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 // Incremental decoding 9 // 10 // Author: somnath (at) google.com (Somnath Banerjee) 11 12 #include <assert.h> 13 #include <string.h> 14 #include <stdlib.h> 15 16 #include "./webpi.h" 17 #include "./vp8i.h" 18 #include "../utils/utils.h" 19 20 #if defined(__cplusplus) || defined(c_plusplus) 21 extern "C" { 22 #endif 23 24 // In append mode, buffer allocations increase as multiples of this value. 25 // Needs to be a power of 2. 26 #define CHUNK_SIZE 4096 27 #define MAX_MB_SIZE 4096 28 29 //------------------------------------------------------------------------------ 30 // Data structures for memory and states 31 32 // Decoding states. State normally flows like HEADER->PARTS0->DATA->DONE. 33 // If there is any error the decoder goes into state ERROR. 34 typedef enum { 35 STATE_PRE_VP8, // All data before that of the first VP8 chunk. 36 STATE_VP8_FRAME_HEADER, // For VP8 Frame header (within VP8 chunk). 37 STATE_VP8_PARTS0, 38 STATE_VP8_DATA, 39 STATE_VP8L_HEADER, 40 STATE_VP8L_DATA, 41 STATE_DONE, 42 STATE_ERROR 43 } DecState; 44 45 // Operating state for the MemBuffer 46 typedef enum { 47 MEM_MODE_NONE = 0, 48 MEM_MODE_APPEND, 49 MEM_MODE_MAP 50 } MemBufferMode; 51 52 // storage for partition #0 and partial data (in a rolling fashion) 53 typedef struct { 54 MemBufferMode mode_; // Operation mode 55 size_t start_; // start location of the data to be decoded 56 size_t end_; // end location 57 size_t buf_size_; // size of the allocated buffer 58 uint8_t* buf_; // We don't own this buffer in case WebPIUpdate() 59 60 size_t part0_size_; // size of partition #0 61 const uint8_t* part0_buf_; // buffer to store partition #0 62 } MemBuffer; 63 64 struct WebPIDecoder { 65 DecState state_; // current decoding state 66 WebPDecParams params_; // Params to store output info 67 int is_lossless_; // for down-casting 'dec_'. 68 void* dec_; // either a VP8Decoder or a VP8LDecoder instance 69 VP8Io io_; 70 71 MemBuffer mem_; // input memory buffer. 72 WebPDecBuffer output_; // output buffer (when no external one is supplied) 73 size_t chunk_size_; // Compressed VP8/VP8L size extracted from Header. 74 }; 75 76 // MB context to restore in case VP8DecodeMB() fails 77 typedef struct { 78 VP8MB left_; 79 VP8MB info_; 80 uint8_t intra_t_[4]; 81 uint8_t intra_l_[4]; 82 VP8BitReader br_; 83 VP8BitReader token_br_; 84 } MBContext; 85 86 //------------------------------------------------------------------------------ 87 // MemBuffer: incoming data handling 88 89 static void RemapBitReader(VP8BitReader* const br, ptrdiff_t offset) { 90 if (br->buf_ != NULL) { 91 br->buf_ += offset; 92 br->buf_end_ += offset; 93 } 94 } 95 96 static WEBP_INLINE size_t MemDataSize(const MemBuffer* mem) { 97 return (mem->end_ - mem->start_); 98 } 99 100 static void DoRemap(WebPIDecoder* const idec, ptrdiff_t offset) { 101 MemBuffer* const mem = &idec->mem_; 102 const uint8_t* const new_base = mem->buf_ + mem->start_; 103 // note: for VP8, setting up idec->io_ is only really needed at the beginning 104 // of the decoding, till partition #0 is complete. 