protected override bool WriteVectors(VorbisCodebook codebook, DataPacket packet, float[][] residue, int channel, int offset, int partitionSize)
{
var chPtr = 0;
offset /= _channels;
for (int c = 0; c < partitionSize;)
{
var entry = codebook.DecodeScalar(packet);
if (entry == -1)
{
return(true);
}
for (var d = 0; d < codebook.Dimensions; d++, c++)
{
residue[chPtr][offset] += codebook[entry, d];
if (++chPtr == _channels)
{
chPtr = 0;
offset++;
}
}
}
return(false);
}
protected override bool WriteVectors(VorbisCodebook codebook, DataPacket packet, float[][] residue, int channel, int offset, int partitionSize)
{
var res = residue[channel];
for (int i = 0; i < partitionSize;)
{
var entry = codebook.DecodeScalar(packet);
if (entry == -1)
{
return(true);
}
for (int j = 0; j < codebook.Dimensions; i++, j++)
{
res[offset + i] += codebook[entry, j];
}
}
return(false);
}
virtual protected bool WriteVectors(VorbisCodebook codebook, DataPacket packet, float[][] residue, int channel, int offset, int partitionSize)
{
var res = residue[channel];
var step = partitionSize / codebook.Dimensions;
for (int i = 0; i < step; i++)
{
if ((_entryCache[i] = codebook.DecodeScalar(packet)) == -1)
{
return(true);
}
}
for (int i = 0; i < codebook.Dimensions; i++)
{
for (int j = 0; j < step; j++, offset++)
{
res[offset] += codebook[_entryCache[j], i];
}
}
return(false);
}
internal override float[][] Decode(DataPacket packet, bool[] doNotDecode, int channels, int blockSize)
{
var residue = GetResidueBuffer(doNotDecode.Length);
// this is pretty well stolen directly from libvorbis... BSD license
var end = _end < blockSize / 2 ? _end : blockSize / 2;
var n = end - _begin;
if (n > 0 && doNotDecode.Contains(false))
{
var partVals = n / _partitionSize;
var partWords = (partVals + _classBook.Dimensions - 1) / _classBook.Dimensions;
for (int j = 0; j < channels; j++)
{
Array.Clear(_partWordCache[j], 0, partWords);
}
for (int s = 0; s < _maxStages; s++)
{
for (int i = 0, l = 0; i < partVals; l++)
{
if (s == 0)
{
for (int j = 0; j < channels; j++)
{
var idx = _classBook.DecodeScalar(packet);
if (idx >= 0 && idx < _decodeMap.Length)
{
_partWordCache[j][l] = _decodeMap[idx];
}
else
{
i = partVals;
s = _maxStages;
break;
}
}
}
for (int k = 0; i < partVals && k < _classBook.Dimensions; k++, i++)
{
var offset = _begin + i * _partitionSize;
for (int j = 0; j < channels; j++)
{
var idx = _partWordCache[j][l][k];
if ((_cascade[idx] & (1 << s)) != 0)
{
var book = _books[idx][s];
if (book != null)
{
if (WriteVectors(book, packet, residue, j, offset, _partitionSize))
{
// bad packet... exit now and try to use what we already have
i = partVals;
s = _maxStages;
break;
}
}
}
}
}
}
}
}
return(residue);
}
