1 /*
2 * Copyright (c) 2017, Alliance for Open Media. All rights reserved
3 *
4 * This source code is subject to the terms of the BSD 2 Clause License and
5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6 * was not distributed with this source code in the LICENSE file, you can
7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8 * Media Patent License 1.0 was not distributed with this source code in the
9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10 */
11
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <assert.h>
16
17 #include "common/obudec.h"
18
19 #include "aom_dsp/aom_dsp_common.h"
20 #include "aom_ports/mem_ops.h"
21 #include "av1/common/common.h"
22 #include "av1/common/obu_util.h"
23
24 #define OBU_BUFFER_SIZE (500 * 1024)
25
26 #define OBU_HEADER_SIZE 1
27 #define OBU_EXTENSION_SIZE 1
28 #define OBU_MAX_LENGTH_FIELD_SIZE 8
29
30 #define OBU_MAX_HEADER_SIZE \
31 (OBU_HEADER_SIZE + OBU_EXTENSION_SIZE + 2 * OBU_MAX_LENGTH_FIELD_SIZE)
32
33 #define OBU_DETECTION_SIZE \
34 (OBU_HEADER_SIZE + OBU_EXTENSION_SIZE + 4 * OBU_MAX_LENGTH_FIELD_SIZE)
35
36 // Reads unsigned LEB128 integer and returns 0 upon successful read and decode.
37 // Stores raw bytes in 'value_buffer', length of the number in 'value_length',
38 // and decoded value in 'value'.
obudec_read_leb128(FILE * f,uint8_t * value_buffer,size_t * value_length,uint64_t * value)39 static int obudec_read_leb128(FILE *f, uint8_t *value_buffer,
40 size_t *value_length, uint64_t *value) {
41 if (!f || !value_buffer || !value_length || !value) return -1;
42 size_t len;
43 for (len = 0; len < OBU_MAX_LENGTH_FIELD_SIZE; ++len) {
44 const size_t num_read = fread(&value_buffer[len], 1, 1, f);
45 if (num_read == 0) {
46 if (len == 0 && feof(f)) {
47 *value_length = 0;
48 return 0;
49 }
50 // Ran out of data before completing read of value.
51 return -1;
52 }
53 if ((value_buffer[len] >> 7) == 0) {
54 ++len;
55 *value_length = len;
56 break;
57 }
58 }
59
60 return aom_uleb_decode(value_buffer, len, value, NULL);
61 }
62
63 // Reads OBU header from 'f'. The 'buffer_capacity' passed in must be large
64 // enough to store an OBU header with extension (2 bytes). Raw OBU data is
65 // written to 'obu_data', parsed OBU header values are written to 'obu_header',
66 // and total bytes read from file are written to 'bytes_read'. Returns 0 for
67 // success, and non-zero on failure. When end of file is reached, the return
68 // value is 0 and the 'bytes_read' value is set to 0.
obudec_read_obu_header(FILE * f,size_t buffer_capacity,int is_annexb,uint8_t * obu_data,ObuHeader * obu_header,size_t * bytes_read)69 static int obudec_read_obu_header(FILE *f, size_t buffer_capacity,
70 int is_annexb, uint8_t *obu_data,
71 ObuHeader *obu_header, size_t *bytes_read) {
72 if (!f || buffer_capacity < (OBU_HEADER_SIZE + OBU_EXTENSION_SIZE) ||
73 !obu_data || !obu_header || !bytes_read) {
74 return -1;
75 }
76 *bytes_read = fread(obu_data, 1, 1, f);
77
78 if (feof(f) && *bytes_read == 0) {
79 return 0;
80 } else if (*bytes_read != 1) {
81 fprintf(stderr, "obudec: Failure reading OBU header.\n");
82 return -1;
83 }
84
85 const int has_extension = (obu_data[0] >> 2) & 0x1;
86 if (has_extension) {
87 if (fread(&obu_data[1], 1, 1, f) != 1) {
88 fprintf(stderr, "obudec: Failure reading OBU extension.");
89 return -1;
90 }
91 ++*bytes_read;
92 }
93
94 size_t obu_bytes_parsed = 0;
95 const aom_codec_err_t parse_result = aom_read_obu_header(
96 obu_data, *bytes_read, &obu_bytes_parsed, obu_header, is_annexb);
97 if (parse_result != AOM_CODEC_OK || *bytes_read != obu_bytes_parsed) {
98 fprintf(stderr, "obudec: Error parsing OBU header.\n");
99 return -1;
100 }
101
102 return 0;
103 }
104
105 // Reads OBU payload from 'f' and returns 0 for success when all payload bytes
106 // are read from the file. Payload data is written to 'obu_data', and actual
107 // bytes read added to 'bytes_read'.
