Develop Reference

E/Camera: Error 2 in Logcat when using camera in app (Java App Development for Android)

Been through hell coding my first android app.
E/Camera: Error 2 in Logcat whenever camera is used (the error code is for multiple camera uses)
I have attached the entire project if you want to and can run it. Kindly help.
Link to Project on Google Drive
I am also attaching the code to the main files in this post if you want to view it directly.
Here is MainActivity.java
package com.example.cse535a1;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.FileProvider;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.Button;
import android.content.Context;
import android.view.View;
import android.hardware.*;
import android.widget.FrameLayout;
import android.widget.TextView;
import org.opencv.core.*;
import org.opencv.videoio.VideoCapture;
import java.io.File;
public class MainActivity extends AppCompatActivity implements SensorEventListener {
private Camera c;
private CameraView cv1;
private FrameLayout view_camera;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (!(getApplicationContext().getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA))) {
this.finish();
System.exit(0);
}
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
VideoCapture video_capture;
Button button_symptoms = (Button)findViewById(R.id.button_symptoms);
Button button_upload_signs = (Button)findViewById(R.id.button_upload_signs);
Button button_measure_heart_rate = (Button)findViewById(R.id.button_measure_heart_rate);
Button button_measure_respiratory_rate = (Button)findViewById(R.id.button_measure_respiratory_rate);
c = getcam();
cv1 = new CameraView(getApplicationContext(), c);
view_camera = (FrameLayout)findViewById(R.id.view_camera);
view_camera.addView(cv1);
TextView finger_on_sensor = (TextView)findViewById(R.id.text_finger_on_sensor);
finger_on_sensor.setVisibility(View.INVISIBLE);
finger_on_sensor.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View arg_view, MotionEvent arg_me) {
finger_on_sensor.setVisibility(View.INVISIBLE);
File file_video = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/video_finger.mp4");
final int VIDEO_CAPTURE = 1;
Intent intent_record_video = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
intent_record_video.putExtra(MediaStore.EXTRA_DURATION_LIMIT, 45);
Uri fileUri = FileProvider.getUriForFile(MainActivity.this, "com.example.cse535a1.provider", file_video);
intent_record_video.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
c.release();
startActivityForResult(intent_record_video, VIDEO_CAPTURE);
c.stopPreview();
return true;
}
});
button_symptoms.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg_view) {
Intent intent = new Intent(getApplicationContext(), Loggin_symptoms.class);
startActivity(intent);
}
});
button_upload_signs.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg_view) {
}
});
button_measure_heart_rate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg_view) {
finger_on_sensor.setVisibility(View.VISIBLE);
}
});
button_measure_respiratory_rate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg_view) {
SensorManager manager_sensor = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
Sensor sensor_accelerometer = manager_sensor.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
manager_sensor.registerListener(MainActivity.this, sensor_accelerometer, SensorManager.SENSOR_DELAY_NORMAL);
}
});
}
#Override
public void onSensorChanged(SensorEvent arg_event) {
float x = arg_event.values[0];
float y = arg_event.values[1];
float z = arg_event.values[2];
Log.i("ACCELEROMETER", String.valueOf(x) + ' ' + String.valueOf(y) + ' ' + String.valueOf(z));
}
#Override
public void onAccuracyChanged(Sensor arg_sensor, int arg_accuracy) {
}
public Camera getcam() {
Camera c = null;
try { c = Camera.open(0); }
catch (Exception e) {
}
return c;
}
#Override
protected void onResume() {
super.onResume();
c = getcam();
cv1 = new CameraView(getApplicationContext(), c);
view_camera.addView(cv1);
}
#Override
protected void onDestroy() {
c.stopPreview();
c.release();
c = null;
super.onDestroy();
}
}
Here is CameraView.java
package com.example.cse535a1;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.content.Context;
import android.hardware.Camera;
import java.io.IOException;
public class CameraView extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder holder_surface;
private Camera camera_selected;
public CameraView(Context arg_context, Camera arg_camera) {
super(arg_context);
// Log.i("Cam", "constructor");
camera_selected = arg_camera;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
holder_surface = getHolder();
holder_surface.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
holder_surface.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder arg_holder) {
// The Surface has been created, now tell the camera where to draw the preview.
try {
camera_selected.setPreviewDisplay(arg_holder);
camera_selected.startPreview();
// Log.i("Cam", "surface creator");
} 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 arg_holder, int arg_format, int arg_width, int arg_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 (holder_surface.getSurface() == null){
// preview surface does not exist
return;
}
// stop preview before making changes
try {
camera_selected.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_selected.setPreviewDisplay(holder_surface);
camera_selected.startPreview();
} catch (Exception e){
// Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
}

