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+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// main entry for the lossless encoder.
+//
+// Author: Vikas Arora (vikaas.arora@gmail.com)
+//
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include "src/dsp/lossless.h"
+#include "src/dsp/lossless_common.h"
+#include "src/enc/backward_references_enc.h"
+#include "src/enc/histogram_enc.h"
+#include "src/enc/vp8i_enc.h"
+#include "src/enc/vp8li_enc.h"
+#include "src/utils/bit_writer_utils.h"
+#include "src/utils/huffman_encode_utils.h"
+#include "src/utils/utils.h"
+#include "src/webp/encode.h"
+#include "src/webp/format_constants.h"
+
+// Maximum number of histogram images (sub-blocks).
+#define MAX_HUFF_IMAGE_SIZE 2600
+
+// Palette reordering for smaller sum of deltas (and for smaller storage).
+
+static int PaletteCompareColorsForQsort(const void* p1, const void* p2) {
+ const uint32_t a = WebPMemToUint32((uint8_t*)p1);
+ const uint32_t b = WebPMemToUint32((uint8_t*)p2);
+ assert(a != b);
+ return (a < b) ? -1 : 1;
+}
+
+static WEBP_INLINE uint32_t PaletteComponentDistance(uint32_t v) {
+ return (v <= 128) ? v : (256 - v);
+}
+
+// Computes a value that is related to the entropy created by the
+// palette entry diff.
+//
+// Note that the last & 0xff is a no-operation in the next statement, but
+// removed by most compilers and is here only for regularity of the code.
+static WEBP_INLINE uint32_t PaletteColorDistance(uint32_t col1, uint32_t col2) {
+ const uint32_t diff = VP8LSubPixels(col1, col2);
+ const int kMoreWeightForRGBThanForAlpha = 9;
+ uint32_t score;
+ score = PaletteComponentDistance((diff >> 0) & 0xff);
+ score += PaletteComponentDistance((diff >> 8) & 0xff);
+ score += PaletteComponentDistance((diff >> 16) & 0xff);
+ score *= kMoreWeightForRGBThanForAlpha;
+ score += PaletteComponentDistance((diff >> 24) & 0xff);
+ return score;
+}
+
+static WEBP_INLINE void SwapColor(uint32_t* const col1, uint32_t* const col2) {
+ const uint32_t tmp = *col1;
+ *col1 = *col2;
+ *col2 = tmp;
+}
+
+static WEBP_INLINE int SearchColorNoIdx(const uint32_t sorted[], uint32_t color,
+ int num_colors) {
+ int low = 0, hi = num_colors;
+ if (sorted[low] == color) return low; // loop invariant: sorted[low] != color
+ while (1) {
+ const int mid = (low + hi) >> 1;
+ if (sorted[mid] == color) {
+ return mid;
+ } else if (sorted[mid] < color) {
+ low = mid;
+ } else {
+ hi = mid;
+ }
+ }
+ assert(0);
+ return 0;
+}
+
+// The palette has been sorted by alpha. This function checks if the other
+// components of the palette have a monotonic development with regards to
+// position in the palette. If all have monotonic development, there is
+// no benefit to re-organize them greedily. A monotonic development
+// would be spotted in green-only situations (like lossy alpha) or gray-scale
+// images.
+static int PaletteHasNonMonotonousDeltas(const uint32_t* const palette,
+ int num_colors) {
+ uint32_t predict = 0x000000;
+ int i;
+ uint8_t sign_found = 0x00;
+ for (i = 0; i < num_colors; ++i) {
+ const uint32_t diff = VP8LSubPixels(palette[i], predict);
+ const uint8_t rd = (diff >> 16) & 0xff;
+ const uint8_t gd = (diff >> 8) & 0xff;
+ const uint8_t bd = (diff >> 0) & 0xff;
+ if (rd != 0x00) {
+ sign_found |= (rd < 0x80) ? 1 : 2;
+ }
+ if (gd != 0x00) {
+ sign_found |= (gd < 0x80) ? 8 : 16;
+ }
+ if (bd != 0x00) {
+ sign_found |= (bd < 0x80) ? 64 : 128;
+ }
+ predict = palette[i];
+ }
+ return (sign_found & (sign_found << 1)) != 0; // two consequent signs.
+}
+
+static void PaletteSortMinimizeDeltas(const uint32_t* const palette_sorted,
+ int num_colors, uint32_t* const palette) {
+ uint32_t predict = 0x00000000;
+ int i, k;
+ memcpy(palette, palette_sorted, num_colors * sizeof(*palette));
+ if (!PaletteHasNonMonotonousDeltas(palette_sorted, num_colors)) return;
+ // Find greedily always the closest color of the predicted color to minimize
+ // deltas in the palette. This reduces storage needs since the
+ // palette is stored with delta encoding.
+ for (i = 0; i < num_colors; ++i) {
+ int best_ix = i;
+ uint32_t best_score = ~0U;
+ for (k = i; k < num_colors; ++k) {
+ const uint32_t cur_score = PaletteColorDistance(palette[k], predict);
+ if (best_score > cur_score) {
+ best_score = cur_score;
+ best_ix = k;
+ }
+ }
+ SwapColor(&palette[best_ix], &palette[i]);
+ predict = palette[i];
+ }
+}
+
+// Sort palette in increasing order and prepare an inverse mapping array.
+static void PrepareMapToPalette(const uint32_t palette[], uint32_t num_colors,
+ uint32_t sorted[], uint32_t idx_map[]) {
+ uint32_t i;
+ memcpy(sorted, palette, num_colors * sizeof(*sorted));
+ qsort(sorted, num_colors, sizeof(*sorted), PaletteCompareColorsForQsort);
+ for (i = 0; i < num_colors; ++i) {
+ idx_map[SearchColorNoIdx(sorted, palette[i], num_colors)] = i;
+ }
+}
+
+// -----------------------------------------------------------------------------
+// Modified Zeng method from "A Survey on Palette Reordering
+// Methods for Improving the Compression of Color-Indexed Images" by Armando J.
+// Pinho and Antonio J. R. Neves.
+
+// Finds the biggest cooccurrence in the matrix.
+static void CoOccurrenceFindMax(const uint32_t* const cooccurrence,
+ uint32_t num_colors, uint8_t* const c1,
+ uint8_t* const c2) {
+ // Find the index that is most frequently located adjacent to other
+ // (different) indexes.
+ uint32_t best_sum = 0u;
+ uint32_t i, j, best_cooccurrence;
+ *c1 = 0u;
+ for (i = 0; i < num_colors; ++i) {
+ uint32_t sum = 0;
+ for (j = 0; j < num_colors; ++j) sum += cooccurrence[i * num_colors + j];
+ if (sum > best_sum) {
+ best_sum = sum;
+ *c1 = i;
+ }
+ }
+ // Find the index that is most frequently found adjacent to *c1.
+ *c2 = 0u;
+ best_cooccurrence = 0u;
+ for (i = 0; i < num_colors; ++i) {
+ if (cooccurrence[*c1 * num_colors + i] > best_cooccurrence) {
+ best_cooccurrence = cooccurrence[*c1 * num_colors + i];
+ *c2 = i;
+ }
+ }
+ assert(*c1 != *c2);
+}
+
+// Builds the cooccurrence matrix
+static int CoOccurrenceBuild(const WebPPicture* const pic,
+ const uint32_t* const palette, uint32_t num_colors,
+ uint32_t* cooccurrence) {
+ uint32_t *lines, *line_top, *line_current, *line_tmp;
+ int x, y;
+ const uint32_t* src = pic->argb;
+ uint32_t prev_pix = ~src[0];
+ uint32_t prev_idx = 0u;
+ uint32_t idx_map[MAX_PALETTE_SIZE] = {0};
+ uint32_t palette_sorted[MAX_PALETTE_SIZE];
+ lines = (uint32_t*)WebPSafeMalloc(2 * pic->width, sizeof(*lines));
+ if (lines == NULL) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ return 0;
+ }
+ line_top = &lines[0];
+ line_current = &lines[pic->width];
+ PrepareMapToPalette(palette, num_colors, palette_sorted, idx_map);
+ for (y = 0; y < pic->height; ++y) {
+ for (x = 0; x < pic->width; ++x) {
+ const uint32_t pix = src[x];
+ if (pix != prev_pix) {
+ prev_idx = idx_map[SearchColorNoIdx(palette_sorted, pix, num_colors)];
+ prev_pix = pix;
+ }
+ line_current[x] = prev_idx;
+ // 4-connectivity is what works best as mentioned in "On the relation
+ // between Memon's and the modified Zeng's palette reordering methods".
+ if (x > 0 && prev_idx != line_current[x - 1]) {
+ const uint32_t left_idx = line_current[x - 1];
+ ++cooccurrence[prev_idx * num_colors + left_idx];
+ ++cooccurrence[left_idx * num_colors + prev_idx];
+ }
+ if (y > 0 && prev_idx != line_top[x]) {
+ const uint32_t top_idx = line_top[x];
+ ++cooccurrence[prev_idx * num_colors + top_idx];
+ ++cooccurrence[top_idx * num_colors + prev_idx];
+ }
+ }
+ line_tmp = line_top;
+ line_top = line_current;
+ line_current = line_tmp;
+ src += pic->argb_stride;
+ }
+ WebPSafeFree(lines);
+ return 1;
+}
+
+struct Sum {
+ uint8_t index;
+ uint32_t sum;
+};
+
+// Implements the modified Zeng method from "A Survey on Palette Reordering
+// Methods for Improving the Compression of Color-Indexed Images" by Armando J.
+// Pinho and Antonio J. R. Neves.
+static int PaletteSortModifiedZeng(
+ const WebPPicture* const pic, const uint32_t* const palette_sorted,
+ uint32_t num_colors, uint32_t* const palette) {
+ uint32_t i, j, ind;
+ uint8_t remapping[MAX_PALETTE_SIZE];
+ uint32_t* cooccurrence;
+ struct Sum sums[MAX_PALETTE_SIZE];
+ uint32_t first, last;
+ uint32_t num_sums;
+ // TODO(vrabaud) check whether one color images should use palette or not.
+ if (num_colors <= 1) return 1;
+ // Build the co-occurrence matrix.
+ cooccurrence =
+ (uint32_t*)WebPSafeCalloc(num_colors * num_colors, sizeof(*cooccurrence));
+ if (cooccurrence == NULL) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ return 0;
+ }
+ if (!CoOccurrenceBuild(pic, palette_sorted, num_colors, cooccurrence)) {
+ return 0;
+ }
+
+ // Initialize the mapping list with the two best indices.
+ CoOccurrenceFindMax(cooccurrence, num_colors, &remapping[0], &remapping[1]);
+
+ // We need to append and prepend to the list of remapping. To this end, we
+ // actually define the next start/end of the list as indices in a vector (with
+ // a wrap around when the end is reached).
+ first = 0;
+ last = 1;
+ num_sums = num_colors - 2; // -2 because we know the first two values
+ if (num_sums > 0) {
+ // Initialize the sums with the first two remappings and find the best one
+ struct Sum* best_sum = &sums[0];
+ best_sum->index = 0u;
+ best_sum->sum = 0u;
+ for (i = 0, j = 0; i < num_colors; ++i) {
+ if (i == remapping[0] || i == remapping[1]) continue;
+ sums[j].index = i;
+ sums[j].sum = cooccurrence[i * num_colors + remapping[0]] +
+ cooccurrence[i * num_colors + remapping[1]];
+ if (sums[j].sum > best_sum->sum) best_sum = &sums[j];
+ ++j;
+ }
+
+ while (num_sums > 0) {
+ const uint8_t best_index = best_sum->index;
+ // Compute delta to know if we need to prepend or append the best index.
