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@gmail.com)
13 //          Jyrki Alakuijala (jyrki@google.com)
14 //          Urvang Joshi (urvang@google.com)
15 
16 #include "src/dsp/dsp.h"
17 
18 #include <assert.h>
19 #include <math.h>
20 #include <stdlib.h>
21 #include "src/dec/vp8li_dec.h"
22 #include "src/utils/endian_inl_utils.h"
23 #include "src/dsp/lossless.h"
24 #include "src/dsp/lossless_common.h"
25 
26 //------------------------------------------------------------------------------
27 // Image transforms.
28 
Average2(uint32_t a0,uint32_t a1)29 static WEBP_INLINE uint32_t Average2(uint32_t a0, uint32_t a1) {
30   return (((a0 ^ a1) & 0xfefefefeu) >> 1) + (a0 & a1);
31 }
32 
Average3(uint32_t a0,uint32_t a1,uint32_t a2)33 static WEBP_INLINE uint32_t Average3(uint32_t a0, uint32_t a1, uint32_t a2) {
34   return Average2(Average2(a0, a2), a1);
35 }
36 
Average4(uint32_t a0,uint32_t a1,uint32_t a2,uint32_t a3)37 static WEBP_INLINE uint32_t Average4(uint32_t a0, uint32_t a1,
38                                      uint32_t a2, uint32_t a3) {
39   return Average2(Average2(a0, a1), Average2(a2, a3));
40 }
41 
Clip255(uint32_t a)42 static WEBP_INLINE uint32_t Clip255(uint32_t a) {
43   if (a < 256) {
44     return a;
45   }
46   // return 0, when a is a negative integer.
47   // return 255, when a is positive.
48   return ~a >> 24;
49 }
50 
AddSubtractComponentFull(int a,int b,int c)51 static WEBP_INLINE int AddSubtractComponentFull(int a, int b, int c) {
52   return Clip255(a + b - c);
53 }
54 
ClampedAddSubtractFull(uint32_t c0,uint32_t c1,uint32_t c2)55 static WEBP_INLINE uint32_t ClampedAddSubtractFull(uint32_t c0, uint32_t c1,
56                                                    uint32_t c2) {
57   const int a = AddSubtractComponentFull(c0 >> 24, c1 >> 24, c2 >> 24);
58   const int r = AddSubtractComponentFull((c0 >> 16) & 0xff,
59                                          (c1 >> 16) & 0xff,
60                                          (c2 >> 16) & 0xff);
61   const int g = AddSubtractComponentFull((c0 >> 8) & 0xff,
62                                          (c1 >> 8) & 0xff,
63                                          (c2 >> 8) & 0xff);
64   const int b = AddSubtractComponentFull(c0 & 0xff, c1 & 0xff, c2 & 0xff);
65   return ((uint32_t)a << 24) | (r << 16) | (g << 8) | b;
66 }
67 
AddSubtractComponentHalf(int a,int b)68 static WEBP_INLINE int AddSubtractComponentHalf(int a, int b) {
69   return Clip255(a + (a - b) / 2);
70 }
71 
ClampedAddSubtractHalf(uint32_t c0,uint32_t c1,uint32_t c2)72 static WEBP_INLINE uint32_t ClampedAddSubtractHalf(uint32_t c0, uint32_t c1,
73                                                    uint32_t c2) {
74   const uint32_t ave = Average2(c0, c1);
75   const int a = AddSubtractComponentHalf(ave >> 24, c2 >> 24);
76   const int r = AddSubtractComponentHalf((ave >> 16) & 0xff, (c2 >> 16) & 0xff);
77   const int g = AddSubtractComponentHalf((ave >> 8) & 0xff, (c2 >> 8) & 0xff);
78   const int b = AddSubtractComponentHalf((ave >> 0) & 0xff, (c2 >> 0) & 0xff);
79   return ((uint32_t)a << 24) | (r << 16) | (g << 8) | b;
80 }
81 
82 // gcc <= 4.9 on ARM generates incorrect code in Select() when Sub3() is
83 // inlined.
