Android Camera2使用

一 简介

1.1 Camera API：

这是旧版本的相机API，也称为Camera1 API。它提供了较简单的使用方式，适用于旧版Android设备。但它存在一些限制，如性能不佳、操作复杂等

1.2 Camera2 API：

这是新版本的相机API，引入自Android 5.0（Lollipop）以后的版本。它提供了更强大和灵活的控制能力，并改善了性能

1.3 Camer2对比camera1优势：

• 灵活度：Camera2 API提供了更多的手动设置选项，例如曝光时间、ISO感光度、焦距等。
• 性能优化：Camera2 API支持并行拍摄和预览，使得在同时进行多个操作时表现更好。
• 特殊特性支持：Camera2 API支持RAW图像捕获和高速连拍模式等新功能。
• 能力检测：通过CameraCharacteristics类，可以检查设备相机的各种特性和功能。

1.4 Camera2 API中主要涉及以下几个关键类：

• CameraManager：摄像头管理器，用于打开和关闭系统摄像头
• CameraCharacteristics：描述摄像头的各种特性，我们可以通过CameraManager的getCameraCharacteristics(@NonNull String cameraId)方法来获取。
• CameraDevice：描述系统摄像头，类似于早期的Camera。
• CameraCaptureSession：Session类，当需要拍照、预览等功能时，需要先创建该类的实例，然后通过该实例里的方法进行控制（例如：拍照 capture()）。
• CaptureRequest：描述了一次操作请求，拍照、预览等操作都需要先传入CaptureRequest参数，具体的参数控制也是通过CameraRequest的成员变量来设置。
• CaptureResult：描述拍照完成后的结果。

二 camera2实现步骤

2.1 定义TextureView作为预览界面：

(TextureView) findViewById(R.id.textureView).setSurfaceTextureListener(textureListener);

当SurfaceTexture准备好会回调onSurfaceTextureAvailable()方法：

TextureView.SurfaceTextureListener textureListener = new TextureView.SurfaceTextureListener() {@Overridepublic void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {//当SurefaceTexture可用的时候，设置相机参数并打开相机setupCamera(width, height);openCamera();}
};

2.2 设置相机参数

private void setupCamera(int width, int height) {//获取摄像头的管理者CameraManagerCameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);try {//遍历所有摄像头for (String cameraId: manager.getCameraIdList()) {CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);//默认打开后置摄像头if (characteristics.get(CameraCharacteristics.LENS_FACING) == CameraCharacteristics.LENS_FACING_FRONT)continue;//获取StreamConfigurationMap，它是管理摄像头支持的所有输出格式和尺寸StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);//根据TextureView的尺寸设置预览尺寸mPreviewSize = getOptimalSize(map.getOutputSizes(SurfaceTexture.class), width, height);mCameraId = cameraId;break;}} catch (CameraAccessException e) {e.printStackTrace();}
}

2.3 开启相机

private void openCamera() {//获取摄像头的管理者CameraManagerCameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);//检查权限try {if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {return;}//打开相机，第一个参数指示打开哪个摄像头，第二个参数stateCallback为相机的状态回调接口，第三个参数用来确定Callback在哪个线程执行，为null的话就在当前线程执行manager.openCamera(mCameraId, stateCallback, null);} catch (CameraAccessException e) {e.printStackTrace();}
}

实现StateCallback 接口，当相机打开后会回调onOpened方法，在这个方法里面开启预览

private final CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback() {@Overridepublic void onOpened(CameraDevice camera) {mCameraDevice = camera;//开启预览startPreview();}
}

 2.4 开启预览

private void startPreview() {SurfaceTexture mSurfaceTexture = mTextureView.getSurfaceTexture();//设置TextureView的缓冲区大小mSurfaceTexture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());//获取Surface显示预览数据Surface mSurface = new Surface(mSurfaceTexture);try {//创建CaptureRequestBuilder，TEMPLATE_PREVIEW比表示预览请求mCaptureRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);//设置Surface作为预览数据的显示界面mCaptureRequestBuilder.addTarget(mSurface);//创建相机捕获会话，第一个参数是捕获数据的输出Surface列表，第二个参数是CameraCaptureSession的状态回调接口，当它创建好后会回调onConfigured方法，第三个参数用来确定Callback在哪个线程执行，为null的话就在当前线程执行mCameraDevice.createCaptureSession(Arrays.asList(mSurface), new CameraCaptureSession.StateCallback() {@Overridepublic void onConfigured(CameraCaptureSession session) {try {//创建捕获请求mCaptureRequest = mCaptureRequestBuilder.build();mPreviewSession = session;//设置反复捕获数据的请求，这样预览界面就会一直有数据显示mPreviewSession.setRepeatingRequest(mCaptureRequest, mSessionCaptureCallback, null);} catch (CameraAccessException e) {e.printStackTrace();}}@Overridepublic void onConfigureFailed(CameraCaptureSession session) {}}, null);} catch (CameraAccessException e) {e.printStackTrace();}
}

