Smooth Streaming is an extension for Internet Information Services (IIS) 7.0 that adapts the quality of a video stream delivered to Silverlight clients in real time, based on a client's available bandwidth and CPU resources. Clients with high-bandwidth connections and fast processors can experience high-definition (HD) video streaming, whereas clients with low-bandwidth connections or slower processors can still receive a stream that is appropriate for their environment, letting all users enjoy the best possible viewing experience at any moment during playback.

Smooth Streaming works with contiguous files stored in a fragmented MPEG-4 (MP4) media container format. This makes it easier to manage the video source media assets. A smooth streaming presentation can contain multiple video and audio files (with .ismv file name extensions), each encoded with different quality levels (bit rates) and resolutions. A presentation also includes accessory XML files that enable Silverlight clients to use smooth streaming heuristics, a stream-switching logic that obtains the best quality video optimized for the client environment at all times. The video files are encoded using a smooth streaming profile, which encodes the media to the correct output format and creates the associated XML files. Encoders that support smooth streaming output include Microsoft® Expression® Encoder 2 Service Pack 1 (SP1).

When a Silverlight client makes a request for a smooth streaming presentation, the Web server delivers an XML file that describes the available quality levels. The client then uses the smooth streaming heuristics to determine the best media file to use at that instant, and then requests an MP4 fragment from the file. The smooth streaming heuristics continuously monitor the environment and at frequent intervals (typically 2 seconds), request the next contiguous MP4 fragment in the file (if available bandwidth and CPU resources have not changed) or a contiguous MP4 fragment from a different file (if available bandwidth and CPU resources have changed). The Smooth Streaming feature in IIS 7.0 dynamically creates the MP4 fragment from the appropriate video source file and delivers it seamlessly to the client. This process continues until the client stops playback or the end of the file is reached, ensuring that the client has the best possible viewing experience without any buffering or stuttering. Smooth streaming client heuristics are hosted in Microsoft® Silverlight™ 2.

Installation Notes

This section describes the installation requirements for IIS Smooth Streaming - Beta.

Requirements

The following prerequisites must be fulfilled to run the Smooth Streaming Beta installation package and install Smooth Streaming:

You must use IIS 7.0 running on Windows Server 2008 or Windows Vista® with Service Pack 1 (SP1).
The IIS Management Console for Internet Information Services 7.0 must be installed to manage the Smooth Streaming module using the IIS 7.0 user interface.
You must install IIS Smooth Streaming - Beta as an administrator. (See "Downloading and Installing" for more information.)

Downloading and Installing

Two separate downloadable installation packages are available for IIS Smooth Streaming - Beta. Download the appropriate installation package for your edition of Windows:

You must be an administrator on the computer to run the installation package. This can be accomplished by logging on to the computer using the Administrator account or an account with administrative privileges.

To run the Smooth Streaming installation package that you downloaded, do the following:

Double-click the Windows Installer (.msi) file that you downloaded, and then complete the Setup wizard.

-or-

Open an elevated command prompt (click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator).
In the Administrator: Command Prompt window, navigate to the folder where the Smooth Streaming Windows Installer (.msi) file is stored.
Type one of the following commands to run the installation: msiexec /I SmoothX32.msi (for the 32-bit edition of the Windows Server 2008 operating system) or msiexec /I SmoothX64.msi (for the 64-bit edition of the Windows Server 2008 operating system).

Note
If you encounter any problems during installation, type one of the following commands in the elevated command prompt to create a log file that contains information about the installation process: msiexec /L Smooth.log /I SmoothX32.msi for the 32-bit edition of the Windows Server 2008 operating system) or msiexec /L Smooth.log /I SmoothX64.msi (for the 64-bit edition of the Windows Server 2008 operating system). Analyze this log file after a failed installation to help determine the cause of the failure.

Note

If you encounter any problems during installation, type one of the following commands in the elevated command prompt to create a log file that contains information about the installation process: msiexec /L Smooth.log /I SmoothX32.msi for the 32-bit edition of the Windows Server 2008 operating system) or msiexec /L Smooth.log /I SmoothX64.msi (for the 64-bit edition of the Windows Server 2008 operating system).

Analyze this log file after a failed installation to help determine the cause of the failure.

Uninstalling

To remove Smooth Streaming, in Programs and Features in Control Panel, click IIS Smooth Streaming - Beta under Uninstall or change a program, and then click Uninstall.

Known Issues

Preventing Static File Download of Smooth Streaming Presentation Files

Smooth Streaming is designed to deliver video fragments in an HTTP response from media source files stored in a fragmented MPEG-4 (MP4) media container format (with .ismv file name extensions). The video fragments that the Smooth Streaming feature dynamically generates from the source files are optimized for the client's currently available bandwidth and CPU resources, as determined by smooth streaming heuristics hosted in the client, which continuously monitor the client environment. The .ismv source files allow for easy management of the video source content on the Web server, but they are not designed to be downloaded by clients. We recommend that you use the Request Filtering feature in IIS 7 to deny access to the .ismv file name extension. For more information, see Request Filtering.

Product Support

You can obtain support for Smooth Streaming by using the following resources:

Self Support

Microsoft Support

To obtain support from Microsoft for Smooth Streaming, visit Microsoft Help and Support.

For More Information

The following documents provide more information about Smooth Streaming and other media extensions for IIS 7.0:

Smooth Streaming Home page. Keep up-to-date with the latest Smooth Streaming news and feature developments.
Encoding Smooth Streaming Video. Learn best practices for creating smooth streaming content.
Silverlight Media Content Delivery. Learn how Silverlight works with adaptive streaming technologies to deliver optimized, enhanced high-definition video experiences that overcome the challenges presented by changing Internet connections.
Media on IIS.net. Learn about additional extensions for IIS 7.0 that make delivery of audio and video content from a Web server simple and cost-effective.