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

浏览数：29 / 时间：2015年06月11日

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

<span style="font-family:Comic Sans MS;font-size:18px;"><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>
</span>

二、AndroidManifest.xml

<span style="font-family:Comic Sans MS;font-size:18px;"><?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>
</span>

三、下面是java代码

1、CameraActivity.java

<span style="font-family:Comic Sans MS;font-size:18px;">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;
            }
        }

    }

}
</span>

2、CameraInterface.java

<span style="font-family:Comic Sans MS;font-size:18px;">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;
        }
    };


}
</span>

3、CameraSurfaceView.java

<span style="font-family:Comic Sans MS;font-size:18px;">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;
    }
    
}
</span>

4、CamParaUtil.java

<span style="font-family:Comic Sans MS;font-size:18px;">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);
        }
    }
}
</span>

5、DisplayUtil.java

<span style="font-family:Comic Sans MS;font-size:18px;">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);
    }
}
</span>

6、FileUtil.java

<span style="font-family:Comic Sans MS;font-size:18px;">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();
        }

    }


}
</span>

7、ImageUtil.java

<span style="font-family:Comic Sans MS;font-size:18px;">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;
    }
}
</span>

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: