FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
avpacket.c
Go to the documentation of this file.
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_free(pkt->data);
38  pkt->data = NULL;
39  pkt->size = 0;
40 }
41 
42 /* a dummy destruct callback for the callers that assume AVPacket.destruct ==
43  * NULL => static data */
44 static void dummy_destruct_packet(AVPacket *pkt)
45 {
46  av_assert0(0);
47 }
48 #endif
49 
50 void av_init_packet(AVPacket *pkt)
51 {
52  pkt->pts = AV_NOPTS_VALUE;
53  pkt->dts = AV_NOPTS_VALUE;
54  pkt->pos = -1;
55  pkt->duration = 0;
56  pkt->convergence_duration = 0;
57  pkt->flags = 0;
58  pkt->stream_index = 0;
59 #if FF_API_DESTRUCT_PACKET
60 FF_DISABLE_DEPRECATION_WARNINGS
61  pkt->destruct = NULL;
62 FF_ENABLE_DEPRECATION_WARNINGS
63 #endif
64  pkt->buf = NULL;
65  pkt->side_data = NULL;
66  pkt->side_data_elems = 0;
67 }
68 
69 static int packet_alloc(AVBufferRef **buf, int size)
70 {
71  int ret;
72  if ((unsigned)size >= (unsigned)size + FF_INPUT_BUFFER_PADDING_SIZE)
73  return AVERROR(EINVAL);
74 
75  ret = av_buffer_realloc(buf, size + FF_INPUT_BUFFER_PADDING_SIZE);
76  if (ret < 0)
77  return ret;
78 
79  memset((*buf)->data + size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
80 
81  return 0;
82 }
83 
84 int av_new_packet(AVPacket *pkt, int size)
85 {
86  AVBufferRef *buf = NULL;
87  int ret = packet_alloc(&buf, size);
88  if (ret < 0)
89  return ret;
90 
91  av_init_packet(pkt);
92  pkt->buf = buf;
93  pkt->data = buf->data;
94  pkt->size = size;
95 #if FF_API_DESTRUCT_PACKET
96 FF_DISABLE_DEPRECATION_WARNINGS
97  pkt->destruct = dummy_destruct_packet;
98 FF_ENABLE_DEPRECATION_WARNINGS
99 #endif
100 
101  return 0;
102 }
103 
104 void av_shrink_packet(AVPacket *pkt, int size)
105 {
106  if (pkt->size <= size)
107  return;
108  pkt->size = size;
109  memset(pkt->data + size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
110 }
111 
112 int av_grow_packet(AVPacket *pkt, int grow_by)
113 {
114  int new_size;
115  av_assert0((unsigned)pkt->size <= INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE);
116  if (!pkt->size)
117  return av_new_packet(pkt, grow_by);
118  if ((unsigned)grow_by >
119  INT_MAX - (pkt->size + FF_INPUT_BUFFER_PADDING_SIZE))
120  return -1;
121 
122  new_size = pkt->size + grow_by + FF_INPUT_BUFFER_PADDING_SIZE;
123  if (pkt->buf) {
124  int ret = av_buffer_realloc(&pkt->buf, new_size);
125  if (ret < 0)
126  return ret;
127  } else {
128  pkt->buf = av_buffer_alloc(new_size);
129  if (!pkt->buf)
130  return AVERROR(ENOMEM);
131  memcpy(pkt->buf->data, pkt->data, FFMIN(pkt->size, pkt->size + grow_by));
132 #if FF_API_DESTRUCT_PACKET
133 FF_DISABLE_DEPRECATION_WARNINGS
134  pkt->destruct = dummy_destruct_packet;
135 FF_ENABLE_DEPRECATION_WARNINGS
136 #endif
137  }
138  pkt->data = pkt->buf->data;
139  pkt->size += grow_by;
140  memset(pkt->data + pkt->size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
141 
142  return 0;
143 }
144 
145 int av_packet_from_data(AVPacket *pkt, uint8_t *data, int size)
146 {
147  if (size >= INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE)
148  return AVERROR(EINVAL);
149 
150  pkt->buf = av_buffer_create(data, size + FF_INPUT_BUFFER_PADDING_SIZE,
151  av_buffer_default_free, NULL, 0);
152  if (!pkt->buf)
153  return AVERROR(ENOMEM);
154 
155  pkt->data = data;
156  pkt->size = size;
157 #if FF_API_DESTRUCT_PACKET
158 FF_DISABLE_DEPRECATION_WARNINGS
159  pkt->destruct = dummy_destruct_packet;
160 FF_ENABLE_DEPRECATION_WARNINGS
161 #endif
162 
163  return 0;
164 }
165 
166 #define ALLOC_MALLOC(data, size) data = av_malloc(size)
167 #define ALLOC_BUF(data, size) \
168 do { \
