信息处理技术信息处理技术Technology of Information Processing Technology of Information Processing

Instructor: Pan Shengmin 潘晟旻潘晟旻Office : Computer Center. Kun Ming University of Science & Technology.

MutiMedia

• Digital Music and Audio• Digital Graphics• Digital Photography and Video• Interactive Media

Please discontinue use of cell phone and turn off ringer

Chapter 9

Digital Media

Digital Media encompasses digital technologies of all kinds that serve and support digital music, video, and graphics.

6.1

Digital Music and Audio

•Digital audio•Digital music•MIDI乐器指令数字化接口

•Podcast 播客•Media player software•Satellite Radio

Key TermsKey Terms

Digital Audio and Music

Digital audio is any type of sound, including voice, music, and sound effects, recorded and stored digitally as a series of 1s and 0s.

Digital music is a subcategory of digital audio that involves recording and storing music.

Digitizing Sound

Digital Music File 100101000100100100010010010010110001010101010100100100101001010001001001000100100100101100010101010101001001001010010100010010010001001001001011000101010101010010010010

30

20

10

0

-10

-20

-30 10 20

ampl

itude

Milliseconds (ms)

1. An analog sound wave is…

-10

-20

-30

30

20

10

0

10 20

2. “sampled” at regular time slice, and

10

-18

-10

-20

-30

30

20

10

0

30

-10

-28

-4

20

12

-4

-10

02

-1-3

42

-10

-18

0

20

3. stored as a sequence of numeric values… (30,-10,-28,-4,20,…)

A sound wave is sampled/ 采样 / at predefined time intervals (sampling rate) the amplitude/ 振幅 / for each sample is stored as a binary number.

The sampling rate for audio CDs is 44,100 samples per second, whereas the sampling rate of your voice on a digital cell phone is 8000 times per second.

Digital Sound For Professionals

Digital Voice Recorders are used in many professions to capture dialogue for future reference.

Digital audio is used in Science, Law Enforcement, Entertainment and Communications

Digital audio techniques are used in speech and voice recognition.

Digital Sound For Professionals

Forensic audio/司法声学 / uses digital processing to denoise, enhance/放大 /, edit, and detect/检测 / sounds to assist in criminal investigations.

Digital Music & Sound

Sound Production StudioWestlake Audio Studio in Hollywood, CA uses millions of dollars worth of digital audio equipment to produce music CDs, sound tracks for motion pictures, and many other audio services.

MIDI

The musical instrument digital interface (MIDI) protocol provides a standard language for digital music devices to use in communicating with each other.

Podcasting

A podcast is an MP3 audio file that contains a recorded broadcast distributed over the Internet.

A podcast aggregator is software that allows you to subscribe to podcasts.

Discussion: Mainstream Media

vs. Consumer Generated Media

A blogger interview also see

http://www.current.tv

Dan Rather on http://www.cbsnews.com

PROS&

CONS

Digital Audio File FormatsFile

ExtensionFormat Description

.aac

.m4pAdvanced Audio Coding

Apple compressed audio file format. A new compressed file format that is more efficient than MP3. Used with Apple’s iTunes music service.

.au Audio Audio file format used mostly on Unix and Apple operating systems.

.cda Compact Disc Audio

Used to store music on traditional music CDs using a storage technology different from typical computer files.

.mid MIDI File format containing MIDI commands to control keyboard synthesizers and other electronic instruments.

.mp3 MP3 A popular compressed audio file format used on file sharing networks and the Internet. Compresses .cda files by a factor of 10 - 14. http://entertainment.howstuffworks.com/mp31.htm

.ra Real Audio Format designed for streaming audio over the Web.

.wav Waveform Audio Windows PC audio file format.

.wma Windows Media Audio

Microsoft Windows compressed audio file format. A new compressed file format that is more efficient than MP3 and provides the distributor with control over copying of the file. Used with most Internet music services other than Apple iTunes.