105 idec->io_.data = new_base; 106 idec->io_.data_size = MemDataSize(mem); 107 108 if (idec->dec_ != NULL) { 109 if (!idec->is_lossless_) { 110 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; 111 const int last_part = dec->num_parts_ - 1; 112 if (offset != 0) { 113 int p; 114 for (p = 0; p <= last_part; ++p) { 115 RemapBitReader(dec->parts_ + p, offset); 116 } 117 // Remap partition #0 data pointer to new offset, but only in MAP 118 // mode (in APPEND mode, partition #0 is copied into a fixed memory). 119 if (mem->mode_ == MEM_MODE_MAP) { 120 RemapBitReader(&dec->br_, offset); 121 } 122 } 123 assert(last_part >= 0); 124 dec->parts_[last_part].buf_end_ = mem->buf_ + mem->end_; 125 } else { // Resize lossless bitreader 126 VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_; 127 VP8LBitReaderSetBuffer(&dec->br_, new_base, MemDataSize(mem)); 128 } 129 } 130 } 131 132 // Appends data to the end of MemBuffer->buf_. It expands the allocated memory 133 // size if required and also updates VP8BitReader's if new memory is allocated. 134 static int AppendToMemBuffer(WebPIDecoder* const idec, 135 const uint8_t* const data, size_t data_size) { 136 MemBuffer* const mem = &idec->mem_; 137 const uint8_t* const old_base = mem->buf_ + mem->start_; 138 assert(mem->mode_ == MEM_MODE_APPEND); 139 if (data_size > MAX_CHUNK_PAYLOAD) { 140 // security safeguard: trying to allocate more than what the format 141 // allows for a chunk should be considered a smoke smell. 142 return 0; 143 } 144 145 if (mem->end_ + data_size > mem->buf_size_) { // Need some free memory 146 const size_t current_size = MemDataSize(mem); 147 const uint64_t new_size = (uint64_t)current_size + data_size; 148 const uint64_t extra_size = (new_size + CHUNK_SIZE - 1) & ~(CHUNK_SIZE - 1); 149 uint8_t* const new_buf = 150 (uint8_t*)WebPSafeMalloc(extra_size, sizeof(*new_buf)); 151 if (new_buf == NULL) return 0; 152 memcpy(new_buf, old_base, current_size); 153 free(mem->buf_); 154 mem->buf_ = new_buf; 155 mem->buf_size_ = (size_t)extra_size; 156 mem->start_ = 0; 157 mem->end_ = current_size; 158 } 159 160 memcpy(mem->buf_ + mem->end_, data, data_size); 161 mem->end_ += data_size; 162 assert(mem->end_ <= mem->buf_size_); 163 164 DoRemap(idec, mem->buf_ + mem->start_ - old_base); 165 return 1; 166 } 167 168 static int RemapMemBuffer(WebPIDecoder* const idec, 169 const uint8_t* const data, size_t data_size) { 170 MemBuffer* const mem = &idec->mem_; 171 const uint8_t* const old_base = mem->buf_ + mem->start_; 172 assert(mem->mode_ == MEM_MODE_MAP); 173 174 if (data_size < mem->buf_size_) return 0; // can't remap to a shorter buffer! 175 176 mem->buf_ = (uint8_t*)data; 177 mem->end_ = mem->buf_size_ = data_size; 178 179 DoRemap(idec, mem->buf_ + mem->start_ - old_base); 180 return 1; 181 } 182 183 static void InitMemBuffer(MemBuffer* const mem) { 184 mem->mode_ = MEM_MODE_NONE; 185 mem->buf_ = NULL; 186 mem->buf_size_ = 0; 187 mem->part0_buf_ = NULL; 188 mem->part0_size_ = 0; 189 } 190 191 static void ClearMemBuffer(MemBuffer* const mem) { 192 assert(mem); 193 if (mem->mode_ == MEM_MODE_APPEND) { 194 free(mem->buf_); 195 free((void*)mem->part0_buf_); 196 } 197 } 198 199 static int CheckMemBufferMode(MemBuffer* const mem, MemBufferMode expected) { 200 if (mem->mode_ == MEM_MODE_NONE) { 201 mem->mode_ = expected; // switch to the expected mode 202 } else if (mem->mode_ != expected) { 203 return 0; // we mixed the modes => error 