Android开发 MediaRecorder使用Camera2配合录制视频

前言

　　之前这个博客碰到了一些问题比如在获取mMediaRecorder.getSurface();的时候老实提示没有初始化导致报错。然后个人因为业务也没需求要Camera2录像，所以一直没有深究。但是最近有大神（感谢利工）指出其实是因为之前用这个行代码设置

这行代码有一个大问题我一致没有注意到，这个MediaRecorder.VideoSource.CAMERA 属性其实是给Camera1使用的。

mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);

需要修改成Camera2的

mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);

这个在官方注释里也有说明，如下

    public final class VideoSource {
      /* Do not change these values without updating their counterparts
       * in include/media/mediarecorder.h!
       */
        private VideoSource() {}
        public static final int DEFAULT = 0;
        /** Camera video source
         * <p>
         * Using the {@link android.hardware.Camera} API as video source.
         * </p>
         */
        public static final int CAMERA = 1;
        /** Surface video source
         * <p>
         * Using a Surface as video source.
         * </p><p>
         * This flag must be used when recording from an
         * {@link android.hardware.camera2} API source.
         * </p><p>
         * When using this video source type, use {@link MediaRecorder#getSurface()}
         * to retrieve the surface created by MediaRecorder.
         */
        public static final int SURFACE = 2;
    }

现在主要问题解决了，我在详细讲解如何使用Camera2配合MediaRecorder录制视频

详解部分

需要的权限

    <uses-permission android:name="android.permission.RECORD_AUDIO"/><!--音频录制权限-->
    <uses-permission android:name="android.permission.CAMERA"/><!--摄像头权限-->
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/><!--存储权限-->
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

Xml布局

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MedioRecorderCamera2Activity">

    <TextureView
        android:id="@+id/textureview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <Button
        android:id="@+id/btn_start"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="开始"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"/>

    <Button
        android:id="@+id/btn_finish"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="结束"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintRight_toRightOf="parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>

代码部分

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Camera;
import android.graphics.ImageFormat;
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.CaptureFailure;
import android.hardware.camera2.CaptureRequest;
import android.hardware.camera2.CaptureResult;
import android.hardware.camera2.TotalCaptureResult;
import android.hardware.camera2.params.StreamConfigurationMap;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Handler;
import android.os.HandlerThread;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.Size;
import android.view.Surface;
import android.view.TextureView;
import android.view.View;
import android.widget.Button;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class MedioRecorderCamera2Activity extends AppCompatActivity {
    private static final String TAG = MedioRecorderCamera2Activity.class.getSimpleName();
    private Button mBtnStatr,mBtnFinish;
    private TextureView mTextureView;
    private CameraManager mCameraManager;
    private CameraDevice mCameraDevice;
    private CameraCaptureSession mCameraCaptureSession;
    private CameraDevice.StateCallback mCameraDeviceStateCallback;
    private CameraCaptureSession.StateCallback mSessionStateCallback;
    private CameraCaptureSession.CaptureCallback mSessionCaptureCallback;
    private CaptureRequest.Builder mPreviewCaptureRequest;
    private CaptureRequest.Builder mRecorderCaptureRequest;
    private MediaRecorder mMediaRecorder;
    private String mCurrentSelectCamera;
    private Handler mChildHandler;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_medio_recorder_camera2);
        mTextureView = findViewById(R.id.textureview);
        mBtnStatr = findViewById(R.id.btn_start);
        mBtnFinish = findViewById(R.id.btn_finish);
        initClickListener();
        initChildHandler();
        initTextureViewStateListener();
        initMediaRecorder();
        initCameraDeviceStateCallback();
        initSessionStateCallback();
        initSessionCaptureCallback();

    }

    private void initClickListener(){
        mBtnStatr.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                config();
                startRecorder();

            }
        });
        mBtnFinish.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                stopRecorder();

            }
        });
    }

    /**
     * 初始化TextureView的纹理生成监听，只有纹理生成准备好了。我们才能去进行摄像头的初始化工作让TextureView接收摄像头预览画面
     */
    private void initTextureViewStateListener(){
        mTextureView.setSurfaceTextureListener(new TextureView.SurfaceTextureListener() {
            @Override
            public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
                //可以使用纹理
                initCameraManager();
                selectCamera();
                openCamera();

            }

            @Override
            public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
                //纹理尺寸变化

            }

            @Override
            public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
                //纹理被销毁
                return false;
            }

            @Override
            public void onSurfaceTextureUpdated(SurfaceTexture surface) {
                //纹理更新

            }
        });
    }

    /**
     * 初始化子线程Handler，操作Camera2需要一个子线程的Handler
     */
    private void initChildHandler(){
        HandlerThread handlerThread = new HandlerThread("Camera2Demo");
        handlerThread.start();
        mChildHandler = new Handler(handlerThread.getLooper());
    }

