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      1 // Copyright 2012 Google Inc. All Rights Reserved.
      2 //
      3 // Use of this source code is governed by a BSD-style license
      4 // that can be found in the COPYING file in the root of the source
      5 // tree. An additional intellectual property rights grant can be found
      6 // in the file PATENTS. All contributing project authors may
      7 // be found in the AUTHORS file in the root of the source tree.
      8 // -----------------------------------------------------------------------------
      9 //
     10 // Image transforms and color space conversion methods for lossless decoder.
     11 //
     12 // Authors: Vikas Arora (vikaas.arora (at) gmail.com)
     13 //          Jyrki Alakuijala (jyrki (at) google.com)
     14 
     15 #ifndef WEBP_DSP_LOSSLESS_H_
     16 #define WEBP_DSP_LOSSLESS_H_
     17 
     18 #include "src/webp/types.h"
     19 #include "src/webp/decode.h"
     20 
     21 #include "src/enc/histogram_enc.h"
     22 #include "src/utils/utils.h"
     23 
     24 #ifdef __cplusplus
     25 extern "C" {
     26 #endif
     27 
     28 #ifdef WEBP_EXPERIMENTAL_FEATURES
     29 #include "src/enc/delta_palettization_enc.h"
     30 #endif  // WEBP_EXPERIMENTAL_FEATURES
     31 
     32 //------------------------------------------------------------------------------
     33 // Decoding
     34 
     35 typedef uint32_t (*VP8LPredictorFunc)(uint32_t left, const uint32_t* const top);
     36 extern VP8LPredictorFunc VP8LPredictors[16];
     37 extern VP8LPredictorFunc VP8LPredictors_C[16];
     38 // These Add/Sub function expects upper[-1] and out[-1] to be readable.
     39 typedef void (*VP8LPredictorAddSubFunc)(const uint32_t* in,
     40                                         const uint32_t* upper, int num_pixels,
     41                                         uint32_t* out);
     42 extern VP8LPredictorAddSubFunc VP8LPredictorsAdd[16];
     43 extern VP8LPredictorAddSubFunc VP8LPredictorsAdd_C[16];
     44 
     45 typedef void (*VP8LProcessDecBlueAndRedFunc)(const uint32_t* src,
     46                                              int num_pixels, uint32_t* dst);
     47 extern VP8LProcessDecBlueAndRedFunc VP8LAddGreenToBlueAndRed;
     48 
     49 typedef struct {
     50   // Note: the members are uint8_t, so that any negative values are
     51   // automatically converted to "mod 256" values.
     52   uint8_t green_to_red_;
     53   uint8_t green_to_blue_;
     54   uint8_t red_to_blue_;
     55 } VP8LMultipliers;
     56 typedef void (*VP8LTransformColorInverseFunc)(const VP8LMultipliers* const m,
     57                                               const uint32_t* src,
     58                                               int num_pixels, uint32_t* dst);
     59 extern VP8LTransformColorInverseFunc VP8LTransformColorInverse;
     60 
     61 struct VP8LTransform;  // Defined in dec/vp8li.h.
     62 
     63 // Performs inverse transform of data given transform information, start and end
     64 // rows. Transform will be applied to rows [row_start, row_end[.
     65 // The *in and *out pointers refer to source and destination data respectively
     66 // corresponding to the intermediate row (row_start).
     67 void VP8LInverseTransform(const struct VP8LTransform* const transform,
     68                           int row_start, int row_end,
     69                           const uint32_t* const in, uint32_t* const out);
     70 
     71 // Color space conversion.
     72 typedef void (*VP8LConvertFunc)(const uint32_t* src, int num_pixels,
     73                                 uint8_t* dst);
     74 extern VP8LConvertFunc VP8LConvertBGRAToRGB;
     75 extern VP8LConvertFunc VP8LConvertBGRAToRGBA;
     76 extern VP8LConvertFunc VP8LConvertBGRAToRGBA4444;
     77 extern VP8LConvertFunc VP8LConvertBGRAToRGB565;
     78 extern VP8LConvertFunc VP8LConvertBGRAToBGR;
     79 
     80 // Converts from BGRA to other color spaces.