2.5 预览回调

private void setupImageReader() {//前三个参数分别是需要的尺寸和格式，最后一个参数代表每次最多获取几帧数据，本例的2代表ImageReader中最多可以获取两帧图像流mImageReader = ImageReader.newInstance(mPreviewSize.getWidth(), mPreviewSize.getHeight(),ImageFormat.JPEG, 2);//监听ImageReader的事件，当有图像流数据可用时会回调onImageAvailable方法，它的参数就是预览帧数据，可以对这帧数据进行处理mImageReader.setOnImageAvailableListener(new ImageReader.OnImageAvailableListener() {@Overridepublic void onImageAvailable(ImageReader reader) {Image image = reader.acquireLatestImage();//我们可以将这帧数据转成字节数组，类似于Camera1的PreviewCallback回调的预览帧数据ByteBuffer buffer = image.getPlanes()[0].getBuffer();byte[] data = new byte[buffer.remaining()];buffer.get(data);image.close();}}, null);
}

三，上面就是基本的使用流程，下面是拍照流程

3.1 Camera2拍照也是通过ImageReader来实现的

第一步，设置拍照参数，如方向、尺寸等

private static final SparseIntArray ORIENTATION = new SparseIntArray();static {//将不同的Surface旋转常量与相应的角度值进行映射ORIENTATION.append(Surface.ROTATION_0, 90); //无旋转，设备屏幕处于纵向（竖直）方向。ORIENTATION.append(Surface.ROTATION_90, 0); //顺时针旋转90度，设备屏幕处于横向（水平）方向，宽度大于高度。ORIENTATION.append(Surface.ROTATION_180, 270); //顺时针旋转180度，设备屏幕处于纵向（竖直）方向。ORIENTATION.append(Surface.ROTATION_270, 180); //顺时针旋转270度，设备屏幕处于横向（水平）方向，宽度大于高度。}

3.2 第二步，设置拍照尺寸，可以跟预览尺寸一起设置，然后ImageReader初始化使用此尺寸

mCaptureSize = Collections.max(Arrays.asList(map.getOutputSizes(ImageFormat.JPEG)), new Comparator<Size>() {@Overridepublic int compare(Size lhs, Size rhs) {return Long.signum(lhs.getWidth() * lhs.getHeight() - rhs.getHeight() * rhs.getWidth());}
});

 3.3 第三步，创建保存图片的线程

public static class imageSaver implements Runnable {private Image mImage;public imageSaver(Image image) {mImage = image;}@Overridepublic void run() {ByteBuffer buffer = mImage.getPlanes()[0].getBuffer();byte[] data = new byte[buffer.remaining()];buffer.get(data);mImageFile = new File(Environment.getExternalStorageDirectory() + "/DCIM/myPicture.jpg");FileOutputStream fos = null;try {fos = new FileOutputStream(mImageFile);fos.write(data, 0 ,data.length);} catch (IOException e) {e.printStackTrace();} finally {mImageFile = null;if (fos != null) {try {fos.close();fos = null;} catch (IOException e) {e.printStackTrace();}}}}}

3.4 第四步，然后当ImageReader有数据时，通过此线程保存图片

//使用前面获取的拍照尺寸
mImageReader = ImageReader.newInstance(mCaptureSize.getWidth(), mCaptureSize.getHeight(),ImageFormat.JPEG, 2);
mImageReader.setOnImageAvailableListener(new ImageReader.OnImageAvailableListener() {@Overridepublic void onImageAvailable(ImageReader reader) {//执行图像保存子线程mCameraHandler.post(new imageSaver(reader.acquireNextImage()));}}, mCameraHandler);

3.5 第五步， 然后开启预览创建CaptureSession时把ImageReader添加进去

mCameraDevice.createCaptureSession(Arrays.asList(previewSurface, mImageReader.getSurface()), new CameraCaptureSession.StateCallback() { 
}

