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@google.com)
13// Vikas (vikasa@google.com)
14
15#include <assert.h>
16#include "src/mux/muxi.h"
17#include "src/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
35static 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 assert(idx != IDX_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.
53static 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 // Correctness checks.
60 if (data_size < CHUNK_HEADER_SIZE) return WEBP_MUX_NOT_ENOUGH_DATA;
61 chunk_size = GetLE32(data + TAG_SIZE);
62 if (chunk_size > MAX_CHUNK_PAYLOAD) return WEBP_MUX_BAD_DATA;
63
64 {
65 const size_t chunk_disk_size = SizeWithPadding(chunk_size);
66 if (chunk_disk_size > riff_size) return WEBP_MUX_BAD_DATA;
67 if (chunk_disk_size > data_size) return WEBP_MUX_NOT_ENOUGH_DATA;
68 }
69
70 // Data assignment.
71 chunk_data.bytes = data + CHUNK_HEADER_SIZE;
72 chunk_data.size = chunk_size;
73 return ChunkAssignData(chunk, &chunk_data, copy_data, GetLE32(data + 0));
74}
75
76int MuxImageFinalize(WebPMuxImage* const wpi) {
77 const WebPChunk* const img = wpi->img_;
78 const WebPData* const image = &img->data_;
79 const int is_lossless = (img->tag_ == kChunks[IDX_VP8L].tag);
80 int w, h;
81 int vp8l_has_alpha = 0;
82 const int ok = is_lossless ?
83 VP8LGetInfo(image->bytes, image->size, &w, &h, &vp8l_has_alpha) :
84 VP8GetInfo(image->bytes, image->size, image->size, &w, &h);
85 assert(img != NULL);
86 if (ok) {
87 // Ignore ALPH chunk accompanying VP8L.
88 if (is_lossless && (wpi->alpha_ != NULL)) {
89 ChunkDelete(wpi->alpha_);
90 wpi->alpha_ = NULL;
91 }
92 wpi->width_ = w;
93 wpi->height_ = h;
94 wpi->has_alpha_ = vp8l_has_alpha || (wpi->alpha_ != NULL);
95 }
96 return ok;
97}
98
99static int MuxImageParse(const WebPChunk* const chunk, int copy_data,
100 WebPMuxImage* const wpi) {
101 const uint8_t* bytes = chunk->data_.bytes;
102 size_t size = chunk->data_.size;
103 const uint8_t* const last = (bytes == NULL) ? NULL : bytes + size;
104 WebPChunk subchunk;
105 size_t subchunk_size;
106 WebPChunk** unknown_chunk_list = &wpi->unknown_;
107 ChunkInit(&subchunk);
108
109 assert(chunk->tag_ == kChunks[IDX_ANMF].tag);
110 assert(!wpi->is_partial_);
111
112 // ANMF.
113 {
114 const size_t hdr_size = ANMF_CHUNK_SIZE;
115 const WebPData temp = { bytes, hdr_size };
116 // Each of ANMF chunk contain a header at the beginning. So, its size should
117 // be at least 'hdr_size'.
118 if (size < hdr_size) goto Fail;
119 if (ChunkAssignData(&subchunk, &temp, copy_data,
120 chunk->tag_) != WEBP_MUX_OK) {
121 goto Fail;
122 }
123 }
124 if (ChunkSetHead(&subchunk, &wpi->header_) != WEBP_MUX_OK) goto Fail;
125 wpi->is_partial_ = 1; // Waiting for ALPH and/or VP8/VP8L chunks.
126
127 // Rest of the chunks.
128 subchunk_size = ChunkDiskSize(&subchunk) - CHUNK_HEADER_SIZE;
129 bytes += subchunk_size;
130 size -= subchunk_size;
131
132 while (bytes != last) {
133 ChunkInit(&subchunk);
134 if (ChunkVerifyAndAssign(&subchunk, bytes, size, size,
135 copy_data) != WEBP_MUX_OK) {
136 goto Fail;
137 }
138 switch (ChunkGetIdFromTag(subchunk.tag_)) {
139 case WEBP_CHUNK_ALPHA:
140 if (wpi->alpha_ != NULL) goto Fail; // Consecutive ALPH chunks.
