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++ // Copyright 2022 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.
++ // -----------------------------------------------------------------------------
++ //
++ // Sharp RGB to YUV conversion.
++ //
++ // Author: Skal (pascal.massimino@gmail.com)
++
++ #include "sharpyuv/sharpyuv.h"
++
++ #include <assert.h>
++ #include <limits.h>
++ #include <stddef.h>
++ #include <stdlib.h>
++ #include <string.h>
++
++ #include "sharpyuv/sharpyuv_cpu.h"
++ #include "sharpyuv/sharpyuv_dsp.h"
++ #include "sharpyuv/sharpyuv_gamma.h"
++ #include "src/webp/types.h"
++
++ //------------------------------------------------------------------------------
++
++ int SharpYuvGetVersion(void) {
++ return SHARPYUV_VERSION;
++ }
++
++ //------------------------------------------------------------------------------
++ // Sharp RGB->YUV conversion
++
++ static const int kNumIterations = 4;
++
++ #define YUV_FIX 16 // fixed-point precision for RGB->YUV
++ static const int kYuvHalf = 1 << (YUV_FIX - 1);
++
++ // Max bit depth so that intermediate calculations fit in 16 bits.
++ static const int kMaxBitDepth = 14;
++
++ // Returns the precision shift to use based on the input rgb_bit_depth.
++ static int GetPrecisionShift(int rgb_bit_depth) {
++ // Try to add 2 bits of precision if it fits in kMaxBitDepth. Otherwise remove
++ // bits if needed.
++ return ((rgb_bit_depth + 2) <= kMaxBitDepth) ? 2
++ : (kMaxBitDepth - rgb_bit_depth);
++ }
++
++ typedef int16_t fixed_t; // signed type with extra precision for UV
++ typedef uint16_t fixed_y_t; // unsigned type with extra precision for W
++
++ //------------------------------------------------------------------------------
++
++ static uint8_t clip_8b(fixed_t v) {
++ return (!(v & ~0xff)) ? (uint8_t)v : (v < 0) ? 0u : 255u;
++ }
++
++ static uint16_t clip(fixed_t v, int max) {
++ return (v < 0) ? 0 : (v > max) ? max : (uint16_t)v;
++ }
++
++ static fixed_y_t clip_bit_depth(int y, int bit_depth) {
++ const int max = (1 << bit_depth) - 1;
++ return (!(y & ~max)) ? (fixed_y_t)y : (y < 0) ? 0 : max;
++ }
++
++ //------------------------------------------------------------------------------
++
++ static int RGBToGray(int64_t r, int64_t g, int64_t b) {
++ const int64_t luma = 13933 * r + 46871 * g + 4732 * b + kYuvHalf;
++ return (int)(luma >> YUV_FIX);
++ }
++
++ static uint32_t ScaleDown(uint16_t a, uint16_t b, uint16_t c, uint16_t d,
++ int rgb_bit_depth,
++ SharpYuvTransferFunctionType transfer_type) {
++ const int bit_depth = rgb_bit_depth + GetPrecisionShift(rgb_bit_depth);
++ const uint32_t A = SharpYuvGammaToLinear(a, bit_depth, transfer_type);
++ const uint32_t B = SharpYuvGammaToLinear(b, bit_depth, transfer_type);
