public static EncodedWavInfo EncodeWavToAdpcm(Stream stream, AdpcmFormat format)
{
var result = new EncodedWavInfo();
result.Format = format;
using (var waveReader = new WaveFileReader(stream))
{
result.SampleRate = waveReader.WaveFormat.SampleRate;
result.SampleCount = ( int )waveReader.SampleCount;
// Try to find the smpl chunk containing loop info
var smplChunk = waveReader.ExtraChunks.FirstOrDefault(x => x.IdentifierAsString == "smpl");
if (smplChunk != null)
{
using (var reader = new BinaryValueReader(waveReader, Amicitia.IO.Streams.StreamOwnership.Retain, Endianness.Big))
{
reader.Seek(smplChunk.StreamPosition + 0x24, SeekOrigin.Begin);
var sampleLoopCount = reader.ReadInt32();
if (sampleLoopCount > 0)
{
reader.Seek(0x04 + 0x08, SeekOrigin.Current);
result.HasLoop = true;
result.LoopStart = reader.ReadInt32();
result.LoopEnd = reader.ReadInt32();
}
}
}
// Get samples
var sampleProvider = waveReader.ToSampleProvider();
sampleProvider = sampleProvider.ToMono();
var samples = new float[result.SampleCount];
sampleProvider.Read(samples, 0, samples.Length);
// Encode
var pcm16 = Waveform.Pcm32ToPcm16(samples);
result.History = new AdpcmHistory[Waveform.GetAdpcmFrameCount(pcm16.Length)];
if (format == AdpcmFormat.Adpcm4)
{
result.Data = Waveform.Pcm16ToAdpcm4(pcm16, result.History);
}
else
{
throw new NotImplementedException();
}
}
return(result);
}
