Camera

ACTION_NEW_PICTURE

String ACTION_NEW_PICTURE

This constant was deprecated in API level 24.
This broadcast is no longer delivered by the system; use JobInfo.Builder.addTriggerContentUri(JobInfo.TriggerContentUri) instead. Broadcast Action: A new picture is taken by the camera, and the entry of the picture has been added to the media store. getData() is URI of the picture.

Constant Value: "android.hardware.action.NEW_PICTURE"

ACTION_NEW_VIDEO

String ACTION_NEW_VIDEO

This constant was deprecated in API level 24.
This broadcast is no longer delivered by the system; use JobInfo.Builder.addTriggerContentUri(JobInfo.TriggerContentUri) instead. Broadcast Action: A new video is recorded by the camera, and the entry of the video has been added to the media store. getData() is URI of the video.

Constant Value: "android.hardware.action.NEW_VIDEO"

CAMERA_ERROR_EVICTED

int CAMERA_ERROR_EVICTED

Camera was disconnected due to use by higher priority user.

Constant Value: 2 (0x00000002)

CAMERA_ERROR_SERVER_DIED

int CAMERA_ERROR_SERVER_DIED

Media server died. In this case, the application must release the Camera object and instantiate a new one.

Constant Value: 100 (0x00000064)

CAMERA_ERROR_UNKNOWN

int CAMERA_ERROR_UNKNOWN

Unspecified camera error.

Constant Value: 1 (0x00000001)

addCallbackBuffer

void addCallbackBuffer (byte[] callbackBuffer)

Adds a pre-allocated buffer to the preview callback buffer queue. Applications can add one or more buffers to the queue. When a preview frame arrives and there is still at least one available buffer, the buffer will be used and removed from the queue. Then preview callback is invoked with the buffer. If a frame arrives and there is no buffer left, the frame is discarded. Applications should add buffers back when they finish processing the data in them.

For formats besides YV12, the size of the buffer is determined by multiplying the preview image width, height, and bytes per pixel. The width and height can be read from getPreviewSize(). Bytes per pixel can be computed from getBitsPerPixel(int) / 8, using the image format from getPreviewFormat().

If using the YV12 format, the size can be calculated using the equations listed in setPreviewFormat(int).

This method is only necessary when setPreviewCallbackWithBuffer(PreviewCallback) is used. When setPreviewCallback(PreviewCallback) or setOneShotPreviewCallback(PreviewCallback) are used, buffers are automatically allocated. When a supplied buffer is too small to hold the preview frame data, preview callback will return null and the buffer will be removed from the buffer queue.

autoFocus

void autoFocus (Camera.AutoFocusCallback cb)

Starts camera auto-focus and registers a callback function to run when the camera is focused. This method is only valid when preview is active (between startPreview() and before stopPreview()).

Callers should check getFocusMode() to determine if this method should be called. If the camera does not support auto-focus, it is a no-op and onAutoFocus(boolean, Camera) callback will be called immediately.

If your application should not be installed on devices without auto-focus, you must declare that your application uses auto-focus with the <uses-feature> manifest element.

If the current flash mode is not FLASH_MODE_OFF, flash may be fired during auto-focus, depending on the driver and camera hardware.

Auto-exposure lock getAutoExposureLock() and auto-white balance locks getAutoWhiteBalanceLock() do not change during and after autofocus. But auto-focus routine may stop auto-exposure and auto-white balance transiently during focusing.

Stopping preview with stopPreview(), or triggering still image capture with takePicture(Camera.ShutterCallback, Camera.PictureCallback, Camera.PictureCallback), will not change the the focus position. Applications must call cancelAutoFocus to reset the focus.

If autofocus is successful, consider using MediaActionSound to properly play back an autofocus success sound to the user.

cancelAutoFocus

void cancelAutoFocus ()

Cancels any auto-focus function in progress. Whether or not auto-focus is currently in progress, this function will return the focus position to the default. If the camera does not support auto-focus, this is a no-op.

enableShutterSound

boolean enableShutterSound (boolean enabled)

Enable or disable the default shutter sound when taking a picture.

By default, the camera plays the system-defined camera shutter sound when takePicture(Camera.ShutterCallback, Camera.PictureCallback, Camera.PictureCallback) is called. Using this method, the shutter sound can be disabled. It is strongly recommended that an alternative shutter sound is played in the Camera.ShutterCallback when the system shutter sound is disabled.

