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 // Read APIs for mux. 11 // 12 // Authors: Urvang (urvang (at) google.com) 13 // Vikas (vikasa (at) google.com) 14 15 #include <assert.h> 16 #include "./muxi.h" 17 #include "../utils/utils.h" 18 19 //------------------------------------------------------------------------------ 20 // Helper method(s). 21 22 // Handy MACRO. 23 #define SWITCH_ID_LIST(INDEX, LIST) \ 24 if (idx == (INDEX)) { \ 25 const WebPChunk* const chunk = ChunkSearchList((LIST), nth, \ 26 kChunks[(INDEX)].tag); \ 27 if (chunk) { \ 28 *data = chunk->data_; \ 29 return WEBP_MUX_OK; \ 30 } else { \ 31 return WEBP_MUX_NOT_FOUND; \ 32 } \ 33 } 34 35 static WebPMuxError MuxGet(const WebPMux* const mux, CHUNK_INDEX idx, 36 uint32_t nth, WebPData* const data) { 37 assert(mux != NULL); 38 assert(!IsWPI(kChunks[idx].id)); 39 WebPDataInit(data); 40 41 SWITCH_ID_LIST(IDX_VP8X, mux->vp8x_); 42 SWITCH_ID_LIST(IDX_ICCP, mux->iccp_); 43 SWITCH_ID_LIST(IDX_ANIM, mux->anim_); 44 SWITCH_ID_LIST(IDX_EXIF, mux->exif_); 45 SWITCH_ID_LIST(IDX_XMP, mux->xmp_); 46 SWITCH_ID_LIST(IDX_UNKNOWN, mux->unknown_); 47 return WEBP_MUX_NOT_FOUND; 48 } 49 #undef SWITCH_ID_LIST 50 51 // Fill the chunk with the given data (includes chunk header bytes), after some 52 // verifications. 53 static WebPMuxError ChunkVerifyAndAssign(WebPChunk* chunk, 54 const uint8_t* data, size_t data_size, 55 size_t riff_size, int copy_data) { 56 uint32_t chunk_size; 57 WebPData chunk_data; 58 59 // Sanity checks. 60 if (data_size < CHUNK_HEADER_SIZE) return WEBP_MUX_NOT_ENOUGH_DATA; 61 chunk_size = GetLE32(data + TAG_SIZE); 62 63 { 64 const size_t chunk_disk_size = SizeWithPadding(chunk_size); 65 if (chunk_disk_size > riff_size) return WEBP_MUX_BAD_DATA; 66 if (chunk_disk_size > data_size) return WEBP_MUX_NOT_ENOUGH_DATA; 67 } 68 69 // Data assignment. 70 chunk_data.bytes = data + CHUNK_HEADER_SIZE; 71 chunk_data.size = chunk_size; 72 return ChunkAssignData(chunk, &chunk_data, copy_data, GetLE32(data + 0)); 73 } 74 75 int MuxImageFinalize(WebPMuxImage* const wpi) { 76 const WebPChunk* const img = wpi->img_; 77 const WebPData* const image = &img->data_; 78 const int is_lossless = (img->tag_ == kChunks[IDX_VP8L].tag); 79 int w, h; 80 int vp8l_has_alpha = 0; 81 const int ok = is_lossless ? 82 VP8LGetInfo(image->bytes, image->size, &w, &h, &vp8l_has_alpha) : 83 VP8GetInfo(image->bytes, image->size, image->size, &w, &h); 84 assert(img != NULL); 85 if (ok) { 86 // Ignore ALPH chunk accompanying VP8L. 87 if (is_lossless && (wpi->alpha_ != NULL)) { 88 ChunkDelete(wpi->alpha_); 89 wpi->alpha_ = NULL; 90 } 91 wpi->width_ = w; 92 wpi->height_ = h; 93 wpi->has_alpha_ = vp8l_has_alpha || (wpi->alpha_ != NULL); 94 } 95 return ok; 96 } 97 98 static int MuxImageParse(const WebPChunk* const chunk, int copy_data, 99 WebPMuxImage* const wpi) { 100 const uint8_t* bytes = chunk->data_.bytes; 101 size_t size = chunk->data_.size; 102 const uint8_t* const last = bytes + size; 103 WebPChunk subchunk; 104 size_t subchunk_size; 105 ChunkInit(&subchunk); 106 107 assert(chunk->tag_ == kChunks[IDX_ANMF].tag); 108 assert(!wpi->is_partial_); 109 110 // ANMF. 111 { 112 const size_t hdr_size = ANMF_CHUNK_SIZE; 113 const WebPData temp = { bytes, hdr_size }; 114 // Each of ANMF chunk contain a header at the beginning. So, its size should 115 // be at least 'hdr_size'. 