Multimedia

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Multimedia

• CIS 145
• Microcomputer Servicing
• Kelvin Kempfer

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Content

• Optical Storage
• Audio Adapter Applications
• Audio Adapter Concepts and Terms
• Audio Adapter Features
• Choosing an Audio Adapter
• Audio Adapter Installation

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Optical Storage

• How a CD-ROM Drive Works
• Types of CD-ROMs
• USB Compared to FireWire

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How a CD-ROM Drive Works

• The laser diode emits a low-energy infrared beam
  toward a reflecting mirror.
• The servo motor, on command from the
  microprocessor, positions the beam onto the
  correct track on the CD-ROM, while rotating the
  reflecting mirror.
• When the beam hits the disc, its refracted light
  is gathered and focused through the first lens
  beneath the platter, bounced off the mirror and
  sent toward the beam splitter.

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How a CD-ROM Drive Works

• 4. The beam splitter hits the returning laser
  light toward another focusing lens.
• 5. The last lens directs the light beam to a
  photo detector that converts the light into
  electric impulses.
• 6. These incoming impulses are decoded by the
  microprocessor and sent along to the host
  computer as data.

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How a CD-ROM Drive Works

• The surface of the reflective layer alternates
  between lands and pits.
• Lands are flat surface areas.
• Light that strikes a land is reflected directly
  back to the detector.
• Light sensing diode
• Pits are tiny depressions in the reflective
  layer.
• Light that strikes a pit is scattered

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How a CD-ROM Drive Works

• HDD Spin rate compared to CD-ROM
• HDD
• Constant angular velocity
• CD-ROM
• Constant linear velocity

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How a CD-ROM Drive Works

• CDs compared to CD-ROMs
• CDs
• Convert the digital information stored on the
  disc into analog signals for a stereo amplifier
  to process
• CD-ROMs
• Have a great deal of additional Error Correcting
  Code (ECC) information written to the disc along
  with reliability and precision to levels that are
  acceptable for data storage.

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Types of CD-ROMs

• When purchasing a CD-ROM, consider three distinct
  sets of criteria
• The drives performance specifications
• The interface the drive requires for connection
  to your PC.
• The physical disc-handling system the drive uses

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Types of CD-ROMs

• The drives performance specifications
• The 52x and faster drives are currently the most
  popular.
• Standard equipment in most new PCs on the market
  today
• Meet the MPC-3 standard
• Data transfer rate 4,800 KB/s
• Access time 85 75 ms

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Types of CD-ROMs

• 2. The interface the drive requires for
  connection to your PC.
• SCSI/ASPI
• (Small Computer System Interface/Advanced ACSI
  Programming Interface)
• IDE/ATAPI
• (Integrated Drive Electronics/AT Attachment
  Packet Interface)
• Parallel port
• USB port

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Types of CD-ROMs

• USB port
• USB 1.1 and earlier CD-RW drives provide read and
  write transfer rates that match the fastest rates
  possible with IEEE-1284 parallel ports.
• USB 2.0 provides a transfer rate up to 480bps,
  which is 40 times faster that USB 1.1, and yet
  fully backward compatible.

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USB Compared to FireWire

• IEEE-1394
• (a.k.a. i.linkFireWire) USB
  1.1 USB 2.0
• PC-host required No Yes Yes
• Max. of devices 63 127 127
• Hot-swappable Yes Yes Yes
• Max. Cable length 4.5m 5m 5m
• Transfer rate 200Mbps 12Mbps 480Mbps
• Future trans. rates 400Mbps None None
• 800Mbps
• 1Gbps
• Typical devices DV camcorders keyboards
  all USB 1.1 devices
• digital cameras mice digital
  cameras
• HDTV joysticks camcorders
• high-speed stuff printers high
  speed stuff

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Audio Adapter Applications

• Creative Labs
• Reasons for audio adapters
• Games
• Multimedia
• Sound Files
• MIDI Files

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Creative Labs

• The Creative Labs Sound Blaster interface is the
  one that most hardware products emulate.
• The one for which most drivers are written
• Failure to support this de facto standard would
  be all but suicidal for a commercial audio
  adapter product.

