//WriteFloatingRIFF
// Subroutine to Write a RIFF waveform to a memory Stream (no disc access)
public bool WriteRIFFStream(ref MemoryStream WaveStream, int intSampleRate, int intFmtChunkLength, ref byte[] aryWaveData)
{
//*************************************************************************
// Here is where the file will be created. A
// wave file is a RIFF file, which has chunks
// of data that describe what the file contains.
// A wave RIFF file is put together like this:
// The 12 byte RIFF chunk is constructed like this:
// Bytes(0 - 3) 'R' 'I' 'F' 'F'
// Bytes 4 - 7 : Length of file, minus the first 8 bytes of the RIFF description.
// (4 bytes for "WAVE" + 24 bytes for format chunk length +
// 8 bytes for data chunk description + actual sample data size.)
// Bytes(8 - 11) 'W' 'A' 'V' 'E'
// The 24 byte FORMAT chunk is constructed like this:
// Bytes(0 - 3) 'f' 'm' 't' ' '
// Bytes 4 - 7 : The format chunk length. This is 16 or 18
// Bytes 8 - 9 : File padding. Always 1.
// Bytes 10- 11: Number of channels. Either 1 for mono, or 2 for stereo.
// Bytes 12- 15: Sample rate.
// Bytes 16- 19: Number of bytes per second.
// Bytes 20- 21: Bytes per sample. 1 for 8 bit mono, 2 for 8 bit stereo or
// 16 bit mono, 4 for 16 bit stereo.
// Bytes 22- 23: Number of bits per sample.
// The DATA chunk is constructed like this:
// Bytes(0 - 3) 'd' 'a' 't' 'a'
// Bytes 4 - 7 : Length of data, in bytes.
// Bytes 8 -...: Actual sample data.
//**************************************************************************
//TODO: Test of "back porch" extension for PTT
//ReDim Preserve aryWaveData(aryWaveData.Length + 1023) ' Adds 42.6 ms additional dead time before removal of PTT
byte[] bytTemp = new byte[-1 + 1];
if (intFmtChunkLength == 16)
{
if ((WaveStream != null))
{
WaveStream.Flush();
}
WaveStream = new MemoryStream(43 + aryWaveData.Length);
}
else if (intFmtChunkLength == 18)
{
if ((WaveStream != null))
{
WaveStream.Flush();
}
WaveStream = new MemoryStream(45 + aryWaveData.Length);
}
else
{
return(false);
}
// Set up file with RIFF chunk info.
short shPad = 1;
// File padding
int intLength = 0;
if (intFmtChunkLength == 16)
{
intLength = aryWaveData.Length + 36;
// File length, minus first 8 bytes of RIFF description.
}
else if (intFmtChunkLength == 18)
{
intLength = aryWaveData.Length + 38;
// File length, minus first 8 bytes of RIFF description.
}
short shBytesPerSample = 2;
// Bytes per sample.
// Fill in the riff info for the wave file.
AppendBytes(ref bytTemp, Globals.GetBytes("RIFF"));
AppendBytes(ref bytTemp, Int32ToBytes(intLength));
AppendBytes(ref bytTemp, Globals.GetBytes("WAVE"));
AppendBytes(ref bytTemp, Globals.GetBytes("fmt "));
AppendBytes(ref bytTemp, Int32ToBytes(intFmtChunkLength));
AppendBytes(ref bytTemp, Int16ToBytes(shPad));
AppendBytes(ref bytTemp, Int16ToBytes(1));
// mono
AppendBytes(ref bytTemp, Int32ToBytes(intSampleRate));
AppendBytes(ref bytTemp, Int32ToBytes(2 * intSampleRate));
AppendBytes(ref bytTemp, Int16ToBytes(2));
// bytes/sample
if (intFmtChunkLength == 18)
{
AppendBytes(ref bytTemp, Int16ToBytes(2));
// bytes/sample
}
AppendBytes(ref bytTemp, Int16ToBytes(16));
// bits/sample
// DateTime.Now fill in the data chunk.
AppendBytes(ref bytTemp, Globals.GetBytes("data"));
AppendBytes(ref bytTemp, Int32ToBytes(aryWaveData.Length));
AppendBytes(ref bytTemp, aryWaveData);
WaveStream.Write(bytTemp, 0, bytTemp.Length);
return(true);
}