1 // Copyright 2011 Google Inc. All Rights Reserved. 2 // 3 // This code is licensed under the same terms as WebM: 4 // Software License Agreement: http://www.webmproject.org/license/software/ 5 // Additional IP Rights Grant: http://www.webmproject.org/license/additional/ 6 // ----------------------------------------------------------------------------- 7 // 8 // functions for sample output. 9 // 10 // Author: Skal (pascal.massimino (at) gmail.com) 11 12 #include <assert.h> 13 #include <stdlib.h> 14 #include "../dec/vp8i.h" 15 #include "./webpi.h" 16 #include "../dsp/dsp.h" 17 #include "../dsp/yuv.h" 18 19 #if defined(__cplusplus) || defined(c_plusplus) 20 extern "C" { 21 #endif 22 23 //------------------------------------------------------------------------------ 24 // Main YUV<->RGB conversion functions 25 26 static int EmitYUV(const VP8Io* const io, WebPDecParams* const p) { 27 WebPDecBuffer* output = p->output; 28 const WebPYUVABuffer* const buf = &output->u.YUVA; 29 uint8_t* const y_dst = buf->y + io->mb_y * buf->y_stride; 30 uint8_t* const u_dst = buf->u + (io->mb_y >> 1) * buf->u_stride; 31 uint8_t* const v_dst = buf->v + (io->mb_y >> 1) * buf->v_stride; 32 const int mb_w = io->mb_w; 33 const int mb_h = io->mb_h; 34 const int uv_w = (mb_w + 1) / 2; 35 const int uv_h = (mb_h + 1) / 2; 36 int j; 37 for (j = 0; j < mb_h; ++j) { 38 memcpy(y_dst + j * buf->y_stride, io->y + j * io->y_stride, mb_w); 39 } 40 for (j = 0; j < uv_h; ++j) { 41 memcpy(u_dst + j * buf->u_stride, io->u + j * io->uv_stride, uv_w); 42 memcpy(v_dst + j * buf->v_stride, io->v + j * io->uv_stride, uv_w); 43 } 44 return io->mb_h; 45 } 46 47 // Point-sampling U/V sampler. 48 static int EmitSampledRGB(const VP8Io* const io, WebPDecParams* const p) { 49 WebPDecBuffer* output = p->output; 50 const WebPRGBABuffer* const buf = &output->u.RGBA; 51 uint8_t* dst = buf->rgba + io->mb_y * buf->stride; 52 const uint8_t* y_src = io->y; 53 const uint8_t* u_src = io->u; 54 const uint8_t* v_src = io->v; 55 const WebPSampleLinePairFunc sample = WebPSamplers[output->colorspace]; 56 const int mb_w = io->mb_w; 57 const int last = io->mb_h - 1; 58 int j; 59 for (j = 0; j < last; j += 2) { 60 sample(y_src, y_src + io->y_stride, u_src, v_src, 61 dst, dst + buf->stride, mb_w); 62 y_src += 2 * io->y_stride; 63 u_src += io->uv_stride; 64 v_src += io->uv_stride; 65 dst += 2 * buf->stride; 66 } 67 if (j == last) { // Just do the last line twice 68 sample(y_src, y_src, u_src, v_src, dst, dst, mb_w); 69 } 70 return io->mb_h; 71 } 72 73 //------------------------------------------------------------------------------ 74 // YUV444 -> RGB conversion 75 76 #if 0 // TODO(skal): this is for future rescaling. 