Develop Reference

Android force AudioRecord to use headphone mic

I use AudioRecord to record music but when I record it uses the phone mic.
how can I force him to use the channel of the Headphone?
I use this code:
int minSize = AudioRecord.getMinBufferSize(8000, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
AudioRecord ar = new AudioRecord(MediaRecorder.AudioSource.DEFAULT, 8000, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, minSize);
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
recorder[0] = false;
}
}, timeInSecondsToRecord * 1000);
short[] buffer = new short[minSize];
ar.startRecording();
Log.d("Started","Reording");
while (recorder[0]) {
ar.read(buffer, 0, minSize);
for (short s : buffer) {
if (s>1000)
System.out.println("signalVal=" + s);
}
}
Log.d("Finished","Reording");
ar.stop();
Thank you

You can use AudioManager.isWiredHeadsetOn() for checking if the headset are plugged in or not. If the above value is false dont perform any action or whatever you want to do. And also you need permission first: MODIFY_AUDIO_SETTINGS
Hope this helps. :)

I had this problem in reverse (trying to force use of the phone's mic instead of the headphone mic). You can choose a mic by scanning the AudioDeviceInfo array in AudioManager. Here's what I think it would look like for you (if TYPE_LINE_ANALOG doesn't work, check out the AudioDeviceInfo page for more possibilities or debug what devices come up):
AudioRecord audioRecord =
new AudioRecord(...);
// Force use of the line in mic
AudioManager audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
for ( AudioDeviceInfo device : audioManager.getDevices(AudioManager.GET_DEVICES_INPUTS)) {
if ( device.getType() == AudioDeviceInfo.TYPE_LINE_ANALOG) {
audioRecord.setPreferredDevice(device);
break;
}
}

Android real time audio signal processor output does not work

I am currently developing realtime audio DSP app for android... Signal is taken from mic input(on the phone or tablet) processed and then played back....
When my app starts, if mic and headphone jack is pressent, Audio DSP gets intialized.... For the first second there is output from the speakers or headphones, but after that there is just silence and it seems that playback has stopped, but recording still works in background....
I use AudioRecorder class to get RAW audio data and for playback I use AudioTrack....
For now I have the following code(I wish i knew why it is not working) for stream reading from mic and playing back:
public void ProcessAudio(){
_track = new AudioTrack(AudioManager.STREAM_MUSIC, _recorder.getSampleRate(),AudioFormat.CHANNEL_OUT_MONO,_recorder.getAudioFormat(), _bufferSize, AudioTrack.MODE_STATIC);
boolean first=true;
while(_IsRecording){
try {
byte sData[] = new byte[_bufferSize];
_recorder.read(sData, 0, _bufferSize);
//TODO:add audio DSP stuff here
_track.write(sData,0,_bufferSize);
if(first){
first = false;
_track.play();
}
}catch (Exception ex){
Log.e(StaticVars.SOFTWARE_TAG, "Failed:" + ex.getMessage());
}
}
_track.flush();
_track.stop();
_track.release();
}

So.... It turns out that i didn't initialize my AudioTrack correctly... once i changed :
_track = new AudioTrack(AudioManager.STREAM_MUSIC, _recorder.getSampleRate(),AudioFormat.CHANNEL_CONFIGURATION_MONO,_recorder.getAudioFormat(), _bufferSize, AudioTrack.MODE_STATIC);
to:
_track = new AudioTrack(AudioManager.STREAM_MUSIC, _recorder.getSampleRate(),AudioFormat.CHANNEL_CONFIGURATION_MONO,_recorder.getAudioFormat(), _bufferSize, AudioTrack.MODE_STREAM);
it started to work....
Edit:
Beacose of latency in Android the realtime audio processing is not plausible atleast on Android 4.4 and down.

Android Java: how to disable microphone input while streaming system audio?

