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| 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. | |
| 35 typedef 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 | |
| 47 typedef 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) | |
| 54 typedef 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 | |
| 65 struct 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 // or if the external one has slow-memory) | |
| 75 WebPDecBuffer* final_output_; // Slow-memory output to copy to eventually. | |
| 76 size_t chunk_size_; // Compressed VP8/VP8L size extracted from Header. | |
| 77 | |
| 78 int last_mb_y_; // last row reached for intra-mode decoding | |
| 79 }; | |
| 80 | |
| 81 // MB context to restore in case VP8DecodeMB() fails | |
| 82 typedef struct { | |
| 83 VP8MB left_; | |
| 84 VP8MB info_; | |
| 85 VP8BitReader token_br_; | |
| 86 } MBContext; | |
| 87 | |
| 88 //------------------------------------------------------------------------------ | |
| 89 // MemBuffer: incoming data handling | |
| 90 | |
| 91 static WEBP_INLINE size_t MemDataSize(const MemBuffer* mem) { | |
| 92 return (mem->end_ - mem->start_); | |
| 93 } | |
| 94 | |
| 95 // Check if we need to preserve the compressed alpha data, as it may not have | |
| 96 // been decoded yet. | |
| 97 static int NeedCompressedAlpha(const WebPIDecoder* const idec) { | |
| 98 if (idec->state_ == STATE_WEBP_HEADER) { | |
| 99 // We haven't parsed the headers yet, so we don't know whether the image is | |
| 100 // lossy or lossless. This also means that we haven't parsed the ALPH chunk. | |
| 101 return 0; | |
| 102 } | |
| 103 if (idec->is_lossless_) { | |
| 104 return 0; // ALPH chunk is not present for lossless images. | |
| 105 } else { | |
| 106 const VP8Decoder* const dec = (VP8Decoder*)idec->dec_; | |
| 107 assert(dec != NULL); // Must be true as idec->state_ != STATE_WEBP_HEADER. | |
| 108 return (dec->alpha_data_ != NULL) && !dec->is_alpha_decoded_; | |
| 109 } | |
| 110 } | |
| 111 | |
| 112 static void DoRemap(WebPIDecoder* const idec, ptrdiff_t offset) { | |
| 113 MemBuffer* const mem = &idec->mem_; | |
| 114 const uint8_t* const new_base = mem->buf_ + mem->start_; | |
| 115 // note: for VP8, setting up idec->io_ is only really needed at the beginning | |
| 116 // of the decoding, till partition #0 is complete. | |
| 117 idec->io_.data = new_base; | |
| 118 idec->io_.data_size = MemDataSize(mem); | |
| 119 | |
| 120 if (idec->dec_ != NULL) { | |
| 121 if (!idec->is_lossless_) { | |
| 122 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; | |
| 123 const uint32_t last_part = dec->num_parts_minus_one_; | |
| 124 if (offset != 0) { | |
| 125 uint32_t p; | |
| 126 for (p = 0; p <= last_part; ++p) { | |
| 127 VP8RemapBitReader(dec->parts_ + p, offset); | |
| 128 } | |
| 129 // Remap partition #0 data pointer to new offset, but only in MAP | |
| 130 // mode (in APPEND mode, partition #0 is copied into a fixed memory). | |
| 131 if (mem->mode_ == MEM_MODE_MAP) { | |
| 132 VP8RemapBitReader(&dec->br_, offset); | |
| 133 } | |
| 134 } | |
| 135 { | |
| 136 const uint8_t* const last_start = dec->parts_[last_part].buf_; | |
| 137 VP8BitReaderSetBuffer(&dec->parts_[last_part], last_start, | |
| 138 mem->buf_ + mem->end_ - last_start); | |
| 139 } | |
| 140 if (NeedCompressedAlpha(idec)) { | |
| 141 ALPHDecoder* const alph_dec = dec->alph_dec_; | |
| 142 dec->alpha_data_ += offset; | |
| 143 if (alph_dec != NULL) { | |
| 144 if (alph_dec->method_ == ALPHA_LOSSLESS_COMPRESSION) { | |
| 145 VP8LDecoder* const alph_vp8l_dec = alph_dec->vp8l_dec_; | |
| 146 assert(alph_vp8l_dec != NULL); | |
| 147 assert(dec->alpha_data_size_ >= ALPHA_HEADER_LEN); | |
| 148 VP8LBitReaderSetBuffer(&alph_vp8l_dec->br_, | |
| 149 dec->alpha_data_ + ALPHA_HEADER_LEN, | |
| 150 dec->alpha_data_size_ - ALPHA_HEADER_LEN); | |
| 151 } else { // alph_dec->method_ == ALPHA_NO_COMPRESSION | |
| 152 // Nothing special to do in this case. | |
| 153 } | |
| 154 } | |
| 155 } | |
| 156 } else { // Resize lossless bitreader | |
| 157 VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_; | |
| 158 VP8LBitReaderSetBuffer(&dec->br_, new_base, MemDataSize(mem)); | |
