/// <summary>Writes the WAV file header.</summary>
private void WriteHeader()
{
// swap byte order if necessary
WavHeader hdrTemp = _header;
_endian.Swap32(ref hdrTemp.Riff.PackageLength);
_endian.Swap32(ref hdrTemp.Format.FormatLen);
_endian.Swap16(ref hdrTemp.Format.Fixed);
_endian.Swap16(ref hdrTemp.Format.ChannelNumber);
_endian.Swap32(ref hdrTemp.Format.SampleRate);
_endian.Swap32(ref hdrTemp.Format.ByteRate);
_endian.Swap16(ref hdrTemp.Format.BytePerSample);
_endian.Swap16(ref hdrTemp.Format.BitsPerSample);
_endian.Swap32(ref hdrTemp.Data.DataLen);
_endian.Swap32(ref hdrTemp.Fact.FactLength);
_endian.Swap32(ref hdrTemp.Fact.FactSampleLength);
// write the supplemented header in the beginning of the file
_fileStream.Seek(0, SeekOrigin.Begin);
int size = Marshal.SizeOf(hdrTemp);
var data = new byte[size];
GCHandle handle = GCHandle.Alloc(data, GCHandleType.Pinned);
try
{
Marshal.StructureToPtr(hdrTemp, handle.AddrOfPinnedObject(), false);
}
finally
{
handle.Free();
}
_fileStream.Write(data, 0, size);
// jump back to the end of the file
_fileStream.Seek(0, SeekOrigin.End);
}
/// <summary>Read WAV file headers.</summary>
/// <returns>zero if all ok, nonzero if file format is invalid.
/// </returns>
private int ReadWavHeaders()
{
_header = new WavHeader();
int res = ReadRiffBlock();
if (res != 0)
{
return(-1);
}
// read header blocks until data block is found
do
{
// read header blocks
res = ReadHeaderBlock();
if (res < 0)
{
return(-1); // error in file structure
}
} while (res == 0);
// check that all required tags are legal
return(CheckCharTags());
}