77 static int EmitRGB(const VP8Io* const io, WebPDecParams* const p) { 78 WebPDecBuffer* output = p->output; 79 const WebPRGBABuffer* const buf = &output->u.RGBA; 80 uint8_t* dst = buf->rgba + io->mb_y * buf->stride; 81 const uint8_t* y_src = io->y; 82 const uint8_t* u_src = io->u; 83 const uint8_t* v_src = io->v; 84 const WebPYUV444Converter convert = WebPYUV444Converters[output->colorspace]; 85 const int mb_w = io->mb_w; 86 const int last = io->mb_h; 87 int j; 88 for (j = 0; j < last; ++j) { 89 convert(y_src, u_src, v_src, dst, mb_w); 90 y_src += io->y_stride; 91 u_src += io->uv_stride; 92 v_src += io->uv_stride; 93 dst += buf->stride; 94 } 95 return io->mb_h; 96 } 97 #endif 98 99 //------------------------------------------------------------------------------ 100 // Fancy upsampling 101 102 #ifdef FANCY_UPSAMPLING 103 static int EmitFancyRGB(const VP8Io* const io, WebPDecParams* const p) { 104 int num_lines_out = io->mb_h; // a priori guess 105 const WebPRGBABuffer* const buf = &p->output->u.RGBA; 106 uint8_t* dst = buf->rgba + io->mb_y * buf->stride; 107 WebPUpsampleLinePairFunc upsample = WebPUpsamplers[p->output->colorspace]; 108 const uint8_t* cur_y = io->y; 109 const uint8_t* cur_u = io->u; 110 const uint8_t* cur_v = io->v; 111 const uint8_t* top_u = p->tmp_u; 112 const uint8_t* top_v = p->tmp_v; 113 int y = io->mb_y; 114 int y_end = io->mb_y + io->mb_h; 115 const int mb_w = io->mb_w; 116 const int uv_w = (mb_w + 1) / 2; 117 118 if (y == 0) { 119 // First line is special cased. We mirror the u/v samples at boundary. 120 upsample(NULL, cur_y, cur_u, cur_v, cur_u, cur_v, NULL, dst, mb_w); 121 } else { 122 // We can finish the left-over line from previous call. 123 upsample(p->tmp_y, cur_y, top_u, top_v, cur_u, cur_v, 124 dst - buf->stride, dst, mb_w); 125 ++num_lines_out; 126 } 127 // Loop over each output pairs of row. 128 for (; y + 2 < y_end; y += 2) { 129 top_u = cur_u; 130 top_v = cur_v; 131 cur_u += io->uv_stride; 132 cur_v += io->uv_stride; 133 dst += 2 * buf->stride; 134 cur_y += 2 * io->y_stride; 135 upsample(cur_y - io->y_stride, cur_y, 136 top_u, top_v, cur_u, cur_v, 137 dst - buf->stride, dst, mb_w); 138 } 139 // move to last row 140 cur_y += io->y_stride; 141 if (io->crop_top + y_end < io->crop_bottom) { 142 // Save the unfinished samples for next call (as we're not done yet). 143 memcpy(p->tmp_y, cur_y, mb_w * sizeof(*p->tmp_y)); 144 memcpy(p->tmp_u, cur_u, uv_w * sizeof(*p->tmp_u)); 145 memcpy(p->tmp_v, cur_v, uv_w * sizeof(*p->tmp_v)); 146 // The fancy upsampler leaves a row unfinished behind 147 // (except for the very last row) 148 num_lines_out--; 149 } else { 150 // Process the very last row of even-sized picture 151 if (!(y_end & 1)) { 152 upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v, 153 dst + buf->stride, NULL, mb_w); 154 } 155 } 156 return num_lines_out; 157 } 158 159 #endif /* FANCY_UPSAMPLING */ 160 161 //------------------------------------------------------------------------------ 162 163 static int EmitAlphaYUV(const VP8Io* const io, WebPDecParams* const p) { 164 const uint8_t* alpha = io->a; 165 const WebPYUVABuffer* const buf = &p->output->u.YUVA; 166 const int mb_w = io->mb_w; 167 const int mb_h = io->mb_h; 168 uint8_t* dst = buf->a + io->mb_y * buf->a_stride; 169 int j; 170 171 if (alpha != NULL) { 172 for (j = 0; j < mb_h; ++j) { 173 memcpy(dst, alpha, mb_w * sizeof(*dst)); 174 alpha += io->width; 175 dst += buf->a_stride; 176 } 177 } else if (buf->a != NULL) { 178 // the user requested alpha, but there is none, set it to opaque. 