Multimedia Technology

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Chapter 10

• Multimedia Technology

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You Will Learn

• About the fundamental workings of multimedia
  technology
• About many multimedia standards and how they have
  helped shape the industry
• CD-ROM storage technology
• How to install CD-ROM drives

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Multimedia Technology

• A type of computer presentation that combines
  text, graphics, animation, photos, sound, and/or
  full-motion video
• Goal
• To create or reproduce lifelike representations
  for audio, video, and animation

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Multimedia Technology

• Key to bridging the world of digital computers
  and the infinite number of variations of sights
  and sounds is two-fold
• Reduce the infinite number of variations to a
  finite few
• Record as many as needed to reproduce an
  approximation of the original sight or sound,
  without overloading the capacity of the computer
  to hold data

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Bits Are Still Bits

• Uniform quality of multimedia devices
• Represent data as a series of 0s and 1s
• Transfer data over same bus to CPU
• May require an IRQ, a DMA channel, an I/O
  address, and room in memory for its BIOS or
  drivers

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Special Challenge Confronting Multimedia
Technology

• To reproduce something that is continuously
  changing (analog) on a PC, which is incapable of
  making continuous changes because it is digital
  (has only two states can only change from one
  state to another, with no gradations in between)

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Multimedia Fundamentals

• Sampling part of the process of converting
  sound or video from analog to digital format

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Multimedia Fundamentals
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What CPU Technologies Do for Multimedia

• MMX (Intel)
• Used by Pentium MMX, Pentium Pro, Pentium II
• Architectural enhancements
• New instructions
• SIMD process
• Increased cache
• SSE (Intel)
• Used by Pentium III
• Improves performance of high-end multimedia
  software

continued
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What CPU Technologies Do for Multimedia

• 3DNow! (AMD)
• A CPU instruction set that helps AMD processors
  perform better in 3D graphics and other
  multimedia data processing

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Devices Supporting Multimedia

• CD-ROM drives
• Sound cards
• Digital cameras
• Video capture cards
• Digital Video Disc (DVD) drives

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CD-ROMs

• Use optical technology to represent bits
• Laser shines on surface
• Amount of reflections indicates 1 or 0
• Capacity
• Standard 650 MB (74 min audio)
• Enhanced 700 MB (80 min audio)

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CD-ROM Drives

• Accommodate large space requirements of video and
  sound files
• Read-only devices data is embedded in disc
  surface (lands and pits)
• Constant linear velocity (CLV) and constant
  angular velocity (CAV)
• Multisession capability

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CD-ROM Drives
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Pits and Lands

• Bits represented by pits and lands
• Land is flat area representing a 1 bit
• Pit is depresessed area representing a 0 bit
• Pits and lands on recordable CDs represented by
  changing surface reflection

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How a CD-ROM Drive Can Interface with the System
Board

• Use an IDE interface
• Use a SCSI interface with a SCSI host adapter
• Use a proprietary expansion card that works only
  with CD-ROMs
• Use a proprietary connection on a sound card
• Be a portable drive and plug into bidirectional
  parallel port on PC

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Installing a CD-ROM Drive
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Configuring an IDE CD-ROM Drive

• Uses ATAPI standard

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Installation Guidelines

• Once installed, the CD-ROM drive becomes just
  another drive on your system with these
  exceptions
• It is read-only
• It holds more data than a hard drive
• It is a little slower to access than a hard drive

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Install the Device Driver for Windows 9x
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Enabling CD-ROM Drives in DOS

• ATAPI hardware and software drivers are generic
• Device driver must be in CONFIG.SYS
• Standard software driver MSCDEX.EXE must be
  loaded in AUTOEXEC.BAT

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MSCDEX.EXE

• Standard DOS CD-ROM driver
• C\WINDOWS\COMMAND\MSCDEX.EXE /Dxxx /Lz
• where
• xxx matches device name in hardware driver
  (required)
• z drive letter assignment (optional)
• Without /Lz, DOS assigns next available drive
  letter

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Optimizing CD-ROM Cache
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Caring for CD-ROM Drives and Discs

• Causes of most problems with CD-ROMs
• Dust
• Fingerprints
• Scratches
• Defects on surface of CD
• Random electrical noise

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CD-ROM Drive and Disc Precautions

• Do
• Hold the CD by the edge
• Clean with a soft, dry cloth
• Do not
• Write on, or paste paper to, the surface of the
  CD
• Subject the CD to heat
• Use cleaners, alcohol, and the like on the CD
• Make the center hole larger
• Bend, drop, or subject the CD to shock
• If a CD gets stuck in the drive, use the
  emergency eject hole to remove it

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CD-R and CD-RW Drives

• CD-recordable (CD-R)
• A CD drive that can record or write data to a CD
• Data cannot be erased once it is written
• May or may not be multisession
• Rewritable CD (CD-RW)
• A CD drive that can record or write data to a CD
• Data can be erased and overwritten
• May or may not be multisession

