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 // functions for sample output. 11 // 12 // Author: Skal (pascal.massimino@gmail.com) 13 14 #include <assert.h> 15 #include <stdlib.h> 16 #include "src/dec/vp8i_dec.h" 17 #include "src/dec/webpi_dec.h" 18 #include "src/dsp/dsp.h" 19 #include "src/dsp/yuv.h" 20 #include "src/utils/utils.h" 21 22 //------------------------------------------------------------------------------ 23 // Main YUV<->RGB conversion functions 24 25 static int EmitYUV(const VP8Io* const io, WebPDecParams* const p) { 26 WebPDecBuffer* output = p->output; 27 const WebPYUVABuffer* const buf = &output->u.YUVA; 28 uint8_t* const y_dst = buf->y + io->mb_y * buf->y_stride; 29 uint8_t* const u_dst = buf->u + (io->mb_y >> 1) * buf->u_stride; 30 uint8_t* const v_dst = buf->v + (io->mb_y >> 1) * buf->v_stride; 31 const int mb_w = io->mb_w; 32 const int mb_h = io->mb_h; 33 const int uv_w = (mb_w + 1) / 2; 34 const int uv_h = (mb_h + 1) / 2; 35 int j; 36 for (j = 0; j < mb_h; ++j) { 37 memcpy(y_dst + j * buf->y_stride, io->y + j * io->y_stride, mb_w); 38 } 39 for (j = 0; j < uv_h; ++j) { 40 memcpy(u_dst + j * buf->u_stride, io->u + j * io->uv_stride, uv_w); 41 memcpy(v_dst + j * buf->v_stride, io->v + j * io->uv_stride, uv_w); 42 } 43 return io->mb_h; 44 } 45 46 // Point-sampling U/V sampler. 47 static int EmitSampledRGB(const VP8Io* const io, WebPDecParams* const p) { 48 WebPDecBuffer* const output = p->output; 49 WebPRGBABuffer* const buf = &output->u.RGBA; 50 uint8_t* const dst = buf->rgba + io->mb_y * buf->stride; 51 WebPSamplerProcessPlane(io->y, io->y_stride, 52 io->u, io->v, io->uv_stride, 53 dst, buf->stride, io->mb_w, io->mb_h, 54 WebPSamplers[output->colorspace]); 55 return io->mb_h; 56 } 57 58 //------------------------------------------------------------------------------ 59 // Fancy upsampling 60 61 #ifdef FANCY_UPSAMPLING 62 static int EmitFancyRGB(const VP8Io* const io, WebPDecParams* const p) { 63 int num_lines_out = io->mb_h; // a priori guess 64 const WebPRGBABuffer* const buf = &p->output->u.RGBA; 65 uint8_t* dst = buf->rgba + io->mb_y * buf->stride; 66 WebPUpsampleLinePairFunc upsample = WebPUpsamplers[p->output->colorspace]; 67 const uint8_t* cur_y = io->y; 68 const uint8_t* cur_u = io->u; 69 const uint8_t* cur_v = io->v; 70 const uint8_t* top_u = p->tmp_u; 71 const uint8_t* top_v = p->tmp_v; 72 int y = io->mb_y; 73 const int y_end = io->mb_y + io->mb_h; 74 const int mb_w = io->mb_w; 75 const int uv_w = (mb_w + 1) / 2; 76 77 if (y == 0) { 78 // First line is special cased. We mirror the u/v samples at boundary. 79 upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v, dst, NULL, mb_w); 80 } else { 81 // We can finish the left-over line from previous call. 82 upsample(p->tmp_y, cur_y, top_u, top_v, cur_u, cur_v, 83 dst - buf->stride, dst, mb_w); 84 ++num_lines_out; 85 } 86 // Loop over each output pairs of row. 87 for (; y + 2 < y_end; y += 2) { 88 top_u = cur_u; 89 top_v = cur_v; 90 cur_u += io->uv_stride; 91 cur_v += io->uv_stride; 92 dst += 2 * buf->stride; 93 cur_y += 2 * io->y_stride; 94 upsample(cur_y - io->y_stride, cur_y, 95 top_u, top_v, cur_u, cur_v, 96 dst - buf->stride, dst, mb_w); 97 } 98 // move to last row 99 cur_y += io->y_stride; 100 if (io->crop_top + y_end < io->crop_bottom) { 101 // Save the unfinished samples for next call (as we're not done yet). 