Transcript Multimedia Communications

Multimedia Computer
Technologies
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Multimedia PC
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The MPC aims
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to deliver a combination of high quality graphics, sound, and
pictures to the home user,
preferably at a reasonable price, all in a computer environment
where it can be manipulated by the customer
MPC Level 3 Specification (1995/1996)
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Video and Graphics
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VGA (Virtual Graphic
Array)
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SVGA
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Resolution: 720x480
pixels, 256 colors
Resolution: 1280x1024
pixels, up to 32-bit colors
Video playback
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Sent to graphic controller
after decompression
30 fps for resolution
352x240 pixels
Or 25 fps for resolution
352x288 pixels
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Audio
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8-bit or 16-bit samples with a
sampling rate of 8, 11.025, 16,
22.05, or 44.1 KHz
Linear PCM codec
Playback or recording of 16bit stereo
CD-ROM drive with CDDigital Audio, Redbook (CDDA) outputs and volume
control
At least two Speakers and a
subwoofer
A MIIDI(Musical Instrument
Digital Interface) port
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Telephony (1)
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CTI (Computer-Telephony Integration) applications
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Telephony (2)
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Windows supports TAPI (Telephone), TSPI (Telephone
Service Programming Interace), MAPI (Messaging),
SAPI (Speech), MCI (Media Control Interface)
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Videoconferencing
Network
ISDN
GSTN
Standards
H.320
H.324
LAN/Internet
H.323
Video
H.261
H.263,
H.261
Audio
G.711, G.722, G.728
G.723
G.711, G.723, G.722,
G.728
Data
T.120
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TV and Radio
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Compact Disks (1)
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CD-DA: Digital Audio (1980)
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CD-ROM (1985)
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Access rate: 150 Kbps, sampling rate: 44.1 KHz,
storage: 682 MB
To store mixed text, data, video and audio
Access rate: 150 Kbps(1X) – 24 x 150 Kbps (24X)
CD-I: Interactive (1986)
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For real-time playback of multimedia and interactive
games
Stores mixed text, graphics, video and audio for highspeed information retrieval
Handles synchronization among interleaved data,
compressed audio, still frames and full-motion video
files
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Compact Disks (2)
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DVI: Digital Video Interactive/Initiative (1986)
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CD-XA: Extended Architecture (1989)
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Use Indevo (Intel Video) – a proprietary compression
method
Non real-time compression, real-time decompression
Improves CD-ROM’s video and audio capability
Contains mixed test and data with audio and video
(similar to CD-I)
Compliant to CD-ROM, CD-I
PhotoCD
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Store max. 100 compressed photos
Uses same format as CD-XA
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Compact Disks (3)
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Video CD (1993)
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CD-R: Recordable (1990)
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Full-motion video (MPEG-1)
Stores 74 minutes of video
Permits appending information to the previously
recorded information
MPC Level 3 specifies that the CD-ROM must
read CD-DA, CD-ROM, CD-XA, CD-I, Video CD,
CD-R, Photo CD, CD Extra.
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Compact Disks (4)
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DVD: Digital Video Disk
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Larger storage space: 682MB  4.7 ~ 17 GB
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Shorter pit length: 0.834  0.4 micron
Tighter track spacing: 1.6  0.74 micron
Shorter wavelength laser: 780nm  635 ~ 650 nm
Store anything a CD is capable of holding
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Even MPEG-2 and Dolby AC-3
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USB: Universal Serial Bus
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Plug-in devices without
configuring
Support almost peripherals
USB 1.1: 1.5Mbps, 12Mbps
USB 2.0: 400Mbps
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IEEE 1394 : FireWire
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Hardware and software standard for transporting
data at 100/200/400/800 Mbps
Industry
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Accepted as the standard digital interface by Digital
VCR Consortium
Digital Video Broadcasters have endorsed IEEE 1393
as Digital TV(DTV) interface
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Proposed 1394 to VESA for Digital Home Network media
EIA 4.1 subcommittee has voted for 1394 as the
point-to-point interface for DTV & multipoint interface
for entertainment system
ANSI has defined Serial Bus Protocol to encapsulate
SCSI-3 for 1394
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IEEE 1394 : FireWire
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Why 1394?
