I have a video running in a view.
The video is streamed from a server. The function
public void onBufferingUpdate(MediaPlayer mp, int i)
is being called through out the time the video is streaming. For example, Even if the full video is buffered, while the video is playing, the buffer is getting drained out. So, the function is called. But this is valid only in lower versions of Android. In case of Android version above 4.0, the function is not called after the buffer value reaches 100, i.e., the period when the buffer is being emptied.
Does anyone know if this is a problem with Android or the ME type. What is the workaround one can carry out.?
Related
When I play a sound in my app it comes off as clippy and distorted. Here is a recording: recording.
Here is the sound file as it was uploaded to android studio: success sound cue
Here is the function that calls the sound from the .raw
public void playCorrectAnswerSound() {
final MediaPlayer mp = MediaPlayer.create(this, R.raw.correct);
mp.start();
}
Heres how I call it:
Thread t = new Thread(){
public void run(){
playCorrectAnswerSound();
}
};
t.start()
This is my first time debugging a sound related issue. I don't know what else to include in this post, so if you need more info please say so.
EDIT: I was asked to record more of the distortion. Here it is. Also I should say that after more testing, my physical device lacks the sound distortion while the sound distortion is present on 3 different emulators.
I'm going to say this is stuttering due to underrun (starvation) of the MediaPlayer's internal playback buffer. That is, the MediaPlayer can't supply data fast enough to keep up with the sound hardware (which suggests a severe lack of processing power). If the buffer starves, it'll start to play back old data (because it's a circular buffer). This causes a sharp phase transition, which sounds like a "click". Presumably the MediaPlayer recovers quickly enough that the "correct" sound resumes playing shortly thereafter.
Here is a picture of the spectrum from Audacity. 0-4KHz. The first row is the clean .mp3; the next four rows are the distorted recordings (in no particular order). All rows have been aligned in time, and are roughly the same amplitude. The large vertical stripes in the last four rows represent the distortion/clicks that you hear.
I'm developing an Android video app where I need to get the current frame number of the video being displayed while in pause mode.
I need to send my Server the frame number currently paused in video and get back a list of items regarding that frame/time, right now I'm sending the current paused time in milliseconds, but it doesn't work quite well, because the Server compare the time sent to a specific frame it calculated, based on the time, but sometimes the comparison is not exact.
I know you can get a bitmap from that frame if you use MediaMetaDataRetriever, and I did it but it returns bitmap image and what I need is an index.
I'm using ExoPlayer (I need that feature for MP4 and for HLS, too, if that matters).
Is there a way to get that info from the video?
I post a solution to my problem, In order to get the exact frame time I simply extended MediaCodecVideoTrackRenderer.java class from ExoPlayer library and used the value of lastOutputBufferTimestamp which is in function:
#Override
protected boolean processOutputBuffer(long positionUs, long elapsedRealtimeUs,
MediaCodec codec, ByteBuffer buffer, MediaCodec.BufferInfo bufferInfo, int bufferIndex,
boolean shouldSkip) {
boolean processed = super.processOutputBuffer(positionUs, elapsedRealtimeUs, codec, buffer,
bufferInfo, bufferIndex, shouldSkip);
if (!shouldSkip && processed) {
lastOutputBufferTimestamp = bufferInfo.presentationTimeUs;
}
return processed;
}
It does give me the exact time and not a rounded time from, last say, mPlayer.getDuration() or something like that.
If you have a constant FPS in your video you can calculate that by division and get the number of the frame.
It was simply enough for me to know the exact frame time.
I'm using ExoPlayer version r1.5.3 so I don't know if this solution will work for newer version since code has probably changed.
I am implementing an Application that includes the functionality of saving Recorded Video in to Different Video Files based on a certain amount of Time.
For Achieving that i have implemented a Custom Camera and used the MediaRecorder.stop() and MediaRecorder.start() in a certain Loop.
But this approach is creating a Lag Effect while restarting Media Recorder (Stop and Start). Is it possible to seamlessly Stop and Start Recording using Media Recorder or any Third Party Library ?
Any help is Highly Appreciated.
I believe the best solution to implement chunks recording is to set maximum time in MediaRecorder Object
mMediaRecorder.setMaxDuration(CHUNK_TIME);
then you can attach an info listener, it will intimate you when it will hit maximum chunk time
mMediaRecorder.setOnInfoListener(new MediaRecorder.OnInfoListener() {
#Override
public void onInfo(MediaRecorder mr, int what, int extra) {
if (what == MediaRecorder.MEDIA_RECORDER_INFO_MAX_DURATION_REACHED) {
// restartVideo()
}
}
});
in restartVideo you should firstly clear previous MediaRecorder Object and start video again.
