Develop Reference

Android Camera is null?

I have spent some time debugging and can't figure why null is occurring. When I run the application immeditaley it crashes and it points to this line:
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
and says the object reference is null. I can't figure out why mCamera is returning null.
My Manifest file has the proper permissions:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
<uses-feature android:name="android.hardware.camera.front" android:required="false" />
Example:
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.CameraInfo;
import android.hardware.Camera.PictureCallback;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.Toast;
public class AndroidCameraExample extends Activity {
private Camera mCamera;
private CameraPreview mPreview;
private PictureCallback mPicture;
private Button capture, switchCamera;
private Context myContext;
private LinearLayout cameraPreview;
private boolean cameraFront = false;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
myContext = this;
initialize();
}
private int findFrontFacingCamera() {
int cameraId = -1;
// Search for the front facing camera
int numberOfCameras = Camera.getNumberOfCameras();
for (int i = 0; i < numberOfCameras; i++) {
CameraInfo info = new CameraInfo();
Camera.getCameraInfo(i, info);
if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
cameraId = i;
cameraFront = true;
break;
}
}
return cameraId;
}
private int findBackFacingCamera() {
int cameraId = -1;
//Search for the back facing camera
//get the number of cameras
int numberOfCameras = Camera.getNumberOfCameras();
//for every camera check
for (int i = 0; i < numberOfCameras; i++) {
CameraInfo info = new CameraInfo();
Camera.getCameraInfo(i, info);
if (info.facing == CameraInfo.CAMERA_FACING_BACK) {
cameraId = i;
cameraFront = false;
break;
}
}
return cameraId;
}
public void onResume() {
super.onResume();
if (!hasCamera(myContext)) {
Toast toast = Toast.makeText(myContext, "Sorry, your phone does not have a camera!", Toast.LENGTH_LONG);
toast.show();
finish();
}
if (mCamera == null) {
//if the front facing camera does not exist
if (findFrontFacingCamera() < 0) {
Toast.makeText(this, "No front facing camera found.", Toast.LENGTH_LONG).show();
switchCamera.setVisibility(View.GONE);
}
mCamera = Camera.open(findBackFacingCamera());
mPicture = getPictureCallback();
mPreview.refreshCamera(mCamera);
}
}
public void initialize() {
cameraPreview = (LinearLayout) findViewById(R.id.camera_preview);
mPreview = new CameraPreview(myContext, mCamera);
cameraPreview.addView(mPreview);
capture = (Button) findViewById(R.id.button_capture);
capture.setOnClickListener(captrureListener);
switchCamera = (Button) findViewById(R.id.button_ChangeCamera);
switchCamera.setOnClickListener(switchCameraListener);
}
OnClickListener switchCameraListener = new OnClickListener() {
#Override
public void onClick(View v) {
//get the number of cameras
int camerasNumber = Camera.getNumberOfCameras();
if (camerasNumber > 1) {
//release the old camera instance
//switch camera, from the front and the back and vice versa
releaseCamera();
chooseCamera();
} else {
Toast toast = Toast.makeText(myContext, "Sorry, your phone has only one camera!", Toast.LENGTH_LONG);
toast.show();
}
}
};
public void chooseCamera() {
//if the camera preview is the front
if (cameraFront) {
int cameraId = findBackFacingCamera();
if (cameraId >= 0) {
//open the backFacingCamera
//set a picture callback
//refresh the preview
mCamera = Camera.open(cameraId);
mPicture = getPictureCallback();
mPreview.refreshCamera(mCamera);
}
} else {
int cameraId = findFrontFacingCamera();
if (cameraId >= 0) {
//open the backFacingCamera
//set a picture callback
//refresh the preview
mCamera = Camera.open(cameraId);
mPicture = getPictureCallback();
mPreview.refreshCamera(mCamera);
}
}
}
#Override
protected void onPause() {
super.onPause();
//when on Pause, release camera in order to be used from other applications
releaseCamera();
}
private boolean hasCamera(Context context) {
//check if the device has camera
if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
return true;
} else {
return false;
}
}
private PictureCallback getPictureCallback() {
PictureCallback picture = new PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
//make a new picture file
