Develop Reference

Want larger camera preview using ZBar scanner Library in Android

I am using ZBarScannerActivity in my android app. but I am getting a small surface view on device. Actually I want full Screen camera preview to scan the QR code.
Any help would be appreciated.
Thank you.
here is the code of ZbarScanner Activity
package com.dm.zbar.android.scanner;
public class ZBarScannerActivity extends Activity implements Camera.PreviewCallback, ZBarConstants {
private static final String TAG = "ZBarScannerActivity";
private CameraPreview mPreview;
private Camera mCamera;
private ImageScanner mScanner;
private Handler mAutoFocusHandler;
private boolean mPreviewing = true;
static {
System.loadLibrary("iconv");
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(!isCameraAvailable()) {
// Cancel request if there is no rear-facing camera.
cancelRequest();
return;
}
// Hide the window title.
//requestWindowFeature(Window.FEATURE_NO_TITLE);
//getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
mAutoFocusHandler = new Handler();
// Create and configure the ImageScanner;
setupScanner();
// Create a RelativeLayout container that will hold a SurfaceView,
// and set it as the content of our activity.
mPreview = new CameraPreview(this, this, autoFocusCB);
setContentView(mPreview);
}
public void setupScanner() {
mScanner = new ImageScanner();
mScanner.setConfig(0, Config.X_DENSITY, 3);
mScanner.setConfig(0, Config.Y_DENSITY, 3);
int[] symbols = getIntent().getIntArrayExtra(SCAN_MODES);
if (symbols != null) {
mScanner.setConfig(Symbol.NONE, Config.ENABLE, 0);
for (int symbol : symbols) {
mScanner.setConfig(symbol, Config.ENABLE, 1);
}
}
}
#Override
protected void onResume() {
super.onResume();
// Open the default i.e. the first rear facing camera.
mCamera = Camera.open();
if(mCamera == null) {
// Cancel request if mCamera is null.
cancelRequest();
return;
}
mPreview.setCamera(mCamera);
mPreview.showSurfaceView();
mPreviewing = true;
}
#Override
protected void onPause() {
super.onPause();
// Because the Camera object is a shared resource, it's very
// important to release it when the activity is paused.
if (mCamera != null) {
mPreview.setCamera(null);
mCamera.cancelAutoFocus();
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
mCamera.release();
// According to Jason Kuang on http://stackoverflow.com/questions/6519120/how-to-recover-camera-preview-from-sleep,
// there might be surface recreation problems when the device goes to sleep. So lets just hide it and
// recreate on resume
mPreview.hideSurfaceView();
mPreviewing = false;
mCamera = null;
}
}
public boolean isCameraAvailable() {
PackageManager pm = getPackageManager();
return pm.hasSystemFeature(PackageManager.FEATURE_CAMERA);
}
public void cancelRequest() {
Intent dataIntent = new Intent();
dataIntent.putExtra(ERROR_INFO, "Camera unavailable.");
setResult(Activity.RESULT_CANCELED, dataIntent);
finish();
}
public void onPreviewFrame(byte[] data, Camera camera) {
Camera.Parameters parameters = camera.getParameters();
Camera.Size size = parameters.getPreviewSize();
Image barcode = new Image(size.width, size.height, "Y800");
barcode.setData(data);
int result = mScanner.scanImage(barcode);
if (result != 0) {
mCamera.cancelAutoFocus();
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
mPreviewing = false;
SymbolSet syms = mScanner.getResults();
for (Symbol sym : syms) {
String symData = sym.getData();
if (!TextUtils.isEmpty(symData)) {
Intent dataIntent = new Intent();
dataIntent.putExtra(SCAN_RESULT, symData);
dataIntent.putExtra(SCAN_RESULT_TYPE, sym.getType());
setResult(Activity.RESULT_OK, dataIntent);
finish();
break;
}
}
}
}
private Runnable doAutoFocus = new Runnable() {
public void run() {
if(mCamera != null && mPreviewing) {
mCamera.autoFocus(autoFocusCB);
}
}
};
// Mimic continuous auto-focusing
Camera.AutoFocusCallback autoFocusCB = new Camera.AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
mAutoFocusHandler.postDelayed(doAutoFocus, 1000);
}
};
and CameraPreview Class
class CameraPreview extends ViewGroup implements SurfaceHolder.Callback {
private final String TAG = "CameraPreview";
SurfaceView mSurfaceView;
SurfaceHolder mHolder;
Size mPreviewSize;
List<Size> mSupportedPreviewSizes;
Camera mCamera;
PreviewCallback mPreviewCallback;
AutoFocusCallback mAutoFocusCallback;
CameraPreview(Context context, PreviewCallback previewCallback, AutoFocusCallback autoFocusCb) {
super(context);
mPreviewCallback = previewCallback;
mAutoFocusCallback = autoFocusCb;
mSurfaceView = new SurfaceView(context);
addView(mSurfaceView);
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void setCamera(Camera camera) {
mCamera = camera;
if (mCamera != null) {
//Changes********
mCamera.setDisplayOrientation(90);
mCamera.getParameters().getMaxNumFocusAreas();
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
requestLayout();
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// We purposely disregard child measurements because act as a
// wrapper to a SurfaceView that centers the camera preview instead
// of stretching it.
final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
setMeasuredDimension(width, height);
if (mSupportedPreviewSizes != null) {
mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
}
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (changed && getChildCount() > 0) {
final View child = getChildAt(0);
final int width = r - l;
final int height = b - t;
int previewWidth = width;
int previewHeight = height;
if (mPreviewSize != null) {
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
}
// Center the child SurfaceView within the parent.
if (width * previewHeight > height * previewWidth) {
final int scaledChildWidth = previewWidth * height / previewHeight;
child.layout((width - scaledChildWidth) / 2, 0,
(width + scaledChildWidth) / 2, height);
} else {
final int scaledChildHeight = previewHeight * width / previewWidth;
child.layout(0, (height - scaledChildHeight) / 2,
width, (height + scaledChildHeight) / 2);
}
}
}
public void hideSurfaceView() {
mSurfaceView.setVisibility(View.INVISIBLE);
}
public void showSurfaceView() {
mSurfaceView.setVisibility(View.VISIBLE);
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, acquire the camera and tell it where
// to draw.
try {
if (mCamera != null) {
mCamera.setPreviewDisplay(holder);
}
} catch (IOException exception) {
Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
if (mCamera != null) {
mCamera.cancelAutoFocus();
mCamera.stopPreview();
}
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) w / h;
if (sizes == null) return null;
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
// Try to find an size match aspect ratio and size
for (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);
}
}
// Cannot find the one match the aspect ratio, ignore the requirement
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
if (holder.getSurface() == null){
// preview surface does not exist
return;
}
if (mCamera != null) {
// Now that the size is known, set up the camera parameters and begin
// the preview.
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
requestLayout();
// mCamera.setDisplayOrientation(90);
mCamera.setParameters(parameters);
mCamera.setPreviewCallback(mPreviewCallback);
mCamera.startPreview();
mCamera.autoFocus(mAutoFocusCallback);
}
}
}
Please help me getting the scenario of Camera Preview size.

