/*
* Receive audio data coming on port 1550 and feed it to the speakers to be played.
*/
private void Receive()
{
try
{
bStop = false;
IPEndPoint remoteEP = new IPEndPoint(IPAddress.Any, 0);
while (!bStop)
{
//Receive data.
byte[] byteData = udpClient.Receive(ref remoteEP);
//G711 compresses the data by 50%, so we allocate a buffer of double
//the size to store the decompressed data.
byte[] byteDecodedData = new byte[byteData.Length * 2];
//Decompress data using the proper vocoder. And decrypt
var decryptedData = AES_Crypto.Decrypt(byteData, CallCurrentPass, CallCurrentSalt);
ALawDecoder.ALawDecode(decryptedData, out byteDecodedData);
//Play the data received to the user.
playbackBuffer = new SecondaryBuffer(playbackBufferDescription, device);
playbackBuffer.Write(0, byteDecodedData, LockFlag.None);
playbackBuffer.Play(0, BufferPlayFlags.Default);
}
}
catch (Exception e)
{
MessageBox.Show(e.Message, "VoiceChat-Receive ()", MessageBoxButton.OK, MessageBoxImage.Error, MessageBoxResult.OK);
}
finally
{
nUdpClientFlag += 1;
}
}
private void UninitializeCall()
{
//Set the flag to end the Send and Receive threads.
bStop = true;
IsCallActive = false;
window.ButtonSetAsync(true, false, false);
if (IsCaller)
{
CallRepo.createCall(Globals.currentUserId, ReceiverID, CallDate.ToString("yyyy-MM-dd hh:mm:ss"), 1);
}
IsCaller = false;
Thread.Sleep(500);
//Reinitialize crypto properties after the call
MyCurrentPass = AES_Crypto.CreatePass();
MyCurrentSalt = AES_Crypto.CreateSalt();
CallCurrentPass = null;
CallCurrentSalt = null;
UserRepo.updateCrypto(MyCurrentPass, MyCurrentSalt);
}
/*
* Initializes all the data members.
*/
public CallManager(System.Windows.Window window)
{
try
{
this.window = (WindowMain)window;
device = new Device();
System.Windows.Interop.WindowInteropHelper helper = new System.Windows.Interop.WindowInteropHelper(window);
device.SetCooperativeLevel(helper.Handle, CooperativeLevel.Normal);
CaptureDevicesCollection captureDeviceCollection = new CaptureDevicesCollection();
DeviceInformation deviceInfo = captureDeviceCollection[0];
capture = new Capture(deviceInfo.DriverGuid);
short channels = 1; //Stereo.
short bitsPerSample = 16; //16Bit, alternatively use 8Bits.
int samplesPerSecond = 22050; //11KHz use 11025 , 22KHz use 22050, 44KHz use 44100 etc.
//Set up the wave format to be captured.
waveFormat = new WaveFormat();
waveFormat.Channels = channels;
waveFormat.FormatTag = WaveFormatTag.Pcm;
waveFormat.SamplesPerSecond = samplesPerSecond;
waveFormat.BitsPerSample = bitsPerSample;
waveFormat.BlockAlign = (short)(channels * (bitsPerSample / (short)8));
waveFormat.AverageBytesPerSecond = waveFormat.BlockAlign * samplesPerSecond;
captureBufferDescription = new CaptureBufferDescription();
captureBufferDescription.BufferBytes = waveFormat.AverageBytesPerSecond / 5;//approx 200 milliseconds of PCM data.
captureBufferDescription.Format = waveFormat;
playbackBufferDescription = new BufferDescription();
playbackBufferDescription.BufferBytes = waveFormat.AverageBytesPerSecond / 5;
playbackBufferDescription.Format = waveFormat;
playbackBuffer = new SecondaryBuffer(playbackBufferDescription, device);
bufferSize = captureBufferDescription.BufferBytes;
IsCallActive = false;
nUdpClientFlag = 0;
//Using UDP sockets
clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
EndPoint ourEP = new IPEndPoint(IPAddress.Any, 1450);
//Listen asynchronously on port 1450 for coming messages (Invite, Bye, etc).
clientSocket.Bind(ourEP);
//Receive data from any IP.
EndPoint remoteEP = (EndPoint)(new IPEndPoint(IPAddress.Any, 0));
byteData = new byte[1024];
//Receive data asynchornously.
clientSocket.BeginReceiveFrom(byteData,
0, byteData.Length,
SocketFlags.None,
ref remoteEP,
new AsyncCallback(OnReceive),
null);
//Create first cryptographic passes
this.MyCurrentPass = AES_Crypto.CreatePass();
this.MyCurrentSalt = AES_Crypto.CreateSalt();
UserRepo.updateCrypto(MyCurrentPass, MyCurrentSalt);
}
catch (Exception e)
{
MessageBox.Show(e.ToString(), "Initialization Error", MessageBoxButton.OK, MessageBoxImage.Error, MessageBoxResult.OK);
}
}
/*
* Send synchronously sends data captured from microphone across the network on port 1550.
