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 "caf.h"
40 
41 typedef struct CafContext {
42  int bytes_per_packet; ///< bytes in a packet, or 0 if variable
43  int frames_per_packet; ///< frames in a packet, or 0 if variable
44  int64_t num_bytes; ///< total number of bytes in stream
45 
46  int64_t packet_cnt; ///< packet counter
47  int64_t frame_cnt; ///< frame counter
48 
49  int64_t data_start; ///< data start position, in bytes
50  int64_t data_size; ///< raw data size, in bytes
51 } CafContext;
52 
53 static int probe(const AVProbeData *p)
54 {
55  if (AV_RB32(p->buf) == MKBETAG('c','a','f','f') && AV_RB16(&p->buf[4]) == 1)
56  return AVPROBE_SCORE_MAX;
57  return 0;
58 }
59 
60 /** Read audio description chunk */
62 {
63  AVIOContext *pb = s->pb;
64  CafContext *caf = s->priv_data;
65  AVStream *st;
66  int flags;
67 
68  /* new audio stream */
69  st = avformat_new_stream(s, NULL);
70  if (!st)
71  return AVERROR(ENOMEM);
72 
73  /* parse format description */
75  st->codecpar->sample_rate = av_clipd(av_int2double(avio_rb64(pb)), 0, INT_MAX);
76  st->codecpar->codec_tag = avio_rl32(pb);
77  flags = avio_rb32(pb);
78  caf->bytes_per_packet = avio_rb32(pb);
80  caf->frames_per_packet = avio_rb32(pb);
83 
84  if (caf->bytes_per_packet < 0 || caf->frames_per_packet < 0 || st->codecpar->ch_layout.nb_channels < 0)
85  return AVERROR_INVALIDDATA;
86 
87  /* calculate bit rate for constant size packets */
88  if (caf->frames_per_packet > 0 && caf->bytes_per_packet > 0) {
89  st->codecpar->bit_rate = (uint64_t)st->codecpar->sample_rate * (uint64_t)caf->bytes_per_packet * 8
90  / (uint64_t)caf->frames_per_packet;
91  } else {
92  st->codecpar->bit_rate = 0;
93  }
94 
95  /* determine codec */
96  if (st->codecpar->codec_tag == MKTAG('l','p','c','m'))
98  else
100  return 0;
101 }
102 
103 /** Read magic cookie chunk */
104 static int read_kuki_chunk(AVFormatContext *s, int64_t size)
105 {
106  AVIOContext *pb = s->pb;
107  AVStream *st = s->streams[0];
108  int ret;
109 
110  if (size < 0 || size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE)
111  return -1;
112 
113  if (st->codecpar->codec_id == AV_CODEC_ID_AAC) {
114  /* The magic cookie format for AAC is an mp4 esds atom.
115  The lavc AAC decoder requires the data from the codec specific
116  description as extradata input. */
117  int strt, skip;
118 
119  strt = avio_tell(pb);
120  ff_mov_read_esds(s, pb);
121  skip = size - (avio_tell(pb) - strt);
122  if (skip < 0 || !st->codecpar->extradata ||
124  av_log(s, AV_LOG_ERROR, "invalid AAC magic cookie\n");
125  return AVERROR_INVALIDDATA;
126  }
127  avio_skip(pb, skip);
128  } else if (st->codecpar->codec_id == AV_CODEC_ID_ALAC) {
129 #define ALAC_PREAMBLE 12
130 #define ALAC_HEADER 36
131 #define ALAC_NEW_KUKI 24
132  uint8_t preamble[12];
133  if (size < ALAC_NEW_KUKI) {
134  av_log(s, AV_LOG_ERROR, "invalid ALAC magic cookie\n");
135  avio_skip(pb, size);
136  return AVERROR_INVALIDDATA;
137  }
138  if (avio_read(pb, preamble, ALAC_PREAMBLE) != ALAC_PREAMBLE) {
139  av_log(s, AV_LOG_ERROR, "failed to read preamble\n");
140  return AVERROR_INVALIDDATA;
141  }
142 
143  if ((ret = ff_alloc_extradata(st->codecpar, ALAC_HEADER)) < 0)
144  return ret;
145 
146  /* For the old style cookie, we skip 12 bytes, then read 36 bytes.
