Android：在藍牙和手機揚聲器之間切換音頻是不一致的

Question

我的要求是根據用戶選擇在藍牙和電話揚聲器之間切換音頻。 以下是代碼段：

//AudioTrack for incoming audio to play as below:

    int mMaxJitter = AudioTrack.getMinBufferSize(8000,               AudioFormat.CHANNEL_OUT_MONO,AudioFormat.ENCODING_PCM_16BIT);                                  
    new AudioTrack(AudioManager.STREAM_VOICE_CALL,8000,
           AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT,
           mMaxJitter, AudioTrack.MODE_STREAM);


//To register broadcast receiver for bluetooth audio routing
    IntentFilter ifil = new IntentFilter();
    ifil.addAction(AudioManager.ACTION_SCO_AUDIO_STATE_UPDATED);
    this.registerReceiver(<receiver instance>,ifil);

//To get AudioManager service
    AudioManager mAudioManager = (AudioManager)getSystemService(Context.AUDIO_SERVICE);

//Whenever user select to route audio to Bluetooth
    mAudioManager.setMode(AudioManager.MODE_IN_CALL);//tried setting with other mode also viz. MODE_NORMAL, MODE_IN_COMMUNICATION but no luck
    mAudioManager.startBluetoothSco();//after this I get AudioManager.SCO_AUDIO_STATE_CONNECTED state in the receiver
    mAudioManager.setBluetoothScoOn(true);
    mAudioManager.setSpeakerphoneOn(false);

//Whenever user select to route audio to Phone Speaker
    mAudioManager.setMode(AudioManager.MODE_NORMAL);
    mAudioManager.stopBluetoothSco();//after this I get      AudioManager.SCO_AUDIO_STATE_DISCONNECTED state in the receiver
    mAudioManager.setBluetoothScoOn(false);
    mAudioManager.setSpeakerphoneOn(true);

問題：1。我能夠路由音頻，但行為不一致，有時它會路由到手機揚聲器，即使用戶選擇路由到藍牙（藍牙連接）2。如果音頻路由到手機揚聲器，音量會變低（請不要說檢查手機音量）3。根據我的選擇，我只能觀察幾次音頻路由是否合適，如果我重復它就像我上面提到的那樣變得怪異。

Android版：Jellybean 4.3

有沒有人遇到類似的行為？

謝謝！

Answer 1

我得到了音頻路由不一致的原因，這是因為我設置了手機揚聲器假，我也使用了不合適的模式...下面的組合對我有用：

//For BT
mAudioManager.setMode(AudioManager.MODE_IN_COMMUNICATION);
mAudioManager.startBluetoothSco();
mAudioManager.setBluetoothScoOn(true);

//For phone ear piece
mAudioManager.setMode(AudioManager.MODE_IN_COMMUNICATION);
mAudioManager.stopBluetoothSco();
mAudioManager.setBluetoothScoOn(false);
mAudioManager.setSpeakerphoneOn(false);

//For phone speaker(loadspeaker)
mAudioManager.setMode(AudioManager.MODE_NORMAL);
mAudioManager.stopBluetoothSco();
mAudioManager.setBluetoothScoOn(false);
mAudioManager.setSpeakerphoneOn(true);

Android版：4.3

謝謝！

Answer 2

如果它仍然與某人相關，這是我的解決方案：

（在三星s7 sm-g9307上測試，安卓版6.0.1）

public class AudioSourceUtil {

private static void reset(AudioManager audioManager) {
    if (audioManager != null) {
        audioManager.setMode(AudioManager.MODE_NORMAL);
        audioManager.stopBluetoothSco();
        audioManager.setBluetoothScoOn(false);
        audioManager.setSpeakerphoneOn(false);
        audioManager.setWiredHeadsetOn(false);
    }
}

public static void connectEarpiece(AudioManager audioManager) {
    reset(audioManager);
    audioManager.setMode(AudioManager.MODE_IN_COMMUNICATION);
}

public static void connectSpeaker(AudioManager audioManager) {
    reset(audioManager);
    audioManager.setSpeakerphoneOn(true);
}

public static void connectHeadphones(AudioManager audioManager) {
    reset(audioManager);
    audioManager.setWiredHeadsetOn(true);
}

public static void connectBluetooth(AudioManager audioManager) {
    reset(audioManager);
}