Note that devices may not always allow disabling the camera shutter sound. If the shutter sound state cannot be set to the desired value, this method will return false. canDisableShutterSound can be used to determine whether the device will allow the shutter sound to be disabled.

getCameraInfo

void getCameraInfo (int cameraId, 
                Camera.CameraInfo cameraInfo)

Returns the information about a particular camera. If getNumberOfCameras() returns N, the valid id is 0 to N-1.

getNumberOfCameras

int getNumberOfCameras ()

Returns the number of physical cameras available on this device.

getParameters

Camera.Parameters getParameters ()

Returns the current settings for this Camera service. If modifications are made to the returned Parameters, they must be passed to setParameters(Camera.Parameters) to take effect.

lock

void lock ()

Re-locks the camera to prevent other processes from accessing it. Camera objects are locked by default unless unlock() is called. Normally reconnect() is used instead.

Since API level 14, camera is automatically locked for applications in start(). Applications can use the camera (ex: zoom) after recording starts. There is no need to call this after recording starts or stops.

If you are not recording video, you probably do not need this method.

open

Camera open ()

Creates a new Camera object to access the first back-facing camera on the device. If the device does not have a back-facing camera, this returns null.

open

Camera open (int cameraId)

Creates a new Camera object to access a particular hardware camera. If the same camera is opened by other applications, this will throw a RuntimeException.

You must call release() when you are done using the camera, otherwise it will remain locked and be unavailable to other applications.

Your application should only have one Camera object active at a time for a particular hardware camera.

Callbacks from other methods are delivered to the event loop of the thread which called open(). If this thread has no event loop, then callbacks are delivered to the main application event loop. If there is no main application event loop, callbacks are not delivered.

Caution: On some devices, this method may take a long time to complete. It is best to call this method from a worker thread (possibly using AsyncTask) to avoid blocking the main application UI thread.

reconnect

void reconnect ()

Reconnects to the camera service after another process used it. After unlock() is called, another process may use the camera; when the process is done, you must reconnect to the camera, which will re-acquire the lock and allow you to continue using the camera.

Since API level 14, camera is automatically locked for applications in start(). Applications can use the camera (ex: zoom) after recording starts. There is no need to call this after recording starts or stops.

If you are not recording video, you probably do not need this method.

release

void release ()

Disconnects and releases the Camera object resources.

You must call this as soon as you're done with the Camera object.

setAutoFocusMoveCallback

void setAutoFocusMoveCallback (Camera.AutoFocusMoveCallback cb)

Sets camera auto-focus move callback.

setDisplayOrientation

void setDisplayOrientation (int degrees)

Set the clockwise rotation of preview display in degrees. This affects the preview frames and the picture displayed after snapshot. This method is useful for portrait mode applications. Note that preview display of front-facing cameras is flipped horizontally before the rotation, that is, the image is reflected along the central vertical axis of the camera sensor. So the users can see themselves as looking into a mirror.

This does not affect the order of byte array passed in onPreviewFrame(byte[], Camera), JPEG pictures, or recorded videos. This method is not allowed to be called during preview.

If you want to make the camera image show in the same orientation as the display, you can use the following code.

 public static void setCameraDisplayOrientation(Activity activity,
         int cameraId, android.hardware.Camera camera) {
     android.hardware.Camera.CameraInfo info =
             new android.hardware.Camera.CameraInfo();
     android.hardware.Camera.getCameraInfo(cameraId, info);
     int rotation = activity.getWindowManager().getDefaultDisplay()
             .getRotation();
     int degrees = 0;
     switch (rotation) {
         case Surface.ROTATION_0: degrees = 0; break;
         case Surface.ROTATION_90: degrees = 90; break;
         case Surface.ROTATION_180: degrees = 180; break;
         case Surface.ROTATION_270: degrees = 270; break;
     }

     int result;
     if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
         result = (info.orientation + degrees) % 360;
         result = (360 - result) % 360;  // compensate the mirror
     } else {  // back-facing
         result = (info.orientation - degrees + 360) % 360;
     }
     camera.setDisplayOrientation(result);
 }
 

Starting from API level 14, this method can be called when preview is active.

Note: Before API level 24, the default value for orientation is 0. Starting in API level 24, the default orientation will be such that applications in forced-landscape mode will have correct preview orientation, which may be either a default of 0 or 180. Applications that operate in portrait mode or allow for changing orientation must still call this method after each orientation change to ensure correct preview display in all cases.

setErrorCallback

void setErrorCallback (Camera.ErrorCallback cb)

Registers a callback to be invoked when an error occurs.

setFaceDetectionListener

void setFaceDetectionListener (Camera.FaceDetectionListener listener)

Registers a listener to be notified about the faces detected in the preview frame.

setOneShotPreviewCallback

void setOneShotPreviewCallback (Camera.PreviewCallback cb)

Installs a callback to be invoked for the next preview frame in addition to displaying it on the screen. After one invocation, the callback is cleared. This method can be called any time, even when preview is live. Any other preview callbacks are overridden.

