玩转Android Camera开发(一):Surfaceview预览Camera,基础拍照功能完整demo

杂家前文是在2012年的除夕之夜仓促完成，后来很多人指出了一些问题，琐事缠身一直没有进行升级。后来随着我自己的使用，越来越发现不出个升级版的demo是不行了。有时候就连我自己用这个demo测一些性能、功能点，用着都不顺手。当初代码是在linux下写的，弄到windows里下全是乱码。还要自己改几分钟才能改好。另外，很多人说不能正常预览，原因是我在布局里把Surfaceview的尺寸写死了。再有就是initCamera()的时候设参数失败，直接黑屏退出，原因也是我把预览尺寸和照片尺寸写死了。再有就是照片变形的问题。为此，今天出一个升级版的demo，争取全面适配所有机型。

上图为此次的代码结构，activity包里就是放CameraActivity，日后添加图库浏览功能再加GalleryActivity。为了使Camera的逻辑和界面的UI耦合度降至最低，封装了CameraInterface类，里面操作Camera的打开、预览、拍照、关闭。preview包里是自定义的Surfaceview。在util包里放着CamParaUtil是专门用来设置、打印Camera的PreviewSize、PictureSize、FocusMode的，并能根据Activity传进来的长宽比(主要是16:9 或 4:3两种尺寸)自动寻找适配的PreviewSize和PictureSize，消除变形。默认的是全屏，因为一些手机全屏时，屏幕的长宽比不是16:9或4:3所以在找尺寸时也是存在一些偏差的。其中有个值，就是判断两个float是否相等，这个参数比较关键，里面设的0.03.经我多个手机测试，这个参数是最合适的，否则的话有些奇葩手机得到的尺寸拍出照片变形。下面上源码：

一、布局 activity_camera.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".CameraActivity" >
    <FrameLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <org.yanzi.camera.preview.CameraSurfaceView
            android:id="@+id/camera_surfaceview"
            android:layout_width="0dip"
            android:layout_height="0dip" />
    </FrameLayout>

    <ImageButton
        android:id="@+id/btn_shutter"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/btn_shutter_background"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true" 
        android:layout_marginBottom="10dip"/>


</RelativeLayout>

二、AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="org.yanzi.playcamera"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="9"
        android:targetSdkVersion="17" />
        <!-- 增加文件存储和访问摄像头的权限 -->
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-feature android:name="android.hardware.camera" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher_icon"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="org.yanzi.activity.CameraActivity"
            android:label="@string/app_name" 
            android:theme="@android:style/Theme.Black.NoTitleBar.Fullscreen"
            android:screenOrientation="portrait">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

三、下面是java代码

1、CameraActivity.java

package org.yanzi.activity;

import org.yanzi.camera.CameraInterface;
import org.yanzi.camera.CameraInterface.CamOpenOverCallback;
import org.yanzi.camera.preview.CameraSurfaceView;
import org.yanzi.playcamera.R;
import org.yanzi.util.DisplayUtil;

import android.app.Activity;
import android.graphics.Point;
import android.os.Bundle;
import android.view.Menu;
import android.view.SurfaceHolder;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageButton;

public class CameraActivity extends Activity implements CamOpenOverCallback {
	private static final String TAG = "yanzi";
	CameraSurfaceView surfaceView = null;
	ImageButton shutterBtn;
	float previewRate = -1f;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		Thread openThread = new Thread(){
			@Override
			public void run() {
				// TODO Auto-generated method stub
				CameraInterface.getInstance().doOpenCamera(CameraActivity.this);
			}
		};
		openThread.start();
		setContentView(R.layout.activity_camera);
		initUI();
		initViewParams();
		
		shutterBtn.setOnClickListener(new BtnListeners());
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.camera, menu);
		return true;
	}

	private void initUI(){
		surfaceView = (CameraSurfaceView)findViewById(R.id.camera_surfaceview);
		shutterBtn = (ImageButton)findViewById(R.id.btn_shutter);
	}
	private void initViewParams(){
		LayoutParams params = surfaceView.getLayoutParams();
		Point p = DisplayUtil.getScreenMetrics(this);
		params.width = p.x;
		params.height = p.y;
		previewRate = DisplayUtil.getScreenRate(this); //默认全屏的比例预览
		surfaceView.setLayoutParams(params);