File pictureFile = getOutputMediaFile();
if (pictureFile == null) {
return;
}
try {
//write the file
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
Toast toast = Toast.makeText(myContext, "Picture saved: " + pictureFile.getName(), Toast.LENGTH_LONG);
toast.show();
} catch (FileNotFoundException e) {
} catch (IOException e) {
}
//refresh camera to continue preview
mPreview.refreshCamera(mCamera);
}
};
return picture;
}
OnClickListener captrureListener = new OnClickListener() {
#Override
public void onClick(View v) {
mCamera.takePicture(null, null, mPicture);
}
};
//make picture and save to a folder
private static File getOutputMediaFile() {
//make a new file directory inside the "sdcard" folder
File mediaStorageDir = new File("/sdcard/", "JCG Camera");
//if this "JCGCamera folder does not exist
if (!mediaStorageDir.exists()) {
//if you cannot make this folder return
if (!mediaStorageDir.mkdirs()) {
return null;
}
}
//take the current timeStamp
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
//and make a media file:
mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_" + timeStamp + ".jpg");
return mediaFile;
}
private void releaseCamera() {
// stop and release camera
if (mCamera != null) {
mCamera.release();
mCamera = null;
}
}
}
CameraPreview:
import java.io.IOException;
import java.util.List;
import android.content.Context;
import android.hardware.Camera;
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 = "CameraPreview";
private Context mContext;
private SurfaceHolder mHolder;
private Camera mCamera;
private List<Camera.Size> mSupportedPreviewSizes;
private Camera.Size mPreviewSize;
public CameraPreview(Context context, Camera camera) {
super(context);
mContext = context;
mCamera = camera;
// supported preview sizes
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
for (Camera.Size str : mSupportedPreviewSizes)
Log.e(TAG, str.width + "/" + str.height);
// 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) {
// empty. surfaceChanged will take care of stuff
}
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) {
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();
} 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);
mCamera.setParameters(parameters);
mCamera.setDisplayOrientation(90);
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e){
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
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);
}
private 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.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;
}
public void refreshCamera(Camera camera) {
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(camera);
try {
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
mCamera.setParameters(parameters);
mCamera.setDisplayOrientation(90);
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e) {
Log.d(VIEW_LOG_TAG, "Error starting camera preview: " + e.getMessage());
}
}
public void setCamera(Camera camera) {
//method to set a camera instance
mCamera = camera;
}
}
As I am using a tutorial, if I use this CameraPreview.java instead (keeping the same Example class) it works, but I needed to make some modifications to the tutorial for the aspect ratio reasons:
import java.io.IOException;
import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;
public CameraPreview(Context context, Camera camera) {
super(context);
mCamera = camera;
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) {
try {
// create the surface and start camera preview
if (mCamera == null) {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
}
} catch (IOException e) {
Log.d(VIEW_LOG_TAG, "Error setting camera preview: " + e.getMessage());
}
}
public void refreshCamera(Camera camera) {
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(camera);
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e) {
Log.d(VIEW_LOG_TAG, "Error starting camera preview: " + e.getMessage());
}
}
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.
refreshCamera(mCamera);
}
public void setCamera(Camera camera) {
//method to set a camera instance
mCamera = camera;
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
// mCamera.release();
}
}
UPDATE: Additionally I tried to put chooseCamera(); right before the mPreview = new CameraPreview(myContext, mCamera); but it did not work.

