sharpyuv.c (21787B)
1 // Copyright 2022 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 // Sharp RGB to YUV conversion. 11 // 12 // Author: Skal (pascal.massimino@gmail.com) 13 14 #include "sharpyuv/sharpyuv.h" 15 16 #include <assert.h> 17 #include <limits.h> 18 #include <stddef.h> 19 #include <stdlib.h> 20 #include <string.h> 21 22 #include "sharpyuv/sharpyuv_cpu.h" 23 #include "sharpyuv/sharpyuv_dsp.h" 24 #include "sharpyuv/sharpyuv_gamma.h" 25 #include "src/webp/types.h" 26 27 //------------------------------------------------------------------------------ 28 29 int SharpYuvGetVersion(void) { 30 return SHARPYUV_VERSION; 31 } 32 33 //------------------------------------------------------------------------------ 34 // Sharp RGB->YUV conversion 35 36 static const int kNumIterations = 4; 37 38 #define YUV_FIX 16 // fixed-point precision for RGB->YUV 39 static const int kYuvHalf = 1 << (YUV_FIX - 1); 40 41 // Max bit depth so that intermediate calculations fit in 16 bits. 42 static const int kMaxBitDepth = 14; 43 44 // Returns the precision shift to use based on the input rgb_bit_depth. 45 static int GetPrecisionShift(int rgb_bit_depth) { 46 // Try to add 2 bits of precision if it fits in kMaxBitDepth. Otherwise remove 47 // bits if needed. 48 return ((rgb_bit_depth + 2) <= kMaxBitDepth) ? 2 49 : (kMaxBitDepth - rgb_bit_depth); 50 } 51 52 typedef int16_t fixed_t; // signed type with extra precision for UV 53 typedef uint16_t fixed_y_t; // unsigned type with extra precision for W 54 55 //------------------------------------------------------------------------------ 56 57 static uint8_t clip_8b(fixed_t v) { 58 return (!(v & ~0xff)) ? (uint8_t)v : (v < 0) ? 0u : 255u; 59 } 60 61 static uint16_t clip(fixed_t v, int max) { 62 return (v < 0) ? 0 : (v > max) ? max : (uint16_t)v; 63 } 64 65 static fixed_y_t clip_bit_depth(int y, int bit_depth) { 66 const int max = (1 << bit_depth) - 1; 67 return (!(y & ~max)) ? (fixed_y_t)y : (y < 0) ? 0 : max; 68 } 69 70 //------------------------------------------------------------------------------ 71 72 static int RGBToGray(int64_t r, int64_t g, int64_t b) { 73 const int64_t luma = 13933 * r + 46871 * g + 4732 * b + kYuvHalf; 74 return (int)(luma >> YUV_FIX); 75 } 76 77 static uint32_t ScaleDown(uint16_t a, uint16_t b, uint16_t c, uint16_t d, 78 int rgb_bit_depth, 79 SharpYuvTransferFunctionType transfer_type) { 80 const int bit_depth = rgb_bit_depth + GetPrecisionShift(rgb_bit_depth); 81 const uint32_t A = SharpYuvGammaToLinear(a, bit_depth, transfer_type); 82 const uint32_t B = SharpYuvGammaToLinear(b, bit_depth, transfer_type); 83 const uint32_t C = SharpYuvGammaToLinear(c, bit_depth, transfer_type); 84 const uint32_t D = SharpYuvGammaToLinear(d, bit_depth, transfer_type); 85 return SharpYuvLinearToGamma((A + B + C + D + 2) >> 2, bit_depth, 86 transfer_type); 87 } 88 89 static WEBP_INLINE void UpdateW(const fixed_y_t* src, fixed_y_t* dst, int w, 