Android下使用camera2和Surfaceview预览图像并取得YUV420p数据回调

Android 5.0(21)之后，android.hardware.Camera被废弃(下面称为Camera1)，还有一个android.graphics.Camera，这个android.graphics.Camera不是用来照相的，是用来处理图像的，可以做出3D的图像效果之类的，之前的Camera1则由android.hardware.Camera2来代替。

Camera2支持RAW输出，可以调节曝光，对焦模式，快门等，功能比原先Camera强大。

由于ImageFormat只有YUV420_888即YUV420系列，这里需要将其做一个转换，转成所需要的YUV420p:yyyyyyyyuuuuvvvv格式，参考文章：android camera2 拿到的yuv420数据到底是什么样的？

1、MainActivity.java文件：

package com.example.tongjiangsong.camera2base;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.ImageFormat;
import android.hardware.camera2.CameraAccessException;
import android.hardware.camera2.CameraCaptureSession;
import android.hardware.camera2.CameraCharacteristics;
import android.hardware.camera2.CameraDevice;
import android.hardware.camera2.CameraManager;
import android.hardware.camera2.CaptureRequest;
import android.media.Image;
import android.media.ImageReader;
import android.os.Build;
import android.os.Environment;
import android.os.Handler;
import android.os.HandlerThread;
import android.support.annotation.RequiresApi;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.util.SparseIntArray;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Arrays;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
    private static final String TAG = "mainactivity" ;

    ///为了使照片竖直显示
    static {
        ORIENTATIONS.append(Surface.ROTATION_0, 90);
        ORIENTATIONS.append(Surface.ROTATION_90, 0);
        ORIENTATIONS.append(Surface.ROTATION_180, 270);
        ORIENTATIONS.append(Surface.ROTATION_270, 180);
    }

    private SurfaceView mSurfaceView;
    private SurfaceHolder mSurfaceHolder;
    private ImageView iv_show;
    private CameraManager mCameraManager;//摄像头管理器
    private Handler childHandler, mainHandler;
    private String mCameraID;//摄像头Id 0 为后  1 为前
    private ImageReader mImageReaderJPG;
    private ImageReader mImageReaderPreview;
    private CameraCaptureSession mCameraCaptureSession;
    private CameraDevice mCameraDevice;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button capture_btn = (Button)findViewById(R.id.capture_btn);
        capture_btn.setOnClickListener(this);
        initVIew();
    }

    /**
     * 初始化
     */
    private void initVIew() {
        iv_show = (ImageView) findViewById(R.id.image_preview);
        //mSurfaceView
        mSurfaceView = (SurfaceView) findViewById(R.id.surface_view);
        mSurfaceView.setOnClickListener(this);
        mSurfaceHolder = mSurfaceView.getHolder();
        mSurfaceHolder.setKeepScreenOn(true);
        // mSurfaceView添加回调
        mSurfaceHolder.addCallback(new SurfaceHolder.Callback() {
            @Override
            public void surfaceCreated(SurfaceHolder holder) { //SurfaceView创建
                // 初始化Camera
                initCamera2();
            }

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

            @Override
            public void surfaceDestroyed(SurfaceHolder holder) { //SurfaceView销毁
                // 释放Camera资源
                if (null != mCameraDevice) {
                    mCameraDevice.close();
                    MainActivity.this.mCameraDevice = null;
                }
            }
        });
    }