Here are updated files. It seems removing statements which release camera seems to remove errors of using camera after releasing. Unlocking the camera in onPause() removed-> E/Camera: Error 2
MainActivity.java
package com.example.cse535a1;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.FileProvider;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.Button;
import android.content.Context;
import android.view.View;
import android.hardware.*;
import android.widget.FrameLayout;
import android.widget.TextView;
import org.opencv.core.*;
import org.opencv.videoio.VideoCapture;
import java.io.File;
public class MainActivity extends AppCompatActivity implements SensorEventListener {
private Camera c;
private CameraView cv1;
private FrameLayout view_camera;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (!(getApplicationContext().getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA))) {
this.finish();
System.exit(0);
}
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
VideoCapture video_capture;
Button button_symptoms = (Button)findViewById(R.id.button_symptoms);
Button button_upload_signs = (Button)findViewById(R.id.button_upload_signs);
Button button_measure_heart_rate = (Button)findViewById(R.id.button_measure_heart_rate);
Button button_measure_respiratory_rate = (Button)findViewById(R.id.button_measure_respiratory_rate);
cv1 = new CameraView(getApplicationContext(), this);
view_camera = (FrameLayout)findViewById(R.id.view_camera);
view_camera.addView(cv1);
TextView finger_on_sensor = (TextView)findViewById(R.id.text_finger_on_sensor);
finger_on_sensor.setVisibility(View.INVISIBLE);
finger_on_sensor.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View arg_view, MotionEvent arg_me) {
finger_on_sensor.setVisibility(View.INVISIBLE);
File file_video = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/video_finger.mp4");
final int VIDEO_CAPTURE = 101;
Intent intent_record_video = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
intent_record_video.putExtra(MediaStore.EXTRA_DURATION_LIMIT, 45);
Uri fileUri = FileProvider.getUriForFile(MainActivity.this, "com.example.cse535a1.provider", file_video);
intent_record_video.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
startActivityForResult(intent_record_video, VIDEO_CAPTURE);
return false;
}
});
button_symptoms.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg_view) {
Intent intent = new Intent(getApplicationContext(), Loggin_symptoms.class);
startActivity(intent);
}
});
button_upload_signs.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg_view) {
}
});
button_measure_heart_rate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg_view) {
finger_on_sensor.setVisibility(View.VISIBLE);
}
});
button_measure_respiratory_rate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg_view) {
SensorManager manager_sensor = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
Sensor sensor_accelerometer = manager_sensor.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
manager_sensor.registerListener(MainActivity.this, sensor_accelerometer, SensorManager.SENSOR_DELAY_NORMAL);
}
});
}
public void setCam(Camera arg_camera) {
c = arg_camera;
}
#Override
public void onSensorChanged(SensorEvent arg_event) {
float x = arg_event.values[0];
float y = arg_event.values[1];
float z = arg_event.values[2];
Log.i("ACCELEROMETER", String.valueOf(x) + ' ' + String.valueOf(y) + ' ' + String.valueOf(z));
}
#Override
public void onAccuracyChanged(Sensor arg_sensor, int arg_accuracy) {
}
public Camera getcam() {
Camera c = null;
try { c = Camera.open(0); }
catch (Exception e) {
}
return c;
}
#Override
protected void onPause() {
super.onPause();
c.unlock();
// if (c != null) {
// c.stopPreview();
// c.release();
// c = null;
// }
}
#Override
protected void onResume() {
super.onResume();
// if (c != null) {
// c.stopPreview();
// c.release();
// c = null;
// }
// cv1 = new CameraView(getApplicationContext(), this);
// view_camera.addView(cv1);
}
#Override
protected void onDestroy() {
if (c != null) {
c.stopPreview();
c.release();
c = null;
}
super.onDestroy();
}
}
CameraView.java
package com.example.cse535a1;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.content.Context;
import android.hardware.Camera;
import java.io.IOException;
public class CameraView extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder holder_surface;
private Camera camera_selected;
MainActivity act1;
public CameraView(Context arg_context, MainActivity arg_activity) {
super(arg_context);
// camera_selected = arg_camera;
act1 = arg_activity;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
holder_surface = getHolder();
holder_surface.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
holder_surface.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder arg_holder) {
// The Surface has been created, now tell the camera where to draw the preview.
try {
// Log.i("CAMNULL", "CAM IS : " + String.valueOf(camera_selected == null));
Camera c = null;
try {
c = Camera.open(0);
} catch (Exception e) {
Log.e("CAMERA", "Camera not opened");
}
act1.setCam(c);
camera_selected = c;
camera_selected.setPreviewDisplay(arg_holder);
// camera_selected.startPreview();
// Log.i("Cam", "surface creator");
} 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.
// if (camera_selected != null) {
// camera_selected.stopPreview();
// camera_selected.release();
// camera_selected = null;
// }
}
public void surfaceChanged(SurfaceHolder arg_holder, int arg_format, int arg_width, int arg_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 (holder_surface.getSurface() == null){
// preview surface does not exist
return;
}
// stop preview before making changes
try {
camera_selected.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_selected.setPreviewDisplay(holder_surface);
camera_selected.startPreview();
} catch (Exception e){
// Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
}