| 159 } | |
| 160 } | |
| 161 } | |
| 162 | |
| 163 // Appends data to the end of MemBuffer->buf_. It expands the allocated memory | |
| 164 // size if required and also updates VP8BitReader's if new memory is allocated. | |
| 165 static int AppendToMemBuffer(WebPIDecoder* const idec, | |
| 166 const uint8_t* const data, size_t data_size) { | |
| 167 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; | |
| 168 MemBuffer* const mem = &idec->mem_; | |
| 169 const int need_compressed_alpha = NeedCompressedAlpha(idec); | |
| 170 const uint8_t* const old_start = mem->buf_ + mem->start_; | |
| 171 const uint8_t* const old_base = | |
| 172 need_compressed_alpha ? dec->alpha_data_ : old_start; | |
| 173 assert(mem->mode_ == MEM_MODE_APPEND); | |
| 174 if (data_size > MAX_CHUNK_PAYLOAD) { | |
| 175 // security safeguard: trying to allocate more than what the format | |
| 176 // allows for a chunk should be considered a smoke smell. | |
| 177 return 0; | |
| 178 } | |
| 179 | |
| 180 if (mem->end_ + data_size > mem->buf_size_) { // Need some free memory | |
| 181 const size_t new_mem_start = old_start - old_base; | |
| 182 const size_t current_size = MemDataSize(mem) + new_mem_start; | |
| 183 const uint64_t new_size = (uint64_t)current_size + data_size; | |
| 184 const uint64_t extra_size = (new_size + CHUNK_SIZE - 1) & ~(CHUNK_SIZE - 1); | |
| 185 uint8_t* const new_buf = | |
| 186 (uint8_t*)WebPSafeMalloc(extra_size, sizeof(*new_buf)); | |
| 187 if (new_buf == NULL) return 0; | |
| 188 memcpy(new_buf, old_base, current_size); | |
| 189 WebPSafeFree(mem->buf_); | |
| 190 mem->buf_ = new_buf; | |
| 191 mem->buf_size_ = (size_t)extra_size; | |
| 192 mem->start_ = new_mem_start; | |
| 193 mem->end_ = current_size; | |
| 194 } | |
| 195 | |
| 196 memcpy(mem->buf_ + mem->end_, data, data_size); | |
| 197 mem->end_ += data_size; | |
| 198 assert(mem->end_ <= mem->buf_size_); | |
| 199 | |
| 200 DoRemap(idec, mem->buf_ + mem->start_ - old_start); | |
| 201 return 1; | |
| 202 } | |
| 203 | |
| 204 static int RemapMemBuffer(WebPIDecoder* const idec, | |
| 205 const uint8_t* const data, size_t data_size) { | |
| 206 MemBuffer* const mem = &idec->mem_; | |
| 207 const uint8_t* const old_buf = mem->buf_; | |
| 208 const uint8_t* const old_start = old_buf + mem->start_; | |
| 209 assert(mem->mode_ == MEM_MODE_MAP); | |
| 210 | |
| 211 if (data_size < mem->buf_size_) return 0; // can't remap to a shorter buffer! | |
| 212 | |
| 213 mem->buf_ = (uint8_t*)data; | |
| 214 mem->end_ = mem->buf_size_ = data_size; | |
| 215 | |
| 216 DoRemap(idec, mem->buf_ + mem->start_ - old_start); | |
| 217 return 1; | |
| 218 } | |
| 219 | |
| 220 static void InitMemBuffer(MemBuffer* const mem) { | |
| 221 mem->mode_ = MEM_MODE_NONE; | |
| 222 mem->buf_ = NULL; | |
| 223 mem->buf_size_ = 0; | |
| 224 mem->part0_buf_ = NULL; | |
| 225 mem->part0_size_ = 0; | |
| 226 } | |
| 227 | |
| 228 static void ClearMemBuffer(MemBuffer* const mem) { | |
| 229 assert(mem); | |
| 230 if (mem->mode_ == MEM_MODE_APPEND) { | |
| 231 WebPSafeFree(mem->buf_); | |
| 232 WebPSafeFree((void*)mem->part0_buf_); | |
| 233 } | |
| 234 } | |
| 235 | |
| 236 static int CheckMemBufferMode(MemBuffer* const mem, MemBufferMode expected) { | |
| 237 if (mem->mode_ == MEM_MODE_NONE) { | |
| 238 mem->mode_ = expected; // switch to the expected mode | |
| 239 } else if (mem->mode_ != expected) { | |
| 240 return 0; // we mixed the modes => error | |
| 241 } | |
| 242 assert(mem->mode_ == expected); // mode is ok | |
| 243 return 1; | |
| 244 } | |
| 245 | |
| 246 // To be called last. | |
| 247 static VP8StatusCode FinishDecoding(WebPIDecoder* const idec) { | |
| 248 const WebPDecoderOptions* const options = idec->params_.options; | |
| 249 WebPDecBuffer* const output = idec->params_.output; | |
| 250 | |
| 251 idec->state_ = STATE_DONE; | |
| 252 if (options != NULL && options->flip) { | |
| 253 const VP8StatusCode status = WebPFlipBuffer(output); | |
| 254 if (status != VP8_STATUS_OK) return status; | |
| 255 } | |
| 256 if (idec->final_output_ != NULL) { | |
| 257 WebPCopyDecBufferPixels(output, idec->final_output_); // do the slow-copy | |
