Chapter · Chapter 8 Video and Audio Systems Chapter . Copyright Goodheart-Willcox Co., Inc. May...

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8 Video and Audio Systems

Chapter

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website.

Objectives

• Recall the characteristics common to all

monitors.

• Explain the basic operation of a CRT, an LCD,

and a gas-plasma monitor.

• Carry out general procedures for

troubleshooting a video display.

• Use the generally-accepted guidelines to

properly clean a display.

• Compare video adapter card types.

• Carry out a video card installation.


Objectives (Continued)

• Use the Appearance and Personalization

dialog box to change the display properties.

• Identify computer monitor and home theater

center connection types.

• Explain how data compression works.

• Explain analog-to-digital conversion.

• Explain the operation of microphones and

speakers.

• Carry out a sound card installation.


Objectives (Continued)

• Recall common codecs and their

characteristics.

• Select components to create a customized

configuration to meet customer specifications.


Key Terms

• active-matrix display

• Advanced Video Coding (AVC)

• alternating-frame rendering

• aspect ratio

• bitmap (BMP)

• buffering

• candela

• cathode ray tube (CRT)

• codec

• color palette

• color/graphics adapter (CGA)

• contrast ratio

• deflection yoke

• degaussing

• digital-to-analog converter (DAC)

• dot pitch


Key Terms (Continued)

• electron guns

• enhanced graphics adapter (EGA)

• extended graphics array (XGA)

• field

• gas-plasma displays

• home theater PC (HTPC)

• inverter

• LED monitor

• liquid crystal display (LCD)

• monochrome

• Moving Picture Experts Group (MPEG)

• multicolor/graphics array (MCGA)

• multimedia



• musical instrument digital interface (MIDI)

• native resolution

• organic LED display (OLED)

• passive-matrix display

• persistence

• pixel

• pixel pitch

• polarized light

• raster

• refresh rate

• resolution

• response time

• run-length encoding (RLE)

• sampling

• Scalable Link Interface (SLI)

• shadow mask



• split-frame rendering

• super VGA (SVGA)

• thin film transistor liquid crystal display (TFT-LCD)

• vector graphics

• video graphics array (VGA)

• viewing angle


Video System and Display Aspects

• The video display system consists of the display

and the video adapter.

• The video display system is often called a video

card or graphics card.

• Display quality depends on

– Color display values

– Display resolution


Video System and Display Aspects (Continued)

• Color display values

– Determined by number of bits used to represent the

individual colors of red, green, and blue.

– Number of bits used can determine the possible

number of color shades.

Color Display Value Number of Colors

8-bit 256

16-bit (True color) 65,536

24-bit (True color) 167,777,216

32-bit (True color) 4,294,967,296

64-bit (Deep color) 281,474,976,710,656 Goodheart-Willcox Publisher



• Display resolution

– Resolution is the amount of detail a monitor is

capable of displaying.

– Resolution is measured in pixels. A pixel is the

smallest unit of color in a screen display.

– First PCs has monochrome monitors. Monochrome

technology displays only one color, usually amber or

green.

– Color/graphics adapter (CGA) was a video

standard that featured two resolutions: 320 x 200 in

four colors and 640 x 200 in two colors.




– The enhanced graphics adapter (EGA) was a

video standard used to improve the resolutions and

color capabilities of the CGA standard.

– The video graphics array (VGA) is the baseline

for video adapters.

– A color palette is a collection of possible different

colors usually in degrees or shades, which can be

displayed on a monitor.




– The multicolor/graphics array (MCGA) was a

video standard supporting CGA and also providing

up to 64 shades of gray.

– Super VGA (SVGA) supports 16 million possible

colors and various resolutions such as 800 x 600,

1024 x 768, 1280 x 1024, and 1600 x 1200.

– Extended graphics array (XGA) is a video standard

that supports a resolution of 640 x 480 with 65,536

colors, or 1024 x 768 with 256 colors.




– The multicolor/graphics array (MCGA) was a

video standard supporting CGA and also providing

up to 64 shades of gray.

– Super VGA (SVGA) supports 16 million possible

colors and various resolutions such as 800 x 600,

1024 x 768, 1280 x 1024, and 1600 x 1200.

– Extended graphics array (XGA) is a video standard

that supports a resolution of 640 x 480 with 65,536

colors, or 1024 x 768 with 256 colors.


Types of Video Displays

• Computer and television display technology have

become more similar.