Open OpenCV Camera via Button on Android Studio

My main activity has a button and I want that button to redirect me to the opencv camera. I have this code below and my app won't open anymore.
MainActivity.java
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;
import nerds.thesis.clartips.adapter.ListProductAdapter;
import nerds.thesis.clartips.database.DatabaseHelper;
import nerds.thesis.clartips.model.Product;
public class CLARTIPS_Home extends AppCompatActivity {
private ListView lvProduct;
private ListProductAdapter adapter;
private List<Product> mProductList;
private DatabaseHelper mDBHelper;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_clartips__home);
lvProduct = (ListView) findViewById(R.id.listview_product);
mDBHelper = new DatabaseHelper(this);
Button tryMe = (Button) findViewById(R.id.tryMe);
tryMe.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
showCam();
}
});
//Check exists database
File database = getApplicationContext().getDatabasePath(DatabaseHelper.DBNAME);
if(false==database.exists()) {
mDBHelper.getReadableDatabase();
//Copy db
if (copyDatabase(this)) {
Toast.makeText(this, "Success Copying Database", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(this, "Error Copying Database", Toast.LENGTH_SHORT).show();
return;
}
}
//Get product list in db when db exists
mProductList = mDBHelper.getListProduct();
//Init adapter
adapter = new ListProductAdapter(this,mProductList);
//Set adapter for listview
lvProduct.setAdapter(adapter);
}
private boolean copyDatabase(Context context) {
try {
InputStream inputStream = context.getAssets().open(DatabaseHelper.DBNAME);
String outFileName = DatabaseHelper.DBLOCATION + DatabaseHelper.DBNAME;
OutputStream outputStream = new FileOutputStream(outFileName);
byte[]buff = new byte[1024];
int length = 0;
while ((length = inputStream.read(buff)) > 0) {
outputStream.write(buff, 0, length);
}
outputStream.flush();
outputStream.close();
Log.w("MainActivity","DB copied");
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu, menu);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected (MenuItem item){
switch (item.getItemId()) {
case R.id.about:
Intent aboutIntent = new Intent(CLARTIPS_Home.this, About.class);
startActivity(aboutIntent);
}
return super.onOptionsItemSelected(item);
}
private void showCam(){
Intent intent = new Intent(this, MA_show_camera.class);
startActivity(intent);
}
}
MA_show_camera.java
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.MenuItem;
import android.view.SurfaceView;
import android.view.WindowManager;
import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.JavaCameraView;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgproc.Imgproc;
//OpenCV Classes
public class MA_show_camera extends AppCompatActivity implements CameraBridgeViewBase.CvCameraViewListener2 {
//Used for logging success or failure messages
private static final String TAG = "OCVSample::Activity";
//Loads camera view of OpenCV for us to use. This lets us to see using OpenCV
private CameraBridgeViewBase mOpenCvCameraView;
//Used in Camera selection from menu (when implemented)
private boolean mIsJavaCamera = true;
private MenuItem mItemSwitchCamera = null;
//These variables are used (at the moment) to fix camera orientation form 270degree to 0degree
Mat mRgba;
Mat mRgbaF;
Mat mRgbaT;
private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
#Override
public void onManagerConnected(int status) {
switch (status){
case LoaderCallbackInterface.SUCCESS:
{
Log.i(TAG, "OpenCV loaded successfully");
mOpenCvCameraView.enableView();
} break;
default:
{
super.onManagerConnected(status);
} break;
}
}
};
public MA_show_camera(){
Log.i(TAG, "Instantiated new " + this.getClass());
}
#Override
protected void onCreate(Bundle savedInstanceState) {
Log.i(TAG, "called onCreate");
super.onCreate(savedInstanceState);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setContentView(R.layout.show_camera);
mOpenCvCameraView = (JavaCameraView) findViewById(R.id.show_camera_activity_java_surface_view);
mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);
mOpenCvCameraView.setCvCameraViewListener(this);
}
#Override
public void onPause(){
super.onPause();
if(mOpenCvCameraView != null)
mOpenCvCameraView.disableView();
}
#Override
public void onResume(){
super.onResume();
if(!OpenCVLoader.initDebug()){
Log.d(TAG, "Internal OpenCV library not found. Using OpenCV Manager for Initialization");
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_4_0, this, mLoaderCallback);
} else{
Log.d(TAG, "Internal OpenCV found inside package. Using it!");
mLoaderCallback.onManagerConnected(LoaderCallbackInterface.SUCCESS);
}
}
public void onDestroy(){
super.onDestroy();
if(mOpenCvCameraView != null)
mOpenCvCameraView.disableView();
}
#Override
public void onCameraViewStarted(int width, int height) {
mRgba = new Mat(height, width, CvType.CV_8UC4);
mRgbaF = new Mat(height, width, CvType.CV_8UC4);
mRgbaT = new Mat(height, width, CvType.CV_8UC4);
}
#Override
public void onCameraViewStopped() {
mRgba.release();
}
#Override
public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame) {
//TODO Auto-generated method sub
mRgba = inputFrame.rgba();
//Rotate mRgba 90 degrees
Core.transpose(mRgba, mRgbaT);
Imgproc.resize(mRgbaT, mRgbaF, mRgbaF.size(), 0,0, 0);
Core.flip(mRgbaF, mRgba, 1);
return mRgba; //This function must return
}
}
I found a tutorial on how to open the camera (the code I used above) but it opens right when you open the app and I wanted it to open via button so I used intent. I'm a beginner so I only know a little about opencv and android development.

