Develop Reference

Android camera preview freezes when switching cameras?

I am writing a custom camera for my app. It's working fine when opening the activity with either of the back or front cameras. But I'm really struggling with switching cameras inside the activity.
When I tap the switching camera button, the preview freezes and nothing happens. I have tried the answers and tips suggested in other questions related to the camera and the preview, but nothing works.
Here is my activity:
public class CameraActivity extends Activity implements SurfaceHolder.Callback {
//================================================================================
// Properties
//================================================================================
// Tag
private final String TAG = "CameraActivity";
// Camera and CameraPreview objects
private Camera mCamera;
// SurfaceHolder object
private SurfaceHolder mSurfaceHolder;
// private CameraPreview mPreview;
// ImageButtons
private ImageButton captureButton;
private ImageButton camSwitchButton;
// Picture previewLayout
FrameLayout previewLayout;
SurfaceView preview;
// Current camera is facing FRONT or BACK
private int currentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT;
// Picture taking callback
private Camera.PictureCallback mPictureCallback;
//================================================================================
// Methods
//================================================================================
#Override
public void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Activity with no notification bar
requestWindowFeature(Window.FEATURE_NO_TITLE);
// Set content view
setContentView(R.layout.activity_camera);
// Initialize activity and previews
InitActivity();
InitPreview();
// Set onClicks
}
/**
* Initialize activity views
*/
private void InitActivity() {
// Create an instance of Camera
mCamera = GetCameraInstance(currentCameraId);
// Set the SurfaceView
preview = (SurfaceView) findViewById(R.id.camera_preview);
mSurfaceHolder = preview.getHolder();
mSurfaceHolder.addCallback(this);
}
/**
* Initialize the camera preview
*/
private void InitPreview() {
if (mCamera != null) {
try {
mCamera.setPreviewDisplay(mSurfaceHolder);
} catch (IOException e) {
// log
}
mCamera.startPreview();
}
}
#Override
protected void onPause() {
super.onPause();
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release(); // release the camera for other applications
// mCamera = null;
}
}
#Override
protected void onResume() {
super.onResume();
if (mCamera == null) {
InitActivity();
InitPreview();
}
}
/**
* Get camera instance
* #return Camera instance (null if doesn't exist)
*/
private Camera GetCameraInstance(int camid) {
Camera c = null;
try {
c = Camera.open(camid); // attempt to get a Camera instance
Camera.Parameters campar = c.getParameters();
// Set auto-focus
if (getPackageManager().hasSystemFeature("android.hardware.camera.autofocus")) {
campar.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
}
c.setParameters(campar);
}
catch (Exception e){
// log
}
return c; // returns null if camera is unavailable
}
/**
* Switch the camera from front to back and vica verca
*/
private void SwitchCamera() {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
// mCamera = null;
}
//swap the id of the camera to be used
if (currentCameraId == Camera.CameraInfo.CAMERA_FACING_BACK) {
currentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT;
}
else currentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT;
// Remove the view and re-add it
ViewGroup rootView = (ViewGroup) preview.getParent();
rootView.removeView(previewLayout);
mCamera = GetCameraInstance(currentCameraId);
InitActivity();
}
#Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
Logger.Log(TAG, "SurfaceCreated");
InitPreview();
}
#Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int format, int width, int height) {
// Return if no surface found
if (mSurfaceHolder.getSurface() == null) {
return;
}
// Start preview with new settings
Camera.Parameters params = mCamera.getParameters();
boolean isPortrait = IsPortrait();
// Configure the parameters (so the image is showing correctly)
ConfigureCameraParameters(params, isPortrait);
// Start preview
InitPreview();
}
#Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
}
/**
* Configure the camer parameters
* #param cameraParams Camera parameters
* #param isPortrait Is the camera in portrait mode?
*/
protected void ConfigureCameraParameters(Camera.Parameters cameraParams, boolean isPortrait) {
int angle;
Display display = getWindowManager().getDefaultDisplay();
// Correct the orientation
switch (display.getRotation()) {
case Surface.ROTATION_0: // This is display orientation
angle = 90; // This is camera orientation
break;
case Surface.ROTATION_90:
angle = 0;
break;
case Surface.ROTATION_180:
angle = 270;
break;
case Surface.ROTATION_270:
angle = 180;
break;
default:
angle = 90;
break;
}
mCamera.setDisplayOrientation(angle);
mCamera.setParameters(cameraParams);
}
/**
* Check whether the camera is in portrait mode
* #return True|False
*/
private boolean IsPortrait() {
return (getResources().getConfiguration().orientation
== Configuration.ORIENTATION_PORTRAIT);
}
}
Permissions in manifest:
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
I really appreciate it if someone could help.