204 } 205 assert(mem->mode_ == expected); // mode is ok 206 return 1; 207 } 208 209 //------------------------------------------------------------------------------ 210 // Macroblock-decoding contexts 211 212 static void SaveContext(const VP8Decoder* dec, const VP8BitReader* token_br, 213 MBContext* const context) { 214 const VP8BitReader* const br = &dec->br_; 215 const VP8MB* const left = dec->mb_info_ - 1; 216 const VP8MB* const info = dec->mb_info_ + dec->mb_x_; 217 218 context->left_ = *left; 219 context->info_ = *info; 220 context->br_ = *br; 221 context->token_br_ = *token_br; 222 memcpy(context->intra_t_, dec->intra_t_ + 4 * dec->mb_x_, 4); 223 memcpy(context->intra_l_, dec->intra_l_, 4); 224 } 225 226 static void RestoreContext(const MBContext* context, VP8Decoder* const dec, 227 VP8BitReader* const token_br) { 228 VP8BitReader* const br = &dec->br_; 229 VP8MB* const left = dec->mb_info_ - 1; 230 VP8MB* const info = dec->mb_info_ + dec->mb_x_; 231 232 *left = context->left_; 233 *info = context->info_; 234 *br = context->br_; 235 *token_br = context->token_br_; 236 memcpy(dec->intra_t_ + 4 * dec->mb_x_, context->intra_t_, 4); 237 memcpy(dec->intra_l_, context->intra_l_, 4); 238 } 239 240 //------------------------------------------------------------------------------ 241 242 static VP8StatusCode IDecError(WebPIDecoder* const idec, VP8StatusCode error) { 243 if (idec->state_ == STATE_VP8_DATA) { 244 VP8Io* const io = &idec->io_; 245 if (io->teardown) { 246 io->teardown(io); 247 } 248 } 249 idec->state_ = STATE_ERROR; 250 return error; 251 } 252 253 static void ChangeState(WebPIDecoder* const idec, DecState new_state, 254 size_t consumed_bytes) { 255 MemBuffer* const mem = &idec->mem_; 256 idec->state_ = new_state; 257 mem->start_ += consumed_bytes; 258 assert(mem->start_ <= mem->end_); 259 idec->io_.data = mem->buf_ + mem->start_; 260 idec->io_.data_size = MemDataSize(mem); 261 } 262 263 // Headers 264 static VP8StatusCode DecodeWebPHeaders(WebPIDecoder* const idec) { 265 MemBuffer* const mem = &idec->mem_; 266 const uint8_t* data = mem->buf_ + mem->start_; 267 size_t curr_size = MemDataSize(mem); 268 VP8StatusCode status; 269 WebPHeaderStructure headers; 270 271 headers.data = data; 272 headers.data_size = curr_size; 273 status = WebPParseHeaders(&headers); 274 if (status == VP8_STATUS_NOT_ENOUGH_DATA) { 275 return VP8_STATUS_SUSPENDED; // We haven't found a VP8 chunk yet. 276 } else if (status != VP8_STATUS_OK) { 277 return IDecError(idec, status); 278 } 279 280 idec->chunk_size_ = headers.compressed_size; 281 idec->is_lossless_ = headers.is_lossless; 282 if (!idec->is_lossless_) { 283 VP8Decoder* const dec = VP8New(); 284 if (dec == NULL) { 285 return VP8_STATUS_OUT_OF_MEMORY; 286 } 287 idec->dec_ = dec; 288 #ifdef WEBP_USE_THREAD 289 dec->use_threads_ = (idec->params_.options != NULL) && 290 (idec->params_.options->use_threads > 0); 291 #else 292 dec->use_threads_ = 0; 293 #endif 294 dec->alpha_data_ = headers.alpha_data; 295 dec->alpha_data_size_ = headers.alpha_data_size; 296 ChangeState(idec, STATE_VP8_FRAME_HEADER, headers.offset); 297 } else { 298 VP8LDecoder* const dec = VP8LNew(); 299 if (dec == NULL) { 300 return VP8_STATUS_OUT_OF_MEMORY; 301 } 302 idec->dec_ = dec; 303 ChangeState(idec, STATE_VP8L_HEADER, headers.offset); 304 } 305 return VP8_STATUS_OK; 306 } 307 308 static VP8StatusCode DecodeVP8FrameHeader(WebPIDecoder* const idec) { 309 const uint8_t* data = idec->mem_.buf_ + idec->mem_.start_; 310 const size_t curr_size = MemDataSize(&idec->mem_); 311 uint32_t bits; 312 313 if (curr_size < VP8_FRAME_HEADER_SIZE) { 314 // Not enough data bytes to extract VP8 Frame Header. 