Intro to Information Systems I

Intro to Information Systems I Multimedia and Communications ISYS 101 Glenn Booker Lecture #3

Multimedia World • Multimedia presentations go beyond the vu-graph mode of presentation applications to blend graphics, animation, video, and sound • Metaphor becomes theater instead of a podium presentation • Many multimedia tools are designed for the Web Lecture #3

Interactivity • A major feature of multimedia presentations can be the use of interactive elements – where the viewer chooses their path through the presentation instead of seeing a fixed series of events • Normal web pages achieve interactivity through hyperlinks Lecture #3

Multimedia Hardware • Basic input and output hardware for multimedia include a CD-ROM or DVD-ROM drive, sound card, and speakers (all now standard on personal computers) • Optional equipment includes a microphone, graphics tablet, digital camera, and a TV video adapter Lecture #3

Multimedia Hardware • Faster video cards and 3-5 speakers instead of just one or two (e.g. adding a subwoofer or going for surround sound or theater-grade THX sound) help too Lecture #3

Multimedia Uses • Multimedia is used increasingly for • Computer based training (CBT) or education (CBE) • Livening up reference materials (encyclopedias) • Creating stand-alone sales or information kiosks, playing a loop of information • Even art is starting to use multimedia Lecture #3

Big Files Need Compression • Multimedia takes a lot more disk space than text, so compression techniques are important • Algorithms are used to calculate how data can be compressed – these algorithms are called “codecs” (for compression/ decompression) Lecture #3

Compression Types • Compression techniques can be lossless or lossy • Lossless techniques retain every bit of original data (literally!) • Lossy techniques sacrifice some low level data detail to produce higher levels of compression Lecture #3

Graphics Compression Formats • GIF (like “gift” without the ‘t’) allows a maximum of 256 colors (8-bit), uses lossless compression, and is often used for simpler Web graphics • JPEG allows up to 16.7 million colors (24-bit), is lossy, and often used for photos or other complex images on the Web Lecture #3

Graphics Compression Formats • PNG is a new format like GIF, but isn’t proprietary (you have to pay royalties to be able to create GIF images) • Bitmap (BMP) is the Windows standard for primitive graphics – is often without compression, so bitmaps are huge • A bitmap describes every pixel’s color Lecture #3

Graphics Software • Graphics software programs tend to fall into three types for working with a single image • Paint programs, which use bit-mapped or raster graphics • Drawing programs, which use vector graphics • Image editors, for modifying existing photos Lecture #3

Paint Programs • Paint programs are designed to create images at the pixel level • Easy to create stuff this way, but harder to edit, and harder to keep smooth • Examples: Fractal Design Painter, Paint Shop Pro, Corel Painter Lecture #3

Drawing Programs • Drawing programs use vector graphics – each line is described by a math formula • Draw and shape lines, then fill in colors and textures among them • Creates smoother images, which can be scaled to any size Lecture #3

Drawing Programs • Saves documents in EPS format, which some printers understand • But EPS isn’t Web friendly • Examples: Adobe Illustrator, Macromedia Freehand, CorelDRAW Lecture #3

Image Editors • Image editors are for manipulating existing pictures (e.g. photos) • Allow you to resize, crop, merge and add special effects to the images • Examples: Adobe Photoshop and PhotoDeluxe Lecture #3

Moving Picture Software • Programs for working with moving pictures include: • 3-D rendering programs, for adding 3-D effects to graphics (lighting, shadows, etc.) • Animation programs, for creating the illusion of moving pictures through graphics • Video editors, for creating and editing digital videos Lecture #3

3-D Rendering Programs • Rendering programs account for specific light sources, and determine shadows, transparency, and other effects • Used to require a supercomputer to do this • Ray tracing is one technique they use • Examples: Renderman, AutoCAD, 3D Studio MAX Lecture #3

Animation Programs • Animation is based on presenting still images rapidly in succession • A movie uses 24 frames per second • Computer animation uses the same idea with GIF images • Some programs recognize background images versus those elements which move Lecture #3

Animation Programs • Examples: Adobe LiveMotion, Macromedia Flash, and Softimage XSI • Some high end ($$$) programs combine animation with 3D rendering, such as Discreet combustion, Maya Complete, and Newtek Lightwave Lecture #3

Video Editors • Video editors take input from a digital video camera, and allow it to be rearranged, add sound, etc. • Examples: Adobe Premiere Lecture #3

Video Formats • Videos are usually in one of three formats • MPEG is the standard for full motion video, such as DVD’s • QuickTime is an Apple standard for high quality video and audio • AVI (formally Video for Windows) tend to be fairly low quality Lecture #3

Streaming Video • One way to get video across the Internet quickly is to use streaming video • A small bit of video is sent continuously to the viewer • Hence the viewer doesn’t need to download the entire video before watching it • But the viewer also never has a copy of the video either Lecture #3

Audio Software • Audio software has improved to where most professional recording studios don’t bother with magnetic tape for recording – they use computers instead • Sound uses can range from simple background music to original compositions Lecture #3

Audio Formats • Audio is digitized at 44.1 kHz for CD’s • Raw audio files are very large, hence compression is important • MP3 is the most common format, can be compressed up to 1/12th of original size • AU format is used on Sun workstations • WAV files are used in Windows, aren’t compressed Lecture #3

Audio Software • Musical instruments use MIDI language to speak to computers • Audio applications include • Notation programs to write music • Recording and editing programs • Mixers and synchronizers to coordinate many musical parts into one piece Lecture #3

Putting it all together • Authoring software is used for assembling multimedia presentations from all of its parts (sound, graphics, video, animation) • Uses a scripting language to coordinate activities • Example: Macromedia Director Lecture #3

