Multimedia

1
Module 8

• Multimedia
• Capabilities

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Multimedia

• Multimedia is a term typically used to mean the
  combination of text, sound, and/or motion video.
  Multimedia has been described as the addition of
  animated images, but typically it means one of
  the following
• Text and sound
• Text, sound, and still or animated graphic images
  
• Text, sound, and video images
• Video and sound
• Multiple display areas, images, or presentations
  presented concurrently
• In live situations, the use of a speaker or
  actors and "props" together with sound, images,
  and motion video

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Multimedia

• The types of computer hardware and software
  necessary to develop multimedia on the PC vary.
• The minimum hardware requirements include
• computer monitor
• video accelerator card
• sound adapter card with attached speakers.

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Key Multimedia Components

• A microphone connected to a sound card to input
  sound.
• CD-ROMs and DVD players are used for input and
  output of multimedia.
• A connection to the Internet via a network
  interface card or a modem. Streaming of audio and
  video is very popular.
• Digital still pictures and video cameras
  connected to standard computer ports or special
  card adapters.
• A video capture card
• MPEG hardware and Web based movie players are
  used to play movies.
• Computer games via DVD or CD require specialized
  hardware.

5
The Video Card

• A video adapter (also called a display adapter or
  video board) is an integrated circuit card in a
  computer that provides digital-to-analog
  conversion, video RAM, and a video controller so
  that data can be sent to a computer's display. In
  a few cases, the video adapter is built in to the
  monitor. Today, almost all displays and video
  adapters adhere to the standard Video Graphics
  Array (VGA).
• In addition to VGA, most displays adhere to one
  or more standards set by the Video Electronics
  Standards Association (VESA). VESA defines how
  software can determine the capability of a
  display. It also identifies resolutions setting
  beyond those of VGA. These resolutions include
  800 X 600, 1024 X 768, 1280 X 1024, and 1600 X
  1200 pixels.

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Display Characteristics

• Displays use bits to describe color and how many
  colors can be displayed.
• The number of bits used to describe a pixel is
  called bit-depth
• VGA video is 256 colors or 8-bit bit-depth
• 24-bit bit-depth is known as true color
• Dot pitch is the size of an individual beam that
  gets through to light up a point of phosphor on
  the screen measured in millimeters with a typical
  display having a .28 mm dot-pitch
• The actual sharpness of a display image is
  measured in dots-per-inch (dpi). The
  dots-per-inch is determined by a combination of
  the screen resolution and the physical screen
  size.

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Display Characteristics
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Display Characteristics
Dot pitch is a diagonal distance between the same
color phosphor dots. The smaller the dot pitch,
the greater the potential image sharpness.
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Display Characteristics

• On desktop computers, the display screen width
  relative to height, known as the aspect ratio, is
  generally standardized at 4 to 3 (usually
  indicated as "43"). Screen sizes are measured in
  either millimeters or inches diagonally from one
  corner to the opposite corner. Common desktop
  screen sizes are 15-, 17-and 19-inch. Notebook
  screen sizes are somewhat smaller.
• The projection technology used by most displays
  is Cathode Ray Tube (CRT) technology, which is
  similar to that used in most television sets. CRT
  technology requires a certain distance from the
  beam projection device to the screen in order to
  function. Using other technologies, displays can
  be much thinner and are known as flat-panel
  displays.

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Media Formats

• Two data-compression standards are commonly used
  with digitized video. These are the Joint
  Photographic Experts Group (JPEG) and the Moving
  Picture Experts Group (MPEG) compression
  standards.
• MiniDV, Digital8, and DVD are digital video
  camera formats
• Other Compression Standards
• Indeo compression standard, developed by Intel.
• Another compression/decompression (codec)
  standard supported by Video for Windows is
  Cinepak. This standard uses an AVI file format to
  produce 401 compression ratios and 30-frames per
  second capture, at 320-by-200 resolution.

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Media Compression

• JPEG provides enough compression to allow
  single-frame digitized images to fit on disk
  drives, but full-motion pictures were going to
  need much greater compression to be useful on
  current technology. Therefore, the MPEG format
  was developed.
• MPEG has compression ratios up to 2001, with
  high-quality video and audio.
• The MPEG standard includes specifications for
  audio compression and decompression in both MPEG1
  and 2. MPEG1 supports a very near CD-quality
  stereo output, at data rates between 128kbps and
  256kbps. The MPEG 2 specification supports
  CD-quality surround-sound (four-channel) output.

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Accelerated Graphics Port

• Newer Pentium systems were the first to include
  an advanced Accelerated Graphics Port (AGP)
  interface for video graphics. The figure below
  shows an AGP interface and its position on the
  motherboard. The AGP interface is a variation of
  the PCI (see Chapter 2) bus design that has been
  modified to handle the intense data throughput
  associated with 3 dimensional graphics.

