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// 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.
#include "lib/jxl/enc_patch_dictionary.h"
#include <jxl/memory_manager.h>
#include <jxl/types.h>
#include <sys/types.h>
#include <algorithm>
#include <atomic>
#include <cstdint>
#include <cstdlib>
#include <utility>
#include <vector>
#include "lib/jxl/base/common.h"
#include "lib/jxl/base/compiler_specific.h"
#include "lib/jxl/base/override.h"
#include "lib/jxl/base/printf_macros.h"
#include "lib/jxl/base/random.h"
#include "lib/jxl/base/rect.h"
#include "lib/jxl/base/status.h"
#include "lib/jxl/dec_cache.h"
#include "lib/jxl/dec_frame.h"
#include "lib/jxl/enc_ans.h"
#include "lib/jxl/enc_aux_out.h"
#include "lib/jxl/enc_cache.h"
#include "lib/jxl/enc_debug_image.h"
#include "lib/jxl/enc_dot_dictionary.h"
#include "lib/jxl/enc_frame.h"
#include "lib/jxl/frame_header.h"
#include "lib/jxl/image.h"
#include "lib/jxl/image_bundle.h"
#include "lib/jxl/image_ops.h"
#include "lib/jxl/pack_signed.h"
#include "lib/jxl/patch_dictionary_internal.h"
namespace jxl {
static constexpr size_t kPatchFrameReferenceId = 3;
// static
Status PatchDictionaryEncoder::Encode(const PatchDictionary& pdic,
BitWriter* writer, LayerType layer,
AuxOut* aux_out) {
JXL_ENSURE(pdic.HasAny());
JxlMemoryManager* memory_manager = writer->memory_manager();
std::vector<std::vector<Token>> tokens(1);
auto add_num = [&](int context, size_t num) {
tokens[0].emplace_back(context, num);
};
size_t num_ref_patch = 0;
for (size_t i = 0; i < pdic.positions_.size();) {
size_t ref_pos_idx = pdic.positions_[i].ref_pos_idx;
while (i < pdic.positions_.size() &&
pdic.positions_[i].ref_pos_idx == ref_pos_idx) {
i++;
}
num_ref_patch++;
}
add_num(kNumRefPatchContext, num_ref_patch);
size_t blend_pos = 0;
size_t blending_stride = pdic.blendings_stride_;
// blending_stride == num_ec + 1; num_ec > 1 =>
bool choose_alpha = (blending_stride > 1 + 1);
for (size_t i = 0; i < pdic.positions_.size();) {
size_t i_start = i;
size_t ref_pos_idx = pdic.positions_[i].ref_pos_idx;
const auto& ref_pos = pdic.ref_positions_[ref_pos_idx];
while (i < pdic.positions_.size() &&
pdic.positions_[i].ref_pos_idx == ref_pos_idx) {
i++;
}
size_t num = i - i_start;
JXL_ENSURE(num > 0);
add_num(kReferenceFrameContext, ref_pos.ref);
add_num(kPatchReferencePositionContext, ref_pos.x0);
add_num(kPatchReferencePositionContext, ref_pos.y0);
add_num(kPatchSizeContext, ref_pos.xsize - 1);
add_num(kPatchSizeContext, ref_pos.ysize - 1);
add_num(kPatchCountContext, num - 1);
for (size_t j = i_start; j < i; j++) {
const PatchPosition& pos = pdic.positions_[j];
if (j == i_start) {
add_num(kPatchPositionContext, pos.x);
add_num(kPatchPositionContext, pos.y);
} else {
add_num(kPatchOffsetContext,
PackSigned(pos.x - pdic.positions_[j - 1].x));
add_num(kPatchOffsetContext,
PackSigned(pos.y - pdic.positions_[j - 1].y));
}
for (size_t j = 0; j < blending_stride; ++j, ++blend_pos) {
const PatchBlending& info = pdic.blendings_[blend_pos];
add_num(kPatchBlendModeContext, static_cast<uint32_t>(info.mode));
if (UsesAlpha(info.mode) && choose_alpha) {
add_num(kPatchAlphaChannelContext, info.alpha_channel);
}
if (UsesClamp(info.mode)) {
add_num(kPatchClampContext, TO_JXL_BOOL(info.clamp));
}
}
}
}
EntropyEncodingData codes;
std::vector<uint8_t> context_map;
JXL_ASSIGN_OR_RETURN(
size_t cost,
BuildAndEncodeHistograms(memory_manager, HistogramParams(),
kNumPatchDictionaryContexts, tokens, &codes,
&context_map, writer, layer, aux_out));
(void)cost;
JXL_RETURN_IF_ERROR(
WriteTokens(tokens[0], codes, context_map, 0, writer, layer, aux_out));
return true;
}
// static
Status PatchDictionaryEncoder::SubtractFrom(const PatchDictionary& pdic,
Image3F* opsin) {
// TODO(veluca): this can likely be optimized knowing it runs on full images.
