private IEnumerator <int> ReadResidualData(FlacBitStreamReader bitReader, int blockSize, int predictorOrder)
{
const byte RiceCodingWith4BitParameter = 0;
const byte RiceCodingWith5BitParameter = 1;
uint residualRiceParamSizeType = bitReader.ReadBits(2);
int residualRiceParamSize;
if (residualRiceParamSizeType == RiceCodingWith4BitParameter)
{
residualRiceParamSize = 4;
}
else if (residualRiceParamSizeType == RiceCodingWith5BitParameter)
{
residualRiceParamSize = 5;
}
else
{
throw new FlacException("Reserved residual coding method");
}
// rice and rice2 almost the same
// read rice partitined method
int partitionOrder = (int)bitReader.ReadBits(4);
int partitionCount = 1 << partitionOrder;
int sampleCount = blockSize >> partitionOrder;
if (sampleCount < predictorOrder || sampleCount < 1 ||
(sampleCount << partitionOrder) != blockSize)
{
throw new FlacException("Invalid partition order");
}
for (int i = 0; i < partitionCount; i++)
{
int skipSamples = i == 0 ? predictorOrder : 0;
int riceParameter = (int)bitReader.ReadBits(residualRiceParamSize);
if (riceParameter + 1 == 1 << residualRiceParamSize)
{
// escape mode
int bitsPerSample = (int)bitReader.ReadBits(5);
for (int j = skipSamples; j < sampleCount; j++)
{
yield return(bitReader.ReadSignedBits(bitsPerSample));
}
}
else
{
int maxRiceK = int.MaxValue >> riceParameter;
for (int j = skipSamples; j < sampleCount; j++)
{
yield return(bitReader.ReadRice(riceParameter));
}
}
}
}
private IEnumerator<int> ReadResidualData(FlacBitStreamReader bitReader, int blockSize, int predictorOrder)
{
const byte RiceCodingWith4BitParameter = 0;
const byte RiceCodingWith5BitParameter = 1;
uint residualRiceParamSizeType = bitReader.ReadBits(2);
int residualRiceParamSize;
if (residualRiceParamSizeType == RiceCodingWith4BitParameter)
residualRiceParamSize = 4;
else if (residualRiceParamSizeType == RiceCodingWith5BitParameter)
residualRiceParamSize = 5;
else
throw new FlacException("Reserved residual coding method");
// rice and rice2 almost the same
// read rice partitined method
int partitionOrder = (int)bitReader.ReadBits(4);
int partitionCount = 1 << partitionOrder;
int sampleCount = blockSize >> partitionOrder;
if (sampleCount < predictorOrder || sampleCount < 1 ||
(sampleCount << partitionOrder) != blockSize )
throw new FlacException("Invalid partition order");
for (int i = 0; i < partitionCount; i++)
{
int skipSamples = i == 0 ? predictorOrder : 0;
int riceParameter = (int)bitReader.ReadBits(residualRiceParamSize);
if (riceParameter + 1 == 1 << residualRiceParamSize)
{
// escape mode
int bitsPerSample = (int)bitReader.ReadBits(5);
for (int j = skipSamples; j < sampleCount; j++)
{
yield return bitReader.ReadSignedBits(bitsPerSample);
}
}
else
{
int maxRiceK = int.MaxValue >> riceParameter;
for (int j = skipSamples; j < sampleCount; j++)
{
yield return bitReader.ReadRice(riceParameter);
}
}
}
}
private void ReadSubframe()
{
uint zeroPadding = bitReader.ReadBits(1);
if (zeroPadding != 0)
{
throw new FlacException("Subframe zero padding is not zero");
}
int subframeType = (int)bitReader.ReadBits(6);
SubframeType type;
int order = 0;
if (subframeType == FlacCommons.ConstantSubframeType)
{
type = SubframeType.SubframeConstant;
}
else if (subframeType == FlacCommons.VerbatimSubframeType)
{
type = SubframeType.SubframeVerbatim;
}
else if (FlacCommons.FixedSubframeTypeStart <= subframeType &&
subframeType <= FlacCommons.FixedSubframeTypeEnd)
{
type = SubframeType.SubframeFixed;
order = subframeType - FlacCommons.FixedSubframeTypeStart;
}
else if (subframeType >= FlacCommons.LpcSubframeTypeStart)
{
type = SubframeType.SubframeLpc;
order = subframeType - FlacCommons.LpcSubframeTypeStart + 1;
}
else
{
throw new FlacException("Subframe type is set to reserved");
}
uint wastedBitsPerSampleFlag = bitReader.ReadBits(1);
if (wastedBitsPerSampleFlag > 0)
{
this.wastedBitsPerSample = 1 + (int)bitReader.ReadUnary();
}
else
{
this.wastedBitsPerSample = 0;
}
this.subframeType = type;
int subframeBitsPerSample = FrameBitsPerSample;
if (ChannelAssignment[subframeIndex] == SoundChannelAssignment.Difference)
{
subframeBitsPerSample++; // undocumented
}
switch (type)
{
case SubframeType.SubframeConstant:
PrepareConstantSubframe(subframeBitsPerSample);
break;
case SubframeType.SubframeVerbatim:
PrepareVerbatimSubframe(subframeBitsPerSample);
break;
case SubframeType.SubframeLpc:
PrepareLpcSubframe(order, subframeBitsPerSample);
break;
case SubframeType.SubframeFixed:
PrepareFixedSubframe(order, subframeBitsPerSample);
break;
}
this.recordType = FlacRecordType.Subframe;
this.dataRead = false;
}
