VRAM_SURFACE_INFO structure (ksmedia.h)

The VRAM_SURFACE_INFO structure describes a region of system or display memory into which an AVStream minidriver captures audio or video data.

Syntax

typedef struct {
  UINT_PTR  hSurface;
  LONGLONG  VramPhysicalAddress;
  DWORD     cbCaptured;
  DWORD     dwWidth;
  DWORD     dwHeight;
  DWORD     dwLinearSize;
  LONG      lPitch;
  ULONGLONG ullReserved[16];
} VRAM_SURFACE_INFO, *PVRAM_SURFACE_INFO;

Members

hSurface

A pointer to a kernel-mode handle that identifies the VRAM surface.

VramPhysicalAddress

This member contains the physical address of the surface in display memory. The minidriver fills in this member in the handler for KSPROPERTY_MAP_CAPTURE_HANDLE_TO_VRAM_ADDRESS.

cbCaptured

This member specifies the number of bytes copied into the VRAM surface. The minidriver sets this value.

dwWidth

This member specifies the width of the video data in pixels. The minidriver sets this value.

dwHeight

This member specifies the height of the video data, in pixels. The minidriver sets this value.

dwLinearSize

This member specifies the linear size, in bytes, of a nonrectangular surface. The minidriver sets this value.

lPitch

This member specifies the pitch of the surface; that is, the distance, in bytes, to the start of the next line. This is also known as the stride of the surface. The minidriver sets this value.

ullReserved[16]

The minidriver can use this member to store information about the surface as it handles a KSPROPERTY_MAP_CAPTURE_HANDLE_TO_VRAM_ADDRESS request. Use caution, however; this structure does not persist across AVStrMiniPinProcess calls.

Remarks

When the minidriver receives VRAM_SURFACE_INFO through a KSPROPERTY_MAP_CAPTURE_HANDLE_TO_VRAM_ADDRESS property call, the members following VramPhysicalAddress in the member list (except for ullReserved) are zeroed out. The capture driver can store capture-related private data in these members.

AVStream then stores this information in the stream header and returns it to the minidriver in the AVStrMiniPinProcess callback function.

The data in these members persists for the lifetime of the stream header. When all clones are deleted or the leading edge is advanced, this data is no longer accessible.

Requirements

See also

AVStrMiniPinProcess

KSPROPERTY_MAP_CAPTURE_HANDLE_TO_VRAM_ADDRESS