FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
oggparsevorbis.c
Go to the documentation of this file.
1 /*
2  * Copyright (C) 2005 Michael Ahlberg, Måns Rullgård
3  *
4  * Permission is hereby granted, free of charge, to any person
5  * obtaining a copy of this software and associated documentation
6  * files (the "Software"), to deal in the Software without
7  * restriction, including without limitation the rights to use, copy,
8  * modify, merge, publish, distribute, sublicense, and/or sell copies
9  * of the Software, and to permit persons to whom the Software is
10  * furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
19  * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
20  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22  * DEALINGS IN THE SOFTWARE.
23  */
24 
25 #include <stdlib.h>
26 
27 #include "libavutil/avstring.h"
28 #include "libavutil/base64.h"
29 #include "libavutil/bswap.h"
30 #include "libavutil/dict.h"
31 #include "libavcodec/bytestream.h"
32 #include "libavcodec/get_bits.h"
34 #include "avformat.h"
35 #include "flac_picture.h"
36 #include "internal.h"
37 #include "oggdec.h"
38 #include "vorbiscomment.h"
39 
41 {
42  int i, cnum, h, m, s, ms, keylen = strlen(key);
43  AVChapter *chapter = NULL;
44 
45  if (keylen < 9 || sscanf(key, "CHAPTER%03d", &cnum) != 1)
46  return 0;
47 
48  if (keylen <= 10) {
49  if (sscanf(val, "%02d:%02d:%02d.%03d", &h, &m, &s, &ms) < 4)
50  return 0;
51 
52  avpriv_new_chapter(as, cnum, (AVRational) { 1, 1000 },
53  ms + 1000 * (s + 60 * (m + 60 * h)),
54  AV_NOPTS_VALUE, NULL);
55  av_free(val);
56  } else if (!strcmp(key + keylen - 4, "NAME")) {
57  for (i = 0; i < as->nb_chapters; i++)
58  if (as->chapters[i]->id == cnum) {
59  chapter = as->chapters[i];
60  break;
61  }
62  if (!chapter)
63  return 0;
64 
65  av_dict_set(&chapter->metadata, "title", val, AV_DICT_DONT_STRDUP_VAL);
66  } else
67  return 0;
68 
69  av_free(key);
70  return 1;
71 }
72 
74  const uint8_t *buf, int size)
75 {
76  const uint8_t *p = buf;
77  const uint8_t *end = buf + size;
78  unsigned n, j;
79  int s;
80 
81  /* must have vendor_length and user_comment_list_length */
82  if (size < 8)
83  return AVERROR_INVALIDDATA;
84 
85  s = bytestream_get_le32(&p);
86 
87  if (end - p - 4 < s || s < 0)
88  return AVERROR_INVALIDDATA;
89 
90  p += s;
91 
92  n = bytestream_get_le32(&p);
93 
94  while (end - p >= 4 && n > 0) {
95  const char *t, *v;
96  int tl, vl;
97 
98  s = bytestream_get_le32(&p);
99 
100  if (end - p < s || s < 0)
101  break;
102 
103  t = p;
104  p += s;
105  n--;
106 
107  v = memchr(t, '=', s);
108  if (!v)
109  continue;
110 
111  tl = v - t;
112  vl = s - tl - 1;
113  v++;
114 
115  if (tl && vl) {
116  char *tt, *ct;
117 
118  tt = av_malloc(tl + 1);
119  ct = av_malloc(vl + 1);
120  if (!tt || !ct) {
121  av_freep(&tt);
122  av_freep(&ct);
123  return AVERROR(ENOMEM);
124  }
125 
126  for (j = 0; j < tl; j++)
127  tt[j] = av_toupper(t[j]);
128  tt[tl] = 0;
129 
130  memcpy(ct, v, vl);
131  ct[vl] = 0;
132 
133  /* The format in which the pictures are stored is the FLAC format.
134  * Xiph says: "The binary FLAC picture structure is base64 encoded
135  * and placed within a VorbisComment with the tag name
136  * 'METADATA_BLOCK_PICTURE'. This is the preferred and
137  * recommended way of embedding cover art within VorbisComments."