90 int rgb_bit_depth, 91 SharpYuvTransferFunctionType transfer_type) { 92 const int bit_depth = rgb_bit_depth + GetPrecisionShift(rgb_bit_depth); 93 int i = 0; 94 do { 95 const uint32_t R = 96 SharpYuvGammaToLinear(src[0 * w + i], bit_depth, transfer_type); 97 const uint32_t G = 98 SharpYuvGammaToLinear(src[1 * w + i], bit_depth, transfer_type); 99 const uint32_t B = 100 SharpYuvGammaToLinear(src[2 * w + i], bit_depth, transfer_type); 101 const uint32_t Y = RGBToGray(R, G, B); 102 dst[i] = (fixed_y_t)SharpYuvLinearToGamma(Y, bit_depth, transfer_type); 103 } while (++i < w); 104 } 105 106 static void UpdateChroma(const fixed_y_t* src1, const fixed_y_t* src2, 107 fixed_t* dst, int uv_w, int rgb_bit_depth, 108 SharpYuvTransferFunctionType transfer_type) { 109 int i = 0; 110 do { 111 const int r = 112 ScaleDown(src1[0 * uv_w + 0], src1[0 * uv_w + 1], src2[0 * uv_w + 0], 113 src2[0 * uv_w + 1], rgb_bit_depth, transfer_type); 114 const int g = 115 ScaleDown(src1[2 * uv_w + 0], src1[2 * uv_w + 1], src2[2 * uv_w + 0], 116 src2[2 * uv_w + 1], rgb_bit_depth, transfer_type); 117 const int b = 118 ScaleDown(src1[4 * uv_w + 0], src1[4 * uv_w + 1], src2[4 * uv_w + 0], 119 src2[4 * uv_w + 1], rgb_bit_depth, transfer_type); 120 const int W = RGBToGray(r, g, b); 121 dst[0 * uv_w] = (fixed_t)(r - W); 122 dst[1 * uv_w] = (fixed_t)(g - W); 123 dst[2 * uv_w] = (fixed_t)(b - W); 124 dst += 1; 125 src1 += 2; 126 src2 += 2; 127 } while (++i < uv_w); 128 } 129 130 static void StoreGray(const fixed_y_t* rgb, fixed_y_t* y, int w) { 131 int i = 0; 132 assert(w > 0); 133 do { 134 y[i] = RGBToGray(rgb[0 * w + i], rgb[1 * w + i], rgb[2 * w + i]); 135 } while (++i < w); 136 } 137 138 //------------------------------------------------------------------------------ 139 140 static WEBP_INLINE fixed_y_t Filter2(int A, int B, int W0, int bit_depth) { 141 const int v0 = (A * 3 + B + 2) >> 2; 142 return clip_bit_depth(v0 + W0, bit_depth); 143 } 144 145 //------------------------------------------------------------------------------ 146 147 static WEBP_INLINE int Shift(int v, int shift) { 148 return (shift >= 0) ? (v << shift) : (v >> -shift); 149 } 150 151 static void ImportOneRow(const uint8_t* const r_ptr, 152 const uint8_t* const g_ptr, 153 const uint8_t* const b_ptr, 154 int rgb_step, 155 int rgb_bit_depth, 156 int pic_width, 157 fixed_y_t* const dst) { 158 // Convert the rgb_step from a number of bytes to a number of uint8_t or 159 // uint16_t values depending the bit depth. 160 const int step = (rgb_bit_depth > 8) ? rgb_step / 2 : rgb_step; 161 int i = 0; 162 const int w = (pic_width + 1) & ~1; 163 do { 164 const int off = i * step; 165 const int shift = GetPrecisionShift(rgb_bit_depth); 166 if (rgb_bit_depth == 8) { 167 dst[i + 0 * w] = Shift(r_ptr[off], shift); 168 dst[i + 1 * w] = Shift(g_ptr[off], shift); 169 dst[i + 2 * w] = Shift(b_ptr[off], shift); 170 } else { 171 dst[i + 0 * w] = Shift(((uint16_t*)r_ptr)[off], shift); 