Pl_TIFFPredictor.cc
3.77 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
#include <qpdf/Pl_TIFFPredictor.hh>
#include <qpdf/BitStream.hh>
#include <qpdf/BitWriter.hh>
#include <qpdf/QTC.hh>
#include <qpdf/Util.hh>
#include <climits>
#include <stdexcept>
using namespace qpdf;
namespace
{
unsigned long long memory_limit{0};
} // namespace
Pl_TIFFPredictor::Pl_TIFFPredictor(
char const* identifier,
Pipeline* next,
action_e action,
unsigned int columns,
unsigned int samples_per_pixel,
unsigned int bits_per_sample) :
Pipeline(identifier, next),
action(action),
columns(columns),
samples_per_pixel(samples_per_pixel),
bits_per_sample(bits_per_sample)
{
util::assertion(next, "Attempt to create Pl_TIFFPredictor with nullptr as next");
util::no_ci_rt_error_if(
samples_per_pixel < 1, "TIFFPredictor created with invalid samples_per_pixel");
util::no_ci_rt_error_if(
bits_per_sample < 1 || bits_per_sample > (8 * (sizeof(unsigned long long))),
"TIFFPredictor created with invalid bits_per_sample");
unsigned long long bpr = ((columns * bits_per_sample * samples_per_pixel) + 7) / 8;
util::no_ci_rt_error_if(
bpr == 0 || bpr > (UINT_MAX - 1), "TIFFPredictor created with invalid columns value");
util::no_ci_rt_error_if(
memory_limit > 0 && bpr > (memory_limit / 2U), "TIFFPredictor memory limit exceeded");
this->bytes_per_row = bpr & UINT_MAX;
}
void
Pl_TIFFPredictor::setMemoryLimit(unsigned long long limit)
{
memory_limit = limit;
}
void
Pl_TIFFPredictor::write(unsigned char const* data, size_t len)
{
auto end = data + len;
auto row_end = data + (bytes_per_row - cur_row.size());
while (row_end <= end) {
// finish off current row
cur_row.insert(cur_row.end(), data, row_end);
data = row_end;
row_end += bytes_per_row;
processRow();
// Prepare for next row
cur_row.clear();
}
cur_row.insert(cur_row.end(), data, end);
}
void
Pl_TIFFPredictor::processRow()
{
QTC::TC("libtests", "Pl_TIFFPredictor processRow", (action == a_decode ? 0 : 1));
previous.assign(samples_per_pixel, 0);
if (bits_per_sample != 8) {
BitWriter bw(next());
BitStream in(cur_row.data(), cur_row.size());
for (unsigned int col = 0; col < this->columns; ++col) {
for (auto& prev: previous) {
long long sample = in.getBitsSigned(this->bits_per_sample);
long long new_sample = sample;
if (action == a_encode) {
new_sample -= prev;
prev = sample;
} else {
new_sample += prev;
prev = new_sample;
}
bw.writeBitsSigned(new_sample, this->bits_per_sample);
}
}
bw.flush();
} else {
out.clear();
auto next_it = cur_row.begin();
auto cr_end = cur_row.end();
auto pr_end = previous.end();
while (next_it != cr_end) {
for (auto prev = previous.begin(); prev != pr_end && next_it != cr_end;
++prev, ++next_it) {
long long sample = *next_it;
long long new_sample = sample;
if (action == a_encode) {
new_sample -= *prev;
*prev = sample;
} else {
new_sample += *prev;
*prev = new_sample;
}
out.push_back(static_cast<unsigned char>(255U & new_sample));
}
}
next()->write(out.data(), out.size());
}
}
void
Pl_TIFFPredictor::finish()
{
if (!cur_row.empty()) {
// write partial row
cur_row.insert(cur_row.end(), bytes_per_row - cur_row.size(), 0);
processRow();
}
cur_row.clear();
next()->finish();
}