libwebp-0.6.0-rc1

third_party/libwebp/dsp/lossless.h

 // 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.
 // -----------------------------------------------------------------------------
 //
 // Image transforms and color space conversion methods for lossless decoder.
 //
 // Authors: Vikas Arora (vikaas.arora@gmail.com)
 //          Jyrki Alakuijala (jyrki@google.com)
 
 #ifndef WEBP_DSP_LOSSLESS_H_
 #define WEBP_DSP_LOSSLESS_H_
 
 #include "../webp/types.h"
 #include "../webp/decode.h"
 
-#include "../enc/histogram.h"
+#include "../enc/histogram_enc.h"
 #include "../utils/utils.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 #ifdef WEBP_EXPERIMENTAL_FEATURES
-#include "../enc/delta_palettization.h"
+#include "../enc/delta_palettization_enc.h"
 #endif  // WEBP_EXPERIMENTAL_FEATURES
 
 //------------------------------------------------------------------------------
 // Decoding
 
 typedef uint32_t (*VP8LPredictorFunc)(uint32_t left, const uint32_t* const top);
 extern VP8LPredictorFunc VP8LPredictors[16];
+extern VP8LPredictorFunc VP8LPredictors_C[16];
+// These Add/Sub function expects upper[-1] and out[-1] to be readable.
+typedef void (*VP8LPredictorAddSubFunc)(const uint32_t* in,
+                                        const uint32_t* upper, int num_pixels,
+                                        uint32_t* out);
+extern VP8LPredictorAddSubFunc VP8LPredictorsAdd[16];
+extern VP8LPredictorAddSubFunc VP8LPredictorsAdd_C[16];
 
-typedef void (*VP8LProcessBlueAndRedFunc)(uint32_t* argb_data, int num_pixels);
-extern VP8LProcessBlueAndRedFunc VP8LAddGreenToBlueAndRed;
+typedef void (*VP8LProcessDecBlueAndRedFunc)(const uint32_t* src,
+                                             int num_pixels, uint32_t* dst);
+extern VP8LProcessDecBlueAndRedFunc VP8LAddGreenToBlueAndRed;
 
 typedef struct {
   // Note: the members are uint8_t, so that any negative values are
   // automatically converted to "mod 256" values.
   uint8_t green_to_red_;
   uint8_t green_to_blue_;
   uint8_t red_to_blue_;
 } VP8LMultipliers;
-typedef void (*VP8LTransformColorFunc)(const VP8LMultipliers* const m,
-                                       uint32_t* argb_data, int num_pixels);
-extern VP8LTransformColorFunc VP8LTransformColorInverse;
+typedef void (*VP8LTransformColorInverseFunc)(const VP8LMultipliers* const m,
+                                              const uint32_t* src,
+                                              int num_pixels, uint32_t* dst);
+extern VP8LTransformColorInverseFunc VP8LTransformColorInverse;
 
 struct VP8LTransform;  // Defined in dec/vp8li.h.
 
 // Performs inverse transform of data given transform information, start and end
 // rows. Transform will be applied to rows [row_start, row_end[.
 // The *in and *out pointers refer to source and destination data respectively
 // corresponding to the intermediate row (row_start).
 void VP8LInverseTransform(const struct VP8LTransform* const transform,
                           int row_start, int row_end,
                           const uint32_t* const in, uint32_t* const out);
 
 // Color space conversion.
 typedef void (*VP8LConvertFunc)(const uint32_t* src, int num_pixels,
                                 uint8_t* dst);
 extern VP8LConvertFunc VP8LConvertBGRAToRGB;
 extern VP8LConvertFunc VP8LConvertBGRAToRGBA;
 extern VP8LConvertFunc VP8LConvertBGRAToRGBA4444;
 extern VP8LConvertFunc VP8LConvertBGRAToRGB565;
 extern VP8LConvertFunc VP8LConvertBGRAToBGR;
 
 // Converts from BGRA to other color spaces.
 void VP8LConvertFromBGRA(const uint32_t* const in_data, int num_pixels,
                          WEBP_CSP_MODE out_colorspace, uint8_t* const rgba);
 