172 dst[i + 1 * w] = Shift(((uint16_t*)g_ptr)[off], shift); 173 dst[i + 2 * w] = Shift(((uint16_t*)b_ptr)[off], shift); 174 } 175 } while (++i < pic_width); 176 if (pic_width & 1) { // replicate rightmost pixel 177 dst[pic_width + 0 * w] = dst[pic_width + 0 * w - 1]; 178 dst[pic_width + 1 * w] = dst[pic_width + 1 * w - 1]; 179 dst[pic_width + 2 * w] = dst[pic_width + 2 * w - 1]; 180 } 181 } 182 183 static void InterpolateTwoRows(const fixed_y_t* const best_y, 184 const fixed_t* prev_uv, 185 const fixed_t* cur_uv, 186 const fixed_t* next_uv, 187 int w, 188 fixed_y_t* out1, 189 fixed_y_t* out2, 190 int rgb_bit_depth) { 191 const int uv_w = w >> 1; 192 const int len = (w - 1) >> 1; // length to filter 193 int k = 3; 194 const int bit_depth = rgb_bit_depth + GetPrecisionShift(rgb_bit_depth); 195 while (k-- > 0) { // process each R/G/B segments in turn 196 // special boundary case for i==0 197 out1[0] = Filter2(cur_uv[0], prev_uv[0], best_y[0], bit_depth); 198 out2[0] = Filter2(cur_uv[0], next_uv[0], best_y[w], bit_depth); 199 200 SharpYuvFilterRow(cur_uv, prev_uv, len, best_y + 0 + 1, out1 + 1, 201 bit_depth); 202 SharpYuvFilterRow(cur_uv, next_uv, len, best_y + w + 1, out2 + 1, 203 bit_depth); 204 205 // special boundary case for i == w - 1 when w is even 206 if (!(w & 1)) { 207 out1[w - 1] = Filter2(cur_uv[uv_w - 1], prev_uv[uv_w - 1], 208 best_y[w - 1 + 0], bit_depth); 209 out2[w - 1] = Filter2(cur_uv[uv_w - 1], next_uv[uv_w - 1], 210 best_y[w - 1 + w], bit_depth); 211 } 212 out1 += w; 213 out2 += w; 214 prev_uv += uv_w; 215 cur_uv += uv_w; 216 next_uv += uv_w; 217 } 218 } 219 220 static WEBP_INLINE int RGBToYUVComponent(int r, int g, int b, 221 const int coeffs[4], int sfix) { 222 const int srounder = 1 << (YUV_FIX + sfix - 1); 223 const int luma = coeffs[0] * r + coeffs[1] * g + coeffs[2] * b + 224 coeffs[3] + srounder; 225 return (luma >> (YUV_FIX + sfix)); 226 } 227 228 static int ConvertWRGBToYUV(const fixed_y_t* best_y, const fixed_t* best_uv, 229 uint8_t* y_ptr, int y_stride, uint8_t* u_ptr, 230 int u_stride, uint8_t* v_ptr, int v_stride, 231 int rgb_bit_depth, 232 int yuv_bit_depth, int width, int height, 233 const SharpYuvConversionMatrix* yuv_matrix) { 234 int i, j; 235 const fixed_t* const best_uv_base = best_uv; 236 const int w = (width + 1) & ~1; 237 const int h = (height + 1) & ~1; 238 const int uv_w = w >> 1; 239 const int uv_h = h >> 1; 240 const int sfix = GetPrecisionShift(rgb_bit_depth); 241 const int yuv_max = (1 << yuv_bit_depth) - 1; 242 243 best_uv = best_uv_base; 244 j = 0; 245 do { 246 i = 0; 247 do { 248 const int off = (i >> 1); 249 const int W = best_y[i]; 250 const int r = best_uv[off + 0 * uv_w] + W; 251 const int g = best_uv[off + 1 * uv_w] + W; 252 const int b = best_uv[off + 2 * uv_w] + W; 253 const int y = RGBToYUVComponent(r, g, b, yuv_matrix->rgb_to_y, sfix); 254 if (yuv_bit_depth <= 8) { 255 y_ptr[i] = clip_8b(y); 256 } else { 257 ((uint16_t*)y_ptr)[i] = clip(y, yuv_max); 258 } 259 } while (++i < width); 260 best_y += w; 261 best_uv += (j & 1) * 3 * uv_w; 262 y_ptr += y_stride; 263 } while (++j < height); 264 265 best_uv = best_uv_base; 266 j = 0; 267 do { 268 i = 0; 269 do { 270 // Note r, g and b values here are off by W, but a constant offset on all 271 // 3 components doesn't change the value of u and v with a YCbCr matrix. 