you need to pass an extra parameter in the
void startActivityForResult (Intent intent, int requestCode) ;
You can look at the docs for more information.
https://developer.android.com/reference/android/app/Activity.html#startActivityForResult(android.content.Intent,int)
hope this helps
In your main activity , in the onTouch() , you can replace
openCam() with
Intent myIntent = new Intent(CLARTIPS_Home.this, MA_show_camera.class);
CLARTIPS_Home.this.startActivity(myIntent);
The in your camera Activity you can get a handle on it like so
#Override
protected void onCreate(Bundle savedInstanceState) {
Intent intent = getIntent();

android.media.MediaRecorder.start(Native Method)

I want to make a video recorder app but it crashes when I click the "Start Recording" button. I get an error saying java.lang.IllegalStateException at android.media.MediaRecorder.start(Native Method). I've also attached the log.
package com.example.cgv.slavecamera;
import android.Manifest;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.media.MediaRecorder;
import android.os.Build;
import android.os.Environment;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.ToggleButton;
import java.io.File;
import java.io.IOException;
public class MainActivity extends AppCompatActivity implements SurfaceHolder.Callback{
private static final String VIDEO_PATH_NAME = "/Pictures/test.3gp";
private static final int MY_REQUEST_CODE = 1;
private MediaRecorder mMediaRecorder;
private Camera mCamera;
private SurfaceView mSurfaceView;
private SurfaceHolder mHolder;
private View mToggleButton;
private boolean mInitSuccesful;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.M){
//use checkSelfPermission()
if (checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[]{Manifest.permission.CAMERA},
MY_REQUEST_CODE);
}
} else {
//simply use the required feature
//as the user has already granted permission to them during installation
}
mSurfaceView = (SurfaceView) findViewById(R.id.surfaceView);
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
mToggleButton = (ToggleButton) findViewById(R.id.toggleRecordingButton);
mToggleButton.setOnClickListener(new View.OnClickListener() {
#Override
// toggle video recording
public void onClick(View v) {
if (((ToggleButton)v).isChecked())
// mMediaRecorder.start();
try {
mMediaRecorder.start();
} catch (IllegalStateException e) {
// This is thrown if the previous calls are not called with the
// proper order
e.printStackTrace();
}
else {
mMediaRecorder.stop();
mMediaRecorder.reset();
try {
initRecorder(mHolder.getSurface());
} catch (IOException e) {
e.printStackTrace();
}
}
}
});
}
private void initRecorder(Surface surface) throws IOException {
if (mCamera == null) {
mCamera = Camera.open();
mCamera.unlock();
}
if (mMediaRecorder == null)
mMediaRecorder = new MediaRecorder();
mMediaRecorder.setPreviewDisplay(surface);
mMediaRecorder.setCamera(mCamera);
mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);
File file = new File(Environment.getExternalStorageDirectory(), VIDEO_PATH_NAME);
// "touch" the file
if (!file.exists()) {
File parent = file.getParentFile();
if (parent != null)
if (!parent.exists())
if (!parent.mkdirs())
throw new IOException("Cannot create " +
"parent directories for file: " + file);
file.createNewFile();
mMediaRecorder.setOutputFile(file.getAbsolutePath());
// No limit. Check the space on disk!
mMediaRecorder.setMaxDuration(-1);
mMediaRecorder.setVideoFrameRate(15);
mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.DEFAULT);
try {
mMediaRecorder.prepare();
} catch (IllegalStateException e) {
// This is thrown if the previous calls are not called with the
// proper order
e.printStackTrace();
}
mInitSuccesful = true;
}
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
try {
if(!mInitSuccesful)
initRecorder(mHolder.getSurface());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
// Release MediaRecorder and especially the Camera as it's a shared
// object that can be used by other applications
mMediaRecorder.reset();
mMediaRecorder.release();
mCamera.release();
// once the objects have been released they can't be reused
mMediaRecorder = null;
mCamera = null;
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == MY_REQUEST_CODE) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// Now user should be able to use camera
}
else {
// Your app will not have this permission. Turn off all functions
// that require this permission or it will force close like your
// original question
}
}
}
}
and I am getting the following error
FATAL EXCEPTION: main
Process: com.example.cgv.slavecamera, PID: 7830
java.lang.IllegalStateException
at android.media.MediaRecorder.stop(Native Method)
at com.example.cgv.slavecamera.MainActivity$1.onClick(MainActivity.java:69)
at android.view.View.performClick(View.java:5207)
at android.widget.CompoundButton.performClick(CompoundButton.java:122)
at android.view.View$PerformClick.run(View.java:21168)
at android.os.Handler.handleCallback(Handler.java:746)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5459)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)