147  * The new style cookie only contains the last 24 bytes of what was
148  * 36 bytes in the old style cookie, so we fabricate the first 12 bytes
149  * in that case to maintain compatibility. */
150  if (!memcmp(&preamble[4], "frmaalac", 8)) {
151  if (size < ALAC_PREAMBLE + ALAC_HEADER) {
152  av_log(s, AV_LOG_ERROR, "invalid ALAC magic cookie\n");
153  av_freep(&st->codecpar->extradata);
154  return AVERROR_INVALIDDATA;
155  }
156  if (avio_read(pb, st->codecpar->extradata, ALAC_HEADER) != ALAC_HEADER) {
157  av_log(s, AV_LOG_ERROR, "failed to read kuki header\n");
158  av_freep(&st->codecpar->extradata);
159  return AVERROR_INVALIDDATA;
160  }
162  } else {
163  AV_WB32(st->codecpar->extradata, 36);
164  memcpy(&st->codecpar->extradata[4], "alac", 4);
165  AV_WB32(&st->codecpar->extradata[8], 0);
166  memcpy(&st->codecpar->extradata[12], preamble, 12);
167  if (avio_read(pb, &st->codecpar->extradata[24], ALAC_NEW_KUKI - 12) != ALAC_NEW_KUKI - 12) {
168  av_log(s, AV_LOG_ERROR, "failed to read new kuki header\n");
169  av_freep(&st->codecpar->extradata);
170  return AVERROR_INVALIDDATA;
171  }
173  }
174  } else if (st->codecpar->codec_id == AV_CODEC_ID_FLAC) {
175  int last, type, flac_metadata_size;
176  uint8_t buf[4];
177  /* The magic cookie format for FLAC consists mostly of an mp4 dfLa atom. */
178  if (size < (16 + FLAC_STREAMINFO_SIZE)) {
179  av_log(s, AV_LOG_ERROR, "invalid FLAC magic cookie\n");
180  return AVERROR_INVALIDDATA;
181  }
182  /* Check cookie version. */
183  if (avio_r8(pb) != 0) {
184  av_log(s, AV_LOG_ERROR, "unknown FLAC magic cookie\n");
185  return AVERROR_INVALIDDATA;
186  }
187  avio_rb24(pb); /* Flags */
188  /* read dfLa fourcc */
189  if (avio_read(pb, buf, 4) != 4) {
190  av_log(s, AV_LOG_ERROR, "failed to read FLAC magic cookie\n");
191  return pb->error < 0 ? pb->error : AVERROR_INVALIDDATA;
192  }
193  if (memcmp(buf, "dfLa", 4)) {
194  av_log(s, AV_LOG_ERROR, "invalid FLAC magic cookie\n");
195  return AVERROR_INVALIDDATA;
196  }
197  /* Check dfLa version. */
198  if (avio_r8(pb) != 0) {
199  av_log(s, AV_LOG_ERROR, "unknown dfLa version\n");
200  return AVERROR_INVALIDDATA;
201  }
202  avio_rb24(pb); /* Flags */
203  if (avio_read(pb, buf, sizeof(buf)) != sizeof(buf)) {
204  av_log(s, AV_LOG_ERROR, "failed to read FLAC metadata block header\n");
205  return pb->error < 0 ? pb->error : AVERROR_INVALIDDATA;
206  }
207  flac_parse_block_header(buf, &last, &type, &flac_metadata_size);
208  if (type != FLAC_METADATA_TYPE_STREAMINFO || flac_metadata_size != FLAC_STREAMINFO_SIZE) {
209  av_log(s, AV_LOG_ERROR, "STREAMINFO must be first FLACMetadataBlock\n");
210  return AVERROR_INVALIDDATA;
211  }
213  if (ret < 0)
214  return ret;
215  if (!last)
216  av_log(s, AV_LOG_WARNING, "non-STREAMINFO FLACMetadataBlock(s) ignored\n");
217  } else if (st->codecpar->codec_id == AV_CODEC_ID_OPUS) {
218  // The data layout for Opus is currently unknown, so we do not export
219  // extradata at all. Multichannel streams are not supported.
