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// Incremental decoding 11// 12// Author: somnath@google.com (Somnath Banerjee) 13 14#include <assert.h> 15#include <string.h> 16#include <stdlib.h> 17 18#include "./alphai.h" 19#include "./webpi.h" 20#include "./vp8i.h" 21#include "../utils/utils.h" 22 23// In append mode, buffer allocations increase as multiples of this value. 24// Needs to be a power of 2. 25#define CHUNK_SIZE 4096 26#define MAX_MB_SIZE 4096 27 28//------------------------------------------------------------------------------ 29// Data structures for memory and states 30 31// Decoding states. State normally flows as: 32// WEBP_HEADER->VP8_HEADER->VP8_PARTS0->VP8_DATA->DONE for a lossy image, and 33// WEBP_HEADER->VP8L_HEADER->VP8L_DATA->DONE for a lossless image. 34// If there is any error the decoder goes into state ERROR. 35typedef enum { 36 STATE_WEBP_HEADER, // All the data before that of the VP8/VP8L chunk. 37 STATE_VP8_HEADER, // The VP8 Frame header (within the VP8 chunk). 38 STATE_VP8_PARTS0, 39 STATE_VP8_DATA, 40 STATE_VP8L_HEADER, 41 STATE_VP8L_DATA, 42 STATE_DONE, 43 STATE_ERROR 44} DecState; 45 46// Operating state for the MemBuffer 47typedef enum { 48 MEM_MODE_NONE = 0, 49 MEM_MODE_APPEND, 50 MEM_MODE_MAP 51} MemBufferMode; 52 53// storage for partition #0 and partial data (in a rolling fashion) 54typedef struct { 55 MemBufferMode mode_; // Operation mode 56 size_t start_; // start location of the data to be decoded 57 size_t end_; // end location 58 size_t buf_size_; // size of the allocated buffer 59 uint8_t* buf_; // We don't own this buffer in case WebPIUpdate() 60 61 size_t part0_size_; // size of partition #0 62 const uint8_t* part0_buf_; // buffer to store partition #0 63} MemBuffer; 64 65struct WebPIDecoder { 66 DecState state_; // current decoding state 67 WebPDecParams params_; // Params to store output info 68 int is_lossless_; // for down-casting 'dec_'. 69 void* dec_; // either a VP8Decoder or a VP8LDecoder instance 70 VP8Io io_; 71 72 MemBuffer mem_; // input memory buffer. 73 WebPDecBuffer output_; // output buffer (when no external one is supplied) 74 size_t chunk_size_; // Compressed VP8/VP8L size extracted from Header. 75 76 int last_mb_y_; // last row reached for intra-mode decoding 77}; 78 79// MB context to restore in case VP8DecodeMB() fails 80typedef struct { 81 VP8MB left_; 82 VP8MB info_; 83 VP8BitReader token_br_; 84} MBContext; 85 86//------------------------------------------------------------------------------ 87// MemBuffer: incoming data handling 88 89static WEBP_INLINE size_t MemDataSize(const MemBuffer* mem) { 90 return (mem->end_ - mem->start_); 91} 92 93// Check if we need to preserve the compressed alpha data, as it may not have 94// been decoded yet. 95static int NeedCompressedAlpha(const WebPIDecoder* const idec) { 96 if (idec->state_ == STATE_WEBP_HEADER) { 97 // We haven't parsed the headers yet, so we don't know whether the image is 98 // lossy or lossless. This also means that we haven't parsed the ALPH chunk. 99 return 0; 100 } 101 if (idec->is_lossless_) { 102 return 0; // ALPH chunk is not present for lossless images. 103 } else { 104 const VP8Decoder* const dec = (VP8Decoder*)idec->dec_; 105 assert(dec != NULL); // Must be true as idec->state_ != STATE_WEBP_HEADER. 106 return (dec->alpha_data_ != NULL) && !dec->is_alpha_decoded_; 107 } 108} 109 110static void DoRemap(WebPIDecoder* const idec, ptrdiff_t offset) { 111 MemBuffer* const mem = &idec->mem_; 112 const uint8_t* const new_base = mem->buf_ + mem->start_; 113 // note: for VP8, setting up idec->io_ is only really needed at the beginning 114 // of the decoding, till partition #0 is complete. 