简易版WoMic（二）

在阅读这篇文章之前，最好可以看一下这篇文章WoMic虚拟麦克风技术剖析。
这篇文章介绍Womic的技术原理，因此这篇文章按照这个技术路线实现简单的WoMic。

WoMic由三个部分进行介绍：
1.虚拟声卡
2.PC端
3.Android 端

虚拟声卡

Womic采用自己开发的虚拟声卡，但是这里我们采用开源的虚拟声卡 Virtual Audio Cables，它是一款免费个人使用的虚拟声卡，它在虚拟麦克风中主要作用就是输入数据并从虚拟麦克中输出声音，应用就可以自由从虚拟声卡中读取数据。

自行从网站上下载并安装，我相信这一点不会难到你，若是安装有问题你回复评论。

Android 端

Android端是用于录制声音的，也就是作为麦克风。Android 采用的AudioTrack获取声音的pcm流，采用的是tcp方式进行传输pcm流，不了解网络传输的可以参考这篇文章Android中socket(tcp|udp)，websocket基本使用。

设置AudioTrack 频率，声道，码率等等，这些必须也pc端保持一致，不然出来的声音会是噪音。

声音采集
下面是声音采集类AudioTrackUtil.class:

public class AudioTrackUtil {AudioRecord mAudioRecord;private Integer mRecordBufferSize;private boolean mWhetherRecord;private void initMinBufferSize() {//获取每一帧的字节流大小mRecordBufferSize = AudioRecord.getMinBufferSize(8000, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_8BIT);}public AudioTrackUtil() {initMinBufferSize();if (mAudioRecord == null) {mAudioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, 8000, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_8BIT, mRecordBufferSize);}}public void startRecord() {mWhetherRecord = true;new Thread(new Runnable() {@Overridepublic void run() {mAudioRecord.startRecording();//开始录制try {byte[] bytes = new byte[mRecordBufferSize];while (mWhetherRecord) {mAudioRecord.read(bytes, 0, bytes.length);//读取流mIAudioCallBack.callBack(bytes);}Log.e("test", "run: 暂停录制");mAudioRecord.stop();//停止录制} catch (Exception e) {e.printStackTrace();mWhetherRecord = false;mAudioRecord.stop();}}}).start();}void stopRecord() {if (mAudioRecord != null) {mAudioRecord.stop();mAudioRecord.release();}}public IAudioCallBack mIAudioCallBack;public interface IAudioCallBack {void callBack(byte[] o);}public void setIAudioCallBackListener(IAudioCallBack audioCallBack) {mIAudioCallBack = audioCallBack;}
}

通过TCP方式发送pcm流
通过Socket类，设置目标IP和Port，通过
socket.getOutputStream().write(msg);
socket.getOutputStream().flush();
进行写数据，并发送到服务端，这里就是pc端。代码如下：