220  if (st->codecpar->ch_layout.nb_channels > 2) {
221  avpriv_request_sample(s, "multichannel Opus in CAF");
222  return AVERROR_PATCHWELCOME;
223  }
224  avio_skip(pb, size);
225  } else if ((ret = ff_get_extradata(s, st->codecpar, pb, size)) < 0) {
226  return ret;
227  }
228 
229  return 0;
230 }
231 
232 /** Read packet table chunk */
233 static int read_pakt_chunk(AVFormatContext *s, int64_t size)
234 {
235  AVIOContext *pb = s->pb;
236  AVStream *st = s->streams[0];
237  CafContext *caf = s->priv_data;
238  int64_t pos = 0, ccount, num_packets;
239  int i;
240  int ret;
241 
242  ccount = avio_tell(pb);
243 
244  num_packets = avio_rb64(pb);
245  if (num_packets < 0 || INT32_MAX / sizeof(AVIndexEntry) < num_packets)
246  return AVERROR_INVALIDDATA;
247 
248  st->nb_frames = avio_rb64(pb); /* valid frames */
249  st->nb_frames += avio_rb32(pb); /* priming frames */
250  st->nb_frames += avio_rb32(pb); /* remainder frames */
251 
252  if (caf->bytes_per_packet > 0 && caf->frames_per_packet > 0) {
253  st->duration = caf->frames_per_packet * num_packets;
254  pos = caf-> bytes_per_packet * num_packets;
255  } else {
256  st->duration = 0;
257  for (i = 0; i < num_packets; i++) {
258  if (avio_feof(pb))
259  return AVERROR_INVALIDDATA;
260  ret = av_add_index_entry(s->streams[0], pos, st->duration, 0, 0, AVINDEX_KEYFRAME);
261  if (ret < 0)
262  return ret;
265  }
266  }
267 
268  if (avio_tell(pb) - ccount > size) {
269  av_log(s, AV_LOG_ERROR, "error reading packet table\n");
270  return AVERROR_INVALIDDATA;
271  }
272  avio_seek(pb, ccount + size, SEEK_SET);
273 
274  caf->num_bytes = pos;
275  return 0;
276 }
277 
278 /** Read information chunk */
279 static void read_info_chunk(AVFormatContext *s, int64_t size)
280 {
281  AVIOContext *pb = s->pb;
282  unsigned int i;
283  unsigned int nb_entries = avio_rb32(pb);
284  for (i = 0; i < nb_entries && !avio_feof(pb); i++) {
285  char key[32];
286  char value[1024];
287  avio_get_str(pb, INT_MAX, key, sizeof(key));
288  avio_get_str(pb, INT_MAX, value, sizeof(value));
289  if (!*key)
290  continue;
291  av_dict_set(&s->metadata, key, value, 0);
292  }
293 }
294 
296 {
297  AVIOContext *pb = s->pb;
298  CafContext *caf = s->priv_data;
299  AVStream *st;
300  uint32_t tag = 0;
301  int found_data, ret;
302  int64_t size, pos;
303 
304  avio_skip(pb, 8); /* magic, version, file flags */
305 
306  /* audio description chunk */
307  if (avio_rb32(pb) != MKBETAG('d','e','s','c')) {
308  av_log(s, AV_LOG_ERROR, "desc chunk not present\n");
309  return AVERROR_INVALIDDATA;
310  }
311  size = avio_rb64(pb);
312  if (size != 32)
313  return AVERROR_INVALIDDATA;
314 
315  ret = read_desc_chunk(s);
316  if (ret)
317  return ret;
318  st = s->streams[0];
319 
320  /* parse each chunk */
321  found_data = 0;
322  while (!avio_feof(pb)) {
323 
324  /* stop at data chunk if seeking is not supported or
325  data chunk size is unknown */
326  if (found_data && (caf->data_size < 0 || !(pb->seekable & AVIO_SEEKABLE_NORMAL)))
327  break;
328 
329  tag = avio_rb32(pb);
330  size = avio_rb64(pb);