}

通過單擊按鈕（標簽布局中的選項卡）進行使用：

/**
 * There are 3 scenarios for the audio source:
 * 1. No headphones and no bluetooth device: toggle phone/ speaker
 * 2. Headphones connected: toggle headphones/ speaker
 * 3. Bluetooth connected: toggle  phone/ speaker/ bluetooth
 *
 * @param tab
 */
private void handleTabAudioSourceClick(TabLayout.Tab tab) {
    View view = tab.getCustomView();
    ImageView icon = (ImageView) view.findViewById(R.id.imageViewIcon);
    int currentAudioSourceIdentifier = (Integer) view.getTag();

    if (audioManager.isWiredHeadsetOn() == false && BluetoothManager.isBluetoothHeadsetConnected() == false) {
        // No headphones and no bluetooth device: toggle phone/ speaker.
        if (currentAudioSourceIdentifier == R.drawable.tab_speaker) {
            // Current audio source is earpiece, moving to speaker.
            view.setTag(android.R.drawable.stat_sys_speakerphone);
            icon.setImageResource(android.R.drawable.stat_sys_speakerphone);
            AudioSourceUtil.connectSpeaker(audioManager);
        } else {
            // Current audio source is speaker, moving to earpiece.
            view.setTag(R.drawable.tab_speaker);
            icon.setImageResource(R.drawable.tab_speaker);
            AudioSourceUtil.connectEarpiece(audioManager);
        }
    } else if (audioManager.isWiredHeadsetOn()) {
        // Headphones connected: toggle headphones/ speaker.
        if (currentAudioSourceIdentifier == android.R.drawable.stat_sys_speakerphone) {
            // Current audio source is speaker, moving to headphones.
            view.setTag(android.R.drawable.stat_sys_headset);
            icon.setImageResource(android.R.drawable.stat_sys_headset);
            AudioSourceUtil.connectHeadphones(audioManager);
        } else {
            // Current audio source is headphones, moving to speaker.
            view.setTag(android.R.drawable.stat_sys_speakerphone);
            icon.setImageResource(android.R.drawable.stat_sys_speakerphone);
            AudioSourceUtil.connectSpeaker(audioManager);
        }
    } else if (BluetoothManager.isBluetoothHeadsetConnected()) {
        // Bluetooth connected: toggle  phone/ speaker/ bluetooth.
        if (currentAudioSourceIdentifier == R.drawable.tab_speaker) {
            // Current audio source is earpiece, moving to speaker.
            view.setTag(android.R.drawable.stat_sys_speakerphone);
            icon.setImageResource(android.R.drawable.stat_sys_speakerphone);
            AudioSourceUtil.connectSpeaker(audioManager);
        } else if (currentAudioSourceIdentifier == android.R.drawable.stat_sys_speakerphone) {
            // Current audio source is speaker, moving to bluetooth.
            view.setTag(android.R.drawable.stat_sys_data_bluetooth);
            icon.setImageResource(android.R.drawable.stat_sys_data_bluetooth);
            AudioSourceUtil.connectBluetooth(audioManager);
        } else {
            // Current audio source is bluetooth, moving to earpiece.
            view.setTag(R.drawable.tab_speaker);
            icon.setImageResource(R.drawable.tab_speaker);
            AudioSourceUtil.connectEarpiece(audioManager);
        }
    }
}

Answer 3

使用MediaRouter api： https ： //developer.android.com/guide/topics/media/mediarouter

它專為此而設計。 像這樣的東西：

mediaRouter = MediaRouter.getInstance(VideoCallingApp.getContext());
mediaRouteSelector = new MediaRouteSelector.Builder()
            .addControlCategory(MediaControlIntent.CATEGORY_LIVE_AUDIO)
            .build();
....

public void onStart() {
    mediaRouter.addCallback(mediaRouteSelector, mMediaRouterCallback,
            MediaRouter.CALLBACK_FLAG_REQUEST_DISCOVERY);
    super.onStart();
}

@Override
public void onStop() {
    mediaRouter.removeCallback(mMediaRouterCallback);
    super.onStop();
}

...當你想切換音頻設備時，請使用mediaRouter.getRoutes（）和mediaRouter.selectRoute（route）API。