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Chapter 9. Multimedia Devices and Mass Storage. You Will Learn…. How multimedia works on a PC About multimedia devices such as sound cards, digital cameras, and MP3 players About optical storage technologies such as CD and DVD
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Chapter 9 Multimedia Devices and Mass Storage
You Will Learn… • How multimedia works on a PC • About multimedia devices such as sound cards, digital cameras, and MP3 players • About optical storage technologies such as CD and DVD • How certain hardware devices are used for backups and fault tolerance • How to install and troubleshoot multimedia and mass storage components
Multimedia on a PC • Goal • To create or reproduce lifelike representations of sight and sound • Challenge • Data storage is digital • Sights and sounds are analog
CPU Technologies for Multimedia • MMX, SSE, and 3DNow! • Improve speed of processing graphics, video, and sound • Use improved methods of handling high-volume repetition during I/O operations • Software must be written to use the specific capabilities
Multimedia Devices • Sound cards • Record sound, save it to a file on hard drive, play it back • Externally attached devices • Digital cameras • MP3 players
Stages of Computerized Sound • Digitize or input sound (analog to digital) • Includes sampling • Data is measured at a series of representative points • Sampling rate = cycles per second, or hertz (Hz) • Store digital data in compressed data file • Reproduce or synthesize sound (digital to analog)
Installing a Sound Card • Physically install the card in an empty PCI slot on the motherboard • Install sound card driver • Install sound applications software
Digital Cameras • Scan field of image and translate light signals into digital values • Digital values can be stored as a file and viewed, manipulated, and printed with software that interprets them appropriately • Use TWAIN format for transferring images
MP3 Players • A device that plays MP3 files (a version of MPEG compression) • MP3 can reduce size of a sound file as much as 1:24 without much loss in quality
Compression Methods Used with MP3 Players • MPEG (Moving Pictures Experts Group) standard • Tracks movement from one frame to the next and stores only what changes • Can yield compression ratio of 100:1 for full-motion video • Cuts out or drastically reduces sound that is not normally heard by the human ear
MPEG Standards • MPEG-1 • Used in business and home applications to compress images • MPEG-2 • Used to compress video films on DVD-ROM • MPEG-3 • Used for audio compression • MPEG-4 • Used for video transmissions over the Internet
How MP3 Players Work • Play MP3 files downloaded from a PC, using internal memory and flash storage devices (eg, SmartMedia, CompactFlash, or Memory Stick)
Video Capture Card • Captures input from a camcorder or directly from TV • Features to look for: • IEEE 1394 (FireWire) port • Data transfer rates • Capture resolution and color-depth capabilities • Ability to transfer data back to digital camcorder or VCR • Stereo audio jacks • Video-editing software
Optical Storage Technology • Patterns of tiny pits on disc surface represent bits, which are readable by a laser beam • Major optical storage technologies • CD-ROM drives • Use CDFS (Compact Disc File System) or UDF (Universal Disk Format) • DVD drives • Use only UDF
CD-ROM • Read-only; data physically embedded into disc surface • Surface laid out as one continuous spiral of sectors of equal length that hold equal amounts of data
CD-ROM • Used to distribute software and sound files • Combines constant linear velocity (CLV) and constant angular velocity (CAV) • Look for multisession feature • CD-ROM drives are read-only and slower to access than hard drives
CD-ROMs • Caring for CD-ROM drives and discs • Use precautions when handling • CD-ROM drive interface with motherboard • IDE interface (most common) • SCSI interface • Proprietary expansion card that works only with CD-ROMs from a particular manufacturer • Proprietary connection on sound card • Portable drive; plug into external port on PC
CD-R and CD-RW • CD-R (CD-recordable) • Enables “burning” your own CDs • Cannot edit or overwrite • Bottom of disk is tinted (eg, blue, black); CDs are silver • Inexpensive • Can be read by all CD-ROM drives • CD-RW (CD-rewritable) • Allows overwriting old data with new data • Cannot always be read by older drives
DVD (Digital Video Disc) • Storage capacity • 8.5 GB (one side) • 17 GB (both sides) • Uses shorter wavelength laser than CD; a second opaque layer also holds data • Uses MPEG-2 video compression; requires MPEG-2 controller to decode compressed data • Audio is stored in Dolby AC-2 compression
Hardware Used for Backups and Fault Tolerance • On standalone PCs or small servers • Tape, Zip, and Jaz drives • Read-write CDs • In a business environment with PC connected to file server • Back up data to file server
Tape Drives • Advantages • Inexpensive and convenient • Large capacity • Several types and formats • Disadvantage • Sequential access
How a Tape Drive Interfaces with a Computer • External • Parallel port • Internal • IDE ATAPI interface • External or internal • SCSI bus • Proprietary controller card or floppy drive interface
Tapes Used by a Tape Drive • Full-sized data cartridges • Minicartridges