    /**
     * 初始化Camera2
     */
    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    private void initCamera2() {
        HandlerThread handlerThread = new HandlerThread("Camera2");
        handlerThread.start();
        childHandler = new Handler(handlerThread.getLooper());
        mainHandler = new Handler(getMainLooper());
        mCameraID = "" + CameraCharacteristics.LENS_FACING_FRONT;//后摄像头
        mImageReaderJPG = ImageReader.newInstance(1080, 1920, ImageFormat.JPEG,1);
        mImageReaderJPG.setOnImageAvailableListener(new ImageReader.OnImageAvailableListener() { //可以在这里处理拍照得到的临时照片 例如，写入本地
            @Override
            public void onImageAvailable(ImageReader reader) {
                //mCameraDevice.close();
                //mSurfaceView.setVisibility(View.GONE);
                //先验证手机是否有sdcard
                String status = Environment.getExternalStorageState();
                if (!status.equals(Environment.MEDIA_MOUNTED)) {
                    Toast.makeText(getApplicationContext(), "你的sd卡不可用。", Toast.LENGTH_SHORT).show();
                    return;
                }
                // 获取捕获的照片数据
                Image image = reader.acquireNextImage();
                ByteBuffer buffer = image.getPlanes()[0].getBuffer();
                byte[] data = new byte[buffer.remaining()];
                buffer.get(data);

                //手机拍照都是存到这个路径
                String filePath = Environment.getExternalStorageDirectory().getPath() + "/DCIM/Camera/";
                String picturePath = System.currentTimeMillis() + ".jpg";
                File file = new File(filePath, picturePath);
                try {
                    //存到本地相册
                    FileOutputStream fileOutputStream = new FileOutputStream(file);
                    fileOutputStream.write(data);
                    fileOutputStream.close();
                    iv_show.setVisibility(View.VISIBLE);
                    //显示图片
                    BitmapFactory.Options options = new BitmapFactory.Options();
                    options.inSampleSize = 2;
                    Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length, options);
                    iv_show.setImageBitmap(bitmap);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    image.close();
                }

            }
        }, mainHandler);
        mImageReaderPreview = ImageReader.newInstance(1080, 1920, ImageFormat.YUV_420_888,1);
        mImageReaderPreview.setOnImageAvailableListener(new ImageReader.OnImageAvailableListener() { //可以在这里处理拍照得到的临时照片 例如，写入本地
            @Override
            public void onImageAvailable(ImageReader reader) {

                // 获取捕获的照片数据
                Image image = reader.acquireNextImage();
                Log.i(TAG,"image format: " +image.getFormat());
                // 从image里获取三个plane
                Image.Plane[] planes = image.getPlanes();

                for (int i = 0; i < planes.length; i++) {
                    ByteBuffer iBuffer = planes[i].getBuffer();
                    int iSize = iBuffer.remaining();
                    Log.i(TAG, "pixelStride  " + planes[i].getPixelStride());
                    Log.i(TAG, "rowStride   " + planes[i].getRowStride());
                    Log.i(TAG, "width  " + image.getWidth());
                    Log.i(TAG, "height  " + image.getHeight());
                    Log.i(TAG, "Finished reading data from plane  " + i);
                }
                int n_image_size = image.getWidth()*image.getHeight()*3/2;
                final byte[] yuv420pbuf = new byte[n_image_size];
                System.arraycopy(ImageUtil.getBytesFromImageAsType(image, 0), 0, yuv420pbuf, 0, n_image_size);

                image.close();
            }
        }, null);
        //获取摄像头管理
        mCameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
        try {
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                return;
            }
            //打开摄像头
            mCameraManager.openCamera(mCameraID, stateCallback, mainHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }


    /**
     * 摄像头创建监听
     */
    private CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback() {
        @Override
        public void onOpened(CameraDevice camera) {//打开摄像头
            mCameraDevice = camera;
            //开启预览
            takePreview();
        }

        @Override
        public void onDisconnected(CameraDevice camera) {//关闭摄像头
            if (null != mCameraDevice) {
                mCameraDevice.close();
                MainActivity.this.mCameraDevice = null;
            }
        }

        @Override
        public void onError(CameraDevice camera, int error) {//发生错误
            Toast.makeText(MainActivity.this, "摄像头开启失败", Toast.LENGTH_SHORT).show();
        }
    };

