Develop Reference

Camera live preview freezes on camera switch

I am creating a custom camera app. The problem I am facing is that the camera preview freezes when I switch between the front and the back camera. When starting the activity with either the front or back camera by calling
boolean opened = safeCameraOpenInView(view, Camera.CameraInfo.CAMERA_FACING_BACK)
in the OnCreateView method of the fragment, both cameras will display on startup as expected. As soon as I call the same method in the on click listener of my switch button, the camera freezes immediately.
This is a new implementation which I tried where all the code is within the same fragment instead of a custom class based on the question here: Custom class camera live preview freezes on camera switch yet the result is exactly the same. I am pretty sure I need to do something with the surface view to bind it to the new camera but I am at a loss of how to do this. Anybody have some pointers?
My activity:
public class Camera2ActivityFragment extends Fragment {
// Native camera.
private Camera mCamera;
// View to display the camera output.
private CameraPreview mPreview;
// Reference to the containing view.
private View mCameraView;
/**
* Default empty constructor.
*/
public Camera2ActivityFragment(){
super();
}
/**
* Static factory method
* #param sectionNumber
* #return
*/
public static Camera2ActivityFragment newInstance(int sectionNumber) {
Camera2ActivityFragment fragment = new Camera2ActivityFragment();
//Bundle args = new Bundle();
//args.putInt(ARG_SECTION_NUMBER, sectionNumber);
//fragment.setArguments(args);
return fragment;
}
/**
* OnCreateView fragment override
* #param inflater
* #param container
* #param savedInstanceState
* #return
*/
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_camera2, container, false);
boolean opened = safeCameraOpenInView(view, Camera.CameraInfo.CAMERA_FACING_BACK);
if(opened == false){
Log.d("CameraGuide","Error, Camera failed to open");
return view;
}
// Trap the capture button.
Button captureButton = (Button) view.findViewById(R.id.btnCameraStart);
captureButton.setOnClickListener(
new View.OnClickListener() {
#Override
public void onClick(View v) {
// get an image from the camera
mCamera.takePicture(null, null, mPicture);
}
}
);
Button switchCameraButton = (Button) view.findViewById(R.id.btnSwitchCamera);
switchCameraButton.setOnClickListener(
new View.OnClickListener() {
#Override
public void onClick(View v) {
safeCameraOpenInView(getView(), Camera.CameraInfo.CAMERA_FACING_FRONT); //ISSUE OCCURS HERE!
}
}
);
return view;
}
/**
* Recommended "safe" way to open the camera.
* #param view
* #return
*/
private boolean safeCameraOpenInView(View view, int camID) {
boolean qOpened = false;
releaseCameraAndPreview();
//mCamera = getCameraInstance(Camera.CameraInfo.CAMERA_FACING_BACK);
mCamera = getCameraInstance(camID);
mCameraView = view;
qOpened = (mCamera != null);
if(qOpened == true){
mPreview = new CameraPreview(getActivity().getBaseContext(), mCamera,view);
FrameLayout preview = (FrameLayout) view.findViewById(R.id.camera_view);
preview.addView(mPreview);
mPreview.startCameraPreview();
}
return qOpened;
}
/**
* Safe method for getting a camera instance.
* #return
*/
public static Camera getCameraInstance(int camID){
Camera c = null;
try {
c = Camera.open(camID); // attempt to get a Camera instance
}
catch (Exception e){
e.printStackTrace();
}
return c; // returns null if camera is unavailable
}
#Override
public void onPause() {
super.onPause();
}
#Override
public void onDestroy() {
super.onDestroy();
releaseCameraAndPreview();
}
/**
* Clear any existing preview / camera.
*/
private void releaseCameraAndPreview() {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
if(mPreview != null){
mPreview.destroyDrawingCache();
mPreview.mCamera = null;
}
}
/**
* Surface on which the camera projects it's capture results. This is derived both from Google's docs and the
* excellent StackOverflow answer provided below.
*
* Reference / Credit: https://stackoverflow.com/questions/7942378/android-camera-will-not-work-startpreview-fails
*/
class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
// SurfaceHolder
private SurfaceHolder mHolder;
// Our Camera.
private Camera mCamera;
// Parent Context.
private Context mContext;
// Camera Sizing (For rotation, orientation changes)
private Camera.Size mPreviewSize;
// List of supported preview sizes
private List<Camera.Size> mSupportedPreviewSizes;
// Flash modes supported by this camera
private List<String> mSupportedFlashModes;
// View holding this camera.
private View mCameraView;
public CameraPreview(Context context, Camera camera, View cameraView) {
super(context);
// Capture the context
mCameraView = cameraView;
mContext = context;
setCamera(camera);
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setKeepScreenOn(true);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
/**
* Begin the preview of the camera input.
*/
public void startCameraPreview()
{
try{
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
}
catch(Exception e){
e.printStackTrace();
}
}
/**
* Extract supported preview and flash modes from the camera.
* #param camera
*/
private void setCamera(Camera camera)
{
// Source: https://stackoverflow.com/questions/7942378/android-camera-will-not-work-startpreview-fails
mCamera = camera;
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
mSupportedFlashModes = mCamera.getParameters().getSupportedFlashModes();
// Set the camera to Auto Flash mode.
if (mSupportedFlashModes != null && mSupportedFlashModes.contains(Camera.Parameters.FLASH_MODE_AUTO)){
Camera.Parameters parameters = mCamera.getParameters();
parameters.setFlashMode(Camera.Parameters.FLASH_MODE_AUTO);
parameters.setRotation(90);
//parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
mCamera.setParameters(parameters);
mCamera.setDisplayOrientation(90);
}
requestLayout();
}
/**
* The Surface has been created, now tell the camera where to draw the preview.
* #param holder
*/
public void surfaceCreated(SurfaceHolder holder) {
try {
mCamera.setPreviewDisplay(holder);
//mCam = Camera.open();
//mCam.setPreviewDisplay(holder);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* Dispose of the camera preview.
* #param holder
*/
public void surfaceDestroyed(SurfaceHolder holder) {
if (mCamera != null){
mCamera.stopPreview();
}
}
/**
* React to surface changed events
* #param holder
* #param format
* #param w
* #param h
*/
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
//Log.e(TAG, "surfaceChanged => w=" + w + ", h=" + h);
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.
if (mHolder.getSurface() == null){
// preview surface does not exist
return;
}
// stop preview before making changes
try {
mCamera.stopPreview();
//mCamera.release();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or reformatting changes here
// start preview with new settings
try {
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
parameters.setRotation(90);
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
mCamera.setParameters(parameters);
mCamera.setDisplayOrientation(90);
mCamera.setPreviewDisplay(mHolder);
mCamera.enableShutterSound(true);
mCamera.startPreview();
} catch (Exception e){
//Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
/**
* Calculate the measurements of the layout
* #param widthMeasureSpec
* #param heightMeasureSpec
*/
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
/*
// Source: https://stackoverflow.com/questions/7942378/android-camera-will-not-work-startpreview-fails
final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
setMeasuredDimension(width, height);
if (mSupportedPreviewSizes != null){
mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
}
*/
final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
if (mSupportedPreviewSizes != null) {
mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
}
float ratio;
if(mPreviewSize.height >= mPreviewSize.width)
ratio = (float) mPreviewSize.height / (float) mPreviewSize.width;
else
ratio = (float) mPreviewSize.width / (float) mPreviewSize.height;
// One of these methods should be used, second method squishes preview slightly
setMeasuredDimension(width, (int) (width * ratio));
// setMeasuredDimension((int) (width * ratio), height);
}
/**
* Update the layout based on rotation and orientation changes.
* #param changed
* #param left
* #param top
* #param right
* #param bottom
*/
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom)
{
// Source: https://stackoverflow.com/questions/7942378/android-camera-will-not-work-startpreview-fails
if (changed) {
final int width = right - left;
final int height = bottom - top;
int previewWidth = width;
int previewHeight = height;
if (mPreviewSize != null){
Display display = ((WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
switch (display.getRotation())
{
case Surface.ROTATION_0:
previewWidth = mPreviewSize.height;
previewHeight = mPreviewSize.width;
mCamera.setDisplayOrientation(90);
break;
case Surface.ROTATION_90:
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
break;
case Surface.ROTATION_180:
previewWidth = mPreviewSize.height;
previewHeight = mPreviewSize.width;
break;
case Surface.ROTATION_270:
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
mCamera.setDisplayOrientation(180);
break;
}
}
final int scaledChildHeight = previewHeight * width / previewWidth;
mCameraView.layout(0, height - scaledChildHeight, width, height);
}
}
/**
*
* #param sizes
* #param width
* #param height
* #return
*/
private Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int width, int height)
{
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) height / width;
if (sizes == null)
return null;
Camera.Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = height;
for (Camera.Size size : sizes) {
double ratio = (double) size.height / size.width;
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE)
continue;
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Camera.Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
}
/**
* Picture Callback for handling a picture capture and saving it out to a file.
*/
private Camera.PictureCallback mPicture = new Camera.PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFile = getOutputMediaFile();
if (pictureFile == null){
Toast.makeText(getActivity(), "Image retrieval failed.", Toast.LENGTH_SHORT)
.show();
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
};
/**
* Used to return the camera File output.
* #return
*/
private File getOutputMediaFile(){
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "Pocket Booth");
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
Log.d("Camera Guide", "Required media storage does not exist");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"IMG_"+ timeStamp + ".jpg");
//DialogHelper.showDialog( "Success!","Your picture has been saved!",getActivity());
return mediaFile;
}
}

