IllegalStateException when calling AudioRecord.start() - android

I'm using AudioRecorder to record short audio clips but I'm getting IllegalStateException when calling AudioRecord.start() I've been looking for hours but can't find the cause of this...
I've set Audio Rec + Write External Storage permissions.
Here's a piece of my code:
// main activity...
// Audio inits
final MediaRecorder recorder = new MediaRecorder();
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recorder.setOutputFile(getTempPath());
...
// called the sound rec async
new SoundComponent(tvmic, pb, tb).execute(recorder);
// SoundComponent.java
// Getting IllegalStateException when calling recorder[0].start();
[..]
protected Long doInBackground(MediaRecorder... recorder) {
try {
recorder[0].prepare();
} catch (IOException e) {
Log.e("100", "prepare() failed");
}
while (tb.isChecked())
{
//publishProgress();
//recorder[0].prepare();
recorder[0].start(); // here it were it throws
try {
Thread.sleep(250);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// int amplitude = recorder[0].getMaxAmplitude();
recorder[0].stop();
}
// TODO Auto-generated method stub
return null;
}
[..]
public String getTempPath() // audio temp path
{
String path = Environment.getExternalStorageDirectory().getAbsolutePath();
path+="/temp/audiorectemp.3gp";
return path;
}

Starting and stopping the MediaRecorder multiple times in a loop probably isn't a good idea. Look closely at what you're doing, I've trimmed your code to make it easier to see...
while (tb.isChecked())
{
recorder[0].start(); // here it were it throws
// Sleep here
recorder[0].stop();
}
It probably isn't throwing an exception the first time you call start() but it will on the second loop. See the state machine diagram...MediaRecorder
Also, to detect when the doInBackground(...) thread should be exited, ther is a method on AsyncTask which can be called from the UI thread to cancel it.
The loop should ideally be while (!isCancelled()) and you should call the AsyncTask.cancel(...) method from the onCheckedChanged listener of tb in the main Activity code (assuming tb is a CheckBox or some other CompoundButton).

Related

How to trigger Vibration on Sound Input?

