diff options
Diffstat (limited to 'drivers/webp/enc/delta_palettization.c')
| -rw-r--r-- | drivers/webp/enc/delta_palettization.c | 455 |
1 files changed, 455 insertions, 0 deletions
diff --git a/drivers/webp/enc/delta_palettization.c b/drivers/webp/enc/delta_palettization.c new file mode 100644 index 0000000000..8bd3a3d233 --- /dev/null +++ b/drivers/webp/enc/delta_palettization.c @@ -0,0 +1,455 @@ +// Copyright 2015 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. +// ----------------------------------------------------------------------------- +// +// Author: Mislav Bradac (mislavm@google.com) +// + +#include "./delta_palettization.h" + +#ifdef WEBP_EXPERIMENTAL_FEATURES +#include "webp/types.h" +#include "../dsp/lossless.h" + +#define MK_COL(r, g, b) (((r) << 16) + ((g) << 8) + (b)) + +// Format allows palette up to 256 entries, but more palette entries produce +// bigger entropy. In the future it will probably be useful to add more entries +// that are far from the origin of the palette or choose remaining entries +// dynamically. +#define DELTA_PALETTE_SIZE 226 + +// Palette used for delta_palettization. Entries are roughly sorted by distance +// of their signed equivalents from the origin. +static const uint32_t kDeltaPalette[DELTA_PALETTE_SIZE] = { + MK_COL(0u, 0u, 0u), + MK_COL(255u, 255u, 255u), + MK_COL(1u, 1u, 1u), + MK_COL(254u, 254u, 254u), + MK_COL(2u, 2u, 2u), + MK_COL(4u, 4u, 4u), + MK_COL(252u, 252u, 252u), + MK_COL(250u, 0u, 0u), + MK_COL(0u, 250u, 0u), + MK_COL(0u, 0u, 250u), + MK_COL(6u, 0u, 0u), + MK_COL(0u, 6u, 0u), + MK_COL(0u, 0u, 6u), + MK_COL(0u, 0u, 248u), + MK_COL(0u, 0u, 8u), + MK_COL(0u, 248u, 0u), + MK_COL(0u, 248u, 248u), + MK_COL(0u, 248u, 8u), + MK_COL(0u, 8u, 0u), + MK_COL(0u, 8u, 248u), + MK_COL(0u, 8u, 8u), + MK_COL(8u, 8u, 8u), + MK_COL(248u, 0u, 0u), + MK_COL(248u, 0u, 248u), + MK_COL(248u, 0u, 8u), + MK_COL(248u, 248u, 0u), + MK_COL(248u, 8u, 0u), + MK_COL(8u, 0u, 0u), + MK_COL(8u, 0u, 248u), + MK_COL(8u, 0u, 8u), + MK_COL(8u, 248u, 0u), + MK_COL(8u, 8u, 0u), + MK_COL(23u, 23u, 23u), + MK_COL(13u, 13u, 13u), + MK_COL(232u, 232u, 232u), + MK_COL(244u, 244u, 244u), + MK_COL(245u, 245u, 250u), + MK_COL(50u, 50u, 50u), + MK_COL(204u, 204u, 204u), + MK_COL(236u, 236u, 236u), + MK_COL(16u, 16u, 16u), + MK_COL(240u, 16u, 16u), + MK_COL(16u, 240u, 16u), + MK_COL(240u, 240u, 16u), + MK_COL(16u, 16u, 240u), + MK_COL(240u, 16u, 240u), + MK_COL(16u, 240u, 240u), + MK_COL(240u, 240u, 240u), + MK_COL(0u, 0u, 232u), + MK_COL(0u, 232u, 0u), + MK_COL(232u, 0u, 0u), + MK_COL(0u, 0u, 24u), + MK_COL(0u, 24u, 0u), + MK_COL(24u, 0u, 0u), + MK_COL(32u, 32u, 32u), + MK_COL(224u, 32u, 32u), + MK_COL(32u, 224u, 