for (size_t y = 0; y < opsin->ysize(); y++) {
float* JXL_RESTRICT rows[3] = {
opsin->PlaneRow(0, y),
opsin->PlaneRow(1, y),
opsin->PlaneRow(2, y),
};
size_t blending_stride = pdic.blendings_stride_;
for (size_t pos_idx : pdic.GetPatchesForRow(y)) {
const size_t blending_idx = pos_idx * blending_stride;
const PatchPosition& pos = pdic.positions_[pos_idx];
const PatchReferencePosition& ref_pos =
pdic.ref_positions_[pos.ref_pos_idx];
const PatchBlendMode mode = pdic.blendings_[blending_idx].mode;
size_t by = pos.y;
size_t bx = pos.x;
size_t xsize = ref_pos.xsize;
JXL_ENSURE(y >= by);
JXL_ENSURE(y < by + ref_pos.ysize);
size_t iy = y - by;
size_t ref = ref_pos.ref;
const float* JXL_RESTRICT ref_rows[3] = {
pdic.reference_frames_->at(ref).frame->color()->ConstPlaneRow(
0, ref_pos.y0 + iy) +
ref_pos.x0,
pdic.reference_frames_->at(ref).frame->color()->ConstPlaneRow(
1, ref_pos.y0 + iy) +
ref_pos.x0,
pdic.reference_frames_->at(ref).frame->color()->ConstPlaneRow(
2, ref_pos.y0 + iy) +
ref_pos.x0,
};
for (size_t ix = 0; ix < xsize; ix++) {
for (size_t c = 0; c < 3; c++) {
if (mode == PatchBlendMode::kAdd) {
rows[c][bx + ix] -= ref_rows[c][ix];
} else if (mode == PatchBlendMode::kReplace) {
rows[c][bx + ix] = 0;
} else if (mode == PatchBlendMode::kNone) {
// Nothing to do.
} else {
return JXL_UNREACHABLE("blending mode %u not yet implemented",
static_cast<uint32_t>(mode));
}
}
}
}
}
return true;
}
namespace {
struct PatchColorspaceInfo {
float kChannelDequant[3];
float kChannelWeights[3];
explicit PatchColorspaceInfo(bool is_xyb) {
if (is_xyb) {
kChannelDequant[0] = 0.01615;
kChannelDequant[1] = 0.08875;
kChannelDequant[2] = 0.1922;
kChannelWeights[0] = 30.0;
kChannelWeights[1] = 3.0;
kChannelWeights[2] = 1.0;
} else {
kChannelDequant[0] = 20.0f / 255;
kChannelDequant[1] = 22.0f / 255;
kChannelDequant[2] = 20.0f / 255;
kChannelWeights[0] = 0.017 * 255;
kChannelWeights[1] = 0.02 * 255;
kChannelWeights[2] = 0.017 * 255;
}
}
float ScaleForQuantization(float val, size_t c) {
return val / kChannelDequant[c];
}
int Quantize(float val, size_t c) {
return truncf(ScaleForQuantization(val, c));
}
bool is_similar_v(const float v1[3], const float v2[3], float threshold) {
float distance = 0;
for (size_t c = 0; c < 3; c++) {
distance += std::fabs(v1[c] - v2[c]) * kChannelWeights[c];
}
return distance <= threshold;
}
};
StatusOr<std::vector<PatchInfo>> FindTextLikePatches(
const CompressParams& cparams, const Image3F& opsin,
const PassesEncoderState* JXL_RESTRICT state, ThreadPool* pool,
AuxOut* aux_out, bool is_xyb) {
std::vector<PatchInfo> info;
if (state->cparams.patches == Override::kOff) return info;
const auto& frame_dim = state->shared.frame_dim;
JxlMemoryManager* memory_manager = opsin.memory_manager();
PatchColorspaceInfo pci(is_xyb);
float kSimilarThreshold = 0.8f;
auto is_similar_impl = [&pci](std::pair<uint32_t, uint32_t> p1,
std::pair<uint32_t, uint32_t> p2,
const float* JXL_RESTRICT rows[3],
size_t stride, float threshold) {
float v1[3];
float v2[3];