3.6 第六步，响应点击拍照事件，我们设置点击拍照按钮调用capture()方法，capture()方法即实现拍照

private void capture() {try {//首先我们创建请求拍照的CaptureRequestfinal CaptureRequest.Builder mCaptureBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);//获取屏幕方向int rotation = getWindowManager().getDefaultDisplay().getRotation();//设置CaptureRequest输出到mImageReadermCaptureBuilder.addTarget(mImageReader.getSurface());//设置拍照方向,ORIENTATION.get(rotation)根据设备屏幕的旋转状态获取相应的角度值。mCaptureBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATION.get(rotation));//这个回调接口用于拍照结束时重启预览，因为拍照会导致预览停止CameraCaptureSession.CaptureCallback mImageSavedCallback = new CameraCaptureSession.CaptureCallback() {@Overridepublic void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {Toast.makeText(getApplicationContext(), "Image Saved!", Toast.LENGTH_SHORT).show();//重启预览restartPreview();}};//停止预览mCameraCaptureSession.stopRepeating();//开始拍照，然后回调上面的接口重启预览，因为mCaptureBuilder设置ImageReader作为target，所以会自动回调ImageReader的onImageAvailable()方法保存图片mCameraCaptureSession.capture(mCaptureBuilder.build(), mImageSavedCallback, null);} catch (CameraAccessException e) {e.printStackTrace();}}

 3.7 第七步，拍照后需要重启预览

 private void restartPreview() {try {//执行setRepeatingRequest方法就行了，注意mCaptureRequest是之前开启预览设置的请求mCameraCaptureSession.setRepeatingRequest(mCaptureRequest, null, mCameraHandler);} catch (CameraAccessException e) {e.printStackTrace();}}

四，完整示例，预览数据+人脸检测+人脸相框

4.1  创建activity_face_camera3.xml，两个TextureView，一个预览，一个人脸框

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"xmlns:app="http://schemas.android.com/apk/res-auto"><!-- TODO: Update blank fragment layout --><TextureViewandroid:id="@+id/textureView"android:layout_width="match_parent"android:layout_height="0dp"app:layout_constraintLeft_toLeftOf="parent"app:layout_constraintRight_toRightOf="parent"app:layout_constraintBottom_toBottomOf="parent"app:layout_constraintTop_toTopOf="parent"app:layout_constraintDimensionRatio="9:16"/><TextureViewandroid:id="@+id/facetextureView"android:layout_width="match_parent"android:layout_height="0dp"app:layout_constraintLeft_toLeftOf="parent"app:layout_constraintRight_toRightOf="parent"app:layout_constraintBottom_toBottomOf="parent"app:layout_constraintTop_toTopOf="parent"app:layout_constraintDimensionRatio="9:16"/>
</androidx.constraintlayout.widget.ConstraintLayout>

4.2 创建FaceCamera3Activity.java

package com.xixia.aiimageupload.opcv;public class FaceCamera3Activity extends Activity {private TextureView textureView;private TextureView faceTextureView;//用于标注人脸private String[] permissions = {Manifest.permission.CAMERA};private List<String> permissionList = new ArrayList();@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_face_camera3);textureView = (TextureView) findViewById(R.id.textureView);faceTextureView = (TextureView) findViewById(R.id.facetextureView);//初始化Camera2Utils.getInstance().init(getWindowManager(), this, textureView, faceTextureView);Camera2Utils.getInstance().setOnPreviewFrameListener(new Camera2Utils.OnPreviewFrameListener() {@Overridepublic void previewFrame(byte[] data, int width, int height) {Log.e("FFF", "previewFrame: " + width);decodeSynQrCode(data, width, height);}});//动态授权getPermission();}private void getPermission() {if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {for (String permission : permissions) {if (ContextCompat.checkSelfPermission(this, permission) != PackageManager.PERMISSION_GRANTED) {permissionList.add(permission);}}if (!permissionList.isEmpty()) {//进行授权ActivityCompat.requestPermissions(this, permissionList.toArray(new String[permissionList.size()]), 1);} else {textureView.setSurfaceTextureListener(textureListener);}}}//只能写在Activity中，下次把授权写到activity中，减少麻烦@Overridepublic void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {super.onRequestPermissionsResult(requestCode, permissions, grantResults);if (requestCode == 1) {if (grantResults.length != 0) {//表示有权限没有授权getPermission();} else {//表示都授权textureView.setSurfaceTextureListener(textureListener);}}}/*SurfaceView状态回调*/TextureView.SurfaceTextureListener textureListener = new TextureView.SurfaceTextureListener() {@Overridepublic void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {Camera2Utils.getInstance().startPreview();}@Overridepublic void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {}@Overridepublic boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {return false;}@Overridepublic void onSurfaceTextureUpdated(SurfaceTexture surface) {}};@Overrideprotected void onDestroy() {super.onDestroy();Camera2Utils.getInstance().closeCamera();}/*** 预览数据回调*/private void decodeSynQrCode(byte[] data, int width, int height) {//获取预览数据//...............//可以保存bitmap或者进行二维码识别}}