Well, Here I'm going to write a tutorial for you about capturing an
image using Camera by enabling some common features of camera.
Step 1 : Create a preview class
/**
* A basic Camera preview class
*/
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private static final String TAG = "CameraPreview";
private SurfaceHolder mHolder;
private Camera mCamera;
public CameraPreview(Context context, Camera camera) {
super(context);
mCamera = camera;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, now tell the camera where to draw the preview.
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.
if (mHolder.getSurface() == null) {
// preview surface does not exist
return;
}
// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e) {
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or
// reformatting changes here
// start preview with new settings
startPreview();
}
public void resetCamera(Camera camera) {
mCamera = camera;
}
public void startPreview() {
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e) {
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
}
Step 2 : Use FrameLayout to hold the preview.
<FrameLayout
android:id="#+id/cameraPreview"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
Step 3 : Get the camera and send to the preview class. you may need to set the parameters that you need prior passing the camera.
/**
* Create our Preview view and set it as the content of UI.
*/
private void initCameraPreview(final int cameraId, final boolean createPreview) {
mCamera = getCameraInstance(cameraId);
setupCameraParameters(cameraId);
if (createPreview) {
mPreview = new CameraPreview(this, mCamera);
mPreviewHolder.addView(mPreview);
}
mReadyToCapture = true;
}
/**
* A safe way to get an instance of the Camera object.
*/
private Camera getCameraInstance(int cameraId) {
Camera c = null;
try {
c = Camera.open(cameraId); // attempt to get a Camera instance
} catch (Exception e) {
e.printStackTrace();
// Camera is not available (in use or does not exist)
}
return c; // returns null if camera is unavailable
}
/**
* Measure and Setup the camera parameters.
*/
private void setupCameraParameters(int cameraId) {
boolean hasFlash;
Camera.Parameters parameters = mCamera.getParameters();
mPreviewSize = determineBestPreviewSize(parameters);
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
Camera.Size bestPictureSize = determineBestPictureSize(parameters);
parameters.setPictureSize(bestPictureSize.width, bestPictureSize.height);
hasFlash = Util.hasSystemFeature(this, PackageManager.FEATURE_CAMERA_FLASH);
if (mCurrentCameraId == Camera.CameraInfo.CAMERA_FACING_FRONT) {
hasFlash = Util.hasFrontCameraFlash(parameters);
} else {
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
}
if (hasFlash)
parameters.setFlashMode(mFlashMode);
int[] orientations = Util.getCameraDisplayOrientation(this, cameraId);
mDisplayOrientation = orientations[0];
mLayoutOrientation = orientations[1];
mCamera.setDisplayOrientation(mDisplayOrientation);
mCamera.setParameters(parameters);
}
private Camera.Size determineBestPreviewSize(Camera.Parameters parameters) {
List<Camera.Size> sizes = parameters.getSupportedPreviewSizes();
return determineBestSize(sizes);
}
private Camera.Size determineBestPictureSize(Camera.Parameters parameters) {
List<Camera.Size> sizes = parameters.getSupportedPictureSizes();
return determineBestSize(sizes);
}
private Camera.Size determineBestSize(List<Camera.Size> sizes) {
Camera.Size bestSize = null;
for (Camera.Size currentSize : sizes) {
boolean isDesiredRatio = (currentSize.width / 4) == (currentSize.height / 3);
boolean isBetterSize = (bestSize == null || currentSize.width > bestSize.width);
boolean isInBounds = currentSize.width <= PICTURE_SIZE_MAX_WIDTH;
if (isDesiredRatio && isInBounds && isBetterSize) {
bestSize = currentSize;
}
}
if (bestSize == null) {
return sizes.get(0);
}
return bestSize;
}
Step 4 : Writing method for swapping camera
/**
* Swapping between system cameras
*/
private void swapCamera() {
if (!(Camera.getNumberOfCameras() > 1)) {
/* No front facing camera to switch.*/
return;
}
mReadyToCapture = false;
mCamera.stopPreview();
releaseCamera(false);
if (mCurrentCameraId == Camera.CameraInfo.CAMERA_FACING_BACK)
mCurrentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT;
else
mCurrentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
initCameraPreview(mCurrentCameraId, false);
mPreview.resetCamera(mCamera);
mPreview.startPreview();
}
Step 5 : Method for toggling flash
/**
* Toggling camera flash to ON/OFF
*/
private void toggleFlash() {
if (Util.hasSystemFeature(this, PackageManager.FEATURE_CAMERA_FLASH)) {
Camera.Parameters parameters = mCamera.getParameters();
if (mCurrentCameraId == Camera.CameraInfo.CAMERA_FACING_FRONT) {
if (!Util.hasFrontCameraFlash(parameters)) {
/* Front facing camera doesn\'t supported flash. */
return;
}
}
mReadyToCapture = false;
if (Camera.Parameters.FLASH_MODE_ON.equals(parameters.getFlashMode())) {
