/// <summary>
/// Hide [messageStream] in [sourceStream],
/// write the result to [destinationStream]
/// </summary>
/// <param name="messageStream">The message to hide</param>
/// <param name="keyStream">
/// A key stream that specifies how many samples shall be
/// left clean between two changed samples
/// </param>
public void Hide(Stream messageStream, Stream keyStream)
{
byte[] waveBuffer = new byte[bytesPerSample];
byte message, bit, waveByte;
int messageBuffer; //receives the next byte of the message or -1
int keyByte; //distance of the next carrier sample
while ((messageBuffer = messageStream.ReadByte()) >= 0)
{
//read one byte of the message stream
message = (byte)messageBuffer;
//for each bit in message
for (int bitIndex = 0; bitIndex < 8; bitIndex++)
{
//read a byte from the key
keyByte = GetKeyValue(keyStream);
//skip a couple of samples
for (int n = 0; n < keyByte - 1; n++)
{
//copy one sample from the clean stream to the carrier stream
sourceStream.Copy(waveBuffer, 0, waveBuffer.Length, destinationStream);
}
//read one sample from the wave stream
sourceStream.Read(waveBuffer, 0, waveBuffer.Length);
waveByte = waveBuffer[bytesPerSample - 1];
//get the next bit from the current message byte...
bit = (byte)(((message & (byte)(1 << bitIndex)) > 0) ? 1 : 0);
//...place it in the last bit of the sample
if ((bit == 1) && ((waveByte % 2) == 0))
{
waveByte += 1;
}
else if ((bit == 0) && ((waveByte % 2) == 1))
{
waveByte -= 1;
}
waveBuffer[bytesPerSample - 1] = waveByte;
//write the result to destinationStream
destinationStream.Write(waveBuffer, 0, bytesPerSample);
}
}
//copy the rest of the wave without changes
waveBuffer = new byte[sourceStream.Length - sourceStream.Position];
sourceStream.Read(waveBuffer, 0, waveBuffer.Length);
destinationStream.Write(waveBuffer, 0, waveBuffer.Length);
}
public void Hide(Stream messageStream, Stream keyStream)
{
byte[] waveBuffer = new byte[bytesPerSample];
byte message, bit, waveByte;
int messageBuffer;
int keyByte;
while ((messageBuffer = messageStream.ReadByte()) >= 0)
{
message = (byte)messageBuffer;
for (int bitIndex = 0; bitIndex < 8; bitIndex++)
{
keyByte = GetKeyValue(keyStream);
for (int n = 0; n < keyByte - 1; n++)
{
sourceStream.Copy(waveBuffer, 0, waveBuffer.Length, destinationStream);
}
sourceStream.Read(waveBuffer, 0, waveBuffer.Length);
waveByte = waveBuffer[bytesPerSample - 1];
bit = (byte)(((message & (byte)(1 << bitIndex)) > 0) ? 1 : 0);
if ((bit == 1) && ((waveByte % 2) == 0))
{
waveByte += 1;
}
else if ((bit == 0) && ((waveByte % 2) == 1))
{
waveByte -= 1;
}
waveBuffer[bytesPerSample - 1] = waveByte;
destinationStream.Write(waveBuffer, 0, bytesPerSample);
}
}
waveBuffer = new byte[sourceStream.Length - sourceStream.Position];
sourceStream.Read(waveBuffer, 0, waveBuffer.Length);
destinationStream.Write(waveBuffer, 0, waveBuffer.Length);
}
public void Hide(Stream messageStream, Stream keyStream)
{
byte[] waveBuffer = new byte[bytesPerSample];
byte message, bit, waveByte;
int messageBuffer, keyByte;
while ((messageBuffer = messageStream.ReadByte()) >= 0)
{
//read one byte of the message
message = (byte)messageBuffer;
//for each bit in message
for (int bitIndex = 0; bitIndex < 8; bitIndex++)
{
//read a byte from the key
keyByte = GetKeyValue(keyStream);
//skip samples
for (int n = 0; n < keyByte - 1; n++)
{
sourceStream.Copy(waveBuffer, 0, waveBuffer.Length, destinationStream);
}
//read one sample from the wave stream
sourceStream.Read(waveBuffer, 0, waveBuffer.Length);
waveByte = waveBuffer[bytesPerSample - 1];
bit = (byte)(((message & (byte)(1 << bitIndex)) > 0) ? 1 : 0);
//change the last bit of the sample
if ((bit == 1) && ((waveByte % 2) == 0))
{
waveByte += 1;
}
else if ((bit == 0) && ((waveByte % 2) == 1))
{
waveByte -= 1;
}
waveBuffer[bytesPerSample - 1] = waveByte;
//write the result to destinationStream
destinationStream.Write(waveBuffer, 0, bytesPerSample);
}
}
waveBuffer = new byte[sourceStream.Length - sourceStream.Position];
sourceStream.Read(waveBuffer, 0, waveBuffer.Length);
destinationStream.Write(waveBuffer, 0, waveBuffer.Length);
}
