Channel Coding 562
13.4.3 DVB Channel Capacity 566
13.5 Conclusion 566
Problems 566
MATLAB Exercise 13.1 569
MATLAB Exercise 13.2 569
MATLAB Exercise 13.3 570
References 570
14. Closed Captioning, Subtitling, and Teletext 571
14.1 Introduction 571
14.2 DVB Subtitles and Teletext 571
14.2.1 Subtitles 572
14.2.2 Teletext 581
14.3 ATSC Closed Captioning 587
14.3.1 Line 21 Data Service 587
14.3.2 Advanced Television Closed Captioning 592
14.4 Conclusion 603
Problems 603
References 604
Appendix. MPEG Tables 605
Index 617 |
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