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Desktop Audio Technology

Book Description

In this thorough introduction to the technology behind audio workstations, Dr Francis Rumsey explains not only how digital audio works but also how to make best use of its capabilities. A combined revision of his two successful titles, MIDI Systems and Control and The Audio Workstation Handbook, this new book covers recent developments such as surround sound formats, direct stream digital, new audio project formats, new interfaces and alternatives to MIDI.

Desktop Audio Technology begins by setting out principles of digital audio and how these are applied in recording, replay and editing within workstations. MIDI and synthetic audio control is then covered, looking at the means by which artificial sounds can be controlled and manipulated. This is followed by explanations of hardware, including storage devices, buses, computer interfaces and audio processing options. Dr Rumsey then focuses on transferring audio between systems, including coverage of audio interfaces, networking and file formats. The next section examines audio software, providing working examples of different commercial packages that exemplify some of the concepts previously described. The final chapter considers operational issues such as recent spatial reproduction formats, consumer format mastering and quality control issues, as well as troubleshooting and systems issues.

If you are a student, lecturer or practitioner in the field of audio and are looking for an authoritative technical guide to the underlying principles of digital audio and MIDI, this book is for you.

Dr Francis Rumsey is a Reader in Sound Recording at the University of Surrey (UK) and a Visiting Professor at the School of Music in Piteå (Sweden). He is a Fellow of the Audio Engineering Society and a regular contributor to the AES Journal. Dr Rumsey is also author of Spatial Audio and co-author of Sound and Recording (with Tim McCormick) and The Digital Interface Handbook (with John Watkinson), all published by Focal Press.

