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| author | Lei Zhang <thestig@chromium.org> | 2018-05-09 18:35:36 +0000 |
|---|---|---|
| committer | Chromium commit bot <commit-bot@chromium.org> | 2018-05-09 18:35:36 +0000 |
| commit | 575ceba24463a2211e8669f8d919d3c91385d72b (patch) | |
| tree | de61b2c00c95f97b9e31ff38aae113702137a9b4 /core/fxcodec/jbig2 | |
| parent | 27924e6c9d43f0eba57d14004853d5a8ba47de26 (diff) | |
| download | pdfium-575ceba24463a2211e8669f8d919d3c91385d72b.tar.xz | |
Make memory usage in CJBig2_HTRDProc::DecodeImage() O(1).
Instead of allocating an N-pixel array to store some temporary values,
just use a single integer.
BUG=chromium:840728
Change-Id: I7a0ff83d814eff127033f25020a7c398db3c2062
Reviewed-on: https://pdfium-review.googlesource.com/32290
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Diffstat (limited to 'core/fxcodec/jbig2')
| -rw-r--r-- | core/fxcodec/jbig2/JBig2_HtrdProc.cpp | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/core/fxcodec/jbig2/JBig2_HtrdProc.cpp b/core/fxcodec/jbig2/JBig2_HtrdProc.cpp index 7d11482225..29c8118883 100644 --- a/core/fxcodec/jbig2/JBig2_HtrdProc.cpp +++ b/core/fxcodec/jbig2/JBig2_HtrdProc.cpp @@ -121,19 +121,15 @@ std::unique_ptr<CJBig2_Image> CJBig2_HTRDProc::DecodeImage( return nullptr; HTREG->fill(HDEFPIXEL); - std::vector<uint32_t> GSVALS(HGW * HGH); for (uint32_t y = 0; y < HGH; ++y) { for (uint32_t x = 0; x < HGW; ++x) { - for (uint8_t J = 0; J < GSPLANES.size(); ++J) - GSVALS[y * HGW + x] |= GSPLANES[J]->getPixel(x, y) << J; - } - } - for (uint32_t mg = 0; mg < HGH; ++mg) { - for (uint32_t ng = 0; ng < HGW; ++ng) { - int32_t x = (HGX + mg * HRY + ng * HRX) >> 8; - int32_t y = (HGY + mg * HRX - ng * HRY) >> 8; - uint32_t pat_index = std::min(GSVALS[mg * HGW + ng], HNUMPATS - 1); - HTREG->ComposeFrom(x, y, (*HPATS)[pat_index].get(), HCOMBOP); + uint32_t gsval = 0; + for (uint8_t i = 0; i < GSPLANES.size(); ++i) + gsval |= GSPLANES[i]->getPixel(x, y) << i; + uint32_t pat_index = std::min(gsval, HNUMPATS - 1); + int32_t out_x = (HGX + y * HRY + x * HRX) >> 8; + int32_t out_y = (HGY + y * HRX - x * HRY) >> 8; + HTREG->ComposeFrom(out_x, out_y, (*HPATS)[pat_index].get(), HCOMBOP); } } return HTREG; |