aiffdec.c
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1 /*
2  * AIFF/AIFF-C demuxer
3  * Copyright (c) 2006 Patrick Guimond
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/mathematics.h"
23 #include "libavutil/dict.h"
24 #include "avformat.h"
25 #include "internal.h"
26 #include "pcm.h"
27 #include "aiff.h"
28 
29 #define AIFF 0
30 #define AIFF_C_VERSION1 0xA2805140
31 
32 typedef struct {
33  int64_t data_end;
35 
36 static enum CodecID aiff_codec_get_id(int bps)
37 {
38  if (bps <= 8)
39  return CODEC_ID_PCM_S8;
40  if (bps <= 16)
41  return CODEC_ID_PCM_S16BE;
42  if (bps <= 24)
43  return CODEC_ID_PCM_S24BE;
44  if (bps <= 32)
45  return CODEC_ID_PCM_S32BE;
46 
47  /* bigger than 32 isn't allowed */
48  return CODEC_ID_NONE;
49 }
50 
51 /* returns the size of the found tag */
52 static int get_tag(AVIOContext *pb, uint32_t * tag)
53 {
54  int size;
55 
56  if (pb->eof_reached)
57  return AVERROR(EIO);
58 
59  *tag = avio_rl32(pb);
60  size = avio_rb32(pb);
61 
62  if (size < 0)
63  size = 0x7fffffff;
64 
65  return size;
66 }
67 
68 /* Metadata string read */
69 static void get_meta(AVFormatContext *s, const char *key, int size)
70 {
71  uint8_t *str = av_malloc(size+1);
72  int res;
73 
74  if (!str) {
75  avio_skip(s->pb, size);
76  return;
77  }
78 
79  res = avio_read(s->pb, str, size);
80  if (res < 0)
81  return;
82 
83  str[res] = 0;
85 }
86 
87 /* Returns the number of sound data frames or negative on error */
88 static unsigned int get_aiff_header(AVIOContext *pb, AVCodecContext *codec,
89  int size, unsigned version)
90 {
91  int exp;
92  uint64_t val;
93  double sample_rate;
94  unsigned int num_frames;
95 
96  if (size & 1)
97  size++;
99  codec->channels = avio_rb16(pb);
100  num_frames = avio_rb32(pb);
101  codec->bits_per_coded_sample = avio_rb16(pb);
102 
103  exp = avio_rb16(pb);
104  val = avio_rb64(pb);
105  sample_rate = ldexp(val, exp - 16383 - 63);
106  codec->sample_rate = sample_rate;
107  size -= 18;
108 
109  /* Got an AIFF-C? */
110  if (version == AIFF_C_VERSION1) {
111  codec->codec_tag = avio_rl32(pb);
113 
114  switch (codec->codec_id) {
115  case CODEC_ID_PCM_S16BE:
118  break;
120  codec->block_align = 34*codec->channels;
121  codec->frame_size = 64;
122  break;
123  case CODEC_ID_MACE3:
124  codec->block_align = 2*codec->channels;
125  codec->frame_size = 6;
126  break;
127  case CODEC_ID_MACE6:
128  codec->block_align = 1*codec->channels;
129  codec->frame_size = 6;
130  break;
131  case CODEC_ID_GSM:
132  codec->block_align = 33;
133  codec->frame_size = 160;
134  break;
135  case CODEC_ID_QCELP:
136  codec->block_align = 35;
137  codec->frame_size= 160;
138  break;
139  default:
140  break;
141  }
142  size -= 4;
143  } else {
144  /* Need the codec type */
147  }
148 
149  /* Block align needs to be computed in all cases, as the definition
150  * is specific to applications -> here we use the WAVE format definition */
151  if (!codec->block_align)
152  codec->block_align = (codec->bits_per_coded_sample * codec->channels) >> 3;
153 
154  codec->bit_rate = (codec->frame_size ? codec->sample_rate/codec->frame_size :
155  codec->sample_rate) * (codec->block_align << 3);
156 
157  /* Chunk is over */
158  if (size)
159  avio_skip(pb, size);
160 
161  return num_frames;
162 }
163 
164 static int aiff_probe(AVProbeData *p)
165 {
166  /* check file header */
167  if (p->buf[0] == 'F' && p->buf[1] == 'O' &&
168  p->buf[2] == 'R' && p->buf[3] == 'M' &&
169  p->buf[8] == 'A' && p->buf[9] == 'I' &&
170  p->buf[10] == 'F' && (p->buf[11] == 'F' || p->buf[11] == 'C'))
171  return AVPROBE_SCORE_MAX;
172  else
173  return 0;
174 }
175 
176 /* aiff input */
178  AVFormatParameters *ap)
179 {
180  int size, filesize;
181  int64_t offset = 0;
182  uint32_t tag;
183  unsigned version = AIFF_C_VERSION1;
184  AVIOContext *pb = s->pb;
185  AVStream * st;
186  AIFFInputContext *aiff = s->priv_data;
187 
