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avpacket.c
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1 /*
2  * AVPacket functions for libavcodec
3  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include <string.h>
23 
24 #include "libavutil/avassert.h"
25 #include "libavutil/common.h"
26 #include "libavutil/internal.h"
27 #include "libavutil/mathematics.h"
28 #include "libavutil/mem.h"
29 #include "avcodec.h"
30 #include "bytestream.h"
31 #include "internal.h"
32 
33 #if FF_API_DESTRUCT_PACKET
34 
35 void av_destruct_packet(AVPacket *pkt)
36 {
37  av_freep(&pkt->data);
38  pkt->size = 0;
39 }
40 
41 /* a dummy destruct callback for the callers that assume AVPacket.destruct ==
42  * NULL => static data */
43 static void dummy_destruct_packet(AVPacket *pkt)
44 {
45  av_assert0(0);
46 }
47 #endif
48 
49 void av_init_packet(AVPacket *pkt)
50 {
51  pkt->pts = AV_NOPTS_VALUE;
52  pkt->dts = AV_NOPTS_VALUE;
53  pkt->pos = -1;
54  pkt->duration = 0;
55  pkt->convergence_duration = 0;
56  pkt->flags = 0;
57  pkt->stream_index = 0;
58 #if FF_API_DESTRUCT_PACKET
59 FF_DISABLE_DEPRECATION_WARNINGS
60  pkt->destruct = NULL;
61 FF_ENABLE_DEPRECATION_WARNINGS
62 #endif
63  pkt->buf = NULL;
64  pkt->side_data = NULL;
65  pkt->side_data_elems = 0;
66 }
67 
68 static int packet_alloc(AVBufferRef **buf, int size)
69 {
70  int ret;
71  if ((unsigned)size >= (unsigned)size + FF_INPUT_BUFFER_PADDING_SIZE)
72  return AVERROR(EINVAL);
73 
74  ret = av_buffer_realloc(buf, size + FF_INPUT_BUFFER_PADDING_SIZE);
75  if (ret < 0)
76  return ret;
77 
78  memset((*buf)->data + size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
79 
80  return 0;
81 }
82 
83 int av_new_packet(AVPacket *pkt, int size)
84 {
85  AVBufferRef *buf = NULL;
86  int ret = packet_alloc(&buf, size);
87  if (ret < 0)
88  return ret;
89 
90  av_init_packet(pkt);
91  pkt->buf = buf;
92  pkt->data = buf->data;
93  pkt->size = size;
94 #if FF_API_DESTRUCT_PACKET
95 FF_DISABLE_DEPRECATION_WARNINGS
96  pkt->destruct = dummy_destruct_packet;
97 FF_ENABLE_DEPRECATION_WARNINGS
98 #endif
99 
100  return 0;
101 }
102 
103 void av_shrink_packet(AVPacket *pkt, int size)
104 {
105  if (pkt->size <= size)
106  return;
107  pkt->size = size;
108  memset(pkt->data + size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
109 }
110 
111 int av_grow_packet(AVPacket *pkt, int grow_by)
112 {
113  int new_size;
114  av_assert0((unsigned)pkt->size <= INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE);
115  if (!pkt->size)
116  return av_new_packet(pkt, grow_by);
117  if ((unsigned)grow_by >
118  INT_MAX - (pkt->size + FF_INPUT_BUFFER_PADDING_SIZE))
119  return -1;
120 
121  new_size = pkt->size + grow_by + FF_INPUT_BUFFER_PADDING_SIZE;
122  if (pkt->buf) {
123  int ret = av_buffer_realloc(&pkt->buf, new_size);
124  if (ret < 0)
125  return ret;
126  } else {
127  pkt->buf = av_buffer_alloc(new_size);
128  if (!pkt->buf)
129  return AVERROR(ENOMEM);
130  memcpy(pkt->buf->data, pkt->data, FFMIN(pkt->size, pkt->size + grow_by));