I am trying to create an android application where I filter one specific frequency of a beep and make the phone vibrate.
I am taking input from the MIC of mobile and using MediaRecorder class, by using this class, I can record, save and play the input. Now I need my mobile to vibrate whenever there is a beep/or any sound.
The input is given by a wire to the Headphone jack of the mobile so I know that there is only one frequency being input.
I have a button, Clicking which starts recording.
I have Permissions to vibrate and record in my manifest file already.
record.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
isRecording=true;
myAudioRecorder.prepare();
myAudioRecorder.start();
...
}
I also tried to search the internet and found kind of the similar question here but I am unable to find any correct answer.
However, I can make the phone vibrate on clicking another button and here is the snipt of code,
Vibrator vibrate;
vibrate = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
Btn1.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v) {
vibrate.vibrate(800);
}
}
I tried calling a Vibrator inside recorder.start(); function but this makes the phone vibrate even when there is no sound anymore.
I also tried getting help from this question so whenever there is silence, the phone should not vibrate, but I am getting confused, I somehow understand that there should be a Boolean which gets true when there is sound and make the phone vibrate, but I am unable to put this logic into code.
Please let me know what can I do in this context and which direction should I be searching in?
UPDATE
I found this toturial for showing the progress bar with amplitude of input sound, it works fine and I tried to make the phone vibrate when there is some value in buffer, Now it vibrates even when the amplitude is zero, I guess thats because of the fact that every vibration makes noise which leads the phone to vibrate. I am unable to check the function via TOAST because of java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare(). Is there any suggestion?
For your main problem, maybe you can check for the amplitude of the sound, and only vibrate if a minimum threshold has been reached. Something like this:
private class DetectAmplitude extends AsyncTask<Void, Void, Void> {
private MediaRecorder mRecorder = null;
private final static int MAX_AMPLITUDE = 32768;
//TODO: Investigate what is the ideal value for this parameter
private final static int MINIMUM_REQUIRED_AVERAGE = 5000;
#Override
protected Void doInBackground(Void... params) {
Boolean soundStarted = true;
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("/dev/null");
try {
mRecorder.prepare();
} catch (IllegalStateException e) {
soundStarted = false;
Log.e(TAG, "Could not detect background noise. Error preparing recorder: " + e.getMessage());
} catch (IOException e) {
soundStarted = false;
Log.e(TAG, "Could not detect background noise. Error preparing recorder: " + e.getMessage());
}
try {
mRecorder.start();
} catch (RuntimeException e) {
Log.e(TAG, "Could not detect background noise. Error starting recorder: " + e.getMessage());
soundStarted = false;
mRecorder.release();
mRecorder = null;
}
}
if (soundStarted) {
// Compute a simple average of the amplitude over one
// second
int nMeasures = 100;
int sumAmpli = 0;
mRecorder.getMaxAmplitude(); // First call returns 0
int n = 0;
for (int i = 0; i < nMeasures; i++) {
if (mRecorder != null) {
int maxAmpli = mRecorder.getMaxAmplitude();
if (maxAmpli > 0) {
sumAmpli += maxAmpli;
n++;
}
} else {
return null;
}
try {
Thread.sleep(1000 / nMeasures);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
mRecorder.stop();
mRecorder.release();
mRecorder = null;
final float avgAmpli = (float) sumAmpli / n;
if (avgAmpli > MINIMUM_REQUIRED_AVERAGE) {
//TODO: Vibrate the device here
}
}
return null;
}
}
For more information regarding the detection of sound level, please refer to the following:
android: detect sound level
What does Android's getMaxAmplitude() function for the MediaRecorder actually give me?
Regarding the exception java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare(), that is happening because the Toast needs to run on the main thread of your app. If your Thread code (like an AsyncTask) is inside an Activity, you can try the following:
runOnUiThread(new Runnable() {
#Override
public void run() {
//Call your Toast here
}
});
Otherwise, you need to somehow pass the conclusion of your method to the Activity for it to run the Toast.
EDIT:
If you want to use this from a Button, you could set its OnClickListener on your Activity's onCreate() call and execute the AsyncTask there. For example:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.your_layout);
Button button = (Button)findViewById(R.id.your_button_id);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
new DetectAmplitude().execute(new Void[]{});
}
});
}
I suggest you take a look at how AsyncTask works before using this in production code.
You want to sample the audio, and analyze it immediately.
MediaRecorder seems to high level for this, it only captures to file. You probably want to use AudioRecorder instead, as it gives direct access to the input samples.
In order to detect a specific tone, you can use the Goertzel algorithm on the input samples. Here is a C++ implementation I did years ago that could serve as an example.
In order to detect any sound over a certain threshold, you can use Root Mean Square analysis on the input samples and make it trigger once the loudness reaches your threshold. Here is a Python example that reacts to loud noises from a microphone.
Try this:
Btn1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
v.post(new Runnable() {
#Override
public void run() {
vibrate.vibrate(800);
}
});
}
});
You can try this:
Handler handler;
Runnable r;
handler = new Handler();
r = new Runnable() {
public void run() {
Vibrator vib = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
vib.vibrate(500);
handler.postDelayed(r, 1000);
}
};
handler.post(r);

How to record audio on Android without crash?

