Develop Reference

Android camera face detection does not work the second time

I copied the code Google example in:
https://developer.android.com/guide/topics/media/camera.html
For the first time I open the Camera, face detection works correctly and the callback is fired, I take the photo, close the camera, open the camera again but this time the face detection callback is not called.
If I'll restart my app, the same thing will happen - face detection will only work for the first time I'll use the camera.
here is my code:
private PictureTakenListener mPictureTakenListener;
AlertDialog mAlertDialog;
private Camera mCamera;
boolean mFaceDetectionAvailable;
private Camera.PictureCallback mPicture = new Camera.PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
showText("took a photo with a size of " + data.length);
releaseCamera();
if (mAlertDialog != null) mAlertDialog.dismiss();
mPictureTakenListener.photoTaken(data);
}
};
public class MyFaceDetectionListener implements Camera.FaceDetectionListener {
#Override
public void onFaceDetection(Camera.Face[] faces, Camera camera) {
if (faces != null)
if (faces.length > 0)
if (faces[0].score >= 40)
if (!takingPhotoFlag.get()){
takingPhotoFlag.set(true);
mCamera.takePicture(null, null, mPicture);
}
}
}
private void takePicture(PictureTakenListener listener){
mPictureTakenListener = listener;
if (this.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
showText("this device has a camera");
showText("device has " + String.valueOf(Camera.getNumberOfCameras()) + " cameras");
int foundCamera = -1;
for (int i = 0; i < Camera.getNumberOfCameras(); i++){
Camera.CameraInfo info = new Camera.CameraInfo(); ;
Camera.getCameraInfo(i, info);
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT){
foundCamera = i;
break;
}
}
if (foundCamera == -1){
return;
}
mCamera = null;
try {
mCamera = Camera.open(foundCamera); // attempt to get a Camera instance
}
catch (Exception e){
e.printStackTrace();
showText("could not open the front camera. " + e.getMessage());
return;
}
showText("successfully opened the camera");
mCamera.setDisplayOrientation(90);
Camera.Parameters params = mCamera.getParameters();
params.setPreviewSize(640, 480);
params.setRotation(270);
params.setPictureSize(640, 480);
mFaceDetectionAvailable = params.getMaxNumDetectedFaces() > 0;
mCamera.setParameters(params);
FrameLayout frameLayout = new FrameLayout(this);
if (!mFaceDetectionAvailable) {
frameLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mCamera.takePicture(null, null, mPicture);
}
});
}
AlertDialog.Builder alert = new AlertDialog.Builder(this);
if (!mFaceDetectionAvailable)
alert.setTitle("CLICK IMAGE TO CAPTURE");
alert.setView(frameLayout).setCancelable(true).setOnCancelListener(new DialogInterface.OnCancelListener() {
#Override
public void onCancel(DialogInterface dialog) {
releaseCamera();
runOnUiThread(new Runnable() {
#Override
public void run() {
//do UI stuff...
}
});
}
});
mAlertDialog = alert.create();
mAlertDialog.show();
mAlertDialog.getCurrentFocus();
mAlertDialog.getWindow().setLayout(960, 1280); //Controlling width and height.
mAlertDialog.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);
CameraPreview mPreview = new CameraPreview(this, mCamera);
frameLayout.addView(mPreview);
} else {
showText("no camera on this device");
}
}
public interface PictureTakenListener{
void photoTaken(byte[] image);
}
/** A basic Camera preview class */
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
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.
}
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();
if (mFaceDetectionAvailable) {
mCamera.startFaceDetection();
mCamera.setFaceDetectionListener(new MyFaceDetectionListener());
}
} catch (Exception e){
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
}
private void releaseCamera(){
if (mCamera != null){
mCamera.setPreviewCallback(null);
mCamera.setFaceDetectionListener(null);
mCamera.stopFaceDetection();
mCamera.setErrorCallback(null);
mCamera.release();
mCamera = null;
showText("released camera");
}
}
Thank you.

