CameraController

Added in 1.1.0

Kotlin |Java

public abstract class CameraController

Known direct subclasses

LifecycleCameraController

LifecycleCameraController

A controller that provides most of the CameraX features.

The abstract base camera controller class.

This a high level controller that provides most of the CameraX core features in a single class. It handles camera initialization, creates and configures UseCases. It also listens to device motion sensor and set the target rotation for the use cases.

The controller is required to be used with a PreviewView. PreviewView provides the UI elements to display camera preview. The layout of the PreviewView is used to set the crop rect so the output from other use cases matches the preview display in a WYSIWYG way. The controller also listens to PreviewView's touch events to handle tap-to-focus and pinch-to-zoom features.

This class provides features of 4 UseCases: Preview, ImageCapture, ImageAnalysis and VideoCapture. Preview is required and always enabled. ImageCapture and ImageAnalysis are enabled by default. The video capture is disabled by default because it might affect other use cases, especially on lower end devices. It might be necessary to disable ImageCapture and/or ImageAnalysis before the video capture feature can be enabled. Disabling/enabling UseCases freezes the preview for a short period of time. To avoid the glitch, the UseCases need to be enabled/disabled before the controller is set on PreviewView.

Summary

Nested types
`public final class CameraController.OutputSize` This class is deprecated. Use `ResolutionSelector` instead.

Nested types

public final class CameraController.OutputSize

This class is deprecated.

Use ResolutionSelector instead.

Constants
`static final int`	`COORDINATE_SYSTEM_VIEW_REFERENCED = 1` This field is deprecated. Use `COORDINATE_SYSTEM_VIEW_REFERENCED` instead.
`static final int`	`IMAGE_ANALYSIS = 2` Bitmask option to enable `ImageAnalysis`.
`static final int`	`IMAGE_CAPTURE = 1` Bitmask option to enable `ImageCapture`.
`static final int`	`TAP_TO_FOCUS_FAILED = 4` The previous tap-to-focus action was failed to complete.
`static final int`	`TAP_TO_FOCUS_FOCUSED = 2` The previous tap-to-focus action was completed successfully and the camera is focused.
`static final int`	`TAP_TO_FOCUS_NOT_FOCUSED = 3` The previous tap-to-focus action was completed successfully but the camera is still unfocused, similar to the `CONTROL_AF_STATE_NOT_FOCUSED_LOCKED` state.
`static final int`	`TAP_TO_FOCUS_NOT_STARTED = 0` No tap-to-focus action has been started by the end user.
`static final int`	`TAP_TO_FOCUS_STARTED = 1` A tap-to-focus action has started but not completed.
`static final int`	`VIDEO_CAPTURE = 4` Bitmask option to enable video capture use case.