I have a guess, as I haven't tested this code, but from looking at it as is, I think that you are calling initialize() before you are instantiating your actually Camera object. Observe this picture of the Android life cycle:
diagram source
You will notice that onResume() is called AFTER onCreate(). In your code you are creating the CameraPreview class with your null mCamera reference in the by calling the initialize() method in onCreate(). Therefore, the line in CameraPreview:
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
is calling a null object reference, mCamera. Instead, move
mCamera = Camera.open(findBackFacingCamera());
to onCreate() (before the call to initialize CameraPreview of course!), keeping the same call in onResume(). Keep the check for a null Camera in onResume() in case the user leaves the activity and Camera is closed for some reason.

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: Getting Camera preview as tilted

I have made a custom Camera application. And i am getting a Tilted camera view. So i want to know the solution for a correct and a normal preview. I have used setDisplayOrientation() Method. But got no result. Searching for a answer that works.
The Compiling API is 2.3 GingerBread!
Thanks in advance.`
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;
String TAG = "MyMsg";
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 {
try {
mCamera.stopPreview();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}
Log.d(TAG, "Surface Creation started");
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d("MyMsg", "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
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e){
Log.d("MyMsg", "Error starting camera preview: " + e.getMessage());
}
}
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);
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
// TODO Auto-generated method stub
}
}
`

Android camera preview flicker

I'm facing a problem with quite a simple Android camera preview using SurfaceView.
I don't know why but whenever the SurfaceView size/position falls outside the visible area, the preview starts to flicker. The intensity of this increases if the objects seen by the camera are moving.
Device: Nexus 7 (first edition), Android 4.4.2
Application targeted for API16.
As soon as the flickering occurs, in the log plenty of messages like below are displayed:
I/hwcomposer( 127): Setting interactive mode: Off
I/hwcomposer( 127): Setting interactive mode: On
I/hwcomposer( 127): Setting interactive mode: Off
I/hwcomposer( 127): Setting interactive mode: On
I/hwcomposer( 127): Setting interactive mode: Off
The problem started on Sony Tablet Z and was reproduced on Nexus 7.
For some reason I don't want to discuss here I don't have full control if the preview area falls outside the visible are. As you can see, even a small preview with (-100, -100) left/top margin causes problems.
The app is very simple. Just one class and XML layout file:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<!--
android:layout_width="1022px"
android:layout_height="1363px"
android:layout_marginLeft="0px"
android:layout_marginTop="0px"
-->
<FrameLayout
android:id="#+id/camera_preview_container"
android:layout_width="500px"
android:layout_height="500px"
android:layout_marginLeft="-100px"
android:layout_marginTop="-100px">
<SurfaceView
android:id="#+id/surface_view"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</FrameLayout>
</FrameLayout>
and the activity code:
package com.example.surfaceviewtest;
import java.io.IOException;
import android.hardware.Camera;
import android.hardware.Camera.CameraInfo;
import android.hardware.Camera.Size;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.util.Log;
import android.view.Menu;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.WindowManager;
public class MainActivity extends Activity implements SurfaceHolder.Callback {
private final String TAG = "com.example.surfaceviewtest";
private Camera camera;
private boolean isPreviewing = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
((SurfaceView)this.findViewById(R.id.surface_view)).getHolder().addCallback(this);
}
#Override
protected void onResume() {
Log.d(TAG, "onResume");
super.onResume();
camera = Camera.open(0);
Camera.Parameters cameraParameters = camera.getParameters();
Size previewSize = cameraParameters.getPreviewSize();
Log.d(TAG, String.format("Preview size: width %d height %d", previewSize.width, previewSize.height));
Size pictureSize = cameraParameters.getPictureSize();
Log.d(TAG, String.format("Picture size: width %d height %d", pictureSize.width, pictureSize.height));
/*cameraParameters.setPictureSize(320, 240);
cameraParameters.setPreviewSize(176, 144);
camera.setParameters(cameraParameters);*/
}
#Override
protected void onPause() {
Log.d(TAG, "onPause");
super.onPause();
stopPreview();
camera.release();
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
Log.d(TAG, "surfaceCreated");
try {
setCameraDisplayOrientation();
setCameraOrientation();
camera.setPreviewDisplay(holder);
startPreview();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
Log.d(TAG, String.format ("surfaceChanged: format %d width %d height %d", format, width, height));
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
Log.d(TAG, "surfaceDestroyed");
stopPreview();
}
private void startPreview() {
if (isPreviewing)
return;
camera.startPreview();
}
private void stopPreview() {
if (isPreviewing == false)
return;
camera.stopPreview();
isPreviewing = false;
}
public int getDisplayOrientation() {
android.hardware.Camera.CameraInfo info = new android.hardware.Camera.CameraInfo();
android.hardware.Camera.getCameraInfo(0, info);
int rotation = ((WindowManager) getSystemService(
Context.WINDOW_SERVICE)).getDefaultDisplay().getRotation();
int degrees = orientationToAngle(rotation);
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 result;
}
protected void setCameraDisplayOrientation() {
int rotation = getDisplayOrientation();
camera.setDisplayOrientation(rotation);
}
protected static int orientationToAngle(int orientation) {
switch (orientation) {
case Surface.ROTATION_0:
return 0;
case Surface.ROTATION_90:
return 90;
case Surface.ROTATION_180:
return 180;
case Surface.ROTATION_270:
return 270;
}
return 0;
}
protected void setCameraOrientation() {
int orientation = ((WindowManager) getSystemService(
Context.WINDOW_SERVICE)).getDefaultDisplay().getRotation();
int degrees = orientationToAngle(orientation);
android.hardware.Camera.CameraInfo info = new android.hardware.Camera.CameraInfo();
android.hardware.Camera.getCameraInfo(0, info);
degrees = (degrees + 45) / 90 * 90;
int rotation = 0;
if (info.facing != CameraInfo.CAMERA_FACING_FRONT) {
rotation = (info.orientation - degrees + 360) % 360;
} else {
rotation = (info.orientation + degrees) % 360;
}
Camera.Parameters parameters = camera.getParameters();
parameters.setRotation(rotation);
camera.setParameters(parameters);
}
}