Table of Contents

  1. Cover
  2. Halftitle
  3. Title
  4. Copyright
  5. Contents
  6. Series introduction
  7. 1 Introduction to desktop audio technology
    1. 1.1 About this book
    2. 1.2 Audio workstations
    3. 1.3 Audio and the computer industry
    4. 1.4 Audio and quality
  8. 2 Digital audio principles
    1. 2.1 Analog and digital information
    2. 2.2 Binary number systems
      1. 2.2.1 Basic binary
      2. 2.2.2 Negative numbers
      3. 2.2.3 Fixed- and floating-point representation
      4. 2.2.4 Logical operations
    3. 2.3 Basic A/D and D/A conversion of control information
    4. 2.4 A/D conversion of audio signals
      1. 2.4.1 Audio sampling
      2. 2.4.2 Filtering and aliasing
      3. 2.4.3 Quantisation
      4. 2.4.4 Relationship between sample resolution and sound quality
      5. 2.4.5 Use of dither
      6. 2.4.6 Types of dither
      7. 2.4.7 Oversampling in A/D conversion
      8. 2.4.8 Noise shaping in A/D conversion
    5. 2.5 D/A conversion
      1. 2.5.1 A basic D/A convertor
      2. 2.5.2 Oversampling in D/A conversion
    6. 2.6 Sound quality versus sample rates and resolutions
      1. 2.6.1 Psychoacoustic limitations
      2. 2.6.2 Sampling rate
      3. 2.6.3 Quantising resolution
    7. 2.7 Direct Stream Digital (DSD)
    8. 2.8 Changing the resolution of an audio signal (requantisation)
    9. 2.9 Dynamic range enhancement
    10. 2.10 Error correction
    11. 2.11 Introduction to digital audio signal processing
      1. 2.11.1 Gain changing (level control)
      2. 2.11.2 Crossfading
      3. 2.11.3 Mixing
      4. 2.11.4 Digital filters and equalisation
      5. 2.11.5 Digital reverberation and other effects
      6. 2.11.6 Dynamics processing
      7. 2.11.7 Sample rate conversion
    12. 2.12 Audio data reduction
      1. 2.12.1 Why reduce the data rate?
      2. 2.12.2 Lossless and lossy coding
      3. 2.12.3 MPEG – an example of lossy coding
      4. 2.12.4 Other data-reduced formats
    13. Further reading
  9. 3 Recording, replay and editing principles
    1. 3.1 The sound file
    2. 3.2 RAM buffering
    3. 3.3 Disk drive performance issues
    4. 3.4 Allocation units or transfer blocks
    5. 3.5 Multichannel recording and replay
      1. 3.5.1 Multitrack or multichannel?
      2. 3.5.2 Inputs, outputs, tracks and channels
      3. 3.5.3 Track usage, storage capacity and disk assignment
      4. 3.5.4 Dropping-in
    6. 3.6 System latency
    7. 3.7 Principles of audio editing
      1. 3.7.1 Advantages of non-linear editing
      2. 3.7.2 Sound files and sound segments
      3. 3.7.3 Edit point handling
      4. 3.7.4 Crossfading
      5. 3.7.5 Editing modes
      6. 3.7.6 Simulation of ‘reel-rocking’
  10. 4 MIDI and synthetic audio control
    1. 4.1 Background
    2. 4.2 What is MIDI?
    3. 4.3 MIDI and digital audio contrasted
    4. 4.4 Basic MIDI principles
      1. 4.4.1 System specifications
      2. 4.4.2 Simple interconnection
      3. 4.4.3 MIDI channels
      4. 4.4.4 Message format
    5. 4.5 MIDI messages in detail
      1. 4.5.1 Channel and system messages contrasted
      2. 4.5.2 Note on and note off messages
      3. 4.5.3 Velocity information
      4. 4.5.4 Running status
      5. 4.5.5 Polyphonic key pressure (aftertouch)
      6. 4.5.6 Control change
      7. 4.5.7 Channel modes
      8. 4.5.8 Program change
      9. 4.5.9 Channel aftertouch
      10. 4.5.10 Pitch bend wheel
      11. 4.5.11 System exclusive
      12. 4.5.12 Universal system exclusive messages
      13. 4.5.13 Tune request
      14. 4.5.14 Active sensing
      15. 4.5.15 Reset
    6. 4.6 MIDI control of sound generators
      1. 4.6.1 MIDI note assignment in synthesisers and samplers
      2. 4.6.2 Polyphony, voice and note assignment
      3. 4.6.3 MIDI functions of sound generators
      4. 4.6.4 MIDI data buffers and latency
      5. 4.6.5 Handling of velocity and aftertouch data
      6. 4.6.6 Handling of controller messages
      7. 4.6.7 Registered and non-registered parameter numbers
      8. 4.6.8 Voice selection
    7. 4.7 MIDI tuning control
    8. 4.8 General MIDI
    9. 4.9 Scalable polyphonic MIDI (SPMIDI)
    10. 4.10 Standard MIDI files (SMF)
      1. 4.10.1 General structure of MIDI files
      2. 4.10.2 Header chunk
      3. 4.10.3 Track chunks
      4. 4.10.4 MIDI file track events
      5. 4.10.5 Time signatures and tempo maps
    11. 4.11 Downloadable Sounds (DLS) and SoundFonts
    12. 4.12 RMID and XMF files
    13. 4.13 SAOL and SASL in MPEG 4 Structured Audio
    14. 4.14 MIDI and synchronisation
      1. 4.14.1 Introduction to MIDI synchronisation
      2. 4.14.2 Music-related timing data
      3. 4.14.3 Timecode and synchronisation
      4. 4.14.4 MIDI timecode (MTC)
    15. 4.15 MIDI machine control (MMC)
    16. 4.16 MIDI over USB
    17. 4.17 MIDI over IEEE 1394
    18. 4.18 After MIDI?
    19. Further reading
    20. Useful websites
  11. 5 Hardware and systems issues
    1. 5.1 Storage media
      1. 5.1.1 Storage requirements of digital audio and video
      2. 5.1.2 Disk drives in general
      3. 5.1.3 Disk drive specifications
      4. 5.1.4 Magnetic hard disk drives
      5. 5.1.5 RAID arrays