You are pretty close, you dont need to destroy the surface view everytime you switch the camera, you only need to destroy the camera session and then make sure you re hook up the camera back to the surfaceview so it can be displayed. I was having some trouble with your front facing rear facing logic on a Razr Max so I just switched it to 1 and 0.
private void SwitchCamera() {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
//swap the id of the camera to be used
if (currentCameraId == Camera.CameraInfo.CAMERA_FACING_FRONT) {
currentCameraId = 0;
} else {
currentCameraId = 1;
}
mCamera = GetCameraInstance(currentCameraId);
InitPreview();
}

Can't update an ImageView on top of a (camera) SurfaceView

In my Android app there is an Activity showing a Camera preview, implemented as a SurfaceView using the documentation here: http://developer.android.com/guide/topics/media/camera.html#custom-camera.
I want to show an ImageView on top of this SurfaceView from the start, but I also want to update its layout (width, height and source image) when the user takes a first photo.
My problem is that the code works in the first step, the image is shown over the SurfaceView when the Activity starts, but its layout doesn't change when I want to.
Here is the XML:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/layout_capture"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".CaptureActivity" >
<RelativeLayout
android:id="#+id/camera_preview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
>
<!-- Here I will programmatically add the SurfaceView -->
<ImageView
android:id="#+id/image_picture"
android:layout_width="100dp"
android:layout_height="80dp"
android:layout_centerInParent="true"
android:contentDescription="picture preview"
android:src="#drawable/image1" />
</RelativeLayout>
<Button
android:id="#+id/button_capture"
android:text="Capture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|center"
/>
</FrameLayout>
The SurfaceView is added with this snippet:
mPreview = new CameraPreview(this, mCamera);
RelativeLayout preview = (RelativeLayout) findViewById(R.id.camera_preview);
preview.addView(mPreview, 0); //
This is the code that should update the ImageView (it's inside the onPictureTaken() method)... but it doesn't work:
LayoutInflater linf = (LayoutInflater) ctx.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
FrameLayout frame = (FrameLayout) linf.inflate(R.layout.activity_capture, null);
ImageView imgw = (ImageView) frame.findViewById(R.id.image_left_picture); // get the ImageView
imgw.setImageResource(R.drawable.image2); // change its source image
imgw.setLayoutParams(new RelativeLayout.LayoutParams(w, h)); //change its size
invalidate(); // also tried to add this method call... nothing changes.

I think the problem is:
FrameLayout frame = (FrameLayout) linf.inflate(R.layout.activity_capture, null);
Have you added this layout to your view group? I didn't see your code. you just inflated it and set the image view inside of this layout.