315 return VP8_STATUS_SUSPENDED; 316 } 317 if (!VP8GetInfo(data, curr_size, idec->chunk_size_, NULL, NULL)) { 318 return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); 319 } 320 321 bits = data[0] | (data[1] << 8) | (data[2] << 16); 322 idec->mem_.part0_size_ = (bits >> 5) + VP8_FRAME_HEADER_SIZE; 323 324 idec->io_.data = data; 325 idec->io_.data_size = curr_size; 326 idec->state_ = STATE_VP8_PARTS0; 327 return VP8_STATUS_OK; 328 } 329 330 // Partition #0 331 static int CopyParts0Data(WebPIDecoder* const idec) { 332 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; 333 VP8BitReader* const br = &dec->br_; 334 const size_t psize = br->buf_end_ - br->buf_; 335 MemBuffer* const mem = &idec->mem_; 336 assert(!idec->is_lossless_); 337 assert(mem->part0_buf_ == NULL); 338 assert(psize > 0); 339 assert(psize <= mem->part0_size_); // Format limit: no need for runtime check 340 if (mem->mode_ == MEM_MODE_APPEND) { 341 // We copy and grab ownership of the partition #0 data. 342 uint8_t* const part0_buf = (uint8_t*)malloc(psize); 343 if (part0_buf == NULL) { 344 return 0; 345 } 346 memcpy(part0_buf, br->buf_, psize); 347 mem->part0_buf_ = part0_buf; 348 br->buf_ = part0_buf; 349 br->buf_end_ = part0_buf + psize; 350 } else { 351 // Else: just keep pointers to the partition #0's data in dec_->br_. 352 } 353 mem->start_ += psize; 354 return 1; 355 } 356 357 static VP8StatusCode DecodePartition0(WebPIDecoder* const idec) { 358 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; 359 VP8Io* const io = &idec->io_; 360 const WebPDecParams* const params = &idec->params_; 361 WebPDecBuffer* const output = params->output; 362 363 // Wait till we have enough data for the whole partition #0 364 if (MemDataSize(&idec->mem_) < idec->mem_.part0_size_) { 365 return VP8_STATUS_SUSPENDED; 366 } 367 368 if (!VP8GetHeaders(dec, io)) { 369 const VP8StatusCode status = dec->status_; 370 if (status == VP8_STATUS_SUSPENDED || 371 status == VP8_STATUS_NOT_ENOUGH_DATA) { 372 // treating NOT_ENOUGH_DATA as SUSPENDED state 373 return VP8_STATUS_SUSPENDED; 374 } 375 return IDecError(idec, status); 376 } 377 378 // Allocate/Verify output buffer now 379 dec->status_ = WebPAllocateDecBuffer(io->width, io->height, params->options, 380 output); 381 if (dec->status_ != VP8_STATUS_OK) { 382 return IDecError(idec, dec->status_); 383 } 384 385 if (!CopyParts0Data(idec)) { 386 return IDecError(idec, VP8_STATUS_OUT_OF_MEMORY); 387 } 388 389 // Finish setting up the decoding parameters. Will call io->setup(). 390 if (VP8EnterCritical(dec, io) != VP8_STATUS_OK) { 391 return IDecError(idec, dec->status_); 392 } 393 394 // Note: past this point, teardown() must always be called 395 // in case of error. 396 idec->state_ = STATE_VP8_DATA; 397 // Allocate memory and prepare everything. 