179 for (j = 0; j < mb_h; ++j) { 180 memset(dst, 0xff, mb_w * sizeof(*dst)); 181 dst += buf->a_stride; 182 } 183 } 184 return 0; 185 } 186 187 static int GetAlphaSourceRow(const VP8Io* const io, 188 const uint8_t** alpha, int* const num_rows) { 189 int start_y = io->mb_y; 190 *num_rows = io->mb_h; 191 192 // Compensate for the 1-line delay of the fancy upscaler. 193 // This is similar to EmitFancyRGB(). 194 if (io->fancy_upsampling) { 195 if (start_y == 0) { 196 // We don't process the last row yet. It'll be done during the next call. 197 --*num_rows; 198 } else { 199 --start_y; 200 // Fortunately, *alpha data is persistent, so we can go back 201 // one row and finish alpha blending, now that the fancy upscaler 202 // completed the YUV->RGB interpolation. 203 *alpha -= io->width; 204 } 205 if (io->crop_top + io->mb_y + io->mb_h == io->crop_bottom) { 206 // If it's the very last call, we process all the remaing rows! 207 *num_rows = io->crop_bottom - io->crop_top - start_y; 208 } 209 } 210 return start_y; 211 } 212 213 static int EmitAlphaRGB(const VP8Io* const io, WebPDecParams* const p) { 214 const uint8_t* alpha = io->a; 215 if (alpha != NULL) { 216 const int mb_w = io->mb_w; 217 int i, j; 218 const WEBP_CSP_MODE colorspace = p->output->colorspace; 219 const int alpha_first = 220 (colorspace == MODE_ARGB || colorspace == MODE_Argb); 221 const WebPRGBABuffer* const buf = &p->output->u.RGBA; 222 int num_rows; 223 const int start_y = GetAlphaSourceRow(io, &alpha, &num_rows); 224 uint32_t alpha_mask = 0xff; 225 226 { 227 uint8_t* const base_rgba = buf->rgba + start_y * buf->stride; 228 uint8_t* dst = base_rgba + (alpha_first ? 0 : 3); 229 for (j = 0; j < num_rows; ++j) { 230 for (i = 0; i < mb_w; ++i) { 231 const uint32_t alpha_value = alpha[i]; 232 dst[4 * i] = alpha_value; 233 alpha_mask &= alpha_value; 234 } 235 alpha += io->width; 236 dst += buf->stride; 237 } 238 // alpha_mask is < 0xff if there's non-trivial alpha to premultiply with. 239 if (alpha_mask != 0xff && WebPIsPremultipliedMode(colorspace)) { 240 WebPApplyAlphaMultiply(base_rgba, alpha_first, 241 mb_w, num_rows, buf->stride); 242 } 243 } 244 } 245 return 0; 246 } 247 248 static int EmitAlphaRGBA4444(const VP8Io* const io, WebPDecParams* const p) { 249 const uint8_t* alpha = io->a; 250 if (alpha != NULL) { 251 const int mb_w = io->mb_w; 252 int i, j; 253 const WebPRGBABuffer* const buf = &p->output->u.RGBA; 254 int num_rows; 255 const int start_y = GetAlphaSourceRow(io, &alpha, &num_rows); 256 uint32_t alpha_mask = 0x0f; 257 258 { 259 uint8_t* const base_rgba = buf->rgba + start_y * buf->stride; 260 uint8_t* alpha_dst = base_rgba + 1; 261 for (j = 0; j < num_rows; ++j) { 262 for (i = 0; i < mb_w; ++i) { 263 // Fill in the alpha value (converted to 4 bits). 