mFlashMode = Camera.Parameters.FLASH_MODE_OFF;
} else {
mFlashMode = Camera.Parameters.FLASH_MODE_ON;
}
mCameraHandler.post(new Runnable() {
#Override
public void run() {
mCamera.stopPreview();
releaseCamera(false);
initCameraPreview(mCurrentCameraId, false);
mPreview.resetCamera(mCamera);
mPreview.startPreview();
}
});
} else {
/* warning_no_flash */
}
}
Step 6: Methods for handling camera during the states changes of a screen
/**
* Release the camera for other applications
*/
private void releaseCamera(boolean remove) {
if (mCamera != null) {
if (remove)
mPreview.getHolder().removeCallback(mPreview);
mCamera.release();
mCamera = null;
}
}
Step 7: Utility classes.
/**
* Check whether the given feature available in s/m
*
* #return Returns true if the devices supports the feature, else
* false.
*/
public static boolean hasSystemFeature(Context context, String feature) {
return context.getPackageManager().hasSystemFeature(feature);
}
/**
* Check whether front camera flash feature available in s/m
*/
public static boolean hasFrontCameraFlash(Camera.Parameters cameraParameters) {
boolean result = true;
if (cameraParameters.getFlashMode() == null) {
result = false;
}
List<String> supportedFlashModes = cameraParameters.getSupportedFlashModes();
if (supportedFlashModes == null || supportedFlashModes.isEmpty()
|| supportedFlashModes.size() == 1 &&
supportedFlashModes.get(0).equals(Camera.Parameters.FLASH_MODE_OFF)) {
result = false;
}
return result;
}
/**
* Showing camera in the same orientation as the display
*/
public static int[] getCameraDisplayOrientation(Activity activity,
int cameraId) {
Camera.CameraInfo info =
new Camera.CameraInfo();
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;
}
return new int[]{result, degrees};
}
Step 8: Capturing
// Get an image from the camera
if (null != mCamera && mReadyToCapture) {
mCameraOrientationListener.rememberOrientation();
mCamera.takePicture(mShutter, null, mPicture)
}
/**
* Camera shutter sound callback,
* used to enable sound while capture
*/
private Camera.ShutterCallback mShutter = new Camera.ShutterCallback() {
#Override
public void onShutter() {
}
};
/**
* Camera picture callback
*/
private Camera.PictureCallback mPicture = new Camera.PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
mReadyToCapture = false;
Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
int rotation = ((mCurrentCameraId == Camera.CameraInfo.CAMERA_FACING_BACK ? mDisplayOrientation :
((360 - mDisplayOrientation) % 360)) + mCameraOrientationListener.getRememberedOrientation()
+ mLayoutOrientation) % 360;
if (rotation != 0) {
Matrix matrix = new Matrix();
matrix.postRotate(rotation);
bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, false);
}
}
};
Step 9: Camera orientation listener for handling image rotation
/**
* Orientation listener to remember the device's orientation when the user presses
* the shutter button.
* <p/>
* The orientation will be normalized to return it in steps of 90 degrees
* (0, 90, 180, 270).
*/
public class CameraOrientationListener extends OrientationEventListener {
private int currentNormalizedOrientation;
private int rememberedNormalizedOrientation;
public CameraOrientationListener(Context context) {
super(context, SensorManager.SENSOR_DELAY_NORMAL);
}
#Override
public void onOrientationChanged(int orientation) {
if (orientation != ORIENTATION_UNKNOWN) {
currentNormalizedOrientation = normalize(orientation);
}
}
private int normalize(int degrees) {
if (degrees > 315 || degrees <= 45) {
return 0;
}
if (degrees > 45 && degrees <= 135) {
return 90;
}
if (degrees > 135 && degrees <= 225) {
return 180;
}
if (degrees > 225 && degrees <= 315) {
return 270;
}
throw new RuntimeException("The physics as we know them are no more. Watch out for anomalies.");
}
public void rememberOrientation() {
rememberedNormalizedOrientation = currentNormalizedOrientation;
}
public int getRememberedOrientation() {
return rememberedNormalizedOrientation;
}
}
Step 10: States handling
#Override
public void onPause() {
super.onPause();
mReadyToCapture = false;
releaseCamera(true);
}
#Override
public void onResume() {
super.onResume();
removePreview();
mReadyToCapture = false;
smoothCameraLoading();
}
private void removePreview() {
mPreviewHolder.removeAllViews();
}
private void smoothCameraLoading() {
mCameraHandler.post(new Runnable() {
#Override
public void run() {
initCameraPreview(mCurrentCameraId, true);
}
});
}
Step 11: Instance variable used
private String mFlashMode = Camera.Parameters.FLASH_MODE_OFF;
private int mCurrentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
private int mDisplayOrientation;
private int mLayoutOrientation;
private boolean mReadyToCapture = false;
private Camera.Size mPreviewSize;
private FrameLayout mPreviewHolder;
private Camera mCamera;
private CameraPreview mPreview;
private Handler mCameraHandler;
private CameraOrientationListener mCameraOrientationListener;
private FrameLayout mRootView;