Custom camera app rotates to front view, but doesn't go back to back view

As the title says, this is my problem.
My camera successfully goes to front camera, but on the second button click, it doesn't change back to back view and stays front view.
CameraActivity.java:
package mano.whatever;
import android.app.Activity;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Picture;
import android.graphics.RectF;
import android.hardware.Camera;
import android.media.Image;
import android.net.Uri;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.annotation.Nullable;
import android.util.Base64;
import android.util.Log;
import android.view.View;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.Toast;
import android.os.AsyncTask;
import com.google.android.gms.identity.intents.AddressConstants;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
public class CameraActivity extends Activity {
private Camera.Size mSize = null;
private Camera mCamera = null;
private CameraView mCameraView=null;
private SurfaceView mPreview;
private SurfaceHolder mSurfaceHolder;
Camera.PictureCallback jpegCallback;
final int CAMERA_CAPTURE = 1;
private Camera.PictureCallback mPictureCallback;
boolean isFront;
int camBackId = Camera.CameraInfo.CAMERA_FACING_BACK;
int camFrontId = Camera.CameraInfo.CAMERA_FACING_FRONT;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_camera);
if (mCamera == null){
initCamera(0);
}
//btn to close the application
ImageView imgClose = (ImageView) findViewById(R.id.left_button);
imgClose.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
toThanksActivity();
}
});
ImageView photo = (ImageView) findViewById(R.id.photo_button);
photo.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
mCamera.autoFocus(new Camera.AutoFocusCallback() {
#Override
public void onAutoFocus(boolean b, Camera camera) {
mCamera.takePicture(shutterCall, PictureCallback, mPicture);
}
});
}
});
ImageView rotate = (ImageView) findViewById(R.id.rotate_camera);
rotate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
rotateCamera();
}
});
}
public void rotateCamera() {
boolean isFront = false;
int CamId = 0;
CamId = Camera.getNumberOfCameras();
int cameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
Camera.CameraInfo currentCamInfo = new Camera.CameraInfo();
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
if (currentCamInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK){
initCamera(1);
}
else{
initCamera(0);
}
}
public void initCamera(int potato){
mCamera = Camera.open(potato);//you can use open(int) to use different cameras
FrameLayout camera_view = (FrameLayout) findViewById(R.id.camera_view);
camera_view.removeView(mCameraView);
if (mCamera != null) {
mCameraView = new CameraView(this, mCamera);//create a SurfaceView to show camera data
camera_view.addView(mCameraView);//add the SurfaceView to the layout
}
}
public void toThanksActivity() {
mCamera.stopPreview();
mCamera.release();
finish();
}
public void toCaptureImage() {
mCamera.takePicture(shutterCall, PictureCallback, mPicture);
}
Camera.ShutterCallback shutterCall = new Camera.ShutterCallback() {
#Override
public void onShutter() {
}
};
Camera.PictureCallback PictureCallback = new Camera.PictureCallback() {
#Override
public void onPictureTaken(byte[] bytes, Camera camera) {
}
};
Camera.PictureCallback mPicture = new Camera.PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyymmddhhmmss");
