IMFAttributes::GetBlobSize method (mfobjects.h)

Retrieves the length of a byte array associated with a key.


HRESULT GetBlobSize(
  [in]  REFGUID guidKey,
  [out] UINT32  *pcbBlobSize


[in] guidKey

GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_BLOB.

[out] pcbBlobSize

If the key is found and the value is a byte array, this parameter receives the size of the array, in bytes.

Return value

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

Return code Description
The method succeeded.
The specified key was not found.
The attribute value is not a byte array.


To get the byte array, call IMFAttributes::GetBlob.

This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed:

  • Windows XP with Service Pack 2 (SP2) and later.
  • Windows XP Media Center Edition 2005 with KB900325 (Windows XP Media Center Edition 2005) and KB925766 (October 2006 Update Rollup for Windows XP Media Center Edition) installed.


Minimum supported client Windows Vista [desktop apps | UWP apps]
Minimum supported server Windows Server 2008 [desktop apps | UWP apps]
Target Platform Windows
Header mfobjects.h (include Mfidl.h)
Library Mfuuid.lib

See also

Attributes and Properties