272 const int r = best_uv[i + 0 * uv_w]; 273 const int g = best_uv[i + 1 * uv_w]; 274 const int b = best_uv[i + 2 * uv_w]; 275 const int u = RGBToYUVComponent(r, g, b, yuv_matrix->rgb_to_u, sfix); 276 const int v = RGBToYUVComponent(r, g, b, yuv_matrix->rgb_to_v, sfix); 277 if (yuv_bit_depth <= 8) { 278 u_ptr[i] = clip_8b(u); 279 v_ptr[i] = clip_8b(v); 280 } else { 281 ((uint16_t*)u_ptr)[i] = clip(u, yuv_max); 282 ((uint16_t*)v_ptr)[i] = clip(v, yuv_max); 283 } 284 } while (++i < uv_w); 285 best_uv += 3 * uv_w; 286 u_ptr += u_stride; 287 v_ptr += v_stride; 288 } while (++j < uv_h); 289 return 1; 290 } 291 292 //------------------------------------------------------------------------------ 293 // Main function 294 295 static void* SafeMalloc(uint64_t nmemb, size_t size) { 296 const uint64_t total_size = nmemb * (uint64_t)size; 297 if (total_size != (size_t)total_size) return NULL; 298 return malloc((size_t)total_size); 299 } 300 301 #define SAFE_ALLOC(W, H, T) ((T*)SafeMalloc((uint64_t)(W) * (H), sizeof(T))) 302 303 static int DoSharpArgbToYuv(const uint8_t* r_ptr, const uint8_t* g_ptr, 304 const uint8_t* b_ptr, int rgb_step, int rgb_stride, 305 int rgb_bit_depth, uint8_t* y_ptr, int y_stride, 306 uint8_t* u_ptr, int u_stride, uint8_t* v_ptr, 307 int v_stride, int yuv_bit_depth, int width, 308 int height, 309 const SharpYuvConversionMatrix* yuv_matrix, 310 SharpYuvTransferFunctionType transfer_type) { 311 // we expand the right/bottom border if needed 312 const int w = (width + 1) & ~1; 313 const int h = (height + 1) & ~1; 314 const int uv_w = w >> 1; 315 const int uv_h = h >> 1; 316 const int y_bit_depth = rgb_bit_depth + GetPrecisionShift(rgb_bit_depth); 317 uint64_t prev_diff_y_sum = ~0; 318 int j, iter; 319 320 // TODO(skal): allocate one big memory chunk. But for now, it's easier 321 // for valgrind debugging to have several chunks. 322 fixed_y_t* const tmp_buffer = SAFE_ALLOC(w * 3, 2, fixed_y_t); // scratch 323 fixed_y_t* const best_y_base = SAFE_ALLOC(w, h, fixed_y_t); 324 fixed_y_t* const target_y_base = SAFE_ALLOC(w, h, fixed_y_t); 325 fixed_y_t* const best_rgb_y = SAFE_ALLOC(w, 2, fixed_y_t); 326 fixed_t* const best_uv_base = SAFE_ALLOC(uv_w * 3, uv_h, fixed_t); 327 fixed_t* const target_uv_base = SAFE_ALLOC(uv_w * 3, uv_h, fixed_t); 328 fixed_t* const best_rgb_uv = SAFE_ALLOC(uv_w * 3, 1, fixed_t); 329 fixed_y_t* best_y = best_y_base; 330 fixed_y_t* target_y = target_y_base; 331 fixed_t* best_uv = best_uv_base; 332 fixed_t* target_uv = target_uv_base; 333 const uint64_t diff_y_threshold = (uint64_t)(3.0 * w * h); 334 int ok; 335 assert(w > 0); 336 assert(h > 0); 337 338 if (best_y_base == NULL || best_uv_base == NULL || 339 target_y_base == NULL || target_uv_base == NULL || 340 best_rgb_y == NULL || best_rgb_uv == NULL || 341 tmp_buffer == NULL) { 342 ok = 0; 343 goto End; 344 } 345 346 // Import RGB samples to W/RGB representation. 