+ int32_t delta = 0;
+ const int32_t n = num_colors - num_sums;
+ for (ind = first, j = 0; (ind + j) % num_colors != last + 1; ++j) {
+ const uint16_t l_j = remapping[(ind + j) % num_colors];
+ delta += (n - 1 - 2 * (int32_t)j) *
+ (int32_t)cooccurrence[best_index * num_colors + l_j];
+ }
+ if (delta > 0) {
+ first = (first == 0) ? num_colors - 1 : first - 1;
+ remapping[first] = best_index;
+ } else {
+ ++last;
+ remapping[last] = best_index;
+ }
+ // Remove best_sum from sums.
+ *best_sum = sums[num_sums - 1];
+ --num_sums;
+ // Update all the sums and find the best one.
+ best_sum = &sums[0];
+ for (i = 0; i < num_sums; ++i) {
+ sums[i].sum += cooccurrence[best_index * num_colors + sums[i].index];
+ if (sums[i].sum > best_sum->sum) best_sum = &sums[i];
+ }
+ }
+ }
+ assert((last + 1) % num_colors == first);
+ WebPSafeFree(cooccurrence);
+
+ // Re-map the palette.
+ for (i = 0; i < num_colors; ++i) {
+ palette[i] = palette_sorted[remapping[(first + i) % num_colors]];
+ }
+ return 1;
+}
+
+// -----------------------------------------------------------------------------
+// Palette
+
+// These five modes are evaluated and their respective entropy is computed.
+typedef enum {
+ kDirect = 0,
+ kSpatial = 1,
+ kSubGreen = 2,
+ kSpatialSubGreen = 3,
+ kPalette = 4,
+ kPaletteAndSpatial = 5,
+ kNumEntropyIx = 6
+} EntropyIx;
+
+typedef enum {
+ kSortedDefault = 0,
+ kMinimizeDelta = 1,
+ kModifiedZeng = 2,
+ kUnusedPalette = 3,
+} PaletteSorting;
+
+typedef enum {
+ kHistoAlpha = 0,
+ kHistoAlphaPred,
+ kHistoGreen,
+ kHistoGreenPred,
+ kHistoRed,
+ kHistoRedPred,
+ kHistoBlue,
+ kHistoBluePred,
+ kHistoRedSubGreen,
+ kHistoRedPredSubGreen,
+ kHistoBlueSubGreen,
+ kHistoBluePredSubGreen,
+ kHistoPalette,
+ kHistoTotal // Must be last.
+} HistoIx;
+
+static void AddSingleSubGreen(int p, uint32_t* const r, uint32_t* const b) {
+ const int green = p >> 8; // The upper bits are masked away later.
+ ++r[((p >> 16) - green) & 0xff];
+ ++b[((p >> 0) - green) & 0xff];
+}
+
+static void AddSingle(uint32_t p,
+ uint32_t* const a, uint32_t* const r,
+ uint32_t* const g, uint32_t* const b) {
+ ++a[(p >> 24) & 0xff];
+ ++r[(p >> 16) & 0xff];
+ ++g[(p >> 8) & 0xff];
+ ++b[(p >> 0) & 0xff];
+}
+
+static WEBP_INLINE uint32_t HashPix(uint32_t pix) {
+ // Note that masking with 0xffffffffu is for preventing an
+ // 'unsigned int overflow' warning. Doesn't impact the compiled code.
+ return ((((uint64_t)pix + (pix >> 19)) * 0x39c5fba7ull) & 0xffffffffu) >> 24;
+}
+
+static int AnalyzeEntropy(const uint32_t* argb,
+ int width, int height, int argb_stride,
+ int use_palette,
+ int palette_size, int transform_bits,
+ EntropyIx* const min_entropy_ix,
+ int* const red_and_blue_always_zero) {
+ // Allocate histogram set with cache_bits = 0.
+ uint32_t* histo;
+
+ if (use_palette && palette_size <= 16) {
+ // In the case of small palettes, we pack 2, 4 or 8 pixels together. In
+ // practice, small palettes are better than any other transform.
+ *min_entropy_ix = kPalette;
+ *red_and_blue_always_zero = 1;
+ return 1;
+ }
+ histo = (uint32_t*)WebPSafeCalloc(kHistoTotal, sizeof(*histo) * 256);
+ if (histo != NULL) {
+ int i, x, y;
+ const uint32_t* prev_row = NULL;
+ const uint32_t* curr_row = argb;
+ uint32_t pix_prev = argb[0]; // Skip the first pixel.
+ for (y = 0; y < height; ++y) {
+ for (x = 0; x < width; ++x) {
+ const uint32_t pix = curr_row[x];
+ const uint32_t pix_diff = VP8LSubPixels(pix, pix_prev);
+ pix_prev = pix;
+ if ((pix_diff == 0) || (prev_row != NULL && pix == prev_row[x])) {
+ continue;
+ }
+ AddSingle(pix,
+ &histo[kHistoAlpha * 256],
+ &histo[kHistoRed * 256],
+ &histo[kHistoGreen * 256],
+ &histo[kHistoBlue * 256]);
+ AddSingle(pix_diff,
+ &histo[kHistoAlphaPred * 256],
+ &histo[kHistoRedPred * 256],
+ &histo[kHistoGreenPred * 256],
+ &histo[kHistoBluePred * 256]);
+ AddSingleSubGreen(pix,
+ &histo[kHistoRedSubGreen * 256],
+ &histo[kHistoBlueSubGreen * 256]);
+ AddSingleSubGreen(pix_diff,
+ &histo[kHistoRedPredSubGreen * 256],
+ &histo[kHistoBluePredSubGreen * 256]);
+ {
+ // Approximate the palette by the entropy of the multiplicative hash.
+ const uint32_t hash = HashPix(pix);
+ ++histo[kHistoPalette * 256 + hash];
+ }
+ }
+ prev_row = curr_row;
+ curr_row += argb_stride;
+ }
+ {
+ float entropy_comp[kHistoTotal];
+ float entropy[kNumEntropyIx];
+ int k;
+ int last_mode_to_analyze = use_palette ? kPalette : kSpatialSubGreen;
+ int j;
+ // Let's add one zero to the predicted histograms. The zeros are removed
+ // too efficiently by the pix_diff == 0 comparison, at least one of the
+ // zeros is likely to exist.
+ ++histo[kHistoRedPredSubGreen * 256];
+ ++histo[kHistoBluePredSubGreen * 256];
+ ++histo[kHistoRedPred * 256];
+ ++histo[kHistoGreenPred * 256];
+ ++histo[kHistoBluePred * 256];
+ ++histo[kHistoAlphaPred * 256];
+
+ for (j = 0; j < kHistoTotal; ++j) {
+ entropy_comp[j] = VP8LBitsEntropy(&histo[j * 256], 256);
+ }
+ entropy[kDirect] = entropy_comp[kHistoAlpha] +
+ entropy_comp[kHistoRed] +
+ entropy_comp[kHistoGreen] +
+ entropy_comp[kHistoBlue];
+ entropy[kSpatial] = entropy_comp[kHistoAlphaPred] +
+ entropy_comp[kHistoRedPred] +
+ entropy_comp[kHistoGreenPred] +
+ entropy_comp[kHistoBluePred];
+ entropy[kSubGreen] = entropy_comp[kHistoAlpha] +
+ entropy_comp[kHistoRedSubGreen] +
+ entropy_comp[kHistoGreen] +
+ entropy_comp[kHistoBlueSubGreen];
+ entropy[kSpatialSubGreen] = entropy_comp[kHistoAlphaPred] +
+ entropy_comp[kHistoRedPredSubGreen] +
+ entropy_comp[kHistoGreenPred] +
+ entropy_comp[kHistoBluePredSubGreen];
+ entropy[kPalette] = entropy_comp[kHistoPalette];
+
+ // When including transforms, there is an overhead in bits from
+ // storing them. This overhead is small but matters for small images.
+ // For spatial, there are 14 transformations.
+ entropy[kSpatial] += VP8LSubSampleSize(width, transform_bits) *
+ VP8LSubSampleSize(height, transform_bits) *
+ VP8LFastLog2(14);
+ // For color transforms: 24 as only 3 channels are considered in a
+ // ColorTransformElement.
+ entropy[kSpatialSubGreen] += VP8LSubSampleSize(width, transform_bits) *
+ VP8LSubSampleSize(height, transform_bits) *
+ VP8LFastLog2(24);
+ // For palettes, add the cost of storing the palette.
+ // We empirically estimate the cost of a compressed entry as 8 bits.
+ // The palette is differential-coded when compressed hence a much
+ // lower cost than sizeof(uint32_t)*8.
+ entropy[kPalette] += palette_size * 8;
+
+ *min_entropy_ix = kDirect;
+ for (k = kDirect + 1; k <= last_mode_to_analyze; ++k) {
+ if (entropy[*min_entropy_ix] > entropy[k]) {
+ *min_entropy_ix = (EntropyIx)k;
+ }
+ }
+ assert((int)*min_entropy_ix <= last_mode_to_analyze);
+ *red_and_blue_always_zero = 1;
+ // Let's check if the histogram of the chosen entropy mode has
+ // non-zero red and blue values. If all are zero, we can later skip
+ // the cross color optimization.
+ {
+ static const uint8_t kHistoPairs[5][2] = {
+ { kHistoRed, kHistoBlue },
+ { kHistoRedPred, kHistoBluePred },
+ { kHistoRedSubGreen, kHistoBlueSubGreen },
+ { kHistoRedPredSubGreen, kHistoBluePredSubGreen },
+ { kHistoRed, kHistoBlue }
+ };
+ const uint32_t* const red_histo =
+ &histo[256 * kHistoPairs[*min_entropy_ix][0]];
+ const uint32_t* const blue_histo =
+ &histo[256 * kHistoPairs[*min_entropy_ix][1]];
+ for (i = 1; i < 256; ++i) {
+ if ((red_histo[i] | blue_histo[i]) != 0) {
+ *red_and_blue_always_zero = 0;
+ break;
+ }
+ }
+ }
+ }
+ WebPSafeFree(histo);
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+static int GetHistoBits(int method, int use_palette, int width, int height) {
+ // Make tile size a function of encoding method (Range: 0 to 6).
+ int histo_bits = (use_palette ? 9 : 7) - method;
+ while (1) {
+ const int huff_image_size = VP8LSubSampleSize(width, histo_bits) *
+ VP8LSubSampleSize(height, histo_bits);
+ if (huff_image_size <= MAX_HUFF_IMAGE_SIZE) break;
+ ++histo_bits;
+ }
+ return (histo_bits < MIN_HUFFMAN_BITS) ? MIN_HUFFMAN_BITS :
+ (histo_bits > MAX_HUFFMAN_BITS) ? MAX_HUFFMAN_BITS : histo_bits;
+}
+
+static int GetTransformBits(int method, int histo_bits) {
+ const int max_transform_bits = (method < 4) ? 6 : (method > 4) ? 4 : 5;
+ const int res =
+ (histo_bits > max_transform_bits) ? max_transform_bits : histo_bits;
+ assert(res <= MAX_TRANSFORM_BITS);
+ return res;
+}
+
+// Set of parameters to be used in each iteration of the cruncher.
+#define CRUNCH_SUBCONFIGS_MAX 2
+typedef struct {
+ int lz77_;
+ int do_no_cache_;
+} CrunchSubConfig;
+typedef struct {
+ int entropy_idx_;
+ PaletteSorting palette_sorting_type_;
+ CrunchSubConfig sub_configs_[CRUNCH_SUBCONFIGS_MAX];
+ int sub_configs_size_;
+} CrunchConfig;
+
+// +2 because we add a palette sorting configuration for kPalette and
+// kPaletteAndSpatial.
