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GPXSee/src/map/IMG/jls.cpp

333 lines
6.1 KiB
C++

#include <cmath>
#include "jls.h"
using namespace IMG;
#define max(a, b) ((a) > (b) ? (a) : (b))
static const quint8 Z[] = {
8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
};
static const int J[] = {
0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3,
4, 4, 5, 5, 6, 6, 7, 7, 8, 9, 10, 11, 12, 13, 14, 15
};
JLS::JLS(quint16 diff, quint16 factor)
{
_maxval = diff;
_near = factor;
_range = ((_maxval + _near * 2) / (_near * 2 + 1)) + 1;
_qbpp = ceil(log2(_range));
quint8 bpp = max(2, ceil(log2(_maxval + 1)));
quint8 LIMIT = 2 * (bpp + max(8, bpp));
_limit = LIMIT - _qbpp - 1;
}
bool JLS::processRunMode(BitStream &bs, quint16 col, quint16 &samples)
{
quint8 z;
quint16 cnt = 0;
while (true) {
if ((qint32)bs.value() < 0) {
z = Z[(bs.value() >> 0x18) ^ 0xff];
for (quint8 i = 0; i < z; i++) {
cnt = cnt + _rg;
if (cnt <= col && _runIndex < 31) {
_runIndex++;
_rk = J[_runIndex];
_rg = 1U << _rk;
}
if (cnt >= col) {
if (!bs.read(i + 1))
return 3;
samples = col;
return true;
}
}
} else
z = 0;
if (z != 8) {
if (!bs.read(z + 1))
return false;
if (_rk) {
samples = (bs.value() >> (32 - _rk)) + cnt;
if (!bs.read(_rk))
return false;
} else
samples = cnt;
_lrk = _rk + 1;
if (_runIndex != 0) {
_runIndex--;
_rk = J[_runIndex];
_rg = 1U << _rk;
}
return true;
}
if (!bs.read(8))
return false;
}
}
bool JLS::decodeError(BitStream &bs, quint8 limit, quint8 k, uint &MErrval)
{
quint8 cnt = 0;
MErrval = 0;
while ((int)bs.value() >= 0) {
cnt = Z[bs.value() >> 0x18];
MErrval += cnt;
if (bs.value() >> 0x18 != 0)
break;
if (!bs.read(8))
return false;
cnt = 0;
}
if (!bs.read(cnt + 1))
return false;
if (MErrval < limit) {
if (k != 0) {
MErrval = (bs.value() >> (0x20 - k)) + (MErrval << k);
if (!bs.read(k))
return false;
}
} else {
MErrval = (bs.value() >> (0x20 - _qbpp)) + 1;
if (!bs.read(_qbpp))
return false;
}
return true;
}
bool JLS::readLine(BitStream &bs)
{
quint8 ictx, rctx;
quint8 k;
uint MErrval;
int Errval;
int Rx;
int Ra = _last[1];
int Rb = _last[1];
int Rc = _last[0];
uint col = 1;
*_current = _last[1];
do {
if (abs(Rb - Ra) > _near) {
int Px = Ra + Rb - Rc;
if (Px < 0)
Px = 0;
else if (Px > _maxval)
Px = _maxval;
for (k = 0; _n[1] << k < _a[1]; k++)
;
if (!decodeError(bs, _limit, k, MErrval))
return false;
int mes, meh;
if (MErrval & 1) {
meh = (MErrval + 1) >> 1;
mes = -meh;
} else {
meh = MErrval >> 1;
mes = meh;
}
if ((_near == 0) && (k == 0) && (_b[1] * 2 <= -_n[1])) {
meh = mes + 1;
mes = -mes - 1;
if (MErrval & 1)
meh = mes;
} else
mes = mes * (_near * 2 + 1);
