typedef struct _VCCALLBACK {
DWORD dwCallback;
DWORD dwFlags;
HDRVR hDevice;
DWORD dwUser;
} VCCALLBACK, *PVCCALLBACK;
The VCCALLBACK structure contains callback information needed by the VC_StreamInit function. The structure is defined in vcuser.h.
Members
dwCallback
Contains either the address of a callback function, a window handle, or NULL, based on flags set in the dwFlags member. The driver should copy the value of the VIDEO_STREAM_INIT_PARMS structure’s dwCallback member into this member.
dwFlags
Contains flags. Can contain one (or none) of the following flags.
Flag | Definition |
CALLBACK_WINDOW | Indicates dwCallback contains a window handle. |
CALLBACK_FUNCTION | Indicates dwCallback contains a callback function address. |
The driver should copy the value of the VIDEO_STREAM_INIT_PARMS structure’s dwFlags member into this member.
hDevice
Contains a handle to a video channel. The driver should copy the value of the VIDEO_STREAM_INIT_PARMS structure’s hVideo member into this member.
dwUser
Contains client-specified instance data passed to the callback function, if CALLBACK_FUNCTION is set in dwFlags. The driver should copy the value of the VIDEO_STREAM_INIT_PARMS structure’s dwCallbackInst member into this member.
Comments
As indicated by the preceding member descriptions above, the VCCALLBACK structure is used to pass VIDEO_STREAM_INIT_PARMS structure members to VC_StreamInit.