+#define CRUNCH_CONFIGS_MAX (kNumEntropyIx + 2)
+
+static int EncoderAnalyze(VP8LEncoder* const enc,
+ CrunchConfig crunch_configs[CRUNCH_CONFIGS_MAX],
+ int* const crunch_configs_size,
+ int* const red_and_blue_always_zero) {
+ const WebPPicture* const pic = enc->pic_;
+ const int width = pic->width;
+ const int height = pic->height;
+ const WebPConfig* const config = enc->config_;
+ const int method = config->method;
+ const int low_effort = (config->method == 0);
+ int i;
+ int use_palette;
+ int n_lz77s;
+ // If set to 0, analyze the cache with the computed cache value. If 1, also
+ // analyze with no-cache.
+ int do_no_cache = 0;
+ assert(pic != NULL && pic->argb != NULL);
+
+ // Check whether a palette is possible.
+ enc->palette_size_ = WebPGetColorPalette(pic, enc->palette_sorted_);
+ use_palette = (enc->palette_size_ <= MAX_PALETTE_SIZE);
+ if (!use_palette) {
+ enc->palette_size_ = 0;
+ } else {
+ qsort(enc->palette_sorted_, enc->palette_size_,
+ sizeof(*enc->palette_sorted_), PaletteCompareColorsForQsort);
+ }
+
+ // Empirical bit sizes.
+ enc->histo_bits_ = GetHistoBits(method, use_palette,
+ pic->width, pic->height);
+ enc->transform_bits_ = GetTransformBits(method, enc->histo_bits_);
+
+ if (low_effort) {
+ // AnalyzeEntropy is somewhat slow.
+ crunch_configs[0].entropy_idx_ = use_palette ? kPalette : kSpatialSubGreen;
+ crunch_configs[0].palette_sorting_type_ =
+ use_palette ? kSortedDefault : kUnusedPalette;
+ n_lz77s = 1;
+ *crunch_configs_size = 1;
+ } else {
+ EntropyIx min_entropy_ix;
+ // Try out multiple LZ77 on images with few colors.
+ n_lz77s = (enc->palette_size_ > 0 && enc->palette_size_ <= 16) ? 2 : 1;
+ if (!AnalyzeEntropy(pic->argb, width, height, pic->argb_stride, use_palette,
+ enc->palette_size_, enc->transform_bits_,
+ &min_entropy_ix, red_and_blue_always_zero)) {
+ return 0;
+ }
+ if (method == 6 && config->quality == 100) {
+ do_no_cache = 1;
+ // Go brute force on all transforms.
+ *crunch_configs_size = 0;
+ for (i = 0; i < kNumEntropyIx; ++i) {
+ // We can only apply kPalette or kPaletteAndSpatial if we can indeed use
+ // a palette.
+ if ((i != kPalette && i != kPaletteAndSpatial) || use_palette) {
+ assert(*crunch_configs_size < CRUNCH_CONFIGS_MAX);
+ crunch_configs[(*crunch_configs_size)].entropy_idx_ = i;
+ if (use_palette && (i == kPalette || i == kPaletteAndSpatial)) {
+ crunch_configs[(*crunch_configs_size)].palette_sorting_type_ =
+ kMinimizeDelta;
+ ++*crunch_configs_size;
+ // Also add modified Zeng's method.
+ crunch_configs[(*crunch_configs_size)].entropy_idx_ = i;
+ crunch_configs[(*crunch_configs_size)].palette_sorting_type_ =
+ kModifiedZeng;
+ } else {
+ crunch_configs[(*crunch_configs_size)].palette_sorting_type_ =
+ kUnusedPalette;
+ }
+ ++*crunch_configs_size;
+ }
+ }
+ } else {
+ // Only choose the guessed best transform.
+ *crunch_configs_size = 1;
+ crunch_configs[0].entropy_idx_ = min_entropy_ix;
+ crunch_configs[0].palette_sorting_type_ =
+ use_palette ? kMinimizeDelta : kUnusedPalette;
+ if (config->quality >= 75 && method == 5) {
+ // Test with and without color cache.
+ do_no_cache = 1;
+ // If we have a palette, also check in combination with spatial.
+ if (min_entropy_ix == kPalette) {
+ *crunch_configs_size = 2;
+ crunch_configs[1].entropy_idx_ = kPaletteAndSpatial;
+ crunch_configs[1].palette_sorting_type_ = kMinimizeDelta;
+ }
+ }
+ }
+ }
+ // Fill in the different LZ77s.
+ assert(n_lz77s <= CRUNCH_SUBCONFIGS_MAX);
+ for (i = 0; i < *crunch_configs_size; ++i) {
+ int j;
+ for (j = 0; j < n_lz77s; ++j) {
+ assert(j < CRUNCH_SUBCONFIGS_MAX);
+ crunch_configs[i].sub_configs_[j].lz77_ =
+ (j == 0) ? kLZ77Standard | kLZ77RLE : kLZ77Box;
+ crunch_configs[i].sub_configs_[j].do_no_cache_ = do_no_cache;
+ }
+ crunch_configs[i].sub_configs_size_ = n_lz77s;
+ }
+ return 1;
+}
+
+static int EncoderInit(VP8LEncoder* const enc) {
+ const WebPPicture* const pic = enc->pic_;
+ const int width = pic->width;
+ const int height = pic->height;
+ const int pix_cnt = width * height;
+ // we round the block size up, so we're guaranteed to have
+ // at most MAX_REFS_BLOCK_PER_IMAGE blocks used:
+ const int refs_block_size = (pix_cnt - 1) / MAX_REFS_BLOCK_PER_IMAGE + 1;
+ int i;
+ if (!VP8LHashChainInit(&enc->hash_chain_, pix_cnt)) return 0;
+
+ for (i = 0; i < 4; ++i) VP8LBackwardRefsInit(&enc->refs_[i], refs_block_size);
+
+ return 1;
+}
+
+// Returns false in case of memory error.
+static int GetHuffBitLengthsAndCodes(
+ const VP8LHistogramSet* const histogram_image,
+ HuffmanTreeCode* const huffman_codes) {
+ int i, k;
+ int ok = 0;
+ uint64_t total_length_size = 0;
+ uint8_t* mem_buf = NULL;
+ const int histogram_image_size = histogram_image->size;
+ int max_num_symbols = 0;
+ uint8_t* buf_rle = NULL;
+ HuffmanTree* huff_tree = NULL;
+
+ // Iterate over all histograms and get the aggregate number of codes used.
+ for (i = 0; i < histogram_image_size; ++i) {
+ const VP8LHistogram* const histo = histogram_image->histograms[i];
+ HuffmanTreeCode* const codes = &huffman_codes[5 * i];
+ assert(histo != NULL);
+ for (k = 0; k < 5; ++k) {
+ const int num_symbols =
+ (k == 0) ? VP8LHistogramNumCodes(histo->palette_code_bits_) :
+ (k == 4) ? NUM_DISTANCE_CODES : 256;
+ codes[k].num_symbols = num_symbols;
+ total_length_size += num_symbols;
+ }
+ }
+
+ // Allocate and Set Huffman codes.
+ {
+ uint16_t* codes;
+ uint8_t* lengths;
+ mem_buf = (uint8_t*)WebPSafeCalloc(total_length_size,
+ sizeof(*lengths) + sizeof(*codes));
+ if (mem_buf == NULL) goto End;
+
+ codes = (uint16_t*)mem_buf;
+ lengths = (uint8_t*)&codes[total_length_size];
+ for (i = 0; i < 5 * histogram_image_size; ++i) {
+ const int bit_length = huffman_codes[i].num_symbols;
+ huffman_codes[i].codes = codes;
+ huffman_codes[i].code_lengths = lengths;
+ codes += bit_length;
+ lengths += bit_length;
+ if (max_num_symbols < bit_length) {
+ max_num_symbols = bit_length;
+ }
+ }
+ }
+
+ buf_rle = (uint8_t*)WebPSafeMalloc(1ULL, max_num_symbols);
+ huff_tree = (HuffmanTree*)WebPSafeMalloc(3ULL * max_num_symbols,
+ sizeof(*huff_tree));
+ if (buf_rle == NULL || huff_tree == NULL) goto End;
+
+ // Create Huffman trees.
+ for (i = 0; i < histogram_image_size; ++i) {
+ HuffmanTreeCode* const codes = &huffman_codes[5 * i];
+ VP8LHistogram* const histo = histogram_image->histograms[i];
+ VP8LCreateHuffmanTree(histo->literal_, 15, buf_rle, huff_tree, codes + 0);
+ VP8LCreateHuffmanTree(histo->red_, 15, buf_rle, huff_tree, codes + 1);
+ VP8LCreateHuffmanTree(histo->blue_, 15, buf_rle, huff_tree, codes + 2);
+ VP8LCreateHuffmanTree(histo->alpha_, 15, buf_rle, huff_tree, codes + 3);
+ VP8LCreateHuffmanTree(histo->distance_, 15, buf_rle, huff_tree, codes + 4);
+ }
+ ok = 1;
+ End:
+ WebPSafeFree(huff_tree);
+ WebPSafeFree(buf_rle);
+ if (!ok) {
+ WebPSafeFree(mem_buf);
+ memset(huffman_codes, 0, 5 * histogram_image_size * sizeof(*huffman_codes));
+ }
+ return ok;
+}
+
+static void StoreHuffmanTreeOfHuffmanTreeToBitMask(
+ VP8LBitWriter* const bw, const uint8_t* code_length_bitdepth) {
+ // RFC 1951 will calm you down if you are worried about this funny sequence.
+ // This sequence is tuned from that, but more weighted for lower symbol count,
+ // and more spiking histograms.
+ static const uint8_t kStorageOrder[CODE_LENGTH_CODES] = {
+ 17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
+ };
+ int i;
+ // Throw away trailing zeros:
+ int codes_to_store = CODE_LENGTH_CODES;
+ for (; codes_to_store > 4; --codes_to_store) {
+ if (code_length_bitdepth[kStorageOrder[codes_to_store - 1]] != 0) {
+ break;
+ }
+ }
+ VP8LPutBits(bw, codes_to_store - 4, 4);
+ for (i = 0; i < codes_to_store; ++i) {
+ VP8LPutBits(bw, code_length_bitdepth[kStorageOrder[i]], 3);
+ }
+}
+
+static void ClearHuffmanTreeIfOnlyOneSymbol(
+ HuffmanTreeCode* const huffman_code) {
+ int k;
+ int count = 0;
+ for (k = 0; k < huffman_code->num_symbols; ++k) {
+ if (huffman_code->code_lengths[k] != 0) {
+ ++count;
+ if (count > 1) return;
+ }
+ }
+ for (k = 0; k < huffman_code->num_symbols; ++k) {
+ huffman_code->code_lengths[k] = 0;
+ huffman_code->codes[k] = 0;
+ }
+}
+
+static void StoreHuffmanTreeToBitMask(
+ VP8LBitWriter* const bw,
+ const HuffmanTreeToken* const tokens, const int num_tokens,
+ const HuffmanTreeCode* const huffman_code) {
+ int i;
+ for (i = 0; i < num_tokens; ++i) {
+ const int ix = tokens[i].code;
+ const int extra_bits = tokens[i].extra_bits;
+ VP8LPutBits(bw, huffman_code->codes[ix], huffman_code->code_lengths[ix]);
+ switch (ix) {
+ case 16:
+ VP8LPutBits(bw, extra_bits, 2);
+ break;
+ case 17:
+ VP8LPutBits(bw, extra_bits, 3);
+ break;
+ case 18:
+ VP8LPutBits(bw, extra_bits, 7);
+ break;
+ }
+ }
+}
+
+// 'huff_tree' and 'tokens' are pre-alloacted buffers.