102 memcpy(p->tmp_y, cur_y, mb_w * sizeof(*p->tmp_y)); 103 memcpy(p->tmp_u, cur_u, uv_w * sizeof(*p->tmp_u)); 104 memcpy(p->tmp_v, cur_v, uv_w * sizeof(*p->tmp_v)); 105 // The fancy upsampler leaves a row unfinished behind 106 // (except for the very last row) 107 num_lines_out--; 108 } else { 109 // Process the very last row of even-sized picture 110 if (!(y_end & 1)) { 111 upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v, 112 dst + buf->stride, NULL, mb_w); 113 } 114 } 115 return num_lines_out; 116 } 117 118 #endif /* FANCY_UPSAMPLING */ 119 120 //------------------------------------------------------------------------------ 121 122 static void FillAlphaPlane(uint8_t* dst, int w, int h, int stride) { 123 int j; 124 for (j = 0; j < h; ++j) { 125 memset(dst, 0xff, w * sizeof(*dst)); 126 dst += stride; 127 } 128 } 129 130 static int EmitAlphaYUV(const VP8Io* const io, WebPDecParams* const p, 131 int expected_num_lines_out) { 132 const uint8_t* alpha = io->a; 133 const WebPYUVABuffer* const buf = &p->output->u.YUVA; 134 const int mb_w = io->mb_w; 135 const int mb_h = io->mb_h; 136 uint8_t* dst = buf->a + io->mb_y * buf->a_stride; 137 int j; 138 (void)expected_num_lines_out; 139 assert(expected_num_lines_out == mb_h); 140 if (alpha != NULL) { 141 for (j = 0; j < mb_h; ++j) { 142 memcpy(dst, alpha, mb_w * sizeof(*dst)); 143 alpha += io->width; 144 dst += buf->a_stride; 145 } 146 } else if (buf->a != NULL) { 147 // the user requested alpha, but there is none, set it to opaque. 148 FillAlphaPlane(dst, mb_w, mb_h, buf->a_stride); 149 } 150 return 0; 151 } 152 153 static int GetAlphaSourceRow(const VP8Io* const io, 154 const uint8_t** alpha, int* const num_rows) { 155 int start_y = io->mb_y; 156 *num_rows = io->mb_h; 157 158 // Compensate for the 1-line delay of the fancy upscaler. 159 // This is similar to EmitFancyRGB(). 160 if (io->fancy_upsampling) { 161 if (start_y == 0) { 162 // We don't process the last row yet. It'll be done during the next call. 163 --*num_rows; 164 } else { 165 --start_y; 166 // Fortunately, *alpha data is persistent, so we can go back 167 // one row and finish alpha blending, now that the fancy upscaler 168 // completed the YUV->RGB interpolation. 169 *alpha -= io->width; 170 } 171 if (io->crop_top + io->mb_y + io->mb_h == io->crop_bottom) { 172 // If it's the very last call, we process all the remaining rows! 173 *num_rows = io->crop_bottom - io->crop_top - start_y; 174 } 175 } 176 return start_y; 177 } 178 179 static int EmitAlphaRGB(const VP8Io* const io, WebPDecParams* const p, 180 int expected_num_lines_out) { 181 const uint8_t* alpha = io->a; 182 if (alpha != NULL) { 183 const int mb_w = io->mb_w; 184 const WEBP_CSP_MODE colorspace = p->output->colorspace; 185 const int alpha_first = 186 (colorspace == MODE_ARGB || colorspace == MODE_Argb); 187 const WebPRGBABuffer* const buf = &p->output->u.RGBA; 188 int num_rows; 189 const int start_y = GetAlphaSourceRow(io, &alpha, &num_rows); 190 uint8_t* const base_rgba = buf->rgba + start_y * buf->stride; 191 uint8_t* const dst = base_rgba + (alpha_first ? 