I'm developing on a Nitro HD with Gingerbread. I want to record audio and I experience an infinite hang while calling MediaRecorder.stop().
I know that my phone can record sound because I have an application that does it exactly.
I read the book "Android for programmers" from Deitel et al. and there is the example VoiceRecorder in chapter 16. Everything seems fine but the app hangs forever when it calls MediaRecorder.stop(). Also, the resource is not released and I have to reboot the phone to release it.
Here is the part of the code where the calls are done (see Deitel et al., "Android for Programmers", Prentice Hall, 2012, chap 16):
// starts/stops a recording
OnCheckedChangeListener recordButtonListener =
new OnCheckedChangeListener()
{
#Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked)
{
if (isChecked)
{
visualizer.clear(); // clear visualizer for next recording
saveButton.setEnabled(false); // disable saveButton
deleteButton.setEnabled(false); // disable deleteButton
viewSavedRecordingsButton.setEnabled(false); // disable
// create MediaRecorder and configure recording options
if (recorder == null)
recorder = new MediaRecorder(); // create MediaRecorder
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
recorder.setOutputFormat(
MediaRecorder.OutputFormat.THREE_GPP);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
recorder.setAudioEncodingBitRate(16);
recorder.setAudioSamplingRate(44100);
try
{
// create temporary file to store recording
File tempFile = File.createTempFile(
"VoiceRecorder", ".3gp", getExternalFilesDir(null));
// store File as tag for saveButton and deleteButton
saveButton.setTag(tempFile);
deleteButton.setTag(tempFile);
// set the MediaRecorder's output file
recorder.setOutputFile(tempFile.getAbsolutePath());
recorder.prepare(); // prepare to record
recorder.start(); // start recording
recording = true; // we are currently recording
handler.post(updateVisualizer); // start updating view
} // end try
catch (IllegalStateException e)
{
Log.e(TAG, e.toString());
} // end catch
catch (IOException e)
{
Log.e(TAG, e.toString());
} // end catch
} // end if
else
{
recorder.stop(); // stop recording
recorder.reset(); // reset the MediaRecorder
recording = false; // we are no longer recording
saveButton.setEnabled(true); // enable saveButton
deleteButton.setEnabled(true); // enable deleteButton
recordButton.setEnabled(false); // disable recordButton
} // end else
} // end method onCheckedChanged
}; // end OnCheckedChangedListener
In a debug session, the "else" scope is entered but it hangs on its first (stop()) line.
I repeat, I know the phone and its OS are correct because another app works correctly. So, do you have any idea on how to solve this problem, a work around maybe?
Thanks!
EDIT When the recorder is started(), there is a handler that is executed at each 50ms to display a graph of the amplitude of the sound. The method recorder.getMaxAmplitude() always returns 0. Maybe this is the symptom of a badly initialized MediaRecorder?
The argument of setAudioEncodingBitRate() might be too low.
what is good setAudioEncodingBitRate on record voice
Hope that's help.
You could have a null recorder at that spot. You're not creating a new MediaRecorder() if you enter the else case of isChecked.
So, 2 things:
The API docs state that if you call stop() before start you'll throw a RuntimeException And if you fail to record anything you'll throw an IllegalStateException.
Check recorder before calling stop:
if (recorder != null) {
recorder.stop();
// some recorder stuff here
}

nulll pointer exception for pause method in Mediaplayer for android

I keep getting null pointer exceptions for methods of MediaPlayer. I was finally able to get the play function to work by moving the code for play and initialize of play functions into a separate method and call that method from inside the onClick listener.
However am still getting null pointer exception for the apps pause function. I am using pause method of media player. How to the get pause to work? I think the problem is somewhere in the structure of my code and how it is organized.
I tried moving the initialization of the Media player to a different place in the code. and and nothing seems to work. Any ideas?
// onclick listener for the playing the selected song
playB.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
playSong();
}
});
// onclick listener for pausing the song that is playing
pauseB.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
pauseSong();
}
});
// method to pause song
public void pauseSong(){
player.pause();
length = player.getCurrentPosition();
}
// method to play song and initialize the MediaPlayer class with one file
// from the drawable folder, need to initialize with something or it will be null
// for that i decided to use an mp3 in R.raw folder
public void playSong(){
// Play song
MediaPlayer player = MediaPlayer.create(this, R.raw.g2);
player.reset();
try {
player.setDataSource(selectedAudioPath);
player.prepare();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
player.seekTo(length);
player.start();
} // play method
You have to make a MediaPlayer player global variable. player is not visible for the pauseSong() method therefore you have nullPointerException. Create a MediaPlayer player in your main class and then in onPlaySong() initialize it only like this:
player = MediaPlayer.create(this, R.raw.g2);

