Develop Reference

Surface View Camera Preview

Having a little trouble getting my SurfaceView to show my camera preview. I've looked at some questions on here and Google'd some tuts but I think it may be a small error on my end that I'm just not seeing.
Code
public class RoofPitchActivity extends Activity implements SensorEventListener {
...
private SurfaceView mSurfaceView;
private SurfaceHolder mSurfaceHolder;
private Camera mCamera;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_roof_pitch);
initViews();
}
private void initViews() {
...
Preview preview = new Preview(this);
mCamera = Camera.open();
preview.setCamera(mCamera);
}
...
...
class Preview extends ViewGroup implements SurfaceHolder.Callback {
public Preview(Context context) {
super(context);
mSurfaceView = (SurfaceView) findViewById(R.id.preview);
mSurfaceView = new SurfaceView(context);
addView(mSurfaceView);
mSurfaceHolder = mSurfaceView.getHolder();
mSurfaceHolder.addCallback(this);
}
public void setCamera(Camera camera) {
if (mCamera == camera) {
return;
}
stopPreviewAndFreeCamera();
mCamera = camera;
if (mCamera != null) {
requestLayout();
try {
mCamera.setPreviewDisplay(mSurfaceHolder);
} catch (IOException e) {
e.printStackTrace();
}
mCamera.startPreview();
}
}
private void stopPreviewAndFreeCamera() {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
mCamera.startPreview();
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(mSurfaceView.getWidth(), mSurfaceView.getHeight());
requestLayout();
mCamera.setParameters(parameters);
mCamera.startPreview();
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
if (mCamera != null) {
mCamera.stopPreview();
}
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
}
}
}
So when the activity is launched the SurfaceView is black. The camera does not appear to be rendering the preview onto the SurfaceView. I'm sure there's something small I'm missing, or maybe it's just a fundemental misunderstanding of how this works. A fresh set of eyes with a little explanation would be very much appreciated. Thanks

So the answer to my question ended up being device specific. The code was acceptable but my device I'm using to debug is a Nexus 7. This means the camera is front facing and the normal call to the camera does not work. An interesting and funny read about this can be found in this article
Camera.open();
does not work. You must use
Camera.open(0);
So my code ended up with a conditional check for the camera and now it works fine.
Like so
public void setCamera() {
stopPreviewAndFreeCamera();
PackageManager pm = getPackageManager();
boolean backCamera = pm.hasSystemFeature(PackageManager.FEATURE_CAMERA);
boolean frontCamera = pm.hasSystemFeature(PackageManager.FEATURE_CAMERA_FRONT);
if (frontCamera) {
mCamera = Camera.open(0);
} else if (backCamera) {
mCamera = Camera.open();
}
if (mCamera != null) {
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(mSurfaceView.getWidth(), mSurfaceView.getHeight());
requestLayout();
try {
mCamera.setParameters(parameters);
mCamera.setPreviewDisplay(mSurfaceHolder);
} catch (IOException e) {
e.printStackTrace();
}
mCamera.startPreview();
}
}

camera preview on lockscreen

I want add a take picture function in lockscreen , and I need to open the preview on screen , but it's fail all the time , logcat say the Error is about "setPreviewWindow - Null ANativeWindow passed to setPreviewWindow" and "startPreview - Preview not started. Preview in progress flag set"
In keyguard_screen_tab_unlock.xml after the digital clock view, put
<FrameLayout
android:id="#+id/mPreview"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
In LockScreen.java constructor:
FrameLayout mFrameLayout = (FrameLayout)findViewById(R.id.mPreview);
SurfacePreview preview = new SurfacePreview(mContext);
preview.setZOrderOnTop(true);
mFrameLayout.addView(preview);
SurfacePreview class :
public class SurfacePreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mSurfaceHolder;
SurfacePreview(Context context) {
super(context);
mSurfaceHolder = this.getHolder();
mSurfaceHolder.addCallback(this);
mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
mCamera = Camera.open(CameraInfo.CAMERA_FACING_BACK);
try {
mCamera.setPreviewDisplay(holder);
} catch (IOException e) {
e.printStackTrace();
}
mCamera.startPreview();
}
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Camera.Parameters parameters = mCamera.getParameters();
mCamera.setParameters(parameters);
mCamera.setDisplayOrientation(90);
}
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.release();
}
}
Anyone kown how to resolve this issue and start prview on LockScreen? Thanks a lot.

Example of Camera preview using SurfaceTexture in Android

I am trying to render camera preview using SurfaceTexture. I read the document but unable to understand how it works.
Can anyone provide one sample example(very basic one) or link which uses SurfaceTexture to preview camera. I googled this but not found what I am looking for.
Thanks in advance.

If you want to use the Camera with TextureSurface you can implement SurfaceTextureListener interface. You'll have to implement 4 methods:
1) onSurfaceTextureAvailable - Here you setup your camera
2)onSurfaceTextureSizeChanged - In your case, the Android's camera will handle this method
3)onSurfaceTextureDestroyed - Here you destroy all camera stuff.
4) onSurfaceTextureUpdated- Update your texture here when you have something to change!
Check the example below:
public class MainActivity extends Activity implements SurfaceTextureListener{
private Camera mCamera;
private TextureView mTextureView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mTextureView = new TextureView(this);
mTextureView.setSurfaceTextureListener(this);
setContentView(mTextureView);
}
#Override
public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
mCamera = Camera.open();
Camera.Size previewSize = mCamera.getParameters().getPreviewSize();
mTextureView.setLayoutParams(new FrameLayout.LayoutParams(
previewSize.width, previewSize.height, Gravity.CENTER));
try {
mCamera.setPreviewTexture(surface);
} catch (IOException t) {
}
mCamera.startPreview();
}
#Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
// Ignored, the Camera does all the work for us
}
#Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
mCamera.stopPreview();
mCamera.release();
return true;
}
#Override
public void onSurfaceTextureUpdated(SurfaceTexture surface) {
// Update your view here!
}
}
Two more things: Don't forget to add the camera permissions in your project's manifest and the SurfaceTexture is available from API 11.

