private RiffSubChunk ParseSubChunk(BinaryReader reader)
{
string id = Utils.ReadUTF8String(reader, 4);
reader.BaseStream.Position -= 4;
long startOffset = reader.BaseStream.Position + 8;
Func <RiffParser, BinaryReader, RiffSubChunk> parser;
RiffSubChunk subChunk = RegisteredSubChunks.TryGetValue(id, out parser) ? parser(this, reader) : new RiffSubChunk(reader);
long endOffset = startOffset + subChunk.SubChunkSize;
int remainingBytes = (int)Math.Max(endOffset - reader.BaseStream.Position, 0);
subChunk.Extra = reader.ReadBytes(remainingBytes);
reader.BaseStream.Position = endOffset + (endOffset & 1); // Subchunks are 2-byte aligned
return(subChunk);
}
public void ParseRiff(Stream file)
{
using (BinaryReader reader = new BinaryReader(file))
{
RiffChunk = RiffChunk.Parse(reader);
SubChunks.Clear();
// Size is counted from after the ChunkSize field, not the RiffType field
long startOffset = reader.BaseStream.Position - 4;
long endOffset = startOffset + RiffChunk.Size;
// Make sure 8 bytes are available for the subchunk header
while (reader.BaseStream.Position + 8 < endOffset)
{
RiffSubChunk subChunk = ParseSubChunk(reader);
SubChunks[subChunk.SubChunkId] = subChunk;
}
}
}