169  av_buffer_realloc(&pkt->buf, size); \
170  data = pkt->buf ? pkt->buf->data : NULL; \
171 } while (0)
172 
173 #define DUP_DATA(dst, src, size, padding, ALLOC) \
174  do { \
175  void *data; \
176  if (padding) { \
177  if ((unsigned)(size) > \
178  (unsigned)(size) + FF_INPUT_BUFFER_PADDING_SIZE) \
179  goto failed_alloc; \
180  ALLOC(data, size + FF_INPUT_BUFFER_PADDING_SIZE); \
181  } else { \
182  ALLOC(data, size); \
183  } \
184  if (!data) \
185  goto failed_alloc; \
186  memcpy(data, src, size); \
187  if (padding) \
188  memset((uint8_t *)data + size, 0, \
189  FF_INPUT_BUFFER_PADDING_SIZE); \
190  dst = data; \
191  } while (0)
192 
193 /* Makes duplicates of data, side_data, but does not copy any other fields */
194 static int copy_packet_data(AVPacket *pkt, const AVPacket *src, int dup)
195 {
196  pkt->data = NULL;
197  pkt->side_data = NULL;
198  if (pkt->buf) {
199  AVBufferRef *ref = av_buffer_ref(src->buf);
200  if (!ref)
201  return AVERROR(ENOMEM);
202  pkt->buf = ref;
203  pkt->data = ref->data;
204  } else {
205  DUP_DATA(pkt->data, src->data, pkt->size, 1, ALLOC_BUF);
206  }
207 #if FF_API_DESTRUCT_PACKET
208 FF_DISABLE_DEPRECATION_WARNINGS
209  pkt->destruct = dummy_destruct_packet;
210 FF_ENABLE_DEPRECATION_WARNINGS
211 #endif
212  if (pkt->side_data_elems && dup)
213  pkt->side_data = src->side_data;
214  if (pkt->side_data_elems && !dup) {
215  return av_copy_packet_side_data(pkt, src);
216  }
217  return 0;
218 
219 failed_alloc:
220  av_free_packet(pkt);
221  return AVERROR(ENOMEM);
222 }
223 
224 int av_copy_packet_side_data(AVPacket *pkt, const AVPacket *src)
225 {
226  if (src->side_data_elems) {
227  int i;
228  DUP_DATA(pkt->side_data, src->side_data,
229  src->side_data_elems * sizeof(*src->side_data), 0, ALLOC_MALLOC);
230  if (src != pkt) {
231  memset(pkt->side_data, 0,
232  src->side_data_elems * sizeof(*src->side_data));
233  }
234  for (i = 0; i < src->side_data_elems; i++) {
235  DUP_DATA(pkt->side_data[i].data, src->side_data[i].data,
236  src->side_data[i].size, 1, ALLOC_MALLOC);
237  pkt->side_data[i].size = src->side_data[i].size;
238  pkt->side_data[i].type = src->side_data[i].type;
239  }
240  }
241  pkt->side_data_elems = src->side_data_elems;
242  return 0;
243 
244 failed_alloc:
245  av_free_packet(pkt);
246  return AVERROR(ENOMEM);
247 }
248 
249 int av_dup_packet(AVPacket *pkt)
250 {
251  AVPacket tmp_pkt;
252 
253 FF_DISABLE_DEPRECATION_WARNINGS
254  if (!pkt->buf && pkt->data
255 #if FF_API_DESTRUCT_PACKET
256  && !pkt->destruct
257 #endif
258  ) {
259 FF_ENABLE_DEPRECATION_WARNINGS
260  tmp_pkt = *pkt;
261  return copy_packet_data(pkt, &tmp_pkt, 1);
262  }
263  return 0;
264 }
265 
266 int av_copy_packet(AVPacket *dst, const AVPacket *src)
267 {
268  *dst = *src;
269  return copy_packet_data(dst, src, 0);
270 }
271 
272 void av_packet_free_side_data(AVPacket *pkt)
273 {
274  int i;
275  for (i = 0; i < pkt->side_data_elems; i++)
276  av_free(pkt->side_data[i].data);
277  av_freep(&pkt->side_data);
278  pkt->side_data_elems = 0;
279 }
280 
281 void av_free_packet(AVPacket *pkt)
282 {
283  if (pkt) {
284 FF_DISABLE_DEPRECATION_WARNINGS
285  if (pkt->buf)
286  av_buffer_unref(&pkt->buf);
287 #if FF_API_DESTRUCT_PACKET
288  else if (pkt->destruct)
289  pkt->destruct(pkt);
290  pkt->destruct = NULL;
291 #endif
292 FF_ENABLE_DEPRECATION_WARNINGS
293  pkt->data = NULL;
294  pkt->size = 0;
295 
296  av_packet_free_side_data(pkt);
297  }
298 }
299 
300 uint8_t *av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
301  int size)
302 {
303  int elems = pkt->side_data_elems;
304 
305  if ((unsigned)elems + 1 > INT_MAX / sizeof(*pkt->side_data))
306  return NULL;
