Develop Reference

Sending a signal from RaspberryPi to Android by Button in Java

I'm making a smart interphone.
If button(raspberryPi) is pressed, smartphone(app) rings.
So I need to Socket Communication.
Because I don't know socket... , I copied it.
I should use Java (android), I found Java pi4v library.
I have server(RaspberryPi) code, client(Android) code, and button code.
But, they're respective and I don't know how to combine them.
I want to send any signal pi to android using button!
Here is Server code.
import java.io.*;
import java.net.*;
public class JavaSocketServer{
public static void main(String[] args){
try{
int portNumber = 10001;
System.out.println("Start Server...");
ServerSocket aServerSocket = new ServerSocket(portNumber);
System.out.println("Listening at port " + portNumber + ",,,");
while(true){
Socket sock = aServerSocket.accept();
InetAddress clientHost = sock.getLocalAddress();
int clientPort = sock.getPort();
System.out.println("A client connected.");
System.out.println("(host : " + clientHost + ", port : " + clientPort);
ObjectInputStream instream = new ObjectInputStream(sock.getInputStream());
Object obj = instream.readObject();
System.out.println("Input : " + obj);
ObjectOutputStream outstream = new ObjectOutputStream(sock.getOutputStream());
outstream.writeObject(obj + " from Server.");
outstream.flush();
sock.close();
}
} catch(Exception ex){
ex.printStackTrace();
}
}
}
Here is Android Client Code.
package org.techtown.socket;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;
/**
*
*
* #author Mike
*
*/
public class MainActivity extends AppCompatActivity {
EditText input01;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
input01 = (EditText) findViewById(R.id.input01);
// 버튼 이벤트 처리
Button button01 = (Button) findViewById(R.id.button01);
button01.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String addr = input01.getText().toString().trim();
ConnectThread thread = new ConnectThread(addr);
thread.start();
}
});
}
/**
* 소켓 연결할 스레드 정의
*/
class ConnectThread extends Thread {
String hostname;
public ConnectThread(String addr) {
hostname = addr;
}
public void run() {
try {
int port = 11001;
Socket sock = new Socket(hostname, port);
ObjectOutputStream outstream = new ObjectOutputStream(sock.getOutputStream());
outstream.writeObject("Hello AndroidTown on Android");
outstream.flush();
ObjectInputStream instream = new ObjectInputStream(sock.getInputStream());
String obj = (String) instream.readObject();
Log.d("MainActivity", "서버에서 받은 메시지 : " + obj);
sock.close();
} catch(Exception ex) {
ex.printStackTrace();
}
}
}
}
Here is Button code.
import com.pi4j.io.gpio.*;
import com.pi4j.io.gpio.event.GpioPinDigitalStateChangeEvent;
import com.pi4j.io.gpio.event.GpioPinListenerDigital;
/**
* This example code demonstrates how to setup a listener
* for GPIO pin state changes on the Raspberry Pi.
*
* #author Robert Savage
*/
public class ListenGpioExample {
public static void main(String args[]) throws InterruptedException {
System.out.println("<--Pi4J--> GPIO Listen Example ... started.");
// create gpio controller
final GpioController gpio = GpioFactory.getInstance();
// provision gpio pin #02 as an input pin with its internal pull down resistor enabled
final GpioPinDigitalInput myButton = gpio.provisionDigitalInputPin(RaspiPin.GPIO_04, PinPullResistance.PULL_DOWN);
// set shutdown state for this input pin
myButton.setShutdownOptions(true);
// create and register gpio pin listener
myButton.addListener(new GpioPinListenerDigital() {
#Override
public void handleGpioPinDigitalStateChangeEvent(GpioPinDigitalStateChangeEvent event) {
// display pin state on console
System.out.println(" --> GPIO PIN STATE CHANGE: " + event.getPin() + " = " + event.getState());
}
});
System.out.println(" ... complete the GPIO #02 circuit and see the listener feedback here in the console.");
// keep program running until user aborts (CTRL-C)
while(true) {
Thread.sleep(500);
}
// stop all GPIO activity/threads by shutting down the GPIO controller
// (this method will forcefully shutdown all GPIO monitoring threads and scheduled tasks)
// gpio.shutdown(); <--- implement this method call if you wish to terminate the Pi4J GPIO
controller
}
}
I have no Idea,,,,