String date = dateFormat.format(new Date());
String photoFile = "Picture_" + date + ".jpg";
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM), "Camera");
String filename = mediaStorageDir.getPath() + File.separator + photoFile;
File pictureFile = new File(filename);
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.flush();
fos.close();
ByteArrayOutputStream stream = new ByteArrayOutputStream();
Bitmap bm = BitmapFactory.decodeFile(filename);
Matrix matrix = new Matrix();
matrix.postRotate(90);
Bitmap rotatedBitmap = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), matrix, true);
FileOutputStream fos2 = new FileOutputStream(pictureFile);
rotatedBitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
byte[] byteArray = stream.toByteArray();
mCamera.stopPreview();
mCamera.release();
Intent intent = new Intent();
intent.putExtra("image", byteArray);
setResult(250, intent);
finish();
} catch (IOException e) {
}
}
};
Camera.AutoFocusCallback myAutoFocusCallback = new Camera.AutoFocusCallback() {
#Override
public void onAutoFocus(boolean b, Camera camera) {
}
};
}
CameraView.java:
package mano.whatever;
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;
import java.io.IOException;
import java.util.List;
public class CameraView extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;
private Camera.Size mSize = null;
public CameraView(Context context, Camera camera) {
super(context);
mCamera = camera;
mCamera.setDisplayOrientation(90);
//get the holder and set this class as the callback, so we can get camera data here
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
#Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
//when the surface is created, we can set the camera to draw images in this surfaceholder
Camera.Parameters parameters = mCamera.getParameters();
List<Camera.Size> previewSizes = parameters.getSupportedPreviewSizes();
// You need to choose the most appropriate previewSize for your app
Size optimalSize = getOptimalPreviewSize(previewSizes, getResources().getDisplayMetrics().widthPixels, getResources().getDisplayMetrics().heightPixels);
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
mCamera.setParameters(parameters);
mCamera.startPreview();
}
#Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i2, int i3) {
//before changing the application orientation, you need to stop the preview, rotate and then start it again
if (mHolder.getSurface() == null)//check if the surface is ready to receive camera data
return;
try {
mCamera.stopPreview();
} catch (Exception e) {
//this will happen when you are trying the camera if it's not running
}
//now, recreate the camera preview
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (IOException e) {
Log.d("ERROR", "Camera error on surfaceChanged " + e.getMessage());
}
}
#Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
//our app has only one screen, so we'll destroy the camera in the surface
//if you are unsing with more screens, please move this code your activity
}
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.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;
}
}
I know this is a sketchy code, but I'd love to hear some suggestions.
Thank you in advance.:)
EDIT
I completely reworked my code, got rid of the CameraView.java class and it works fluently thanks to Android camera preview freezes when switching cameras?