32u), + MK_COL(224u, 224u, 32u), + MK_COL(32u, 32u, 224u), + MK_COL(224u, 32u, 224u), + MK_COL(32u, 224u, 224u), + MK_COL(224u, 224u, 224u), + MK_COL(0u, 0u, 176u), + MK_COL(0u, 0u, 80u), + MK_COL(0u, 176u, 0u), + MK_COL(0u, 176u, 176u), + MK_COL(0u, 176u, 80u), + MK_COL(0u, 80u, 0u), + MK_COL(0u, 80u, 176u), + MK_COL(0u, 80u, 80u), + MK_COL(176u, 0u, 0u), + MK_COL(176u, 0u, 176u), + MK_COL(176u, 0u, 80u), + MK_COL(176u, 176u, 0u), + MK_COL(176u, 80u, 0u), + MK_COL(80u, 0u, 0u), + MK_COL(80u, 0u, 176u), + MK_COL(80u, 0u, 80u), + MK_COL(80u, 176u, 0u), + MK_COL(80u, 80u, 0u), + MK_COL(0u, 0u, 152u), + MK_COL(0u, 0u, 104u), + MK_COL(0u, 152u, 0u), + MK_COL(0u, 152u, 152u), + MK_COL(0u, 152u, 104u), + MK_COL(0u, 104u, 0u), + MK_COL(0u, 104u, 152u), + MK_COL(0u, 104u, 104u), + MK_COL(152u, 0u, 0u), + MK_COL(152u, 0u, 152u), + MK_COL(152u, 0u, 104u), + MK_COL(152u, 152u, 0u), + MK_COL(152u, 104u, 0u), + MK_COL(104u, 0u, 0u), + MK_COL(104u, 0u, 152u), + MK_COL(104u, 0u, 104u), + MK_COL(104u, 152u, 0u), + MK_COL(104u, 104u, 0u), + MK_COL(216u, 216u, 216u), + MK_COL(216u, 216u, 40u), + MK_COL(216u, 216u, 176u), + MK_COL(216u, 216u, 80u), + MK_COL(216u, 40u, 216u), + MK_COL(216u, 40u, 40u), + MK_COL(216u, 40u, 176u), + MK_COL(216u, 40u, 80u), + MK_COL(216u, 176u, 216u), + MK_COL(216u, 176u, 40u), + MK_COL(216u, 176u, 176u), + MK_COL(216u, 176u, 80u), + MK_COL(216u, 80u, 216u), + MK_COL(216u, 80u, 40u), + MK_COL(216u, 80u, 176u), + MK_COL(216u, 80u, 80u), + MK_COL(40u, 216u, 216u), + MK_COL(40u, 216u, 40u), + MK_COL(40u, 216u, 176u), + MK_COL(40u, 216u, 80u), + MK_COL(40u, 40u, 216u), + MK_COL(40u, 40u, 40u), + MK_COL(40u, 40u, 176u), + MK_COL(40u, 40u, 80u), + MK_COL(40u, 176u, 216u), + MK_COL(40u, 176u, 40u), + MK_COL(40u, 176u, 176u), + MK_COL(40u, 176u, 80u), + MK_COL(40u, 80u, 216u), + MK_COL(40u, 80u, 40u), + MK_COL(40u, 80u, 176u), + MK_COL(40u, 80u, 80u), + MK_COL(80u, 216u, 216u), + MK_COL(80u, 216u, 40u), + MK_COL(80u, 216u, 176u), + MK_COL(80u, 216u, 80u), + MK_COL(80u, 40u, 216u), + MK_COL(80u, 40u, 40u), + MK_COL(80u, 40u, 176u), + MK_COL(80u, 40u, 80u), + MK_COL(80u, 176u, 216u), + MK_COL(80u, 176u, 40u), + MK_COL(80u, 176u, 176u), + MK_COL(80u, 176u, 80u), + MK_COL(80u, 80u, 216u), + MK_COL(80u, 80u, 40u), + MK_COL(80u, 80u, 176u), + MK_COL(80u, 80u, 80u), + MK_COL(0u, 0u, 192u), + MK_COL(0u, 0u, 64u), + MK_COL(0u, 0u, 128u), + MK_COL(0u, 192u, 0u), + MK_COL(0u, 192u, 192u), + MK_COL(0u, 192u, 64u), + MK_COL(0u, 192u, 128u), + MK_COL(0u, 64u, 0u), + MK_COL(0u, 64u, 192u), + MK_COL(0u, 64u, 64u), + MK_COL(0u, 64u, 128u), + MK_COL(0u, 128u, 0u), + MK_COL(0u, 128u, 192u), + MK_COL(0u, 128u, 64u), + MK_COL(0u, 128u, 128u), + MK_COL(176u, 216u, 