1 // Copyright 2011 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 // WebPPicture utils: colorspace conversion, crop, ... 11 // 12 // Author: Skal (pascal.massimino (at) gmail.com) 13 14 #include <assert.h> 15 #include <stdlib.h> 16 #include <math.h> 17 18 #include "./vp8enci.h" 19 #include "../utils/rescaler.h" 20 #include "../utils/utils.h" 21 #include "../dsp/dsp.h" 22 #include "../dsp/yuv.h" 23 24 #if defined(__cplusplus) || defined(c_plusplus) 25 extern "C" { 26 #endif 27 28 #define HALVE(x) (((x) + 1) >> 1) 29 #define IS_YUV_CSP(csp, YUV_CSP) (((csp) & WEBP_CSP_UV_MASK) == (YUV_CSP)) 30 31 static const union { 32 uint32_t argb; 33 uint8_t bytes[4]; 34 } test_endian = { 0xff000000u }; 35 #define ALPHA_IS_LAST (test_endian.bytes[3] == 0xff) 36 37 //------------------------------------------------------------------------------ 38 // WebPPicture 39 //------------------------------------------------------------------------------ 40 41 int WebPPictureAlloc(WebPPicture* picture) { 42 if (picture != NULL) { 43 const WebPEncCSP uv_csp = picture->colorspace & WEBP_CSP_UV_MASK; 44 const int has_alpha = picture->colorspace & WEBP_CSP_ALPHA_BIT; 45 const int width = picture->width; 46 const int height = picture->height; 47 48 if (!picture->use_argb) { 49 const int y_stride = width; 50 const int uv_width = HALVE(width); 51 const int uv_height = HALVE(height); 52 const int uv_stride = uv_width; 53 int uv0_stride = 0; 54 int a_width, a_stride; 55 uint64_t y_size, uv_size, uv0_size, a_size, total_size; 56 uint8_t* mem; 57 58 // U/V 59 switch (uv_csp) { 60 case WEBP_YUV420: 61 break; 62 #ifdef WEBP_EXPERIMENTAL_FEATURES 63 case WEBP_YUV400: // for now, we'll just reset the U/V samples 64 break; 65 case WEBP_YUV422: 66 uv0_stride = uv_width; 67 break; 68 case WEBP_YUV444: 69 uv0_stride = width; 70 break; 71 #endif 72 default: 73 return 0; 74 } 75 uv0_size = height * uv0_stride; 76 77 // alpha 78 a_width = has_alpha ? width : 0; 79 a_stride = a_width; 80 y_size = (uint64_t)y_stride * height; 81 uv_size = (uint64_t)uv_stride * uv_height; 82 a_size = (uint64_t)a_stride * height; 83 84 total_size = y_size + a_size + 2 * uv_size + 2 * uv0_size; 85 86 // Security and validation checks 87 if (width <= 0 || height <= 0 || // luma/alpha param error 88 uv_width < 0 || uv_height < 0) { // u/v param error 89 return 0; 90 } 91 // Clear previous buffer and allocate a new one. 92 WebPPictureFree(picture); // erase previous buffer 93 mem = (uint8_t*)WebPSafeMalloc(total_size, sizeof(*mem)); 94 if (mem == NULL) return 0; 95 96 // From now on, we're in the clear, we can no longer fail... 97 picture->memory_ = (void*)mem; 98 picture->y_stride = y_stride; 99 picture->uv_stride = uv_stride; 100 picture->a_stride = a_stride; 101 picture->uv0_stride = uv0_stride; 102 // TODO(skal): we could align the y/u/v planes and adjust stride. 103 picture->y = mem; 104 mem += y_size; 105 106 picture->u = mem; 107 mem += uv_size; 108 picture->v = mem; 109 mem += uv_size; 110 111 if (a_size) { 112 picture->a = mem; 113 mem += a_size; 114 } 115 if (uv0_size) { 116 picture->u0 = mem; 117 mem += uv0_size; 118 picture->v0 = mem; 119 mem += uv0_size; 120 } 121 } else { 122 void* memory; 123 const uint64_t argb_size = (uint64_t)width * height; 124 if (width <= 0 || height <= 0) { 125 return 0; 126 } 127 // Clear previous buffer and allocate a new one. 128 WebPPictureFree(picture); // erase previous buffer 129 memory = WebPSafeMalloc(argb_size, sizeof(*picture->argb)); 130 if (memory == NULL) return 0; 131 132 // TODO(skal): align plane to cache line? 133 picture->memory_argb_ = memory; 134 picture->argb = (uint32_t*)memory; 135 picture->argb_stride = width; 136 } 137 } 138 return 1; 139 } 140 141 // Remove reference to the ARGB buffer (doesn't free anything). 142 static void PictureResetARGB(WebPPicture* const picture) { 143 picture->memory_argb_ = NULL; 144 picture->argb = NULL; 145 picture->argb_stride = 0; 146 } 147 148 // Remove reference to the YUVA buffer (doesn't free anything). 149 static void PictureResetYUVA(WebPPicture* const picture) { 150 picture->memory_ = NULL; 151 picture->y = picture->u = picture->v = picture->a = NULL; 152 picture->u0 = picture->v0 = NULL; 153 picture->y_stride = picture->uv_stride = 0; 154 picture->a_stride = 0; 155 picture->uv0_stride = 0; 156 } 157 158 // Grab the 'specs' (writer, *opaque, width, height...) from 'src' and copy them 159 // into 'dst'. Mark 'dst' as not owning any memory. 