android - Get/modify frames while recording mp4 with MediaRecorder

Question

I am recording mp4 with the following code. But while I am recording,

1- is it possible get frames of video in real time in array Data or another format?

2- is it possible to modify frames? For example, to invert the colors and make it look negative.

public class MainActivity extends Activity implements OnClickListener, SurfaceHolder.Callback {
MediaRecorder recorder;
SurfaceHolder holder;
boolean recording = false;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

    recorder = new MediaRecorder();
    initRecorder();
    setContentView(R.layout.activity_main);

    SurfaceView cameraView = (SurfaceView) findViewById(R.id.surfaceView1);
    holder = cameraView.getHolder();
    holder.addCallback(this);
    holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

    cameraView.setClickable(true);
    cameraView.setOnClickListener(this);
}

private void initRecorder() {
    recorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);
    recorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);

    CamcorderProfile cpHigh = CamcorderProfile
            .get(CamcorderProfile.QUALITY_HIGH);
    recorder.setProfile(cpHigh);

    recorder.setOutputFile(Environment.getExternalStorageDirectory().getPath() + "/video.mp4");
    recorder.setMaxDuration(50 * 1000); // 50 seconds
    recorder.setMaxFileSize(5 * 1000000); // Approximately 5 megabytes
}

private void prepareRecorder() {
    recorder.setPreviewDisplay(holder.getSurface());

    try {
        recorder.prepare();
    } catch (IllegalStateException e) {
        e.printStackTrace();
        finish();
    } catch (IOException e) {
        e.printStackTrace();
        finish();
    }
}

public void onClick(View v) {
    if (recording) {
        recorder.stop();
        recording = false;


        // Let's initRecorder so we can record again
        initRecorder();
        prepareRecorder();
    } else {
        recording = true;
        recorder.start();
    }
}

public void surfaceCreated(SurfaceHolder holder) {
    prepareRecorder();
}

public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
}

public void surfaceDestroyed(SurfaceHolder holder) {
    if (recording) {
        recorder.stop();
        recording = false;
    }
    recorder.release();
    finish();
}

}

Answer 1

I used JavaCV library (which wraps FFMPEG and OpenCV) for editing Frames. Capture frames on onPreviewFrame and record them through FFMPEG recorder.

Following is the RecordActivity.java sample.

public class RecordActivity extends Activity implements OnClickListener {

    private final static String CLASS_LABEL = "RecordActivity";
    private final static String LOG_TAG = CLASS_LABEL;

    private PowerManager.WakeLock mWakeLock;

    private String ffmpeg_link = "/mnt/sdcard/stream.flv";

    long startTime = 0;
    boolean recording = false;

    private volatile FFmpegFrameRecorder recorder;

    private boolean isPreviewOn = false;

    private int sampleAudioRateInHz = 44100;
    private int imageWidth = 320;
    private int imageHeight = 240;
    private int frameRate = 30;

    /* audio data getting thread */
    private AudioRecord audioRecord;
    private AudioRecordRunnable audioRecordRunnable;
    private Thread audioThread;
    volatile boolean runAudioThread = true;

    /* video data getting thread */
    private Camera cameraDevice;
    private CameraView cameraView;

    private IplImage yuvIplimage = null;

    /* layout setting */
    private final int bg_screen_bx = 232;
    private final int bg_screen_by = 128;
    private final int bg_screen_width = 700;
    private final int bg_screen_height = 500;
    private final int bg_width = 1123;
    private final int bg_height = 715;
    private final int live_width = 640;
    private final int live_height = 480;
    private int screenWidth, screenHeight;
    private Button btnRecorderControl;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

        setContentView(R.layout.main);

        PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE); 
        mWakeLock = pm.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK, CLASS_LABEL); 
        mWakeLock.acquire(); 

        initLayout();
        initRecorder();
    }


    @Override
    protected void onResume() {
        super.onResume();

        if (mWakeLock == null) {
           PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
           mWakeLock = pm.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK, CLASS_LABEL);
           mWakeLock.acquire();
        }
    }