    /**
     * 开始预览
     */
    private void takePreview() {
        try {
            // 创建预览需要的CaptureRequest.Builder
            final CaptureRequest.Builder previewRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
            // 将SurfaceView的surface作为CaptureRequest.Builder的目标
            previewRequestBuilder.addTarget(mSurfaceHolder.getSurface());
            previewRequestBuilder.addTarget(mImageReaderPreview.getSurface());
            // 创建CameraCaptureSession，该对象负责管理处理预览请求和拍照请求
            mCameraDevice.createCaptureSession(Arrays.asList(mSurfaceHolder.getSurface(), mImageReaderPreview.getSurface()), new CameraCaptureSession.StateCallback() // ③
            {
                @Override
                public void onConfigured(CameraCaptureSession cameraCaptureSession) {
                    if (null == mCameraDevice) return;
                    // 当摄像头已经准备好时，开始显示预览
                    mCameraCaptureSession = cameraCaptureSession;
                    try {
                        // 自动对焦
                        previewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
                        // 打开闪光灯
                        previewRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH);
                        // 显示预览
                        CaptureRequest previewRequest = previewRequestBuilder.build();
                        mCameraCaptureSession.setRepeatingRequest(previewRequest, null, childHandler);
                    } catch (CameraAccessException e) {
                        e.printStackTrace();
                    }
                }

                @Override
                public void onConfigureFailed(CameraCaptureSession cameraCaptureSession) {
                    Toast.makeText(MainActivity.this, "配置失败", Toast.LENGTH_SHORT).show();
                }
            }, childHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    /**
     * 点击事件
     */
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.capture_btn:
                takePicture();
                Toast.makeText(MainActivity.this, "拍照", Toast.LENGTH_SHORT).show();
                break;
        }
    }

    /**
     * 拍照
     */
    private void takePicture() {
        if (mCameraDevice == null) return;
        // 创建拍照需要的CaptureRequest.Builder
        final CaptureRequest.Builder captureRequestBuilder;
        try {
            captureRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
            // 将imageReader的surface作为CaptureRequest.Builder的目标
            captureRequestBuilder.addTarget(mImageReaderJPG.getSurface());
            // 自动对焦
            captureRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
            // 自动曝光
            captureRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH);
            // 获取手机方向
            int rotation = getWindowManager().getDefaultDisplay().getRotation();
            // 根据设备方向计算设置照片的方向
            captureRequestBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation));
            //拍照
            CaptureRequest mCaptureRequest = captureRequestBuilder.build();
            mCameraCaptureSession.capture(mCaptureRequest, null, childHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }
}

2、ImageUtil.java文件下

package com.example.tongjiangsong.camera2base;

import android.graphics.ImageFormat;
import android.media.Image;
import android.util.Log;

import java.nio.ByteBuffer;

/**
 * yuv420p:  yyyyyyyyuuvv
 * yuv420sp: yyyyyyyyuvuv
 * nv21:     yyyyyyyyvuvu
 */

public class ImageUtil {
    public static final int YUV420P = 0;
    public static final int YUV420SP = 1;
    public static final int NV21 = 2;
    private static final String TAG = "ImageUtil";

    /***
     * 此方法内注释以640*480为例
     * 未考虑CropRect的
     */
    public static byte[] getBytesFromImageAsType(Image image, int type) {
        try {
            //获取源数据，如果是YUV格式的数据planes.length = 3
            //plane[i]里面的实际数据可能存在byte[].length <= capacity (缓冲区总大小)
            final Image.Plane[] planes = image.getPlanes();

            //数据有效宽度，一般的，图片width <= rowStride，这也是导致byte[].length <= capacity的原因
            // 所以我们只取width部分
            int width = image.getWidth();
            int height = image.getHeight();

            //此处用来装填最终的YUV数据，需要1.5倍的图片大小，因为Y U V 比例为 4:1:1
            byte[] yuvBytes = new byte[width * height * ImageFormat.getBitsPerPixel(ImageFormat.YUV_420_888) / 8];
            //目标数组的装填到的位置
            int dstIndex = 0;