Receiving data via Bluetooth and viewing it on app screen

I am currently building an application that will connect to a device via bluetooth and receive data from it. Currently i am able to connect with the paired devices, but can't seem to find any good resources on how to receive data from that device. I have attached 2 images of the application, the first one; is the main menu. In there you'll see a button that says "connect to TANGO", in which i have put in all the code below. That allows me to connect to any paired devices. Also in the main menu, there's a "Translate" button, and that's were i am trying to receive data in, and view them, but so far i haven't been able to do so.
Here's the code for the "connect to TANGO" connection.java
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Set;
public class connection extends AppCompatActivity {
Button b1,b2,b3,b4;
private BluetoothAdapter BA;
private Set<BluetoothDevice>pairedDevices;
ListView lv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_connection);
b1 = (Button)findViewById(R.id.button);
b2=(Button)findViewById(R.id.button2);
b3=(Button)findViewById(R.id.button3);
b4=(Button)findViewById(R.id.button4);
BA = BluetoothAdapter.getDefaultAdapter();
lv = (ListView)findViewById(R.id.listView);
}
public void on(View v){
if (!BA.isEnabled()) {
Intent turnOn = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(turnOn, 0);
Toast.makeText(getApplicationContext(), "Turned on",Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(), "Already on", Toast.LENGTH_LONG).show();
}
}
public void off(View v){
if (BA.disable());
Toast.makeText(getApplicationContext(), "Turned off" ,Toast.LENGTH_LONG).show();
}
public void visible(View v){
Intent getVisible = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
startActivityForResult(getVisible, 0);
}
public void list(View v){
pairedDevices = BA.getBondedDevices();
ArrayList list = new ArrayList();
for(BluetoothDevice bt : pairedDevices) list.add(bt.getName());
Toast.makeText(getApplicationContext(), "Showing Paired Devices",Toast.LENGTH_SHORT).show();
final ArrayAdapter adapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1, list);
lv.setAdapter(adapter);
}
}

When you have a reference to a paired BluetoothDevice you need to create a socket and listen to it. Simplified example follows:
Create a BluetoothSocket and connect to it:
BluetoothSocket socket = device.createRfcommSocketToServiceRecord(<your-device>.getUuids()[0].getUuid());
socket.connect();
Listen to the socket (Get data from the device)
InputStream inStream = socket.getInputStream();
while (inStream.available() > 0) {
inStream.read(); // <-- data from device
}
Write to the socket (Send data to the device)
OutputStream outStream = socket.getOutputStream();
byte[] bytes = <some-data>
outStream.write(bytes);
For more detailed information, with examples, see the docs

#krekle would this code work.
import android.bluetooth.BluetoothSocket;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class display extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display);
}
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
private android.os.Handler mHandler;
public display (BluetoothSocket socket, Handler mHandler) {
mmSocket = socket;
this.mHandler = mHandler;
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the input and output streams, using temp objects because
// member streams are final
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) { }
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run() {
byte[] buffer = new byte[1024]; // buffer store for the stream
int bytes; // bytes returned from read()
// Keep listening to the InputStream until an exception occurs
while (true) {
try {
// Read from the InputStream
bytes = mmInStream.read(buffer);
// Send the obtained bytes to the UI activity
int MESSAGE_READ = 0;
mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
.sendToTarget();
} catch (IOException e) {
break;
}
}
}
/* Call this from the main activity to send data to the remote device */
public void write(byte[] bytes) {
try {
mmOutStream.write(bytes);
} catch (IOException e) { }
}
/* Call this from the main activity to shutdown the connection */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
}
i only had to change "ConnectThread" to "display" and "Thread" to "AppCompatActivity" just to match with the activities that i already made before.