+static void StoreFullHuffmanCode(VP8LBitWriter* const bw,
+ HuffmanTree* const huff_tree,
+ HuffmanTreeToken* const tokens,
+ const HuffmanTreeCode* const tree) {
+ uint8_t code_length_bitdepth[CODE_LENGTH_CODES] = { 0 };
+ uint16_t code_length_bitdepth_symbols[CODE_LENGTH_CODES] = { 0 };
+ const int max_tokens = tree->num_symbols;
+ int num_tokens;
+ HuffmanTreeCode huffman_code;
+ huffman_code.num_symbols = CODE_LENGTH_CODES;
+ huffman_code.code_lengths = code_length_bitdepth;
+ huffman_code.codes = code_length_bitdepth_symbols;
+
+ VP8LPutBits(bw, 0, 1);
+ num_tokens = VP8LCreateCompressedHuffmanTree(tree, tokens, max_tokens);
+ {
+ uint32_t histogram[CODE_LENGTH_CODES] = { 0 };
+ uint8_t buf_rle[CODE_LENGTH_CODES] = { 0 };
+ int i;
+ for (i = 0; i < num_tokens; ++i) {
+ ++histogram[tokens[i].code];
+ }
+
+ VP8LCreateHuffmanTree(histogram, 7, buf_rle, huff_tree, &huffman_code);
+ }
+
+ StoreHuffmanTreeOfHuffmanTreeToBitMask(bw, code_length_bitdepth);
+ ClearHuffmanTreeIfOnlyOneSymbol(&huffman_code);
+ {
+ int trailing_zero_bits = 0;
+ int trimmed_length = num_tokens;
+ int write_trimmed_length;
+ int length;
+ int i = num_tokens;
+ while (i-- > 0) {
+ const int ix = tokens[i].code;
+ if (ix == 0 || ix == 17 || ix == 18) {
+ --trimmed_length; // discount trailing zeros
+ trailing_zero_bits += code_length_bitdepth[ix];
+ if (ix == 17) {
+ trailing_zero_bits += 3;
+ } else if (ix == 18) {
+ trailing_zero_bits += 7;
+ }
+ } else {
+ break;
+ }
+ }
+ write_trimmed_length = (trimmed_length > 1 && trailing_zero_bits > 12);
+ length = write_trimmed_length ? trimmed_length : num_tokens;
+ VP8LPutBits(bw, write_trimmed_length, 1);
+ if (write_trimmed_length) {
+ if (trimmed_length == 2) {
+ VP8LPutBits(bw, 0, 3 + 2); // nbitpairs=1, trimmed_length=2
+ } else {
+ const int nbits = BitsLog2Floor(trimmed_length - 2);
+ const int nbitpairs = nbits / 2 + 1;
+ assert(trimmed_length > 2);
+ assert(nbitpairs - 1 < 8);
+ VP8LPutBits(bw, nbitpairs - 1, 3);
+ VP8LPutBits(bw, trimmed_length - 2, nbitpairs * 2);
+ }
+ }
+ StoreHuffmanTreeToBitMask(bw, tokens, length, &huffman_code);
+ }
+}
+
+// 'huff_tree' and 'tokens' are pre-alloacted buffers.
+static void StoreHuffmanCode(VP8LBitWriter* const bw,
+ HuffmanTree* const huff_tree,
+ HuffmanTreeToken* const tokens,
+ const HuffmanTreeCode* const huffman_code) {
+ int i;
+ int count = 0;
+ int symbols[2] = { 0, 0 };
+ const int kMaxBits = 8;
+ const int kMaxSymbol = 1 << kMaxBits;
+
+ // Check whether it's a small tree.
+ for (i = 0; i < huffman_code->num_symbols && count < 3; ++i) {
+ if (huffman_code->code_lengths[i] != 0) {
+ if (count < 2) symbols[count] = i;
+ ++count;
+ }
+ }
+
+ if (count == 0) { // emit minimal tree for empty cases
+ // bits: small tree marker: 1, count-1: 0, large 8-bit code: 0, code: 0
+ VP8LPutBits(bw, 0x01, 4);
+ } else if (count <= 2 && symbols[0] < kMaxSymbol && symbols[1] < kMaxSymbol) {
+ VP8LPutBits(bw, 1, 1); // Small tree marker to encode 1 or 2 symbols.
+ VP8LPutBits(bw, count - 1, 1);
+ if (symbols[0] <= 1) {
+ VP8LPutBits(bw, 0, 1); // Code bit for small (1 bit) symbol value.
+ VP8LPutBits(bw, symbols[0], 1);
+ } else {
+ VP8LPutBits(bw, 1, 1);
+ VP8LPutBits(bw, symbols[0], 8);
+ }
+ if (count == 2) {
+ VP8LPutBits(bw, symbols[1], 8);
+ }
+ } else {
+ StoreFullHuffmanCode(bw, huff_tree, tokens, huffman_code);
+ }
+}
+
+static WEBP_INLINE void WriteHuffmanCode(VP8LBitWriter* const bw,
+ const HuffmanTreeCode* const code,
+ int code_index) {
+ const int depth = code->code_lengths[code_index];
+ const int symbol = code->codes[code_index];
+ VP8LPutBits(bw, symbol, depth);
+}
+
+static WEBP_INLINE void WriteHuffmanCodeWithExtraBits(
+ VP8LBitWriter* const bw,
+ const HuffmanTreeCode* const code,
+ int code_index,
+ int bits,
+ int n_bits) {
+ const int depth = code->code_lengths[code_index];
+ const int symbol = code->codes[code_index];
+ VP8LPutBits(bw, (bits << depth) | symbol, depth + n_bits);
+}
+
+static int StoreImageToBitMask(
+ VP8LBitWriter* const bw, int width, int histo_bits,
+ const VP8LBackwardRefs* const refs,
+ const uint16_t* histogram_symbols,
+ const HuffmanTreeCode* const huffman_codes, const WebPPicture* const pic) {
+ const int histo_xsize = histo_bits ? VP8LSubSampleSize(width, histo_bits) : 1;
+ const int tile_mask = (histo_bits == 0) ? 0 : -(1 << histo_bits);
+ // x and y trace the position in the image.
+ int x = 0;
+ int y = 0;
+ int tile_x = x & tile_mask;
+ int tile_y = y & tile_mask;
+ int histogram_ix = histogram_symbols[0];
+ const HuffmanTreeCode* codes = huffman_codes + 5 * histogram_ix;
+ VP8LRefsCursor c = VP8LRefsCursorInit(refs);
+ while (VP8LRefsCursorOk(&c)) {
+ const PixOrCopy* const v = c.cur_pos;
+ if ((tile_x != (x & tile_mask)) || (tile_y != (y & tile_mask))) {
+ tile_x = x & tile_mask;
+ tile_y = y & tile_mask;
+ histogram_ix = histogram_symbols[(y >> histo_bits) * histo_xsize +
+ (x >> histo_bits)];
+ codes = huffman_codes + 5 * histogram_ix;
+ }
+ if (PixOrCopyIsLiteral(v)) {
+ static const uint8_t order[] = { 1, 2, 0, 3 };
+ int k;
+ for (k = 0; k < 4; ++k) {
+ const int code = PixOrCopyLiteral(v, order[k]);
+ WriteHuffmanCode(bw, codes + k, code);
+ }
+ } else if (PixOrCopyIsCacheIdx(v)) {
+ const int code = PixOrCopyCacheIdx(v);
+ const int literal_ix = 256 + NUM_LENGTH_CODES + code;
+ WriteHuffmanCode(bw, codes, literal_ix);
+ } else {
+ int bits, n_bits;
+ int code;
+
+ const int distance = PixOrCopyDistance(v);
+ VP8LPrefixEncode(v->len, &code, &n_bits, &bits);
+ WriteHuffmanCodeWithExtraBits(bw, codes, 256 + code, bits, n_bits);
+
+ // Don't write the distance with the extra bits code since
+ // the distance can be up to 18 bits of extra bits, and the prefix
+ // 15 bits, totaling to 33, and our PutBits only supports up to 32 bits.
+ VP8LPrefixEncode(distance, &code, &n_bits, &bits);
+ WriteHuffmanCode(bw, codes + 4, code);
+ VP8LPutBits(bw, bits, n_bits);
+ }
+ x += PixOrCopyLength(v);
+ while (x >= width) {
+ x -= width;
+ ++y;
+ }
+ VP8LRefsCursorNext(&c);
+ }
+ if (bw->error_) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ return 0;
+ }
+ return 1;
+}
+
+// Special case of EncodeImageInternal() for cache-bits=0, histo_bits=31.
+// pic and percent are for progress.
+static int EncodeImageNoHuffman(VP8LBitWriter* const bw,
+ const uint32_t* const argb,
+ VP8LHashChain* const hash_chain,
+ VP8LBackwardRefs* const refs_array, int width,
+ int height, int quality, int low_effort,
+ const WebPPicture* const pic, int percent_range,
+ int* const percent) {
+ int i;
+ int max_tokens = 0;
+ VP8LBackwardRefs* refs;
+ HuffmanTreeToken* tokens = NULL;
+ HuffmanTreeCode huffman_codes[5] = {{0, NULL, NULL}};
+ const uint16_t histogram_symbols[1] = {0}; // only one tree, one symbol
+ int cache_bits = 0;
+ VP8LHistogramSet* histogram_image = NULL;
+ HuffmanTree* const huff_tree = (HuffmanTree*)WebPSafeMalloc(
+ 3ULL * CODE_LENGTH_CODES, sizeof(*huff_tree));
+ if (huff_tree == NULL) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+
+ // Calculate backward references from ARGB image.
+ if (!VP8LHashChainFill(hash_chain, quality, argb, width, height, low_effort,
+ pic, percent_range / 2, percent)) {
+ goto Error;
+ }
+ if (!VP8LGetBackwardReferences(width, height, argb, quality, /*low_effort=*/0,
+ kLZ77Standard | kLZ77RLE, cache_bits,
+ /*do_no_cache=*/0, hash_chain, refs_array,
+ &cache_bits, pic,
+ percent_range - percent_range / 2, percent)) {
+ goto Error;
+ }
+ refs = &refs_array[0];
+ histogram_image = VP8LAllocateHistogramSet(1, cache_bits);
+ if (histogram_image == NULL) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+ VP8LHistogramSetClear(histogram_image);
+
+ // Build histogram image and symbols from backward references.
+ VP8LHistogramStoreRefs(refs, histogram_image->histograms[0]);
+
+ // Create Huffman bit lengths and codes for each histogram image.
+ assert(histogram_image->size == 1);
+ if (!GetHuffBitLengthsAndCodes(histogram_image, huffman_codes)) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+
+ // No color cache, no Huffman image.
+ VP8LPutBits(bw, 0, 1);
+
+ // Find maximum number of symbols for the huffman tree-set.
+ for (i = 0; i < 5; ++i) {
+ HuffmanTreeCode* const codes = &huffman_codes[i];
+ if (max_tokens < codes->num_symbols) {
+ max_tokens = codes->num_symbols;
+ }
+ }
+
+ tokens = (HuffmanTreeToken*)WebPSafeMalloc(max_tokens, sizeof(*tokens));
+ if (tokens == NULL) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+
+ // Store Huffman codes.
+ for (i = 0; i < 5; ++i) {
+ HuffmanTreeCode* const codes = &huffman_codes[i];
+ StoreHuffmanCode(bw, huff_tree, tokens, codes);
+ ClearHuffmanTreeIfOnlyOneSymbol(codes);
+ }
+
+ // Store actual literals.