		//手动设置拍照ImageButton的大小为120dip×120dip,原图片大小是64×64
		LayoutParams p2 = shutterBtn.getLayoutParams();
		p2.width = DisplayUtil.dip2px(this, 80);
		p2.height = DisplayUtil.dip2px(this, 80);;		
		shutterBtn.setLayoutParams(p2);	

	}

	@Override
	public void cameraHasOpened() {
		// TODO Auto-generated method stub
		SurfaceHolder holder = surfaceView.getSurfaceHolder();
		CameraInterface.getInstance().doStartPreview(holder, previewRate);
	}
	private class BtnListeners implements OnClickListener{

		@Override
		public void onClick(View v) {
			// TODO Auto-generated method stub
			switch(v.getId()){
			case R.id.btn_shutter:
				CameraInterface.getInstance().doTakePicture();
				break;
			default:break;
			}
		}

	}

}

2、CameraInterface.java

package org.yanzi.camera;

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

import org.yanzi.util.CamParaUtil;
import org.yanzi.util.FileUtil;
import org.yanzi.util.ImageUtil;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.hardware.Camera.ShutterCallback;
import android.hardware.Camera.Size;
import android.util.Log;
import android.view.SurfaceHolder;

public class CameraInterface {
	private static final String TAG = "yanzi";
	private Camera mCamera;
	private Camera.Parameters mParams;
	private boolean isPreviewing = false;
	private float mPreviwRate = -1f;
	private static CameraInterface mCameraInterface;

	public interface CamOpenOverCallback{
		public void cameraHasOpened();
	}

	private CameraInterface(){

	}
	public static synchronized CameraInterface getInstance(){
		if(mCameraInterface == null){
			mCameraInterface = new CameraInterface();
		}
		return mCameraInterface;
	}
	/**打开Camera
	 * @param callback
	 */
	public void doOpenCamera(CamOpenOverCallback callback){
		Log.i(TAG, "Camera open....");
		mCamera = Camera.open();
		Log.i(TAG, "Camera open over....");
		callback.cameraHasOpened();
	}
	/**开启预览
	 * @param holder
	 * @param previewRate
	 */
	public void doStartPreview(SurfaceHolder holder, float previewRate){
		Log.i(TAG, "doStartPreview...");
		if(isPreviewing){
			mCamera.stopPreview();
			return;
		}
		if(mCamera != null){

			mParams = mCamera.getParameters();
			mParams.setPictureFormat(PixelFormat.JPEG);//设置拍照后存储的图片格式
			CamParaUtil.getInstance().printSupportPictureSize(mParams);
			CamParaUtil.getInstance().printSupportPreviewSize(mParams);
			//设置PreviewSize和PictureSize
			Size pictureSize = CamParaUtil.getInstance().getPropPictureSize(
					mParams.getSupportedPictureSizes(),previewRate, 800);
			mParams.setPictureSize(pictureSize.width, pictureSize.height);
			Size previewSize = CamParaUtil.getInstance().getPropPreviewSize(
					mParams.getSupportedPreviewSizes(), previewRate, 800);
			mParams.setPreviewSize(previewSize.width, previewSize.height);

			mCamera.setDisplayOrientation(90);

			CamParaUtil.getInstance().printSupportFocusMode(mParams);
			List<String> focusModes = mParams.getSupportedFocusModes();
			if(focusModes.contains("continuous-video")){
				mParams.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
			}
			mCamera.setParameters(mParams);	

			try {
				mCamera.setPreviewDisplay(holder);
				mCamera.startPreview();//开启预览
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}

			isPreviewing = true;
			mPreviwRate = previewRate;