264 const uint32_t alpha_value = alpha[i] >> 4; 265 alpha_dst[2 * i] = (alpha_dst[2 * i] & 0xf0) | alpha_value; 266 alpha_mask &= alpha_value; 267 } 268 alpha += io->width; 269 alpha_dst += buf->stride; 270 } 271 if (alpha_mask != 0x0f && p->output->colorspace == MODE_rgbA_4444) { 272 WebPApplyAlphaMultiply4444(base_rgba, mb_w, num_rows, buf->stride); 273 } 274 } 275 } 276 return 0; 277 } 278 279 //------------------------------------------------------------------------------ 280 // YUV rescaling (no final RGB conversion needed) 281 282 static int Rescale(const uint8_t* src, int src_stride, 283 int new_lines, WebPRescaler* const wrk) { 284 int num_lines_out = 0; 285 while (new_lines > 0) { // import new contributions of source rows. 286 const int lines_in = WebPRescalerImport(wrk, new_lines, src, src_stride); 287 src += lines_in * src_stride; 288 new_lines -= lines_in; 289 num_lines_out += WebPRescalerExport(wrk); // emit output row(s) 290 } 291 return num_lines_out; 292 } 293 294 static int EmitRescaledYUV(const VP8Io* const io, WebPDecParams* const p) { 295 const int mb_h = io->mb_h; 296 const int uv_mb_h = (mb_h + 1) >> 1; 297 const int num_lines_out = Rescale(io->y, io->y_stride, mb_h, &p->scaler_y); 298 Rescale(io->u, io->uv_stride, uv_mb_h, &p->scaler_u); 299 Rescale(io->v, io->uv_stride, uv_mb_h, &p->scaler_v); 300 return num_lines_out; 301 } 302 303 static int EmitRescaledAlphaYUV(const VP8Io* const io, WebPDecParams* const p) { 304 if (io->a != NULL) { 305 Rescale(io->a, io->width, io->mb_h, &p->scaler_a); 306 } 307 return 0; 308 } 309 310 static int InitYUVRescaler(const VP8Io* const io, WebPDecParams* const p) { 311 const int has_alpha = WebPIsAlphaMode(p->output->colorspace); 312 const WebPYUVABuffer* const buf = &p->output->u.YUVA; 313 const int out_width = io->scaled_width; 314 const int out_height = io->scaled_height; 315 const int uv_out_width = (out_width + 1) >> 1; 316 const int uv_out_height = (out_height + 1) >> 1; 317 const int uv_in_width = (io->mb_w + 1) >> 1; 318 const int uv_in_height = (io->mb_h + 1) >> 1; 319 const size_t work_size = 2 * out_width; // scratch memory for luma rescaler 320 const size_t uv_work_size = 2 * uv_out_width; // and for each u/v ones 321 size_t tmp_size; 322 int32_t* work; 323 324 tmp_size = work_size + 2 * uv_work_size; 325 if (has_alpha) { 326 tmp_size += work_size; 327 } 328 p->memory = calloc(1, tmp_size * sizeof(*work)); 329 if (p->memory == NULL) { 330 return 0; // memory error 331 } 332 work = (int32_t*)p->memory; 333 WebPRescalerInit(&p->scaler_y, io->mb_w, io->mb_h, 334 buf->y, out_width, out_height, buf->y_stride, 1, 335 io->mb_w, out_width, io->mb_h, out_height, 336 work); 337 WebPRescalerInit(&p->scaler_u, uv_in_width, uv_in_height, 338 buf->u, uv_out_width, uv_out_height, buf->u_stride, 1, 339 uv_in_width, uv_out_width, 340 uv_in_height, uv_out_height, 341 work + work_size); 342 WebPRescalerInit(&p->scaler_v, uv_in_width, uv_in_height, 343 buf->v, uv_out_width, uv_out_height, buf->v_stride, 1, 344 uv_in_width, uv_out_width, 345 uv_in_height, uv_out_height, 346 work + work_size + uv_work_size); 347 p->emit = EmitRescaledYUV; 348 349 if (has_alpha) { 350 WebPRescalerInit(&p->scaler_a, io->mb_w, io->mb_h, 351 buf->a, out_width, out_height, buf->a_stride, 1, 352 io->mb_w, out_width, io->mb_h, out_height, 353 work + work_size + 2 * uv_work_size); 354 p->emit_alpha = EmitRescaledAlphaYUV; 355 } 356 return 1; 357 } 358 359 //------------------------------------------------------------------------------ 