Try this... it might be helpful to you...
public class CameraActivity extends Activity implements PictureCallback{
protected static final String EXTRA_IMAGE_PATH = "com.blundell.tut.cameraoverlay.ui.CameraActivity.EXTRA_IMAGE_PATH";
ImageView img;
private Camera camera;
private CameraPreview cameraPreview;
int windowwidth;
int windowheight;
#SuppressWarnings("unused")
private LayoutParams layoutParams;
#SuppressWarnings("deprecation")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_camera);
windowwidth = getWindowManager().getDefaultDisplay().getWidth();
windowheight = getWindowManager().getDefaultDisplay().getHeight();
img=(ImageView) findViewById(R.id.img);
img.setImageResource(R.drawable.img1);
setResult(RESULT_CANCELED);
// Camera may be in use by another activity or the system or not available at all
camera = getCameraInstance();
if(cameraAvailable(camera)){
initCameraPreview();
} else {
finish();
}
}
// Show the camera view on the activity
private void initCameraPreview() {
cameraPreview = (CameraPreview) findViewById(R.id.camera_preview);
cameraPreview.init(camera);
cameraPreview.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
LayoutParams layoutParams = (LayoutParams) img
.getLayoutParams();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
break;
case MotionEvent.ACTION_MOVE:
int x_cord = (int) event.getRawX();
int y_cord = (int) event.getRawY();
if (x_cord > windowwidth) {
x_cord = windowwidth;
}
if (y_cord > windowheight) {
y_cord = windowheight;
}
layoutParams.leftMargin = x_cord - 25;
layoutParams.topMargin = y_cord - 75;
img.setLayoutParams(layoutParams);
break;
default:
break;
}
return true;
}
});
}
#FromXML
public void onCaptureClick(View button){
// Take a picture with a callback when the photo has been created
// Here you can add callbacks if you want to give feedback when the picture is being taken
camera.takePicture(null, null, this);
}
#Override
public void onPictureTaken(byte[] data, Camera camera) {
Log.d("Picture taken");
String path = savePictureToFileSystem(data);
setResult(path);
finish();
}
private static String savePictureToFileSystem(byte[] data) {
File file = getOutputMediaFile();
saveToFile(data, file);
return file.getAbsolutePath();
}
private void setResult(String path) {
Intent intent = new Intent();
intent.putExtra(EXTRA_IMAGE_PATH, path);
setResult(RESULT_OK, intent);
}
// ALWAYS remember to release the camera when you are finished
#Override
protected void onPause() {
super.onPause();
releaseCamera();
}
private void releaseCamera() {
if(camera != null){
camera.release();
camera = null;
}
}
}
And Camera Preiew...
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private Camera camera;
private SurfaceHolder holder;
public CameraPreview(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public CameraPreview(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CameraPreview(Context context) {
super(context);
}
public void init(Camera camera) {
this.camera = camera;
initSurfaceHolder();
}
#SuppressWarnings("deprecation") // needed for < 3.0
private void initSurfaceHolder() {
holder = getHolder();
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
initCamera(holder);
}
private void initCamera(SurfaceHolder holder) {
try {
camera.setPreviewDisplay(holder);
camera.startPreview();
} catch (Exception e) {
Log.d("Error setting camera preview", e);
}
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
}
}

SurfaceView goes black when comes to foreground, for Camera App

I am using Camera feature in my app. Everything works fine but when the device gets locked/sleep, upon returning to the app the camera portion(SurfaceView) is just black. Below is my code. Can someone please identify the problem?
public class Activity_Camera extends Activity implements SurfaceHolder.Callback, Camera.AutoFocusCallback, Observer
{
// Surface vars
private SurfaceView preview;
private SurfaceHolder previewHolder;
// Camera vars
private Camera mCamera;
private boolean mPreviewRunning = false;
private boolean mCaptureFrame = false;
private int frame_number = 1;
private byte[] frame = new byte[1];
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
preview = (SurfaceView) findViewById(R.id.preview);
previewHolder = preview.getHolder();
previewHolder.addCallback(this);
previewHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
#Override
public void onPause()
{
super.onPause();
if (mPreviewRunning)
{
mCamera.stopPreview();
mPreviewRunning = false;
}
mCamera.setPreviewCallback(null);
mCamera.release();
}
// implements SurfaceHolder.Callback
public void surfaceCreated(SurfaceHolder holder)
{
mCamera = Camera.open();
}
// implements SurfaceHolder.Callback
public void surfaceDestroyed(SurfaceHolder holder)
{
mPreviewRunning = false;
}
// implements Camera.AutoFocusCallback
public void onAutoFocus(boolean success, Camera camera)
{
}
PreviewCallback previewCallback = new PreviewCallback()
{
public void onPreviewFrame(byte[] data, Camera camera)
{
}
};
// implements SurfaceHolder.Callback
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height)
{
if (mPreviewRunning)
{
mCamera.stopPreview();
}
Camera.Parameters p = mCamera.getParameters();
p.setPreviewSize(640, 480);
mCamera.setParameters(p);
try
{
mCamera.setPreviewDisplay(holder);
} catch (IOException e)
{
e.printStackTrace();
}
mCamera.setPreviewCallback(previewCallback);
int rotation = getWindowManager().getDefaultDisplay().getRotation();
int degrees = 0;
switch (rotation)
{
case Surface.ROTATION_0:
degrees = 90;
break;
case Surface.ROTATION_90:
degrees = 0;
break;
case Surface.ROTATION_180:
degrees = 270;
break;
case Surface.ROTATION_270:
degrees = 180;
break;
}
Log.i("DEGREES ARE WHAT??", Integer.toString(degrees));
// mCamera.setDisplayOrientation(degrees);
mCamera.setDisplayOrientation(90);
mCamera.startPreview();
mPreviewRunning = true;
}
// implements Observer
// captures a frame when the compass listener says it is appropriate
public void update(Observable observable, Object data)
{
mCaptureFrame = true;
}
}
Please identify the issue, as I suspect something wrong with onPause(), it also gives me exception when I press back button after the black camera screen:
java.lang.RuntimeException: Method called after release()
on this line:
mCamera.setPreviewCallback(null); // (in onPause())
Here is the XML:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:background="#E6E5E6">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:gravity="center_horizontal">
<TextView
android:id="#+id/tv_camera_url"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:maxLines="1"
android:textColor="#android:color/black"
android:text="URL goes here........"
android:layout_marginTop="3dp"
android:textStyle="bold"/>
<TextView
android:id="#+id/tv_speaknow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="3dp"
android:background="#ffffff"
android:layout_marginTop="3dp"
android:text="Speak Now"
android:textColor="#ff0000"
android:textStyle="bold"/>
</LinearLayout>
<RelativeLayout
android:id="#+id/rl_main"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<SurfaceView
android:id="#+id/preview"
android:layout_width="480px"
android:layout_height="640px"
android:layout_alignParentBottom="true"/>
<Button
android:id="#+id/btn_take_picture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/camera"
android:layout_alignBottom="#+id/preview"
android:layout_centerHorizontal="true"
android:layout_marginBottom="5dp"/>
</RelativeLayout>
</LinearLayout>

