private void ReadRiffHeader(BinaryReader br)
{
int header = br.ReadInt32();
if (header == ChunkIdentifier.ChunkIdentifierToInt32("RF64"))
{
this.isRf64 = true;
}
else if (header != ChunkIdentifier.ChunkIdentifierToInt32("RIFF"))
{
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 = ChunkIdentifier.ChunkIdentifierToInt32("ds64");
int chunkId = reader.ReadInt32();
if (chunkId != ds64ChunkId)
{
throw new FormatException("Invalid RF64 WAV file - No ds64 chunk found");
}
int chunkSize = reader.ReadInt32();
this.riffSize = reader.ReadInt64();
this.dataChunkLength = reader.ReadInt64();
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)
{
this.dataChunkPosition = -1;
this.waveFormat = null;
this.riffChunks = new List <RiffChunk>();
this.dataChunkLength = 0;
var br = new BinaryReader(stream);
ReadRiffHeader(br);
this.riffSize = br.ReadUInt32(); // read the file size (minus 8 bytes)
if (br.ReadInt32() != ChunkIdentifier.ChunkIdentifierToInt32("WAVE"))
{
throw new FormatException("Not a WAVE file - no WAVE header");
}
if (isRf64)
{
ReadDs64Chunk(br);
}
int dataChunkId = ChunkIdentifier.ChunkIdentifierToInt32("data");
int formatChunkId = ChunkIdentifier.ChunkIdentifierToInt32("fmt ");
// 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();
var chunkLength = br.ReadUInt32();
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)
{
if (chunkLength > Int32.MaxValue)
{
throw new InvalidDataException(string.Format("Format chunk length must be between 0 and {0}.", Int32.MaxValue));
}
waveFormat = WaveFormat.FromFormatChunk(br, (int)chunkLength);
}
else
{
// check for invalid chunk length
if (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)
{
if (chunkLength > Int32.MaxValue)
{
throw new InvalidDataException(string.Format("RiffChunk chunk length must be between 0 and {0}.", Int32.MaxValue));
}
riffChunks.Add(GetRiffChunk(stream, chunkIdentifier, (int)chunkLength));
}
stream.Position += chunkLength;
}
// All Chunks have to be word aligned.
// https://www.tactilemedia.com/info/MCI_Control_Info.html
// "If the chunk size is an odd number of bytes, a pad byte with value zero is
// written after ckData. Word aligning improves access speed (for chunks resident in memory)
// and maintains compatibility with EA IFF. The ckSize value does not include the pad byte."
if (((chunkLength % 2) != 0) && (br.PeekChar() == 0))
{
stream.Position++;
}
}
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");
}
}