for (size_t c = 0; c < 3; c++) {
v1[c] = rows[c][p1.second * stride + p1.first];
v2[c] = rows[c][p2.second * stride + p2.first];
}
return pci.is_similar_v(v1, v2, threshold);
};
std::atomic<bool> has_screenshot_areas{false};
const size_t opsin_stride = opsin.PixelsPerRow();
const float* JXL_RESTRICT opsin_rows[3] = {opsin.ConstPlaneRow(0, 0),
opsin.ConstPlaneRow(1, 0),
opsin.ConstPlaneRow(2, 0)};
auto is_same = [&opsin_rows, opsin_stride](std::pair<uint32_t, uint32_t> p1,
std::pair<uint32_t, uint32_t> p2) {
for (auto& opsin_row : opsin_rows) {
float v1 = opsin_row[p1.second * opsin_stride + p1.first];
float v2 = opsin_row[p2.second * opsin_stride + p2.first];
if (std::fabs(v1 - v2) > 1e-4) {
return false;
}
}
return true;
};
auto is_similar = [&](std::pair<uint32_t, uint32_t> p1,
std::pair<uint32_t, uint32_t> p2) {
return is_similar_impl(p1, p2, opsin_rows, opsin_stride, kSimilarThreshold);
};
constexpr int64_t kPatchSide = 4;
constexpr int64_t kExtraSide = 4;
// Look for kPatchSide size squares, naturally aligned, that all have the same
// pixel values.
JXL_ASSIGN_OR_RETURN(
ImageB is_screenshot_like,
ImageB::Create(memory_manager, DivCeil(frame_dim.xsize, kPatchSide),
DivCeil(frame_dim.ysize, kPatchSide)));
ZeroFillImage(&is_screenshot_like);
uint8_t* JXL_RESTRICT screenshot_row = is_screenshot_like.Row(0);
const size_t screenshot_stride = is_screenshot_like.PixelsPerRow();
const auto process_row = [&](const uint32_t y,
size_t /* thread */) -> Status {
for (uint64_t x = 0; x < frame_dim.xsize / kPatchSide; x++) {
bool all_same = true;
for (size_t iy = 0; iy < static_cast<size_t>(kPatchSide); iy++) {
for (size_t ix = 0; ix < static_cast<size_t>(kPatchSide); ix++) {
size_t cx = x * kPatchSide + ix;
size_t cy = y * kPatchSide + iy;
if (!is_same({cx, cy}, {x * kPatchSide, y * kPatchSide})) {
all_same = false;
break;
}
}
}
if (!all_same) continue;
size_t num = 0;
size_t num_same = 0;
for (int64_t iy = -kExtraSide; iy < kExtraSide + kPatchSide; iy++) {
for (int64_t ix = -kExtraSide; ix < kExtraSide + kPatchSide; ix++) {
int64_t cx = x * kPatchSide + ix;
int64_t cy = y * kPatchSide + iy;
if (cx < 0 || static_cast<uint64_t>(cx) >= frame_dim.xsize || //
cy < 0 || static_cast<uint64_t>(cy) >= frame_dim.ysize) {
continue;
}
num++;
if (is_same({cx, cy}, {x * kPatchSide, y * kPatchSide})) num_same++;
}
}
// Too few equal pixels nearby.
if (num_same * 8 < num * 7) continue;
screenshot_row[y * screenshot_stride + x] = 1;
has_screenshot_areas = true;
}
return true;
};
JXL_RETURN_IF_ERROR(RunOnPool(pool, 0, frame_dim.ysize / kPatchSide,
ThreadPool::NoInit, process_row,
"IsScreenshotLike"));
// TODO(veluca): also parallelize the rest of this function.
if (WantDebugOutput(cparams)) {
JXL_RETURN_IF_ERROR(
DumpPlaneNormalized(cparams, "screenshot_like", is_screenshot_like));
}
constexpr int kSearchRadius = 1;
if (!ApplyOverride(state->cparams.patches, has_screenshot_areas)) {
return info;
}
// Search for "similar enough" pixels near the screenshot-like areas.