If its the first time you are launching the app, the onPause really shouldn't be the problem.
But I'd move down the creation and such to onResume instead of onCreate.
And can i see your xml of the surfaceview?
Do you just want 1 picture?
if (mPreviewRunning)
{
mCamera.stopPreview();
}
And most people startPreview from onResume. try to move it up there..

adding image to the captured image in android

I am capturing an image using the following code
public class PictureDemo extends Activity {
private SurfaceView preview=null;
private SurfaceHolder previewHolder=null;
private Camera camera=null;
private boolean inPreview=false;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
save=(Button)findViewById(R.id.save);
save.setOnClickListener(this);
image=(ImageView)findViewById(R.id.image);
image.setImageResource(R.drawable.sofa);
preview=(SurfaceView)findViewById(R.id.preview);
previewHolder=preview.getHolder();
previewHolder.addCallback(surfaceCallback);
previewHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
#Override
public void onResume() {
super.onResume();
camera=CameraFinder.INSTANCE.open();
}
#Override
public void onPause() {
if (inPreview) {
camera.stopPreview();
}
camera.release();
camera=null;
inPreview=false;
super.onPause();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
new MenuInflater(this).inflate(R.menu.options, menu);
return(super.onCreateOptionsMenu(menu));
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId()==R.id.camera) {
if (inPreview) {
camera.takePicture(null, null, photoCallback);
inPreview=false;
}
return(true);
}
return(super.onOptionsItemSelected(item));
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode==KeyEvent.KEYCODE_CAMERA ||
keyCode==KeyEvent.KEYCODE_SEARCH) {
return(true);
}
return(super.onKeyDown(keyCode, event));
}
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;
}
}
}
}
return(result);
}
SurfaceHolder.Callback surfaceCallback=new SurfaceHolder.Callback() {
public void surfaceCreated(SurfaceHolder holder) {
try {
camera.setPreviewDisplay(previewHolder);
}
catch (Throwable t) {
Log.e("PictureDemo-surfaceCallback",
"Exception in setPreviewDisplay()", t);
Toast
.makeText(PictureDemo.this, t.getMessage(), Toast.LENGTH_LONG)
.show();
}
}
public void surfaceChanged(SurfaceHolder holder,
int format, int width,
int height) {
Camera.Parameters parameters=camera.getParameters();
Camera.Size size=getBestPreviewSize(width, height,
parameters);
if (size!=null) {
parameters.setPreviewSize(size.width, size.height);
parameters.setPictureFormat(PixelFormat.JPEG);
camera.setParameters(parameters);
camera.startPreview();
inPreview=true;
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// no-op
}
};
Camera.PictureCallback photoCallback=new Camera.PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
new SavePhotoTask().execute(data);
camera.startPreview();
inPreview=true;
}
};
class SavePhotoTask extends AsyncTask<byte[], String, String> {
#Override
protected String doInBackground(byte[]... jpeg) {
File photo=new File(Environment.getExternalStorageDirectory(),
"photo.jpg");
if (photo.exists()) {
photo.delete();
}
try {
FileOutputStream fos=new FileOutputStream(photo.getPath());
fos.write(jpeg[0]);
fos.close();
}
catch (java.io.IOException e) {
Log.e("PictureDemo", "Exception in photoCallback", e);
}
return(null);
}
}
}
and the xml file is
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<android.view.SurfaceView
android:id="#+id/surface"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
<ImageView
android:id="#+id/image"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="matrix"
android:layout_centerInParent="true"
/>
<Button
android:id="#+id/save"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="save"
android:layout_alignParentRight="true"
/>
</FrameLayout>
I can capture an image with this code but i need to add the image which was given to the ImageView to the captured image.
How to do that.
Thanks in advance.