160 static void WebPPictureGrabSpecs(const WebPPicture* const src, 161 WebPPicture* const dst) { 162 assert(src != NULL && dst != NULL); 163 *dst = *src; 164 PictureResetYUVA(dst); 165 PictureResetARGB(dst); 166 } 167 168 // Allocate a new argb buffer, discarding any existing one and preserving 169 // the other YUV(A) buffer. 170 static int PictureAllocARGB(WebPPicture* const picture) { 171 WebPPicture tmp; 172 free(picture->memory_argb_); 173 PictureResetARGB(picture); 174 picture->use_argb = 1; 175 WebPPictureGrabSpecs(picture, &tmp); 176 if (!WebPPictureAlloc(&tmp)) { 177 return WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY); 178 } 179 picture->memory_argb_ = tmp.memory_argb_; 180 picture->argb = tmp.argb; 181 picture->argb_stride = tmp.argb_stride; 182 return 1; 183 } 184 185 // Release memory owned by 'picture' (both YUV and ARGB buffers). 186 void WebPPictureFree(WebPPicture* picture) { 187 if (picture != NULL) { 188 free(picture->memory_); 189 free(picture->memory_argb_); 190 PictureResetYUVA(picture); 191 PictureResetARGB(picture); 192 } 193 } 194 195 //------------------------------------------------------------------------------ 196 // Picture copying 197 198 // Not worth moving to dsp/enc.c (only used here). 199 static void CopyPlane(const uint8_t* src, int src_stride, 200 uint8_t* dst, int dst_stride, int width, int height) { 201 while (height-- > 0) { 202 memcpy(dst, src, width); 203 src += src_stride; 204 dst += dst_stride; 205 } 206 } 207 208 // Adjust top-left corner to chroma sample position. 209 static void SnapTopLeftPosition(const WebPPicture* const pic, 210 int* const left, int* const top) { 211 if (!pic->use_argb) { 212 const int is_yuv422 = IS_YUV_CSP(pic->colorspace, WEBP_YUV422); 213 if (IS_YUV_CSP(pic->colorspace, WEBP_YUV420) || is_yuv422) { 214 *left &= ~1; 215 if (!is_yuv422) *top &= ~1; 216 } 217 } 218 } 219 220 // Adjust top-left corner and verify that the sub-rectangle is valid. 221 static int AdjustAndCheckRectangle(const WebPPicture* const pic, 222 int* const left, int* const top, 223 int width, int height) { 224 SnapTopLeftPosition(pic, left, top); 225 if ((*left) < 0 || (*top) < 0) return 0; 226 if (width <= 0 || height <= 0) return 0; 227 if ((*left) + width > pic->width) return 0; 228 if ((*top) + height > pic->height) return 0; 229 return 1; 230 } 231 232 int WebPPictureCopy(const WebPPicture* src, WebPPicture* dst) { 233 if (src == NULL || dst == NULL) return 0; 234 if (src == dst) return 1; 235 236 WebPPictureGrabSpecs(src, dst); 237 if (!WebPPictureAlloc(dst)) return 0; 238 239 if (!src->use_argb) { 240 CopyPlane(src->y, src->y_stride, 241 dst->y, dst->y_stride, dst->width, dst->height); 242 CopyPlane(src->u, src->uv_stride, 243 dst->u, dst->uv_stride, HALVE(dst->width), HALVE(dst->height)); 244 CopyPlane(src->v, src->uv_stride, 245 dst->v, dst->uv_stride, HALVE(dst->width), HALVE(dst->height)); 246 if (dst->a != NULL) { 247 CopyPlane(src->a, src->a_stride, 248 dst->a, dst->a_stride, dst->width, dst->height); 249 } 250 #ifdef WEBP_EXPERIMENTAL_FEATURES 251 if (dst->u0 != NULL) { 252 int uv0_width = src->width; 253 if (IS_YUV_CSP(dst->colorspace, WEBP_YUV422)) { 254 uv0_width = HALVE(uv0_width); 255 } 256 CopyPlane(src->u0, src->uv0_stride, 257 dst->u0, dst->uv0_stride, uv0_width, dst->height); 258 CopyPlane(src->v0, src->uv0_stride, 259 dst->v0, dst->uv0_stride, uv0_width, dst->height); 260 } 261 #endif 262 } else { 263 CopyPlane((const uint8_t*)src->argb, 4 * src->argb_stride, 264 (uint8_t*)dst->argb, 4 * dst->argb_stride, 265 4 * dst->width, dst->height); 266 } 267 return 1; 268 } 269 270 int WebPPictureIsView(const WebPPicture* picture) { 271 if (picture == NULL) return 0; 272 if (picture->use_argb) { 273 return (picture->memory_argb_ == NULL); 274 } 275 return (picture->memory_ == NULL); 276 } 277 278 int WebPPictureView(const WebPPicture* src, 279 int left, int top, int width, int height, 280 WebPPicture* dst) { 281 if (src == NULL || dst == NULL) return 0; 282 283 // verify rectangle position. 284 if (!AdjustAndCheckRectangle(src, &left, &top, width, height)) return 0; 285 286 if (src != dst) { // beware of aliasing! We don't want to leak 'memory_'. 