0 : 3); 192 const int has_alpha = WebPDispatchAlpha(alpha, io->width, mb_w, 193 num_rows, dst, buf->stride); 194 (void)expected_num_lines_out; 195 assert(expected_num_lines_out == num_rows); 196 // has_alpha is true if there's non-trivial alpha to premultiply with. 197 if (has_alpha && WebPIsPremultipliedMode(colorspace)) { 198 WebPApplyAlphaMultiply(base_rgba, alpha_first, 199 mb_w, num_rows, buf->stride); 200 } 201 } 202 return 0; 203 } 204 205 static int EmitAlphaRGBA4444(const VP8Io* const io, WebPDecParams* const p, 206 int expected_num_lines_out) { 207 const uint8_t* alpha = io->a; 208 if (alpha != NULL) { 209 const int mb_w = io->mb_w; 210 const WEBP_CSP_MODE colorspace = p->output->colorspace; 211 const WebPRGBABuffer* const buf = &p->output->u.RGBA; 212 int num_rows; 213 const int start_y = GetAlphaSourceRow(io, &alpha, &num_rows); 214 uint8_t* const base_rgba = buf->rgba + start_y * buf->stride; 215 #if (WEBP_SWAP_16BIT_CSP == 1) 216 uint8_t* alpha_dst = base_rgba; 217 #else 218 uint8_t* alpha_dst = base_rgba + 1; 219 #endif 220 uint32_t alpha_mask = 0x0f; 221 int i, j; 222 for (j = 0; j < num_rows; ++j) { 223 for (i = 0; i < mb_w; ++i) { 224 // Fill in the alpha value (converted to 4 bits). 225 const uint32_t alpha_value = alpha[i] >> 4; 226 alpha_dst[2 * i] = (alpha_dst[2 * i] & 0xf0) | alpha_value; 227 alpha_mask &= alpha_value; 228 } 229 alpha += io->width; 230 alpha_dst += buf->stride; 231 } 232 (void)expected_num_lines_out; 233 assert(expected_num_lines_out == num_rows); 234 if (alpha_mask != 0x0f && WebPIsPremultipliedMode(colorspace)) { 235 WebPApplyAlphaMultiply4444(base_rgba, mb_w, num_rows, buf->stride); 236 } 237 } 238 return 0; 239 } 240 241 //------------------------------------------------------------------------------ 242 // YUV rescaling (no final RGB conversion needed) 243 244 #if !defined(WEBP_REDUCE_SIZE) 245 static int Rescale(const uint8_t* src, int src_stride, 246 int new_lines, WebPRescaler* const wrk) { 247 int num_lines_out = 0; 248 while (new_lines > 0) { // import new contributions of source rows. 249 const int lines_in = WebPRescalerImport(wrk, new_lines, src, src_stride); 250 src += lines_in * src_stride; 251 new_lines -= lines_in; 252 num_lines_out += WebPRescalerExport(wrk); // emit output row(s) 253 } 254 return num_lines_out; 255 } 256 257 static int EmitRescaledYUV(const VP8Io* const io, WebPDecParams* const p) { 258 const int mb_h = io->mb_h; 259 const int uv_mb_h = (mb_h + 1) >> 1; 260 WebPRescaler* const scaler = p->scaler_y; 261 int num_lines_out = 0; 262 if (WebPIsAlphaMode(p->output->colorspace) && io->a != NULL) { 263 // Before rescaling, we premultiply the luma directly into the io->y 264 // internal buffer. This is OK since these samples are not used for 265 // intra-prediction (the top samples are saved in cache_y_/u_/v_). 266 // But we need to cast the const away, though. 267 WebPMultRows((uint8_t*)io->y, io->y_stride, 268 io->a, io->width, io->mb_w, mb_h, 0); 269 } 270 num_lines_out = Rescale(io->y, io->y_stride, mb_h, scaler); 271 Rescale(io->u, io->uv_stride, uv_mb_h, p->scaler_u); 272 Rescale(io->v, io->uv_stride, uv_mb_h, p->scaler_v); 273 return num_lines_out; 274 } 275 276 static int EmitRescaledAlphaYUV(const VP8Io* const io, WebPDecParams* const p, 277 int expected_num_lines_out) { 278 const WebPYUVABuffer* const buf = &p->output->u.YUVA; 279 uint8_t* const