116 if (size < hdr_size) goto Fail; 117 ChunkAssignData(&subchunk, &temp, copy_data, chunk->tag_); 118 } 119 ChunkSetNth(&subchunk, &wpi->header_, 1); 120 wpi->is_partial_ = 1; // Waiting for ALPH and/or VP8/VP8L chunks. 121 122 // Rest of the chunks. 123 subchunk_size = ChunkDiskSize(&subchunk) - CHUNK_HEADER_SIZE; 124 bytes += subchunk_size; 125 size -= subchunk_size; 126 127 while (bytes != last) { 128 ChunkInit(&subchunk); 129 if (ChunkVerifyAndAssign(&subchunk, bytes, size, size, 130 copy_data) != WEBP_MUX_OK) { 131 goto Fail; 132 } 133 switch (ChunkGetIdFromTag(subchunk.tag_)) { 134 case WEBP_CHUNK_ALPHA: 135 if (wpi->alpha_ != NULL) goto Fail; // Consecutive ALPH chunks. 136 if (ChunkSetNth(&subchunk, &wpi->alpha_, 1) != WEBP_MUX_OK) goto Fail; 137 wpi->is_partial_ = 1; // Waiting for a VP8 chunk. 138 break; 139 case WEBP_CHUNK_IMAGE: 140 if (ChunkSetNth(&subchunk, &wpi->img_, 1) != WEBP_MUX_OK) goto Fail; 141 if (!MuxImageFinalize(wpi)) goto Fail; 142 wpi->is_partial_ = 0; // wpi is completely filled. 143 break; 144 case WEBP_CHUNK_UNKNOWN: 145 if (wpi->is_partial_) goto Fail; // Encountered an unknown chunk 146 // before some image chunks. 147 if (ChunkSetNth(&subchunk, &wpi->unknown_, 0) != WEBP_MUX_OK) goto Fail; 148 break; 149 default: 150 goto Fail; 151 break; 152 } 153 subchunk_size = ChunkDiskSize(&subchunk); 154 bytes += subchunk_size; 155 size -= subchunk_size; 156 } 157 if (wpi->is_partial_) goto Fail; 158 return 1; 159 160 Fail: 161 ChunkRelease(&subchunk); 162 return 0; 163 } 164 165 //------------------------------------------------------------------------------ 166 // Create a mux object from WebP-RIFF data. 167 168 WebPMux* WebPMuxCreateInternal(const WebPData* bitstream, int copy_data, 169 int version) { 170 size_t riff_size; 171 uint32_t tag; 172 const uint8_t* end; 173 WebPMux* mux = NULL; 174 WebPMuxImage* wpi = NULL; 175 const uint8_t* data; 176 size_t size; 177 WebPChunk chunk; 178 ChunkInit(&chunk); 179 180 // Sanity checks. 181 if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_MUX_ABI_VERSION)) { 182 return NULL; // version mismatch 183 } 184 if (bitstream == NULL) return NULL; 185 186 data = bitstream->bytes; 187 size = bitstream->size; 188 189 if (data == NULL) return NULL; 190 if (size < RIFF_HEADER_SIZE) return NULL; 191 if (GetLE32(data + 0) != MKFOURCC('R', 'I', 'F', 'F') || 192 GetLE32(data + CHUNK_HEADER_SIZE) != MKFOURCC('W', 'E', 'B', 'P')) { 193 return NULL; 194 } 195 196 mux = WebPMuxNew(); 