216u), + MK_COL(176u, 216u, 40u), + MK_COL(176u, 216u, 176u), + MK_COL(176u, 216u, 80u), + MK_COL(176u, 40u, 216u), + MK_COL(176u, 40u, 40u), + MK_COL(176u, 40u, 176u), + MK_COL(176u, 40u, 80u), + MK_COL(176u, 176u, 216u), + MK_COL(176u, 176u, 40u), + MK_COL(176u, 176u, 176u), + MK_COL(176u, 176u, 80u), + MK_COL(176u, 80u, 216u), + MK_COL(176u, 80u, 40u), + MK_COL(176u, 80u, 176u), + MK_COL(176u, 80u, 80u), + MK_COL(192u, 0u, 0u), + MK_COL(192u, 0u, 192u), + MK_COL(192u, 0u, 64u), + MK_COL(192u, 0u, 128u), + MK_COL(192u, 192u, 0u), + MK_COL(192u, 192u, 192u), + MK_COL(192u, 192u, 64u), + MK_COL(192u, 192u, 128u), + MK_COL(192u, 64u, 0u), + MK_COL(192u, 64u, 192u), + MK_COL(192u, 64u, 64u), + MK_COL(192u, 64u, 128u), + MK_COL(192u, 128u, 0u), + MK_COL(192u, 128u, 192u), + MK_COL(192u, 128u, 64u), + MK_COL(192u, 128u, 128u), + MK_COL(64u, 0u, 0u), + MK_COL(64u, 0u, 192u), + MK_COL(64u, 0u, 64u), + MK_COL(64u, 0u, 128u), + MK_COL(64u, 192u, 0u), + MK_COL(64u, 192u, 192u), + MK_COL(64u, 192u, 64u), + MK_COL(64u, 192u, 128u), + MK_COL(64u, 64u, 0u), + MK_COL(64u, 64u, 192u), + MK_COL(64u, 64u, 64u), + MK_COL(64u, 64u, 128u), + MK_COL(64u, 128u, 0u), + MK_COL(64u, 128u, 192u), + MK_COL(64u, 128u, 64u), + MK_COL(64u, 128u, 128u), + MK_COL(128u, 0u, 0u), + MK_COL(128u, 0u, 192u), + MK_COL(128u, 0u, 64u), + MK_COL(128u, 0u, 128u), + MK_COL(128u, 192u, 0u), + MK_COL(128u, 192u, 192u), + MK_COL(128u, 192u, 64u), + MK_COL(128u, 192u, 128u), + MK_COL(128u, 64u, 0u), + MK_COL(128u, 64u, 192u), + MK_COL(128u, 64u, 64u), + MK_COL(128u, 64u, 128u), + MK_COL(128u, 128u, 0u), + MK_COL(128u, 128u, 192u), + MK_COL(128u, 128u, 64u), + MK_COL(128u, 128u, 128u), +}; + +#undef MK_COL + +//------------------------------------------------------------------------------ +// TODO(skal): move the functions to dsp/lossless.c when the correct +// granularity is found. For now, we'll just copy-paste some useful bits +// here instead. + +// In-place sum of each component with mod 256. +static WEBP_INLINE void AddPixelsEq(uint32_t* a, uint32_t b) { + const uint32_t alpha_and_green = (*a & 0xff00ff00u) + (b & 0xff00ff00u); + const uint32_t red_and_blue = (*a & 0x00ff00ffu) + (b & 0x00ff00ffu); + *a = (alpha_and_green & 0xff00ff00u) | (red_and_blue & 0x00ff00ffu); +} + +static WEBP_INLINE uint32_t Clip255(uint32_t a) { + if (a < 256) { + return a; + } + // return 0, when a is a negative integer. + // return 255, when a is positive. + return ~a >> 24; +} + +// Delta palettization functions. +static WEBP_INLINE int Square(int x) { + return x * x; +} + +static WEBP_INLINE uint32_t Intensity(uint32_t a) { + return + 30 * ((a >> 16) & 0xff) + + 59 * ((a >> 8) & 0xff) + + 11 * ((a >> 0) & 