JXL_ASSIGN_OR_RETURN(
ImageB is_background,
ImageB::Create(memory_manager, frame_dim.xsize, frame_dim.ysize));
ZeroFillImage(&is_background);
JXL_ASSIGN_OR_RETURN(
Image3F background,
Image3F::Create(memory_manager, frame_dim.xsize, frame_dim.ysize));
ZeroFillImage(&background);
constexpr size_t kDistanceLimit = 50;
float* JXL_RESTRICT background_rows[3] = {
background.PlaneRow(0, 0),
background.PlaneRow(1, 0),
background.PlaneRow(2, 0),
};
const size_t background_stride = background.PixelsPerRow();
uint8_t* JXL_RESTRICT is_background_row = is_background.Row(0);
const size_t is_background_stride = is_background.PixelsPerRow();
std::vector<
std::pair<std::pair<uint32_t, uint32_t>, std::pair<uint32_t, uint32_t>>>
queue;
size_t queue_front = 0;
for (size_t y = 0; y < frame_dim.ysize; y++) {
for (size_t x = 0; x < frame_dim.xsize; x++) {
if (!screenshot_row[screenshot_stride * (y / kPatchSide) +
(x / kPatchSide)])
continue;
queue.push_back({{x, y}, {x, y}});
}
}
while (queue.size() != queue_front) {
std::pair<uint32_t, uint32_t> cur = queue[queue_front].first;
std::pair<uint32_t, uint32_t> src = queue[queue_front].second;
queue_front++;
if (is_background_row[cur.second * is_background_stride + cur.first])
continue;
is_background_row[cur.second * is_background_stride + cur.first] = 1;
for (size_t c = 0; c < 3; c++) {
background_rows[c][cur.second * background_stride + cur.first] =
opsin_rows[c][src.second * opsin_stride + src.first];
}
for (int dx = -kSearchRadius; dx <= kSearchRadius; dx++) {
for (int dy = -kSearchRadius; dy <= kSearchRadius; dy++) {
if (dx == 0 && dy == 0) continue;
int next_first = cur.first + dx;
int next_second = cur.second + dy;
if (next_first < 0 || next_second < 0 ||
static_cast<uint32_t>(next_first) >= frame_dim.xsize ||
static_cast<uint32_t>(next_second) >= frame_dim.ysize) {
continue;
}
if (static_cast<uint32_t>(
std::abs(next_first - static_cast<int>(src.first)) +
std::abs(next_second - static_cast<int>(src.second))) >
kDistanceLimit) {
continue;
}
std::pair<uint32_t, uint32_t> next{next_first, next_second};
if (is_similar(src, next)) {
if (!screenshot_row[next.second / kPatchSide * screenshot_stride +
next.first / kPatchSide] ||
is_same(src, next)) {
if (!is_background_row[next.second * is_background_stride +
next.first])
queue.emplace_back(next, src);
}
}
}
}
}
queue.clear();
ImageF ccs;
Rng rng(0);
bool paint_ccs = false;
if (WantDebugOutput(cparams)) {
JXL_RETURN_IF_ERROR(
DumpPlaneNormalized(cparams, "is_background", is_background));
if (is_xyb) {
JXL_RETURN_IF_ERROR(DumpXybImage(cparams, "background", background));
} else {
JXL_RETURN_IF_ERROR(DumpImage(cparams, "background", background));
}
JXL_ASSIGN_OR_RETURN(
ccs, ImageF::Create(memory_manager, frame_dim.xsize, frame_dim.ysize));
ZeroFillImage(&ccs);
paint_ccs = true;
}
constexpr float kVerySimilarThreshold = 0.03f;
constexpr float kHasSimilarThreshold = 0.03f;
const float* JXL_RESTRICT const_background_rows[3] = {
background_rows[0], background_rows[1], background_rows[2]};
auto is_similar_b = [&](std::pair<int, int> p1, std::pair<int, int> p2) {
return is_similar_impl(p1, p2, const_background_rows, background_stride,
kVerySimilarThreshold);
};
constexpr int kMinPeak = 2;
constexpr int kHasSimilarRadius = 2;
// Find small CC outside the "similar enough" areas, compute bounding boxes,
// and run heuristics to exclude some patches.
