FFmpeg
cafdec.c
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1 /*
2  * Core Audio Format demuxer
3  * Copyright (c) 2007 Justin Ruggles
4  * Copyright (c) 2009 Peter Ross
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * Core Audio Format demuxer
26  */
27 
28 #include <inttypes.h>
29 
30 #include "avformat.h"
31 #include "demux.h"
32 #include "internal.h"
33 #include "isom.h"
34 #include "mov_chan.h"
35 #include "libavcodec/flac.h"
36 #include "libavutil/intreadwrite.h"
37 #include "libavutil/intfloat.h"
38 #include "libavutil/dict.h"
39 #include "libavutil/mem.h"
40 #include "caf.h"
41 
42 typedef struct CafContext {
43  int bytes_per_packet; ///< bytes in a packet, or 0 if variable
44  int frames_per_packet; ///< frames in a packet, or 0 if variable
45  int64_t num_bytes; ///< total number of bytes in stream
46 
47  int64_t packet_cnt; ///< packet counter
48  int64_t frame_cnt; ///< frame counter
49 
50  int64_t data_start; ///< data start position, in bytes
51  int64_t data_size; ///< raw data size, in bytes
52 } CafContext;
53 
54 static int probe(const AVProbeData *p)
55 {
56  if (AV_RB32(p->buf) != MKBETAG('c','a','f','f'))
57  return 0;
58  if (AV_RB16(&p->buf[4]) != 1)
59  return 0;
60  if (AV_RB32(p->buf + 8) != MKBETAG('d','e','s','c'))
61  return 0;
62  if (AV_RB64(p->buf + 12) != 32)
63  return 0;
64  return AVPROBE_SCORE_MAX;
65 }
66 
67 /** Read audio description chunk */
69 {
70  AVIOContext *pb = s->pb;
71  CafContext *caf = s->priv_data;
72  AVStream *st;
73  int flags;
74 
75  /* new audio stream */
76  st = avformat_new_stream(s, NULL);
77  if (!st)
78  return AVERROR(ENOMEM);
79 
80  /* parse format description */
82  st->codecpar->sample_rate = av_clipd(av_int2double(avio_rb64(pb)), 0, INT_MAX);
83  st->codecpar->codec_tag = avio_rl32(pb);
84  flags = avio_rb32(pb);
85  caf->bytes_per_packet = avio_rb32(pb);
87  caf->frames_per_packet = avio_rb32(pb);
90 
91  if (caf->bytes_per_packet < 0 || caf->frames_per_packet < 0 || st->codecpar->ch_layout.nb_channels < 0)
92  return AVERROR_INVALIDDATA;
93 
94  /* calculate bit rate for constant size packets */
95  if (caf->frames_per_packet > 0 && caf->bytes_per_packet > 0) {
96  st->codecpar->bit_rate = (uint64_t)st->codecpar->sample_rate * (uint64_t)caf->bytes_per_packet * 8
97  / (uint64_t)caf->frames_per_packet;
98  } else {
99  st->codecpar->bit_rate = 0;
100  }
101 
102  /* determine codec */
103  if (st->codecpar->codec_tag == MKTAG('l','p','c','m'))
105  else
107  return 0;
108 }
109 
110 /** Read magic cookie chunk */
111 static int read_kuki_chunk(AVFormatContext *s, int64_t size)
112 {
113  AVIOContext *pb = s->pb;
114  AVStream *st = s->streams[0];
115  int ret;
116 
117  if (size < 0 || size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE)
118  return -1;
119 
120  if (st->codecpar->codec_id == AV_CODEC_ID_AAC) {
121  /* The magic cookie format for AAC is an mp4 esds atom.
