I am trying to implement a tap to record feature like in vine. A sample for handling recording (not touch to record) provided in javacv is https://github.com/bytedeco/javacv/blob/master/samples/RecordActivity.java. I am trying to modify it so that in onPreviewFrame method frames are added to buffer only when user has his finger placed on screen. These frames are then tried to be combined into final video in stopRecording method.
The issue is that if I set the timestamp as given in below code snippet (in stopRecording method)
if (t > recorder.getTimestamp())
{
recorder.setTimestamp(t);
}
the behavior is as below
Case 1
If I tap on screen to record for 2 seconds and take the finger away from screen for 3 seconds and then again place finger back on screen to record for another 4 seconds the resulting video is like,
For 1st 2 seconds video has recorded content. For next 3 seconds (time when finger is put away from screen). video just shows the last frame recorded when finger was placed on screen last. Then the video has recorded video content for next 4 seconds. So there seems to be an issue in handling video recording when finger is removed from screen.
Case 2
Next I removed the code setting time stamp to recorder(the code snippet given above) in stopRecording method.
Now the resulting video (for the same steps tried in case 1) does not contain the middle 3 seconds(which is what is required) when finger was taken away from screen. But video is playing at a faster rate. So it seems that we need to set time stamp so that video plays at normal rate.
Full code of my activity is given below. (Please note that video recording is mainly handled from onPreviewFrame and stopRecording methods)
public class TouchToRecordActivity extends Activity implements OnClickListener, View.OnTouchListener {
private final static String CLASS_LABEL = "TouchToRecordActivity";
private final static String LOG_TAG = CLASS_LABEL;
private String ffmpeg_link = "/mnt/sdcard/stream.mp4";
long startTime = 0;
boolean recording = false;
boolean rec = false;
private FFmpegFrameRecorder recorder;
private boolean isPreviewOn = false;
private int sampleAudioRateInHz = 44100;
private int imageWidth = 640;
private int imageHeight = 480;
private int destWidth = 480;
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 Frame yuvImage = 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;
/* The number of seconds in the continuous record loop (or 0 to disable loop). */
final int RECORD_LENGTH = 20;
Frame[] images;
long[] timestamps;
ShortBuffer[] samples;
int imagesIndex, samplesIndex;
long firstTime = 0;
long startPauseTime = 0;
long totalPauseTime = 0;
long pausedTime = 0;
long stopPauseTime = 0;
long totalTime = 0;
long totalRecordedTS = 0;
private TextView txtTimer;
private Handler mHandler = new Handler();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
setContentView(R.layout.touch_main);
initLayout();
}
@Override
protected void onDestroy() {
super.onDestroy();
recording = false;
if (cameraView != null) {
cameraView.stopPreview();
}
if (cameraDevice != null) {
cameraDevice.stopPreview();
cameraDevice.release();
cameraDevice = 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.touch_main, null);
layoutParam = new RelativeLayout.LayoutParams(screenWidth, screenHeight);
topLayout.addView(preViewLayout, layoutParam);
txtTimer = (TextView) preViewLayout.findViewById(R.id.txtTimer);
/* 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);
topLayout.setOnTouchListener(this);
Log.i(LOG_TAG, "cameara preview start: OK");
}
//---------------------------------------
// initialize ffmpeg_recorder
//---------------------------------------
private void initRecorder() {
Log.w(LOG_TAG, "init recorder");
if (RECORD_LENGTH > 0) {
imagesIndex = 0;
images = new Frame[RECORD_LENGTH * frameRate];
timestamps = new long[images.length];
for (int i = 0; i < images.length; i++) {
images[i] = new Frame(destWidth, imageHeight, Frame.DEPTH_UBYTE, 2);
