Chapter 7 Multimedia

Chapter 7Chapter 7Experiencing MultimediaExperiencing Multimedia

Learning ObjectivesLearning Objectives

Summarize how Internet audio and streaming audio Summarize how Internet audio and streaming audio and video works.and video works.

Explain peer-to-peer file sharing networks.Explain peer-to-peer file sharing networks.

Differentiate between the various methods used to Differentiate between the various methods used to create animated content on the Web.create animated content on the Web.

Demonstrate how to use the Windows Media Player.Demonstrate how to use the Windows Media Player.

Chapter FocusChapter Focus

Browsers and MultimediaBrowsers and Multimedia

ImagesImages

AudioAudio

Animated ContentAnimated Content

Windows Media PlayerWindows Media Player


The use of more than one type of mediaThe use of more than one type of media

TextText

GraphicsGraphics

Animated graphicsAnimated graphics

VideoVideo

AudioAudio

HypertextHypertext

Browser extensionsBrowser extensions

Extend the function of a browserExtend the function of a browser

Helper ApplicationsHelper Applications

Plug-ins and ActiveX ControlsPlug-ins and ActiveX Controls


Helper ApplicationsHelper ApplicationsStand-alone programs that a browser can call on Stand-alone programs that a browser can call on to display different media content once the to display different media content once the browser downloads the contentbrowser downloads the contentWhen a browser encounters a file it looks at the When a browser encounters a file it looks at the file extension to determine its MIME file extension to determine its MIME (Multipurpose Internet Mail Extension)(Multipurpose Internet Mail Extension)


Helper ApplicationsHelper Applications

Browsers use MIME type to determine how to Browsers use MIME type to determine how to display or handle a filedisplay or handle a file

For example, if theFor example, if thebrowser is askedbrowser is askedto display a file withto display a file witha .pdf extension ita .pdf extension itlooks for a copy oflooks for a copy ofAdobe AcrobatAdobe AcrobatReader applicationReader applicationand opens theand opens theprogram to displayprogram to displaythe filethe file



Two most common plug-in types are Netscape-Two most common plug-in types are Netscape-style plug-ins and ActiveX Controlsstyle plug-ins and ActiveX Controls

ActiveX Controls help expand Internet Explorer ActiveX Controls help expand Internet Explorer capabilities but can let spyware, adware, and capabilities but can let spyware, adware, and other programs install themselves without other programs install themselves without knowledge of userknowledge of user

Disabling ActiveX controls is one solution to Disabling ActiveX controls is one solution to potential dangerpotential danger



Small programs that extend the capability of Small programs that extend the capability of browsers in dealing with different types of mediabrowsers in dealing with different types of media

Not stand-aloneNot stand-alone

Do not require content to be downloadedDo not require content to be downloaded

Plug-ins reside in aPlug-ins reside in abrowser’s plug-insbrowser’s plug-insfolder insidefolder insidebrowser applicationbrowser applicationfolderfolder plug-ins

folder

plug-ins

Browsers and MultimediaBrowsers and MultimediaReviewReview

What is the difference between a helper application What is the difference between a helper application and a plug-in?and a plug-in?

What are MIME types, and what role do they play in What are MIME types, and what role do they play in browser functionality?browser functionality?

Why do some computer users disable ActiveX Why do some computer users disable ActiveX controls?controls?

ImagesImages

Images in Web pages are not saved as part of the Images in Web pages are not saved as part of the Web page document, but exist as separate filesWeb page document, but exist as separate files

The file size of an HTML page plus all of its images The file size of an HTML page plus all of its images added together should be less than 100 KB added together should be less than 100 KB whenever possiblewhenever possible

An image repeated on a Web page is only loaded An image repeated on a Web page is only loaded onceonce

How images How images are are

displayeddisplayed

ImagesImages

ImagesImages

Image FormatsImage Formats

Bitmap or raster filesBitmap or raster files

Resolution dependentResolution dependent

Image quality will be Image quality will be adversely affected if adversely affected if an image is enlarged an image is enlarged or reducedor reduced

Uncompressed bitmap Uncompressed bitmap file formats produce file formats produce file sizes too large for file sizes too large for Web useWeb use