Camera is being used after Camera.release() was called in Galaxy s6 Edge

I have the following exception on Galaxy s6 edge device
java.lang.RuntimeException: Camera is being used after Camera.release() was called
at android.hardware.Camera.setPreviewSurface(Native Method)
at android.hardware.Camera.setPreviewDisplay(Camera.java:702)
at com.forsale.forsale.view.uicomponent.qrcode.CameraPreview.surfaceCreated(CameraPreview.java:59)
at android.view.SurfaceView.updateWindow(SurfaceView.java:712)
at android.view.SurfaceView.onWindowVisibilityChanged(SurfaceView.java:316)
at android.view.View.dispatchWindowVisibilityChanged(View.java:10434)
at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1328)
at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1328)
at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1328)
at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1328)
at android.view.ViewGroup.dispatchWindowVisibilityChanged(ViewGroup.java:1328)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1750)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1437)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7397)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:920)
at android.view.Choreographer.doCallbacks(Choreographer.java:695)
at android.view.Choreographer.doFrame(Choreographer.java:631)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:906)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
this is my code :
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);
}
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());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Camera preview released in activity
}
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());
}
}
}
this is the code of the activity
public class QRCodeActivity extends BaseActivity
{
private Camera mCamera;
private CameraPreview mPreview;
private Handler mAutoFocusHandler;
private ImageScanner mScanner;
private boolean mBarcodeScanned = false;
private boolean mPreviewing = true;
static {
System.loadLibrary("iconv");
}
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_qrcode);
initializeActionBar();
setActionBarTitle(getString(R.string.qrcode));
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
mAutoFocusHandler = new Handler();
mCamera = getCameraInstance();
mScanner = new ImageScanner();
mScanner.setConfig(0, Config.X_DENSITY, 3);
mScanner.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();
}
public static Camera getCameraInstance(){
Camera c = null;
try {
c = Camera.open();
} catch (Exception e){
}
return c;
}
private void releaseCamera() {
if (mCamera != null) {
mPreviewing = false;
mCamera.setPreviewCallback(null);
mCamera.release();
mCamera = null;
}
}
private Runnable doAutoFocus = new Runnable() {
public void run() {
if (mPreviewing)
mCamera.autoFocus(autoFocusCB);
}
};
PreviewCallback previewCb = new PreviewCallback() {
public void onPreviewFrame(byte[] data, Camera camera) {
Parameters parameters = camera.getParameters();
Size size = parameters.getPreviewSize();
Image barcode = new Image(size.width, size.height, "Y800");
barcode.setData(data);
int result = mScanner.scanImage(barcode);
if (result != 0) {
mPreviewing = false;
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
SymbolSet syms = mScanner.getResults();
for (Symbol sym : syms) {
showProgressDialog();
ForSaleServerManager.getInstance().verifyQRCode(QRCodeActivity.this, PhoneUtils.getDeviceId(QRCodeActivity.this) , sym.getData() , new VerifyQRCodeUIListener() {
#Override
public void onVerifyQRCodeCompleted(QRCodeResponse response, AppError error) {
hideProgressDialog();
if (error != null) {
DialogUtils.showDialogMessage(
QRCodeActivity.this,
getString(R.string.error),
PhoneUtils.getErrorMessage(QRCodeActivity.this, error),
getString(R.string.ok), null);
} else {
if (response != null && response.getError() == null) {
DialogUtils.showDialogMessage(QRCodeActivity.this, getString(R.string.info),
response.getMessage(), getString(R.string.ok), new View.OnClickListener() {
#Override
public void onClick(View view) {
finish();
}
});
} else if (response != null && response.getError() != null) {
DialogUtils.showDialogMessage(
QRCodeActivity.this,
getString(R.string.error),
response.getError().getMessage(),
getString(R.string.ok), null);
}
}
}
});
mBarcodeScanned = true;
}
}
}
};
AutoFocusCallback autoFocusCB = new AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
mAutoFocusHandler.postDelayed(doAutoFocus, 1000);
}
};
#Override
protected void initializeUIComponents() {
}
#Override
protected void initializeUIComponentsData() {
}
#Override
protected void initializeUIComponentsTheme() {
}
#Override
protected void initializeUIComponentsAction() {
}
#Override
public void goodTimeToReleaseMemory() {
/*mCamera = null;
mPreview = null;
mAutoFocusHandler = null;
mScanner = null;*/
Runtime.getRuntime().gc();
finish();
}
}

There is a serious flaw in your code: mCamera.release() is called on every onPause, but Camera.open() is only called onCreate.
This said, it is a bad practice to open camera on the main (UI) thread: this call may take too long on some devices (not on Samsung Galaxy 6) and even cause ANR.
The best practice is to open camera on a background HandlerThread (see https://stackoverflow.com/a/19154438/192373). This will guarantee that the camera callbacks (including onPictureTaken()) don't freeze your UI thread.
At any rate, to keep the mCamera object synchronized with the lifecycle of your activity and its SurfaceView, I recommend to start Camera.open() from surfaceCreated and mCamera.release() - from surfaceDestroyed.