++ const uint32_t C = SharpYuvGammaToLinear(c, bit_depth, transfer_type);
++ const uint32_t D = SharpYuvGammaToLinear(d, bit_depth, transfer_type);
++ return SharpYuvLinearToGamma((A + B + C + D + 2) >> 2, bit_depth,
++ transfer_type);
++ }
++
++ static WEBP_INLINE void UpdateW(const fixed_y_t* src, fixed_y_t* dst, int w,
++ int rgb_bit_depth,
++ SharpYuvTransferFunctionType transfer_type) {
++ const int bit_depth = rgb_bit_depth + GetPrecisionShift(rgb_bit_depth);
++ int i = 0;
++ do {
++ const uint32_t R =
++ SharpYuvGammaToLinear(src[0 * w + i], bit_depth, transfer_type);
++ const uint32_t G =
++ SharpYuvGammaToLinear(src[1 * w + i], bit_depth, transfer_type);
++ const uint32_t B =
++ SharpYuvGammaToLinear(src[2 * w + i], bit_depth, transfer_type);
++ const uint32_t Y = RGBToGray(R, G, B);
++ dst[i] = (fixed_y_t)SharpYuvLinearToGamma(Y, bit_depth, transfer_type);
++ } while (++i < w);
++ }
++
++ static void UpdateChroma(const fixed_y_t* src1, const fixed_y_t* src2,
++ fixed_t* dst, int uv_w, int rgb_bit_depth,
++ SharpYuvTransferFunctionType transfer_type) {
++ int i = 0;
++ do {
++ const int r =
++ ScaleDown(src1[0 * uv_w + 0], src1[0 * uv_w + 1], src2[0 * uv_w + 0],
++ src2[0 * uv_w + 1], rgb_bit_depth, transfer_type);
++ const int g =
++ ScaleDown(src1[2 * uv_w + 0], src1[2 * uv_w + 1], src2[2 * uv_w + 0],
++ src2[2 * uv_w + 1], rgb_bit_depth, transfer_type);
++ const int b =
++ ScaleDown(src1[4 * uv_w + 0], src1[4 * uv_w + 1], src2[4 * uv_w + 0],
++ src2[4 * uv_w + 1], rgb_bit_depth, transfer_type);
++ const int W = RGBToGray(r, g, b);
++ dst[0 * uv_w] = (fixed_t)(r - W);
++ dst[1 * uv_w] = (fixed_t)(g - W);
++ dst[2 * uv_w] = (fixed_t)(b - W);
++ dst += 1;
++ src1 += 2;
++ src2 += 2;
++ } while (++i < uv_w);
++ }
++
++ static void StoreGray(const fixed_y_t* rgb, fixed_y_t* y, int w) {
++ int i = 0;
++ assert(w > 0);
++ do {
++ y[i] = RGBToGray(rgb[0 * w + i], rgb[1 * w + i], rgb[2 * w + i]);
++ } while (++i < w);
++ }
++
++ //------------------------------------------------------------------------------
++
++ static WEBP_INLINE fixed_y_t Filter2(int A, int B, int W0, int bit_depth) {
++ const int v0 = (A * 3 + B + 2) >> 2;
++ return clip_bit_depth(v0 + W0, bit_depth);
++ }
++
++ //------------------------------------------------------------------------------
++
++ static WEBP_INLINE int Shift(int v, int shift) {
++ return (shift >= 0) ? (v << shift) : (v >> -shift);
++ }
++
++ static void ImportOneRow(const uint8_t* const r_ptr,
++ const uint8_t* const g_ptr,
++ const uint8_t* const b_ptr,
++ int rgb_step,
++ int rgb_bit_depth,
++ int pic_width,
++ fixed_y_t* const dst) {
++ // Convert the rgb_step from a number of bytes to a number of uint8_t or
++ // uint16_t values depending the bit depth.
