Develop Reference

Android media recording and unhandled events

Hi I am using android with java. I have set up a very simple button which when held down records audio and when released stops recording. I have two questions:
When I run the following implementation of my idea, I get runtime a warning mediarecorder went away with unhandled events every time the button is released. I can't find what is causing this! I see that this has been answered previously on this forum many years ago with the suggestion to add mediaRecorder.update(), but this does not address why the warning is occurring. What does it mean by unhandled events and what could be causing it? I have done nothing different I can see than in the documentation, other than using an onTouchListener...
Second, should I be wary of user's being able to switch on and off the button very rapidly - could this cause runtime problems and should I take steps to guard against this?
The relevant code I use is more-or-less this:
public void set() {
View.OnTouchListener recordOnTouchListener = new View.OnTouchListener() {
#Override
public boolean onTouch(View view, MotionEvent motionEvent) {
switch (motionEvent.getAction()) {
case MotionEvent.ACTION_DOWN:
if (requestMultiplePermissions(Permissions).granted) {
audioSetup();
recordAudio();
}
return true;
case MotionEvent.ACTION_UP:
stopAudio();
return true;
default:
return false;
}
}
binding.addnewvocabRecordVocab.setOnTouchListener(recordOnTouchListener)
}
where
private void audioSetup() {
File filedir = new File(filepath);
if (!filedir.exists()) {filedir.mkdirs();
file = new File(filepath,filename);
if (file.exists()) { file.delete();}
}
public void recordAudio () {
isRecording = true;
if (mediaRecorder != null) {
mediaRecorder.stop();
mediaRecorder.release();
mediaRecorder = null;
}
try {
mediaRecorder = new MediaRecorder();
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mediaRecorder.setOutputFile(file);
mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
mediaRecorder.prepare();
} catch (Exception e) {
e.printStackTrace();
}
mediaRecorder.start();
}
public void stopAudio () {
if (isRecording) {
mediaRecorder.stop();
mediaRecorder.release();
mediaRecorder = null;
isRecording = false;
}
}

This isn't a full answer to my own question, and the question still stands. But after playing with this a while, I have learnt a few lessons.
If the user taps the record button for a second, then mediarecorder.stop() will produce an error if there is not sufficient data recorded. See this. So if one wants to prevent the app from crashing, one needs to wrap mediarecorder.stop() in some catch - as the discussion in the link advises us. In fact, on some shortish taps, the stop method seems to take rather a long time (well over a second), so it might be worth considering disabling the button just before and after the stop method is called.
Another problem with fast repeated tapping is that it seems to keep adding to the main thread queue, which is probably inadvisable. I have found that using an executor thread with submit is a nice way of dealing with this. Schematically we can
public class audioLibrary() {
//or could go directly in main code
ExecutorService executor;
public void onStartRecord() {
if (executor == null) {
this.executor = Executors.newSingleThreadExecutor();
executor.submit(() -> {
//check isRecording and record stuff
});
}
}
public void onStopRecord() {
if (executor != null) {
executor.submit(() -> {
//check isRecording and shut down mediarecorder
//together with catch for onStop.
});
executor.shutdown();
}
}
}
Clearly, one must be a little careful to make sure the thread really does always get shut down.
Curiously, I do not get the `unhandled events' when I do this now...
Maybe someone could expand on this and comment on my code above to see whether they agree with the gist of it, whether it is necessary and on possible improvements.

MediaPlayer: start called in state 0, mPlayer(0x0)

I'm developing a simple music player, but an error appeared sometimes(just one line error):
Error: start called in state 0, mPlayer(0x0)
I have a MusicService for operating something about music. Part of it:
#Override
public void onCreate() {
super.onCreate();
mediaPlayer = new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setOnBufferingUpdateListener(this);
mediaPlayer.setOnPreparedListener(this);
mediaPlayer.setOnCompletionListener(this);
}
...
public void play(String url) {
try {
mediaPlayer.reset();
mediaPlayer.setDataSource(url);
mediaPlayer.prepareAsync();
} catch (Exception e) {
e.printStackTrace();
}
}
...
#Override
public void onPrepared(MediaPlayer mp) {
mp.start();
addTimer();
status = MUSIC_STATUS_PLAYING;
}
When I open a Activity, and bind MusicService, execute play(), the error appeared sometimes.
Any idea?

