typedef struct {
DWORD dwSize;
FOURCC fccType;
FOURCC fccComp;
DWORD dwVersion;
DWORD dwFlags;
DWORD dwError;
LPVOID pV1Reserved;
LPVOID pV2Reserved;
DWORD dnDevNode;
} VIDEO_OPEN_PARMS;
The VIDEO_OPEN_PARMS structure defines the type of channel to open on a video-capture device. User-mode video capture drivers receive this structure along with a DRV_OPEN message. The structure is defined in msviddrv.h.
Members
dwSize
Contains the size of the VIDEO_OPEN_PARMS structure.
fccType
Contains a four-character code identifying the type of channel being opened. Must be “vcap”.
fccComp
Not used.
dwVersion
Contains the current version of the video capture API, which is defined by VIDEOAPIVERSION in msviddrv.h.
dwFlags
Specifies flags used to indicate the type of channel. The following flags are defined.
| Flag | Definition |
| VIDEO_EXTERNALIN | Data path from an external video source, such as a TV, VCR, or camera, into a frame buffer. |
| VIDEO_IN | Data path from the frame buffer to system memory. |
| VIDEO_OUT | Data path from system memory to the frame buffer. |
| VIDEO_EXTERNALOUT | Data path from the frame buffer to an output display, such as an overlay window on a user’s screen. |
dwError
Error value supplied by the driver if the open operation fails.
pV1Reserved
Reserved.
pV2Reserved
Reserved.
dnDevNode
Devnode for PnP devices.
Comments
The VIDEO_OPEN_PARMS structure is identical to the ICOPEN structure used by installable compressors, allowing a single driver to handle both video capture and compression messages.
For more information about the VIDEO_OPEN_PARMS structure, see DriverProc in User-Mode Video Capture Drivers and Opening Video Channels.