JXL_ASSIGN_OR_RETURN(
ImageB visited,
ImageB::Create(memory_manager, frame_dim.xsize, frame_dim.ysize));
ZeroFillImage(&visited);
uint8_t* JXL_RESTRICT visited_row = visited.Row(0);
const size_t visited_stride = visited.PixelsPerRow();
std::vector<std::pair<uint32_t, uint32_t>> cc;
std::vector<std::pair<uint32_t, uint32_t>> stack;
for (size_t y = 0; y < frame_dim.ysize; y++) {
for (size_t x = 0; x < frame_dim.xsize; x++) {
if (is_background_row[y * is_background_stride + x]) continue;
cc.clear();
stack.clear();
stack.emplace_back(x, y);
size_t min_x = x;
size_t max_x = x;
size_t min_y = y;
size_t max_y = y;
std::pair<uint32_t, uint32_t> reference;
bool found_border = false;
bool all_similar = true;
while (!stack.empty()) {
std::pair<uint32_t, uint32_t> cur = stack.back();
stack.pop_back();
if (visited_row[cur.second * visited_stride + cur.first]) continue;
visited_row[cur.second * visited_stride + cur.first] = 1;
if (cur.first < min_x) min_x = cur.first;
if (cur.first > max_x) max_x = cur.first;
if (cur.second < min_y) min_y = cur.second;
if (cur.second > max_y) max_y = cur.second;
if (paint_ccs) {
cc.push_back(cur);
}
for (int dx = -kSearchRadius; dx <= kSearchRadius; dx++) {
for (int dy = -kSearchRadius; dy <= kSearchRadius; dy++) {
if (dx == 0 && dy == 0) continue;
int next_first = static_cast<int32_t>(cur.first) + dx;
int next_second = static_cast<int32_t>(cur.second) + dy;
if (next_first < 0 || next_second < 0 ||
static_cast<uint32_t>(next_first) >= frame_dim.xsize ||
static_cast<uint32_t>(next_second) >= frame_dim.ysize) {
continue;
}
std::pair<uint32_t, uint32_t> next{next_first, next_second};
if (!is_background_row[next.second * is_background_stride +
next.first]) {
stack.push_back(next);
} else {
if (!found_border) {
reference = next;
found_border = true;
} else {
if (!is_similar_b(next, reference)) all_similar = false;
}
}
}
}
}
if (!found_border || !all_similar || max_x - min_x >= kMaxPatchSize ||
max_y - min_y >= kMaxPatchSize) {
continue;
}
size_t bpos = background_stride * reference.second + reference.first;
float ref[3] = {background_rows[0][bpos], background_rows[1][bpos],
background_rows[2][bpos]};
bool has_similar = false;
for (size_t iy = std::max<int>(
static_cast<int32_t>(min_y) - kHasSimilarRadius, 0);
iy < std::min(max_y + kHasSimilarRadius + 1, frame_dim.ysize);
iy++) {
for (size_t ix = std::max<int>(
static_cast<int32_t>(min_x) - kHasSimilarRadius, 0);
ix < std::min(max_x + kHasSimilarRadius + 1, frame_dim.xsize);
ix++) {
size_t opos = opsin_stride * iy + ix;
float px[3] = {opsin_rows[0][opos], opsin_rows[1][opos],
opsin_rows[2][opos]};
if (pci.is_similar_v(ref, px, kHasSimilarThreshold)) {
has_similar = true;
}
}
}
if (!has_similar) continue;
info.emplace_back();
info.back().second.emplace_back(min_x, min_y);
QuantizedPatch& patch = info.back().first;
patch.xsize = max_x - min_x + 1;
patch.ysize = max_y - min_y + 1;
int max_value = 0;
for (size_t c : {1, 0, 2}) {
for (size_t iy = min_y; iy <= max_y; iy++) {
for (size_t ix = min_x; ix <= max_x; ix++) {
size_t offset = (iy - min_y) * patch.xsize + ix - min_x;
patch.fpixels[c][offset] =
opsin_rows[c][iy * opsin_stride + ix] - ref[c];
int val = pci.Quantize(patch.fpixels[c][offset], c);
patch.pixels[c][offset] = val;
if (std::abs(val) > max_value) max_value = std::abs(val);
}
}
}
if (max_value < kMinPeak) {
info.pop_back();
continue;
}
if (paint_ccs) {
float cc_color = rng.UniformF(0.5, 1.0);
for (std::pair<uint32_t, uint32_t> p : cc) {
ccs.Row(p.second)[p.first] = cc_color;
}
}
}
}
if (paint_ccs) {
JXL_ENSURE(WantDebugOutput(cparams));
JXL_RETURN_IF_ERROR(DumpPlaneNormalized(cparams, "ccs", ccs));
}
if (info.empty()) {
return info;
}
// Remove duplicates.
