If you have an application that handles Windows Media content and you need an effective way to track content usage, Windows Media 9 Series now offers Digital Rights Management (DRM). It allows you to take advantage of the peer-to-peer distribution model and still redirect users back to your app once they have downloaded your content (prior to viewing). It also provides you with the ability to create an expiration date for your content.

The Windows Media 9 Series How-To page for Windows Media DRM provides information on all the functionality that DRM offers. Digital Rights Management can be implemented as an additional application layer to add security, tracking, and site redirection to your content regardless of where that content travels. This layer can also be completely transparent to your existing app, and there are several different ways you can implement it.

If you want users to have full access to content and use DRM only for tracking, you can use the technology to catch play "events" that are kicked off by the Windows Media Player. Each time your content is played by a user who is connected to the Internet, a message will be sent by the Windows Media Player to your DRM server. Your DRM server then records the play event, automatically responds with a license for content playback, and then plays the content. The user isn't even aware of the DRM process.

With a bit more integration work, you can tie the content security mechanism offered by DRM into your current user authorization mechanism, ensuring that your content is only viewed by authorized users. You can even tie the content to the individual PC that accesses your site, a process known as individualization.

The Windows Media 9 Series How-To page for Windows Media DRM documents a sample DRM application that easily integrates with your existing Web applications. This app can protect your content from unlicensed users and control its availability. The sample DRM app is a .NET Framework Web-based application that users can be redirected to for licensing. Upon licensing, users are redirected back to your original application. The entire trip usually takes less than a second, so users may not even notice that they have left your site.

You can control the kind of license that the sample DRM application provides to the user by giving licensing information to the sample DRM application as form variables associated with the redirection. The sample DRM application uses the submitted form variables to create the appropriate license, which is then stored in the user's license store through a client-side control (the license store and the delivery control are part of Windows Media Player version 7.0 and later).

This pre-licensing can be done any time prior to content playback. The sample DRM application also supports post-licensing, which occurs when a user attempts to play content that has not yet been licensed. When the Windows Media Player is asked to play a piece of content with DRM, it first checks the license store for an available license. If it fails to find the correct license, it opens up a mini-browser that accesses a licensing URL (which is embedded in the content header during DRM encryption). A full HTTP session is hosted in the mini-browser at this point, during which time your app can require the user to provide the credentials you require for playback. Once these are provided, your app can redirect the user to the sample DRM app for licensing. After a license has been delivered, the mini-browser enables a play button that closes the mini-browser and begins content playback.

The sample DRM application is available to licensed users of the Windows Media Digital Rights Management SDK. The Windows Media Licensing Form can be downloaded at http://wmlicense.smdisp.net/licenserequest/.