287 WebPPictureGrabSpecs(src, dst); 288 } 289 dst->width = width; 290 dst->height = height; 291 if (!src->use_argb) { 292 dst->y = src->y + top * src->y_stride + left; 293 dst->u = src->u + (top >> 1) * src->uv_stride + (left >> 1); 294 dst->v = src->v + (top >> 1) * src->uv_stride + (left >> 1); 295 dst->y_stride = src->y_stride; 296 dst->uv_stride = src->uv_stride; 297 if (src->a != NULL) { 298 dst->a = src->a + top * src->a_stride + left; 299 dst->a_stride = src->a_stride; 300 } 301 #ifdef WEBP_EXPERIMENTAL_FEATURES 302 if (src->u0 != NULL) { 303 const int left_pos = 304 IS_YUV_CSP(dst->colorspace, WEBP_YUV422) ? (left >> 1) : left; 305 dst->u0 = src->u0 + top * src->uv0_stride + left_pos; 306 dst->v0 = src->v0 + top * src->uv0_stride + left_pos; 307 dst->uv0_stride = src->uv0_stride; 308 } 309 #endif 310 } else { 311 dst->argb = src->argb + top * src->argb_stride + left; 312 dst->argb_stride = src->argb_stride; 313 } 314 return 1; 315 } 316 317 //------------------------------------------------------------------------------ 318 // Picture cropping 319 320 int WebPPictureCrop(WebPPicture* pic, 321 int left, int top, int width, int height) { 322 WebPPicture tmp; 323 324 if (pic == NULL) return 0; 325 if (!AdjustAndCheckRectangle(pic, &left, &top, width, height)) return 0; 326 327 WebPPictureGrabSpecs(pic, &tmp); 328 tmp.width = width; 329 tmp.height = height; 330 if (!WebPPictureAlloc(&tmp)) return 0; 331 332 if (!pic->use_argb) { 333 const int y_offset = top * pic->y_stride + left; 334 const int uv_offset = (top / 2) * pic->uv_stride + left / 2; 335 CopyPlane(pic->y + y_offset, pic->y_stride, 336 tmp.y, tmp.y_stride, width, height); 337 CopyPlane(pic->u + uv_offset, pic->uv_stride, 338 tmp.u, tmp.uv_stride, HALVE(width), HALVE(height)); 339 CopyPlane(pic->v + uv_offset, pic->uv_stride, 340 tmp.v, tmp.uv_stride, HALVE(width), HALVE(height)); 341 342 if (tmp.a != NULL) { 343 const int a_offset = top * pic->a_stride + left; 344 CopyPlane(pic->a + a_offset, pic->a_stride, 345 tmp.a, tmp.a_stride, width, height); 346 } 347 #ifdef WEBP_EXPERIMENTAL_FEATURES 348 if (tmp.u0 != NULL) { 349 int w = width; 350 int left_pos = left; 351 if (IS_YUV_CSP(tmp.colorspace, WEBP_YUV422)) { 352 w = HALVE(w); 353 left_pos = HALVE(left_pos); 354 } 355 CopyPlane(pic->u0 + top * pic->uv0_stride + left_pos, pic->uv0_stride, 356 tmp.u0, tmp.uv0_stride, w, height); 357 CopyPlane(pic->v0 + top * pic->uv0_stride + left_pos, pic->uv0_stride, 358 tmp.v0, tmp.uv0_stride, w, height); 359 } 360 #endif 361 } else { 362 const uint8_t* const src = 363 (const uint8_t*)(pic->argb + top * pic->argb_stride + left); 364 CopyPlane(src, pic->argb_stride * 4, 365 (uint8_t*)tmp.argb, tmp.argb_stride * 4, 366 width * 4, height); 367 } 368 WebPPictureFree(pic); 369 *pic = tmp; 370 return 1; 371 } 372 373 //------------------------------------------------------------------------------ 374 // Simple picture rescaler 375 376 static void RescalePlane(const uint8_t* src, 377 int src_width, int src_height, int src_stride, 378 uint8_t* dst, 379 int dst_width, int dst_height, int dst_stride, 380 int32_t* const work, 381 int num_channels) { 382 WebPRescaler rescaler; 383 int y = 0; 384 WebPRescalerInit(&rescaler, src_width, src_height, 385 dst, dst_width, dst_height, dst_stride, 386 num_channels, 387 src_width, dst_width, 388 src_height, dst_height, 389 work); 390 memset(work, 0, 2 * dst_width * num_channels * sizeof(*work)); 391 while (y < src_height) { 392 y += WebPRescalerImport(&rescaler, src_height - y, 393 src + y * src_stride, src_stride); 394 WebPRescalerExport(&rescaler); 395 } 396 } 397 398 int WebPPictureRescale(WebPPicture* pic, int width, int height) { 399 WebPPicture tmp; 400 int prev_width, prev_height; 401 int32_t* work; 402 403 if (pic == NULL) return 0; 404 prev_width = pic->width; 405 prev_height = pic->height; 406 // if width is unspecified, scale original proportionally to height ratio. 407 if (width == 0) { 408 width = (prev_width * height + prev_height / 2) / prev_height; 409 } 410 // if height is unspecified, scale original proportionally to width ratio. 411 if (height == 0) { 412 height = (prev_height * width + prev_width / 2) / prev_width; 413 } 414 // Check if the overall dimensions still make sense. 