122  The lavc AAC decoder requires the data from the codec specific
123  description as extradata input. */
124  int strt, skip;
125 
126  strt = avio_tell(pb);
127  ff_mov_read_esds(s, pb);
128  skip = size - (avio_tell(pb) - strt);
129  if (skip < 0 || !st->codecpar->extradata ||
131  av_log(s, AV_LOG_ERROR, "invalid AAC magic cookie\n");
132  return AVERROR_INVALIDDATA;
133  }
134  avio_skip(pb, skip);
135  } else if (st->codecpar->codec_id == AV_CODEC_ID_ALAC) {
136 #define ALAC_PREAMBLE 12
137 #define ALAC_HEADER 36
138 #define ALAC_NEW_KUKI 24
139  uint8_t preamble[12];
140  if (size < ALAC_NEW_KUKI) {
141  av_log(s, AV_LOG_ERROR, "invalid ALAC magic cookie\n");
142  avio_skip(pb, size);
143  return AVERROR_INVALIDDATA;
144  }
145  if (avio_read(pb, preamble, ALAC_PREAMBLE) != ALAC_PREAMBLE) {
146  av_log(s, AV_LOG_ERROR, "failed to read preamble\n");
147  return AVERROR_INVALIDDATA;
148  }
149 
150  if ((ret = ff_alloc_extradata(st->codecpar, ALAC_HEADER)) < 0)
151  return ret;
152 
153  /* For the old style cookie, we skip 12 bytes, then read 36 bytes.
154  * The new style cookie only contains the last 24 bytes of what was
155  * 36 bytes in the old style cookie, so we fabricate the first 12 bytes
156  * in that case to maintain compatibility. */
157  if (!memcmp(&preamble[4], "frmaalac", 8)) {
158  if (size < ALAC_PREAMBLE + ALAC_HEADER) {
159  av_log(s, AV_LOG_ERROR, "invalid ALAC magic cookie\n");
160  av_freep(&st->codecpar->extradata);
161  return AVERROR_INVALIDDATA;
162  }
163  if (avio_read(pb, st->codecpar->extradata, ALAC_HEADER) != ALAC_HEADER) {
164  av_log(s, AV_LOG_ERROR, "failed to read kuki header\n");
165  av_freep(&st->codecpar->extradata);
166  return AVERROR_INVALIDDATA;
167  }
169  } else {
170  AV_WB32(st->codecpar->extradata, 36);
171  memcpy(&st->codecpar->extradata[4], "alac", 4);
172  AV_WB32(&st->codecpar->extradata[8], 0);
173  memcpy(&st->codecpar->extradata[12], preamble, 12);
174  if (avio_read(pb, &st->codecpar->extradata[24], ALAC_NEW_KUKI - 12) != ALAC_NEW_KUKI - 12) {
175  av_log(s, AV_LOG_ERROR, "failed to read new kuki header\n");
176  av_freep(&st->codecpar->extradata);
177  return AVERROR_INVALIDDATA;
178  }
180  }
181  } else if (st->codecpar->codec_id == AV_CODEC_ID_FLAC) {
182  int last, type, flac_metadata_size;
183  uint8_t buf[4];
184  /* The magic cookie format for FLAC consists mostly of an mp4 dfLa atom. */
185  if (size < (16 + FLAC_STREAMINFO_SIZE)) {
186  av_log(s, AV_LOG_ERROR, "invalid FLAC magic cookie\n");
187  return AVERROR_INVALIDDATA;
188  }
189  /* Check cookie version. */
190  if (avio_r8(pb) != 0) {
191  av_log(s, AV_LOG_ERROR, "unknown FLAC magic cookie\n");
192  return AVERROR_INVALIDDATA;
193  }
194  avio_rb24(pb); /* Flags */
195  /* read dfLa fourcc */
196  if (avio_read(pb, buf, 4) != 4) {
197  av_log(s, AV_LOG_ERROR, "failed to read FLAC magic cookie\n");
198  return pb->error < 0 ? pb->error : AVERROR_INVALIDDATA;
199  }
200  if (memcmp(buf, "dfLa", 4)) {
201  av_log(s, AV_LOG_ERROR, "invalid FLAC magic cookie\n");
202  return AVERROR_INVALIDDATA;
203  }
204  /* Check dfLa version. */
205  if (avio_r8(pb) != 0) {
206  av_log(s, AV_LOG_ERROR, "unknown dfLa version\n");
207  return AVERROR_INVALIDDATA;
208  }
209  avio_rb24(pb); /* Flags */
210  if (avio_read(pb, buf, sizeof(buf)) != sizeof(buf)) {
211  av_log(s, AV_LOG_ERROR, "failed to read FLAC metadata block header\n");
212  return pb->error < 0 ? pb->error : AVERROR_INVALIDDATA;
213  }
214  flac_parse_block_header(buf, &last, &type, &flac_metadata_size);
215  if (type != FLAC_METADATA_TYPE_STREAMINFO || flac_metadata_size != FLAC_STREAMINFO_SIZE) {
216  av_log(s, AV_LOG_ERROR, "STREAMINFO must be first FLACMetadataBlock\n");
217  return AVERROR_INVALIDDATA;
218  }
220  if (ret < 0)
221  return ret;
222  if (!last)
223  av_log(s, AV_LOG_WARNING, "non-STREAMINFO FLACMetadataBlock(s) ignored\n");
224  } else if (st->codecpar->codec_id == AV_CODEC_ID_OPUS) {
225  // The data layout for Opus is currently unknown, so we do not export
226  // extradata at all. Multichannel streams are not supported.