    @Override
    protected void onPause() {
        super.onPause();

        if (mWakeLock != null) {
            mWakeLock.release();
            mWakeLock = null;
        }
    }

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

        recording = false;

        if (cameraView != null) {
            cameraView.stopPreview();
        }

        if(cameraDevice != null) {
           cameraDevice.stopPreview();
           cameraDevice.release();
           cameraDevice = null;
        }

        if (mWakeLock != null) {
            mWakeLock.release();
            mWakeLock = null;
        }
    }


    private void initLayout() {

        /* get size of screen */
        Display display = ((WindowManager) getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
        screenWidth = display.getWidth();
        screenHeight = display.getHeight();
        RelativeLayout.LayoutParams layoutParam = null; 
        LayoutInflater myInflate = null; 
        myInflate = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        RelativeLayout topLayout = new RelativeLayout(this);
        setContentView(topLayout);
        LinearLayout preViewLayout = (LinearLayout) myInflate.inflate(R.layout.main, null);
        layoutParam = new RelativeLayout.LayoutParams(screenWidth, screenHeight);
        topLayout.addView(preViewLayout, layoutParam);

        /* add control button: start and stop */
        btnRecorderControl = (Button) findViewById(R.id.recorder_control);
        btnRecorderControl.setText("Start");
        btnRecorderControl.setOnClickListener(this);

        /* add camera view */
        int display_width_d = (int) (1.0 * bg_screen_width * screenWidth / bg_width);
        int display_height_d = (int) (1.0 * bg_screen_height * screenHeight / bg_height);
        int prev_rw, prev_rh;
        if (1.0 * display_width_d / display_height_d > 1.0 * live_width / live_height) {
            prev_rh = display_height_d;
            prev_rw = (int) (1.0 * display_height_d * live_width / live_height);
        } else {
            prev_rw = display_width_d;
            prev_rh = (int) (1.0 * display_width_d * live_height / live_width);
        }
        layoutParam = new RelativeLayout.LayoutParams(prev_rw, prev_rh);
        layoutParam.topMargin = (int) (1.0 * bg_screen_by * screenHeight / bg_height);
        layoutParam.leftMargin = (int) (1.0 * bg_screen_bx * screenWidth / bg_width);

        cameraDevice = Camera.open();
        Log.i(LOG_TAG, "cameara open");
        cameraView = new CameraView(this, cameraDevice);
        topLayout.addView(cameraView, layoutParam);
        Log.i(LOG_TAG, "cameara preview start: OK");
    }

    //---------------------------------------
    // initialize ffmpeg_recorder
    //---------------------------------------
    private void initRecorder() {

        Log.w(LOG_TAG,"init recorder");

        if (yuvIplimage == null) {
            yuvIplimage = IplImage.create(imageWidth, imageHeight, IPL_DEPTH_8U, 2);
            Log.i(LOG_TAG, "create yuvIplimage");
        }

        Log.i(LOG_TAG, "ffmpeg_url: " + ffmpeg_link);
        recorder = new FFmpegFrameRecorder(ffmpeg_link, imageWidth, imageHeight, 1);
        recorder.setFormat("flv");
        recorder.setSampleRate(sampleAudioRateInHz);
        // Set in the surface changed method
        recorder.setFrameRate(frameRate);

        Log.i(LOG_TAG, "recorder initialize success");

        audioRecordRunnable = new AudioRecordRunnable();
        audioThread = new Thread(audioRecordRunnable);
        runAudioThread = true;
    }

    public void startRecording() {

        try {
            recorder.start();
            startTime = System.currentTimeMillis();
            recording = true;
            audioThread.start();

