public IRiffContainer Encode(ISound sound, int samplesPerBlock)
{
var sampleRate = sound[NumericData.Rate];
if (sampleRate == null)
{
var sampleRates = sound
.Samples
.Select(s => s[NumericData.Rate])
.Where(r => r != null)
.Distinct()
.ToArray();
sampleRate = sampleRates.SingleOrDefault();
}
if (sampleRate == null)
{
sampleRate = 44100;
}
var channels = sound.Samples.Count;
var byteRate = sampleRate * channels * 2 / 4; //not accurate but not far off
var container = new RiffContainer
{
Format = "WAVE",
Chunks = new List <IRiffChunk>()
};
var extraFormat = new MicrosoftAdpcmFormat
{
Coefficients = MicrosoftAdpcmConstants.DefaultCoefficients,
SamplesPerBlock = 500
};
var format = new RiffFormat
{
Format = 2,
SampleRate = (int)sampleRate,
Channels = channels,
ByteRate = (int)byteRate,
BitsPerSample = 4,
BlockAlign = _microsoftAdpcmEncoder.GetBlockSize(samplesPerBlock, channels),
ExtraData = extraFormat.ToBytes()
};
container.Chunks.Add(_formatEncoder.Encode(format));
container.Chunks.Add(new RiffChunk
{
Id = "data",
Data = _microsoftAdpcmEncoder.Encode(sound, samplesPerBlock)
});
return(container);
}
public RiffDescriptorChunk(RiffFormat format = RiffFormat.WAVE, uint fileLength = 36)
{
ChunkID = BitConverter.GetBytes((uint)RiffChunkId.RIFF).Reverse().ToArray();
ChunkSize = BitConverter.GetBytes(fileLength);
Data = BitConverter.GetBytes((uint)format).Reverse().ToArray();
}
public IRiffContainer Encode(ISound sound)
{
var sampleRate = sound[NumericData.Rate];
if (sampleRate == null)
{
var sampleRates = sound
.Samples
.Select(s => s[NumericData.Rate])
.Where(r => r != null)
.Distinct()
.ToArray();
sampleRate = sampleRates.SingleOrDefault();
}
if (sampleRate == null)
{
sampleRate = 44100;
}
var channels = sound.Samples.Count;
var byteRate = sampleRate * channels * 2;
var container = new RiffContainer
{
Format = "WAVE",
Chunks = new List <IRiffChunk>()
};
var format = new RiffFormat
{
Format = 1,
SampleRate = (int)sampleRate,
Channels = channels,
ByteRate = (int)byteRate,
BitsPerSample = 16,
BlockAlign = channels * 2,
ExtraData = new byte[0]
};
container.Chunks.Add(_formatEncoder.Encode(format));
var totalSamples = sound.Samples.Max(s => s.Data.Count);
using (var stream = new MemoryStream())
using (var writer = new BinaryWriter(stream))
{
for (var i = 0; i < totalSamples; i++)
{
for (var j = 0; j < sound.Samples.Count; j++)
{
var sample = sound.Samples[j];
var source = sample.Data;
var sourceValue = i < source.Count ? source[i] : 0f;
var value = Math.Round(sourceValue * 32767f);
if (value > 32767f)
{
value = 32767f;
}
else if (value < -32767f)
{
value = -32767f;
}
writer.Write((short)value);
}
}
container.Chunks.Add(new RiffChunk
{
Id = "data",
Data = stream.ToArray()
});
}
return(container);
}