347 for (j = 0; j < height; j += 2) { 348 const int is_last_row = (j == height - 1); 349 fixed_y_t* const src1 = tmp_buffer + 0 * w; 350 fixed_y_t* const src2 = tmp_buffer + 3 * w; 351 352 // prepare two rows of input 353 ImportOneRow(r_ptr, g_ptr, b_ptr, rgb_step, rgb_bit_depth, width, 354 src1); 355 if (!is_last_row) { 356 ImportOneRow(r_ptr + rgb_stride, g_ptr + rgb_stride, b_ptr + rgb_stride, 357 rgb_step, rgb_bit_depth, width, src2); 358 } else { 359 memcpy(src2, src1, 3 * w * sizeof(*src2)); 360 } 361 StoreGray(src1, best_y + 0, w); 362 StoreGray(src2, best_y + w, w); 363 364 UpdateW(src1, target_y, w, rgb_bit_depth, transfer_type); 365 UpdateW(src2, target_y + w, w, rgb_bit_depth, transfer_type); 366 UpdateChroma(src1, src2, target_uv, uv_w, rgb_bit_depth, transfer_type); 367 memcpy(best_uv, target_uv, 3 * uv_w * sizeof(*best_uv)); 368 best_y += 2 * w; 369 best_uv += 3 * uv_w; 370 target_y += 2 * w; 371 target_uv += 3 * uv_w; 372 r_ptr += 2 * rgb_stride; 373 g_ptr += 2 * rgb_stride; 374 b_ptr += 2 * rgb_stride; 375 } 376 377 // Iterate and resolve clipping conflicts. 378 for (iter = 0; iter < kNumIterations; ++iter) { 379 const fixed_t* cur_uv = best_uv_base; 380 const fixed_t* prev_uv = best_uv_base; 381 uint64_t diff_y_sum = 0; 382 383 best_y = best_y_base; 384 best_uv = best_uv_base; 385 target_y = target_y_base; 386 target_uv = target_uv_base; 387 j = 0; 388 do { 389 fixed_y_t* const src1 = tmp_buffer + 0 * w; 390 fixed_y_t* const src2 = tmp_buffer + 3 * w; 391 { 392 const fixed_t* const next_uv = cur_uv + ((j < h - 2) ? 3 * uv_w : 0); 393 InterpolateTwoRows(best_y, prev_uv, cur_uv, next_uv, w, 394 src1, src2, rgb_bit_depth); 395 prev_uv = cur_uv; 396 cur_uv = next_uv; 397 } 398 399 UpdateW(src1, best_rgb_y + 0 * w, w, rgb_bit_depth, transfer_type); 400 UpdateW(src2, best_rgb_y + 1 * w, w, rgb_bit_depth, transfer_type); 401 UpdateChroma(src1, src2, best_rgb_uv, uv_w, rgb_bit_depth, transfer_type); 402 403 // update two rows of Y and one row of RGB 404 diff_y_sum += 405 SharpYuvUpdateY(target_y, best_rgb_y, best_y, 2 * w, y_bit_depth); 406 SharpYuvUpdateRGB(target_uv, best_rgb_uv, best_uv, 3 * uv_w); 407 408 best_y += 2 * w; 409 best_uv += 3 * uv_w; 410 target_y += 2 * w; 411 target_uv += 3 * uv_w; 412 j += 2; 413 } while (j < h); 414 // test exit condition 415 if (iter > 0) { 416 if (diff_y_sum < diff_y_threshold) break; 417 if (diff_y_sum > prev_diff_y_sum) break; 418 } 419 prev_diff_y_sum = diff_y_sum; 420 } 421 422 // final reconstruction 423 ok = ConvertWRGBToYUV(best_y_base, best_uv_base, y_ptr, y_stride, u_ptr, 424 