public void WriteWav(Stream target)
{
BinaryWriter writer = new BinaryWriter(target);
// Calculate wav values
int wavFileSize = this.fileSize - (this.fmtHeaderSize - 16); // Calculate fmt chunk size difference
ushort sampleFrameSize = (ushort)(this.channels * 2);
uint averageBytesPerSecond = this.sampleRate * sampleFrameSize;
// Write header
writer.Write(Encoding.ASCII.GetBytes("RIFF"));
writer.Write(this.fileSize);
writer.Write(Encoding.ASCII.GetBytes("WAVE"));
// Write FMT Chunk
writer.Write(Encoding.ASCII.GetBytes("fmt ")); // Chunk Id
writer.Write((int)16); // Chunk size
writer.Write((ushort)0x0001); // Format tag
writer.Write(this.channels); // Channels
writer.Write(this.sampleRate); // Sample Rate
writer.Write(averageBytesPerSecond); // Average bytes per second
writer.Write(sampleFrameSize); // Sample frame size
writer.Write((ushort)16); // Bits per sample
// Write data chunks
while (this.stream.Position < this.stream.Length)
{
WChunk chunk = this.ReadChunk(this.reader);
writer.Write(Encoding.ASCII.GetBytes(chunk.ID));
writer.Write(chunk.DataSize);
writer.Write(chunk.Data);
}
writer.Flush();
}
private WChunk ReadChunk(BinaryReader reader, bool readData = true)
{
WChunk chunk = new WChunk();
chunk.ID = Encoding.ASCII.GetString(reader.ReadBytes(4));
chunk.DataSize = reader.ReadInt32();
if (readData)
{
chunk.Data = reader.ReadBytes(chunk.DataSize);
}
return(chunk);
}
public WEMFile(Stream stream)
{
this.stream = stream;
this.reader = new BinaryReader(this.stream);
// Validate header
{
// Do not read chunk data here, as DataSize contains the whole file
WChunk wemHead = this.ReadChunk(this.reader, false);
if (wemHead.ID != "RIFF")
{
throw new FormatException();
}
// RIFF chunk should always be followed by "WAVE"
if (Encoding.ASCII.GetString(reader.ReadBytes(4)) != "WAVE")
{
throw new FormatException();
}
this.fileSize = wemHead.DataSize;
}
// Read format definition
{
WChunk wemFmt;
do
{
wemFmt = this.ReadChunk(this.reader);
if (wemFmt.ID != "fmt ")
{
Console.Error.WriteLine($"Unexpected WEM chunk \"{wemFmt.ID}\". Expected \"fmt\". Skipping...");
this.stream.Seek(wemFmt.DataSize, SeekOrigin.Current);
continue;
}
this.fmtHeaderSize = wemFmt.DataSize;
BinaryReader fmtReader = new BinaryReader(new MemoryStream(wemFmt.Data));
fmtReader.ReadUInt16(); // Format tag is not relevant for WEM
this.channels = fmtReader.ReadUInt16();
this.sampleRate = fmtReader.ReadUInt32();
// We ignore all other values as they are not important to us
} while (wemFmt.ID != "fmt ");
}
// We are set and ready
}
