Android AudioRecord/AudioTrack: Playing recording from buffer

Question

need some help since i can't get a sample to work (check all other questions and googled my ass off, also tried all the solutions i found). i think i have made one or more logical (and ofc some bugs in the code) mistakes.

public class MainActivity extends ActionBarActivity {

private static final String TAG = MainActivity.class.getName();

private AudioTrack track = null;

private static final int SAMPLERATE = 8000; 
private static final int TRACK_CHANNELS = AudioFormat.CHANNEL_OUT_MONO; 
private static final int AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;

byte[] buffer;

private Thread myThread;
private boolean isRunning = false;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    setButtonHandlers();

    enableButton(R.id.btnStartRecording,true);
    enableButton(R.id.btnStopRecording,false);

}

private void enableButton(int id,boolean isEnable){
    ((Button)findViewById(id)).setEnabled(isEnable);
}

private void setButtonHandlers() {
    ((Button)findViewById(R.id.btnStartRecording)).setOnClickListener(btnClick);
    ((Button)findViewById(R.id.btnStopRecording)).setOnClickListener(btnClick);
}

private View.OnClickListener btnClick = new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        switch(v.getId()){
            case R.id.btnStartRecording:{
                isRunning = true;
                runThread(isRunning);
                enableButton(R.id.btnStartRecording,false);
                enableButton(R.id.btnStopRecording, true);
                break;
            }
            case R.id.btnStopRecording:{
                isRunning = false;
                runThread(isRunning);
                enableButton(R.id.btnStartRecording,true);
                enableButton(R.id.btnStopRecording, false);
                break;
            }
        }
    }
};

private void runThread(final boolean flag){
    myThread = new Thread(new Runnable() {
        @Override
        public void run() {
            runRunnable(flag);
        }
    });
    myThread.start();
}

public AudioTrack findAudioTrack (AudioTrack track) {

    int myBufferSize = AudioTrack.getMinBufferSize(SAMPLERATE, TRACK_CHANNELS, AUDIO_ENCODING);

    track = new AudioTrack(AudioManager.STREAM_MUSIC, SAMPLERATE, TRACK_CHANNELS, AUDIO_ENCODING, myBufferSize, AudioTrack.MODE_STREAM);

    return track;
}

public void runRunnable(boolean isRunning){

    if (isRunning == false) {

        if (AudioRecord.STATE_INITIALIZED == recorder.getState()) {
            recorder.stop();
            recorder.release();
        }

        if (AudioTrack.STATE_INITIALIZED == track.getState()) {
            track.stop();
            track.release();
        }
        return;
    }

    recorder = findAudioRecord();

    track = findAudioTrack(track);

    if ((AudioRecord.STATE_INITIALIZED == recorder.getState()) && (AudioTrack.STATE_INITIALIZED == track.getState())) {

        recorder.startRecording();

        recorder.stop();
        recorder.read(buffer, 0, buffer.length);

        track.play();
        track.write(buffer, 0, buffer.length);

        for (int i = 0; i <minBufferSize; i++) {
            Log.d(TAG,"data " + i + " content : " + buffer[i]);
        }

    } 

    return;

}

private static int[] mSampleRates = new int[] { 8000, 11025, 22050, 44100 };
public AudioRecord findAudioRecord() {
    for (int rate : mSampleRates) {
        for (short audioFormat : new short[] { AudioFormat.ENCODING_PCM_8BIT, AudioFormat.ENCODING_PCM_16BIT }) {
            for (short channelConfig : new short[] { AudioFormat.CHANNEL_IN_MONO, AudioFormat.CHANNEL_IN_STEREO }) {
                try {
                    int bufferSize = AudioRecord.getMinBufferSize(rate, channelConfig, audioFormat);

                    if (bufferSize != AudioRecord.ERROR_BAD_VALUE) {
                        AudioRecord recorder = new AudioRecord(MediaRecorder.AudioSource.MIC, rate, channelConfig, audioFormat, bufferSize);

                        if (recorder.getState() == AudioRecord.STATE_INITIALIZED)
                            return recorder;
                    }
                } catch (Exception e) {
                    Log.e(TAG, rate + "Exception, keep trying.",e);
                }
            }
        }
    }
    return null;
}

}

does anybody know and can explain to me why nothing is written inside the buffer?

i had tweaked some code yesterday and got some values inside the buffer but messed up the code today again. still nothing was played yesterday.

thanks a lot in advance for your help!