115 idec->io_.data = new_base; 116 idec->io_.data_size = MemDataSize(mem); 117 118 if (idec->dec_ != NULL) { 119 if (!idec->is_lossless_) { 120 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; 121 const int last_part = dec->num_parts_ - 1; 122 if (offset != 0) { 123 int p; 124 for (p = 0; p <= last_part; ++p) { 125 VP8RemapBitReader(dec->parts_ + p, offset); 126 } 127 // Remap partition #0 data pointer to new offset, but only in MAP 128 // mode (in APPEND mode, partition #0 is copied into a fixed memory). 129 if (mem->mode_ == MEM_MODE_MAP) { 130 VP8RemapBitReader(&dec->br_, offset); 131 } 132 } 133 assert(last_part >= 0); 134 dec->parts_[last_part].buf_end_ = mem->buf_ + mem->end_; 135 if (NeedCompressedAlpha(idec)) { 136 ALPHDecoder* const alph_dec = dec->alph_dec_; 137 dec->alpha_data_ += offset; 138 if (alph_dec != NULL) { 139 if (alph_dec->method_ == ALPHA_LOSSLESS_COMPRESSION) { 140 VP8LDecoder* const alph_vp8l_dec = alph_dec->vp8l_dec_; 141 assert(alph_vp8l_dec != NULL); 142 assert(dec->alpha_data_size_ >= ALPHA_HEADER_LEN); 143 VP8LBitReaderSetBuffer(&alph_vp8l_dec->br_, 144 dec->alpha_data_ + ALPHA_HEADER_LEN, 145 dec->alpha_data_size_ - ALPHA_HEADER_LEN); 146 } else { // alph_dec->method_ == ALPHA_NO_COMPRESSION 147 // Nothing special to do in this case. 148 } 149 } 150 } 151 } else { // Resize lossless bitreader 152 VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_; 153 VP8LBitReaderSetBuffer(&dec->br_, new_base, MemDataSize(mem)); 154 } 155 } 156} 157 158// Appends data to the end of MemBuffer->buf_. It expands the allocated memory 159// size if required and also updates VP8BitReader's if new memory is allocated. 160static int AppendToMemBuffer(WebPIDecoder* const idec, 161 const uint8_t* const data, size_t data_size) { 162 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; 163 MemBuffer* const mem = &idec->mem_; 164 const int need_compressed_alpha = NeedCompressedAlpha(idec); 165 const uint8_t* const old_start = mem->buf_ + mem->start_; 166 const uint8_t* const old_base = 167 need_compressed_alpha ? dec->alpha_data_ : old_start; 168 assert(mem->mode_ == MEM_MODE_APPEND); 169 if (data_size > MAX_CHUNK_PAYLOAD) { 170 // security safeguard: trying to allocate more than what the format 171 // allows for a chunk should be considered a smoke smell. 172 return 0; 173 } 174 175 if (mem->end_ + data_size > mem->buf_size_) { // Need some free memory 176 const size_t new_mem_start = old_start - old_base; 177 const size_t current_size = MemDataSize(mem) + new_mem_start; 178 const uint64_t new_size = (uint64_t)current_size + data_size; 179 const uint64_t extra_size = (new_size + CHUNK_SIZE - 1) & ~(CHUNK_SIZE - 1); 180 uint8_t* const new_buf = 181 (uint8_t*)WebPSafeMalloc(extra_size, sizeof(*new_buf)); 182 if (new_buf == NULL) return 0; 183 memcpy(new_buf, old_base, current_size); 184 WebPSafeFree(mem->buf_); 185 mem->buf_ = new_buf; 186 mem->buf_size_ = (size_t)extra_size; 187 mem->start_ = new_mem_start; 188 mem->end_ = current_size; 189 } 190 191 memcpy(mem->buf_ + mem->end_, data, data_size); 192 mem->end_ += data_size; 193 assert(mem->end_ <= mem->buf_size_); 194 195 DoRemap(idec, mem->buf_ + mem->start_ - old_start); 196 return 1; 197} 198 199static int RemapMemBuffer(WebPIDecoder* const idec, 200 const uint8_t* const data, size_t data_size) { 201 MemBuffer* const mem = &idec->mem_; 202 const uint8_t* const old_buf = mem->buf_; 203 const uint8_t* const old_start = old_buf + mem->start_; 204 assert(mem->mode_ == MEM_MODE_MAP); 205 206 if (data_size < mem->buf_size_) return 0; // can't remap to a shorter buffer! 