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virtualx-engine/thirdparty/libwebp/dsp/lossless.c
Rémi Verschelde ee3cf211c6 webp: Make it a module and unbundle libwebp thirdparty files 
Note that there are two Godot-specific changes made to libwebp
for the javascript/HTML5 platform. They are documented in the
README.md.
2016-10-15 11:50:39 +02:00

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// 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) {
*a = VP8LAddPixels(*a, b);
}
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)
WebPUint32ToMem(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;
}
//------------------------------------------------------------------------------
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