     81 void VP8LConvertFromBGRA(const uint32_t* const in_data, int num_pixels,
     82                          WEBP_CSP_MODE out_colorspace, uint8_t* const rgba);
     83 
     84 typedef void (*VP8LMapARGBFunc)(const uint32_t* src,
     85                                 const uint32_t* const color_map,
     86                                 uint32_t* dst, int y_start,
     87                                 int y_end, int width);
     88 typedef void (*VP8LMapAlphaFunc)(const uint8_t* src,
     89                                  const uint32_t* const color_map,
     90                                  uint8_t* dst, int y_start,
     91                                  int y_end, int width);
     92 
     93 extern VP8LMapARGBFunc VP8LMapColor32b;
     94 extern VP8LMapAlphaFunc VP8LMapColor8b;
     95 
     96 // Similar to the static method ColorIndexInverseTransform() that is part of
     97 // lossless.c, but used only for alpha decoding. It takes uint8_t (rather than
     98 // uint32_t) arguments for 'src' and 'dst'.
     99 void VP8LColorIndexInverseTransformAlpha(
    100     const struct VP8LTransform* const transform, int y_start, int y_end,
    101     const uint8_t* src, uint8_t* dst);
    102 
    103 // Expose some C-only fallback functions
    104 void VP8LTransformColorInverse_C(const VP8LMultipliers* const m,
    105                                  const uint32_t* src, int num_pixels,
    106                                  uint32_t* dst);
    107 
    108 void VP8LConvertBGRAToRGB_C(const uint32_t* src, int num_pixels, uint8_t* dst);
    109 void VP8LConvertBGRAToRGBA_C(const uint32_t* src, int num_pixels, uint8_t* dst);
    110 void VP8LConvertBGRAToRGBA4444_C(const uint32_t* src,
    111                                  int num_pixels, uint8_t* dst);
    112 void VP8LConvertBGRAToRGB565_C(const uint32_t* src,
    113                                int num_pixels, uint8_t* dst);
    114 void VP8LConvertBGRAToBGR_C(const uint32_t* src, int num_pixels, uint8_t* dst);
    115 void VP8LAddGreenToBlueAndRed_C(const uint32_t* src, int num_pixels,
    116                                 uint32_t* dst);
    117 
    118 // Must be called before calling any of the above methods.
    119 void VP8LDspInit(void);
    120 
    121 //------------------------------------------------------------------------------
    122 // Encoding
    123 
    124 typedef void (*VP8LProcessEncBlueAndRedFunc)(uint32_t* dst, int num_pixels);
    125 extern VP8LProcessEncBlueAndRedFunc VP8LSubtractGreenFromBlueAndRed;
    126 typedef void (*VP8LTransformColorFunc)(const VP8LMultipliers* const m,
    127                                        uint32_t* dst, int num_pixels);
    128 extern VP8LTransformColorFunc VP8LTransformColor;
    129 typedef void (*VP8LCollectColorBlueTransformsFunc)(
    130     const uint32_t* argb, int stride,
    131     int tile_width, int tile_height,
    132     int green_to_blue, int red_to_blue, int histo[]);
    133 extern VP8LCollectColorBlueTransformsFunc VP8LCollectColorBlueTransforms;
    134 
    135 typedef void (*VP8LCollectColorRedTransformsFunc)(
    136     const uint32_t* argb, int stride,
    137     int tile_width, int tile_height,
    138     int green_to_red, int histo[]);
    139 extern VP8LCollectColorRedTransformsFunc VP8LCollectColorRedTransforms;
    140 
    141 // Expose some C-only fallback functions
    142 void VP8LTransformColor_C(const VP8LMultipliers* const m,
    143                           uint32_t* data, int num_pixels);
    144 void VP8LSubtractGreenFromBlueAndRed_C(uint32_t* argb_data, int num_pixels);
    145 void VP8LCollectColorRedTransforms_C(const uint32_t* argb, int stride,
    146                                      int tile_width, int tile_height,
    147                                      int green_to_red, int histo[]);
    148 void VP8LCollectColorBlueTransforms_C(const uint32_t* argb, int stride,
    149                                       int tile_width, int tile_height,
    150                                       int green_to_blue, int red_to_blue,
    151                                       int histo[]);
    152 
    153 extern VP8LPredictorAddSubFunc VP8LPredictorsSub[16];
    154 extern VP8LPredictorAddSubFunc VP8LPredictorsSub_C[16];
    155 
    156 // -----------------------------------------------------------------------------
    157 // Huffman-cost related functions.
