PCAM_START_CAPTURE_ROUTINE callback function (usbcamdi.h)

Article
02/22/2024

[CamStartCapture is not supported and may be altered or unavailable in the future. Instead, use CamStartCaptureEx. ]

A camera minidriver's CamStartCapture callback function selects the appropriate alternate setting within the USB video streaming interface and prepares the device to stream.

Syntax

PCAM_START_CAPTURE_ROUTINE PcamStartCaptureRoutine;

NTSTATUS PcamStartCaptureRoutine(
  PDEVICE_OBJECT BusDeviceObject,
  PVOID DeviceContext
)
{...}

Parameters

BusDeviceObject

Pointer to camera minidriver's device object created by the USB hub.

DeviceContext

Pointer to camera minidriver's device context.

Return value

CamStartCapture returns STATUS_SUCCESS or an appropriate error code. This return value is the completion code for the read IRP.

Remarks

Camera minidrivers that must maintain backward compatibility with the original USBCAMD must use the USBCAMD_DEVICE_DATA structure and its associated callback functions (that is, callback functions that do not contain the "Ex" suffix).

USBCAMD calls the camera minidriver's CamStartCapture callback function immediately prior to the start of the isochronous video capture stream. CamStartCapture is called in the context of a Run command.

This function is required.

Requirements

Requirement	Value
Target Platform	Desktop
Header	usbcamdi.h (include Usbcamdi.h)