197 if (mux == NULL) return NULL; 198 199 if (size < RIFF_HEADER_SIZE + TAG_SIZE) goto Err; 200 201 tag = GetLE32(data + RIFF_HEADER_SIZE); 202 if (tag != kChunks[IDX_VP8].tag && 203 tag != kChunks[IDX_VP8L].tag && 204 tag != kChunks[IDX_VP8X].tag) { 205 goto Err; // First chunk should be VP8, VP8L or VP8X. 206 } 207 208 riff_size = SizeWithPadding(GetLE32(data + TAG_SIZE)); 209 if (riff_size > MAX_CHUNK_PAYLOAD || riff_size > size) { 210 goto Err; 211 } else { 212 if (riff_size < size) { // Redundant data after last chunk. 213 size = riff_size; // To make sure we don't read any data beyond mux_size. 214 } 215 } 216 217 end = data + size; 218 data += RIFF_HEADER_SIZE; 219 size -= RIFF_HEADER_SIZE; 220 221 wpi = (WebPMuxImage*)WebPSafeMalloc(1ULL, sizeof(*wpi)); 222 if (wpi == NULL) goto Err; 223 MuxImageInit(wpi); 224 225 // Loop over chunks. 226 while (data != end) { 227 size_t data_size; 228 WebPChunkId id; 229 WebPChunk** chunk_list; 230 if (ChunkVerifyAndAssign(&chunk, data, size, riff_size, 231 copy_data) != WEBP_MUX_OK) { 232 goto Err; 233 } 234 data_size = ChunkDiskSize(&chunk); 235 id = ChunkGetIdFromTag(chunk.tag_); 236 switch (id) { 237 case WEBP_CHUNK_ALPHA: 238 if (wpi->alpha_ != NULL) goto Err; // Consecutive ALPH chunks. 239 if (ChunkSetNth(&chunk, &wpi->alpha_, 1) != WEBP_MUX_OK) goto Err; 240 wpi->is_partial_ = 1; // Waiting for a VP8 chunk. 241 break; 242 case WEBP_CHUNK_IMAGE: 243 if (ChunkSetNth(&chunk, &wpi->img_, 1) != WEBP_MUX_OK) goto Err; 244 if (!MuxImageFinalize(wpi)) goto Err; 245 wpi->is_partial_ = 0; // wpi is completely filled. 246 PushImage: 247 // Add this to mux->images_ list. 248 if (MuxImagePush(wpi, &mux->images_) != WEBP_MUX_OK) goto Err; 249 MuxImageInit(wpi); // Reset for reading next image. 250 break; 251 case WEBP_CHUNK_ANMF: 252 if (wpi->is_partial_) goto Err; // Previous wpi is still incomplete. 253 if (!MuxImageParse(&chunk, copy_data, wpi)) goto Err; 254 ChunkRelease(&chunk); 255 goto PushImage; 256 break; 257 default: // A non-image chunk. 258 if (wpi->is_partial_) goto Err; // Encountered a non-image chunk before 259 // getting all chunks of an image. 260 chunk_list = MuxGetChunkListFromId(mux, id); // List to add this chunk. 261 if (ChunkSetNth(&chunk, chunk_list, 0) != WEBP_MUX_OK) goto Err; 262 if (id == WEBP_CHUNK_VP8X) { // grab global specs 263 mux->canvas_width_ = GetLE24(data + 12) + 1; 264 mux->canvas_height_ = GetLE24(data + 15) + 1; 265 } 266 break; 267 } 268 data += data_size; 269 size -= data_size; 270 ChunkInit(&chunk); 271 } 272 273 // Validate mux if complete. 274 if (MuxValidate(mux) != WEBP_MUX_OK) goto Err; 275 276 MuxImageDelete(wpi); 277 return mux; // All OK; 278 279 Err: // Something bad happened. 280 ChunkRelease(&chunk); 281 MuxImageDelete(wpi); 282 WebPMuxDelete(mux); 283 return NULL; 284 } 285 286 //------------------------------------------------------------------------------ 287 // Get API(s). 