-// color mapping related functions.
-static WEBP_INLINE uint32_t VP8GetARGBIndex(uint32_t idx) {
-  return (idx >> 8) & 0xff;
-}
-
-static WEBP_INLINE uint8_t VP8GetAlphaIndex(uint8_t idx) {
-  return idx;
-}
-
-static WEBP_INLINE uint32_t VP8GetARGBValue(uint32_t val) {
-  return val;
-}
-
-static WEBP_INLINE uint8_t VP8GetAlphaValue(uint32_t val) {
-  return (val >> 8) & 0xff;
-}
-
 typedef void (*VP8LMapARGBFunc)(const uint32_t* src,
                                 const uint32_t* const color_map,
                                 uint32_t* dst, int y_start,
                                 int y_end, int width);
 typedef void (*VP8LMapAlphaFunc)(const uint8_t* src,
                                  const uint32_t* const color_map,
                                  uint8_t* dst, int y_start,
                                  int y_end, int width);
 
 extern VP8LMapARGBFunc VP8LMapColor32b;
 extern VP8LMapAlphaFunc VP8LMapColor8b;
 
 // Similar to the static method ColorIndexInverseTransform() that is part of
 // lossless.c, but used only for alpha decoding. It takes uint8_t (rather than
 // uint32_t) arguments for 'src' and 'dst'.
 void VP8LColorIndexInverseTransformAlpha(
     const struct VP8LTransform* const transform, int y_start, int y_end,
     const uint8_t* src, uint8_t* dst);
 
 // Expose some C-only fallback functions
 void VP8LTransformColorInverse_C(const VP8LMultipliers* const m,
-                                 uint32_t* data, int num_pixels);
+                                 const uint32_t* src, int num_pixels,
+                                 uint32_t* dst);
 
 void VP8LConvertBGRAToRGB_C(const uint32_t* src, int num_pixels, uint8_t* dst);
 void VP8LConvertBGRAToRGBA_C(const uint32_t* src, int num_pixels, uint8_t* dst);
 void VP8LConvertBGRAToRGBA4444_C(const uint32_t* src,
                                  int num_pixels, uint8_t* dst);
 void VP8LConvertBGRAToRGB565_C(const uint32_t* src,
                                int num_pixels, uint8_t* dst);
 void VP8LConvertBGRAToBGR_C(const uint32_t* src, int num_pixels, uint8_t* dst);
-void VP8LAddGreenToBlueAndRed_C(uint32_t* data, int num_pixels);
+void VP8LAddGreenToBlueAndRed_C(const uint32_t* src, int num_pixels,
+                                uint32_t* dst);
 
 // Must be called before calling any of the above methods.
 void VP8LDspInit(void);
 
 //------------------------------------------------------------------------------
 // Encoding
 
-extern VP8LProcessBlueAndRedFunc VP8LSubtractGreenFromBlueAndRed;
+typedef void (*VP8LProcessEncBlueAndRedFunc)(uint32_t* dst, int num_pixels);
+extern VP8LProcessEncBlueAndRedFunc VP8LSubtractGreenFromBlueAndRed;
+typedef void (*VP8LTransformColorFunc)(const VP8LMultipliers* const m,
+                                       uint32_t* const dst, int num_pixels);
 extern VP8LTransformColorFunc VP8LTransformColor;
 typedef void (*VP8LCollectColorBlueTransformsFunc)(
     const uint32_t* argb, int stride,
     int tile_width, int tile_height,
     int green_to_blue, int red_to_blue, int histo[]);
 extern VP8LCollectColorBlueTransformsFunc VP8LCollectColorBlueTransforms;
 
 typedef void (*VP8LCollectColorRedTransformsFunc)(
     const uint32_t* argb, int stride,
     int tile_width, int tile_height,
     int green_to_red, int histo[]);
 extern VP8LCollectColorRedTransformsFunc VP8LCollectColorRedTransforms;
 