331  pos = avio_tell(pb);
332  if (avio_feof(pb))
333  break;
334 
335  switch (tag) {
336  case MKBETAG('d','a','t','a'):
337  avio_skip(pb, 4); /* edit count */
338  caf->data_start = avio_tell(pb);
339  caf->data_size = size < 0 ? -1 : size - 4;
340  if (caf->data_size > 0 && (pb->seekable & AVIO_SEEKABLE_NORMAL))
341  avio_skip(pb, caf->data_size);
342  found_data = 1;
343  break;
344 
345  case MKBETAG('c','h','a','n'):
346  if ((ret = ff_mov_read_chan(s, s->pb, st, size)) < 0)
347  return ret;
348  break;
349 
350  /* magic cookie chunk */
351  case MKBETAG('k','u','k','i'):
352  if (read_kuki_chunk(s, size))
353  return AVERROR_INVALIDDATA;
354  break;
355 
356  /* packet table chunk */
357  case MKBETAG('p','a','k','t'):
358  if (read_pakt_chunk(s, size))
359  return AVERROR_INVALIDDATA;
360  break;
361 
362  case MKBETAG('i','n','f','o'):
364  break;
365 
366  default:
368  "skipping CAF chunk: %08"PRIX32" (%s), size %"PRId64"\n",
370  case MKBETAG('f','r','e','e'):
371  if (size < 0 && found_data)
372  goto found_data;
373  if (size < 0)
374  return AVERROR_INVALIDDATA;
375  break;
376  }
377 
378  if (size > 0 && (pb->seekable & AVIO_SEEKABLE_NORMAL)) {
379  if (pos > INT64_MAX - size)
380  return AVERROR_INVALIDDATA;
381  avio_seek(pb, pos + size, SEEK_SET);
382  }
383  }
384 
385  if (!found_data)
386  return AVERROR_INVALIDDATA;
387 
388 found_data:
389  if (caf->bytes_per_packet > 0 && caf->frames_per_packet > 0) {
390  if (caf->data_size > 0 && caf->data_size / caf->bytes_per_packet < INT64_MAX / caf->frames_per_packet)
391  st->nb_frames = (caf->data_size / caf->bytes_per_packet) * caf->frames_per_packet;
392  } else if (ffstream(st)->nb_index_entries && st->duration > 0) {
393  if (st->codecpar->sample_rate && caf->data_size / st->duration > INT64_MAX / st->codecpar->sample_rate / 8) {
394  av_log(s, AV_LOG_ERROR, "Overflow during bit rate calculation %d * 8 * %"PRId64"\n",
395  st->codecpar->sample_rate, caf->data_size / st->duration);
396  return AVERROR_INVALIDDATA;
397  }
398  st->codecpar->bit_rate = st->codecpar->sample_rate * 8LL *
399  (caf->data_size / st->duration);
400  } else {
401  av_log(s, AV_LOG_ERROR, "Missing packet table. It is required when "
402  "block size or frame size are variable.\n");
403  return AVERROR_INVALIDDATA;
404  }
405 
406  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
407  st->start_time = 0;
408 
409  /* position the stream at the start of data */
410  if (caf->data_size >= 0)
411  avio_seek(pb, caf->data_start, SEEK_SET);
412 
413  return 0;
414 }
415 
416 #define CAF_MAX_PKT_SIZE 4096
417 
419 {
420  AVIOContext *pb = s->pb;
421  AVStream *st = s->streams[0];
422  FFStream *const sti = ffstream(st);
423  CafContext *caf = s->priv_data;
424  int res, pkt_size = 0, pkt_frames = 0;
425  int64_t left = CAF_MAX_PKT_SIZE;
426 
427  if (avio_feof(pb))
428  return AVERROR_EOF;
429 
430  /* don't read past end of data chunk */
431  if (caf->data_size > 0) {
432  left = (caf->data_start + caf->data_size) - avio_tell(pb);
433  if (!left)
434  return AVERROR_EOF;