207 208 mem->buf_ = (uint8_t*)data; 209 mem->end_ = mem->buf_size_ = data_size; 210 211 DoRemap(idec, mem->buf_ + mem->start_ - old_start); 212 return 1; 213} 214 215static void InitMemBuffer(MemBuffer* const mem) { 216 mem->mode_ = MEM_MODE_NONE; 217 mem->buf_ = NULL; 218 mem->buf_size_ = 0; 219 mem->part0_buf_ = NULL; 220 mem->part0_size_ = 0; 221} 222 223static void ClearMemBuffer(MemBuffer* const mem) { 224 assert(mem); 225 if (mem->mode_ == MEM_MODE_APPEND) { 226 WebPSafeFree(mem->buf_); 227 WebPSafeFree((void*)mem->part0_buf_); 228 } 229} 230 231static int CheckMemBufferMode(MemBuffer* const mem, MemBufferMode expected) { 232 if (mem->mode_ == MEM_MODE_NONE) { 233 mem->mode_ = expected; // switch to the expected mode 234 } else if (mem->mode_ != expected) { 235 return 0; // we mixed the modes => error 236 } 237 assert(mem->mode_ == expected); // mode is ok 238 return 1; 239} 240 241// To be called last. 242static VP8StatusCode FinishDecoding(WebPIDecoder* const idec) { 243#if WEBP_DECODER_ABI_VERSION > 0x0203 244 const WebPDecoderOptions* const options = idec->params_.options; 245 WebPDecBuffer* const output = idec->params_.output; 246 247 idec->state_ = STATE_DONE; 248 if (options != NULL && options->flip) { 249 return WebPFlipBuffer(output); 250 } 251#endif 252 idec->state_ = STATE_DONE; 253 return VP8_STATUS_OK; 254} 255 256//------------------------------------------------------------------------------ 257// Macroblock-decoding contexts 258 259static void SaveContext(const VP8Decoder* dec, const VP8BitReader* token_br, 260 MBContext* const context) { 261 context->left_ = dec->mb_info_[-1]; 262 context->info_ = dec->mb_info_[dec->mb_x_]; 263 context->token_br_ = *token_br; 264} 265 266static void RestoreContext(const MBContext* context, VP8Decoder* const dec, 267 VP8BitReader* const token_br) { 268 dec->mb_info_[-1] = context->left_; 269 dec->mb_info_[dec->mb_x_] = context->info_; 270 *token_br = context->token_br_; 271} 272 273//------------------------------------------------------------------------------ 274 275static VP8StatusCode IDecError(WebPIDecoder* const idec, VP8StatusCode error) { 276 if (idec->state_ == STATE_VP8_DATA) { 277 VP8Io* const io = &idec->io_; 278 if (io->teardown != NULL) { 279 io->teardown(io); 280 } 281 } 282 idec->state_ = STATE_ERROR; 283 return error; 284} 285 286static void ChangeState(WebPIDecoder* const idec, DecState new_state, 287 size_t consumed_bytes) { 288 MemBuffer* const mem = &idec->mem_; 289 idec->state_ = new_state; 290 mem->start_ += consumed_bytes; 291 assert(mem->start_ <= mem->end_); 292 idec->io_.data = mem->buf_ + mem->start_; 293 idec->io_.data_size = MemDataSize(mem); 294} 295 296// Headers 297static VP8StatusCode DecodeWebPHeaders(WebPIDecoder* const idec) { 298 MemBuffer* const mem = &idec->mem_; 299 const uint8_t* data = mem->buf_ + mem->start_; 300 size_t curr_size = MemDataSize(mem); 301 VP8StatusCode status; 302 WebPHeaderStructure headers; 303 304 headers.data = data; 305 headers.data_size = curr_size; 306 headers.have_all_data = 0; 307 status = WebPParseHeaders(&headers); 308 if (status == VP8_STATUS_NOT_ENOUGH_DATA) { 309 return VP8_STATUS_SUSPENDED; // We haven't found a VP8 chunk yet. 310 } else if (status != VP8_STATUS_OK) { 311 return IDecError(idec, status); 312 } 313 314 idec->chunk_size_ = headers.compressed_size; 315 idec->is_lossless_ = headers.is_lossless; 316 if (!idec->is_lossless_) { 317 VP8Decoder* const dec = VP8New(); 318 if (dec == NULL) { 319 