• There are several types of displays.

– Cathode ray tube displays

– Liquid crystal displays

– Gas-plasma displays


Types of Video Displays (Continued)

• A cathode ray tube (CRT) is a glass tube in which

electrons are used to produce a picture.

– Electron guns are located at the back of the CRT.

– The deflection yoke area contains electromagnets

used to deflect the electron beam in a CRT.

– The shadow mask determines the dot pitch of the

monitor.

– Persistence is the continuation of the glow after the

electron beam ceased to strike the phosphor areas.

– The correction of the remnant magnetic field is called

degaussing.



• Cathode ray tube (CRT)

– Monitor size

• Length from corner to corner determines size of

monitor.

• Viewing varies from one monitor to the next.

– The dot pitch is the distance measured in

millimeters between two color dots on the screen.

• Reflects the quality of the image displayed.

• Cannot be adjusted.



• Cathode ray tube (CRT)

– Refresh rate

• Refresh rate is the rate at which the beam sweeps

across the screen.

• Can be adjusted in the Control Panel.

– Raster display

• The method of producing a picture on a monitor

using sweeping electronic beams.

• The sweep of the electronic beam is called a raster.

• A complete sweep of the entire screen area is called

a field.



• A liquid crystal display (LCD) is a type of

monitor using polarized light, which passes

through liquid crystal to create an image on

screen.

– Operates on the principles of polarized light and

the effect of an electrical voltage applied to a

crystal structure.

– Polarized light is light energy composed of light

beams with a matching wave angle.

– Backlighting from CCFL or LED lights is required.



LCD Display

Goodheart-Willcox Publisher



• Liquid crystal displays

– An LED monitor is a portable LCD screen that

uses an LED backlight.

– Organic LED display (OLED) technology is made

from carbon-based materials rather than

crystalline.

– Passive-matrix display consists of a grid of

semitransparent conductors that run to each crystal

that makes up the individual pixels.

– In an active-matrix display, each individual cell in

the grid has its own individual transistor.




Passive Matrix Display




Active Matrix Display




– Contrast ratio is the numeric expression of the

amount of contrast between darkest and lightest

pixel in the image.

• The higher the ratio, the better the colors will be

represented on the display unit.

• Ranges from 500:1 to 1000:1.

– Brightness

• Produced by backlighting.

• Main factor for determining if the monitor will display

in a bright environment.




– The viewing angle is a measurement of the angle

at which a person can adequately see an image.

• Today, viewing angle is of less concern.

• Varies from one manufacturer to the next.

– Pixel pitch is the distance between two same color

pixels on the display area.

• Each color pixel is composed of three pels

(subpixel), one for each of the three colors that

compose a pixel.

• Expressed in millimeters (mm).




– Native resolution is the resolution that matches

the pixel design of the display.

• If a resolution other than the native resolution is

chosen, an image will appear slightly blurred.

• Products the sharpest image with the least distortion

of the original images and text.

– Response time is the amount of time for TFT pixel

to display after signal is sent.

• Measured in milliseconds (ms).

• Typical response time ranges from 15 ms to 40 ms.




– Monitor size

• Measured in a diagonal line across the front panel of

the display.

• CRT monitor will display less than measured size

compared to LCD monitor.




– Aspect ratio refers to the ratio of the display area’s

height and width.

• Creation of wide-aspect ratio has created a need for

newer video resolution identification.

• Wide-aspect ratio allows more information to be

displayed and matched the HDTV standard.



• Gas-plasma displays operate on the principle of

electroluminescence.

– Electroluminescence is the display of light created

when a high frequency passes through a gas to a

layer, resulting in the release of photons.

– Transparent electrodes run horizontally behind the

front panel on top of the cells.

– Top electrode is called the row electrode; bottom

electrode is call the column electrode.

– Unlike LCDs, gas-plasma displays do not require a

backlight.




Gas-Plasma Technology


Why is the term organic used to describe

organic LED displays?

The term organic is used because the

construction of the LED is from carbon-based

materials, which are organic in nature.

Review


Troubleshooting Video Displays

• Video displays have no serviceable parts.

• Before replacing a monitor, check the following.

– Is the monitor turned on?

– Is the power cord plugged in?

– Does the wall outlet have voltage?

– Is the video cable between the computer and the

display unit intact or loose?


Troubleshooting Video Displays (Continued)

• Check the video card in the monitor as well.