435  if (left < 0)
436  return AVERROR(EIO);
437  }
438 
439  pkt_frames = caf->frames_per_packet;
440  pkt_size = caf->bytes_per_packet;
441 
442  if (pkt_size > 0 && pkt_frames == 1) {
443  pkt_size = (CAF_MAX_PKT_SIZE / pkt_size) * pkt_size;
444  pkt_size = FFMIN(pkt_size, left);
445  pkt_frames = pkt_size / caf->bytes_per_packet;
446  } else if (sti->nb_index_entries) {
447  if (caf->packet_cnt < sti->nb_index_entries - 1) {
448  pkt_size = sti->index_entries[caf->packet_cnt + 1].pos - sti->index_entries[caf->packet_cnt].pos;
449  pkt_frames = sti->index_entries[caf->packet_cnt + 1].timestamp - sti->index_entries[caf->packet_cnt].timestamp;
450  } else if (caf->packet_cnt == sti->nb_index_entries - 1) {
451  pkt_size = caf->num_bytes - sti->index_entries[caf->packet_cnt].pos;
452  pkt_frames = st->duration - sti->index_entries[caf->packet_cnt].timestamp;
453  } else {
454  return AVERROR(EIO);
455  }
456  }
457 
458  if (pkt_size == 0 || pkt_frames == 0 || pkt_size > left)
459  return AVERROR(EIO);
460 
461  res = av_get_packet(pb, pkt, pkt_size);
462  if (res < 0)
463  return res;
464 
465  pkt->size = res;
466  pkt->stream_index = 0;
467  pkt->dts = pkt->pts = caf->frame_cnt;
468 
469  caf->packet_cnt++;
470  caf->frame_cnt += pkt_frames;
471 
472  return 0;
473 }
474 
475 static int read_seek(AVFormatContext *s, int stream_index,
476  int64_t timestamp, int flags)
477 {
478  AVStream *st = s->streams[0];
479  FFStream *const sti = ffstream(st);
480  CafContext *caf = s->priv_data;
481  int64_t pos, packet_cnt, frame_cnt;
482 
483  timestamp = FFMAX(timestamp, 0);
484 
485  if (caf->frames_per_packet > 0 && caf->bytes_per_packet > 0) {
486  /* calculate new byte position based on target frame position */
487  pos = caf->bytes_per_packet * (timestamp / caf->frames_per_packet);
488  if (caf->data_size > 0)
489  pos = FFMIN(pos, caf->data_size);
490  packet_cnt = pos / caf->bytes_per_packet;
491  frame_cnt = caf->frames_per_packet * packet_cnt;
492  } else if (sti->nb_index_entries) {
493  packet_cnt = av_index_search_timestamp(st, timestamp, flags);
494  frame_cnt = sti->index_entries[packet_cnt].timestamp;
495  pos = sti->index_entries[packet_cnt].pos;
496  } else {
497  return -1;
498  }
499 
500  if (avio_seek(s->pb, pos + caf->data_start, SEEK_SET) < 0)
501  return -1;
502 
503  caf->packet_cnt = packet_cnt;
504  caf->frame_cnt = frame_cnt;
505 
506  return 0;
507 }
508 
510  .name = "caf",
511  .long_name = NULL_IF_CONFIG_SMALL("Apple CAF (Core Audio Format)"),
512  .priv_data_size = sizeof(CafContext),
513  .read_probe = probe,
516  .read_seek = read_seek,
517  .codec_tag = ff_caf_codec_tags_list,
518 };
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:76
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
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: options.c:237
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:58
CafContext::packet_cnt
int64_t packet_cnt
packet counter
Definition: cafdec.c:46
read_info_chunk
static void read_info_chunk(AVFormatContext *s, int64_t size)
Read information chunk.