141 if (ChunkSetHead(&subchunk, &wpi->alpha_) != WEBP_MUX_OK) goto Fail;
142 wpi->is_partial_ = 1; // Waiting for a VP8 chunk.
143 break;
144 case WEBP_CHUNK_IMAGE:
145 if (wpi->img_ != NULL) goto Fail; // Only 1 image chunk allowed.
146 if (ChunkSetHead(&subchunk, &wpi->img_) != WEBP_MUX_OK) goto Fail;
147 if (!MuxImageFinalize(wpi)) goto Fail;
148 wpi->is_partial_ = 0; // wpi is completely filled.
149 break;
150 case WEBP_CHUNK_UNKNOWN:
151 if (wpi->is_partial_) {
152 goto Fail; // Encountered an unknown chunk
153 // before some image chunks.
154 }
155 if (ChunkAppend(&subchunk, &unknown_chunk_list) != WEBP_MUX_OK) {
156 goto Fail;
157 }
158 break;
159 default:
160 goto Fail;
161 }
162 subchunk_size = ChunkDiskSize(&subchunk);
163 bytes += subchunk_size;
164 size -= subchunk_size;
165 }
166 if (wpi->is_partial_) goto Fail;
167 return 1;
168
169 Fail:
170 ChunkRelease(&subchunk);
171 return 0;
172}
173
174//------------------------------------------------------------------------------
175// Create a mux object from WebP-RIFF data.
176
177WebPMux* WebPMuxCreateInternal(const WebPData* bitstream, int copy_data,
178 int version) {
179 size_t riff_size;
180 uint32_t tag;
181 const uint8_t* end;
182 WebPMux* mux = NULL;
183 WebPMuxImage* wpi = NULL;
184 const uint8_t* data;
185 size_t size;
186 WebPChunk chunk;
187 // Stores the end of the chunk lists so that it is faster to append data to
188 // their ends.
189 WebPChunk** chunk_list_ends[WEBP_CHUNK_NIL + 1] = { NULL };
190 ChunkInit(&chunk);
191
192 if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_MUX_ABI_VERSION)) {
193 return NULL; // version mismatch
194 }
195 if (bitstream == NULL) return NULL;
196
197 data = bitstream->bytes;
198 size = bitstream->size;
199
200 if (data == NULL) return NULL;
201 if (size < RIFF_HEADER_SIZE + CHUNK_HEADER_SIZE) return NULL;
202 if (GetLE32(data + 0) != MKFOURCC('R', 'I', 'F', 'F') ||
203 GetLE32(data + CHUNK_HEADER_SIZE) != MKFOURCC('W', 'E', 'B', 'P')) {
204 return NULL;
205 }
206
207 mux = WebPMuxNew();
208 if (mux == NULL) return NULL;
209
210 tag = GetLE32(data + RIFF_HEADER_SIZE);
211 if (tag != kChunks[IDX_VP8].tag &&
212 tag != kChunks[IDX_VP8L].tag &&
213 tag != kChunks[IDX_VP8X].tag) {
214 goto Err; // First chunk should be VP8, VP8L or VP8X.
215 }
216
217 riff_size = GetLE32(data + TAG_SIZE);
218 if (riff_size > MAX_CHUNK_PAYLOAD) goto Err;
219
220 // Note this padding is historical and differs from demux.c which does not
221 // pad the file size.
222 riff_size = SizeWithPadding(riff_size);
223 if (riff_size < CHUNK_HEADER_SIZE) goto Err;
224 if (riff_size > size) goto Err;
225 // There's no point in reading past the end of the RIFF chunk.