Preview camera frame not capturing Android

I have the code setup (obviously not correctly but it seems ok)
My test code for capturing frame is like this:
frameCallback = new Camera.PreviewCallback() {
public void onPreviewFrame(byte[] data, Camera camera) {
System.out.println("preview frame captured");
But this onPreviewFrame is never ran, as the print statement tests.
The weird thing is, the preview is showing up perfectly on my surface. i.e- I can see it on my screen and there is no errors. Why isn't onPreviewFrame being called then?
Here is all my code for reference:
public class HuntActivity extends AppCompatActivity implements SurfaceHolder.Callback{
Camera camera;
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
Camera.PreviewCallback frameCallback;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_hunt);
surfaceView = (SurfaceView) findViewById(R.id.surfaceView);
surfaceHolder = surfaceView.getHolder();
surfaceHolder.addCallback(this);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
frameCallback = new Camera.PreviewCallback() {
public void onPreviewFrame(byte[] data, Camera camera) {
System.out.println("preview frame captured");
}
};
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
try {camera = Camera.open();
} catch (RuntimeException e) {
System.err.println(e);
return;
}
camera.setPreviewCallback(frameCallback);
Camera.Parameters param;
param = camera.getParameters();
param.setPreviewSize(800, 480);
camera.setDisplayOrientation(90);
camera.setParameters(param);
try {
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
} catch (Exception e) {
System.err.println(e);
return;
}
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
refreshCamera();
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
camera.stopPreview();
camera.release();
camera = null;
}
public void refreshCamera() {
if (surfaceHolder.getSurface() == null) {return;}
try {camera.stopPreview();
} catch (Exception e){}
try {
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
} catch (Exception e) {}
}

refreshCamera();
Do not call that function there. It will stop the preview functionality before you can use it.
Move following code to onSurfaceChanged() and use the width and heigth parameters
Camera.Parameters param;
param = camera.getParameters();
//param.setPreviewSize(800, 480);
param.setPreviewSize(width, height);
... and the rest of those lines...
Never hardcode resolutions like 800x480

try to unlock
camera.unlock();
camera.reconnect();
frameCallback.setPreviewCallback(mCallback);

java.lang.RuntimeException: stop failed at android.media.MediaRecorder.stop(MediaRecorder.java)

I have integrated camera in my app.When user click on capture button i am making toolbar hide so that camera preview screen size increases.This crashes the app on stopping the recording on line - mMediaRecorder.stop();.
java.lang.RuntimeException: stop failed.
at android.media.MediaRecorder.stop(MediaRecorder.java)
However if i don't hide the toolbar or never show the toolbar then there is no crash.So the problem is because the camera params changes after i hide the toolbar.How could i resolve this?I have seen this answer and added tht code to CameraPreview class.
private Camera mCamera;
private CameraPreview mPreview;
mCamera = getCameraInstance();
mCamera.setDisplayOrientation(90);
mPreview = new CameraPreview(mActivity, mCamera);
preview = (FrameLayout) view.findViewById(R.id.camera_preview);
preview.addView(mPreview);
capture.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
mToolbar.setVisibility(View.GONE);
if (prepareVideoRecorder()) {
// Camera is available and unlocked, MediaRecorder is prepared,
// now you can start recording
mMediaRecorder.start();
}
}
}):
stop.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
mMediaRecorder.stop(); // stop the recording
releaseMediaRecorder(); // release the MediaRecorder object
mCamera.lock();
}
}):
CameraPreview.class
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
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 {
// if(mCamera==null)
// mCamera = getCameraInstance();
CamcorderProfile profile = CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH);
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(profile.videoFrameWidth,profile.videoFrameHeight);
mCamera.setParameters(parameters);
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d("error", "Error setting camera preview: " + e.getMessage());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
Log.e("surfaceDestroyed issue","surfaceDestroyed called");
if ((mCamera != null)&&(!CameraActivity.getInstance().getOnBackPressedListener().isPreview())) {
Log.e("surfaceDestroyed issue","surface destroyed");
try {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}catch(Exception e){}
}
}
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("error", "Error starting camera preview: " + e.getMessage());
}
}
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
}
Error-
java.lang.RuntimeException: stop failed.
at android.media.MediaRecorder.stop(MediaRecorder.java)
at xyzCameraFragment$5.onClick(CameraFragment.java:208)
at android.view.View.performClick(View.java:4761)
at android.view.View$PerformClick.run(View.java:19767)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5312)
at java.lang.reflect.Method.invoke(Method.java)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:901)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:696)

