Develop Reference

Audio Routing in tinyAlsa

We are working on Custom Board having Audio Codec, AM/FM Tuner, BT Headset, BT Classic all controlled by I2S peripheral. We wants to route audio from BT Classic to Audio Codec, BT Classic to BT headset and so on.
We were planning to have seperate threads for connecting 2 audio devices. In application space, we will provide seperate device IDs which will indicate what device should play the Audio.
I needs to know how we can create a thread interlinking 2 audio devices? Also, is there any other ways to route various audio devices output to another audio devices?

BluetoothAdapter.getDefaultAdapter().getProfileProxy(this, mScanCallback, BluetoothProfile.A2DP);
BluetoothProfile.ServiceListener mScanCallback = new BluetoothProfile.ServiceListener() {
#Override
public void onServiceConnected(int profile, BluetoothProfile proxy) {
if (profile == BluetoothProfile.A2DP) {
proxy.getConnectedDevices().forEach(device -> {
if (selectedDevice1 != null
&& selectedDevice1.getDeviceMAC().equalsIgnoreCase(device.getAddress())) {
try {
Class clazz = Class.forName("android.bluetooth.BluetoothA2dp");
Method method = clazz.getMethod("setActiveDevice", BluetoothDevice.class);
method.invoke(proxy, device);
} catch (Exception e) {
Log.e("TEST", "", e);
}
}
});
}
}
#Override
public void onServiceDisconnected(int i) {
}
};

App does not connect audio to headphones Sinch App to App (Android)

I created App to App Android Sinch Application. When user on call without headphone its working on speaker but if user connect headphone its not automatically connecting to headphone instead of that i need to manually mute speaker and its connecting to headphone. Please check the code i done.
private void enableSpeaker(boolean enable) {
AudioController audioController = getSinchServiceInterface().getAudioController();
if (enable)
audioController.enableSpeaker();
else
audioController.disableSpeaker();
switchVolume.setImageDrawable(ContextCompat.getDrawable(this, isSpeaker ? R.drawable.ic_speaker : R.drawable.ic_speaker_off));
}
private void setMuteUnmute() {
AudioController audioController = getSinchServiceInterface().getAudioController();
if (isMute) {
audioController.mute();
switchMic.setImageDrawable(ContextCompat.getDrawable(this, R.drawable.ic_mic_off));
} else {
audioController.unmute();
switchMic.setImageDrawable(ContextCompat.getDrawable(this, R.drawable.ic_mic_on));
}
}

I think you enabled Speaker in your onCallEstablished method.
Remove enableSpeaker() method from onCallEstablished method and add enableAutomaticAudioRouting() like below.
For more details check sinch documentation Here
#Override
public void onCallEstablished(Call call)
{
AudioController audioController = getSinchServiceInterface().getAudioController();
audioController.enableAutomaticAudioRouting(true, AudioController.UseSpeakerphone.SPEAKERPHONE_AUTO);
}

Android respond bluetooth audio buttons in car - ExoPlayer

I have made android audio application.
And now some users reporting that app is not responding on media buttons (play, pause, next) when they connected the device via Bluetooth in the car.
At the same time, I tested app with Bluetooth speaker - play/pause button works as needed.
Are there any differences between Bluetooth speaker and Bluetooth radio in the car??? It is very strange
I'm using ExoPlayer and have this code for handling media buttons:
Intent mediaButtonIntent = new Intent(Intent.ACTION_MEDIA_BUTTON, null, getApplicationContext(), MediaButtonReceiver.class);
mSession.setMediaButtonReceiver(PendingIntent.getBroadcast(getApplicationContext(), 0, mediaButtonIntent, 0));
MediaSessionConnector mediaSessionConnector = new MediaSessionConnector(mSession, new DefaultPlaybackController(), false, null);
mediaSessionConnector.setQueueNavigator(new QueueNavigatorAdapter() {
#Override
public void onSkipToPrevious(Player player) {
playPrevious();
}
#Override
public void onSkipToNext(Player player) {
playNext();
}
});
mediaSessionConnector.setPlayer(mPlayer, null);
and
mPlayer.prepare(source);
mSession.setActive(true);
mPlayer.setPlayWhenReady(true);
I know about AudioManager.registerMediaButtonEventReceiver() and handling KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE etc. but I was sure mSession.setMediaButtonReceiver && MediaSessionConnector do it for me.
Maybe I'm wrong and it is not enough?
minSdkVersion 21

As I remember, you need to perform something like this:
if (event.getAction() == KeyEvent.ACTION_DOWN && event.getKeyCode()==25)
based on Bluetooth device you are working with, in this case, Bluetooth radio in the car. You need manual for car radio device.

