public PpmdStream(PpmdProperties properties, Stream stream, bool compress)
{
_properties = properties;
_stream = stream;
_compress = compress;
if (properties.Version == PpmdVersion.I1)
{
_model = new Model();
if (compress)
{
_model.EncodeStart(properties);
}
else
{
_model.DecodeStart(stream, properties);
}
}
if (properties.Version == PpmdVersion.H)
{
_modelH = new ModelPpm();
if (compress)
{
throw new NotImplementedException();
}
_modelH.DecodeInit(stream, properties.ModelOrder, properties.AllocatorSize);
}
if (properties.Version == PpmdVersion.H7Z)
{
_modelH = new ModelPpm();
if (compress)
{
throw new NotImplementedException();
}
_modelH.DecodeInit(null, properties.ModelOrder, properties.AllocatorSize);
_decoder = new Decoder();
_decoder.Init(stream);
}
}
private bool ReadTables()
{
byte[] bitLength = new byte[PackDef.BC];
byte[] table = new byte[PackDef.HUFF_TABLE_SIZE];
if (inAddr > readTop - 25)
{
if (!unpReadBuf())
{
return(false);
}
}
AddBits((8 - inBit) & 7);
long bitField = GetBits() & unchecked ((int)0xffFFffFF);
if ((bitField & 0x8000) != 0)
{
unpBlockType = BlockTypes.BLOCK_PPM;
return(ppm.DecodeInit(this, PpmEscChar));
}
unpBlockType = BlockTypes.BLOCK_LZ;
prevLowDist = 0;
lowDistRepCount = 0;
if ((bitField & 0x4000) == 0)
{
Utility.Fill(unpOldTable, (byte)0); // memset(UnpOldTable,0,sizeof(UnpOldTable));
}
AddBits(2);
for (int i = 0; i < PackDef.BC; i++)
{
int length = (Utility.URShift(GetBits(), 12)) & 0xFF;
AddBits(4);
if (length == 15)
{
int zeroCount = (Utility.URShift(GetBits(), 12)) & 0xFF;
AddBits(4);
if (zeroCount == 0)
{
bitLength[i] = 15;
}
else
{
zeroCount += 2;
while (zeroCount-- > 0 && i < bitLength.Length)
{
bitLength[i++] = 0;
}
i--;
}
}
else
{
bitLength[i] = (byte)length;
}
}
UnpackUtility.makeDecodeTables(bitLength, 0, BD, PackDef.BC);
int TableSize = PackDef.HUFF_TABLE_SIZE;
for (int i = 0; i < TableSize;)
{
if (inAddr > readTop - 5)
{
if (!unpReadBuf())
{
return(false);
}
}
int Number = this.decodeNumber(BD);
if (Number < 16)
{
table[i] = (byte)((Number + unpOldTable[i]) & 0xf);
i++;
}
else if (Number < 18)
{
int N;
if (Number == 16)
{
N = (Utility.URShift(GetBits(), 13)) + 3;
AddBits(3);
}
else
{
N = (Utility.URShift(GetBits(), 9)) + 11;
AddBits(7);
}
while (N-- > 0 && i < TableSize)
{
table[i] = table[i - 1];
i++;
}
}
else
{
int N;
if (Number == 18)
{
N = (Utility.URShift(GetBits(), 13)) + 3;
AddBits(3);
}
else
{
N = (Utility.URShift(GetBits(), 9)) + 11;
AddBits(7);
}
while (N-- > 0 && i < TableSize)
{
table[i++] = 0;
}
}
}
tablesRead = true;
if (inAddr > readTop)
{
return(false);
}
UnpackUtility.makeDecodeTables(table, 0, LD, PackDef.NC);
UnpackUtility.makeDecodeTables(table, PackDef.NC, DD, PackDef.DC);
UnpackUtility.makeDecodeTables(table, PackDef.NC + PackDef.DC, LDD, PackDef.LDC);
UnpackUtility.makeDecodeTables(table, PackDef.NC + PackDef.DC + PackDef.LDC, RD, PackDef.RC);
// memcpy(unpOldTable,table,sizeof(unpOldTable));
Buffer.BlockCopy(table, 0, unpOldTable, 0, unpOldTable.Length);
return(true);
}