227  if (st->codecpar->ch_layout.nb_channels > 2) {
228  avpriv_request_sample(s, "multichannel Opus in CAF");
229  return AVERROR_PATCHWELCOME;
230  }
231  avio_skip(pb, size);
232  } else if ((ret = ff_get_extradata(s, st->codecpar, pb, size)) < 0) {
233  return ret;
234  }
235 
236  return 0;
237 }
238 
239 /** Read packet table chunk */
240 static int read_pakt_chunk(AVFormatContext *s, int64_t size)
241 {
242  AVIOContext *pb = s->pb;
243  AVStream *st = s->streams[0];
244  CafContext *caf = s->priv_data;
245  int64_t pos = 0, ccount, num_packets;
246  int i;
247  int ret;
248 
249  ccount = avio_tell(pb);
250 
251  num_packets = avio_rb64(pb);
252  if (num_packets < 0 || INT32_MAX / sizeof(AVIndexEntry) < num_packets)
253  return AVERROR_INVALIDDATA;
254 
255  st->nb_frames = avio_rb64(pb); /* valid frames */
256  st->nb_frames += avio_rb32(pb); /* priming frames */
257  st->nb_frames += avio_rb32(pb); /* remainder frames */
258 
259  if (caf->bytes_per_packet > 0 && caf->frames_per_packet > 0) {
260  st->duration = caf->frames_per_packet * num_packets;
261  pos = caf-> bytes_per_packet * num_packets;
262  } else {
263  st->duration = 0;
264  for (i = 0; i < num_packets; i++) {
265  if (avio_feof(pb))
266  return AVERROR_INVALIDDATA;
267  ret = av_add_index_entry(s->streams[0], pos, st->duration, 0, 0, AVINDEX_KEYFRAME);
268  if (ret < 0)
269  return ret;
272  }
273  }
274 
275  if (avio_tell(pb) - ccount > size || size > INT64_MAX - ccount) {
276  av_log(s, AV_LOG_ERROR, "error reading packet table\n");
277  return AVERROR_INVALIDDATA;
278  }
279  avio_seek(pb, ccount + size, SEEK_SET);
280 
281  caf->num_bytes = pos;
282  return 0;
283 }
284 
285 /** Read information chunk */
286 static void read_info_chunk(AVFormatContext *s, int64_t size)
287 {
288  AVIOContext *pb = s->pb;
289  unsigned int i;
290  unsigned int nb_entries = avio_rb32(pb);
291  for (i = 0; i < nb_entries && !avio_feof(pb); i++) {
292  char key[32];
293  char value[1024];
294  avio_get_str(pb, INT_MAX, key, sizeof(key));
295  avio_get_str(pb, INT_MAX, value, sizeof(value));
296  if (!*key)
297  continue;
298  av_dict_set(&s->metadata, key, value, 0);
299  }
300 }
301 
303 {
304  AVIOContext *pb = s->pb;
305  CafContext *caf = s->priv_data;
306  AVStream *st;
307  uint32_t tag = 0;
308  int found_data, ret;
309  int64_t size, pos;
310 
311  avio_skip(pb, 8); /* magic, version, file flags */
312 
313  /* audio description chunk */
314  if (avio_rb32(pb) != MKBETAG('d','e','s','c')) {
315  av_log(s, AV_LOG_ERROR, "desc chunk not present\n");
316  return AVERROR_INVALIDDATA;
317  }
318  size = avio_rb64(pb);
319  if (size != 32)
320  return AVERROR_INVALIDDATA;
321 
322  ret = read_desc_chunk(s);
323  if (ret)
324  return ret;
325  st = s->streams[0];
326 
327  /* parse each chunk */
328  found_data = 0;
329  while (!avio_feof(pb)) {
330 
331  /* stop at data chunk if seeking is not supported or
332  data chunk size is unknown */
333  if (found_data && (caf->data_size < 0 || !(pb->seekable & AVIO_SEEKABLE_NORMAL)))
334  break;
335 
336  tag = avio_rb32(pb);
337  size = avio_rb64(pb);