84 #if defined(__arm__) && defined(__GNUC__) && LOCAL_GCC_VERSION <= 0x409
85 # define LOCAL_INLINE __attribute__ ((noinline))
86 #else
87 # define LOCAL_INLINE WEBP_INLINE
88 #endif
89 
Sub3(int a,int b,int c)90 static LOCAL_INLINE int Sub3(int a, int b, int c) {
91   const int pb = b - c;
92   const int pa = a - c;
93   return abs(pb) - abs(pa);
94 }
95 
96 #undef LOCAL_INLINE
97 
Select(uint32_t a,uint32_t b,uint32_t c)98 static WEBP_INLINE uint32_t Select(uint32_t a, uint32_t b, uint32_t c) {
99   const int pa_minus_pb =
100       Sub3((a >> 24)       , (b >> 24)       , (c >> 24)       ) +
101       Sub3((a >> 16) & 0xff, (b >> 16) & 0xff, (c >> 16) & 0xff) +
102       Sub3((a >>  8) & 0xff, (b >>  8) & 0xff, (c >>  8) & 0xff) +
103       Sub3((a      ) & 0xff, (b      ) & 0xff, (c      ) & 0xff);
104   return (pa_minus_pb <= 0) ? a : b;
105 }
106 
107 //------------------------------------------------------------------------------
108 // Predictors
109 
VP8LPredictor0_C(uint32_t left,const uint32_t * const top)110 uint32_t VP8LPredictor0_C(uint32_t left, const uint32_t* const top) {
111   (void)top;
112   (void)left;
113   return ARGB_BLACK;
114 }
VP8LPredictor1_C(uint32_t left,const uint32_t * const top)115 uint32_t VP8LPredictor1_C(uint32_t left, const uint32_t* const top) {
116   (void)top;
117   return left;
118 }
VP8LPredictor2_C(uint32_t left,const uint32_t * const top)119 uint32_t VP8LPredictor2_C(uint32_t left, const uint32_t* const top) {
120   (void)left;
121   return top[0];
122 }
VP8LPredictor3_C(uint32_t left,const uint32_t * const top)123 uint32_t VP8LPredictor3_C(uint32_t left, const uint32_t* const top) {
124   (void)left;
125   return top[1];
126 }
VP8LPredictor4_C(uint32_t left,const uint32_t * const top)127 uint32_t VP8LPredictor4_C(uint32_t left, const uint32_t* const top) {
128   (void)left;
129   return top[-1];
130 }
VP8LPredictor5_C(uint32_t left,const uint32_t * const top)131 uint32_t VP8LPredictor5_C(uint32_t left, const uint32_t* const top) {
132   const uint32_t pred = Average3(left, top[0], top[1]);
133   return pred;
134 }
VP8LPredictor6_C(uint32_t left,const uint32_t * const top)135 uint32_t VP8LPredictor6_C(uint32_t left, const uint32_t* const top) {
136   const uint32_t pred = Average2(left, top[-1]);
137   return pred;
138 }
VP8LPredictor7_C(uint32_t left,const uint32_t * const top)139 uint32_t VP8LPredictor7_C(uint32_t left, const uint32_t* const top) {
140   const uint32_t pred = Average2(left, top[0]);
141   return pred;
142 }
VP8LPredictor8_C(uint32_t left,const uint32_t * const top)143 uint32_t VP8LPredictor8_C(uint32_t left, const uint32_t* const top) {
144   const uint32_t pred = Average2(top[-1], top[0]);
145   (void)left;
146   return pred;
147 }
VP8LPredictor9_C(uint32_t left,const uint32_t * const top)148 uint32_t VP8LPredictor9_C(uint32_t left, const uint32_t* const top) {
149   const uint32_t pred = Average2(top[0], top[1]);
150   (void)left;
151   return pred;
152 }
VP8LPredictor10_C(uint32_t left,const uint32_t * const top)153 uint32_t VP8LPredictor10_C(uint32_t left, const uint32_t* const top) {
154   const uint32_t pred = Average4(left, top[-1], top[0], top[1]);
155   return pred;
156 }
VP8LPredictor11_C(uint32_t left,const uint32_t * const top)157 uint32_t VP8LPredictor11_C(uint32_t left, const uint32_t* const top) {
158   const uint32_t pred = Select(top[0], left, top[-1]);
159   return pred;
160 }
VP8LPredictor12_C(uint32_t left,const uint32_t * const top)161 uint32_t VP8LPredictor12_C(uint32_t left, const uint32_t* const top) {