– If the video card needs to be replaced, install the

new one in any available slot.

– Before replacing the video card, reinstall or update

video card drivers.


Cleaning Video Displays

• Methods of cleaning video displays are debated

and conflicting.

• Always consult manufacturer documentation.

• Generally-accepted guidelines for properly

cleaning displays include the following.

– Unplug electrical supply.

– Use a dry lint-free soft cloth.

– Never use paper towel.

– Never spray liquids directly on display.


If you are troubleshooting a computer with a

video display problem, what should you do

before changing the monitor?

Check if the monitor is turned on; Check if

power cord is plugged in; Check if the wall

outlet has voltage; Check the video cable

between the computer and the display unit.

What should you use to clean an LCD display?

A dry lint-free cloth.

Review


Video Adapter Cards

• One of the ways to attach a monitor to a computer

is by using a video adapter card.

• The heart of the video adapter card is the digital-

to-analog converter (DAC), which converts the

digital signal from the computer to an analog

signal that is displayed on the computer’s monitor.


Video Adapter Cards (Continued)

• The video adapter card is plugged into one of

three types of slots on the motherboard.

– AGP

– PCI-X

– PCIe

• Video performance depends on the amount of

available memory to create and process images.



• AGP

– A slot used strictly for AGP adapter cards

– Designed with graphics as a priority

– Most used in older equipment

• PCI-X

– Also known as PCI Extended

– Designed as a successor to PCI bus

– Not used by many current video card systems



• PCIe

– Also known as the PCIe x16

– The preferred video card

– Provides about twice the graphics data throughput

as AGP x8

• Multiple video cards

– Two or more video cards can be installed to

increase performance

– When using split-frame rendering, each card is

responsible for half of the frame image.



• Multiple video cards

– Alternating-frame rendering is a method of

sharing the video workload in which each card is

responsible for rendering every other frame.

– Scalable Link Interface (SLI) is a proprietary

video card system owned by the NVIDIA

Corporation.

– ATI CrossFire is the multiple card technology with

two or more cards configured for the computer.


Installing a Video Adapter Card

• The procedure for installing a video adapter card is

standard between different cards.

– Always back up critical files before installation.

– Power off and unplug the computer.

– Read installation procedures.

– Take ESD precautions.

– Check for debris in the slot.

– Insert card by applying even force to the top.

– Connect the monitor and turn on PC.

– Install driver and any patches or upgrades.


Personalizing Display Properties

• Use Appearance and Personalization dialog

box.

• Personalization dialog box allows the user to

select themes for appearance.

• Display dialog box allows the user to configure

screen resolution.

• Configuration options are similar in Windows

Vista, Windows 7, and Windows 8.

• Windows XP options are not as similar.


When using Appearance and

Personalization, what does the Display dialog

box allow a user to do?

When streaming, you can actually view the

contents of the file while performing the

download.

Review


Television and Computers

• High-definition television

– HDTV resolution requires a display resolution of at

least 1080 x 720.

– VGA uses three separate analog signals, while with

digital signals, the data are carried in a series of

square waves.

• Windows Media Center

– This feature allows users to record and playback

television, tune in to radio, play music, etc.

– Windows Media center was first introduced in

Windows XP.


Television and Computers (Continued)

• A home theater PC (HTPC) is a customized

computer used to enhance the television viewing

experience.

– Additional software/hardware may be used to

support multimedia recording and playback.

– Quality of video streaming is based on the ability of

the system.

• Smart TVs

– Smart TVs include support for Internet connections

and Wi-Fi.

– Software applications vary.



• Home theater boxes

– These components provide the same services as

Smart TVs, video recording, and Internet services

in one box.

– A home theater box connects directly to the TV or

Internet.



• Home Theater Center Connection types

– A home theater is often a collection of many types

of devices connected together.

– There are several connection types.

• Composition video

• S-Video

• Component Video

• HDMI

• Sony/Philips Digital Interconnect Format

• TOSLINK

• RF and F-Type




Various Home Theater Cables




Various Home Theater Connections




– Composition video

• Uses a RCA-type connector

• Uses one cable for video signal and two for stereo

sound

– S-Video

• A simple way to connect components

• Supports better signal quality then composite video

• Nine-pin version used for video in and out

configurations; four-pin used for video in only




– Component Video

• Consists of three RCA connector

• Found on high-performance devices

– HDMI

• Stands for High Definition Multimedia Interface

• Used to supply video and audio in an

uncompressed, all digital signal

– Sony/Philips Digital Interconnect Format

– TOSLINK

– RF and F-Type




– Sony/Philips Digital Interconnect Format

• Proprietary digital audio connection/cable

– TOSLINK

• Optical proprietary connector developed by Sony

and Phillips

• Consists of glass and plastic core

– RF and F-Type

• Provides poorest quality video images

• Standard coaxial cable used only with old

technologies


Graphic Coding

• There are many different methods used to code the

data of an image.