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Reasons for audio adapters

• Adding stereo sound to multimedia entertainment
  software
• Increasing the effectiveness of educational
  software
• Adding sound effects to business presentations
  and training software
• Creating music by using Musical Instrument
  Digital Interface (MIDI) hardware and software
• Adding voice notes to files
• Audioconferencing and network telephony
• Adding sound effects to operating system events
• Enabling PC use by handicapped individuals
• Playing audio CDs

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Games

• Audio adapters were originally designed to play
  games
• Adapters include a game adapter interface.
• Connects a joystick or control paddles
• also use this interface to connect a plug
  providing MIDI connector.

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Multimedia

• Multimedia deals with video, sound and storage.
• PC multimedia means the capability to merge
  images, data and sound on a computer into a
  unified perceptual experience.

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Multimedia

• Multimedia PC (MPC) Marketing Council
• Originally formed by Microsoft
• created several standards
• Software Publishers Associations Multimedia PC
  Working Group
• Created a new MPC standard

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Software Publishers Associations Multimedia PC
Working Group

• MPC Level 1 MPC Level 2 MPC Level 3
• Processor 16Mhz 386SX 25MHz 486SX 75MHz Pentium
• RAM 2M 4M 8M
• Hard disk 30M 160M 540M
• Floppy disk 1.44M 1.44M 1.44M
• 3.5 inch 3.5 inch 3.5 inch
• CD-ROM Single-Speed Double-speed Quad-speed
• Audio 8-bit 16-bit 16-bit
• VGA video 640x480 640x480 640x480
• Resolution 16k colors 64k colors 64k colors
• Other I/O Serial, Parallel Serial, Parallel
  Serial, Parallel
• MIDI, Game MIDI, Game MIDI, Game
• Software Microsoft Microsoft Microsoft
• Windows 3.1 Windows 3.1 Windows 3.1
• Date Introduced 1990 1993 June 1995

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Additional Capabilities

• Digital audio recording
• Playback
• Music synthesis
• Audio mixing

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Recommendation

• Ram 32MB
• Processor 200Mhz Pentium
• Hard Disk 2G
• CD-ROM fastest
• Video highest resolution

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Sound Files

• Sound file
• Uses formats like WAV, VOC, AU and AIFF
• contain waveform data (analog - digital)
• Sound File Resolutions
• Default sound resolution levels used in
• Windows 9x and Windows Me (Millennium)
• Resolution Frequency Bandwidth File Size
• Telephone quality 11,025Hz 8-bit mono 11k/sec
• Radio quality 22,050Hz 8-bit mono 22k/sec
• CD quality 44,100Hz 16-bit stereo 172k/sec

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Moving Pictures Experts Group (MPEG)

• MPEG Standards
• MPEG-1
• used in business and home applications to
  compress audio on CD
• Is the basis for MP3
• MPEG-2
• used to compress video films on DVD-ROM
• MPEG-4
• used for video transmissions over the internet

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MPEG
How does MPEG work?
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MPEG
How does MPEG work? It is a very simple process.
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MPEG
How does MPEG work? It is a very simple
process. Basically, you save only the changes.
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MPEG
How does MPEG work? It is a very simple
process. Basically, you save only the
changes. Very much like this show.
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MPEG
How does MPEG work? It is a very simple
process. Basically, you save only the
changes. Very much like this show. Is all of this
information saved on one slide?
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MPEG
How does MPEG work? It is a very simple
process. Basically, you save only the
changes. Very much like this show. Is all of this
information saved on one slide? Or have you seen
several slides?
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MPEG
How does MPEG work? It is a very simple
process. Basically, you save only the
changes. Very much like this show. Is all of this
information saved on one slide? Or have you seen
several slides? The answer is
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MPEG
8 different slides.
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Sound Files

• MP3s
• Latest sound format being popularized by the Web.
• Digital sound-only favor of MPEG.
• Near-CD quality
• Allows for downloading quality music
  (www.mp3.com) and transformation CDs into MP3
  tracks.
• Converts CD-quality 50MB WAV ( five-minute song)
  to an MP3 4MB file.