162   const uint32_t pred = ClampedAddSubtractFull(left, top[0], top[-1]);
163   return pred;
164 }
VP8LPredictor13_C(uint32_t left,const uint32_t * const top)165 uint32_t VP8LPredictor13_C(uint32_t left, const uint32_t* const top) {
166   const uint32_t pred = ClampedAddSubtractHalf(left, top[0], top[-1]);
167   return pred;
168 }
169 
PredictorAdd0_C(const uint32_t * in,const uint32_t * upper,int num_pixels,uint32_t * out)170 static void PredictorAdd0_C(const uint32_t* in, const uint32_t* upper,
171                             int num_pixels, uint32_t* out) {
172   int x;
173   (void)upper;
174   for (x = 0; x < num_pixels; ++x) out[x] = VP8LAddPixels(in[x], ARGB_BLACK);
175 }
PredictorAdd1_C(const uint32_t * in,const uint32_t * upper,int num_pixels,uint32_t * out)176 static void PredictorAdd1_C(const uint32_t* in, const uint32_t* upper,
177                             int num_pixels, uint32_t* out) {
178   int i;
179   uint32_t left = out[-1];
180   (void)upper;
181   for (i = 0; i < num_pixels; ++i) {
182     out[i] = left = VP8LAddPixels(in[i], left);
183   }
184 }
GENERATE_PREDICTOR_ADD(VP8LPredictor2_C,PredictorAdd2_C)185 GENERATE_PREDICTOR_ADD(VP8LPredictor2_C, PredictorAdd2_C)
186 GENERATE_PREDICTOR_ADD(VP8LPredictor3_C, PredictorAdd3_C)
187 GENERATE_PREDICTOR_ADD(VP8LPredictor4_C, PredictorAdd4_C)
188 GENERATE_PREDICTOR_ADD(VP8LPredictor5_C, PredictorAdd5_C)
189 GENERATE_PREDICTOR_ADD(VP8LPredictor6_C, PredictorAdd6_C)
190 GENERATE_PREDICTOR_ADD(VP8LPredictor7_C, PredictorAdd7_C)
191 GENERATE_PREDICTOR_ADD(VP8LPredictor8_C, PredictorAdd8_C)
192 GENERATE_PREDICTOR_ADD(VP8LPredictor9_C, PredictorAdd9_C)
193 GENERATE_PREDICTOR_ADD(VP8LPredictor10_C, PredictorAdd10_C)
194 GENERATE_PREDICTOR_ADD(VP8LPredictor11_C, PredictorAdd11_C)
195 GENERATE_PREDICTOR_ADD(VP8LPredictor12_C, PredictorAdd12_C)
196 GENERATE_PREDICTOR_ADD(VP8LPredictor13_C, PredictorAdd13_C)
197 
198 //------------------------------------------------------------------------------
199 
200 // Inverse prediction.
201 static void PredictorInverseTransform_C(const VP8LTransform* const transform,
202                                         int y_start, int y_end,
203                                         const uint32_t* in, uint32_t* out) {
204   const int width = transform->xsize_;
205   if (y_start == 0) {  // First Row follows the L (mode=1) mode.
206     PredictorAdd0_C(in, NULL, 1, out);
207     PredictorAdd1_C(in + 1, NULL, width - 1, out + 1);
208     in += width;
209     out += width;
210     ++y_start;
211   }
212 
213   {
214     int y = y_start;
215     const int tile_width = 1 << transform->bits_;
216     const int mask = tile_width - 1;
217     const int tiles_per_row = VP8LSubSampleSize(width, transform->bits_);
218     const uint32_t* pred_mode_base =
219         transform->data_ + (y >> transform->bits_) * tiles_per_row;
220 
221     while (y < y_end) {
222       const uint32_t* pred_mode_src = pred_mode_base;
223       int x = 1;
224       // First pixel follows the T (mode=2) mode.
225       PredictorAdd2_C(in, out - width, 1, out);
226       // .. the rest:
227       while (x < width) {
228         const VP8LPredictorAddSubFunc pred_func =
229             VP8LPredictorsAdd[((*pred_mode_src++) >> 8) & 0xf];
230         int x_end = (x & ~mask) + tile_width;
231         if (x_end > width) x_end = width;
232         pred_func(in + x, out + x - width, x_end - x, out + x);
233         x = x_end;
234       }
235       in += width;
236       out += width;
237       ++y;
238       if ((y & mask) == 0) {   // Use the same mask, since tiles are squares.