Basically, my program records user input via the microphone and store it as a .pcm file in the sdcard/ directory. It'll be overwritten should there be an existing one. The file is then later sent for playback and analysis (mainly FFT, RMS computation).
I have added another function which allows the program to record system audio, so it allows user's mp3 files to be analyzed as well. It streams the system audio and store it as a .pcm file for later playback and analysis.
It's all functioning well. However, there's a slight issue, when the program streams audio, it captures input from the mic and there'll be noises in the playback. I do not want this as it'll affect the analysis reading. I googled for a solution and found that I can actually mute the mic. So now, I want to mute the mic when the mp3 file is being streamed.
The code I have found is,
AudioManager.setMicrophoneMute(true);
I tried to implement it but it just crashes my application. I tried to find for solutions these few days but I cannot seem to get any.
Here is my code snippet for the part where I want to stream system audio and muting the microphone before it starts streaming.
//create a new AudioRecord object to record the audio data of an mp3 file
int bufferSize = AudioRecord.getMinBufferSize(frequency, channelConfiguration, audioEncoding);
audioRecord = new AudioRecord(AudioManager.STREAM_MUSIC,
frequency, channelConfiguration,
audioEncoding, bufferSize);
//a short array to store raw pcm data
short[] buffer = new short[bufferSize];
Log.i("decoder", "The audio record created fine ready to record");
try {
audioManager.setMicrophoneMute(true);
} catch (Exception e) {
e.printStackTrace();
}
audioRecord.startRecording();
isDecoding = true;
When the setMicrophoneMute(true) line is surrounded with try-catch, the program would only crash when I want to send the recording for play back. Errors are as follow:
"AudioFlinger could not create track, status: -12"
"Error initializing AudioTrack"
"[android.media.AudioTrack] Error code -20 when initializing AudioTrack."
When it is not surrounded with try-catch, the program would just crash the moment I click on the start streaming button.
"Decoding failed" < this is an error log from catching a throwable.
How can I mute the microphone input while streaming the system audio? Let me know if I can provide you with more codes. Thank you!
**EDIT
I have implemented my mutemicrophone successfully, it even returns me a true for isMicrophoneMute(), however, it's not muted as it still records from the microphone; it's a false true.
Based on the suggested answer, I have already created a class for audio focus as below:
private final Context c;
private final AudioManager.OnAudioFocusChangeListener changeListener =
new AudioManager.OnAudioFocusChangeListener()
{
public void onAudioFocusChange(int focusChange)
{
//nothing to do
}
};
AudioFocus(Context context)
{
c = context;
}
public void grabFocus()
{
final AudioManager am = (AudioManager) c.getSystemService(Context.AUDIO_SERVICE);
final int result = am.requestAudioFocus(changeListener,
AudioManager.STREAM_MUSIC,
AudioManager.AUDIOFOCUS_GAIN);
Log.d("audiofocus","Grab audio focus: " + result);
}
public void releaseFocus()
{
final AudioManager am = (AudioManager) c.getSystemService(Context.AUDIO_SERVICE);
final int result = am.abandonAudioFocus(changeListener);
Log.d("audiofocus","Abandon audio focus: " + result);
}
I then call the method from my Decoder class to request for audio focus:
int bufferSize = AudioRecord.getMinBufferSize(frequency, channelConfiguration, audioEncoding);
audioFocus.grabFocus();
audioRecord = new AudioRecord(AudioManager.STREAM_MUSIC,
frequency, channelConfiguration,
audioEncoding, bufferSize);
//a short array to store raw pcm data
short[] buffer = new short[bufferSize];
Log.i("decoder", "The audio record created fine ready to record");
audioRecord.startRecording();
isDecoding = true;
Log.i("decoder", "Start recording fine");
And then release the focus when stop decoding is pressed:
//stops recording
public void stopDecoding(){
isDecoding = false;
Log.i("decoder", "Out of recording");
audioRecord.stop();
try {
dos.close();
} catch (IOException e) {
e.printStackTrace();
}
mp.stop();
mp.release();
audioFocus.releaseFocus();
}
However, this makes my application crash. Where did I went wrong?

The following snippet requests permanent audio focus on the music audio stream. You should request the audio focus immediately before you begin playback, such as when the user presses play. I think this would be the way to go rather than muting the input microphone. Check out the developer audio focus docs for more information
AudioManager am = mContext.getSystemService(Context.AUDIO_SERVICE);
...
// Request audio focus for playback
int result = am.requestAudioFocus(afChangeListener,
// Use the music stream.
AudioManager.STREAM_MUSIC,
// Request permanent focus.
AudioManager.AUDIOFOCUS_GAIN);
if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
am.registerMediaButtonEventReceiver(RemoteControlReceiver);
// Start playback.
}

Streaming Audio to a Device via MediaRouter

I want to stream an audio file from my android device to another via the MediaRouter Class. As far as I understood I need the
mediarouter.addCallback(MediaRouter.ROUTE_TYPE_LIVE_AUDIO, mCallback);
function to listen if a connected Device is playing audio. However I'm not sure about that.
My Question is how do I get the audio stream ?