If you are using the preview data to create video or still images, strongly consider using MediaActionSound to properly indicate image capture or recording start/stop to the user.

setParameters

void setParameters (Camera.Parameters params)

Changes the settings for this Camera service.

setPreviewCallback

void setPreviewCallback (Camera.PreviewCallback cb)

Installs a callback to be invoked for every preview frame in addition to displaying them on the screen. The callback will be repeatedly called for as long as preview is active. This method can be called at any time, even while preview is live. Any other preview callbacks are overridden.

If you are using the preview data to create video or still images, strongly consider using MediaActionSound to properly indicate image capture or recording start/stop to the user.

setPreviewCallbackWithBuffer

void setPreviewCallbackWithBuffer (Camera.PreviewCallback cb)

Installs a callback to be invoked for every preview frame, using buffers supplied with addCallbackBuffer(byte[]), in addition to displaying them on the screen. The callback will be repeatedly called for as long as preview is active and buffers are available. Any other preview callbacks are overridden.

The purpose of this method is to improve preview efficiency and frame rate by allowing preview frame memory reuse. You must call addCallbackBuffer(byte[]) at some point -- before or after calling this method -- or no callbacks will received.

The buffer queue will be cleared if this method is called with a null callback, setPreviewCallback(Camera.PreviewCallback) is called, or setOneShotPreviewCallback(Camera.PreviewCallback) is called.

If you are using the preview data to create video or still images, strongly consider using MediaActionSound to properly indicate image capture or recording start/stop to the user.

setPreviewDisplay

void setPreviewDisplay (SurfaceHolder holder)

Sets the Surface to be used for live preview. Either a surface or surface texture is necessary for preview, and preview is necessary to take pictures. The same surface can be re-set without harm. Setting a preview surface will un-set any preview surface texture that was set via setPreviewTexture(SurfaceTexture).

The SurfaceHolder must already contain a surface when this method is called. If you are using SurfaceView, you will need to register a SurfaceHolder.Callback with addCallback(SurfaceHolder.Callback) and wait for surfaceCreated(SurfaceHolder) before calling setPreviewDisplay() or starting preview.

This method must be called before startPreview(). The one exception is that if the preview surface is not set (or set to null) before startPreview() is called, then this method may be called once with a non-null parameter to set the preview surface. (This allows camera setup and surface creation to happen in parallel, saving time.) The preview surface may not otherwise change while preview is running.

setPreviewTexture

void setPreviewTexture (SurfaceTexture surfaceTexture)

Sets the SurfaceTexture to be used for live preview. Either a surface or surface texture is necessary for preview, and preview is necessary to take pictures. The same surface texture can be re-set without harm. Setting a preview surface texture will un-set any preview surface that was set via setPreviewDisplay(SurfaceHolder).

This method must be called before startPreview(). The one exception is that if the preview surface texture is not set (or set to null) before startPreview() is called, then this method may be called once with a non-null parameter to set the preview surface. (This allows camera setup and surface creation to happen in parallel, saving time.) The preview surface texture may not otherwise change while preview is running.

The timestamps provided by getTimestamp() for a SurfaceTexture set as the preview texture have an unspecified zero point, and cannot be directly compared between different cameras or different instances of the same camera, or across multiple runs of the same program.

If you are using the preview data to create video or still images, strongly consider using MediaActionSound to properly indicate image capture or recording start/stop to the user.

setZoomChangeListener

void setZoomChangeListener (Camera.OnZoomChangeListener listener)

Registers a listener to be notified when the zoom value is updated by the camera driver during smooth zoom.

startFaceDetection

void startFaceDetection ()

Starts the face detection. This should be called after preview is started. The camera will notify Camera.FaceDetectionListener of the detected faces in the preview frame. The detected faces may be the same as the previous ones. Applications should call stopFaceDetection() to stop the face detection. This method is supported if getMaxNumDetectedFaces() returns a number larger than 0. If the face detection has started, apps should not call this again.

When the face detection is running, setWhiteBalance(String), setFocusAreas(List), and setMeteringAreas(List) have no effect. The camera uses the detected faces to do auto-white balance, auto exposure, and autofocus.

If the apps call autoFocus(AutoFocusCallback), the camera will stop sending face callbacks. The last face callback indicates the areas used to do autofocus. After focus completes, face detection will resume sending face callbacks. If the apps call cancelAutoFocus(), the face callbacks will also resume.