Digital Music Media

CDs, CD-Rs, CD-RWs, Mini-disksFlash MemoryHard Drive

Creative's Sound Blaster Wireless Music (listed at $250) is the first digital media receiver to offer music-file

navigation via a remote control with a large LCD. The idea is that once you've configured the small, modem-size base

unit to work with your Wi-Fi network, you'll be able to stream music over the system to any stereo or even a set

of powered speakers.

http://reviews.cnet.com/4521-6531_7-5021436-2.html?tag=dir.top

Players and Software

Media player software such as Windows Media Player, and RealPlayer, allows users to organize and play digital music, audio, and video files on PCs and media devices.

Digital Music Distribution Channels

Purchase new on CD Internet music services

Per-songMonthly Subscription /按月预订 /

Satellite Radio Illegal methods

File sharing networksCopying CDs

$9.99 pm

$12.95 pm

$14.95 pmor 99 cents

99 cents

9.2

Digital Graphics

•Digital graphics•Pixels•Bit-mapped graphics•Vector graphics

•CAD

•3D Modeling Software

Key Terms

Digital Graphics

Digital graphics refers to computer-based media applications that support creating, editing, and viewing 2D and 3D images and animation.

Uses of Digital Graphics

Creative Expression Presenting Information Communicating Ideas Exploring New Ideas

Scientific visualization uses computer graphics to provide visual representations that improve our understanding of some phenomenon.

Electrons in a nanotube

Uses of Digital Graphics

Entertainment Documenting Life Designing Real-World

Objects Computer-assisted

design (CAD) software assists designers, engineers, and architects in designing three-dimensional objects.

Vector Graphics Software

Vector Graphics Software, or drawing software, provides tools to create, arrange, and layer graphical objects on the screen to create pictures.

3D Modeling Software

3D Modeling Software provides graphics tools that allow artists to create pictures of realistic 3D models.Objects are created using a wire

framework.Surface textures are applied to the

objects.Light source is defined.The scene is rendered – lighting, shapes,

and surfaces are calculated to create a 3D appearance on a 2D display.

3-D Modeling Software

3D Modeling is sometimes referred to as Ray Tracing.

Computer Animation

2D AnimationAnimated GIFsMacromedia Flash

3D AnimationInvolves rendering 24 3D images per second.Expensive SoftwareAvars are used to provide hinges for movements

of characters.

Defines avar for blinking eyelid.

Digital Photography and Video

•Photo-editing Software•Video-editing Software

Key Terms

Digital Photography

Digital photos are created, or acquired, using a digital camera or scanner and are saved as bit-mapped images.

Photo Editing

Photo-editing software, such as Adobe Photoshop Elements and Microsoft Picture It!, includes special tools and effects that you can use to improve or manipulate bit-mapped photograph images.

Today’s technology makes it easy to create realistic looking faked photos – thus photos are no longer trusted as evidence in court.

Digital Video

Digital video cameras, called digital camcorders, are available in a wide range of prices with wide-ranging capabilities.

Video Editing

Video-editing software allows professional and amateur videographers to edit bad footage out and rearrange the good footage to produce a professional-style video production.

Video editing storyline

Portable Digital Video HardwarePortable Media Player (PMP)

便携媒体播放器

Interactive Media

•Interactive media•Video game consoles•Interactive TV

Key Terms

Interactive Media 交换媒体

Interactive media refers to digital media presentations that involve user interaction for education, training, or entertainment.

Interactive Media in Education

Authorware provides a toolkit for creating interactive 2-D tutorials and training for delivery on computer.

Software from companies like Mind Avenue provide tools for creating 3-D tutorials and training.

Interactive Media in E-commerce

Game Consoles

Video game consoles, such as the Nintendo GameCube, the Sony Playstation 2 (PS2), and Microsoft’s Xbox, are high-powered multiprocessor computers designed to support 3D interactive multimedia.

Portable Gaming Hardware

PlayStation PortableNintendo DS 任天堂便携游戏机

Interactive TV

Interactive TV is a digital television service that includes one or more of the following:Video on demandPersonal video recorderT-CommerceInternet access on TVVideo games over TV

The Media Center PC

Windows XP Media Center Edition runs on media PCs to provide the following services:Television Receiver Electronic program guideWeb browserPersonal video recorderDVD PlayerDigital Music PlayerDigital Personal Photo and Video Library

Chapter 9 Questions?

Don’t forget to turn your phone on!!