// 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) // Urvang Joshi (urvang@google.com) #include "./dsp.h" #include <math.h> #include <stdlib.h> #include "../dec/vp8li.h" #include "../utils/endian_inl.h" #include "./lossless.h" #define MAX_DIFF_COST (1e30f) //------------------------------------------------------------------------------ // Image transforms. // 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 Average2(uint32_t a0, uint32_t a1) { return (((a0 ^ a1) & 0xfefefefeu) >> 1) + (a0 & a1); } static WEBP_INLINE uint32_t Average3(uint32_t a0, uint32_t a1, uint32_t a2) { return Average2(Average2(a0, a2), a1); } static WEBP_INLINE uint32_t Average4(uint32_t a0, uint32_t a1, uint32_t a2, uint32_t a3) { return Average2(Average2(a0, a1), Average2(a2, a3)); } 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; } static WEBP_INLINE int AddSubtractComponentFull(int a, int b, int c) { return Clip255(a + b - c); } static WEBP_INLINE uint32_t ClampedAddSubtractFull(uint32_t c0, uint32_t c1, uint32_t c2) { const int a = AddSubtractComponentFull(c0 >> 24, c1 >> 24, c2 >> 24); const int r = AddSubtractComponentFull((c0 >> 16) & 0xff, (c1 >> 16) & 0xff, (c2 >> 16) & 0xff); const int g = AddSubtractComponentFull((c0 >> 8) & 0xff, (c1 >> 8) & 0xff, (c2 >> 8) & 0xff); const int b = AddSubtractComponentFull(c0 & 0xff, c1 & 0xff, c2 & 0xff); return ((uint32_t)a << 24) | (r << 16) | (g << 8) | b; } static WEBP_INLINE int AddSubtractComponentHalf(int a, int b) { return Clip255(a + (a - b) / 2); } static WEBP_INLINE uint32_t ClampedAddSubtractHalf(uint32_t c0, uint32_t c1, uint32_t c2) { const uint32_t ave = Average2(c0, c1); const int a = AddSubtractComponentHalf(ave >> 24, c2 >> 24); const int r = AddSubtractComponentHalf((ave >> 16) & 0xff, (c2 >> 16) & 0xff); const int g = AddSubtractComponentHalf((ave >> 8) & 0xff, (c2 >> 8) & 0xff); const int b = AddSubtractComponentHalf((ave >> 0) & 0xff, (c2 >> 0) & 0xff); return ((uint32_t)a << 24) | (r << 16) | (g << 8) | b; } // gcc-4.9 on ARM generates incorrect code in Select() when Sub3() is inlined. #if defined(__arm__) && LOCAL_GCC_VERSION == 0x409 # define LOCAL_INLINE __attribute__ ((noinline)) #else # define LOCAL_INLINE WEBP_INLINE #endif static LOCAL_INLINE int Sub3(int a, int b, int c) { const int pb = b - c; const int pa = a - c; return abs(pb) - abs(pa); } #undef LOCAL_INLINE static WEBP_INLINE uint32_t Select(uint32_t a, uint32_t b, uint32_t c) { const int pa_minus_pb = Sub3((a >> 24) , (b >> 24) , (c >> 24) ) + Sub3((a >> 16) & 0xff, (b >> 16) & 0xff, (c >> 16) & 0xff) + Sub3((a >> 8) & 0xff, (b >> 8) & 0xff, (c >> 8) & 0xff) + Sub3((a ) & 0xff, (b ) & 0xff, (c ) & 0xff); return (pa_minus_pb <= 0) ? a : b; } //------------------------------------------------------------------------------ // Predictors static uint32_t Predictor0(uint32_t left, const uint32_t* const top) { (void)top; (void)left; return ARGB_BLACK; } static uint32_t Predictor1(uint32_t left, const uint32_t* const top) { (void)top; return left; } static uint32_t Predictor2(uint32_t left, const uint32_t* const top) { (void)left; return top[0]; } static uint32_t Predictor3(uint32_t left, const uint32_t* const top) { (void)left; return top[1]; } static uint32_t Predictor4(uint32_t left, const uint32_t* const top) { (void)left; return top[-1]; } static uint32_t Predictor5(uint32_t left, const uint32_t* const top) { const uint32_t pred = Average3(left, top[0], top[1]); return pred; } static uint32_t Predictor6(uint32_t left, const uint32_t* const top) { const uint32_t pred = Average2(left, top[-1]); return pred; } static uint32_t Predictor7(uint32_t left, const uint32_t* const