I had the same issue in Kotlin, and I was able to tackle it.
In my case I added the MediaPlayer.create() inside a Boolean statement, so let's say in fragment 1 I use a Boolean called "globalAudio", I set this Boolean globally true from "MyModel" class, hence it will execute MediaPlayer.create as normal since it is true outside the conditional body. But, if I move to fragment 2 and set the Boolean "globalAudio" to false and when I go back to fragment 1, the Logcat will throw me error "pause called in state 64, mPlayer(0xca47c070)" and "error (-38, 0)", because I am attempting to start the audio without Media.create() being set up.
I attached the problem and the solution below to make the understanding easier for you
Problem
if (MyModel.StaticData.globalAudio) { // A
homeAudio = MediaPlayer.create(requireActivity(), R.raw.background1)
homeAudio.setVolume(MyModel.StaticData.backgroundVolume, MyModel.StaticData.backgroundVolume)
}
if (homeAudio.isPlaying) { // B
homeAudio.pause() // pause
homeAudio.seekTo(0) // set start from 00:00
}
if (!homeAudio.isPlaying) { // C
homeAudio.start() // throws error if A is not executed
}
Solution
//A
homeAudio = MediaPlayer.create(requireActivity(), R.raw.background1)
homeAudio.setVolume(MyModel.StaticData.backgroundVolume, MyModel.StaticData.backgroundVolume)
if (homeAudio.isPlaying) { // B
homeAudio.pause() // pause
homeAudio.seekTo(0) // set start from 00:00
}
if (!homeAudio.isPlaying) { // C
homeAudio.start() // won't throw error because A is always executed
}
Here I provide you a Kotlin code that it can be automatically converted to Java in Android Studio:
var myAudio = MediaPlayer.create(requireActivity(), R.raw.[yourAudio])
myAudio.setVolume([leftChannelInFLoat], [rightChannelInFLoat])
if (myAudio.isPlaying) {
myAudio.pause()
myAudio.seekTo(0)
}
if (!hmyAudio.isPlaying) {
myAudio.start()
}

MediaRecorder causing IllegalStateException

This only happens when a user presses the back button and re-enters the intent. I think the issue is I have a file that starts a MediaRecorder to grab sound, but when the user backs out the MediaRecorder isn't closing or I have a runOnUiThread that might not be closing either when the back button is pressed?
I have the following code which I thought would work:
#Override
public void onBackPressed() {
try {
stop();
} catch (IOException e) {
e.printStackTrace();
}
}
public void stop() throws IOException {
if (mRecorder != null) {
mRecorder.stop();
mRecorder.release();
mRecorder = null;
}
}
The whole class this is in I have in a runOnUiThread block, in
private class CustomSense extends TimerTask {
private String amps;
#Override
public void run() {
runOnUiThread(new Runnable() {
#Override
public void run() {
amps = String.valueOf(sounder.getAmplitude());
soundDisplay.setText(amps);
}
});
}
public String getAmps() {
return amps;
}
}
But maybe I don't quite understand how onBack works or runOnUiThread? I've been going over the documentation for both of those and MediaRecorder so I could easily be missing something in there (note this does not occur when going into another intent and back through, only when pressing the back button and re-starting the intent)
I feel like the issue is I'm not closing either when the back button is pressed and it's trying to run two instances of them causing the IllegalStateException, but I can't figure out how to actually close them when a user presses their phone's back button.
The StackTrace is as follows:
FATAL EXCEPTION: main
Process: PID: 28671
java.lang.RuntimeException: Unable to start activity ComponentInfo{SensorDisplayActivity}: java.lang.IllegalStateException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2671)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2736)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1478)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6154)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:757)
Caused by: java.lang.IllegalStateException
at android.media.MediaRecorder.start(Native Method)
at SoundDetect.start(SoundDetect.java:62)
at SoundDetect.<init>(SoundDetect.java:82)
at SensorDisplayActivity.onCreate(SensorDisplayActivity.java:89)
at android.app.Activity.performCreate(Activity.java:6683)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1140)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2624)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2736) 
at android.app.ActivityThread.-wrap12(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1478) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:154) 
at android.app.ActivityThread.main(ActivityThread.java:6154) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:757)
SoundDetect: 62 is mRecorder.start() in
public void start() throws IOException {
mFileName = Environment.getExternalStorageDirectory().getAbsolutePath();
mFileName += "/null.3gp";
if (mRecorder == null) {
mRecorder = new MediaRecorder();
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
mRecorder.setOutputFile(mFileName);
mRecorder.prepare();
mRecorder.start();
}
}
SoundDetect 82 is just a .start() call