obudec_read_obu_payload(FILE * f,size_t payload_length,uint8_t * obu_data,size_t * bytes_read)108 static int obudec_read_obu_payload(FILE *f, size_t payload_length,
109 uint8_t *obu_data, size_t *bytes_read) {
110 if (!f || payload_length == 0 || !obu_data || !bytes_read) return -1;
111
112 if (fread(obu_data, 1, payload_length, f) != payload_length) {
113 fprintf(stderr, "obudec: Failure reading OBU payload.\n");
114 return -1;
115 }
116
117 *bytes_read += payload_length;
118 return 0;
119 }
120
obudec_read_obu_header_and_size(FILE * f,size_t buffer_capacity,int is_annexb,uint8_t * buffer,size_t * bytes_read,size_t * payload_length,ObuHeader * obu_header)121 static int obudec_read_obu_header_and_size(FILE *f, size_t buffer_capacity,
122 int is_annexb, uint8_t *buffer,
123 size_t *bytes_read,
124 size_t *payload_length,
125 ObuHeader *obu_header) {
126 const size_t kMinimumBufferSize = OBU_MAX_HEADER_SIZE;
127 if (!f || !buffer || !bytes_read || !payload_length || !obu_header ||
128 buffer_capacity < kMinimumBufferSize) {
129 return -1;
130 }
131
132 size_t leb128_length_obu = 0;
133 size_t leb128_length_payload = 0;
134 uint64_t obu_size = 0;
135 if (is_annexb) {
136 if (obudec_read_leb128(f, &buffer[0], &leb128_length_obu, &obu_size) != 0) {
137 fprintf(stderr, "obudec: Failure reading OBU size length.\n");
138 return -1;
139 } else if (leb128_length_obu == 0) {
140 *payload_length = 0;
141 return 0;
142 }
143 if (obu_size > UINT32_MAX) {
144 fprintf(stderr, "obudec: OBU payload length too large.\n");
145 return -1;
146 }
147 }
148
149 size_t header_size = 0;
150 if (obudec_read_obu_header(f, buffer_capacity - leb128_length_obu, is_annexb,
151 buffer + leb128_length_obu, obu_header,
152 &header_size) != 0) {
153 return -1;
154 } else if (header_size == 0) {
155 *payload_length = 0;
156 return 0;
157 }
158
159 if (!obu_header->has_size_field) {
160 assert(is_annexb);
161 if (obu_size < header_size) {
162 fprintf(stderr, "obudec: OBU size is too small.\n");
163 return -1;
164 }
165 *payload_length = (size_t)obu_size - header_size;
166 } else {
167 uint64_t u64_payload_length = 0;
168 if (obudec_read_leb128(f, &buffer[leb128_length_obu + header_size],
169 &leb128_length_payload, &u64_payload_length) != 0) {
170 fprintf(stderr, "obudec: Failure reading OBU payload length.\n");
171 return -1;
172 }
173 if (u64_payload_length > UINT32_MAX) {
174 fprintf(stderr, "obudec: OBU payload length too large.\n");
175 return -1;
176 }
177
178 *payload_length = (size_t)u64_payload_length;
179 }
180
181 *bytes_read = leb128_length_obu + header_size + leb128_length_payload;
182 return 0;
183 }
184
obudec_grow_buffer(size_t growth_amount,uint8_t ** obu_buffer,size_t * obu_buffer_capacity)185 static int obudec_grow_buffer(size_t growth_amount, uint8_t **obu_buffer,
186 size_t *obu_buffer_capacity) {
187 if (!*obu_buffer || !obu_buffer_capacity || growth_amount == 0) {
188 return -1;
189 }
190
191 const size_t capacity = *obu_buffer_capacity;
192 if (SIZE_MAX - growth_amount < capacity) {
193 fprintf(stderr, "obudec: cannot grow buffer, capacity will roll over.\n");