If you play your audio using AudioTrack you need to make sure that the streamType matches the route's streamType. To get the route's streamType, simply do:
private final MediaRouter.Callback mMediaRouterCallback =
new MediaRouter.Callback() {
#Override
public void onRouteSelected(MediaRouter router, MediaRouter.RouteInfo route) {
Log.i(TAG, "streamType = " + route.getPlaybackStream());
}
};
Usually it will be AudioManager.STREAM_MUSIC. So when you initialize your AudioTrack make sure to:
_audioTrack = new AudioTrack(
AudioManager.STREAM_MUSIC,
sampleRate,
channelConfig,
audioFormat,
bufferSize,
mode);

Android - Getting audio to play through earpiece

I currently have code that reads a recording in from the devices mic using the AudioRecord class and then playing it back out using the AudioTrack class.
My problem is that when I play it out it plays via the speaker phone.
I want it to play out via the ear piece on the device.
Here is my code:
public class LoopProg extends Activity {
boolean isRecording; //currently not used
AudioManager am;
int count = 0;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
am = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
am.setMicrophoneMute(true);
while(count <= 1000000){
Record record = new Record();
record.run();
count ++;
Log.d("COUNT", "Count is : " + count);
}
}
public class Record extends Thread{
static final int bufferSize = 200000;
final short[] buffer = new short[bufferSize];
short[] readBuffer = new short[bufferSize];
public void run() {
isRecording = true;
android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);
int buffersize = AudioRecord.getMinBufferSize(11025, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT);
AudioRecord arec = new AudioRecord(MediaRecorder.AudioSource.MIC, 11025, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT, buffersize);
AudioTrack atrack = new AudioTrack(AudioManager.STREAM_MUSIC, 11025, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT, buffersize, AudioTrack.MODE_STREAM);
am.setRouting(AudioManager.MODE_NORMAL,1, AudioManager.STREAM_MUSIC);
int ok = am.getRouting(AudioManager.ROUTE_EARPIECE);
Log.d("ROUTING", "getRouting = " + ok);
setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);
//am.setSpeakerphoneOn(true);
Log.d("SPEAKERPHONE", "Is speakerphone on? : " + am.isSpeakerphoneOn());
am.setSpeakerphoneOn(false);
Log.d("SPEAKERPHONE", "Is speakerphone on? : " + am.isSpeakerphoneOn());
atrack.setPlaybackRate(11025);
byte[] buffer = new byte[buffersize];
arec.startRecording();
atrack.play();
while(isRecording) {
arec.read(buffer, 0, buffersize);
atrack.write(buffer, 0, buffer.length);
}
arec.stop();
atrack.stop();
isRecording = false;
}
}
}
As you can see if the code I have tried using the AudioManager class and its methods including the deprecated setRouting method and nothing works, the setSpeakerphoneOn method seems to have no effect at all, neither does the routing method.
Has anyone got any ideas on how to get it to play via the earpiece instead of the spaker phone?

Just got it to work on 2.2. I still needed the In_Call setup which I don't really like but I'll deal with it for now. I was able to ditch the call routing stuff which is deprecated now. I found you definitely need the Modify_Audio_Settings permission, no error without it but it the setSpeakerPhone method just does nothing. Here is the mock up of the code I used.
private AudioManager m_amAudioManager;
m_amAudioManager = (AudioManager)getSystemService(Context.AUDIO_SERVICE);
m_amAudioManager.setMode(AudioManager.MODE_IN_CALL);
m_amAudioManager.setSpeakerphoneOn(false);

Please use this code, works well:
//PLAY ON EARPIECE
mPlayer.setAudioStreamType(AudioManager.STREAM_VOICE_CALL);
audioManager.setMode(AudioManager.MODE_IN_CALL);
audioManager.setSpeakerphoneOn(false);
//PLAY ON SPEAKER
mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
audioManager.setMode(AudioManager.MODE_IN_CALL);
audioManager.setSpeakerphoneOn(true);

There was some related discussion in this recent question:
Android - can I mute currently playing audio applications?
Based on the AudioManager source code, it seems that you must be in "call mode" before the setSpeakerphoneOn method has any effect.
However, I recently saw an application that could seamlessly switch between earpiece and speakerphone while still showing the current stream as the "media" stream, so I would be interested in any further answers.