307  if ((unsigned)size > INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE)
308  return NULL;
309 
310  pkt->side_data = av_realloc(pkt->side_data,
311  (elems + 1) * sizeof(*pkt->side_data));
312  if (!pkt->side_data)
313  return NULL;
314 
315  pkt->side_data[elems].data = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
316  if (!pkt->side_data[elems].data)
317  return NULL;
318  pkt->side_data[elems].size = size;
319  pkt->side_data[elems].type = type;
320  pkt->side_data_elems++;
321 
322  return pkt->side_data[elems].data;
323 }
324 
325 uint8_t *av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
326  int *size)
327 {
328  int i;
329 
330  for (i = 0; i < pkt->side_data_elems; i++) {
331  if (pkt->side_data[i].type == type) {
332  if (size)
333  *size = pkt->side_data[i].size;
334  return pkt->side_data[i].data;
335  }
336  }
337  return NULL;
338 }
339 
340 #define FF_MERGE_MARKER 0x8c4d9d108e25e9feULL
341 
342 int av_packet_merge_side_data(AVPacket *pkt){
343  if(pkt->side_data_elems){
344  AVBufferRef *buf;
345  int i;
346  uint8_t *p;
347  uint64_t size= pkt->size + 8LL + FF_INPUT_BUFFER_PADDING_SIZE;
348  AVPacket old= *pkt;
349  for (i=0; i<old.side_data_elems; i++) {
350  size += old.side_data[i].size + 5LL;
351  }
352  if (size > INT_MAX)
353  return AVERROR(EINVAL);
354  buf = av_buffer_alloc(size);
355  if (!buf)
356  return AVERROR(ENOMEM);
357  pkt->buf = buf;
358  pkt->data = p = buf->data;
359 #if FF_API_DESTRUCT_PACKET
360 FF_DISABLE_DEPRECATION_WARNINGS
361  pkt->destruct = dummy_destruct_packet;
362 FF_ENABLE_DEPRECATION_WARNINGS
363 #endif
364  pkt->size = size - FF_INPUT_BUFFER_PADDING_SIZE;
365  bytestream_put_buffer(&p, old.data, old.size);
366  for (i=old.side_data_elems-1; i>=0; i--) {
367  bytestream_put_buffer(&p, old.side_data[i].data, old.side_data[i].size);
368  bytestream_put_be32(&p, old.side_data[i].size);
369  *p++ = old.side_data[i].type | ((i==old.side_data_elems-1)*128);
370  }
371  bytestream_put_be64(&p, FF_MERGE_MARKER);
372  av_assert0(p-pkt->data == pkt->size);
373  memset(p, 0, FF_INPUT_BUFFER_PADDING_SIZE);
374  av_free_packet(&old);
375  pkt->side_data_elems = 0;
376  pkt->side_data = NULL;
377  return 1;
378  }
379  return 0;
380 }
381 
382 int av_packet_split_side_data(AVPacket *pkt){
383  if (!pkt->side_data_elems && pkt->size >12 && AV_RB64(pkt->data + pkt->size - 8) == FF_MERGE_MARKER){
384  int i;
385  unsigned int size;
386  uint8_t *p;
387 
388  p = pkt->data + pkt->size - 8 - 5;
389  for (i=1; ; i++){
390  size = AV_RB32(p);
391  if (size>INT_MAX || p - pkt->data < size)
392  return 0;
393  if (p[4]&128)
394  break;
395  p-= size+5;
396  }
397 
398  pkt->side_data = av_malloc_array(i, sizeof(*pkt->side_data));
399  if (!pkt->side_data)
400  return AVERROR(ENOMEM);
401 
402  p= pkt->data + pkt->size - 8 - 5;
403  for (i=0; ; i++){
404  size= AV_RB32(p);
405  av_assert0(size<=INT_MAX && p - pkt->data >= size);
406  pkt->side_data[i].data = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
407  pkt->side_data[i].size = size;
408  pkt->side_data[i].type = p[4]&127;
409  if (!pkt->side_data[i].data)
410  return AVERROR(ENOMEM);
411  memcpy(pkt->side_data[i].data, p-size, size);
412  pkt->size -= size + 5;
413  if(p[4]&128)
414  break;
415  p-= size+5;
416  }
417  pkt->size -= 8;
418  pkt->side_data_elems = i+1;
419  return 1;
420  }
421  return 0;
422 }
423 
424 uint8_t *av_packet_pack_dictionary(AVDictionary *dict, int *size)
425 {
426  AVDictionaryEntry *t = NULL;
427  uint8_t *data = NULL;
428  *size = 0;
429 
430  if (!dict)
431  return NULL;
432 
433  while ((t = av_dict_get(dict, "", t, AV_DICT_IGNORE_SUFFIX))) {
434  const size_t keylen = strlen(t->key);