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

    public void stopRecording() {

        runAudioThread = false;
        try {
            audioThread.join();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        audioRecordRunnable = null;
        audioThread = null;

        if (recorder != null && recording) {
            recording = false;
            Log.v(LOG_TAG,"Finishing recording, calling stop and release on recorder");
            try {
                recorder.stop();
                recorder.release();
            } catch (FFmpegFrameRecorder.Exception e) {
                e.printStackTrace();
            }
            recorder = null;

        }
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {

        if (keyCode == KeyEvent.KEYCODE_BACK) {
            if (recording) {
                stopRecording();
            }

            finish();

            return true;
        }

        return super.onKeyDown(keyCode, event);
    }


    //---------------------------------------------
    // audio thread, gets and encodes audio data
    //---------------------------------------------
    class AudioRecordRunnable implements Runnable {

        @Override
        public void run() {
            android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);

            // Audio
            int bufferSize;
            short[] audioData;
            int bufferReadResult;

            bufferSize = AudioRecord.getMinBufferSize(sampleAudioRateInHz, 
                    AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
            audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, sampleAudioRateInHz, 
                    AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSize);

            audioData = new short[bufferSize];

            Log.d(LOG_TAG, "audioRecord.startRecording()");
            audioRecord.startRecording();

            /* ffmpeg_audio encoding loop */
            while (runAudioThread) {
                //Log.v(LOG_TAG,"recording? " + recording);
                bufferReadResult = audioRecord.read(audioData, 0, audioData.length);
                if (bufferReadResult > 0) {
                    Log.v(LOG_TAG,"bufferReadResult: " + bufferReadResult);
                    // If "recording" isn't true when start this thread, it never get's set according to this if statement...!!!
                    // Why?  Good question...
                    if (recording) {
                        try {
                            recorder.record(ShortBuffer.wrap(audioData, 0, bufferReadResult));
                            //Log.v(LOG_TAG,"recording " + 1024*i + " to " + 1024*i+1024);
                        } catch (FFmpegFrameRecorder.Exception e) {
                            Log.v(LOG_TAG,e.getMessage());
                            e.printStackTrace();
                        }
                    }
                }
            }
            Log.v(LOG_TAG,"AudioThread Finished, release audioRecord");

            /* encoding finish, release recorder */
            if (audioRecord != null) {
                audioRecord.stop();
                audioRecord.release();
                audioRecord = null;
                Log.v(LOG_TAG,"audioRecord released");
            }
        }
    }

    //---------------------------------------------
    // camera thread, gets and encodes video data
    //---------------------------------------------
    class CameraView extends SurfaceView implements SurfaceHolder.Callback, PreviewCallback {

        private SurfaceHolder mHolder;
        private Camera mCamera;

        public CameraView(Context context, Camera camera) {
            super(context);
            Log.w("camera","camera view");
            mCamera = camera;
            mHolder = getHolder();
            mHolder.addCallback(CameraView.this);
            mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
            mCamera.setPreviewCallback(CameraView.this);
        }

        @Override
        public void surfaceCreated(SurfaceHolder holder) {
            try {
                stopPreview();
                mCamera.setPreviewDisplay(holder);
            } catch (IOException exception) {
                mCamera.release();
                mCamera = null;
            }
        }

        public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
            Log.v(LOG_TAG,"Setting imageWidth: " + imageWidth + " imageHeight: " + imageHeight + " frameRate: " + frameRate);
            Camera.Parameters camParams = mCamera.getParameters();
            camParams.setPreviewSize(imageWidth, imageHeight);

            Log.v(LOG_TAG,"Preview Framerate: " + camParams.getPreviewFrameRate());

            camParams.setPreviewFrameRate(frameRate);
            mCamera.setParameters(camParams);
            startPreview();
        }

        @Override
        public void surfaceDestroyed(SurfaceHolder holder) {
            try {
                mHolder.addCallback(null);
                mCamera.setPreviewCallback(null);
            } catch (RuntimeException e) {
                // The camera has probably just been release