| 258 WebPFreeDecBuffer(&idec->output_); | |
| 259 *output = *idec->final_output_; | |
| 260 idec->final_output_ = NULL; | |
| 261 } | |
| 262 return VP8_STATUS_OK; | |
| 263 } | |
| 264 | |
| 265 //------------------------------------------------------------------------------ | |
| 266 // Macroblock-decoding contexts | |
| 267 | |
| 268 static void SaveContext(const VP8Decoder* dec, const VP8BitReader* token_br, | |
| 269 MBContext* const context) { | |
| 270 context->left_ = dec->mb_info_[-1]; | |
| 271 context->info_ = dec->mb_info_[dec->mb_x_]; | |
| 272 context->token_br_ = *token_br; | |
| 273 } | |
| 274 | |
| 275 static void RestoreContext(const MBContext* context, VP8Decoder* const dec, | |
| 276 VP8BitReader* const token_br) { | |
| 277 dec->mb_info_[-1] = context->left_; | |
| 278 dec->mb_info_[dec->mb_x_] = context->info_; | |
| 279 *token_br = context->token_br_; | |
| 280 } | |
| 281 | |
| 282 //------------------------------------------------------------------------------ | |
| 283 | |
| 284 static VP8StatusCode IDecError(WebPIDecoder* const idec, VP8StatusCode error) { | |
| 285 if (idec->state_ == STATE_VP8_DATA) { | |
| 286 VP8Io* const io = &idec->io_; | |
| 287 if (io->teardown != NULL) { | |
| 288 io->teardown(io); | |
| 289 } | |
| 290 } | |
| 291 idec->state_ = STATE_ERROR; | |
| 292 return error; | |
| 293 } | |
| 294 | |
| 295 static void ChangeState(WebPIDecoder* const idec, DecState new_state, | |
| 296 size_t consumed_bytes) { | |
| 297 MemBuffer* const mem = &idec->mem_; | |
| 298 idec->state_ = new_state; | |
| 299 mem->start_ += consumed_bytes; | |
| 300 assert(mem->start_ <= mem->end_); | |
| 301 idec->io_.data = mem->buf_ + mem->start_; | |
| 302 idec->io_.data_size = MemDataSize(mem); | |
| 303 } | |
| 304 | |
| 305 // Headers | |
| 306 static VP8StatusCode DecodeWebPHeaders(WebPIDecoder* const idec) { | |
| 307 MemBuffer* const mem = &idec->mem_; | |
| 308 const uint8_t* data = mem->buf_ + mem->start_; | |
| 309 size_t curr_size = MemDataSize(mem); | |
| 310 VP8StatusCode status; | |
| 311 WebPHeaderStructure headers; | |
| 312 | |
| 313 headers.data = data; | |
| 314 headers.data_size = curr_size; | |
| 315 headers.have_all_data = 0; | |
| 316 status = WebPParseHeaders(&headers); | |
| 317 if (status == VP8_STATUS_NOT_ENOUGH_DATA) { | |
| 318 return VP8_STATUS_SUSPENDED; // We haven't found a VP8 chunk yet. | |
| 319 } else if (status != VP8_STATUS_OK) { | |
| 320 return IDecError(idec, status); | |
| 321 } | |
| 322 | |
| 323 idec->chunk_size_ = headers.compressed_size; | |
| 324 idec->is_lossless_ = headers.is_lossless; | |
| 325 if (!idec->is_lossless_) { | |
| 326 VP8Decoder* const dec = VP8New(); | |
| 327 if (dec == NULL) { | |
| 328 return VP8_STATUS_OUT_OF_MEMORY; | |
| 329 } | |
| 330 idec->dec_ = dec; | |
| 331 dec->alpha_data_ = headers.alpha_data; | |
| 332 dec->alpha_data_size_ = headers.alpha_data_size; | |
| 333 ChangeState(idec, STATE_VP8_HEADER, headers.offset); | |
| 334 } else { | |
| 335 VP8LDecoder* const dec = VP8LNew(); | |
| 336 if (dec == NULL) { | |
| 337 return VP8_STATUS_OUT_OF_MEMORY; | |
| 338 } | |
| 339 idec->dec_ = dec; | |
| 340 ChangeState(idec, STATE_VP8L_HEADER, headers.offset); | |
| 341 } | |
| 342 return VP8_STATUS_OK; | |
| 343 } | |
| 344 | |
| 345 static VP8StatusCode DecodeVP8FrameHeader(WebPIDecoder* const idec) { | |
| 346 const uint8_t* data = idec->mem_.buf_ + idec->mem_.start_; | |
| 347 const size_t curr_size = MemDataSize(&idec->mem_); | |
| 348 int width, height; | |
| 349 uint32_t bits; | |
| 350 | |
| 351 if (curr_size < VP8_FRAME_HEADER_SIZE) { | |
| 352 // Not enough data bytes to extract VP8 Frame Header. | |
| 353 return VP8_STATUS_SUSPENDED; | |
| 354 } | |
| 355 if (!VP8GetInfo(data, curr_size, idec->chunk_size_, &width, &height)) { | |
| 356 return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); | |
| 357 } | |
| 358 | |
| 359 bits = data[0] | (data[1] << 8) | (data[2] << 16); | |
| 360 idec->mem_.part0_size_ = (bits >> 5) + VP8_FRAME_HEADER_SIZE; | |
| 361 | |
| 362 idec->io_.data = data; | |
| 363 idec->io_.data_size = curr_size; | |
| 364 idec->state_ = STATE_VP8_PARTS0; | |