++ const int step = (rgb_bit_depth > 8) ? rgb_step / 2 : rgb_step;
++ int i = 0;
++ const int w = (pic_width + 1) & ~1;
++ do {
++ const int off = i * step;
++ const int shift = GetPrecisionShift(rgb_bit_depth);
++ if (rgb_bit_depth == 8) {
++ dst[i + 0 * w] = Shift(r_ptr[off], shift);
++ dst[i + 1 * w] = Shift(g_ptr[off], shift);
++ dst[i + 2 * w] = Shift(b_ptr[off], shift);
++ } else {
++ dst[i + 0 * w] = Shift(((uint16_t*)r_ptr)[off], shift);
++ dst[i + 1 * w] = Shift(((uint16_t*)g_ptr)[off], shift);
++ dst[i + 2 * w] = Shift(((uint16_t*)b_ptr)[off], shift);
++ }
++ } while (++i < pic_width);
++ if (pic_width & 1) { // replicate rightmost pixel
++ dst[pic_width + 0 * w] = dst[pic_width + 0 * w - 1];
++ dst[pic_width + 1 * w] = dst[pic_width + 1 * w - 1];
++ dst[pic_width + 2 * w] = dst[pic_width + 2 * w - 1];
++ }
++ }
++
++ static void InterpolateTwoRows(const fixed_y_t* const best_y,
++ const fixed_t* prev_uv,
++ const fixed_t* cur_uv,
++ const fixed_t* next_uv,
++ int w,
++ fixed_y_t* out1,
++ fixed_y_t* out2,
++ int rgb_bit_depth) {
++ const int uv_w = w >> 1;
++ const int len = (w - 1) >> 1; // length to filter
++ int k = 3;
++ const int bit_depth = rgb_bit_depth + GetPrecisionShift(rgb_bit_depth);
++ while (k-- > 0) { // process each R/G/B segments in turn
++ // special boundary case for i==0
++ out1[0] = Filter2(cur_uv[0], prev_uv[0], best_y[0], bit_depth);
++ out2[0] = Filter2(cur_uv[0], next_uv[0], best_y[w], bit_depth);
++
++ SharpYuvFilterRow(cur_uv, prev_uv, len, best_y + 0 + 1, out1 + 1,
++ bit_depth);
++ SharpYuvFilterRow(cur_uv, next_uv, len, best_y + w + 1, out2 + 1,
++ bit_depth);
++
++ // special boundary case for i == w - 1 when w is even
++ if (!(w & 1)) {
++ out1[w - 1] = Filter2(cur_uv[uv_w - 1], prev_uv[uv_w - 1],
++ best_y[w - 1 + 0], bit_depth);
++ out2[w - 1] = Filter2(cur_uv[uv_w - 1], next_uv[uv_w - 1],
++ best_y[w - 1 + w], bit_depth);
++ }
++ out1 += w;
++ out2 += w;
++ prev_uv += uv_w;
++ cur_uv += uv_w;
++ next_uv += uv_w;
++ }
++ }
++
++ static WEBP_INLINE int RGBToYUVComponent(int r, int g, int b,
++ const int coeffs[4], int sfix) {
++ const int srounder = 1 << (YUV_FIX + sfix - 1);
++ const int luma = coeffs[0] * r + coeffs[1] * g + coeffs[2] * b +
++ coeffs[3] + srounder;
++ return (luma >> (YUV_FIX + sfix));
++ }
++
++ static int ConvertWRGBToYUV(const fixed_y_t* best_y, const fixed_t* best_uv,
++ uint8_t* y_ptr, int y_stride, uint8_t* u_ptr,
++ int u_stride, uint8_t* v_ptr, int v_stride,
++ int rgb_bit_depth,
++ int yuv_bit_depth, int width, int height,
++ const SharpYuvConversionMatrix* yuv_matrix) {
++ int i, j;
++ const fixed_t* const best_uv_base = best_uv;
++ const int w = (width + 1) & ~1;
++ const int h = (height + 1) & ~1;
++ const int uv_w = w >> 1;
++ const int uv_h = h >> 1;
++ const int sfix = GetPrecisionShift(rgb_bit_depth);
++ const int yuv_max = (1 << yuv_bit_depth) - 1;
++
++ best_uv = best_uv_base;
++ j = 0;
++ do {
++ i = 0;
++ do {
++ const int off = (i >> 1);
++ const int W = best_y[i];
++ const int r = best_uv[off + 0 * uv_w] + W;
++ const int g = best_uv[off + 1 * uv_w] + W;
++ const int b = best_uv[off + 2 * uv_w] + W;
++ const int y = RGBToYUVComponent(r, g, b, yuv_matrix->rgb_to_y, sfix);
++ if (yuv_bit_depth <= 8) {
++ y_ptr[i] = clip_8b(y);
++ } else {
++ ((uint16_t*)y_ptr)[i] = clip(y, yuv_max);
++ }
++ } while (++i < width);
++ best_y += w;
++ best_uv += (j & 1) * 3 * uv_w;
++ y_ptr += y_stride;
++ } while (++j < height);
++
++ best_uv = best_uv_base;
++ j = 0;
++ do {
++ i = 0;
++ do {
++ // Note r, g and b values here are off by W, but a constant offset on all
++ // 3 components doesn't change the value of u and v with a YCbCr matrix.