288 289 // Validates that the given mux has a single image. 290 static WebPMuxError ValidateForSingleImage(const WebPMux* const mux) { 291 const int num_images = MuxImageCount(mux->images_, WEBP_CHUNK_IMAGE); 292 const int num_frames = MuxImageCount(mux->images_, WEBP_CHUNK_ANMF); 293 294 if (num_images == 0) { 295 // No images in mux. 296 return WEBP_MUX_NOT_FOUND; 297 } else if (num_images == 1 && num_frames == 0) { 298 // Valid case (single image). 299 return WEBP_MUX_OK; 300 } else { 301 // Frame case OR an invalid mux. 302 return WEBP_MUX_INVALID_ARGUMENT; 303 } 304 } 305 306 // Get the canvas width, height and flags after validating that VP8X/VP8/VP8L 307 // chunk and canvas size are valid. 308 static WebPMuxError MuxGetCanvasInfo(const WebPMux* const mux, 309 int* width, int* height, uint32_t* flags) { 310 int w, h; 311 uint32_t f = 0; 312 WebPData data; 313 assert(mux != NULL); 314 315 // Check if VP8X chunk is present. 316 if (MuxGet(mux, IDX_VP8X, 1, &data) == WEBP_MUX_OK) { 317 if (data.size < VP8X_CHUNK_SIZE) return WEBP_MUX_BAD_DATA; 318 f = GetLE32(data.bytes + 0); 319 w = GetLE24(data.bytes + 4) + 1; 320 h = GetLE24(data.bytes + 7) + 1; 321 } else { 322 const WebPMuxImage* const wpi = mux->images_; 323 // Grab user-forced canvas size as default. 324 w = mux->canvas_width_; 325 h = mux->canvas_height_; 326 if (w == 0 && h == 0 && ValidateForSingleImage(mux) == WEBP_MUX_OK) { 327 // single image and not forced canvas size => use dimension of first frame 328 assert(wpi != NULL); 329 w = wpi->width_; 330 h = wpi->height_; 331 } 332 if (wpi != NULL) { 333 if (wpi->has_alpha_) f |= ALPHA_FLAG; 334 } 335 } 336 if (w * (uint64_t)h >= MAX_IMAGE_AREA) return WEBP_MUX_BAD_DATA; 337 338 if (width != NULL) *width = w; 339 if (height != NULL) *height = h; 340 if (flags != NULL) *flags = f; 341 return WEBP_MUX_OK; 342 } 343 344 WebPMuxError WebPMuxGetCanvasSize(const WebPMux* mux, int* width, int* height) { 345 if (mux == NULL || width == NULL || height == NULL) { 346 return WEBP_MUX_INVALID_ARGUMENT; 347 } 348 return MuxGetCanvasInfo(mux, width, height, NULL); 349 } 350 351 WebPMuxError WebPMuxGetFeatures(const WebPMux* mux, uint32_t* flags) { 352 if (mux == NULL || flags == NULL) return WEBP_MUX_INVALID_ARGUMENT; 353 return MuxGetCanvasInfo(mux, NULL, NULL, flags); 354 } 355 356 static uint8_t* EmitVP8XChunk(uint8_t* const dst, int width, 357 int height, uint32_t flags) { 358 const size_t vp8x_size = CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE; 359 assert(width >= 1 && height >= 1); 360 assert(width <= MAX_CANVAS_SIZE && height <= MAX_CANVAS_SIZE); 361 assert(width * (uint64_t)height < MAX_IMAGE_AREA); 362 PutLE32(dst, MKFOURCC('V', 'P', '8', 'X')); 363 PutLE32(dst + TAG_SIZE, VP8X_CHUNK_SIZE); 364 PutLE32(dst + CHUNK_HEADER_SIZE, flags); 365 PutLE24(dst + CHUNK_HEADER_SIZE + 4, width - 1); 366 PutLE24(dst + CHUNK_HEADER_SIZE + 7, height - 1); 367 return dst + vp8x_size; 368 } 369 370 // Assemble a single image WebP bitstream from 'wpi'. 