226 if (size > riff_size + CHUNK_HEADER_SIZE) {
227 size = riff_size + CHUNK_HEADER_SIZE;
228 }
229
230 end = data + size;
231 data += RIFF_HEADER_SIZE;
232 size -= RIFF_HEADER_SIZE;
233
234 wpi = (WebPMuxImage*)WebPSafeMalloc(1ULL, sizeof(*wpi));
235 if (wpi == NULL) goto Err;
236 MuxImageInit(wpi);
237
238 // Loop over chunks.
239 while (data != end) {
240 size_t data_size;
241 WebPChunkId id;
242 if (ChunkVerifyAndAssign(&chunk, data, size, riff_size,
243 copy_data) != WEBP_MUX_OK) {
244 goto Err;
245 }
246 data_size = ChunkDiskSize(&chunk);
247 id = ChunkGetIdFromTag(chunk.tag_);
248 switch (id) {
249 case WEBP_CHUNK_ALPHA:
250 if (wpi->alpha_ != NULL) goto Err; // Consecutive ALPH chunks.
251 if (ChunkSetHead(&chunk, &wpi->alpha_) != WEBP_MUX_OK) goto Err;
252 wpi->is_partial_ = 1; // Waiting for a VP8 chunk.
253 break;
254 case WEBP_CHUNK_IMAGE:
255 if (ChunkSetHead(&chunk, &wpi->img_) != WEBP_MUX_OK) goto Err;
256 if (!MuxImageFinalize(wpi)) goto Err;
257 wpi->is_partial_ = 0; // wpi is completely filled.
258 PushImage:
259 // Add this to mux->images_ list.
260 if (MuxImagePush(wpi, &mux->images_) != WEBP_MUX_OK) goto Err;
261 MuxImageInit(wpi); // Reset for reading next image.
262 break;
263 case WEBP_CHUNK_ANMF:
264 if (wpi->is_partial_) goto Err; // Previous wpi is still incomplete.
265 if (!MuxImageParse(&chunk, copy_data, wpi)) goto Err;
266 ChunkRelease(&chunk);
267 goto PushImage;
268 default: // A non-image chunk.
269 if (wpi->is_partial_) goto Err; // Encountered a non-image chunk before
270 // getting all chunks of an image.
271 if (chunk_list_ends[id] == NULL) {
272 chunk_list_ends[id] =
273 MuxGetChunkListFromId(mux, id); // List to add this chunk.
274 }
275 if (ChunkAppend(&chunk, &chunk_list_ends[id]) != WEBP_MUX_OK) goto Err;
276 if (id == WEBP_CHUNK_VP8X) { // grab global specs
277 if (data_size < CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE) goto Err;
278 mux->canvas_width_ = GetLE24(data + 12) + 1;
279 mux->canvas_height_ = GetLE24(data + 15) + 1;
280 }
281 break;
282 }
283 data += data_size;
284 size -= data_size;
285 ChunkInit(&chunk);
286 }
287
288 // Incomplete image.
289 if (wpi->is_partial_) goto Err;
290
291 // Validate mux if complete.
292 if (MuxValidate(mux) != WEBP_MUX_OK) goto Err;
293
294 MuxImageDelete(wpi);
295 return mux; // All OK;
296
297 Err: // Something bad happened.
298 ChunkRelease(&chunk);
299 MuxImageDelete(wpi);
300 WebPMuxDelete(mux);
301 return NULL;
302}
303
304//------------------------------------------------------------------------------
305// Get API(s).
306
307// Validates that the given mux has a single image.
308static WebPMuxError ValidateForSingleImage(const WebPMux* const mux) {
309 const int num_images = MuxImageCount(mux->images_, WEBP_CHUNK_IMAGE);
310 const int num_frames = MuxImageCount(mux->images_, WEBP_CHUNK_ANMF);
311
312 if (num_images == 0) {
313 // No images in mux.