++ const int r = best_uv[i + 0 * uv_w];
++ const int g = best_uv[i + 1 * uv_w];
++ const int b = best_uv[i + 2 * uv_w];
++ const int u = RGBToYUVComponent(r, g, b, yuv_matrix->rgb_to_u, sfix);
++ const int v = RGBToYUVComponent(r, g, b, yuv_matrix->rgb_to_v, sfix);
++ if (yuv_bit_depth <= 8) {
++ u_ptr[i] = clip_8b(u);
++ v_ptr[i] = clip_8b(v);
++ } else {
++ ((uint16_t*)u_ptr)[i] = clip(u, yuv_max);
++ ((uint16_t*)v_ptr)[i] = clip(v, yuv_max);
++ }
++ } while (++i < uv_w);
++ best_uv += 3 * uv_w;
++ u_ptr += u_stride;
++ v_ptr += v_stride;
++ } while (++j < uv_h);
++ return 1;
++ }
++
++ //------------------------------------------------------------------------------
++ // Main function
++
++ static void* SafeMalloc(uint64_t nmemb, size_t size) {
++ const uint64_t total_size = nmemb * (uint64_t)size;
++ if (total_size != (size_t)total_size) return NULL;
++ return malloc((size_t)total_size);
++ }
++
++ #define SAFE_ALLOC(W, H, T) ((T*)SafeMalloc((uint64_t)(W) * (H), sizeof(T)))
++
++ static int DoSharpArgbToYuv(const uint8_t* r_ptr, const uint8_t* g_ptr,
++ const uint8_t* b_ptr, int rgb_step, int rgb_stride,
++ int rgb_bit_depth, uint8_t* y_ptr, int y_stride,
++ uint8_t* u_ptr, int u_stride, uint8_t* v_ptr,
++ int v_stride, int yuv_bit_depth, int width,
++ int height,
++ const SharpYuvConversionMatrix* yuv_matrix,
++ SharpYuvTransferFunctionType transfer_type) {
++ // we expand the right/bottom border if needed
++ const int w = (width + 1) & ~1;
++ const int h = (height + 1) & ~1;
++ const int uv_w = w >> 1;
++ const int uv_h = h >> 1;
++ const int y_bit_depth = rgb_bit_depth + GetPrecisionShift(rgb_bit_depth);
++ uint64_t prev_diff_y_sum = ~0;
++ int j, iter;
++
++ // TODO(skal): allocate one big memory chunk. But for now, it's easier
++ // for valgrind debugging to have several chunks.
++ fixed_y_t* const tmp_buffer = SAFE_ALLOC(w * 3, 2, fixed_y_t); // scratch
++ fixed_y_t* const best_y_base = SAFE_ALLOC(w, h, fixed_y_t);
++ fixed_y_t* const target_y_base = SAFE_ALLOC(w, h, fixed_y_t);
++ fixed_y_t* const best_rgb_y = SAFE_ALLOC(w, 2, fixed_y_t);
++ fixed_t* const best_uv_base = SAFE_ALLOC(uv_w * 3, uv_h, fixed_t);
++ fixed_t* const target_uv_base = SAFE_ALLOC(uv_w * 3, uv_h, fixed_t);
++ fixed_t* const best_rgb_uv = SAFE_ALLOC(uv_w * 3, 1, fixed_t);
++ fixed_y_t* best_y = best_y_base;
++ fixed_y_t* target_y = target_y_base;
++ fixed_t* best_uv = best_uv_base;
++ fixed_t* target_uv = target_uv_base;
++ const uint64_t diff_y_threshold = (uint64_t)(3.0 * w * h);
++ int ok;
++ assert(w > 0);
++ assert(h > 0);
++
++ if (best_y_base == NULL || best_uv_base == NULL ||
++ target_y_base == NULL || target_uv_base == NULL ||
++ best_rgb_y == NULL || best_rgb_uv == NULL ||
++ tmp_buffer == NULL) {
++ ok = 0;
++ goto End;
++ }
++
++ // Import RGB samples to W/RGB representation.