338  pos = avio_tell(pb);
339  if (avio_feof(pb))
340  break;
341 
342  switch (tag) {
343  case MKBETAG('d','a','t','a'):
344  avio_skip(pb, 4); /* edit count */
345  caf->data_start = avio_tell(pb);
346  caf->data_size = size < 0 ? -1 : size - 4;
347  if (caf->data_start < 0 || caf->data_size > INT64_MAX - caf->data_start)
348  return AVERROR_INVALIDDATA;
349 
350  if (caf->data_size > 0 && (pb->seekable & AVIO_SEEKABLE_NORMAL))
351  avio_skip(pb, caf->data_size);
352  found_data = 1;
353  break;
354 
355  case MKBETAG('c','h','a','n'):
356  if ((ret = ff_mov_read_chan(s, s->pb, st, size)) < 0)
357  return ret;
358  break;
359 
360  /* magic cookie chunk */
361  case MKBETAG('k','u','k','i'):
362  if (read_kuki_chunk(s, size))
363  return AVERROR_INVALIDDATA;
364  break;
365 
366  /* packet table chunk */
367  case MKBETAG('p','a','k','t'):
368  if (read_pakt_chunk(s, size))
369  return AVERROR_INVALIDDATA;
370  break;
371 
372  case MKBETAG('i','n','f','o'):
374  break;
375 
376  default:
378  "skipping CAF chunk: %08"PRIX32" (%s), size %"PRId64"\n",
380  case MKBETAG('f','r','e','e'):
381  if (size < 0 && found_data)
382  goto found_data;
383  if (size < 0)
384  return AVERROR_INVALIDDATA;
385  break;
386  }
387 
388  if (size > 0 && (pb->seekable & AVIO_SEEKABLE_NORMAL)) {
389  if (pos > INT64_MAX - size)
390  return AVERROR_INVALIDDATA;
391  avio_seek(pb, pos + size, SEEK_SET);
392  }
393  }
394 
395  if (!found_data)
396  return AVERROR_INVALIDDATA;
397 
398 found_data:
399  if (caf->bytes_per_packet > 0 && caf->frames_per_packet > 0) {
400  if (caf->data_size > 0 && caf->data_size / caf->bytes_per_packet < INT64_MAX / caf->frames_per_packet)
401  st->nb_frames = (caf->data_size / caf->bytes_per_packet) * caf->frames_per_packet;
402  } else if (ffstream(st)->nb_index_entries && st->duration > 0) {
403  if (st->codecpar->sample_rate && caf->data_size / st->duration > INT64_MAX / st->codecpar->sample_rate / 8) {
404  av_log(s, AV_LOG_ERROR, "Overflow during bit rate calculation %d * 8 * %"PRId64"\n",
405  st->codecpar->sample_rate, caf->data_size / st->duration);
406  return AVERROR_INVALIDDATA;
407  }
408  st->codecpar->bit_rate = st->codecpar->sample_rate * 8LL *
409  (caf->data_size / st->duration);
410  } else {
411  av_log(s, AV_LOG_ERROR, "Missing packet table. It is required when "
412  "block size or frame size are variable.\n");
413  return AVERROR_INVALIDDATA;
414  }
415 
416  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
417  st->start_time = 0;
418 
419  /* position the stream at the start of data */
420  if (caf->data_size >= 0)
421  avio_seek(pb, caf->data_start, SEEK_SET);
422 
423  return 0;
424 }
425 
426 #define CAF_MAX_PKT_SIZE 4096
427 
429 {
430  AVIOContext *pb = s->pb;
431  AVStream *st = s->streams[0];
432  FFStream *const sti = ffstream(st);
433  CafContext *caf = s->priv_data;
434  int res, pkt_size = 0, pkt_frames = 0;
435  int64_t left = CAF_MAX_PKT_SIZE;
436 
437  if (avio_feof(pb))
438  return AVERROR_EOF;
439 
440  /* don't read past end of data chunk */
441  if (caf->data_size > 0) {
442  left = (caf->data_start + caf->data_size) - avio_tell(pb);
