/// <summary>
/// Parse the MsAdpcm format wav.
/// </summary>
private void ParseMsAdpcm()
{
int offset = Chunk_fmt_.Offset;
Sanity.RequiresWave(Chunk_fmt_.Length >= 30, "fmt_ chunk is shorter than expected.");
switch (SampleRate)
{
case 8000:
case 11025:
Sanity.RequiresWave(BlockAlign == 256, "MsAdpcm BlockAlign mismatch.");
break;
case 22050:
Sanity.RequiresWave(BlockAlign == 512, "MsAdpcm BlockAlign mismatch.");
break;
case 44100:
Sanity.RequiresWave(BlockAlign == 1024, "MsAdpcm BlockAlign mismatch.");
break;
default:
break;
}
CbSize = BitConverter.ToInt16(WaveBytes, offset + 24);
SamplesPerBlock = BitConverter.ToInt16(WaveBytes, offset + 26);
NumCoef = BitConverter.ToInt16(WaveBytes, offset + 28);
Sanity.RequiresWave(NumCoef * 4 + 4 == CbSize, "CbSize mismatch.");
Sanity.RequiresWave(BitsPerSample == 4, "bits/sample should be 4 in MsAdpcm.");
Sanity.RequiresWave(SampleRate * BlockAlign / SamplesPerBlock == ByteRate, "ByteRate equation error.");
Sanity.RequiresWave((BlockAlign - 7 * NumChannels) * 8 / (BitsPerSample * NumChannels) + 2 == SamplesPerBlock, "SamplesPerBlock equation error.");
CoefList = Enumerable.Range(0, NumCoef * 2).Select(x => BitConverter.ToInt16(WaveBytes, offset + 30 + x * 2)).ToList();
Sanity.RequiresWave(CoefStandardList.SequenceEqual(CoefList.Take(2 * NumCoef)), "Coef list mismatch.");
}
public void ParseData()
{
Sanity.Requires(DeepFlag, "Parse data requires deep parse.");
ParseDataFlag = true;
AudioBits = BlockAlign / NumChannels * 8;
DataValues = CalcValues().ToArray();
RMS = CalculateRms();
}
/// <summary>
/// Parse the extra parts, typically for alaw and ulaw.
/// </summary>
private void ParseWaveFormatEx()
{
if (Chunk_fmt_.Length >= 18)
{
CbSize = BitConverter.ToInt16(WaveBytes, 24);
}
Sanity.RequiresWave(ByteRate == NumChannels * SampleRate * BitsPerSample / 8, "Byte rate equation error.");
Sanity.RequiresWave(BlockAlign == NumChannels * BitsPerSample / 8, "BlockAlign equation error.");
Sanity.RequiresWave(CbSize == Chunk_fmt_.Length - 16, "CbSize Error.");
}
public static byte[] ReadBytes(string path, int n)
{
Sanity.Requires(File.Exists(path), "The file doesn't exist.");
Sanity.Requires(n >= 0, "The bytes required cannot be negative.");
using (FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read))
{
using (BinaryReader br = new BinaryReader(fs))
{
return(br.ReadBytes(n));
}
}
}
/// <summary>
/// Check the chunks after all the parsing are done.
/// </summary>
private void PostCheck()
{
Sanity.RequiresWave(!string.IsNullOrEmpty(Chunk_fmt_.Name), "Missing fmt_ chunk.");
Sanity.RequiresWave(!string.IsNullOrEmpty(Chunk_data.Name), "Missing data chunk.");
if (DeepFlag)
{
DataBytes = new byte[Chunk_data.Length];
DataBytes = WaveBytes.ArraySkip(Chunk_data.Offset + 8);
//Array.Copy(WaveBytes, Chunk_data.Offset + 8, DataBytes, 0, Chunk_data.Length);
}
ParseFormat();
AudioLength = 1.0 * Chunk_data.Length / ByteRate;
}
/// <summary>
/// Parse the RIFF chunk.
/// </summary>
private void ParseRiff()
{
Sanity.RequiresWave(WaveBytes.Length >= 44, "Wave size is less than min requirement(44 bytes).");
string riffName = Encoding.ASCII.GetString(WaveBytes, 0, 4);
Sanity.RequiresWave(riffName == "RIFF", "Riff header broken.");
int length = BitConverter.ToInt32(WaveBytes, 4);
Sanity.RequiresWave(!DeepFlag || length + 8 == WaveBytes.Length, "Riff length broken.");
string waveName = Encoding.ASCII.GetString(WaveBytes, 8, 4);
Sanity.RequiresWave(waveName == "WAVE", "Wave header broken.");
ParseChunk(12);
}
/// <summary>
/// Parse the chunk.
/// </summary>
/// <param name="offset">The offset of the chunk</param>
private void ParseChunk(int offset)
{
if (offset == WaveBytes.Length)
{
return;
}
if (offset + 8 > WaveBytes.Length)
{
Sanity.RequiresWave(!DeepFlag, "Wave is shorter than expected.");
return;
}
string name = Encoding.ASCII.GetString(WaveBytes, offset, 4);
int length = BitConverter.ToInt32(WaveBytes, offset + 4);
if ((length & 1) == 1)
{
length++;
}
switch (name)
{
case "fmt ":
Sanity.RequiresWave(string.IsNullOrEmpty(Chunk_fmt_.Name), "fmt_ chunk duplication.");
Chunk_fmt_ = new Chunk {
Name = name, Length = length, Offset = offset
};
break;
case "data":
Sanity.RequiresWave(string.IsNullOrEmpty(Chunk_data.Name), "data chunk duplication.");
Chunk_data = new Chunk {
Name = name, Length = length, Offset = offset
};
break;
default:
Chunks.Add(new Chunk()
{
Name = name, Length = length, Offset = offset
});
break;
}
ParseChunk(offset + 8 + length);
}
/// <summary>
/// Calculate the root mean square of the audio.
/// </summary>
/// <returns>The RMS value</returns>
private double CalculateRms()
{
Sanity.Requires(ParseDataFlag, "The wave data has to be parsed in order to get RMS.");
return(Math.Sqrt(DataValues.Sum(x => x * x) / DataValues.Length));
}
public static int ToInt24(byte[] bytes, int offset)
{
Sanity.Requires(offset + 3 <= bytes.Length, "Offset exceeds array length.");
return(ToInt24(bytes[offset], bytes[offset + 1], bytes[offset + 2]));
}