 // Expose some C-only fallback functions
 void VP8LTransformColor_C(const VP8LMultipliers* const m,
                           uint32_t* data, int num_pixels);
 void VP8LSubtractGreenFromBlueAndRed_C(uint32_t* argb_data, int num_pixels);
 void VP8LCollectColorRedTransforms_C(const uint32_t* argb, int stride,
                                      int tile_width, int tile_height,
                                      int green_to_red, int histo[]);
 void VP8LCollectColorBlueTransforms_C(const uint32_t* argb, int stride,
                                       int tile_width, int tile_height,
                                       int green_to_blue, int red_to_blue,
                                       int histo[]);
 
-//------------------------------------------------------------------------------
-// Image transforms.
-
-void VP8LResidualImage(int width, int height, int bits, int low_effort,
-                       uint32_t* const argb, uint32_t* const argb_scratch,
-                       uint32_t* const image, int near_lossless, int exact,
-                       int used_subtract_green);
-
-void VP8LColorSpaceTransform(int width, int height, int bits, int quality,
-                             uint32_t* const argb, uint32_t* image);
-
-//------------------------------------------------------------------------------
-// Misc methods.
-
-// Computes sampled size of 'size' when sampling using 'sampling bits'.
-static WEBP_INLINE uint32_t VP8LSubSampleSize(uint32_t size,
-                                              uint32_t sampling_bits) {
-  return (size + (1 << sampling_bits) - 1) >> sampling_bits;
-}
-
-// Converts near lossless quality into max number of bits shaved off.
-static WEBP_INLINE int VP8LNearLosslessBits(int near_lossless_quality) {
-  //    100 -> 0
-  // 80..99 -> 1
-  // 60..79 -> 2
-  // 40..59 -> 3
-  // 20..39 -> 4
-  //  0..19 -> 5
-  return 5 - near_lossless_quality / 20;
-}
-
-// -----------------------------------------------------------------------------
-// Faster logarithm for integers. Small values use a look-up table.
-
-// The threshold till approximate version of log_2 can be used.
-// Practically, we can get rid of the call to log() as the two values match to
-// very high degree (the ratio of these two is 0.99999x).
-// Keeping a high threshold for now.
-#define APPROX_LOG_WITH_CORRECTION_MAX  65536
-#define APPROX_LOG_MAX                   4096
-#define LOG_2_RECIPROCAL 1.44269504088896338700465094007086
-#define LOG_LOOKUP_IDX_MAX 256
-extern const float kLog2Table[LOG_LOOKUP_IDX_MAX];
-extern const float kSLog2Table[LOG_LOOKUP_IDX_MAX];
-typedef float (*VP8LFastLog2SlowFunc)(uint32_t v);
-
-extern VP8LFastLog2SlowFunc VP8LFastLog2Slow;
-extern VP8LFastLog2SlowFunc VP8LFastSLog2Slow;
-
-static WEBP_INLINE float VP8LFastLog2(uint32_t v) {
-  return (v < LOG_LOOKUP_IDX_MAX) ? kLog2Table[v] : VP8LFastLog2Slow(v);
-}
-// Fast calculation of v * log2(v) for integer input.
-static WEBP_INLINE float VP8LFastSLog2(uint32_t v) {
-  return (v < LOG_LOOKUP_IDX_MAX) ? kSLog2Table[v] : VP8LFastSLog2Slow(v);
-}
+extern VP8LPredictorAddSubFunc VP8LPredictorsSub[16];
+extern VP8LPredictorAddSubFunc VP8LPredictorsSub_C[16];
 
 // -----------------------------------------------------------------------------
 // Huffman-cost related functions.
 
 typedef double (*VP8LCostFunc)(const uint32_t* population, int length);
 typedef double (*VP8LCostCombinedFunc)(const uint32_t* X, const uint32_t* Y,
                                        int length);
 typedef float (*VP8LCombinedShannonEntropyFunc)(const int X[256],
                                                 const int Y[256]);
 
 extern VP8LCostFunc VP8LExtraCost;
 extern VP8LCostCombinedFunc VP8LExtraCostCombined;
 extern VP8LCombinedShannonEntropyFunc VP8LCombinedShannonEntropy;
 
 typedef struct {        // small struct to hold counters
   int counts[2];        // index: 0=zero steak, 1=non-zero streak
   int streaks[2][2];    // [zero/non-zero][streak<3 / streak>=3]
 } VP8LStreaks;
 