In my camera app, it works with somethings different from yours:
1. Open camera when surfaceCreated.
2. StartPreview and no stopPreview in surfaceChanged.
3. Release camera in surfaceDestoryed.
To change the camera, simply set the surfaceView to INVISIBLE, then set your camera parameters, then set the surfaceView to VISIBLE again. In my app, I only do it like this:
mbtCamera.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(cameraMax > 1){
mSurfaceView.setVisibility(View.INVISIBLE);
if(mCameraParam.isZoomSupported()) cameraZoomRatios.clear();
if(cameraUsing == 0) cameraUsing = 1; else cameraUsing = 0;
mCameraOverlayView.setScaleFactor(1.0f);
mSurfaceView.setVisibility(View.VISIBLE);
}
}
});
Hope this will help!
The complete callback:
class CameraSurfaceHolderCallback implements SurfaceHolder.Callback {
#Override
public void surfaceCreated(SurfaceHolder holder) {
mCamera = Camera.open(cameraUsing);
mCameraParam = mCamera.getParameters();
supportFlashMode = mCameraParam.getSupportedFlashModes();
if(supportFlashMode == null) mbtFlash.setVisibility(View.INVISIBLE);
android.hardware.Camera.CameraInfo info = new android.hardware.Camera.CameraInfo();
android.hardware.Camera.getCameraInfo(cameraUsing, info);
int rotation = 0;
if (info.facing == CameraInfo.CAMERA_FACING_FRONT){
rotation = (info.orientation - rt + 360) % 360;
if(mCameraParam.getSupportedFlashModes() == null) mbtFlash.setVisibility(View.INVISIBLE);
}
else{ // back-facing camera
rotation = (info.orientation + rt) % 360;
mbtFlash.setVisibility(View.VISIBLE);
if(flashMode.equals(Camera.Parameters.FLASH_MODE_AUTO)) icons[0] = BitmapFactory.decodeResource(getResources(), R.drawable.ic_action_flash_automatic);
else if(flashMode.equals(Camera.Parameters.FLASH_MODE_OFF)) icons[0] = BitmapFactory.decodeResource(getResources(), R.drawable.ic_action_flash_off);
else if(flashMode.equals(Camera.Parameters.FLASH_MODE_ON)) icons[0] = BitmapFactory.decodeResource(getResources(), R.drawable.ic_action_flash_on);
Matrix rot = new Matrix();
rot.setRotate(360-rt, icons[0].getWidth()/2, icons[0].getHeight()/2);
icons[0] = Bitmap.createBitmap(icons[0], 0, 0, icons[0].getWidth(), icons[0].getHeight(), rot, true);
mbtFlash.setImageBitmap(icons[0]);
mCameraParam.setFlashMode(flashMode);
}
if(mCameraParam.isZoomSupported()){
cameraZoomRatios = mCameraParam.getZoomRatios();
mCameraOverlayView.setMaxScaleFactor(cameraZoomRatios.get(mCameraParam.getMaxZoom())/100f);
}else mCameraOverlayView.setMaxScaleFactor(1.0f);
List<Size> ss = mCameraParam.getSupportedPictureSizes();
Size maxResolution = ss.get(0);
long pixel1, pixel2;
pixel1 = maxResolution.width * maxResolution.height;
for(int i=0; i<ss.size(); i++){
pixel2 = ss.get(i).width * ss.get(i).height;
if(pixel2 > pixel1){
maxResolution = ss.get(i);
pixel1 = pixel2;
}
}
mCameraParam.setPictureSize(maxResolution.width, maxResolution.height);
mCameraParam.setJpegQuality(100);
LayoutParams rlParams = (LayoutParams) mSurfaceView.getLayoutParams();
WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);
Display dp = wm.getDefaultDisplay();
DisplayMetrics dm = new DisplayMetrics();
dp.getMetrics(dm);
float dpiScale = dm.density;
float wScaleFactor = (dm.widthPixels-10*dpiScale)/maxResolution.height;
float hScaleFactor = (dm.heightPixels-mllTopButtons.getHeight()-mllBotButtons.getHeight()-10*dpiScale)/maxResolution.width;
if(wScaleFactor < hScaleFactor){
rlParams.width = (int) (dm.widthPixels - 10*dpiScale);
rlParams.height = (int) (maxResolution.width * wScaleFactor);
}else{
rlParams.width = (int) (maxResolution.height * hScaleFactor);
rlParams.height = (int) (dm.heightPixels-mllTopButtons.getHeight()-mllBotButtons.getHeight()-10*dpiScale);
}
mSurfaceView.setLayoutParams(rlParams);
mCameraOverlayView.setLayoutParams(rlParams);
ss = mCameraParam.getSupportedJpegThumbnailSizes();
float photoAspectRatio, thumbAspectRatio;
photoAspectRatio = (float)maxResolution.width / maxResolution.height;
thumbAspectRatio = 0;
pixel1 = 0;
for(int i=0; i<ss.size(); i++){
if(ss.get(i).height != 0) thumbAspectRatio = (float)ss.get(i).width / ss.get(i).height;
if(thumbAspectRatio == photoAspectRatio){
if(pixel1 == 0)
{
maxResolution = ss.get(i);
pixel1 = ss.get(i).width * ss.get(i).height;
}else{
pixel2 = ss.get(i).width * ss.get(i).height;
if((pixel2 < pixel1)&&(pixel2 != 0)){
maxResolution = ss.get(i);
pixel1 = pixel2;
}
}
}
}
if(pixel1 != 0){
mCameraParam.setJpegThumbnailSize(maxResolution.width, maxResolution.height);
mCameraParam.setJpegThumbnailQuality(100);
}
List<String> focusModes = mCameraParam.getSupportedFocusModes();
if(focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)){
mCameraParam.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
focusingColor = Color.YELLOW;
}
int minEv = mCameraParam.getMinExposureCompensation();
int maxEv = mCameraParam.getMaxExposureCompensation();
if((minEv == 0)&&(maxEv == 0)) mCameraOverlayView.setEVCompensate(false);
else mCameraOverlayView.setEVCompensate(minEv, maxEv);
mCameraParam.setRotation(rotation);
mCamera.setParameters(mCameraParam);
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
try {
mCamera.setDisplayOrientation(90);
mCamera.setPreviewDisplay(mSurfaceView.getHolder());
List<Size> ss = mCameraParam.getSupportedPreviewSizes();
Size maxResolution = ss.get(0);
long pixel1, pixel2;
float photoAspectRatio, previewAspectRatio;
photoAspectRatio = (float)mCameraParam.getPictureSize().width / mCameraParam.getPictureSize().height;
previewAspectRatio = 0;
pixel1 = 0;
for(int i=0; i<ss.size(); i++){
if(ss.get(i).height != 0) previewAspectRatio = (float)ss.get(i).width / ss.get(i).height;
if(previewAspectRatio == photoAspectRatio){
if(pixel1 == 0)
{
maxResolution = ss.get(i);
pixel1 = ss.get(i).width * ss.get(i).height;
}else{
pixel2 = ss.get(i).width * ss.get(i).height;
if(pixel2 > pixel1){
maxResolution = ss.get(i);
pixel1 = pixel2;
}
}
}
}
if(pixel1 != 0) mCameraParam.setPreviewSize(maxResolution.width, maxResolution.height);
mCamera.setParameters(mCameraParam);
mCamera.startPreview();
}
catch(Exception e){}
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mCamera.release();
}
}
I used it in activity and no fragment. I am not sure this will make something different.

