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1 // Copyright 2015 The Chromium Authors. All rights reserved. | 1 // Copyright 2015 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "media/filters/jpeg_parser.h" | 5 #include "media/filters/jpeg_parser.h" |
6 | 6 |
7 #include "base/big_endian.h" | 7 #include "base/big_endian.h" |
8 #include "base/logging.h" | 8 #include "base/logging.h" |
9 | 9 |
10 using base::BigEndianReader; | 10 using base::BigEndianReader; |
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262 return false; | 262 return false; |
263 } | 263 } |
264 if (point_transform != 0) { | 264 if (point_transform != 0) { |
265 DLOG(ERROR) << "Point transform should be 0 for baseline mode"; | 265 DLOG(ERROR) << "Point transform should be 0 for baseline mode"; |
266 return false; | 266 return false; |
267 } | 267 } |
268 | 268 |
269 return true; | 269 return true; |
270 } | 270 } |
271 | 271 |
272 // |eoi_ptr| will point to the end of image (after EOI marker) after search | |
273 // succeeds. Returns true on EOI marker found, or false. | |
274 static bool SearchEOI(const char* buffer, size_t length, const char** eoi_ptr) { | |
275 DCHECK(buffer); | |
276 DCHECK(eoi_ptr); | |
277 BigEndianReader reader(buffer, length); | |
278 uint8_t marker2; | |
279 | |
280 while (reader.remaining() > 0) { | |
281 const char* marker1_offset = static_cast<const char*>( | |
kcwu
2015/08/20 09:59:09
s/offset/ptr/
henryhsu
2015/08/20 10:13:58
Done.
| |
282 memchr(reader.ptr(), JPEG_MARKER_PREFIX, reader.remaining())); | |
283 if (!marker1_offset) | |
284 return false; | |
285 reader.Skip(marker1_offset - reader.ptr() + 1); | |
286 | |
287 do { | |
288 READ_U8_OR_RETURN_FALSE(&marker2); | |
289 } while (marker2 == JPEG_MARKER_PREFIX); // skip fill bytes | |
290 | |
291 switch (marker2) { | |
292 // Compressed data escape. | |
293 case 0x00: | |
294 break; | |
295 // Restart | |
296 case JPEG_RST0: | |
297 case JPEG_RST1: | |
298 case JPEG_RST2: | |
299 case JPEG_RST3: | |
300 case JPEG_RST4: | |
301 case JPEG_RST5: | |
302 case JPEG_RST6: | |
303 case JPEG_RST7: | |
304 break; | |
305 case JPEG_EOI: | |
306 *eoi_ptr = reader.ptr(); | |
307 return true; | |
308 default: | |
309 // Skip for other markers. | |
310 uint16_t size; | |
311 READ_U16_OR_RETURN_FALSE(&size); | |
312 if (size < sizeof(size)) { | |
313 DLOG(ERROR) << "Ill-formed JPEG. Segment size (" << size | |
314 << ") is smaller than size field (" << sizeof(size) | |
315 << ")"; | |
316 return false; | |
317 } | |
318 size -= sizeof(size); | |
319 | |
320 if (!reader.Skip(size)) { | |
321 DLOG(ERROR) << "Ill-formed JPEG. Remaining size (" | |
322 << reader.remaining() | |
323 << ") is smaller than header specified (" << size << ")"; | |
324 return false; | |
325 } | |
326 break; | |
327 } | |
328 } | |
329 return false; | |
330 } | |
331 | |
272 // |result| is already initialized to 0 in ParseJpegPicture. | 332 // |result| is already initialized to 0 in ParseJpegPicture. |
273 static bool ParseSOI(const char* buffer, | 333 static bool ParseSOI(const char* buffer, |
274 size_t length, | 334 size_t length, |
275 JpegParseResult* result) { | 335 JpegParseResult* result) { |
