// ntddvdeo.h

// CTL_CODE(0x0023, 0x117, METHOD_BUFFERED, FILE_ANY_ACCESS)
#define IOCTL_VIDEO_UNMAP_VIDEO_MEMORY 0x0023045C
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Windows Driver Kit DDI reference (ni-ntddvdeo-ioctl_video_unmap_video_memory)

IOCTL_VIDEO_UNMAP_VIDEO_MEMORY IOCTL

Description

Releases a mapping between the virtual address space and the adapter's frame buffer and video RAM. Miniport drivers are required to support this nonmodal request.

Parameters

Major code

Input buffer

The VRP InputBuffer contains a VIDEO_MEMORY structure, specifying the previously mapped virtual base address to be released with VideoPortUnmapMemory.

Input buffer length

Output buffer

None

Output buffer length

Input/output buffer

Input/output buffer length

Status block

The miniport driver does not set the Information member of the STATUS_BLOCK structure.

IOCTL_VIDEO_UNMAP_VIDEO_MEMORY - NtDoc