Noise in Audio Streaming from Android to PC using UDP with Python Server

I am streaming my phone's microphone input data to the PC using UDP with Android App as Client and a Python Server. It works fine, no errors.
But even after tweaking a lot, I get a lot of noise on my server side.
I'd like to know if there is anything wrong with my code or it's normal?
Client:
public class MainActivity extends Activity {
private Button startButton,stopButton;
public byte[] buffer;
public static DatagramSocket socket;
private int port=8080;
AudioRecord recorder;
private int sampleRate = 44100 ; // 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;
Log.d("VS", "Address retrieved");
final InetAddress destination = InetAddress.getByName("10.0.0.2");
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",e);
} catch (IOException e) {
e.printStackTrace();
Log.e("VS", ""+ e);
}
}
});
streamThread.start();
}
}
Server:
import pyaudio
import socket
from threading import Thread
import numpy as np
from matplotlib import pyplot as plt
frames = []
def udpStream(CHUNK):
udp = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
udp.bind(("0.0.0.0", 8080))
while True:
# soundData, addr = udp.recvfrom(CHUNK)
soundData, addr = udp.recvfrom(CHUNK * CHANNELS * 2)
frames.append(soundData)
print numpydata
plt.plot(numpydata)
plt.show()
udp.close()
def play(stream, CHUNK):
BUFFER = 10
while True:
if len(frames) == BUFFER:
while True:
try:
stream.write(frames.pop(0), CHUNK)
except:
pass
if __name__ == "__main__":
FORMAT = pyaudio.paInt16
CHUNK = 1024
CHANNELS = 2
RATE = 44100
p = pyaudio.PyAudio()
stream = p.open(format=FORMAT,
channels = CHANNELS,
rate = RATE,
output = True,
input=True,
frames_per_buffer = CHUNK,
)
Ts = Thread(target = udpStream, args=(CHUNK,))
Tp = Thread(target = play, args=(stream, CHUNK,))
Ts.setDaemon(True)
Tp.setDaemon(True)
Ts.start()
Tp.start()
Ts.join()
Tp.join()

I was able to use your Android app code with a much simpler server setup and it works fairly well.
import pyaudio
import socket
FORMAT = pyaudio.paInt16
CHANNELS = 1
RATE = 44100
CHUNK = 4096
udp = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
udp.bind(("0.0.0.0", 5001))
audio = pyaudio.PyAudio()
stream = audio.open(format=FORMAT, channels=CHANNELS, rate=RATE, output=True, frames_per_buffer=CHUNK)
try:
while True:
data, addr = udp.recvfrom(CHUNK)
stream.write(data)
except KeyboardInterrupt:
pass
print('Shutting down')
udp.close()
stream.close()
audio.terminate()

Your code includes no audio safety buffer to handle jitter in the UDP network transmission rate. UDP over WiFi is neither a media synchronous nor a reliable transport, so some fraction of a second of pre-filled safety buffer, plus something to handle dropouts smoothly, may be required.