Public methods
`void`	`@MainThread clearEffects()` Removes all effects.
`void`	`@MainThread clearImageAnalysisAnalyzer()` Removes a previously set analyzer.
`@NonNull ListenableFuture<Void>`	`@MainThread enableTorch(boolean torchEnabled)` Enable the torch or disable the torch.
`@Nullable CameraControl`	`@MainThread getCameraControl()` Gets the `CameraControl` of the currently attached camera.
`@Nullable CameraInfo`	`@MainThread getCameraInfo()` Gets the `CameraInfo` of the currently attached camera.
`@NonNull CameraSelector`	`@MainThread getCameraSelector()` Gets the `CameraSelector`.
`@Nullable Executor`	`@MainThread getImageAnalysisBackgroundExecutor()` Gets the default executor for `ImageAnalysis` background tasks.
`int`	`@MainThread getImageAnalysisBackpressureStrategy()` Returns the mode with which images are acquired.
`int`	`@MainThread getImageAnalysisImageQueueDepth()` Gets the image queue depth of `ImageAnalysis`.
`int`	`@MainThread getImageAnalysisOutputImageFormat()` Gets the output image format for `ImageAnalysis`.
`@Nullable ResolutionSelector`	`@MainThread getImageAnalysisResolutionSelector()` Returns the `ResolutionSelector` for `ImageAnalysis`.
`@Nullable CameraController.OutputSize`	`@MainThread getImageAnalysisTargetSize()` This method is deprecated. Use `getImageAnalysisResolutionSelector` instead.
`int`	`@MainThread getImageCaptureFlashMode()` Gets the flash mode for `ImageCapture`.
`@Nullable Executor`	`@MainThread getImageCaptureIoExecutor()` Gets the default executor for `ImageCapture` IO tasks.
`int`	`@MainThread getImageCaptureMode()` Returns the image capture mode.
`@Nullable ResolutionSelector`	`@MainThread getImageCaptureResolutionSelector()` Returns the `ResolutionSelector` for `ImageCapture`.
`@Nullable CameraController.OutputSize`	`@MainThread getImageCaptureTargetSize()` This method is deprecated. Use `getImageCaptureResolutionSelector` instead.
`@NonNull ListenableFuture<Void>`	`getInitializationFuture()` Gets a `ListenableFuture` that completes when camera initialization completes.
`@Nullable ResolutionSelector`	`@MainThread getPreviewResolutionSelector()` Returns the `ResolutionSelector` for `Preview`.
`@Nullable CameraController.OutputSize`	`@MainThread getPreviewTargetSize()` This method is deprecated. Use `getPreviewResolutionSelector` instead.
`@NonNull LiveData<TapToFocusInfo>`	`@MainThread getTapToFocusInfoState()` Returns a `LiveData` with a `TapToFocusInfo` containing the latest focus state and corresponding tap position.
`@NonNull LiveData<Integer>`	`@MainThread getTapToFocusState()` This method is deprecated. Use `getTapToFocusInfoState` instead.
`@NonNull LiveData<Integer>`	`@MainThread getTorchState()` Returns a `LiveData` of current `TorchState`.
`@NonNull DynamicRange`	`@MainThread getVideoCaptureDynamicRange()` Gets the `DynamicRange` for video capture.
`int`	`@MainThread getVideoCaptureMirrorMode()` Gets the mirror mode for video capture.
`@NonNull QualitySelector`	`@MainThread getVideoCaptureQualitySelector()` Returns the `QualitySelector` for `VIDEO_CAPTURE`.
`@NonNull Range<Integer>`	`@MainThread getVideoCaptureTargetFrameRate()` Gets the target frame rate in frames per second for video capture.
`@NonNull LiveData<ZoomState>`	`@MainThread getZoomState()` Returns a `LiveData` of `ZoomState`.
`boolean`	`@MainThread hasCamera(@NonNull CameraSelector cameraSelector)` Checks if the given `CameraSelector` can be resolved to a camera.
`boolean`	`@MainThread isImageAnalysisEnabled()` Checks if `ImageAnalysis` is enabled.
`boolean`	`@MainThread isImageCaptureEnabled()` Checks if `ImageCapture` is enabled.
`boolean`	`@MainThread isPinchToZoomEnabled()` Returns whether pinch-to-zoom is enabled.
`boolean`	`@MainThread isRecording()` Returns whether there is an in-progress video recording.
`boolean`	`@MainThread isTapToFocusEnabled()` Returns whether tap-to-focus is enabled.
`boolean`	`@MainThread isVideoCaptureEnabled()` Checks if video capture is enabled.
`void`	`@MainThread setCameraSelector(@NonNull CameraSelector cameraSelector)` Sets the `CameraSelector`.
`void`	`@MainThread setEffects(@NonNull Set<CameraEffect> effects)` Sets `CameraEffect`.
`void`	`@MainThread setEnabledUseCases(int enabledUseCases)` Enables or disables use cases.
`void`	`@MainThread setImageAnalysisAnalyzer( @NonNull Executor executor, @NonNull ImageAnalysis.Analyzer analyzer )` Sets an analyzer to receive and analyze images.
`void`	`@MainThread setImageAnalysisBackgroundExecutor(@Nullable Executor executor)` Sets the executor that will be used for `ImageAnalysis` background tasks.
`void`	`@MainThread setImageAnalysisBackpressureStrategy(int strategy)` Sets the backpressure strategy to apply to the image producer to deal with scenarios where images may be produced faster than they can be analyzed.
`void`	`@MainThread setImageAnalysisImageQueueDepth(int depth)` Sets the image queue depth of `ImageAnalysis`.
`void`	`@MainThread setImageAnalysisOutputImageFormat(int imageAnalysisOutputImageFormat)` Sets the output image format for `ImageAnalysis`.
`void`	`@MainThread setImageAnalysisResolutionSelector( @Nullable ResolutionSelector resolutionSelector )` Sets the `ResolutionSelector` for `ImageAnalysis`.
`void`	`@MainThread setImageAnalysisTargetSize( @Nullable CameraController.OutputSize targetSize )` This method is deprecated. Use `setImageAnalysisResolutionSelector` instead.
`void`	`@MainThread setImageCaptureFlashMode(int flashMode)` Sets the flash mode for `ImageCapture`.
`void`	`@MainThread setImageCaptureIoExecutor(@Nullable Executor executor)` Sets the default executor that will be used for `ImageCapture` IO tasks.
`void`	`@MainThread setImageCaptureMode(int captureMode)` Sets the image capture mode.
`void`	`@MainThread setImageCaptureResolutionSelector( @Nullable ResolutionSelector resolutionSelector )` Sets the `ResolutionSelector` for `ImageCapture`.
`void`	`@MainThread setImageCaptureTargetSize( @Nullable CameraController.OutputSize targetSize )` This method is deprecated. Use `setImageCaptureResolutionSelector` instead.
`@NonNull ListenableFuture<Void>`	`@MainThread setLinearZoom(@FloatRange(from = 0.0, to = 1.0) float linearZoom)` Sets current zoom by a linear zoom value ranging from 0f to 1.0f.
`void`	`@MainThread setPinchToZoomEnabled(boolean enabled)` Enables/disables pinch-to-zoom.
`void`	`@MainThread setPreviewResolutionSelector( @Nullable ResolutionSelector resolutionSelector )` Sets the `ResolutionSelector` for `Preview`.
`void`	`@MainThread setPreviewTargetSize(@Nullable CameraController.OutputSize targetSize)` This method is deprecated. Use `setPreviewResolutionSelector` instead.
`void`	`@MainThread setTapToFocusAutoCancelDuration( @IntRange(from = 0) long duration, @NonNull TimeUnit timeUnit )` Sets the auto-cancel duration for tap-to-focus events.
`void`	`@MainThread setTapToFocusEnabled(boolean enabled)` Enables/disables tap-to-focus.
`void`	`@MainThread setVideoCaptureDynamicRange(@NonNull DynamicRange dynamicRange)` Sets the `DynamicRange` for video capture.
`void`	`@MainThread setVideoCaptureMirrorMode(int mirrorMode)` Sets the mirror mode for video capture.
`void`	`@MainThread setVideoCaptureQualitySelector(@NonNull QualitySelector qualitySelector)` Sets the `QualitySelector` for `VIDEO_CAPTURE`.
`void`	`@MainThread setVideoCaptureTargetFrameRate(@NonNull Range<Integer> targetFrameRate)` Sets the target frame rate range in frames per second for video capture.
`@NonNull ListenableFuture<Void>`	`@MainThread setZoomRatio(float zoomRatio)` Sets current zoom by ratio.
`@NonNull Recording`	`@RequiresApi(value = 26) @MainThread startRecording( @NonNull FileDescriptorOutputOptions outputOptions, @NonNull AudioConfig audioConfig, @NonNull Executor executor, @NonNull Consumer<VideoRecordEvent> listener )` Takes a video to a given file descriptor.
`@NonNull Recording`	`@MainThread startRecording( @NonNull FileOutputOptions outputOptions, @NonNull AudioConfig audioConfig, @NonNull Executor executor, @NonNull Consumer<VideoRecordEvent> listener )` Takes a video to a given file.
`@NonNull Recording`	`@MainThread startRecording( @NonNull MediaStoreOutputOptions outputOptions, @NonNull AudioConfig audioConfig, @NonNull Executor executor, @NonNull Consumer<VideoRecordEvent> listener )` Takes a video to MediaStore.
`void`	`@MainThread takePicture( @NonNull Executor executor, @NonNull ImageCapture.OnImageCapturedCallback callback )` Captures a new still image for in memory access.
`void`	`@MainThread takePicture( @NonNull ImageCapture.OutputFileOptions outputFileOptions, @NonNull Executor executor, @NonNull ImageCapture.OnImageSavedCallback imageSavedCallback )` Captures a new still image and saves to a file along with application specified metadata.