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Troubleshooting Problems with CD-ROM Installation

• Error message Invalid Drive Specification
  appears while system is starting up
• Install process is terminated with message
  MSCDEX.EXE Not Found
• Error message Not Enough Drive Letters appears
  during startup process
• Conflict errors exist
• Computer does not recognize CD-ROM drive
• There is no sound

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Sound Cards

• Expansion cards that record sound, save it to a
  file on the hard drive, and play it back
• Have ports for external stereo speakers and
  microphone input
• May be Sound Blaster compatible

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Stages Sound Goes Through when Computerized

• Digitize or input the sound (analog-to-digital
  conversion)
• Store the digital data in a compressed data file
• Reproduce or synthesize the sound
  (digital-to-analog conversion)

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Sampling and Digitizing the Sound

• Done by a method called pulse code modulation
  (PCM)
• Involves a component called analog-to-digital
  converter (A/C or ADC) and a component called a
  digital-to-analog converter (DAC)
• Sample size
• Refers to samples taken when converting a signal
  from analog to digital
• A measure of the amount of storage allocated to a
  single measurement of a single sample

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Two Ways of Storing Sound in Files

• MIDI (musical instrument digital interface) files
• Dictate a specific number of sound samples and
  quality
• Have a .mid extension
• Use data compression due to size of files
• Used to store most game music
• WAV files
• Have a .wav extension
• Used to store most multimedia sound

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Compressing Data
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MPEG Data Compression Standard

• Stores full motion video and sound
• Tracks movement from one frame to the next and
  only stores what changes, rather than compressing
  individual frames
• A type of lossy compression (refers to
  compressing the data by eliminating some of it)

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Current MPEG Standards

• MPEG-1
• Used in business and home applications to
  compress images
• MPEG-2
• Used to compress video films
• MPEG-3
• Best known for audio compression
• MPEG-4
• Used for video transmissions over the Internet

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Methods of Digital-to-Analog Conversion

• FM (frequency modulation) synthesis
• Creates a sound by artificially creating a wave
  similar to the sound wave produced by the
  instrument
• Sound is reproduced by making a mathematical
  approximation of the musical sound wave
• Wavetable synthesis
• Produces the sound by using a sample recording of
  the real instrument
• Produces better sound that does FM synthesis, but
  is also more expensive

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Installing a Sound Card and Software
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Steps in Installing a Sound Card

• Install the card itself in an empty PCI slot on
  the system board
• Install the driver under Windows 98
• Install the applications stored on the sound
  cards CD

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Installing a Sound Card
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Installing a Sound Card Driver
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Using Sound with Windows 9x

• Windows 9x offers some support for sound
• Playing a music CD or a WAV file
• Providing sound when performing certain Windows
  functions

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Using Sound with Windows 9x
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Using Sound with Windows 9x
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Using Sound with Windows 9x
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Using Sound with Windows 9x
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Using Sound with Windows 9x
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Using Sound with Windows 9x
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Recording Sound Using Windows 9x
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Controlling Windows 9x Sounds
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Digital Cameras

• Faster than scanner technology
• Scan field of image set by picture taker
• Translate light signals into digital values,
  which can be stored as a file and viewed with
  software that can interpret the stored values
• Picture files are usually stored in JPEG (Joint
  Photographic Experts Group) format

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Digital Cameras
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Kinds of Image Sensing Technology

• Infrared sensor
• Charge-coupled device (CCD)

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MP3 Player

• MP3
• A method to compress audio files that uses MPEG
  level 3
• Can reduce sound files as low as a 124 ratio
  without losing sound quality
• Streaming audio
• Downloading audio data from the Internet in a
  continuous stream of data without first
  downloading an entire audio file

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Video-capturing Card

• Captures input from a camcorder or directly from
  TV
• Features to look for
• An IEEE 1394 port to interface with a digital
  camcorder
• Data transfer rates which affect price of the
  card
• Capture resolution and color-depth capabilities
• Ability to transfer data back to the digital
  camcorder or VCR
• Stereo audio jacks
• Video editing software bundled with the card

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Digital Video Disc (DVD)

• Faster, larger, CD-ROM format
• Can read older CDs
• Can store over 8 gigabytes of data can hold
  full-length motion picture videos
• Uses MPEG-2 video compression and requires an
  MPEG-2 controller card to decode the compressed
  data

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A DVD Device
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How a PC Can Use DVD Data
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Other DVD Devices
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Chapter Summary

• Multimedia devices, what they can do, how they
  work, and how to support them
• Requirements of multimedia technology
• Large amounts of storage capacity
• Ability to process large quantities of data at
  high speed and at lowest possible cost

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