131 #if FF_API_DESTRUCT_PACKET
132 FF_DISABLE_DEPRECATION_WARNINGS
133  pkt->destruct = dummy_destruct_packet;
134 FF_ENABLE_DEPRECATION_WARNINGS
135 #endif
136  }
137  pkt->data = pkt->buf->data;
138  pkt->size += grow_by;
139  memset(pkt->data + pkt->size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
140 
141  return 0;
142 }
143 
144 int av_packet_from_data(AVPacket *pkt, uint8_t *data, int size)
145 {
146  if (size >= INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE)
147  return AVERROR(EINVAL);
148 
149  pkt->buf = av_buffer_create(data, size + FF_INPUT_BUFFER_PADDING_SIZE,
150  av_buffer_default_free, NULL, 0);
151  if (!pkt->buf)
152  return AVERROR(ENOMEM);
153 
154  pkt->data = data;
155  pkt->size = size;
156 #if FF_API_DESTRUCT_PACKET
157 FF_DISABLE_DEPRECATION_WARNINGS
158  pkt->destruct = dummy_destruct_packet;
159 FF_ENABLE_DEPRECATION_WARNINGS
160 #endif
161 
162  return 0;
163 }
164 
165 #define ALLOC_MALLOC(data, size) data = av_malloc(size)
166 #define ALLOC_BUF(data, size) \
167 do { \
168  av_buffer_realloc(&pkt->buf, size); \
169  data = pkt->buf ? pkt->buf->data : NULL; \
170 } while (0)
171 
172 #define DUP_DATA(dst, src, size, padding, ALLOC) \
173  do { \
174  void *data; \
175  if (padding) { \
176  if ((unsigned)(size) > \
177  (unsigned)(size) + FF_INPUT_BUFFER_PADDING_SIZE) \
178  goto failed_alloc; \
179  ALLOC(data, size + FF_INPUT_BUFFER_PADDING_SIZE); \
180  } else { \
181  ALLOC(data, size); \
182  } \
183  if (!data) \
184  goto failed_alloc; \
185  memcpy(data, src, size); \
186  if (padding) \
187  memset((uint8_t *)data + size, 0, \
188  FF_INPUT_BUFFER_PADDING_SIZE); \
189  dst = data; \
190  } while (0)
191 
192 /* Makes duplicates of data, side_data, but does not copy any other fields */
193 static int copy_packet_data(AVPacket *pkt, const AVPacket *src, int dup)
194 {
195  pkt->data = NULL;
196  pkt->side_data = NULL;
197  if (pkt->buf) {
198  AVBufferRef *ref = av_buffer_ref(src->buf);
199  if (!ref)
200  return AVERROR(ENOMEM);
201  pkt->buf = ref;
202  pkt->data = ref->data;
203  } else {
204  DUP_DATA(pkt->data, src->data, pkt->size, 1, ALLOC_BUF);
205  }
206 #if FF_API_DESTRUCT_PACKET
207 FF_DISABLE_DEPRECATION_WARNINGS
208  pkt->destruct = dummy_destruct_packet;
209 FF_ENABLE_DEPRECATION_WARNINGS
210 #endif
211  if (pkt->side_data_elems && dup)
212  pkt->side_data = src->side_data;
213  if (pkt->side_data_elems && !dup) {
214  return av_copy_packet_side_data(pkt, src);
215  }
216  return 0;
217 
218 failed_alloc:
219  av_free_packet(pkt);
220  return AVERROR(ENOMEM);
221 }
222 
223 int av_copy_packet_side_data(AVPacket *pkt, const AVPacket *src)
224 {
225  if (src->side_data_elems) {
226  int i;
227  DUP_DATA(pkt->side_data, src->side_data,
228  src->side_data_elems * sizeof(*src->side_data), 0, ALLOC_MALLOC);
229  if (src != pkt) {
230  memset(pkt->side_data, 0,
231  src->side_data_elems * sizeof(*src->side_data));
232  }
233  for (i = 0; i < src->side_data_elems; i++) {
234  DUP_DATA(pkt->side_data[i].data, src->side_data[i].data,