 4.3 Camera2工具类

package com.xixia.aiimageupload;import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ImageFormat;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.SurfaceTexture;
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.CameraMetadata;
import android.hardware.camera2.CaptureRequest;
import android.hardware.camera2.CaptureResult;
import android.hardware.camera2.TotalCaptureResult;
import android.hardware.camera2.params.Face;
import android.hardware.camera2.params.StreamConfigurationMap;
import android.media.Image;
import android.media.ImageReader;
import android.os.Build;
import android.os.Handler;
import android.os.HandlerThread;
import android.util.Log;
import android.util.Size;
import android.util.SparseIntArray;
import android.view.Surface;
import android.view.TextureView;
import android.view.WindowManager;import androidx.annotation.RequiresApi;import com.luck.picture.lib.tools.ToastUtils;import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;public class Camera2Utils {private static final String TAG = "Camera2Utils";private static Camera2Utils mCameraUtils;private CameraManager cManager;private Size cPixelSize;//相机成像尺寸private int cOrientation;private Size captureSize;private int[] faceDetectModes;private TextureView cView;//用于相机预览private TextureView faceTextView;//用于相机预览private Surface previewSurface;//预览Surfaceprivate ImageReader cImageReader;private Surface captureSurface;//拍照Surfaceprivate HandlerThread cHandlerThread;//相机处理线程private Handler cHandler;//相机处理private CameraDevice cDevice;private CameraCaptureSession cSession;private CameraDevice.StateCallback cDeviceOpenCallback = null;//相机开启回调private CaptureRequest.Builder previewRequestBuilder;//预览请求构建private CaptureRequest previewRequest;//预览请求private CameraCaptureSession.CaptureCallback previewCallback;//预览回调private CaptureRequest captureRequest;private CameraCaptureSession.CaptureCallback captureCallback;private Context mContext;private WindowManager mWindowManager;private boolean isFront = false;//为了使照片竖直显示private static final SparseIntArray ORIENTATIONS = new SparseIntArray();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);}public static Camera2Utils getInstance() {if (mCameraUtils == null) {synchronized (Camera2Utils.class) {if (mCameraUtils == null) {mCameraUtils = new Camera2Utils();}}}return mCameraUtils;}public void init(WindowManager windowManager, Context context, TextureView textureView, TextureView faceTextView) {this.mWindowManager = windowManager;this.mContext = context;this.cView = textureView;this.faceTextView = faceTextView;}@SuppressLint("MissingPermission")public void startPreview() {//前置摄像头String cId;if (isFront) {cId = CameraCharacteristics.LENS_FACING_BACK + "";} else {cId = CameraCharacteristics.LENS_FACING_FRONT + "";}cManager = (CameraManager) mContext.getSystemService(Context.CAMERA_SERVICE);//根据摄像头ID，开启摄像头try {//获取开启相机的相关参数CameraCharacteristics characteristics = cManager.getCameraCharacteristics(cId);StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);Size[] previewSizes = map.getOutputSizes(SurfaceTexture.class);//获取预览尺寸Size[] captureSizes = map.getOutputSizes(ImageFormat.JPEG);//获取拍照尺寸cOrientation = characteristics.get(CameraCharacteristics.SENSOR_ORIENTATION);//获取相机角度cPixelSize = characteristics.get(CameraCharacteristics.SENSOR_INFO_PIXEL_ARRAY_SIZE);//获取成像区域尺寸，同上//可用于判断是否支持人脸检测，以及支持到哪种程度,支持的人脸检测模式faceDetectModes = characteristics.get(CameraCharacteristics.STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES);//支持的最大检测人脸数量int maxFaceCount = characteristics.get(CameraCharacteristics.STATISTICS_INFO_MAX_FACE_COUNT);int mFaceDetectMode = CaptureRequest.STATISTICS_FACE_DETECT_MODE_OFF;for (int i = 0; i < faceDetectModes.length; i++) {int face = faceDetectModes[i];if (face == CaptureRequest.STATISTICS_FACE_DETECT_MODE_FULL || face == CaptureRequest.STATISTICS_FACE_DETECT_MODE_SIMPLE) {mFaceDetectMode = CaptureRequest.STATISTICS_FACE_DETECT_MODE_FULL;break;}}if (mFaceDetectMode == CaptureRequest.STATISTICS_FACE_DETECT_MODE_OFF) {//Log.i(TAG, "相机硬件不支持人脸检测");ToastUtils.s(mContext, "相机硬件不支持人脸检测");return;}//此处写死640*480，实际从预览尺寸列表选择Size previewSize = new Size(1920, 1080);//设置预览尺寸（避免控件尺寸与预览画面尺寸不一致时画面变形）//transformImage(previewSizes, cView.getWidth(), cView.getHeight());cView.getSurfaceTexture().setDefaultBufferSize(previewSize.getWidth(), previewSize.getHeight());cManager.openCamera(cId, getCDeviceOpenCallback(), getCHandler());} catch (CameraAccessException e) {e.printStackTrace();}}//设置预览尺寸（避免控件尺寸与预览画面尺寸不一致时画面变形）private void transformImage(Size[] previewSizes, int width, int height) {Size mPreviewSize = getOptimalSize(previewSizes, width, height);if (mPreviewSize == null || cView == null) {return;}Matrix matrix = new Matrix();int rotation = mWindowManager.getDefaultDisplay().getRotation();RectF textureRectF = new RectF(0, 0, width, height);RectF previewRectF = new RectF(0, 0, mPreviewSize.getHeight(), mPreviewSize.getWidth());float centerX = textureRectF.centerX();float centery = textureRectF.centerY();if (rotation == Surface.ROTATION_90 || rotation == Surface.ROTATION_270) {previewRectF.offset(centerX - previewRectF.centerX(), centery - previewRectF.centerY());matrix.setRectToRect(textureRectF, previewRectF, Matrix.ScaleToFit.FILL);float scale = Math.max((float) width / mPreviewSize.getWidth(), (float) height / mPreviewSize.getHeight());matrix.postScale(scale, scale, centerX, centery);matrix.postRotate(90 * (rotation - 2), centerX, centery);cView.setTransform(matrix);}}/*** 获取最佳尺寸，解决预览变形问题** @param sizeMap* @param width* @param height* @return*///选择sizeMap中大于并且最接近width和height的sizeprivate Size getOptimalSize(Size[] sizeMap, int width, int height) {List<Size> sizeList = new ArrayList<>();for (Size option : sizeMap) {if (width > height) {if (option.getWidth() > width && option.getHeight() > height) {sizeList.add(option);}} else {if (option.getWidth() > height && option.getHeight() > width) {sizeList.add(option);}}}if (sizeList.size() > 0) {return Collections.min(sizeList, new Comparator<Size>() {@Overridepublic int compare(Size lhs, Size rhs) {return Long.signum(lhs.getWidth() * lhs.getHeight() - rhs.getWidth() * rhs.getHeight());}});}return sizeMap[0];}private Size getOptimalPreviewSize(Size[] sizes, int w, int h) {final double ASPECT_TOLERANCE = 0.1;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 sizeSize size = null;for (int i = 0; i < sizes.length; i++) {size = sizes[i];double ratio = (double) size.getWidth() / size.getHeight();if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;if (Math.abs(size.getHeight() - targetHeight) < minDiff) {optimalSize = size;minDiff = Math.abs(size.getHeight() - targetHeight);}}// Cannot find the one match the aspect ratio, ignore the requirementif (optimalSize == null) {minDiff = Double.MAX_VALUE;for (int i = 0; i < sizes.length; i++) {size = sizes[i];if (Math.abs(size.getHeight() - targetHeight) < minDiff) {optimalSize = size;minDiff = Math.abs(size.getHeight() - targetHeight);}}}return optimalSize;}private void configureTransform(int viewWidth, int viewHeight) {int rotation = 1;Matrix matrix = new Matrix();RectF viewRect = new RectF(0, 0, viewWidth, viewHeight);float centerX = viewRect.centerX();float centerY = viewRect.centerY();if (Surface.ROTATION_90 == rotation || Surface.ROTATION_270 == rotation) {matrix.postRotate(90 * (rotation - 2), centerX, centerY);} else if (Surface.ROTATION_180 == rotation) {matrix.postRotate(180, centerX, centerY);}cView.setTransform(matrix);}/*** 初始化并获取相机开启回调对象。