top) { const uint32_t pred = Average2(left, top[0]); return pred; } static uint32_t Predictor8(uint32_t left, const uint32_t* const top) { const uint32_t pred = Average2(top[-1], top[0]); (void)left; return pred; } static uint32_t Predictor9(uint32_t left, const uint32_t* const top) { const uint32_t pred = Average2(top[0], top[1]); (void)left; return pred; } static uint32_t Predictor10(uint32_t left, const uint32_t* const top) { const uint32_t pred = Average4(left, top[-1], top[0], top[1]); return pred; } static uint32_t Predictor11(uint32_t left, const uint32_t* const top) { const uint32_t pred = Select(top[0], left, top[-1]); return pred; } static uint32_t Predictor12(uint32_t left, const uint32_t* const top) { const uint32_t pred = ClampedAddSubtractFull(left, top[0], top[-1]); return pred; } static uint32_t Predictor13(uint32_t left, const uint32_t* const top) { const uint32_t pred = ClampedAddSubtractHalf(left, top[0], top[-1]); return pred; } //------------------------------------------------------------------------------ // Inverse prediction. static void PredictorInverseTransform(const VP8LTransform* const transform, int y_start, int y_end, uint32_t* data) { const int width = transform->xsize_; if (y_start == 0) { // First Row follows the L (mode=1) mode. int x; const uint32_t pred0 = Predictor0(data[-1], NULL); AddPixelsEq(data, pred0); for (x = 1; x < width; ++x) { const uint32_t pred1 = Predictor1(data[x - 1], NULL); AddPixelsEq(data + x, pred1); } data += width; ++y_start; } { int y = y_start; const int tile_width = 1 << transform->bits_; const int mask = tile_width - 1; const int safe_width = width & ~mask; const int tiles_per_row = VP8LSubSampleSize(width, transform->bits_); const uint32_t* pred_mode_base = transform->data_ + (y >> transform->bits_) * tiles_per_row; while (y < y_end) { const uint32_t pred2 = Predictor2(data[-1], data - width); const uint32_t* pred_mode_src = pred_mode_base; VP8LPredictorFunc pred_func; int x = 1; int t = 1; // First pixel follows the T (mode=2) mode. AddPixelsEq(data, pred2); // .. the rest: while (x < safe_width) { pred_func = VP8LPredictors[((*pred_mode_src++) >> 8) & 0xf]; for (; t < tile_width; ++t, ++x) { const uint32_t pred = pred_func(data[x - 1], data + x - width); AddPixelsEq(data + x, pred); } t = 0; } if (x < width) { pred_func = VP8LPredictors[((*pred_mode_src++) >> 8) & 0xf]; for (; x < width; ++x) { const uint32_t pred = pred_func(data[x - 1], data + x - width); AddPixelsEq(data + x, pred); } } data += width; ++y; if ((y & mask) == 0) { // Use the same mask, since tiles are squares. pred_mode_base += tiles_per_row; } } } } // Add green to blue and red channels (i.e. perform the inverse transform of // 'subtract green'). void VP8LAddGreenToBlueAndRed_C(uint32_t* data, int num_pixels) { int i; for (i = 0; i < num_pixels; ++i) { const uint32_t argb = data[i]; const uint32_t green = ((argb >> 8) & 0xff); uint32_t red_blue = (argb & 0x00ff00ffu); red_blue += (green << 16) | green; red_blue &= 0x00ff00ffu; data[i] = (argb & 0xff00ff00u) | red_blue; } } static WEBP_INLINE uint32_t ColorTransformDelta(int8_t color_pred, int8_t color) { return (uint32_t)((int)(color_pred) * color) >> 5; } static WEBP_INLINE void ColorCodeToMultipliers(uint32_t color_code, VP8LMultipliers* const m) { m->green_to_red_ = (color_code >> 0) & 0xff; m->green_to_blue_ = (color_code >> 8) & 0xff; m->red_to_blue_ = (color_code >> 16) & 0xff; } void VP8LTransformColorInverse_C(const VP8LMultipliers* const m, uint32_t* data, int num_pixels) { int i; for (i = 0; i < num_pixels; ++i) { const uint32_t argb = data[i]; const uint32_t green = argb >> 8; const uint32_t