Chpt10 Multimedia Technology

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Chapter 10

Multimedia Technology


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Slide 2Ver 1.0 10 April 2001

CPU Multimedia Technologies

Why is there a need for specialmultimedia instructions?

Consume too much CPU resources. 10%of multimedia application instructionsused up to 90% of the processing time

What the the instructions added toIntel CPU to handle 2D multimedia andaudio?

57 instructions know as MultimediaExtension (MMX) are added to Pentiumcomputers/PII/Celeron.

How do they supports multimedia?process video and audio datasimultaneously

How does Intel support 3D graphics,video and audio streaming and voicerecognition?

SSE or Streaming SIMD Extension. 70new instructions are added to PentiumIII processors.

How does AMD CPUs handlemultimedia?

3DNow!. 21 instructions supporting 3Dare added to K6, K6-2 and Athlon.

What are the new multimedia features

of Anthon XP?3DNow! Professional technology thatincludes 52 new instructions.


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CD-ROM

What are the uses of CD-ROM?To hold music, data or computersoftware. They have become thestandard medium for distributing largequantities of information in a reliablepackage

What is 1x?1x is the standard speed of audio CD.The transfer rate is 150Kbps.Therefore a 12x CD-ROM has atransfer speed of 1.8Mbps.

How are data stored on the CD-ROM?Data are stored from the centre andspiral outwards as lands and pits.Lands represent 1 where the pitsrepresent 0.

Land Pit

What is CAV?Constant Angular Velocity. Disk is rotates ata constant speed. This method is easier onthe spindle motor, but it means that thedata-transfer rate varies for the outer andinner tracks.


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CD-ROM

What is CLV?Constant Linear Velocity. Use by olderCD-ROM drive. Data is read at aconstant rate.

How is data being at a constant rate?

Disk is rotated at varying speeds.Faster on the inside and slower on theoutside.


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CD-ROM Player

What is the function of the CD-ROMPlayer?Focus the laser to find and read thedata stored as bumps on the CD. It isan exceptionally precise piece ofequipment since the bumps are verysmall.

What are the components of the drive?1. A drive motor spins the disc. It is

precisely controlled to rotatebetween 200 and 500 rpmdepending on which track is beingread.

2. A laser and a lens system focus inon and read the bumps.

3. A tracking mechanism moves thelaser assembly so that the laser'sbeam can follow the spiral track.The tracking system has to be ableto move the laser at micronresolutions.

What are the available type of CD-ROMinterfaces?1. Internal CD-ROM

IDE SCSI

2. External Parallel USB SCSI


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CD-ROM Standards

High Sierra

Standard created in 1984 Replaced by ISO 9660

ISO 9660 International standard (include the High Sierrastandard)

Current CD-ROM and CD-R format

CD-ROM standards

(Books)

Red Book media, recording and mastering process

Yellow Book error correction data, detectionhardware and firmware (data storage beneath thelogo)

Orange CD-Recorder, extend the Red and Yellowbook

MPC Define the minimal standard to run multimedia

productsEl Torito standard Bootable CD-ROM. Components required:

Bootable CD-ROM mechanism

BIOS supports bootable CD-ROM

CD with boot code and an operating system


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CD-ROM Requirement (DOS)

This section is for Real-Mode software under DOS onlySoftware Description

Device Driver 1. Low level driver allowing program to access CD-ROM,CD-R or CD-RW

2. Has .SYS extension eg IDECD.SYS

3. Configured and activated with CONFIG.SYS DEVICE=IDECD.SYS /D:MSCD000

MSCDEX.EXE 1. Provided by Microsoft

2. Microsoft CD Extension (MSCDEX)

3. Allows access to 650MB of information in CD

4. Loaded through the AUTOEXEC.BAT MSCDEX /D:MSCD000


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Common CD-ROM Problems

Errors under DOS (use startup disk to boot PC)

Invalid DriveSpecification

(when typing the DriveLetter eg D:)

1. Driver not activated

2. Error in config.sys or autoexec.bat

(both files must present in order to work)

3. IDE Cable connection properly

4. IDE CD-ROM, check master/slave setting

MSCDEX Not Found 1. Error in autoexec.bat

2. Cannot find MSCDEX.EXE

In Windows, CD-ROMdrive is not recognised

1. Check cable and power connection

2. IDE CD-ROM, check master/slave setting

3. SCSI CD-ROM, check for proper ID and

termination4. Check for IRQ conflict

5. Scan for virus


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CD-Recordable (CD-R)

What is a CD-R Disk?A CD-R disk needs to allow the drive towrite data onto the disk. Can be used tocreate data, audio and video disk.

How does a data is written to CD-Rdisk?

For a CD-R disk to work, a laser writesdata by creating non-reflective area onthe disk. On a new CD-R disk the entiresurface of the disk is reflective.

What is disk comprises of?

Disk has an a layer that the laser canmodify. This extra layer is a greenishdye. It also has a plastic substrate, anda reflective gold layer

What happens when data is beingwritten?When you write data to a CD-R, thewriting laser (which is much morepowerful than the reading laser) heatsup the dye layer and changes itstransparency. The change in the dyecreates the equivalent of a non-

reflective bump and is permanent. BothCD and CD-R drives can read themodified dye as a bump later on.

Why are the media different in colour?Cause by the dye colour and thegold/silver reflective layer.

Can colour of media different quality?Gold is consider the best, lasting 100

years. Green is the lowest grade. Blue isclaimed by manufacturer to have theGold quality.