Definition: cafdec.c:279
caf.h
CAF_MAX_PKT_SIZE
#define CAF_MAX_PKT_SIZE
Definition: cafdec.c:416
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:451
AVIOContext::error
int error
contains the error code or 0 if no error happened
Definition: avio.h:245
AVCodecParameters::codec_tag
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: codec_par.h:66
AV_CODEC_ID_FLAC
@ AV_CODEC_ID_FLAC
Definition: codec_id.h:447
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:311
intfloat.h
AVIndexEntry
Definition: avformat.h:807
AVINDEX_KEYFRAME
#define AVINDEX_KEYFRAME
Definition: avformat.h:815
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:355
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:465
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:763
ffstream
static av_always_inline FFStream * ffstream(AVStream *st)
Definition: internal.h:413
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:120
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:510
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
ff_caf_demuxer
const AVInputFormat ff_caf_demuxer
Definition: cafdec.c:509
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:998
read_desc_chunk
static int read_desc_chunk(AVFormatContext *s)
Read audio description chunk.
Definition: cafdec.c:61
av_bswap32
#define av_bswap32
Definition: bswap.h:33
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:792
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
AVInputFormat
Definition: avformat.h:656
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:256
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:661
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:455
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:809
key
const char * key
Definition: hwcontext_opencl.c:174
CafContext::data_size
int64_t data_size
raw data size, in bytes
Definition: cafdec.c:50
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:408
AVFormatContext
Format I/O context.
Definition: avformat.h:1216
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1108
NULL
#define NULL
Definition: coverity.c:32
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:64
read_probe
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
read_header
static int read_header(AVFormatContext *s)
Definition: cafdec.c:295
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:939
CafContext::data_start
int64_t data_start
data start position, in bytes
Definition: cafdec.c:49
FFStream::nb_index_entries
int nb_index_entries
Definition: internal.h:253
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:453
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:104
AVCodecParameters::ch_layout
AVChannelLayout ch_layout
Audio only.
Definition: codec_par.h:213
CafContext::num_bytes
int64_t num_bytes
total number of bytes in stream
Definition: cafdec.c:44
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:178
AVStream::nb_frames
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:1000
AV_WB32
#define AV_WB32(p, v)
Definition: intreadwrite.h:419
AV_CODEC_ID_AAC
@ AV_CODEC_ID_AAC
Definition: codec_id.h:437
read_seek
static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: cafdec.c:475
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:761
ALAC_NEW_KUKI
#define ALAC_NEW_KUKI
AVIOContext
Bytestream IO Context.
Definition: avio.h:166
avio_rb24
unsigned int avio_rb24(AVIOContext *s)
Definition: aviobuf.c:785
AVPacket::size
int size
Definition: packet.h:375
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:115
ff_codec_get_id
enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
Definition: utils.c:144
AVIOContext::seekable
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:267
FFStream
Definition: internal.h:196
CafContext::bytes_per_packet
int bytes_per_packet
bytes in a packet, or 0 if variable
Definition: cafdec.c:42
FLAC_METADATA_TYPE_STREAMINFO
@ FLAC_METADATA_TYPE_STREAMINFO
Definition: flac.h:46
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:897
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:43
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:495
AVPacket::dts
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:373
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:634
ff_mp4_read_descr_len
int ff_mp4_read_descr_len(AVIOContext *pb)
Definition: isom.c:281
CafContext
Definition: cafdec.c:41
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:367
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:185
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:102
mov_chan.h
tag
uint32_t tag
Definition: movenc.c:1647
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:948
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:262
pos
unsigned int pos
Definition: spdifenc.c:412
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:643
AVIndexEntry::pos
int64_t pos
Definition: avformat.h:808
AVPacket::stream_index
int stream_index
Definition: packet.h:376
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:349
FFStream::index_entries
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: internal.h:251
AVCodecParameters::bits_per_coded_sample
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: codec_par.h:104
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:62
AVPacket
This structure stores compressed data.
Definition: packet.h:351
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:86
CafContext::frame_cnt
int64_t frame_cnt
frame counter
Definition: cafdec.c:47
read_packet
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: cafdec.c:418
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
AVCodecParameters::bit_rate
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: codec_par.h:91
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:988
probe
static int probe(const AVProbeData *p)
Definition: cafdec.c:53
flac.h
ALAC_HEADER
#define ALAC_HEADER
av_clipd
av_clipd
Definition: af_crystalizer.c:132
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:354
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:496
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:240
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:238
read_pakt_chunk
static int read_pakt_chunk(AVFormatContext *s, int64_t size)
Read packet table chunk.
Definition: cafdec.c:233
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:377