Android MediaPlayer : IllegalStateException when app closes/press back button

Im streaming an mp3 audio from a url by using mediaplayer, Now im able to play music , But when i press back button or close the app, it crashes.
can anyone pls help me to find my mistake.
thank you.
My code is :
private ImageView play, forward, backward;
private MediaPlayer mediaPlayer;
private boolean playing = false;
private ProgressDialog dialog;
private String mp3link;
private SeekBar seekbar;
private Handler handler = new Handler();
private int mediaPos;
private int mediaMax;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final String url ="";
initWidgets();
}
private void initWidgets() {
mp3link = "http://loc8app.com/church/uploads/audio/749928ad6fcb7b1aceefdf03bd7a9465.mp3";
play = (ImageView) findViewById(R.id.control);
seekbar = (SeekBar) findViewById(R.id.seekBar);
// forward = (ImageView) findViewById(R.id.playeer_forward);
// backward = (ImageView) findViewById(R.id.playeer_back);
mediaPlayer = new MediaPlayer();
play.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
playFunction();
}
});
seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
if(mediaPlayer != null && fromUser){
mediaPlayer.seekTo(progress);
}
}
});
}
private void playFunction() {
if (!playing) {
try {
dialog = ProgressDialog
.show(MainActivity.this,
"",
getString(com.root5solutions.music.R.string.buffering),
true);
dialog.setCancelable(true);
dialog.show();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDataSource(mp3link);
mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
#Override
public void onPrepared(MediaPlayer mp) {
play.setBackgroundResource(R.drawable.pause);
playing = true;
//this is new
mediaPos = mp.getCurrentPosition();
mediaMax = mp.getDuration();
seekbar.setMax(mediaMax);
seekbar.setProgress(mediaPos);
//this line is the error
handler.removeCallbacks(moveSeekBarThread);
handler.postDelayed(moveSeekBarThread, 100);
mp.start();
dialog.dismiss();
}
});
mediaPlayer.prepareAsync();
} catch (Exception e) {
e.printStackTrace();
dialog.dismiss();
}
} else {
play.setBackgroundResource(R.drawable.play);
mediaPlayer.stop();
mediaPlayer.release();
playing = false;
}
}
#Override
public void onBackPressed() {
super.onBackPressed();
if (mediaPlayer.isPlaying()) {
mediaPlayer.stop();
mediaPlayer.release();
}
}
private Runnable moveSeekBarThread = new Runnable() {
public void run() {
if (mediaPlayer.isPlaying()) {
int mediaPos_new = mediaPlayer.getCurrentPosition();
int mediaMax_new = mediaPlayer.getDuration();
seekbar.setMax(mediaMax_new);
seekbar.setProgress(mediaPos_new);
handler.postDelayed(this, 1000); // Looping the thread after 1 second
}
}
};
}
Logcat shows :
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.root.music, PID: 26981
java.lang.IllegalStateException
at android.media.MediaPlayer.isPlaying(Native Method)
at com.root.music.MainActivity$4.run(MainActivity.java:132)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5351)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:947)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:742)