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Video Capture Cards

• Video capture software is used to capture frames
  of television video and convert them into digital
  formats that can be processed by the system. One
  of the popular file formats for video is the
  Microsoft Audio Visual Interface (AVI) format.
• Video capture cards are responsible for
  converting video signals from different sources
  into digital signals that can be manipulated by
  the computer. As in the audio conversion process,
  the video card samples the incoming video signal
  by feeding it through an A-to-D
  (analog-to-digital) converter.
• One of the jobs of the video capture card is to
  convert the YUV format into an RGB VGA-compatible
  signal.
• YUV is a video encoding format that is different
  than RGB.

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Video Card Installation

• After the video card has been installed and the
  monitor has been connected to the video card and
  plugged into the power outlet, it will be
  necessary to install the correct drivers for the
  video card. The Windows 9x operating systems
  should detect the video card, start the system
  with basic VGA video drivers, and ask you if you
  want to install the manufacturer's video drivers
  (automated).
• The Windows 2000 operating system is even more
  proactive. It will detect the new video card,
  tell you that it has found the new card, and then
  automatically load its video drivers. The only
  time that you should need to be directly involved
  with the system's video drivers is when PnP fails
  or the video card is not recognized by the
  operating system.

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Driver Installation

• Automated Installation
• Install the card
• Restart the computer
• Windows initiates the driver installation via
  prompts
• Manual Installation another method to
  installing a driver
• Install the card
• Install the driver using Device Manager utility

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Video Memory and Resolution

• Monitors are analog, not digital devices. In
  order for the monitor to work, the digital
  information in the video memory must be
  translated into analog form for export to the
  monitor screen. This is the role of the Random
  Access Memory Digital-to-Analog Converter
  (RAMDAC) chip. The RAMDAC chip reads the video
  memory contents, converts it to analog, and sends
  it over a cable to the video monitor. The quality
  of this chip impacts the quality of the image,
  speed of the refresh rate, and maximum resolution
  capability. Refresh rate refers to the number of
  times per second that the video display screen
  can be redrawn.

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Video Memory and Resolution

• The video chip set relies on video memory to
  render the image requested. The basic element of
  every video image is a dot (or pixel). Many dots
  comprise what you see displayed on the monitor.
  Every dot has a location reserved in video
  memory. The maximum number of dots, which can be
  displayed, relates to the resolution.
• Resolution is expressed as a pair of numbers.
  Each pair of numbers represents the maximum
  possible number of dots on a horizontal and
  vertical axis. The basic VGA resolution is 640 by
  480. The higher the resolution, the sharper and
  clearer the image.

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Sound Cards

• Audio is an integral component of the multimedia
  experience, but for a PC to have audio
  capabilities, it requires the use of a sound
  card.
• A sound card is a device (either in the form of
  an expansion card or a chipset) that allows the
  computer to handle audio information.
• Input Sound cards can "capture" audio
  information from many different sources. These
  sources include microphones, CD players, DAT, and
  MIDI devices.
• Processing The processing capability of a sound
  card allows it convert audio information in
  different formats as well as add effects to the
  sound data.
• Output Simple sound card output devices include
  headphones and speakers while more complicated
  devices consist of surround-sound digital theatre
  systems, DAT and CD recorders, and other musical
  devices

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CD-ROMs

• CDs are 120mm in diameter, 1.2mm thick, and can
  store up to 800 MB of information.
• CD-ROM drives can be mounted internally in the
  computer or as an external drive.
• They connect either directly to an external port
  on the computer (such as USB, FireWire, or
  parallel) or to a controller installed in one of
  the computer's expansion slots (usually SCSI).
• Common internal connections include IDE and SCSI.
• IDE communication cables are 40-pin ribbon cables
  that connect to the drive and the motherboard.

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CD-ROMs

• Currently there are two major types of CD
  recorders CD-R and CD-RW.
• CD-R CD-R stands for Compact Disc - Recordable
  and was the first of the two technologies
  conceived.
• CD-RW CD-RW stands for Compact Disc -
  Rewritable.
• CD-ROM drive speed rating is based upon multiples
  of 150 kbps
• A CD drive that can write at 3000kb per second is
  shown as having a 20x (or 20 times 150kb) write
  speed. A drive listed as 24x/40x has a write
  speed of 24x and a read speed of 40x.

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CD Recording Formats (Physical Standards)
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CD Recording Formats (Physical Standards)

• Red Book defines the format for audio CDs
• Yellow Book defines the format for data CDs
• Green Book defines the format for interactive
  CDs
• Orange Book defines the format for recordable
  CDs
• White Book defines the format for video CDs
• Blue Book defines the format for enhanced CDs