I think that there is a little problem in the safeCameraOpenInView method and that is:
Your new camera view is made under the frozen picture.
So you should edit this line: preview.addView(mPreview);
as this: preview.addView(mPreview, preview.getChildCount());
Or you can first delete the previous camera view and then add new one :
preview.removeAllViews();
preview.addView(mPreview);
Hope that this will work.

Android - OnPreviewFrame not called

This is my cameraPreview I have set the listener in SurfaceChanged.
I can see the camera inside the app - yet the OnPreviewFrame is never called.
Here is most of the code
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private static boolean DEBUGGING = true;
private static final String LOG_TAG = "CameraPreviewSample";
private static final String CAMERA_PARAM_ORIENTATION = "orientation";
private static final String CAMERA_PARAM_LANDSCAPE = "landscape";
private static final String CAMERA_PARAM_PORTRAIT = "portrait";
protected Activity mActivity;
private SurfaceHolder mHolder;
protected Camera mCamera;
protected List<Camera.Size> mPreviewSizeList;
protected List<Camera.Size> mPictureSizeList;
protected Camera.Size mPreviewSize;
protected Camera.Size mPictureSize;
private int mSurfaceChangedCallDepth = 0;
private int mCameraId;
private LayoutMode mLayoutMode;
private int mCenterPosX = -1;
private int mCenterPosY;
public Mat frame1=null;
public Mat frame2=null;
PreviewReadyCallback mPreviewReadyCallback = null;
//////Alon
public static int SENSITIVITY_VALUE = 20;
public static int BLUR_SIZE = 10;
public Rect objectBoundingRectangle = new Rect(0, 0, 0, 0);
double ballAverage = 131.5;
int frameCounter = 0;
public static enum LayoutMode {
FitToParent, // Scale to the size that no side is larger than the parent
NoBlank // Scale to the size that no side is smaller than the parent
};
public interface PreviewReadyCallback {
public void onPreviewReady();
}
/**
* State flag: true when surface's layout size is set and surfaceChanged()
* process has not been completed.
*/
protected boolean mSurfaceConfiguring = false;
public CameraPreview(Activity activity, int cameraId, LayoutMode mode) {
super(activity); // Always necessary
mActivity = activity;
mLayoutMode = mode;
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
if (Camera.getNumberOfCameras() > cameraId) {
mCameraId = cameraId;
} else {
mCameraId = 0;
}
} else {
mCameraId = 0;
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
mCamera = Camera.open(mCameraId);
} else {
mCamera = Camera.open();
}
Camera.Parameters cameraParams = mCamera.getParameters();
mPreviewSizeList = cameraParams.getSupportedPreviewSizes();
mPictureSizeList = cameraParams.getSupportedPictureSizes();
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
try {
mCamera.setPreviewDisplay(mHolder);
} catch (IOException e) {
mCamera.release();
mCamera = null;
}
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
mSurfaceChangedCallDepth++;
doSurfaceChanged(width, height);
mSurfaceChangedCallDepth--;
}
private void doSurfaceChanged(int width, int height) {
mCamera.stopPreview();
Camera.Parameters cameraParams = mCamera.getParameters();
boolean portrait = isPortrait();
// The code in this if-statement is prevented from executed again when surfaceChanged is
// called again due to the change of the layout size in this if-statement.
if (!mSurfaceConfiguring) {
Camera.Size previewSize = determinePreviewSize(portrait, width, height);
Camera.Size pictureSize = determinePictureSize(previewSize);
if (DEBUGGING) { Log.v(LOG_TAG, "Desired Preview Size - w: " + width + ", h: " + height); }
mPreviewSize = previewSize;
mPictureSize = pictureSize;
mSurfaceConfiguring = adjustSurfaceLayoutSize(previewSize, portrait, width, height);
// Continue executing this method if this method is called recursively.
// Recursive call of surfaceChanged is very special case, which is a path from
// the catch clause at the end of this method.
// The later part of this method should be executed as well in the recursive
// invocation of this method, because the layout change made in this recursive
// call will not trigger another invocation of this method.
if (mSurfaceConfiguring && (mSurfaceChangedCallDepth <= 1)) {
return;
}
}
configureCameraParameters(cameraParams, portrait);
mSurfaceConfiguring = false;
try {
mCamera.startPreview();
} catch (Exception e) {
Log.w(LOG_TAG, "Failed to start preview: " + e.getMessage());
// Remove failed size
mPreviewSizeList.remove(mPreviewSize);
mPreviewSize = null;
// Reconfigure
if (mPreviewSizeList.size() > 0) { // prevent infinite loop
surfaceChanged(null, 0, width, height);
} else {
Toast.makeText(mActivity, "Can't start preview", Toast.LENGTH_LONG).show();
Log.w(LOG_TAG, "Gave up starting preview");
}
}
if (null != mPreviewReadyCallback) {
mPreviewReadyCallback.onPreviewReady();
}
//////////////////////////Alon
if (mCamera == null) {
return;
}
mCamera.setPreviewCallback(new PreviewCallback() {
#Override
public void onPreviewFrame(byte[] data, Camera camera) {
Mat frame = Byte_to_Mat(data);
if(frame1==null) {
frame1 = frame;
}
else
{
if (frame2 == null)
{
frame2 = frame;
}
else
{
frame1 = frame2;
frame2 = frame;
}
detectBall(frame1,frame2);
}
}
});
}
public Mat Byte_to_Mat(byte[] data) {
Mat jpegData = new Mat(1, data.length, CvType.CV_8UC1);
jpegData.put(0, 0, data);
return jpegData;
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
stop();
}
public void stop() {
if (null == mCamera) {
return;
}
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
public boolean isPortrait() {
return (mActivity.getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT);
}
public void setOneShotPreviewCallback(PreviewCallback callback) {
if (null == mCamera) {
return;
}
mCamera.setOneShotPreviewCallback(callback);
}
public void setPreviewCallback(PreviewCallback callback) {
if (null == mCamera) {
return;
}
mCamera.setPreviewCallback(callback);
}
public Camera.Size getPreviewSize() {
return mPreviewSize;
}
public void setOnPreviewReady(PreviewReadyCallback cb) {
mPreviewReadyCallback = cb;
}
I have tried setting the setPreviewCallback in the constructor too.
And also on Surface Created.
Does someone know the source of this?

