private void decodePlay_Click(object sender, EventArgs e)
{
// Decode the data.
// Get the dataSize which is in the first 11 pixels (32 / 3 = 10.67).
int dataSize = 0;
byte zero = 1;
int bitShift = 31;
for (int i = 0, j = 0; j < 11; j++)
{
Color color = ((Bitmap)(encryptedImageBox.Image)).GetPixel(i, j);
dataSize += ((color.R & zero) << bitShift);
bitShift--;
dataSize += ((color.G & zero) << bitShift);
bitShift--;
if (11 != j)
{
dataSize += ((color.B & zero) << bitShift);
bitShift--;
}
}
if (dataSize > (encryptedImageBox.Width * encryptedImageBox.Height) || dataSize < 128)
{
MessageBox.Show("WARNING: It is likely the image is not encrypted or has been corrupted.");
}
// Get the sample rate.
int sampleRate = 0;
bitShift = 31;
for (int i = 0, j = 10; j < 22; j++)
{
Color color = ((Bitmap)(encryptedImageBox.Image)).GetPixel(i, j);
if (10 == j)
{
sampleRate = ((color.B & zero) << bitShift);
bitShift--;
}
else if (21 == j)
{
sampleRate += ((color.R & zero) << bitShift);
bitShift--;
}
else
{
sampleRate += ((color.R & zero) << bitShift);
bitShift--;
sampleRate += ((color.G & zero) << bitShift);
bitShift--;
sampleRate += ((color.B & zero) << bitShift);
bitShift--;
}
}
// Get the average bytes per second.
int fmtAvgBPS = 0;
bitShift = 31;
for (int i = 0, j = 21; j < 32; j++)
{
Color color = ((Bitmap)(encryptedImageBox.Image)).GetPixel(i, j);
if (21 == j)
{
fmtAvgBPS = ((color.G & zero) << bitShift);
bitShift--;
fmtAvgBPS = ((color.B & zero) << bitShift);
bitShift--;
}
else
{
fmtAvgBPS += ((color.R & zero) << bitShift);
bitShift--;
fmtAvgBPS += ((color.G & zero) << bitShift);
bitShift--;
fmtAvgBPS += ((color.B & zero) << bitShift);
bitShift--;
}
}
// Get the block align.
int blockAlign = 0;
bitShift = 15;
for (int i = 0, j = 32; j < 38; j++)
{
Color color = ((Bitmap)(encryptedImageBox.Image)).GetPixel(i, j);
blockAlign += ((color.R & zero) << bitShift);
bitShift--;
if (37 != j)
{
blockAlign += ((color.G & zero) << bitShift);
bitShift--;
blockAlign += ((color.B & zero) << bitShift);
bitShift--;
}
}
// Get the bit depth.
int bitDepth = 0;
bitShift = 15;
for (int i = 0, j = 37; j < 43; j++)
{
Color color = ((Bitmap)(encryptedImageBox.Image)).GetPixel(i, j);
if (37 == j)
{
bitDepth += ((color.G & zero) << bitShift);
bitShift--;
bitDepth += ((color.B & zero) << bitShift);
bitShift--;
}
else if (42 == j)
{
bitDepth += ((color.R & zero) << bitShift);
bitShift--;
bitDepth += ((color.G & zero) << bitShift);
bitShift--;
}
else
{
bitDepth += ((color.R & zero) << bitShift);
bitShift--;
bitDepth += ((color.G & zero) << bitShift);
bitShift--;
bitDepth += ((color.B & zero) << bitShift);
bitShift--;
}
}
// Grab the first value, which is the most significant bit.
// Bit shift it to the leftmost byte position, and store it into the data array.
// Move the bit shift counter one to the right (meaning divide it by 2).
// If the counter is zero, reset to leftmost bit = 1.
if (16 == bitDepth)
{
List<short> waveData = new List<short>();
waveData.Add(0);
int shift = 7;
int wavIndex = 0;
dataSize /= 2; // Divide by two for shorts (2 bytes long).
/* A short is two bytes, xy. It's stored in wave file in reverse order (little-endian).
