public int CodeSlice(ZPCodec zp)
{
if (_curbit < 0)
{
return 0;
}
if (IsNullSlice(_curbit, _curband) == 0)
{
for (int blockno = 0; blockno < _map.Nb; blockno++)
{
int fbucket = Bandbuckets[_curband].Start;
int nbucket = Bandbuckets[_curband].Size;
DecodeBuckets(zp, _curbit, _curband, _map.Blocks[blockno], fbucket, nbucket);
}
}
if (++_curband >= Bandbuckets.Length)
{
_curband = 0;
_curbit++;
if (NextQuant() == 0)
{
_curbit = -1;
return 0;
}
}
return 1;
}
public IDataCoder CreateCoder(Stream stream, bool encoding = false, bool compatibility = true)
{
ZPCodec codec = new ZPCodec {
DjvuCompat = compatibility, Encoding = encoding
};
return(codec.Initializa(stream));
}
/// <summary>
///
/// </summary>
/// <param name="input"></param>
/// <returns></returns>
public BSInputStream Init(Stream input)
{
zp = new ZPCodec().Init(input);
for (int i = 0; i < ctx.Length;)
{
ctx[i++] = new MutableValue <sbyte>();
}
return(this);
}
private void DecodeBuckets(ZPCodec zp, int bit, int band, IWBlock blk, int fbucket, int nbucket)
{
int thres = _quantHi[band];
int bbstate = 0;
sbyte[] cstate = _coeffstate;
int cidx = 0;
for (int buckno = 0; buckno < nbucket; )
{
int bstatetmp = 0;
short[] pcoeff = blk.GetBlock(fbucket + buckno);
if (pcoeff == null)
{
bstatetmp = 8;
}
else
{
for (int i = 0; i < 16; i++)
{
int cstatetmp = cstate[cidx + i] & 1;
if (cstatetmp == 0)
{
if (pcoeff[i] != 0)
{
cstatetmp |= 2;
}
else
{
cstatetmp |= 8;
}
}
cstate[cidx + i] = (sbyte)cstatetmp;
bstatetmp |= cstatetmp;
}
}
_bucketstate[buckno] = (sbyte)bstatetmp;
bbstate |= bstatetmp;
buckno++;
cidx += 16;
}
if ((nbucket < 16) || ((bbstate & 2) != 0))
{
bbstate |= 4;
}
else if ((bbstate & 8) != 0)
{
if (zp.Decoder(_ctxRoot) != 0)
{
bbstate |= 4;
}
}
if ((bbstate & 4) != 0)
{
for (int buckno = 0; buckno < nbucket; buckno++)
{
if ((_bucketstate[buckno] & 8) != 0)
{
int ctx = 0;
//if (!DjVuOptions.NOCTX_BUCKET_UPPER && (band > 0))
if ((band > 0))
{
int k = (fbucket + buckno) << 2;
short[] b = blk.GetBlock(k >> 4);
if (b != null)
{
k &= 0xf;
if (b[k] != 0)
{
ctx++;
}
if (b[k + 1] != 0)
{
ctx++;
}
if (b[k + 2] != 0)
{
ctx++;
}
if ((ctx < 3) && (b[k + 3] != 0))
{
ctx++;
}
}
}
//if (!DjVuOptions.NOCTX_BUCKET_ACTIVE && ((bbstate & 2) != 0))
if (((bbstate & 2) != 0))
{
ctx |= 4;
}
if (zp.Decoder(_ctxBucket[band][ctx]) != 0)
{
_bucketstate[buckno] |= 4;
}
}
}
}
if ((bbstate & 4) != 0)
{
cstate = _coeffstate;
cidx = 0;
for (int buckno = 0; buckno < nbucket; )
{
if ((_bucketstate[buckno] & 4) != 0)
{
short[] pcoeff = blk.GetBlock(fbucket + buckno);
if (pcoeff == null)
{
pcoeff = blk.GetInitializedBlock(fbucket + buckno);
for (int i = 0; i < 16; i++)
{
if ((cstate[cidx + i] & 1) == 0)
{
cstate[cidx + i] = 8;
}
}
}
int gotcha = 0;
int maxgotcha = 7;
//if (!DjVuOptions.NOCTX_EXPECT)
{
for (int i = 0; i < 16; i++)
{
if ((cstate[cidx + i] & 8) != 0)
{
gotcha++;
}
}
}
for (int i = 0; i < 16; i++)
{
if ((cstate[cidx + i] & 8) != 0)
{
if (band == 0)
{
thres = _quantLo[i];
}