188  /* check FORM header */
189  filesize = get_tag(pb, &tag);
190  if (filesize < 0 || tag != MKTAG('F', 'O', 'R', 'M'))
191  return AVERROR_INVALIDDATA;
192 
193  /* AIFF data type */
194  tag = avio_rl32(pb);
195  if (tag == MKTAG('A', 'I', 'F', 'F')) /* Got an AIFF file */
196  version = AIFF;
197  else if (tag != MKTAG('A', 'I', 'F', 'C')) /* An AIFF-C file then */
198  return AVERROR_INVALIDDATA;
199 
200  filesize -= 4;
201 
202  st = avformat_new_stream(s, NULL);
203  if (!st)
204  return AVERROR(ENOMEM);
205 
206  while (filesize > 0) {
207  /* parse different chunks */
208  size = get_tag(pb, &tag);
209  if (size < 0)
210  return size;
211 
212  filesize -= size + 8;
213 
214  switch (tag) {
215  case MKTAG('C', 'O', 'M', 'M'): /* Common chunk */
216  /* Then for the complete header info */
217  st->nb_frames = get_aiff_header(pb, st->codec, size, version);
218  if (st->nb_frames < 0)
219  return st->nb_frames;
220  if (offset > 0) // COMM is after SSND
221  goto got_sound;
222  break;
223  case MKTAG('F', 'V', 'E', 'R'): /* Version chunk */
224  version = avio_rb32(pb);
225  break;
226  case MKTAG('N', 'A', 'M', 'E'): /* Sample name chunk */
227  get_meta(s, "title" , size);
228  break;
229  case MKTAG('A', 'U', 'T', 'H'): /* Author chunk */
230  get_meta(s, "author" , size);
231  break;
232  case MKTAG('(', 'c', ')', ' '): /* Copyright chunk */
233  get_meta(s, "copyright", size);
234  break;
235  case MKTAG('A', 'N', 'N', 'O'): /* Annotation chunk */
236  get_meta(s, "comment" , size);
237  break;
238  case MKTAG('S', 'S', 'N', 'D'): /* Sampled sound chunk */
239  aiff->data_end = avio_tell(pb) + size;
240  offset = avio_rb32(pb); /* Offset of sound data */
241  avio_rb32(pb); /* BlockSize... don't care */
242  offset += avio_tell(pb); /* Compute absolute data offset */
243  if (st->codec->block_align) /* Assume COMM already parsed */
244  goto got_sound;
245  if (!pb->seekable) {
246  av_log(s, AV_LOG_ERROR, "file is not seekable\n");
247  return -1;
248  }
249  avio_skip(pb, size - 8);
250  break;
251  case MKTAG('w', 'a', 'v', 'e'):
252  if ((uint64_t)size > (1<<30))
253  return -1;
255  if (!st->codec->extradata)
256  return AVERROR(ENOMEM);
257  st->codec->extradata_size = size;
258  avio_read(pb, st->codec->extradata, size);
259  break;
260  default: /* Jump */
261  if (size & 1) /* Always even aligned */
262  size++;
263  avio_skip(pb, size);
264  }
265  }
266 
267 got_sound:
268  if (!st->codec->block_align) {
269  av_log(s, AV_LOG_ERROR, "could not find COMM tag or invalid block_align value\n");
270  return -1;
271  }
272 
273  /* Now positioned, get the sound data start and end */
274  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
275  st->start_time = 0;
276  st->duration = st->codec->frame_size ?
277  st->nb_frames * st->codec->frame_size : st->nb_frames;
278 
279  /* Position the stream at the first block */
280  avio_seek(pb, offset, SEEK_SET);
281 
282  return 0;
283 }
284 
285 #define MAX_SIZE 4096
286 
288  AVPacket *pkt)
289 {
290  AVStream *st = s->streams[0];
291  AIFFInputContext *aiff = s->priv_data;
292  int64_t max_size;
293  int res, size;
294 
295  /* calculate size of remaining data */
296  max_size = aiff->data_end - avio_tell(s->pb);
297  if (max_size <= 0)
298  return AVERROR_EOF;
299 
300  /* Now for that packet */
301  if (st->codec->block_align >= 33) // GSM, QCLP, IMA4
302  size = st->codec->block_align;
303  else
304  size = (MAX_SIZE / st->codec->block_align) * st->codec->block_align;
305  size = FFMIN(max_size, size);
306  res = av_get_packet(s->pb, pkt, size);
307  if (res < 0)
308  return res;
309 
310  /* Only one stream in an AIFF file */
311  pkt->stream_index = 0;
312  return 0;
313 }
314 
316  .name = "aiff",
317  .long_name = NULL_IF_CONFIG_SMALL("Audio IFF"),
318  .priv_data_size = sizeof(AIFFInputContext),
323  .codec_tag= (const AVCodecTag* const []){ff_codec_aiff_tags, 0},
324 };