u_stride, v_ptr, v_stride, rgb_bit_depth, yuv_bit_depth, 425 width, height, yuv_matrix); 426 427 End: 428 free(best_y_base); 429 free(best_uv_base); 430 free(target_y_base); 431 free(target_uv_base); 432 free(best_rgb_y); 433 free(best_rgb_uv); 434 free(tmp_buffer); 435 return ok; 436 } 437 438 #undef SAFE_ALLOC 439 440 #if defined(WEBP_USE_THREAD) && !defined(_WIN32) 441 #include <pthread.h> // NOLINT 442 443 #define LOCK_ACCESS \ 444 static pthread_mutex_t sharpyuv_lock = PTHREAD_MUTEX_INITIALIZER; \ 445 if (pthread_mutex_lock(&sharpyuv_lock)) return 446 #define UNLOCK_ACCESS_AND_RETURN \ 447 do { \ 448 (void)pthread_mutex_unlock(&sharpyuv_lock); \ 449 return; \ 450 } while (0) 451 #else // !(defined(WEBP_USE_THREAD) && !defined(_WIN32)) 452 #define LOCK_ACCESS do {} while (0) 453 #define UNLOCK_ACCESS_AND_RETURN return 454 #endif // defined(WEBP_USE_THREAD) && !defined(_WIN32) 455 456 // Hidden exported init function. 457 // By default SharpYuvConvert calls it with SharpYuvGetCPUInfo. If needed, 458 // users can declare it as extern and call it with an alternate VP8CPUInfo 459 // function. 460 extern VP8CPUInfo SharpYuvGetCPUInfo; 461 SHARPYUV_EXTERN void SharpYuvInit(VP8CPUInfo cpu_info_func); 462 void SharpYuvInit(VP8CPUInfo cpu_info_func) { 463 static volatile VP8CPUInfo sharpyuv_last_cpuinfo_used = 464 (VP8CPUInfo)&sharpyuv_last_cpuinfo_used; 465 LOCK_ACCESS; 466 // Only update SharpYuvGetCPUInfo when called from external code to avoid a 467 // race on reading the value in SharpYuvConvert(). 468 if (cpu_info_func != (VP8CPUInfo)&SharpYuvGetCPUInfo) { 469 SharpYuvGetCPUInfo = cpu_info_func; 470 } 471 if (sharpyuv_last_cpuinfo_used == SharpYuvGetCPUInfo) { 472 UNLOCK_ACCESS_AND_RETURN; 473 } 474 475 SharpYuvInitDsp(); 476 SharpYuvInitGammaTables(); 477 478 sharpyuv_last_cpuinfo_used = SharpYuvGetCPUInfo; 479 UNLOCK_ACCESS_AND_RETURN; 480 } 481 482 int SharpYuvConvert(const void* r_ptr, const void* g_ptr, const void* b_ptr, 483 int rgb_step, int rgb_stride, int rgb_bit_depth, 484 void* y_ptr, int y_stride, void* u_ptr, int u_stride, 485 void* v_ptr, int v_stride, int yuv_bit_depth, int width, 486 int height, const SharpYuvConversionMatrix* yuv_matrix) { 487 SharpYuvOptions options; 488 options.yuv_matrix = yuv_matrix; 489 options.transfer_type = kSharpYuvTransferFunctionSrgb; 490 return SharpYuvConvertWithOptions( 491 r_ptr, g_ptr, b_ptr, rgb_step, rgb_stride, rgb_bit_depth, y_ptr, y_stride, 492 u_ptr, u_stride, v_ptr, v_stride, yuv_bit_depth, width, height, &options); 493 } 494 495 int SharpYuvOptionsInitInternal(const SharpYuvConversionMatrix* yuv_matrix, 496 SharpYuvOptions* options, int version) { 497 const int major = (version >> 24); 498 const int minor = (version >> 16) & 0xff; 499 if (options == NULL || yuv_matrix == NULL || 500 (major == SHARPYUV_VERSION_MAJOR && major == 0 && 501 minor != SHARPYUV_VERSION_MINOR) || 502 (major != SHARPYUV_VERSION_MAJOR)) { 503 return 0; 