int ctx = 0;
//if (!DjVuOptions.NOCTX_EXPECT)
{
if (gotcha >= maxgotcha)
{
ctx = maxgotcha;
}
else
{
ctx = gotcha;
}
}
//if (!DjVuOptions.NOCTX_ACTIVE && ((bucketstate[buckno] & 2) != 0))
if (((_bucketstate[buckno] & 2) != 0))
{
ctx |= 8;
}
if (zp.Decoder(_ctxStart[ctx]) != 0)
{
cstate[cidx + i] |= 4;
int halfthres = thres >> 1;
int coeff = (thres + halfthres) - (halfthres >> 2);
if (zp.IWDecoder() != 0)
{
pcoeff[i] = (short)(-coeff);
}
else
{
pcoeff[i] = (short)coeff;
}
}
//if (!DjVuOptions.NOCTX_EXPECT)
{
if ((cstate[cidx + i] & 4) != 0)
{
gotcha = 0;
}
else if (gotcha > 0)
{
gotcha--;
}
}
}
}
}
buckno++;
cidx += 16;
}
}
if ((bbstate & 2) != 0)
{
cstate = _coeffstate;
cidx = 0;
for (int buckno = 0; buckno < nbucket; )
{
if ((_bucketstate[buckno] & 2) != 0)
{
short[] pcoeff = blk.GetBlock(fbucket + buckno);
for (int i = 0; i < 16; i++)
{
if ((cstate[cidx + i] & 2) != 0)
{
int coeff = pcoeff[i];
if (coeff < 0)
{
coeff = -coeff;
}
if (band == 0)
{
thres = _quantLo[i];
}
if (coeff <= (3 * thres))
{
coeff += (thres >> 2);
if (zp.Decoder(_ctxMant) != 0)
{
coeff += (thres >> 1);
}
else
{
coeff = (coeff - thres) + (thres >> 1);
}
}
else
{
if (zp.IWDecoder() != 0)
{
coeff += (thres >> 1);
}
else
{
coeff = (coeff - thres) + (thres >> 1);
}
}
if (pcoeff[i] > 0)
{
pcoeff[i] = (short)coeff;
}
else
{
pcoeff[i] = (short)(-coeff);
}
}
}
}
buckno++;
cidx += 16;
}
}
}
public virtual void Init(BinaryReader gbs, JB2Dictionary zdict)
{
this._zdict = zdict;
_zp = new ZPCodec(gbs.BaseStream);
}
public virtual void Decode(BinaryReader bs)
{
if (_ycodec == null)
{
_cslice = _cserial = 0;
_ymap = null;
}
byte serial = bs.ReadByte();
if (serial != _cserial)
{
throw new IOException("Chunk does not bear expected serial number");
}
int nslices = _cslice + bs.ReadByte();
if (_cserial == 0)
{
int major = bs.ReadByte();
int minor = bs.ReadByte();
if ((major & 0x7f) != 1)
{
throw new IOException("File has been compressed with an incompatible Codec");
}
if (minor > 2)
{
throw new IOException("File has been compressed with a more recent Codec");
}
int header3size = 5;
if (minor < 2)
{
header3size = 4;
}
int w = (bs.ReadByte() << 8);
w |= bs.ReadByte();
int h = (bs.ReadByte() << 8);
h |= bs.ReadByte();
_crcbDelay = 0;
_crcbHalf = false;
int b = bs.ReadByte();
if (minor >= 2)
{
_crcbDelay = 0x7f & b;
}
if (minor >= 2)
{
_crcbHalf = ((0x80 & b) == 0);
}
if ((major & 0x80) != 0)
{
_crcbDelay = -1;
}
_ymap = new IWMap().Init(w, h);
_ycodec = new IWCodec().Init(_ymap);
if (_crcbDelay >= 0)
{
_cbmap = new IWMap().Init(w, h);
_crmap = new IWMap().Init(w, h);
_cbcodec = new IWCodec().Init(_cbmap);
_crcodec = new IWCodec().Init(_crmap);
}
}
ZPCodec zp = new ZPCodec().Init(bs.BaseStream);
for (int flag = 1; (flag != 0) && (_cslice < nslices); _cslice++)
{
flag = _ycodec.CodeSlice(zp);
if ((_crcodec != null) && (_cbcodec != null) && (_crcbDelay <= _cslice))
{
flag |= _cbcodec.CodeSlice(zp);
flag |= _crcodec.CodeSlice(zp);
}
}
_cserial++;
// return nslices;
}