+ if (!StoreImageToBitMask(bw, width, 0, refs, histogram_symbols, huffman_codes,
+ pic)) {
+ goto Error;
+ }
+
+ Error:
+ WebPSafeFree(tokens);
+ WebPSafeFree(huff_tree);
+ VP8LFreeHistogramSet(histogram_image);
+ WebPSafeFree(huffman_codes[0].codes);
+ return (pic->error_code == VP8_ENC_OK);
+}
+
+// pic and percent are for progress.
+static int EncodeImageInternal(
+ VP8LBitWriter* const bw, const uint32_t* const argb,
+ VP8LHashChain* const hash_chain, VP8LBackwardRefs refs_array[4], int width,
+ int height, int quality, int low_effort, int use_cache,
+ const CrunchConfig* const config, int* cache_bits, int histogram_bits,
+ size_t init_byte_position, int* const hdr_size, int* const data_size,
+ const WebPPicture* const pic, int percent_range, int* const percent) {
+ const uint32_t histogram_image_xysize =
+ VP8LSubSampleSize(width, histogram_bits) *
+ VP8LSubSampleSize(height, histogram_bits);
+ int remaining_percent = percent_range;
+ int percent_start = *percent;
+ VP8LHistogramSet* histogram_image = NULL;
+ VP8LHistogram* tmp_histo = NULL;
+ int histogram_image_size = 0;
+ size_t bit_array_size = 0;
+ HuffmanTree* const huff_tree = (HuffmanTree*)WebPSafeMalloc(
+ 3ULL * CODE_LENGTH_CODES, sizeof(*huff_tree));
+ HuffmanTreeToken* tokens = NULL;
+ HuffmanTreeCode* huffman_codes = NULL;
+ uint16_t* const histogram_symbols = (uint16_t*)WebPSafeMalloc(
+ histogram_image_xysize, sizeof(*histogram_symbols));
+ int sub_configs_idx;
+ int cache_bits_init, write_histogram_image;
+ VP8LBitWriter bw_init = *bw, bw_best;
+ int hdr_size_tmp;
+ VP8LHashChain hash_chain_histogram; // histogram image hash chain
+ size_t bw_size_best = ~(size_t)0;
+ assert(histogram_bits >= MIN_HUFFMAN_BITS);
+ assert(histogram_bits <= MAX_HUFFMAN_BITS);
+ assert(hdr_size != NULL);
+ assert(data_size != NULL);
+
+ memset(&hash_chain_histogram, 0, sizeof(hash_chain_histogram));
+ if (!VP8LBitWriterInit(&bw_best, 0)) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+
+ // Make sure we can allocate the different objects.
+ if (huff_tree == NULL || histogram_symbols == NULL ||
+ !VP8LHashChainInit(&hash_chain_histogram, histogram_image_xysize)) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+
+ percent_range = remaining_percent / 5;
+ if (!VP8LHashChainFill(hash_chain, quality, argb, width, height,
+ low_effort, pic, percent_range, percent)) {
+ goto Error;
+ }
+ percent_start += percent_range;
+ remaining_percent -= percent_range;
+
+ if (use_cache) {
+ // If the value is different from zero, it has been set during the
+ // palette analysis.
+ cache_bits_init = (*cache_bits == 0) ? MAX_COLOR_CACHE_BITS : *cache_bits;
+ } else {
+ cache_bits_init = 0;
+ }
+ // If several iterations will happen, clone into bw_best.
+ if ((config->sub_configs_size_ > 1 || config->sub_configs_[0].do_no_cache_) &&
+ !VP8LBitWriterClone(bw, &bw_best)) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+
+ for (sub_configs_idx = 0; sub_configs_idx < config->sub_configs_size_;
+ ++sub_configs_idx) {
+ const CrunchSubConfig* const sub_config =
+ &config->sub_configs_[sub_configs_idx];
+ int cache_bits_best, i_cache;
+ int i_remaining_percent = remaining_percent / config->sub_configs_size_;
+ int i_percent_range = i_remaining_percent / 4;
+ i_remaining_percent -= i_percent_range;
+
+ if (!VP8LGetBackwardReferences(
+ width, height, argb, quality, low_effort, sub_config->lz77_,
+ cache_bits_init, sub_config->do_no_cache_, hash_chain,
+ &refs_array[0], &cache_bits_best, pic, i_percent_range, percent)) {
+ goto Error;
+ }
+
+ for (i_cache = 0; i_cache < (sub_config->do_no_cache_ ? 2 : 1); ++i_cache) {
+ const int cache_bits_tmp = (i_cache == 0) ? cache_bits_best : 0;
+ // Speed-up: no need to study the no-cache case if it was already studied
+ // in i_cache == 0.
+ if (i_cache == 1 && cache_bits_best == 0) break;
+
+ // Reset the bit writer for this iteration.
+ VP8LBitWriterReset(&bw_init, bw);
+
+ // Build histogram image and symbols from backward references.
+ histogram_image =
+ VP8LAllocateHistogramSet(histogram_image_xysize, cache_bits_tmp);
+ tmp_histo = VP8LAllocateHistogram(cache_bits_tmp);
+ if (histogram_image == NULL || tmp_histo == NULL) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+
+ i_percent_range = i_remaining_percent / 3;
+ i_remaining_percent -= i_percent_range;
+ if (!VP8LGetHistoImageSymbols(
+ width, height, &refs_array[i_cache], quality, low_effort,
+ histogram_bits, cache_bits_tmp, histogram_image, tmp_histo,
+ histogram_symbols, pic, i_percent_range, percent)) {
+ goto Error;
+ }
+ // Create Huffman bit lengths and codes for each histogram image.
+ histogram_image_size = histogram_image->size;
+ bit_array_size = 5 * histogram_image_size;
+ huffman_codes = (HuffmanTreeCode*)WebPSafeCalloc(bit_array_size,
+ sizeof(*huffman_codes));
+ // Note: some histogram_image entries may point to tmp_histos[], so the
+ // latter need to outlive the following call to
+ // GetHuffBitLengthsAndCodes().
+ if (huffman_codes == NULL ||
+ !GetHuffBitLengthsAndCodes(histogram_image, huffman_codes)) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+ // Free combined histograms.
+ VP8LFreeHistogramSet(histogram_image);
+ histogram_image = NULL;
+
+ // Free scratch histograms.
+ VP8LFreeHistogram(tmp_histo);
+ tmp_histo = NULL;
+
+ // Color Cache parameters.
+ if (cache_bits_tmp > 0) {
+ VP8LPutBits(bw, 1, 1);
+ VP8LPutBits(bw, cache_bits_tmp, 4);
+ } else {
+ VP8LPutBits(bw, 0, 1);
+ }
+
+ // Huffman image + meta huffman.
+ write_histogram_image = (histogram_image_size > 1);
+ VP8LPutBits(bw, write_histogram_image, 1);
+ if (write_histogram_image) {
+ uint32_t* const histogram_argb = (uint32_t*)WebPSafeMalloc(
+ histogram_image_xysize, sizeof(*histogram_argb));
+ int max_index = 0;
+ uint32_t i;
+ if (histogram_argb == NULL) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+ for (i = 0; i < histogram_image_xysize; ++i) {
+ const int symbol_index = histogram_symbols[i] & 0xffff;
+ histogram_argb[i] = (symbol_index << 8);
+ if (symbol_index >= max_index) {
+ max_index = symbol_index + 1;
+ }
+ }
+ histogram_image_size = max_index;
+
+ VP8LPutBits(bw, histogram_bits - 2, 3);
+ i_percent_range = i_remaining_percent / 2;
+ i_remaining_percent -= i_percent_range;
+ if (!EncodeImageNoHuffman(
+ bw, histogram_argb, &hash_chain_histogram, &refs_array[2],
+ VP8LSubSampleSize(width, histogram_bits),
+ VP8LSubSampleSize(height, histogram_bits), quality, low_effort,
+ pic, i_percent_range, percent)) {
+ WebPSafeFree(histogram_argb);
+ goto Error;
+ }
+ WebPSafeFree(histogram_argb);
+ }
+
+ // Store Huffman codes.
+ {
+ int i;
+ int max_tokens = 0;
+ // Find maximum number of symbols for the huffman tree-set.
+ for (i = 0; i < 5 * histogram_image_size; ++i) {
+ HuffmanTreeCode* const codes = &huffman_codes[i];
+ if (max_tokens < codes->num_symbols) {
+ max_tokens = codes->num_symbols;
+ }
+ }
+ tokens = (HuffmanTreeToken*)WebPSafeMalloc(max_tokens, sizeof(*tokens));
+ if (tokens == NULL) goto Error;
+ for (i = 0; i < 5 * histogram_image_size; ++i) {
+ HuffmanTreeCode* const codes = &huffman_codes[i];
+ StoreHuffmanCode(bw, huff_tree, tokens, codes);
+ ClearHuffmanTreeIfOnlyOneSymbol(codes);
+ }
+ }
+ // Store actual literals.
+ hdr_size_tmp = (int)(VP8LBitWriterNumBytes(bw) - init_byte_position);
+ if (!StoreImageToBitMask(bw, width, histogram_bits, &refs_array[i_cache],
+ histogram_symbols, huffman_codes, pic)) {
+ goto Error;
+ }
+ // Keep track of the smallest image so far.
+ if (VP8LBitWriterNumBytes(bw) < bw_size_best) {
+ bw_size_best = VP8LBitWriterNumBytes(bw);
+ *cache_bits = cache_bits_tmp;
+ *hdr_size = hdr_size_tmp;
+ *data_size =
+ (int)(VP8LBitWriterNumBytes(bw) - init_byte_position - *hdr_size);
+ VP8LBitWriterSwap(bw, &bw_best);
+ }
+ WebPSafeFree(tokens);
+ tokens = NULL;
+ if (huffman_codes != NULL) {
+ WebPSafeFree(huffman_codes->codes);
+ WebPSafeFree(huffman_codes);
+ huffman_codes = NULL;
+ }
+ }
+ }
+ VP8LBitWriterSwap(bw, &bw_best);
+
+ if (!WebPReportProgress(pic, percent_start + remaining_percent, percent)) {
+ goto Error;
+ }
+
+ Error:
+ WebPSafeFree(tokens);
+ WebPSafeFree(huff_tree);
+ VP8LFreeHistogramSet(histogram_image);
+ VP8LFreeHistogram(tmp_histo);
+ VP8LHashChainClear(&hash_chain_histogram);
+ if (huffman_codes != NULL) {
+ WebPSafeFree(huffman_codes->codes);
+ WebPSafeFree(huffman_codes);
+ }
+ WebPSafeFree(histogram_symbols);
+ VP8LBitWriterWipeOut(&bw_best);
+ return (pic->error_code == VP8_ENC_OK);
+}
+
+// -----------------------------------------------------------------------------
+// Transforms
+
+static void ApplySubtractGreen(VP8LEncoder* const enc, int width, int height,
+ VP8LBitWriter* const bw) {
+ VP8LPutBits(bw, TRANSFORM_PRESENT, 1);
+ VP8LPutBits(bw, SUBTRACT_GREEN, 2);
+ VP8LSubtractGreenFromBlueAndRed(enc->argb_, width * height);
+}
+
+static int ApplyPredictFilter(const VP8LEncoder* const enc, int width,
+ int height, int quality, int low_effort,
+ int used_subtract_green, VP8LBitWriter* const bw,
+ int percent_range, int* const percent) {
+ const int pred_bits = enc->transform_bits_;
+ const int transform_width = VP8LSubSampleSize(width, pred_bits);
+ const int transform_height = VP8LSubSampleSize(height, pred_bits);
+ // we disable near-lossless quantization if palette is used.
