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;
}
public void Decode(Frame fr, StreamInfo streamInfo, BitReader str, int bitsPerSample, int channelNum)
{
byte header;
this.channelNum = channelNum;
header = (byte) str.ReadByte();
if ((header & 0x80) != 0)
{
//TODO: handle corrupt bit
return;
}
byte subtype = (byte)((header & 0x7E) >> 1);
if (subtype == 0)
{
type = SubframeType.Constant;
}
else if (subtype == 1)
{
type = SubframeType.Verbatim;
}
else if ((subtype >= 8)&&(subtype<=12))
{
type = SubframeType.Fixed;
order = (uint)(subtype & 0x7);
}
else if ((subtype & 0x20) != 0)
{
type = SubframeType.LPC;
order = (uint)(subtype & 0x1F) + 1;
}
else
{
//TODO: handle reserved frame types
return;
}
wastedBits = 0;
if ((header & 0x1) != 0)
{
int buff = 0;
do
{
str.ReadBit(ref buff);
wastedBits++;
} while (buff == 0);
}
numSamples = 0;
numResiduals = 0;
switch (type)
{
case SubframeType.Constant:
ProcessConstant(fr, str, bitsPerSample);
break;
case SubframeType.Verbatim:
ProcessVerbatim(fr, str, bitsPerSample);
break;
case SubframeType.Fixed:
ProcessFixed(fr, str, bitsPerSample);
break;
case SubframeType.LPC:
ProcessLPC(fr, str, bitsPerSample);
break;
}
}
protected FlacMethodFirBased(SubframeType subframeType, int estimatedSize, int order, FlacResidualCoefficeints residual)
: base(subframeType, estimatedSize)
{
this.order = order;
this.residual = residual;
}
protected FlacMethod(SubframeType subframeType, int estimatedSize)
{
this.subframeType = subframeType;
this.estimatedSize = estimatedSize;
}
protected FlacMethodFirBased(SubframeType subframeType, int estimatedSize, int order, FlacResidualCoefficeints residual)
: base(subframeType, estimatedSize)
{
this.order = order;
this.residual = residual;
}
protected FlacMethod(SubframeType subframeType, int estimatedSize)
{
this.subframeType = subframeType;
this.estimatedSize = estimatedSize;
}