return VP8_STATUS_OUT_OF_MEMORY; 320 } 321 idec->dec_ = dec; 322 dec->alpha_data_ = headers.alpha_data; 323 dec->alpha_data_size_ = headers.alpha_data_size; 324 ChangeState(idec, STATE_VP8_HEADER, headers.offset); 325 } else { 326 VP8LDecoder* const dec = VP8LNew(); 327 if (dec == NULL) { 328 return VP8_STATUS_OUT_OF_MEMORY; 329 } 330 idec->dec_ = dec; 331 ChangeState(idec, STATE_VP8L_HEADER, headers.offset); 332 } 333 return VP8_STATUS_OK; 334} 335 336static VP8StatusCode DecodeVP8FrameHeader(WebPIDecoder* const idec) { 337 const uint8_t* data = idec->mem_.buf_ + idec->mem_.start_; 338 const size_t curr_size = MemDataSize(&idec->mem_); 339 int width, height; 340 uint32_t bits; 341 342 if (curr_size < VP8_FRAME_HEADER_SIZE) { 343 // Not enough data bytes to extract VP8 Frame Header. 344 return VP8_STATUS_SUSPENDED; 345 } 346 if (!VP8GetInfo(data, curr_size, idec->chunk_size_, &width, &height)) { 347 return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); 348 } 349 350 bits = data[0] | (data[1] << 8) | (data[2] << 16); 351 idec->mem_.part0_size_ = (bits >> 5) + VP8_FRAME_HEADER_SIZE; 352 353 idec->io_.data = data; 354 idec->io_.data_size = curr_size; 355 idec->state_ = STATE_VP8_PARTS0; 356 return VP8_STATUS_OK; 357} 358 359// Partition #0 360static VP8StatusCode CopyParts0Data(WebPIDecoder* const idec) { 361 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; 362 VP8BitReader* const br = &dec->br_; 363 const size_t part_size = br->buf_end_ - br->buf_; 364 MemBuffer* const mem = &idec->mem_; 365 assert(!idec->is_lossless_); 366 assert(mem->part0_buf_ == NULL); 367 // the following is a format limitation, no need for runtime check: 368 assert(part_size <= mem->part0_size_); 369 if (part_size == 0) { // can't have zero-size partition #0 370 return VP8_STATUS_BITSTREAM_ERROR; 371 } 372 if (mem->mode_ == MEM_MODE_APPEND) { 373 // We copy and grab ownership of the partition #0 data. 374 uint8_t* const part0_buf = (uint8_t*)WebPSafeMalloc(1ULL, part_size); 375 if (part0_buf == NULL) { 376 return VP8_STATUS_OUT_OF_MEMORY; 377 } 378 memcpy(part0_buf, br->buf_, part_size); 379 mem->part0_buf_ = part0_buf; 380 br->buf_ = part0_buf; 381 br->buf_end_ = part0_buf + part_size; 382 } else { 383 // Else: just keep pointers to the partition #0's data in dec_->br_. 384 } 385 mem->start_ += part_size; 386 return VP8_STATUS_OK; 387} 388 389static VP8StatusCode DecodePartition0(WebPIDecoder* const idec) { 390 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; 391 VP8Io* const io = &idec->io_; 392 const WebPDecParams* const params = &idec->params_; 393 WebPDecBuffer* const output = params->output; 394 395 // Wait till we have enough data for the whole partition #0 396 if (MemDataSize(&idec->mem_) < idec->mem_.part0_size_) { 397 return VP8_STATUS_SUSPENDED; 398 } 399 400 if (!VP8GetHeaders(dec, io)) { 401 const VP8StatusCode status = dec->status_; 402 if (status == VP8_STATUS_SUSPENDED || 403 status == VP8_STATUS_NOT_ENOUGH_DATA) { 404 // treating NOT_ENOUGH_DATA as SUSPENDED state 405 return VP8_STATUS_SUSPENDED; 406 } 407 return IDecError(idec, status); 408 } 409 410 // Allocate/Verify output buffer now 411 dec->status_ = WebPAllocateDecBuffer(io->width, io->height, params->options, 412 output); 413 if (dec->status_ != VP8_STATUS_OK) { 414 return IDecError(idec, dec->status_); 415 } 416 // This change must be done before calling VP8InitFrame() 417 dec->mt_method_ = VP8GetThreadMethod(params->options, NULL, 418 io->width, io->height); 419 VP8InitDithering(params->options, dec); 420 421 dec->status_ = CopyParts0Data(idec); 422 if (dec->status_ != VP8_STATUS_OK) { 423 return IDecError(idec, dec->status_); 424 } 425 426 // Finish setting up the decoding parameters. Will call io->setup(). 