FFmpeg
aadec.c
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1 /*
2  * Audible AA demuxer
3  * Copyright (c) 2015 Vesselin Bontchev
4  *
5  * Header parsing is borrowed from https://github.com/jteeuwen/audible project.
6  * Copyright (c) 2001-2014, Jim Teeuwen
7  *
8  * Redistribution and use in source and binary forms, with or without modification,
9  * are permitted provided that the following conditions are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright notice, this
12  * list of conditions and the following disclaimer.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
18  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
21  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
23  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include "avformat.h"
27 #include "demux.h"
28 #include "internal.h"
29 #include "libavutil/avstring.h"
30 #include "libavutil/dict.h"
31 #include "libavutil/intreadwrite.h"
32 #include "libavutil/tea.h"
33 #include "libavutil/opt.h"
34 
35 #define AA_MAGIC 1469084982 /* this identifies an audible .aa file */
36 #define MAX_TOC_ENTRIES 16
37 #define MAX_DICTIONARY_ENTRIES 128
38 #define TEA_BLOCK_SIZE 8
39 #define CHAPTER_HEADER_SIZE 8
40 #define TIMEPREC 1000
41 #define MP3_FRAME_SIZE 104
42 
43 typedef struct AADemuxContext {
44  AVClass *class;
45  uint8_t *aa_fixed_key;
50  struct AVTEA *tea_ctx;
51  uint8_t file_key[16];
53  int64_t content_start;
54  int64_t content_end;
57 
58 static int get_second_size(char *codec_name)
59 {
60  int result = -1;
61 
62  if (!strcmp(codec_name, "mp332")) {
63  result = 3982;
64  } else if (!strcmp(codec_name, "acelp16")) {
65  result = 2000;
66  } else if (!strcmp(codec_name, "acelp85")) {
67  result = 1045;
68  }
69 
70  return result;
71 }
72 
74 {
75  int largest_idx = -1;
76  uint32_t toc_size, npairs, header_seed = 0, start;
77  char codec_name[64] = {0};
78  uint8_t buf[24];
79  int64_t largest_size = -1, current_size = -1, chapter_pos;
80  struct toc_entry {
81  uint32_t offset;
82  uint32_t size;
83  } TOC[MAX_TOC_ENTRIES];
84  uint8_t header_key[16] = {0};
85  AADemuxContext *c = s->priv_data;
86  char file_key[2 * sizeof(c->file_key) + 1];
87  AVIOContext *pb = s->pb;
88  AVStream *st;
89  FFStream *sti;
90  int ret;
91 
92  /* parse .aa header */
93  avio_skip(pb, 4); // file size
94  avio_skip(pb, 4); // magic string
95  toc_size = avio_rb32(pb); // TOC size
96  avio_skip(pb, 4); // unidentified integer
97  if (toc_size > MAX_TOC_ENTRIES || toc_size < 2)
98  return AVERROR_INVALIDDATA;
99  for (uint32_t i = 0; i < toc_size; i++) { // read TOC
100  avio_skip(pb, 4); // TOC entry index
101  TOC[i].offset = avio_rb32(pb); // block offset
102  TOC[i].size = avio_rb32(pb); // block size
103  }
104  avio_skip(pb, 24); // header termination block (ignored)
105  npairs = avio_rb32(pb); // read dictionary entries
106  if (npairs > MAX_DICTIONARY_ENTRIES)
107  return AVERROR_INVALIDDATA;
108  for (uint32_t i = 0; i < npairs; i++) {
109  char key[128], val[128];
110  uint32_t nkey, nval;
111 
112  avio_skip(pb, 1); // unidentified integer
113  nkey = avio_rb32(pb); // key string length
114  nval = avio_rb32(pb); // value string length
115  avio_get_str(pb, nkey, key, sizeof(key));
116  avio_get_str(pb, nval, val, sizeof(val));
117  if (!strcmp(key, "codec")) {
118  av_log(s, AV_LOG_DEBUG, "Codec is <%s>\n", val);
119  av_strlcpy(codec_name, val, sizeof(codec_name));
120  } else if (!strcmp(key, "HeaderSeed")) {
121  av_log(s, AV_LOG_DEBUG, "HeaderSeed is <%s>\n", val);
122  header_seed = atoi(val);
123  } else if (!strcmp(key, "HeaderKey")) { // this looks like "1234567890 1234567890 1234567890 1234567890"
124  uint32_t header_key_part[4];
125  av_log(s, AV_LOG_DEBUG, "HeaderKey is <%s>\n", val);
126 
127  ret = sscanf(val, "%"SCNu32"%"SCNu32"%"SCNu32"%"SCNu32,
128  &header_key_part[0], &header_key_part[1], &header_key_part[2], &header_key_part[3]);
129  if (ret != 4)
130  return AVERROR_INVALIDDATA;
131 
132  for (int idx = 0; idx < 4; idx++)