    /**
     * 初始化MediaRecorder
     */
    private void initMediaRecorder(){
        mMediaRecorder = new MediaRecorder();
    }

    /**
     * 配置录制视频相关数据
     */
    private void configMediaRecorder(){
        File file = new File(getExternalCacheDir(),"demo.mp4");
        if (file.exists()){
            file.delete();
        }
        mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);//设置音频来源
        mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);//设置视频来源
        mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);//设置输出格式
        mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);//设置音频编码格式，请注意这里使用默认，实际app项目需要考虑兼容问题，应该选择AAC
        mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.DEFAULT);//设置视频编码格式，请注意这里使用默认，实际app项目需要考虑兼容问题，应该选择H264
        mMediaRecorder.setVideoEncodingBitRate(8*1024*1920);//设置比特率 一般是 1*分辨率 到 10*分辨率 之间波动。比特率越大视频越清晰但是视频文件也越大。
        mMediaRecorder.setVideoFrameRate(30);//设置帧数 选择 30即可， 过大帧数也会让视频文件更大当然也会更流畅，但是没有多少实际提升。人眼极限也就30帧了。
        Size size = getMatchingSize2();
        mMediaRecorder.setVideoSize(size.getWidth(),size.getHeight());
        mMediaRecorder.setOrientationHint(90);
        Surface surface = new Surface(mTextureView.getSurfaceTexture());
        mMediaRecorder.setPreviewDisplay(surface);
        mMediaRecorder.setOutputFile(file.getAbsolutePath());
        try {
            mMediaRecorder.prepare();
        } catch (IOException e) {
            e.printStackTrace();
        }


    }

    /**
     * 重新配置录制视频时的CameraCaptureSession
     */
    private void config(){
        try {
            mCameraCaptureSession.stopRepeating();//停止预览，准备切换到录制视频
            mCameraCaptureSession.close();//关闭预览的会话，需要重新创建录制视频的会话
            mCameraCaptureSession = null;
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
        configMediaRecorder();
        Size cameraSize = getMatchingSize2();
        SurfaceTexture surfaceTexture = mTextureView.getSurfaceTexture();
        surfaceTexture.setDefaultBufferSize(cameraSize.getWidth(),cameraSize.getHeight());
        Surface previewSurface = new Surface(surfaceTexture);
        Surface recorderSurface = mMediaRecorder.getSurface();//从获取录制视频需要的Surface
        try {
            mPreviewCaptureRequest = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
            mPreviewCaptureRequest.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
            mPreviewCaptureRequest.addTarget(previewSurface);
            mPreviewCaptureRequest.addTarget(recorderSurface);
            //请注意这里设置了Arrays.asList(previewSurface,recorderSurface) 2个Surface，很好理解录制视频也需要有画面预览，第一个是预览的Surface，第二个是录制视频使用的Surface
            mCameraDevice.createCaptureSession(Arrays.asList(previewSurface,recorderSurface),mSessionStateCallback,mChildHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }

    }

    /**
     * 开始录制视频
     */
    private void startRecorder(){
        mMediaRecorder.start();


    }

    /**
     * 暂停录制视频（暂停后视频文件会自动保存）
     */
    private void stopRecorder(){
        mMediaRecorder.stop();
        mMediaRecorder.reset();
    }

    /**
     * 初始化Camera2的相机管理，CameraManager用于获取摄像头分辨率，摄像头方向，摄像头id与打开摄像头的工作
     */
    private void initCameraManager(){
        mCameraManager = (CameraManager)getSystemService(Context.CAMERA_SERVICE);

    }

    /**
     * 选择一颗我们需要使用的摄像头，主要是选择使用前摄还是后摄或者是外接摄像头
     */
    private void selectCamera(){
        if (mCameraManager != null) {
            Log.e(TAG, "selectCamera: CameraManager is null");

        }
        try {
            String[] cameraIdList = mCameraManager.getCameraIdList();   //获取当前设备的全部摄像头id集合
            if (cameraIdList.length == 0){
                Log.e(TAG, "selectCamera: cameraIdList length is 0");
            }
            for (String cameraId : cameraIdList){ //遍历所有摄像头
                CameraCharacteristics characteristics = mCameraManager.getCameraCharacteristics(cameraId);//得到当前id的摄像头描述特征
                Integer facing = characteristics.get(CameraCharacteristics.LENS_FACING); //获取摄像头的方向特征信息
                if (facing == CameraCharacteristics.LENS_FACING_BACK){ //这里选择了后摄像头
                    mCurrentSelectCamera = cameraId;