239         pred_mode_base += tiles_per_row;
240       }
241     }
242   }
243 }
244 
245 // Add green to blue and red channels (i.e. perform the inverse transform of
246 // 'subtract green').
VP8LAddGreenToBlueAndRed_C(const uint32_t * src,int num_pixels,uint32_t * dst)247 void VP8LAddGreenToBlueAndRed_C(const uint32_t* src, int num_pixels,
248                                 uint32_t* dst) {
249   int i;
250   for (i = 0; i < num_pixels; ++i) {
251     const uint32_t argb = src[i];
252     const uint32_t green = ((argb >> 8) & 0xff);
253     uint32_t red_blue = (argb & 0x00ff00ffu);
254     red_blue += (green << 16) | green;
255     red_blue &= 0x00ff00ffu;
256     dst[i] = (argb & 0xff00ff00u) | red_blue;
257   }
258 }
259 
ColorTransformDelta(int8_t color_pred,int8_t color)260 static WEBP_INLINE int ColorTransformDelta(int8_t color_pred,
261                                            int8_t color) {
262   return ((int)color_pred * color) >> 5;
263 }
264 
ColorCodeToMultipliers(uint32_t color_code,VP8LMultipliers * const m)265 static WEBP_INLINE void ColorCodeToMultipliers(uint32_t color_code,
266                                                VP8LMultipliers* const m) {
267   m->green_to_red_  = (color_code >>  0) & 0xff;
268   m->green_to_blue_ = (color_code >>  8) & 0xff;
269   m->red_to_blue_   = (color_code >> 16) & 0xff;
270 }
271 
VP8LTransformColorInverse_C(const VP8LMultipliers * const m,const uint32_t * src,int num_pixels,uint32_t * dst)272 void VP8LTransformColorInverse_C(const VP8LMultipliers* const m,
273                                  const uint32_t* src, int num_pixels,
274                                  uint32_t* dst) {
275   int i;
276   for (i = 0; i < num_pixels; ++i) {
277     const uint32_t argb = src[i];
278     const int8_t green = (int8_t)(argb >> 8);
279     const uint32_t red = argb >> 16;
280     int new_red = red & 0xff;
281     int new_blue = argb & 0xff;
282     new_red += ColorTransformDelta(m->green_to_red_, green);
283     new_red &= 0xff;
284     new_blue += ColorTransformDelta(m->green_to_blue_, green);
285     new_blue += ColorTransformDelta(m->red_to_blue_, (int8_t)new_red);
286     new_blue &= 0xff;
287     dst[i] = (argb & 0xff00ff00u) | (new_red << 16) | (new_blue);
288   }
289 }
290 
291 // Color space inverse transform.
ColorSpaceInverseTransform_C(const VP8LTransform * const transform,int y_start,int y_end,const uint32_t * src,uint32_t * dst)292 static void ColorSpaceInverseTransform_C(const VP8LTransform* const transform,
293                                          int y_start, int y_end,
294                                          const uint32_t* src, uint32_t* dst) {
295   const int width = transform->xsize_;
296   const int tile_width = 1 << transform->bits_;
297   const int mask = tile_width - 1;
298   const int safe_width = width & ~mask;
299   const int remaining_width = width - safe_width;
300   const int tiles_per_row = VP8LSubSampleSize(width, transform->bits_);
301   int y = y_start;
302   const uint32_t* pred_row =
303       transform->data_ + (y >> transform->bits_) * tiles_per_row;
304 
305   while (y < y_end) {
306     const uint32_t* pred = pred_row;
307     VP8LMultipliers m = { 0, 0, 0 };
308     const uint32_t* const src_safe_end = src + safe_width;
309     const uint32_t* const src_end = src + width;
310     while (src < src_safe_end) {
311       ColorCodeToMultipliers(*pred++, &m);
312       VP8LTransformColorInverse(&m, src, tile_width, dst);
313       src += tile_width;
314       dst += tile_width;
315     }
316     if (src < src_end) {  // Left-overs using C-version.
317       ColorCodeToMultipliers(*pred++, &m);
318       VP8LTransformColorInverse(&m, src, remaining_width, dst);
319       src += remaining_width;
320       dst += remaining_width;
321     }
322     ++y;
323     if ((y & mask) == 0) pred_row += tiles_per_row;
324   }
325 }
326 
327 // Separate out pixels packed together using pixel-bundling.