415 if (width <= 0 || height <= 0) return 0; 416 417 WebPPictureGrabSpecs(pic, &tmp); 418 tmp.width = width; 419 tmp.height = height; 420 if (!WebPPictureAlloc(&tmp)) return 0; 421 422 if (!pic->use_argb) { 423 work = (int32_t*)WebPSafeMalloc(2ULL * width, sizeof(*work)); 424 if (work == NULL) { 425 WebPPictureFree(&tmp); 426 return 0; 427 } 428 429 RescalePlane(pic->y, prev_width, prev_height, pic->y_stride, 430 tmp.y, width, height, tmp.y_stride, work, 1); 431 RescalePlane(pic->u, 432 HALVE(prev_width), HALVE(prev_height), pic->uv_stride, 433 tmp.u, 434 HALVE(width), HALVE(height), tmp.uv_stride, work, 1); 435 RescalePlane(pic->v, 436 HALVE(prev_width), HALVE(prev_height), pic->uv_stride, 437 tmp.v, 438 HALVE(width), HALVE(height), tmp.uv_stride, work, 1); 439 440 if (tmp.a != NULL) { 441 RescalePlane(pic->a, prev_width, prev_height, pic->a_stride, 442 tmp.a, width, height, tmp.a_stride, work, 1); 443 } 444 #ifdef WEBP_EXPERIMENTAL_FEATURES 445 if (tmp.u0 != NULL) { 446 const int s = IS_YUV_CSP(tmp.colorspace, WEBP_YUV422) ? 2 : 1; 447 RescalePlane( 448 pic->u0, (prev_width + s / 2) / s, prev_height, pic->uv0_stride, 449 tmp.u0, (width + s / 2) / s, height, tmp.uv0_stride, work, 1); 450 RescalePlane( 451 pic->v0, (prev_width + s / 2) / s, prev_height, pic->uv0_stride, 452 tmp.v0, (width + s / 2) / s, height, tmp.uv0_stride, work, 1); 453 } 454 #endif 455 } else { 456 work = (int32_t*)WebPSafeMalloc(2ULL * width * 4, sizeof(*work)); 457 if (work == NULL) { 458 WebPPictureFree(&tmp); 459 return 0; 460 } 461 462 RescalePlane((const uint8_t*)pic->argb, prev_width, prev_height, 463 pic->argb_stride * 4, 464 (uint8_t*)tmp.argb, width, height, 465 tmp.argb_stride * 4, 466 work, 4); 467 } 468 WebPPictureFree(pic); 469 free(work); 470 *pic = tmp; 471 return 1; 472 } 473 474 //------------------------------------------------------------------------------ 475 // WebPMemoryWriter: Write-to-memory 476 477 void WebPMemoryWriterInit(WebPMemoryWriter* writer) { 478 writer->mem = NULL; 479 writer->size = 0; 480 writer->max_size = 0; 481 } 482 483 int WebPMemoryWrite(const uint8_t* data, size_t data_size, 484 const WebPPicture* picture) { 485 WebPMemoryWriter* const w = (WebPMemoryWriter*)picture->custom_ptr; 486 uint64_t next_size; 487 if (w == NULL) { 488 return 1; 489 } 490 next_size = (uint64_t)w->size + data_size; 491 if (next_size > w->max_size) { 492 uint8_t* new_mem; 493 uint64_t next_max_size = 2ULL * w->max_size; 494 if (next_max_size < next_size) next_max_size = next_size; 495 if (next_max_size < 8192ULL) next_max_size = 8192ULL; 496 new_mem = (uint8_t*)WebPSafeMalloc(next_max_size, 1); 497 if (new_mem == NULL) { 498 return 0; 499 } 500 if (w->size > 0) { 501 memcpy(new_mem, w->mem, w->size); 502 } 503 free(w->mem); 504 w->mem = new_mem; 505 // down-cast is ok, thanks to WebPSafeMalloc 506 w->max_size = (size_t)next_max_size; 507 } 508 if (data_size > 0) { 509 memcpy(w->mem + w->size, data, data_size); 510 w->size += data_size; 511 } 512 return 1; 513 } 514 515 //------------------------------------------------------------------------------ 516 // Detection of non-trivial transparency 517 518 // Returns true if alpha[] has non-0xff values. 519 static int CheckNonOpaque(const uint8_t* alpha, int width, int height, 520 int x_step, int y_step) { 521 if (alpha == NULL) return 0; 522 while (height-- > 0) { 523 int x; 524 for (x = 0; x < width * x_step; x += x_step) { 525 if (alpha[x] != 0xff) return 1; // TODO(skal): check 4/8 bytes at a time. 526 } 527 alpha += y_step; 528 } 529 return 0; 530 } 531 532 // Checking for the presence of non-opaque alpha. 533 int WebPPictureHasTransparency(const WebPPicture* picture) { 534 if (picture == NULL) return 0; 535 if (!picture->use_argb) { 536 return CheckNonOpaque(picture->a, picture->width, picture->height, 537 1, picture->a_stride); 538 } else { 539 int x, y; 540 const uint32_t* argb = picture->argb; 541 if (argb == NULL) return 0; 542 for (y = 0; y < picture->height; ++y) { 543 for (x = 0; x < picture->width; ++x) { 544 if (argb[x] < 0xff000000u) return 1; // test any alpha values != 0xff 545 } 546 argb += picture->argb_stride; 547 } 548 } 549 return 0; 550 } 551 552 //------------------------------------------------------------------------------ 553 // RGB -> YUV conversion 554 555 // TODO: we can do better than simply 2x2 averaging on U/V samples. 