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Multimedia. Chapter 20. Overview. In this chapter, you will learn how to Describe how to implement sound in a PC Install and configure video capture hardware and software Set up a PC to view television signals. Sound-Capture Basics. Four components for capturing and outputting sound

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Multimedia

Chapter 20


Overview
Overview

In this chapter, you will learn how to

Describe how to implement sound in a PC

Install and configure video capture hardware and software

Set up a PC to view television signals


Sound capture basics
Sound-Capture Basics

Four components for capturing and outputting sound

Sound card

Speakers

Microphone

Recording/Playback software


Sound capture basics continued
Sound-Capture Basics (continued)

Sampling = capturing sound

Sampling rate is measured in cycles per second (KHz)

Low quality (11 KHz) to high quality (192 KHz)

Doesn’t capture every nanosecond of sound

Takes samples and extrapolates, or predicts, what the data is between samples

Dotted line—can you connect the dots?


Sound capture basics continued1

Sampling = capturing sound

Bit depth—number of characteristics of a particular sound (for each sample)

Amplitude (loudness)

Frequency (tone)

Timbre (qualities from different instruments)

Sound-Capture Basics (continued)


Sound capture basics continued2
Sound-Capture Basics (continued)

Sound waves are commonly sampled with either 8 or 16 bits per sample

8-bit stores 28 or 256 different characteristics

16-bit stores 216 or 65,536 different characteristics

Tracks

Monaural—one track

Stereo—two tracks

CD quality

44.1 KHz

16-bit depth


Recorded sound formats
Recorded Sound Formats

Pulse code modulation (PCM)

Developed for telephone calls

Better known as the WAV format (waveform)

Large files

Four-minute song at 44.1 KHz and 16-bit stereo is greater than 40 MB

Compressor/decompressor (CODEC) programs

Algorithms developed to compress sound files

MPEG-1 Layer 3 codec or MP3 is one example of a codec


Playing sounds
Playing Sounds

Every sound card can play WAV files using sound player software

Windows Media Player comes with Windows

iTunes is Apple’s media program

Many other good sound players are available


MIDI

Musical Instrument Digital Interface

MIDI file is a text file

Contains a series of commands that describe

What note to play

How long to play it

Which instruments to use

Tiny in size compared to WAV files

First movement of Beethoven’s Fifth Symphony is 78 MB as a WAV file and 60 KB as a MIDI file


Midi continued
MIDI (continued)

Sound cards play MIDI files using one of two technologies

FM synthesis

Strictly electronic—software says what to play

Wave table synthesis

Uses recorded sounds (WAV files) to start

Modifies characteristics of sounds to create amplitude, frequency, and timbre desired

Polyphony of card—how many instruments it can play at once (64 instruments is common)


Other file formats
Other File Formats

Over 100 sound formats

AAC –Advanced Audio Coding –the native format for Apple’s iTunes

AIFF –Audio Interchange File Format – popular format for Macintosh computers

ASM - Assembly Language Source – compressed files often seen on the Internet and used in streaming sound

ASX – Microsoft Advanced Streaming Redirector

AU –Often seen in Windows, Sun, Next, UNIX, and Mac

OGG – Vorbis format – open source codex

RM – RealMedia – audio or audio and video

WMA – Windows Media Audio - proprietary


Playing sounds1
Playing Sounds

Streaming quality improving, with many stations outputting 128-Kbps signals

Media Player

iTunes

RealPlayer

WinAmp


Getting the right sound card
Getting the Right Sound Card

Getting the Right Sound Card


Sound cards
Sound Cards

A sound card typically has many built-in features

Two separate processors (one for MIDI and one for the rest)

Support chips for joysticks

Recording capabilities

MIDI instrument support

Surround sound

Can be a separate sound card

Often just a chip on the motherboard or part of the Southbridge


Sound card differences
Sound Card Differences

Sound cards differ in six basic areas

Processor capabilities

Audio standards

Speaker support

Recording quality

Jacks

Extra features

Processor handles communication among the application, OS, and CPU

Low-end sound cards let your CPU do most of the work

Better sound cards do most of the processing, which accelerates the sound process and provides better sound quality