public class MainActivity extends AppCompatActivity {private Button mBtnSendMessage;public Socket socket;private AudioTrackUtil mAudioTrackUtil;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mBtnSendMessage = findViewById(R.id.btn_start_send_message);mAudioTrackUtil = new AudioTrackUtil();final String ip = "192.168.40.57";//10.5.169.16服务端的IP地址;10.5.206.92final int port = 5678;//自己定义个端口号要与服务端匹配。startClient(ip, port);if (ActivityCompat.checkSelfPermission(this, Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED ||ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED ||ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.RECORD_AUDIO,Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE}, 1);}mBtnSendMessage.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (socket == null) {startClient(ip, port);}if (socket.isConnected()) {mAudioTrackUtil.startRecord();mAudioTrackUtil.setIAudioCallBackListener(new AudioTrackUtil.IAudioCallBack() {@Overridepublic void callBack(byte[] o) {sendTcpMessage(o);}});}}});findViewById(R.id.btn_stop_send_message).setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (socket != null) {try {sendTcpMessage("我要结束了".getBytes());socket.close();} catch (IOException e) {e.printStackTrace();}}}});}@Overrideprotected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {super.onActivityResult(requestCode, resultCode, data);mAudioTrackUtil.startRecord();}public void startClient(final String address, final int port) {if (address == null) {return;}if (socket == null) {new Thread(new Runnable() {@Overridepublic void run() {try {Log.i("tcp", "启动客户端");socket = new Socket(address, port);Log.i("tcp", "客户端连接成功");InputStream inputStream = socket.getInputStream();byte[] buffer = new byte[1024];int len = -1;while ((len = inputStream.read(buffer)) != -1) {String data = new String(buffer, 0, len);Log.i("tcp", "收到服务器的数据-------------------:" + data);}Log.i("tcp", "客户端断开连接");} catch (Exception EE) {EE.printStackTrace();Log.i("tcp", "客户端无法连接服务器" + EE.getMessage());} finally {try {if (socket != null) {socket.close();}} catch (IOException e) {e.printStackTrace();}socket = null;}}}).start();}}public void sendTcpMessage(final byte[] msg) {if (socket != null && socket.isConnected()) {new Thread(new Runnable() {@Overridepublic void run() {try {socket.getOutputStream().write(msg);socket.getOutputStream().flush();} catch (IOException e) {e.printStackTrace();}}}).start();}}@Overrideprotected void onDestroy() {super.onDestroy();try {if (socket != null) {socket.close();}} catch (IOException e) {e.printStackTrace();}mAudioTrackUtil.stopRecord();}}

pc端

第一步，获取虚拟声卡，需要设置采样频率，样本位数，声道等，需要和Android的参数一致，不然是噪音。

public class AudioVirtualCableUtile {SourceDataLine auline = null;public AudioVirtualCableUtile() {AudioFormat.Encoding encoding = new AudioFormat.Encoding("PCM_SIGNED");AudioFormat format = new AudioFormat(encoding,8000,16,2,2,8000,true);//编码格式，采样率，每个样本的位数，声道，帧长（字节），帧数，是否按big-endian字节顺序存储DataLine.Info info = new DataLine.Info(SourceDataLine.class, format);try {Mixer.Info[] mixerInfos = AudioSystem.getMixerInfo();Mixer mixer = null;for (int i = 0; i < mixerInfos.length; i++) {System.out.println(mixerInfos[i]);if (mixerInfos[i].getName().equals("CABLE Input (VB-Audio Virtual Cable)")) {mixer = AudioSystem.getMixer(mixerInfos[i]);System.out.println("get successful");}}auline = (SourceDataLine) mixer.getLine(info);auline.open(format);} catch (LineUnavailableException e) {e.printStackTrace();return;} catch (Exception e) {e.printStackTrace();return;}}SourceDataLine getAudioLine() {return auline;}

第二步，获取从Android过来的pcm流，并写入到虚拟声卡中。

private static ServerSocket mServerSocket;private static Socket mSocket;private static AudioVirtualCableUtile pcmUtile = new AudioVirtualCableUtile();public static void main(String args[]) {startServer();}static void startServer() {if (mServerSocket == null) {new Thread(new Runnable() {@Overridepublic void run() {try {mServerSocket = new ServerSocket(5678);System.out.println("tcp connecting");mSocket = mServerSocket.accept();System.out.println("tcp connected");InputStream inputStream = mSocket.getInputStream();byte[] buffer = new byte[1024];int len = -1;
//pcmUtile.getAudioLine().start();while ((len = inputStream.read(buffer)) != -1) {pcmUtile.getAudioLine().write(buffer, 0, len);//写入到虚拟声卡中System.out.println("----" + System.currentTimeMillis());}} catch (IOException e) {e.printStackTrace();try {mSocket.close();mServerSocket.close();} catch (IOException e1) {e1.printStackTrace();}}}}).start();}}
}

运行pc和Android代码，你会发现麦克有音量变化

到此代码基本已经完成，还需要持续优化，本篇文章中的代码纯demo，没有过多考虑，只要功能满足即可。

备注：
需要手动切换虚拟声卡。需要先启动pc端，在启动Android，因为pc端为服务端。