328 // We define two methods for ARGB data (uint32_t) and alpha-only data (uint8_t).
329 #define COLOR_INDEX_INVERSE(FUNC_NAME, F_NAME, STATIC_DECL, TYPE, BIT_SUFFIX,  \
330                             GET_INDEX, GET_VALUE)                              \
331 static void F_NAME(const TYPE* src, const uint32_t* const color_map,           \
332                    TYPE* dst, int y_start, int y_end, int width) {             \
333   int y;                                                                       \
334   for (y = y_start; y < y_end; ++y) {                                          \
335     int x;                                                                     \
336     for (x = 0; x < width; ++x) {                                              \
337       *dst++ = GET_VALUE(color_map[GET_INDEX(*src++)]);                        \
338     }                                                                          \
339   }                                                                            \
340 }                                                                              \
341 STATIC_DECL void FUNC_NAME(const VP8LTransform* const transform,               \
342                            int y_start, int y_end, const TYPE* src,            \
343                            TYPE* dst) {                                        \
344   int y;                                                                       \
345   const int bits_per_pixel = 8 >> transform->bits_;                            \
346   const int width = transform->xsize_;                                         \
347   const uint32_t* const color_map = transform->data_;                          \
348   if (bits_per_pixel < 8) {                                                    \
349     const int pixels_per_byte = 1 << transform->bits_;                         \
350     const int count_mask = pixels_per_byte - 1;                                \
351     const uint32_t bit_mask = (1 << bits_per_pixel) - 1;                       \
352     for (y = y_start; y < y_end; ++y) {                                        \
353       uint32_t packed_pixels = 0;                                              \
354       int x;                                                                   \
355       for (x = 0; x < width; ++x) {                                            \
356         /* We need to load fresh 'packed_pixels' once every                */  \
357         /* 'pixels_per_byte' increments of x. Fortunately, pixels_per_byte */  \
358         /* is a power of 2, so can just use a mask for that, instead of    */  \
359         /* decrementing a counter.                                         */  \
360         if ((x & count_mask) == 0) packed_pixels = GET_INDEX(*src++);          \
361         *dst++ = GET_VALUE(color_map[packed_pixels & bit_mask]);               \
362         packed_pixels >>= bits_per_pixel;                                      \
363       }                                                                        \
364     }                                                                          \
365   } else {                                                                     \
366     VP8LMapColor##BIT_SUFFIX(src, color_map, dst, y_start, y_end, width);      \
367   }                                                                            \
368 }
369 
370 COLOR_INDEX_INVERSE(ColorIndexInverseTransform_C, MapARGB_C, static,
371                     uint32_t, 32b, VP8GetARGBIndex, VP8GetARGBValue)
372 COLOR_INDEX_INVERSE(VP8LColorIndexInverseTransformAlpha, MapAlpha_C, ,
373                     uint8_t, 8b, VP8GetAlphaIndex, VP8GetAlphaValue)
374 
375 #undef COLOR_INDEX_INVERSE
376 
VP8LInverseTransform(const VP8LTransform * const transform,int row_start,int row_end,const uint32_t * const in,uint32_t * const out)377 void VP8LInverseTransform(const VP8LTransform* const transform,
378                           int row_start, int row_end,
379                           const uint32_t* const in, uint32_t* const out) {
380   const int width = transform->xsize_;
381   assert(row_start < row_end);
382   assert(row_end <= transform->ysize_);
383   switch (transform->type_) {
384     case SUBTRACT_GREEN:
385       VP8LAddGreenToBlueAndRed(in, (row_end - row_start) * width, out);
386       break;
387     case PREDICTOR_TRANSFORM:
388       PredictorInverseTransform_C(transform, row_start, row_end, in, out);
389       if (row_end != transform->ysize_) {
390         // The last predicted row in this iteration will be the top-pred row
391         // for the first row in next iteration.
392         memcpy(out - width, out + (row_end - row_start - 1) * width,
393                width * sizeof(*out));
394       }
395       break;
396     case CROSS_COLOR_TRANSFORM:
397       ColorSpaceInverseTransform_C(transform, row_start, row_end, in, out);
398       break;
399     case COLOR_INDEXING_TRANSFORM:
400       if (in == out && transform->bits_ > 0) {
401         // Move packed pixels to the end of unpacked region, so that unpacking
402         // can occur seamlessly.