当准备就绪后，发起预览请求*/@SuppressLint("NewApi")private CameraDevice.StateCallback getCDeviceOpenCallback() {if (cDeviceOpenCallback == null) {cDeviceOpenCallback = new CameraDevice.StateCallback() {@Overridepublic void onOpened(CameraDevice camera) {//打开摄像头cDevice = camera;try {//创建Session，需先完成画面呈现目标（此处为预览和拍照Surface）的初始化camera.createCaptureSession(Arrays.asList(getPreviewSurface(), getCaptureSurface()), newCameraCaptureSession.StateCallback() {@Overridepublic void onConfigured(CameraCaptureSession session) {cSession = session;//构建预览请求，并发起请求Log.i(TAG, "[发出预览请求]");try {session.setRepeatingRequest(getPreviewRequest(), getPreviewCallback(),getCHandler());} catch (CameraAccessException e) {Log.i(TAG, "--" + e.getMessage());}}@Overridepublic void onConfigureFailed(CameraCaptureSession session) {session.close();}}, getCHandler());} catch (CameraAccessException e) {Log.i(TAG, "--" + e.getMessage());}}@Overridepublic void onDisconnected(CameraDevice camera) {//关闭摄像头camera.close();}@Overridepublic void onError(CameraDevice camera, int error) {//发生错误camera.close();}};}return cDeviceOpenCallback;}/*** 初始化并获取相机线程处理** @return*/private Handler getCHandler() {if (cHandler == null) {//单独开一个线程给相机使用cHandlerThread = new HandlerThread("cHandlerThread");cHandlerThread.start();cHandler = new Handler(cHandlerThread.getLooper());}return cHandler;}/*** 获取支持的最高人脸检测级别** @return*/private int getFaceDetectMode() {if (faceDetectModes == null) {Log.i(TAG, "getFaceDetectMode: ----");return CaptureRequest.STATISTICS_FACE_DETECT_MODE_FULL;} else {Log.i(TAG, "getFaceDetectMode: --2--" + faceDetectModes[faceDetectModes.length - 1]);return faceDetectModes[faceDetectModes.length - 1];}}/*** 初始化并获取预览回调对象** @return*/@SuppressLint("NewApi")private CameraCaptureSession.CaptureCallback getPreviewCallback() {if (previewCallback == null) {previewCallback = new CameraCaptureSession.CaptureCallback() {@Overridepublic void onCaptureCompleted(CameraCaptureSession session, CaptureRequestrequest, TotalCaptureResult result) {onCameraImagePreviewed(result);}};}return previewCallback;}/*** 生成并获取预览请求** @return*/@SuppressLint("NewApi")private CaptureRequest getPreviewRequest() {previewRequest = getPreviewRequestBuilder().build();return previewRequest;}/*** 初始化并获取预览请求构建对象，进行通用配置，并每次获取时进行人脸检测级别配置** @return*/@SuppressLint("NewApi")private CaptureRequest.Builder getPreviewRequestBuilder() {if (previewRequestBuilder == null) {try {previewRequestBuilder = cSession.getDevice().createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);previewRequestBuilder.addTarget(getPreviewSurface());previewRequestBuilder.addTarget(getCaptureSurface());previewRequestBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);//自动曝光、白平衡、对焦} catch (CameraAccessException e) {Log.i(TAG, "--" + e.getMessage());}}
//        previewRequestBuilder.set(CaptureRequest.STATISTICS_FACE_DETECT_MODE, getFaceDetectMode());//设置人脸检测级别previewRequestBuilder.set(CaptureRequest.STATISTICS_FACE_DETECT_MODE, CameraCharacteristics.STATISTICS_FACE_DETECT_MODE_SIMPLE);//设置人脸检测级别previewRequestBuilder.set(CaptureRequest.JPEG_ORIENTATION, 0);return previewRequestBuilder;}/*** 获取预览Surface** @return*/private Surface getPreviewSurface() {if (previewSurface == null) {previewSurface = new Surface(cView.getSurfaceTexture());}return previewSurface;}/*** 处理相机画面处理完成事件，获取检测到的人脸坐标，换算并绘制方框** @param result*/@SuppressLint({"NewApi", "LocalSuppress"})private void onCameraImagePreviewed(CaptureResult result) {Face[] faces = result.get(CaptureResult.STATISTICS_FACES);if (faces.length > 0) {Log.i(TAG, "检测到有人脸，-----------------------------------");Log.i(TAG, "检测到有人脸，进行拍照操作：faceLength=" + faces.length);//检测到有人脸，控制相机进行拍照操作//executeCapture();}if (faceTextView != null) {drawFace(faces);}}/*** 绘制人脸框*/private Paint