The issue appears to be being caused by the moveSeekBarThread Runnable, from which the exception is being raised, continuing to execute after mediaPlayer is released in onBackPressed(). This results in the the isPlaying() method being executed, which as per the documentation will result in an IllegalStateException:
if the internal player engine has not been initialized or has been released.
Looking at moveSeekBarThread, it seems to be configured to reschedule itself endlessly by posting itself back into the handler Handler instance with a delay. This process is not being stopped when the user leaves the activity, which explains why moveSeekBarThread keeps running. So, based on the above, one solution could be to make sure that any instances of moveSeekBarThread in handler's queue are removed before calling mediaPlayer.release() when the user leaves the activity.
You should be able to do that by calling handler.removeCallbacks(moveSeekBarThread); before you call mediaPlayer.release(). For example, as follows:
#Override
public void onBackPressed() {
super.onBackPressed();
handler.removeCallbacks(moveSeekBarThread);
if (mediaPlayer.isPlaying()) {
mediaPlayer.stop();
mediaPlayer.release();
}
}
It should be okay to call it right before mediaPlayer.release(), but I think it's safer to call it regardless of whether mediaPlayer is playing. This way, if the Runnable does get or remain started somehow despite the media player not having being started or having been stopped, the Runnable will still be cleared.
As an aside, while I don't have any experience with MediaPlayer, I happened to notice that the documentation of the release method has the following to say:
It is considered good practice to call this method when you're done using the MediaPlayer. In particular, whenever an Activity of an application is paused (its onPause() method is called), or stopped (its onStop() method is called), this method should be invoked to release the MediaPlayer object, unless the application has a special need to keep the object around. In addition to unnecessary resources (such as memory and instances of codecs) being held, failure to call this method immediately if a MediaPlayer object is no longer needed may also lead to continuous battery consumption for mobile devices, and playback failure for other applications if no multiple instances of the same codec are supported on a device.
So unless there is that special need to keep the media player around in the activity in your case, it might be better to handle the release process (including clearing moveSeekBarThread from handler) in onPause or onStop instead.
Hope that helps!

you are getting IllegalStateException .
Signals that a method has been invoked at an illegal or inappropriate
time .
Call super.onBackPressed(); after if condition
#Override
public void onBackPressed()
{
if (mediaPlayer!= null)
{
if(mediaPlayer.isPlaying())
mediaPlayer.stop();
mediaPlayer.release();
}
super.onBackPressed(); // Call here
}

First you need to understand what illegalStateException means:
According to Android docs:
It Signals that a method has been invoked at an illegal or inappropriate time. In other words, the Java environment or Java application is not in an appropriate state for the requested operation.
have a look at the state diagram of a media player:
https://developer.android.com/images/mediaplayer_state_diagram.gif
Calling setDataSource(FileDescriptor), or setDataSource(String), or setDataSource(Context, Uri), or setDataSource(FileDescriptor, long, long), or setDataSource(MediaDataSource) transfers a MediaPlayer object in the Idle state to the Initialized state.
An IllegalStateException is thrown if setDataSource() is called in any other state.
It is good programming practice to always look out for IllegalArgumentException and IOException that may be thrown from the overloaded setDataSource methods.

Android Camera 2 Api

I have been trying camera2 API. I have downloaded code from
https://developer.android.com/samples/Camera2Video/index.html to learn about how it works. It works fine till I stop recording. When I stop recording it runs following code.
private void stopRecordingVideo() {
// UI
mIsRecordingVideo = false;
mBtn_Video.setText(R.string.record);
// Stop recording
try {
mMediaRecorder.stop();
mMediaRecorder.reset();
}
catch (Exception e) {
e.printStackTrace();
}
Activity activity = getActivity();
if (null != activity) {
System.out.println("file " + getVideoFile(activity));
Toast.makeText(activity, "Video saved: " + getVideoFile(activity),
Toast.LENGTH_SHORT).show();
}
startPreview();
at mMediaRecorder.stop(); it throw following error
01-12 16:24:23.115 2161-2200/com.cameratwoapi E/Surface﹕ queueBuffer: error queuing buffer to SurfaceTexture, -19
01-12 16:24:23.135 2161-2200/com.cameratwoapi E/EGL_emulation﹕ tid 2200: swapBuffers(285): error 0x3003 (EGL_BAD_ALLOC)
01-12 16:24:23.197 2161-2200/com.cameratwoapi E/CameraDeviceGLThread-0﹕ Received exception on GL render thread:
java.lang.IllegalStateException: swapBuffers: EGL error: 0x3003
at android.hardware.camera2.legacy.SurfaceTextureRenderer.checkEglError(SurfaceTextureRenderer.java:487)
at android.hardware.camera2.legacy.SurfaceTextureRenderer.swapBuffers(SurfaceTextureRenderer.java:480)
at android.hardware.camera2.legacy.SurfaceTextureRenderer.drawIntoSurfaces(SurfaceTextureRenderer.java:681)
at android.hardware.camera2.legacy.GLThreadManager$1.handleMessage(GLThreadManager.java:103)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:135)
at android.os.HandlerThread.run(HandlerThread.java:61)
Any Idea what I am doing wrong. I spent few hours but couldn't find any solution.
Edit - I am using geneymotion emulator. The path I am using
file /storage/emulated/0/Android/data/com.gold.cameratwoapi/files/video.mp4
Thanks

