Edit

ITocEntry::GetDescriptionData method (wmcodecdsp.h)

  • Article

The GetDescriptionData method gets a description data block that was previously associated with the entry by a call to SetDescriptionData.

Syntax

HRESULT GetDescriptionData(
  [in, out] DWORD *pdwDescriptionDataSize,
  [out]     BYTE  *pbtDescriptionData,
  [out]     GUID  *pGuidType
);

Parameters

[in, out] pdwDescriptionDataSize

If pbtDescriptionData is NULL, this is an output parameter that receives the size, in bytes, of the description data block. If pbtDescriptionData is not NULL, this is an input parameter that specifies the size, in bytes, of the caller-allocated buffer pointed to by pbtDescriptionData.

[out] pbtDescriptionData

NULL, or a pointer to a caller-allocated buffer that, on successful completion, receives the description data block.

[out] pGuidType

Pointer to a variable that receives a globally unique identifier (GUID) that identifies the type of data in the description data block. See Remarks.

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 method succeeded.
MF_E_BUFFERTOOSMALL
 The method returns this error code if pbtDescriptionData is not NULL and the context block is larger than the size specified by pdwDescriptionDataSize. In that case, pdwDescriptionDataSize serves as an output parameter and receives the size, in bytes, of the required buffer.

Remarks

You can associate only one description data block with a given entry at a given time. However, you might want to design different types of description data blocks and identify each type of block with a globally unique identifier (GUID). That way, when you call SetDescriptionData, you can mark the data block as being of a specific type. When you call GetDescriptionData, you can determine the type of the data block retrieved by inspecting the value returned in pGuidType.

Requirements

Requirement Value
Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2008 [desktop apps only]
Target Platform Windows
Header wmcodecdsp.h
DLL Wmvdspa.dll

See also

ITocEntry

SetDescriptionData