Adding the ContentDistributor Attribute

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[The feature associated with this page, Windows Media Player SDK, is a legacy feature. It has been superseded by MediaPlayer. MediaPlayer has been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer instead of Windows Media Player SDK, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

When the user attempts to play online store content or to copy the content to a CD or device, Windows Media Player calls certain methods in your COM object. To do this, the Player needs a way to differentiate your content from that of other online store providers. By adding your online store key name as the value for the ContentDistributor (which is an alias for the Windows Media Format SDK attribute named WM/ContentDistributor) attribute to your Windows Media-based content, you ensure that the Player can identify the content associated with your service.

Adding a value for ContentDistributor also ensures that Windows Media Player will create a node in the library for content you provide. See Library Integration.

You can specify this value two ways:

  • Use the Windows Media Player object model. When you do this, Windows Media Player adds the value you specify to the library database. Eventually, the Player will also write the attribute value to the digital media file.
  • Use the Windows Media Format SDK to programmatically add the WM/ContentDistributor attribute. When you do this, Windows Media Player reads the attribute value and adds it to the database when the digital media file is added to the library.

When creating your online store COM object, the file attribute value you set for ContentDistributor and the value assigned to the constant kszContentDistributorID in YourProject.h must match exactly. Recall that you specified this constant value for your COM object when you created the project by using the project wizard. You can change this value manually. Just be sure to use a string that uniquely identifies your service.

Using the Windows Media Player Object Model

To specify a value for ContentDistributor using the Windows Media Player object model, use the Media.setItemInfo method. The following example code specifies the value "Proseware" for ContentDistributor for the currently playing media item:

// Retrieve the current media item.
var theMedia = Player.currentMedia;

//Test whether the media item was retrieved.
if(theMedia)
{
    // Set the ContentDistributor value.
    theMedia.setItemInfo("ContentDistributor", "Proseware");
}

Using the Windows Media Format SDK

The Windows Media Player SDK includes a sample C++ file, named SetContentDistributor.cpp, which demonstrates how to use the Windows Media Format 9 Series SDK to add the WM/ContentDistributor attribute. You can locate this sample file in the folder named Metadata where you installed the SDK. To use this code you must follow these steps:

  1. Install the Windows Media Format 9 Series SDK and configure the runtime as described in the documentation.
  2. Create a new empty C++ project in Visual Studio and add the sample file named SetContentDistributor.cpp to the project.
  3. Add the path to the Windows Media Format 9 Series SDK Lib folders to your list of file paths. From the Tools menu, choose Options.
  4. In the Options dialog box, click Projects, and then click VC++ Directories.
  5. In the Show Directories for drop-down list box, click Library files.
  6. Use the buttons to add the paths to the list boxes.
  7. Open the property pages dialog box for your project. Choose Configuration Properties, then Linker, and then Input. Type "wmvcore.lib" in the Additional Dependencies text box.

The sample code creates a command-line program. The arguments you provide when running the program specify the path to the digital media file to modify and a string for the ContentDistributor attribute value. The code uses IWMHeaderInfo::SetAttribute to add the attribute to the file you specified. You can use this sample as is or use it as a starting point for your own program.

Information Common to Type 1 and Type 2 Online Stores