Android Speech Recognizer with Bluetooth Microphone

I've been writing a chat app to work with bluetooth headsets/earphones.
So far I've been able to record audio files via the mic in a bluetooth headset and
I've been able to get Speech-to-text working with the Android device's built in microphone, using RecogniserIntent etc.
But I can't find a way of getting SpeechRecogniser to listen through the Bluetooth mic.Is it even possible to do so, and if so, how?
Current Device: Samsung Galax
Android Version: 4.4.2
Edit: I found some options hidden in my tablets settings for the Speech Recognizer, one of these is a tick box labeled "use bluetooth microphone" but it seems to have no effect.

Found the answer to my own question so I'm posting it for others to use:
In order to get speak recognition to work with a Bluetooth Mic you first need to get the device as a BluetoothHeadset Object and then call .startVoiceRecognition() on it, this will set the mode to Voice recognition.
Once finished you need to call .stopVoiceRecognition().
You get the BluetoothHeadset as such:
private void SetupBluetooth()
{
btAdapter = BluetoothAdapter.getDefaultAdapter();
pairedDevices = btAdapter.getBondedDevices();
BluetoothProfile.ServiceListener mProfileListener = new BluetoothProfile.ServiceListener() {
public void onServiceConnected(int profile, BluetoothProfile proxy)
{
if (profile == BluetoothProfile.HEADSET)
{
btHeadset = (BluetoothHeadset) proxy;
}
}
public void onServiceDisconnected(int profile)
{
if (profile == BluetoothProfile.HEADSET) {
btHeadset = null;
}
}
};
btAdapter.getProfileProxy(SpeechActivity.this, mProfileListener, BluetoothProfile.HEADSET);
}
Then you get call startVoiceRecognition() and send off your voice recognition intent like so:
private void startVoice()
{
if(btAdapter.isEnabled())
{
for (BluetoothDevice tryDevice : pairedDevices)
{
//This loop tries to start VoiceRecognition mode on every paired device until it finds one that works(which will be the currently in use bluetooth headset)
if (btHeadset.startVoiceRecognition(tryDevice))
{
break;
}
}
}
recogIntent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
recogIntent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
recog = SpeechRecognizer.createSpeechRecognizer(SpeechActivity.this);
recog.setRecognitionListener(new RecognitionListener()
{
.........
});
recog.startListening(recogIntent);
}