443  if (!left)
444  return AVERROR_EOF;
445  if (left < 0)
446  return AVERROR(EIO);
447  }
448 
449  pkt_frames = caf->frames_per_packet;
450  pkt_size = caf->bytes_per_packet;
451 
452  if (pkt_size > 0 && pkt_frames == 1) {
453  pkt_size = (CAF_MAX_PKT_SIZE / pkt_size) * pkt_size;
454  pkt_size = FFMIN(pkt_size, left);
455  pkt_frames = pkt_size / caf->bytes_per_packet;
456  } else if (sti->nb_index_entries) {
457  if (caf->packet_cnt < sti->nb_index_entries - 1) {
458  pkt_size = sti->index_entries[caf->packet_cnt + 1].pos - sti->index_entries[caf->packet_cnt].pos;
459  pkt_frames = sti->index_entries[caf->packet_cnt + 1].timestamp - sti->index_entries[caf->packet_cnt].timestamp;
460  } else if (caf->packet_cnt == sti->nb_index_entries - 1) {
461  pkt_size = caf->num_bytes - sti->index_entries[caf->packet_cnt].pos;
462  pkt_frames = st->duration - sti->index_entries[caf->packet_cnt].timestamp;
463  } else {
464  return AVERROR(EIO);
465  }
466  }
467 
468  if (pkt_size == 0 || pkt_frames == 0 || pkt_size > left)
469  return AVERROR(EIO);
470 
471  res = av_get_packet(pb, pkt, pkt_size);
472  if (res < 0)
473  return res;
474 
475  pkt->size = res;
476  pkt->stream_index = 0;
477  pkt->dts = pkt->pts = caf->frame_cnt;
478 
479  caf->packet_cnt++;
480  caf->frame_cnt += pkt_frames;
481 
482  return 0;
483 }
484 
485 static int read_seek(AVFormatContext *s, int stream_index,
486  int64_t timestamp, int flags)
487 {
488  AVStream *st = s->streams[0];
489  FFStream *const sti = ffstream(st);
490  CafContext *caf = s->priv_data;
491  int64_t pos, packet_cnt, frame_cnt;
492 
493  timestamp = FFMAX(timestamp, 0);
494 
495  if (caf->frames_per_packet > 0 && caf->bytes_per_packet > 0) {
496  /* calculate new byte position based on target frame position */
497  pos = caf->bytes_per_packet * (timestamp / caf->frames_per_packet);
498  if (caf->data_size > 0)
499  pos = FFMIN(pos, caf->data_size);
500  packet_cnt = pos / caf->bytes_per_packet;
501  frame_cnt = caf->frames_per_packet * packet_cnt;
502  } else if (sti->nb_index_entries) {
503  packet_cnt = av_index_search_timestamp(st, timestamp, flags);
504  frame_cnt = sti->index_entries[packet_cnt].timestamp;
505  pos = sti->index_entries[packet_cnt].pos;
506  } else {
507  return -1;
508  }
509 
510  if (avio_seek(s->pb, pos + caf->data_start, SEEK_SET) < 0)
511  return -1;
512 
513  caf->packet_cnt = packet_cnt;
514  caf->frame_cnt = frame_cnt;
515 
516  return 0;
517 }
518 
520  .p.name = "caf",
521  .p.long_name = NULL_IF_CONFIG_SMALL("Apple CAF (Core Audio Format)"),
522  .p.codec_tag = ff_caf_codec_tags_list,
523  .priv_data_size = sizeof(CafContext),
524  .read_probe = probe,
527  .read_seek = read_seek,
528 };
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
AVCodecParameters::extradata
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:69
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
CafContext::packet_cnt
int64_t packet_cnt
packet counter
Definition: cafdec.c:47
read_info_chunk
static void read_info_chunk(AVFormatContext *s, int64_t size)
Read information chunk.
