如何从应用程序后台录制视频：Android

我正在开发一个应用程序，它将能够通过使用从应用程序后台录制视频Service.

问题描述 ：

1-我创建了一个活动来启动服务，如下所示：

package com.android.camerarecorder;

import android.app.Activity;
import android.content.Intent;
import android.hardware.Camera;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;

public class CameraRecorder extends Activity implements SurfaceHolder.Callback {
    private static final String TAG = "Recorder";
    public static SurfaceView mSurfaceView;
    public static SurfaceHolder mSurfaceHolder;
    public static Camera mCamera ;
    public static boolean mPreviewRunning;
    
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        mSurfaceView = (SurfaceView) findViewById(R.id.surfaceView1);
        mSurfaceHolder = mSurfaceView.getHolder();
        mSurfaceHolder.addCallback(this);
        mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        
        Button btnStart = (Button) findViewById(R.id.StartService);
        btnStart.setOnClickListener(new View.OnClickListener()
        {
            public void onClick(View v)
            {
                Intent intent = new Intent(CameraRecorder.this, RecorderService.class);
                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                startService(intent);
                finish();
            }
        });

        Button btnStop = (Button) findViewById(R.id.StopService);
        btnStop.setOnClickListener(new View.OnClickListener()
        {
            public void onClick(View v)
            {
                stopService(new Intent(CameraRecorder.this, RecorderService.class));
            }
        });
    }
    
    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    }
    
    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // TODO Auto-generated method stub

    }
}

2 - 现在我已经创建了在后台录制视频的服务像这样：

    package com.android.camerarecorder;
    import java.io.IOException;
    import java.util.List;
    import android.app.Service;
    import android.content.Intent;
    import android.graphics.PixelFormat;
    import android.hardware.Camera;
    import android.hardware.Camera.Size;
    import android.media.MediaRecorder;
    import android.os.IBinder;
    import android.util.Log;
    import android.view.SurfaceHolder;
    import android.view.SurfaceView;
    import android.widget.Toast;

    public class RecorderService extends Service {
        private static final String TAG = "RecorderService";
        private SurfaceView mSurfaceView;
        private SurfaceHolder mSurfaceHolder;
        private static Camera mServiceCamera;
        private boolean mRecordingStatus;
        private MediaRecorder mMediaRecorder;
        
        @Override
        public void onCreate() {
            mRecordingStatus = false;
            //mServiceCamera = CameraRecorder.mCamera;
            mServiceCamera = Camera.open(1);
            mSurfaceView = CameraRecorder.mSurfaceView;
            mSurfaceHolder = CameraRecorder.mSurfaceHolder;
            
            super.onCreate();
            if (mRecordingStatus == false)
                startRecording();
        }
    
        @Override
        public IBinder onBind(Intent intent) {
            // TODO Auto-generated method stub
            return null;
        }
    
        @Override
        public void onDestroy() {
            stopRecording();
            mRecordingStatus = false;
            
            super.onDestroy();
        }   
    
        public boolean startRecording(){
            try {
                Toast.makeText(getBaseContext(), "Recording Started", Toast.LENGTH_SHORT).show();
                
                //mServiceCamera = Camera.open();
                Camera.Parameters params = mServiceCamera.getParameters();
                mServiceCamera.setParameters(params);
                Camera.Parameters p = mServiceCamera.getParameters();
                
                final List<Size> listSize = p.getSupportedPreviewSizes();
                Size mPreviewSize = listSize.get(2);
                Log.v(TAG, "use: width = " + mPreviewSize.width 
                            + " height = " + mPreviewSize.height);
                p.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
                p.setPreviewFormat(PixelFormat.YCbCr_420_SP);
                mServiceCamera.setParameters(p);
    
                try {
                    mServiceCamera.setPreviewDisplay(mSurfaceHolder);
                    mServiceCamera.startPreview();
                }
                catch (IOException e) {
                    Log.e(TAG, e.getMessage());
                    e.printStackTrace();
                }
                
                mServiceCamera.unlock();
                
                mMediaRecorder = new MediaRecorder();
                mMediaRecorder.setCamera(mServiceCamera);
                mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
                mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
                mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
                mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
                mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.DEFAULT);
                mMediaRecorder.setOutputFile("/sdcard/video.mp4");
                mMediaRecorder.setVideoFrameRate(30);
                mMediaRecorder.setVideoSize(mPreviewSize.width, mPreviewSize.height);
                mMediaRecorder.setPreviewDisplay(mSurfaceHolder.getSurface());
                
                mMediaRecorder.prepare();
                mMediaRecorder.start(); 
    
                mRecordingStatus = true;
                
                return true;
            } catch (IllegalStateException e) {
                Log.d(TAG, e.getMessage());
                e.printStackTrace();
                return false;
            } catch (IOException e) {
                Log.d(TAG, e.getMessage());
                e.printStackTrace();
                return false;
            }
        }
    
        public void stopRecording() {
            Toast.makeText(getBaseContext(), "Recording Stopped", Toast.LENGTH_SHORT).show();
            try {
                mServiceCamera.reconnect();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            mMediaRecorder.stop();
            mMediaRecorder.reset();
            
            mServiceCamera.stopPreview();
            mMediaRecorder.release();
            
            mServiceCamera.release();
            mServiceCamera = null;
        }
    }

它将在您的 SD 卡中创建一个文件 video.mp4。您可以更改代码以添加更多功能，但基本功能是通过此代码实现的，即在后台录制视频。

注意：我已经通过活动中的按钮单击启动了该服务，但您可以通过任何其他方式启动它，例如广播接收器等。