我目前正在尝试将直播麦克风音频从Android设备流式传输到Java程序。我首先在两个Android设备之间发送实时音频,以确认我的方法正确。在接收设备上几乎没有任何延迟地可以完美地听到音频。接下来,我将相同的音频流发送到一个小型Java程序,并验证了数据也已正确发送到此处。现在,我想要做的是对这些数据进行编码,并以某种方式在运行Java程序的服务器上对其进行回放。我宁愿在使用HTML5或JavaScript的网络浏览器中播放它,但可以使用VLC等替代方法。
这是发送实时麦克风音频的Android应用的代码
public class MainActivity extends Activity { private Button startButton,stopButton; public byte[] buffer; public static DatagramSocket socket; AudioRecord recorder; private int sampleRate = 44100; private int channelConfig = AudioFormat.CHANNEL_CONFIGURATION_MONO; private int audioFormat = AudioFormat.ENCODING_PCM_16BIT; int minBufSize = AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat); private boolean status = true; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); startButton = (Button) findViewById (R.id.start_button); stopButton = (Button) findViewById (R.id.stop_button); startButton.setOnClickListener(startListener); stopButton.setOnClickListener(stopListener); minBufSize += 2048; } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); return true; } private final OnClickListener stopListener = new OnClickListener() { @Override public void onClick(View arg0) { status = false; recorder.release(); Log.d("VS","Recorder released"); } }; private final OnClickListener startListener = new OnClickListener() { @Override public void onClick(View arg0) { status = true; startStreaming(); } }; public void startStreaming() { Thread streamThread = new Thread(new Runnable(){ @Override public void run() { try{ DatagramSocket socket = new DatagramSocket(); Log.d("VS", "Socket Created"); byte[] buffer = new byte[minBufSize]; Log.d("VS","Buffer created of size " + minBufSize); Log.d("VS", "Address retrieved"); recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,sampleRate,channelConfig,audioFormat,minBufSize); Log.d("VS", "Recorder initialized"); recorder.startRecording(); InetAddress IPAddress = InetAddress.getByName("192.168.1.5"); byte[] sendData = new byte[1024]; byte[] receiveData = new byte[1024]; while (status == true) { DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, 50005); socket.send(sendPacket); } } catch(UnknownHostException e) { Log.e("VS", "UnknownHostException"); } catch (IOException e) { Log.e("VS", "IOException"); e.printStackTrace(); } } }); streamThread.start(); } }
这是Java程序读取数据的代码。
class Server { public static void main(String args[]) throws Exception { DatagramSocket serverSocket = new DatagramSocket(50005); byte[] receiveData = new byte[1024]; byte[] sendData = new byte[1024]; while(true) { DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length); serverSocket.receive(receivePacket); String sentence = new String( receivePacket.getData().toString()); System.out.println("RECEIVED: " + sentence); } } }
我知道在将音频发送到Java程序之前,应该先在应用程序端对音频进行编码,但是我不确定在使用AudioRecorder时如何进行编码。我宁愿不使用NDK,因为我没有使用它的经验,也没有时间去学习如何使用它。
所以我解决了我的问题。问题主要在接收方。接收器接收音频流,并将其推送到PC的扬声器。产生的声音仍然很漫长和破碎,但是仍然有效。尝试使用缓冲区大小可以改善这一点。
编辑:您可以使用线程读取音频,以免产生延迟。另外,最好使用16 000的采样大小,因为这样可以进行语音处理。
Android代码:
package com.example.mictest2; import java.io.IOException; import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.InetAddress; import java.net.UnknownHostException; import android.app.Activity; import android.media.AudioFormat; import android.media.AudioRecord; import android.media.MediaRecorder; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class Send extends Activity { private Button startButton,stopButton; public byte[] buffer; public static DatagramSocket socket; private int port=50005; AudioRecord recorder; private int sampleRate = 16000 ; // 44100 for music private int channelConfig = AudioFormat.CHANNEL_CONFIGURATION_MONO; private int audioFormat = AudioFormat.ENCODING_PCM_16BIT; int minBufSize = AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat); private boolean status = true; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); startButton = (Button) findViewById (R.id.start_button); stopButton = (Button) findViewById (R.id.stop_button); startButton.setOnClickListener (startListener); stopButton.setOnClickListener (stopListener); } private final