timestamps[i] = -1;
}
} else if (yuvImage == null) {
yuvImage = new Frame(destWidth, imageHeight, Frame.DEPTH_UBYTE, 2);
Log.i(LOG_TAG, "create yuvImage");
}
Log.i(LOG_TAG, "ffmpeg_url: " + ffmpeg_link);
recorder = new FFmpegFrameRecorder(ffmpeg_link, destWidth, imageHeight, 1);
recorder.setFormat("mp4");
recorder.setVideoCodecName("libx264");
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() {
initRecorder();
mHandler.removeCallbacks(mUpdateTimeTask);
mHandler.postDelayed(mUpdateTimeTask, 100);
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) {
if (RECORD_LENGTH > 0) {
Log.v(LOG_TAG, "Writing frames");
try {
int firstIndex = imagesIndex % samples.length;
int lastIndex = (imagesIndex - 1) % images.length;
if (imagesIndex <= images.length) {
firstIndex = 0;
lastIndex = imagesIndex - 1;
}
if ((startTime = timestamps[lastIndex] - RECORD_LENGTH * 1000000L) < 0) {
startTime = 0;
}
if (lastIndex < firstIndex) {
lastIndex += images.length;
}
int videoCounter = 0;
for (int i = firstIndex; i <= lastIndex; i++) {
if (timestamps[i] == -1) {
Log.v(LOG_TAG, "frame not recorded");
}
if (timestamps[i] != -1) {
long t = timestamps[i % timestamps.length] - startTime;
if (t >= 0) {
videoCounter++;
/*if (((i % images.length) != 0) && images[i % images.length] != images[(i % images.length) - 1]) {
if (t > recorder.getTimestamp()) {
recorder.setTimestamp(t);
}*/
Log.v(LOG_TAG, "imageIndex=" + (i % images.length));
recorder.record(images[i % images.length]);
/* }*/
Log.v(LOG_TAG, "videoCounter=" + videoCounter);
}
}
}
firstIndex = samplesIndex % samples.length;
lastIndex = (samplesIndex - 1) % samples.length;
if (samplesIndex <= samples.length) {
firstIndex = 0;
lastIndex = samplesIndex - 1;
}
if (lastIndex < firstIndex) {
lastIndex += samples.length;
}
for (int i = firstIndex; i <= lastIndex; i++) {
if (timestamps[i] != -1) {
recorder.recordSamples(samples[i % samples.length]);
}
}
} catch (FFmpegFrameRecorder.Exception e) {
Log.v(LOG_TAG, e.getMessage());
e.printStackTrace();
}
}
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);
}
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
switch (motionEvent.getAction()) {
case MotionEvent.ACTION_DOWN:
Log.v(LOG_TAG, "ACTION_DOWN" + recording);
if (!recording) {
startRecording();
} else {
stopPauseTime = System.currentTimeMillis();
totalPauseTime = stopPauseTime - startPauseTime - ((long) (1.0 / (double) frameRate) * 1000);
pausedTime += totalPauseTime;
}
rec = true;
setTotalVideoTime();
btnRecorderControl.setText(getResources().getString(R.string.stop));
break;
case MotionEvent.ACTION_MOVE:
rec = true;
setTotalVideoTime();
break;
case MotionEvent.ACTION_UP:
Log.v(LOG_TAG, "ACTION_UP");
rec = false;
startPauseTime = System.currentTimeMillis();
break;
}
return true;
}
private Runnable mUpdateTimeTask = new Runnable() {
public void run() {
if (recording) {
setTotalVideoTime();
}
mHandler.postDelayed(this, 500);
}
};
private synchronized void setTotalVideoTime() {
totalTime = System.currentTimeMillis() - firstTime - pausedTime - ((long) (1.0 / (double) frameRate) * 1000);
if (totalTime > 0)
txtTimer.setText(getRecordingTimeFromMillis(totalTime));
}
private String getRecordingTimeFromMillis(long millis) {
String strRecordingTime = null;
int seconds = (int) (millis / 1000);
int minutes = seconds / 60;
int hours = minutes / 60;
if (hours >= 0 && hours < 10)
strRecordingTime = "0" + hours + ":";
else
strRecordingTime = hours + ":";
if (hours > 0)
minutes = minutes % 60;
if (minutes >= 0 && minutes < 10)
strRecordingTime += "0" + minutes + ":";
else
strRecordingTime += minutes + ":";
seconds = seconds % 60;
if (seconds >= 0 && seconds < 10)
strRecordingTime += "0" + seconds;
else
strRecordingTime += seconds;
return strRecordingTime;
}
//---------------------------------------------
// 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;
ShortBuffer 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);