| 365 return VP8_STATUS_OK; | |
| 366 } | |
| 367 | |
| 368 // Partition #0 | |
| 369 static VP8StatusCode CopyParts0Data(WebPIDecoder* const idec) { | |
| 370 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; | |
| 371 VP8BitReader* const br = &dec->br_; | |
| 372 const size_t part_size = br->buf_end_ - br->buf_; | |
| 373 MemBuffer* const mem = &idec->mem_; | |
| 374 assert(!idec->is_lossless_); | |
| 375 assert(mem->part0_buf_ == NULL); | |
| 376 // the following is a format limitation, no need for runtime check: | |
| 377 assert(part_size <= mem->part0_size_); | |
| 378 if (part_size == 0) { // can't have zero-size partition #0 | |
| 379 return VP8_STATUS_BITSTREAM_ERROR; | |
| 380 } | |
| 381 if (mem->mode_ == MEM_MODE_APPEND) { | |
| 382 // We copy and grab ownership of the partition #0 data. | |
| 383 uint8_t* const part0_buf = (uint8_t*)WebPSafeMalloc(1ULL, part_size); | |
| 384 if (part0_buf == NULL) { | |
| 385 return VP8_STATUS_OUT_OF_MEMORY; | |
| 386 } | |
| 387 memcpy(part0_buf, br->buf_, part_size); | |
| 388 mem->part0_buf_ = part0_buf; | |
| 389 VP8BitReaderSetBuffer(br, part0_buf, part_size); | |
| 390 } else { | |
| 391 // Else: just keep pointers to the partition #0's data in dec_->br_. | |
| 392 } | |
| 393 mem->start_ += part_size; | |
| 394 return VP8_STATUS_OK; | |
| 395 } | |
| 396 | |
| 397 static VP8StatusCode DecodePartition0(WebPIDecoder* const idec) { | |
| 398 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; | |
| 399 VP8Io* const io = &idec->io_; | |
| 400 const WebPDecParams* const params = &idec->params_; | |
| 401 WebPDecBuffer* const output = params->output; | |
| 402 | |
| 403 // Wait till we have enough data for the whole partition #0 | |
| 404 if (MemDataSize(&idec->mem_) < idec->mem_.part0_size_) { | |
| 405 return VP8_STATUS_SUSPENDED; | |
| 406 } | |
| 407 | |
| 408 if (!VP8GetHeaders(dec, io)) { | |
| 409 const VP8StatusCode status = dec->status_; | |
| 410 if (status == VP8_STATUS_SUSPENDED || | |
| 411 status == VP8_STATUS_NOT_ENOUGH_DATA) { | |
| 412 // treating NOT_ENOUGH_DATA as SUSPENDED state | |
| 413 return VP8_STATUS_SUSPENDED; | |
| 414 } | |
| 415 return IDecError(idec, status); | |
| 416 } | |
| 417 | |
| 418 // Allocate/Verify output buffer now | |
| 419 dec->status_ = WebPAllocateDecBuffer(io->width, io->height, params->options, | |
| 420 output); | |
| 421 if (dec->status_ != VP8_STATUS_OK) { | |
| 422 return IDecError(idec, dec->status_); | |
| 423 } | |
| 424 // This change must be done before calling VP8InitFrame() | |
| 425 dec->mt_method_ = VP8GetThreadMethod(params->options, NULL, | |
| 426 io->width, io->height); | |
| 427 VP8InitDithering(params->options, dec); | |
| 428 | |
| 429 dec->status_ = CopyParts0Data(idec); | |
| 430 if (dec->status_ != VP8_STATUS_OK) { | |
| 431 return IDecError(idec, dec->status_); | |
| 432 } | |
| 433 | |
| 434 // Finish setting up the decoding parameters. Will call io->setup(). | |
| 435 if (VP8EnterCritical(dec, io) != VP8_STATUS_OK) { | |
| 436 return IDecError(idec, dec->status_); | |
| 437 } | |
| 438 | |
| 439 // Note: past this point, teardown() must always be called | |
| 440 // in case of error. | |
| 441 idec->state_ = STATE_VP8_DATA; | |
| 442 // Allocate memory and prepare everything. | |
| 443 if (!VP8InitFrame(dec, io)) { | |
| 444 return IDecError(idec, dec->status_); | |
| 445 } | |
| 446 return VP8_STATUS_OK; | |
| 447 } | |
| 448 | |
| 449 // Remaining partitions | |
| 450 static VP8StatusCode DecodeRemaining(WebPIDecoder* const idec) { | |
| 451 VP8Decoder* const dec = (VP8Decoder*)idec->dec_; | |
| 452 VP8Io* const io = &idec->io_; | |
| 453 | |
| 454 assert(dec->ready_); | |
| 455 for (; dec->mb_y_ < dec->mb_h_; ++dec->mb_y_) { | |
| 456 if (idec->last_mb_y_ != dec->mb_y_) { | |
| 457 if (!VP8ParseIntraModeRow(&dec->br_, dec)) { | |
| 458 // note: normally, error shouldn't occur since we already have the whole | |
| 459 // partition0 available here in DecodeRemaining(). Reaching EOF while | |
| 460 // reading intra modes really means a BITSTREAM_ERROR. | |
| 461 return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); | |
| 462 } | |
| 463 idec->last_mb_y_ = dec->mb_y_; | |