427 if (VP8EnterCritical(dec, io) != VP8_STATUS_OK) { 428 return IDecError(idec, dec->status_); 429 } 430 431 // Note: past this point, teardown() must always be called 432 // in case of error. 433 idec->state_ = STATE_VP8_DATA; 434 // Allocate memory and prepare everything. 435 if (!VP8InitFrame(dec, io)) { 436 return IDecError(idec, dec->status_); 437 } 438 return VP8_STATUS_OK; 439} 440 441// Remaining partitions 442static VP8StatusCode DecodeRemaining(WebPIDecoder* const idec) { 443 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; 444 VP8Io* const io = &idec->io_; 445 446 assert(dec->ready_); 447 for (; dec->mb_y_ < dec->mb_h_; ++dec->mb_y_) { 448 if (idec->last_mb_y_ != dec->mb_y_) { 449 if (!VP8ParseIntraModeRow(&dec->br_, dec)) { 450 // note: normally, error shouldn't occur since we already have the whole 451 // partition0 available here in DecodeRemaining(). Reaching EOF while 452 // reading intra modes really means a BITSTREAM_ERROR. 453 return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); 454 } 455 idec->last_mb_y_ = dec->mb_y_; 456 } 457 for (; dec->mb_x_ < dec->mb_w_; ++dec->mb_x_) { 458 VP8BitReader* const token_br = 459 &dec->parts_[dec->mb_y_ & (dec->num_parts_ - 1)]; 460 MBContext context; 461 SaveContext(dec, token_br, &context); 462 if (!VP8DecodeMB(dec, token_br)) { 463 // We shouldn't fail when MAX_MB data was available 464 if (dec->num_parts_ == 1 && MemDataSize(&idec->mem_) > MAX_MB_SIZE) { 465 return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); 466 } 467 RestoreContext(&context, dec, token_br); 468 return VP8_STATUS_SUSPENDED; 469 } 470 // Release buffer only if there is only one partition 471 if (dec->num_parts_ == 1) { 472 idec->mem_.start_ = token_br->buf_ - idec->mem_.buf_; 473 assert(idec->mem_.start_ <= idec->mem_.end_); 474 } 475 } 476 VP8InitScanline(dec); // Prepare for next scanline 477 478 // Reconstruct, filter and emit the row. 479 if (!VP8ProcessRow(dec, io)) { 480 return IDecError(idec, VP8_STATUS_USER_ABORT); 481 } 482 } 483 // Synchronize the thread and check for errors. 484 if (!VP8ExitCritical(dec, io)) { 485 return IDecError(idec, VP8_STATUS_USER_ABORT); 486 } 487 dec->ready_ = 0; 488 return FinishDecoding(idec); 489} 490 491static VP8StatusCode ErrorStatusLossless(WebPIDecoder* const idec, 492 VP8StatusCode status) { 493 if (status == VP8_STATUS_SUSPENDED || status == VP8_STATUS_NOT_ENOUGH_DATA) { 494 return VP8_STATUS_SUSPENDED; 495 } 496 return IDecError(idec, status); 497} 498 499static VP8StatusCode DecodeVP8LHeader(WebPIDecoder* const idec) { 500 VP8Io* const io = &idec->io_; 501 VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_; 502 const WebPDecParams* const params = &idec->params_; 503 WebPDecBuffer* const output = params->output; 504 size_t curr_size = MemDataSize(&idec->mem_); 505 assert(idec->is_lossless_); 506 507 // Wait until there's enough data for decoding header. 508 if (curr_size < (idec->chunk_size_ >> 3)) { 509 return VP8_STATUS_SUSPENDED; 510 } 511 if (!VP8LDecodeHeader(dec, io)) { 512 return ErrorStatusLossless(idec, dec->status_); 513 } 514 // Allocate/verify output buffer now. 515 dec->status_ = WebPAllocateDecBuffer(io->width, io->height, params->options, 516 output); 517 if (dec->status_ != VP8_STATUS_OK) { 518 return IDecError(idec, dec->status_); 519 } 520 521 idec->state_ = STATE_VP8L_DATA; 522 return VP8_STATUS_OK; 523} 524 525static VP8StatusCode DecodeVP8LData(WebPIDecoder* const idec) { 526 VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_; 527 const size_t curr_size = MemDataSize(&idec->mem_); 528 assert(idec->is_lossless_); 529 530 // At present Lossless decoder can't decode image incrementally. So wait till 531 // all the image data is aggregated before image can be decoded. 