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Silent License Acquisition

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 It has been superseded by Source Reader and Sink Writer.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

Silent license acquisition requires only a single method call that handles all of the network communications with the license server asynchronously.

This type of license acquisition is usually used as a response to the end user trying to access protected content—for example, trying to play a protected file in a media player application. Because silent license acquisition gets the license with a single call, it cannot be used if additional input from the user, such as payment for the content, is required.

To perform silent license acquisition, use the following steps:

  1. Call the IWMDRMLicenseManagement::AcquireLicense method. Pass in the DRM header from the protected file as the bstrHeaderData parameter. Specify what rights you want the license to grant in the bstrActions parameter. Finally, set the dwFlags parameter to WMDRM_ACQUIRE_LICENSE_SILENT.
  2. Trap events for the IWMDRMLicenseManagement interface. When you receive the MEWMDRMLicenseAcquisitionCompleted event, check its return code by calling the IMFMediaEvent::GetStatus method, which is documented in the Media Foundation documentation. If the retrieved HRESULT value is a success code, then the license was successfully downloaded and is in the local license store ready for use.

Acquiring Licenses

Using the Media Foundation Event Model