194 return -1;
195 }
196
197 const size_t new_capacity = capacity + growth_amount;
198
199 #if defined AOM_MAX_ALLOCABLE_MEMORY
200 if (new_capacity > AOM_MAX_ALLOCABLE_MEMORY) {
201 fprintf(stderr, "obudec: OBU size exceeds max alloc size.\n");
202 return -1;
203 }
204 #endif
205
206 uint8_t *new_buffer = (uint8_t *)realloc(*obu_buffer, new_capacity);
207 if (!new_buffer) {
208 fprintf(stderr, "obudec: Failed to allocate compressed data buffer.\n");
209 return -1;
210 }
211
212 *obu_buffer = new_buffer;
213 *obu_buffer_capacity = new_capacity;
214 return 0;
215 }
216
obudec_read_one_obu(FILE * f,uint8_t ** obu_buffer,size_t obu_bytes_buffered,size_t * obu_buffer_capacity,size_t * obu_length,ObuHeader * obu_header,int is_annexb)217 static int obudec_read_one_obu(FILE *f, uint8_t **obu_buffer,
218 size_t obu_bytes_buffered,
219 size_t *obu_buffer_capacity, size_t *obu_length,
220 ObuHeader *obu_header, int is_annexb) {
221 if (!f || !(*obu_buffer) || !obu_buffer_capacity || !obu_length ||
222 !obu_header) {
223 return -1;
224 }
225
226 size_t bytes_read = 0;
227 size_t obu_payload_length = 0;
228 size_t available_buffer_capacity = *obu_buffer_capacity - obu_bytes_buffered;
229
230 if (available_buffer_capacity < OBU_MAX_HEADER_SIZE) {
231 if (obudec_grow_buffer(AOMMAX(*obu_buffer_capacity, OBU_MAX_HEADER_SIZE),
232 obu_buffer, obu_buffer_capacity) != 0) {
233 *obu_length = bytes_read;
234 return -1;
235 }
236 available_buffer_capacity +=
237 AOMMAX(*obu_buffer_capacity, OBU_MAX_HEADER_SIZE);
238 }
239
240 const int status = obudec_read_obu_header_and_size(
241 f, available_buffer_capacity, is_annexb, *obu_buffer + obu_bytes_buffered,
242 &bytes_read, &obu_payload_length, obu_header);
243 if (status < 0) return status;
244
245 if (obu_payload_length > SIZE_MAX - bytes_read) return -1;
246
247 if (obu_payload_length > 256 * 1024 * 1024) {
248 fprintf(stderr, "obudec: Read invalid OBU size (%u)\n",
249 (unsigned int)obu_payload_length);
250 *obu_length = bytes_read + obu_payload_length;
251 return -1;
252 }
253
254 if (bytes_read + obu_payload_length > available_buffer_capacity &&
255 obudec_grow_buffer(AOMMAX(*obu_buffer_capacity, obu_payload_length),
256 obu_buffer, obu_buffer_capacity) != 0) {
257 *obu_length = bytes_read + obu_payload_length;
258 return -1;
259 }
260
261 if (obu_payload_length > 0 &&
262 obudec_read_obu_payload(f, obu_payload_length,
263 *obu_buffer + obu_bytes_buffered + bytes_read,
264 &bytes_read) != 0) {
265 return -1;
266 }
267
268 *obu_length = bytes_read;
269 return 0;
270 }
271
file_is_obu(struct ObuDecInputContext * obu_ctx)272 int file_is_obu(struct ObuDecInputContext *obu_ctx) {
273 if (!obu_ctx || !obu_ctx->avx_ctx) return 0;
274
275 struct AvxInputContext *avx_ctx = obu_ctx->avx_ctx;
276 uint8_t detect_buf[OBU_DETECTION_SIZE] = { 0 };
277 const int is_annexb = obu_ctx->is_annexb;
278 FILE *f = avx_ctx->file;
279 size_t payload_length = 0;
280 ObuHeader obu_header;
281 memset(&obu_header, 0, sizeof(obu_header));
282 size_t length_of_unit_size = 0;