			mParams = mCamera.getParameters(); //重新get一次
			Log.i(TAG, "最终设置:PreviewSize--With = " + mParams.getPreviewSize().width
					+ "Height = " + mParams.getPreviewSize().height);
			Log.i(TAG, "最终设置:PictureSize--With = " + mParams.getPictureSize().width
					+ "Height = " + mParams.getPictureSize().height);
		}
	}
	/**
	 * 停止预览，释放Camera
	 */
	public void doStopCamera(){
		if(null != mCamera)
		{
			mCamera.setPreviewCallback(null);
			mCamera.stopPreview(); 
			isPreviewing = false; 
			mPreviwRate = -1f;
			mCamera.release();
			mCamera = null;     
		}
	}
	/**
	 * 拍照
	 */
	public void doTakePicture(){
		if(isPreviewing && (mCamera != null)){
			mCamera.takePicture(mShutterCallback, null, mJpegPictureCallback);
		}
	}

	/*为了实现拍照的快门声音及拍照保存照片需要下面三个回调变量*/
	ShutterCallback mShutterCallback = new ShutterCallback() 
	//快门按下的回调，在这里我们可以设置类似播放“咔嚓”声之类的操作。默认的就是咔嚓。
	{
		public void onShutter() {
			// TODO Auto-generated method stub
			Log.i(TAG, "myShutterCallback:onShutter...");
		}
	};
	PictureCallback mRawCallback = new PictureCallback() 
	// 拍摄的未压缩原数据的回调,可以为null
	{

		public void onPictureTaken(byte[] data, Camera camera) {
			// TODO Auto-generated method stub
			Log.i(TAG, "myRawCallback:onPictureTaken...");

		}
	};
	PictureCallback mJpegPictureCallback = new PictureCallback() 
	//对jpeg图像数据的回调,最重要的一个回调
	{
		public void onPictureTaken(byte[] data, Camera camera) {
			// TODO Auto-generated method stub
			Log.i(TAG, "myJpegCallback:onPictureTaken...");
			Bitmap b = null;
			if(null != data){
				b = BitmapFactory.decodeByteArray(data, 0, data.length);//data是字节数据，将其解析成位图
				mCamera.stopPreview();
				isPreviewing = false;
			}
			//保存图片到sdcard
			if(null != b)
			{
				//设置FOCUS_MODE_CONTINUOUS_VIDEO)之后，myParam.set("rotation", 90)失效。
				//图片竟然不能旋转了，故这里要旋转下
				Bitmap rotaBitmap = ImageUtil.getRotateBitmap(b, 90.0f);
				FileUtil.saveBitmap(rotaBitmap);
			}
			//再次进入预览
			mCamera.startPreview();
			isPreviewing = true;
		}
	};


}

3、CameraSurfaceView.java

package org.yanzi.camera.preview;

import org.yanzi.camera.CameraInterface;

import android.content.Context;
import android.graphics.PixelFormat;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class CameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback {
	private static final String TAG = "yanzi";
	CameraInterface mCameraInterface;
	Context mContext;
	SurfaceHolder mSurfaceHolder;
	public CameraSurfaceView(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
		mContext = context;
		mSurfaceHolder = getHolder();
		mSurfaceHolder.setFormat(PixelFormat.TRANSPARENT);//translucent半透明 transparent透明
		mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
		mSurfaceHolder.addCallback(this);
	}

	@Override
	public void surfaceCreated(SurfaceHolder holder) {
		// TODO Auto-generated method stub
		Log.i(TAG, "surfaceCreated...");
	}

	@Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width,
			int height) {
		// TODO Auto-generated method stub
		Log.i(TAG, "surfaceChanged...");
	}

	@Override
	public void surfaceDestroyed(SurfaceHolder holder) {
		// TODO Auto-generated method stub
		Log.i(TAG, "surfaceDestroyed...");
		CameraInterface.getInstance().doStopCamera();
	}
	public SurfaceHolder getSurfaceHolder(){
		return mSurfaceHolder;
	}
	
}

4、CamParaUtil.java

package org.yanzi.util;

import java.util.Collections;
import java.util.Comparator;
import java.util.List;

import android.hardware.Camera;
import android.hardware.Camera.Size;
import android.util.Log;

public class CamParaUtil {
	private static final String TAG = "yanzi";
	private CameraSizeComparator sizeComparator = new CameraSizeComparator();
	private static CamParaUtil myCamPara = null;
	private CamParaUtil(){