In you capture click set a boolean variable
capture.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
mToolbar.setVisibility(View.GONE);
startCapture = true;
}):
Hiding the ToolBar causes surfaceChanged to get called.
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("error", "Error starting camera preview: " + e.getMessage());
}
//Check if capture is set and start recording
if(startCapture)
{
if (prepareVideoRecorder()) {
mMediaRecorder.start();
}
startCapture = false;
}
}

Capturing Photo from SurfaceView

I'm trying to capture an image from a SurfaceView custom camera. I have set up the initial code but I don't know how to call the 'take photo' method so that I can see the preview on the surface.
Currently this code displays the preview in realtime. I need to take the picture and access the byte[] array
Please help me complete the code:
private SurfaceView mSurfaceView;
private SurfaceHolder mSurfaceHolder;
private Camera mCamera;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_camera);
captureImage = (ImageButton) findViewById(R.id.captureImage);
mSurfaceView = (SurfaceView) findViewById(R.id.surfaceView);
captureImage.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//this button press should take the picture
}
});
mSurfaceView.getHolder().addCallback(this);
mSurfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
mCamera = Camera.open();
}
#Override
public void onPause() {
super.onPause();
mCamera.stopPreview();
}
#Override
public void onDestroy() {
super.onDestroy();
mCamera.release();
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
try {
mCamera.setPreviewDisplay(mSurfaceView.getHolder());
} catch (Exception e) {
e.printStackTrace();
}
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Camera.Parameters params = mCamera.getParameters();
List<Camera.Size> sizes = params.getSupportedPreviewSizes();
Camera.Size selected = sizes.get(0);
params.setPreviewSize(selected.width,selected.height);
mCamera.setParameters(params);
mCamera.setDisplayOrientation(90);
mCamera.startPreview();
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
I need to get the bytes [] data so that I can convert the image to a base64 string. How do I call the necessary methods to take the picture using the code above?

Check "jpegCallback" in my example:
public class CameraActivity extends ActionBarActivity implements SurfaceHolder.Callback {
Camera camera;
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
PictureCallback jpegCallback;
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_camera);
surfaceView = (SurfaceView) findViewById(R.id.surfaceView);
surfaceHolder = surfaceView.getHolder();
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
surfaceHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
jpegCallback = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
FileOutputStream outStream = null;
try {
outStream = new FileOutputStream(String.format("/sdcard/%d.jpg", System.currentTimeMillis()));
outStream.write(data);
outStream.close();
Log.d("Log", "onPictureTaken - wrote bytes: " + data.length);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
}
Toast.makeText(getApplicationContext(), "Picture Saved", 2000).show();
refreshCamera();
}
};
}
public void captureImage(View v) throws IOException {
//take the picture
camera.takePicture(null, null, jpegCallback);
}
#Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
try {
// open the camera
camera = Camera.open();
} catch (RuntimeException e) {
// check for exceptions
System.err.println(e);
return;
}
Camera.Parameters param;
param = camera.getParameters();
// modify parameter
List<Camera.Size> sizes = param.getSupportedPreviewSizes();
Camera.Size selected = sizes.get(0);
param.setPreviewSize(selected.width,selected.height);
camera.setParameters(param);
try {
// The Surface has been created, now tell the camera where to draw
// the preview.
camera.setDisplayOrientation(90);
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
} catch (Exception e) {
// check for exceptions
System.err.println(e);
return;
}
}
#Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
// Now that the size is known, set up the camera parameters and begin
// the preview.
refreshCamera();
}
#Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
// stop preview and release camera
camera.stopPreview();
camera.release();
camera = null;
}
public void refreshCamera() {
if (surfaceHolder.getSurface() == null) {
// preview surface does not exist
return;
}
// stop preview before making changes
try {
camera.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.setPreviewDisplay(surfaceHolder);
camera.startPreview();
} catch (Exception e) {
}
}
}