dst_a = buf->a + p->last_y * buf->a_stride; 280 if (io->a != NULL) { 281 uint8_t* const dst_y = buf->y + p->last_y * buf->y_stride; 282 const int num_lines_out = Rescale(io->a, io->width, io->mb_h, p->scaler_a); 283 assert(expected_num_lines_out == num_lines_out); 284 if (num_lines_out > 0) { // unmultiply the Y 285 WebPMultRows(dst_y, buf->y_stride, dst_a, buf->a_stride, 286 p->scaler_a->dst_width, num_lines_out, 1); 287 } 288 } else if (buf->a != NULL) { 289 // the user requested alpha, but there is none, set it to opaque. 290 assert(p->last_y + expected_num_lines_out <= io->scaled_height); 291 FillAlphaPlane(dst_a, io->scaled_width, expected_num_lines_out, 292 buf->a_stride); 293 } 294 return 0; 295 } 296 297 static int InitYUVRescaler(const VP8Io* const io, WebPDecParams* const p) { 298 const int has_alpha = WebPIsAlphaMode(p->output->colorspace); 299 const WebPYUVABuffer* const buf = &p->output->u.YUVA; 300 const int out_width = io->scaled_width; 301 const int out_height = io->scaled_height; 302 const int uv_out_width = (out_width + 1) >> 1; 303 const int uv_out_height = (out_height + 1) >> 1; 304 const int uv_in_width = (io->mb_w + 1) >> 1; 305 const int uv_in_height = (io->mb_h + 1) >> 1; 306 const size_t work_size = 2 * out_width; // scratch memory for luma rescaler 307 const size_t uv_work_size = 2 * uv_out_width; // and for each u/v ones 308 size_t tmp_size, rescaler_size; 309 rescaler_t* work; 310 WebPRescaler* scalers; 311 const int num_rescalers = has_alpha ? 4 : 3; 312 313 tmp_size = (work_size + 2 * uv_work_size) * sizeof(*work); 314 if (has_alpha) { 315 tmp_size += work_size * sizeof(*work); 316 } 317 rescaler_size = num_rescalers * sizeof(*p->scaler_y) + WEBP_ALIGN_CST; 318 319 p->memory = WebPSafeMalloc(1ULL, tmp_size + rescaler_size); 320 if (p->memory == NULL) { 321 return 0; // memory error 322 } 323 work = (rescaler_t*)p->memory; 324 325 scalers = (WebPRescaler*)WEBP_ALIGN((const uint8_t*)work + tmp_size); 326 p->scaler_y = &scalers[0]; 327 p->scaler_u = &scalers[1]; 328 p->scaler_v = &scalers[2]; 329 p->scaler_a = has_alpha ? &scalers[3] : NULL; 330 331 WebPRescalerInit(p->scaler_y, io->mb_w, io->mb_h, 332 buf->y, out_width, out_height, buf->y_stride, 1, 333 work); 334 WebPRescalerInit(p->scaler_u, uv_in_width, uv_in_height, 335 buf->u, uv_out_width, uv_out_height, buf->u_stride, 1, 336 work + work_size); 337 WebPRescalerInit(p->scaler_v, uv_in_width, uv_in_height, 338 buf->v, uv_out_width, uv_out_height, buf->v_stride, 1, 339 work + work_size + uv_work_size); 340 p->emit = EmitRescaledYUV; 341 342 if (has_alpha) { 343 WebPRescalerInit(p->scaler_a, io->mb_w, io->mb_h, 344 buf->a, out_width, out_height, buf->a_stride, 1, 345 work + work_size + 2 * uv_work_size); 346 p->emit_alpha = EmitRescaledAlphaYUV; 347 WebPInitAlphaProcessing(); 348 } 349 return 1; 350 } 351 352 //------------------------------------------------------------------------------ 353 // RGBA rescaling 354 355 static int ExportRGB(WebPDecParams* const p, int y_pos) { 356 const WebPYUV444Converter convert = 357 WebPYUV444Converters[p->output->colorspace]; 358 const WebPRGBABuffer* const buf = &p->output->u.RGBA; 359 uint8_t* dst = buf->rgba + y_pos * buf->stride; 360 int num_lines_out = 0; 361 // For RGB rescaling, because of