使用Camera预览显示变形问题

昵__称 2015-01-12 06:16:19

我使用Camera显示预览图竖屏显示会有一些拉伸。感觉被拉长了。
我已经选择了最接近的比例了，但是还是有拉伸。

package com.example.zxing_android;



import java.io.IOException;

import java.util.List;



import com.example.zxing_android.R.color;



import android.app.Activity;

import android.hardware.Camera;

import android.hardware.Camera.Size;

import android.os.Bundle;

import android.util.Log;

import android.view.SurfaceHolder;

import android.view.SurfaceHolder.Callback;

import android.view.SurfaceView;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.LinearLayout.LayoutParams;





/**

 */

public class CameraActivity extends Activity {

	SurfaceView mSurface;

	SurfaceHolder mSurfaceHolder;

	Camera mCamera;

	boolean isInit;

	Button btn;



	// int viewWidth, viewHeight;



	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_camera);

		mSurface = (SurfaceView) findViewById(R.id.camera);

		btn = (Button) findViewById(R.id.btn);

		btn.setOnClickListener(new OnClickListener() {

			@Override

			public void onClick(View v) {

				mCamera.autoFocus(null);// 自动对焦

			}

		});

		mSurfaceHolder = mSurface.getHolder(); // get the camera holder

		mSurfaceHolder.addCallback(new Callback() {

			@Override

			public void surfaceCreated(SurfaceHolder arg0) {

				mCamera = Camera.open(); // open camera

				isInit = false;

				try {

					mCamera.setPreviewDisplay(mSurfaceHolder); // set the //

				} catch (IOException e) {

					e.printStackTrace();

					if (mCamera != null) {

						mCamera.release();

						mCamera = null;

					}

				}

				mCamera.startPreview(); // state preview

			}



			@Override

			public void surfaceDestroyed(SurfaceHolder arg0) {

				// mSurface.setLayoutParams(new LayoutParams(viewWidth,

				// viewHeight));

				mCamera.setPreviewCallback(null); // ！！这个必须在前，不然退出出错

				mCamera.stopPreview();

				mCamera.release();

				mCamera = null;

			}



			@Override

			public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

				initCamera(width, height);

			}

		});

	}



	private void initCamera(int width, int height) {

		if (!isInit) {

			// viewWidth = width;

			// viewHeight = height;

			isInit = true;

			mCamera.autoFocus(null);

			Camera.Parameters parameters = mCamera.getParameters();

			// 摄像头旋转

			// if (android.os.Build.VERSION_CODES.GINGERBREAD >

			// android.os.Build.VERSION.SDK_INT) {

			mCamera.setDisplayOrientation(90);

			// } else {

			// parameters.set("rotation", 180);

			// }

			List<Size> previewSizes = mCamera.getParameters().getSupportedPreviewSizes();

			double aspectTolerance = Double.MAX_VALUE;

			int preWidth = 0, preHeight = 0;

			double scale = ((double) width) / height;

			for (int i = 0, len = previewSizes.size(); i < len; i++) {

				Size s = previewSizes.get(i);

				double sizeScale = ((double) s.height) / s.width;

				if (Math.abs(scale - sizeScale) < aspectTolerance) {

					aspectTolerance = Math.abs(scale - sizeScale);

					preWidth = s.height;

					preHeight = s.width;

				}

			}

			if (preWidth != 0) {

				parameters.setPreviewSize(preWidth, preHeight);

				// mSurface.setLayoutParams(new LayoutParams(720, 1280));

				Size s = parameters.getPreviewSize();

				Log.e("", s.width + " " + s.height);

			}

		}

	}

}