Bewerken

Delen via

VideoPortLockBuffer function (video.h)

  • Artikel

The VideoPortLockBuffer function probes the specified buffer, makes the buffer's memory pages resident in memory, and locks the physical pages mapped by the virtual address range.

Syntax

VIDEOPORT_DEPRECATED VIDEOPORT_API PVOID VideoPortLockBuffer(
  [in] IN PVOID             HwDeviceExtension,
  [in] IN PVOID             BaseAddress,
  [in] IN ULONG             Length,
  [in] IN VP_LOCK_OPERATION Operation
);

Parameters

[in] HwDeviceExtension

Pointer to the miniport driver's device extension.

[in] BaseAddress

Specifies the virtual address of the buffer to be locked.

[in] Length

Specifies the length in bytes of the buffer to be locked.

[in] Operation

Specifies the type of operation for which the caller wants the access rights probed and the pages locked. The operation can be one of the following: VpReadAccess, VpWriteAccess, or VpModifyAccess.

Return value

Returns a pointer to a memory descriptor list (MDL), or a NULL pointer if the MDL for the memory to be locked cannot be allocated.

Remarks

To unlock the buffer, the video miniport driver should call VideoPortUnlockBuffer.

Requirements

Requirement Value
Minimum supported client Available in Windows XP and later versions of the Windows operating systems.
Target Platform Desktop
Header video.h (include Video.h)
Library Videoprt.lib
DLL Videoprt.sys
IRQL PASSIVE_LEVEL

See also

VideoPortUnlockBuffer