133  AV_WB32(&header_key[idx * 4], header_key_part[idx]); // convert each part to BE!
134  ff_data_to_hex(key, header_key, sizeof(header_key), 1);
135  av_log(s, AV_LOG_DEBUG, "Processed HeaderKey is %s\n", key);
136  } else {
137  av_dict_set(&s->metadata, key, val, 0);
138  }
139  }
140 
141  /* verify fixed key */
142  if (c->aa_fixed_key_len != 16) {
143  av_log(s, AV_LOG_ERROR, "aa_fixed_key value needs to be 16 bytes!\n");
144  return AVERROR(EINVAL);
145  }
146 
147  /* verify codec */
148  if ((c->codec_second_size = get_second_size(codec_name)) == -1) {
149  av_log(s, AV_LOG_ERROR, "unknown codec <%s>!\n", codec_name);
150  return AVERROR(EINVAL);
151  }
152 
153  /* decryption key derivation */
154  c->tea_ctx = av_tea_alloc();
155  if (!c->tea_ctx)
156  return AVERROR(ENOMEM);
157  av_tea_init(c->tea_ctx, c->aa_fixed_key, 16);
158  for (int i = 0; i < 6; i++)
159  AV_WB32(buf + 4 * i, header_seed + i);
160  av_tea_crypt(c->tea_ctx, buf, buf, 3, NULL, 0);
161  AV_WN64(c->file_key, AV_RN64(buf + 2) ^ AV_RN64(header_key));
162  AV_WN64(c->file_key + 8, AV_RN64(buf + 10) ^ AV_RN64(header_key + 8));
163  ff_data_to_hex(file_key, c->file_key, sizeof(c->file_key), 1);
164  av_log(s, AV_LOG_DEBUG, "File key is %s\n", file_key);
165  av_tea_init(c->tea_ctx, c->file_key, 16);
166 
167  /* decoder setup */
168  st = avformat_new_stream(s, NULL);
169  if (!st)
170  return AVERROR(ENOMEM);
171  sti = ffstream(st);
173  if (!strcmp(codec_name, "mp332")) {
175  st->codecpar->sample_rate = 22050;
177  avpriv_set_pts_info(st, 64, 8, 32000 * TIMEPREC);
178  // encoded audio frame is MP3_FRAME_SIZE bytes (+1 with padding, unlikely)
179  } else if (!strcmp(codec_name, "acelp85")) {
181  st->codecpar->block_align = 19;
182  st->codecpar->ch_layout.nb_channels = 1;
183  st->codecpar->sample_rate = 8500;
184  st->codecpar->bit_rate = 8500;
186  avpriv_set_pts_info(st, 64, 8, 8500 * TIMEPREC);
187  } else if (!strcmp(codec_name, "acelp16")) {
189  st->codecpar->block_align = 20;
190  st->codecpar->ch_layout.nb_channels = 1;
191  st->codecpar->sample_rate = 16000;
192  st->codecpar->bit_rate = 16000;
194  avpriv_set_pts_info(st, 64, 8, 16000 * TIMEPREC);
195  }
196 
197  /* determine, and jump to audio start offset */
198  for (uint32_t i = 1; i < toc_size; i++) { // skip the first entry!
199  current_size = TOC[i].size;
200  if (current_size > largest_size) {
201  largest_idx = i;
202  largest_size = current_size;
203  }
204  }
205  start = TOC[largest_idx].offset;
206  avio_seek(pb, start, SEEK_SET);
207 
208  // extract chapter positions. since all formats have constant bit rate, use it
209  // as time base in bytes/s, for easy stream position <-> timestamp conversion
210  st->start_time = 0;
211  c->content_start = start;
212  c->content_end = start + largest_size;
213 
214  while ((chapter_pos = avio_tell(pb)) >= 0 && chapter_pos < c->content_end) {
215  unsigned chapter_idx = s->nb_chapters;
216  uint32_t chapter_size = avio_rb32(pb);
217  if (chapter_size == 0 || avio_feof(pb))
218  break;
219  chapter_pos -= start + CHAPTER_HEADER_SIZE * chapter_idx;
220  avio_skip(pb, 4 + chapter_size);
221  if (!avpriv_new_chapter(s, chapter_idx, st->time_base,
222  chapter_pos * TIMEPREC,
223  (chapter_pos + chapter_size) * TIMEPREC, NULL))
224  return AVERROR(ENOMEM);
225  }
226 
227  st->duration = (largest_size - CHAPTER_HEADER_SIZE * s->nb_chapters) * TIMEPREC;
228 
229  avpriv_update_cur_dts(s, st, 0);
230  avio_seek(pb, start, SEEK_SET);
231  c->current_chapter_size = 0;
232  c->seek_offset = 0;
233 
234  return 0;
235 }
236 
238 {
239  int ret;
240  AADemuxContext *c = s->priv_data;
241  uint64_t pos = avio_tell(s->pb);
242 
243  // are we at the end of the audio content?