| 464 } | |
| 465 for (; dec->mb_x_ < dec->mb_w_; ++dec->mb_x_) { | |
| 466 VP8BitReader* const token_br = | |
| 467 &dec->parts_[dec->mb_y_ & dec->num_parts_minus_one_]; | |
| 468 MBContext context; | |
| 469 SaveContext(dec, token_br, &context); | |
| 470 if (!VP8DecodeMB(dec, token_br)) { | |
| 471 // We shouldn't fail when MAX_MB data was available | |
| 472 if (dec->num_parts_minus_one_ == 0 && | |
| 473 MemDataSize(&idec->mem_) > MAX_MB_SIZE) { | |
| 474 return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR); | |
| 475 } | |
| 476 RestoreContext(&context, dec, token_br); | |
| 477 return VP8_STATUS_SUSPENDED; | |
| 478 } | |
| 479 // Release buffer only if there is only one partition | |
| 480 if (dec->num_parts_minus_one_ == 0) { | |
| 481 idec->mem_.start_ = token_br->buf_ - idec->mem_.buf_; | |
| 482 assert(idec->mem_.start_ <= idec->mem_.end_); | |
| 483 } | |
| 484 } | |
| 485 VP8InitScanline(dec); // Prepare for next scanline | |
| 486 | |
| 487 // Reconstruct, filter and emit the row. | |
| 488 if (!VP8ProcessRow(dec, io)) { | |
| 489 return IDecError(idec, VP8_STATUS_USER_ABORT); | |
| 490 } | |
| 491 } | |
| 492 // Synchronize the thread and check for errors. | |
| 493 if (!VP8ExitCritical(dec, io)) { | |
| 494 return IDecError(idec, VP8_STATUS_USER_ABORT); | |
| 495 } | |
| 496 dec->ready_ = 0; | |
| 497 return FinishDecoding(idec); | |
| 498 } | |
| 499 | |
| 500 static VP8StatusCode ErrorStatusLossless(WebPIDecoder* const idec, | |
| 501 VP8StatusCode status) { | |
| 502 if (status == VP8_STATUS_SUSPENDED || status == VP8_STATUS_NOT_ENOUGH_DATA) { | |
| 503 return VP8_STATUS_SUSPENDED; | |
| 504 } | |
| 505 return IDecError(idec, status); | |
| 506 } | |
| 507 | |
| 508 static VP8StatusCode DecodeVP8LHeader(WebPIDecoder* const idec) { | |
| 509 VP8Io* const io = &idec->io_; | |
| 510 VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_; | |
| 511 const WebPDecParams* const params = &idec->params_; | |
| 512 WebPDecBuffer* const output = params->output; | |
| 513 size_t curr_size = MemDataSize(&idec->mem_); | |
| 514 assert(idec->is_lossless_); | |
| 515 | |
| 516 // Wait until there's enough data for decoding header. | |
| 517 if (curr_size < (idec->chunk_size_ >> 3)) { | |
| 518 dec->status_ = VP8_STATUS_SUSPENDED; | |
| 519 return ErrorStatusLossless(idec, dec->status_); | |
| 520 } | |
| 521 | |
| 522 if (!VP8LDecodeHeader(dec, io)) { | |
| 523 if (dec->status_ == VP8_STATUS_BITSTREAM_ERROR && | |
| 524 curr_size < idec->chunk_size_) { | |
| 525 dec->status_ = VP8_STATUS_SUSPENDED; | |
| 526 } | |
| 527 return ErrorStatusLossless(idec, dec->status_); | |
| 528 } | |
| 529 // Allocate/verify output buffer now. | |
| 530 dec->status_ = WebPAllocateDecBuffer(io->width, io->height, params->options, | |
| 531 output); | |
| 532 if (dec->status_ != VP8_STATUS_OK) { | |
| 533 return IDecError(idec, dec->status_); | |
| 534 } | |
| 535 | |
| 536 idec->state_ = STATE_VP8L_DATA; | |
| 537 return VP8_STATUS_OK; | |
| 538 } | |
| 539 | |
| 540 static VP8StatusCode DecodeVP8LData(WebPIDecoder* const idec) { | |
| 541 VP8LDecoder* const dec = (VP8LDecoder*)idec->dec_; | |
| 542 const size_t curr_size = MemDataSize(&idec->mem_); | |
| 543 assert(idec->is_lossless_); | |
| 544 | |
| 545 // Switch to incremental decoding if we don't have all the bytes available. | |
| 546 dec->incremental_ = (curr_size < idec->chunk_size_); | |
| 547 | |
| 548 if (!VP8LDecodeImage(dec)) { | |
| 549 return ErrorStatusLossless(idec, dec->status_); | |
| 550 } | |
| 551 assert(dec->status_ == VP8_STATUS_OK || dec->status_ == VP8_STATUS_SUSPENDED); | |
| 552 return (dec->status_ == VP8_STATUS_SUSPENDED) ? dec->status_ | |
| 553 : FinishDecoding(idec); | |
| 554 } | |
| 555 | |
| 556 // Main decoding loop | |
| 557 static VP8StatusCode IDecode(WebPIDecoder* idec) { | |
| 558 VP8StatusCode status = VP8_STATUS_SUSPENDED; | |
| 559 | |
| 560 if (idec->state_ == STATE_WEBP_HEADER) { | |
| 561 status = DecodeWebPHeaders(idec); | |
| 562 } else { | |
| 563 if (idec->dec_ == NULL) { | |
| 564 return VP8_STATUS_SUSPENDED; // can't continue if we have no decoder. | |
| 565 } | |
| 566 } | |