ImagesImages

Image Formats Image Formats

GIF imagesGIF images

Most commonly used on the WebMost commonly used on the Web

Result of lossless technology that shrinks an Result of lossless technology that shrinks an image’s file size without sacrificing any of the image’s file size without sacrificing any of the original dataoriginal data

Supports only 256 colorsSupports only 256 colors

Often used for drawings or illustrationsOften used for drawings or illustrations

Interlacing allowsInterlacing allowsthe Web browserthe Web browserto display anto display animage graduallyimage graduallyas the imageas the imagedownloadsdownloadsTransparency allowsTransparency allowsWeb page backgroundWeb page backgroundcolor to show through acolor to show through aselected portion of an imageselected portion of an imageAnimated GIFs create anAnimated GIFs create anillusion of motion by instructing a browser to illusion of motion by instructing a browser to load two or more images in successionload two or more images in succession

ImagesImages

Interlaced Interlaced GIF Image GIF Image

LoadingLoading

ImagesImages


JPEG imagesJPEG images

Use a lossy image compression technology Use a lossy image compression technology that supports more than 16 million colorsthat supports more than 16 million colors

Best Web image for photographsBest Web image for photographs

Lossy technologies discard some data during Lossy technologies discard some data during compression processcompression process

Saving an image as a JPEG file causes some Saving an image as a JPEG file causes some of the original data to be lostof the original data to be lost

ImagesImages


PNG ImagesPNG Images

Supported by browser versions 4.x and aboveSupported by browser versions 4.x and above

Should not be used on Web pages likely to be Should not be used on Web pages likely to be viewed by people using older browsersviewed by people using older browsers

ImagesImages

Using Web ImagesUsing Web Images

Without permission may violate copyright lawWithout permission may violate copyright law

If a Web page does not contain a copyright If a Web page does not contain a copyright statement, it may still not be free for download statement, it may still not be free for download and useand use

ImagesImages

Copying Web ImagesCopying Web Images

Right-click image to access Save menuRight-click image to access Save menu

Option may not be available if a Web page Option may not be available if a Web page contains scripting to disable the right-click contains scripting to disable the right-click functionfunction

ImagesImages

Copying Web ImagesCopying Web Images

User can use screen capture software to User can use screen capture software to capture images, and can crop to save a capture images, and can crop to save a portion of the screenportion of the screen

cropped area

ImagesImages

Finding imagesFinding images

Several search engines allow users to click Several search engines allow users to click hyperlink or button that enables image-only hyperlink or button that enables image-only searchingsearching

Many US government agencyMany US government agencyWeb sites contain images thatWeb sites contain images thatcan be used freelycan be used freely

A number of Web sites offerA number of Web sites offercopyright-free, royalty-free, orcopyright-free, royalty-free, orpublic domain images andpublic domain images andclipart that can be used onclipart that can be used onWeb pagesWeb pages

ImagesImagesReviewReview

What are the three principal image formats used in What are the three principal image formats used in Web pages?Web pages?

Which of the three image formats uses lossy Which of the three image formats uses lossy compression?compression?

Which image format supports interlacing, Which image format supports interlacing, transparency, and animation?transparency, and animation?

How can an image be saved from a Web page?How can an image be saved from a Web page?

AudioAudio

Early audio filesEarly audio files

Huge file sizes to offer high-fidelity soundHuge file sizes to offer high-fidelity sound

3-minute song recorded using uncompressed 3-minute song recorded using uncompressed WAV audio file format could result in a 30 MB WAV audio file format could result in a 30 MB filefile

Developments in audio technologyDevelopments in audio technology

Compressed audio formatsCompressed audio formats

Streaming audioStreaming audio

AudioAudio

Compressed audio formatsCompressed audio formats

Offers satisfactory sound quality, small file sizesOffers satisfactory sound quality, small file sizes

CodecsCodecs

Technology used to compress and Technology used to compress and decompress audio filesdecompress audio files

Lossy codecs remove irrelevant or redundant Lossy codecs remove irrelevant or redundant datadata

Average person will not notice difference Average person will not notice difference between uncompressed and compressed between uncompressed and compressed audioaudio