Misleaded by some answers here for quite a lot of time. I'm using Android 2.2. "audioManager.setSpeakerphoneOn(false);" is working.
audioManager.setSpeakerphoneOn(false);
...
mediaPlayer.setDataSource(..);
mediaPlayer.setAudioStreamType(AudioManager.STREAM_VOICE_CALL);
mediaPlayer.prepare();

public MediaPlayer m_mpSpeakerPlayer;
private AudioManager m_amAudioManager;
m_amAudioManager = (AudioManager)getSystemService(Context.AUDIO_SERVICE);
// 從Receiver Earpiece發音
m_amAudioManager.setSpeakerphoneOn(false);
m_amAudioManager.setRouting(AudioManager.MODE_NORMAL, AudioManager.ROUTE_EARPIECE, AudioManager.ROUTE_ALL);
Log.i(TAG, String.valueOf(m_amAudioManager.getRouting(AudioManager.ROUTE_EARPIECE)));
setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);
// 把聲音設定成從Earpiece出來
// 重點在這行，要把它設定為正在通話中
m_amAudioManager.setMode(AudioManager.MODE_IN_CALL);
// 開始放音樂
m_mpSpeakerPlayer.reset();
m_mpSpeakerPlayer.setDataSource("sdcard/receiver.mp3");
m_mpSpeakerPlayer.prepare();
m_mpSpeakerPlayer.start();
//最後再把它設定從Speaker放音，達成！
m_amAudioManager.setMode(AudioManager.MODE_NORMAL);

I appear to have got it working on 1.6.
So I said I'd post here how I done it.
To get it working in 1.6 I:
Used the AudioManager class to set setSpeakerphoneOn(false), I then used the Voice_Call_Stream and add volume control to the Voice_Call_Stream.
The setSpeakerphoneOn(false) method is used in onCreate() of the activity and this appears to route to the headset, I then used a button and used the setSpeakerphoneOn(true) method and the audio gets routed to the speaker.
The method only appears to work when it is used in onCreate() for me and I haven't tested it extensively but for the moment it allows me to switch between headset and speaker on a 1.6 device

now in 2022 in Android S (12, API31) setSpeakerphoneOn(false) isn't working reliablie, it is in fact deprecated! instead we can use new API and setCommunicationDevice(AudioDeviceInfo) method. (works with AudioManager.STREAM_VOICE_CALL)
some sample
Boolean result = null;
ArrayList<Integer> targetTypes = new ArrayList<>();
if (earpieceMode) {
targetTypes.add(AudioDeviceInfo.TYPE_BUILTIN_EARPIECE);
} else { // play out loud
targetTypes.add(AudioDeviceInfo.TYPE_BUILTIN_SPEAKER);
}
AudioDeviceInfo currentDevice = audioManager.getCommunicationDevice();
if (currentDevice!=null) {
for (Integer targetType : targetTypes) {
if (targetType == currentDevice.getType()) {
Log.i("AUDIO_MANAGER", "setCommunicationDevice targetType ALREADY SET UP!!");
result = true;
break;
}
}
}
if (result == null) {
List<AudioDeviceInfo> devices = audioManager.getAvailableCommunicationDevices();
outer:
for (Integer targetType : targetTypes) {
for (AudioDeviceInfo device : devices) {
if (device.getType() == targetType) {
result = audioManager.setCommunicationDevice(device);
Log.i("AUDIO_MANAGER", "setCommunicationDevice type:" + targetType + " result:" + result);
if (result) break outer;
}
}
}
}
if (result == null) {
Log.i("AUDIO_MANAGER", "setCommunicationDevice targetType NOT FOUND!!");
}
else if (!result) {
Log.i("AUDIO_MANAGER", "setCommunicationDevice targetType FAILED TO SET!!");
}

If the ear piece is connected to the phone with bluetooth (which I assume it is), have you tried calling AudioManager.setBluetoothScoOn(true)?
I've been through the Android reference and this is the only thing I could find that you didn't mention trying.