435  const size_t valuelen = strlen(t->value);
436  const size_t new_size = *size + keylen + 1 + valuelen + 1;
437  uint8_t *const new_data = av_realloc(data, new_size);
438 
439  if (!new_data)
440  goto fail;
441  data = new_data;
442  if (new_size > INT_MAX)
443  goto fail;
444 
445  memcpy(data + *size, t->key, keylen + 1);
446  memcpy(data + *size + keylen + 1, t->value, valuelen + 1);
447 
448  *size = new_size;
449  }
450 
451  return data;
452 
453 fail:
454  av_freep(&data);
455  *size = 0;
456  return NULL;
457 }
458 
459 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict)
460 {
461  const uint8_t *end = data + size;
462  int ret = 0;
463 
464  if (!dict || !data || !size)
465  return ret;
466  if (size && end[-1])
467  return AVERROR_INVALIDDATA;
468  while (data < end) {
469  const uint8_t *key = data;
470  const uint8_t *val = data + strlen(key) + 1;
471 
472  if (val >= end)
473  return AVERROR_INVALIDDATA;
474 
475  ret = av_dict_set(dict, key, val, 0);
476  if (ret < 0)
477  break;
478  data = val + strlen(val) + 1;
479  }
480 
481  return ret;
482 }
483 
484 int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
485  int size)
486 {
487  int i;
488 
489  for (i = 0; i < pkt->side_data_elems; i++) {
490  if (pkt->side_data[i].type == type) {
491  if (size > pkt->side_data[i].size)
492  return AVERROR(ENOMEM);
493  pkt->side_data[i].size = size;
494  return 0;
495  }
496  }
497  return AVERROR(ENOENT);
498 }
499 
500 int av_packet_copy_props(AVPacket *dst, const AVPacket *src)
501 {
502  int i;
503 
504  dst->pts = src->pts;
505  dst->dts = src->dts;
506  dst->pos = src->pos;
507  dst->duration = src->duration;
508  dst->convergence_duration = src->convergence_duration;
509  dst->flags = src->flags;
510  dst->stream_index = src->stream_index;
511 
512  for (i = 0; i < src->side_data_elems; i++) {
513  enum AVPacketSideDataType type = src->side_data[i].type;
514  int size = src->side_data[i].size;
515  uint8_t *src_data = src->side_data[i].data;
516  uint8_t *dst_data = av_packet_new_side_data(dst, type, size);
517 
518  if (!dst_data) {
519  av_packet_free_side_data(dst);
520  return AVERROR(ENOMEM);
521  }
522  memcpy(dst_data, src_data, size);
523  }
524 
525  return 0;
526 }
527 
528 void av_packet_unref(AVPacket *pkt)
529 {
530  av_packet_free_side_data(pkt);
531  av_buffer_unref(&pkt->buf);
532  av_init_packet(pkt);
533  pkt->data = NULL;
534  pkt->size = 0;
535 }
536 
537 int av_packet_ref(AVPacket *dst, const AVPacket *src)
538 {
539  int ret;
540 
541  ret = av_packet_copy_props(dst, src);
542  if (ret < 0)
543  return ret;
544 
545  if (!src->buf) {
546  ret = packet_alloc(&dst->buf, src->size);
547  if (ret < 0)
548  goto fail;
549  memcpy(dst->buf->data, src->data, src->size);
550  } else
551  dst->buf = av_buffer_ref(src->buf);
552 
553  dst->size = src->size;
554  dst->data = dst->buf->data;
555  return 0;
556 fail:
557  av_packet_free_side_data(dst);
558  return ret;
559 }
560 
561 void av_packet_move_ref(AVPacket *dst, AVPacket *src)
562 {
563  *dst = *src;
564  av_init_packet(src);
565 }
566 
567 void av_packet_rescale_ts(AVPacket *pkt, AVRational src_tb, AVRational dst_tb)
568 {
569  if (pkt->pts != AV_NOPTS_VALUE)
570  pkt->pts = av_rescale_q(pkt->pts, src_tb, dst_tb);
571  if (pkt->dts != AV_NOPTS_VALUE)
572  pkt->dts = av_rescale_q(pkt->dts, src_tb, dst_tb);
573  if (pkt->duration > 0)
574  pkt->duration = av_rescale_q(pkt->duration, src_tb, dst_tb);
575  if (pkt->convergence_duration > 0)
576  pkt->convergence_duration = av_rescale_q(pkt->convergence_duration, src_tb, dst_tb);
577 }
Generated on Sun Sep 14 2014 18:55:52 for FFmpeg by   doxygen 1.8.2