++ for (j = 0; j < height; j += 2) {
++ const int is_last_row = (j == height - 1);
++ fixed_y_t* const src1 = tmp_buffer + 0 * w;
++ fixed_y_t* const src2 = tmp_buffer + 3 * w;
++
++ // prepare two rows of input
++ ImportOneRow(r_ptr, g_ptr, b_ptr, rgb_step, rgb_bit_depth, width,
++ src1);
++ if (!is_last_row) {
++ ImportOneRow(r_ptr + rgb_stride, g_ptr + rgb_stride, b_ptr + rgb_stride,
++ rgb_step, rgb_bit_depth, width, src2);
++ } else {
++ memcpy(src2, src1, 3 * w * sizeof(*src2));
++ }
++ StoreGray(src1, best_y + 0, w);
++ StoreGray(src2, best_y + w, w);
++
++ UpdateW(src1, target_y, w, rgb_bit_depth, transfer_type);
++ UpdateW(src2, target_y + w, w, rgb_bit_depth, transfer_type);
++ UpdateChroma(src1, src2, target_uv, uv_w, rgb_bit_depth, transfer_type);
++ memcpy(best_uv, target_uv, 3 * uv_w * sizeof(*best_uv));
++ best_y += 2 * w;
++ best_uv += 3 * uv_w;
++ target_y += 2 * w;
++ target_uv += 3 * uv_w;
++ r_ptr += 2 * rgb_stride;
++ g_ptr += 2 * rgb_stride;
++ b_ptr += 2 * rgb_stride;
++ }
++
++ // Iterate and resolve clipping conflicts.
++ for (iter = 0; iter < kNumIterations; ++iter) {
++ const fixed_t* cur_uv = best_uv_base;
++ const fixed_t* prev_uv = best_uv_base;
++ uint64_t diff_y_sum = 0;
++
++ best_y = best_y_base;
++ best_uv = best_uv_base;
++ target_y = target_y_base;
++ target_uv = target_uv_base;
++ j = 0;
++ do {
++ fixed_y_t* const src1 = tmp_buffer + 0 * w;
++ fixed_y_t* const src2 = tmp_buffer + 3 * w;
++ {
++ const fixed_t* const next_uv = cur_uv + ((j < h - 2) ? 3 * uv_w : 0);
++ InterpolateTwoRows(best_y, prev_uv, cur_uv, next_uv, w,
++ src1, src2, rgb_bit_depth);
++ prev_uv = cur_uv;
++ cur_uv = next_uv;
++ }
++
++ UpdateW(src1, best_rgb_y + 0 * w, w, rgb_bit_depth, transfer_type);
++ UpdateW(src2, best_rgb_y + 1 * w, w, rgb_bit_depth, transfer_type);
++ UpdateChroma(src1, src2, best_rgb_uv, uv_w, rgb_bit_depth, transfer_type);
++
++ // update two rows of Y and one row of RGB
++ diff_y_sum +=
++ SharpYuvUpdateY(target_y, best_rgb_y, best_y, 2 * w, y_bit_depth);
++ SharpYuvUpdateRGB(target_uv, best_rgb_uv, best_uv, 3 * uv_w);
++
++ best_y += 2 * w;
++ best_uv += 3 * uv_w;
++ target_y += 2 * w;
++ target_uv += 3 * uv_w;
++ j += 2;
++ } while (j < h);
++ // test exit condition
++ if (iter > 0) {
++ if (diff_y_sum < diff_y_threshold) break;
++ if (diff_y_sum > prev_diff_y_sum) break;
++ }
++ prev_diff_y_sum = diff_y_sum;
++ }
++
++ // final reconstruction
++ ok = ConvertWRGBToYUV(best_y_base, best_uv_base, y_ptr, y_stride, u_ptr,
++ u_stride, v_ptr, v_stride, rgb_bit_depth, yuv_bit_depth,
++ width, height, yuv_matrix);
++
++ End:
++ free(best_y_base);
++ free(best_uv_base);
++ free(target_y_base);
++ free(target_uv_base);
++ free(best_rgb_y);
++ free(best_rgb_uv);
++ free(tmp_buffer);
++ return ok;
++ }
++
++ #undef SAFE_ALLOC
++
++ #if defined(WEBP_USE_THREAD) && !defined(_WIN32)
++ #include <pthread.h> // NOLINT
++
++ #define LOCK_ACCESS \
++ static pthread_mutex_t sharpyuv_lock = PTHREAD_MUTEX_INITIALIZER; \
++ if (pthread_mutex_lock(&sharpyuv_lock)) return
++ #define UNLOCK_ACCESS_AND_RETURN \
++ do { \
++ (void)pthread_mutex_unlock(&sharpyuv_lock); \
++ return; \
++ } while (0)
++ #else // !(defined(WEBP_USE_THREAD) && !defined(_WIN32))
++ #define LOCK_ACCESS do {} while (0)
++ #define UNLOCK_ACCESS_AND_RETURN return
++ #endif // defined(WEBP_USE_THREAD) && !defined(_WIN32)
++
++ // Hidden exported init function.
