Contains information defining the channel type to open on a video capture device.
typedef struct { DWORD dwSize; //size of this structure FOURCC fccType; //see below FOURCC fccComp; //reserved; not used DWORD dwVersion; //see below DWORD dwFlags; //see below DWORD dwError; //see below LPVOID pV1Reserved; //reserved; not used LPVOID pV2Reserved; //reserved; not used DWORD dwDevNode; //see below } VIDEO_OPEN_PARMS; //see below
fccType
Four-character code identifying the type of channel being opened. For capture devices, this is set to "vcap".
dwVersion
Current version number of the video capture command being used. Set this to VIDEOAPIVERSION.
dwFlags
Flags identifying the type of channel. The following flags are defined:
VIDEO_EXTERNALIN | Specifies a channel that loads data from an external source into a frame buffer. This can also be called the capture channel. |
VIDEO_IN | Specifies a channel that transfers data from the frame buffer to system memory. |
VIDEO_OUT | Specifies a channel that transfers data from system memory to the frame buffer. |
VIDEO_EXTERNALOUT | Specifies a channel that controls display of frame buffer images. Display might be either on a second monitor, or via overlay. |
dwError
Error value the driver should return to the client application if it fails the open.
dwDevNode
Device node in the registry for the plug and play capture driver; the value refers to the section of the registry that contains configuration information for the driver.
This structure is identical to the ICOPEN structure used by installable compressors. This lets a driver handle both video capture and decompressor messages with a single DriverProc entry point.