Android 4.0中的背景视频录制

23
我尝试在Android 4.0中组织后台视频录制,但由于以下问题而无法实现:

  1. 虚拟表面在MediaRecorder中不起作用(错误:无效表面)

  2. 如果在Activity上使用1 x 1像素的Surface,则会在Activity暂停时销毁Surface(录制停止)

  3. 如果在WindowsManager上使用1 x 1像素的Surface,则会在应用程序暂停时销毁Surface(录制停止)

  4. SurfaceTexture在MediaRecorder.setPreviewDisplay(new Surface(SurfaceTexture))中不起作用

  5. 小部件不允许处理1 x 1像素的表面

  6. 状态栏不允许处理1 x 1像素的表面

请帮助我找到正确的方法。

1
你能给我一个隐藏摄像头的代码吗? - Ravi Vaghela
3个回答

44

简单示例代码(在Jelly Bean,SGS2上测试通过):

public class BackgroundVideoRecorder extends Service implements SurfaceHolder.Callback {

    private WindowManager windowManager;
    private SurfaceView surfaceView;
    private Camera camera = null;
    private MediaRecorder mediaRecorder = null;

    @Override
    public void onCreate() {

        // Start foreground service to avoid unexpected kill
        Notification notification = new Notification.Builder(this)
            .setContentTitle("Background Video Recorder")
            .setContentText("")
            .setSmallIcon(R.drawable.ic_launcher)
            .build();
        startForeground(1234, notification);

        // Create new SurfaceView, set its size to 1x1, move it to the top left corner and set this service as a callback
        windowManager = (WindowManager) this.getSystemService(Context.WINDOW_SERVICE);
        surfaceView = new SurfaceView(this);
        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);

    }

    // Method called right after Surface created (initializing and starting MediaRecorder)
    @Override
    public void surfaceCreated(SurfaceHolder surfaceHolder) {

        camera = Camera.open();
        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_HIGH));

        mediaRecorder.setOutputFile(
                Environment.getExternalStorageDirectory()+"/"+
                DateFormat.format("yyyy-MM-dd_kk-mm-ss", new Date().getTime())+
                ".mp4"
        );

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

    }

    // Stop recording and remove SurfaceView
    @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; }

}

不要忘记权限:

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

刚要发布这个。诀窍是在OnSurfaceCreated上设置MediaRecorder,之后就变得非常简单了。 - Felipe Leusin
谢谢你提供这么棒的代码,但是我遇到了一个小问题。我在Nexus 5X上测试时,发现相机倒置了。我尝试使用camera.setDisplayOrientation(90)和camera.getParameters().setRotation(90),但是相机方向没有改变。你有任何想法如何解决吗? - Michal
1
非常抱歉回复晚了。希望这可以帮到你:https://plus.google.com/+AndroidDevelopers/posts/jXNFNKWxsc3 - 如果不行,你可以尝试这个:mediaRecorder.setOrientationHint(180); - 它不会改变相机的方向,但会告诉视频播放器在播放时更改方向。这就是我所知道的。 - cman
这个解决方案可行,但在开始录制时屏幕会冻结。已在Nought中进行了测试。 - Trupti Nasit

2
try { 
        mediaRecorder.prepare(); 
    } catch (Exception e) {}
    mediaRecorder.start();
    Timer t = new Timer();
    t.schedule(new TimerTask() {
        @Override
        public void run() {
            stopSelf();
        }
    }, 5000);
}catch(Exception e){}

对上面的代码进行一小部分修改...它将5秒文件保存到SD卡的根目录中...根据您的需要修改计时器即可。在Nexus 4和Micromax上都可以工作。


-4
我找到了答案:需要使用WindowManager并从Service中调用它。

2
请提交代码! - nick

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