send udp message from PC(windows)(client) to android phone(server) not working

I want to send a UDP message from PC(server) to my android phone 4.2(client) using WIFI connection. My phone and PC are connected via wireless router. But no message is received from phone to mobile.
I have understood from debugging that the program is waiting at socket.receive(packet);. So, there is no update on the UI.
I want to show message to the UI when server received a message from client and this process will be continue.
I would be grateful, if you could help me. Thank you. I have added necessary permission.
server:
package com.example.abuttontest;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import android.app.Activity;
import android.os.Bundle;
import android.provider.Settings.System;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity
{
private TextView tv;
int i =0;
// String s;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button1 = (Button) findViewById(R.id.button1);
tv = (TextView) findViewById(R.id.textView1);
//TextView textMessage = (TextView) findViewById(R.id.textView2);
button1.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
/*cheack ping message*/
//boolean morgan= isOnline();
//String s = String.valueOf(morgan);
tv.setText("kkkkkkkkkk"); // print ping message
Log.d("MyTag#","This is sample log message");
}
});
/* Thread for receiving Data from CLient */
runThread();
}
private void runThread()
{
new Thread()
{
public void run()
{
Log.d("p2p", "1");
while (i++ < 1000)
{
Log.d("p2p", "2");
try {
/////////////////////
//System.out.println("aaa");
byte[] inbuf = new byte[1000]; // default size
DatagramPacket packet = new DatagramPacket(inbuf, inbuf.length);
Log.d("p2p", "3");
DatagramSocket socket = new DatagramSocket(6000);
socket.receive(packet);
Log.d("p2p", "4");
int numBytesReceived = packet.getLength();
//System.out.println(numBytesReceived);
String s = new String(inbuf);
//System.out.println(s);
//System.out.println(inbuf[2]);
socket.close();
Log.d("p2p", "5");
runOnUiThread(new Runnable()
{
#Override
public void run()
{
tv.setText("#" + i);
}
});
Thread.sleep(300);
}
catch (InterruptedException e)
{
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}.start();
}
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.one)
{
Toast.makeText(getApplicationContext(), "Toast Message ONE", Toast.LENGTH_LONG).show();
}
if (id == R.id.two)
{
Toast.makeText(getApplicationContext(), "Toast Message TWO", Toast.LENGTH_LONG).show();
}
if (id == R.id.action_settings)
{
return true;
}
return super.onOptionsItemSelected(item);
}
}
client:
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
/*packets in the IP layer are called the datagrams */
/*After creating a packet, the process of sending or receiving it involves calling the send or receive method of DatagramSocket. More specifically, you create a packet, then you create a socket. After you create the socket, you call the send method of DatagramSocket to send the datagram packet or use the receive method of DatagramSocket to receive a packet. You can also use the same DatagramSocket to send and receive multiple packets, each going to different destinations and coming from different sources.*/
public class client
{
public static void main(String args[])
{
System.out.println("from client");
try{
//InetAddress ipaddress = InetAddress.getByName("localhost");
// InetAddress ipaddress = InetAddress.getByName("192.168.0.103");
// while(true)
// {
InetAddress ipaddress = InetAddress.getByName("192.168.0.102");
int port = 6000;
//byte[] buffer = new byte[1024]; // empty byte array
String msg ="hello goooooooogle"; // send this message to the server
byte [] b_array = msg.getBytes();
//on SERVER side DatagramSocket able to receive packets on 8080 port
DatagramPacket packet = new DatagramPacket(b_array, b_array.length, ipaddress, port);// DatagramPacket(byte[], byte_length, InetAddress, port_number)
DatagramSocket socket = new DatagramSocket();
socket.send(packet);
socket.close();
// }
}
catch(Exception e)
{
System.out.println(e);
}
}
}

In your MainActivity you have not mentioned the port number which your server has to listen on.