235  src->side_data[i].size, 1, ALLOC_MALLOC);
236  pkt->side_data[i].size = src->side_data[i].size;
237  pkt->side_data[i].type = src->side_data[i].type;
238  }
239  }
240  pkt->side_data_elems = src->side_data_elems;
241  return 0;
242 
243 failed_alloc:
244  av_free_packet(pkt);
245  return AVERROR(ENOMEM);
246 }
247 
248 int av_dup_packet(AVPacket *pkt)
249 {
250  AVPacket tmp_pkt;
251 
252 FF_DISABLE_DEPRECATION_WARNINGS
253  if (!pkt->buf && pkt->data
254 #if FF_API_DESTRUCT_PACKET
255  && !pkt->destruct
256 #endif
257  ) {
258 FF_ENABLE_DEPRECATION_WARNINGS
259  tmp_pkt = *pkt;
260  return copy_packet_data(pkt, &tmp_pkt, 1);
261  }
262  return 0;
263 }
264 
265 int av_copy_packet(AVPacket *dst, const AVPacket *src)
266 {
267  *dst = *src;
268  return copy_packet_data(dst, src, 0);
269 }
270 
271 void av_packet_free_side_data(AVPacket *pkt)
272 {
273  int i;
274  for (i = 0; i < pkt->side_data_elems; i++)
275  av_freep(&pkt->side_data[i].data);
276  av_freep(&pkt->side_data);
277  pkt->side_data_elems = 0;
278 }
279 
280 void av_free_packet(AVPacket *pkt)
281 {
282  if (pkt) {
283 FF_DISABLE_DEPRECATION_WARNINGS
284  if (pkt->buf)
285  av_buffer_unref(&pkt->buf);
286 #if FF_API_DESTRUCT_PACKET
287  else if (pkt->destruct)
288  pkt->destruct(pkt);
289  pkt->destruct = NULL;
290 #endif
291 FF_ENABLE_DEPRECATION_WARNINGS
292  pkt->data = NULL;
293  pkt->size = 0;
294 
295  av_packet_free_side_data(pkt);
296  }
297 }
298 
299 uint8_t *av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
300  int size)
301 {
302  int elems = pkt->side_data_elems;
303 
304  if ((unsigned)elems + 1 > INT_MAX / sizeof(*pkt->side_data))
305  return NULL;
306  if ((unsigned)size > INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE)
307  return NULL;
308 
309  pkt->side_data = av_realloc(pkt->side_data,
310  (elems + 1) * sizeof(*pkt->side_data));
311  if (!pkt->side_data)
312  return NULL;
313 
314  pkt->side_data[elems].data = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
315  if (!pkt->side_data[elems].data)
316  return NULL;
317  pkt->side_data[elems].size = size;
318  pkt->side_data[elems].type = type;
319  pkt->side_data_elems++;
320 
321  return pkt->side_data[elems].data;
322 }
323 
324 uint8_t *av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
325  int *size)
326 {
327  int i;
328 
329  for (i = 0; i < pkt->side_data_elems; i++) {
330  if (pkt->side_data[i].type == type) {
331  if (size)
332  *size = pkt->side_data[i].size;
333  return pkt->side_data[i].data;
334  }
335  }
336  return NULL;
337 }
338 
339 #define FF_MERGE_MARKER 0x8c4d9d108e25e9feULL
340 
341 int av_packet_merge_side_data(AVPacket *pkt){
342  if(pkt->side_data_elems){
343  AVBufferRef *buf;
344  int i;
345  uint8_t *p;
346  uint64_t size= pkt->size + 8LL + FF_INPUT_BUFFER_PADDING_SIZE;
347  AVPacket old= *pkt;
348  for (i=0; i<old.side_data_elems; i++) {
349  size += old.side_data[i].size + 5LL;
350  }
351  if (size > INT_MAX)
352  return AVERROR(EINVAL);
353  buf = av_buffer_alloc(size);