403         // Also, note that this is the only transform that applies on
404         // the effective width of VP8LSubSampleSize(xsize_, bits_). All other
405         // transforms work on effective width of xsize_.
406         const int out_stride = (row_end - row_start) * width;
407         const int in_stride = (row_end - row_start) *
408             VP8LSubSampleSize(transform->xsize_, transform->bits_);
409         uint32_t* const src = out + out_stride - in_stride;
410         memmove(src, out, in_stride * sizeof(*src));
411         ColorIndexInverseTransform_C(transform, row_start, row_end, src, out);
412       } else {
413         ColorIndexInverseTransform_C(transform, row_start, row_end, in, out);
414       }
415       break;
416   }
417 }
418 
419 //------------------------------------------------------------------------------
420 // Color space conversion.
421 
is_big_endian(void)422 static int is_big_endian(void) {
423   static const union {
424     uint16_t w;
425     uint8_t b[2];
426   } tmp = { 1 };
427   return (tmp.b[0] != 1);
428 }
429 
VP8LConvertBGRAToRGB_C(const uint32_t * src,int num_pixels,uint8_t * dst)430 void VP8LConvertBGRAToRGB_C(const uint32_t* src,
431                             int num_pixels, uint8_t* dst) {
432   const uint32_t* const src_end = src + num_pixels;
433   while (src < src_end) {
434     const uint32_t argb = *src++;
435     *dst++ = (argb >> 16) & 0xff;
436     *dst++ = (argb >>  8) & 0xff;
437     *dst++ = (argb >>  0) & 0xff;
438   }
439 }
440 
VP8LConvertBGRAToRGBA_C(const uint32_t * src,int num_pixels,uint8_t * dst)441 void VP8LConvertBGRAToRGBA_C(const uint32_t* src,
442                              int num_pixels, uint8_t* dst) {
443   const uint32_t* const src_end = src + num_pixels;
444   while (src < src_end) {
445     const uint32_t argb = *src++;
446     *dst++ = (argb >> 16) & 0xff;
447     *dst++ = (argb >>  8) & 0xff;
448     *dst++ = (argb >>  0) & 0xff;
449     *dst++ = (argb >> 24) & 0xff;
450   }
451 }
452 
VP8LConvertBGRAToRGBA4444_C(const uint32_t * src,int num_pixels,uint8_t * dst)453 void VP8LConvertBGRAToRGBA4444_C(const uint32_t* src,
454                                  int num_pixels, uint8_t* dst) {
455   const uint32_t* const src_end = src + num_pixels;
456   while (src < src_end) {
457     const uint32_t argb = *src++;
458     const uint8_t rg = ((argb >> 16) & 0xf0) | ((argb >> 12) & 0xf);
459     const uint8_t ba = ((argb >>  0) & 0xf0) | ((argb >> 28) & 0xf);
460 #if (WEBP_SWAP_16BIT_CSP == 1)
461     *dst++ = ba;
462     *dst++ = rg;
463 #else
464     *dst++ = rg;
465     *dst++ = ba;
466 #endif
467   }
468 }
469 
VP8LConvertBGRAToRGB565_C(const uint32_t * src,int num_pixels,uint8_t * dst)470 void VP8LConvertBGRAToRGB565_C(const uint32_t* src,
471                                int num_pixels, uint8_t* dst) {
472   const uint32_t* const src_end = src + num_pixels;
473   while (src < src_end) {
474     const uint32_t argb = *src++;
475     const uint8_t rg = ((argb >> 16) & 0xf8) | ((argb >> 13) & 0x7);
