libwebp: update to 0.5.0

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 "../utils/utils.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+#ifdef WEBP_EXPERIMENTAL_FEATURES
+#include "../enc/delta_palettization.h"
+#endif  // WEBP_EXPERIMENTAL_FEATURES
+
 //------------------------------------------------------------------------------
-// Signatures and generic function-pointers
+// Decoding
 
 typedef uint32_t (*VP8LPredictorFunc)(uint32_t left, const uint32_t* const top);
 extern VP8LPredictorFunc VP8LPredictors[16];
 
 typedef void (*VP8LProcessBlueAndRedFunc)(uint32_t* argb_data, int num_pixels);
-extern VP8LProcessBlueAndRedFunc VP8LSubtractGreenFromBlueAndRed;
 extern VP8LProcessBlueAndRedFunc 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 VP8LTransformColor;
 extern VP8LTransformColorFunc 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 VP8LTransformColor_C(const VP8LMultipliers* const m,
-                          uint32_t* data, int num_pixels);
 void VP8LTransformColorInverse_C(const VP8LMultipliers* const m,
                                  uint32_t* data, int num_pixels);
 
 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 VP8LSubtractGreenFromBlueAndRed_C(uint32_t* argb_data, int num_pixels);
 void VP8LAddGreenToBlueAndRed_C(uint32_t* data, int num_pixels);
 
 // Must be called before calling any of the above methods.
 void VP8LDspInit(void);
 
 //------------------------------------------------------------------------------
+// Encoding
+
+extern VP8LProcessBlueAndRedFunc VP8LSubtractGreenFromBlueAndRed;
+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.
 
-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);
-
-// 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);
-
-void VP8LResidualImage(int width, int height, int bits,
+void VP8LResidualImage(int width, int height, int bits, int low_effort,
                        uint32_t* const argb, uint32_t* const argb_scratch,
-                       uint32_t* const image);
+                       uint32_t* const image, int exact);
 
 void VP8LColorSpaceTransform(int width, int height, int bits, int quality,
                              uint32_t* const argb, uint32_t* image);
 
 //------------------------------------------------------------------------------
-// Color space conversion.
-
-// 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);
-
-//------------------------------------------------------------------------------
 // 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;
 }
 
 // -----------------------------------------------------------------------------
 // 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);
 }
 
 // -----------------------------------------------------------------------------
 // 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 (*VP8LCostCountFunc)(const uint32_t* population,
-                                         int length);
 typedef VP8LStreaks (*VP8LCostCombinedCountFunc)(const uint32_t* X,
                                                  const uint32_t* Y, int length);
 
-extern VP8LCostCountFunc VP8LHuffmanCostCount;
 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);
+// Get the entropy for the distribution 'X'.
+void VP8LGetEntropyUnrefined(const uint32_t* const X, int length,
+                             VP8LBitEntropy* const bit_entropy,
+                             VP8LStreaks* const stats);
+
+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()
 
 static WEBP_INLINE int VP8LBitsLog2Ceiling(uint32_t n) {
   const int log_floor = BitsLog2Floor(n);
@@ skipping 62 matching lines @@
   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);
 
+// Must be called before calling any of the above methods.
+void VP8LEncDspInit(void);
+
 //------------------------------------------------------------------------------
 
 #ifdef __cplusplus
 }    // extern "C"
 #endif
 
 #endif  // WEBP_DSP_LOSSLESS_H_