Camera Preview stretched on setDisplayOrientation(90)

I am able to rotate the camera preview from portrait to landscape by using the setDisplayOrientation(90) method but preview won't look realistic and is stretched in landscape mode. I have gone through multiple posts related to the same but not able to succeed with required view. I am trying this on the rooted android Jellybeans version.
Can you please suggest the ways to improve the preview in landscape mode?
below is my code set of CameraPreview and Activity class:
import java.io.IOException;
import java.util.List;
import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.Size;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private static final String TAG = null;
private SurfaceHolder mHolder;
private Camera mCamera;
List<Size> sizes;
Camera.Size mPreviewSize;
public CameraPreview(Context context, Camera camera) {
super(context);
mCamera = camera;
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, now tell the camera where to draw the preview.
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.
if (mHolder.getSurface() == null){
// preview surface does not exist
return;
}
// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or
// reformatting changes here
// start preview with new settings
setCamera(mCamera);
try {
mCamera.setDisplayOrientation(90);
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e){
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
public void setCamera(Camera camera) {
if (mCamera == camera) { return; }
mCamera = camera;
if (mCamera != null) {
requestLayout();
try {
mCamera.setPreviewDisplay(mHolder);
} catch (IOException e) {
e.printStackTrace();
}
if(mCamera != null){
//Setting the camera's aspect ratio
Camera.Parameters parameters = mCamera.getParameters();
sizes = parameters.getSupportedPreviewSizes();
Size optimalSize = getOptimalPreviewSize(sizes, getResources().getDisplayMetrics().widthPixels, getResources().getDisplayMetrics().heightPixels);
mCamera.setDisplayOrientation(90);
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
mCamera.setParameters(parameters);
}
/*
Important: Call startPreview() to start updating the preview surface. Preview must
be started before you can take a picture.
*/
mCamera.startPreview();
}
}
public Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.1;
double targetRatio=(double)h / w;
if (sizes == null) return null;
Camera.Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
for (Camera.Size size : sizes) {
double ratio = (double) size.width / size.height;
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Camera.Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
setMeasuredDimension(width, height);
sizes = mCamera.getParameters().getSupportedPreviewSizes();
if (sizes != null) {
mPreviewSize = getOptimalPreviewSize(sizes, width, height);
}
}
}
public class TestCameraActivity extends Activity {
public static final int MEDIA_TYPE_IMAGE = 1;
public static final int MEDIA_TYPE_VIDEO = 2;
protected static final String TAG = null;
private PictureCallback mPicture;
/** Called when the activity is first created. */
Context ctx;
Camera mCamera;
CameraPreview mPreview;
Camera.Size optimalSize;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
boolean cameraAvailable = checkCameraHardware(this);
if(cameraAvailable){
mCamera = getCameraInstance();
}else Toast.makeText(this, "No Camera Available",Toast.LENGTH_LONG).show();
double aspectRatio =0;
mPreview = new CameraPreview(this,mCamera);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(mPreview);
mPicture = getPictureCallback();
if(mCamera != null){
//Setting the camera's aspect ratio
Camera.Parameters parameters = mCamera.getParameters();
List<Size> sizes = parameters.getSupportedPreviewSizes();
optimalSize = mPreview.getOptimalPreviewSize(sizes, getResources().getDisplayMetrics().widthPixels, getResources().getDisplayMetrics().heightPixels);
aspectRatio = (float)optimalSize.width/optimalSize.height;
}
// if(optimalSize!= null){
// FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(LayoutParams.MATCH_PARENT, (int)(getResources().getDisplayMetrics().widthPixels*aspectRatio));
// preview.setLayoutParams(params);
// LayoutParams surfaceParams = new LayoutParams(LayoutParams.MATCH_PARENT, (int)(getResources().getDisplayMetrics().widthPixels*aspectRatio));
// mPreview.setLayoutParams(surfaceParams);
// }
mPreview.setCamera(mCamera);
Button capture = (Button) findViewById(R.id.button_capture);
capture.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
mCamera.takePicture(null, null, mPicture);
}
});
}
private PictureCallback getPictureCallback() {
PictureCallback picture = new PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
if (pictureFile == null){
Log.d(TAG, "Error creating media file, check storage permissions: " );
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
Log.d(TAG, "File not found: " + e.getMessage());
} catch (IOException e) {
Log.d(TAG, "Error accessing file: " + e.getMessage());
}
}
};
return picture;};
#Override
protected void onPause() {
super.onPause();
releaseCamera(); // release the camera immediately on pause event
}
private void releaseCamera(){
if (mCamera != null){
mCamera.release(); // release the camera for other applications
mCamera = null;
}
}
public static Camera getCameraInstance(){
Camera c = null;
try {
c = Camera.open(); // attempt to get a Camera instance
}
catch (Exception e){
// Camera is not available (in use or does not exist)
}
return c; // returns null if camera is unavailable
}
/** Create a File for saving an image or video */
private static File getOutputMediaFile(int type){
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "MyCameraApp");
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
if (type == MEDIA_TYPE_IMAGE){
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"IMG_"+ timeStamp + ".jpg");
} else if(type == MEDIA_TYPE_VIDEO) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"VID_"+ timeStamp + ".mp4");
} else {
return null;
}
return mediaFile;
}
/** Check if this device has a camera */
private boolean checkCameraHardware(Context context) {
if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
// this device has a camera
return true;`enter code here`
} else {
// no camera on this device
return false;
}
}
}

The value that you pass to setDisplayOrientation is not fixed: it's dependent on the individual camera's orientation (where the "top" of the camera is) as well as the current orientation of the device itself. By setting it to a constant value, your preview may look correct in one orientation but in another will be as you described.
The documentation provides the math that you need to take both into account when setting this value:
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);
}

Android camera app freezes black screen after onResume()