360 // RGBA rescaling 361 362 static int ExportRGB(WebPDecParams* const p, int y_pos) { 363 const WebPYUV444Converter convert = 364 WebPYUV444Converters[p->output->colorspace]; 365 const WebPRGBABuffer* const buf = &p->output->u.RGBA; 366 uint8_t* dst = buf->rgba + (p->last_y + y_pos) * buf->stride; 367 int num_lines_out = 0; 368 // For RGB rescaling, because of the YUV420, current scan position 369 // U/V can be +1/-1 line from the Y one. Hence the double test. 370 while (WebPRescalerHasPendingOutput(&p->scaler_y) && 371 WebPRescalerHasPendingOutput(&p->scaler_u)) { 372 assert(p->last_y + y_pos + num_lines_out < p->output->height); 373 assert(p->scaler_u.y_accum == p->scaler_v.y_accum); 374 WebPRescalerExportRow(&p->scaler_y); 375 WebPRescalerExportRow(&p->scaler_u); 376 WebPRescalerExportRow(&p->scaler_v); 377 convert(p->scaler_y.dst, p->scaler_u.dst, p->scaler_v.dst, 378 dst, p->scaler_y.dst_width); 379 dst += buf->stride; 380 ++num_lines_out; 381 } 382 return num_lines_out; 383 } 384 385 static int EmitRescaledRGB(const VP8Io* const io, WebPDecParams* const p) { 386 const int mb_h = io->mb_h; 387 const int uv_mb_h = (mb_h + 1) >> 1; 388 int j = 0, uv_j = 0; 389 int num_lines_out = 0; 390 while (j < mb_h) { 391 const int y_lines_in = 392 WebPRescalerImport(&p->scaler_y, mb_h - j, 393 io->y + j * io->y_stride, io->y_stride); 394 const int u_lines_in = 395 WebPRescalerImport(&p->scaler_u, uv_mb_h - uv_j, 396 io->u + uv_j * io->uv_stride, io->uv_stride); 397 const int v_lines_in = 398 WebPRescalerImport(&p->scaler_v, uv_mb_h - uv_j, 399 io->v + uv_j * io->uv_stride, io->uv_stride); 400 (void)v_lines_in; // remove a gcc warning 401 assert(u_lines_in == v_lines_in); 402 j += y_lines_in; 403 uv_j += u_lines_in; 404 num_lines_out += ExportRGB(p, num_lines_out); 405 } 406 return num_lines_out; 407 } 408 409 static int ExportAlpha(WebPDecParams* const p, int y_pos) { 410 const WebPRGBABuffer* const buf = &p->output->u.RGBA; 411 uint8_t* const base_rgba = buf->rgba + (p->last_y + y_pos) * buf->stride; 412 const WEBP_CSP_MODE colorspace = p->output->colorspace; 413 const int alpha_first = 414 (colorspace == MODE_ARGB || colorspace == MODE_Argb); 415 uint8_t* dst = base_rgba + (alpha_first ? 0 : 3); 416 int num_lines_out = 0; 417 const int is_premult_alpha = WebPIsPremultipliedMode(colorspace); 418 uint32_t alpha_mask = 0xff; 419 const int width = p->scaler_a.dst_width; 420 421 while (WebPRescalerHasPendingOutput(&p->scaler_a)) { 422 int i; 423 assert(p->last_y + y_pos + num_lines_out < p->output->height); 424 WebPRescalerExportRow(&p->scaler_a); 425 for (i = 0; i < width; ++i) { 426 const uint32_t alpha_value = p->scaler_a.dst[i]; 427 dst[4 * i] = alpha_value; 428 alpha_mask &= alpha_value; 429 } 430 dst += buf->stride; 431 ++num_lines_out; 432 } 433 if (is_premult_alpha && alpha_mask != 0xff) { 434 WebPApplyAlphaMultiply(base_rgba, alpha_first, 435 width, num_lines_out, buf->stride); 436 } 437 return num_lines_out; 438 } 439 440 static int ExportAlphaRGBA4444(WebPDecParams* const p, int y_pos) { 441 const WebPRGBABuffer* const buf = &p->output->u.RGBA; 442 uint8_t* const