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mirror of https://github.com/qpdf/qpdf.git synced 2025-02-08 22:58:25 +00:00

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

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

View File

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

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