EDIT:

Okay cool many thanks :> read seems to work properly now.

what do you meant exactly by having isRunning as static member? variable?

public class MainActivity extends ActionBarActivity {

private static final String TAG = MainActivity.class.getName();

private AudioRecord recorder = null;
private AudioTrack track = null;

private static final int SAMPLERATE = 8000; // 44100
private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_MONO; // stereo
private static final int TRACK_CHANNELS = AudioFormat.CHANNEL_OUT_MONO; // stereo
private static final int AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;

private int minBufferSize;
byte[] buffer;

private Thread myThread;
private boolean isRunning = false;

private AudioManager manager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    setButtonHandlers();

    enableButton(R.id.btnStartRecording,true);
    enableButton(R.id.btnStopRecording,false);

    minBufferSize = AudioRecord.getMinBufferSize(SAMPLERATE,RECORDER_CHANNELS,AUDIO_ENCODING);
    buffer = new byte[minBufferSize];

    manager = (AudioManager)this.getSystemService(Context.AUDIO_SERVICE);
    manager.setMode(AudioManager.MODE_NORMAL);
    setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);

}

private void enableButton(int id,boolean isEnable){
    ((Button)findViewById(id)).setEnabled(isEnable);
}

private void setButtonHandlers() {
    ((Button)findViewById(R.id.btnStartRecording)).setOnClickListener(btnClick);
    ((Button)findViewById(R.id.btnStopRecording)).setOnClickListener(btnClick);
}

private View.OnClickListener btnClick = new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        switch(v.getId()){
            case R.id.btnStartRecording:{
                isRunning = true;
                runThread(isRunning);
                enableButton(R.id.btnStartRecording,false);
                enableButton(R.id.btnStopRecording, true);
                break;
            }
            case R.id.btnStopRecording:{
                isRunning = false;
                runThread(isRunning);
                enableButton(R.id.btnStartRecording,true);
                enableButton(R.id.btnStopRecording, false);
                break;
            }
        }
    }
};

private void runThread(final boolean flag){
    myThread = new Thread(new Runnable() {
        @Override
        public void run() {
            runRunnable(flag);
        }
    });
    myThread.start();
}

public AudioTrack findAudioTrack (AudioTrack track) {
    int myBufferSize = AudioTrack.getMinBufferSize(SAMPLERATE, TRACK_CHANNELS, AUDIO_ENCODING);

    if (myBufferSize != AudioTrack.ERROR_BAD_VALUE) {
        track = new AudioTrack(AudioManager.STREAM_MUSIC, SAMPLERATE, TRACK_CHANNELS, AUDIO_ENCODING, myBufferSize, AudioTrack.MODE_STREAM);

        if (track.getState() == AudioTrack.STATE_UNINITIALIZED) {
            Log.e(TAG, "AudioTrack Uninit");
            return null;
        }
    }
    return track;
}

public void runRunnable(boolean isRunning){

    if (isRunning == false) {

        for (int i = 0; i <minBufferSize; i++) {
            Log.d(TAG,"data " + i + " content : " + buffer[i]);
        }

        if (AudioRecord.STATE_INITIALIZED == recorder.getState()) {
            recorder.stop();
            recorder.release();
        }

        if (track != null && AudioTrack.STATE_INITIALIZED == track.getState()) {

            if (track.getPlayState() != AudioTrack.PLAYSTATE_STOPPED) {

                try{
                    track.stop();
                }catch (IllegalStateException e)
                {
                    e.printStackTrace();
                }

            }

            track.release();
            manager.setMode(AudioManager.MODE_NORMAL);
        }
        return;
    }

    recorder = findAudioRecord();
    if (recorder == null) {
        Log.e(TAG, "findAudioRecord error");
        return;
    }

    track = findAudioTrack(track);
    if (track == null) {
        Log.e(TAG, "findAudioTrack error");
        return;
    }
    track.setPlaybackRate(SAMPLERATE);

    if ((AudioRecord.STATE_INITIALIZED == recorder.getState()) && (AudioTrack.STATE_INITIALIZED == track.getState())) {
        recorder.startRecording();
        track.play();

        while (isRunning) {
            recorder.read(buffer, 0, minBufferSize);
            track.write(buffer, 0, buffer.length);
        }

    } else {
        Log.d(TAG, "Init for Recorder and Track failed");
        return;
    }
    return;