476     const uint8_t gb = ((argb >>  5) & 0xe0) | ((argb >>  3) & 0x1f);
477 #if (WEBP_SWAP_16BIT_CSP == 1)
478     *dst++ = gb;
479     *dst++ = rg;
480 #else
481     *dst++ = rg;
482     *dst++ = gb;
483 #endif
484   }
485 }
486 
VP8LConvertBGRAToBGR_C(const uint32_t * src,int num_pixels,uint8_t * dst)487 void VP8LConvertBGRAToBGR_C(const uint32_t* src,
488                             int num_pixels, uint8_t* dst) {
489   const uint32_t* const src_end = src + num_pixels;
490   while (src < src_end) {
491     const uint32_t argb = *src++;
492     *dst++ = (argb >>  0) & 0xff;
493     *dst++ = (argb >>  8) & 0xff;
494     *dst++ = (argb >> 16) & 0xff;
495   }
496 }
497 
CopyOrSwap(const uint32_t * src,int num_pixels,uint8_t * dst,int swap_on_big_endian)498 static void CopyOrSwap(const uint32_t* src, int num_pixels, uint8_t* dst,
499                        int swap_on_big_endian) {
500   if (is_big_endian() == swap_on_big_endian) {
501     const uint32_t* const src_end = src + num_pixels;
502     while (src < src_end) {
503       const uint32_t argb = *src++;
504       WebPUint32ToMem(dst, BSwap32(argb));
505       dst += sizeof(argb);
506     }
507   } else {
508     memcpy(dst, src, num_pixels * sizeof(*src));
509   }
510 }
511 
VP8LConvertFromBGRA(const uint32_t * const in_data,int num_pixels,WEBP_CSP_MODE out_colorspace,uint8_t * const rgba)512 void VP8LConvertFromBGRA(const uint32_t* const in_data, int num_pixels,
513                          WEBP_CSP_MODE out_colorspace, uint8_t* const rgba) {
514   switch (out_colorspace) {
515     case MODE_RGB:
516       VP8LConvertBGRAToRGB(in_data, num_pixels, rgba);
517       break;
518     case MODE_RGBA:
519       VP8LConvertBGRAToRGBA(in_data, num_pixels, rgba);
520       break;
521     case MODE_rgbA:
522       VP8LConvertBGRAToRGBA(in_data, num_pixels, rgba);
523       WebPApplyAlphaMultiply(rgba, 0, num_pixels, 1, 0);
524       break;
525     case MODE_BGR:
526       VP8LConvertBGRAToBGR(in_data, num_pixels, rgba);
527       break;
528     case MODE_BGRA:
529       CopyOrSwap(in_data, num_pixels, rgba, 1);
530       break;
531     case MODE_bgrA:
532       CopyOrSwap(in_data, num_pixels, rgba, 1);
533       WebPApplyAlphaMultiply(rgba, 0, num_pixels, 1, 0);
534       break;
535     case MODE_ARGB:
536       CopyOrSwap(in_data, num_pixels, rgba, 0);
537       break;
538     case MODE_Argb:
539       CopyOrSwap(in_data, num_pixels, rgba, 0);
540       WebPApplyAlphaMultiply(rgba, 1, num_pixels, 1, 0);
541       break;
542     case MODE_RGBA_4444:
543       VP8LConvertBGRAToRGBA4444(in_data, num_pixels, rgba);
544       break;
545     case MODE_rgbA_4444:
546       VP8LConvertBGRAToRGBA4444(in_data, num_pixels, rgba);
547       WebPApplyAlphaMultiply4444(rgba, num_pixels, 1, 0);
548       break;
549     case MODE_RGB_565:
550       VP8LConvertBGRAToRGB565(in_data, num_pixels, rgba);
551       break;
552     default:
553       assert(0);          // Code flow should not reach here.