Android AcousticEchoCanceler does not cancel out echo

I've been having a fairly annoying problem with a video chat app I'm developing, and that's the issue of audio echoing.
I am at best a rank amateur at this, but the project I'm working on requires at least fully functional audio communication. Video turned out to be a lot easier than I originally anticipated.
The intended structure is eventually a thread taking input and another playing output on the same phone, for developing this, I've made two small apps that take in mic input on one phone, and send it via Datagram socket to the other. The phones in question are LG Optimus L7-2 running Android 4.1.2 and Alcatel Idol Mini (I think it's also advertized as Onetouch or some such.) running Android 4.2.2.
The code that transfers audio works perfectly, with minimal background noise (I'm guessing thanks to my choice of input as well as the post processing), however, as long as the two phones are close enough, I get a rather alarming echo, which is only made worse if I dare attempt to put input/output in the same app at the same time.
After my initial attempts at somehow filtering it out failed (AcousticEchoCanceler seems to help less than NoiseSupressor, and AutomaticGainControl seems to do more damage than good), I've done a bit of reading but found nothing that could help.
I am at this point rather confused as I can't seem to shake the feeling that I'm missing something obvious, and that it shouldn't be THAT complicated to set up.
I'm in addition putting up the base code I'm using for the audio recording/playing.
The recorder segment
package com.example.audiotest;
import java.io.IOException;
import java.io.InputStream;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;
import android.app.Activity;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.AudioTrack;
import android.media.MediaRecorder;
import android.media.audiofx.AcousticEchoCanceler;
import android.media.audiofx.AutomaticGainControl;
import android.media.audiofx.NoiseSuppressor;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
private Button startButton,stopButton;
public byte[] buffer;
public static DatagramSocket socket;
private int port=50005;
AudioRecord recorder;
private int sampleRate = 22050;
private int channelConfig = AudioFormat.CHANNEL_IN_MONO;
private int audioFormat = AudioFormat.ENCODING_PCM_16BIT;
private 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);
Log.v("AudioPlayerApp","minBufSize: " + minBufSize);
//minBufSize += 2048;
minBufSize = 4096;
System.out.println("minBufSize: " + minBufSize);
}
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("AudioPlayerApp"", "Socket Created");
minBufSize = 4096;
byte[] buffer = new byte[minBufSize];
Log.d("AudioPlayerApp","Buffer created of size " + minBufSize);
DatagramPacket packet;
final InetAddress destination = InetAddress.getByName("192.168.0.13");
recorder = new AudioRecord(MediaRecorder.AudioSource.VOICE_RECOGNITION,sampleRate,channelConfig,audioFormat,minBufSize);
AcousticEchoCanceler canceler = AcousticEchoCanceler.create(recorder.getAudioSessionId());
NoiseSuppressor ns = NoiseSuppressor.create(recorder.getAudioSessionId());
AutomaticGainControl agc = AutomaticGainControl.create(recorder.getAudioSessionId());
canceler.setEnabled(true);
ns.setEnabled(true);
//agc.setEnabled(true);
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);
}
} catch(UnknownHostException e) {
Log.e("AudioPlayerApp", "UnknownHostException");
} catch (IOException e) {
e.printStackTrace();
Log.e("AudioPlayerApp", "IOException");
}
}
});
streamThread.start();
}
}
And the player segment.
package com.test.playsound;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.ServerSocket;
import java.net.Socket;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioTrack;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
public class MainActivity extends Activity {
static int port = 50005;
static String address = "";
static int sampleRate = 22050;
private boolean running = true;
private AudioTrack audioTrack;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.v("Player", "Init complete");
openPlaySocket();
}
private void openPlaySocket() {
// TODO Auto-generated method stub
Thread t = new Thread(new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
try {
Log.v("AudioPlayerApp", "Opening socket");
DatagramSocket sSock = new DatagramSocket(port);
byte[] output = new byte[4096];
Log.v("AudioPlayerApp", "Generating AudioTrack");
int minBufferSize = AudioTrack.getMinBufferSize(sampleRate,
AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT);
audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
sampleRate, AudioFormat.CHANNEL_OUT_MONO,
AudioFormat.ENCODING_PCM_16BIT, minBufferSize,
AudioTrack.MODE_STREAM);
DatagramPacket receivePacket = new DatagramPacket(output,
output.length);
//Log.v("AudioPlayerApp", "Playing AudioTrack");
audioTrack.play();
while (running) {
//Log.v("AudioPlayerApp", "Waiting Packet");
sSock.receive(receivePacket);
Log.v("AudioPlayerApp","REcieved packet");
//Log.v("AudioPlayerApp", "Packet recieved");
try {
//Log.v("AudioPlayerApp", "writing data to audioTrack");
audioTrack.write(receivePacket.getData(), 0,
receivePacket.getData().length);
} catch (Exception e) {
Log.v("AudioPlayerApp",
"Failed to write audio: " + e.getMessage());
}
}
/*Log.v("AudioPlayerApp","Opening socket");
ServerSocket sSock = new ServerSocket(port);
Socket sock = sSock.accept();
Log.v("AudioPlayerApp","Socket opened "+port);
*/
} catch (Exception e) {
// TODO: handle exception
Log.v("AudioPlayerApp", "Error: " + e.getMessage());
}
}
});
Log.v("Player", "Starting thread");
t.start();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
I'm aware it contains bad practices (such as not checking whether the device in question has support for certain things, or releasing resources and such) however, this was in an effort to start testing out and fixing the echo as fast as possible. I've confirmed that both phones have access to AcousticEchoCanceller, NoiseSupression, recording rights, internet rights, and aside for the fact that AudioFormat.VOICECOMMUNICATION causes my AudioRecord to crash, I've had no other problems.
I'm looking for any ideas or advice on the subject, as I'm quite frankly stumped. What can be done to fix the issue of echoing while recording and playing voice?

the AcousticEchoCanceler class is for canceling or removing the audio played by speaker and captured by microphone of the same device and there is small delay between play and capture.
the AcousticEchoCanceler class can not remove the echo caused by placing two phone near each other because of long and variable nature of echo delay of echo path.

You need to leverage the build in echo cancellation at the hardware level, check if AcousticEchoCanceler.isAvailable() check and return true
Then you can try the following combinations from here on SO