Compressed audio formatCompressed audio formatLossless formats becoming more popular with Lossless formats becoming more popular with increasing availability of broadband Internetincreasing availability of broadband InternetSampling rate and bit rateSampling rate and bit rate

Determines the quality and size of digital audio Determines the quality and size of digital audio encodingencodingVariable bit rateVariable bit rateencoding (VBR)encoding (VBR)featuresfeaturescontinuouslycontinuouslychanging bit ratechanging bit ratedepending ondepending oncomplexity of thecomplexity of thecontent encodedcontent encoded

AudioAudio

AudioAudio

MP3 Audio File FormatMP3 Audio File Format

Most popular audio file format in use on the Most popular audio file format in use on the Internet todayInternet today

Developed to comply with standards created by Developed to comply with standards created by the Moving Picture Experts Group (MPEG)the Moving Picture Experts Group (MPEG)

Can be used to produce CD-quality audio using Can be used to produce CD-quality audio using only a fraction of the spaceonly a fraction of the space

AudioAudio

Nullsoft Winamp Media Player InterfaceNullsoft Winamp Media Player Interface

AudioAudio

File SharingFile Sharing

Client computers Client computers connect to connect to servers in what servers in what is known as a is known as a client/server client/server system or modelsystem or model

AudioAudio

File SharingFile Sharing

Number of companies allow users to legally Number of companies allow users to legally purchase and download songs over the purchase and download songs over the InternetInternet

One of the most successful examples of an One of the most successful examples of an online musiconline musicstore isstore isApple iTunesApple iTunes

AudioAudio


Eliminated the need for downloading by Eliminated the need for downloading by delivering audio content on a continuous just-in-delivering audio content on a continuous just-in-time basistime basis

Works by transmitting portions of audio data (and Works by transmitting portions of audio data (and more recently video) data that can be played as more recently video) data that can be played as soon as it is receivedsoon as it is received

Avoids the necessity of downloading an entire Avoids the necessity of downloading an entire file before it can be playedfile before it can be played

BufferingBuffering

Avoids broadcast interruptions due to Avoids broadcast interruptions due to bandwidth fluctuationsbandwidth fluctuations

AudioAudio


Thousands of radio stations offer streaming Thousands of radio stations offer streaming broadcasts from around the worldbroadcasts from around the world

Number of sources offer webcasts available Number of sources offer webcasts available via thevia theInternetInternetonlyonly

AudioAudio

Live streamingLive streaming

Makes broadcast available only during a certain Makes broadcast available only during a certain time periodtime period

On-demandOn-demandstreamingstreaming

Makes a broadcast Makes a broadcast available on useravailable on userrequestrequest

On-Demand Program ListingOn-Demand Program Listing

AudioAudio

Embedded AudioEmbedded Audio

Audio files can also be embedded in Web pages Audio files can also be embedded in Web pages to create background musicto create background music

Musical Instrument Digital Interface (MIDI) audio Musical Instrument Digital Interface (MIDI) audio file formatfile format

Often used for embedding background music Often used for embedding background music on Web pageson Web pages

MIDI files are usually very small because a file MIDI files are usually very small because a file contains musical instructions rather than an contains musical instructions rather than an actual sound recordingactual sound recording

AudioAudioReviewReview

What is a codec?What is a codec?

What is a sampling rate?What is a sampling rate?

What is streaming audio?What is streaming audio?


Animated content is the process used to create the Animated content is the process used to create the impression of animation or motion on a Web page impression of animation or motion on a Web page and is the same process used to produce the motion and is the same process used to produce the motion effect seen in film or videoeffect seen in film or video

The most frequently used frame speed is 12 frames The most frequently used frame speed is 12 frames per second (fps) for Web animationper second (fps) for Web animation

Different technologies usedDifferent technologies used

JavaScript, Java Applets, animated GIF images, JavaScript, Java Applets, animated GIF images, Flash and Shockwave movies, and different video Flash and Shockwave movies, and different video formatsformats

Bouncing ball animation effectBouncing ball animation effect



JavaScriptJavaScript

A scripted programming language that resides A scripted programming language that resides within an HTML documentwithin an HTML document

Enables a browser to change page content Enables a browser to change page content dynamically in response to viewer inputdynamically in response to viewer input

JavaScript combined with HTML and CSS-P JavaScript combined with HTML and CSS-P (Cascading Style Sheets-Positioning)(Cascading Style Sheets-Positioning)

Creates dynamic HTML (DHTML)Creates dynamic HTML (DHTML)

Rollover JavaScriptRollover JavaScript



Java appletsJava applets

Small applications (programs) created using the Small applications (programs) created using the Java programming languageJava programming language

Provides interactivity in a Web pageProvides interactivity in a Web page

CalculatorsCalculators

GamesGames

Other interactive tools for Web sitesOther interactive tools for Web sites


Copy and pastethis code into anHTML document.