public class VideoCapture extends Activity implements OnClickListener, SurfaceHolder.Callback {
MediaRecorder recorder;
SurfaceHolder holder;
boolean recording = false;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
recorder = new MediaRecorder();
initRecorder();
SurfaceView cameraView = new SurfaceView(this);
holder = cameraView.getHolder();
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
cameraView.setClickable(true);
cameraView.setOnClickListener(this);
}
private void initRecorder() {
recorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);
recorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);
CamcorderProfile cpHigh = CamcorderProfile
.get(CamcorderProfile.QUALITY_HIGH);
recorder.setProfile(cpHigh);
recorder.setOutputFile("/sdcard/videocapture_example.mp4");
recorder.setMaxDuration(50000); // 50 seconds
recorder.setMaxFileSize(5000000); // Approximately 5 megabytes
}
private void prepareRecorder() {
recorder.setPreviewDisplay(holder.getSurface());
try {
recorder.prepare();
} catch (IllegalStateException e) {
e.printStackTrace();
finish();
} catch (IOException e) {
e.printStackTrace();
finish();
}
}
public void onClick(View v) {
if (recording) {
recorder.stop();
recording = false;
// Let's initRecorder so we can record again
initRecorder();
prepareRecorder();
} else {
recording = true;
recorder.start();
}
}
public void surfaceCreated(SurfaceHolder holder) {
prepareRecorder();
}
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
}
public void surfaceDestroyed(SurfaceHolder holder) {
if (recording) {
recorder.stop();
recording = false;
}
recorder.release();
finish();
}
}

unable to display camera view properly in android?

In my android app i m using the camera and starting it programmatically .I run my code on samsung gt-s5360 ,but the view is rotated by 90 degree anti clock wise.my code works fine on HTC wildfire-s.On this device the camera view is showing correctly without rotating the view .But it is not showing the correct view on each device.So how can i write the code that works for all devices(android) .My android jar is 2.2 and API level is 8.Please help me .Here is my code.
public class AndroidCamera extends Activity implements SurfaceHolder.Callback{
int rotate=90;
Camera camera;
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
boolean previewing = false;
LayoutInflater controlInflater = null;
public static ArrayList<Activity> activities=new ArrayList<Activity>();
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
activities.add(this);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
getWindow().setFormat(PixelFormat.TRANSLUCENT);
surfaceView = (SurfaceView)findViewById(R.id.camerapreview);
surfaceHolder = surfaceView.getHolder();
surfaceHolder.addCallback(this);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
Intent i=new Intent();
i.setClassName("a.b.c","a.b.c.DialPad");
startActivity(i);
}
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
//this.camera.setDisplayOrientation(90);
if(previewing){
camera.stopPreview();
previewing = false;
}
if (camera != null){
try {
camera.setPreviewDisplay(surfaceHolder);
camera.startPreview();
//camera.setDisplayOrientation(90);
previewing = true;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
camera = Camera.open();
camera.setDisplayOrientation(rotate);
//Parameters p= camera.getParameters();
//p.setRotation(90);
/*if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT)
{
p.set("orientation", "portrait");
p.set("rotation",90);
Toast.makeText(getApplicationContext(), "Potrait Mode", Toast.LENGTH_SHORT).show();
}
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE)
{
p.set("orientation", "landscape");
p.set("rotation", 90);
Toast.makeText(getApplicationContext(), "Landscape Mode", Toast.LENGTH_SHORT).show();
}*/
}
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
camera.stopPreview();
camera.release();
camera = null;
previewing = false;
}

Android camera preview: 1:1 aspect ratio, how?

Hi
I am trying to use the camera to capture an image in one of my application. What is special is that I need a square preview area (and picture in the end). I tried defining the size of both picture and preview to 1:1 pixel ratios, but nothing seams to work. No matter what I does the picture looks "squashed" on a square.
Anyone who has any idea about how to resolve this?
code:
public class AddFromCameraActivity extends Activity implements SurfaceHolder.Callback {
private Camera mCamera;
private Parameters mParameters;
private SurfaceView mCameraPreview;
private SurfaceHolder mSurfaceHolder;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.addimagefromcameramain);
initialise();
//Testing area
mCamera = Camera.open();
mParameters = mCamera.getParameters();
mParameters.setFlashMode(Camera.Parameters.FLASH_MODE_AUTO);
mParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
mParameters.setJpegQuality(50);
mParameters.setJpegThumbnailQuality(50);
mParameters.setPictureSize(1024, 1024);
//mParameters.setPreviewFormat(ImageFormat.JPEG);
mParameters.setJpegThumbnailSize(256, 256);
mParameters.setPreviewSize(500, 500);
mCamera.setParameters(mParameters);
}
private void initialise()
{
mCameraPreview = (SurfaceView)findViewById(R.id.cameraSurfaceView);
mSurfaceHolder = mCameraPreview.getHolder();
mSurfaceHolder.addCallback(this);
mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
mSurfaceHolder.setFixedSize(500, 500);
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
try {
mCamera.setPreviewDisplay(mSurfaceHolder);
mCamera.startPreview();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mCamera.release();
}
#Override
public void onPause()
{
mCamera.release();
}
}
thanks

You can take a look at the CameraPreview sample code from the Android SDK. The getOptimalPreviewSize method shows how to deal with different camera sizes and the onLayout method shows how to layout the preview surface in the activity.