facePaint;private void drawFace(Face[] faces) {if (facePaint == null) {facePaint = new Paint();facePaint.setColor(Color.BLUE);facePaint.setStrokeWidth(10);facePaint.setStyle(Paint.Style.STROKE);//使绘制的矩形中空//隐藏背景色，以免标注人脸时挡住预览画面faceTextView.setAlpha(0.9f);}Canvas canvas = faceTextView.lockCanvas();if (canvas != null) {canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);//旧画面清理覆盖if (faces.length > 0) {for (int i = 0; i < faces.length; i++) {Rect fRect = faces[i].getBounds();Log.e(TAG, "[R" + i + "]:[left:" + fRect.left + ",top:" + fRect.top + ",right:" + fRect.right + ",bottom:" + fRect.bottom + "]");//人脸检测坐标基于相机成像画面尺寸以及坐标原点。此处进行比例换算//成像画面与方框绘制画布长宽比比例（同画面角度情况下的长宽比例（此处前后摄像头成像画面相对预览画面倒置（±90°），计算比例时长宽互换））float scaleWidth = canvas.getHeight() * 1.0f / cPixelSize.getWidth();float scaleHeight = canvas.getWidth() * 1.0f / cPixelSize.getHeight();//坐标缩放int l = (int) (fRect.left * scaleWidth);int t = (int) (fRect.top * scaleHeight);int r = (int) (fRect.right * scaleWidth);int b = (int) (fRect.bottom * scaleHeight);Log.e(TAG, "[T" + i + "]:[left:" + l + ",top:" + t + ",right:" + r + ",bottom:" + b + "]");//人脸检测坐标基于相机成像画面尺寸以及坐标原点。此处进行坐标转换以及原点(0,0)换算//人脸检测：坐标原点为相机成像画面的左上角，left、top、bottom、right以成像画面左上下右为基准//画面旋转后：原点位置不一样，根据相机成像画面的旋转角度需要换算到画布的左上角，left、top、bottom、right基准也与原先不一样，//如相对预览画面相机成像画面角度为90°那么成像画面坐标的top，在预览画面就为left。如果再翻转，那成像画面的top就为预览画面的right，且坐标起点为右，需要换算到左边if (isFront) {//此处前置摄像头成像画面相对于预览画面顺时针90°+翻转。left、top、bottom、right变为bottom、right、top、left，并且由于坐标原点由左上角变为右下角，X,Y方向都要进行坐标换算canvas.drawRect(canvas.getWidth() - b, canvas.getHeight() - r, canvas.getWidth() - t, canvas.getHeight() - l, facePaint);} else {//此处后置摄像头成像画面相对于预览画面顺时针270°，left、top、bottom、right变为bottom、left、top、right，并且由于坐标原点由左上角变为左下角，Y方向需要进行坐标换算canvas.drawRect(canvas.getWidth() - b, l, canvas.getWidth() - t, r, facePaint);}}}faceTextView.unlockCanvasAndPost(canvas);}}/*** 初始化拍照相关*/@SuppressLint("NewApi")private Surface getCaptureSurface() {if (cImageReader == null) {cImageReader = ImageReader.newInstance(getCaptureSize().getWidth(), getCaptureSize().getHeight(),ImageFormat.YUV_420_888, 2);cImageReader.setOnImageAvailableListener(new ImageReader.OnImageAvailableListener() {@Overridepublic void onImageAvailable(ImageReader reader) {//拍照最终回调onCaptureFinished(reader);}}, getCHandler());captureSurface = cImageReader.getSurface();}return captureSurface;}/*** 获取拍照尺寸** @return*/@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)private Size getCaptureSize() {if (captureSize != null) {return captureSize;} else {return new Size(cView.getWidth(), cView.getHeight());}}@SuppressLint("NewApi")private void onCaptureFinished(ImageReader reader) {if (reader != null) {Image image = reader.acquireLatestImage();if (image != null && image.getPlanes() != null && image.getPlanes().length > 0) {int width = image.getWidth();int height = image.getHeight();ByteBuffer buffer = image.getPlanes()[0].getBuffer();byte[] data = new byte[buffer.remaining()];buffer.get(data);image.close();buffer.clear();if (onPreviewFrameListener != null) {onPreviewFrameListener.previewFrame(data,width, height);}//onPreviewFrameToBitmap(data);}}}/*** 预览数据转为bitmap*/Bitmap takeBitmap = null;Bitmap takeBitmap2 = null;private void onPreviewFrameToBitmap(byte[] data) {takeBitmap = BitmapFactory.decodeByteArray(data, 0, data.length);/*** 为了解决预览和拍照左右颠倒问题*/Matrix m = new Matrix();m.postScale(-1, 1); // 镜像水平翻转takeBitmap2 = Bitmap.createBitmap(takeBitmap, 0, 0, takeBitmap.getWidth(), takeBitmap.getHeight(), m, true);if (ioShowBitmapListener != null) {ioShowBitmapListener.showBitmap(takeBitmap2);}}@SuppressLint("NewApi")public void closeCamera() {if (cSession != null) {try {cSession.stopRepeating();} catch (CameraAccessException e) {e.printStackTrace();}cSession.close();cSession = null;}if (cDevice != null) {cDevice.close();cDevice = null;}if (cImageReader != null) {cImageReader.close();cImageReader = null;}if (cHandlerThread != null) {cHandlerThread.quitSafely();try {cHandlerThread.join();cHandlerThread = null;cHandler = null;} catch (InterruptedException e) {Log.i(TAG, "--" + e.getMessage());}}//        if (captureRequestBuilder != null) {