red = argb >> 16; uint32_t new_red = red; uint32_t new_blue = argb; new_red += ColorTransformDelta(m->green_to_red_, green); new_red &= 0xff; new_blue += ColorTransformDelta(m->green_to_blue_, green); new_blue += ColorTransformDelta(m->red_to_blue_, new_red); new_blue &= 0xff; data[i] = (argb & 0xff00ff00u) | (new_red << 16) | (new_blue); } } // Color space inverse transform. static void ColorSpaceInverseTransform(const VP8LTransform* const transform, int y_start, int y_end, uint32_t* data) { const int width = transform->xsize_; const int tile_width = 1 << transform->bits_; const int mask = tile_width - 1; const int safe_width = width & ~mask; const int remaining_width = width - safe_width; const int tiles_per_row = VP8LSubSampleSize(width, transform->bits_); int y = y_start; const uint32_t* pred_row = transform->data_ + (y >> transform->bits_) * tiles_per_row; while (y < y_end) { const uint32_t* pred = pred_row; VP8LMultipliers m = { 0, 0, 0 }; const uint32_t* const data_safe_end = data + safe_width; const uint32_t* const data_end = data + width; while (data < data_safe_end) { ColorCodeToMultipliers(*pred++, &m); VP8LTransformColorInverse(&m, data, tile_width); data += tile_width; } if (data < data_end) { // Left-overs using C-version. ColorCodeToMultipliers(*pred++, &m); VP8LTransformColorInverse(&m, data, remaining_width); data += remaining_width; } ++y; if ((y & mask) == 0) pred_row += tiles_per_row; } } // Separate out pixels packed together using pixel-bundling. // We define two methods for ARGB data (uint32_t) and alpha-only data (uint8_t). #define COLOR_INDEX_INVERSE(FUNC_NAME, F_NAME, STATIC_DECL, TYPE, BIT_SUFFIX, \ GET_INDEX, GET_VALUE) \ static void F_NAME(const TYPE* src, const uint32_t* const color_map, \ TYPE* dst, int y_start, int y_end, int width) { \ int y; \ for (y = y_start; y < y_end; ++y) { \ int x; \ for (x = 0; x < width; ++x) { \ *dst++ = GET_VALUE(color_map[GET_INDEX(*src++)]); \ } \ } \ } \ STATIC_DECL void FUNC_NAME(const VP8LTransform* const transform, \ int y_start, int y_end, const TYPE* src, \ TYPE* dst) { \ int y; \ const int bits_per_pixel = 8 >> transform->bits_; \ const int width = transform->xsize_; \ const uint32_t* const color_map = transform->data_; \ if (bits_per_pixel < 8) { \ const int pixels_per_byte = 1 << transform->bits_; \ const int count_mask = pixels_per_byte - 1; \ const uint32_t bit_mask = (1 << bits_per_pixel) - 1; \ for (y = y_start; y < y_end; ++y) { \ uint32_t packed_pixels = 0; \ int x; \ for (x = 0; x < width; ++x) { \ /* We need to load fresh 'packed_pixels' once every */ \ /* 'pixels_per_byte' increments of x. Fortunately, pixels_per_byte */ \ /* is a power of 2, so can just use a mask for that, instead of */ \ /* decrementing a counter. */ \ if ((x & count_mask) == 0) packed_pixels = GET_INDEX(*src++); \ *dst++ = GET_VALUE(color_map[packed_pixels & bit_mask]); \ packed_pixels >>= bits_per_pixel; \ } \ } \ } else { \ VP8LMapColor##BIT_SUFFIX(src, color_map, dst, y_start, y_end, width); \ } \ } COLOR_INDEX_INVERSE(ColorIndexInverseTransform, MapARGB, static, uint32_t, 32b, VP8GetARGBIndex, VP8GetARGBValue) COLOR_INDEX_INVERSE(VP8LColorIndexInverseTransformAlpha, MapAlpha, , uint8_t, 8b, VP8GetAlphaIndex, VP8GetAlphaValue) #undef COLOR_INDEX_INVERSE void VP8LInverseTransform(const VP8LTransform* const transform, int row_start, int row_end, const uint32_t* const in, uint32_t* const out) { const int width = transform->xsize_; assert(row_start < row_end); assert(row_end <= transform->ysize_); switch (transform->type_) { case SUBTRACT_GREEN: VP8LAddGreenToBlueAndRed(out, (row_end - row_start) * width); break; case PREDICTOR_TRANSFORM: PredictorInverseTransform(transform, row_start, row_end, out); if (row_end != transform->ysize_) { // The last predicted row in this iteration will be the top-pred row // for the first row in next iteration. memcpy(out - width, out + (row_end - row_start - 1) * width, width * sizeof(*out)); } break; case CROSS_COLOR_TRANSFORM: ColorSpaceInverseTransform(transform, row_start, row_end, out); break; case COLOR_INDEXING_TRANSFORM: if (in == out && transform->bits_ > 0) { // Move packed pixels to the end of unpacked region, so that unpacking // can occur seamlessly. // Also, note that this is the only transform that applies on // the effective width of VP8LSubSampleSize(xsize_, bits_). All other // transforms work on effective width of xsize_. const int out_stride = (row_end - row_start) * width; const int in_stride = (row_end - row_start) * VP8LSubSampleSize(transform->xsize_, transform->bits_); uint32_t* const src = out + out_stride - in_stride; memmove(src, out, in_stride * sizeof(*src)); ColorIndexInverseTransform(transform, row_start, row_end, src, out); } else { ColorIndexInverseTransform(transform, row_start, row_end, in, out); } break; } } //------------------------------------------------------------------------------ // Color space conversion. static int is_big_endian(void) { static const union { uint16_t w; uint8_t b[2]; } tmp = { 1 }; return (tmp.b[0] != 1); } void VP8LConvertBGRAToRGB_C(const uint32_t* src, int num_pixels, uint8_t* dst) { const uint32_t* const src_end = src + num_pixels; while (src < src_end) { const uint32_t argb = *src++; *dst++ = (argb >> 16) & 0xff; *dst++ = (argb >> 8) & 0xff; *dst++ = (argb >> 0) & 0xff; } } void VP8LConvertBGRAToRGBA_C(const uint32_t* src, int num_pixels, uint8_t* dst) { const uint32_t* const src_end = src + num_pixels; while (src < src_end) { const uint32_t argb = *src++; *dst++ = (argb >> 16) & 0xff; *dst++ = (argb >> 8) & 0xff; *dst++ = (argb >> 0) & 0xff; *dst++ = (argb >> 24) & 0xff; } } void VP8LConvertBGRAToRGBA4444_C(const uint32_t* src, int num_pixels, uint8_t* dst) { const uint32_t* const src_end = src + num_pixels; while (src < src_end) { const uint32_t argb = *src++; const uint8_t rg = ((argb >> 16) & 0xf0) | ((argb >> 12) & 0xf); const uint8_t ba = ((argb >> 0) & 0xf0) | ((argb >> 28) & 0xf); #ifdef WEBP_SWAP_16BIT_CSP *dst++ = ba; *dst++ = rg; #else *dst++ = rg; *dst++ = ba; #endif } } void VP8LConvertBGRAToRGB565_C(const uint32_t* src, int num_pixels, uint8_t* dst) { const uint32_t* const src_end = src + num_pixels; while (src < src_end) { const uint32_t argb = *src++; const uint8_t rg = ((argb >> 16) & 0xf8) | ((argb >> 13) & 0x7); const uint8_t gb = ((argb >> 5) & 0xe0) | ((argb >> 3) & 0x1f); #ifdef WEBP_SWAP_16BIT_CSP *dst++ = gb; *dst++ = rg; #else *dst++ = rg; *dst++ = gb; #endif } } void VP8LConvertBGRAToBGR_C(const uint32_t* src, int num_pixels, uint8_t* dst) { const uint32_t* const src_end = src + num_pixels; while (src < src_end) { const uint32_t argb = *src++; *dst++ = (argb >> 0) & 0xff; *dst++ = (argb >> 8) & 0xff; *dst++ = (argb >> 16) & 0xff; } } static void CopyOrSwap(const uint32_t* src, int num_pixels, uint8_t* dst, int swap_on_big_endian) { if (is_big_endian() == swap_on_big_endian) { const uint32_t* const src_end = src + num_pixels; while (src < src_end) { const uint32_t argb = *src++; #if !defined(WORDS_BIGENDIAN) #if !defined(WEBP_REFERENCE_IMPLEMENTATION) *(uint32_t*)dst = BSwap32(argb); #else // WEBP_REFERENCE_IMPLEMENTATION dst[0] = (argb >> 24) & 0xff; dst[1] = (argb >> 16) & 0xff; dst[2] = (argb >> 8) & 0xff; dst[3] = (argb >> 0) & 0xff; #endif #else // WORDS_BIGENDIAN dst[0] = (argb >> 0) & 