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MP3s

• Create your own MP3 tracks
• Audio sources that you own
• An MP3 ripper program, such as Winamp
• A sound card with speaker or headphones for
  output and input

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MP3s

• To record your own MP3 mix CD for personal use.
• An MP3-encoding program such as MusicMatch
  Jukebox
• An MP3-to-WAV conversion program such as Winamp
• A CD-R or CD-RW drive with recording software
• CD-R media rated for the maximum speed of your
  recorder

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Sound Files

• MIDI Files
• developed in the 80s to permit electronic
  musical instruments to communicate.
• MID or RMI extensions
• contains the instructions that the audio hardware
  uses to create the sound
• MIDI format requires less than 500k for an hour
  of stereo music

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MIDI Files

• MIDI files are not intended to be a replacement
  for sound files such as WAVs. They should be
  considered a complementary technology. The
  biggest drawback of MIDI is that the playback
  technology is limited to sounds that are readily
  synthesizable. The most obvious shortcoming is
  that MIDI files are incapable of producing voices.

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MIDI Files

• Synthesizer
• generates the appropriate sound for each channel
• patch - a set of instructions that the
  synthesizer uses to create sound similar to a
  particular instrument.
• FM Synthesis
• most sound board generate sounds by using FM
  synthesis
• creates an artificial sound that mimics an
  instrument
• (continued)

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MIDI Files

• Wavetable Synthesis
• Takes a sample of an instrument playing a single
  note and modify its frequency to play any note on
  the scale
• The best quality adapters on the market usually
  have several megabytes of memory on board.

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MIDI Devices

• Electronic Keyboards, sound generator, and a drum
  machine
• The MIDI specification calls for the use of two
  or three 5-pin DIN connectors.

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5
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3
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Audio Adapter Concepts and Terms

• Properties of sound
• Pitch - the rate at which vibrations are produced
  (Hz). The higher the frequency, the higher the
  pitch
• Amplitude - intensity of a sound. The intensity
  ditermines the sounds volume
• decibels measurement of loudness of sounds

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Audio Adapter Concepts and Terms

• Frequency Response
• the range in which an audio system can record
  and/or play at a constant and audible amplitude
  level.
• 30 - 20kHz
• Total Harmonic Distortion
• measure of accurate sound reproduction.
• Sampling
• the process of turning the original analog sound
  waves into digital signals

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Audio Adapter Features

• Stereo line, or audio, out connector
• connector is used to send sound signals for the
  audio adapter to a device outside the computer
• Stereo line, or audio, in connector
• connector used to record or mix sound signals
  from an external source
• Speaker/headphone connector
• provided on most audio adapters
• line out may be used
• Microphone, or mono, in connector
• used to connect a microphone for recording your
  voice or other sounds to disk

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Audio Adapter Features

• Joystick connector
• MIDI connector
• Internal pin-type connector
• used to plug an internal CD-ROM drive directly
  into the adapter

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Choosing an Audio Adapter

• It is difficult to beat the best
• Software
• text-to-speech conversion programs
• applications for playing, editing and recording
  audio files
• audio CD-player programs
• stereo sound-mixer programs
• sequence4r software
• various sound clips

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Audio Adapter Installation

• Sound Cards can be purchased for under 40.
• The number of settings varies according to the
  features of the card
• IRQ I/O Address DMA Channels
• 8-, 16- or 32-bit in reference to sound cards
  deals with the sampling rate.

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Audio Adapter Installation

• Several sound cards have CD-ROM interface
  connectors and audio pass-through cable
  connectors.
• Most are secondary EIDE controllers and should be
  disabled if you have a working EIDE secondary
  controller.

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The End