Errval = (Ra < Rb) ? mes : -mes;
Rx = Px + Errval;
if (Rx < -_near)
Rx += (_near * 2 + 1) * _range;
else if (Rx > _maxval + _near)
Rx -= (_near * 2 + 1) * _range;
if (Rx < 0)
Rx = 0;
if (Rx > _maxval)
Rx = _maxval;
_a[1] = _a[1] + meh;
_b[1] = _b[1] + mes;
if (_n[1] == 0x40) {
_a[1] = _a[1] >> 1;
if (_b[1] >= 0)
_b[1] = _b[1] >> 1;
else
_b[1] = -((1 - _b[1]) >> 1);
_n[1] = 0x21;
} else {
_n[1] = _n[1] + 1;
}
if (_b[1] <= -_n[1]) {
_b[1] = _b[1] + _n[1];
if (_b[1] <= -_n[1])
_b[1] = 1 - _n[1];
} else if (_b[1] > 0)
_b[1] = ((_b[1] - _n[1]) >> 0xf) & (_b[1] - _n[1]);
Rc = Rb;
Rb = _last[col + 1];
} else {
quint16 samples;
if (!processRunMode(bs, _w - col + 1, samples))
return false;
if (samples != 0) {
for (int i = 0; i < samples; i++) {
if (col > _w)
return false;
_current[col] = Ra;
col++;
}
if (col > _w)
break;
Rc = _last[col];
Rb = _last[col + 1];
} else {
Rc = Rb;
Rb = _last[col + 1];
}
rctx = (abs(Rc - Ra) <= _near);
quint16 TEMP = _a[rctx + 2];
if (rctx)
TEMP += _n[rctx + 2] >> 1;
ictx = rctx | 2;
for (k = 0; _n[rctx + 2] << k < TEMP; k++)
;
if (!decodeError(bs, _limit - _lrk, k, MErrval))
return false;
quint16 s = ((k == 0) && (rctx || MErrval)) ?
(_b[ictx] * 2 < _n[ictx]) : 0;
Errval = MErrval + rctx + s;
int evh;
if ((Errval & 1) == 0) {
Errval = Errval / 2;
evh = Errval;
} else {
Errval = s - ((Errval + 1) >> 1);
evh = -Errval;
_b[ictx] = _b[ictx] + 1;
}
Errval *= (_near * 2 + 1);
if (!rctx) {
if (Ra == Rc)
return false;
if (Ra < Rc)
Rx = Rc + Errval;
else
Rx = Rc - Errval;
} else
Rx = Ra + Errval;
if (Rx < -_near)
Rx += (_near * 2 + 1) * _range;
else if (Rx > _maxval + _near)
Rx -= (_near * 2 + 1) * _range;
if (Rx < 0)
Rx = 0;
if (Rx > _maxval)
Rx = _maxval;
_a[ictx] = _a[ictx] + (evh - rctx);
if (_n[ictx] == 0x40) {
_a[ictx] = _a[ictx] >> 1;
if (_b[ictx] >= 0)
_b[ictx] = _b[ictx] >> 1;
else
_b[ictx] = -((1 - _b[ictx]) >> 1);
_n[ictx] = 0x21;
} else
_n[ictx] = _n[ictx] + 1;
}
_current[col] = Rx;
Ra = Rx;
col = col + 1;
} while (col <= _w);
return true;
}
bool JLS::decode(const SubFile *file, SubFile::Handle &hdl, Matrix<qint16> &img)
{
BitStream bs(file, hdl);
if (!bs.init())
return false;
_w = img.w();
_data = QVector<quint16>((_w + 3) * 2);
_last = _data.data();
_current = _data.data() + (_w + 3);
_runIndex = 0;
_rk = 0;
_rg = 1;
_lrk = 0;
quint16 A = max(2, (_range + 32) / 64);
for (int i = 0; i < 4; i++) {
_a[i] = A;
_b[i] = 0;
_n[i] = 1;
}
for (int i = 0; i < img.h(); i++) {
if (!readLine(bs))
return false;
memcpy(&img.at(i, 0), _current + 1, _w * sizeof(quint16));
quint16 *tmp = _last;
_last = _current;
_current = tmp;
}
return true;
}