I am getting a small surface view on device. Actually I want full Screen camera preview to scan the QR code
If you are saying that camera isn't occupying the entire screen then try to change the
android:layout_width="match_parent"
android:layout_height="match_parent"
of SurfaceView and parent_layout
If it is about the scan area that you want to be in full screen, here it goes:
mScannerView = new ZBarScannerView(this) {
/**
* this will alter the scanning area
**/
#Override
protected IViewFinder createViewFinderView(Context context) {
return new CustomViewFinderView(context);
}
};
private class CustomViewFinderView extends ViewFinderView {
Context context;
public CustomViewFinderView(Context context) {
super(context);
this.context = context;
setLaserEnabled(true);
}
#Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (getFramingRect() != null) {
updateFrameRect();
setBorderColor(ContextCompat.getColor(context, R.color.colorPrimary));
}
}
private void updateFrameRect() {
Point viewResolution = new Point(this.getWidth(), this.getHeight());
int height = (int) ((float) this.getHeight());
int width = (int) ((float) this.getWidth());
int leftOffset = (viewResolution.x - width) / 2;
int topOffset = (viewResolution.y - height) / 2;
getFramingRect().left = leftOffset;
getFramingRect().top = topOffset;
getFramingRect().right = leftOffset + width;
getFramingRect().bottom = topOffset + height;
}
}
Result:

I have solved this by removing following code from Camerapreview Class
if (mPreviewSize != null) {
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
}
it worked for me.
It will give you full screen camera.
Thank you.

android.hardware.Camera.setParameters getting runTime Exception(android)