138  */
139  if (!strcmp(tt, "METADATA_BLOCK_PICTURE")) {
140  int ret;
141  char *pict = av_malloc(vl);
142 
143  if (!pict) {
144  av_log(as, AV_LOG_WARNING, "out-of-memory error. Skipping cover art block.\n");
145  av_freep(&tt);
146  av_freep(&ct);
147  continue;
148  }
149  if ((ret = av_base64_decode(pict, ct, vl)) > 0)
150  ret = ff_flac_parse_picture(as, pict, ret);
151  av_freep(&tt);
152  av_freep(&ct);
153  av_freep(&pict);
154  if (ret < 0) {
155  av_log(as, AV_LOG_WARNING, "Failed to parse cover art block.\n");
156  continue;
157  }
158  } else if (!ogm_chapter(as, tt, ct))
159  av_dict_set(m, tt, ct,
162  }
163  }
164 
165  if (p != end)
166  av_log(as, AV_LOG_INFO,
167  "%ti bytes of comment header remain\n", end - p);
168  if (n > 0)
169  av_log(as, AV_LOG_INFO,
170  "truncated comment header, %i comments not found\n", n);
171 
173 
174  return 0;
175 }
176 
177 /*
178  * Parse the vorbis header
179  *
180  * Vorbis Identification header from Vorbis_I_spec.html#vorbis-spec-codec
181  * [vorbis_version] = read 32 bits as unsigned integer | Not used
182  * [audio_channels] = read 8 bit integer as unsigned | Used
183  * [audio_sample_rate] = read 32 bits as unsigned integer | Used
184  * [bitrate_maximum] = read 32 bits as signed integer | Not used yet
185  * [bitrate_nominal] = read 32 bits as signed integer | Not used yet
186  * [bitrate_minimum] = read 32 bits as signed integer | Used as bitrate
187  * [blocksize_0] = read 4 bits as unsigned integer | Not Used
188  * [blocksize_1] = read 4 bits as unsigned integer | Not Used
189  * [framing_flag] = read one bit | Not Used
190  */
191 
193  unsigned int len[3];
194  unsigned char *packet[3];
196  int64_t final_pts;
198 };
199 
201  struct oggvorbis_private *priv,
202  uint8_t **buf)
203 {
204  int i, offset, len, err;
205  int buf_len;
206  unsigned char *ptr;
207 
208  len = priv->len[0] + priv->len[1] + priv->len[2];
209  buf_len = len + len / 255 + 64;
210  ptr = *buf = av_realloc(NULL, buf_len);
211  if (!ptr)
212  return AVERROR(ENOMEM);
213  memset(*buf, '\0', buf_len);
214 
215  ptr[0] = 2;
216  offset = 1;
217  offset += av_xiphlacing(&ptr[offset], priv->len[0]);
218  offset += av_xiphlacing(&ptr[offset], priv->len[1]);
219  for (i = 0; i < 3; i++) {
220  memcpy(&ptr[offset], priv->packet[i], priv->len[i]);
221  offset += priv->len[i];
222  av_freep(&priv->packet[i]);
223  }
224  if ((err = av_reallocp(buf, offset + FF_INPUT_BUFFER_PADDING_SIZE)) < 0)
225  return err;
226  return offset;
227 }
228 
229 static void vorbis_cleanup(AVFormatContext *s, int idx)
230 {
231  struct ogg *ogg = s->priv_data;
232  struct ogg_stream *os = ogg->streams + idx;
233  struct oggvorbis_private *priv = os->private;
234  int i;
235  if (os->private)
236  for (i = 0; i < 3; i++)
237  av_freep(&priv->packet[i]);
238 }
239 
240 static int vorbis_header(AVFormatContext *s, int idx)
241 {
242  struct ogg *ogg = s->priv_data;
243  AVStream *st = s->streams[idx];
244  struct ogg_stream *os = ogg->streams + idx;
245  struct oggvorbis_private *priv;
246  int pkt_type = os->buf[os->pstart];
247 
248  if (!os->private) {
249  os->private = av_mallocz(sizeof(struct oggvorbis_private));
250  if (!os->private)
251  return AVERROR(ENOMEM);
252  }
253 
254  if (!(pkt_type & 1))
255  return 0;
256 
257  if (os->psize < 1 || pkt_type > 5)
258  return AVERROR_INVALIDDATA;
259 
260  priv = os->private;
261 
262  if (priv->packet[pkt_type >> 1])
263  return AVERROR_INVALIDDATA;
264  if (pkt_type > 1 && !priv->packet[0] || pkt_type > 3 && !priv->packet[1])
265  return AVERROR_INVALIDDATA;
266 
267  priv->len[pkt_type >> 1] = os->psize;
268  priv->packet[pkt_type >> 1] = av_mallocz(os->psize);
269  if (!priv->packet[pkt_type >> 1])
270  return AVERROR(ENOMEM);
271  memcpy(priv->packet[pkt_type >> 1], os->buf + os->pstart, os->psize);
272  if (os->buf[os->pstart] == 1) {
273  const uint8_t *p = os->buf + os->pstart + 7; /* skip "\001vorbis" tag */
274  unsigned blocksize, bs0, bs1;
275  int srate;
276  int channels;
277 
278  if (os->psize != 30)
279  return AVERROR_INVALIDDATA;
280 
281  if (bytestream_get_le32(&p) != 0) /* vorbis_version */
282  return AVERROR_INVALIDDATA;
283 
284  channels = bytestream_get_byte(&p);