constexpr size_t kMinPatchOccurrences = 2;
std::sort(info.begin(), info.end());
size_t unique = 0;
for (size_t i = 1; i < info.size(); i++) {
if (info[i].first == info[unique].first) {
info[unique].second.insert(info[unique].second.end(),
info[i].second.begin(), info[i].second.end());
} else {
if (info[unique].second.size() >= kMinPatchOccurrences) {
unique++;
}
info[unique] = info[i];
}
}
if (info[unique].second.size() >= kMinPatchOccurrences) {
unique++;
}
info.resize(unique);
size_t max_patch_size = 0;
for (const auto& patch : info) {
size_t pixels = patch.first.xsize * patch.first.ysize;
if (pixels > max_patch_size) max_patch_size = pixels;
}
// don't use patches if all patches are smaller than this
constexpr size_t kMinMaxPatchSize = 20;
if (max_patch_size < kMinMaxPatchSize) {
info.clear();
}
return info;
}
} // namespace
Status FindBestPatchDictionary(const Image3F& opsin,
PassesEncoderState* JXL_RESTRICT state,
const JxlCmsInterface& cms, ThreadPool* pool,
AuxOut* aux_out, bool is_xyb) {
JXL_ASSIGN_OR_RETURN(
std::vector<PatchInfo> info,
FindTextLikePatches(state->cparams, opsin, state, pool, aux_out, is_xyb));
JxlMemoryManager* memory_manager = opsin.memory_manager();
// TODO(veluca): this doesn't work if both dots and patches are enabled.
// For now, since dots and patches are not likely to occur in the same kind of
// images, disable dots if some patches were found.
if (info.empty() &&
ApplyOverride(
state->cparams.dots,
state->cparams.speed_tier <= SpeedTier::kSquirrel &&
state->cparams.butteraugli_distance >= kMinButteraugliForDots &&
!state->cparams.disable_perceptual_optimizations)) {
Rect rect(0, 0, state->shared.frame_dim.xsize,
state->shared.frame_dim.ysize);
JXL_ASSIGN_OR_RETURN(info,
FindDotDictionary(state->cparams, opsin, rect,
state->shared.cmap.base(), pool));
}
if (info.empty()) return true;
std::sort(
info.begin(), info.end(), [&](const PatchInfo& a, const PatchInfo& b) {
return a.first.xsize * a.first.ysize > b.first.xsize * b.first.ysize;
});
size_t max_x_size = 0;
size_t max_y_size = 0;
size_t total_pixels = 0;
for (const auto& patch : info) {
size_t pixels = patch.first.xsize * patch.first.ysize;
if (max_x_size < patch.first.xsize) max_x_size = patch.first.xsize;
if (max_y_size < patch.first.ysize) max_y_size = patch.first.ysize;
total_pixels += pixels;
}
// Bin-packing & conversion of patches.
constexpr float kBinPackingSlackness = 1.05f;
size_t ref_xsize = std::max<float>(max_x_size, std::sqrt(total_pixels));
size_t ref_ysize = std::max<float>(max_y_size, std::sqrt(total_pixels));
std::vector<std::pair<size_t, size_t>> ref_positions(info.size());
// TODO(veluca): allow partial overlaps of patches that have the same pixels.
size_t max_y = 0;
do {
max_y = 0;
// Increase packed image size.
ref_xsize = ref_xsize * kBinPackingSlackness + 1;
ref_ysize = ref_ysize * kBinPackingSlackness + 1;
JXL_ASSIGN_OR_RETURN(ImageB occupied,
ImageB::Create(memory_manager, ref_xsize, ref_ysize));
ZeroFillImage(&occupied);
uint8_t* JXL_RESTRICT occupied_rows = occupied.Row(0);
size_t occupied_stride = occupied.PixelsPerRow();
bool success = true;
// For every patch...