++ // By default SharpYuvConvert calls it with SharpYuvGetCPUInfo. If needed,
++ // users can declare it as extern and call it with an alternate VP8CPUInfo
++ // function.
++ extern VP8CPUInfo SharpYuvGetCPUInfo;
++ SHARPYUV_EXTERN void SharpYuvInit(VP8CPUInfo cpu_info_func);
++ void SharpYuvInit(VP8CPUInfo cpu_info_func) {
++ static volatile VP8CPUInfo sharpyuv_last_cpuinfo_used =
++ (VP8CPUInfo)&sharpyuv_last_cpuinfo_used;
++ LOCK_ACCESS;
++ // Only update SharpYuvGetCPUInfo when called from external code to avoid a
++ // race on reading the value in SharpYuvConvert().
++ if (cpu_info_func != (VP8CPUInfo)&SharpYuvGetCPUInfo) {
++ SharpYuvGetCPUInfo = cpu_info_func;
++ }
++ if (sharpyuv_last_cpuinfo_used == SharpYuvGetCPUInfo) {
++ UNLOCK_ACCESS_AND_RETURN;
++ }
++
++ SharpYuvInitDsp();
++ SharpYuvInitGammaTables();
++
++ sharpyuv_last_cpuinfo_used = SharpYuvGetCPUInfo;
++ UNLOCK_ACCESS_AND_RETURN;
++ }
++
++ int SharpYuvConvert(const void* r_ptr, const void* g_ptr, const void* b_ptr,
++ int rgb_step, int rgb_stride, int rgb_bit_depth,
++ void* y_ptr, int y_stride, void* u_ptr, int u_stride,
++ void* v_ptr, int v_stride, int yuv_bit_depth, int width,
++ int height, const SharpYuvConversionMatrix* yuv_matrix) {
++ SharpYuvOptions options;
++ options.yuv_matrix = yuv_matrix;
++ options.transfer_type = kSharpYuvTransferFunctionSrgb;
++ return SharpYuvConvertWithOptions(
++ r_ptr, g_ptr, b_ptr, rgb_step, rgb_stride, rgb_bit_depth, y_ptr, y_stride,
++ u_ptr, u_stride, v_ptr, v_stride, yuv_bit_depth, width, height, &options);
++ }
++
++ int SharpYuvOptionsInitInternal(const SharpYuvConversionMatrix* yuv_matrix,
++ SharpYuvOptions* options, int version) {
++ const int major = (version >> 24);
++ const int minor = (version >> 16) & 0xff;
++ if (options == NULL || yuv_matrix == NULL ||
++ (major == SHARPYUV_VERSION_MAJOR && major == 0 &&
++ minor != SHARPYUV_VERSION_MINOR) ||
++ (major != SHARPYUV_VERSION_MAJOR)) {
++ return 0;
++ }
++ options->yuv_matrix = yuv_matrix;
++ options->transfer_type = kSharpYuvTransferFunctionSrgb;
++ return 1;
++ }
++
++ int SharpYuvConvertWithOptions(const void* r_ptr, const void* g_ptr,
++ const void* b_ptr, int rgb_step, int rgb_stride,
++ int rgb_bit_depth, void* y_ptr, int y_stride,
++ void* u_ptr, int u_stride, void* v_ptr,
++ int v_stride, int yuv_bit_depth, int width,
++ int height, const SharpYuvOptions* options) {
