An Introduction to
Microsoft NetShow Services and
Advanced Streaming Format(ASF)
By Huang Yi-Chin
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Outline Part I : NetShow Services
IntroductionStreaming media components
NetShow ServerNetShow ToolsWindows Media Player
Part II : Advanced Streaming FormatIntroductionFile Format OrganizationSample Files
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Part I: NetShow Services
NetShow is .. “…NetShow Services is a platform for streaming
multimedia content over networks that range from low-bandwidth, dial-up Internet connections, to high-bandwidth local area networks (LANs).” [1]
Streaming is .. “…data that is streamed is transmitted so that it is
accessible without delay…” [2]
not as the download-and-play technology.
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Introduction(1/2)
How NetShow Services Work
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Introduction(2/2)
Key FeaturesWidest bandwidth rangeIntelligent streamingBuild-in multicast serviceCodec independence
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Streaming media components(1/3)
NetShow ServerNetShow Administrator: A set of administrative
tools to manage, configure and monitor NetShow Services.
Publishing Point(unicast)On-demand Unicast p.p.Broadcast Unicast p.p.
Station Content(multicast)
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Streaming media components(2/3)
NetShow ToolsNetShow Encoder NetShow T.A.G. Author (Digital Renaissance)
Media On-Demand Producer (Sonic Foundry Inc.)
NetShow IndexerAdobe Premiere plug-inPublish to ASF(PowerPoint plug-in)Other utility program: VidToAsf, WavToAsf...
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Streaming media components(3/3)
Windows Media PlayerBased on DirectShow API architecture.An universal player.Automatic codec downloading.Supporting ASX (ASF Stream Redirector) files
to enhanced content. Other features: Marker menu, Logo, Banner,
Playlist …
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Part II: Advanced Streaming Format
What is ASF? An extensible file format designed to store
synchronized multimedia data. [4]
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ASF Features(1/2)
Extensible Media Typeseasy to define new media types
Component DownloadStream-specific information (ie. Codec) is
stored in the file header. Scalable Media Types
It stores each “band” for a media as a distinct media stream.
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Multiple Languagessupports multiple languages.
Author-specified Stream Prioritizationex. Multiple streams for different bandwidth.
Bibliographic InformationBibliographic Information can apply to either
the whole file or a single media stream.
ASF Features(2/2)
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File Format Organization(1/3)
ASF Objectthe base unit of organization - ASF Object
Object ID
Object Size
16 Bytes
8 Bytes
?? Bytes
Object Data
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High-level File StructureThree Top-level Objects
Header ObjectData ObjectIndex Object
Minimal Implementation1 File Properties Object1 Stream Properties Object1 Language List Object1 Data Object with only 1 Data unit
Index Object
<Other Objects>
Header Object
Data Object
File Properties Object Stream Properties Object 1
Stream Properties Object N
...
<Other Header Objects>
Data Unit...
Data Unit
File Format Organization(2/3)
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ASF Header Objectis a container that can hold other ASF objects:File Properties ObjectStream Properties ObjectContent Description ObjectScript Command ObjectMarker ObjectComponent Download ObjectScalable Object
Prioritization ObjectMutual Exclusion ObjectInter-Media Dependency ObjectRating ObjectIndex Parameters ObjectColor Table ObjectLanguage List Object
File Format Organization(3/3)
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Stream Property Object
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Script Command Property Object
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Marker Object
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Index Parameter Object
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Data Object
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Index Object
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Sample files
Sample1:
Sample2:
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Reference [1] Windows NT Server NetShow Service Deployment Guild [2] Microsoft NetShow 3.0 Reviewer’s Guild [3] NetShow Overview White Paper [4] Advanced Streaming Format Specification Ver1.0
http://www.microsoft.com/ntserver/mediaserv/default.asp http://www.microsoft.com/asf
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