for (size_t patch = 0; patch < info.size(); patch++) {
size_t x0 = 0;
size_t y0 = 0;
size_t xsize = info[patch].first.xsize;
size_t ysize = info[patch].first.ysize;
bool found = false;
// For every possible start position ...
for (; y0 + ysize <= ref_ysize; y0++) {
x0 = 0;
for (; x0 + xsize <= ref_xsize; x0++) {
bool has_occupied_pixel = false;
size_t x = x0;
// Check if it is possible to place the patch in this position in the
// reference frame.
for (size_t y = y0; y < y0 + ysize; y++) {
x = x0;
for (; x < x0 + xsize; x++) {
if (occupied_rows[y * occupied_stride + x]) {
has_occupied_pixel = true;
break;
}
}
} // end of positioning check
if (!has_occupied_pixel) {
found = true;
break;
}
x0 = x; // Jump to next pixel after the occupied one.
}
if (found) break;
} // end of start position checking
// We didn't find a possible position: repeat from the beginning with a
// larger reference frame size.
if (!found) {
success = false;
break;
}
// We found a position: mark the corresponding positions in the reference
// image as used.
ref_positions[patch] = {x0, y0};
for (size_t y = y0; y < y0 + ysize; y++) {
for (size_t x = x0; x < x0 + xsize; x++) {
occupied_rows[y * occupied_stride + x] = JXL_TRUE;
}
}
max_y = std::max(max_y, y0 + ysize);
}
if (success) break;
} while (true);
JXL_ENSURE(ref_ysize >= max_y);
ref_ysize = max_y;
JXL_ASSIGN_OR_RETURN(Image3F reference_frame,
Image3F::Create(memory_manager, ref_xsize, ref_ysize));
// TODO(veluca): figure out a better way to fill the image.
ZeroFillImage(&reference_frame);
std::vector<PatchPosition> positions;
std::vector<PatchReferencePosition> pref_positions;
std::vector<PatchBlending> blendings;
float* JXL_RESTRICT ref_rows[3] = {
reference_frame.PlaneRow(0, 0),
reference_frame.PlaneRow(1, 0),
reference_frame.PlaneRow(2, 0),
};
size_t ref_stride = reference_frame.PixelsPerRow();
size_t num_ec = state->shared.metadata->m.num_extra_channels;
for (size_t i = 0; i < info.size(); i++) {
PatchReferencePosition ref_pos;
ref_pos.xsize = info[i].first.xsize;
ref_pos.ysize = info[i].first.ysize;
ref_pos.x0 = ref_positions[i].first;
ref_pos.y0 = ref_positions[i].second;
ref_pos.ref = kPatchFrameReferenceId;
for (size_t y = 0; y < ref_pos.ysize; y++) {
for (size_t x = 0; x < ref_pos.xsize; x++) {
for (size_t c = 0; c < 3; c++) {
ref_rows[c][(y + ref_pos.y0) * ref_stride + x + ref_pos.x0] =
info[i].first.fpixels[c][y * ref_pos.xsize + x];
}
}
}
for (const auto& pos : info[i].second) {
JXL_DEBUG_V(4, "Patch %" PRIuS "x%" PRIuS " at position %u,%u",
ref_pos.xsize, ref_pos.ysize, pos.first, pos.second);
positions.emplace_back(
PatchPosition{pos.first, pos.second, pref_positions.size()});
// Add blending for color channels, ignore other channels.
blendings.push_back({PatchBlendMode::kAdd, 0, false});
for (size_t j = 0; j < num_ec; ++j) {
blendings.push_back({PatchBlendMode::kNone, 0, false});
}
}
pref_positions.emplace_back(ref_pos);
}
CompressParams cparams = state->cparams;
// Recursive application of patches could create very weird issues.
cparams.patches = Override::kOff;
JXL_RETURN_IF_ERROR(RoundtripPatchFrame(&reference_frame, state,
kPatchFrameReferenceId, cparams, cms,
pool, aux_out, /*subtract=*/true));
// TODO(veluca): this assumes that applying patches is commutative, which is
// not true for all blending modes. This code only produces kAdd patches, so
// this works out.