      6. 5.1.6 Removable magnetic media
      7. 5.1.7 Optical disks in general
      8. 5.1.8 CAV and CLV modes in optical storage
      9. 5.1.9 The magneto-optical (M-O) drive
      10. 5.1.10 Phase-change optical recording
      11. 5.1.11 Compact discs and drives
      12. 5.1.12 DVD
      13. 5.1.13 Optical disc filing structures
      14. 5.1.14 Tape storage media
    2. 5.2 Peripheral interfaces
      1. 5.2.1 SCSI
      2. 5.2.2 ATA/IDE interface
      3. 5.2.3 PCMCIA
      4. 5.2.4 IEEE 1394 (Firewire) and USB
    3. 5.3 Filing systems and volume partitions
    4. 5.4 Formatting, fragmentation and optimisation of media
    5. 5.5 Audio processing and synthesis hardware
      1. 5.5.1 Introduction
      2. 5.5.2 Audio processing latency
      3. 5.5.3 DSP cards
      4. 5.5.4 Host-based audio processing
      5. 5.5.5 Integrated sound cards
      6. 5.5.6 Synthesis engines on sound cards
    6. 5.6 External synchronisation interfaces
    7. 5.7 User interfaces
    8. 5.8 Serial control interfaces
      1. 5.8.1 RS-232 and RS-422
      2. 5.8.2 The basic MIDI interface
      3. 5.8.3 MIDI connectors and cables
      4. 5.8.4 Interfacing a computer to a MIDI system
    9. 5.9 Drivers and audio I/O software
    10. Useful websites
  12. 6 Audio formats and data interchange
    1. 6.1 Audio file formats
      1. 6.1.1 Introduction
      2. 6.1.2 File formats in general
      3. 6.1.3 Sound Designer I format
      4. 6.1.4 Sound Designer II format
      5. 6.1.5 AIFF and AIFF-C formats
      6. 6.1.6 RIFF WAVE format
      7. 6.1.7 WAVE-format extensible
      8. 6.1.8 Broadcast WAVE format
      9. 6.1.9 MPEG audio file formats
      10. 6.1.10 DSD-IFF file format
      11. 6.1.11 Edit decision list (EDL) files
      12. 6.1.12 AES 31 format
      13. 6.1.13 The Open Media Framework Interchange (OMFI)
      14. 6.1.14 MXF – the Media Exchange Format
      15. 6.1.15 AAF – the Advanced Authoring Format
    2. 6.2 Disk pre-mastering formats
    3. 6.3 Interconnecting audio devices
    4. 6.4 Computer networks and digital audio interfaces compared
    5. 6.5 Dedicated audio interface formats
      1. 6.5.1 Digital interface types
      2. 6.5.2 The AES 3 interface (AES 3)
      3. 6.5.3 Standard consumer interface (IEC 60958-3)
      4. 6.5.4 Carrying data-reduced audio over standard digital interfaces
      5. 6.5.5 Tascam digital interface (TDIF)
      6. 6.5.6 Alesis digital interface
      7. 6.5.7 Roland R-bus
      8. 6.5.8 Sony digital interface for DSD (SDIF-3)
      9. 6.5.9 Sony multichannel DSD interface (MAC-DSD)
    6. 6.6 Networking
      1. 6.6.1 Basic principles of networking
      2. 6.6.2 Extending a network
      3. 6.6.3 Network standards
      4. 6.6.4 Network protocols
      5. 6.6.5 Audio network requirements
      6. 6.6.6 ISDN
      7. 6.6.7 Protocols for the Internet
      8. 6.6.8 Wireless networks
    7. 6.7 Streaming audio over computer interfaces
      1. 6.7.1 Audio over Firewire (IEEE 1394)
      2. 6.7.2 Audio over universal serial bus (USB)
      3. 6.7.3 AES 47: Audio over ATM
      4. 6.7.4 CobraNet
      5. 6.7.5 MAGIC
      6. 6.7.6 MOST
      7. 6.7.7 BSS SoundWeb
    8. 6.8 Digital content protection
    9. Further reading
    10. Useful websites
  13. 7 Audio software
    1. 7.1 Sequencers
      1. 7.1.1 Introduction
      2. 7.1.2 Tracks, channels, instruments and environments
      3. 7.1.3 Input and output filters
      4. 7.1.4 Timing resolution
      5. 7.1.5 Displaying, manipulating and editing information
      6. 7.1.6 Quantisation of rhythm
      7. 7.1.7 Automation and non-note MIDI events
      8. 7.1.8 MIDI mixing and external control
      9. 7.1.9 Synchronisation
      10. 7.1.10 Synchronised digital video
    2. 7.2 Plug-in architectures
      1. 7.2.1 What is a plug-in?
      2. 7.2.2 Plug-in examples
    3. 7.3 Virtual instruments
    4. 7.4 Librarians and editors
    5. 7.5 Audio editing and post-production software
      1. 7.5.1 Sonic Studio HD
      2. 7.5.2 SADiE
    6. 7.6 Mastering and restoration software
    7. 7.7 Advanced audio processing software and development tools
    8. 7.8 Computer music software
    9. Further reading
  14. 8 Operational and systems issues
    1. 8.1 Level control and metering
    2. 8.2 Spatial reproduction formats
      1. 8.2.1 Introduction to multichannel formats
      2. 8.2.2 4-channel surround (3-1 stereo)
      3. 8.2.3 5.1 channel surround (3-2 stereo)
      4. 8.2.4 Dolby EX
      5. 8.2.5 7.1 channel surround
      6. 8.2.6 Surround panning and spatial effects
    3. 8.3 Controlling and maintaining sound quality
    4. 8.4 Preparing for and understanding release media
      1. 8.4.1 CD-Audio
      2. 8.4.2 DVD
      3. 8.4.3 Super Audio CD (SACD)
      4. 8.4.4 MP3
      5. 8.4.5 MPEG-4, web and interactive authoring
    5. 8.5 Synchronisation
      1. 8.5.1 Requirements for synchronisation
      2. 8.5.2 Timecode synchronisation
      3. 8.5.3 Synchronisation to external audio, film or video references
    6. 8.6 System troubleshooting
      1. 8.6.1 Troubleshooting MIDI
      2. 8.6.2 Digital interface troubleshooting
      3. 8.6.3 Troubleshooting software
    7. Further reading
  15. Index