[移动开发]Android camera预览

我们先了解几个类

CameraManager 管理手机摄像头的类

CameraDevice 摄像头

CameraCaptureSession  摄像头数据捕获场景

CameraCharacteristics 摄像头属性类

手机一般都是有前后摄像头，我们会通过CameraCharacteristics对象的

 public static final Key<Integer> LENS_FACING =
            new Key<Integer>("android.lens.facing", int.class);

LENS_FACING 对应的value来判断前后摄像头

                    String[] cameraIdArray = cameraManager.getCameraIdList();
                    for(String ele : cameraIdArray){
                        CameraCharacteristics cameraCharacteristics = cameraManager.getCameraCharacteristics(ele);
                        if (cameraCharacteristics.get(CameraCharacteristics.LENS_FACING) == CameraCharacteristics.LENS_FACING_FRONT) {
                            frontCameraId = ele;
                        } else if (cameraCharacteristics.get(CameraCharacteristics.LENS_FACING) == CameraCharacteristics.LENS_FACING_BACK) {
                            backCameraId = ele;
                        }
                    }

我们通过CameraManager来打开摄像头

    @RequiresPermission(android.Manifest.permission.CAMERA)
    public void openCamera(@NonNull String cameraId,
            @NonNull @CallbackExecutor Executor executor,
            @NonNull final CameraDevice.StateCallback callback)
            throws CameraAccessException {
        if (executor == null) {
            throw new IllegalArgumentException("executor was null");
        }
        openCameraForUid(cameraId, callback, executor, USE_CALLING_UID);
    }

cameraId 就是上面我们获取的id

executor 我们callback要执行的线程

CameraDevice.StateCallback callback 定义了打开camera后的回调

cameraManager.openCamera(backCameraId,
                            mExecutorService,
                            new CameraDevice.StateCallback() {
                                @Override
                                public void onOpened(@NonNull CameraDevice camera) {
                                    Log.e("CameraActivity", "onOpened");
                                    mCamera = camera;
                                    preview();
                                }

                                @Override
                                public void onDisconnected(@NonNull CameraDevice camera) {
                                    Log.e("CameraActivity", "onDisconnected");

                                }

                                @Override
                                public void onError(@NonNull CameraDevice camera, int error) {
                                    Log.e("CameraActivity", "onError");

                                }
                            }

                    );

onOpened的回调告诉我们摄像头已经打开

CameraDevice中的方法

public void createCaptureSession(
            SessionConfiguration config) throws CameraAccessException {
        throw new UnsupportedOperationException("No default implementation");
    }

创建摄像头捕获的场景

 OutputConfiguration outputConfiguration = new OutputConfiguration(binding.surfaceView.getHolder().getSurface());
            List<OutputConfiguration> outputs = new ArrayList<>();
            outputs.add(outputConfiguration);
            SessionConfiguration  sessionConfiguration
                    =  new SessionConfiguration(SessionConfiguration.SESSION_REGULAR,
                    outputs,
                    mExecutorService,
                    new CameraCaptureSession.StateCallback() {
                        @Override
                        public void onConfigured(@NonNull CameraCaptureSession session) {
                            mCameraCaptureSession = session;
                            previewBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_VIDEO);
                            CaptureRequest previewRequest = previewBuilder.build();
                            try {
                                mCameraCaptureSession.setSingleRepeatingRequest(previewRequest, mExecutorService, new CameraCaptureSession.CaptureCallback() {
                                    @Override
                                    public void onCaptureStarted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, long timestamp, long frameNumber) {
                                        super.onCaptureStarted(session, request, timestamp, frameNumber);
                                    }

                                    @Override
                                    public void onCaptureProgressed(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull CaptureResult partialResult) {
                                        super.onCaptureProgressed(session, request, partialResult);
                                    }

                                    @Override
                                    public void onCaptureCompleted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
                                        super.onCaptureCompleted(session, request, result);
                                    }