OnClickListener stopListener = new OnClickListener() { @Override public void onClick(View arg0) { status = false; recorder.release(); Log.d("VS","Recorder released"); } }; private final OnClickListener startListener = new OnClickListener() { @Override public void onClick(View arg0) { status = true; startStreaming(); } }; public void startStreaming() { Thread streamThread = new Thread(new Runnable() { @Override public void run() { try { DatagramSocket socket = new DatagramSocket(); Log.d("VS", "Socket Created"); byte[] buffer = new byte[minBufSize]; Log.d("VS","Buffer created of size " + minBufSize); DatagramPacket packet; final InetAddress destination = InetAddress.getByName("192.168.1.5"); Log.d("VS", "Address retrieved"); recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,sampleRate,channelConfig,audioFormat,minBufSize*10); Log.d("VS", "Recorder initialized"); recorder.startRecording(); while(status == true) { //reading data from MIC into buffer minBufSize = recorder.read(buffer, 0, buffer.length); //putting buffer in the packet packet = new DatagramPacket (buffer,buffer.length,destination,port); socket.send(packet); System.out.println("MinBufferSize: " +minBufSize); } } catch(UnknownHostException e) { Log.e("VS", "UnknownHostException"); } catch (IOException e) { e.printStackTrace(); Log.e("VS", "IOException"); } } }); streamThread.start(); } }
Android XML:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context=".MainActivity" > <TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/hello_world" /> <Button android:id="@+id/start_button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@+id/textView1" android:layout_centerHorizontal="true" android:layout_marginTop="130dp" android:text="Start" /> <Button android:id="@+id/stop_button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignLeft="@+id/button1" android:layout_below="@+id/button1" android:layout_marginTop="64dp" android:text="Stop" /> </RelativeLayout>
服务器代码:
package com.datagram; import java.io.ByteArrayInputStream; import java.net.DatagramPacket; import java.net.DatagramSocket; import javax.sound.sampled.AudioFormat; import javax.sound.sampled.AudioInputStream; import javax.sound.sampled.AudioSystem; import javax.sound.sampled.DataLine; import javax.sound.sampled.FloatControl; import javax.sound.sampled.SourceDataLine; class Server { AudioInputStream audioInputStream; static AudioInputStream ais; static AudioFormat format; static boolean status = true; static int port = 50005; static int sampleRate = 44100; public static void main(String args[]) throws Exception { DatagramSocket serverSocket = new DatagramSocket(50005); byte[] receiveData = new byte[1280]; // ( 1280 for 16 000Hz and 3584 for 44 100Hz (use AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat) to get the correct size) format = new AudioFormat(sampleRate, 16, 1, true, false); while (status == true) { DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length); serverSocket.receive(receivePacket); ByteArrayInputStream baiss = new ByteArrayInputStream( receivePacket.getData()); ais = new AudioInputStream(baiss, format, receivePacket.getLength()); // A thread solve the problem of chunky audio new Thread(new Runnable() { @Override public void run() { toSpeaker(receivePacket.getData()); } }).start(); } } public static void toSpeaker(byte soundbytes[]) { try { DataLine.Info dataLineInfo = new DataLine.Info(SourceDataLine.class, format); SourceDataLine sourceDataLine = (SourceDataLine) AudioSystem.getLine(dataLineInfo); sourceDataLine.open(format); FloatControl volumeControl = (FloatControl) sourceDataLine.getControl(FloatControl.Type.MASTER_GAIN); volumeControl.setValue(100.0f); sourceDataLine.start(); sourceDataLine.open(format); sourceDataLine.start(); System.out.println("format? :" + sourceDataLine.getFormat()); sourceDataLine.write(soundbytes, 0, soundbytes.length); System.out.println(soundbytes.toString()); sourceDataLine.drain(); sourceDataLine.close(); } catch (Exception e) { System.out.println("Not working in speakers..."); e.printStackTrace(); } } }
我希望这可以帮助某人节省几个小时的痛苦:)