Camera : setDisplayOrientation function is not working for Samsung Galaxy ACE with Android 2.3.6

I was trying to create a simple camera application for research.
I Read Android Camera Official Document and then started coding.
so I did some steps to get it work
1.Added required permissions for Camera feature in app.
2.locked my activity to PORTRAIT mode only.
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
3.Added several camera callbacks to get my camera works.
SurfaceHolder.Callback,
Camera.PreviewCallback
AutoFocusCallback
ShutterCallback
PictureCallback for RAW image data
PictureCallback for JPG image data
4.In surfaceChanged method I am customizing camera settings.
and so far I got working this for almost all android devices
LG
Spice
Samsung
HTC
Micromax
Sony
Motorola
Google Nexus series.
But then I tested on Samsung Galaxy ACE with Android Version 2.3.6
and found Camera Display Preview is Rotated to landscape mode.
So after putting log-cat/break points I come to know that below methods are not working for this particular model
//This method is not working for Samsung Galaxy ACE
camera.setDisplayOrientation(90);
//or
parameters.set("orientation", "portrait");
//or
parameters.setRotation(90);
Note: I Hunted bunch of solutions over Google and SO as well but so far didn't get any luck in this
Issus reported here
android camera surfaceview orientation
Android portrait locked Camera Preview
Android - Camera preview is sideways
Android camera rotate
Android: Camera preview Rotated
How to set Android camera orientation properly?
For your reference My sample code is below
#Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
Log.v(TAG, "surfaceChanged get called");
if (previewing) {
camera.stopPreview();
previewing = false;
}
if (camera != null) {
try {
Camera.Parameters parameters = camera.getParameters();
List<Size> sizes = parameters.getSupportedPictureSizes();
Camera.Size result = null;
for (int i = 0; i < sizes.size(); i++) {
result = (Size) sizes.get(i);
Log.i("PictureSize", "Supported Size. Width: "
+ result.width + "height : " + result.height);
if (result.width == 640) {
parameters.setPreviewSize(result.width, result.height);// 640*480
parameters.setPictureSize(result.width, result.height);
} else {
}
}
//**************************************************************//
/*
* Here is the logic I have added to Manage Camera Display Orientation
* It checks Current Orientation and SDK and then rotate display to make it Portrait view.
*/
int currentSDKVersion = android.os.Build.VERSION.SDK_INT;
Log.d(TAG, "currentVersion " + currentSDKVersion);
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {
if (currentSDKVersion != 7) {
camera.setDisplayOrientation(90);
parameters.setRotation(90);
} else {
parameters.setRotation(90);
/*
* params.set("orientation", "portrait");
* params.set("rotation",90);
*/
}
} else if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
if (currentSDKVersion != 7) {
camera.setDisplayOrientation(0);
} else {
parameters.set("orientation", "landscape");
parameters.set("rotation", 90);
}
}
//**************************************************************//
camera.setParameters(parameters);
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
camera.autoFocus(myAutoFocusCallback);
camera.setOneShotPreviewCallback(cameraPreviewCallback);
previewing = true;
} catch (IOException e) {
e.printStackTrace();
}
}
}
My Camera Activity (MainActivity.java) Full code is:
public class MainActivity extends Activity implements SurfaceHolder.Callback,
OnClickListener {
public static final String TAG = "CameraActivity";
private Context context = null;
Camera camera = null;
private SurfaceView surfaceView = null;
private SurfaceHolder surfaceHolder = null;
boolean previewing = false;
private LayoutInflater controlInflater = null;
private Button buttonTakePicture = null;
//private TextView textViewResultInfo = null;
#SuppressWarnings("deprecation")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Log.v(TAG, "onCreate get called");
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
