public unsafe FlacSubFrameFixed(FlacBitReader reader, FlacFrameHeader header, FlacSubFrameData data, int bitsPerSample, int order)
: base(header)
{
for (int i = 0; i < order; i++) //order = predictor order
{
data.ResidualBuffer[i] = data.DestinationBuffer[i] = reader.ReadBitsSigned(bitsPerSample);
}
var residual = new FlacResidual(reader, header, data, order); //necessary for decoding
RestoreSignal(data, header.BlockSize - order, order);
#if FLAC_DEBUG
Residual = residual;
#endif
}
public unsafe FlacSubFrameLPC(FlacBitReader reader, FlacFrameHeader header, FlacSubFrameData data, int bitsPerSample, int order)
: base(header)
{
var warmup = new int[order];
for (int i = 0; i < order; i++)
{
warmup[i] = data.ResidualBuffer[i] = reader.ReadBitsSigned(bitsPerSample);
}
int coefPrecision = (int)reader.ReadBits(4);
if (coefPrecision == 0x0F)
{
throw new FlacException("Invalid \"quantized linear predictor coefficients' precision in bits\" was invalid. Must not be 0x0F.",
FlacLayer.SubFrame);
}
coefPrecision += 1;
int shiftNeeded = reader.ReadBitsSigned(5);
if (shiftNeeded < 0)
{
throw new FlacException("'\"Quantized linear predictor coefficient shift needed in bits\" was negative.", FlacLayer.SubFrame);
}
var q = new int[order];
for (int i = 0; i < order; i++)
{
q[i] = reader.ReadBitsSigned(coefPrecision);
}
//decode the residual
var residual = new FlacResidual(reader, header, data, order);
for (int i = 0; i < order; i++)
{
data.DestinationBuffer[i] = data.ResidualBuffer[i];
}
int *residualBuffer0 = data.ResidualBuffer + order;
int *destinationBuffer0 = data.DestinationBuffer + order;
int blockSizeToProcess = header.BlockSize - order;
if (bitsPerSample + coefPrecision + Log2(order) <= 32)
{
RestoreLPCSignal32(residualBuffer0, destinationBuffer0, blockSizeToProcess, order, q, shiftNeeded);
}
else
{
RestoreLPCSignal64(residualBuffer0, destinationBuffer0, blockSizeToProcess, order, q, shiftNeeded);
}
#if FLAC_DEBUG
QLPCoeffPrecision = coefPrecision;
LPCShiftNeeded = shiftNeeded;
Warmup = warmup;
Residual = residual;
QLPCoeffs = q;
#endif
}