554   }
555 }
556 
557 //------------------------------------------------------------------------------
558 
559 VP8LProcessDecBlueAndRedFunc VP8LAddGreenToBlueAndRed;
560 VP8LPredictorAddSubFunc VP8LPredictorsAdd[16];
561 VP8LPredictorFunc VP8LPredictors[16];
562 
563 // exposed plain-C implementations
564 VP8LPredictorAddSubFunc VP8LPredictorsAdd_C[16];
565 
566 VP8LTransformColorInverseFunc VP8LTransformColorInverse;
567 
568 VP8LConvertFunc VP8LConvertBGRAToRGB;
569 VP8LConvertFunc VP8LConvertBGRAToRGBA;
570 VP8LConvertFunc VP8LConvertBGRAToRGBA4444;
571 VP8LConvertFunc VP8LConvertBGRAToRGB565;
572 VP8LConvertFunc VP8LConvertBGRAToBGR;
573 
574 VP8LMapARGBFunc VP8LMapColor32b;
575 VP8LMapAlphaFunc VP8LMapColor8b;
576 
577 extern void VP8LDspInitSSE2(void);
578 extern void VP8LDspInitNEON(void);
579 extern void VP8LDspInitMIPSdspR2(void);
580 extern void VP8LDspInitMSA(void);
581 
582 #define COPY_PREDICTOR_ARRAY(IN, OUT) do {                \
583   (OUT)[0] = IN##0_C;                                     \
584   (OUT)[1] = IN##1_C;                                     \
585   (OUT)[2] = IN##2_C;                                     \
586   (OUT)[3] = IN##3_C;                                     \
587   (OUT)[4] = IN##4_C;                                     \
588   (OUT)[5] = IN##5_C;                                     \
589   (OUT)[6] = IN##6_C;                                     \
590   (OUT)[7] = IN##7_C;                                     \
591   (OUT)[8] = IN##8_C;                                     \
592   (OUT)[9] = IN##9_C;                                     \
593   (OUT)[10] = IN##10_C;                                   \
594   (OUT)[11] = IN##11_C;                                   \
595   (OUT)[12] = IN##12_C;                                   \
596   (OUT)[13] = IN##13_C;                                   \
597   (OUT)[14] = IN##0_C; /* <- padding security sentinels*/ \
598   (OUT)[15] = IN##0_C;                                    \
599 } while (0);
600 
WEBP_DSP_INIT_FUNC(VP8LDspInit)601 WEBP_DSP_INIT_FUNC(VP8LDspInit) {
602   COPY_PREDICTOR_ARRAY(VP8LPredictor, VP8LPredictors)
603   COPY_PREDICTOR_ARRAY(PredictorAdd, VP8LPredictorsAdd)
604   COPY_PREDICTOR_ARRAY(PredictorAdd, VP8LPredictorsAdd_C)
605 
606 #if !WEBP_NEON_OMIT_C_CODE
607   VP8LAddGreenToBlueAndRed = VP8LAddGreenToBlueAndRed_C;
608 
609   VP8LTransformColorInverse = VP8LTransformColorInverse_C;
610 
611   VP8LConvertBGRAToRGBA = VP8LConvertBGRAToRGBA_C;
612   VP8LConvertBGRAToRGB = VP8LConvertBGRAToRGB_C;
613   VP8LConvertBGRAToBGR = VP8LConvertBGRAToBGR_C;
614 #endif
615 
616   VP8LConvertBGRAToRGBA4444 = VP8LConvertBGRAToRGBA4444_C;
617   VP8LConvertBGRAToRGB565 = VP8LConvertBGRAToRGB565_C;
618 
619   VP8LMapColor32b = MapARGB_C;
620   VP8LMapColor8b = MapAlpha_C;
621 
622   // If defined, use CPUInfo() to overwrite some pointers with faster versions.
623   if (VP8GetCPUInfo != NULL) {
624 #if defined(WEBP_USE_SSE2)
625     if (VP8GetCPUInfo(kSSE2)) {
626       VP8LDspInitSSE2();
627     }
628 #endif
629 #if defined(WEBP_USE_MIPS_DSP_R2)
630     if (VP8GetCPUInfo(kMIPSdspR2)) {
631       VP8LDspInitMIPSdspR2();
632     }
633 #endif
634 #if defined(WEBP_USE_MSA)
635     if (VP8GetCPUInfo(kMSA)) {
636       VP8LDspInitMSA();
637     }
638 #endif
639   }
640 
641 #if defined(WEBP_USE_NEON)
642   if (WEBP_NEON_OMIT_C_CODE ||
643       (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kNEON))) {
644     VP8LDspInitNEON();
645   }
646 #endif
647 
648   assert(VP8LAddGreenToBlueAndRed != NULL);
649   assert(VP8LTransformColorInverse != NULL);
650   assert(VP8LConvertBGRAToRGBA != NULL);
651   assert(VP8LConvertBGRAToRGB != NULL);
652   assert(VP8LConvertBGRAToBGR != NULL);
653   assert(VP8LConvertBGRAToRGBA4444 != NULL);
654   assert(VP8LConvertBGRAToRGB565 != NULL);
655   assert(VP8LMapColor32b != NULL);
656   assert(VP8LMapColor8b != NULL);
657 }
658 #undef COPY_PREDICTOR_ARRAY
659 
660 //------------------------------------------------------------------------------
661