                                    @Override
                                    public void onCaptureFailed(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull CaptureFailure failure) {
                                        super.onCaptureFailed(session, request, failure);
                                    }

                                    @Override
                                    public void onCaptureSequenceCompleted(@NonNull CameraCaptureSession session, int sequenceId, long frameNumber) {
                                        super.onCaptureSequenceCompleted(session, sequenceId, frameNumber);
                                    }

                                    @Override
                                    public void onCaptureSequenceAborted(@NonNull CameraCaptureSession session, int sequenceId) {
                                        super.onCaptureSequenceAborted(session, sequenceId);
                                    }

                                    @Override
                                    public void onCaptureBufferLost(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull Surface target, long frameNumber) {
                                        super.onCaptureBufferLost(session, request, target, frameNumber);
                                    }
                                });
                            } catch (CameraAccessException e) {
                                e.printStackTrace();
                            }
                        }

                        @Override
                        public void onConfigureFailed(@NonNull CameraCaptureSession session) {

                        }
                    }
            );

            mCamera.createCaptureSession(sessionConfiguration);

OutputConfiguration定义了我们要把视频数据输出到哪里

SessionConfiguration.SESSION_REGULAR  普通场景

CameraCaptureSession.StateCallback的onConfigured回调说明已经场景已经配置好了 

final CaptureRequest.Builder previewBuilder
                    = mCamera.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
            previewBuilder.addTarget(binding.surfaceView.getHolder().getSurface());

 mCameraCaptureSession = session;
                            previewBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_VIDEO);
                            CaptureRequest previewRequest = previewBuilder.build();
                            try {
                                mCameraCaptureSession.setSingleRepeatingRequest(previewRequest, mExecutorService, new CameraCaptureSession.CaptureCallback() {
                                    @Override
                                    public void onCaptureStarted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, long timestamp, long frameNumber) {
                                        super.onCaptureStarted(session, request, timestamp, frameNumber);
                                    }

                                    @Override
                                    public void onCaptureProgressed(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull CaptureResult partialResult) {
                                        super.onCaptureProgressed(session, request, partialResult);
                                    }

                                    @Override
                                    public void onCaptureCompleted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
                                        super.onCaptureCompleted(session, request, result);
                                    }

                                    @Override
                                    public void onCaptureFailed(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull CaptureFailure failure) {
                                        super.onCaptureFailed(session, request, failure);
                                    }

                                    @Override
                                    public void onCaptureSequenceCompleted(@NonNull CameraCaptureSession session, int sequenceId, long frameNumber) {
                                        super.onCaptureSequenceCompleted(session, sequenceId, frameNumber);
                                    }

                                    @Override
                                    public void onCaptureSequenceAborted(@NonNull CameraCaptureSession session, int sequenceId) {
                                        super.onCaptureSequenceAborted(session, sequenceId);
                                    }

                                    @Override
                                    public void onCaptureBufferLost(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull Surface target, long frameNumber) {
                                        super.onCaptureBufferLost(session, request, target, frameNumber);
                                    }
                                });
                            } catch (CameraAccessException e) {
                                e.printStackTrace();
                            }

previewBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_VIDEO); 设置视频对焦

 public int setSingleRepeatingRequest(@NonNull CaptureRequest request,
            @NonNull @CallbackExecutor Executor executor, @NonNull CaptureCallback listener)
            throws CameraAccessException {
        throw new UnsupportedOperationException("Subclasses must override this method");
    }