398 if (!VP8InitFrame(dec, io)) { 399 return IDecError(idec, dec->status_); 400 } 401 return VP8_STATUS_OK; 402 } 403 404 // Remaining partitions 405 static VP8StatusCode DecodeRemaining(WebPIDecoder* const idec) { 406 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; 407 VP8Io* const io = &idec->io_; 408 409 assert(dec->ready_); 410 411 for (; dec->mb_y_ < dec->mb_h_; ++dec->mb_y_) { 412 VP8BitReader* token_br = &dec->parts_[dec->mb_y_ & (dec->num_parts_ - 1)]; 413 if (dec->mb_x_ == 0) { 414 VP8InitScanline(dec); 415 } 416 for (; dec->mb_x_ < dec->mb_w_; dec->mb_x_++) { 417 MBContext context; 418 SaveContext(dec, token_br, &context); 419 420 if (!VP8DecodeMB(dec, token_br)) { 421 RestoreContext(&context, dec, token_br); 422 // We shouldn't fail when MAX_MB data was available 423 if (dec->num_parts_ == 1 && MemDataSize(&idec->mem_) > MAX_MB_SIZE) { 424 return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); 425 } 426 return VP8_STATUS_SUSPENDED; 427 } 428 // Reconstruct and emit samples. 429 VP8ReconstructBlock(dec); 430 431 // Release buffer only if there is only one partition 432 if (dec->num_parts_ == 1) { 433 idec->mem_.start_ = token_br->buf_ - idec->mem_.buf_; 434 assert(idec->mem_.start_ <= idec->mem_.end_); 435 } 436 } 437 if (!VP8ProcessRow(dec, io)) { 438 return IDecError(idec, VP8_STATUS_USER_ABORT); 439 } 440 dec->mb_x_ = 0; 441 } 442 // Synchronize the thread and check for errors. 443 if (!VP8ExitCritical(dec, io)) { 444 return IDecError(idec, VP8_STATUS_USER_ABORT); 445 } 446 dec->ready_ = 0; 447 idec->state_ = STATE_DONE; 448 449 return VP8_STATUS_OK; 450 } 451 452 static int ErrorStatusLossless(WebPIDecoder* const idec, VP8StatusCode status) { 453 if (status == VP8_STATUS_SUSPENDED || status == VP8_STATUS_NOT_ENOUGH_DATA) { 454 return VP8_STATUS_SUSPENDED; 455 } 456 return IDecError(idec, status); 457 } 458 459 static VP8StatusCode DecodeVP8LHeader(WebPIDecoder* const idec) { 460 VP8Io* const io = &idec->io_; 461 VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_; 462 const WebPDecParams* const params = &idec->params_; 463 WebPDecBuffer* const output = params->output; 464 size_t curr_size = MemDataSize(&idec->mem_); 465 assert(idec->is_lossless_); 466 467 // Wait until there's enough data for decoding header. 468 if (curr_size < (idec->chunk_size_ >> 3)) { 469 return VP8_STATUS_SUSPENDED; 470 } 471 if (!VP8LDecodeHeader(dec, io)) { 472 return ErrorStatusLossless(idec, dec->status_); 473 } 474 // Allocate/verify output buffer now. 475 dec->status_ = WebPAllocateDecBuffer(io->width, io->height, params->options, 476 output); 477 if (dec->status_ != VP8_STATUS_OK) { 478 return IDecError(idec, dec->status_); 479 } 480 481 idec->state_ = STATE_VP8L_DATA; 482 return VP8_STATUS_OK; 483 } 484 485 static VP8StatusCode DecodeVP8LData(WebPIDecoder* const idec) { 486 VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_; 487 const size_t curr_size = MemDataSize(&idec->mem_); 488 assert(idec->is_lossless_); 489 490 // At present Lossless decoder can't decode image incrementally. So wait till 491 // all the image data is aggregated before image can be decoded. 