Audio standards
Audio Standards

AC’97

Up to 6 channels

48 KHz/20-bit

Obviously an old standard, but implemented on many motherboards still

High Definition Audio (HDA)

Intel standard

Up to 8 channels

192 KHz/32-bit

Code name: Azalia

Often see implementations using “Azalia”


Sound card differences continued
Sound Card Differences (continued)

Speaker support

Basic support—two speakers or headphones

Better sound cards support five or more speakers

Often have a subwoofer

5.1 means 5 speakers with 1 subwoofer

Recording quality

Signal-to-noise (S/N) ratio expressed in decibels

Low-end cards have S/N ratio of 30 to 50 decibels

Records artifacts (noise) when there is no actual noise

High-end cards offer a 96 to 100+ S/N ratio


Sound card differences continued1
Sound Card Differences (continued)

Jacks

Line In and Line Out converters enable the sound card to send and receive input and output from other devices

The Line In connector runs to a Line Out or Aux connector on the back of a stereo receiving system

Rear Out connects to the rear speakers for surround sound

Analog/Digital Out for external digital connections

Microphone and Joystick


Sound card connections
Sound Card Connections

Mini-audio connections

Main stereo speaker is green

Line In connector is blue

Microphone connector is pink


Sound card differences continued2
Sound Card Differences (continued)

Extra Features

Almost all motherboards have built-in sound

Extra goodies needed to entice buyers for standalone sound cards

Digital output to integrate PC with home entertainment system or DVD receiver

Surround-sound speaker connections

Breakout box adding ports to front of PC

More


Lab sound hardware
Lab – Sound Hardware

Most current motherboards have built-in sound, does yours?

How can you determine if the motherboard has built-in sound hardware?

What audio standard does the sound hardware support?

How many speakers does it support?


Audio cables
Audio Cables

Playing audio CDs through your sound card used to require a cable from your optical drive to the sound card

Most optical drives come with an MPC2 audio cable for this purpose

Modern systems don'tuse this cable


Speaker standards
Speaker Standards

Stereo

Left and right

2.1 systems

Pair of speakers calledsatellites and a subwoofer


Surround sound standards
Surround-Sound Standards

Dolby Digital

Supports five channels plus subwoofer (5.1)

Front right, front left, front center, rear left, rear right

Digital Theatre System (DTS)

Competing standard that also supports 5.1

Sony/Philips Digital Interface (S/PDIF)

Uses single connector for entire 5.1 (or greater) system


Surround sound standards continued
Surround-Sound Standards (continued)

DirectX provides applications, primarily games, with direct access to hardware

Offers developers easy-to-use commands

Easy to program sounds in the desired channel

DirectSound3D (DS3D)

Can place a sound anywhere in 3-D space

Known as positional audio

R.I.P. in Vista (Try OpenAL now)

Environmental audio extensions (EAX)

Creative Labs’ response to DS3D

Audio presets for realism in sound


Speaker features
Speaker Features

Controls

Volume controllers

On/off switch

Can be on speakersor on special box

Headphone jack

Some systemscan automaticallysense when plugged in



Physical installation
Physical Installation

Installs like any other PCI card

Plug in the card

Load the drivers

Test

Hardest part may be identifying where to plug in speakers

Refer to documentation

Typical stereo or 2.1 speaker system plugs into Speaker or Speaker 1 port

Surround-sound speakers may use single S/PDIF


Physical installation continued
Physical Installation (continued)

Basic steps

Shut down your computer, unplug it, and open the case

Find an open PCI or PCIe slot and install the card

Connect the CD audio cable to the drive and the card


Installing drivers
Installing Drivers

Let Windows install drivers

If necessary/desired, use CD that came with sound card

If installing a USB sound card

Follow the cardinal rule for USB drivers: Install the USB driver before the USB device

