Ramesh Bugatha Ramesh Bugatha - 3 months ago 28
Android Question

camera.setParameters failed in android

I have included the camera functionality in my application. I have also launched the app in the market. I got an error message from one of the users that he is getting an error while opening the camera.

I have tested the app on the device on 2.1. The error I got from the user is using nexus one which will mostly run 2.2...Here's the logcat error that I've received...

java.lang.RuntimeException: setParameters failed
at android.hardware.Camera.native_setParameters(Native Method)
at android.hardware.Camera.setParameters(Camera.java:647)
at com.CameraApp.Preview.surfaceChanged(Preview.java:67)
at android.view.SurfaceView.updateWindow(SurfaceView.java:538)
at android.view.SurfaceView.dispatchDraw(SurfaceView.java:339)
at android.view.ViewGroup.drawChild(ViewGroup.java:1638)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)
at android.view.ViewGroup.drawChild(ViewGroup.java:1638)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)
at android.view.ViewGroup.drawChild(ViewGroup.java:1638)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)
at android.view.View.draw(View.java:6743)
at android.widget.FrameLayout.draw(FrameLayout.java:352)
at android.view.ViewGroup.drawChild(ViewGroup.java:1640)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)
at android.view.View.draw(View.java:6743)
at android.widget.FrameLayout.draw(FrameLayout.java:352)
at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1842)
at android.view.ViewRoot.draw(ViewRoot.java:1407)
at android.view.ViewRoot.performTraversals(ViewRoot.java:1163)
at android.view.ViewRoot.handleMessage(ViewRoot.java:1727)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4627)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
at dalvik.system.NativeStart.main(Native Method)


I ran the app on 2.2 emulator also to check it. But it worked fine. Can anyone please tell me why the error is occurring?

Here is the class which I mentioned in the comments:

class Preview extends SurfaceView implements SurfaceHolder.Callback
{
private static final String TAG = "Preview";

SurfaceHolder mHolder;
public Camera camera;

Preview(Context context)
{
super(context);

// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

public void surfaceCreated(SurfaceHolder holder)
{
// The Surface has been created, acquire the camera and tell it where
// to draw.
camera = Camera.open();
try {
camera.setPreviewDisplay(holder);
} catch (IOException exception) {
camera.release();
camera = null;
// TODO: add more exception handling logic here
}
}

public void surfaceDestroyed(SurfaceHolder holder)
{
// Surface will be destroyed when we return, so stop the preview.
// Because the CameraDevice object is not a shared resource, it's very
// important to release it when the activity is paused.
camera.stopPreview();
camera.release();
camera = null;
}

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.

Camera.Parameters parameters = camera.getParameters();
parameters.setPreviewSize(w, h);
camera.setParameters(parameters);
camera.startPreview();
}

@Override
public void draw(Canvas canvas)
{
super.draw(canvas);
Paint p= new Paint(Color.RED);
Log.d(TAG,"draw");
canvas.drawText("PREVIEW", canvas.getWidth()/2, canvas.getHeight()/2, p );
}
}

Answer

It is failing because not all devices support arbitrary preview sizes. Apparently some do but you can't rely on it. In your surfaceChanged method you need to do something like this:

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
    Camera.Parameters parameters = camera.getParameters();
    List<Camera.Size> previewSizes = parameters.getSupportedPreviewSizes();

    // You need to choose the most appropriate previewSize for your app
    Camera.Size previewSize = // .... select one of previewSizes here

    parameters.setPreviewSize(previewSize.width, previewSize.height);
    camera.setParameters(parameters);
    camera.startPreview();
}

You'll have to figure out a way to scale this so that you don't lose the aspect ratio etc.

For reference here is the Android SDK doc.

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