//textViewResultInfo = (TextView) findViewById(R.id.textViewResultInfo);
context = this;
getWindow().setFormat(PixelFormat.UNKNOWN);
surfaceView = (SurfaceView) findViewById(R.id.surfaceview);
surfaceHolder = surfaceView.getHolder();
surfaceHolder.addCallback(this);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
controlInflater = LayoutInflater.from(getBaseContext());
View viewControl = controlInflater.inflate(R.layout.control, null);
LayoutParams layoutParamsControl = new LayoutParams(
LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
this.addContentView(viewControl, layoutParamsControl);
buttonTakePicture = (Button) findViewById(R.id.takepicture);
buttonTakePicture.setOnClickListener(this);
}
#Override
public void surfaceCreated(SurfaceHolder arg0) {
Log.v(TAG, "surfaceCreated get called");
camera = Camera.open();
if (camera != null) {
try {
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
previewing = true;
} catch (IOException e) {
e.printStackTrace();
}
}
}
#Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
Log.v(TAG, "surfaceChanged get called");
if (previewing) {
camera.stopPreview();
previewing = false;
}
if (camera != null) {
try {
//new MainActivity().setCameraDisplayOrientation();
Camera.Parameters parameters = camera.getParameters();
// List<String> focusModes =
// parameters.getSupportedFocusModes();
// if (focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO))
// {
// parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
// }
List<Size> sizes = parameters.getSupportedPictureSizes();
Camera.Size result = null;
for (int i = 0; i < sizes.size(); i++) {
result = (Size) sizes.get(i);
Log.i("PictureSize", "Supported Size. Width: "
+ result.width + "height : " + result.height);
if (result.width == 640) {
parameters.setPreviewSize(result.width, result.height);// 640*480
parameters.setPictureSize(result.width, result.height);
} else {
}
}
//**************************************************************//
Display display = ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
int rotation = display.getRotation();
Log.v(TAG, "Current Device Orientation is ="+rotation);
/*
* Here is the logic I have added to Manage Camera Display Orientation
* It checks Current Orientation and SDK and then rotate display to make it Portrait view.
*/
int currentSDKVersion = android.os.Build.VERSION.SDK_INT;
Log.d(TAG, "currentVersion " + currentSDKVersion);
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {
if (currentSDKVersion != 7) {
Log.i(TAG, "ORIENTATION_PORTRAIT +SDK is: " + currentSDKVersion
+ "rotate 90");
camera.setDisplayOrientation(90);
parameters.setRotation(90);
} else {
Log.i(TAG, "ORIENTATION_PORTRAIT +SDK is: " + currentSDKVersion
+ "rotate 90");
parameters.setRotation(90);
/*
* params.set("orientation", "portrait");
* params.set("rotation",90);
*/
}
} else if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
if (currentSDKVersion != 7) {
Log.i(TAG, "ORIENTATION_LANDSCAPE +SDK is: " + currentSDKVersion
+ "rotate 90");
camera.setDisplayOrientation(0);
} else {
Log.i(TAG, "ORIENTATION_LANDSCAPE +SDK is: " + currentSDKVersion
+ "rotate 90");
parameters.set("orientation", "landscape");
parameters.set("rotation", 90);
}
}
//**************************************************************//
camera.setParameters(parameters);
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
camera.autoFocus(myAutoFocusCallback);
camera.setOneShotPreviewCallback(cameraPreviewCallback);
previewing = true;
} catch (IOException e) {
e.printStackTrace();
}
}
}
#Override
public void surfaceDestroyed(SurfaceHolder arg0) {
Log.v(TAG, "surfaceDestroyed get called");
camera.stopPreview();
camera.release();
camera = null;
previewing = false;
}
public void setCameraDisplayOrientation()
{
Log.v(TAG, "setCameraDisplayOrientation get called");
if (camera == null)
{
Log.d(TAG,"setCameraDisplayOrientation - camera null");
return;
}
Camera.CameraInfo info = new Camera.CameraInfo();
Camera.getCameraInfo(1, info);
WindowManager winManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
