将数据写入Android音频插孔

Question

我正在从蓝牙耳机的麦克风上录制现场音频，并将其播放到手机的扬声器上。

 int bufferSize = AudioRecord.getMinBufferSize(samplingRate, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
        arec = new AudioRecord(MediaRecorder.AudioSource.VOICE_COMMUNICATION, samplingRate, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSize);
        //STREAM_MUSIC - no sound
        //STREAM_ALARM - beep from phone's speaker
        //STREAM_RING - no sound
        //STREAM_NOTIFICATION - no sound
        //STREAM_SYSTEM - no sound
        //STREAM_VOICE_CALL - plays back on bt headset
        //STREAM_DTMF - sound from loud speaker, not very clear but works for now
        atrack = new AudioTrack(AudioManager.STREAM_VOICE_CALL, samplingRate, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSize, AudioTrack.MODE_STREAM);
        atrack.setPlaybackRate(samplingRate);
        byte[] buffer = new byte[bufferSize];
        arec.startRecording();
        atrack.play();
        while(isRecording) {
            arec.read(buffer, 0, bufferSize);
            atrack.write(buffer, 0, buffer.length);
        }

audioManager.setBluetoothScoOn(true);
    audioManager.startBluetoothSco();
    //works for MODE_IN_COMMUNICATION - however there's a lot of echo when on speaker phone
    //works fine for MODE_IN_CALL
    audioManager.setMode(AudioManager.MODE_IN_CALL);
    //turning speakerphone on causes a lot of disturbance
    //audioManager.setSpeakerphoneOn(true);
    //samplingRate = AudioTrack.getNativeOutputSampleRate(AudioManager.STREAM_VOICE_CALL);
    samplingRate = 16000;

但是，即使我有setSpeakerPhoneon（false）并将耳机插入音频插孔，音频也是从手机本身而不是耳机播放的。我如何克服这一点？把扩音器打开会产生很大的噪音。

我使用16000的采样率，因为不用耳机也能听到。当我使用本地采样率时，我显然只是听到了真正的高频噪声。我怎样才能让这种声音在耳机上播放，而不是在电话扬声器上播放？

Answer 1

对您来说不幸的是，由于不支持显式路由，不支持蓝牙和扬声器设置的组合，这将使您能够使用蓝牙耳机的麦克风，但使用手机的扬声器（耳机/耳机或扬声器）。考虑到许多可能的荒谬组合，我怀疑这是转向更简单API的理由。

您可以尝试调用不推荐的setRouting（）函数，但是这可能会产生意想不到的副作用和/或甚至不能工作，这取决于硬件的能力以及底层子系统/驱动程序中正确管理的情况。