Apps Problems in setting camera preview sizes.

[KarthikVPai]

Guys I am working on Camera API for first time. I have followed vogella tutorial, and some other tutorial too to generate a preview and take pictures. My photos are perfectly fine. But I am not able to generate a proper preview,however, i am getting some preview. Please suggest me how should i go by it.Here is my code for preview class


import java.io.IOException;
import java.util.List;

import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.Size;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;

public CameraPreview(Context context, Camera camera) {
super(context);
mCamera = camera;

// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
// mHolder.setType(SurfaceHolder.);
}

public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, now tell the camera where to draw the preview.
try {

mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d(null, "Error setting camera preview: " + e.getMessage());
}
}

public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.

if (mHolder.getSurface() == null){
// preview surface does not exist
return;
}

// stop preview before making changes
try {

mCamera.stopPreview();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}

// set preview size and make any resize, rotate or
// reformatting changes here
Camera.Parameters parameters;
try {
//
parameters = mCamera.getParameters();
// int Jpegquality=parameters.getJpegQuality();
// String allPara= parameters.flatten();
// System.out.println(allPara);
//


List<Size> sizes = parameters.getSupportedPreviewSizes();
// Size optimalSize = getOptimalPreviewSize(sizes, w, h);
// parameters.setPreviewSize(optimalSize.width, optimalSize.height);
//
// mCamera.setParameters(parameters);
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}

// start preview with new settings
try {

mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();

} catch (Exception e){
// Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.05;
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;
}
}
Please help me.I am working independently despite being new to Android app development.