You can create two instances of MediaRecorder which will overlap slightly (i.e. when the stream is close to the end of the first chunk you can prepare and start the second one). It is possible to record 2 video files using 2 MediaRecorders at the same time if they capture only the video. Unfortunately sharing the mic between 2 MediaRecorder instances is not supported.
I try to stream (progressive e.g: http://server.com/video.mp4)
when i use the standard google mediaplayer (VideoView from android package) and register an onBufferingUpdateListener then i get the bufferpercentage that refers to the download state of the hole video. This player has also a loading view where i can see the buffer state.
This bufferpercentage and view shows me how much of the video has been downloaded.
Now when i use the Vitamio player, the onBufferingUpdateListener shows me after a few seconds 99 percent of buffering and there is no loading view too. And when i pause the playback it stops buffering immediately instead of continue buffering like the google videoview does. This is very usefull if you have a slow http stream.
Is there a way to make the vitamio-videoplayer buffer the videofiles in the same way as the google videoplayer does?
thank you
daniel
Sorry i posted that question as wrong user. Here the Answer of what i tried:
VideoView (android default - just plays few video formats) from inside the android.widget and from io.vov.vitamio.widget (vitamio - plays most video formats) package has the same structure. In both you can register an OnBufferingUdateListener that returns the bufferstate in percent:
videoview.setOnBufferingUpdateListener(new io.vov.vitamio.MediaPlayer.OnBufferingUpdateListener() {
public void onBufferingUpdate(io.vov.vitamio.MediaPlayer mp, int i) {
Log.v(TAG, "Buffer percentage done: "+i);
}
});
or with the android default VideoView:
videoview.setOnBufferingUpdateListener(new android.media.MediaPlayer.OnBufferingUpdateListener() {
public void onBufferingUpdate(android.media.MediaPlayer mp, int i) {
Log.v(TAG, "Buffer percentage done: "+i);
}
});
If i use android.widget.VideoView the buffer percentage slowly increases until it reaches 100% - The video file has been downloaded completely. And it continues updating BufferingUpdate when i press the pause button.
When i use io.vov.vitamio.widget.VideoView the percentage reaches 100% within seconds. Then the video starts and the OnBufferingUpdateListener never gets called again (when i call getBufferPercentage it is always at 99 percent. That seems to be the reason). And as i sayed: It seems to stop buffering when i press the pause button.
I think the buffering works different in vitamio. But that's crap. Especially when i stream videos from the web and the video datarate is higher than the download speed i need to prebuffer the video by pressing pause and wait until it has downloaded enough data to watch it smoothly. Hope you got what i mean. thank you
I created a simple application that generates a square wave of given frequency and plays it using AudioTrack in STREAM mode (STREAM_MUSIC). Everything seems to be working fine and the sound plays okay, however when the stream is finished I get messages in the log:
W/AudioTrack( 7579): obtainBuffer() track 0x14c228 disabled, restarting ...
Even after calling the stop() function I still get these.
I believe I properly set the AudioTrack buffer size, based on minimal size required by AudioTrack (in my case 6x1024). I feed it with smaller buffers of 1024 shorts.
Is it okay that I'm getting these and should I leave it like that?
Ok, I think the problem is solved. The error is generated when the buffer is not completely filled with data on time (buffer underrun) . I have no idea what the timeout is but if you experience this make sure that:
You don't call the play method until you have some data in the buffer.
You can generate the data fast enough to beat the timeout.
After you are finished feeding the buffer with data, before you call stop() method, make sure that the "last" buffer was completely filled with data before timeout.
I dealt with the last issue by always waiting a little (until timeout) then sending 1 buffer full of zeroes and finally calling the stop() function.
Keep in mind that you must always send the buffer in smaller chunks, even if you have the big chunk ready. It still bothers me a bit that I'm not 100% sure if that is the right way but the errors are gone so I guess I can live with that :)
I've found that even when the buffer is technically long enough, and filled with bytes, if they aren't properly formatted (audio shorts converted to a byte array) it will still throw you that error.
I was getting that warning when I instantiated the Audiotrack, called audioTrack.play() and there was a slight delay between the play() call and the audioTrack.write(). If I called play() right before write() the warning disappeared.
I've solved by this
if (mAudioTrack.getPlayState()!=AudioTrack.PLAYSTATE_PLAYING)
mAudioTrack.play();
mAudioTrack.write(b, 0, sz * 2);
mAudioTrack.stop();
mAudioTrack.flush();