IMFMediaBuffer::Unlock method (mfobjects.h)

Unlocks a buffer that was previously locked. Call this method once for every call to IMFMediaBuffer::Lock.


HRESULT Unlock();

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.
For Direct3D surface buffers, an error occurred when unlocking the surface.


It is an error to call Unlock if you did not call Lock previously.

After calling this method, do not use the pointer returned by the Lock method. It is no longer guaranteed to be valid.

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.


Requirement Value
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


Media Buffers