* We extract it by first grabbing the lower significant byte with the shift initialized
* to 7, then grabbing the most significant byte with shift = 15. When the shift = 7
* again, we add to the list and continue.
*/
for (int i = 0; i < encryptedImageBox.Image.Width; i++)
{
for (int j = 0; j < encryptedImageBox.Image.Height && wavIndex != dataSize; j++)
{
Color pixel = ((Bitmap)(encryptedImageBox.Image)).GetPixel(i, j);
if (0 == i && 0 == j)
{ // Get the first bit of data, not the header information.
j = 42;
waveData[wavIndex] += (short)((pixel.B & zero) << shift);
shift--;
}
else
{
waveData[wavIndex] += (short)((pixel.R & zero) << shift);
shift--;
if (7 == shift)
{
waveData.Add(0);
wavIndex++;
}
else if (-1 == shift)
{
shift = 15;
}
waveData[wavIndex] += (short)((pixel.G & zero) << shift);
shift--;
if (7 == shift)
{
waveData.Add(0);
wavIndex++;
}
else if (-1 == shift)
{
shift = 15;
}
waveData[wavIndex] += (short)((pixel.B & zero) << shift);
shift--;
if (7 == shift)
{
waveData.Add(0);
wavIndex++;
}
else if (-1 == shift)
{
shift = 15;
}
}
}
}
// Create the .wav file.
string filePath16 = @"C:\Users\onlyo\OneDrive\Pictures\SeniorDesign\tempWavs\temp.wav";
wave = new WaveGenerator(WaveExampleType.Decrypt, waveData);
wave.format.dwSamplesPerSec = (uint)sampleRate;
wave.format.dwAvgBytesPerSec = (uint)fmtAvgBPS;
wave.format.wBlockAlign = (ushort)blockAlign;
wave.format.wBitsPerSample = (ushort)bitDepth;
wave.saveWave(filePath16);
}
else if (8 == bitDepth)
{
List<byte> waveData = new List<byte>();
waveData.Add(0);
int shift = 7;
int wavIndex = 0;
for (int i = 0; i < encryptedImageBox.Image.Width; i++)
{
for (int j = 0; j < encryptedImageBox.Image.Height && wavIndex != dataSize; j++)
{
Color pixel = ((Bitmap)(encryptedImageBox.Image)).GetPixel(i, j);
if (0 == i && 0 == j)
{ // Get the first bit of data, not the header information.
j = 42;
waveData[wavIndex] += (byte)((pixel.B & zero) << shift);
shift--;
}
else
{
waveData[wavIndex] += (byte)((pixel.R & zero) << shift);
shift--;
if (-1 == shift)
{
waveData.Add(0);
wavIndex++;
shift = 7;
}
waveData[wavIndex] += (byte)((pixel.G & zero) << shift);
shift--;
if (-1 == shift)
{
waveData.Add(0);
wavIndex++;
shift = 7;
}
waveData[wavIndex] += (byte)((pixel.B & zero) << shift);
shift--;
if (-1 == shift)
{
waveData.Add(0);
wavIndex++;
shift = 7;
}
}
}
}
// Create the .wav file.
string filePath8 = @"C:\Users\onlyo\OneDrive\Pictures\SeniorDesign\tempWavs\temp.wav";
wave = new WaveGenerator(WaveExampleType.Decrypt, waveData);
wave.format.dwSamplesPerSec = (uint)sampleRate;
wave.format.dwAvgBytesPerSec = (uint)fmtAvgBPS;
wave.format.wBlockAlign = (ushort)blockAlign;
wave.format.wBitsPerSample = (ushort)bitDepth;
wave.saveWave(filePath8);
}
else
{
MessageBox.Show("Terminating: Unencrypted or corrupted image. Bits per sample: " + bitDepth);
return;
}
string filePath = @"C:\Users\onlyo\OneDrive\Pictures\SeniorDesign\tempWavs\temp.wav";
// Play the sound.
SoundPlayer player = new SoundPlayer(filePath);
player.Play();
}
