从Android Camera接口切换到Camera2接口

Question

我使用的是一台运行Android 5.1的平板电脑。我已经使用Camera接口实现了一个服务，用于在后台录制前置摄像头。代码如下所示。现在我想把它改成Camera2接口。此外，我还想手动设置光圈和曝光时间(我想这只适用于Camera2应用编程接口，但不适用于Camera应用编程接口)。我如何调整我的代码？

import android.app.Notification;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.media.CamcorderProfile;
import android.media.MediaRecorder;
import android.os.IBinder;
import android.support.v7.app.NotificationCompat;
import android.view.Gravity;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.WindowManager;
import inf.ethz.ch.affectivestudy.MainActivity;

public class RecorderService extends Service implements SurfaceHolder.Callback {
    private WindowManager windowManager;
    private SurfaceView surfaceView;
    private Camera camera = null;
    private MediaRecorder mediaRecorder = null;

    @Override
    public void onCreate() {
        windowManager = (WindowManager) this.getSystemService(Context.WINDOW_SERVICE);

        surfaceView = new SurfaceView(this);
        WindowManager.LayoutParams layoutParams = new WindowManager.LayoutParams(
                1, 1,
                WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
                WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH,
                PixelFormat.TRANSLUCENT
        );
        layoutParams.gravity = Gravity.LEFT | Gravity.TOP;
        windowManager.addView(surfaceView, layoutParams);
        surfaceView.getHolder().addCallback(this);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Intent notificationIntent = new Intent(this, MainActivity.class);

        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0,
                notificationIntent, 0);

        Notification notification = new NotificationCompat.Builder(this)
                //.setSmallIcon(R.mipmap.app_icon)
                .setContentTitle("Background Video Recorder")
                .setContentText("")
                .setContentIntent(pendingIntent).build();

        startForeground(MainActivity.NOTIFICATION_ID_RECORDER_SERVICE, notification);

        return Service.START_NOT_STICKY;
    }

    @Override
    public void surfaceCreated(SurfaceHolder surfaceHolder) {
        camera = Camera.open(1);
        mediaRecorder = new MediaRecorder();
        camera.unlock();

        mediaRecorder.setPreviewDisplay(surfaceHolder.getSurface());
        mediaRecorder.setCamera(camera);
        mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
        mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
        mediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_720P));

        mediaRecorder.setOutputFile("/storage/emulated/0/Study/Camera/test.mp4");

        try { mediaRecorder.prepare(); } catch (Exception ignored) {}
        mediaRecorder.start();
    }

    @Override
    public void onDestroy() {
        mediaRecorder.stop();
        mediaRecorder.reset();
        mediaRecorder.release();

        camera.lock();
        camera.release();

        windowManager.removeView(surfaceView);
    }

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

    @Override
    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {}

    @Override
    public IBinder onBind(Intent intent) { return null; }
}

Answer 1

Camera2是完全不同的，所以适应起来并不简单。

我建议你看看谷歌的示例应用程序，特别是Camera2Video，看看如何用camera2进行录音。

一旦你运行了它，你就可以考虑在支持它的设备上使用手动控制(具有MANUAL_SENSOR功能)；但请注意，很少有手机实际上具有可变光圈。