Declare a Bitmap in your class
public class PictureDemo extends Activity {
Bitmap bitmap;
...
I think you can get the image you just took with this:
public void onPictureTaken(byte[] data, Camera camera) {
new SavePhotoTask().execute(data);
camera.startPreview();
inPreview=true;
bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
}
And then set the bitmap to your ImageView like this:
image.setImageBitmap(bitmap);

Trying doing something like this:
Bitmap bitmap = new Bitmap(define the size and other params you like).
Canvas canvas = new Canvas();
canvas.drawBitmap(your captured image);
canvas.drawBitmap(the overlay image);
// Now the bitmap will include both captured imaged and overlayed image
You can look in here and here

You can do mFrameLayout.getDrawingCache() to get a bitmap of the whole layout. The drawing cache should be enabled. I dont know its default state.

How can I make a SurfaceView larger than the screen?

I would like to effectively make a simple digital zoom for the camera preview, so I thought I would simply resize my SurfaceView to be larger than the screen. Other questions (such as 3813049) seem to indicate that this is easy, so I created the sample code below which I expect to let me see only half of the image horizontally (since the SurfaceView is twice as wide as the screen) and have the image only take up half of the screen horizontally. However, running it (when targeted to SDK version 4 on my Thunderbolt with Android 2.2.1) results in being able to see the whole image horizontally while filling the screen horizontally. The SurfaceView appears to behave as intended vertically (when I make it smaller than the screen), but Android won't allow me to make the SurfaceView larger than the screen.
How can I implement a digital zoom? (No, I cannot use Camera.Parameters.setZoom; not only is this not supported by Android 1.6, but different cameras support and implement this differently)
public class MagnifyTestActivity extends Activity implements SurfaceHolder.Callback {
private MagnificationView mPreview;
private SurfaceHolder mHolder;
private Camera mCamera = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPreview = new MagnificationView(this);
setContentView(mPreview);
mHolder = mPreview.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public class MagnificationView extends SurfaceView {
public MagnificationView(Context context) {
super(context);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth()*2;
int height = display.getHeight()/2;
widthMeasureSpec = MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY);
heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
public void surfaceCreated(SurfaceHolder holder) {
mCamera = Camera.open();
try {
mCamera.setPreviewDisplay(holder);
} catch (IOException e) {
e.printStackTrace();
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
mHolder.setFixedSize(w, h);
mCamera.startPreview();
}
}
UPDATE: Based on #Pulkit Sethi's response, it is possible to stretch/magnify the SurfaceView vertically, just not horizontally. To magnify the SurfaceView vertically, simply replace display.getHeight()/2 with display.getHeight()*2 above. Also observe that changing the width doesn't produce any horizontal magnification, either in my code or in Pulkit's.