base_rgba = buf->rgba + (p->last_y + y_pos) * buf->stride; 443 uint8_t* alpha_dst = base_rgba + 1; 444 int num_lines_out = 0; 445 const WEBP_CSP_MODE colorspace = p->output->colorspace; 446 const int width = p->scaler_a.dst_width; 447 const int is_premult_alpha = WebPIsPremultipliedMode(colorspace); 448 uint32_t alpha_mask = 0x0f; 449 450 while (WebPRescalerHasPendingOutput(&p->scaler_a)) { 451 int i; 452 assert(p->last_y + y_pos + num_lines_out < p->output->height); 453 WebPRescalerExportRow(&p->scaler_a); 454 for (i = 0; i < width; ++i) { 455 // Fill in the alpha value (converted to 4 bits). 456 const uint32_t alpha_value = p->scaler_a.dst[i] >> 4; 457 alpha_dst[2 * i] = (alpha_dst[2 * i] & 0xf0) | alpha_value; 458 alpha_mask &= alpha_value; 459 } 460 alpha_dst += buf->stride; 461 ++num_lines_out; 462 } 463 if (is_premult_alpha && alpha_mask != 0x0f) { 464 WebPApplyAlphaMultiply4444(base_rgba, width, num_lines_out, buf->stride); 465 } 466 return num_lines_out; 467 } 468 469 static int EmitRescaledAlphaRGB(const VP8Io* const io, WebPDecParams* const p) { 470 if (io->a != NULL) { 471 WebPRescaler* const scaler = &p->scaler_a; 472 int j = 0; 473 int pos = 0; 474 while (j < io->mb_h) { 475 j += WebPRescalerImport(scaler, io->mb_h - j, 476 io->a + j * io->width, io->width); 477 pos += p->emit_alpha_row(p, pos); 478 } 479 } 480 return 0; 481 } 482 483 static int InitRGBRescaler(const VP8Io* const io, WebPDecParams* const p) { 484 const int has_alpha = WebPIsAlphaMode(p->output->colorspace); 485 const int out_width = io->scaled_width; 486 const int out_height = io->scaled_height; 487 const int uv_in_width = (io->mb_w + 1) >> 1; 488 const int uv_in_height = (io->mb_h + 1) >> 1; 489 const size_t work_size = 2 * out_width; // scratch memory for one rescaler 490 int32_t* work; // rescalers work area 491 uint8_t* tmp; // tmp storage for scaled YUV444 samples before RGB conversion 492 size_t tmp_size1, tmp_size2; 493 494 tmp_size1 = 3 * work_size; 495 tmp_size2 = 3 * out_width; 496 if (has_alpha) { 497 tmp_size1 += work_size; 498 tmp_size2 += out_width; 499 } 500 p->memory = 501 calloc(1, tmp_size1 * sizeof(*work) + tmp_size2 * sizeof(*tmp)); 502 if (p->memory == NULL) { 503 return 0; // memory error 504 } 505 work = (int32_t*)p->memory; 506 tmp = (uint8_t*)(work + tmp_size1); 507 WebPRescalerInit(&p->scaler_y, io->mb_w, io->mb_h, 508 tmp + 0 * out_width, out_width, out_height, 0, 1, 509 io->mb_w, out_width, io->mb_h, out_height, 510 work + 0 * work_size); 511 WebPRescalerInit(&p->scaler_u, uv_in_width, uv_in_height, 512 tmp + 1 * out_width, out_width, out_height, 0, 1, 513 io->mb_w, 2 * out_width, io->mb_h, 2 * out_height, 514 work + 1 * work_size); 515 WebPRescalerInit(&p->scaler_v, uv_in_width, uv_in_height, 516 tmp + 2 * out_width, out_width, out_height, 0, 1, 517 io->mb_w, 2 * out_width, io->mb_h, 2 * out_height, 518 work + 2 * work_size); 519 p->emit = EmitRescaledRGB; 520 521 if (has_alpha) { 522 WebPRescalerInit(&p->scaler_a, io->mb_w, io->mb_h, 523 tmp + 3 * out_width, out_width, out_height, 0, 1, 524 io->mb_w, out_width, io->mb_h, out_height, 525 work + 3 * work_size); 