}

private static int[] mSampleRates = new int[] { 8000, 11025, 22050, 44100 };
public AudioRecord findAudioRecord() {
    for (int rate : mSampleRates) {
        for (short audioFormat : new short[] { AudioFormat.ENCODING_PCM_8BIT, AudioFormat.ENCODING_PCM_16BIT }) {
            for (short channelConfig : new short[] { AudioFormat.CHANNEL_IN_MONO, AudioFormat.CHANNEL_IN_STEREO }) {
                try {
                    Log.d(TAG, "Attempting rate " + rate + "Hz, bits: " + audioFormat + ", channel: "
                            + channelConfig);
                    int bufferSize = AudioRecord.getMinBufferSize(rate, channelConfig, audioFormat);

                    if (bufferSize != AudioRecord.ERROR_BAD_VALUE) {
                        Log.d(TAG, "Found rate " + rate + "Hz, bits: " + audioFormat + ", channel: "
                                + channelConfig);
                        AudioRecord recorder = new AudioRecord(MediaRecorder.AudioSource.MIC, rate, channelConfig, audioFormat, bufferSize);

                        if (recorder.getState() == AudioRecord.STATE_INITIALIZED)
                            return recorder;
                    }
                } catch (Exception e) {
                    Log.e(TAG, rate + "Exception, keep trying.",e);
                }
            }
        }
    }
    return null;
}
}

working on an audiotrack fix since i get an "Unable to retrieve AudioTrack pointer for write()" error.

EDIT 2:

sorry my answer took so long. so thanks second buffer works great! in case somebody is interested in the code (only tested on nexus 5 but working awesome there):

public class MainActivity extends ActionBarActivity {

private AudioRecord recorder = null;
private AudioTrack track = null;

private static final int SAMPLERATE = 8000;
private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_MONO;
private static final int TRACK_CHANNELS = AudioFormat.CHANNEL_OUT_MONO;
private static final int AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;

private int minBufferSizeRec;
short[] bufferRec;

private Thread myThread;
private boolean isRunning = false;

private AudioManager manager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    setButtonHandlers();

    enableButton(R.id.btnStartRecording,true);
    enableButton(R.id.btnStopRecording,false);

    minBufferSizeRec = AudioRecord.getMinBufferSize(SAMPLERATE,RECORDER_CHANNELS,AUDIO_ENCODING);
    bufferRec = new short[minBufferSizeRec/2];

    manager = (AudioManager)this.getSystemService(Context.AUDIO_SERVICE);
    manager.setMode(AudioManager.MODE_NORMAL);
    setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);

}

private void enableButton(int id,boolean isEnable){
    ((Button)findViewById(id)).setEnabled(isEnable);
}

private void setButtonHandlers() {
((Button)findViewById(R.id.btnStartRecording)).setOnClickListener(btnClick);                        
((Button)findViewById(R.id.btnStopRecording)).setOnClickListener(btnClick);
}

private View.OnClickListener btnClick = new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        switch(v.getId()){
            case R.id.btnStartRecording:{
                isRunning = true;
                runThread(isRunning);
                enableButton(R.id.btnStartRecording,false);
                enableButton(R.id.btnStopRecording, true);
                break;
            }
            case R.id.btnStopRecording:{
                isRunning = false;
                runThread(isRunning);
                enableButton(R.id.btnStartRecording,true);
                enableButton(R.id.btnStopRecording, false);
                break;
            }
        }
    }
};

private void runThread(final boolean flag){
    myThread = new Thread(new Runnable() {
        @Override
        public void run() {
            runRunnable(flag);
        }
    });
    android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);
    myThread.start();
}

public AudioTrack findAudioTrack (AudioTrack track) {
    int myBufferSize = AudioTrack.getMinBufferSize(SAMPLERATE, TRACK_CHANNELS, AUDIO_ENCODING);
    if (myBufferSize != AudioTrack.ERROR_BAD_VALUE) {
        track = new AudioTrack(AudioManager.STREAM_MUSIC, SAMPLERATE, TRACK_CHANNELS, AUDIO_ENCODING, myBufferSize, AudioTrack.MODE_STREAM);

        track.setPlaybackRate(SAMPLERATE);

        if (track.getState() == AudioTrack.STATE_UNINITIALIZED) {
            Log.e(TAG, "AudioTrack Uninitialized");
            return null;
        }
    }
    return track;
}

public void runRunnable(boolean isRunning){
    if (isRunning == false) {
        if (AudioRecord.STATE_INITIALIZED == recorder.getState()) {
            recorder.stop();
            recorder.release();
        }

        if (track != null && AudioTrack.STATE_INITIALIZED == track.getState()) {

            if (track.getPlayState() != AudioTrack.PLAYSTATE_STOPPED) {

                try{
                    track.stop();
                }catch (IllegalStateException e)
                {
                    e.printStackTrace();
                }