-typedef VP8LStreaks (*VP8LCostCombinedCountFunc)(const uint32_t* X,
-                                                 const uint32_t* Y, int length);
-
-extern VP8LCostCombinedCountFunc VP8LHuffmanCostCombinedCount;
-
 typedef struct {            // small struct to hold bit entropy results
   double entropy;           // entropy
   uint32_t sum;             // sum of the population
   int nonzeros;             // number of non-zero elements in the population
   uint32_t max_val;         // maximum value in the population
   uint32_t nonzero_code;    // index of the last non-zero in the population
 } VP8LBitEntropy;
 
 void VP8LBitEntropyInit(VP8LBitEntropy* const entropy);
 
 // Get the combined symbol bit entropy and Huffman cost stats for the
 // distributions 'X' and 'Y'. Those results can then be refined according to
 // codec specific heuristics.
-void VP8LGetCombinedEntropyUnrefined(const uint32_t* const X,
-                                     const uint32_t* const Y, int length,
-                                     VP8LBitEntropy* const bit_entropy,
-                                     VP8LStreaks* const stats);
+typedef void (*VP8LGetCombinedEntropyUnrefinedFunc)(
+    const uint32_t X[], const uint32_t Y[], int length,
+    VP8LBitEntropy* const bit_entropy, VP8LStreaks* const stats);
+extern VP8LGetCombinedEntropyUnrefinedFunc VP8LGetCombinedEntropyUnrefined;
+
 // Get the entropy for the distribution 'X'.
-void VP8LGetEntropyUnrefined(const uint32_t* const X, int length,
-                             VP8LBitEntropy* const bit_entropy,
-                             VP8LStreaks* const stats);
+typedef void (*VP8LGetEntropyUnrefinedFunc)(const uint32_t X[], int length,
+                                            VP8LBitEntropy* const bit_entropy,
+                                            VP8LStreaks* const stats);
+extern VP8LGetEntropyUnrefinedFunc VP8LGetEntropyUnrefined;
 
 void VP8LBitsEntropyUnrefined(const uint32_t* const array, int n,
                               VP8LBitEntropy* const entropy);
 
-typedef void (*GetEntropyUnrefinedHelperFunc)(uint32_t val, int i,
-                                              uint32_t* const val_prev,
-                                              int* const i_prev,
-                                              VP8LBitEntropy* const bit_entropy,
-                                              VP8LStreaks* const stats);
-// Internal function used by VP8LGet*EntropyUnrefined.
-extern GetEntropyUnrefinedHelperFunc VP8LGetEntropyUnrefinedHelper;
-
 typedef void (*VP8LHistogramAddFunc)(const VP8LHistogram* const a,
                                      const VP8LHistogram* const b,
                                      VP8LHistogram* const out);
 extern VP8LHistogramAddFunc VP8LHistogramAdd;
 
 // -----------------------------------------------------------------------------
 // PrefixEncode()
 
 typedef int (*VP8LVectorMismatchFunc)(const uint32_t* const array1,
                                       const uint32_t* const array2, int length);
 // Returns the first index where array1 and array2 are different.
 extern VP8LVectorMismatchFunc VP8LVectorMismatch;
 