+ const int near_lossless_strength =
+ enc->use_palette_ ? 100 : enc->config_->near_lossless;
+
+ if (!VP8LResidualImage(
+ width, height, pred_bits, low_effort, enc->argb_, enc->argb_scratch_,
+ enc->transform_data_, near_lossless_strength, enc->config_->exact,
+ used_subtract_green, enc->pic_, percent_range / 2, percent)) {
+ return 0;
+ }
+ VP8LPutBits(bw, TRANSFORM_PRESENT, 1);
+ VP8LPutBits(bw, PREDICTOR_TRANSFORM, 2);
+ assert(pred_bits >= 2);
+ VP8LPutBits(bw, pred_bits - 2, 3);
+ return EncodeImageNoHuffman(
+ bw, enc->transform_data_, (VP8LHashChain*)&enc->hash_chain_,
+ (VP8LBackwardRefs*)&enc->refs_[0], transform_width, transform_height,
+ quality, low_effort, enc->pic_, percent_range - percent_range / 2,
+ percent);
+}
+
+static int ApplyCrossColorFilter(const VP8LEncoder* const enc, int width,
+ int height, int quality, int low_effort,
+ VP8LBitWriter* const bw, int percent_range,
+ int* const percent) {
+ const int ccolor_transform_bits = enc->transform_bits_;
+ const int transform_width = VP8LSubSampleSize(width, ccolor_transform_bits);
+ const int transform_height = VP8LSubSampleSize(height, ccolor_transform_bits);
+
+ if (!VP8LColorSpaceTransform(width, height, ccolor_transform_bits, quality,
+ enc->argb_, enc->transform_data_, enc->pic_,
+ percent_range / 2, percent)) {
+ return 0;
+ }
+ VP8LPutBits(bw, TRANSFORM_PRESENT, 1);
+ VP8LPutBits(bw, CROSS_COLOR_TRANSFORM, 2);
+ assert(ccolor_transform_bits >= 2);
+ VP8LPutBits(bw, ccolor_transform_bits - 2, 3);
+ return EncodeImageNoHuffman(
+ bw, enc->transform_data_, (VP8LHashChain*)&enc->hash_chain_,
+ (VP8LBackwardRefs*)&enc->refs_[0], transform_width, transform_height,
+ quality, low_effort, enc->pic_, percent_range - percent_range / 2,
+ percent);
+}
+
+// -----------------------------------------------------------------------------
+
+static int WriteRiffHeader(const WebPPicture* const pic, size_t riff_size,
+ size_t vp8l_size) {
+ uint8_t riff[RIFF_HEADER_SIZE + CHUNK_HEADER_SIZE + VP8L_SIGNATURE_SIZE] = {
+ 'R', 'I', 'F', 'F', 0, 0, 0, 0, 'W', 'E', 'B', 'P',
+ 'V', 'P', '8', 'L', 0, 0, 0, 0, VP8L_MAGIC_BYTE,
+ };
+ PutLE32(riff + TAG_SIZE, (uint32_t)riff_size);
+ PutLE32(riff + RIFF_HEADER_SIZE + TAG_SIZE, (uint32_t)vp8l_size);
+ return pic->writer(riff, sizeof(riff), pic);
+}
+
+static int WriteImageSize(const WebPPicture* const pic,
+ VP8LBitWriter* const bw) {
+ const int width = pic->width - 1;
+ const int height = pic->height - 1;
+ assert(width < WEBP_MAX_DIMENSION && height < WEBP_MAX_DIMENSION);
+
+ VP8LPutBits(bw, width, VP8L_IMAGE_SIZE_BITS);
+ VP8LPutBits(bw, height, VP8L_IMAGE_SIZE_BITS);
+ return !bw->error_;
+}
+
+static int WriteRealAlphaAndVersion(VP8LBitWriter* const bw, int has_alpha) {
+ VP8LPutBits(bw, has_alpha, 1);
+ VP8LPutBits(bw, VP8L_VERSION, VP8L_VERSION_BITS);
+ return !bw->error_;
+}
+
+static int WriteImage(const WebPPicture* const pic, VP8LBitWriter* const bw,
+ size_t* const coded_size) {
+ const uint8_t* const webpll_data = VP8LBitWriterFinish(bw);
+ const size_t webpll_size = VP8LBitWriterNumBytes(bw);
+ const size_t vp8l_size = VP8L_SIGNATURE_SIZE + webpll_size;
+ const size_t pad = vp8l_size & 1;
+ const size_t riff_size = TAG_SIZE + CHUNK_HEADER_SIZE + vp8l_size + pad;
+
+ if (!WriteRiffHeader(pic, riff_size, vp8l_size) ||
+ !pic->writer(webpll_data, webpll_size, pic)) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_WRITE);
+ return 0;
+ }
+
+ if (pad) {
+ const uint8_t pad_byte[1] = { 0 };
+ if (!pic->writer(pad_byte, 1, pic)) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_BAD_WRITE);
+ return 0;
+ }
+ }
+ *coded_size = CHUNK_HEADER_SIZE + riff_size;
+ return 1;
+}
+
+// -----------------------------------------------------------------------------
+
+static void ClearTransformBuffer(VP8LEncoder* const enc) {
+ WebPSafeFree(enc->transform_mem_);
+ enc->transform_mem_ = NULL;
+ enc->transform_mem_size_ = 0;
+}
+
+// Allocates the memory for argb (W x H) buffer, 2 rows of context for
+// prediction and transform data.
+// Flags influencing the memory allocated:
+// enc->transform_bits_
+// enc->use_predict_, enc->use_cross_color_
+static int AllocateTransformBuffer(VP8LEncoder* const enc, int width,
+ int height) {
+ const uint64_t image_size = width * height;
+ // VP8LResidualImage needs room for 2 scanlines of uint32 pixels with an extra
+ // pixel in each, plus 2 regular scanlines of bytes.
+ // TODO(skal): Clean up by using arithmetic in bytes instead of words.
+ const uint64_t argb_scratch_size =
+ enc->use_predict_ ? (width + 1) * 2 + (width * 2 + sizeof(uint32_t) - 1) /
+ sizeof(uint32_t)
+ : 0;
+ const uint64_t transform_data_size =
+ (enc->use_predict_ || enc->use_cross_color_)
+ ? VP8LSubSampleSize(width, enc->transform_bits_) *
+ VP8LSubSampleSize(height, enc->transform_bits_)
+ : 0;
+ const uint64_t max_alignment_in_words =
+ (WEBP_ALIGN_CST + sizeof(uint32_t) - 1) / sizeof(uint32_t);
+ const uint64_t mem_size = image_size + max_alignment_in_words +
+ argb_scratch_size + max_alignment_in_words +
+ transform_data_size;
+ uint32_t* mem = enc->transform_mem_;
+ if (mem == NULL || mem_size > enc->transform_mem_size_) {
+ ClearTransformBuffer(enc);
+ mem = (uint32_t*)WebPSafeMalloc(mem_size, sizeof(*mem));
+ if (mem == NULL) {
+ WebPEncodingSetError(enc->pic_, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ return 0;
+ }
+ enc->transform_mem_ = mem;
+ enc->transform_mem_size_ = (size_t)mem_size;
+ enc->argb_content_ = kEncoderNone;
+ }
+ enc->argb_ = mem;
+ mem = (uint32_t*)WEBP_ALIGN(mem + image_size);
+ enc->argb_scratch_ = mem;
+ mem = (uint32_t*)WEBP_ALIGN(mem + argb_scratch_size);
+ enc->transform_data_ = mem;
+
+ enc->current_width_ = width;
+ return 1;
+}
+
+static int MakeInputImageCopy(VP8LEncoder* const enc) {
+ const WebPPicture* const picture = enc->pic_;
+ const int width = picture->width;
+ const int height = picture->height;
+
+ if (!AllocateTransformBuffer(enc, width, height)) return 0;
+ if (enc->argb_content_ == kEncoderARGB) return 1;
+
+ {
+ uint32_t* dst = enc->argb_;
+ const uint32_t* src = picture->argb;
+ int y;
+ for (y = 0; y < height; ++y) {
+ memcpy(dst, src, width * sizeof(*dst));
+ dst += width;
+ src += picture->argb_stride;
+ }
+ }
+ enc->argb_content_ = kEncoderARGB;
+ assert(enc->current_width_ == width);
+ return 1;
+}
+
+// -----------------------------------------------------------------------------
+
+#define APPLY_PALETTE_GREEDY_MAX 4
+
+static WEBP_INLINE uint32_t SearchColorGreedy(const uint32_t palette[],
+ int palette_size,
+ uint32_t color) {
+ (void)palette_size;
+ assert(palette_size < APPLY_PALETTE_GREEDY_MAX);
+ assert(3 == APPLY_PALETTE_GREEDY_MAX - 1);
+ if (color == palette[0]) return 0;
+ if (color == palette[1]) return 1;
+ if (color == palette[2]) return 2;
+ return 3;
+}
+
+static WEBP_INLINE uint32_t ApplyPaletteHash0(uint32_t color) {
+ // Focus on the green color.
+ return (color >> 8) & 0xff;
+}
+
+#define PALETTE_INV_SIZE_BITS 11
+#define PALETTE_INV_SIZE (1 << PALETTE_INV_SIZE_BITS)
+
+static WEBP_INLINE uint32_t ApplyPaletteHash1(uint32_t color) {
+ // Forget about alpha.
+ return ((uint32_t)((color & 0x00ffffffu) * 4222244071ull)) >>
+ (32 - PALETTE_INV_SIZE_BITS);
+}
+
+static WEBP_INLINE uint32_t ApplyPaletteHash2(uint32_t color) {
+ // Forget about alpha.
+ return ((uint32_t)((color & 0x00ffffffu) * ((1ull << 31) - 1))) >>
+ (32 - PALETTE_INV_SIZE_BITS);
+}
+
+// Use 1 pixel cache for ARGB pixels.
+#define APPLY_PALETTE_FOR(COLOR_INDEX) do { \
+ uint32_t prev_pix = palette[0]; \
+ uint32_t prev_idx = 0; \
+ for (y = 0; y < height; ++y) { \
+ for (x = 0; x < width; ++x) { \
+ const uint32_t pix = src[x]; \
+ if (pix != prev_pix) { \
+ prev_idx = COLOR_INDEX; \
+ prev_pix = pix; \
+ } \
+ tmp_row[x] = prev_idx; \
+ } \
+ VP8LBundleColorMap(tmp_row, width, xbits, dst); \
+ src += src_stride; \
+ dst += dst_stride; \
+ } \
+} while (0)
+
+// Remap argb values in src[] to packed palettes entries in dst[]
+// using 'row' as a temporary buffer of size 'width'.
+// We assume that all src[] values have a corresponding entry in the palette.
+// Note: src[] can be the same as dst[]
+static int ApplyPalette(const uint32_t* src, uint32_t src_stride, uint32_t* dst,
+ uint32_t dst_stride, const uint32_t* palette,
+ int palette_size, int width, int height, int xbits,
+ const WebPPicture* const pic) {
+ // TODO(skal): this tmp buffer is not needed if VP8LBundleColorMap() can be
+ // made to work in-place.
