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-rw-r--r--src/main/jni/libwebp/utils/filters.c266
1 files changed, 0 insertions, 266 deletions
diff --git a/src/main/jni/libwebp/utils/filters.c b/src/main/jni/libwebp/utils/filters.c
deleted file mode 100644
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--- a/src/main/jni/libwebp/utils/filters.c
+++ /dev/null
@@ -1,266 +0,0 @@
-// Copyright 2011 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.
-// -----------------------------------------------------------------------------
-//
-// Spatial prediction using various filters
-//
-// Author: Urvang (urvang@google.com)
-
-#include "./filters.h"
-#include <assert.h>
-#include <stdlib.h>
-#include <string.h>
-
-//------------------------------------------------------------------------------
-// Helpful macro.
-
-# define SANITY_CHECK(in, out) \
- assert(in != NULL); \
- assert(out != NULL); \
- assert(width > 0); \
- assert(height > 0); \
- assert(stride >= width); \
- assert(row >= 0 && num_rows > 0 && row + num_rows <= height); \
- (void)height; // Silence unused warning.
-
-static WEBP_INLINE void PredictLine(const uint8_t* src, const uint8_t* pred,
- uint8_t* dst, int length, int inverse) {
- int i;
- if (inverse) {
- for (i = 0; i < length; ++i) dst[i] = src[i] + pred[i];
- } else {
- for (i = 0; i < length; ++i) dst[i] = src[i] - pred[i];
- }
-}
-
-//------------------------------------------------------------------------------
-// Horizontal filter.
-
-static WEBP_INLINE void DoHorizontalFilter(const uint8_t* in,
- int width, int height, int stride,
- int row, int num_rows,
- int inverse, uint8_t* out) {
- const uint8_t* preds;
- const size_t start_offset = row * stride;
- const int last_row = row + num_rows;
- SANITY_CHECK(in, out);
- in += start_offset;
- out += start_offset;
- preds = inverse ? out : in;
-
- if (row == 0) {
- // Leftmost pixel is the same as input for topmost scanline.
- out[0] = in[0];
- PredictLine(in + 1, preds, out + 1, width - 1, inverse);
- row = 1;
- preds += stride;
- in += stride;
- out += stride;
- }
-
- // Filter line-by-line.
- while (row < last_row) {
- // Leftmost pixel is predicted from above.
- PredictLine(in, preds - stride, out, 1, inverse);
- PredictLine(in + 1, preds, out + 1, width - 1, inverse);
- ++row;
- preds += stride;
- in += stride;
- out += stride;
- }
-}
-
-static void HorizontalFilter(const uint8_t* data, int width, int height,
- int stride, uint8_t* filtered_data) {
- DoHorizontalFilter(data, width, height, stride, 0, height, 0, filtered_data);
-}
-
-static void HorizontalUnfilter(int width, int height, int stride, int row,
- int num_rows, uint8_t* data) {
- DoHorizontalFilter(data, width, height, stride, row, num_rows, 1, data);
-}
-
-//------------------------------------------------------------------------------
-// Vertical filter.
-
-static WEBP_INLINE void DoVerticalFilter(const uint8_t* in,
- int width, int height, int stride,
- int row, int num_rows,
- int inverse, uint8_t* out) {
- const uint8_t* preds;
- const size_t start_offset = row * stride;
- const int last_row = row + num_rows;
- SANITY_CHECK(in, out);
- in += start_offset;
- out += start_offset;
- preds = inverse ? out : in;
-
- if (row == 0) {
- // Very first top-left pixel is copied.
- out[0] = in[0];
- // Rest of top scan-line is left-predicted.
- PredictLine(in + 1, preds, out + 1, width - 1, inverse);
- row = 1;
- in += stride;
- out += stride;
- } else {
- // We are starting from in-between. Make sure 'preds' points to prev row.
- preds -= stride;
- }
-
- // Filter line-by-line.
- while (row < last_row) {
- PredictLine(in, preds, out, width, inverse);
- ++row;
- preds += stride;
- in += stride;
- out += stride;
- }
-}
-
-static void VerticalFilter(const uint8_t* data, int width, int height,
- int stride, uint8_t* filtered_data) {
- DoVerticalFilter(data, width, height, stride, 0, height, 0, filtered_data);
-}
-
-static void VerticalUnfilter(int width, int height, int stride, int row,
- int num_rows, uint8_t* data) {
- DoVerticalFilter(data, width, height, stride, row, num_rows, 1, data);
-}
-
-//------------------------------------------------------------------------------
-// Gradient filter.