492 if (curr_size < idec->chunk_size_) { 493 return VP8_STATUS_SUSPENDED; 494 } 495 496 if (!VP8LDecodeImage(dec)) { 497 return ErrorStatusLossless(idec, dec->status_); 498 } 499 500 idec->state_ = STATE_DONE; 501 502 return VP8_STATUS_OK; 503 } 504 505 // Main decoding loop 506 static VP8StatusCode IDecode(WebPIDecoder* idec) { 507 VP8StatusCode status = VP8_STATUS_SUSPENDED; 508 509 if (idec->state_ == STATE_PRE_VP8) { 510 status = DecodeWebPHeaders(idec); 511 } else { 512 if (idec->dec_ == NULL) { 513 return VP8_STATUS_SUSPENDED; // can't continue if we have no decoder. 514 } 515 } 516 if (idec->state_ == STATE_VP8_FRAME_HEADER) { 517 status = DecodeVP8FrameHeader(idec); 518 } 519 if (idec->state_ == STATE_VP8_PARTS0) { 520 status = DecodePartition0(idec); 521 } 522 if (idec->state_ == STATE_VP8_DATA) { 523 status = DecodeRemaining(idec); 524 } 525 if (idec->state_ == STATE_VP8L_HEADER) { 526 status = DecodeVP8LHeader(idec); 527 } 528 if (idec->state_ == STATE_VP8L_DATA) { 529 status = DecodeVP8LData(idec); 530 } 531 return status; 532 } 533 534 //------------------------------------------------------------------------------ 535 // Public functions 536 537 WebPIDecoder* WebPINewDecoder(WebPDecBuffer* output_buffer) { 538 WebPIDecoder* idec = (WebPIDecoder*)calloc(1, sizeof(*idec)); 539 if (idec == NULL) { 540 return NULL; 541 } 542 543 idec->state_ = STATE_PRE_VP8; 544 idec->chunk_size_ = 0; 545 546 InitMemBuffer(&idec->mem_); 547 WebPInitDecBuffer(&idec->output_); 548 VP8InitIo(&idec->io_); 549 550 WebPResetDecParams(&idec->params_); 551 idec->params_.output = output_buffer ? output_buffer : &idec->output_; 552 WebPInitCustomIo(&idec->params_, &idec->io_); // Plug the I/O functions. 553 554 return idec; 555 } 556 557 WebPIDecoder* WebPIDecode(const uint8_t* data, size_t data_size, 558 WebPDecoderConfig* config) { 559 WebPIDecoder* idec; 560 561 // Parse the bitstream's features, if requested: 562 if (data != NULL && data_size > 0 && config != NULL) { 563 if (WebPGetFeatures(data, data_size, &config->input) != VP8_STATUS_OK) { 564 return NULL; 565 } 566 } 567 // Create an instance of the incremental decoder 568 idec = WebPINewDecoder(config ? &config->output : NULL); 569 if (idec == NULL) { 570 return NULL; 571 } 572 // Finish initialization 573 if (config != NULL) { 574 idec->params_.options = &config->options; 575 } 576 return idec; 577 } 578 579 void WebPIDelete(WebPIDecoder* idec) { 580 if (idec == NULL) return; 581 if (idec->dec_ != NULL) { 582 if (!idec->is_lossless_) { 583 VP8Delete(idec->dec_); 584 } else { 585 VP8LDelete(idec->dec_); 586 } 587 } 588 ClearMemBuffer(&idec->mem_); 589 WebPFreeDecBuffer(&idec->output_); 590 free(idec); 591 } 592 593 //------------------------------------------------------------------------------ 594 // Wrapper toward WebPINewDecoder 595 596 WebPIDecoder* WebPINewRGB(WEBP_CSP_MODE mode, uint8_t* output_buffer, 597 size_t output_buffer_size, int output_stride) { 598 const int is_external_memory = (output_buffer != NULL); 599 WebPIDecoder* idec; 600 601 if (mode >= MODE_YUV) return NULL; 602 if (!is_external_memory) { // Overwrite parameters to sane values. 603 output_buffer_size = 0; 604 output_stride = 0; 605 } else { // A buffer was passed. Validate the other params. 606 if (output_stride == 0 || output_buffer_size == 0) { 607 return NULL; // invalid parameter. 