the YUV420, current scan position 362 // U/V can be +1/-1 line from the Y one. Hence the double test. 363 while (WebPRescalerHasPendingOutput(p->scaler_y) && 364 WebPRescalerHasPendingOutput(p->scaler_u)) { 365 assert(y_pos + num_lines_out < p->output->height); 366 assert(p->scaler_u->y_accum == p->scaler_v->y_accum); 367 WebPRescalerExportRow(p->scaler_y); 368 WebPRescalerExportRow(p->scaler_u); 369 WebPRescalerExportRow(p->scaler_v); 370 convert(p->scaler_y->dst, p->scaler_u->dst, p->scaler_v->dst, 371 dst, p->scaler_y->dst_width); 372 dst += buf->stride; 373 ++num_lines_out; 374 } 375 return num_lines_out; 376 } 377 378 static int EmitRescaledRGB(const VP8Io* const io, WebPDecParams* const p) { 379 const int mb_h = io->mb_h; 380 const int uv_mb_h = (mb_h + 1) >> 1; 381 int j = 0, uv_j = 0; 382 int num_lines_out = 0; 383 while (j < mb_h) { 384 const int y_lines_in = 385 WebPRescalerImport(p->scaler_y, mb_h - j, 386 io->y + j * io->y_stride, io->y_stride); 387 j += y_lines_in; 388 if (WebPRescaleNeededLines(p->scaler_u, uv_mb_h - uv_j)) { 389 const int u_lines_in = 390 WebPRescalerImport(p->scaler_u, uv_mb_h - uv_j, 391 io->u + uv_j * io->uv_stride, io->uv_stride); 392 const int v_lines_in = 393 WebPRescalerImport(p->scaler_v, uv_mb_h - uv_j, 394 io->v + uv_j * io->uv_stride, io->uv_stride); 395 (void)v_lines_in; // remove a gcc warning 396 assert(u_lines_in == v_lines_in); 397 uv_j += u_lines_in; 398 } 399 num_lines_out += ExportRGB(p, p->last_y + num_lines_out); 400 } 401 return num_lines_out; 402 } 403 404 static int ExportAlpha(WebPDecParams* const p, int y_pos, int max_lines_out) { 405 const WebPRGBABuffer* const buf = &p->output->u.RGBA; 406 uint8_t* const base_rgba = buf->rgba + y_pos * buf->stride; 407 const WEBP_CSP_MODE colorspace = p->output->colorspace; 408 const int alpha_first = 409 (colorspace == MODE_ARGB || colorspace == MODE_Argb); 410 uint8_t* dst = base_rgba + (alpha_first ? 0 : 3); 411 int num_lines_out = 0; 412 const int is_premult_alpha = WebPIsPremultipliedMode(colorspace); 413 uint32_t non_opaque = 0; 414 const int width = p->scaler_a->dst_width; 415 416 while (WebPRescalerHasPendingOutput(p->scaler_a) && 417 num_lines_out < max_lines_out) { 418 assert(y_pos + num_lines_out < p->output->height); 419 WebPRescalerExportRow(p->scaler_a); 420 non_opaque |= WebPDispatchAlpha(p->scaler_a->dst, 0, width, 1, dst, 0); 421 dst += buf->stride; 422 ++num_lines_out; 423 } 424 if (is_premult_alpha && non_opaque) { 425 WebPApplyAlphaMultiply(base_rgba, alpha_first, 426 width, num_lines_out, buf->stride); 427 } 428 return num_lines_out; 429 } 430 431 static int ExportAlphaRGBA4444(WebPDecParams* const p, int y_pos, 432 int max_lines_out) { 433 const WebPRGBABuffer* const buf = &p->output->u.RGBA; 434 uint8_t* const base_rgba = buf->rgba + y_pos * buf->stride; 435 #if (WEBP_SWAP_16BIT_CSP == 1) 436 uint8_t* alpha_dst = base_rgba; 437 #else 438 uint8_t* alpha_dst = base_rgba + 1; 439 #endif 440 int num_lines_out = 0; 441 const WEBP_CSP_MODE colorspace = p->output->colorspace; 442 const int width = p->scaler_a->dst_width; 443 const int is_premult_alpha = WebPIsPremultipliedMode(colorspace); 444 uint32_t alpha_mask = 0x0f; 445 446 while (WebPRescalerHasPendingOutput(p->scaler_a) && 447 num_lines_out < max_lines_out) { 448 int i; 449 assert(y_pos + num_lines_out < p->output->height); 450 WebPRescalerExportRow(p->scaler_a); 451 for (i = 0; i < width; ++i) { 452 // Fill in the alpha value (converted to 4 bits). 