283 size_t annexb_header_length = 0;
284 uint64_t unit_size = 0;
285
286 if (is_annexb) {
287 // read the size of first temporal unit
288 if (obudec_read_leb128(f, &detect_buf[0], &length_of_unit_size,
289 &unit_size) != 0) {
290 fprintf(stderr, "obudec: Failure reading temporal unit header\n");
291 return 0;
292 }
293
294 // read the size of first frame unit
295 if (obudec_read_leb128(f, &detect_buf[length_of_unit_size],
296 &annexb_header_length, &unit_size) != 0) {
297 fprintf(stderr, "obudec: Failure reading frame unit header\n");
298 return 0;
299 }
300 annexb_header_length += length_of_unit_size;
301 }
302
303 size_t bytes_read = 0;
304 if (obudec_read_obu_header_and_size(
305 f, OBU_DETECTION_SIZE - annexb_header_length, is_annexb,
306 &detect_buf[annexb_header_length], &bytes_read, &payload_length,
307 &obu_header) != 0) {
308 fprintf(stderr, "obudec: Failure reading first OBU.\n");
309 rewind(f);
310 return 0;
311 }
312
313 if (is_annexb) {
314 bytes_read += annexb_header_length;
315 }
316
317 if (obu_header.type != OBU_TEMPORAL_DELIMITER &&
318 obu_header.type != OBU_SEQUENCE_HEADER) {
319 return 0;
320 }
321
322 if (obu_header.has_size_field) {
323 if (obu_header.type == OBU_TEMPORAL_DELIMITER && payload_length != 0) {
324 fprintf(
325 stderr,
326 "obudec: Invalid OBU_TEMPORAL_DELIMITER payload length (non-zero).");
327 rewind(f);
328 return 0;
329 }
330 } else if (!is_annexb) {
331 fprintf(stderr, "obudec: OBU size fields required, cannot decode input.\n");
332 rewind(f);
333 return 0;
334 }
335
336 // Appears that input is valid Section 5 AV1 stream.
337 obu_ctx->buffer = (uint8_t *)malloc(OBU_BUFFER_SIZE);
338 if (!obu_ctx->buffer) {
339 fprintf(stderr, "Out of memory.\n");
340 rewind(f);
341 return 0;
342 }
343 obu_ctx->buffer_capacity = OBU_BUFFER_SIZE;
344
345 memcpy(obu_ctx->buffer, &detect_buf[0], bytes_read);
346 obu_ctx->bytes_buffered = bytes_read;
347 // If the first OBU is a SEQUENCE_HEADER, then it will have a payload.
348 // We need to read this in so that our buffer only contains complete OBUs.
349 if (payload_length > 0) {
350 if (payload_length > (obu_ctx->buffer_capacity - bytes_read)) {
351 fprintf(stderr, "obudec: First OBU's payload is too large\n");
352 rewind(f);
353 return 0;
354 }
355
356 size_t payload_bytes = 0;
357 const int status = obudec_read_obu_payload(
358 f, payload_length, &obu_ctx->buffer[bytes_read], &payload_bytes);
359 if (status < 0) {
360 rewind(f);
361 return 0;
362 }
363 obu_ctx->bytes_buffered += payload_bytes;
364 }
365 return 1;
366 }
367
obudec_read_temporal_unit(struct ObuDecInputContext * obu_ctx,uint8_t ** buffer,size_t * bytes_read,size_t * buffer_size)368 int obudec_read_temporal_unit(struct ObuDecInputContext *obu_ctx,
369 uint8_t **buffer, size_t *bytes_read,
370 size_t *buffer_size) {
371 FILE *f = obu_ctx->avx_ctx->file;
372 if (!f) return -1;
373
374 *buffer_size = 0;
375 *bytes_read = 0;
376
377 if (feof(f)) {
378 return 1;
379 }
380
381 size_t tu_size;
382 size_t obu_size = 0;
383 size_t length_of_temporal_unit_size = 0;
384 uint8_t tuheader[OBU_MAX_LENGTH_FIELD_SIZE] = { 0 };
