private void ParseChunk(bool isDeep, int offset)
{
if (offset + 8 < bytes.Length)
{
Sanity.Requires(!isDeep, $"Audio length mismatch in 0x{offset.ToString("x")}.");
return;
}
string name = Encoding.ASCII.GetString(bytes, offset, 4);
int length = BitConverter.ToInt32(bytes, offset + 4);
Chunk currentChunk = new Chunk()
{
Name = name, Length = length, Offset = offset
};
switch (name)
{
case fmt_:
ChunkFmt_ = currentChunk;
break;
case data:
ChunkData = currentChunk;
break;
case list:
ChunkList = currentChunk;
break;
case fact:
ChunkFact = currentChunk;
break;
default:
Chunks.Add(currentChunk);
break;
}
if (offset + 8 + length == bytes.Length)
{
return;
}
if (offset + 8 + length > bytes.Length)
{
Sanity.Requires(!isDeep, $"Audio length mismatch in {name}.");
return;
}
ParseChunk(isDeep, offset + 8 + length);
}
private void PostProcess()
{
Sanity.Requires(!string.IsNullOrWhiteSpace(ChunkFmt_.Name), "Missing format chunk.");
Sanity.Requires(!string.IsNullOrWhiteSpace(ChunkData.Name), "Missing data chunk.");
int offset = ChunkFmt_.Offset + 8;
AudioTypeId = BitConverter.ToInt16(bytes, offset);
Sanity.Requires(AudioTypeDict.ContainsKey(AudioTypeId), "Unsupported audio type.");
AudioTypeString = AudioTypeDict[AudioTypeId];
Channel = BitConverter.ToInt16(bytes, offset + 2);
SampleRate = BitConverter.ToInt32(bytes, offset + 4);
ByteRate = BitConverter.ToInt32(bytes, offset + 8);
BlockAlign = BitConverter.ToInt16(bytes, offset + 12);
BitsPerSample = BitConverter.ToInt16(bytes, offset + 14);
AudioLength = 1.0 * ChunkData.Length / ByteRate;
}
private void ParseRiff(byte[] bytes, bool isDeep)
{
this.bytes = bytes;
Sanity.Requires(bytes.Length >= 44, "File is less than 44 bytes.");
Sanity.Requires(RIFF == Encoding.ASCII.GetString(bytes, 0, 4), $"File is not a {RIFF} file.");
int length = BitConverter.ToInt32(bytes, 4);
if (isDeep)
{
Sanity.Requires(bytes.Length == length + 8, "Audio length mismatch in RIFF");
}
Sanity.Requires(WAVE == Encoding.ASCII.GetString(bytes, 8, 4));
ChunkRiff = new Chunk()
{
Name = "RIFF", Length = length, Offset = 0
};
ParseChunk(isDeep, 12);
}