I'm working on a project which has some camera functionalities. I have been facing a problem related to surface view. At first I implemented according to this article: Android SurfaceView Example. But this had some drawbacks: it captured the image in a stretched aspect ratio. I created a CustomView which Implemented SurfaceHolder.Callback to calculate the width and Height of the hosting view with mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes(); But now android.hardware.Camera.setParameters got me
public class Preview extends ViewGroup implements SurfaceHolder.Callback {
private final String TAG = "Preview";
SurfaceView mSurfaceView;
SurfaceHolder mHolder;
Size mPreviewSize;
List<Size> mSupportedPreviewSizes;
Camera mCamera;
Context activecontext;
private int cameraId = 1;
Preview(Context context, SurfaceView sv) {
super(context);
activecontext = context;
mSurfaceView = sv;
// addView(mSurfaceView);
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void setCamera(Camera camera) {
mCamera = camera;
if (mCamera != null) {
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
requestLayout();
// get Camera parameters
Camera.Parameters params = mCamera.getParameters();
List<String> focusModes = params.getSupportedFocusModes();
if (focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
// set the focus mode
params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
// set Camera parameters
mCamera.setParameters(params);
}
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// We purposely disregard child measurements because act as a
// wrapper to a SurfaceView that centers the camera preview instead
// of stretching it.
final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
setMeasuredDimension(width, height);
if (mSupportedPreviewSizes != null) {
mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
}
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (changed && getChildCount() > 0) {
final View child = getChildAt(0);
final int width = r - l;
final int height = b - t;
int previewWidth = width;
int previewHeight = height;
if (mPreviewSize != null) {
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
}
// Center the child SurfaceView within the parent.
if (width * previewHeight > height * previewWidth) {
final int scaledChildWidth = previewWidth * height / previewHeight;
child.layout((width - scaledChildWidth) / 2, 0,
(width + scaledChildWidth) / 2, height);
} else {
final int scaledChildHeight = previewHeight * width / previewWidth;
child.layout(0, (height - scaledChildHeight) / 2,
width, (height + scaledChildHeight) / 2);
}
}
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, acquire the camera and tell it where
// to draw.
try {
if (mCamera != null) {
mCamera.setPreviewDisplay(holder);
}
} catch (IOException exception) {
Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
if (mCamera != null) {
mCamera.stopPreview();
}
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) w / h;
if (sizes == null) return null;
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
// Try to find an size match aspect ratio and size
for (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);
}
}
// Cannot find the one match the aspect ratio, ignore the requirement
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
Log.d(TAG,"cameraPreviewWidth:"+optimalSize.width+" cameraPreviewHeight:"+optimalSize.height);
return optimalSize;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
if(mCamera != null) {
Camera.Parameters parameters = mCamera.getParameters();
requestLayout();
parameters.setPictureSize(720,480);
mCamera.setParameters(parameters);
setCameraDisplayOrientation((MainActivity) activecontext,cameraId,mCamera);
mCamera.startPreview();
}
}
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_BACK) {
result = (info.orientation + degrees) % 360;
result = (360 - result) % 360; // compensate the mirror
} else { // back-facing
result = (info.orientation - degrees + 360) % 360;
}
camera.setDisplayOrientation(result);
}
}
and on activity `setContentView(R.layout.main);
preview = new Preview(this, (SurfaceView)findViewById(R.id.surfaceView));
preview.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
((FrameLayout) findViewById(R.id.layout)).addView(preview);
preview.setKeepScreenOn(true);
preview.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
camera.takePicture(shutterCallback, rawCallback, jpegCallback);
}
}); ..................................................................................................................................................#Override
protected void onResume() {
super.onResume();
int numCams = Camera.getNumberOfCameras();
if(numCams > 0){
try{
camera = Camera.open(0);
camera.startPreview();
preview.setCamera(camera);
} catch (RuntimeException ex){
Toast.makeText(ctx, getString(R.string.camera_not_found), Toast.LENGTH_LONG).show();
}
}
}
#Override
protected void onPause() {
if(camera != null) {
camera.stopPreview();
preview.setCamera(null);
camera.release();
camera = null;
}
super.onPause();
}
private void resetCam() {
camera.startPreview();
preview.setCamera(camera);
}
private void refreshGallery(File file) {
Intent mediaScanIntent = new Intent( Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
mediaScanIntent.setData(Uri.fromFile(file));
sendBroadcast(mediaScanIntent);
}
ShutterCallback shutterCallback = new ShutterCallback() {
public void onShutter() {
// Log.d(TAG, "onShutter'd");
}
};
PictureCallback rawCallback = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
// Log.d(TAG, "onPictureTaken - raw");
}
};
PictureCallback jpegCallback = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
new SaveImageTask().execute(data);
resetCam();
Log.d(TAG, "onPictureTaken - jpeg");
}
};
private class SaveImageTask extends AsyncTask<byte[], Void, Void> {
#Override
protected Void doInBackground(byte[]... data) {
FileOutputStream outStream = null;
// Write to SD Card
try {
File sdCard = Environment.getExternalStorageDirectory();
File dir = new File (sdCard.getAbsolutePath() + "/camtest");
dir.mkdirs();
String fileName = String.format("%d.jpg", System.currentTimeMillis());
File outFile = new File(dir, fileName);
outStream = new FileOutputStream(outFile);
outStream.write(data[0]);
outStream.flush();
outStream.close();
Log.d(TAG, "onPictureTaken - wrote bytes: " + data.length + " to " + outFile.getAbsolutePath());
refreshGallery(outFile);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
}
return null;
}
}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
if(mCamera != null) {
Camera.Parameters parameters = mCamera.getParameters();
requestLayout();
parameters.setPictureSize(720,480);
mCamera.setParameters(parameters);
setCameraDisplayOrientation((MainActivity) activecontext,cameraId,mCamera);
mCamera.startPreview();
}
}
Here you are trying to hardcode the picture size. There is a possibility that this pic size may not be supported. Get the closest value from parameter.getSupportedPictureSizes(). This could be the issue.