244  if (pos >= c->content_end) {
245  return AVERROR_EOF;
246  }
247 
248  // are we at the start of a chapter?
249  if (c->current_chapter_size == 0) {
250  c->current_chapter_size = avio_rb32(s->pb);
251  if (c->current_chapter_size == 0) {
252  return AVERROR_EOF;
253  }
254  av_log(s, AV_LOG_DEBUG, "Chapter %d (%" PRId64 " bytes)\n", c->chapter_idx, c->current_chapter_size);
255  c->chapter_idx = c->chapter_idx + 1;
256  avio_skip(s->pb, 4); // data start offset
257  c->current_codec_second_size = c->codec_second_size;
258  }
259 
260  // is this the last block in this chapter?
261  if (c->current_chapter_size / c->current_codec_second_size == 0) {
262  c->current_codec_second_size = c->current_chapter_size % c->current_codec_second_size;
263  }
264 
265  ret = av_get_packet(s->pb, pkt, c->current_codec_second_size);
266  if (ret != c->current_codec_second_size)
267  return AVERROR_EOF;
268 
269  // decrypt c->current_codec_second_size bytes in blocks of TEA_BLOCK_SIZE
270  // trailing bytes are left unencrypted!
271  av_tea_crypt(c->tea_ctx, pkt->data, pkt->data,
272  c->current_codec_second_size / TEA_BLOCK_SIZE, NULL, 1);
273 
274  // update state
275  c->current_chapter_size = c->current_chapter_size - c->current_codec_second_size;
276  if (c->current_chapter_size <= 0)
277  c->current_chapter_size = 0;
278 
279  if (c->seek_offset > c->current_codec_second_size)
280  c->seek_offset = 0; // ignore wrong estimate
281  pkt->data += c->seek_offset;
282  pkt->size -= c->seek_offset;
283  c->seek_offset = 0;
284 
285  return 0;
286 }
287 
289  int stream_index, int64_t timestamp, int flags)
290 {
291  AADemuxContext *c = s->priv_data;
292  AVChapter *ch;
293  int64_t chapter_pos, chapter_start, chapter_size;
294  int chapter_idx = 0;
295 
296  // find chapter containing seek timestamp
297  if (timestamp < 0)
298  timestamp = 0;
299 
300  while (chapter_idx < s->nb_chapters && timestamp >= s->chapters[chapter_idx]->end) {
301  ++chapter_idx;
302  }
303 
304  if (chapter_idx >= s->nb_chapters) {
305  chapter_idx = s->nb_chapters - 1;
306  if (chapter_idx < 0) return -1; // there is no chapter.
307  timestamp = s->chapters[chapter_idx]->end;
308  }
309 
310  ch = s->chapters[chapter_idx];
311 
312  // sync by clamping timestamp to nearest valid block position in its chapter
313  chapter_size = ch->end / TIMEPREC - ch->start / TIMEPREC;
314  chapter_pos = av_rescale_rnd((timestamp - ch->start) / TIMEPREC,
315  1, c->codec_second_size,
317  * c->codec_second_size;
318  if (chapter_pos >= chapter_size)
319  chapter_pos = chapter_size;
320  chapter_start = c->content_start + (ch->start / TIMEPREC) + CHAPTER_HEADER_SIZE * (1 + chapter_idx);
321 
322  // reinit read state
323  avio_seek(s->pb, chapter_start + chapter_pos, SEEK_SET);
324  c->current_codec_second_size = c->codec_second_size;
325  c->current_chapter_size = chapter_size - chapter_pos;
326  c->chapter_idx = 1 + chapter_idx;
327 
328  // for unaligned frames, estimate offset of first frame in block (assume no padding)
329  if (s->streams[0]->codecpar->codec_id == AV_CODEC_ID_MP3) {
330  c->seek_offset = (MP3_FRAME_SIZE - chapter_pos % MP3_FRAME_SIZE) % MP3_FRAME_SIZE;
331  }
332 
333  avpriv_update_cur_dts(s, s->streams[0], ch->start + (chapter_pos + c->seek_offset) * TIMEPREC);
334 
335  return 1;
336 }
337 
338 static int aa_probe(const AVProbeData *p)
339 {
340  uint8_t *buf = p->buf;
341 
342  // first 4 bytes are file size, next 4 bytes are the magic
343  if (AV_RB32(buf+4) != AA_MAGIC)
344  return 0;
345 
346  return AVPROBE_SCORE_MAX / 2;
347 }
348 
350 {
351  AADemuxContext *c = s->priv_data;
352 
353  av_freep(&c->tea_ctx);
354 
355  return 0;
356 }
357 
358 #define OFFSET(x) offsetof(AADemuxContext, x)
359 static const AVOption aa_options[] = {
360  { "aa_fixed_key", // extracted from libAAX_SDK.so and AAXSDKWin.dll files!