0xff); +} + +static uint32_t CalcDist(uint32_t predicted_value, uint32_t actual_value, + uint32_t palette_entry) { + int i; + uint32_t distance = 0; + AddPixelsEq(&predicted_value, palette_entry); + for (i = 0; i < 32; i += 8) { + const int32_t av = (actual_value >> i) & 0xff; + const int32_t pv = (predicted_value >> i) & 0xff; + distance += Square(pv - av); + } + // We sum square of intensity difference with factor 10, but because Intensity + // returns 100 times real intensity we need to multiply differences of colors + // by 1000. + distance *= 1000u; + distance += Square(Intensity(predicted_value) + - Intensity(actual_value)); + return distance; +} + +static uint32_t Predict(int x, int y, uint32_t* image) { + const uint32_t t = (y == 0) ? ARGB_BLACK : image[x]; + const uint32_t l = (x == 0) ? ARGB_BLACK : image[x - 1]; + const uint32_t p = + (((((t >> 24) & 0xff) + ((l >> 24) & 0xff)) / 2) << 24) + + (((((t >> 16) & 0xff) + ((l >> 16) & 0xff)) / 2) << 16) + + (((((t >> 8) & 0xff) + ((l >> 8) & 0xff)) / 2) << 8) + + (((((t >> 0) & 0xff) + ((l >> 0) & 0xff)) / 2) << 0); + if (x == 0 && y == 0) return ARGB_BLACK; + if (x == 0) return t; + if (y == 0) return l; + return p; +} + +static WEBP_INLINE int AddSubtractComponentFullWithCoefficient( + int a, int b, int c) { + return Clip255(a + ((b - c) >> 2)); +} + +static WEBP_INLINE uint32_t ClampedAddSubtractFullWithCoefficient( + uint32_t c0, uint32_t c1, uint32_t c2) { + const int a = AddSubtractComponentFullWithCoefficient( + c0 >> 24, c1 >> 24, c2 >> 24); + const int r = AddSubtractComponentFullWithCoefficient((c0 >> 16) & 0xff, + (c1 >> 16) & 0xff, + (c2 >> 16) & 0xff); + const int g = AddSubtractComponentFullWithCoefficient((c0 >> 8) & 0xff, + (c1 >> 8) & 0xff, + (c2 >> 8) & 0xff); + const int b = AddSubtractComponentFullWithCoefficient( + c0 & 0xff, c1 & 0xff, c2 & 0xff); + return ((uint32_t)a << 24) | (r << 16) | (g << 8) | b; +} + +//------------------------------------------------------------------------------ + +// Find palette entry with minimum error from difference of actual pixel value +// and predicted pixel value. Propagate error of pixel to its top and left pixel +// in src array. Write predicted_value + palette_entry to new_image. Return +// index of best palette entry. +static int FindBestPaletteEntry(uint32_t src, uint32_t predicted_value, + const uint32_t palette[], int palette_size) { + int i; + int idx = 0; + uint32_t best_distance = CalcDist(predicted_value, src, palette[0]); + for (i = 1; i < palette_size; ++i) { + const uint32_t distance = CalcDist(predicted_value, src, palette[i]); + if (distance < best_distance) { + best_distance = distance; + idx = i; + } + } + return