0xff; dst[1] = (argb >> 8) & 0xff; dst[2] = (argb >> 16) & 0xff; dst[3] = (argb >> 24) & 0xff; #endif dst += sizeof(argb); } } else { memcpy(dst, src, num_pixels * sizeof(*src)); } } void VP8LConvertFromBGRA(const uint32_t* const in_data, int num_pixels, WEBP_CSP_MODE out_colorspace, uint8_t* const rgba) { switch (out_colorspace) { case MODE_RGB: VP8LConvertBGRAToRGB(in_data, num_pixels, rgba); break; case MODE_RGBA: VP8LConvertBGRAToRGBA(in_data, num_pixels, rgba); break; case MODE_rgbA: VP8LConvertBGRAToRGBA(in_data, num_pixels, rgba); WebPApplyAlphaMultiply(rgba, 0, num_pixels, 1, 0); break; case MODE_BGR: VP8LConvertBGRAToBGR(in_data, num_pixels, rgba); break; case MODE_BGRA: CopyOrSwap(in_data, num_pixels, rgba, 1); break; case MODE_bgrA: CopyOrSwap(in_data, num_pixels, rgba, 1); WebPApplyAlphaMultiply(rgba, 0, num_pixels, 1, 0); break; case MODE_ARGB: CopyOrSwap(in_data, num_pixels, rgba, 0); break; case MODE_Argb: CopyOrSwap(in_data, num_pixels, rgba, 0); WebPApplyAlphaMultiply(rgba, 1, num_pixels, 1, 0); break; case MODE_RGBA_4444: VP8LConvertBGRAToRGBA4444(in_data, num_pixels, rgba); break; case MODE_rgbA_4444: VP8LConvertBGRAToRGBA4444(in_data, num_pixels, rgba); WebPApplyAlphaMultiply4444(rgba, num_pixels, 1, 0); break; case MODE_RGB_565: VP8LConvertBGRAToRGB565(in_data, num_pixels, rgba); break; default: assert(0); // Code flow should not reach here. } } //------------------------------------------------------------------------------ VP8LProcessBlueAndRedFunc VP8LAddGreenToBlueAndRed; VP8LPredictorFunc VP8LPredictors[16]; VP8LTransformColorFunc VP8LTransformColorInverse; VP8LConvertFunc VP8LConvertBGRAToRGB; VP8LConvertFunc VP8LConvertBGRAToRGBA; VP8LConvertFunc VP8LConvertBGRAToRGBA4444; VP8LConvertFunc VP8LConvertBGRAToRGB565; VP8LConvertFunc VP8LConvertBGRAToBGR; VP8LMapARGBFunc VP8LMapColor32b; VP8LMapAlphaFunc VP8LMapColor8b; extern void VP8LDspInitSSE2(void); extern void VP8LDspInitNEON(void); extern void VP8LDspInitMIPSdspR2(void); static volatile VP8CPUInfo lossless_last_cpuinfo_used = (VP8CPUInfo)&lossless_last_cpuinfo_used; WEBP_TSAN_IGNORE_FUNCTION void VP8LDspInit(void) { if (lossless_last_cpuinfo_used == VP8GetCPUInfo) return; VP8LPredictors[0] = Predictor0; VP8LPredictors[1] = Predictor1; VP8LPredictors[2] = Predictor2; VP8LPredictors[3] = Predictor3; VP8LPredictors[4] = Predictor4; VP8LPredictors[5] = Predictor5; VP8LPredictors[6] = Predictor6; VP8LPredictors[7] = Predictor7; VP8LPredictors[8] = Predictor8; VP8LPredictors[9] = Predictor9; VP8LPredictors[10] = Predictor10; VP8LPredictors[11] = Predictor11; VP8LPredictors[12] = Predictor12; VP8LPredictors[13] = Predictor13; VP8LPredictors[14] = Predictor0; // <- padding security sentinels VP8LPredictors[15] = Predictor0; VP8LAddGreenToBlueAndRed = VP8LAddGreenToBlueAndRed_C; VP8LTransformColorInverse = VP8LTransformColorInverse_C; VP8LConvertBGRAToRGB = VP8LConvertBGRAToRGB_C; VP8LConvertBGRAToRGBA = VP8LConvertBGRAToRGBA_C; VP8LConvertBGRAToRGBA4444 = VP8LConvertBGRAToRGBA4444_C; VP8LConvertBGRAToRGB565 = VP8LConvertBGRAToRGB565_C; VP8LConvertBGRAToBGR = VP8LConvertBGRAToBGR_C; VP8LMapColor32b = MapARGB; VP8LMapColor8b = MapAlpha; // If defined, use CPUInfo() to overwrite some pointers with faster versions. if (VP8GetCPUInfo != NULL) { #if defined(WEBP_USE_SSE2) if (VP8GetCPUInfo(kSSE2)) { VP8LDspInitSSE2(); } #endif #if defined(WEBP_USE_NEON) if (VP8GetCPUInfo(kNEON)) { VP8LDspInitNEON(); } #endif #if defined(WEBP_USE_MIPS_DSP_R2) if (VP8GetCPUInfo(kMIPSdspR2)) { VP8LDspInitMIPSdspR2(); } #endif } lossless_last_cpuinfo_used = VP8GetCPUInfo; } //------------------------------------------------------------------------------