CaptureFunc

BOOLEAN
CaptureFunc(
    PDEVICE_INFO pDevInfo,
    BOOL bCapture
    );

The CaptureFunc function is provided by kernel-mode video capture drivers to enable and disable capturing video data. The CaptureFunc name is a placeholder for a driver-specified function name.

Parameters

pDevInfo

Pointer to the DEVICE_INFO structure returned by VC_Init.

bCapture

Set to TRUE if data capture is to be enabled, and FALSE if it is to be disabled.

Return Value

Returns TRUE if the operation succeeds. Otherwise returns FALSE. If FALSE, VCKernel.lib sets the Win32 error code value to STATUS_DEVICE_CONFIGURATION_ERROR.

Comments

The VCKernel.lib library calls a kernel-mode driver’s CaptureFunc function when the driver receives an IOCTL_VIDC_CAPTURE_ON or IOCTL_VIDC_CAPTURE_OFF control code. User-mode drivers using VCUser.lib send this control code by calling VC_Capture.

The driver might also call the CaptureFunc function itself, while transferring streams of captured data. The driver typically disables data acquisition between the time the frame buffer has been filled and the time the driver has finished copying its contents, and then re-enables it.

Support for a CaptureFunc function is required. The driver must place the address of its CaptureFunc function in the VC_CALLBACK structure supplied by VCKernel.lib. If the driver does not support the function, VCKernel.lib sets the Win32 error code value to STATUS_INVALID_DEVICE_REQUEST if the driver receives an IOCTL_VIDC_CAPTURE_ON or IOCTL_VIDC_CAPTURE_OFF control code.

If possible, the function should disable data acquisition in a manner that freezes the current overlay display.