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Digital Interface : No need to convert digital data into
analog and tolerate a loss of data integrity
Physically small : Thin serial cable
Easy to use : no need for terminator, device Ids, or
elaborate setup
Hot pluggable : users can add or remove 1394
devices with bus active
Inexpensive : priced for consumer products
Scaleable architecture : support daisy chaining and
branching to true peer-to-peer communication
Non-proprietary : no licensing problem to use for
products
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IEEE 1394 : Standard
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1394:1995
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1394a : 1998
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Power management clean up
Open Host Controller Interface : 1998
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Support up to 400 Mbps, 6 pin cables
Single driver for OS
1394b : 1999
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Speed increase to 3.2 Gbps
Support distance of 100 meters
Significantly reduces latency times by using
arbitration pipelining
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IEEE 1394 : Usage & Growth
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IEEE 1394 : Protocol Stack
Serial Soft API
Configuration &
Error Control
Read, Write, Lock
Isochronous
Channel
Transaction Layer
Packets
Serial Bus
Management
Link Layer(Cycle control, Packet
Transmitter, Packet Receiver)
Symbols
Physical Layer(Encode/Decode,
Arbitration, Media Interface)
Electrical Signal &
Mechanical Interface
IEEE 1394
Physical Interface
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IEEE 1394 : Protocol Stack
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PHY Layer
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Physical layer provides initialization and arbitration services
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Electrical signaling, mechanical connectors & cabling, arbitration
mechanism, serial coding & decoding, transfer speed detection
Link Layer
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Assures that only one node at a time is sending data
Gets data packets, Error detection & correction, Retransmission
Handles provision of cycle control for Isochronous channels
Supplies an acknowledged datagram to the Transaction Layer
Transaction Layer
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Request-response protocol
Requires conform to
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IEEE 1212, Control Status Register(CSR) architecture
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IEEE 1394 : Data Transfer
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Asynchronous
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Targeted to a specific node with an explicit address
Not guaranteed a specific amount of bandwidth on the bus
Data is sent in one direction followed by acknowledgement to the
requestor
Isochronous
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Broadcast in a one-to-one or one-to-many fashion
No error correction nor retransmission
Up to 80% of the available bus bandwidth can be used for
Isochronous transfer
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Data channels provide guaranteed data transport at a predetermined rate
Delegation of bandwidth is tracked by a node
Especially important for time-critical multimedia data where justin-time delivery eliminates the need for costly buffering
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USB 2.0 vs. IEEE 1394
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USB 2.0 is the preferred connection for most PC
peripherals
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1394’s primary target : AV CE, DVD, DVCR, DTV
Both USB 2.0 & 1394 are expected to co-exist on many
consumer systems in the future
USB requires a CPU to perform the bus master function
while 1394 is peer-to-peer
USB throughput is not nearly as fast as advertised
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When shipping data directly from a peripheral to host, OK
When shipping data from a peripheral to another peripheral, real
bandwidth drops in half
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All data must be moved from the peripheral to the host and then
from host to the target peripheral
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USB 2.0 vs. IEEE 1394
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USB 2.0 hubs are more complicated
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Require entire USB 1.1 HOST controller and a new
USB 2.0 hub controller
Require high-speed signal repeater, routing logic,
dual function port
1394 is for device where the high performance is
a priority and price is not
USB is for device where price is priority and high
performance is not
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Multimedia Processor
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Intel MMX technology
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Uses single instruction, multiple data (SIMD)
architecture to process multiple data bits
simultaneously
1.5 times faster for MPEG-1 video decoding
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