556 #define SUM4(ptr) ((ptr)[0] + (ptr)[step] + \ 557 (ptr)[rgb_stride] + (ptr)[rgb_stride + step]) 558 #define SUM2H(ptr) (2 * (ptr)[0] + 2 * (ptr)[step]) 559 #define SUM2V(ptr) (2 * (ptr)[0] + 2 * (ptr)[rgb_stride]) 560 #define SUM1(ptr) (4 * (ptr)[0]) 561 #define RGB_TO_UV(x, y, SUM) { \ 562 const int src = (2 * (step * (x) + (y) * rgb_stride)); \ 563 const int dst = (x) + (y) * picture->uv_stride; \ 564 const int r = SUM(r_ptr + src); \ 565 const int g = SUM(g_ptr + src); \ 566 const int b = SUM(b_ptr + src); \ 567 picture->u[dst] = VP8RGBToU(r, g, b); \ 568 picture->v[dst] = VP8RGBToV(r, g, b); \ 569 } 570 571 #define RGB_TO_UV0(x_in, x_out, y, SUM) { \ 572 const int src = (step * (x_in) + (y) * rgb_stride); \ 573 const int dst = (x_out) + (y) * picture->uv0_stride; \ 574 const int r = SUM(r_ptr + src); \ 575 const int g = SUM(g_ptr + src); \ 576 const int b = SUM(b_ptr + src); \ 577 picture->u0[dst] = VP8RGBToU(r, g, b); \ 578 picture->v0[dst] = VP8RGBToV(r, g, b); \ 579 } 580 581 static void MakeGray(WebPPicture* const picture) { 582 int y; 583 const int uv_width = HALVE(picture->width); 584 const int uv_height = HALVE(picture->height); 585 for (y = 0; y < uv_height; ++y) { 586 memset(picture->u + y * picture->uv_stride, 128, uv_width); 587 memset(picture->v + y * picture->uv_stride, 128, uv_width); 588 } 589 } 590 591 static int ImportYUVAFromRGBA(const uint8_t* const r_ptr, 592 const uint8_t* const g_ptr, 593 const uint8_t* const b_ptr, 594 const uint8_t* const a_ptr, 595 int step, // bytes per pixel 596 int rgb_stride, // bytes per scanline 597 WebPPicture* const picture) { 598 const WebPEncCSP uv_csp = picture->colorspace & WEBP_CSP_UV_MASK; 599 int x, y; 600 const int width = picture->width; 601 const int height = picture->height; 602 const int has_alpha = CheckNonOpaque(a_ptr, width, height, step, rgb_stride); 603 604 picture->colorspace = uv_csp; 605 picture->use_argb = 0; 606 if (has_alpha) { 607 picture->colorspace |= WEBP_CSP_ALPHA_BIT; 608 } 609 if (!WebPPictureAlloc(picture)) return 0; 610 611 // Import luma plane 612 for (y = 0; y < height; ++y) { 613 for (x = 0; x < width; ++x) { 614 const int offset = step * x + y * rgb_stride; 615 picture->y[x + y * picture->y_stride] = 616 VP8RGBToY(r_ptr[offset], g_ptr[offset], b_ptr[offset]); 617 } 618 } 619 620 // Downsample U/V plane 621 if (uv_csp != WEBP_YUV400) { 622 for (y = 0; y < (height >> 1); ++y) { 623 for (x = 0; x < (width >> 1); ++x) { 624 RGB_TO_UV(x, y, SUM4); 625 } 626 if (width & 1) { 627 RGB_TO_UV(x, y, SUM2V); 628 } 629 } 630 if (height & 1) { 631 for (x = 0; x < (width >> 1); ++x) { 632 RGB_TO_UV(x, y, SUM2H); 633 } 634 if (width & 1) { 635 RGB_TO_UV(x, y, SUM1); 636 } 637 } 638 639 #ifdef WEBP_EXPERIMENTAL_FEATURES 640 // Store original U/V samples too 641 if (uv_csp == WEBP_YUV422) { 642 for (y = 0; y < height; ++y) { 643 for (x = 0; x < (width >> 1); ++x) { 644 RGB_TO_UV0(2 * x, x, y, SUM2H); 645 } 646 if (width & 1) { 647 RGB_TO_UV0(2 * x, x, y, SUM1); 648 } 649 } 650 } else if (uv_csp == WEBP_YUV444) { 651 for (y = 0; y < height; ++y) { 652 for (x = 0; x < width; ++x) { 653 RGB_TO_UV0(x, x, y, SUM1); 654 } 655 } 656 } 657 #endif 658 } else { 659 MakeGray(picture); 660 } 661 662 if (has_alpha) { 663 assert(step >= 4); 664 for (y = 0; y < height; ++y) { 665 for (x = 0; x < width; ++x) { 666 picture->a[x + y * picture->a_stride] = 667 a_ptr[step * x + y * rgb_stride]; 668 } 669 } 670 } 671 return 1; 672 } 673 674 static int Import(WebPPicture* const picture, 675 const uint8_t* const rgb, int rgb_stride, 676 int step, int swap_rb, int import_alpha) { 677 const uint8_t* const r_ptr = rgb + (swap_rb ? 2 : 0); 678 const uint8_t* const g_ptr = rgb + 1; 679 const uint8_t* const b_ptr = rgb + (swap_rb ? 0 : 2); 680 const uint8_t* const a_ptr = import_alpha ? rgb + 3 : NULL; 681 const int width = picture->width; 682 const int height = picture->height; 683 684 if (!picture->use_argb) { 685 return ImportYUVAFromRGBA(r_ptr, g_ptr, b_ptr, a_ptr, step, rgb_stride, 686 picture); 687 } 688 if (import_alpha) { 689 picture->colorspace |= WEBP_CSP_ALPHA_BIT; 690 } else { 691 picture->colorspace &= ~WEBP_CSP_ALPHA_BIT; 692 } 693 if (!WebPPictureAlloc(picture)) return 0; 694 695 if (!import_alpha) { 696 int x, y; 697 for (y = 0; y < height; ++y) { 698 for (x = 0; x < width; ++x) { 699 const int offset = step * x + y * rgb_stride; 700 const uint32_t argb = 701 0xff000000u | 702 (r_ptr[offset] << 16) | 703 (g_ptr[offset] << 8) | 704 (b_ptr[offset]); 705 picture->argb[x + y * picture->argb_stride] = argb; 706 } 707 } 708 } else { 709 int x, y; 710 assert(step >= 4); 711 for (y = 0; y < height; ++y) { 712 for (x = 0; x < width; ++x) { 713 const int offset = step * x + y * rgb_stride; 714 const uint32_t argb = ((uint32_t)a_ptr[offset] << 24) | 715 (r_ptr[offset] << 16) | 716 (g_ptr[offset] << 8) | 717 (b_ptr[offset]); 718 picture->argb[x + y * picture->argb_stride] = argb; 719 } 720 } 721 } 722 return 1; 723 } 724 #undef SUM4 725 #undef SUM2V 726 #undef SUM2H 727 #undef SUM1 728 #undef RGB_TO_UV 729 730 int WebPPictureImportRGB(WebPPicture* picture, 731 const uint8_t* rgb, int rgb_stride) { 732 return Import(picture, rgb, rgb_stride, 3, 0, 0); 733 } 734 735 int WebPPictureImportBGR(WebPPicture* picture, 736 const uint8_t* rgb, int rgb_stride) { 737 return Import(picture, rgb, rgb_stride, 3, 1, 0); 738 } 739 740 int WebPPictureImportRGBA(WebPPicture* picture, 741 const uint8_t* rgba, int rgba_stride) { 742 return Import(picture, rgba, rgba_stride, 4, 0, 1); 743 } 744 745 int WebPPictureImportBGRA(WebPPicture* picture, 746 const uint8_t* rgba, int rgba_stride) { 747 return Import(picture, rgba, rgba_stride, 4, 1, 1); 748 } 749 750 int WebPPictureImportRGBX(WebPPicture* picture, 751 const uint8_t* rgba, int rgba_stride) { 752 return Import(picture, rgba, rgba_stride, 4, 0, 0); 753 } 754 755 int WebPPictureImportBGRX(WebPPicture* picture, 756 const uint8_t* rgba, int rgba_stride) { 757 return Import(picture, rgba, rgba_stride, 4, 1, 0); 758 } 759 760 //------------------------------------------------------------------------------ 761 // Automatic YUV <-> ARGB conversions. 762 763 int WebPPictureYUVAToARGB(WebPPicture* picture) { 764 if (picture == NULL) return 0; 765 if (picture->memory_ == NULL || picture->y == NULL || 766 picture->u == NULL || picture->v == NULL) { 767 return WebPEncodingSetError(picture, VP8_ENC_ERROR_NULL_PARAMETER); 768 } 769 if ((picture->colorspace & WEBP_CSP_ALPHA_BIT) && picture->a == NULL) { 770 return WebPEncodingSetError(picture, VP8_ENC_ERROR_NULL_PARAMETER); 771 } 772 if ((picture->colorspace & WEBP_CSP_UV_MASK) != WEBP_YUV420) { 773 return WebPEncodingSetError(picture, VP8_ENC_ERROR_INVALID_CONFIGURATION); 774 } 775 // Allocate a new argb buffer (discarding the previous one). 776 if (!PictureAllocARGB(picture)) return 0; 777 778 // Convert 779 { 780 int y; 781 const int width = picture->width; 782 const int height = picture->height; 783 const int argb_stride = 4 * picture->argb_stride; 784 uint8_t* dst = (uint8_t*)picture->argb; 785 const uint8_t *cur_u = picture->u, *cur_v = picture->v, *cur_y = picture->y; 786 WebPUpsampleLinePairFunc upsample = WebPGetLinePairConverter(ALPHA_IS_LAST); 787 788 // First row, with replicated top samples. 789 upsample(NULL, cur_y, cur_u, cur_v, cur_u, cur_v, NULL, dst, width); 790 cur_y += picture->y_stride; 791 dst += argb_stride; 792 // Center rows. 793 for (y = 1; y + 1 < height; y += 2) { 794 const uint8_t* const top_u = cur_u; 795 const uint8_t* const top_v = cur_v; 796 cur_u += picture->uv_stride; 797 cur_v += picture->uv_stride; 798 upsample(cur_y, cur_y + picture->y_stride, top_u, top_v, cur_u, cur_v, 799 dst, dst + argb_stride, width); 800 cur_y += 2 * picture->y_stride; 801 dst += 2 * argb_stride; 802 } 803 // Last row (if needed), with replicated bottom samples. 804 if (height > 1 && !(height & 1)) { 805 upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v, dst, NULL, width); 806 } 807 // Insert alpha values if needed, in replacement for the default 0xff ones. 808 if (picture->colorspace & WEBP_CSP_ALPHA_BIT) { 809 for (y = 0; y < height; ++y) { 810 uint32_t* const argb_dst = picture->argb + y * picture->argb_stride; 811 const uint8_t* const src = picture->a + y * picture->a_stride; 812 int x; 813 for (x = 0; x < width; ++x) { 814 argb_dst[x] = (argb_dst[x] & 0x00ffffffu) | ((uint32_t)src[x] << 24); 815 } 816 } 817 } 818 } 819 return 1; 820 } 821 822 int WebPPictureARGBToYUVA(WebPPicture* picture, WebPEncCSP colorspace) { 823 if (picture == NULL) return 0; 824 if (picture->argb == NULL) { 825 return WebPEncodingSetError(picture, VP8_ENC_ERROR_NULL_PARAMETER); 826 } else { 827 const uint8_t* const argb = (const uint8_t*)picture->argb; 828 const uint8_t* const r = ALPHA_IS_LAST ? argb + 2 : argb + 1; 829 const uint8_t* const g = ALPHA_IS_LAST ? argb + 1 : argb + 2; 830 const uint8_t* const b = ALPHA_IS_LAST ? argb + 0 : argb + 3; 831 const uint8_t* const a = ALPHA_IS_LAST ? argb + 3 : argb + 0; 832 // We work on a tmp copy of 'picture', because ImportYUVAFromRGBA() 833 // would be calling WebPPictureFree(picture) otherwise. 