            }
            track.release();
            manager.setMode(AudioManager.MODE_NORMAL);
        }
        return;

    } else if (isRunning == true) {

        recorder = findAudioRecord();
        if (recorder == null) {
            Log.e(TAG, "findAudioRecord error");
            return;
        }

        track = findAudioTrack(track);
        if (track == null) {
            Log.e(TAG, "findAudioTrack error");
            return;
        }
        track.setPlaybackRate(SAMPLERATE);

        if ((AudioRecord.STATE_INITIALIZED == recorder.getState()) && (AudioTrack.STATE_INITIALIZED == track.getState())) {

            short[] data = new short[minBufferSizeRec/2];

            recorder.startRecording();
            track.play();

            while (isRunning) {
                recorder.read(bufferRec, 0, (minBufferSizeRec/2));
                for (int i = 0; i < data.length; i++) {
                    data[i] = bufferRec[i];
                }
                track.write(data, 0, data.length);
                bufferRec = new short[minBufferSizeRec/2];
                data = new short[minBufferSizeRec/2];
            }

        } else {
            Log.d(TAG, "Init for Recorder and Track failed");
            return;
        }
        return;

    }
    myThread.interrupt();
}

private static int[] mSampleRates = new int[] { 8000, 11025, 22050, 44100 };
public AudioRecord findAudioRecord() {

    for (int rate : mSampleRates) {
        for (short audioFormat : new short[] { AudioFormat.ENCODING_PCM_8BIT, AudioFormat.ENCODING_PCM_16BIT }) {
            for (short channelConfig : new short[] { AudioFormat.CHANNEL_IN_MONO, AudioFormat.CHANNEL_IN_STEREO }) {
                try {
int bufferSize = AudioRecord.getMinBufferSize(rate, channelConfig, audioFormat);

                    if (bufferSize != AudioRecord.ERROR_BAD_VALUE) {
                        AudioRecord recorder = new AudioRecord(MediaRecorder.AudioSource.MIC, rate, channelConfig, audioFormat, bufferSize);

                        if (recorder.getState() == AudioRecord.STATE_INITIALIZED)
                            return recorder;
                    }
                } catch (Exception e) {
                    Log.e(TAG, rate + "Exception, keep trying.",e);
                }
            }
        }
    }
    return null;
}

}

why are you stoping recording !! – Preethi Rao Apr 17 '15 at 09:27 — Preethi Rao, Apr 17 '15 at 09:27

Preethi Rao · Accepted Answer · 2015-04-17T10:59:17.413

2

Remove stop recording !!

   track.play();

   while(isRunning)
    {
     buffer = new Byte[mBufferSize];

        recorder.read(buffer, 0, buffer.length);


        track.write(buffer, 0, buffer.length);

        for (int i = 0; i <minBufferSize; i++) {
            Log.d(TAG,"data " + i + " content : " + buffer[i]);
        }
}

even if you want stop recording put it after reading..

edited Apr 17 '15 at 10:59

answered Apr 17 '15 at 09:28

Preethi Rao

5,117
1
16
29

Oh well thanks *facepalmmyself. I still don't get why nothing is played back and also the buffer's first 300 entries are always 0. – dmkscr Apr 17 '15 at 09:32
thats because you returning so after reading one set of sample – Preethi Rao Apr 17 '15 at 09:33
keep your isRunning as static member variable.. and when you make it false.. it will automatically comes out of loop – Preethi Rao Apr 17 '15 at 09:39
@dmkscr first entries of samples usually will be 0 – Preethi Rao Apr 17 '15 at 10:16
appreciate it! thank you (: i edited my question with new code. so read into buffer seems now fine. sound is missing – dmkscr Apr 17 '15 at 10:47
yes get an "Unable to retrieve AudioTrack pointer for write()" error thrown. ill try to fix that. – dmkscr Apr 17 '15 at 10:50
i am not sure .. but try initializing new buffer ... dont use the old one – Preethi Rao Apr 17 '15 at 10:58
cause the audiotrack queue up the data and plays accordingly,,, so it never plays data as soon as u submite.. So there might a case where before it reads u might be overriding old data – Preethi Rao Apr 17 '15 at 11:01

score 0 · Answer 2 · edited May 23 '17 at 10:24

0

You need to loop over the recorder input, not just do a one-time read!

Take a look here.

edited May 23 '17 at 10:24

Community

1
1

answered Apr 17 '15 at 09:29

bonnyz

13,458
5
46
70

Android AudioRecord/AudioTrack: Playing recording from buffer

2 Answers2