285  if (st->codec->channels && channels != st->codec->channels) {
286  av_log(s, AV_LOG_ERROR, "Channel change is not supported\n");
287  return AVERROR_PATCHWELCOME;
288  }
289  st->codec->channels = channels;
290  srate = bytestream_get_le32(&p);
291  p += 4; // skip maximum bitrate
292  st->codec->bit_rate = bytestream_get_le32(&p); // nominal bitrate
293  p += 4; // skip minimum bitrate
294 
295  blocksize = bytestream_get_byte(&p);
296  bs0 = blocksize & 15;
297  bs1 = blocksize >> 4;
298 
299  if (bs0 > bs1)
300  return AVERROR_INVALIDDATA;
301  if (bs0 < 6 || bs1 > 13)
302  return AVERROR_INVALIDDATA;
303 
304  if (bytestream_get_byte(&p) != 1) /* framing_flag */
305  return AVERROR_INVALIDDATA;
306 
309 
310  if (srate > 0) {
311  st->codec->sample_rate = srate;
312  avpriv_set_pts_info(st, 64, 1, srate);
313  }
314  } else if (os->buf[os->pstart] == 3) {
315  if (os->psize > 8 &&
316  ff_vorbis_comment(s, &st->metadata, os->buf + os->pstart + 7,
317  os->psize - 8) >= 0) {
318  // drop all metadata we parsed and which is not required by libvorbis
319  unsigned new_len = 7 + 4 + AV_RL32(priv->packet[1] + 7) + 4 + 1;
320  if (new_len >= 16 && new_len < os->psize) {
321  AV_WL32(priv->packet[1] + new_len - 5, 0);
322  priv->packet[1][new_len - 1] = 1;
323  priv->len[1] = new_len;
324  }
325  }
326  } else {
327  int ret = fixup_vorbis_headers(s, priv, &st->codec->extradata);
328  if (ret < 0) {
329  st->codec->extradata_size = 0;
330  return ret;
331  }
332  st->codec->extradata_size = ret;
333  if ((ret = avpriv_vorbis_parse_extradata(st->codec, &priv->vp))) {
334  av_freep(&st->codec->extradata);
335  st->codec->extradata_size = 0;
336  return ret;
337  }
338  }
339 
340  return 1;
341 }
342 
343 static int vorbis_packet(AVFormatContext *s, int idx)
344 {
345  struct ogg *ogg = s->priv_data;
346  struct ogg_stream *os = ogg->streams + idx;
347  struct oggvorbis_private *priv = os->private;
348  int duration;
349 
350  /* first packet handling
351  * here we parse the duration of each packet in the first page and compare
352  * the total duration to the page granule to find the encoder delay and
353  * set the first timestamp */
354  if ((!os->lastpts || os->lastpts == AV_NOPTS_VALUE) && !(os->flags & OGG_FLAG_EOS)) {
355  int seg, d;
356  uint8_t *last_pkt = os->buf + os->pstart;
357  uint8_t *next_pkt = last_pkt;
358 
360  duration = 0;
361  seg = os->segp;
362  d = avpriv_vorbis_parse_frame(&priv->vp, last_pkt, 1);
363  if (d < 0) {
365  return 0;
366  }
367  duration += d;
368  last_pkt = next_pkt = next_pkt + os->psize;
369  for (; seg < os->nsegs; seg++) {
370  if (os->segments[seg] < 255) {
371  int d = avpriv_vorbis_parse_frame(&priv->vp, last_pkt, 1);
372  if (d < 0) {
373  duration = os->granule;
374  break;
375  }
376  duration += d;
377  last_pkt = next_pkt + os->segments[seg];
378  }
379  next_pkt += os->segments[seg];
380  }
381  os->lastpts =
382  os->lastdts = os->granule - duration;
383  if (s->streams[idx]->start_time == AV_NOPTS_VALUE) {
384  s->streams[idx]->start_time = FFMAX(os->lastpts, 0);
385  if (s->streams[idx]->duration)
386  s->streams[idx]->duration -= s->streams[idx]->start_time;
387  }
388  priv->final_pts = AV_NOPTS_VALUE;
390  }
391 
392  /* parse packet duration */
393  if (os->psize > 0) {
394  duration = avpriv_vorbis_parse_frame(&priv->vp, os->buf + os->pstart, 1);
395  if (duration < 0) {
397  return 0;
398  }
399  os->pduration = duration;
400  }
401 
402  /* final packet handling
403  * here we save the pts of the first packet in the final page, sum up all
404  * packet durations in the final page except for the last one, and compare
405  * to the page granule to find the duration of the final packet */
406  if (os->flags & OGG_FLAG_EOS) {
407  if (os->lastpts != AV_NOPTS_VALUE) {
408  priv->final_pts = os->lastpts;
409  priv->final_duration = 0;
410  }
411  if (os->segp == os->nsegs)
412  os->pduration = os->granule - priv->final_pts - priv->final_duration;
413  priv->final_duration += os->pduration;
414  }
415 
416  return 0;
417 }
418 
419 const struct ogg_codec ff_vorbis_codec = {
420  .magic = "\001vorbis",
421  .magicsize = 7,
422  .header = vorbis_header,
423  .packet = vorbis_packet,
424  .cleanup = vorbis_cleanup,
425  .nb_header = 3,
426 };