• Coding methods are designed for one of two

purposes.

– Compress content

– Preserve quality


Graphic Coding (Continued)

• A bitmap (BMP) is a graphics standard for

uncompressed encoding of images.

• Vector graphics are based on a series of

mathematical formulas that can be converted into

geometric shapes representing the image to be

displayed.

• Graphics compression

– Image data can be compressed to decrease the

amount of memory space needed for storage.

– Run-length encoding (RLE) replaces a series of

repeated pixels with a single pixel and the length of the

series (run).


What Is Sound?

• Sound is comprised of vibrations that are put into

motion through a medium such as air or water.

• Measuring an analog signal at regular intervals is

called sampling.

• Audio resolution is based on two key factors.

– Sampling

– Number of bits used to represent the analog sound

• Musical instrument digital interface (MIDI) is a

file standard developed for music synthesizers.


Audio Devices

• Most audio devices are tied into the PC through

the sound card.

• Common audio devices

– Microphone

– Speakers

– Sound cards

– Video capture device


Audio Devices (Continued)

• Microphone

– Simple electronic device used to convert sound

waves into electrical energy.

– When the sound is stored as a digital code, it is

often referred to as a wave file.

• Speakers

– Converts electrical energy to sound energy.

– A speaker with a built-in amplifier is called an

active speaker; a passive speaker does not have a

its own amplification.


Audio Devices (Continued)

• Sound cards

– Most sound cards are PCI adapter cards (Plug and

Play).

– System conflicts are quite common for older cards.

• Video capture device

– Used to send audio and video from a device such

as a VCR or camcorder to a PC.

– Can also be used to capture live video from a

device such as a television or game.


Installing a Sound Card

• Review IRQs, DMA, memory addresses, and I/O

port address topics before installing a sound card.

• Plug and Play should eliminate most conflicts.

• The installation of a sound card requires 10 steps.

1. Back up all computer files.

2. Power off the computer and unplug the power

cord from the outlet.

3. Read installation procedures and specification for

the sound card.

4. Take normal ESD precautions.


Installing a Sound Card (Continued)

• For the installation of a typical sound card, steps

continued.

5. Check for debris in the expansion slot.

6. Insert the card into the slot by applying even force

to the top of the card.

7. Check for any cables that might interfere with the

sound card.

8. Connect the speakers.

9. Visit the manufacturer’s website for drivers.

10. Power on the computer.


Installing a Sound Card (Continued)


Typical Sound Card


Multimedia

• A format that includes interaction with audio and

video is referred to as multimedia.

• A codec is any hardware, software, or

combination hardware and software that can

compress and decompress data.

• The Moving Picture Experts Group (MPEG),

developed data compression standards and file

formats for storing both audio and video data. A

variety of standard and file formats exist.


Multimedia (Continued)

• Buffering is used to play a downloaded file without

skips or quiet spots during playback.

– Buffering collects downloaded data and

reassembles it in its original order.

• Audio and video players are often referred to as a

plug-ins.

– Needed to access sound and video tracks

recorded on a PC.

– Some players are only designed to allow you to

play through the Internet.


What is the purpose of a codec?

A codec is any hardware, software, or

combination hardware and software that can

compress and decompress data.

Review


Building a Custom Computer System

• When selecting components to build a customized

computer system, consider the tasks the computer

must be able to accomplish.

• Components will typically include

– Motherboard/chipset and processor

– Power supply

– Video card

– Display

– Sound card

– TV tuner card

– Storage

– Software


Building a Custom Computer System (Continued)

• Video Performance Information and Tools

− This feature determines the overall performance of

a computer system.

− This feature can be used to identify performance

capabilities.

− DirectX Diagnostic Tool

− Performs a quick check of the computer video and

audio systems.

− Windows 8 will not produce the DirectX Diagnostic

Tool when a search is conducted.


What is the name of the tool used to generate a

Windows Experience Index?

Performance Information and Tools.

Review

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