IWMDRMReader::GetDRMProperty method

[GetDRMProperty is available for use in the operating systems specified in the Requirements section. It may be altered or unavailable in subsequent versions. Instead, use Microsoft PlayReady. ]

The GetDRMProperty method retrieves DRM-specific file attributes and run-time properties.

Syntax

HRESULT GetDRMProperty(
  LPCWSTR           pwstrName,
  WMT_ATTR_DATATYPE *pdwType,
  BYTE              *pValue,
  WORD              *pcbLength
);

Parameters

pwstrName

Specifies the property or file attribute to retrieve.

pdwType

Pointer that receives the data type of the returned value.

pValue

Pointer to the value requested in pwstrName.

pcbLength

Size of pValue, in bytes.

Return value

If the method succeeds, it returns S_OK. If it fails, it returns an HRESULT error code.

Remarks

This method can be used to retrieve both DRM header attributes and DRM license information for the current file. DRM-related constants are defined in drmexternals.idl and wmsdkidl.idl.

If you specify a "license state" constant, the returned data is a pointer to a WM_LICENSE_STATE_DATA structure that fully describes the terms of the license for the particular right. The supported license state constants are described in the following table.

Constant Literal string value Description
g_wszWMDRM_LicenseState_CollaborativePlay "LicenseStateData.CollaborativePlay" License restrictions on playing the file as part of a collaborative peer-to-peer networking scenario.
g_wszWMDRM_LicenseState_Copy "LicenseStateData.Copy" License restrictions on copying the file to a device.
g_wszWMDRM_LicenseState_CopyToCD "LicenseStateData.Print.redbook" License restrictions on copying the file to CD.For DRM version 10 licenses, use g_wszWMDRM_LicenseState_Copy for all copy actions.
g_wszWMDRM_LicenseState_CopyToNonSDMIDevice "LicenseStateData.Transfer.NONSDMI" License restrictions on copying the file to a non-SMDI device.For DRM version 10 licenses, use g_wszWMDRM_LicenseState_Copy for all copy actions.
g_wszWMDRM_LicenseState_CopyToSDMIDevice "LicenseStateData.Transfer.SDMI" License restrictions on copying the file to an SDMI device.For DRM version 10 licenses, use g_wszWMDRM_LicenseState_Copy for all copy actions.
g_wszWMDRM_LicenseState_Playback "LicenseStateData.Play" License restrictions on playing the file.
g_wszWMDRM_LicenseState_PlaylistBurn "LicenseStateData.PlaylistBurn" License restrictions on copying the file to Red Book audio CD as part of a playlist.
 

If you specify an "action allowed" constant, the returned data is a Boolean that indicates whether a specified action is allowed at this time. The supported constants are:

Constant Literal string value Description
g_wszWMDRM_ActionAllowed_Backup "ActionAllowed.Backup" Right to back up the file now.
g_wszWMDRM_ActionAllowed_CollaborativePlay "ActionAllowed.CollaborativePlay" Right to play the file as part of a collaborative peer-to-peer networking scenario.
g_wszWMDRM_ActionAllowed_Copy "ActionAllowed.Copy" Right to copy the file to a device.
g_wszWMDRM_ActionAllowed_CopyToCD "ActionAllowed.Print.redbook" Right to copy file to CD.For DRM version 10 licenses, check g_wszWMDRM_ActionAllowed_Copy for all copy actions.
g_wszWMDRM_ActionAllowed_CopyToSDMIDevice "ActionAllowed.Transfer.SDMI" Right to copy file to an SDMI device.For DRM version 10 licenses, check g_wszWMDRM_ActionAllowed_Copy for all copy actions.
g_wszWMDRM_ActionAllowed_CopyToNonSDMIDevice "ActionAllowed.Transfer.NONSDMI" Right to copy file to a non-SMDI device.For DRM version 10 licenses, check g_wszWMDRM_ActionAllowed_Copy for all copy actions.
g_wszWMDRM_ActionAllowed_Playback "ActionAllowed.Play" Right to play file.
g_wszWMDRM_ActionAllowed_PlaylistBurn "ActionAllowed.PlaylistBurn" Right to copy the file to Red Book audio CD as part of a playlist.
 

If you specify a "DRM Header" constant, the returned value is the string literal for the specified property. The supported DRM Header constants are:

Constant Literal string value Description
g_wszWMDRM_DRMHeader_KeyID "DRMHeader.KID" DRM key value.
g_wszWMDRM_DRMHeader_LicenseAcqURL "DRMHeader.LAINFO" DRM license acquisition URL.
g_wszWMDRM_DRMHeader_ContentID "DRMHeader.CID" DRM content ID.
g_wszWMDRM_DRMHeader_IndividualizedVersion "DRMHeader.SECURITYVERSION" Individualized version.
g_wszWMDRM_DRMHeader_ContentDistributor "DRMHeader.ContentDistributor" Content distributor.
g_wszWMDRM_DRMHeader_SubscriptionContentID "DRMHeader.SubscriptionContentID" Subscription content ID.
 

Before calling this method on a new file, always call the helper function WMIsContentProtected to ensure that the file is protected with DRM. It is important to do this because in some cases this method might succeed when called on unprotected content.

Requirements

   
Minimum supported client Windows 2000 Professional [desktop apps only],Windows Media Format 7 SDK, or later versions of the SDK
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header wmsdkidl.h (include Wmsdk.h)
Library WMStubDRM.lib

See also

DRM Attribute List

DRM Properties

IWMDRMEditor::GetDRMProperty

IWMDRMReader Interface

IWMDRMReader::SetDRMProperty

WMT_ATTR_DATATYPE