ExternalCamera Class Reference

Public Member Functions
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	open ()=0
	Open the camera.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	close ()=0
	Close the camera.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	start (CameraMode cameraMode, CameraCallback *cb)=0
	Start the camera.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	stop ()=0
	Stop the camera.
virtual uint32_t VUFORIA_DRIVER_CALLING_CONVENTION	getNumSupportedCameraModes ()=0
	Get the number of supported camera modes.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	getSupportedCameraMode (uint32_t index, CameraMode *cameraMode)=0
	Get a camera mode from a certain index.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	supportsExposureMode (ExposureMode exposureMode)=0
	Check whether a particular exposure mode is supported.
virtual ExposureMode VUFORIA_DRIVER_CALLING_CONVENTION	getExposureMode ()=0
	Get current exposure mode.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	setExposureMode (ExposureMode exposureMode)=0
	Set the current exposure mode.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	supportsExposureValue ()=0
	Check whether setting the exposure manually is supported.
virtual uint64_t VUFORIA_DRIVER_CALLING_CONVENTION	getExposureValueMin ()=0
	Get the minimum supported value for manual exposure.
virtual uint64_t VUFORIA_DRIVER_CALLING_CONVENTION	getExposureValueMax ()=0
	Get the maximum supported value for manual exposure.
virtual uint64_t VUFORIA_DRIVER_CALLING_CONVENTION	getExposureValue ()=0
	Get the current manual exposure value.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	setExposureValue (uint64_t exposureTime)=0
	Set the current manual exposure value.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	supportsFocusMode (FocusMode focusMode)=0
	Check whether a particular focus mode is supported.
virtual FocusMode VUFORIA_DRIVER_CALLING_CONVENTION	getFocusMode ()=0
	Get the current focus mode.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	setFocusMode (FocusMode mode)=0
	Set the current focus mode.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	supportsFocusValue ()=0
	Get whether setting manual focus distance is supported.
virtual float VUFORIA_DRIVER_CALLING_CONVENTION	getFocusValueMin ()=0
	Get the minimum supported value for manual focus distance.
virtual float VUFORIA_DRIVER_CALLING_CONVENTION	getFocusValueMax ()=0
	Get the maximum supported value for manual focus distance.
virtual float VUFORIA_DRIVER_CALLING_CONVENTION	getFocusValue ()=0
	Get the current manual focus distance.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	setFocusValue (float focusValue)=0
	Set the current manual focus value.
virtual bool VUFORIA_DRIVER_CALLING_CONVENTION	processFramesOnThread ()
	Function called by Vuforia to determine whether it should create a separate thread to process frame data.

Detailed Description

Interface used by Vuforia to interact with the external camera implementation.

Note

The sequence of events between Vuforia and the external camera implementation is as follows:

1. Vuforia calls VuforiaDriver::createExternalCamera() when the driver capability includes CAMERA_IMAGE.
2. The implementation creates an ExternalCamera instance and returns it to Vuforia.
3. Vuforia calls ExternalCamera::open() on the returned instance.
4. Vuforia discovers supported camera modes by iterating them by getting the number of modes with ExternalCamera::getNumSupportedCameraModes() and then iterates over the list with ExternalCamera::getSupportedCameraMode().
5. Vuforia calls ExternalCamera::processFramesOnThread()
6. Vuforia calls ExternalCamera::start(), which starts the flow of frames into the provided CameraCallback.
7. On shutdown Vuforia calls -> ExternalCamera::stop() -> ExternalCamera::close() -> and finally VuforiaDriver::destroyExternalCamera().

Member Function Documentation

open()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION open ( )

pure virtual

Open the camera.

Note

After opening the camera, the supported video modes should be available to be queried with getNumSupportedCameraModes() and getSupportedCameraMode().

Returns

True if the camera was opened, false otherwise

close()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION close ( )

pure virtual

Close the camera.

Returns

True if the camera was closed, false otherwise

start()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION start ( CameraMode cameraMode, CameraCallback * cb )

pure virtual

Start the camera.

Parameters

cameraMode	The requested camera mode that the camera should deliver the frames in
cb	Callback that the camera frames should be delivered to

Returns

True if the camera was started, false otherwise

stop()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION stop ( )

pure virtual

Stop the camera.

Returns

True if the camera was stopped, false otherwise

getNumSupportedCameraModes()

virtual uint32_t VUFORIA_DRIVER_CALLING_CONVENTION getNumSupportedCameraModes ( )

pure virtual

Get the number of supported camera modes.

Note

This function returns the total number of supported camera modes. Vuforia uses this number to query the camera modes with getSupportedCameraMode(), which iterates from 0 to (totalNumber - 1).

