#pragma warning disable 162 // unreachable code
private void DecodeType2Image (RLEDecodeContext context)
{
if (m_info.BPP != 8)
throw new InvalidFormatException();
throw new NotImplementedException ("Arithmetic compression not implemented");
if (EriCode.ArithmeticCode == m_info.Architecture)
{
// (context as ArithmeticContext).InitArithmeticContext (8);
m_ptrLineBuf = new sbyte[m_info.Width*4];
}
else
throw new NotImplementedException();
int dst = m_dst;
for (int nPosY = 0; nPosY < (int)m_info.Height; ++nPosY)
{
if (context.DecodeBytes (m_ptrLineBuf, m_info.Width) < m_info.Width)
throw new InvalidFormatException();
for (int x = 0; x < (int)m_info.Width; ++x)
m_output[dst+x] = (byte)m_ptrLineBuf[4 * x];
dst += m_dwBytesPerLine;
}
}
private void DecodeLosslessImage (RLEDecodeContext context)
{
context.FlushBuffer();
uint nERIVersion = context.GetNBits (8);
uint fOpTable = context.GetNBits (8);
uint fEncodeType = context.GetNBits (8);
uint nBitCount = context.GetNBits (8);
if (0 != fOpTable || 0 != (fEncodeType & 0xFE))
{
throw new InvalidFormatException();
}
switch (nERIVersion)
{
case 1:
if (nBitCount != 0)
throw new InvalidFormatException();
break;
case 2:
if (nBitCount != 0 || fEncodeType != 0)
throw new InvalidFormatException();
DecodeType2Image (context);
return;
case 8:
if (nBitCount != 8)
throw new InvalidFormatException();
break;
case 16:
if ((nBitCount != 8) || (fEncodeType != 0))
throw new InvalidFormatException();
break;
default:
throw new InvalidFormatException();
}
m_nDstPixelBytes = m_info.BPP >> 3;
m_nDstLineBytes = m_dwBytesPerLine;
var pfnRestoreFunc = GetLLRestoreFunc (m_info.FormatType, m_info.BPP);
if (null == pfnRestoreFunc)
throw new InvalidFormatException();
if (EriCode.Nemesis == m_info.Architecture)
{
Debug.Assert (m_pProbERISA != null);
m_pProbERISA.Initialize();
}
int i;
int ptrNextOperation = 0; // index within m_ptrOperations
if ((0 != (fEncodeType & 1)) && (m_nChannelCount >= 3))
{
if (m_info.Architecture == EriCode.Nemesis)
throw new InvalidFormatException();
int nAllBlockCount = m_nWidthBlocks * m_nHeightBlocks;
for (i = 0; i < nAllBlockCount; i++)
{
if (EriCode.RunlengthGamma == m_info.Architecture)
{
m_ptrOperations[i] = (byte)(context.GetNBits(4) | 0xC0);
}
else
{
Debug.Assert (EriCode.RunlengthHuffman == m_info.Architecture);
m_ptrOperations[i] = (byte)(context as HuffmanDecodeContext).GetHuffmanCode (m_pHuffmanTree);
}
}
}
if (context.GetABit() != 0)
throw new InvalidFormatException();
if (EriCode.RunlengthGamma == m_info.Architecture)
{
if (0 != (fEncodeType & 1))
{
context.InitGammaContext();
}
}
else if (EriCode.RunlengthHuffman == m_info.Architecture)
{
(context as HuffmanDecodeContext).PrepareToDecodeERINACode();
}
else
{
Debug.Assert (EriCode.Nemesis == m_info.Architecture);
(context as ProbDecodeContext).PrepareToDecodeERISACode();
}
int nWidthSamples = m_nChannelCount * m_nWidthBlocks * m_nBlockSize;
for (i = 0; i < nWidthSamples; ++i)
m_ptrLineBuf[i] = 0;
int nAllBlockLines = m_nBlockSize * m_nChannelCount;
int nLeftHeight = (int)m_info.Height;
for (int nPosY = 0; nPosY < m_nHeightBlocks; ++nPosY)
{
int nColumnBufSamples = m_nBlockSize * m_nChannelCount;
for (i = 0; i < nColumnBufSamples; ++i)
m_ptrColumnBuf[i] = 0;
m_ptrDstBlock = m_dst + nPosY * m_dwBytesPerLine * m_nBlockSize;
m_nDstHeight = Math.Min (m_nBlockSize, nLeftHeight);
int nLeftWidth = (int)m_info.Width;
int ptrNextLineBuf = 0; // m_ptrLineBuf;
for (int nPosX = 0; nPosX < m_nWidthBlocks; ++nPosX)
{
m_nDstWidth = Math.Min (m_nBlockSize, nLeftWidth);
uint dwOperationCode;
if (m_nChannelCount >= 3)
{
if (0 != (fEncodeType & 1))
{
dwOperationCode = m_ptrOperations[ptrNextOperation++];
}
else if (m_info.Architecture == EriCode.RunlengthHuffman)
{
dwOperationCode = (uint)(context as HuffmanDecodeContext).GetHuffmanCode (m_pHuffmanTree);
}
else if (m_info.Architecture == EriCode.Nemesis)
{
dwOperationCode = (uint)(context as ProbDecodeContext).DecodeERISACode (m_pProbERISA);
}
else
{
Debug.Assert (EriCode.RunlengthGamma == m_info.Architecture);
dwOperationCode = context.GetNBits (4) | 0xC0;
context.InitGammaContext();
}
}
else
{
if (EriType.Gray == m_info.FormatType)
{
dwOperationCode = 0xC0;
}
else
{
dwOperationCode = 0;
}
if (0 == (fEncodeType & 1) && m_info.Architecture == EriCode.RunlengthGamma)
{
context.InitGammaContext();
}
}
if (context.DecodeBytes (m_ptrArrangeBuf, (uint)m_nBlockSamples) < m_nBlockSamples)
{
throw new InvalidFormatException();
}
PerformOperation (dwOperationCode, nAllBlockLines, m_ptrLineBuf, ptrNextLineBuf);
ptrNextLineBuf += nColumnBufSamples;
pfnRestoreFunc();
m_ptrDstBlock += m_nDstPixelBytes * m_nBlockSize;
nLeftWidth -= m_nBlockSize;
}
nLeftHeight -= m_nBlockSize;
}
}