+ uint8_t* const tmp_row = (uint8_t*)WebPSafeMalloc(width, sizeof(*tmp_row));
+ int x, y;
+
+ if (tmp_row == NULL) {
+ WebPEncodingSetError(pic, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ return 0;
+ }
+
+ if (palette_size < APPLY_PALETTE_GREEDY_MAX) {
+ APPLY_PALETTE_FOR(SearchColorGreedy(palette, palette_size, pix));
+ } else {
+ int i, j;
+ uint16_t buffer[PALETTE_INV_SIZE];
+ uint32_t (*const hash_functions[])(uint32_t) = {
+ ApplyPaletteHash0, ApplyPaletteHash1, ApplyPaletteHash2
+ };
+
+ // Try to find a perfect hash function able to go from a color to an index
+ // within 1 << PALETTE_INV_SIZE_BITS in order to build a hash map to go
+ // from color to index in palette.
+ for (i = 0; i < 3; ++i) {
+ int use_LUT = 1;
+ // Set each element in buffer to max uint16_t.
+ memset(buffer, 0xff, sizeof(buffer));
+ for (j = 0; j < palette_size; ++j) {
+ const uint32_t ind = hash_functions[i](palette[j]);
+ if (buffer[ind] != 0xffffu) {
+ use_LUT = 0;
+ break;
+ } else {
+ buffer[ind] = j;
+ }
+ }
+ if (use_LUT) break;
+ }
+
+ if (i == 0) {
+ APPLY_PALETTE_FOR(buffer[ApplyPaletteHash0(pix)]);
+ } else if (i == 1) {
+ APPLY_PALETTE_FOR(buffer[ApplyPaletteHash1(pix)]);
+ } else if (i == 2) {
+ APPLY_PALETTE_FOR(buffer[ApplyPaletteHash2(pix)]);
+ } else {
+ uint32_t idx_map[MAX_PALETTE_SIZE];
+ uint32_t palette_sorted[MAX_PALETTE_SIZE];
+ PrepareMapToPalette(palette, palette_size, palette_sorted, idx_map);
+ APPLY_PALETTE_FOR(
+ idx_map[SearchColorNoIdx(palette_sorted, pix, palette_size)]);
+ }
+ }
+ WebPSafeFree(tmp_row);
+ return 1;
+}
+#undef APPLY_PALETTE_FOR
+#undef PALETTE_INV_SIZE_BITS
+#undef PALETTE_INV_SIZE
+#undef APPLY_PALETTE_GREEDY_MAX
+
+// Note: Expects "enc->palette_" to be set properly.
+static int MapImageFromPalette(VP8LEncoder* const enc, int in_place) {
+ const WebPPicture* const pic = enc->pic_;
+ const int width = pic->width;
+ const int height = pic->height;
+ const uint32_t* const palette = enc->palette_;
+ const uint32_t* src = in_place ? enc->argb_ : pic->argb;
+ const int src_stride = in_place ? enc->current_width_ : pic->argb_stride;
+ const int palette_size = enc->palette_size_;
+ int xbits;
+
+ // Replace each input pixel by corresponding palette index.
+ // This is done line by line.
+ if (palette_size <= 4) {
+ xbits = (palette_size <= 2) ? 3 : 2;
+ } else {
+ xbits = (palette_size <= 16) ? 1 : 0;
+ }
+
+ if (!AllocateTransformBuffer(enc, VP8LSubSampleSize(width, xbits), height)) {
+ return 0;
+ }
+ if (!ApplyPalette(src, src_stride,
+ enc->argb_, enc->current_width_,
+ palette, palette_size, width, height, xbits, pic)) {
+ return 0;
+ }
+ enc->argb_content_ = kEncoderPalette;
+ return 1;
+}
+
+// Save palette_[] to bitstream.
+static WebPEncodingError EncodePalette(VP8LBitWriter* const bw, int low_effort,
+ VP8LEncoder* const enc,
+ int percent_range, int* const percent) {
+ int i;
+ uint32_t tmp_palette[MAX_PALETTE_SIZE];
+ const int palette_size = enc->palette_size_;
+ const uint32_t* const palette = enc->palette_;
+ VP8LPutBits(bw, TRANSFORM_PRESENT, 1);
+ VP8LPutBits(bw, COLOR_INDEXING_TRANSFORM, 2);
+ assert(palette_size >= 1 && palette_size <= MAX_PALETTE_SIZE);
+ VP8LPutBits(bw, palette_size - 1, 8);
+ for (i = palette_size - 1; i >= 1; --i) {
+ tmp_palette[i] = VP8LSubPixels(palette[i], palette[i - 1]);
+ }
+ tmp_palette[0] = palette[0];
+ return EncodeImageNoHuffman(bw, tmp_palette, &enc->hash_chain_,
+ &enc->refs_[0], palette_size, 1, /*quality=*/20,
+ low_effort, enc->pic_, percent_range, percent);
+}
+
+// -----------------------------------------------------------------------------
+// VP8LEncoder
+
+static VP8LEncoder* VP8LEncoderNew(const WebPConfig* const config,
+ const WebPPicture* const picture) {
+ VP8LEncoder* const enc = (VP8LEncoder*)WebPSafeCalloc(1ULL, sizeof(*enc));
+ if (enc == NULL) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ return NULL;
+ }
+ enc->config_ = config;
+ enc->pic_ = picture;
+ enc->argb_content_ = kEncoderNone;
+
+ VP8LEncDspInit();
+
+ return enc;
+}
+
+static void VP8LEncoderDelete(VP8LEncoder* enc) {
+ if (enc != NULL) {
+ int i;
+ VP8LHashChainClear(&enc->hash_chain_);
+ for (i = 0; i < 4; ++i) VP8LBackwardRefsClear(&enc->refs_[i]);
+ ClearTransformBuffer(enc);
+ WebPSafeFree(enc);
+ }
+}
+
+// -----------------------------------------------------------------------------
+// Main call
+
+typedef struct {
+ const WebPConfig* config_;
+ const WebPPicture* picture_;
+ VP8LBitWriter* bw_;
+ VP8LEncoder* enc_;
+ int use_cache_;
+ CrunchConfig crunch_configs_[CRUNCH_CONFIGS_MAX];
+ int num_crunch_configs_;
+ int red_and_blue_always_zero_;
+ WebPAuxStats* stats_;
+} StreamEncodeContext;
+
+static int EncodeStreamHook(void* input, void* data2) {
+ StreamEncodeContext* const params = (StreamEncodeContext*)input;
+ const WebPConfig* const config = params->config_;
+ const WebPPicture* const picture = params->picture_;
+ VP8LBitWriter* const bw = params->bw_;
+ VP8LEncoder* const enc = params->enc_;
+ const int use_cache = params->use_cache_;
+ const CrunchConfig* const crunch_configs = params->crunch_configs_;
+ const int num_crunch_configs = params->num_crunch_configs_;
+ const int red_and_blue_always_zero = params->red_and_blue_always_zero_;
+#if !defined(WEBP_DISABLE_STATS)
+ WebPAuxStats* const stats = params->stats_;
+#endif
+ const int quality = (int)config->quality;
+ const int low_effort = (config->method == 0);
+#if (WEBP_NEAR_LOSSLESS == 1)
+ const int width = picture->width;
+#endif
+ const int height = picture->height;
+ const size_t byte_position = VP8LBitWriterNumBytes(bw);
+ int percent = 2; // for WebPProgressHook
+#if (WEBP_NEAR_LOSSLESS == 1)
+ int use_near_lossless = 0;
+#endif
+ int hdr_size = 0;
+ int data_size = 0;
+ int use_delta_palette = 0;
+ int idx;
+ size_t best_size = ~(size_t)0;
+ VP8LBitWriter bw_init = *bw, bw_best;
+ (void)data2;
+
+ if (!VP8LBitWriterInit(&bw_best, 0) ||
+ (num_crunch_configs > 1 && !VP8LBitWriterClone(bw, &bw_best))) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+
+ for (idx = 0; idx < num_crunch_configs; ++idx) {
+ const int entropy_idx = crunch_configs[idx].entropy_idx_;
+ int remaining_percent = 97 / num_crunch_configs, percent_range;
+ enc->use_palette_ =
+ (entropy_idx == kPalette) || (entropy_idx == kPaletteAndSpatial);
+ enc->use_subtract_green_ =
+ (entropy_idx == kSubGreen) || (entropy_idx == kSpatialSubGreen);
+ enc->use_predict_ = (entropy_idx == kSpatial) ||
+ (entropy_idx == kSpatialSubGreen) ||
+ (entropy_idx == kPaletteAndSpatial);
+ // When using a palette, R/B==0, hence no need to test for cross-color.
+ if (low_effort || enc->use_palette_) {
+ enc->use_cross_color_ = 0;
+ } else {
+ enc->use_cross_color_ = red_and_blue_always_zero ? 0 : enc->use_predict_;
+ }
+ // Reset any parameter in the encoder that is set in the previous iteration.
+ enc->cache_bits_ = 0;
+ VP8LBackwardRefsClear(&enc->refs_[0]);
+ VP8LBackwardRefsClear(&enc->refs_[1]);
+
+#if (WEBP_NEAR_LOSSLESS == 1)
+ // Apply near-lossless preprocessing.
+ use_near_lossless = (config->near_lossless < 100) && !enc->use_palette_ &&
+ !enc->use_predict_;
+ if (use_near_lossless) {
+ if (!AllocateTransformBuffer(enc, width, height)) goto Error;
+ if ((enc->argb_content_ != kEncoderNearLossless) &&
+ !VP8ApplyNearLossless(picture, config->near_lossless, enc->argb_)) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+ enc->argb_content_ = kEncoderNearLossless;
+ } else {
+ enc->argb_content_ = kEncoderNone;
+ }
+#else
+ enc->argb_content_ = kEncoderNone;
+#endif
+
+ // Encode palette
+ if (enc->use_palette_) {
+ if (crunch_configs[idx].palette_sorting_type_ == kSortedDefault) {
+ // Nothing to do, we have already sorted the palette.
+ memcpy(enc->palette_, enc->palette_sorted_,
+ enc->palette_size_ * sizeof(*enc->palette_));
+ } else if (crunch_configs[idx].palette_sorting_type_ == kMinimizeDelta) {
+ PaletteSortMinimizeDeltas(enc->palette_sorted_, enc->palette_size_,
+ enc->palette_);
+ } else {
+ assert(crunch_configs[idx].palette_sorting_type_ == kModifiedZeng);
+ if (!PaletteSortModifiedZeng(enc->pic_, enc->palette_sorted_,
+ enc->palette_size_, enc->palette_)) {
+ goto Error;
+ }
+ }
+ percent_range = remaining_percent / 4;
+ if (!EncodePalette(bw, low_effort, enc, percent_range, &percent)) {
+ goto Error;
+ }
+ remaining_percent -= percent_range;
+ if (!MapImageFromPalette(enc, use_delta_palette)) goto Error;
+ // If using a color cache, do not have it bigger than the number of
+ // colors.
+ if (use_cache && enc->palette_size_ < (1 << MAX_COLOR_CACHE_BITS)) {
+ enc->cache_bits_ = BitsLog2Floor(enc->palette_size_) + 1;
+ }
+ }
+ if (!use_delta_palette) {
+ // In case image is not packed.
+ if (enc->argb_content_ != kEncoderNearLossless &&
+ enc->argb_content_ != kEncoderPalette) {
+ if (!MakeInputImageCopy(enc)) goto Error;
+ }
+
+ // -----------------------------------------------------------------------
+ // Apply transforms and write transform data.
+
+ if (enc->use_subtract_green_) {
+ ApplySubtractGreen(enc, enc->current_width_, height, bw);
+ }
+
+ if (enc->use_predict_) {
+ percent_range = remaining_percent / 3;
+ if (!ApplyPredictFilter(enc, enc->current_width_, height, quality,
+ low_effort, enc->use_subtract_green_, bw,
+ percent_range, &percent)) {
+ goto Error;
+ }
+ remaining_percent -= percent_range;
+ }
+
+ if (enc->use_cross_color_) {
+ percent_range = remaining_percent / 2;
+ if (!ApplyCrossColorFilter(enc, enc->current_width_, height, quality,
+ low_effort, bw, percent_range, &percent)) {
+ goto Error;
+ }
+ remaining_percent -= percent_range;
+ }
+ }
+
+ VP8LPutBits(bw, !TRANSFORM_PRESENT, 1); // No more transforms.