608 } 609 } 610 idec = WebPINewDecoder(NULL); 611 if (idec == NULL) return NULL; 612 idec->output_.colorspace = mode; 613 idec->output_.is_external_memory = is_external_memory; 614 idec->output_.u.RGBA.rgba = output_buffer; 615 idec->output_.u.RGBA.stride = output_stride; 616 idec->output_.u.RGBA.size = output_buffer_size; 617 return idec; 618 } 619 620 WebPIDecoder* WebPINewYUVA(uint8_t* luma, size_t luma_size, int luma_stride, 621 uint8_t* u, size_t u_size, int u_stride, 622 uint8_t* v, size_t v_size, int v_stride, 623 uint8_t* a, size_t a_size, int a_stride) { 624 const int is_external_memory = (luma != NULL); 625 WebPIDecoder* idec; 626 WEBP_CSP_MODE colorspace; 627 628 if (!is_external_memory) { // Overwrite parameters to sane values. 629 luma_size = u_size = v_size = a_size = 0; 630 luma_stride = u_stride = v_stride = a_stride = 0; 631 u = v = a = NULL; 632 colorspace = MODE_YUVA; 633 } else { // A luma buffer was passed. Validate the other parameters. 634 if (u == NULL || v == NULL) return NULL; 635 if (luma_size == 0 || u_size == 0 || v_size == 0) return NULL; 636 if (luma_stride == 0 || u_stride == 0 || v_stride == 0) return NULL; 637 if (a != NULL) { 638 if (a_size == 0 || a_stride == 0) return NULL; 639 } 640 colorspace = (a == NULL) ? MODE_YUV : MODE_YUVA; 641 } 642 643 idec = WebPINewDecoder(NULL); 644 if (idec == NULL) return NULL; 645 646 idec->output_.colorspace = colorspace; 647 idec->output_.is_external_memory = is_external_memory; 648 idec->output_.u.YUVA.y = luma; 649 idec->output_.u.YUVA.y_stride = luma_stride; 650 idec->output_.u.YUVA.y_size = luma_size; 651 idec->output_.u.YUVA.u = u; 652 idec->output_.u.YUVA.u_stride = u_stride; 653 idec->output_.u.YUVA.u_size = u_size; 654 idec->output_.u.YUVA.v = v; 655 idec->output_.u.YUVA.v_stride = v_stride; 656 idec->output_.u.YUVA.v_size = v_size; 657 idec->output_.u.YUVA.a = a; 658 idec->output_.u.YUVA.a_stride = a_stride; 659 idec->output_.u.YUVA.a_size = a_size; 660 return idec; 661 } 662 663 WebPIDecoder* WebPINewYUV(uint8_t* luma, size_t luma_size, int luma_stride, 664 uint8_t* u, size_t u_size, int u_stride, 665 uint8_t* v, size_t v_size, int v_stride) { 666 return WebPINewYUVA(luma, luma_size, luma_stride, 667 u, u_size, u_stride, 668 v, v_size, v_stride, 669 NULL, 0, 0); 670 } 671 672 //------------------------------------------------------------------------------ 673 674 static VP8StatusCode IDecCheckStatus(const WebPIDecoder* const idec) { 675 assert(idec); 676 if (idec->state_ == STATE_ERROR) { 677 return VP8_STATUS_BITSTREAM_ERROR; 678 } 679 if (idec->state_ == STATE_DONE) { 680 return VP8_STATUS_OK; 681 } 682 return VP8_STATUS_SUSPENDED; 683 } 684 685 VP8StatusCode WebPIAppend(WebPIDecoder* idec, 686 const uint8_t* data, size_t data_size) { 687 VP8StatusCode status; 688 if (idec == NULL || data == NULL) { 689 return VP8_STATUS_INVALID_PARAM; 690 } 691 status = IDecCheckStatus(idec); 692 if (status != VP8_STATUS_SUSPENDED) { 693 return status; 694 } 695 // Check mixed calls between RemapMemBuffer and AppendToMemBuffer. 696 if (!CheckMemBufferMode(&idec->mem_, MEM_MODE_APPEND)) { 697 return VP8_STATUS_INVALID_PARAM; 698 } 699 // Append data to memory buffer 700 if (!AppendToMemBuffer(idec, data, data_size)) { 701 return VP8_STATUS_OUT_OF_MEMORY; 702 } 703 return IDecode(idec); 704 } 705 706 VP8StatusCode WebPIUpdate(WebPIDecoder* idec, 707 const uint8_t* data, size_t data_size) { 708 VP8StatusCode status; 709 if (idec == NULL || data == NULL) { 710 return VP8_STATUS_INVALID_PARAM; 711 } 712 status = IDecCheckStatus(idec); 713 if (status != VP8_STATUS_SUSPENDED) { 714 return status; 715 } 716 // Check mixed calls between RemapMemBuffer and AppendToMemBuffer. 