Using android camera2 API to display camera feed

I'm trying to create a very simple app which shows the picture received from the camera on the display. I'm using the camera2 API, because I am new to this, so I try to use the most recent technology.
I reach the point where I call createCaptureSession(), but then onConfigureFailed() gets called and I don't know what the problem is or how to find it.
Here is my source:
SurfaceView mSurfaceView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(TAG, "onCreate() start");
setContentView(R.layout.activity_main);
mSurfaceView = (SurfaceView) findViewById(R.id.surfaceView);
}
protected void onResume() {
super.onResume();
Log.d(TAG, "onResume() start");
initCamera();
}
private void initCamera() {
Log.d(TAG, "initCamera() start");
CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
Log.d(TAG, "acquired cameraManager: " + cameraManager);
String[] cameraIdList;
try {
cameraIdList = cameraManager.getCameraIdList();
} catch (CameraAccessException e) {
Log.e(TAG, "couldn't get camera list", e);
return;
}
Log.d(TAG, "acquired cameraIdList: length: " + cameraIdList.length);
if (cameraIdList.length == 0) {
Log.w(TAG, "couldn't detect a camera");
return;
}
String camera0Id = cameraIdList[0];
Log.d(TAG, "chosen camera: " + camera0Id);
try {
cameraManager.openCamera(camera0Id, deviceCallback, null);
} catch (CameraAccessException e) {
Log.e(TAG, "couldn't open camera", e);
}
Log.d(TAG, "called cameraManager.openCamera()");
}
CameraDevice.StateCallback deviceCallback = new CameraDevice.StateCallback() {
#Override
public void onOpened(CameraDevice camera) {
Log.d(TAG, "deviceCallback.onOpened() start");
Surface surface = mSurfaceView.getHolder().getSurface();
Log.d(TAG, "surface: " + surface);
List<Surface> surfaceList = Collections.singletonList(surface);
try {
camera.createCaptureSession(surfaceList, sessionCallback, null);
} catch (CameraAccessException e) {
Log.e(TAG, "couldn't create capture session for camera: " + camera.getId(), e);
return;
}
}
#Override
public void onDisconnected(CameraDevice camera) {
Log.d(TAG, "deviceCallback.onDisconnected() start");
}
#Override
public void onError(CameraDevice camera, int error) {
Log.d(TAG, "deviceCallback.onError() start");
}
};
CameraCaptureSession.StateCallback sessionCallback = new CameraCaptureSession.StateCallback() {
#Override
public void onConfigured(CameraCaptureSession session) {
Log.i(TAG, "capture session configured: " + session);
}
#Override
public void onConfigureFailed(CameraCaptureSession session) {
Log.e(TAG, "capture session configure failed: " + session);
}
};
And the output is:
...﹕ onCreate() start
...﹕ onResume() start
...﹕ initCamera() start
...﹕ acquired cameraManager: android.hardware.camera2.CameraManager#5d68786
...﹕ acquired cameraIdList: length: 2
...﹕ chosen camera: 0
...﹕ called cameraManager.openCamera()
...﹕ deviceCallback.onOpened() start
...﹕ surface: Surface(name=null)/#0x52c91e3
...﹕ capture session configure failed: android.hardware.camera2.impl.CameraCaptureSessionImpl#1a8c7a99
The following is in my AndroidManifest.xml:
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera2" />

you should set the size of preview
mSurfaceView.getHolder().setFixedSize(previewSize.getWidth(), previewSize.getHeight());

Since the asker mentioned that he was testing on the Galaxy S4, maybe it had something to do with the fact that some of the Samsung's Lollipop phones haven't implemented the Camera2 API. DPReview