if (RECORD_LENGTH > 0) {
samplesIndex = 0;
samples = new ShortBuffer[RECORD_LENGTH * sampleAudioRateInHz * 2 / bufferSize + 1];
for (int i = 0; i < samples.length; i++) {
samples[i] = ShortBuffer.allocate(bufferSize);
}
} else {
audioData = ShortBuffer.allocate(bufferSize);
}
Log.d(LOG_TAG, "audioRecord.startRecording()");
audioRecord.startRecording();
/* ffmpeg_audio encoding loop */
while (runAudioThread) {
if (RECORD_LENGTH > 0) {
audioData = samples[samplesIndex++ % samples.length];
audioData.position(0).limit(0);
}
//Log.v(LOG_TAG,"recording? " + recording);
bufferReadResult = audioRecord.read(audioData.array(), 0, audioData.capacity());
audioData.limit(bufferReadResult);
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 && rec) {
Log.v(LOG_TAG, "Recording audio");
if (RECORD_LENGTH <= 0) try {
recorder.recordSamples(audioData);
//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) {
stopPreview();
Camera.Parameters camParams = mCamera.getParameters();
List<Camera.Size> sizes = camParams.getSupportedPreviewSizes();
// Sort the list in ascending order
Collections.sort(sizes, new Comparator<Camera.Size>() {
public int compare(final Camera.Size a, final Camera.Size b) {
return a.width * a.height - b.width * b.height;
}
});
camParams.setPreviewSize(imageWidth, imageHeight);
Log.v(LOG_TAG, "Setting imageWidth: " + imageWidth + " imageHeight: " + imageHeight + " frameRate: " + frameRate);
camParams.setPreviewFrameRate(frameRate);
Log.v(LOG_TAG, "Preview Framerate: " + camParams.getPreviewFrameRate());
mCamera.setParameters(camParams);
List<Camera.Size> videoSizes = mCamera.getParameters().getSupportedVideoSizes();
// Set the holder (which might have changed) again
try {
mCamera.setPreviewDisplay(holder);
mCamera.setPreviewCallback(CameraView.this);
startPreview();
} catch (Exception e) {
Log.e(LOG_TAG, "Could not set preview display in surfaceChanged");
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
try {
mHolder.addCallback(null);
mCamera.setPreviewCallback(null);
} catch (RuntimeException e) {
// The camera has probably just been released, ignore.
}
}
public void startPreview() {
if (!isPreviewOn && mCamera != null) {
isPreviewOn = true;
mCamera.startPreview();
}
}
public void stopPreview() {
if (isPreviewOn && mCamera != null) {
isPreviewOn = false;
mCamera.stopPreview();
}
}
@Override
public void onPreviewFrame(byte[] data, Camera camera) {
if (audioRecord == null || audioRecord.getRecordingState() != AudioRecord.RECORDSTATE_RECORDING) {
startTime = System.currentTimeMillis();
return;
}
if (RECORD_LENGTH > 0) {
int i = imagesIndex++ % images.length;
Log.v(LOG_TAG, "recording:" + recording + "rec:" + rec);
if (recording && rec) {
yuvImage = images[i];
timestamps[i] = 1000 * (System.currentTimeMillis() - startTime);
totalRecordedTS++;
} else {
Log.v(LOG_TAG, "recording is paused");
yuvImage = null;
timestamps[i] = -1;
}
}
/* get video data */
if (yuvImage != null && recording && rec) {
if (data.length != imageWidth * imageHeight) {
Camera.Size sz = camera.getParameters().getPreviewSize();
imageWidth = sz.width;
imageHeight = sz.height;
destWidth = imageHeight;
Log.v(LOG_TAG, "data length:" + data.length);
}
ByteBuffer bb = (ByteBuffer) yuvImage.image[0].position(0); // resets the buffer
int start = 2 * ((imageWidth - destWidth) / 4); // this must be even
for (int row = 0; row < imageHeight * 3 / 2; row++) {
bb.put(data, start, destWidth);
start += imageWidth;
}
}
}
}
@Override
public void onClick(View v) {
if (!recording) {
startRecording();
Log.w(LOG_TAG, "Start Button Pushed");
btnRecorderControl.setText("Stop");
} else {
// This will trigger the audio recording loop to stop and then set isRecorderStart = false;
stopRecording();
Log.w(LOG_TAG, "Stop Button Pushed");
btnRecorderControl.setText("Start");
}
}}
Changes made as per Alex Cohn's suggestions
Suggestion 1 - Estimate average frame rate
public void stopRecording() {
..............................
