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-rw-r--r-- | third_party/jpeg-xl/lib/jxl/dec_patch_dictionary.h | 151 |
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diff --git a/third_party/jpeg-xl/lib/jxl/dec_patch_dictionary.h b/third_party/jpeg-xl/lib/jxl/dec_patch_dictionary.h new file mode 100644 index 0000000000..a950e83e85 --- /dev/null +++ b/third_party/jpeg-xl/lib/jxl/dec_patch_dictionary.h @@ -0,0 +1,151 @@ +// Copyright (c) the JPEG XL Project Authors. All rights reserved. +// +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#ifndef LIB_JXL_DEC_PATCH_DICTIONARY_H_ +#define LIB_JXL_DEC_PATCH_DICTIONARY_H_ + +// Chooses reference patches, and avoids encoding them once per occurrence. + +#include <stddef.h> +#include <string.h> +#include <sys/types.h> + +#include <tuple> +#include <vector> + +#include "lib/jxl/base/status.h" +#include "lib/jxl/common.h" +#include "lib/jxl/dec_bit_reader.h" +#include "lib/jxl/image.h" +#include "lib/jxl/opsin_params.h" + +namespace jxl { + +enum class PatchBlendMode : uint8_t { + // The new values are the old ones. Useful to skip some channels. + kNone = 0, + // The new values (in the crop) replace the old ones: sample = new + kReplace = 1, + // The new values (in the crop) get added to the old ones: sample = old + new + kAdd = 2, + // The new values (in the crop) get multiplied by the old ones: + // sample = old * new + // This blend mode is only supported if BlendColorSpace is kEncoded. The + // range of the new value matters for multiplication purposes, and its + // nominal range of 0..1 is computed the same way as this is done for the + // alpha values in kBlend and kAlphaWeightedAdd. + kMul = 3, + // The new values (in the crop) replace the old ones if alpha>0: + // For first alpha channel: + // alpha = old + new * (1 - old) + // For other channels if !alpha_associated: + // sample = ((1 - new_alpha) * old * old_alpha + new_alpha * new) / alpha + // For other channels if alpha_associated: + // sample = (1 - new_alpha) * old + new + // The alpha formula applies to the alpha used for the division in the other + // channels formula, and applies to the alpha channel itself if its + // blend_channel value matches itself. + // If using kBlendAbove, new is the patch and old is the original image; if + // using kBlendBelow, the meaning is inverted. + kBlendAbove = 4, + kBlendBelow = 5, + // The new values (in the crop) are added to the old ones if alpha>0: + // For first alpha channel: sample = sample = old + new * (1 - old) + // For other channels: sample = old + alpha * new + kAlphaWeightedAddAbove = 6, + kAlphaWeightedAddBelow = 7, + kNumBlendModes, +}; + +inline bool UsesAlpha(PatchBlendMode mode) { + return mode == PatchBlendMode::kBlendAbove || + mode == PatchBlendMode::kBlendBelow || + mode == PatchBlendMode::kAlphaWeightedAddAbove || + mode == PatchBlendMode::kAlphaWeightedAddBelow; +} +inline bool UsesClamp(PatchBlendMode mode) { + return UsesAlpha(mode) || mode == PatchBlendMode::kMul; +} + +struct PatchBlending { + PatchBlendMode mode; + uint32_t alpha_channel; + bool clamp; +}; + +// Position and size of the patch in the reference frame. +struct PatchReferencePosition { + size_t ref, x0, y0, xsize, ysize; +}; + +struct PatchPosition { + // Position of top-left corner of the patch in the image. + size_t x, y; + size_t ref_pos_idx; +}; + +struct PassesSharedState; + +// Encoder-side helper class to encode the PatchesDictionary. +class PatchDictionaryEncoder; + +class PatchDictionary { + public: + PatchDictionary() = default; + + void SetPassesSharedState(const PassesSharedState* shared) { + shared_ = shared; + } + + bool HasAny() const { return !positions_.empty(); } + + Status Decode(BitReader* br, size_t xsize, size_t ysize, + bool* uses_extra_channels); + + void Clear() { + positions_.clear(); + ComputePatchTree(); + } + + // Adds patches to a segment of `xsize` pixels, starting at `inout`, assumed + // to be located at position (x0, y) in the frame. + void AddOneRow(float* const* inout, size_t y, size_t x0, size_t xsize) const; + + // Returns dependencies of this patch dictionary on reference frame ids as a + // bit mask: bits 0-3 indicate reference frame 0-3. + int GetReferences() const; + + std::vector<size_t> GetPatchesForRow(size_t y) const; + + private: + friend class PatchDictionaryEncoder; + + const PassesSharedState* shared_; + std::vector<PatchPosition> positions_; + std::vector<PatchReferencePosition> ref_positions_; + std::vector<PatchBlending> blendings_; + + // Interval tree on the y coordinates of the patches. + struct PatchTreeNode { + ssize_t left_child; + ssize_t right_child; + size_t y_center; + // Range of patches in sorted_patches_y0_ and sorted_patches_y1_ that + // contain the row y_center. + size_t start; + size_t num; + }; + std::vector<PatchTreeNode> patch_tree_; + // Number of patches for each row. + std::vector<size_t> num_patches_; + std::vector<std::pair<size_t, size_t>> sorted_patches_y0_; + std::vector<std::pair<size_t, size_t>> sorted_patches_y1_; + + void ComputePatchTree(); +}; + +} // namespace jxl + +#endif // LIB_JXL_DEC_PATCH_DICTIONARY_H_ |