Definition: cafdec.c:286
caf.h
CAF_MAX_PKT_SIZE
#define CAF_MAX_PKT_SIZE
Definition: cafdec.c:426
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
av_int2double
static av_always_inline double av_int2double(uint64_t i)
Reinterpret a 64-bit integer as a double.
Definition: intfloat.h:60
AV_CODEC_ID_ALAC
@ AV_CODEC_ID_ALAC
Definition: codec_id.h:456
AVIOContext::error
int error
contains the error code or 0 if no error happened
Definition: avio.h:239
AVCodecParameters::codec_tag
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: codec_par.h:59
AV_CODEC_ID_FLAC
@ AV_CODEC_ID_FLAC
Definition: codec_id.h:452
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:313
intfloat.h
AVIndexEntry
Definition: avformat.h:602
AVINDEX_KEYFRAME
#define AVINDEX_KEYFRAME
Definition: avformat.h:610
ff_get_extradata
int ff_get_extradata(void *logctx, AVCodecParameters *par, AVIOContext *pb, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0 and f...
Definition: demux_utils.c:335
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:463
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:853
ffstream
static av_always_inline FFStream * ffstream(AVStream *st)
Definition: internal.h:417
av_add_index_entry
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
Definition: seek.c:121
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:494
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:802
read_desc_chunk
static int read_desc_chunk(AVFormatContext *s)
Read audio description chunk.
Definition: cafdec.c:68
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:761
pkt
AVPacket * pkt
Definition: movenc.c:60
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
ff_mov_read_esds
int ff_mov_read_esds(AVFormatContext *fc, AVIOContext *pb)
Definition: mov_esds.c:23
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:553
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:453
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AVIndexEntry::timestamp
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
Definition: avformat.h:604
key
const char * key
Definition: hwcontext_opencl.c:189
CafContext::data_size
int64_t data_size
raw data size, in bytes
Definition: cafdec.c:51
ff_mov_get_lpcm_codec_id
static enum AVCodecID ff_mov_get_lpcm_codec_id(int bps, int flags)
Compute codec id for 'lpcm' tag.
Definition: isom.h:438
AVFormatContext
Format I/O context.
Definition: avformat.h:1255
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:766
NULL
#define NULL
Definition: coverity.c:32
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:64
read_header
static int read_header(AVFormatContext *s)
Definition: cafdec.c:302
isom.h
flac_parse_block_header
static av_always_inline void flac_parse_block_header(const uint8_t *block_header, int *last, int *type, int *size)
Parse the metadata block parameters from the header.
Definition: flac.h:63
ALAC_PREAMBLE
#define ALAC_PREAMBLE
avio_rb64
uint64_t avio_rb64(AVIOContext *s)
Definition: aviobuf.c:908
CafContext::data_start
int64_t data_start
data start position, in bytes
Definition: cafdec.c:50
FFStream::nb_index_entries
int nb_index_entries
Definition: internal.h:251
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:451
FLAC_STREAMINFO_SIZE
#define FLAC_STREAMINFO_SIZE
Definition: flac.h:32
read_kuki_chunk
static int read_kuki_chunk(AVFormatContext *s, int64_t size)
Read magic cookie chunk.
Definition: cafdec.c:111
AVCodecParameters::ch_layout
AVChannelLayout ch_layout
Audio only.
Definition: codec_par.h:180
ff_caf_demuxer
const FFInputFormat ff_caf_demuxer
Definition: cafdec.c:519
CafContext::num_bytes
int64_t num_bytes
total number of bytes in stream
Definition: cafdec.c:45
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:184
AVStream::nb_frames
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:804
AV_WB32
#define AV_WB32(p, v)
Definition: intreadwrite.h:417
AV_CODEC_ID_AAC
@ AV_CODEC_ID_AAC
Definition: codec_id.h:442
read_seek
static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: cafdec.c:485
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:730
ALAC_NEW_KUKI
#define ALAC_NEW_KUKI
AVIOContext
Bytestream IO Context.