Animated GIF FilesAnimated GIF Files

A software program known as GIF animator is A software program known as GIF animator is used to stitch together a series of GIF imagesused to stitch together a series of GIF images


Adobe FlashAdobe Flash®® and Shockwave and Shockwave®® players players

Two very popular vector-based animation Two very popular vector-based animation applications used to create Web page animationapplications used to create Web page animation

ScalableScalable

They can be enlarged or reduced without They can be enlarged or reduced without suffering a loss of image qualitysuffering a loss of image quality

Plays inside a browser window and can be Plays inside a browser window and can be streamed so that the animation begins playing streamed so that the animation begins playing before the entire file downloadsbefore the entire file downloads


VideoVideo

Digital video is the digital equivalent of the motion Digital video is the digital equivalent of the motion picture film used to record real-life motion picture film used to record real-life motion picturespictures

A broadband connection is recommended for the A broadband connection is recommended for the best results in viewing streaming video best results in viewing streaming video broadcastsbroadcasts

Animated ContentAnimated ContentReviewReview

What is the best kind of Internet connection for What is the best kind of Internet connection for viewing streaming video?viewing streaming video?

What can cause interruptions to a streaming video What can cause interruptions to a streaming video broadcast?broadcast?

Comes installed with Windows VistaComes installed with Windows Vista

A multifunctional media playerA multifunctional media player

Play music located on CDs, computer drives, Play music located on CDs, computer drives, or other mediaor other media

Play Internet radio programsPlay Internet radio programs

View DVDs and VCDsView DVDs and VCDs

Play Internet videoPlay Internet video

Rip songs from CDs, store them on your Rip songs from CDs, store them on your computer, and burn them to CD-Rcomputer, and burn them to CD-R

Create playlists and organize media contentCreate playlists and organize media content

Synchronize content to portable devicesSynchronize content to portable devices


Windows Media Player VisualizationWindows Media Player Visualizationand Song Informationand Song Information


To display menu bar (which is hidden by default) To display menu bar (which is hidden by default) click the Library tab, click Layout Options menu, click the Library tab, click Layout Options menu, then click Show Classic Menusthen click Show Classic Menus

Media files can be opened in the media player by Media files can be opened in the media player by clicking File on the menu bar and then clicking Open clicking File on the menu bar and then clicking Open or Open URLor Open URL

Library tab can be used to create song playlists Library tab can be used to create song playlists and organize contentand organize content

Rip tab enables user to copy tracks from audio Rip tab enables user to copy tracks from audio CDCD

Burn or copy to CD-R by clicking Burn tabBurn or copy to CD-R by clicking Burn tab


Sync tab enables user to synchronize content to Sync tab enables user to synchronize content to portable media playerportable media player

Button to right of the Sync button changes to Button to right of the Sync button changes to display the selected music store, the Windows display the selected music store, the Windows Media Guide, or a list of online storesMedia Guide, or a list of online stores


Click one to visit the store and purchase musicClick one to visit the store and purchase music


Displaying the Media Guide and clicking Internet Displaying the Media Guide and clicking Internet Radio link displays a list of radio stations sorted Radio link displays a list of radio stations sorted by genreby genre


Stop Previous Play Next Mute Volume

Can also select other media types such as Can also select other media types such as cartoons, high definition movies and gamescartoons, high definition movies and games


Windows Media PlayerWindows Media PlayerReviewReview

What can the Windows Media Player be used for?What can the Windows Media Player be used for?

How can an online store be changed?How can an online store be changed?

How can a radio station be saved to the My Stations How can a radio station be saved to the My Stations group?group?