Set Custom camera code:
import java.io.IOException;
import java.util.List;
import android.annotation.SuppressLint;
import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.hardware.Camera.Size;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup;
#SuppressWarnings("deprecation")
public class Preview extends ViewGroup implements SurfaceHolder.Callback {
private final String TAG = "Preview";
SurfaceView mSurfaceView;
SurfaceHolder mHolder;
Size mPreviewSize;
List<Size> mSupportedPreviewSizes;
Camera mCamera;
public Preview(Context context, SurfaceView sv) {
super(context);
mSurfaceView = sv;
// addView(mSurfaceView);
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void setCamera(Camera camera) {
mCamera = camera;
if (mCamera != null) {
mSupportedPreviewSizes = mCamera.getParameters()
.getSupportedPreviewSizes();
requestLayout();
mCamera.setDisplayOrientation(90);
setCamFocusMode();
// // get Camera parameters
// Camera.Parameters params = mCamera.getParameters();
//
// List<String> focusModes = params.getSupportedFocusModes();
// if (focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
// // set the focus mode
// params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
// // set Camera parameters
// mCamera.setParameters(params);
//
// }
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// We purposely disregard child measurements because act as a
// wrapper to a SurfaceView that centers the camera preview instead
// of stretching it.
final int width = resolveSize(getSuggestedMinimumWidth(),
widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(),
heightMeasureSpec);
setMeasuredDimension(width, height);
if (mSupportedPreviewSizes != null) {
mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width,
height);
}
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (changed && getChildCount() > 0) {
final View child = getChildAt(0);
final int width = r - l;
final int height = b - t;
int previewWidth = width;
int previewHeight = height;
if (mPreviewSize != null) {
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
}
// Center the child SurfaceView within the parent.
if (width * previewHeight > height * previewWidth) {
final int scaledChildWidth = previewWidth * height
/ previewHeight;
child.layout((width - scaledChildWidth) / 2, 0,
(width + scaledChildWidth) / 2, height);
} else {
final int scaledChildHeight = previewHeight * width
/ previewWidth;
child.layout(0, (height - scaledChildHeight) / 2, width,
(height + scaledChildHeight) / 2);
}
}
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, acquire the camera and tell it where
// to draw.
try {
if (mCamera != null) {
mCamera.setPreviewDisplay(holder);
}
} catch (IOException exception) {
Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
if (mCamera != null) {
mCamera.stopPreview();
}
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) w / h;
if (sizes == null)
return null;
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
// Try to find an size match aspect ratio and size
for (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);
}
}
// Cannot find the one match the aspect ratio, ignore the requirement
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
if (mCamera != null) {
Camera.Parameters parameters = mCamera.getParameters();
List<Camera.Size> previewSizes = parameters
.getSupportedPreviewSizes();
// You need to choose the most appropriate previewSize for your app
Camera.Size previewSize;
try {
previewSize = previewSizes.get(1);
parameters.setPreviewSize(previewSize.width, previewSize.height);
mCamera.setParameters(parameters);
mCamera.startPreview();
} catch (Exception e) {
previewSize = previewSizes.get(0);
parameters.setPreviewSize(previewSize.width, previewSize.height);
mCamera.setParameters(parameters);
mCamera.startPreview();
}
}
}
#SuppressLint("InlinedApi")
private void setCamFocusMode() {
if (null == mCamera) {
return;
}
/* Set Auto focus */
Parameters parameters = mCamera.getParameters();
List<String> focusModes = parameters.getSupportedFocusModes();
if (focusModes
.contains(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE)) {
parameters
.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
} else if (focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
}
mCamera.setParameters(parameters);
}
// Check Flash in Camera or not
public boolean hasFlash() {
if (mCamera == null) {
return false;
}
Camera.Parameters parameters = mCamera.getParameters();
if (parameters.getFlashMode() == null) {
return false;
}
List<String> supportedFlashModes = parameters.getSupportedFlashModes();
if (supportedFlashModes == null
|| supportedFlashModes.isEmpty()
|| supportedFlashModes.size() == 1
&& supportedFlashModes.get(0).equals(
Camera.Parameters.FLASH_MODE_OFF)) {
return false;
}
return true;
}
public boolean setFlash(int flashMode) {
if (mCamera == null) {
return false;
}
Camera.Parameters parameters = mCamera.getParameters();
if (parameters.getFlashMode() == null) {
return false;
}
List<String> supportedFlashModes = parameters.getSupportedFlashModes();
if (flashMode == 1 && supportedFlashModes.get(2).equals(
Camera.Parameters.FLASH_MODE_AUTO)) {
parameters.setFlashMode(Camera.Parameters.FLASH_MODE_AUTO);
} else if (flashMode == 2 && supportedFlashModes.get(1).equals(
Camera.Parameters.FLASH_MODE_ON)) {
parameters.setFlashMode(Camera.Parameters.FLASH_MODE_ON);
} else if (flashMode == 3 && supportedFlashModes.get(0).equals(
Camera.Parameters.FLASH_MODE_OFF)) {
parameters.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
}
mCamera.setParameters(parameters);
return true;
}
}
You can set camera preview size in "surfaceChanged()" method.
This code is work for me in Android 5.0.1 and 5.1.1 also.