532 if (curr_size < idec->chunk_size_) { 533 return VP8_STATUS_SUSPENDED; 534 } 535 536 if (!VP8LDecodeImage(dec)) { 537 // The decoding is called after all the data-bytes are aggregated. Change 538 // the error to VP8_BITSTREAM_ERROR in case lossless decoder fails to decode 539 // all the pixels (VP8_STATUS_SUSPENDED). 540 if (dec->status_ == VP8_STATUS_SUSPENDED) { 541 dec->status_ = VP8_STATUS_BITSTREAM_ERROR; 542 } 543 return ErrorStatusLossless(idec, dec->status_); 544 } 545 546 return FinishDecoding(idec); 547} 548 549 // Main decoding loop 550static VP8StatusCode IDecode(WebPIDecoder* idec) { 551 VP8StatusCode status = VP8_STATUS_SUSPENDED; 552 553 if (idec->state_ == STATE_WEBP_HEADER) { 554 status = DecodeWebPHeaders(idec); 555 } else { 556 if (idec->dec_ == NULL) { 557 return VP8_STATUS_SUSPENDED; // can't continue if we have no decoder. 558 } 559 } 560 if (idec->state_ == STATE_VP8_HEADER) { 561 status = DecodeVP8FrameHeader(idec); 562 } 563 if (idec->state_ == STATE_VP8_PARTS0) { 564 status = DecodePartition0(idec); 565 } 566 if (idec->state_ == STATE_VP8_DATA) { 567 status = DecodeRemaining(idec); 568 } 569 if (idec->state_ == STATE_VP8L_HEADER) { 570 status = DecodeVP8LHeader(idec); 571 } 572 if (idec->state_ == STATE_VP8L_DATA) { 573 status = DecodeVP8LData(idec); 574 } 575 return status; 576} 577 578//------------------------------------------------------------------------------ 579// Public functions 580 581WebPIDecoder* WebPINewDecoder(WebPDecBuffer* output_buffer) { 582 WebPIDecoder* idec = (WebPIDecoder*)WebPSafeCalloc(1ULL, sizeof(*idec)); 583 if (idec == NULL) { 584 return NULL; 585 } 586 587 idec->state_ = STATE_WEBP_HEADER; 588 idec->chunk_size_ = 0; 589 590 idec->last_mb_y_ = -1; 591 592 InitMemBuffer(&idec->mem_); 593 WebPInitDecBuffer(&idec->output_); 594 VP8InitIo(&idec->io_); 595 596 WebPResetDecParams(&idec->params_); 597 idec->params_.output = (output_buffer != NULL) ? output_buffer 598 : &idec->output_; 599 WebPInitCustomIo(&idec->params_, &idec->io_); // Plug the I/O functions. 600 601 return idec; 602} 603 604WebPIDecoder* WebPIDecode(const uint8_t* data, size_t data_size, 605 WebPDecoderConfig* config) { 606 WebPIDecoder* idec; 607 608 // Parse the bitstream's features, if requested: 609 if (data != NULL && data_size > 0 && config != NULL) { 610 if (WebPGetFeatures(data, data_size, &config->input) != VP8_STATUS_OK) { 611 return NULL; 612 } 613 } 614 // Create an instance of the incremental decoder 615 idec = WebPINewDecoder(config ? &config->output : NULL); 616 if (idec == NULL) { 617 return NULL; 618 } 619 // Finish initialization 620 if (config != NULL) { 621 idec->params_.options = &config->options; 622 } 623 return idec; 624} 625 626void WebPIDelete(WebPIDecoder* idec) { 627 if (idec == NULL) return; 628 if (idec->dec_ != NULL) { 629 if (!idec->is_lossless_) { 630 if (idec->state_ == STATE_VP8_DATA) { 631 // Synchronize the thread, clean-up and check for errors. 