| 567 if (idec->state_ == STATE_VP8_HEADER) { | |
| 568 status = DecodeVP8FrameHeader(idec); | |
| 569 } | |
| 570 if (idec->state_ == STATE_VP8_PARTS0) { | |
| 571 status = DecodePartition0(idec); | |
| 572 } | |
| 573 if (idec->state_ == STATE_VP8_DATA) { | |
| 574 status = DecodeRemaining(idec); | |
| 575 } | |
| 576 if (idec->state_ == STATE_VP8L_HEADER) { | |
| 577 status = DecodeVP8LHeader(idec); | |
| 578 } | |
| 579 if (idec->state_ == STATE_VP8L_DATA) { | |
| 580 status = DecodeVP8LData(idec); | |
| 581 } | |
| 582 return status; | |
| 583 } | |
| 584 | |
| 585 //------------------------------------------------------------------------------ | |
| 586 // Internal constructor | |
| 587 | |
| 588 static WebPIDecoder* NewDecoder(WebPDecBuffer* const output_buffer, | |
| 589 const WebPBitstreamFeatures* const features) { | |
| 590 WebPIDecoder* idec = (WebPIDecoder*)WebPSafeCalloc(1ULL, sizeof(*idec)); | |
| 591 if (idec == NULL) { | |
| 592 return NULL; | |
| 593 } | |
| 594 | |
| 595 idec->state_ = STATE_WEBP_HEADER; | |
| 596 idec->chunk_size_ = 0; | |
| 597 | |
| 598 idec->last_mb_y_ = -1; | |
| 599 | |
| 600 InitMemBuffer(&idec->mem_); | |
| 601 WebPInitDecBuffer(&idec->output_); | |
| 602 VP8InitIo(&idec->io_); | |
| 603 | |
| 604 WebPResetDecParams(&idec->params_); | |
| 605 if (output_buffer == NULL || WebPAvoidSlowMemory(output_buffer, features)) { | |
| 606 idec->params_.output = &idec->output_; | |
| 607 idec->final_output_ = output_buffer; | |
| 608 if (output_buffer != NULL) { | |
| 609 idec->params_.output->colorspace = output_buffer->colorspace; | |
| 610 } | |
| 611 } else { | |
| 612 idec->params_.output = output_buffer; | |
| 613 idec->final_output_ = NULL; | |
| 614 } | |
| 615 WebPInitCustomIo(&idec->params_, &idec->io_); // Plug the I/O functions. | |
| 616 | |
| 617 return idec; | |
| 618 } | |
| 619 | |
| 620 //------------------------------------------------------------------------------ | |
| 621 // Public functions | |
| 622 | |
| 623 WebPIDecoder* WebPINewDecoder(WebPDecBuffer* output_buffer) { | |
| 624 return NewDecoder(output_buffer, NULL); | |
| 625 } | |
| 626 | |
| 627 WebPIDecoder* WebPIDecode(const uint8_t* data, size_t data_size, | |
| 628 WebPDecoderConfig* config) { | |
| 629 WebPIDecoder* idec; | |
| 630 WebPBitstreamFeatures tmp_features; | |
| 631 WebPBitstreamFeatures* const features = | |
| 632 (config == NULL) ? &tmp_features : &config->input; | |
| 633 memset(&tmp_features, 0, sizeof(tmp_features)); | |
| 634 | |
| 635 // Parse the bitstream's features, if requested: | |
| 636 if (data != NULL && data_size > 0) { | |
| 637 if (WebPGetFeatures(data, data_size, features) != VP8_STATUS_OK) { | |
| 638 return NULL; | |
| 639 } | |
| 640 } | |
| 641 | |
| 642 // Create an instance of the incremental decoder | |
| 643 idec = (config != NULL) ? NewDecoder(&config->output, features) | |
| 644 : NewDecoder(NULL, features); | |
| 645 if (idec == NULL) { | |
| 646 return NULL; | |
| 647 } | |
| 648 // Finish initialization | |
| 649 if (config != NULL) { | |
| 650 idec->params_.options = &config->options; | |
| 651 } | |
| 652 return idec; | |
| 653 } | |
| 654 | |
| 655 void WebPIDelete(WebPIDecoder* idec) { | |
| 656 if (idec == NULL) return; | |
| 657 if (idec->dec_ != NULL) { | |
| 658 if (!idec->is_lossless_) { | |
| 659 if (idec->state_ == STATE_VP8_DATA) { | |
| 660 // Synchronize the thread, clean-up and check for errors. | |
| 661 VP8ExitCritical((VP8Decoder*)idec->dec_, &idec->io_); | |
| 662 } | |
| 663 VP8Delete((VP8Decoder*)idec->dec_); | |
| 664 } else { | |
| 665 VP8LDelete((VP8LDecoder*)idec->dec_); | |
| 666 } | |
| 667 } | |
| 668 ClearMemBuffer(&idec->mem_); | |
| 669 WebPFreeDecBuffer(&idec->output_); | |
| 670 WebPSafeFree(idec); | |
| 671 } | |
| 672 | |
| 673 //------------------------------------------------------------------------------ | |
| 674 // Wrapper toward WebPINewDecoder | |
| 675 | |
| 676 WebPIDecoder* WebPINewRGB(WEBP_CSP_MODE mode, uint8_t* output_buffer, | |
| 677 size_t output_buffer_size, int output_stride) { | |
| 678 const int is_external_memory = (output_buffer != NULL) ? 1 : 0; | |
| 679 WebPIDecoder* idec; | |
| 680 | |