Bluetooth SCO fails after incoming call

I am trying to send all the audio of an application via SCO.
I am able to successfully send the audio,
But when an incoming call comes I need to disconnect form SCO so that the application audio will not interfere with the call,
The problem is that, when I try to reroute the audio to SCO after the call, it does not work.
Here is the code I use to send the audio to SCO:
public class BluetoothManager {
// For Bluetooth connectvity
private static String TAG = "BluetoothManager";
private static BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
private static AudioManager aM;
/**
* Set the audio manager of the device.
* #param c: The context this method is called from
*/
public static void setAudioManager(Context c) {
aM = (android.media.AudioManager)c.getSystemService(Context.AUDIO_SERVICE);
}
/**
* Check if a Bluetooth headset is connected. If so, route audio to Bluetooth SCO.
*/
private static void initializeAudioMode(Context context) {
BluetoothProfile.ServiceListener mProfileListener = new BluetoothProfile.ServiceListener() {
public void onServiceConnected(int profile, BluetoothProfile proxy) {
if (profile == BluetoothProfile.HEADSET) {
BluetoothHeadset bh = (BluetoothHeadset) proxy;
List<BluetoothDevice> devices = bh.getConnectedDevices();
if (devices.size() > 0) {
enableBluetoothSCO();
}
}
mBluetoothAdapter.closeProfileProxy(profile, proxy);
}
public void onServiceDisconnected(int profile) {}
};
mBluetoothAdapter.getProfileProxy(context, mProfileListener, BluetoothProfile.HEADSET);
}
/**
* Bluetooth Connectvity
* The following methods are associated with enabling/disabling Bluetooth.
* In the future we may want to disable other sources of audio.
*/
private static void enableBluetoothSCO() {
aM.setMode(AudioManager.MODE_IN_CALL);
aM.startBluetoothSco();
aM.setBluetoothScoOn(true);
}
/** Right now, this simply enables Bluetooth */
#SuppressLint("NewApi")
public static boolean enableBluetooth(Context c) {
// If there is an adapter, enable it if not already enabled
if (mBluetoothAdapter != null) {
if (!mBluetoothAdapter.isEnabled()) {
mBluetoothAdapter.enable();
}
setAudioManager(c);
initializeAudioMode(c);
Log.e(TAG, "SCO: " + aM.isBluetoothScoOn());
Log.e(TAG, "A2DP: " + aM.isSpeakerphoneOn());
return true;
} else {
Log.v(TAG, "There is no bluetooth adapter");
return false;
}
}
/** Right now, this simply disables Bluetooth */
public static void disableBluetooth() {
// If there is an adapter, disabled it if not already disabled
if (mBluetoothAdapter != null) {
if (mBluetoothAdapter.isEnabled()) {
mBluetoothAdapter.disable();
}
} else {
Log.v(TAG, "There is no bluetooth adapter");
}
}
public static void restartBluetooth(){
aM.setMode(AudioManager.MODE_IN_CALL);
}
public static void stopBluetooth(){
aM.setMode(AudioManager.MODE_NORMAL);
}
}
When I call stopBluetooth() correctly the audio of the application is not sent to the headset anymore,
But when I call restartBluetooth() the audio plays NOT form the headset as intended, but from the phone speakers.

Is it possible that the SCO link was brought down after the call ended? If this is the case then the SCO link would also have to be brought up along with routing the audio.
Have you tried calling enableBluetoothSCO() within restartBluetooth()

You probably need to call:
aM.startBluetoothSco();
aM.setBluetoothScoOn(true);
after you set the mode.

inside your restart function initialize everything again, and see if it works. like so:
public static void restartBluetooth(){
enableBluetooth(getApplicationContext());
}
if this works then it means that when the call is ended the last initialization is lost for some reason.

Google Doc say's that
"Phone application always has the priority on the usage of the SCO connection for telephony. If this method is called while the phone is in call it will be ignored. Similarly, if a call is received or sent while an application is using the SCO connection, the connection will be lost for the application and NOT returned automatically when the call ends."
So when call is disconnected you must have to re-establish the connection by calling startBluetoothSco()

For anyone that is still having issues with this, there are a few things that need to be done. The first thing you need to do is to keep track of the phone state. You can see how to do that here:
How to know Phone call has ended?
When the state is idle that means the incoming call has ended. Now if you try to reconnect the bluetooth at this point you'll find it still does not work since it takes a while (roughly 2 seconds) for the call to "release" the bluetooth device.
So you have two option, wait a bit then try to reconnect, or you can add another listener to BluetoothHeadset.ACTION_AUDIO_STATE_CHANGED.
You can then add a global boolean value isIdle that is true when TelephonyManager.CALL_STATE_IDLE or false when TelephonyManager.CALL_STATE_OFFHOOK (Otherwise you'll reconnect to BlueTooth during the incoming call). At this point when BluetoothHeadset.STATE_DISCONNECTED and isIdle is true, then reconnect to Bluetooth.
#Override public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals((BluetoothHeadset.ACTION_AUDIO_STATE_CHANGED))){
int state = intent.getIntExtra(BluetoothHeadset.EXTRA_STATE, BluetoothHeadset.STATE_AUDIO_DISCONNECTED);
switch(state) {
case BluetoothHeadset.STATE_AUDIO_DISCONNECTED:
if (isIdle){
//reconnect bluetooth
}
break;
}
}
if(("OFFHOOK").equals(intent.getStringExtra(TelephonyManager.EXTRA_STATE))) {
isIdle = false;
// turn bluetooth off
}
if(("IDLE").equals(intent.getStringExtra(TelephonyManager.EXTRA_STATE))) {
isIdle = true;
}
}