Camera preview stretched even after setting the correct dimensions

I'm creating a camera app that implements it's own camera preview for taking pictures.
The app is currently forced into portrait mode.
My problem is that the preview from the camera is slightly stretched (the aspect ratio is a bit off).
The funny thing is that I'm setting my SurfaceView size to always match the preview size. This ensures that the aspect ratio should always be perserved... but it isn't...
Here is the layout i use to show my camera preview:
public class Cp extends ViewGroup implements SurfaceHolder.Callback {
private final String TAG = "CameraPreview";
private boolean mPreviewRunning = false;
private SurfaceView mSurfaceView;
private SurfaceHolder mHolder;
private Size mPreviewSize;
private List<Size> mSupportedPreviewSizes;
private Camera mCamera;
public boolean IsPreviewRunning() {
return mPreviewRunning;
}
public Cp(Context context) {
this(context, null, 0);
}
public Cp(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public Cp(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mSurfaceView = new SurfaceView(context);
addView(mSurfaceView);
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void setCamera(Camera camera) {
mCamera = camera;
if (mCamera != null) {
requestLayout();
}
}
public void switchCamera(Camera camera) {
setCamera(camera);
try {
camera.setPreviewDisplay(mHolder);
} catch (IOException exception) {
Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
}
Camera.Parameters parameters = camera.getParameters();
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
requestLayout();
camera.setParameters(parameters);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// We purposely disregard child measurements because act as a wrapper to
// a SurfaceView that
// centers the camera preview instead of stretching it.
final int width = resolveSize(getSuggestedMinimumWidth(),
widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(),
heightMeasureSpec);
setMeasuredDimension(width, height);
if (mSupportedPreviewSizes == null && mCamera != null) {
mSupportedPreviewSizes = mCamera.getParameters()
.getSupportedPreviewSizes();
}
if (mSupportedPreviewSizes != null) {
mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width,
height);
}
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (changed && getChildCount() > 0) {
final View child = getChildAt(0);
final int width = r - l;
final int height = b - t;
int previewWidth = width;
int previewHeight = height;
if (mPreviewSize != null) {
previewWidth = mPreviewSize.height;
previewHeight = mPreviewSize.width;
}
if (previewWidth == 0) {
previewWidth = 1;
}
if (previewHeight == 0) {
previewHeight = 1;
}
// Center the child SurfaceView within the parent.
if (width * previewHeight > height * previewWidth) {
final int scaledChildWidth = previewWidth * height
/ previewHeight;
child.layout((width - scaledChildWidth) / 2, 0,
(width + scaledChildWidth) / 2, height);
} else {
final int scaledChildHeight = previewHeight * width
/ previewWidth;
child.layout(0, (height - scaledChildHeight) / 2, width,
(height + scaledChildHeight) / 2);
}
}
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, acquire the camera and tell it where to
// draw.
try {
if (mCamera != null) {
Parameters params = mCamera.getParameters();
mSupportedPreviewSizes = params.getSupportedPreviewSizes();
mCamera.setPreviewDisplay(holder);
}
} catch (IOException exception) {
Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
}
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
stop();
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) w / h;
if (sizes == null)
return null;
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
// Try to find an size match aspect ratio and size
for (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);
}
}
// Cannot find the one match the aspect ratio, ignore the requirement
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
if (mCamera != null) {
// Now that the size is known, set up the camera parameters and
// begin the preview.
Camera.Parameters parameters = mCamera.getParameters();
if (mPreviewSize != null) {
parameters.setPreviewSize(mPreviewSize.width,
mPreviewSize.height);
}
requestLayout();
mCamera.setParameters(parameters);
mCamera.startPreview();
mPreviewRunning = true;
}
}
public void stop() {
if (mCamera != null) {
mCamera.stopPreview();
mPreviewRunning = false;
mCamera = null;
}
}
}
Please note that in onLayout width and height are swapped because the app is always running in portrait.
I'm including some pictures to show you what the problem looks like:
I've debugged the code. The preview size is being set to 1280x720 and the size of the layout is also being correctly adjusted to match that size.
I've also tried different layouts but the result was always the same...