314 return WEBP_MUX_NOT_FOUND;
315 } else if (num_images == 1 && num_frames == 0) {
316 // Valid case (single image).
317 return WEBP_MUX_OK;
318 } else {
319 // Frame case OR an invalid mux.
320 return WEBP_MUX_INVALID_ARGUMENT;
321 }
322}
323
324// Get the canvas width, height and flags after validating that VP8X/VP8/VP8L
325// chunk and canvas size are valid.
326static WebPMuxError MuxGetCanvasInfo(const WebPMux* const mux,
327 int* width, int* height, uint32_t* flags) {
328 int w, h;
329 uint32_t f = 0;
330 WebPData data;
331 assert(mux != NULL);
332
333 // Check if VP8X chunk is present.
334 if (MuxGet(mux, IDX_VP8X, 1, &data) == WEBP_MUX_OK) {
335 if (data.size < VP8X_CHUNK_SIZE) return WEBP_MUX_BAD_DATA;
336 f = GetLE32(data.bytes + 0);
337 w = GetLE24(data.bytes + 4) + 1;
338 h = GetLE24(data.bytes + 7) + 1;
339 } else {
340 const WebPMuxImage* const wpi = mux->images_;
341 // Grab user-forced canvas size as default.
342 w = mux->canvas_width_;
343 h = mux->canvas_height_;
344 if (w == 0 && h == 0 && ValidateForSingleImage(mux) == WEBP_MUX_OK) {
345 // single image and not forced canvas size => use dimension of first frame
346 assert(wpi != NULL);
347 w = wpi->width_;
348 h = wpi->height_;
349 }
350 if (wpi != NULL) {
351 if (wpi->has_alpha_) f |= ALPHA_FLAG;
352 }
353 }
354 if (w * (uint64_t)h >= MAX_IMAGE_AREA) return WEBP_MUX_BAD_DATA;
355
356 if (width != NULL) *width = w;
357 if (height != NULL) *height = h;
358 if (flags != NULL) *flags = f;
359 return WEBP_MUX_OK;
360}
361
362WebPMuxError WebPMuxGetCanvasSize(const WebPMux* mux, int* width, int* height) {
363 if (mux == NULL || width == NULL || height == NULL) {
364 return WEBP_MUX_INVALID_ARGUMENT;
365 }
366 return MuxGetCanvasInfo(mux, width, height, NULL);
367}
368
369WebPMuxError WebPMuxGetFeatures(const WebPMux* mux, uint32_t* flags) {
370 if (mux == NULL || flags == NULL) return WEBP_MUX_INVALID_ARGUMENT;
371 return MuxGetCanvasInfo(mux, NULL, NULL, flags);
372}
373
374static uint8_t* EmitVP8XChunk(uint8_t* const dst, int width,
375 int height, uint32_t flags) {
376 const size_t vp8x_size = CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE;
377 assert(width >= 1 && height >= 1);
378 assert(width <= MAX_CANVAS_SIZE && height <= MAX_CANVAS_SIZE);
379 assert(width * (uint64_t)height < MAX_IMAGE_AREA);
380 PutLE32(dst, MKFOURCC('V', 'P', '8', 'X'));
381 PutLE32(dst + TAG_SIZE, VP8X_CHUNK_SIZE);
382 PutLE32(dst + CHUNK_HEADER_SIZE, flags);
383 PutLE24(dst + CHUNK_HEADER_SIZE + 4, width - 1);
384 PutLE24(dst + CHUNK_HEADER_SIZE + 7, height - 1);
385 return dst + vp8x_size;
386}
387
388// Assemble a single image WebP bitstream from 'wpi'.
389static WebPMuxError SynthesizeBitstream(const WebPMuxImage* const wpi,
390 WebPData* const bitstream) {
391 uint8_t* dst;
392
393 // Allocate data.