    158 
    159 typedef double (*VP8LCostFunc)(const uint32_t* population, int length);
    160 typedef double (*VP8LCostCombinedFunc)(const uint32_t* X, const uint32_t* Y,
    161                                        int length);
    162 typedef float (*VP8LCombinedShannonEntropyFunc)(const int X[256],
    163                                                 const int Y[256]);
    164 
    165 extern VP8LCostFunc VP8LExtraCost;
    166 extern VP8LCostCombinedFunc VP8LExtraCostCombined;
    167 extern VP8LCombinedShannonEntropyFunc VP8LCombinedShannonEntropy;
    168 
    169 typedef struct {        // small struct to hold counters
    170   int counts[2];        // index: 0=zero steak, 1=non-zero streak
    171   int streaks[2][2];    // [zero/non-zero][streak<3 / streak>=3]
    172 } VP8LStreaks;
    173 
    174 typedef struct {            // small struct to hold bit entropy results
    175   double entropy;           // entropy
    176   uint32_t sum;             // sum of the population
    177   int nonzeros;             // number of non-zero elements in the population
    178   uint32_t max_val;         // maximum value in the population
    179   uint32_t nonzero_code;    // index of the last non-zero in the population
    180 } VP8LBitEntropy;
    181 
    182 void VP8LBitEntropyInit(VP8LBitEntropy* const entropy);
    183 
    184 // Get the combined symbol bit entropy and Huffman cost stats for the
    185 // distributions 'X' and 'Y'. Those results can then be refined according to
    186 // codec specific heuristics.
    187 typedef void (*VP8LGetCombinedEntropyUnrefinedFunc)(
    188     const uint32_t X[], const uint32_t Y[], int length,
    189     VP8LBitEntropy* const bit_entropy, VP8LStreaks* const stats);
    190 extern VP8LGetCombinedEntropyUnrefinedFunc VP8LGetCombinedEntropyUnrefined;
    191 
    192 // Get the entropy for the distribution 'X'.
    193 typedef void (*VP8LGetEntropyUnrefinedFunc)(const uint32_t X[], int length,
    194                                             VP8LBitEntropy* const bit_entropy,
    195                                             VP8LStreaks* const stats);
    196 extern VP8LGetEntropyUnrefinedFunc VP8LGetEntropyUnrefined;
    197 
    198 void VP8LBitsEntropyUnrefined(const uint32_t* const array, int n,
    199                               VP8LBitEntropy* const entropy);
    200 
    201 typedef void (*VP8LHistogramAddFunc)(const VP8LHistogram* const a,
    202                                      const VP8LHistogram* const b,
    203                                      VP8LHistogram* const out);
    204 extern VP8LHistogramAddFunc VP8LHistogramAdd;
    205 
    206 // -----------------------------------------------------------------------------
    207 // PrefixEncode()
    208 
    209 typedef int (*VP8LVectorMismatchFunc)(const uint32_t* const array1,
    210                                       const uint32_t* const array2, int length);
    211 // Returns the first index where array1 and array2 are different.
    212 extern VP8LVectorMismatchFunc VP8LVectorMismatch;
    213 
    214 typedef void (*VP8LBundleColorMapFunc)(const uint8_t* const row, int width,
    215                                        int xbits, uint32_t* dst);
    216 extern VP8LBundleColorMapFunc VP8LBundleColorMap;
    217 void VP8LBundleColorMap_C(const uint8_t* const row, int width, int xbits,
    218                           uint32_t* dst);
    219 
    220 // Must be called before calling any of the above methods.
    221 void VP8LEncDspInit(void);
    222 
    223 //------------------------------------------------------------------------------
    224 
    225 #ifdef __cplusplus
    226 }    // extern "C"
    227 #endif
    228 
    229 #endif  // WEBP_DSP_LOSSLESS_H_
    230