IltmmMemory::LockRegion

#include "ltmm.h"

C Syntax	HRESULT IltmmMemory_LockRegion(pMem, Index, Count, pVal)
C++ Syntax	HRESULT LockRegion(Index, Count, pVal)

IltmmMemory *pMem;	/* pointer to an interface */
long Index;	/* offset */
long Count;	/* size */
VARIANT *pVal;	/* pointer to a VARIANT */

Locks a region in the object’s buffer.

Parameter	Description
pMem	Pointer to an IltmmMemory interface.
Index	Zero based index, or offset, of the region to lock.
Count	Size of the region to lock, in bytes.
pVal	Pointer to a variable to be updated with a VARIANT containing a SAFEARRAY reference to the locked region.

Returns

S_OK	The function was successful.
<> S_OK	An error occurred. Refer to the Error Codes or the HRESULT error codes in the DirectShow documentation.

Comments

If the requested size of the region is larger than the size available after the offset, the function locks only the region between the offset and the end of the buffer.

This function obtains a pointer to the region in the form of a SAFEARRAY embedded in a VARIANT.

Call IltmmMemory::Unlock to unlock the region when it is no longer being used.

Required DLLs and Libraries

LTMM

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Win32, x64

Elements:	IltmmMemory::LockBuffer, IltmmMemory::Unlock
Topics:	Multimedia Function Group