这个函数的作用是重复发送，从摄像头捕获的数据到surfaceView

完整代码

package com.yuanxuzhen.androidmedia.video;

import android.Manifest;
import android.content.pm.PackageManager;
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.CaptureFailure;
import android.hardware.camera2.CaptureRequest;
import android.hardware.camera2.CaptureResult;
import android.hardware.camera2.TotalCaptureResult;
import android.hardware.camera2.params.OutputConfiguration;
import android.hardware.camera2.params.SessionConfiguration;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.View;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;

import com.yuanxuzhen.androidmedia.databinding.ActivityCameraLayoutBinding;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import permissions.dispatcher.NeedsPermission;
import permissions.dispatcher.OnNeverAskAgain;
import permissions.dispatcher.OnPermissionDenied;
import permissions.dispatcher.RuntimePermissions;

@RuntimePermissions
public class CameraActivity extends AppCompatActivity {
    ActivityCameraLayoutBinding binding;
    ExecutorService mExecutorService;
    CameraManager cameraManager;
    CameraDevice mCamera;
    private String frontCameraId = "";
    private String backCameraId = "";
    CameraCaptureSession mCameraCaptureSession;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        cameraManager = (CameraManager) getSystemService(CAMERA_SERVICE);
        mExecutorService = Executors.newSingleThreadExecutor();
        binding = ActivityCameraLayoutBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());
        binding.startRecord.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                CameraActivityPermissionsDispatcher.startCameraWithPermissionCheck(CameraActivity.this);
            }
        });
        binding.stopRecord.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                stopCamera();
            }
        });

        binding.surfaceView.getHolder().addCallback(new SurfaceHolder.Callback() {
            @Override
            public void surfaceCreated(@NonNull SurfaceHolder holder) {
                CameraActivityPermissionsDispatcher.startCameraWithPermissionCheck(CameraActivity.this);
            }

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

            }

            @Override
            public void surfaceDestroyed(@NonNull SurfaceHolder holder) {

            }
        });
    }

    @NeedsPermission({Manifest.permission.RECORD_AUDIO, Manifest.permission.CAMERA})
    public void startCamera() {
        Log.e("CameraActivity", "startCamera");
        mExecutorService.execute(new Runnable() {
            @Override
            public void run() {
                try {
                    if (ActivityCompat.checkSelfPermission(CameraActivity.this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                        // TODO: Consider calling
                        //    ActivityCompat#requestPermissions
                        // here to request the missing permissions, and then overriding
                        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                        //                                          int[] grantResults)
                        // to handle the case where the user grants the permission. See the documentation
                        // for ActivityCompat#requestPermissions for more details.
                        return;
                    }
                    String[] cameraIdArray = cameraManager.getCameraIdList();
                    for(String ele : cameraIdArray){
                        CameraCharacteristics cameraCharacteristics = cameraManager.getCameraCharacteristics(ele);
                        if (cameraCharacteristics.get(CameraCharacteristics.LENS_FACING) == CameraCharacteristics.LENS_FACING_FRONT) {
                            frontCameraId = ele;
                        } else if (cameraCharacteristics.get(CameraCharacteristics.LENS_FACING) == CameraCharacteristics.LENS_FACING_BACK) {
                            backCameraId = ele;
                        }
                    }


                    cameraManager.openCamera(backCameraId,
                            mExecutorService,
                            new CameraDevice.StateCallback() {
                                @Override
                                public void onOpened(@NonNull CameraDevice camera) {
                                    Log.e("CameraActivity", "onOpened");
                                    mCamera = camera;
                                    preview();
                                }

                                @Override
                                public void onDisconnected(@NonNull CameraDevice camera) {
                                    Log.e("CameraActivity", "onDisconnected");

                                }

                                @Override
                                public void onError(@NonNull CameraDevice camera, int error) {
                                    Log.e("CameraActivity", "onError");

                                }
                            }

                    );
                }catch (Exception e){
                    e.printStackTrace();
                }

            }
        });

    }

    public void stopCamera(){
        Log.e("CameraActivity", "stopCamera");
        if(mCamera != null){
            mCamera.close();
            mCamera = null;
        }

    }
    @OnPermissionDenied(Manifest.permission.RECORD_AUDIO)
    public void onDeniedAudio() {
        Toast.makeText(this, "录音权限拒绝", Toast.LENGTH_SHORT).show();
    }