	}
	public static CamParaUtil getInstance(){
		if(myCamPara == null){
			myCamPara = new CamParaUtil();
			return myCamPara;
		}
		else{
			return myCamPara;
		}
	}

	public  Size getPropPreviewSize(List<Camera.Size> list, float th, int minWidth){
		Collections.sort(list, sizeComparator);

		int i = 0;
		for(Size s:list){
			if((s.width >= minWidth) && equalRate(s, th)){
				Log.i(TAG, "PreviewSize:w = " + s.width + "h = " + s.height);
				break;
			}
			i++;
		}
		if(i == list.size()){
			i = 0;//如果没找到，就选最小的size
		}
		return list.get(i);
	}
	public Size getPropPictureSize(List<Camera.Size> list, float th, int minWidth){
		Collections.sort(list, sizeComparator);

		int i = 0;
		for(Size s:list){
			if((s.width >= minWidth) && equalRate(s, th)){
				Log.i(TAG, "PictureSize : w = " + s.width + "h = " + s.height);
				break;
			}
			i++;
		}
		if(i == list.size()){
			i = 0;//如果没找到，就选最小的size
		}
		return list.get(i);
	}

	public boolean equalRate(Size s, float rate){
		float r = (float)(s.width)/(float)(s.height);
		if(Math.abs(r - rate) <= 0.03)
		{
			return true;
		}
		else{
			return false;
		}
	}

	public  class CameraSizeComparator implements Comparator<Camera.Size>{
		public int compare(Size lhs, Size rhs) {
			// TODO Auto-generated method stub
			if(lhs.width == rhs.width){
				return 0;
			}
			else if(lhs.width > rhs.width){
				return 1;
			}
			else{
				return -1;
			}
		}

	}

	/**打印支持的previewSizes
	 * @param params
	 */
	public  void printSupportPreviewSize(Camera.Parameters params){
		List<Size> previewSizes = params.getSupportedPreviewSizes();
		for(int i=0; i< previewSizes.size(); i++){
			Size size = previewSizes.get(i);
			Log.i(TAG, "previewSizes:width = "+size.width+" height = "+size.height);
		}
	
	}

	/**打印支持的pictureSizes
	 * @param params
	 */
	public  void printSupportPictureSize(Camera.Parameters params){
		List<Size> pictureSizes = params.getSupportedPictureSizes();
		for(int i=0; i< pictureSizes.size(); i++){
			Size size = pictureSizes.get(i);
			Log.i(TAG, "pictureSizes:width = "+ size.width
					+" height = " + size.height);
		}
	}
	/**打印支持的聚焦模式
	 * @param params
	 */
	public void printSupportFocusMode(Camera.Parameters params){
		List<String> focusModes = params.getSupportedFocusModes();
		for(String mode : focusModes){
			Log.i(TAG, "focusModes--" + mode);
		}
	}
}

5、DisplayUtil.java

package org.yanzi.util;

import android.content.Context;
import android.graphics.Point;
import android.util.DisplayMetrics;
import android.util.Log;

public class DisplayUtil {
	private static final String TAG = "DisplayUtil";
	/**
	 * dip转px
	 * @param context
	 * @param dipValue
	 * @return
	 */
	public static int dip2px(Context context, float dipValue){            
		final float scale = context.getResources().getDisplayMetrics().density;                 
		return (int)(dipValue * scale + 0.5f);         
	}     
	
	/**
	 * px转dip
	 * @param context
	 * @param pxValue
	 * @return
	 */
	public static int px2dip(Context context, float pxValue){                
		final float scale = context.getResources().getDisplayMetrics().density;                 
		return (int)(pxValue / scale + 0.5f);         
	} 
	
	/**
	 * 获取屏幕宽度和高度，单位为px
	 * @param context
	 * @return
	 */
	public static Point getScreenMetrics(Context context){
		DisplayMetrics dm =context.getResources().getDisplayMetrics();
		int w_screen = dm.widthPixels;
		int h_screen = dm.heightPixels;
		Log.i(TAG, "Screen---Width = " + w_screen + " Height = " + h_screen + " densityDpi = " + dm.densityDpi);
		return new Point(w_screen, h_screen);
		