if (((i % images.length) != 0) && images[i % images.length] != images[(i % images.length) - 1]) {
if (t > recorder.getTimestamp()) {
t += 1000000 / frameRate;
recorder.setTimestamp(t);
}
recorder.record(images[i % images.length]);
}
..........................................
}
Change made was adding t += 1000000 / frameRate; But this caused the video to freeze (as in case 1 described above) in portions when finger was placed away from screen.
Suggestion 2 - Modification in onPreviewFrame()
long[] timestampsForRecorder;
private void initRecorder() {
Log.w(LOG_TAG, "init recorder");
if (RECORD_LENGTH > 0) {
.......................................................
timestampsForRecorder = new long[images.length];
for (int i = 0; i < images.length; i++) {
images[i] = new Frame(destWidth, imageHeight, Frame.DEPTH_UBYTE, 2);
timestamps[i] = -1;
timestampsForRecorder[i] = -1;
}
} else if (yuvImage == null) {
yuvImage = new Frame(destWidth, imageHeight, Frame.DEPTH_UBYTE, 2);
Log.i(LOG_TAG, "create yuvImage");
}
...................................................
}
@Override
public void onPreviewFrame(byte[] data, Camera camera) {
if (audioRecord == null || audioRecord.getRecordingState() != AudioRecord.RECORDSTATE_RECORDING) {
startTime = SystemClock.elapsedRealtime();
return;
}
if (RECORD_LENGTH > 0) {
int i = imagesIndex++ % images.length;
Log.v(LOG_TAG, "recording:" + recording + "rec:" + rec);
if (recording && rec) {
yuvImage = images[i];
long thisFrameTime = SystemClock.elapsedRealtime();
timestamps[i] = thisFrameTime;
long lastFrameTime = timestamps[(int) (imagesIndex == 0 ? startTime : ((imagesIndex-1) % images.length))];
Log.v(LOG_TAG, "lastFrameTime:" + lastFrameTime+",stopPauseTime:" + stopPauseTime);
if (lastFrameTime > stopPauseTime) {
timestampsForRecorder[i] = 1000 * (thisFrameTime - Math.max(stopPauseTime, lastFrameTime));
}
}
}
.....................................................
}
public void stopRecording() {
.......................................................
if (recorder != null && recording) {
if (RECORD_LENGTH > 0) {
Log.v(LOG_TAG, "Writing frames");
try {
int firstIndex = imagesIndex % samples.length;
int lastIndex = (imagesIndex - 1) % images.length;
if (imagesIndex <= images.length) {
firstIndex = 0;
lastIndex = imagesIndex - 1;
}
if ((startTime = timestampsForRecorder[lastIndex] - RECORD_LENGTH * 1000000L) < 0) {
startTime = 0;
}
if (lastIndex < firstIndex) {
lastIndex += images.length;
}
for (int i = firstIndex; i <= lastIndex; i++) {
if (timestampsForRecorder[i] != -1) {
long t = timestampsForRecorder[i % timestampsForRecorder.length] - startTime;
if (t >= 0) {
if (((i % images.length) != 0) && images[i % images.length] != images[(i % images.length) - 1]) {
if (t > recorder.getTimestamp()) {
recorder.setTimestamp(t);
}
Log.v(LOG_TAG, "imageIndex=" + (i % images.length));
recorder.record(images[i % images.length]);
}
}
}
}
.............................................
} catch (FFmpegFrameRecorder.Exception e) {
.................................
}
}
...........................................
}
}
The video recorded using this was having the issue in case 2 mentioned above. ie,It was playing at a faster rate
