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