++ const SharpYuvConversionMatrix* yuv_matrix = options->yuv_matrix;
++ SharpYuvTransferFunctionType transfer_type = options->transfer_type;
++ SharpYuvConversionMatrix scaled_matrix;
++ const int rgb_max = (1 << rgb_bit_depth) - 1;
++ const int rgb_round = 1 << (rgb_bit_depth - 1);
++ const int yuv_max = (1 << yuv_bit_depth) - 1;
++ const int sfix = GetPrecisionShift(rgb_bit_depth);
++
++ if (width < 1 || height < 1 || width == INT_MAX || height == INT_MAX ||
++ r_ptr == NULL || g_ptr == NULL || b_ptr == NULL || y_ptr == NULL ||
++ u_ptr == NULL || v_ptr == NULL) {
++ return 0;
++ }
++ if (rgb_bit_depth != 8 && rgb_bit_depth != 10 && rgb_bit_depth != 12 &&
++ rgb_bit_depth != 16) {
++ return 0;
++ }
++ if (yuv_bit_depth != 8 && yuv_bit_depth != 10 && yuv_bit_depth != 12) {
++ return 0;
++ }
++ if (rgb_bit_depth > 8 && (rgb_step % 2 != 0 || rgb_stride % 2 != 0)) {
++ // Step/stride should be even for uint16_t buffers.
++ return 0;
++ }
++ if (yuv_bit_depth > 8 &&
++ (y_stride % 2 != 0 || u_stride % 2 != 0 || v_stride % 2 != 0)) {
++ // Stride should be even for uint16_t buffers.
++ return 0;
++ }
++ // The address of the function pointer is used to avoid a read race.
++ SharpYuvInit((VP8CPUInfo)&SharpYuvGetCPUInfo);
++
++ // Add scaling factor to go from rgb_bit_depth to yuv_bit_depth, to the
++ // rgb->yuv conversion matrix.
++ if (rgb_bit_depth == yuv_bit_depth) {
++ memcpy(&scaled_matrix, yuv_matrix, sizeof(scaled_matrix));
++ } else {
++ int i;
++ for (i = 0; i < 3; ++i) {
++ scaled_matrix.rgb_to_y[i] =
++ (yuv_matrix->rgb_to_y[i] * yuv_max + rgb_round) / rgb_max;
++ scaled_matrix.rgb_to_u[i] =
++ (yuv_matrix->rgb_to_u[i] * yuv_max + rgb_round) / rgb_max;
++ scaled_matrix.rgb_to_v[i] =
++ (yuv_matrix->rgb_to_v[i] * yuv_max + rgb_round) / rgb_max;
++ }
++ }
++ // Also incorporate precision change scaling.
++ scaled_matrix.rgb_to_y[3] = Shift(yuv_matrix->rgb_to_y[3], sfix);
++ scaled_matrix.rgb_to_u[3] = Shift(yuv_matrix->rgb_to_u[3], sfix);
++ scaled_matrix.rgb_to_v[3] = Shift(yuv_matrix->rgb_to_v[3], sfix);
++
++ return DoSharpArgbToYuv(
++ (const uint8_t*)r_ptr, (const uint8_t*)g_ptr, (const uint8_t*)b_ptr,
++ rgb_step, rgb_stride, rgb_bit_depth, (uint8_t*)y_ptr, y_stride,
++ (uint8_t*)u_ptr, u_stride, (uint8_t*)v_ptr, v_stride, yuv_bit_depth,
++ width, height, &scaled_matrix, transfer_type);
++ }
++
++ //------------------------------------------------------------------------------