*/
private void Send()
{
try
{
captureBuffer = new CaptureBuffer(captureBufferDescription, capture);
//The following lines get audio from microphone and then send them
//across network
CreateNotifyPositions();
int halfBuffer = bufferSize / 2;
captureBuffer.Start(true);
bool readFirstBufferPart = true;
int offset = 0;
MemoryStream memStream = new MemoryStream(halfBuffer);
bStop = false;
while (!bStop)
{
if (!IsMuted)
{
autoResetEvent.WaitOne();
memStream.Seek(0, SeekOrigin.Begin);
captureBuffer.Read(offset, memStream, halfBuffer, LockFlag.None);
readFirstBufferPart = !readFirstBufferPart;
offset = readFirstBufferPart ? 0 : halfBuffer;
//Encode and encrypt data.
byte[] dataEncoded = ALawEncoder.ALawEncode(memStream.GetBuffer());
byte[] dataToWrite = AES_Crypto.Encrypt(dataEncoded, CallCurrentPass, CallCurrentSalt);
udpClient.Send(dataToWrite, dataToWrite.Length, otherPartyIP.Address.ToString(), 1550);
}
}
}
catch (Exception e)
{
MessageBox.Show(e.ToString(), "VoiceChat-Send ()", MessageBoxButton.OK, MessageBoxImage.Error, MessageBoxResult.OK);
}
finally
{
captureBuffer.Stop();
captureBuffer.Dispose();
//Increment flag by one.
nUdpClientFlag += 1;
//When flag is two then it means we have got out of loops in Send and Receive.
while (nUdpClientFlag != 2)
{
}
//Clear the flag.
nUdpClientFlag = 0;
//Close the socket.
udpClient.Close();
}
}
/*
* Commands are received asynchronously. OnReceive is the handler for them.
*/
private void OnReceive(IAsyncResult ar)
{
try
{
EndPoint receivedFromEP = new IPEndPoint(IPAddress.Any, 0);
//Get the IP from where we got a message.
clientSocket.EndReceiveFrom(ar, ref receivedFromEP);
//Convert the bytes received into an object of type Data.
Data msgReceived = new Data(byteData);
//Act according to the received message.
switch (msgReceived.cmdCommand)
{
//We have an incoming call.
case Command.Invite:
{
if (IsCallActive == false)
{
//We have no active call.
//Ask the user to accept the call or not.
if (MessageBox.Show("Call coming from " + msgReceived.strName + ".\r\n\r\nAccept it?",
"VoiceChat", MessageBoxButton.YesNo, MessageBoxImage.Question, MessageBoxResult.Yes) == MessageBoxResult.Yes)
{
//Get someones crypto information
var cryptoTuple = UserRepo.fetchUsersCrypto(msgReceived.strName);
CallCurrentPass = cryptoTuple.Item1;
CallCurrentSalt = cryptoTuple.Item2;
SendMessage(Command.OK, receivedFromEP);
otherPartyEP = receivedFromEP;
otherPartyIP = (IPEndPoint)receivedFromEP;
InitializeCall();
}
else
{
//The call is declined. Send a busy response.
SendMessage(Command.Busy, receivedFromEP);
}
}
else
{
//We already have an existing call. Send a busy response.
SendMessage(Command.Busy, receivedFromEP);
}
break;
}
//OK is received in response to an Invite.
case Command.OK:
{
//Start a call.
InitializeCall();
MessageBox.Show("Person has answered. Call started.", "Call handler", MessageBoxButton.OK, MessageBoxImage.Information, MessageBoxResult.OK);
break;
}
//Remote party is busy.
case Command.Busy:
{
MessageBox.Show("User busy.", "VoiceChat", MessageBoxButton.OK, MessageBoxImage.Exclamation, MessageBoxResult.OK);
CallRepo.createCall(Globals.currentUserId, ReceiverID, CallDate.ToString("yyyy-MM-dd hh:mm:ss"), 5);
IsCaller = false;
window.ButtonSetAsync(true, false, false);
//Reinitialize crypto properties after the call
MyCurrentPass = AES_Crypto.CreatePass();
MyCurrentSalt = AES_Crypto.CreateSalt();
CallCurrentPass = null;
CallCurrentSalt = null;
UserRepo.updateCrypto(MyCurrentPass, MyCurrentSalt);
break;
}
case Command.Bye:
{
//Check if the Bye command has indeed come from the user/IP with which we have
//a call established. This is used to prevent other users from sending a Bye, which
//would otherwise end the call.
if (receivedFromEP.Equals(otherPartyEP) == true)
{
//End the call.
UninitializeCall();
}
MessageBox.Show("Person has disconnected", "Call handler", MessageBoxButton.OK, MessageBoxImage.Information, MessageBoxResult.OK);
break;
}
}
byteData = new byte[1024];
//Get ready to receive more commands.
clientSocket.BeginReceiveFrom(byteData, 0, byteData.Length, SocketFlags.None, ref receivedFromEP, new AsyncCallback(OnReceive), null);
}
catch (Exception e)
{
MessageBox.Show(e.Message, "VoiceChat-OnReceive ()", MessageBoxButton.OK, MessageBoxImage.Error, MessageBoxResult.OK);
}
}