Constants

COORDINATE_SYSTEM_VIEW_REFERENCED

Added in 1.1.0

Deprecated in 1.4.0

public static final int COORDINATE_SYSTEM_VIEW_REFERENCED = 1

ImageAnalysis.Analyzer option for returning PreviewView coordinates.

When the ImageAnalysis.Analyzer is configured with this option, it will receive a Matrix that will receive a value that represents the transformation from camera sensor to the PreviewView, which can be used for highlighting detected result in PreviewView. For example, laying over a bounding box on top of the detected face.

Note this option only works if the ImageAnalysis.Analyzer is set via setImageAnalysisAnalyzer. It will not be effective when used with camera-core directly.

See also
`ImageAnalysis.Analyzer`

IMAGE_ANALYSIS

Added in 1.1.0

public static final int IMAGE_ANALYSIS = 2

Bitmask option to enable ImageAnalysis. In setEnabledUseCases, if (enabledUseCases & IMAGE_ANALYSIS) != 0, then controller will enable image analysis features.

IMAGE_CAPTURE

Added in 1.1.0

public static final int IMAGE_CAPTURE = 1

Bitmask option to enable ImageCapture. In setEnabledUseCases, if (enabledUseCases & IMAGE_CAPTURE) != 0, then controller will enable image capture features.