            //临时存储uv数据的
            byte uBytes[] = new byte[width * height / 4];
            byte vBytes[] = new byte[width * height / 4];
            int uIndex = 0;
            int vIndex = 0;

            int pixelsStride, rowStride;
            for (int i = 0; i < planes.length; i++) {
                pixelsStride = planes[i].getPixelStride();
                rowStride = planes[i].getRowStride();

                ByteBuffer buffer = planes[i].getBuffer();

                //如果pixelsStride==2，一般的Y的buffer长度=640*480，UV的长度=640*480/2-1
                //源数据的索引，y的数据是byte中连续的，u的数据是v向左移以为生成的，两者都是偶数位为有效数据
                byte[] bytes = new byte[buffer.capacity()];
                buffer.get(bytes);

                int srcIndex = 0;
                if (i == 0) {
                    //直接取出来所有Y的有效区域，也可以存储成一个临时的bytes，到下一步再copy
                    for (int j = 0; j < height; j++) {
                        System.arraycopy(bytes, srcIndex, yuvBytes, dstIndex, width);
                        srcIndex += rowStride;
                        dstIndex += width;
                    }
                } else if (i == 1) {
                    //根据pixelsStride取相应的数据
                    for (int j = 0; j < height / 2; j++) {
                        for (int k = 0; k < width / 2; k++) {
                            uBytes[uIndex++] = bytes[srcIndex];
                            srcIndex += pixelsStride;
                        }
                        if (pixelsStride == 2) {
                            srcIndex += rowStride - width;
                        } else if (pixelsStride == 1) {
                            srcIndex += rowStride - width / 2;
                        }
                    }
                } else if (i == 2) {
                    //根据pixelsStride取相应的数据
                    for (int j = 0; j < height / 2; j++) {
                        for (int k = 0; k < width / 2; k++) {
                            vBytes[vIndex++] = bytes[srcIndex];
                            srcIndex += pixelsStride;
                        }
                        if (pixelsStride == 2) {
                            srcIndex += rowStride - width;
                        } else if (pixelsStride == 1) {
                            srcIndex += rowStride - width / 2;
                        }
                    }
                }
            }

            image.close();

            //根据要求的结果类型进行填充
            switch (type) {
                case YUV420P:
                    System.arraycopy(uBytes, 0, yuvBytes, dstIndex, uBytes.length);
                    System.arraycopy(vBytes, 0, yuvBytes, dstIndex + uBytes.length, vBytes.length);
                    break;
                case YUV420SP:
                    for (int i = 0; i < vBytes.length; i++) {
                        yuvBytes[dstIndex++] = uBytes[i];
                        yuvBytes[dstIndex++] = vBytes[i];
                    }
                    break;
                case NV21:
                    for (int i = 0; i < vBytes.length; i++) {
                        yuvBytes[dstIndex++] = vBytes[i];
                        yuvBytes[dstIndex++] = uBytes[i];
                    }
                    break;
            }
            return yuvBytes;
        } catch (final Exception e) {
            if (image != null) {
                image.close();
            }
            Log.i(TAG, e.toString());
        }
        return null;
    }
}

3、activity_main.xml文件下

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextureView
        android:id="@+id/tv"
        android:layout_above="@+id/ll_bottom"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
    <RelativeLayout
        android:id="@+id/ll_bottom"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:layout_alignParentBottom="true">

        <ImageView
            android:id="@+id/iv"
            android:layout_width="wrap_content"
            android:layout_height="70dp"
            android:layout_centerVertical="true"
            android:layout_marginLeft="10dp"
            android:src="@mipmap/ic_launcher"/>
        <Button
            android:id="@+id/btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:layout_marginRight="10dp"
            android:text="拍照"/>
    </RelativeLayout>
</RelativeLayout>

3、设置权限：

    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>