After calling takePicture(Camera.ShutterCallback, Camera.PictureCallback, Camera.PictureCallback) or stopPreview(), and then resuming preview with startPreview(), the apps should call this method again to resume face detection.

startPreview

void startPreview ()

Starts capturing and drawing preview frames to the screen. Preview will not actually start until a surface is supplied with setPreviewDisplay(SurfaceHolder) or setPreviewTexture(SurfaceTexture).

If setPreviewCallback(Camera.PreviewCallback), setOneShotPreviewCallback(Camera.PreviewCallback), or setPreviewCallbackWithBuffer(Camera.PreviewCallback) were called, onPreviewFrame(byte[], Camera) will be called when preview data becomes available.

startSmoothZoom

void startSmoothZoom (int value)

Zooms to the requested value smoothly. The driver will notify Camera.OnZoomChangeListener of the zoom value and whether zoom is stopped at the time. For example, suppose the current zoom is 0 and startSmoothZoom is called with value 3. The onZoomChange(int, boolean, Camera) method will be called three times with zoom values 1, 2, and 3. Applications can call stopSmoothZoom() to stop the zoom earlier. Applications should not call startSmoothZoom again or change the zoom value before zoom stops. If the supplied zoom value equals to the current zoom value, no zoom callback will be generated. This method is supported if isSmoothZoomSupported() returns true.

stopFaceDetection

void stopFaceDetection ()

Stops the face detection.

stopPreview

void stopPreview ()

Stops capturing and drawing preview frames to the surface, and resets the camera for a future call to startPreview().

stopSmoothZoom

void stopSmoothZoom ()

Stops the smooth zoom. Applications should wait for the Camera.OnZoomChangeListener to know when the zoom is actually stopped. This method is supported if isSmoothZoomSupported() is true.

takePicture

void takePicture (Camera.ShutterCallback shutter, 
                Camera.PictureCallback raw, 
                Camera.PictureCallback postview, 
                Camera.PictureCallback jpeg)

Triggers an asynchronous image capture. The camera service will initiate a series of callbacks to the application as the image capture progresses. The shutter callback occurs after the image is captured. This can be used to trigger a sound to let the user know that image has been captured. The raw callback occurs when the raw image data is available (NOTE: the data will be null if there is no raw image callback buffer available or the raw image callback buffer is not large enough to hold the raw image). The postview callback occurs when a scaled, fully processed postview image is available (NOTE: not all hardware supports this). The jpeg callback occurs when the compressed image is available. If the application does not need a particular callback, a null can be passed instead of a callback method.

This method is only valid when preview is active (after startPreview()). Preview will be stopped after the image is taken; callers must call startPreview() again if they want to re-start preview or take more pictures. This should not be called between start() and stop().

After calling this method, you must not call startPreview() or take another picture until the JPEG callback has returned.

takePicture

void takePicture (Camera.ShutterCallback shutter, 
                Camera.PictureCallback raw, 
                Camera.PictureCallback jpeg)

Equivalent to takePicture(shutter, raw, null, jpeg).

unlock

void unlock ()

Unlocks the camera to allow another process to access it. Normally, the camera is locked to the process with an active Camera object until release() is called. To allow rapid handoff between processes, you can call this method to release the camera temporarily for another process to use; once the other process is done you can call reconnect() to reclaim the camera.

This must be done before calling setCamera(Camera). This cannot be called after recording starts.

If you are not recording video, you probably do not need this method.

finalize

void finalize ()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. A subclass overrides the finalize method to dispose of system resources or to perform other cleanup.

The general contract of finalize is that it is invoked if and when the Java^TM virtual machine has determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, except as a result of an action taken by the finalization of some other object or class which is ready to be finalized. The finalize method may take any action, including making this object available again to other threads; the usual purpose of finalize, however, is to perform cleanup actions before the object is irrevocably discarded. For example, the finalize method for an object that represents an input/output connection might perform explicit I/O transactions to break the connection before the object is permanently discarded.

The finalize method of class Object performs no special action; it simply returns normally. Subclasses of Object may override this definition.

The Java programming language does not guarantee which thread will invoke the finalize method for any given object. It is guaranteed, however, that the thread that invokes finalize will not be holding any user-visible synchronization locks when finalize is invoked. If an uncaught exception is thrown by the finalize method, the exception is ignored and finalization of that object terminates.

After the finalize method has been invoked for an object, no further action is taken until the Java virtual machine has again determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, including possible actions by other objects or classes which are ready to be finalized, at which point the object may be discarded.

The finalize method is never invoked more than once by a Java virtual machine for any given object.

Any exception thrown by the finalize method causes the finalization of this object to be halted, but is otherwise ignored.