Haven't try but try something like this, hope it works?
public void rotateCamera() {
boolean isFront = false;
int CamId = 0;
CamId = Camera.getNumberOfCameras();
int cameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
Camera.CameraInfo currentCamInfo = new Camera.CameraInfo();
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
if (currentCamInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK){
camera = Camera.open(Camera.CameraInfo.CAMERA_FACING_BACK);
}
else{
camera = Camera.open(Camera.CameraInfo.CAMERA_FACING_FRONT);
}
if (mCamera != null) {
try {
mCamera.setPreviewDisplay(surfaceView.getHolder());
mCamera.startPreview();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

ZBar Scanner QR only

I'm using ZBar QR scanner for my android application. Everything is running fine and have no problems with the library and the settings. The problem is that I want to make ZBar to scan only QR codes and no barcodes.
Is there a way to do it? How?
This is my scanning Activity code:
import net.sourceforge.zbar.Config;
import net.sourceforge.zbar.Image;
import net.sourceforge.zbar.ImageScanner;
import net.sourceforge.zbar.Symbol;
import net.sourceforge.zbar.SymbolSet;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.content.res.Resources;
import android.graphics.Color;
import android.hardware.Camera;
import android.hardware.Camera.AutoFocusCallback;
import android.hardware.Camera.PreviewCallback;
import android.hardware.Camera.Size;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.TextView;
public class QRScanActivity extends Activity {
private Camera mCamera;
private CameraPreview mPreview;
private Handler autoFocusHandler;
TextView scanText;
Button scanButton;
ImageScanner scanner;
private boolean barcodeScanned = false;
private boolean previewing = true;
static {
System.loadLibrary("iconv");
}
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_qrscan);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
autoFocusHandler = new Handler();
mCamera = getCameraInstance();
// 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);
}
public void onPause() {
super.onPause();
releaseCamera();
}
/** 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() {
public void run() {
if (previewing)
mCamera.autoFocus(autoFocusCB);
}
};
PreviewCallback previewCb = new PreviewCallback() {
public void onPreviewFrame(byte[] data, Camera camera) {
Camera.Parameters parameters = camera.getParameters();
Size size = parameters.getPreviewSize();
Image barcode = new Image(size.width, size.height, "Y800");
barcode.setData(data);
int result = scanner.scanImage(barcode);
Log.d("ZbarScanner",result+"");
if (result != 0) {
previewing = false;
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
SymbolSet syms = scanner.getResults();
for (Symbol sym : syms) {
barcodeScanned = true;
Intent returnIntent = new Intent();
returnIntent.putExtra("result",sym.getData());
setResult(RESULT_OK,returnIntent);
finish();
}
}
}
};
// Mimic continuous auto-focusing
AutoFocusCallback autoFocusCB = new AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
autoFocusHandler.postDelayed(doAutoFocus, 1000);
}
};
public void backToMain(View v){
Intent returnIntent = new Intent();
setResult(RESULT_CANCELED, returnIntent);
finish();
}
}

You can add these codes for ImageScanner
scanner.setConfig(0, Config.ENABLE, 0); //Disable all the Symbols
scanner.setConfig(Symbol.QRCODE, Config.ENABLE, 1); //Only QRCODE is enable
Besides, you can also use the intent action "org.magiclen.barcodescanner.SCAN" to use a zbar-based barcode scanner.
final Intent intent = new Intent("org.magiclen.barcodescanner.SCAN");
final List<ResolveInfo> list = getPackageManager().queryIntentActivities(intent, PackageManager.GET_ACTIVITIES);
if (list.size() > 0) {
intent.putExtra("SCAN_MODE", "QR_CODE_MODE"); // Can also use PRODUCT_MODE, SCAN_MODE, QR_CODE_MODE
startActivityForResult(intent, 0);
} else {
// You may ask your user to install Easy Barcode Scanner
}
To get the scanning result, you must override onActivityResult method:
public void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
if (requestCode == 0) {
if (resultCode == Activity.RESULT_OK) {
final String result = data.getStringExtra("SCAN_RESULT"); // Get scanning result
final String type = data.getStringExtra("code_type"); // Get code type
} else {
// Not scan any code yet
}
}
}