Definition: avio.h:160
avio_rb24
unsigned int avio_rb24(AVIOContext *s)
Definition: aviobuf.c:754
AVPacket::size
int size
Definition: packet.h:525
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:94
ff_codec_get_id
enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
Definition: utils.c:133
AVIOContext::seekable
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:261
FFStream
Definition: internal.h:193
av_bswap32
#define av_bswap32
Definition: bswap.h:28
CafContext::bytes_per_packet
int bytes_per_packet
bytes in a packet, or 0 if variable
Definition: cafdec.c:43
avio_get_str
int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen)
Read a string from pb into buf.
Definition: aviobuf.c:866
size
int size
Definition: twinvq_data.h:10344
CafContext::frames_per_packet
int frames_per_packet
frames in a packet, or 0 if variable
Definition: cafdec.c:44
MKBETAG
#define MKBETAG(a, b, c, d)
Definition: macros.h:56
AV_RB32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:96
AV_CODEC_ID_OPUS
@ AV_CODEC_ID_OPUS
Definition: codec_id.h:500
FFInputFormat::p
AVInputFormat p
The public AVInputFormat.
Definition: demux.h:41
AVPacket::dts
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:523
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:603
ff_mp4_read_descr_len
int ff_mp4_read_descr_len(AVIOContext *pb)
Definition: isom.c:282
CafContext
Definition: cafdec.c:42
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:517
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:191
value
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default value
Definition: writing_filters.txt:86
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
ff_codec_caf_tags
const AVCodecTag ff_codec_caf_tags[]
Known codec tags for CAF.
Definition: caf.c:34
demux.h
av_get_packet
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:91
mov_chan.h
tag
uint32_t tag
Definition: movenc.c:1851
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:743
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:231
pos
unsigned int pos
Definition: spdifenc.c:414
avformat.h
dict.h
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: defs.h:40
left
Tag MUST be and< 10hcoeff half pel interpolation filter coefficients, hcoeff[0] are the 2 middle coefficients[1] are the next outer ones and so on, resulting in a filter like:...eff[2], hcoeff[1], hcoeff[0], hcoeff[0], hcoeff[1], hcoeff[2] ... the sign of the coefficients is not explicitly stored but alternates after each coeff and coeff[0] is positive, so ...,+,-,+,-,+,+,-,+,-,+,... hcoeff[0] is not explicitly stored but found by subtracting the sum of all stored coefficients with signs from 32 hcoeff[0]=32 - hcoeff[1] - hcoeff[2] - ... a good choice for hcoeff and htaps is htaps=6 hcoeff={40,-10, 2} an alternative which requires more computations at both encoder and decoder side and may or may not be better is htaps=8 hcoeff={42,-14, 6,-2}ref_frames minimum of the number of available reference frames and max_ref_frames for example the first frame after a key frame always has ref_frames=1spatial_decomposition_type wavelet type 0 is a 9/7 symmetric compact integer wavelet 1 is a 5/3 symmetric compact integer wavelet others are reserved stored as delta from last, last is reset to 0 if always_reset||keyframeqlog quality(logarithmic quantizer scale) stored as delta from last, last is reset to 0 if always_reset||keyframemv_scale stored as delta from last, last is reset to 0 if always_reset||keyframe FIXME check that everything works fine if this changes between framesqbias dequantization bias stored as delta from last, last is reset to 0 if always_reset||keyframeblock_max_depth maximum depth of the block tree stored as delta from last, last is reset to 0 if always_reset||keyframequant_table quantization tableHighlevel bitstream structure:==============================--------------------------------------------|Header|--------------------------------------------|------------------------------------|||Block0||||split?||||yes no||||......... intra?||||:Block01 :yes no||||:Block02 :....... ..........||||:Block03 ::y DC ::ref index:||||:Block04 ::cb DC ::motion x :||||......... :cr DC ::motion y :||||....... ..........|||------------------------------------||------------------------------------|||Block1|||...|--------------------------------------------|------------ ------------ ------------|||Y subbands||Cb subbands||Cr subbands||||--- ---||--- ---||--- ---|||||LL0||HL0||||LL0||HL0||||LL0||HL0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||LH0||HH0||||LH0||HH0||||LH0||HH0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HL1||LH1||||HL1||LH1||||HL1||LH1|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HH1||HL2||||HH1||HL2||||HH1||HL2|||||...||...||...