idx; +} + +static void ApplyBestPaletteEntry(int x, int y, + uint32_t new_value, uint32_t palette_value, + uint32_t* src, int src_stride, + uint32_t* new_image) { + AddPixelsEq(&new_value, palette_value); + if (x > 0) { + src[x - 1] = ClampedAddSubtractFullWithCoefficient(src[x - 1], + new_value, src[x]); + } + if (y > 0) { + src[x - src_stride] = + ClampedAddSubtractFullWithCoefficient(src[x - src_stride], + new_value, src[x]); + } + new_image[x] = new_value; +} + +//------------------------------------------------------------------------------ +// Main entry point + +static WebPEncodingError ApplyDeltaPalette(uint32_t* src, uint32_t* dst, + uint32_t src_stride, + uint32_t dst_stride, + const uint32_t* palette, + int palette_size, + int width, int height, + int num_passes) { + int x, y; + WebPEncodingError err = VP8_ENC_OK; + uint32_t* new_image = (uint32_t*)WebPSafeMalloc(width, sizeof(*new_image)); + uint8_t* const tmp_row = (uint8_t*)WebPSafeMalloc(width, sizeof(*tmp_row)); + if (new_image == NULL || tmp_row == NULL) { + err = VP8_ENC_ERROR_OUT_OF_MEMORY; + goto Error; + } + + while (num_passes--) { + uint32_t* cur_src = src; + uint32_t* cur_dst = dst; + for (y = 0; y < height; ++y) { + for (x = 0; x < width; ++x) { + const uint32_t predicted_value = Predict(x, y, new_image); + tmp_row[x] = FindBestPaletteEntry(cur_src[x], predicted_value, + palette, palette_size); + ApplyBestPaletteEntry(x, y, predicted_value, palette[tmp_row[x]], + cur_src, src_stride, new_image); + } + for (x = 0; x < width; ++x) { + cur_dst[x] = palette[tmp_row[x]]; + } + cur_src += src_stride; + cur_dst += dst_stride; + } + } + Error: + WebPSafeFree(new_image); + WebPSafeFree(tmp_row); + return err; +} + +// replaces enc->argb_ by a palettizable approximation of it, +// and generates optimal enc->palette_[] +WebPEncodingError WebPSearchOptimalDeltaPalette(VP8LEncoder* const enc) { + const WebPPicture* const pic = enc->pic_; + uint32_t* src = pic->argb; + uint32_t* dst = enc->argb_; + const int width = pic->width; + const int height = pic->height; + + WebPEncodingError err = VP8_ENC_OK; + memcpy(enc->palette_, kDeltaPalette, sizeof(kDeltaPalette)); + enc->palette_[DELTA_PALETTE_SIZE - 1] = src[0] - 0xff000000u; + enc->palette_size_ = DELTA_PALETTE_SIZE; + err = ApplyDeltaPalette(src, dst, pic->argb_stride, enc->current_width_, + enc->palette_, enc->palette_size_, + width, height, 2); + if (err != VP8_ENC_OK) goto Error; + + Error: + return err; +} + +#else // !WEBP_EXPERIMENTAL_FEATURES + +WebPEncodingError WebPSearchOptimalDeltaPalette(VP8LEncoder* const enc) { + (void)enc; + return VP8_ENC_ERROR_INVALID_CONFIGURATION; +} + +#endif // WEBP_EXPERIMENTAL_FEATURES |