354  if (!buf)
355  return AVERROR(ENOMEM);
356  pkt->buf = buf;
357  pkt->data = p = buf->data;
358 #if FF_API_DESTRUCT_PACKET
359 FF_DISABLE_DEPRECATION_WARNINGS
360  pkt->destruct = dummy_destruct_packet;
361 FF_ENABLE_DEPRECATION_WARNINGS
362 #endif
363  pkt->size = size - FF_INPUT_BUFFER_PADDING_SIZE;
364  bytestream_put_buffer(&p, old.data, old.size);
365  for (i=old.side_data_elems-1; i>=0; i--) {
366  bytestream_put_buffer(&p, old.side_data[i].data, old.side_data[i].size);
367  bytestream_put_be32(&p, old.side_data[i].size);
368  *p++ = old.side_data[i].type | ((i==old.side_data_elems-1)*128);
369  }
370  bytestream_put_be64(&p, FF_MERGE_MARKER);
371  av_assert0(p-pkt->data == pkt->size);
372  memset(p, 0, FF_INPUT_BUFFER_PADDING_SIZE);
373  av_free_packet(&old);
374  pkt->side_data_elems = 0;
375  pkt->side_data = NULL;
376  return 1;
377  }
378  return 0;
379 }
380 
381 int av_packet_split_side_data(AVPacket *pkt){
382  if (!pkt->side_data_elems && pkt->size >12 && AV_RB64(pkt->data + pkt->size - 8) == FF_MERGE_MARKER){
383  int i;
384  unsigned int size;
385  uint8_t *p;
386 
387  p = pkt->data + pkt->size - 8 - 5;
388  for (i=1; ; i++){
389  size = AV_RB32(p);
390  if (size>INT_MAX || p - pkt->data < size)
391  return 0;
392  if (p[4]&128)
393  break;
394  p-= size+5;
395  }
396 
397  pkt->side_data = av_malloc_array(i, sizeof(*pkt->side_data));
398  if (!pkt->side_data)
399  return AVERROR(ENOMEM);
400 
401  p= pkt->data + pkt->size - 8 - 5;
402  for (i=0; ; i++){
403  size= AV_RB32(p);
404  av_assert0(size<=INT_MAX && p - pkt->data >= size);
405  pkt->side_data[i].data = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
406  pkt->side_data[i].size = size;
407  pkt->side_data[i].type = p[4]&127;
408  if (!pkt->side_data[i].data)
409  return AVERROR(ENOMEM);
410  memcpy(pkt->side_data[i].data, p-size, size);
411  pkt->size -= size + 5;
412  if(p[4]&128)
413  break;
414  p-= size+5;
415  }
416  pkt->size -= 8;
417  pkt->side_data_elems = i+1;
418  return 1;
419  }
420  return 0;
421 }
422 
423 uint8_t *av_packet_pack_dictionary(AVDictionary *dict, int *size)
424 {
425  AVDictionaryEntry *t = NULL;
426  uint8_t *data = NULL;
427  *size = 0;
428 
429  if (!dict)
430  return NULL;
431 
432  while ((t = av_dict_get(dict, "", t, AV_DICT_IGNORE_SUFFIX))) {
433  const size_t keylen = strlen(t->key);
434  const size_t valuelen = strlen(t->value);
435  const size_t new_size = *size + keylen + 1 + valuelen + 1;
436  uint8_t *const new_data = av_realloc(data, new_size);
437 
438  if (!new_data)
439  goto fail;
440  data = new_data;
441  if (new_size > INT_MAX)
442  goto fail;
443 
444  memcpy(data + *size, t->key, keylen + 1);
445  memcpy(data + *size + keylen + 1, t->value, valuelen + 1);
446 
447  *size = new_size;
448  }
449 
450  return data;
451 
452 fail:
453  av_freep(&data);
454  *size = 0;
455  return NULL;
456 }
457 
458 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict)
459 {
460  const uint8_t *end = data + size;
461  int ret = 0;
462 
463  if (!dict || !data || !size)