I am developing an app that is going to be something like camscanner. In my app i have an camera api tha i call. When the app is first opened and i press the camera button it works, but when i click home button and open again my app it freezes and shows a black screen without the app crashing. I found similar questions but none could give me a right answer, i know i probably have to change something in the onResume or onPause and need help to figure out what.
below i have my CameraScreen activity:
public class CameraScreen extends Activity {
ImageView image;
Activity context;
Preview preview;
Camera camera;
Button exitButton;
ImageView fotoButton;
LinearLayout progressLayout;
String path = "/sdcard/KutCamera/cache/images/";
FrameLayout frame;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.camera_layout);
context=this;
fotoButton = (ImageView) findViewById(R.id.imageView_foto);
exitButton = (Button) findViewById(R.id.button_exit);
image = (ImageView) findViewById(R.id.imageView_photo);
progressLayout = (LinearLayout) findViewById(R.id.progress_layout);
preview = new Preview(this,
(SurfaceView) findViewById(R.id.KutCameraFragment));
frame = (FrameLayout) findViewById(R.id.preview);
frame.addView(preview);
preview.setKeepScreenOn(true);
fotoButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
try {
takeFocusedPicture();
} catch (Exception e) {
}
exitButton.setClickable(true);
fotoButton.setClickable(false);
progressLayout.setVisibility(View.VISIBLE);
}
});
}
#Override
protected void onPause() {
super.onPause();
//releaseMediaRecorder(); // if you are using MediaRecorder, release it first
//releaseCamera();
if(null != camera){
camera.release();
camera = null;
}
frame.removeView(preview);
preview = null;// release the camera immediately on pause event
}
private void releaseCamera(){
if (camera != null){
camera.release(); // release the camera for other applications
camera = null;
}
}
#Override
protected void onResume() {
super.onResume();
// TODO Auto-generated method stub
if(camera==null){
Log.d("Camera tes", "Camera==null");
//camera.setPreviewCallback(null);
camera = Camera.open();
camera.startPreview();
camera.setErrorCallback(new ErrorCallback() {
public void onError(int error, Camera mcamera) {
camera.release();
camera = Camera.open();
Log.d("Camera died", "error camera");
}
});
}
if (camera != null) {
//camera.setPreviewCallback(null);
Log.d("Camera tes", "Camera!=null");
if (Build.VERSION.SDK_INT >= 14)
setCameraDisplayOrientation(context,
CameraInfo.CAMERA_FACING_BACK, camera);
preview.setCamera(camera);
}
}
private 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);
}
Camera.AutoFocusCallback mAutoFocusCallback = new Camera.AutoFocusCallback() {
#Override
public void onAutoFocus(boolean success, Camera camera) {
try{
camera.takePicture(mShutterCallback, null, jpegCallback);
}catch(Exception e){
}
}
};
Camera.ShutterCallback mShutterCallback = new ShutterCallback() {
#Override
public void onShutter() {
// TODO Auto-generated method stub
}
};
public void takeFocusedPicture() {
camera.autoFocus(mAutoFocusCallback);
}
PictureCallback rawCallback = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
// Log.d(TAG, "onPictureTaken - raw");
}
};
PictureCallback jpegCallback = new PictureCallback() {
#SuppressWarnings("deprecation")
public void onPictureTaken(byte[] data, Camera camera) {
FileOutputStream outStream = null;
Calendar c = Calendar.getInstance();
File videoDirectory = new File(path);
if (!videoDirectory.exists()) {
videoDirectory.mkdirs();
}
try {
// Write to SD Card
outStream = new FileOutputStream(path + c.getTime().getSeconds() + ".jpg");
outStream.write(data);
outStream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
}
Bitmap realImage;
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 5;
options.inPurgeable=true; //Tell to gc that whether it needs free memory, the Bitmap can be cleared
options.inInputShareable=true; //Which kind of reference will be used to recover the Bitmap data after being clear, when it will be used in the future
realImage = BitmapFactory.decodeByteArray(data,0,data.length,options);
ExifInterface exif = null;
try {
exif = new ExifInterface(path + c.getTime().getSeconds()
+ ".jpg");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
Log.d("EXIF value",
exif.getAttribute(ExifInterface.TAG_ORIENTATION));
if (exif.getAttribute(ExifInterface.TAG_ORIENTATION)
.equalsIgnoreCase("1")) {
realImage = rotate(realImage, 90);
} else if (exif.getAttribute(ExifInterface.TAG_ORIENTATION)
.equalsIgnoreCase("8")) {
realImage = rotate(realImage, 90);
} else if (exif.getAttribute(ExifInterface.TAG_ORIENTATION)
.equalsIgnoreCase("3")) {
realImage = rotate(realImage, 90);
} else if (exif.getAttribute(ExifInterface.TAG_ORIENTATION)
.equalsIgnoreCase("0")) {
realImage = rotate(realImage, 90);
}
} catch (Exception e) {
}
image.setImageBitmap(realImage);
fotoButton.setClickable(true);
camera.startPreview();
progressLayout.setVisibility(View.GONE);
exitButton.setClickable(true);
}
};
public static Bitmap rotate(Bitmap source, float angle) {
Matrix matrix = new Matrix();
matrix.postRotate(angle);
return Bitmap.createBitmap(source, 0, 0, source.getWidth(),
source.getHeight(), matrix, false);
}
}
And here i have my Preview class:
class Preview extends ViewGroup implements SurfaceHolder.Callback {
private final String TAG = "Preview";
SurfaceView mSurfaceView;
SurfaceHolder mHolder;
int heightmax ;
int widthmax ;
Size mPreviewSize;
List<Size> mSupportedPreviewSizes;
Camera mCamera;
#SuppressWarnings("deprecation")
Preview(Context context, SurfaceView sv) {
super(context);
mSurfaceView = sv;
// addView(mSurfaceView);
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void setCamera(Camera camera) {
mCamera = camera;
if (mCamera != null) {
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPictureSizes();
requestLayout();
// get Camera parameters
Camera.Parameters params = mCamera.getParameters();
List<String> focusModes = params.getSupportedFocusModes();
if (focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
// set the focus mode
params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
// set Camera parameters
mCamera.setParameters(params);
}
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// We purposely disregard child measurements because act as a
// wrapper to a SurfaceView that centers the camera preview instead
// of stretching it.
final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
setMeasuredDimension(width, height);
if (mSupportedPreviewSizes != null) {
mPreviewSize=maxSize();
}
}
public Size maxSize(){
Size sizeMax=mSupportedPreviewSizes.get(0);
maxsize=mSupportedPreviewSizes.get(0)
.height*mSupportedPreviewSizes.get(0).width;
for(Size size:mSupportedPreviewSizes){
if(size.height*size.width>sizeMax.width*sizeMax.height){
sizeMax = size;
}
}
return sizeMax;
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (changed && getChildCount() > 0) {
final View child = getChildAt(0);
final int width = r - l;
final int height = b - t;
int previewWidth = width;
int previewHeight = height;
if (mPreviewSize != null) {
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
}
// Center the child SurfaceView within the parent.
if (width * previewHeight > height * previewWidth) {
final int scaledChildWidth = previewWidth * height / previewHeight;
child.layout((width - scaledChildWidth) / 2, 0,
(width + scaledChildWidth) / 2, height);
} else {
final int scaledChildHeight = previewHeight * width / previewWidth;
child.layout(0, (height - scaledChildHeight) / 2,
width, (height + scaledChildHeight) / 2);
}
}
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, acquire the camera and tell it where
// to draw.
try {
if (mCamera != null) {
mCamera.setPreviewDisplay(holder);
}
} catch (IOException exception) {
Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
/*
mCamera.stopPreview();
mCamera.setPreviewCallback(null);
mCamera.release();
mCamera = null;
if (mCamera != null) {
mCamera.stopPreview();
}
*/
}
Camera.AutoFocusCallback mnAutoFocusCallback = new Camera.AutoFocusCallback() {
#Override
public void onAutoFocus(boolean success, Camera camera) {
}
};
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
/*
if(mCamera != null) {
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPictureSize(mPreviewSize.width, mPreviewSize.height);
requestLayout();
mCamera.setParameters(parameters);
mCamera.startPreview();
}
*/
}
}
I would appriciate any help or guides you can give me.