632 VP8ExitCritical((VP8Decoder*)idec->dec_, &idec->io_); 633 } 634 VP8Delete((VP8Decoder*)idec->dec_); 635 } else { 636 VP8LDelete((VP8LDecoder*)idec->dec_); 637 } 638 } 639 ClearMemBuffer(&idec->mem_); 640 WebPFreeDecBuffer(&idec->output_); 641 WebPSafeFree(idec); 642} 643 644//------------------------------------------------------------------------------ 645// Wrapper toward WebPINewDecoder 646 647WebPIDecoder* WebPINewRGB(WEBP_CSP_MODE mode, uint8_t* output_buffer, 648 size_t output_buffer_size, int output_stride) { 649 const int is_external_memory = (output_buffer != NULL); 650 WebPIDecoder* idec; 651 652 if (mode >= MODE_YUV) return NULL; 653 if (!is_external_memory) { // Overwrite parameters to sane values. 654 output_buffer_size = 0; 655 output_stride = 0; 656 } else { // A buffer was passed. Validate the other params. 657 if (output_stride == 0 || output_buffer_size == 0) { 658 return NULL; // invalid parameter. 659 } 660 } 661 idec = WebPINewDecoder(NULL); 662 if (idec == NULL) return NULL; 663 idec->output_.colorspace = mode; 664 idec->output_.is_external_memory = is_external_memory; 665 idec->output_.u.RGBA.rgba = output_buffer; 666 idec->output_.u.RGBA.stride = output_stride; 667 idec->output_.u.RGBA.size = output_buffer_size; 668 return idec; 669} 670 671WebPIDecoder* WebPINewYUVA(uint8_t* luma, size_t luma_size, int luma_stride, 672 uint8_t* u, size_t u_size, int u_stride, 673 uint8_t* v, size_t v_size, int v_stride, 674 uint8_t* a, size_t a_size, int a_stride) { 675 const int is_external_memory = (luma != NULL); 676 WebPIDecoder* idec; 677 WEBP_CSP_MODE colorspace; 678 679 if (!is_external_memory) { // Overwrite parameters to sane values. 680 luma_size = u_size = v_size = a_size = 0; 681 luma_stride = u_stride = v_stride = a_stride = 0; 682 u = v = a = NULL; 683 colorspace = MODE_YUVA; 684 } else { // A luma buffer was passed. Validate the other parameters. 685 if (u == NULL || v == NULL) return NULL; 686 if (luma_size == 0 || u_size == 0 || v_size == 0) return NULL; 687 if (luma_stride == 0 || u_stride == 0 || v_stride == 0) return NULL; 688 if (a != NULL) { 689 if (a_size == 0 || a_stride == 0) return NULL; 690 } 691 colorspace = (a == NULL) ? MODE_YUV : MODE_YUVA; 692 } 693 694 idec = WebPINewDecoder(NULL); 695 if (idec == NULL) return NULL; 696 697 idec->output_.colorspace = colorspace; 698 idec->output_.is_external_memory = is_external_memory; 699 idec->output_.u.YUVA.y = luma; 700 idec->output_.u.YUVA.y_stride = luma_stride; 701 idec->output_.u.YUVA.y_size = luma_size; 702 idec->output_.u.YUVA.u = u; 703 idec->output_.u.YUVA.u_stride = u_stride; 704 idec->output_.u.YUVA.u_size = u_size; 705 idec->output_.u.YUVA.v = v; 706 idec->output_.u.YUVA.v_stride = v_stride; 707 idec->output_.u.YUVA.v_size = v_size; 708 idec->output_.u.YUVA.a = a; 709 idec->output_.u.YUVA.a_stride = a_stride; 710 idec->output_.u.YUVA.a_size = a_size; 711 return idec; 712} 713 714WebPIDecoder* WebPINewYUV(uint8_t* luma, size_t luma_size, int luma_stride, 715 uint8_t* u, size_t u_size, int u_stride, 716 uint8_t* v, size_t v_size, int v_stride) { 717 return WebPINewYUVA(luma, luma_size, luma_stride, 718 u, u_size, u_stride, 719 v, v_size, v_stride, 720 NULL, 0, 0); 721} 722 723//------------------------------------------------------------------------------ 724 725static VP8StatusCode IDecCheckStatus(const WebPIDecoder* const idec) { 726 assert(idec); 727 if (idec->state_ == STATE_ERROR) { 728 return VP8_STATUS_BITSTREAM_ERROR; 729 } 730 if (idec->state_ == STATE_DONE) { 731 return VP8_STATUS_OK; 732 } 733 return VP8_STATUS_SUSPENDED; 734} 735 736VP8StatusCode WebPIAppend(WebPIDecoder* idec, 737 const uint8_t* data, size_t data_size) { 738 VP8StatusCode status; 739 if (idec == NULL || data == NULL) { 740 return VP8_STATUS_INVALID_PARAM; 741 } 742 status = IDecCheckStatus(idec); 743 if (status != VP8_STATUS_SUSPENDED) { 744 return status; 745 } 746 // Check mixed calls between RemapMemBuffer and AppendToMemBuffer. 