    @OnNeverAskAgain(Manifest.permission.RECORD_AUDIO)
    public void onNeverAskAgainAudio() {
        Toast.makeText(this, "录音权限再不询问", Toast.LENGTH_SHORT).show();
    }

    @OnPermissionDenied(Manifest.permission.CAMERA)
    public void onDeniedCamera() {
        Toast.makeText(this, "录像权限拒绝", Toast.LENGTH_SHORT).show();
    }

    @OnNeverAskAgain(Manifest.permission.CAMERA)
    public void onNeverAskAgainCamera() {
        Toast.makeText(this, "录像权限再不询问", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        CameraActivityPermissionsDispatcher.onRequestPermissionsResult(this, requestCode, grantResults);
    }


    /** Check if this device has a camera */
    private boolean checkCameraHardware() {
        if (getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
            // this device has a camera
            return true;
        } else {
            // no camera on this device
            return false;
        }
    }

    @Override
    protected void onDestroy() {
        stopCamera();
        super.onDestroy();
    }

    @RequiresApi(api = Build.VERSION_CODES.N)
    private void preview()  {
        try{
            final CaptureRequest.Builder previewBuilder
                    = mCamera.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
            previewBuilder.addTarget(binding.surfaceView.getHolder().getSurface());
            OutputConfiguration outputConfiguration = new OutputConfiguration(binding.surfaceView.getHolder().getSurface());
            List<OutputConfiguration> outputs = new ArrayList<>();
            outputs.add(outputConfiguration);
            SessionConfiguration  sessionConfiguration
                    =  new SessionConfiguration(SessionConfiguration.SESSION_REGULAR,
                    outputs,
                    mExecutorService,
                    new CameraCaptureSession.StateCallback() {
                        @Override
                        public void onConfigured(@NonNull CameraCaptureSession session) {
                            mCameraCaptureSession = session;
                            previewBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_VIDEO);
                            CaptureRequest previewRequest = previewBuilder.build();
                            try {
                                mCameraCaptureSession.setSingleRepeatingRequest(previewRequest, mExecutorService, new CameraCaptureSession.CaptureCallback() {
                                    @Override
                                    public void onCaptureStarted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, long timestamp, long frameNumber) {
                                        super.onCaptureStarted(session, request, timestamp, frameNumber);
                                    }

                                    @Override
                                    public void onCaptureProgressed(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull CaptureResult partialResult) {
                                        super.onCaptureProgressed(session, request, partialResult);
                                    }

                                    @Override
                                    public void onCaptureCompleted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
                                        super.onCaptureCompleted(session, request, result);
                                    }

                                    @Override
                                    public void onCaptureFailed(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull CaptureFailure failure) {
                                        super.onCaptureFailed(session, request, failure);
                                    }

                                    @Override
                                    public void onCaptureSequenceCompleted(@NonNull CameraCaptureSession session, int sequenceId, long frameNumber) {
                                        super.onCaptureSequenceCompleted(session, sequenceId, frameNumber);
                                    }

                                    @Override
                                    public void onCaptureSequenceAborted(@NonNull CameraCaptureSession session, int sequenceId) {
                                        super.onCaptureSequenceAborted(session, sequenceId);
                                    }

                                    @Override
                                    public void onCaptureBufferLost(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull Surface target, long frameNumber) {
                                        super.onCaptureBufferLost(session, request, target, frameNumber);
                                    }
                                });
                            } catch (CameraAccessException e) {
                                e.printStackTrace();
                            }
                        }

                        @Override
                        public void onConfigureFailed(@NonNull CameraCaptureSession session) {

                        }
                    }
            );

            mCamera.createCaptureSession(sessionConfiguration);

        }catch (Exception e){

        }

    }


}

?

gitee地址

https://gitee.com/creat151/android-media.git