PatchDictionaryEncoder::SetPositions(
&state->shared.image_features.patches, std::move(positions),
std::move(pref_positions), std::move(blendings), num_ec + 1);
return true;
}
Status RoundtripPatchFrame(Image3F* reference_frame,
PassesEncoderState* JXL_RESTRICT state, int idx,
CompressParams& cparams, const JxlCmsInterface& cms,
ThreadPool* pool, AuxOut* aux_out, bool subtract) {
JxlMemoryManager* memory_manager = state->memory_manager();
FrameInfo patch_frame_info;
cparams.resampling = 1;
cparams.ec_resampling = 1;
cparams.dots = Override::kOff;
cparams.noise = Override::kOff;
cparams.modular_mode = true;
cparams.responsive = 0;
cparams.progressive_dc = 0;
cparams.progressive_mode = Override::kOff;
cparams.qprogressive_mode = Override::kOff;
// Use gradient predictor and not Predictor::Best.
cparams.options.predictor = Predictor::Gradient;
patch_frame_info.save_as_reference = idx; // always saved.
patch_frame_info.frame_type = FrameType::kReferenceOnly;
patch_frame_info.save_before_color_transform = true;
ImageBundle ib(memory_manager, &state->shared.metadata->m);
// TODO(veluca): metadata.color_encoding is a lie: ib is in XYB, but there is
// no simple way to express that yet.
patch_frame_info.ib_needs_color_transform = false;
JXL_RETURN_IF_ERROR(ib.SetFromImage(
std::move(*reference_frame), state->shared.metadata->m.color_encoding));
if (!ib.metadata()->extra_channel_info.empty()) {
// Add placeholder extra channels to the patch image: patch encoding does
// not yet support extra channels, but the codec expects that the amount of
// extra channels in frames matches that in the metadata of the codestream.
std::vector<ImageF> extra_channels;
extra_channels.reserve(ib.metadata()->extra_channel_info.size());
for (size_t i = 0; i < ib.metadata()->extra_channel_info.size(); i++) {
JXL_ASSIGN_OR_RETURN(
ImageF ch, ImageF::Create(memory_manager, ib.xsize(), ib.ysize()));
extra_channels.emplace_back(std::move(ch));
// Must initialize the image with data to not affect blending with
// uninitialized memory.
// TODO(lode): patches must copy and use the real extra channels instead.
ZeroFillImage(&extra_channels.back());
}
JXL_RETURN_IF_ERROR(ib.SetExtraChannels(std::move(extra_channels)));
}
auto special_frame = jxl::make_unique<BitWriter>(memory_manager);
AuxOut patch_aux_out;
JXL_RETURN_IF_ERROR(EncodeFrame(
memory_manager, cparams, patch_frame_info, state->shared.metadata, ib,
cms, pool, special_frame.get(), aux_out ? &patch_aux_out : nullptr));
if (aux_out) {
for (const auto& l : patch_aux_out.layers) {
aux_out->layer(LayerType::Dictionary).Assimilate(l);
}
}
const Span<const uint8_t> encoded = special_frame->GetSpan();
state->special_frames.emplace_back(std::move(special_frame));
if (subtract) {
ImageBundle decoded(memory_manager, &state->shared.metadata->m);
PassesDecoderState dec_state(memory_manager);
JXL_RETURN_IF_ERROR(dec_state.output_encoding_info.SetFromMetadata(
*state->shared.metadata));
const uint8_t* frame_start = encoded.data();
size_t encoded_size = encoded.size();
JXL_RETURN_IF_ERROR(DecodeFrame(&dec_state, pool, frame_start, encoded_size,
/*frame_header=*/nullptr, &decoded,
*state->shared.metadata));
frame_start += decoded.decoded_bytes();
encoded_size -= decoded.decoded_bytes();
size_t ref_xsize =
dec_state.shared_storage.reference_frames[idx].frame->color()->xsize();
// if the frame itself uses patches, we need to decode another frame
if (!ref_xsize) {
JXL_RETURN_IF_ERROR(DecodeFrame(
&dec_state, pool, frame_start, encoded_size,
/*frame_header=*/nullptr, &decoded, *state->shared.metadata));
}
JXL_ENSURE(encoded_size == 0);
state->shared.reference_frames[idx] =
std::move(dec_state.shared_storage.reference_frames[idx]);
} else {
*state->shared.reference_frames[idx].frame = std::move(ib);
}
return true;
}
} // namespace jxl