| 681 if (mode >= MODE_YUV) return NULL; | |
| 682 if (is_external_memory == 0) { // Overwrite parameters to sane values. | |
| 683 output_buffer_size = 0; | |
| 684 output_stride = 0; | |
| 685 } else { // A buffer was passed. Validate the other params. | |
| 686 if (output_stride == 0 || output_buffer_size == 0) { | |
| 687 return NULL; // invalid parameter. | |
| 688 } | |
| 689 } | |
| 690 idec = WebPINewDecoder(NULL); | |
| 691 if (idec == NULL) return NULL; | |
| 692 idec->output_.colorspace = mode; | |
| 693 idec->output_.is_external_memory = is_external_memory; | |
| 694 idec->output_.u.RGBA.rgba = output_buffer; | |
| 695 idec->output_.u.RGBA.stride = output_stride; | |
| 696 idec->output_.u.RGBA.size = output_buffer_size; | |
| 697 return idec; | |
| 698 } | |
| 699 | |
| 700 WebPIDecoder* WebPINewYUVA(uint8_t* luma, size_t luma_size, int luma_stride, | |
| 701 uint8_t* u, size_t u_size, int u_stride, | |
| 702 uint8_t* v, size_t v_size, int v_stride, | |
| 703 uint8_t* a, size_t a_size, int a_stride) { | |
| 704 const int is_external_memory = (luma != NULL) ? 1 : 0; | |
| 705 WebPIDecoder* idec; | |
| 706 WEBP_CSP_MODE colorspace; | |
| 707 | |
| 708 if (is_external_memory == 0) { // Overwrite parameters to sane values. | |
| 709 luma_size = u_size = v_size = a_size = 0; | |
| 710 luma_stride = u_stride = v_stride = a_stride = 0; | |
| 711 u = v = a = NULL; | |
| 712 colorspace = MODE_YUVA; | |
| 713 } else { // A luma buffer was passed. Validate the other parameters. | |
| 714 if (u == NULL || v == NULL) return NULL; | |
| 715 if (luma_size == 0 || u_size == 0 || v_size == 0) return NULL; | |
| 716 if (luma_stride == 0 || u_stride == 0 || v_stride == 0) return NULL; | |
| 717 if (a != NULL) { | |
| 718 if (a_size == 0 || a_stride == 0) return NULL; | |
| 719 } | |
| 720 colorspace = (a == NULL) ? MODE_YUV : MODE_YUVA; | |
| 721 } | |
| 722 | |
| 723 idec = WebPINewDecoder(NULL); | |
| 724 if (idec == NULL) return NULL; | |
| 725 | |
| 726 idec->output_.colorspace = colorspace; | |
| 727 idec->output_.is_external_memory = is_external_memory; | |
| 728 idec->output_.u.YUVA.y = luma; | |
| 729 idec->output_.u.YUVA.y_stride = luma_stride; | |
| 730 idec->output_.u.YUVA.y_size = luma_size; | |
| 731 idec->output_.u.YUVA.u = u; | |
| 732 idec->output_.u.YUVA.u_stride = u_stride; | |
| 733 idec->output_.u.YUVA.u_size = u_size; | |
| 734 idec->output_.u.YUVA.v = v; | |
| 735 idec->output_.u.YUVA.v_stride = v_stride; | |
| 736 idec->output_.u.YUVA.v_size = v_size; | |
| 737 idec->output_.u.YUVA.a = a; | |
| 738 idec->output_.u.YUVA.a_stride = a_stride; | |
| 739 idec->output_.u.YUVA.a_size = a_size; | |
| 740 return idec; | |
| 741 } | |
| 742 | |
| 743 WebPIDecoder* WebPINewYUV(uint8_t* luma, size_t luma_size, int luma_stride, | |
| 744 uint8_t* u, size_t u_size, int u_stride, | |
| 745 uint8_t* v, size_t v_size, int v_stride) { | |
| 746 return WebPINewYUVA(luma, luma_size, luma_stride, | |
| 747 u, u_size, u_stride, | |
| 748 v, v_size, v_stride, | |
| 749 NULL, 0, 0); | |
| 750 } | |
| 751 | |
| 752 //------------------------------------------------------------------------------ | |
| 753 | |
| 754 static VP8StatusCode IDecCheckStatus(const WebPIDecoder* const idec) { | |
| 755 assert(idec); | |
| 756 if (idec->state_ == STATE_ERROR) { | |
| 757 return VP8_STATUS_BITSTREAM_ERROR; | |
| 758 } | |
| 759 if (idec->state_ == STATE_DONE) { | |
| 760 return VP8_STATUS_OK; | |
| 761 } | |
| 762 return VP8_STATUS_SUSPENDED; | |
| 763 } | |
| 764 | |
| 765 VP8StatusCode WebPIAppend(WebPIDecoder* idec, | |
| 766 const uint8_t* data, size_t data_size) { | |
| 767 VP8StatusCode status; | |
| 768 if (idec == NULL || data == NULL) { | |
| 769 return VP8_STATUS_INVALID_PARAM; | |
| 770 } | |
| 771 status = IDecCheckStatus(idec); | |
| 772 if (status != VP8_STATUS_SUSPENDED) { | |
| 773 return status; | |
| 774 } | |
| 775 // Check mixed calls between RemapMemBuffer and AppendToMemBuffer. | |
| 776 if (!CheckMemBufferMode(&idec->mem_, MEM_MODE_APPEND)) { | |
| 777 return VP8_STATUS_INVALID_PARAM; | |
| 778 } | |
| 779 // Append data to memory buffer | |
| 780 if (!AppendToMemBuffer(idec, data, data_size)) { | |