834 WebPPicture tmp = *picture; 835 PictureResetARGB(&tmp); // reset ARGB buffer so that it's not free()'d. 836 tmp.use_argb = 0; 837 tmp.colorspace = colorspace & WEBP_CSP_UV_MASK; 838 if (!ImportYUVAFromRGBA(r, g, b, a, 4, 4 * picture->argb_stride, &tmp)) { 839 return WebPEncodingSetError(picture, VP8_ENC_ERROR_OUT_OF_MEMORY); 840 } 841 // Copy back the YUV specs into 'picture'. 842 tmp.argb = picture->argb; 843 tmp.argb_stride = picture->argb_stride; 844 tmp.memory_argb_ = picture->memory_argb_; 845 *picture = tmp; 846 } 847 return 1; 848 } 849 850 //------------------------------------------------------------------------------ 851 // Helper: clean up fully transparent area to help compressibility. 852 853 #define SIZE 8 854 #define SIZE2 (SIZE / 2) 855 static int is_transparent_area(const uint8_t* ptr, int stride, int size) { 856 int y, x; 857 for (y = 0; y < size; ++y) { 858 for (x = 0; x < size; ++x) { 859 if (ptr[x]) { 860 return 0; 861 } 862 } 863 ptr += stride; 864 } 865 return 1; 866 } 867 868 static WEBP_INLINE void flatten(uint8_t* ptr, int v, int stride, int size) { 869 int y; 870 for (y = 0; y < size; ++y) { 871 memset(ptr, v, size); 872 ptr += stride; 873 } 874 } 875 876 void WebPCleanupTransparentArea(WebPPicture* pic) { 877 int x, y, w, h; 878 const uint8_t* a_ptr; 879 int values[3] = { 0 }; 880 881 if (pic == NULL) return; 882 883 a_ptr = pic->a; 884 if (a_ptr == NULL) return; // nothing to do 885 886 w = pic->width / SIZE; 887 h = pic->height / SIZE; 888 for (y = 0; y < h; ++y) { 889 int need_reset = 1; 890 for (x = 0; x < w; ++x) { 891 const int off_a = (y * pic->a_stride + x) * SIZE; 892 const int off_y = (y * pic->y_stride + x) * SIZE; 893 const int off_uv = (y * pic->uv_stride + x) * SIZE2; 894 if (is_transparent_area(a_ptr + off_a, pic->a_stride, SIZE)) { 895 if (need_reset) { 896 values[0] = pic->y[off_y]; 897 values[1] = pic->u[off_uv]; 898 values[2] = pic->v[off_uv]; 899 need_reset = 0; 900 } 901 flatten(pic->y + off_y, values[0], pic->y_stride, SIZE); 902 flatten(pic->u + off_uv, values[1], pic->uv_stride, SIZE2); 903 flatten(pic->v + off_uv, values[2], pic->uv_stride, SIZE2); 904 } else { 905 need_reset = 1; 906 } 907 } 908 // ignore the left-overs on right/bottom 909 } 910 } 911 912 #undef SIZE 913 #undef SIZE2 914 915 //------------------------------------------------------------------------------ 916 // local-min distortion 917 // 918 // For every pixel in the *reference* picture, we search for the local best 919 // match in the compressed image. This is not a symmetrical measure. 920 921 // search radius. Shouldn't be too large. 922 #define RADIUS 2 923 924 static float AccumulateLSIM(const uint8_t* src, int src_stride, 925 const uint8_t* ref, int ref_stride, 926 int w, int h) { 927 int x, y; 928 double total_sse = 0.; 929 for (y = 0; y < h; ++y) { 930 const int y_0 = (y - RADIUS < 0) ? 0 : y - RADIUS; 931 const int y_1 = (y + RADIUS + 1 >= h) ? h : y + RADIUS + 1; 932 for (x = 0; x < w; ++x) { 933 const int x_0 = (x - RADIUS < 0) ? 0 : x - RADIUS; 934 const int x_1 = (x + RADIUS + 1 >= w) ? w : x + RADIUS + 1; 935 double best_sse = 255. * 255.; 936 const double value = (double)ref[y * ref_stride + x]; 937 int i, j; 938 for (j = y_0; j < y_1; ++j) { 939 const uint8_t* s = src + j * src_stride; 940 for (i = x_0; i < x_1; ++i) { 941 const double sse = (double)(s[i] - value) * (s[i] - value); 942 if (sse < best_sse) best_sse = sse; 943 } 944 } 945 total_sse += best_sse; 946 } 947 } 948 return (float)total_sse; 949 } 950 #undef RADIUS 951 952 //------------------------------------------------------------------------------ 953 // Distortion 954 955 // Max value returned in case of exact similarity. 956 static const double kMinDistortion_dB = 99.; 957 static float GetPSNR(const double v) { 958 return (float)((v > 0.) ? -4.3429448 * log(v / (255 * 255.)) 959 : kMinDistortion_dB); 960 } 961 962 int WebPPictureDistortion(const WebPPicture* src, const WebPPicture* ref, 963 int type, float result[5]) { 964 DistoStats stats[5]; 965 int has_alpha; 966 int uv_w, uv_h; 967 968 if (src == NULL || ref == NULL || 969 src->width != ref->width || src->height != ref->height || 970 src->y == NULL || ref->y == NULL || 971 src->u == NULL || ref->u == NULL || 972 src->v == NULL || ref->v == NULL || 973 result == NULL) { 974 return 0; 975 } 976 // TODO(skal): provide distortion for ARGB too. 977 if (src->use_argb == 1 || src->use_argb != ref->use_argb) { 978 return 0; 979 } 980 981 has_alpha = !!(src->colorspace & WEBP_CSP_ALPHA_BIT); 982 if (has_alpha != !!