//Activity class
public class CameraActivity extends Activity implements SurfaceListener {
private static final String TAG = "CameraActivity";
Camera mCamera;
CameraPreview mPreview;
private FrameLayout mCameraPreview;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_camera);
mCamera = getCameraInstance();
mPreview = new CameraPreview(this, mCamera);
mCameraPreview = (FrameLayout) findViewById(R.id.camera_preview);
mCameraPreview.addView(mPreview);
}
#Override
protected void onPause() {
super.onPause();
releaseCamera();
}
private Camera getCameraInstance() {
Camera camera = null;
try {
camera = Camera.open();
} catch (Exception e) {
}
return camera;
}
private void releaseCamera() {
if (null != mCamera) {
mCamera.release();
}
mCamera = null;
}
#Override
public void surfaceCreated() {
//Change these mate
int width = 1000;
int height = 1000;
// Set parent window params
getWindow().setLayout(width, height);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
width, height);
mCameraPreview.setLayoutParams(params);
mCameraPreview.requestLayout();
}
}
// Preview class
public class CameraPreview extends SurfaceView implements
SurfaceHolder.Callback {
private static final String TAG = "CameraPreview";
Context mContext;
Camera mCamera;
SurfaceHolder mHolder;
public interface SurfaceListener{
public void surfaceCreated();
}
SurfaceListener listener;
public CameraPreview(Context context, Camera camera) {
super(context);
mContext = context;
listener = (SurfaceListener)mContext;
mCamera = camera;
mHolder = getHolder();
mHolder.addCallback(this);
// Required prior 3.0 HC
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
try {
mCamera.setPreviewDisplay(holder);
Parameters params = mCamera.getParameters();
//Change parameters here
mCamera.setParameters(params);
mCamera.startPreview();
listener.surfaceCreated();
} catch (Exception e) {
// TODO: handle exception
}
}
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.
Log.i(TAG, "Surface changed called");
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
mCamera.setDisplayOrientation(90);
// start preview with new settings
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e) {
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
}
//Layout file
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<FrameLayout
android:id="#+id/camera_preview"
android:layout_width="300dp"
android:layout_height="400dp"
android:layout_centerHorizontal="true"
android:paddingTop="10dp" >
</FrameLayout>
</RelativeLayout>

You can't make your surfaceView bigger than the screen. That being said there are ways around it.
I found you can adjust the size of the canvas in the SurfaceView, which will allow zooming.
public class DrawingThread extends Thread {
private MagnificationView mainPanel;
private SurfaceHolder surfaceHolder;
private boolean run;
public DrawingThread(SurfaceHolder surface, MagnificationView panel){
surfaceHolder = surface;
mainPanel = panel;
}
public SurfaceHolder getSurfaceHolder(){
return surfaceHolder;
}
public void setRunning (boolean run){
this.run = run;
}
public void run(){
Canvas c;
while (run){
c = null;
try {
c = surfaceHolder.lockCanvas(null);
synchronized (surfaceHolder){
mainPanel.OnDraw(c);
}
} finally {
if (c != null){
surfaceHolder.unlockCanvasAndPost(c);
}
}
}
}
}
In the MagnificationView class add a method:
public void OnDraw(Canvas canvas){
if (canvas!=null){
canvas.save();
canvas.scale(scaleX,scaleY);
canvas.restore();
}
}
DrawingThread would be a thread you start in in your Activity. Also in your MagnificationView class override the OnTouchEvent to handle your own pinch-zoom (which will modify scaleX & scaleY.
Hope This solves your issue

What you can do is to get the window and set its height:
getWindow().setLayout(1000, 1000);
This makes your window larger than the screen making your root view and consequently your surfaceview, probably contained inside a Framelayout larger than screen.
This worked for me let me know.
The above would work no matter what. What you would want to do is listen for onSurfaceCreated event for your surface view. Then after you have the started the camera view and you are able to calculate size of your widget holding the preview, you would want to change size of the container widget.
The concept is your container widget (probably FrameLayout) wants to grow larger than screen. The screen itself is restricted by the activity so first set size of your window,
then set size of your framelayout (it would always be shrunk to max size of windows, so set accordingly).
I do all this logic after my onSurfaceCreated is finished I have started the preview. I listen for this event in my activity by implementing a small interface, as my Camera preview is a separate class.
Working on all API level >= 8

Here's my TouchSurfaceView's onMeasure that performs zoom:
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
setMeasuredDimension((int) (width * scaleFactor), (int) (height * scaleFactor));
}
This properly zooms in and out depending on scaleFactor.
I haven't tested this with camera, but it works properly with MediaPlayer (behaving as VideoView).