July 1998
Compaq Computer
Corporation
ECG Emerging Markets
and Advanced
Technology
C
O N T E N T S
V
T
.............. 3
IDEO
ECHNOLOGY
The Human Eye ....................... 3
Analog Video............................ 4
Analog Composite Video.............. 4
Analog Component Video ............ 4
Digital Video ............................. 5
Digital Video Formats .................. 5
Network Delivery Challenges ....... 6
The Bandwidth Problem............ 6
Scaling ........................................ 7
Compressing—Codecs ................ 8
Video Codec Standards............ 9
H.261 .......................................... 9
H.263 .......................................... 9
JPEG and MJPEG....................... 9
MPEG ....................................... 10
V
-S
.............. 12
IDEO
TREAMING
Isochronous Video...................13
Video Streaming System .........14
Network Considerations...........15
LANs/Intranets .......................... 17
Public Internet ........................... 18
Public Broadband Networks ....... 20
V
S
.................. 22
IDEO
ERVERS
Application Software................22
Video Server Hardware............23
High Capacity Disk Storage ....... 24
High Sustainable Throughput ..... 24
High Performance Network ........ 24
Multiple CPUs ........................... 24
Expandable System Memory ..... 24
High Availability ......................... 24
Rack-mount for Easy Access..... 25
Attractive Cost per Stream......... 25
Example: Compaq ProLiant .....25
A
......................... 27
CRONYMS
R
....................... 28
ESOURCES
ECG068/0798
W
HITE
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Video Streaming Technology
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If a picture is worth a thousand words, then a video is worth a thousand pictures. The
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sights and sounds of video teach us, entertain us, and bring our fantasies to life. While
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text, graphics, and animation provide for interesting content, people naturally gravitate
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to the richer and more realistic experience of video. That is because video—with audio—
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adds the ultimate level of realism to human communication that people have come to
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expect from decades of watching moving pictures in the real-world media of TV and
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movies.
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As all such real-world media continues to migrate toward "everything digital", video too
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is becoming digital. Video delivery has evolved from the analog videotape format of the
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1980s to a digital format delivered via CD-ROM, DVD-ROM and computer networks. As
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a series of digital numbers, digital video has the advantage of not degrading from
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generation to generation, and, because it can reside on a computer disk, it is easy to
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store, search, and retrieve. It can also be edited and easily integrated with other media
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such as text, graphics, images, sound, music, as well as transmitted without any loss in
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quality. And now it is possible to deliver digital video over computer networks including
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corporate Intranets and public Internets directly to desktop computers.
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What makes this network delivery possible is the emergence of new technology called
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"video-streaming". Video streaming takes advantage of new video and audio
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compression algorithms as well as new real-time network protocols that have been
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developed specifically for streaming multimedia. With video streaming, files can play as
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they are downloaded to the client, thus eliminating the necessity to completely download
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the file before playing, as has been the case in the past. This has the advantages of
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playing sooner, not occupying as much disk space, minimizing copyright concerns, and
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reducing the bandwidth requirements of the video.
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This white paper discusses the salient characteristics of this new video-streaming
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technology. How the properties of human vision shape the requirements of the
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underlying video technology. How the high bit rate and high capacity storage needs of
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video drives the demand for high video compression and high bandwidth networks. How
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the real-time nature of video demands the utmost in I/O performance for high levels of
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sustained throughput. How the characteristics of video streaming shapes the
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requirements of video server hardware. And finally, how Compaq video streaming
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servers meet these demanding requirements through high performance I/O architectures
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and the adherence to industry standards.
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Please direct comments regarding this communication to the ECG Emerging Markets and Advanced Technology Group at:
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EMAT@compaq.com
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1
P
APER