Camera

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

Unspecified camera error.

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.

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().

This method is only necessary when setPreviewCallbackWithBuffer(PreviewCallback) is used. When setPreviewCallback(PreviewCallback) or setOneShotPreviewCallback(PreviewCallback) are used, buffers are automatically allocated.

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.

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.

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

Returns the number of physical cameras available on this device.

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.

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.

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

Creates a new Camera object to access a particular hardware camera.

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.

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.

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.

This must be done after MediaRecorder is done recording if setCamera(Camera) was used.

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

Disconnects and releases the Camera object resources.

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

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);
 }
 

Registers a callback to be invoked when an error occurs.

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.

Changes the settings for this Camera service.

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.

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.

Sets the Surface to be used for live preview. A surface is necessary for preview, and preview is necessary to take pictures. The same surface can be re-set without harm.

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.

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

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

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

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.

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

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.

Equivalent to takePicture(shutter, raw, null, 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 may be null if the hardware does not have enough memory to make a copy). 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.

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

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).

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

Called before the object's memory is reclaimed by the VM. This can only happen once the garbage collector has detected that the object is no longer reachable by any thread of the running application.

The method can be used to free system resources or perform other cleanup before the object is garbage collected. The default implementation of the method is empty, which is also expected by the VM, but subclasses can override finalize() as required. Uncaught exceptions which are thrown during the execution of this method cause it to terminate immediately but are otherwise ignored.

Note that the VM does guarantee that finalize() is called at most once for any object, but it doesn't guarantee when (if at all) finalize() will be called. For example, object B's finalize() can delay the execution of object A's finalize() method and therefore it can delay the reclamation of A's memory. To be safe, use a ReferenceQueue, because it provides more control over the way the VM deals with references during garbage collection.