-static WEBP_INLINE int VP8LBitsLog2Ceiling(uint32_t n) {
-  const int log_floor = BitsLog2Floor(n);
-  if (n == (n & ~(n - 1)))  // zero or a power of two.
-    return log_floor;
-  else
-    return log_floor + 1;
-}
-
-// Splitting of distance and length codes into prefixes and
-// extra bits. The prefixes are encoded with an entropy code
-// while the extra bits are stored just as normal bits.
-static WEBP_INLINE void VP8LPrefixEncodeBitsNoLUT(int distance, int* const code,
-                                                  int* const extra_bits) {
-  const int highest_bit = BitsLog2Floor(--distance);
-  const int second_highest_bit = (distance >> (highest_bit - 1)) & 1;
-  *extra_bits = highest_bit - 1;
-  *code = 2 * highest_bit + second_highest_bit;
-}
-
-static WEBP_INLINE void VP8LPrefixEncodeNoLUT(int distance, int* const code,
-                                              int* const extra_bits,
-                                              int* const extra_bits_value) {
-  const int highest_bit = BitsLog2Floor(--distance);
-  const int second_highest_bit = (distance >> (highest_bit - 1)) & 1;
-  *extra_bits = highest_bit - 1;
-  *extra_bits_value = distance & ((1 << *extra_bits) - 1);
-  *code = 2 * highest_bit + second_highest_bit;
-}
-
-#define PREFIX_LOOKUP_IDX_MAX   512
-typedef struct {
-  int8_t code_;
-  int8_t extra_bits_;
-} VP8LPrefixCode;
-
-// These tables are derived using VP8LPrefixEncodeNoLUT.
-extern const VP8LPrefixCode kPrefixEncodeCode[PREFIX_LOOKUP_IDX_MAX];
-extern const uint8_t kPrefixEncodeExtraBitsValue[PREFIX_LOOKUP_IDX_MAX];
-static WEBP_INLINE void VP8LPrefixEncodeBits(int distance, int* const code,
-                                             int* const extra_bits) {
-  if (distance < PREFIX_LOOKUP_IDX_MAX) {
-    const VP8LPrefixCode prefix_code = kPrefixEncodeCode[distance];
-    *code = prefix_code.code_;
-    *extra_bits = prefix_code.extra_bits_;
-  } else {
-    VP8LPrefixEncodeBitsNoLUT(distance, code, extra_bits);
-  }
-}
-
-static WEBP_INLINE void VP8LPrefixEncode(int distance, int* const code,
-                                         int* const extra_bits,
-                                         int* const extra_bits_value) {
-  if (distance < PREFIX_LOOKUP_IDX_MAX) {
-    const VP8LPrefixCode prefix_code = kPrefixEncodeCode[distance];
-    *code = prefix_code.code_;
-    *extra_bits = prefix_code.extra_bits_;
-    *extra_bits_value = kPrefixEncodeExtraBitsValue[distance];
-  } else {
-    VP8LPrefixEncodeNoLUT(distance, code, extra_bits, extra_bits_value);
-  }
-}
-
-// Sum of each component, mod 256.
-static WEBP_INLINE uint32_t VP8LAddPixels(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);
-  return (alpha_and_green & 0xff00ff00u) | (red_and_blue & 0x00ff00ffu);
-}
-
-// Difference of each component, mod 256.
-static WEBP_INLINE uint32_t VP8LSubPixels(uint32_t a, uint32_t b) {
-  const uint32_t alpha_and_green =
-      0x00ff00ffu + (a & 0xff00ff00u) - (b & 0xff00ff00u);
-  const uint32_t red_and_blue =
-      0xff00ff00u + (a & 0x00ff00ffu) - (b & 0x00ff00ffu);
-  return (alpha_and_green & 0xff00ff00u) | (red_and_blue & 0x00ff00ffu);
-}
-
-void VP8LBundleColorMap(const uint8_t* const row, int width,
-                        int xbits, uint32_t* const dst);
+typedef void (*VP8LBundleColorMapFunc)(const uint8_t* const row, int width,
+                                       int xbits, uint32_t* dst);
+extern VP8LBundleColorMapFunc VP8LBundleColorMap;
+void VP8LBundleColorMap_C(const uint8_t* const row, int width, int xbits,
+                          uint32_t* dst);
 
 // Must be called before calling any of the above methods.
 void VP8LEncDspInit(void);
 
 //------------------------------------------------------------------------------
 
 #ifdef __cplusplus
 }    // extern "C"
 #endif
 
 #endif  // WEBP_DSP_LOSSLESS_H_