TAP_TO_FOCUS_FAILED

Added in 1.1.0

public static final int TAP_TO_FOCUS_FAILED = 4

The previous tap-to-focus action was failed to complete. This is usually due to device limitations.

TAP_TO_FOCUS_FOCUSED

Added in 1.1.0

public static final int TAP_TO_FOCUS_FOCUSED = 2

The previous tap-to-focus action was completed successfully and the camera is focused.

TAP_TO_FOCUS_NOT_FOCUSED

Added in 1.1.0

public static final int TAP_TO_FOCUS_NOT_FOCUSED = 3

The previous tap-to-focus action was completed successfully but the camera is still unfocused, similar to the CONTROL_AF_STATE_NOT_FOCUSED_LOCKED state. The end user might be able to get a better result by trying again with different camera distances and/or lighting.

TAP_TO_FOCUS_NOT_STARTED

Added in 1.1.0

public static final int TAP_TO_FOCUS_NOT_STARTED = 0

No tap-to-focus action has been started by the end user.

TAP_TO_FOCUS_STARTED

Added in 1.1.0

public static final int TAP_TO_FOCUS_STARTED = 1

A tap-to-focus action has started but not completed. The app also gets notified with this state if a new action happens before the previous one could finish.

VIDEO_CAPTURE

Added in 1.1.0

public static final int VIDEO_CAPTURE = 4

Bitmask option to enable video capture use case. In setEnabledUseCases, if (enabledUseCases & VIDEO_CAPTURE) != 0, then controller will enable video capture features.

Public methods

clearEffects

Added in 1.3.0

@MainThread
public void clearEffects()

Removes all effects.

Once called, CameraX will remove all the effects and rebind the UseCase.

clearImageAnalysisAnalyzer

Added in 1.1.0

@MainThread
public void clearImageAnalysisAnalyzer()

Removes a previously set analyzer.

This will stop data from streaming to the ImageAnalysis.

If the current getDefaultTargetResolution returns non-null value, calling this method will reconfigure the camera which might cause additional latency. To avoid this, call this method when the lifecycle is not active.

See also
`clearAnalyzer`

enableTorch

Added in 1.1.0

@MainThread
public @NonNull ListenableFuture<Void> enableTorch(boolean torchEnabled)

Enable the torch or disable the torch.

If the value is set before the camera is ready, CameraController waits for the camera to be ready and then enables the torch.

Parameters
`boolean torchEnabled`	`true` to turn on the torch, `false` to turn it off.

Returns
`@NonNull ListenableFuture<Void>`	A `ListenableFuture` which is successful when the torch was changed to the value specified. It fails when it is unable to change the torch state. Cancellation of this future is a no-op.

See also
`enableTorch`

getCameraControl

Added in 1.1.0

@MainThread
public @Nullable CameraControl getCameraControl()

Gets the CameraControl of the currently attached camera.

For controls available directly through CameraController as well as CameraControl, it's recommended to use the ones with CameraController, e.g. setLinearZoom v.s. setLinearZoom. CameraControl is a lower-layer API and may require more steps to achieve the same effect, and will not maintain control values when switching between cameras.

Returns
`@Nullable CameraControl`	The `CameraControl` of the current camera. Returns `null` if camera is not ready.

See also
`getCameraControl`

getCameraInfo

Added in 1.1.0

@MainThread
public @Nullable CameraInfo getCameraInfo()

Gets the CameraInfo of the currently attached camera.

For info available directly through CameraController as well as CameraInfo, it's recommended to use the ones with CameraController, e.g. getTorchState v.s. getTorchState. CameraInfo is a lower-layer API and may require more steps to achieve the same effect, and will not maintain values when switching between cameras.

Returns
`@Nullable CameraInfo`	The `CameraInfo` of the current camera. Returns `null` if camera is not ready.

See also
`getCameraInfo`

getCameraSelector

Added in 1.1.0

@MainThread
public @NonNull CameraSelector getCameraSelector()

Gets the CameraSelector.

The default value isDEFAULT_BACK_CAMERA.

See also
`CameraSelector`

CameraController

Summary

Nested types

Constants

Public methods

Constants

COORDINATE_SYSTEM_VIEW_REFERENCED

IMAGE_ANALYSIS

IMAGE_CAPTURE

TAP_TO_FOCUS_FAILED

TAP_TO_FOCUS_FOCUSED

TAP_TO_FOCUS_NOT_FOCUSED

TAP_TO_FOCUS_NOT_STARTED

TAP_TO_FOCUS_STARTED

VIDEO_CAPTURE

Public methods

clearEffects

clearImageAnalysisAnalyzer

enableTorch

getCameraControl

getCameraInfo

getCameraSelector

getImageAnalysisBackgroundExecutor