|||------------ ------------ ------------|--------------------------------------------Decoding process:=================------------|||Subbands|------------||||------------|Intra DC||||LL0 subband prediction ------------|\ Dequantization ------------------- \||Reference frames|\ IDWT|------- -------|Motion \|||Frame 0||Frame 1||Compensation . OBMC v -------|------- -------|--------------. \------> Frame n output Frame Frame<----------------------------------/|...|------------------- Range Coder:============Binary Range Coder:------------------- The implemented range coder is an adapted version based upon "Range encoding: an algorithm for removing redundancy from a digitised message." by G. N. N. Martin. The symbols encoded by the Snow range coder are bits(0|1). The associated probabilities are not fix but change depending on the symbol mix seen so far. bit seen|new state ---------+----------------------------------------------- 0|256 - state_transition_table[256 - old_state];1|state_transition_table[old_state];state_transition_table={ 0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 190, 191, 192, 194, 194, 195, 196, 197, 198, 199, 200, 201, 202, 202, 204, 205, 206, 207, 208, 209, 209, 210, 211, 212, 213, 215, 215, 216, 217, 218, 219, 220, 220, 222, 223, 224, 225, 226, 227, 227, 229, 229, 230, 231, 232, 234, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 248, 0, 0, 0, 0, 0, 0, 0};FIXME Range Coding of integers:------------------------- FIXME Neighboring Blocks:===================left and top are set to the respective blocks unless they are outside of the image in which case they are set to the Null block top-left is set to the top left block unless it is outside of the image in which case it is set to the left block if this block has no larger parent block or it is at the left side of its parent block and the top right block is not outside of the image then the top right block is used for top-right else the top-left block is used Null block y, cb, cr are 128 level, ref, mx and my are 0 Motion Vector Prediction:=========================1. the motion vectors of all the neighboring blocks are scaled to compensate for the difference of reference frames scaled_mv=(mv *(256 *(current_reference+1)/(mv.reference+1))+128)> the median of the scaled left
Definition: snow.txt:386
ff_caf_codec_tags_list
const AVCodecTag *const ff_caf_codec_tags_list[]
Definition: caf.c:82
AVIO_SEEKABLE_NORMAL
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:41
avio_read
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:612
AVIndexEntry::pos
int64_t pos
Definition: avformat.h:603
AVPacket::stream_index
int stream_index
Definition: packet.h:526
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:318
FFStream::index_entries
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: internal.h:249
read_probe
static int read_probe(const AVProbeData *p)
Definition: cdg.c:30
AVCodecParameters::bits_per_coded_sample
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: codec_par.h:110
mem.h
avpriv_request_sample
#define avpriv_request_sample(...)
Definition: tableprint_vlc.h:36
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
FLAC_METADATA_TYPE_STREAMINFO
@ FLAC_METADATA_TYPE_STREAMINFO
Definition: flac.h:46
AVPacket
This structure stores compressed data.
Definition: packet.h:501
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
av_dict_set
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:88
FFInputFormat
Definition: demux.h:37
CafContext::frame_cnt
int64_t frame_cnt
frame counter
Definition: cafdec.c:48
read_packet
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: cafdec.c:428
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
AVCodecParameters::bit_rate
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: codec_par.h:97
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55
AVStream::start_time
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base.
Definition: avformat.h:792
probe
static int probe(const AVProbeData *p)
Definition: cafdec.c:54
flac.h
ALAC_HEADER
#define ALAC_HEADER
skip
static void BS_FUNC() skip(BSCTX *bc, unsigned int n)
Skip n bits in the buffer.
Definition: bitstream_template.h:375
AV_RB64
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_RB64
Definition: bytestream.h:95
av_clipd
av_clipd
Definition: af_crystalizer.c:131
AV_RB16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:98
av_fourcc2str
#define av_fourcc2str(fourcc)
Definition: avutil.h:345
ff_mov_read_chan
int ff_mov_read_chan(AVFormatContext *s, AVIOContext *pb, AVStream *st, int64_t size)
Read 'chan' tag from the input stream.
Definition: mov_chan.c:526
av_index_search_timestamp
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: seek.c:244
ff_alloc_extradata
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0.
Definition: utils.c:227
read_pakt_chunk
static int read_pakt_chunk(AVFormatContext *s, int64_t size)
Read packet table chunk.
Definition: cafdec.c:240
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:346