PCAM_FREE_BW_ROUTINE_EX callback function (usbcamdi.h)
A camera minidriver's CamFreeBandwidthEx callback function selects an alternate setting within the USB video streaming interface that uses no bandwidth.
Syntax
PCAM_FREE_BW_ROUTINE_EX PcamFreeBwRoutineEx;
NTSTATUS PcamFreeBwRoutineEx(
PDEVICE_OBJECT BusDeviceObject,
PVOID DeviceContext,
ULONG STreamNumber
)
{...}
Parameters
BusDeviceObject
Pointer to the camera minidriver's device object created by the USB hub.
DeviceContext
Pointer to the camera minidriver's device context.
STreamNumber
Indicates stream number.
Return value
CamFreeBandwidthEx returns STATUS_SUCCESS or an appropriate error code.
Remarks
USBCAMD calls the camera minidriver's CamFreeBandwidthEx callback function after the isochronous video stream has stopped.
Typically, this function calls the USBCAMD_SelectAlternateInterface service to select the correct alternate interface and prepare for streaming video.
The original USBCAMD does not call CamFreeBandwidthEx.
This function is required.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Desktop |
| Header | usbcamdi.h (include Usbcamdi.h) |