394 const int need_vp8x = (wpi->alpha_ != NULL);
395 const size_t vp8x_size = need_vp8x ? CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE : 0;
396 const size_t alpha_size = need_vp8x ? ChunkDiskSize(wpi->alpha_) : 0;
397 // Note: No need to output ANMF chunk for a single image.
398 const size_t size = RIFF_HEADER_SIZE + vp8x_size + alpha_size +
399 ChunkDiskSize(wpi->img_);
400 uint8_t* const data = (uint8_t*)WebPSafeMalloc(1ULL, size);
401 if (data == NULL) return WEBP_MUX_MEMORY_ERROR;
402
403 // There should be at most one alpha_ chunk and exactly one img_ chunk.
404 assert(wpi->alpha_ == NULL || wpi->alpha_->next_ == NULL);
405 assert(wpi->img_ != NULL && wpi->img_->next_ == NULL);
406
407 // Main RIFF header.
408 dst = MuxEmitRiffHeader(data, size);
409
410 if (need_vp8x) {
411 dst = EmitVP8XChunk(dst, wpi->width_, wpi->height_, ALPHA_FLAG); // VP8X.
412 dst = ChunkListEmit(wpi->alpha_, dst); // ALPH.
413 }
414
415 // Bitstream.
416 dst = ChunkListEmit(wpi->img_, dst);
417 assert(dst == data + size);
418
419 // Output.
420 bitstream->bytes = data;
421 bitstream->size = size;
422 return WEBP_MUX_OK;
423}
424
425WebPMuxError WebPMuxGetChunk(const WebPMux* mux, const char fourcc[4],
426 WebPData* chunk_data) {
427 CHUNK_INDEX idx;
428 if (mux == NULL || fourcc == NULL || chunk_data == NULL) {
429 return WEBP_MUX_INVALID_ARGUMENT;
430 }
431 idx = ChunkGetIndexFromFourCC(fourcc);
432 if (IsWPI(kChunks[idx].id)) { // An image chunk.
433 return WEBP_MUX_INVALID_ARGUMENT;
434 } else if (idx != IDX_UNKNOWN) { // A known chunk type.
435 return MuxGet(mux, idx, 1, chunk_data);
436 } else { // An unknown chunk type.
437 const WebPChunk* const chunk =
438 ChunkSearchList(mux->unknown_, 1, ChunkGetTagFromFourCC(fourcc));
439 if (chunk == NULL) return WEBP_MUX_NOT_FOUND;
440 *chunk_data = chunk->data_;
441 return WEBP_MUX_OK;
442 }
443}
444
445static WebPMuxError MuxGetImageInternal(const WebPMuxImage* const wpi,
446 WebPMuxFrameInfo* const info) {
447 // Set some defaults for unrelated fields.
448 info->x_offset = 0;
449 info->y_offset = 0;
450 info->duration = 1;
451 info->dispose_method = WEBP_MUX_DISPOSE_NONE;
452 info->blend_method = WEBP_MUX_BLEND;
453 // Extract data for related fields.
454 info->id = ChunkGetIdFromTag(wpi->img_->tag_);
455 return SynthesizeBitstream(wpi, &info->bitstream);
456}
457
458static WebPMuxError MuxGetFrameInternal(const WebPMuxImage* const wpi,
459 WebPMuxFrameInfo* const frame) {
460 const int is_frame = (wpi->header_->tag_ == kChunks[IDX_ANMF].tag);
461 const WebPData* frame_data;
462 if (!is_frame) return WEBP_MUX_INVALID_ARGUMENT;
463 assert(wpi->header_ != NULL); // Already checked by WebPMuxGetFrame().
464 // Get frame chunk.
465 frame_data = &wpi->header_->data_;
466 if (frame_data->size < kChunks[IDX_ANMF].size) return WEBP_MUX_BAD_DATA;
467 // Extract info.