717 if (!CheckMemBufferMode(&idec->mem_, MEM_MODE_MAP)) { 718 return VP8_STATUS_INVALID_PARAM; 719 } 720 // Make the memory buffer point to the new buffer 721 if (!RemapMemBuffer(idec, data, data_size)) { 722 return VP8_STATUS_INVALID_PARAM; 723 } 724 return IDecode(idec); 725 } 726 727 //------------------------------------------------------------------------------ 728 729 static const WebPDecBuffer* GetOutputBuffer(const WebPIDecoder* const idec) { 730 if (idec == NULL || idec->dec_ == NULL) { 731 return NULL; 732 } 733 if (idec->state_ <= STATE_VP8_PARTS0) { 734 return NULL; 735 } 736 return idec->params_.output; 737 } 738 739 const WebPDecBuffer* WebPIDecodedArea(const WebPIDecoder* idec, 740 int* left, int* top, 741 int* width, int* height) { 742 const WebPDecBuffer* const src = GetOutputBuffer(idec); 743 if (left != NULL) *left = 0; 744 if (top != NULL) *top = 0; 745 // TODO(skal): later include handling of rotations. 746 if (src) { 747 if (width != NULL) *width = src->width; 748 if (height != NULL) *height = idec->params_.last_y; 749 } else { 750 if (width != NULL) *width = 0; 751 if (height != NULL) *height = 0; 752 } 753 return src; 754 } 755 756 uint8_t* WebPIDecGetRGB(const WebPIDecoder* idec, int* last_y, 757 int* width, int* height, int* stride) { 758 const WebPDecBuffer* const src = GetOutputBuffer(idec); 759 if (src == NULL) return NULL; 760 if (src->colorspace >= MODE_YUV) { 761 return NULL; 762 } 763 764 if (last_y != NULL) *last_y = idec->params_.last_y; 765 if (width != NULL) *width = src->width; 766 if (height != NULL) *height = src->height; 767 if (stride != NULL) *stride = src->u.RGBA.stride; 768 769 return src->u.RGBA.rgba; 770 } 771 772 uint8_t* WebPIDecGetYUVA(const WebPIDecoder* idec, int* last_y, 773 uint8_t** u, uint8_t** v, uint8_t** a, 774 int* width, int* height, 775 int* stride, int* uv_stride, int* a_stride) { 776 const WebPDecBuffer* const src = GetOutputBuffer(idec); 777 if (src == NULL) return NULL; 778 if (src->colorspace < MODE_YUV) { 779 return NULL; 780 } 781 782 if (last_y != NULL) *last_y = idec->params_.last_y; 783 if (u != NULL) *u = src->u.YUVA.u; 784 if (v != NULL) *v = src->u.YUVA.v; 785 if (a != NULL) *a = src->u.YUVA.a; 786 if (width != NULL) *width = src->width; 787 if (height != NULL) *height = src->height; 788 if (stride != NULL) *stride = src->u.YUVA.y_stride; 789 if (uv_stride != NULL) *uv_stride = src->u.YUVA.u_stride; 790 if (a_stride != NULL) *a_stride = src->u.YUVA.a_stride; 791 792 return src->u.YUVA.y; 793 } 794 795 int WebPISetIOHooks(WebPIDecoder* const idec, 796 VP8IoPutHook put, 797 VP8IoSetupHook setup, 798 VP8IoTeardownHook teardown, 799 void* user_data) { 800 if (idec == NULL || idec->state_ > STATE_PRE_VP8) { 801 return 0; 802 } 803 804 idec->io_.put = put; 805 idec->io_.setup = setup; 806 idec->io_.teardown = teardown; 807 idec->io_.opaque = user_data; 808 809 return 1; 810 } 811 812 #if defined(__cplusplus) || defined(c_plusplus) 813 } // extern "C" 814 #endif 815