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CD-Recordable

What is Multi-sessions?Allow the CD-R disk to be written overseveral sessions. Previous session needsto be import before a new session canbe written.

What is DISC-AT-ONCE?

Writing mode requiring data to bewritten continuously withoutinterruption

What is the Standard used for CD-R?

Orange Book Standard

Upgrading CD-R/CD-RW firmware

Can be update to correct bugs or fixdrive compatibility problems with youPC

What is Buffer underrun?Flow of data from the hard disk to CD-R is interrupted and the buffer isempty

What causes Buffer underruns?

Cause by slow hard disk, backgroundprogram (virus s/w), low quality disc,insufficient free hard disk space, etc


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El Torito

What is El Torito Standard?Specification that says how a CD-ROMshould be formatted such that it candirectly boot a PC

How it works?

The El Torito standard works by makingthe CD drive appear, through BIOScalls, to be a normal floppy drive.

How is it done?

Put any floppy size image, BOOT.IMG(exactly 1440k for a 1.44 meg floppy)

somewhere in the ISO filesystem.Adaptec CD-Creator created a fileBOOT.IMG in the CD-ROM.

How to make a Bootable CD usingAdaptec CD-Creator Version 5?

1. Prepare a Windows Startup Disk

2. Launch Adaptec CD-Creator andstart a New Bootable CD Project

3. Put the Startup Disk and a blank CDinto the respective drive

4. Click OK on the dialogue box (seebelow)

5. Select the file to be included in theCD

6. Start Recording


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Digital Versatile Disc ROM

What is a DVD?Quite similar to CD but have muchlarger storage capacity.

How much data can a DVD disc holds?

A standard DVD holds about seventimes more data than a CD does.Depending on the Number of sides andLayers, it can hold 4.38GB to 17GB

What are the standards used?Book A, Book B, Book C, Book D, Book E

What is the format for movie in DVD?

When movies are put onto DVDs, theyare encoded in MPEG-2 format and thenstored on the disc.

How are MPEG Movie formatted?

30 frames for NTSC and 25 frames forPAL. High resolution is achieved in PAL.


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Sound Card

How does the Sound Card increase thefunctionality of the PC?

It enable the computer to input,process, and deliver sound.

What are the 4 main functions of theSound card?

1. Synthesizer to generating sounds

2. MIDI interface

3. Aanalog-to-digital conversion (used,for example, in recording soundfrom a microphone)

4. Digital-to-analog conversion (used,

for example, to reproduce soundfor a speaker)

How does the Sound card createssound?

The three methods of sound synthesisare:

1. Frequency modulation (FM)technology

2. Wavetable

3. Physical modeling

What is Frequency Modulation (FM)?

Sounds are simulated by using formulato create sine waves that are as closeto the sound as possible. In another

word, sound are sampled and recreated.For example, the sound of a guitar canbe simulated, although the result doesnot really sound very much like a guitar.


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Sound Card

How is Sound created by Wavetable?Wavetable uses actual, digitallyrecorded sound samples stored on thecard for the highest performance.

How is Sound created by Physicalmodeling?

Physical modeling is a new type ofsynthesizing, in which sounds aresimulated through a complexprogramming procedure. Some soundcards can also have sounds downloadedto them.

How are Sound card connected in thePC?

ISA and PCI bus. PCI is preferredbecause it uses less CPUs resources.


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Recording/Playback Process

Sound

MicrophoneAnalogsignal

Digitalsignal

Softwaredriver

StorageDevice

(Hard Disk)

Sound Board Hardware

Sound

Recording Process

Softwaredriver

Digital

signal

Analog

signal

LeftSpeaker

Sound Board Hardware

Playback Process

RightSpeaker

StorageDevice

(Hard Disk)


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Sampling Rate

Waveform A: original Waveform B: original

Waveform A: reconstructed Waveform B: reconstructed

More sampling taken, thereconstructed sound is closed to the

original sound

Not enough sampling taken, thereconstructed sound is not closed to

the original sound


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MIDI

What does MIDI stands for?Musical Instrument Digital Interface

What is is for?

For recording and playing back music ondigital synthesizers

How it works?Rather than representing musical sounddirectly, it transmits information abouthow music is produced. The commandset includes note-ons, note-offs, keyvelocity, pitch bend and other methodsof controlling a synthesizer. It is more

concise than formats that the sounddirectly

MIDIPort Synthesizer Speaker

HardDrive

Sequencersoftware

MIDI instrumentPath of MIDI

signals throughthe PC


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Sound Card Block Diagram

Speaker Out

MIDIInstrumentOr

Joystick

PC Bus

Bus Interface Circuits

DigigalSignal

Processor(DSP)

RAM

ROM

Analog-to-Digital

Converter

Synthesizer

Mixer/filter

AudioAmpifier

Audio

Amplifier

MIDI/JoystickInterface

Mic InLine In

CD audio

Line Out


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Tips to Troubleshoot a Sound Card

Following tip helps to nail down a problem quickly:

1. Speaker is connected, and turned on

2. Speaker volume and sound card master volume are turned up

3. Make sure the music or sound files are installed properly

4. Check that all sound card and multimedia drivers are installed properly

5. Make sure drivers are up-to-date

6. Check resource conflicts between sound card and other devices using thedevice manager

Check:

IRQ (interrupt Request)

Direct Memory Access (DMA)

Memory Address

The most common is an IRQ conflict. You may need to change the IRQ ofthe sound card. Or even change BUS types if all else fails.

7. Sound card is enable in the CMOS (for motherboard with integrated with thesound card)

Chpt10 Multimedia Technology

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