453 const uint32_t alpha_value = p->scaler_a->dst[i] >> 4; 454 alpha_dst[2 * i] = (alpha_dst[2 * i] & 0xf0) | alpha_value; 455 alpha_mask &= alpha_value; 456 } 457 alpha_dst += buf->stride; 458 ++num_lines_out; 459 } 460 if (is_premult_alpha && alpha_mask != 0x0f) { 461 WebPApplyAlphaMultiply4444(base_rgba, width, num_lines_out, buf->stride); 462 } 463 return num_lines_out; 464 } 465 466 static int EmitRescaledAlphaRGB(const VP8Io* const io, WebPDecParams* const p, 467 int expected_num_out_lines) { 468 if (io->a != NULL) { 469 WebPRescaler* const scaler = p->scaler_a; 470 int lines_left = expected_num_out_lines; 471 const int y_end = p->last_y + lines_left; 472 while (lines_left > 0) { 473 const int row_offset = scaler->src_y - io->mb_y; 474 WebPRescalerImport(scaler, io->mb_h + io->mb_y - scaler->src_y, 475 io->a + row_offset * io->width, io->width); 476 lines_left -= p->emit_alpha_row(p, y_end - lines_left, lines_left); 477 } 478 } 479 return 0; 480 } 481 482 static int InitRGBRescaler(const VP8Io* const io, WebPDecParams* const p) { 483 const int has_alpha = WebPIsAlphaMode(p->output->colorspace); 484 const int out_width = io->scaled_width; 485 const int out_height = io->scaled_height; 486 const int uv_in_width = (io->mb_w + 1) >> 1; 487 const int uv_in_height = (io->mb_h + 1) >> 1; 488 const size_t work_size = 2 * out_width; // scratch memory for one rescaler 489 rescaler_t* work; // rescalers work area 490 uint8_t* tmp; // tmp storage for scaled YUV444 samples before RGB conversion 491 size_t tmp_size1, tmp_size2, total_size, rescaler_size; 492 WebPRescaler* scalers; 493 const int num_rescalers = has_alpha ? 4 : 3; 494 495 tmp_size1 = 3 * work_size; 496 tmp_size2 = 3 * out_width; 497 if (has_alpha) { 498 tmp_size1 += work_size; 499 tmp_size2 += out_width; 500 } 501 total_size = tmp_size1 * sizeof(*work) + tmp_size2 * sizeof(*tmp); 502 rescaler_size = num_rescalers * sizeof(*p->scaler_y) + WEBP_ALIGN_CST; 503 504 p->memory = WebPSafeMalloc(1ULL, total_size + rescaler_size); 505 if (p->memory == NULL) { 506 return 0; // memory error 507 } 508 work = (rescaler_t*)p->memory; 509 tmp = (uint8_t*)(work + tmp_size1); 510 511 scalers = (WebPRescaler*)WEBP_ALIGN((const uint8_t*)work + total_size); 512 p->scaler_y = &scalers[0]; 513 p->scaler_u = &scalers[1]; 514 p->scaler_v = &scalers[2]; 515 p->scaler_a = has_alpha ? &scalers[3] : NULL; 516 517 WebPRescalerInit(p->scaler_y, io->mb_w, io->mb_h, 518 tmp + 0 * out_width, out_width, out_height, 0, 1, 519 work + 0 * work_size); 520 WebPRescalerInit(p->scaler_u, uv_in_width, uv_in_height, 521 tmp + 1 * out_width, out_width, out_height, 0, 1, 522 work + 1 * work_size); 523 WebPRescalerInit(p->scaler_v, uv_in_width, uv_in_height, 524 tmp + 2 * out_width, out_width, out_height, 0, 1, 525 work + 2 * work_size); 526 p->emit = EmitRescaledRGB; 527 WebPInitYUV444Converters(); 528 529 if (has_alpha) { 530 WebPRescalerInit(p->scaler_a, io->mb_w, io->mb_h, 531 tmp + 3 * out_width, out_width, out_height, 0, 1, 532 work + 3 * work_size); 533 p->emit_alpha = EmitRescaledAlphaRGB; 534 if (p->output->colorspace == MODE_RGBA_4444 || 535 p->output->colorspace == MODE_rgbA_4444) { 536 p->emit_alpha_row = ExportAlphaRGBA4444; 537 } else { 538 p->emit_alpha_row = ExportAlpha; 539 } 540 WebPInitAlphaProcessing(); 541 } 542 return 1; 543 } 544 545 #endif // WEBP_REDUCE_SIZE 546 547 //------------------------------------------------------------------------------ 548 // Default custom functions 549 550 static int CustomSetup(VP8Io* io) { 551 WebPDecParams* const p = (WebPDecParams*)io->opaque; 552 const WEBP_CSP_MODE colorspace = p->output->colorspace; 553 const int is_rgb = WebPIsRGBMode(colorspace); 554 const int is_alpha = WebPIsAlphaMode(colorspace); 555 556 p->memory = NULL; 557 p->emit = NULL; 558 p->emit_alpha = NULL; 559 p->emit_alpha_row = NULL; 560 if (!WebPIoInitFromOptions(p->options, io, is_alpha ? MODE_YUV : MODE_YUVA)) { 561 return 0; 562 } 563 if (is_alpha && WebPIsPremultipliedMode(colorspace)) { 564 WebPInitUpsamplers(); 565 } 566 if (io->use_scaling) { 567 #if !defined(WEBP_REDUCE_SIZE) 568 const int ok = is_rgb ? InitRGBRescaler(io, p) : InitYUVRescaler(io, p); 569 if (!ok) { 570 return 0; // memory error 571 } 572 #else 573 return 0; // rescaling support not compiled 574 #endif 575 } else { 576 if (is_rgb) { 577 WebPInitSamplers(); 578 p->emit = EmitSampledRGB; // default 579 if (io->fancy_upsampling) { 580 #ifdef FANCY_UPSAMPLING 581 const int uv_width = (io->mb_w + 1) >> 1; 582 p->memory = WebPSafeMalloc(1ULL, (size_t)(io->mb_w + 2 * uv_width)); 583 if (p->memory == NULL) { 584 return 0; // memory error. 585 } 586 p->tmp_y = (uint8_t*)p->memory; 587 p->tmp_u = p->tmp_y + io->mb_w; 588 p->tmp_v = p->tmp_u + uv_width; 589 p->emit = EmitFancyRGB; 590 WebPInitUpsamplers(); 591 #endif 592 } 593 } else { 594 p->emit = EmitYUV; 595 } 596 if (is_alpha) { // need transparency output 597 p->emit_alpha = 598 (colorspace == MODE_RGBA_4444 || colorspace == MODE_rgbA_4444) ? 599 EmitAlphaRGBA4444 600 : is_rgb ? EmitAlphaRGB 601 : EmitAlphaYUV; 602 if (is_rgb) { 603 WebPInitAlphaProcessing(); 604 } 605 } 606 } 607 608 return 1; 609 } 610 611 //------------------------------------------------------------------------------ 612 613 static int CustomPut(const VP8Io* io) { 614 WebPDecParams* const p = (WebPDecParams*)io->opaque; 615 const int mb_w = io->mb_w; 616 const int mb_h = io->mb_h; 617 int num_lines_out; 618 assert(!(io->mb_y & 1)); 619 620 if (mb_w <= 0 || mb_h <= 0) { 621 return 0; 622 } 623 num_lines_out = p->emit(io, p); 624 if (p->emit_alpha != NULL) { 625 p->emit_alpha(io, p, num_lines_out); 626 } 627 p->last_y += num_lines_out; 628 return 1; 629 } 630 631 //------------------------------------------------------------------------------ 632 633 static void CustomTeardown(const VP8Io* io) { 634 WebPDecParams* const p = (WebPDecParams*)io->opaque; 635 WebPSafeFree(p->memory); 636 p->memory = NULL; 637 } 638 639 //------------------------------------------------------------------------------ 640 // Main entry point 641 642 void WebPInitCustomIo(WebPDecParams* const params, VP8Io* const io) { 643 io->put = CustomPut; 644 io->setup = CustomSetup; 645 io->teardown = CustomTeardown; 646 io->opaque = params; 647 } 648 649 //------------------------------------------------------------------------------ 650