My solution is to change void stopRecordingVideo() as following:
private void stopRecordingVideo() {
// UI
mIsRecordingVideo = false;
mButtonVideo.setText(R.string.record);
// Added by Ben Ning, to resolve exception issue when stop recording.
try {
mPreviewSession.stopRepeating();
mPreviewSession.abortCaptures();
} catch (CameraAccessException e) {
e.printStackTrace();
}
// Stop recording
mMediaRecorder.stop();
mMediaRecorder.reset();
}
Key is:
try {
mPreviewSession.stopRepeating();
mPreviewSession.abortCaptures();
} catch (CameraAccessException e) {
e.printStackTrace();
}

private void stopRecordingVideo() {
// UI
mIsRecordingVideo = false;
mButtonVideo.setText(R.string.record);
// Added by Ben Ning, to resolve exception issue when stop recording.
try {
mPreviewSession.stopRepeating();
mPreviewSession.abortCaptures();
} catch (CameraAccessException e) {
e.printStackTrace();
}
// Stop recording
mMediaRecorder.stop();
mMediaRecorder.reset();
Activity activity = getActivity();
if (null != activity) {
Toast.makeText(activity, "Video saved: " + getVideoFile(activity),
Toast.LENGTH_SHORT).show();
}
startPreview();
}
this is working for me.

After calling mMediaRecorder.stop() an IllegalStateException is always thrown. I've noticed that on devices with INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY the CameraDevice changes status to error, immediately calling onError() in the CameraDevice.StateCallback.
In the sample you referenced, onError() closes the camera and finishes the activity, so just change onError() to re-open the camera, like this:
#Override
public void onError(CameraDevice cameraDevice, int error) {
// mCameraOpenCloseLock.release();
// cameraDevice.close();
// mCameraDevice = null;
// Activity activity = getActivity();
// if (null != activity) {
// activity.finish();
// }
closeCamera();
openCamera(mTextureView.getWidth(), mTextureView.getHeight());
}
It'd also be a good idea to put some check in there to make sure that if an error really did happen, that the commented out code gets called instead of entering a loop of trying to open the camera over and over.
Tested on a Moto G 2nd gen, with Android 5.0.2

It depends on what you are doing with the CameraCaptureSession and the MediaRecorder but when you call mMediaRecorder.stop() I think it is destroying the surface used for the camera preview session which causes this error because the documentation says
Once recording is stopped, you will have to configure it again as if it has just been constructed
Therefore if you call PreviewSession.abortCaptures() (mPreviewSession.stopRepeating(); isn't necessary from what I gather) it stops the camera sending output to the recorder surface which will allow you to stop the MediaRecorder without issue.
PreviewSession.abortCaptures(); doesn't instantly stop the camera preview output so you might find you need to call MediaRecorder.stop() in the onClosed() or onReady() method of the CameraCaptureSession.StateCallback

In my case, I use TimerTask and a Handler. There is error direct to the mMediaRecorder.stop(). So I use this method
final Handler mTimerHandler = new Handler(Looper.getMainLooper());
mIsRecordingVideo = false;
// Stop recording
try {
mPreviewSession.stopRepeating();
mPreviewSession.abortCaptures();
} catch (CameraAccessException e) {
e.printStackTrace();
}
try{
Timer timer = new Timer();
TimerTask timerTask = new TimerTask() {
#Override
public void run() {
mTimerHandler.post(new Runnable() {
#Override
public void run() {
mMediaRecorder.stop();
mMediaRecorder.reset();
}
});
}
};
timer.schedule(timerTask,30);
}catch(RuntimeException e){
Log.e("----------------","---->>>>>>>>>"+e);
e.printStackTrace();
}