Is there an Eclipse project example of a soundboard using only one mediaplayer

I have been trying to develop an Andriod app of a simple sound board, which will play several long sounds, and only one at a time, not simultaneously. I can easily do a soundboard that uses repetitive code and many mediaplayers, but that will likely crash many devices due to allocating too many instances of MediaPlayer. I want to use a map so that I only use one mediaplayer, but after several hours, I’m still having compile problems. I could also use the App Inventor at MIT, but I don’t think I could upload that to market place without extensive key/signing hacks, so I don’t think that is a good option.
Does anyone know if there a working code example with just a couple of sounds that use just 1 mediaplayer included with the SDK, or available online? If I could start with just a basic working design, it would save me so much time.
My code looks like the below:
public class newBoard extends Activity {
int selectedSoundId;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
*//below line causes an error due to use of "newboard"*
setContentView(R.layout.newboard);
final MediaPlayer player = new MediaPlayer();
final Resources res = getResources();
//just keep them in the same order, e.g. button01 is tied to backtoyou
final int[] buttonIds = { R.id.button01, R.id.button02, R.id.button03,
R.id.button04, R.id.button05, R.id.button06,
R.id.button07, R.id.button08, R.id.button09,
R.id.button10, R.id.button11, R.id.button12,
R.id.button13, R.id.button14, R.id.button15,
R.id.button16, R.id.button16, R.id.button17,
R.id.button18, R.id.button19, R.id.button20,
R.id.button21, R.id.button22, R.id.button23,
R.id.button24, R.id.button25 };
final int[] soundIds = { R.raw.sound01, R.raw.sound02, R.raw.sound03,
R.raw.sound04, R.raw.sound05, R.raw.sound06,
R.raw.sound07, R.raw.sound08, R.raw.sound09,
R.raw.sound10, R.raw.sound11, R.raw.sound12,
R.raw.sound13, R.raw.sound14, R.raw.sound15,
R.raw.sound16, R.raw.sound16, R.raw.sound17,
R.raw.sound18, R.raw.sound19, R.raw.sound20,
R.raw.sound21, R.raw.sound22, R.raw.sound23,
R.raw.sound24, R.raw.sound25 };
View.OnClickListener listener = new View.OnClickListener() {
public void onClick(View v) {
//find the index that matches the button's ID, and then reset
//the MediaPlayer instance, set the data source to the corresponding
//sound effect, prepare it, and start it playing.
for(int i = 0; i < buttonIds.length; i++) {
if(v.getId() == buttonIds[i]) {
selectedSoundId = soundIds[i];
AssetFileDescriptor afd = res.openRawResourceFd(soundIds[i]);
player.reset();
try {
player.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
player.prepare();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
player.start();
break;
}
}
}
};
//set the same listener for every button ID, no need
//to keep a reference to every button
for(int i = 0; i < buttonIds.length; i++) {
Button soundButton = (Button)findViewById(buttonIds[i]);
registerForContextMenu(soundButton);
soundButton.setOnClickListener(listener);
}
}
}
I have only one error:
newboard cannot be resolved, or is not a field Type: Java problem
A nice project download that could be used as a foundation would be optimal, if that exists!
Thanks in advance for any guidance!
Maytag87
The error means that it can't find your layout XML file.
Does the file /res/layout/newboard.xml exist in your Eclipse project? Perhaps the layout is called something else, like main.xml, in which case you should use R.layout.main in your Java code when you call setContentView().

MediaRecorder on Android interfeering with other Media Aplications

I am using the MediaRecorder in my app to measure decibel. For this a new MediaRecorder-Object is created once every 10 seconds, it runs for one second during which getMaxAmplitude() is called 10 times and the average is calculated. After this the MediaRecorder object is stopped and deleted.
The Method to start the Recorder looks like this
public boolean start()
{
mRecorder = new MediaRecorder();
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
mRecorder.setOutputFile("/dev/null");
try
{
mRecorder.prepare();
}
catch (IllegalStateException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
return false;
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
return false;
}
catch(Exception e)
{
e.printStackTrace();
return false;
}
mRecorder.start();
mRecorder.getMaxAmplitude();
return true;
}
and the Method to stop looks like this
public void stop()
{
//Log.d("SPLService", "stop()");
mRecorder.stop();
mRecorder.reset();
mRecorder.release();
mRecorder=null;
}
This is pretty much the way the tutorial on the Android Website instructed.
The problem arises when I use this app in parallel with other Apps using Media, like the Mediaplayer on Android. Whenever a sound measurement is taken using my App other media Apps stop or even crash, even though their objects should be independent of mine.
I have tried using AudioRecord instead of MediaRecorder but the interference with other apps was the same.
I guess my question would be: how can I avoid such interference?

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