-
-static WEBP_INLINE int GradientPredictor(uint8_t a, uint8_t b, uint8_t c) {
- const int g = a + b - c;
- return ((g & ~0xff) == 0) ? g : (g < 0) ? 0 : 255; // clip to 8bit
-}
-
-static WEBP_INLINE void DoGradientFilter(const uint8_t* in,
- int width, int height, int stride,
- int row, int num_rows,
- int inverse, uint8_t* out) {
- const uint8_t* preds;
- const size_t start_offset = row * stride;
- const int last_row = row + num_rows;
- SANITY_CHECK(in, out);
- in += start_offset;
- out += start_offset;
- preds = inverse ? out : in;
-
- // left prediction for top scan-line
- if (row == 0) {
- out[0] = in[0];
- PredictLine(in + 1, preds, out + 1, width - 1, inverse);
- row = 1;
- preds += stride;
- in += stride;
- out += stride;
- }
-
- // Filter line-by-line.
- while (row < last_row) {
- int w;
- // leftmost pixel: predict from above.
- PredictLine(in, preds - stride, out, 1, inverse);
- for (w = 1; w < width; ++w) {
- const int pred = GradientPredictor(preds[w - 1],
- preds[w - stride],
- preds[w - stride - 1]);
- out[w] = in[w] + (inverse ? pred : -pred);
- }
- ++row;
- preds += stride;
- in += stride;
- out += stride;
- }
-}
-
-static void GradientFilter(const uint8_t* data, int width, int height,
- int stride, uint8_t* filtered_data) {
- DoGradientFilter(data, width, height, stride, 0, height, 0, filtered_data);
-}
-
-static void GradientUnfilter(int width, int height, int stride, int row,
- int num_rows, uint8_t* data) {
- DoGradientFilter(data, width, height, stride, row, num_rows, 1, data);
-}
-
-#undef SANITY_CHECK
-
-// -----------------------------------------------------------------------------
-// Quick estimate of a potentially interesting filter mode to try.
-
-#define SMAX 16
-#define SDIFF(a, b) (abs((a) - (b)) >> 4) // Scoring diff, in [0..SMAX)
-
-WEBP_FILTER_TYPE EstimateBestFilter(const uint8_t* data,
- int width, int height, int stride) {
- int i, j;
- int bins[WEBP_FILTER_LAST][SMAX];
- memset(bins, 0, sizeof(bins));
-
- // We only sample every other pixels. That's enough.
- for (j = 2; j < height - 1; j += 2) {
- const uint8_t* const p = data + j * stride;
- int mean = p[0];
- for (i = 2; i < width - 1; i += 2) {
- const int diff0 = SDIFF(p[i], mean);
- const int diff1 = SDIFF(p[i], p[i - 1]);
- const int diff2 = SDIFF(p[i], p[i - width]);
- const int grad_pred =
- GradientPredictor(p[i - 1], p[i - width], p[i - width - 1]);
- const int diff3 = SDIFF(p[i], grad_pred);
- bins[WEBP_FILTER_NONE][diff0] = 1;
- bins[WEBP_FILTER_HORIZONTAL][diff1] = 1;
- bins[WEBP_FILTER_VERTICAL][diff2] = 1;
- bins[WEBP_FILTER_GRADIENT][diff3] = 1;
- mean = (3 * mean + p[i] + 2) >> 2;
- }
- }
- {
- int filter;
- WEBP_FILTER_TYPE best_filter = WEBP_FILTER_NONE;
- int best_score = 0x7fffffff;
- for (filter = WEBP_FILTER_NONE; filter < WEBP_FILTER_LAST; ++filter) {
- int score = 0;
- for (i = 0; i < SMAX; ++i) {
- if (bins[filter][i] > 0) {
- score += i;
- }
- }
- if (score < best_score) {
- best_score = score;
- best_filter = (WEBP_FILTER_TYPE)filter;
- }
- }
- return best_filter;
- }
-}
-
-#undef SMAX
-#undef SDIFF
-
-//------------------------------------------------------------------------------
-
-const WebPFilterFunc WebPFilters[WEBP_FILTER_LAST] = {
- NULL, // WEBP_FILTER_NONE
- HorizontalFilter, // WEBP_FILTER_HORIZONTAL
- VerticalFilter, // WEBP_FILTER_VERTICAL
- GradientFilter // WEBP_FILTER_GRADIENT
-};
-
-const WebPUnfilterFunc WebPUnfilters[WEBP_FILTER_LAST] = {
- NULL, // WEBP_FILTER_NONE
- HorizontalUnfilter, // WEBP_FILTER_HORIZONTAL
- VerticalUnfilter, // WEBP_FILTER_VERTICAL
- GradientUnfilter // WEBP_FILTER_GRADIENT
-};
-
-//------------------------------------------------------------------------------
-
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-30 17:34:37 +0000