464  return ret;
465  if (size && end[-1])
466  return AVERROR_INVALIDDATA;
467  while (data < end) {
468  const uint8_t *key = data;
469  const uint8_t *val = data + strlen(key) + 1;
470 
471  if (val >= end)
472  return AVERROR_INVALIDDATA;
473 
474  ret = av_dict_set(dict, key, val, 0);
475  if (ret < 0)
476  break;
477  data = val + strlen(val) + 1;
478  }
479 
480  return ret;
481 }
482 
483 int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
484  int size)
485 {
486  int i;
487 
488  for (i = 0; i < pkt->side_data_elems; i++) {
489  if (pkt->side_data[i].type == type) {
490  if (size > pkt->side_data[i].size)
491  return AVERROR(ENOMEM);
492  pkt->side_data[i].size = size;
493  return 0;
494  }
495  }
496  return AVERROR(ENOENT);
497 }
498 
499 int av_packet_copy_props(AVPacket *dst, const AVPacket *src)
500 {
501  int i;
502 
503  dst->pts = src->pts;
504  dst->dts = src->dts;
505  dst->pos = src->pos;
506  dst->duration = src->duration;
507  dst->convergence_duration = src->convergence_duration;
508  dst->flags = src->flags;
509  dst->stream_index = src->stream_index;
510 
511  for (i = 0; i < src->side_data_elems; i++) {
512  enum AVPacketSideDataType type = src->side_data[i].type;
513  int size = src->side_data[i].size;
514  uint8_t *src_data = src->side_data[i].data;
515  uint8_t *dst_data = av_packet_new_side_data(dst, type, size);
516 
517  if (!dst_data) {
518  av_packet_free_side_data(dst);
519  return AVERROR(ENOMEM);
520  }
521  memcpy(dst_data, src_data, size);
522  }
523 
524  return 0;
525 }
526 
527 void av_packet_unref(AVPacket *pkt)
528 {
529  av_packet_free_side_data(pkt);
530  av_buffer_unref(&pkt->buf);
531  av_init_packet(pkt);
532  pkt->data = NULL;
533  pkt->size = 0;
534 }
535 
536 int av_packet_ref(AVPacket *dst, const AVPacket *src)
537 {
538  int ret;
539 
540  ret = av_packet_copy_props(dst, src);
541  if (ret < 0)
542  return ret;
543 
544  if (!src->buf) {
545  ret = packet_alloc(&dst->buf, src->size);
546  if (ret < 0)
547  goto fail;
548  memcpy(dst->buf->data, src->data, src->size);
549  } else {
550  dst->buf = av_buffer_ref(src->buf);
551  if (!dst->buf) {
552  ret = AVERROR(ENOMEM);
553  goto fail;
554  }
555  }
556 
557  dst->size = src->size;
558  dst->data = dst->buf->data;
559  return 0;
560 fail:
561  av_packet_free_side_data(dst);
562  return ret;
563 }
564 
565 void av_packet_move_ref(AVPacket *dst, AVPacket *src)
566 {
567  *dst = *src;
568  av_init_packet(src);
569 }
570 
571 void av_packet_rescale_ts(AVPacket *pkt, AVRational src_tb, AVRational dst_tb)
572 {
573  if (pkt->pts != AV_NOPTS_VALUE)
574  pkt->pts = av_rescale_q(pkt->pts, src_tb, dst_tb);
575  if (pkt->dts != AV_NOPTS_VALUE)
576  pkt->dts = av_rescale_q(pkt->dts, src_tb, dst_tb);
577  if (pkt->duration > 0)
578  pkt->duration = av_rescale_q(pkt->duration, src_tb, dst_tb);
579  if (pkt->convergence_duration > 0)
580  pkt->convergence_duration = av_rescale_q(pkt->convergence_duration, src_tb, dst_tb);
581 }
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