385
386 if (obu_ctx->is_annexb) {
387 uint64_t size = 0;
388
389 if (obu_ctx->bytes_buffered == 0) {
390 if (obudec_read_leb128(f, &tuheader[0], &length_of_temporal_unit_size,
391 &size) != 0) {
392 fprintf(stderr, "obudec: Failure reading temporal unit header\n");
393 return -1;
394 }
395 if (size == 0 && feof(f)) {
396 return 1;
397 }
398 } else {
399 // temporal unit size was already stored in buffer
400 if (aom_uleb_decode(obu_ctx->buffer, obu_ctx->bytes_buffered, &size,
401 &length_of_temporal_unit_size) != 0) {
402 fprintf(stderr, "obudec: Failure reading temporal unit header\n");
403 return -1;
404 }
405 }
406
407 if (size > UINT32_MAX || size + length_of_temporal_unit_size > UINT32_MAX) {
408 fprintf(stderr, "obudec: TU too large.\n");
409 return -1;
410 }
411
412 size += length_of_temporal_unit_size;
413 tu_size = (size_t)size;
414 } else {
415 while (1) {
416 ObuHeader obu_header;
417 memset(&obu_header, 0, sizeof(obu_header));
418
419 if (obudec_read_one_obu(f, &obu_ctx->buffer, obu_ctx->bytes_buffered,
420 &obu_ctx->buffer_capacity, &obu_size, &obu_header,
421 0) != 0) {
422 fprintf(stderr, "obudec: read_one_obu failed in TU loop\n");
423 return -1;
424 }
425
426 if (obu_header.type == OBU_TEMPORAL_DELIMITER || obu_size == 0) {
427 tu_size = obu_ctx->bytes_buffered;
428 break;
429 } else {
430 obu_ctx->bytes_buffered += obu_size;
431 }
432 }
433 }
434
435 #if defined AOM_MAX_ALLOCABLE_MEMORY
436 if (tu_size > AOM_MAX_ALLOCABLE_MEMORY) {
437 fprintf(stderr, "obudec: Temporal Unit size exceeds max alloc size.\n");
438 return -1;
439 }
440 #endif
441 if (tu_size > 0) {
442 uint8_t *new_buffer = (uint8_t *)realloc(*buffer, tu_size);
443 if (!new_buffer) {
444 free(*buffer);
445 fprintf(stderr, "obudec: Out of memory.\n");
446 return -1;
447 }
448 *buffer = new_buffer;
449 }
450 *bytes_read = tu_size;
451 *buffer_size = tu_size;
452
453 if (!obu_ctx->is_annexb) {
454 memcpy(*buffer, obu_ctx->buffer, tu_size);
455
456 // At this point, (obu_ctx->buffer + obu_ctx->bytes_buffered + obu_size)
457 // points to the end of the buffer.
458 memmove(obu_ctx->buffer, obu_ctx->buffer + obu_ctx->bytes_buffered,
459 obu_size);
460 obu_ctx->bytes_buffered = obu_size;
461 } else {
462 if (!feof(f)) {
463 size_t data_size;
464 size_t offset;
465 if (!obu_ctx->bytes_buffered) {
466 data_size = tu_size - length_of_temporal_unit_size;
467 memcpy(*buffer, &tuheader[0], length_of_temporal_unit_size);
468 offset = length_of_temporal_unit_size;
469 } else {
470 const size_t copy_size = AOMMIN(obu_ctx->bytes_buffered, tu_size);
471 memcpy(*buffer, obu_ctx->buffer, copy_size);
472 offset = copy_size;
473 data_size = tu_size - copy_size;
474 obu_ctx->bytes_buffered -= copy_size;
475 }
476
477 if (fread(*buffer + offset, 1, data_size, f) != data_size) {
478 fprintf(stderr, "obudec: Failed to read full temporal unit\n");
479 return -1;
480 }
481 }
482 }
483 return 0;
484 }
485
obudec_free(struct ObuDecInputContext * obu_ctx)486 void obudec_free(struct ObuDecInputContext *obu_ctx) { free(obu_ctx->buffer); }
487