The Art of Digital Video

Fourth Edition

John Watkinson

AMSTERDAM • BOSTON • HEIDELBERG • LONDON • NEW YORK • OXFORD

PARIS • SAN DIEGO • SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO

E L S E V I E R Focal Press is an imprint of Elsevier

Contents

PREFACE TO FOURTH EDITION xiii

ACKNOWLEDGMENTS xv

CHAPTER1 Introducing Digital Video

Television Systems 1

Videosignals 2

Digital video 4

Standard and high-definition video 8

Colour 9

Convergence of video and Information technology 11

Basics: transmission, storage, and compression 17

Time compression and packetising 18

Synchronisation and time base correction 21

Error correction and concealment 25

Transmission 27

Storage 29

Video compression and MPEG 33

Real time? 36

Digital audio 37

Digital cinema 38

References ! 38

CHAPTER 2 Optical and Video Principles

Introduction 39

Whatislight? 4 0

Sources of light 41

Optical principles 4 4

Photometrie units 47

The human visual System 51

The eye 53

Motion portrayal and dynamic resolution 6 0

Scanning 62

ESSAY: Progressive or interlaced scan? 6 4

CONTENTS

Synchronising 69

Bandwidth and definition 76

Aperture effect 77

Scanning formats for SD and HDTV 79

Colour vision 79

Colorimetry 8 0

Colour difference signals 8 8

C H A P T E R 3 Digital Principles

Introduction 95

Digital processing 100

Binary addition 106

Gain control by multiplication 110

The Computer 110

Interrupts 113

Digital signal processors 117

Time base correction 121

Multiplexing principles 124

Statistical multiplexing 127

Digital faders and controls 127

ESSAY: The Galois field 131

Filters 134

Transforms 137

Convolution 138

FIRandl IRf i l ters 141

FIRfilters 142

Sampling-rate conversion 147

Transformsand duality 159

The Fourier transform 162

The discrete cosine transform (DCT) 170

The wavelet transform 174

References 176

CHAPTER 4 Conversion

Introduction to conversion 179

Sampling and aliasing 180

Reconstruction 183

Filter design 185

Two-dimensional sampling spectra 187

Sampling clockjitter 192

Quantizing 195

Quantizing error 196

Introduction to dither 201

Requantizing and digital dither 203

ESSAY: Dither techniques 207

Basic digital-to-analog conversion 211

Basic analog-to-digital conversion 213

ESSAY: Oversampling 215

Factors affecting convertor quality 221

ESSAY: Digitizing component video 223

Colour in the digital domain 230

References 235

CHAPTER S Digital Video Processing

Introduction 237

A simple digital vision mixer 237

Blanking 241

Keying 241

Chroma keying 242

Simple effects 246

Planar digital video effects 251

Address generation and interpolation 251

Skewand rotation 255

Perspective rotation 258

Non-planar effects 262

Controlling effects 263

Graphics 2 6 4

ESSAY: Converting between Computer and video formats 270

Graphic art/paint Systems 275

Linear and non-linear editing 276

Online and offline editing 277

Digital filmmaking 278

The non-linear Workstation 2 8 0

Locating the edit point 2 8 2

Performing the edit 2 8 4

Applications of motion compensation 2 8 6

ESSAY: Motion-estimation techniques 289

Motion-compensated Standards conversion 301

CONTENTS

Camera-shake compensation 307

De-interlacing 310

Noise reduction 314

References 315

CHAPTER 6 Video Compression and MPEG

Introduction to compression 317

What isMPEG? 325

Spatial and temporal redundancy in MPEG 329

I and P coding 338

Coding applications 342

Spatial compression 343

Scanning and run-length/variable-length coding 3 4 8

A bi-directional coder 352

Slices 357

An MPEG-2 coder 362

The elementary stream 3 6 4

An MPEG-2 decoder 365

MPEG-4 and advanced video coding (AVC) 367

Texture coding 369

Advanced video coding 375

Motion compensation (MC) in AVC 381

AnAVCcodec 383

Coding artifacts 385

Processing MPEG-2 and concatenation 3 8 8

References 395

CHAPTER 7 Digital Audio in Video

Whatissound? 397

Level and loudness 4 0 0

Critical bands 4 0 2

ESSAY: Stereo and Surround sound 4 0 6

Choice of sampling rate for audio 413

Basic digital-to-analog conversion 415

Basic analog-to-digital conversion 423

Alternative convertors 4 2 8

Oversampling and noise shaping 431

One-bit convertors 439

Operating levels in digital audio 4 4 3

MPEG audio compression 4 4 4

Dolby AC-3 457

References 4 5 8

CHAPTER 8 Digital Coding Principles

Introduction 461

Typesof transmission Channel 463

Transmission lines 4 6 4

Types of recording medium 467

Magnetic recording 4 6 8

Opticaland magneto-optical disks 475

Equalization and data Separation 477

Slicingandjitter rejection 478

Channel coding 4 8 4

Simple codes 4 8 6

Group codes 4 9 0

Randomizing and encryption 493

ESSAY: Partial response 4 9 6

Basic error correction 501

Concealment by interpolation 5 0 6

Block and convolutional codes 507

Cyclic codes 5 0 9

ESSAY: The Reed-Solomon codes 519

References 531

CHAPTER 9 Storage Technology

Introduction 533

Disk storage 534

Magnetic disks 537

Accessing the blocks 541

Servo-surface disks 543

The disk Controller 545

Defect handling 551

Disk Servers 553

Optical disk principles 554

Focus and tracking Systems 557

Structure of a DVD player 5 6 4

Digital videotape 569

The rotary head tape transport 571

Digital video cassettes 573

Digital VTR block diagram 574

DVandDVCPRO 5 8 0

C H A P T E R I O Communication Systems

Introduction 587

Production-related interfaces 591

Serial digital video interfaces 592

Synchronising 5 9 4

SD-SDI 597

HD-SDI 6 0 1

Ancillary data 603

SDTI 603

ASI .....605

AES/EBU 6 0 5

Telephone-based Systems 611

Digital television broadcasting 615

MPEG packets and time stamps 618

Program-specific Information (PSI) 621

Transport stream multiplexing 6 2 4

Broadcast modulation techniques 627

ESSAY: OFDM 633

Error correction in digital television broadcasting 637

DVB 637

The DVB receiver 6 4 0

ATSC 641

Networks 647

Network arbitration 6 4 9

FireWire 6 5 4

Broadband networks and ATM 657

ATMAALs 6 6 0

References 663

INDEX 665