371 static WebPMuxError SynthesizeBitstream(const WebPMuxImage* const wpi, 372 WebPData* const bitstream) { 373 uint8_t* dst; 374 375 // Allocate data. 376 const int need_vp8x = (wpi->alpha_ != NULL); 377 const size_t vp8x_size = need_vp8x ? CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE : 0; 378 const size_t alpha_size = need_vp8x ? ChunkDiskSize(wpi->alpha_) : 0; 379 // Note: No need to output ANMF chunk for a single image. 380 const size_t size = RIFF_HEADER_SIZE + vp8x_size + alpha_size + 381 ChunkDiskSize(wpi->img_); 382 uint8_t* const data = (uint8_t*)WebPSafeMalloc(1ULL, size); 383 if (data == NULL) return WEBP_MUX_MEMORY_ERROR; 384 385 // Main RIFF header. 386 dst = MuxEmitRiffHeader(data, size); 387 388 if (need_vp8x) { 389 dst = EmitVP8XChunk(dst, wpi->width_, wpi->height_, ALPHA_FLAG); // VP8X. 390 dst = ChunkListEmit(wpi->alpha_, dst); // ALPH. 391 } 392 393 // Bitstream. 394 dst = ChunkListEmit(wpi->img_, dst); 395 assert(dst == data + size); 396 397 // Output. 398 bitstream->bytes = data; 399 bitstream->size = size; 400 return WEBP_MUX_OK; 401 } 402 403 WebPMuxError WebPMuxGetChunk(const WebPMux* mux, const char fourcc[4], 404 WebPData* chunk_data) { 405 CHUNK_INDEX idx; 406 if (mux == NULL || fourcc == NULL || chunk_data == NULL) { 407 return WEBP_MUX_INVALID_ARGUMENT; 408 } 409 idx = ChunkGetIndexFromFourCC(fourcc); 410 if (IsWPI(kChunks[idx].id)) { // An image chunk. 411 return WEBP_MUX_INVALID_ARGUMENT; 412 } else if (idx != IDX_UNKNOWN) { // A known chunk type. 413 return MuxGet(mux, idx, 1, chunk_data); 414 } else { // An unknown chunk type. 415 const WebPChunk* const chunk = 416 ChunkSearchList(mux->unknown_, 1, ChunkGetTagFromFourCC(fourcc)); 417 if (chunk == NULL) return WEBP_MUX_NOT_FOUND; 418 *chunk_data = chunk->data_; 419 return WEBP_MUX_OK; 420 } 421 } 422 423 static WebPMuxError MuxGetImageInternal(const WebPMuxImage* const wpi, 424 WebPMuxFrameInfo* const info) { 425 // Set some defaults for unrelated fields. 426 info->x_offset = 0; 427 info->y_offset = 0; 428 info->duration = 1; 429 info->dispose_method = WEBP_MUX_DISPOSE_NONE; 430 info->blend_method = WEBP_MUX_BLEND; 431 // Extract data for related fields. 432 info->id = ChunkGetIdFromTag(wpi->img_->tag_); 433 return SynthesizeBitstream(wpi, &info->bitstream); 434 } 435 436 static WebPMuxError MuxGetFrameInternal(const WebPMuxImage* const wpi, 437 WebPMuxFrameInfo* const frame) { 438 const int is_frame = (wpi->header_->tag_ == kChunks[IDX_ANMF].tag); 439 const WebPData* frame_data; 440 if (!is_frame) return WEBP_MUX_INVALID_ARGUMENT; 441 assert(wpi->header_ != NULL); // Already checked by WebPMuxGetFrame(). 442 // Get frame chunk. 