Verify driver is installed by checking Device Manager

Test


Windows configuration applications
Windows Configuration Applications

Most sound card configuration can be done with the operating system utilities

Control Panel applet: Sound in Vista, Sounds and Audio Devices applet in Windows XP, Sounds and Multimedia in Windows 2000

Five tabs in 2000/XP

Volume

Sounds

Audio

Voice

Hardware


Windows configuration applications continued
Windows Configuration Applications (continued)

Vista has better support for multiple speakers and HDMI


Proprietary configuration apps
Proprietary Configuration Apps

Adds access to other features that aren’t otherwise available

Autosensing—allows hardware to be plugged in using different ports and the ports adjust

Plug microphone into speaker port and speaker port becomes a microphone port


Installing applications

Some sound cards install extra software

Goal is to provide user with extra free software

These programs aren’t needed to use any of the features

Intended to provide extra value for the purchase

Installing Applications


Hardware problems
Hardware Problems

Volume

Check physical controls

Check software controls

Windows Volume controls

Speakers

Ensure they are turned on and getting good power

Make sure they are plugged in

Check for visual indicators that a sound is playing

Replace speakers if blown speakers suspected


Configuration problems
Configuration Problems

First place to check: Device Manager

Consider reinstalling driver

Ensure the latest device drivers are installed

Check the manufacturer’s Web site for updates

Review the Sounds and Audio Devices applet settings


Application problems
Application Problems

First, look for an error message

Check the application’s support site

Second, check the sound file

Sound files might be corrupted

Last, reinstall the application


Video capture

Hardware

Designed to accept incoming video

Video Capture


Video capture continued

Software

Controls the hardware

Usually also edits

Video Capture (continued)


Multimedia file formats

Consists of two parts, video and audio

Each part may have its own compression

Compressed audio and video combined into a container file (wrapper)

The file name does not always tell you the compression

Multimedia File Formats


Video codecs

Videos typically have sound built in

Some common video codecs:

Video Codecs

Acronym

Description

MPEG-2

Used for DVDs

MPEG-4

Used in Internet broadcasts

H.264

Used in high-def movies for Blu-ray discs & others

WMV

Windows Media Video

Theora

Open source codec for Ogg project

TrueMotion

Used in Adobe Flash (VP6) and Skype (VP7)

VC-1

Microsoft hi-def codec usually wrapped in WMV file


Video wrappers
Video Wrappers

Somecommon multimedia wrappers

Acronym

Description

ASF

Mainly for WMA/WMV streams

AVI

Standard file for Windows

FLV

Flash Video can use H.263, VP6 or H.264

MOV

Apple QuickTime container for Mac and Windows

MPEG-TS

MPEG-2 Transport Stream for many streams

Ogg

Open source container for Vorbis & Theora codecs


Troubleshooting video
Troubleshooting Video

Try these if you experience dropped frames

Turn off unnecessary programs

Turn off background processes

Turn off playback/preview

Try these for sync problems

Change or update software

Try capturing analog to digital video cam and then go from video cam to PC

Check out www.digitalfaq.com


Troubleshooting video continued
Troubleshooting Video (continued)

For poor capture quality, try these

See “dropped frames”

Upgrade hardware

Should have a top-notch CPU

Need gobs of RAM

Check video source

Not much can be done if source is degraded


Troubleshooting video continued1
Troubleshooting Video (continued)

Missing Codecs

Sound, but no video

Player will warn you

Check your codecs


Tuner hardware
Tuner Hardware

Acts as the interface between cable/satellite or over-the-air TV signals and your computer


Tuner software
Tuner Software

Controls the tuner hardware to let you watch TV programs


Beyond a
Beyond A+

Sound card benchmarking

PC performance issues may be related to your sound card

Analyze your sound card with RightMark 3DSound from iXBT.Com/Digit-Life

http://audio.rightmark.org


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