276 // Spec B.2.1 High-level syntax | 336 // Spec B.2.1 High-level syntax |
277 DCHECK(buffer); | 337 DCHECK(buffer); |
278 DCHECK(result); | 338 DCHECK(result); |
279 BigEndianReader reader(buffer, length); | 339 BigEndianReader reader(buffer, length); |
280 uint8_t marker1; | 340 uint8_t marker1; |
281 uint8_t marker2; | 341 uint8_t marker2; |
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365 } | 425 } |
366 | 426 |
367 if (!has_marker_dqt) { | 427 if (!has_marker_dqt) { |
368 DLOG(ERROR) << "No DQT marker found"; | 428 DLOG(ERROR) << "No DQT marker found"; |
369 return false; | 429 return false; |
370 } | 430 } |
371 | 431 |
372 // Scan data follows scan header immediately. | 432 // Scan data follows scan header immediately. |
373 result->data = reader.ptr(); | 433 result->data = reader.ptr(); |
374 result->data_size = reader.remaining(); | 434 result->data_size = reader.remaining(); |
435 const size_t kSoiSize = 2; | |
436 result->image_size = length + kSoiSize; | |
375 | 437 |
376 return true; | 438 return true; |
377 } | 439 } |
378 | 440 |
379 bool ParseJpegPicture(const uint8_t* buffer, | 441 bool ParseJpegPicture(const uint8_t* buffer, |
380 size_t length, | 442 size_t length, |
381 JpegParseResult* result) { | 443 JpegParseResult* result) { |
382 DCHECK(buffer); | 444 DCHECK(buffer); |
383 DCHECK(result); | 445 DCHECK(result); |
384 BigEndianReader reader(reinterpret_cast<const char*>(buffer), length); | 446 BigEndianReader reader(reinterpret_cast<const char*>(buffer), length); |
385 memset(result, 0, sizeof(JpegParseResult)); | 447 memset(result, 0, sizeof(JpegParseResult)); |
386 | 448 |
387 uint8_t marker1, marker2; | 449 uint8_t marker1, marker2; |
388 READ_U8_OR_RETURN_FALSE(&marker1); | 450 READ_U8_OR_RETURN_FALSE(&marker1); |
389 READ_U8_OR_RETURN_FALSE(&marker2); | 451 READ_U8_OR_RETURN_FALSE(&marker2); |
390 if (marker1 != JPEG_MARKER_PREFIX || marker2 != JPEG_SOI) { | 452 if (marker1 != JPEG_MARKER_PREFIX || marker2 != JPEG_SOI) { |
391 DLOG(ERROR) << "Not a JPEG"; | 453 DLOG(ERROR) << "Not a JPEG"; |
392 return false; | 454 return false; |
393 } | 455 } |
394 | 456 |
395 return ParseSOI(reader.ptr(), reader.remaining(), result); | 457 return ParseSOI(reader.ptr(), reader.remaining(), result); |
396 } | 458 } |
397 | 459 |
460 bool ParseJpegStream(const uint8_t* buffer, | |
461 size_t length, | |
462 JpegParseResult* result) { | |
463 DCHECK(buffer); | |
464 DCHECK(result); | |
465 if (!ParseJpegPicture(buffer, length, result)) | |
466 return false; | |
467 | |
468 BigEndianReader reader( | |
469 reinterpret_cast<const char*>(result->data), result->data_size); | |
470 const char* eoi_ptr = nullptr; | |
471 if (!SearchEOI(reader.ptr(), reader.remaining(), &eoi_ptr)) { | |
472 DLOG(ERROR) << "SearchEOI failed"; | |
473 return false; | |
474 } | |
475 DCHECK(eoi_ptr); | |
476 result->data_size = eoi_ptr - result->data; | |
477 result->image_size = eoi_ptr - reinterpret_cast<const char*>(buffer); | |
478 return true; | |
479 } | |
480 | |
398 } // namespace media | 481 } // namespace media |
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