IMDSPObject2::ReadOnClearChannel method (mswmdm.h)

The ReadOnClearChannel method reads data from the object at the current position without using secure authenticated channels. This is still secure for use with DRM-protected content. This operation is valid only if the storage object represents a file. If IMDSPObject2 is supported, this method must be implemented. Windows Media Device Manager does not fall back to IMDSPObject::Read if this method fails.


HRESULT ReadOnClearChannel(
  [out]     BYTE  *pData,
  [in, out] DWORD *pdwSize


[out] pData

Pointer to a buffer to receive the data read from the object.

[in, out] pdwSize

Pointer to a DWORD specifying the number of bytes of data to read. Upon return, this parameter contains the actual amount of data read.

Return value

The method returns an HRESULT. All the interface methods in Windows Media Device Manager can return any of the following classes of error codes:

  • Standard COM error codes
  • Windows error codes converted to HRESULT values
  • Windows Media Device Manager error codes
For an extensive list of possible error codes, see Error Codes.


This method can be used for DRM-protected content. This method is more efficient than IMDSPObject::Read because this method does not involve encrypting and decrypting parameters.


Target Platform Windows
Header mswmdm.h
Library Mssachlp.lib

See also

Enabling Synchronization with Windows Media Player

IMDSPObject2 Interface