Returns

Number of camera modes that this camera supports

getSupportedCameraMode()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION getSupportedCameraMode ( uint32_t index, CameraMode * cameraMode )

pure virtual

Get a camera mode from a certain index.

Parameters

index	The index of the mode to get, in the range [0 .. getNumSupportedCameraModes()-1]
cameraMode	On return, this output parameter will be populated with the camera mode corresponding to the requested index.

Returns

True on success, or false if the index was out of bounds

supportsExposureMode()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION supportsExposureMode ( ExposureMode exposureMode )

pure virtual

Check whether a particular exposure mode is supported.

Parameters

exposureMode

The exposure mode to check

Returns

True if the exposure mode is supported, false otherwise

getExposureMode()

virtual ExposureMode VUFORIA_DRIVER_CALLING_CONVENTION getExposureMode ( )

pure virtual

Get current exposure mode.

Returns

The current exposure mode

setExposureMode()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION setExposureMode ( ExposureMode exposureMode )

pure virtual

Set the current exposure mode.

Parameters

exposureMode

New exposure mode

Returns

True if setting the exposure mode succeeded, false otherwise

supportsExposureValue()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION supportsExposureValue ( )

pure virtual

Check whether setting the exposure manually is supported.

Returns

True if usage of setExposureValue() is supported, false otherwise

getExposureValueMin()

virtual uint64_t VUFORIA_DRIVER_CALLING_CONVENTION getExposureValueMin ( )

pure virtual

Get the minimum supported value for manual exposure.

Returns

The minimum value that can be provided for setExposureValue()

getExposureValueMax()

virtual uint64_t VUFORIA_DRIVER_CALLING_CONVENTION getExposureValueMax ( )

pure virtual

Get the maximum supported value for manual exposure.

Returns

The maximum value that can be provided for setExposureValue()

getExposureValue()

virtual uint64_t VUFORIA_DRIVER_CALLING_CONVENTION getExposureValue ( )

pure virtual

Get the current manual exposure value.

Returns

The current camera exposure value

setExposureValue()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION setExposureValue ( uint64_t exposureTime )

pure virtual

Set the current manual exposure value.

Parameters

exposureTime

New value for manual exposure

Note

To use this function, supportsExposureValue() must return true and the provided value must be in the range specified by getExposureValueMin() and getExposureValueMax() inclusive.

Returns

True if value was set successfully, false otherwise

supportsFocusMode()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION supportsFocusMode ( FocusMode focusMode )

pure virtual

Check whether a particular focus mode is supported.

Parameters

focusMode

The focus mode to check

Returns

True if the mode is supported, false otherwise

getFocusMode()

virtual FocusMode VUFORIA_DRIVER_CALLING_CONVENTION getFocusMode ( )

pure virtual

Get the current focus mode.

Returns

The current focus mode

setFocusMode()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION setFocusMode ( FocusMode mode )

pure virtual

Set the current focus mode.

Parameters

mode	The new focus mode

Returns

True if value was set successfully, false otherwise

supportsFocusValue()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION supportsFocusValue ( )

pure virtual

Get whether setting manual focus distance is supported.

Returns

True if usage of setFocusValue() is supported, false otherwise

getFocusValueMin()

virtual float VUFORIA_DRIVER_CALLING_CONVENTION getFocusValueMin ( )

pure virtual

Get the minimum supported value for manual focus distance.

Returns

The minimum value in millimeters that can be provided for setFocusValue()

getFocusValueMax()

virtual float VUFORIA_DRIVER_CALLING_CONVENTION getFocusValueMax ( )

pure virtual

Get the maximum supported value for manual focus distance.

Returns

The maximum value in millimeters that can be provided for setFocusValue()

getFocusValue()

virtual float VUFORIA_DRIVER_CALLING_CONVENTION getFocusValue ( )

pure virtual

Get the current manual focus distance.

Returns

Current manual focus value in millimeters

setFocusValue()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION setFocusValue ( float focusValue )

pure virtual

Set the current manual focus value.

Parameters

focusValue

The new value for manual focus distance in millimeters

Note

To use this supportsFocusValue() must return true and the provided value must be in the range specified by getFocusValueMin() and getFocusValueMax() inclusive.

Returns

True value was set successfully, false otherwise

processFramesOnThread()

virtual bool VUFORIA_DRIVER_CALLING_CONVENTION processFramesOnThread ( )

inlinevirtual

Function called by Vuforia to determine whether it should create a separate thread to process frame data.

Note

By default this method returns false and Vuforia will process the frame in the callback. Once the callback returns a new Vuforia state will be ready for the App to interrogate for results. If this method returns true Vuforia will create a separate thread to process the frame, during the callback Vuforia will just copy the provided data and queue it for processing on the thread.