int rotation = winManager.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);
}
#Override
public void onClick(View v) {
Log.v(TAG, "onClick get called");
if (v == buttonTakePicture) {
camera.takePicture(myShutterCallback, myPictureCallback_RAW,
myPictureCallback_JPG);
}
}
private Camera.PreviewCallback cameraPreviewCallback = new Camera.PreviewCallback() {
#Override
public void onPreviewFrame(byte[] data, Camera camera) {
Log.i(TAG, "onPreviewFrame size=" + data.length);
}
};
AutoFocusCallback myAutoFocusCallback = new AutoFocusCallback() {
#Override
public void onAutoFocus(boolean arg0, Camera arg1) {
Log.v(TAG, "onAutoFocus get called");
buttonTakePicture.setEnabled(true);
}
};
ShutterCallback myShutterCallback = new ShutterCallback() {
#Override
public void onShutter() {
Log.v(TAG, "onShutter get called");
}
};
PictureCallback myPictureCallback_RAW = new PictureCallback() {
#Override
public void onPictureTaken(byte[] arg0, Camera arg1) {
Log.v(TAG, "onPictureTaken-RAW get called");
}
};
public static Bitmap RotateBitmap(Bitmap source, float angle) {
Matrix matrix = new Matrix();
matrix.postRotate(angle);
return Bitmap.createBitmap(source, 0, 0, source.getWidth(),
source.getHeight(), matrix, true);
}
PictureCallback myPictureCallback_JPG = new PictureCallback() {
#Override
public void onPictureTaken(byte[] arg0, Camera arg1) {
Bitmap rawImage = BitmapFactory.decodeByteArray(arg0, 0,
arg0.length);
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {
Log.v(TAG, "##### ORIENTATION_PORTRAIT ####");
rawImage = MainActivity.RotateBitmap(rawImage, 90);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
rawImage.compress(Bitmap.CompressFormat.JPEG, 100, stream);
arg0 = stream.toByteArray();
} else if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
Log.v(TAG, "##### ORIENTATION_LANDSCAPE #####");
}
Intent intent = new Intent(MainActivity.this, ResultActivity.class);
intent.putExtra("picture", arg0);
startActivity(intent);
Log.v(TAG, "onPictureTaken-JPG get called");
}
};
/**
* Get the size in bitmap.
*
* #param bitmap
* #return size in bytes
*/
#TargetApi(12)
public static int getBitmapSize(Bitmap bitmap) {
if (MainActivity.hasHoneycombMR1()) {
return bitmap.getByteCount();
}
// Pre HC-MR1
return bitmap.getRowBytes() * bitmap.getHeight();
}
public static boolean hasHoneycombMR1() {
return Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR1;
}
}
Edit : I have posted Comment on Developer forum but no response.
Please!! Someone have any Idea regarding this problem.
I would really appreciate for any kind of suggestion.

When I had a similar problem with the original Galaxy Tab running 2.2.1, I was able to solve it by doing the following:
Camera.Parameters parameters = camera.getParameters();
parameters.set("orientation", "portrait");
parameters.setRotation(90);
camera.setParameters(parameters);
However, it looks like you may have already tried that exact combination, given that you have identical (but commented out) code above. However, the way you have the code right now, the Ace is going to bypass where you have that commented code because of it's API level (10). Try it specifically inside this block:
if (currentSDKVersion != 7) { }
And let me know if it works, please. Thanks!

I was searching for a solution for hours too. Its really crazy.
My solution was to just use the camera preview in landscape mode (in my portrait app) and mask out the parts of the preview I don't need. I did this by overlaying upper and lower pars of my fullscreen preview with some views. Of cause you have to crop the photo you are getting from the camera then, WHICH RESULTS IN LESS RESOLUTION. For my app this was no issue.
I am totally happy with my solution now- users don't see any difference;

I have handled camera by writing some code that was majorly adapted from the ZXing project: http://code.google.com/p/zxing/
You could try using those. If you are trying to use this, I would recommend going through the solution of this stackoverflow question
This may not be the perfect solution to your question, but I had ran through this issue and had decided to use Zxing.