private void ReadRiffHeader(BinaryReader br)
{
int header = br.ReadInt32();
if (header == WaveInterop.mmioStringToFOURCC("RF64", 0))
{
isRf64 = true;
}
else if (header != WaveInterop.mmioStringToFOURCC("RIFF", 0))
{
throw new FormatException("Not a WAVE file - no RIFF header");
}
}
/// <summary>
/// http://tech.ebu.ch/docs/tech/tech3306-2009.pdf
/// </summary>
private void ReadDs64Chunk(BinaryReader reader)
{
int ds64ChunkId = WaveInterop.mmioStringToFOURCC("ds64", 0);
int chunkId = reader.ReadInt32();
if (chunkId != ds64ChunkId)
{
throw new FormatException("Invalid RF64 WAV file - No ds64 chunk found");
}
int chunkSize = reader.ReadInt32();
riffSize = reader.ReadInt64();
dataChunkLength = reader.ReadInt64();
// ReSharper disable once UnusedVariable
long sampleCount = reader.ReadInt64(); // replaces the value in the fact chunk
reader.ReadBytes(chunkSize - 24); // get to the end of this chunk (should parse extra stuff later)
}
public void ReadWaveHeader(Stream stream)
{
dataChunkPosition = -1;
waveFormat = null;
riffChunks = new List <RiffChunk>();
dataChunkLength = 0;
BinaryReader br = new BinaryReader(stream);
ReadRiffHeader(br);
riffSize = br.ReadUInt32(); // read the file size (minus 8 bytes)
if (br.ReadInt32() != WaveInterop.mmioStringToFOURCC("WAVE", 0))
{
throw new FormatException("Not a WAVE file - no WAVE header");
}
if (isRf64)
{
ReadDs64Chunk(br);
}
int dataChunkID = WaveInterop.mmioStringToFOURCC("data", 0);
int formatChunkId = WaveInterop.mmioStringToFOURCC("fmt ", 0);
// sometimes a file has more data than is specified after the RIFF header
long stopPosition = Math.Min(riffSize + 8, stream.Length);
// this -8 is so we can be sure that there are at least 8 bytes for a chunk id and length
while (stream.Position <= stopPosition - 8)
{
Int32 chunkIdentifier = br.ReadInt32();
Int32 chunkLength = br.ReadInt32();
if (chunkIdentifier == dataChunkID)
{
dataChunkPosition = stream.Position;
if (!isRf64) // we already know the dataChunkLength if this is an RF64 file
{
dataChunkLength = chunkLength;
}
stream.Position += chunkLength;
}
else if (chunkIdentifier == formatChunkId)
{
waveFormat = WaveFormat.FromFormatChunk(br, chunkLength);
}
else
{
// check for invalid chunk length
if (chunkLength < 0 || chunkLength > stream.Length - stream.Position)
{
if (strictMode)
{
Debug.Assert(false, String.Format("Invalid chunk length {0}, pos: {1}. length: {2}",
chunkLength, stream.Position, stream.Length));
}
// an exception will be thrown further down if we haven't got a format and data chunk yet,
// otherwise we will tolerate this file despite it having corrupt data at the end
break;
}
if (storeAllChunks)
{
riffChunks.Add(GetRiffChunk(stream, chunkIdentifier, chunkLength));
}
stream.Position += chunkLength;
}
}
if (waveFormat == null)
{
throw new FormatException("Invalid WAV file - No fmt chunk found");
}
if (dataChunkPosition == -1)
{
throw new FormatException("Invalid WAV file - No data chunk found");
}
}