I was having the same problem, after some days in this puzzle, my Java class end up on this code:
So, The problem was happening because the camera display had a size (hight x width) 576x720, and my display was 1184x720. So, the camera preview (my surface view class) stretched to fill in the parent.
So, the approach that worked is to make this view bigger than my screen, and that just display the area of my screen. So, I had to use this weird frame combination (a relative layout inside a linearlayout), so that the size of the relative will be as big as I want - the surface view will fill in it -, and the linear will take just the part that I wanna display.
package com.example.frame.camera;
import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.ViewGroup.LayoutParams;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.Toast;
import com.example.frame.MainActivity;
public class NativeCamera extends SurfaceView implements SurfaceHolder.Callback {
static private NativeCamera instance;
private LinearLayout frame = null;
private RelativeLayout innerFrame = null;
private Camera camera;
private final SurfaceHolder previewHolder;
private static final String TAG = "NativeCamera.java";
private boolean inPreview = false;
private boolean cameraConfigured = false;
private boolean frontCamera = false;
private Camera.Size size;
static public NativeCamera getInstance() {
if (NativeCamera.instance == null) {
if (MainActivity.debug) {
Log.d(TAG, "Creating Camera Singleton");
}
NativeCamera.instance = new NativeCamera(MainActivity.instance);
}
return NativeCamera.instance;
}
public void onResume() {
if (MainActivity.debug) {
Log.d(TAG, "onResume");
}
camera = Camera.open();
if (size != null) {
initPreview(size.width, size.height);
}
startPreview();
}
public void onPause() {
if (MainActivity.debug) {
Log.d(TAG, "onPause");
}
if (inPreview) {
camera.stopPreview();
}
camera.release();
camera = null;
inPreview = false;
}
public void onDestroy() {
if (MainActivity.debug) {
Log.d(TAG, "onDestroy");
}
NativeCamera.instance = null;
}
public void onSwitch() {
frontCamera = !frontCamera;
if (inPreview) {
camera.stopPreview();
}
camera.release();
int cam = frontCamera ? 1 : 0;
camera = Camera.open(cam);
if (size != null) {
initPreview(size.width, size.height);
}
startPreview();
}
private NativeCamera(Context context) {
super(context);
// TODO Auto-generated constructor stub
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
previewHolder = getHolder();
previewHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
// previewHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
innerFrame = new RelativeLayout(MainActivity.instance);
innerFrame.addView(this);
frame = new LinearLayout(MainActivity.instance);
frame.addView(innerFrame);
}
public LinearLayout getFrame() {
return frame;
}
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
if (MainActivity.debug) {
Log.d(TAG, "surfaceChanged");
}
initPreview(width, height);
startPreview();
}
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
// no-op -- wait until surfaceChanged()
}
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
// no-op
}
private Camera.Size getBestPreviewSize(int width, int height,
Camera.Parameters parameters) {
Camera.Size result = null;
for (Camera.Size size : parameters.getSupportedPreviewSizes()) {
if (size.width <= width && size.height <= height) {
if (result == null) {
result = size;
} else {
int resultArea = result.width * result.height;
int newArea = size.width * size.height;
if (newArea > resultArea) {
result = size;
}
}
}
}
this.size = result;
return (result);
}
private void initPreview(int width, int height) {
if (camera != null && previewHolder.getSurface() != null) {
if (!cameraConfigured) {
Camera.Parameters parameters = camera.getParameters();
Camera.Size size = getBestPreviewSize(width, height, parameters);
if (size != null) {
parameters.setPreviewSize(size.width, size.height);
camera.setParameters(parameters);
cameraConfigured = true;
// Setting up correctly the view
double ratio = size.height / (double) size.width;
LayoutParams params = innerFrame.getLayoutParams();
params.height = MainActivity.size.y;
params.width = (int) (MainActivity.size.y * ratio);
innerFrame.setLayoutParams(params);
int deslocationX = (int) (params.width / 2.0 - MainActivity.size.x / 2.0);
innerFrame.animate().translationX(-deslocationX);
}
}
try {
camera.setPreviewDisplay(previewHolder);
camera.setDisplayOrientation(90);
} catch (Throwable t) {
Log.e(TAG, "Exception in setPreviewDisplay()", t);
Toast.makeText(MainActivity.instance, t.getMessage(), Toast.LENGTH_LONG).show();
}
}
}
private void startPreview() {
if (MainActivity.debug) {
Log.d(TAG, "startPreview");
}
if (cameraConfigured && camera != null) {
camera.startPreview();
inPreview = true;
}
}
}