526 p->emit_alpha = EmitRescaledAlphaRGB; 527 if (p->output->colorspace == MODE_RGBA_4444 || 528 p->output->colorspace == MODE_rgbA_4444) { 529 p->emit_alpha_row = ExportAlphaRGBA4444; 530 } else { 531 p->emit_alpha_row = ExportAlpha; 532 } 533 } 534 return 1; 535 } 536 537 //------------------------------------------------------------------------------ 538 // Default custom functions 539 540 static int CustomSetup(VP8Io* io) { 541 WebPDecParams* const p = (WebPDecParams*)io->opaque; 542 const WEBP_CSP_MODE colorspace = p->output->colorspace; 543 const int is_rgb = WebPIsRGBMode(colorspace); 544 const int is_alpha = WebPIsAlphaMode(colorspace); 545 546 p->memory = NULL; 547 p->emit = NULL; 548 p->emit_alpha = NULL; 549 p->emit_alpha_row = NULL; 550 if (!WebPIoInitFromOptions(p->options, io, is_alpha ? MODE_YUV : MODE_YUVA)) { 551 return 0; 552 } 553 554 if (io->use_scaling) { 555 const int ok = is_rgb ? InitRGBRescaler(io, p) : InitYUVRescaler(io, p); 556 if (!ok) { 557 return 0; // memory error 558 } 559 } else { 560 if (is_rgb) { 561 p->emit = EmitSampledRGB; // default 562 #ifdef FANCY_UPSAMPLING 563 if (io->fancy_upsampling) { 564 const int uv_width = (io->mb_w + 1) >> 1; 565 p->memory = malloc(io->mb_w + 2 * uv_width); 566 if (p->memory == NULL) { 567 return 0; // memory error. 568 } 569 p->tmp_y = (uint8_t*)p->memory; 570 p->tmp_u = p->tmp_y + io->mb_w; 571 p->tmp_v = p->tmp_u + uv_width; 572 p->emit = EmitFancyRGB; 573 WebPInitUpsamplers(); 574 } 575 #endif 576 } else { 577 p->emit = EmitYUV; 578 } 579 if (is_alpha) { // need transparency output 580 if (WebPIsPremultipliedMode(colorspace)) WebPInitPremultiply(); 581 p->emit_alpha = 582 (colorspace == MODE_RGBA_4444 || colorspace == MODE_rgbA_4444) ? 583 EmitAlphaRGBA4444 584 : is_rgb ? EmitAlphaRGB 585 : EmitAlphaYUV; 586 } 587 } 588 589 if (is_rgb) { 590 VP8YUVInit(); 591 } 592 return 1; 593 } 594 595 //------------------------------------------------------------------------------ 596 597 static int CustomPut(const VP8Io* io) { 598 WebPDecParams* p = (WebPDecParams*)io->opaque; 599 const int mb_w = io->mb_w; 600 const int mb_h = io->mb_h; 601 int num_lines_out; 602 assert(!(io->mb_y & 1)); 603 604 if (mb_w <= 0 || mb_h <= 0) { 605 return 0; 606 } 607 num_lines_out = p->emit(io, p); 608 if (p->emit_alpha) { 609 p->emit_alpha(io, p); 610 } 611 p->last_y += num_lines_out; 612 return 1; 613 } 614 615 //------------------------------------------------------------------------------ 616 617 static void CustomTeardown(const VP8Io* io) { 618 WebPDecParams* const p = (WebPDecParams*)io->opaque; 619 free(p->memory); 620 p->memory = NULL; 621 } 622 623 //------------------------------------------------------------------------------ 624 // Main entry point 625 626 void WebPInitCustomIo(WebPDecParams* const params, VP8Io* const io) { 627 io->put = CustomPut; 628 io->setup = CustomSetup; 629 io->teardown = CustomTeardown; 630 io->opaque = params; 631 } 632 633 //------------------------------------------------------------------------------ 634 635 #if defined(__cplusplus) || defined(c_plusplus) 636 } // extern "C" 637 #endif 638