                }
            }

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

    private void initCameraDeviceStateCallback(){
        mCameraDeviceStateCallback = new CameraDevice.StateCallback() {
            @Override
            public void onOpened(@NonNull CameraDevice camera) {
                //摄像头被打开
                try {
                    mCameraDevice = camera;
                    Size cameraSize = getMatchingSize2();//计算获取需要的摄像头分辨率
                    SurfaceTexture surfaceTexture = mTextureView.getSurfaceTexture();//得到纹理
                    surfaceTexture.setDefaultBufferSize(cameraSize.getWidth(),cameraSize.getHeight());
                    Surface previewSurface = new Surface(surfaceTexture);
                    mPreviewCaptureRequest = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
                    mPreviewCaptureRequest.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
                    mPreviewCaptureRequest.addTarget(previewSurface);
                    mCameraDevice.createCaptureSession(Arrays.asList(previewSurface),mSessionStateCallback,mChildHandler);//创建数据捕获会话，用于摄像头画面预览，这里需要等待mSessionStateCallback回调
                } catch (CameraAccessException e) {
                    e.printStackTrace();
                }

            }

            @Override
            public void onDisconnected(@NonNull CameraDevice camera) {
                //摄像头断开

            }

            @Override
            public void onError(@NonNull CameraDevice camera, int error) {
                //异常

            }
        };
    }

    private void initSessionStateCallback(){
        mSessionStateCallback = new CameraCaptureSession.StateCallback() {
            @Override
            public void onConfigured(@NonNull CameraCaptureSession session) {
                mCameraCaptureSession = session;
                try {
                    //执行重复获取数据请求，等于一直获取数据呈现预览画面，mSessionCaptureCallback会返回此次操作的信息回调
                    mCameraCaptureSession.setRepeatingRequest(mPreviewCaptureRequest.build(),mSessionCaptureCallback,mChildHandler);
                } catch (CameraAccessException e) {
                    e.printStackTrace();
                }

            }

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

            }
        };
    }

    private void initSessionCaptureCallback(){
        mSessionCaptureCallback = 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);
            }
        };
    }

    /**
     * 打开摄像头，这里打开摄像头后，我们需要等待mCameraDeviceStateCallback的回调
     */
    @SuppressLint("MissingPermission")
    private void openCamera(){
        try {
            mCameraManager.openCamera(mCurrentSelectCamera,mCameraDeviceStateCallback,mChildHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    /**
     * 计算需要的使用的摄像头分辨率
     * @return
     */
    private Size getMatchingSize2(){
        Size selectSize = null;
        try {
            CameraCharacteristics cameraCharacteristics = mCameraManager.getCameraCharacteristics(mCurrentSelectCamera);
            StreamConfigurationMap streamConfigurationMap = cameraCharacteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
            Size[] sizes = streamConfigurationMap.getOutputSizes(ImageFormat.JPEG);
            DisplayMetrics displayMetrics = getResources().getDisplayMetrics(); //因为我这里是将预览铺满屏幕,所以直接获取屏幕分辨率
            int deviceWidth = displayMetrics.widthPixels; //屏幕分辨率宽
            int deviceHeigh = displayMetrics.heightPixels; //屏幕分辨率高
            Log.e(TAG, "getMatchingSize2: 屏幕密度宽度="+deviceWidth);
            Log.e(TAG, "getMatchingSize2: 屏幕密度高度="+deviceHeigh );
            /**
             * 循环40次,让宽度范围从最小逐步增加,找到最符合屏幕宽度的分辨率,
             * 你要是不放心那就增加循环,肯定会找到一个分辨率,不会出现此方法返回一个null的Size的情况
             * ,但是循环越大后获取的分辨率就越不匹配
             */
            for (int j = 1; j < 41; j++) {
                for (int i = 0; i < sizes.length; i++) { //遍历所有Size
                    Size itemSize = sizes[i];
                    Log.e(TAG,"当前itemSize 宽="+itemSize.getWidth()+"高="+itemSize.getHeight());
                    //判断当前Size高度小于屏幕宽度+j*5  &&  判断当前Size高度大于屏幕宽度-j*5  &&  判断当前Size宽度小于当前屏幕高度
                    if (itemSize.getHeight() < (deviceWidth + j*5) && itemSize.getHeight() > (deviceWidth - j*5)) {
                        if (selectSize != null){ //如果之前已经找到一个匹配的宽度
                            if (Math.abs(deviceHeigh-itemSize.getWidth()) < Math.abs(deviceHeigh - selectSize.getWidth())){ //求绝对值算出最接近设备高度的尺寸
                                selectSize = itemSize;
                                continue;
                            }
                        }else {
                            selectSize = itemSize;
                        }

                    }
                }
                if (selectSize != null){ //如果不等于null 说明已经找到了 跳出循环
                    break;
                }
            }
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
        Log.e(TAG, "getMatchingSize2: 选择的分辨率宽度="+selectSize.getWidth());
        Log.e(TAG, "getMatchingSize2: 选择的分辨率高度="+selectSize.getHeight());
        return selectSize;
    }


}

End