(ref->colorspace & WEBP_CSP_ALPHA_BIT) || 983 (has_alpha && (src->a == NULL || ref->a == NULL))) { 984 return 0; 985 } 986 987 memset(stats, 0, sizeof(stats)); 988 989 uv_w = HALVE(src->width); 990 uv_h = HALVE(src->height); 991 if (type >= 2) { 992 float sse[4]; 993 sse[0] = AccumulateLSIM(src->y, src->y_stride, 994 ref->y, ref->y_stride, src->width, src->height); 995 sse[1] = AccumulateLSIM(src->u, src->uv_stride, 996 ref->u, ref->uv_stride, uv_w, uv_h); 997 sse[2] = AccumulateLSIM(src->v, src->uv_stride, 998 ref->v, ref->uv_stride, uv_w, uv_h); 999 sse[3] = has_alpha ? AccumulateLSIM(src->a, src->a_stride, 1000 ref->a, ref->a_stride, 1001 src->width, src->height) 1002 : 0.f; 1003 result[0] = GetPSNR(sse[0] / (src->width * src->height)); 1004 result[1] = GetPSNR(sse[1] / (uv_w * uv_h)); 1005 result[2] = GetPSNR(sse[2] / (uv_w * uv_h)); 1006 result[3] = GetPSNR(sse[3] / (src->width * src->height)); 1007 { 1008 double total_sse = sse[0] + sse[1] + sse[2]; 1009 int total_pixels = src->width * src->height + 2 * uv_w * uv_h; 1010 if (has_alpha) { 1011 total_pixels += src->width * src->height; 1012 total_sse += sse[3]; 1013 } 1014 result[4] = GetPSNR(total_sse / total_pixels); 1015 } 1016 } else { 1017 int c; 1018 VP8SSIMAccumulatePlane(src->y, src->y_stride, 1019 ref->y, ref->y_stride, 1020 src->width, src->height, &stats[0]); 1021 VP8SSIMAccumulatePlane(src->u, src->uv_stride, 1022 ref->u, ref->uv_stride, 1023 uv_w, uv_h, &stats[1]); 1024 VP8SSIMAccumulatePlane(src->v, src->uv_stride, 1025 ref->v, ref->uv_stride, 1026 uv_w, uv_h, &stats[2]); 1027 if (has_alpha) { 1028 VP8SSIMAccumulatePlane(src->a, src->a_stride, 1029 ref->a, ref->a_stride, 1030 src->width, src->height, &stats[3]); 1031 } 1032 for (c = 0; c <= 4; ++c) { 1033 if (type == 1) { 1034 const double v = VP8SSIMGet(&stats[c]); 1035 result[c] = (float)((v < 1.) ? -10.0 * log10(1. - v) 1036 : kMinDistortion_dB); 1037 } else { 1038 const double v = VP8SSIMGetSquaredError(&stats[c]); 1039 result[c] = GetPSNR(v); 1040 } 1041 // Accumulate forward 1042 if (c < 4) VP8SSIMAddStats(&stats[c], &stats[4]); 1043 } 1044 } 1045 return 1; 1046 } 1047 1048 //------------------------------------------------------------------------------ 1049 // Simplest high-level calls: 1050 1051 typedef int (*Importer)(WebPPicture* const, const uint8_t* const, int); 1052 1053 static size_t Encode(const uint8_t* rgba, int width, int height, int stride, 1054 Importer import, float quality_factor, int lossless, 1055 uint8_t** output) { 1056 WebPPicture pic; 1057 WebPConfig config; 1058 WebPMemoryWriter wrt; 1059 int ok; 1060 1061 if (!WebPConfigPreset(&config, WEBP_PRESET_DEFAULT, quality_factor) || 1062 !WebPPictureInit(&pic)) { 1063 return 0; // shouldn't happen, except if system installation is broken 1064 } 1065 1066 config.lossless = !!lossless; 1067 pic.use_argb = !!lossless; 1068 pic.width = width; 1069 pic.height = height; 1070 pic.writer = WebPMemoryWrite; 1071 pic.custom_ptr = &wrt; 1072 WebPMemoryWriterInit(&wrt); 1073 1074 ok = import(&pic, rgba, stride) && WebPEncode(&config, &pic); 1075 WebPPictureFree(&pic); 1076 if (!ok) { 1077 free(wrt.mem); 1078 *output = NULL; 1079 return 0; 1080 } 1081 *output = wrt.mem; 1082 return wrt.size; 1083 } 1084 1085 #define ENCODE_FUNC(NAME, IMPORTER) \ 1086 size_t NAME(const uint8_t* in, int w, int h, int bps, float q, \ 1087 uint8_t** out) { \ 1088 return Encode(in, w, h, bps, IMPORTER, q, 0, out); \ 1089 } 1090 1091 ENCODE_FUNC(WebPEncodeRGB, WebPPictureImportRGB); 1092 ENCODE_FUNC(WebPEncodeBGR, WebPPictureImportBGR); 1093 ENCODE_FUNC(WebPEncodeRGBA, WebPPictureImportRGBA); 1094 ENCODE_FUNC(WebPEncodeBGRA, WebPPictureImportBGRA); 1095 1096 #undef ENCODE_FUNC 1097 1098 #define LOSSLESS_DEFAULT_QUALITY 70. 1099 #define LOSSLESS_ENCODE_FUNC(NAME, IMPORTER) \ 1100 size_t NAME(const uint8_t* in, int w, int h, int bps, uint8_t** out) { \ 1101 return Encode(in, w, h, bps, IMPORTER, LOSSLESS_DEFAULT_QUALITY, 1, out); \ 1102 } 1103 1104 LOSSLESS_ENCODE_FUNC(WebPEncodeLosslessRGB, WebPPictureImportRGB); 1105 LOSSLESS_ENCODE_FUNC(WebPEncodeLosslessBGR, WebPPictureImportBGR); 1106 LOSSLESS_ENCODE_FUNC(WebPEncodeLosslessRGBA, WebPPictureImportRGBA); 1107 LOSSLESS_ENCODE_FUNC(WebPEncodeLosslessBGRA, WebPPictureImportBGRA); 1108 1109 #undef LOSSLESS_ENCODE_FUNC 1110 1111 //------------------------------------------------------------------------------ 1112 1113 #if defined(__cplusplus) || defined(c_plusplus) 1114 } // extern "C" 1115 #endif 1116
