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Merge branch 'fz' of github.com:m-holger/qpdf into fz

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This commit is contained in:
Jay Berkenbilt 2024-02-03 11:21:35 -05:00
commit b1ec5ba883
2 changed files with 58 additions and 45 deletions
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83
libqpdf/Pl_TIFFPredictor.cc
View File

@ -3,12 +3,9 @@
#include <qpdf/BitStream.hh>
#include <qpdf/BitWriter.hh>
#include <qpdf/QTC.hh>
#include <qpdf/QUtil.hh>
#include <climits>
#include <cstring>
#include <stdexcept>
#include <vector>
Pl_TIFFPredictor::Pl_TIFFPredictor(
char const* identifier,
@ -22,7 +19,7 @@ Pl_TIFFPredictor::Pl_TIFFPredictor(
columns(columns),
samples_per_pixel(samples_per_pixel),
bits_per_sample(bits_per_sample),
pos(0)
p_next(getNext())
{
if (samples_per_pixel < 1) {
throw std::runtime_error("TIFFPredictor created with invalid samples_per_pixel");
@ -35,71 +32,83 @@ Pl_TIFFPredictor::Pl_TIFFPredictor(
throw std::runtime_error("TIFFPredictor created with invalid columns value");
}
this->bytes_per_row = bpr & UINT_MAX;
this->cur_row = QUtil::make_shared_array<unsigned char>(this->bytes_per_row);
memset(this->cur_row.get(), 0, this->bytes_per_row);
}
void
Pl_TIFFPredictor::write(unsigned char const* data, size_t len)
{
size_t left = this->bytes_per_row - this->pos;
size_t offset = 0;
while (len >= left) {
auto end = data + len;
auto row_end = data + (bytes_per_row - cur_row.size());
while (row_end <= end) {
// finish off current row
memcpy(this->cur_row.get() + this->pos, data + offset, left);
offset += left;
len -= left;
cur_row.insert(cur_row.end(), data, row_end);
data = row_end;
row_end += bytes_per_row;
processRow();
// Prepare for next row
memset(this->cur_row.get(), 0, this->bytes_per_row);
left = this->bytes_per_row;
this->pos = 0;
cur_row.clear();
}
if (len) {
memcpy(this->cur_row.get() + this->pos, data + offset, len);
}
this->pos += len;
cur_row.insert(cur_row.end(), data, end);
}
void
Pl_TIFFPredictor::processRow()
{
QTC::TC("libtests", "Pl_TIFFPredictor processRow", (action == a_decode ? 0 : 1));
BitWriter bw(this->getNext());
BitStream in(this->cur_row.get(), this->bytes_per_row);
std::vector<long long> prev;
for (unsigned int i = 0; i < this->samples_per_pixel; ++i) {
long long sample = in.getBitsSigned(this->bits_per_sample);
bw.writeBitsSigned(sample, this->bits_per_sample);
prev.push_back(sample);
}
for (unsigned int col = 1; col < this->columns; ++col) {
for (unsigned int i = 0; i < this->samples_per_pixel; ++i) {
previous.assign(samples_per_pixel, 0);
if (bits_per_sample != 8) {
BitWriter bw(p_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[i];
prev[i] = sample;
new_sample -= prev;
prev = sample;
} else {
new_sample += prev[i];
prev[i] = new_sample;
new_sample += prev;
prev = new_sample;
}
bw.writeBitsSigned(new_sample, this->bits_per_sample);
}
}
bw.flush();
} else {
out.clear();
auto next = cur_row.begin();
auto cr_end = cur_row.end();
auto pr_end = previous.end();
while (next != cr_end) {
for (auto prev = previous.begin(); prev != pr_end && next != cr_end; ++prev, ++next) {
long long sample = *next;
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));
}
}
p_next->write(out.data(), out.size());
}
}
void
Pl_TIFFPredictor::finish()
{
if (this->pos) {
if (!cur_row.empty()) {
// write partial row
cur_row.insert(cur_row.end(), bytes_per_row - cur_row.size(), 0);
processRow();
}
this->pos = 0;
memset(this->cur_row.get(), 0, this->bytes_per_row);
getNext()->finish();
cur_row.clear();
p_next->finish();
}

8
libqpdf/qpdf/Pl_TIFFPredictor.hh
View File

@ -6,6 +6,8 @@
#include <qpdf/Pipeline.hh>
#include<vector>
class Pl_TIFFPredictor: public Pipeline
{
public:
@ -31,8 +33,10 @@ class Pl_TIFFPredictor: public Pipeline
unsigned int bytes_per_row;
unsigned int samples_per_pixel;
unsigned int bits_per_sample;
std::shared_ptr<unsigned char> cur_row;
size_t pos;
std::vector<unsigned char> cur_row;
std::vector<long long> previous;
std::vector<unsigned char> out;
Pipeline* p_next;
};
#endif // PL_TIFFPREDICTOR_HH