octoleo/qpdf
2
1
Fork 0
mirror of https://github.com/qpdf/qpdf.git synced 2024-06-05 03:40:53 +00:00
Code Issues Releases Wiki Activity

In Pl_TIFFPredictor::processRow avoid repeated vector allocation

Browse Source 
Also, modernize for loop.
This commit is contained in:
m-holger 2024-01-26 19:13:34 +00:00
parent 2e8b5f290c
commit c01fc3c2ae
2 changed files with 10 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
libqpdf/Pl_TIFFPredictor.cc
View File

@ -7,6 +7,7 @@
#include <climits> #include <climits>
#include <stdexcept> #include <stdexcept>
#include <vector> #include <vector>
#include <iostream>
Pl_TIFFPredictor::Pl_TIFFPredictor( Pl_TIFFPredictor::Pl_TIFFPredictor(
char const* identifier, char const* identifier,
@ -60,23 +61,23 @@ 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(p_next); BitWriter bw(p_next);
BitStream in(this->cur_row.data(), this->bytes_per_row); BitStream in(cur_row.data(), cur_row.size());
std::vector<long long> prev; previous.clear();
for (unsigned int i = 0; i < this->samples_per_pixel; ++i) { for (unsigned int i = 0; i < this->samples_per_pixel; ++i) {
long long sample = in.getBitsSigned(this->bits_per_sample); long long sample = in.getBitsSigned(this->bits_per_sample);
bw.writeBitsSigned(sample, this->bits_per_sample); bw.writeBitsSigned(sample, this->bits_per_sample);
prev.push_back(sample); previous.push_back(sample);
} }
for (unsigned int col = 1; col < this->columns; ++col) { for (unsigned int col = 1; col < this->columns; ++col) {
for (unsigned int i = 0; i < this->samples_per_pixel; ++i) { for (auto& prev : previous) {
long long sample = in.getBitsSigned(this->bits_per_sample); long long sample = in.getBitsSigned(this->bits_per_sample);
long long new_sample = sample; long long new_sample = sample;
if (action == a_encode) { if (action == a_encode) {
new_sample -= prev[i]; new_sample -= prev;
prev[i] = sample; prev = sample;
} else { } else {
new_sample += prev[i]; new_sample += prev;
prev[i] = new_sample; prev = new_sample;
} }
bw.writeBitsSigned(new_sample, this->bits_per_sample); bw.writeBitsSigned(new_sample, this->bits_per_sample);
} }

1
libqpdf/qpdf/Pl_TIFFPredictor.hh
View File

@ -34,6 +34,7 @@ class Pl_TIFFPredictor: public Pipeline
unsigned int samples_per_pixel; unsigned int samples_per_pixel;
unsigned int bits_per_sample; unsigned int bits_per_sample;
std::vector<unsigned char> cur_row; std::vector<unsigned char> cur_row;
std::vector<long long> previous;
Pipeline* p_next; Pipeline* p_next;
}; };