504 } 505 options->yuv_matrix = yuv_matrix; 506 options->transfer_type = kSharpYuvTransferFunctionSrgb; 507 return 1; 508 } 509 510 int SharpYuvConvertWithOptions(const void* r_ptr, const void* g_ptr, 511 const void* b_ptr, int rgb_step, int rgb_stride, 512 int rgb_bit_depth, void* y_ptr, int y_stride, 513 void* u_ptr, int u_stride, void* v_ptr, 514 int v_stride, int yuv_bit_depth, int width, 515 int height, const SharpYuvOptions* options) { 516 const SharpYuvConversionMatrix* yuv_matrix = options->yuv_matrix; 517 SharpYuvTransferFunctionType transfer_type = options->transfer_type; 518 SharpYuvConversionMatrix scaled_matrix; 519 const int rgb_max = (1 << rgb_bit_depth) - 1; 520 const int rgb_round = 1 << (rgb_bit_depth - 1); 521 const int yuv_max = (1 << yuv_bit_depth) - 1; 522 const int sfix = GetPrecisionShift(rgb_bit_depth); 523 524 if (width < 1 || height < 1 || width == INT_MAX || height == INT_MAX || 525 r_ptr == NULL || g_ptr == NULL || b_ptr == NULL || y_ptr == NULL || 526 u_ptr == NULL || v_ptr == NULL) { 527 return 0; 528 } 529 if (rgb_bit_depth != 8 && rgb_bit_depth != 10 && rgb_bit_depth != 12 && 530 rgb_bit_depth != 16) { 531 return 0; 532 } 533 if (yuv_bit_depth != 8 && yuv_bit_depth != 10 && yuv_bit_depth != 12) { 534 return 0; 535 } 536 if (rgb_bit_depth > 8 && (rgb_step % 2 != 0 || rgb_stride % 2 != 0)) { 537 // Step/stride should be even for uint16_t buffers. 538 return 0; 539 } 540 if (yuv_bit_depth > 8 && 541 (y_stride % 2 != 0 || u_stride % 2 != 0 || v_stride % 2 != 0)) { 542 // Stride should be even for uint16_t buffers. 543 return 0; 544 } 545 // The address of the function pointer is used to avoid a read race. 546 SharpYuvInit((VP8CPUInfo)&SharpYuvGetCPUInfo); 547 548 // Add scaling factor to go from rgb_bit_depth to yuv_bit_depth, to the 549 // rgb->yuv conversion matrix. 550 if (rgb_bit_depth == yuv_bit_depth) { 551 memcpy(&scaled_matrix, yuv_matrix, sizeof(scaled_matrix)); 552 } else { 553 int i; 554 for (i = 0; i < 3; ++i) { 555 scaled_matrix.rgb_to_y[i] = 556 (yuv_matrix->rgb_to_y[i] * yuv_max + rgb_round) / rgb_max; 557 scaled_matrix.rgb_to_u[i] = 558 (yuv_matrix->rgb_to_u[i] * yuv_max + rgb_round) / rgb_max; 559 scaled_matrix.rgb_to_v[i] = 560 (yuv_matrix->rgb_to_v[i] * yuv_max + rgb_round) / rgb_max; 561 } 562 } 563 // Also incorporate precision change scaling. 564 scaled_matrix.rgb_to_y[3] = Shift(yuv_matrix->rgb_to_y[3], sfix); 565 scaled_matrix.rgb_to_u[3] = Shift(yuv_matrix->rgb_to_u[3], sfix); 566 scaled_matrix.rgb_to_v[3] = Shift(yuv_matrix->rgb_to_v[3], sfix); 567 568 return DoSharpArgbToYuv( 569 (const uint8_t*)r_ptr, (const uint8_t*)g_ptr, (const uint8_t*)b_ptr, 570 rgb_step, rgb_stride, rgb_bit_depth, (uint8_t*)y_ptr, y_stride, 571 (uint8_t*)u_ptr, u_stride, (uint8_t*)v_ptr, v_stride, yuv_bit_depth, 572 width, height, &scaled_matrix, transfer_type); 573 } 574 575 //------------------------------------------------------------------------------