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Diffstat (limited to 'drivers/webp/enc/near_lossless.c')
-rw-r--r--drivers/webp/enc/near_lossless.c122
1 files changed, 0 insertions, 122 deletions
diff --git a/drivers/webp/enc/near_lossless.c b/drivers/webp/enc/near_lossless.c
deleted file mode 100644
index f4ab91f571..0000000000
--- a/drivers/webp/enc/near_lossless.c
+++ /dev/null
@@ -1,122 +0,0 @@
-// Copyright 2014 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.
-// -----------------------------------------------------------------------------
-//
-// Near-lossless image preprocessing adjusts pixel values to help
-// compressibility with a guarantee of maximum deviation between original and
-// resulting pixel values.
-//
-// Author: Jyrki Alakuijala (jyrki@google.com)
-// Converted to C by Aleksander Kramarz (akramarz@google.com)
-
-#include <assert.h>
-#include <stdlib.h>
-
-#include "../dsp/lossless.h"
-#include "../utils/utils.h"
-#include "./vp8enci.h"
-
-#define MIN_DIM_FOR_NEAR_LOSSLESS 64
-#define MAX_LIMIT_BITS 5
-
-// Quantizes the value up or down to a multiple of 1<<bits (or to 255),
-// choosing the closer one, resolving ties using bankers' rounding.
-static int FindClosestDiscretized(int a, int bits) {
- const int mask = (1 << bits) - 1;
- const int biased = a + (mask >> 1) + ((a >> bits) & 1);
- assert(bits > 0);
- if (biased > 0xff) return 0xff;
- return biased & ~mask;
-}
-
-// Applies FindClosestDiscretized to all channels of pixel.
-static uint32_t ClosestDiscretizedArgb(uint32_t a, int bits) {
- return
- (FindClosestDiscretized(a >> 24, bits) << 24) |
- (FindClosestDiscretized((a >> 16) & 0xff, bits) << 16) |
- (FindClosestDiscretized((a >> 8) & 0xff, bits) << 8) |
- (FindClosestDiscretized(a & 0xff, bits));
-}
-
-// Checks if distance between corresponding channel values of pixels a and b
-// is within the given limit.
-static int IsNear(uint32_t a, uint32_t b, int limit) {
- int k;
- for (k = 0; k < 4; ++k) {
- const int delta =
- (int)((a >> (k * 8)) & 0xff) - (int)((b >> (k * 8)) & 0xff);
- if (delta >= limit || delta <= -limit) {
- return 0;
- }
- }
- return 1;
-}
-
-static int IsSmooth(const uint32_t* const prev_row,
- const uint32_t* const curr_row,
- const uint32_t* const next_row,
- int ix, int limit) {
- // Check that all pixels in 4-connected neighborhood are smooth.
- return (IsNear(curr_row[ix], curr_row[ix - 1], limit) &&
- IsNear(curr_row[ix], curr_row[ix + 1], limit) &&
- IsNear(curr_row[ix], prev_row[ix], limit) &&
- IsNear(curr_row[ix], next_row[ix], limit));
-}
-
-// Adjusts pixel values of image with given maximum error.
-static void NearLossless(int xsize, int ysize, uint32_t* argb,
- int limit_bits, uint32_t* copy_buffer) {
- int x, y;
- const int limit = 1 << limit_bits;
- uint32_t* prev_row = copy_buffer;
- uint32_t* curr_row = prev_row + xsize;
- uint32_t* next_row = curr_row + xsize;
- memcpy(copy_buffer, argb, xsize * 2 * sizeof(argb[0]));
-
- for (y = 1; y < ysize - 1; ++y) {
- uint32_t* const curr_argb_row = argb + y * xsize;
- uint32_t* const next_argb_row = curr_argb_row + xsize;
- memcpy(next_row, next_argb_row, xsize * sizeof(argb[0]));
- for (x = 1; x < xsize - 1; ++x) {
- if (!IsSmooth(prev_row, curr_row, next_row, x, limit)) {
- curr_argb_row[x] = ClosestDiscretizedArgb(curr_row[x], limit_bits);
- }
- }
- {
- // Three-way swap.
- uint32_t* const temp = prev_row;
- prev_row = curr_row;
- curr_row = next_row;
- next_row = temp;
- }
- }
-}
-
-int VP8ApplyNearLossless(int xsize, int ysize, uint32_t* argb, int quality) {
- int i;
- uint32_t* const copy_buffer =
- (uint32_t*)WebPSafeMalloc(xsize * 3, sizeof(*copy_buffer));
- const int limit_bits = VP8LNearLosslessBits(quality);
- assert(argb != NULL);
- assert(limit_bits >= 0);
- assert(limit_bits <= MAX_LIMIT_BITS);
- if (copy_buffer == NULL) {
- return 0;
- }
- // For small icon images, don't attempt to apply near-lossless compression.
- if (xsize < MIN_DIM_FOR_NEAR_LOSSLESS && ysize < MIN_DIM_FOR_NEAR_LOSSLESS) {
- WebPSafeFree(copy_buffer);
- return 1;
- }
-
- for (i = limit_bits; i != 0; --i) {
- NearLossless(xsize, ysize, argb, i, copy_buffer);
- }
- WebPSafeFree(copy_buffer);
- return 1;
-}