I have been trying to solve the same issue... Below code worked for me:
private void setMyPreviewSize(int width, int height) {
// Get the set dimensions
float newProportion = (float) width / (float) height;
// Get the width of the screen
int screenWidth = getWindowManager().getDefaultDisplay().getWidth();
int screenHeight = getWindowManager().getDefaultDisplay().getHeight();
float screenProportion = (float) screenWidth / (float) screenHeight;
// Get the SurfaceView layout parameters
android.view.ViewGroup.LayoutParams lp = surfaceView.getLayoutParams();
if (newProportion > screenProportion) {
lp.width = screenWidth;
lp.height = (int) ((float) screenWidth / newProportion );
} else {
lp.width = (int) (newProportion * (float) screenHeight);
lp.height = screenHeight;
}
// Commit the layout parameters
surfaceView.setLayoutParams(lp);
}
You can see the thread: Resizing surface view for aspect ratio change in video display in android

Here's a solution
surfaceChanged is just to get the best preview size
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Log.e("MYTAG", "surfaceChanged " );
Camera.Parameters myParameters = camera.getParameters();
Camera.Size myBestSize = getBestPreviewSize(width, height, myParameters);
if(myBestSize != null){
myParameters.setPreviewSize(myBestSize.width, myBestSize.height);
camera.setParameters(myParameters);
camera.startPreview();
}
}
#Override
public void onPictureTaken(byte[] data, Camera camera) {
Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
imageReview.setImageBitmap(bitmap);
}
This will set the captured image on imageReview, but you need a method to get the rotation of the bitmap
you need to set imageView scaleType attribute for stretched image issue
<ImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
/>

in android, stream camera preview onto a view

I want to stream the camera preview of the android camera, onto a view. The intention is to afterwards add various things to the view, using onDraw(). I don't need to actually capture the image at any time.
It doesn't have to be in the highest quality or largest number of frames per second.
Does anyone have an idea how this can be done?

add this to your xml:
<SurfaceView
android:id="#+id/camerapreview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
into your activity-class:
private Preview mPreview;
Camera mCamera;
int numberOfCameras;
int cameraCurrentlyLocked;
int defaultCameraId;
onCreate-Method:
mPreview = new Preview(this);
setContentView(mPreview);
mPreview.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
mCamera.autoFocus(null);
}
});
#Override
protected void onPause() {
super.onPause();
// Because the Camera object is a shared resource, it's very
// important to release it when the activity is paused.
if (mCamera != null) {
mPreview.setCamera(null);
mCamera.release();
mCamera = null;
}
}
#Override
protected void onResume() {
super.onResume();
// Open the default i.e. the first rear facing camera.
mCamera = Camera.open();
cameraCurrentlyLocked = defaultCameraId;
mPreview.setCamera(mCamera);
}
and the preview-class:
public class Preview extends ViewGroup implements SurfaceHolder.Callback {
private final String TAG = "Preview";
SurfaceView mSurfaceView;
SurfaceHolder mHolder;
Size mPreviewSize;
List<Size> mSupportedPreviewSizes;
Camera mCamera;
public Preview(Context context) {
super(context);
mSurfaceView = new SurfaceView(context);
addView(mSurfaceView);
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void setCamera(Camera camera) {
mCamera = camera;
if (mCamera != null) {
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
requestLayout();
}
}
public void switchCamera(Camera camera) {
setCamera(camera);
try {
camera.setPreviewDisplay(mHolder);
} catch (IOException exception) {
Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
}
Camera.Parameters parameters = camera.getParameters();
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
requestLayout();
camera.setParameters(parameters);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// We purposely disregard child measurements because act as a
// wrapper to a SurfaceView that centers the camera preview instead
// of stretching it.
final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
setMeasuredDimension(width, height);
if (mSupportedPreviewSizes != null) {
mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
}
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (changed && getChildCount() > 0) {
final View child = getChildAt(0);
final int width = r - l;
final int height = b - t;
int previewWidth = width;
int previewHeight = height;
if (mPreviewSize != null) {
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
}
// Center the child SurfaceView within the parent.
if (width * previewHeight > height * previewWidth) {
final int scaledChildWidth = previewWidth * height / previewHeight;
child.layout((width - scaledChildWidth) / 2, 0,
(width + scaledChildWidth) / 2, height);
} else {
final int scaledChildHeight = previewHeight * width / previewWidth;
child.layout(0, (height - scaledChildHeight) / 2,
width, (height + scaledChildHeight) / 2);
}
}
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, acquire the camera and tell it where
// to draw.
try {
if (mCamera != null) {
mCamera.setPreviewDisplay(holder);
}
} catch (IOException exception) {
Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
if (mCamera != null) {
mCamera.stopPreview();
}
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) w / h;
if (sizes == null) return null;
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
// Try to find an size match aspect ratio and size
for (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);
}
}
// Cannot find the one match the aspect ratio, ignore the requirement
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// Now that the size is known, set up the camera parameters and begin
// the preview.
if(mCamera != null){
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
requestLayout();
mCamera.setParameters(parameters);
mCamera.startPreview();
}
}
}