| 781 return VP8_STATUS_OUT_OF_MEMORY; | |
| 782 } | |
| 783 return IDecode(idec); | |
| 784 } | |
| 785 | |
| 786 VP8StatusCode WebPIUpdate(WebPIDecoder* idec, | |
| 787 const uint8_t* data, size_t data_size) { | |
| 788 VP8StatusCode status; | |
| 789 if (idec == NULL || data == NULL) { | |
| 790 return VP8_STATUS_INVALID_PARAM; | |
| 791 } | |
| 792 status = IDecCheckStatus(idec); | |
| 793 if (status != VP8_STATUS_SUSPENDED) { | |
| 794 return status; | |
| 795 } | |
| 796 // Check mixed calls between RemapMemBuffer and AppendToMemBuffer. | |
| 797 if (!CheckMemBufferMode(&idec->mem_, MEM_MODE_MAP)) { | |
| 798 return VP8_STATUS_INVALID_PARAM; | |
| 799 } | |
| 800 // Make the memory buffer point to the new buffer | |
| 801 if (!RemapMemBuffer(idec, data, data_size)) { | |
| 802 return VP8_STATUS_INVALID_PARAM; | |
| 803 } | |
| 804 return IDecode(idec); | |
| 805 } | |
| 806 | |
| 807 //------------------------------------------------------------------------------ | |
| 808 | |
| 809 static const WebPDecBuffer* GetOutputBuffer(const WebPIDecoder* const idec) { | |
| 810 if (idec == NULL || idec->dec_ == NULL) { | |
| 811 return NULL; | |
| 812 } | |
| 813 if (idec->state_ <= STATE_VP8_PARTS0) { | |
| 814 return NULL; | |
| 815 } | |
| 816 if (idec->final_output_ != NULL) { | |
| 817 return NULL; // not yet slow-copied | |
| 818 } | |
| 819 return idec->params_.output; | |
| 820 } | |
| 821 | |
| 822 const WebPDecBuffer* WebPIDecodedArea(const WebPIDecoder* idec, | |
| 823 int* left, int* top, | |
| 824 int* width, int* height) { | |
| 825 const WebPDecBuffer* const src = GetOutputBuffer(idec); | |
| 826 if (left != NULL) *left = 0; | |
| 827 if (top != NULL) *top = 0; | |
| 828 if (src != NULL) { | |
| 829 if (width != NULL) *width = src->width; | |
| 830 if (height != NULL) *height = idec->params_.last_y; | |
| 831 } else { | |
| 832 if (width != NULL) *width = 0; | |
| 833 if (height != NULL) *height = 0; | |
| 834 } | |
| 835 return src; | |
| 836 } | |
| 837 | |
| 838 uint8_t* WebPIDecGetRGB(const WebPIDecoder* idec, int* last_y, | |
| 839 int* width, int* height, int* stride) { | |
| 840 const WebPDecBuffer* const src = GetOutputBuffer(idec); | |
| 841 if (src == NULL) return NULL; | |
| 842 if (src->colorspace >= MODE_YUV) { | |
| 843 return NULL; | |
| 844 } | |
| 845 | |
| 846 if (last_y != NULL) *last_y = idec->params_.last_y; | |
| 847 if (width != NULL) *width = src->width; | |
| 848 if (height != NULL) *height = src->height; | |
| 849 if (stride != NULL) *stride = src->u.RGBA.stride; | |
| 850 | |
| 851 return src->u.RGBA.rgba; | |
| 852 } | |
| 853 | |
| 854 uint8_t* WebPIDecGetYUVA(const WebPIDecoder* idec, int* last_y, | |
| 855 uint8_t** u, uint8_t** v, uint8_t** a, | |
| 856 int* width, int* height, | |
| 857 int* stride, int* uv_stride, int* a_stride) { | |
| 858 const WebPDecBuffer* const src = GetOutputBuffer(idec); | |
| 859 if (src == NULL) return NULL; | |
| 860 if (src->colorspace < MODE_YUV) { | |
| 861 return NULL; | |
| 862 } | |
| 863 | |
| 864 if (last_y != NULL) *last_y = idec->params_.last_y; | |
| 865 if (u != NULL) *u = src->u.YUVA.u; | |
| 866 if (v != NULL) *v = src->u.YUVA.v; | |
| 867 if (a != NULL) *a = src->u.YUVA.a; | |
| 868 if (width != NULL) *width = src->width; | |
| 869 if (height != NULL) *height = src->height; | |
| 870 if (stride != NULL) *stride = src->u.YUVA.y_stride; | |
| 871 if (uv_stride != NULL) *uv_stride = src->u.YUVA.u_stride; | |
| 872 if (a_stride != NULL) *a_stride = src->u.YUVA.a_stride; | |
| 873 | |
| 874 return src->u.YUVA.y; | |
| 875 } | |
| 876 | |
| 877 int WebPISetIOHooks(WebPIDecoder* const idec, | |
| 878 VP8IoPutHook put, | |
| 879 VP8IoSetupHook setup, | |
| 880 VP8IoTeardownHook teardown, | |
| 881 void* user_data) { | |
| 882 if (idec == NULL || idec->state_ > STATE_WEBP_HEADER) { | |
| 883 return 0; | |
| 884 } | |
| 885 | |
| 886 idec->io_.put = put; | |
| 887 idec->io_.setup = setup; | |
| 888 idec->io_.teardown = teardown; | |
| 889 idec->io_.opaque = user_data; | |
| 890 | |
| 891 return 1; | |
| 892 } | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 2651883004:
libwebp-0.6.0-rc1 (Closed)