Virtual Environments • Massive improvements in multimedia have led to the concept of creating virtual environments • Hardware like head-mounted displays make it possible to present a realistic fake environment Lecture #3

Virtual Formats • VRML (Virtual Reality Modeling Language) is a front-runner in providing a virtual environment via the Internet • Used for games, training, and data visualization • One common game environment is the Multi-User Dungeon (MUD) Lecture #3

Telecommunications • Some aspects of computer networking depend on the existing telecommunications infrastructure • Most home users use analog telephone lines for their modem connection to the Internet • Telecom is moving from analog signals on copper wires to digital signals Lecture #3

Telecommunications • Analog wires can go up to T1 speed (1.5 Mb/s) or 24 voice signals • Digital signals may be sent across fiber optic cables, or beamed using microwaves • Fiber optics can go up to T3 speed (43 Mb/s) or 672 voice signals using pulses of light Lecture #3

Telecom Standards • Telecom standards are defined by the ITU, a branch of the United Nations • Telecom is a vital service for safety, so it is heavily regulated to ensure service to unprofitable regions • Private or leased lines can be used for communication too Lecture #3

Modems • Modems modulate and demodulate signals • That converts a digital signal to analog, and back again at the other end • Modem speeds evolved from 300 bits/sec (circa 1970’s) to the theoretical limit of 56,000 bps Lecture #3

Modem Standards • The current limit is defined by the V.90 standard (56 kbps) • Earlier standards were V.34 (28.8 kbps) and V.32 (14.4 kbps) • Modems negotiate the fastest connection both sides can handle • Faxes can also be sent, generally at 9.6 kbps Lecture #3

Need for Speed • Bandwidth, or the speed at which data can be sent and received, is critical for emerging applications • Video conferencing needs 10 Mbps • High definition TV (HDTV) needs 11 Mbps • Broadband refers to digital telecom at speeds of 1.5 Mbps and up (T1 or better) Lecture #3

Broadband Options • ISDN is the most common broadband service • Basic ISDN goes up to 128 kbps • Primary ISDN goes up to 1.5 Mbps (T1) • Broadband ISDN doesn’t exist yet; claims up to 622 Mbps Lecture #3

Broadband Options • Digital Subscriber Lines (DSL) is still rare • Some versions are asymmetric (you can have much slower upload speed than download) • Range from 128 kbps to 9.1 Mbps speeds • Speed varies depending on how far you are from the provider • SONET is a future possibility; range from 52 Mbps to 1 Gbps Lecture #3

Cable Modems • Cable modems use coaxial cable from your TV cable provider to feed Internet access • Cable bandwidth is shared among the users in the local area – more users online means slower speeds for each user • Speed can range from 100 kbps to over 2000 kbps Lecture #3

Power Lines? • Internet connections can be passed over power lines too • Still experimental • Not likely to work in the US Lecture #3

Phone, TV, and Internet Merge • Some appliances can let a normal TV show the Internet (WebTV) • Phone service and Internet service can share the same lines, and some computer applications handle phone and fax functions over normal phone lines • The lines of distinction are blurring Lecture #3

Computer Networking • Networking allows computers to communicate with each other, and share resources (e.g. printers) • Networks range in size from global to consumer • Networks are much faster than just using telecom equipment Lecture #3

Types of Networks • A single building or group of buildings might use a Local Area Network (LAN) • Several related sets of facilities might use a Metropolitan Area Network (MAN) • Global corporations use a Wide Area Network (WAN) • Networks can be public or private Lecture #3

Switching • Networks control the flow of data using switching • Two major types of switching • Circuit switching changes the circuit to produce a physically direct connection; is very fast • Packet switching sends packets of data which get reassembled at the other end to produce the message; is much cheaper than circuit Lecture #3

Protocols • Network protocols are the language spoken across the network • TCP/IP is the language of the Internet • NetBEUI is a Windows networking protocol • AppleTalk is an Apple networking protocol • IPX is a Novell protocol Lecture #3

Network Layers • Networks function by taking data and adding various pieces of information to it in order to help it get to its destination • The layers of the network describe what that information is and how it is used • The OSI reference model is the most common system for networking Lecture #3

Network Hardware • Networks rely on each computer having a network interface card (NIC) to allow them to be connected to the network • Like a modem allows connection to the Internet • Most NIC’s are for Ethernet networks • Ethernet speeds include 10, 100, and 1000 Mbps (the last one is Gigabit Ethernet) Lecture #3

Network Hardware • Most networks still use cables • Thick, thin, or 10base-T Ethernet cables • Token Ring cables • Coaxial cable • Fiber-optic cable • Infrared and radio signals are used for wireless networks Lecture #3

Network Hardware • Other network hardware might include: • Switches, to control where data may go • Router, to convert one language into another • Hubs, to connect computers which speak the same language (protocol) • Bridges, to connect major parts of the network together Lecture #3

Network Terminology • Every device on a network (computer, printer, etc.) is a “node” • Peer to peer networks work well for small offices and home; allow sharing of files, printers, and Internet connection • Client/server networks use servers to manage the network, and control access to different nodes Lecture #3

Network Operating System • Normal operating systems routinely include software to allow peer to peer networking • Client/Server networks require a networking operating system (NOS) • Windows Servers (NT, 2000, etc.) • Novell NetWare • Unix Lecture #3

Network Topology • Network topology is the layout of a network, like a street map to show where roads go • The “bus” topology connects everything along a line (like a bus route) – good for peer to peer networks Lecture #3

Intro to Information Systems I