	}
	
	/**
	 * 获取屏幕长宽比
	 * @param context
	 * @return
	 */
	public static float getScreenRate(Context context){
		Point P = getScreenMetrics(context);
		float H = P.y;
		float W = P.x;
		return (H/W);
	}
}

6、FileUtil.java

package org.yanzi.util;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import android.graphics.Bitmap;
import android.os.Environment;
import android.util.Log;

public class FileUtil {
	private static final  String TAG = "FileUtil";
	private static final File parentPath = Environment.getExternalStorageDirectory();
	private static   String storagePath = "";
	private static final String DST_FOLDER_NAME = "PlayCamera";

	/**初始化保存路径
	 * @return
	 */
	private static String initPath(){
		if(storagePath.equals("")){
			storagePath = parentPath.getAbsolutePath()+"/" + DST_FOLDER_NAME;
			File f = new File(storagePath);
			if(!f.exists()){
				f.mkdir();
			}
		}
		return storagePath;
	}

	/**保存Bitmap到sdcard
	 * @param b
	 */
	public static void saveBitmap(Bitmap b){

		String path = initPath();
		long dataTake = System.currentTimeMillis();
		String jpegName = path + "/" + dataTake +".jpg";
		Log.i(TAG, "saveBitmap:jpegName = " + jpegName);
		try {
			FileOutputStream fout = new FileOutputStream(jpegName);
			BufferedOutputStream bos = new BufferedOutputStream(fout);
			b.compress(Bitmap.CompressFormat.JPEG, 100, bos);
			bos.flush();
			bos.close();
			Log.i(TAG, "saveBitmap成功");
		} catch (IOException e) {
			// TODO Auto-generated catch block
			Log.i(TAG, "saveBitmap:失败");
			e.printStackTrace();
		}

	}


}

7、ImageUtil.java

package org.yanzi.util;

import android.graphics.Bitmap;
import android.graphics.Matrix;

public class ImageUtil {
	/**
	 * 旋转Bitmap
	 * @param b
	 * @param rotateDegree
	 * @return
	 */
	public static Bitmap getRotateBitmap(Bitmap b, float rotateDegree){
		Matrix matrix = new Matrix();
		matrix.postRotate((float)rotateDegree);
		Bitmap rotaBitmap = Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(), matrix, false);
		return rotaBitmap;
	}
}

几点说明：

1、包括我之前的博文在内的大量网上链接，都是在Surfaceview create的时候进行打开Camera的操作，在Surfaceview Changed的时候进行开预览。而Surfaceview create的时候一定是在setContentView之后，Surfaceview实例化之后。为了优化开启Camera时间，我再setContentView之前new了一个线程专门去Open Camera。经过测试，但就执行Camera.open（）这句话一般需要140ms左右。如果放在主线程里无疑是一种浪费。而在140ms之后，Surfaceview里因为无需触发关于Camera的操作，所以加载的特别快。也就是说Open完后，Surfaceview一定完成了实例化。所以我设置了CamOpenOverCallback回调，在Camera打开完毕后通知Activity立即执行开预览的操作。

2、开预览因为用Surfaceview预览，需传递Surfaceview的SurfaceHolder。

3、CameraInterface是个单例模式，所有关于Camera的流程性操作一律封装在这里面。

4、Activity设置了全屏无标题且强制竖屏，像这种操作能再xml写就不要再java代码里弄。

图片资源上，杂家还真是一番精心挑选，对比了Camera360、相机360、美颜相机，UI上总的来说三个app感觉都很垃圾，都整的太复杂了，图片也不好看。最后勉强用了相机360里的一个button,自己想用PS把按键点击时的图标色彩P亮点，一个没留神，还给P的更暗了色彩。汗，不过按键的对比效果更明显了。日后，会将一些OpenCV4Android的一些小demo都整合到PlayCamera系列。

下为效果图:

------------本文系原创，转载请注明作者yanzi1225627

版本号:PlayCamera_V1.0.0[2014-6-22].zip

CSDN下载链接:http://download.csdn.net/detail/yanzi1225627/7540873

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