WMCreateReader function (wmsdkidl.h)

Статья
4/26/2023

[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 It has been superseded by Source Reader and Sink Writer.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.]

The WMCreateReader function creates a reader object.

Syntax

HRESULT WMCreateReader(
  [in]  IUnknown  *pUnkCert,
  [in]  DWORD     dwRights,
  [out] IWMReader **ppReader
);

Parameters

[in] pUnkCert

This value must be set to NULL.

[in] dwRights

DWORD indicating the desired operation. Set to one of the values from the WMT_RIGHTS enumeration type, indicating the operation that is performed on this file. If multiple operations are being performed, dwRights must consist of multiple values from WMT_RIGHTS combined by using the bitwise OR operator.

[out] ppReader

Pointer to a pointer to the IWMReader interface of the newly created reader object.

Return value

The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.

Return code	Description
S_OK	The function succeeded.
E_OUTOFMEMORY	The function is unable to allocate memory for the new object.

Remarks

After this object has been created, you can modify the rights that will be requested for the next file opened by calling IWMDRMReader::SetDRMProperty with the DRM_Rights property. Note that when using this property, the rights are specified as strings, not as DWORD values.

The dwRights parameter may be set to 0 when reading non-DRM content. If dwRights is set to 0 and you open a protected file, you can access license related metadata, but you cannot read data from any streams in the file.

Requirements

Requirement	Value
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	Wmvcore.lib
DLL	Wmvcore.dll

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