468 frame->x_offset = 2 * GetLE24(frame_data->bytes + 0);
469 frame->y_offset = 2 * GetLE24(frame_data->bytes + 3);
470 {
471 const uint8_t bits = frame_data->bytes[15];
472 frame->duration = GetLE24(frame_data->bytes + 12);
473 frame->dispose_method =
474 (bits & 1) ? WEBP_MUX_DISPOSE_BACKGROUND : WEBP_MUX_DISPOSE_NONE;
475 frame->blend_method = (bits & 2) ? WEBP_MUX_NO_BLEND : WEBP_MUX_BLEND;
476 }
477 frame->id = ChunkGetIdFromTag(wpi->header_->tag_);
478 return SynthesizeBitstream(wpi, &frame->bitstream);
479}
480
481WebPMuxError WebPMuxGetFrame(
482 const WebPMux* mux, uint32_t nth, WebPMuxFrameInfo* frame) {
483 WebPMuxError err;
484 WebPMuxImage* wpi;
485
486 if (mux == NULL || frame == NULL) {
487 return WEBP_MUX_INVALID_ARGUMENT;
488 }
489
490 // Get the nth WebPMuxImage.
491 err = MuxImageGetNth((const WebPMuxImage**)&mux->images_, nth, &wpi);
492 if (err != WEBP_MUX_OK) return err;
493
494 // Get frame info.
495 if (wpi->header_ == NULL) {
496 return MuxGetImageInternal(wpi, frame);
497 } else {
498 return MuxGetFrameInternal(wpi, frame);
499 }
500}
501
502WebPMuxError WebPMuxGetAnimationParams(const WebPMux* mux,
503 WebPMuxAnimParams* params) {
504 WebPData anim;
505 WebPMuxError err;
506
507 if (mux == NULL || params == NULL) return WEBP_MUX_INVALID_ARGUMENT;
508
509 err = MuxGet(mux, IDX_ANIM, 1, &anim);
510 if (err != WEBP_MUX_OK) return err;
511 if (anim.size < kChunks[WEBP_CHUNK_ANIM].size) return WEBP_MUX_BAD_DATA;
512 params->bgcolor = GetLE32(anim.bytes);
513 params->loop_count = GetLE16(anim.bytes + 4);
514
515 return WEBP_MUX_OK;
516}
517
518// Get chunk index from chunk id. Returns IDX_NIL if not found.
519static CHUNK_INDEX ChunkGetIndexFromId(WebPChunkId id) {
520 int i;
521 for (i = 0; kChunks[i].id != WEBP_CHUNK_NIL; ++i) {
522 if (id == kChunks[i].id) return (CHUNK_INDEX)i;
523 }
524 return IDX_NIL;
525}
526
527// Count number of chunks matching 'tag' in the 'chunk_list'.
528// If tag == NIL_TAG, any tag will be matched.
529static int CountChunks(const WebPChunk* const chunk_list, uint32_t tag) {
530 int count = 0;
531 const WebPChunk* current;
532 for (current = chunk_list; current != NULL; current = current->next_) {
533 if (tag == NIL_TAG || current->tag_ == tag) {
534 count++; // Count chunks whose tags match.
535 }
536 }
537 return count;
538}
539
540WebPMuxError WebPMuxNumChunks(const WebPMux* mux,
541 WebPChunkId id, int* num_elements) {
542 if (mux == NULL || num_elements == NULL) {
543 return WEBP_MUX_INVALID_ARGUMENT;
544 }
545
546 if (IsWPI(id)) {
547 *num_elements = MuxImageCount(mux->images_, id);
548 } else {
549 WebPChunk* const* chunk_list = MuxGetChunkListFromId(mux, id);
550 const CHUNK_INDEX idx = ChunkGetIndexFromId(id);
551 *num_elements = CountChunks(*chunk_list, kChunks[idx].tag);
552 }
553
554 return WEBP_MUX_OK;
555}
556
557//------------------------------------------------------------------------------
558