//            captureRequestBuilder.removeTarget(captureSurface);
//            captureRequestBuilder = null;
//        }if (captureSurface != null) {captureSurface.release();captureSurface = null;}if (previewRequestBuilder != null) {previewRequestBuilder.removeTarget(previewSurface);previewRequestBuilder = null;}if (previewSurface != null) {previewSurface.release();previewSurface = null;}if (takeBitmap != null) {takeBitmap.recycle();takeBitmap = null;}}/*** 帧数据回调*/private OnPreviewFrameListener onPreviewFrameListener;public void setOnPreviewFrameListener(OnPreviewFrameListener onPreviewFrameListener) {this.onPreviewFrameListener = onPreviewFrameListener;}public interface OnPreviewFrameListener {void previewFrame(byte[] data, int width, int height);}/*** 帧数据bitmap回调*/private IOShowBitmapListener ioShowBitmapListener;public void setIoShowBitmapListener(IOShowBitmapListener ioShowBitmapListener) {this.ioShowBitmapListener = ioShowBitmapListener;}public interface IOShowBitmapListener {void showBitmap(Bitmap bitmap);}//    /**
//     * 执行拍照
//     */
//    private CaptureRequest.Builder captureRequestBuilder;
//    @SuppressLint("NewApi")
//    private void executeCapture() {
//        try {
//            Log.i(TAG, "发出请求");
//            cSession.capture(getCaptureRequest(), getCaptureCallback(), getCHandler());
//        } catch (CameraAccessException e) {
//            Log.i(TAG, "--" + e.getMessage());
//        }
//    }
//
//    @SuppressLint("NewApi")
//    private CaptureRequest getCaptureRequest() {
//        captureRequest = getCaptureRequestBuilder().build();
//        return captureRequest;
//    }
//
//    @SuppressLint("NewApi")
//    private CaptureRequest.Builder getCaptureRequestBuilder() {
//        if (captureRequestBuilder == null) {
//            try {
//                captureRequestBuilder = cDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
//                captureRequestBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
//                //设置拍照回调接口
//                captureRequestBuilder.addTarget(getCaptureSurface());
//                //TODO 1 照片旋转int rotation =getWindowManager().getDefaultDisplay().getRotation();
//                int rotation = 0;
//                int rotationTo = getOrientation(rotation);
//
//                captureRequestBuilder.set(CaptureRequest.JPEG_ORIENTATION, rotationTo);
//            } catch (CameraAccessException e) {
//                Log.i(TAG, "--" + e.getMessage());
//            }
//        }
//        return captureRequestBuilder;
//    }//    @SuppressLint("NewApi")
//    private CameraCaptureSession.CaptureCallback getCaptureCallback() {
//        if (captureCallback == null) {
//            captureCallback = new CameraCaptureSession.CaptureCallback() {
//                @Override
//                public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest
//                        request, TotalCaptureResult result) {
//                }
//            };
//        }
//        return captureCallback;
//    }//    /**
//     * Retrieves the JPEG orientation from the specified screen rotation.
//     *
//     * @param rotation The screen rotation.
//     * @return The JPEG orientation (one of 0, 90, 270, and 360)
//     */
//    private int getOrientation(int rotation) {
//        return (ORIENTATIONS.get(rotation) + cOrientation + 270) % 360;
//    }}