443 frame_data = &wpi->header_->data_; 444 if (frame_data->size < kChunks[IDX_ANMF].size) return WEBP_MUX_BAD_DATA; 445 // Extract info. 446 frame->x_offset = 2 * GetLE24(frame_data->bytes + 0); 447 frame->y_offset = 2 * GetLE24(frame_data->bytes + 3); 448 { 449 const uint8_t bits = frame_data->bytes[15]; 450 frame->duration = GetLE24(frame_data->bytes + 12); 451 frame->dispose_method = 452 (bits & 1) ? WEBP_MUX_DISPOSE_BACKGROUND : WEBP_MUX_DISPOSE_NONE; 453 frame->blend_method = (bits & 2) ? WEBP_MUX_NO_BLEND : WEBP_MUX_BLEND; 454 } 455 frame->id = ChunkGetIdFromTag(wpi->header_->tag_); 456 return SynthesizeBitstream(wpi, &frame->bitstream); 457 } 458 459 WebPMuxError WebPMuxGetFrame( 460 const WebPMux* mux, uint32_t nth, WebPMuxFrameInfo* frame) { 461 WebPMuxError err; 462 WebPMuxImage* wpi; 463 464 // Sanity checks. 465 if (mux == NULL || frame == NULL) { 466 return WEBP_MUX_INVALID_ARGUMENT; 467 } 468 469 // Get the nth WebPMuxImage. 470 err = MuxImageGetNth((const WebPMuxImage**)&mux->images_, nth, &wpi); 471 if (err != WEBP_MUX_OK) return err; 472 473 // Get frame info. 474 if (wpi->header_ == NULL) { 475 return MuxGetImageInternal(wpi, frame); 476 } else { 477 return MuxGetFrameInternal(wpi, frame); 478 } 479 } 480 481 WebPMuxError WebPMuxGetAnimationParams(const WebPMux* mux, 482 WebPMuxAnimParams* params) { 483 WebPData anim; 484 WebPMuxError err; 485 486 if (mux == NULL || params == NULL) return WEBP_MUX_INVALID_ARGUMENT; 487 488 err = MuxGet(mux, IDX_ANIM, 1, &anim); 489 if (err != WEBP_MUX_OK) return err; 490 if (anim.size < kChunks[WEBP_CHUNK_ANIM].size) return WEBP_MUX_BAD_DATA; 491 params->bgcolor = GetLE32(anim.bytes); 492 params->loop_count = GetLE16(anim.bytes + 4); 493 494 return WEBP_MUX_OK; 495 } 496 497 // Get chunk index from chunk id. Returns IDX_NIL if not found. 498 static CHUNK_INDEX ChunkGetIndexFromId(WebPChunkId id) { 499 int i; 500 for (i = 0; kChunks[i].id != WEBP_CHUNK_NIL; ++i) { 501 if (id == kChunks[i].id) return (CHUNK_INDEX)i; 502 } 503 return IDX_NIL; 504 } 505 506 // Count number of chunks matching 'tag' in the 'chunk_list'. 507 // If tag == NIL_TAG, any tag will be matched. 508 static int CountChunks(const WebPChunk* const chunk_list, uint32_t tag) { 509 int count = 0; 510 const WebPChunk* current; 511 for (current = chunk_list; current != NULL; current = current->next_) { 512 if (tag == NIL_TAG || current->tag_ == tag) { 513 count++; // Count chunks whose tags match. 514 } 515 } 516 return count; 517 } 518 519 WebPMuxError WebPMuxNumChunks(const WebPMux* mux, 520 WebPChunkId id, int* num_elements) { 521 if (mux == NULL || num_elements == NULL) { 522 return WEBP_MUX_INVALID_ARGUMENT; 523 } 524 525 if (IsWPI(id)) { 526 *num_elements = MuxImageCount(mux->images_, id); 527 } else { 528 WebPChunk* const* chunk_list = MuxGetChunkListFromId(mux, id); 529 const CHUNK_INDEX idx = ChunkGetIndexFromId(id); 530 *num_elements = CountChunks(*chunk_list, kChunks[idx].tag); 531 } 532 533 return WEBP_MUX_OK; 534 } 535 536 //------------------------------------------------------------------------------ 537
