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author | Jay Berkenbilt <ejb@ql.org> | 2024-02-03 17:21:35 +0100 |
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committer | Jay Berkenbilt <ejb@ql.org> | 2024-02-03 17:21:35 +0100 |
commit | b1ec5ba88333f173888a4dbdaa65e30fe9f557df (patch) | |
tree | aa8aa980ab4b60b7ba353493c1c4de5251fbfea2 /libqpdf/Pl_TIFFPredictor.cc | |
parent | 3279c21e13a84c9607b5bda38925b520507234a5 (diff) | |
parent | d946ad6c3076073b9950df2ee25304c2d2a999ad (diff) | |
download | qpdf-b1ec5ba88333f173888a4dbdaa65e30fe9f557df.tar.zst |
Merge branch 'fz' of github.com:m-holger/qpdf into fz
Diffstat (limited to 'libqpdf/Pl_TIFFPredictor.cc')
-rw-r--r-- | libqpdf/Pl_TIFFPredictor.cc | 95 |
1 files changed, 52 insertions, 43 deletions
diff --git a/libqpdf/Pl_TIFFPredictor.cc b/libqpdf/Pl_TIFFPredictor.cc index 51594d11..ec477049 100644 --- a/libqpdf/Pl_TIFFPredictor.cc +++ b/libqpdf/Pl_TIFFPredictor.cc @@ -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) { - 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; - } else { - new_sample += prev[i]; - prev[i] = new_sample; + 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; + prev = sample; + } else { + 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)); } - bw.writeBitsSigned(new_sample, this->bits_per_sample); } + p_next->write(out.data(), out.size()); } - bw.flush(); } 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(); } |