Windows Media Support

The LEADTOOLS Multimedia toolkit wraps many of the Windows Media objects and interfaces to provide the maximum flexibility for authoring digital media.

WMV Files

The Advanced Systems Format is the container for the Windows Media-based digital content. Windows Media Video (WMV) is used to store and play back synchronized digital media streams, or to transmit such streams over networks. For more information on the WMV format, refer to the Microsoft documentation on the WMV Format.


A profile is a collection of data that describes the configuration of an WMV file that contains at least one stream. The profile contains information about each stream, stream configuration, and the relationships between the different streams (for example, mutual exclusion).

The profile object and its subordinate objects are used to configure various aspects of the profile. Profiles can be saved to disk for later use. For more information on WMV profiles, refer to the following topics:

ltmmWMProfileManager object

ltmmWMProfile object

IltmmWMProfileManager interface

IltmmWMProfile interface

Stream Configuration and Mutual Exclusion

The Stream Configuration object is used to specify stream properties like the stream type, number, name, bit-rate, quality, etc. For more information on Stream Configuration, refer to the ltmmWMStreamConfig object and the IltmmWMStreamConfig interface.

 The Mutual Exclusion object helps multiple streams co-exist, and delivers streams one at a time. For more information about the Mutual Exclusion object, refer to the ltmmWMMutualExclusion object and the IltmmWMMutualExclusion interface.

Pushing Data to the Windows Media Server

Push data to a Windows Media Server while compressing for real-time streaming using the LEAD MMS Sink filter (without having to use the Windows Media Encoder utility). The video can be compressed with H264 or with the Windows Media Video codec. For more information on pushing data to a Windows Media Server, refer to Using LEAD MMS Sink.

Adding Script Metadata

You can add script metadata at various points to a Windows Media file using the IltmmWMScript interface and the ltmmWMScript Object.

Script metadata can be detected during playback and playback applications can respond to metadata in various ways. For example, a  Windows Media Player could automatically open an URL in a browser whenever an URL command is issued. See the Microsoft documentation, Using Script Commands Supported by Windows Media Player, for a complete list of script commands supported by the Windows Media Player.

Windows Media 9.5 Redistributable

It is best to redistribute the Windows Media Format components with your application. These components are included in an installation package named wmfdist95.exe, which can be found in your Redist\MM folder. These components are also included in Windows Media Player 9 and later versions. Therefore it is not necessary to install these components on computers that already have Windows Media player installed. For more information on how to install this redistributable, refer to the Microsoft documentation.

There is also a LEAD Windows Media Reader filter which you should redistribute in order to be able to play Windows Media files from an URL under Vista. This filter provides the ILMWMReader interface for controlling the filter's behaviour.

The LEAD Windows Media Reader and LEAD MMS Sink filters require WMVCore.DLL to be present on the machine. If this library is missing, these filters will return either the REGDB_E_CLASSNOTREG or LTMM_E_WMVCORE_MISSING error code.

Some versions of Windows do not come preinstalled with WMVCORE.DLL, and the Windows feature needed to install it can vary. For more information on how to install Windows Media Player, please see the Get Windows Media Player topic from Microsoft.

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LEADTOOLS Multimedia C API Help
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2021 LEAD Technologies, Inc. All Rights Reserved.