How to change area of scan Zbar?

I want to change the area of camera scan. Now I take image to scan as big as screen of device. I'm trying to crop image to analyze. So just the center of preview will be source to scan. Is there any option to set captured preview to be smaller or creating Bitmap from byte[] data and crop it is the only way to get smaller area? I was trying to read something about it but documentation for Zbar Android is very poor (comparing to iOS).
Picture here:
https://postimg.cc/image/4wk4u0mln/
MainActivity
public class MainActivity extends Activity
{
private Camera mCamera;
private Context context;
private CameraPreview mPreview;
private Handler autoFocusHandler;
TextView scanText;
Button scanButton;
ImageScanner scanner;
private PowerManager.WakeLock wl;
private boolean barcodeScanned = false;
private boolean previewing = true;
static {
System.loadLibrary("iconv");
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
autoFocusHandler = new Handler();
mCamera = getCameraInstance();
context = getApplicationContext();
/* Instance barcode scanner */
scanner = new ImageScanner();
scanner.setConfig(0, Config.X_DENSITY, 3);
scanner.setConfig(0, Config.Y_DENSITY, 3);
mPreview = new CameraPreview(this, mCamera, previewCb, autoFocusCB);
FrameLayout preview = (FrameLayout)findViewById(R.id.cameraPreview);
preview.addView(mPreview);
scanText = (TextView)findViewById(R.id.scanText);
}
#Override
public void onPause() {
super.onPause();
releaseCamera();
}
#Override
protected void onResume() {
// TODO Auto-generated method stub
onStart();
}
#Override
protected void onStop() {
// TODO Auto-generated method stub
super.onStop();
finish();
}
/** A safe way to get an instance of the Camera object. */
public static Camera getCameraInstance(){
Camera c = null;
try {
c = Camera.open();
} catch (Exception e){
}
return c;
}
private void releaseCamera() {
if (mCamera != null) {
previewing = false;
mCamera.setPreviewCallback(null);
mCamera.release();
mCamera = null;
}
}
private Runnable doAutoFocus = new Runnable() {
#Override
public void run() {
if (previewing)
mCamera.autoFocus(autoFocusCB);
}
};
PreviewCallback previewCb = new PreviewCallback() {
#Override
public void onPreviewFrame(byte[] data, Camera camera) {
Camera.Parameters parameters = camera.getParameters();
Size size = parameters.getPreviewSize();
//HERE we read taken picture from prieview
Image barcode = new Image(size.width, size.height, "Y800");
barcode.setData(data);
int result = scanner.scanImage(barcode);
if (result != 0) {
previewing = false;
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
SymbolSet syms = scanner.getResults();
for (Symbol sym : syms) {
if (sym.getType() == Symbol.CODE128) {
sym.getData());
MediaPlayer mp = MediaPlayer.create(context, R.raw.beep_ok);
mp.start();
} else {
MediaPlayer mp = MediaPlayer.create(context, R.raw.beep_wrong);
mp.start();
}
mCamera.setPreviewCallback(previewCb);
mCamera.startPreview();
previewing = true;
mCamera.autoFocus(autoFocusCB);
}
}
}
};
// Mimic continuous auto-focusing
AutoFocusCallback autoFocusCB = new AutoFocusCallback() {
#Override
public void onAutoFocus(boolean success, Camera camera) {
autoFocusHandler.postDelayed(doAutoFocus, 1000);
}
};
//Method to crop Bitmap in case of use
public Bitmap scaleCenterCrop(Bitmap source, int newHeight, int newWidth) {
int sourceWidth = source.getWidth();
int sourceHeight = source.getHeight();
float xScale = (float) newWidth / sourceWidth;
float yScale = (float) newHeight / sourceHeight;
float scale = Math.max(xScale, yScale);
float scaledWidth = scale * sourceWidth;
float scaledHeight = scale * sourceHeight;
float left = (newWidth - scaledWidth) / 2;
float top = (newHeight - scaledHeight) / 2;
RectF targetRect = new RectF(left, top, left + scaledWidth, top + scaledHeight);
Bitmap dest = Bitmap.createBitmap(newWidth, newHeight, source.getConfig());
Canvas canvas = new Canvas(dest);
canvas.drawBitmap(source, null, targetRect, null);
return dest;
}
}
CameraPrieview.java
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;
private PreviewCallback previewCallback;
private AutoFocusCallback autoFocusCallback;
public CameraPreview(Context context, Camera camera,
PreviewCallback previewCb,
AutoFocusCallback autoFocusCb) {
super(context);
mCamera = camera;
previewCallback = previewCb;
autoFocusCallback = autoFocusCb;
/*
* Set camera to continuous focus if supported, otherwise use
* software auto-focus. Only works for API level >=9.
*/
/*
Camera.Parameters parameters = camera.getParameters();
for (String f : parameters.getSupportedFocusModes()) {
if (f == Parameters.FOCUS_MODE_CONTINUOUS_PICTURE) {
mCamera.setFocusMode(Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
autoFocusCallback = null;
break;
}
}
*/
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, now tell the camera where to draw the preview.
try {
mCamera.setPreviewDisplay(holder);
} catch (IOException e) {
Log.d("DBG", "Error setting camera preview: " + e.getMessage());
}
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
// Camera preview released in activity
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
/*
* If your preview can change or rotate, take care of those events here.
* Make sure to stop the preview before resizing or reformatting it.
*/
if (mHolder.getSurface() == null){
// preview surface does not exist
return;
}
// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}
try {
// Hard code camera surface rotation 90 degs to match Activity view in portrait
mCamera.setDisplayOrientation(90);
mCamera.setPreviewDisplay(mHolder);
mCamera.setPreviewCallback(previewCallback);
mCamera.startPreview();
mCamera.autoFocus(autoFocusCallback);
} catch (Exception e){
Log.d("DBG", "Error starting camera preview: " + e.getMessage());
}
}
}

In the PreviewCallback you can actually crop the scanning area. In the onPreviewFrame method, after calling barcode.setData() you can call barcode.setCrop(left,top,width,height). All measurements in pixels.
Also make sure to set the crop size with respect to the preview image size and not the device screen size.
Note: Please make sure that the x-axis is always the longest side even though you orient the phone in portrait mode.
Please refer below Image for better understanding of the arguments.
This solution is specific to zbar for android.