+
+ // -------------------------------------------------------------------------
+ // Encode and write the transformed image.
+ if (!EncodeImageInternal(
+ bw, enc->argb_, &enc->hash_chain_, enc->refs_, enc->current_width_,
+ height, quality, low_effort, use_cache, &crunch_configs[idx],
+ &enc->cache_bits_, enc->histo_bits_, byte_position, &hdr_size,
+ &data_size, picture, remaining_percent, &percent)) {
+ goto Error;
+ }
+
+ // If we are better than what we already have.
+ if (VP8LBitWriterNumBytes(bw) < best_size) {
+ best_size = VP8LBitWriterNumBytes(bw);
+ // Store the BitWriter.
+ VP8LBitWriterSwap(bw, &bw_best);
+#if !defined(WEBP_DISABLE_STATS)
+ // Update the stats.
+ if (stats != NULL) {
+ stats->lossless_features = 0;
+ if (enc->use_predict_) stats->lossless_features |= 1;
+ if (enc->use_cross_color_) stats->lossless_features |= 2;
+ if (enc->use_subtract_green_) stats->lossless_features |= 4;
+ if (enc->use_palette_) stats->lossless_features |= 8;
+ stats->histogram_bits = enc->histo_bits_;
+ stats->transform_bits = enc->transform_bits_;
+ stats->cache_bits = enc->cache_bits_;
+ stats->palette_size = enc->palette_size_;
+ stats->lossless_size = (int)(best_size - byte_position);
+ stats->lossless_hdr_size = hdr_size;
+ stats->lossless_data_size = data_size;
+ }
+#endif
+ }
+ // Reset the bit writer for the following iteration if any.
+ if (num_crunch_configs > 1) VP8LBitWriterReset(&bw_init, bw);
+ }
+ VP8LBitWriterSwap(&bw_best, bw);
+
+ Error:
+ VP8LBitWriterWipeOut(&bw_best);
+ // The hook should return false in case of error.
+ return (params->picture_->error_code == VP8_ENC_OK);
+}
+
+int VP8LEncodeStream(const WebPConfig* const config,
+ const WebPPicture* const picture,
+ VP8LBitWriter* const bw_main, int use_cache) {
+ VP8LEncoder* const enc_main = VP8LEncoderNew(config, picture);
+ VP8LEncoder* enc_side = NULL;
+ CrunchConfig crunch_configs[CRUNCH_CONFIGS_MAX];
+ int num_crunch_configs_main, num_crunch_configs_side = 0;
+ int idx;
+ int red_and_blue_always_zero = 0;
+ WebPWorker worker_main, worker_side;
+ StreamEncodeContext params_main, params_side;
+ // The main thread uses picture->stats, the side thread uses stats_side.
+ WebPAuxStats stats_side;
+ VP8LBitWriter bw_side;
+ WebPPicture picture_side;
+ const WebPWorkerInterface* const worker_interface = WebPGetWorkerInterface();
+ int ok_main;
+
+ if (enc_main == NULL || !VP8LBitWriterInit(&bw_side, 0)) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ VP8LEncoderDelete(enc_main);
+ return 0;
+ }
+
+ // Avoid "garbage value" error from Clang's static analysis tool.
+ WebPPictureInit(&picture_side);
+
+ // Analyze image (entropy, num_palettes etc)
+ if (!EncoderAnalyze(enc_main, crunch_configs, &num_crunch_configs_main,
+ &red_and_blue_always_zero) ||
+ !EncoderInit(enc_main)) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+
+ // Split the configs between the main and side threads (if any).
+ if (config->thread_level > 0) {
+ num_crunch_configs_side = num_crunch_configs_main / 2;
+ for (idx = 0; idx < num_crunch_configs_side; ++idx) {
+ params_side.crunch_configs_[idx] =
+ crunch_configs[num_crunch_configs_main - num_crunch_configs_side +
+ idx];
+ }
+ params_side.num_crunch_configs_ = num_crunch_configs_side;
+ }
+ num_crunch_configs_main -= num_crunch_configs_side;
+ for (idx = 0; idx < num_crunch_configs_main; ++idx) {
+ params_main.crunch_configs_[idx] = crunch_configs[idx];
+ }
+ params_main.num_crunch_configs_ = num_crunch_configs_main;
+
+ // Fill in the parameters for the thread workers.
+ {
+ const int params_size = (num_crunch_configs_side > 0) ? 2 : 1;
+ for (idx = 0; idx < params_size; ++idx) {
+ // Create the parameters for each worker.
+ WebPWorker* const worker = (idx == 0) ? &worker_main : &worker_side;
+ StreamEncodeContext* const param =
+ (idx == 0) ? &params_main : &params_side;
+ param->config_ = config;
+ param->use_cache_ = use_cache;
+ param->red_and_blue_always_zero_ = red_and_blue_always_zero;
+ if (idx == 0) {
+ param->picture_ = picture;
+ param->stats_ = picture->stats;
+ param->bw_ = bw_main;
+ param->enc_ = enc_main;
+ } else {
+ // Create a side picture (error_code is not thread-safe).
+ if (!WebPPictureView(picture, /*left=*/0, /*top=*/0, picture->width,
+ picture->height, &picture_side)) {
+ assert(0);
+ }
+ picture_side.progress_hook = NULL; // Progress hook is not thread-safe.
+ param->picture_ = &picture_side; // No need to free a view afterwards.
+ param->stats_ = (picture->stats == NULL) ? NULL : &stats_side;
+ // Create a side bit writer.
+ if (!VP8LBitWriterClone(bw_main, &bw_side)) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+ param->bw_ = &bw_side;
+ // Create a side encoder.
+ enc_side = VP8LEncoderNew(config, &picture_side);
+ if (enc_side == NULL || !EncoderInit(enc_side)) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+ // Copy the values that were computed for the main encoder.
+ enc_side->histo_bits_ = enc_main->histo_bits_;
+ enc_side->transform_bits_ = enc_main->transform_bits_;
+ enc_side->palette_size_ = enc_main->palette_size_;
+ memcpy(enc_side->palette_, enc_main->palette_,
+ sizeof(enc_main->palette_));
+ memcpy(enc_side->palette_sorted_, enc_main->palette_sorted_,
+ sizeof(enc_main->palette_sorted_));
+ param->enc_ = enc_side;
+ }
+ // Create the workers.
+ worker_interface->Init(worker);
+ worker->data1 = param;
+ worker->data2 = NULL;
+ worker->hook = EncodeStreamHook;
+ }
+ }
+
+ // Start the second thread if needed.
+ if (num_crunch_configs_side != 0) {
+ if (!worker_interface->Reset(&worker_side)) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+#if !defined(WEBP_DISABLE_STATS)
+ // This line is here and not in the param initialization above to remove a
+ // Clang static analyzer warning.
+ if (picture->stats != NULL) {
+ memcpy(&stats_side, picture->stats, sizeof(stats_side));
+ }
+#endif
+ worker_interface->Launch(&worker_side);
+ }
+ // Execute the main thread.
+ worker_interface->Execute(&worker_main);
+ ok_main = worker_interface->Sync(&worker_main);
+ worker_interface->End(&worker_main);
+ if (num_crunch_configs_side != 0) {
+ // Wait for the second thread.
+ const int ok_side = worker_interface->Sync(&worker_side);
+ worker_interface->End(&worker_side);
+ if (!ok_main || !ok_side) {
+ if (picture->error_code == VP8_ENC_OK) {
+ assert(picture_side.error_code != VP8_ENC_OK);
+ WebPEncodingSetError(picture, picture_side.error_code);
+ }
+ goto Error;
+ }
+ if (VP8LBitWriterNumBytes(&bw_side) < VP8LBitWriterNumBytes(bw_main)) {
+ VP8LBitWriterSwap(bw_main, &bw_side);
+#if !defined(WEBP_DISABLE_STATS)
+ if (picture->stats != NULL) {
+ memcpy(picture->stats, &stats_side, sizeof(*picture->stats));
+ }
+#endif
+ }
+ }
+
+ Error:
+ VP8LBitWriterWipeOut(&bw_side);
+ VP8LEncoderDelete(enc_main);
+ VP8LEncoderDelete(enc_side);
+ return (picture->error_code == VP8_ENC_OK);
+}
+
+#undef CRUNCH_CONFIGS_MAX
+#undef CRUNCH_SUBCONFIGS_MAX
+
+int VP8LEncodeImage(const WebPConfig* const config,
+ const WebPPicture* const picture) {
+ int width, height;
+ int has_alpha;
+ size_t coded_size;
+ int percent = 0;
+ int initial_size;
+ VP8LBitWriter bw;
+
+ if (picture == NULL) return 0;
+
+ if (config == NULL || picture->argb == NULL) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_NULL_PARAMETER);
+ return 0;
+ }
+
+ width = picture->width;
+ height = picture->height;
+ // Initialize BitWriter with size corresponding to 16 bpp to photo images and
+ // 8 bpp for graphical images.
+ initial_size = (config->image_hint == WEBP_HINT_GRAPH) ?
+ width * height : width * height * 2;
+ if (!VP8LBitWriterInit(&bw, initial_size)) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+
+ if (!WebPReportProgress(picture, 1, &percent)) {
+ UserAbort:
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_USER_ABORT);
+ goto Error;
+ }
+ // Reset stats (for pure lossless coding)
+ if (picture->stats != NULL) {
+ WebPAuxStats* const stats = picture->stats;
+ memset(stats, 0, sizeof(*stats));
+ stats->PSNR[0] = 99.f;
+ stats->PSNR[1] = 99.f;
+ stats->PSNR[2] = 99.f;
+ stats->PSNR[3] = 99.f;
+ stats->PSNR[4] = 99.f;
+ }
+
+ // Write image size.
+ if (!WriteImageSize(picture, &bw)) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+
+ has_alpha = WebPPictureHasTransparency(picture);
+ // Write the non-trivial Alpha flag and lossless version.
+ if (!WriteRealAlphaAndVersion(&bw, has_alpha)) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ goto Error;
+ }
+
+ if (!WebPReportProgress(picture, 2, &percent)) goto UserAbort;
+
+ // Encode main image stream.
+ if (!VP8LEncodeStream(config, picture, &bw, 1 /*use_cache*/)) goto Error;
+
+ if (!WebPReportProgress(picture, 99, &percent)) goto UserAbort;
+
+ // Finish the RIFF chunk.
+ if (!WriteImage(picture, &bw, &coded_size)) goto Error;
+
+ if (!WebPReportProgress(picture, 100, &percent)) goto UserAbort;
+
+#if !defined(WEBP_DISABLE_STATS)
+ // Save size.
+ if (picture->stats != NULL) {
+ picture->stats->coded_size += (int)coded_size;
+ picture->stats->lossless_size = (int)coded_size;
+ }
+#endif
+
+ if (picture->extra_info != NULL) {
+ const int mb_w = (width + 15) >> 4;
+ const int mb_h = (height + 15) >> 4;
+ memset(picture->extra_info, 0, mb_w * mb_h * sizeof(*picture->extra_info));
+ }
+
+ Error:
+ if (bw.error_) {
+ WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY);
+ }
+ VP8LBitWriterWipeOut(&bw);
+ return (picture->error_code == VP8_ENC_OK);
+}
+
+//------------------------------------------------------------------------------
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 23:57:34 +0000