我正在构建一个应用程序，它需要麦克风来消除来自扬声器的任何声音。看起来这个问题几乎是一个在线阴谋，因为其他有完全相同问题的人在很长一段时间内都没有得到回应。
Android 的原生硬件加速 AcousticEchoCanceler 似乎不适用于大多数设备。在许多设备上进行的测试以及似乎工作的设备包括 Nexus 5 和 Moto X，而几乎所有测试的三星设备都无法消除背景声音。注意：所有测试的手机都返回 trueAcousticEchoCanceler.isAvailable()
但是，必须有一个解决方案，因为诸如 Skype 或 WhatsApp 之类的应用程序似乎会取消其应用程序上下文之外的声音，即扬声器上有呼叫，而麦克风会取消收到的任何反馈。
这个简化的录音应用程序将声音录制到文件中，然后在单击播放时播放。
MainActivity.java
public class MainActivity extends Activity {
Button startRec, stopRec, playBack;
int minBufferSizeIn;
AudioRecord audioRecord;
short[] audioData;
Boolean recording;
int sampleRateInHz = 48000;
private String TAG = "TAG";
/**
* Called when the activity is first created.
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
startRec = (Button) findViewById(R.id.startrec);
stopRec = (Button) findViewById(R.id.stoprec);
playBack = (Button) findViewById(R.id.playback);
startRec.setOnClickListener(startRecOnClickListener);
stopRec.setOnClickListener(stopRecOnClickListener);
playBack.setOnClickListener(playBackOnClickListener);
playBack.setEnabled(false);
startRec.setEnabled(true);
stopRec.setEnabled(false);
minBufferSizeIn = AudioRecord.getMinBufferSize(sampleRateInHz,
AudioFormat.CHANNEL_IN_MONO,
AudioFormat.ENCODING_PCM_16BIT);
audioData = new short[minBufferSizeIn];
audioRecord = new AudioRecord(MediaRecorder.AudioSource.VOICE_COMMUNICATION,
sampleRateInHz,
AudioFormat.CHANNEL_IN_MONO,
AudioFormat.ENCODING_PCM_16BIT,
minBufferSizeIn);
}
OnClickListener startRecOnClickListener
= new OnClickListener() {
@Override
public void onClick(View arg0) {
playBack.setEnabled(false);
startRec.setEnabled(false);
stopRec.setEnabled(true);
Thread recordThread = new Thread(new Runnable() {
@Override
public void run() {
recording = true;
startRecord();
}
});
recordThread.start();
}
};
OnClickListener stopRecOnClickListener
= new OnClickListener() {
@Override
public void onClick(View arg0) {
playBack.setEnabled(true);
startRec.setEnabled(false);
stopRec.setEnabled(false);
recording = false;
}
};
OnClickListener playBackOnClickListener
= new OnClickListener() {
@Override
public void onClick(View v) {
playBack.setEnabled(false);
startRec.setEnabled(true);
stopRec.setEnabled(false);
playRecord();
}
};
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
private void startRecord() {
File file = new File(Environment.getExternalStorageDirectory(), "test.pcm");
try {
FileOutputStream outputStream = new FileOutputStream(file);
BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(outputStream);
DataOutputStream dataOutputStream = new DataOutputStream(bufferedOutputStream);
NoiseSuppressor ns;
AcousticEchoCanceler aec;
if (NoiseSuppressor.isAvailable()) {
ns = NoiseSuppressor.create(audioRecord.getAudioSessionId());
if (ns != null) {
ns.setEnabled(true);
} else {
Log.e(TAG, "AudioInput: NoiseSuppressor is null and not enabled");
}
}
if (AcousticEchoCanceler.isAvailable()) {
aec = AcousticEchoCanceler.create(audioRecord.getAudioSessionId());
if (aec != null) {
aec.setEnabled(true);
} else {
Log.e(TAG, "AudioInput: AcousticEchoCanceler is null and not enabled");
}
}
audioRecord.startRecording();
while (recording) {
int numberOfShort = audioRecord.read(audioData, 0, minBufferSizeIn);
for (int i = 0; i < numberOfShort; i++) {
dataOutputStream.writeShort(audioData[i]);
}
}
audioRecord.stop();
dataOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
void playRecord() {
File file = new File(Environment.getExternalStorageDirectory(), "test.pcm");
int shortSizeInBytes = Short.SIZE / Byte.SIZE;
int bufferSizeInBytes = (int) (file.length() / shortSizeInBytes);
short[] audioData = new short[bufferSizeInBytes];
try {
FileInputStream inputStream = new FileInputStream(file);
BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);
DataInputStream dataInputStream = new DataInputStream(bufferedInputStream);
int i = 0;
while (dataInputStream.available() > 0) {
audioData[i] = dataInputStream.readShort();
i++;
}
dataInputStream.close();
AudioTrack audioTrack = new AudioTrack(
AudioManager.STREAM_MUSIC, sampleRateInHz,
AudioFormat.CHANNEL_OUT_MONO,
AudioFormat.ENCODING_PCM_16BIT,
bufferSizeInBytes,
AudioTrack.MODE_STREAM);
while(audioTrack.getState() != AudioTrack.STATE_INITIALIZED){
}
audioTrack.play();
audioTrack.write(audioData, 0, bufferSizeInBytes);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello_world" />
<Button
android:id="@+id/startrec"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Start Recording Test" />
<Button
android:id="@+id/stoprec"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Stop Recording" />
<Button
android:id="@+id/playback"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Play Back" />
</LinearLayout>
AndroidManfist.xml 权限
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS"/>
<uses-permission android:name="android.permission.RECORD_AUDIO"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
要验证设备是否正常工作，只需在后台播放一些内容，然后单击Start Recording录制一个小扇区，然后单击Stop Recording此时单击Play Back并检查您是否听到背景声音。如果您能听到背景声音，则 AEC 不工作。但是为什么会出现这种不一致，或者我如何实现回声消除（我已经在我的应用程序中使用 WebRTC 在我的应用程序上下文中消除噪音）
任何帮助，将不胜感激 ！