747 if (!CheckMemBufferMode(&idec->mem_, MEM_MODE_APPEND)) { 748 return VP8_STATUS_INVALID_PARAM; 749 } 750 // Append data to memory buffer 751 if (!AppendToMemBuffer(idec, data, data_size)) { 752 return VP8_STATUS_OUT_OF_MEMORY; 753 } 754 return IDecode(idec); 755} 756 757VP8StatusCode WebPIUpdate(WebPIDecoder* idec, 758 const uint8_t* data, size_t data_size) { 759 VP8StatusCode status; 760 if (idec == NULL || data == NULL) { 761 return VP8_STATUS_INVALID_PARAM; 762 } 763 status = IDecCheckStatus(idec); 764 if (status != VP8_STATUS_SUSPENDED) { 765 return status; 766 } 767 // Check mixed calls between RemapMemBuffer and AppendToMemBuffer. 768 if (!CheckMemBufferMode(&idec->mem_, MEM_MODE_MAP)) { 769 return VP8_STATUS_INVALID_PARAM; 770 } 771 // Make the memory buffer point to the new buffer 772 if (!RemapMemBuffer(idec, data, data_size)) { 773 return VP8_STATUS_INVALID_PARAM; 774 } 775 return IDecode(idec); 776} 777 778//------------------------------------------------------------------------------ 779 780static const WebPDecBuffer* GetOutputBuffer(const WebPIDecoder* const idec) { 781 if (idec == NULL || idec->dec_ == NULL) { 782 return NULL; 783 } 784 if (idec->state_ <= STATE_VP8_PARTS0) { 785 return NULL; 786 } 787 return idec->params_.output; 788} 789 790const WebPDecBuffer* WebPIDecodedArea(const WebPIDecoder* idec, 791 int* left, int* top, 792 int* width, int* height) { 793 const WebPDecBuffer* const src = GetOutputBuffer(idec); 794 if (left != NULL) *left = 0; 795 if (top != NULL) *top = 0; 796 // TODO(skal): later include handling of rotations. 797 if (src) { 798 if (width != NULL) *width = src->width; 799 if (height != NULL) *height = idec->params_.last_y; 800 } else { 801 if (width != NULL) *width = 0; 802 if (height != NULL) *height = 0; 803 } 804 return src; 805} 806 807uint8_t* WebPIDecGetRGB(const WebPIDecoder* idec, int* last_y, 808 int* width, int* height, int* stride) { 809 const WebPDecBuffer* const src = GetOutputBuffer(idec); 810 if (src == NULL) return NULL; 811 if (src->colorspace >= MODE_YUV) { 812 return NULL; 813 } 814 815 if (last_y != NULL) *last_y = idec->params_.last_y; 816 if (width != NULL) *width = src->width; 817 if (height != NULL) *height = src->height; 818 if (stride != NULL) *stride = src->u.RGBA.stride; 819 820 return src->u.RGBA.rgba; 821} 822 823uint8_t* WebPIDecGetYUVA(const WebPIDecoder* idec, int* last_y, 824 uint8_t** u, uint8_t** v, uint8_t** a, 825 int* width, int* height, 826 int* stride, int* uv_stride, int* a_stride) { 827 const WebPDecBuffer* const src = GetOutputBuffer(idec); 828 if (src == NULL) return NULL; 829 if (src->colorspace < MODE_YUV) { 830 return NULL; 831 } 832 833 if (last_y != NULL) *last_y = idec->params_.last_y; 834 if (u != NULL) *u = src->u.YUVA.u; 835 if (v != NULL) *v = src->u.YUVA.v; 836 if (a != NULL) *a = src->u.YUVA.a; 837 if (width != NULL) *width = src->width; 838 if (height != NULL) *height = src->height; 839 if (stride != NULL) *stride = src->u.YUVA.y_stride; 840 if (uv_stride != NULL) *uv_stride = src->u.YUVA.u_stride; 841 if (a_stride != NULL) *a_stride = src->u.YUVA.a_stride; 842 843 return src->u.YUVA.y; 844} 845 846int WebPISetIOHooks(WebPIDecoder* const idec, 847 VP8IoPutHook put, 848 VP8IoSetupHook setup, 849 VP8IoTeardownHook teardown, 850 void* user_data) { 851 if (idec == NULL || idec->state_ > STATE_WEBP_HEADER) { 852 return 0; 853 } 854 855 idec->io_.put = put; 856 idec->io_.setup = setup; 857 idec->io_.teardown = teardown; 858 idec->io_.opaque = user_data; 859 860 return 1; 861} 862 863