361  "Fixed key used for handling Audible AA files", OFFSET(aa_fixed_key),
362  AV_OPT_TYPE_BINARY, {.str="77214d4b196a87cd520045fd2a51d673"},
363  .flags = AV_OPT_FLAG_DECODING_PARAM },
364  { NULL },
365 };
366 
367 static const AVClass aa_class = {
368  .class_name = "aa",
369  .item_name = av_default_item_name,
370  .option = aa_options,
371  .version = LIBAVUTIL_VERSION_INT,
372 };
373 
375  .name = "aa",
376  .long_name = NULL_IF_CONFIG_SMALL("Audible AA format files"),
377  .priv_class = &aa_class,
378  .priv_data_size = sizeof(AADemuxContext),
379  .extensions = "aa",
380  .read_probe = aa_probe,
386  .flags_internal = FF_FMT_INIT_CLEANUP,
387 };
avpriv_new_chapter
AVChapter * avpriv_new_chapter(AVFormatContext *s, int64_t id, AVRational time_base, int64_t start, int64_t end, const char *title)
Add a new chapter.
Definition: demux_utils.c:42
AADemuxContext::content_end
int64_t content_end
Definition: aadec.c:54
AVFMT_NO_BYTE_SEEK
#define AVFMT_NO_BYTE_SEEK
Format does not allow seeking by bytes.
Definition: avformat.h:489
FF_FMT_INIT_CLEANUP
#define FF_FMT_INIT_CLEANUP
For an AVInputFormat with this flag set read_close() needs to be called by the caller upon read_heade...
Definition: internal.h:47
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
opt.h
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
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
aa_read_packet
static int aa_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: aadec.c:237
TIMEPREC
#define TIMEPREC
Definition: aadec.c:40
AV_RN64
#define AV_RN64(p)
Definition: intreadwrite.h:368
AVPacket::data
uint8_t * data
Definition: packet.h:374
AVOption
AVOption.
Definition: opt.h:251
AVChapter::start
int64_t start
Definition: avformat.h:1178
aa_read_seek
static int aa_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: aadec.c:288
av_tea_crypt
void av_tea_crypt(AVTEA *ctx, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt)
Encrypt or decrypt a buffer using a previously initialized context.
Definition: tea.c:95
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:311
aa_read_close
static int aa_read_close(AVFormatContext *s)
Definition: aadec.c:349
avpriv_update_cur_dts
void avpriv_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp)
Update cur_dts of all streams based on the given timestamp and AVStream.
Definition: seek.c:35
aa_class
static const AVClass aa_class
Definition: aadec.c:367
AADemuxContext::tea_ctx
struct AVTEA * tea_ctx
Definition: aadec.c:50
AADemuxContext::aa_fixed_key
uint8_t * aa_fixed_key
Definition: aadec.c:45
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:465
AADemuxContext::aa_fixed_key_len
int aa_fixed_key_len
Definition: aadec.c:46
AADemuxContext::codec_second_size
int codec_second_size
Definition: aadec.c:47
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
MAX_DICTIONARY_ENTRIES
#define MAX_DICTIONARY_ENTRIES
Definition: aadec.c:37
AV_OPT_TYPE_BINARY
@ AV_OPT_TYPE_BINARY
offset must point to a pointer immediately followed by an int for the length
Definition: opt.h:231
ffstream
static av_always_inline FFStream * ffstream(AVStream *st)
Definition: internal.h:413
read_seek
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:151
read_close
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:143
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:510
AVChapter
Definition: avformat.h:1175
val
static double val(void *priv, double ch)
Definition: aeval.c:77
AV_ROUND_UP
@ AV_ROUND_UP
Round toward +infinity.
Definition: mathematics.h:83
AV_CODEC_ID_MP3
@ AV_CODEC_ID_MP3
preferred ID for decoding MPEG audio layer 1, 2 or 3
Definition: codec_id.h:436
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:998
ff_data_to_hex
char * ff_data_to_hex(char *buf, const uint8_t *src, int size, int lowercase)
Write hexadecimal string corresponding to given binary data.
Definition: utils.c:454
AV_CODEC_ID_SIPR
@ AV_CODEC_ID_SIPR
Definition: codec_id.h:476
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
tea.h
Public header for libavutil TEA algorithm.
AVChapter::end
int64_t end
chapter start/end time in time_base units
Definition: avformat.h:1178
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
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:201
AA_MAGIC
#define AA_MAGIC
Definition: aadec.c:35
key
const char * key
Definition: hwcontext_opencl.c:174
aa_options
static const AVOption aa_options[]
Definition: aadec.c:359
aa_probe
static int aa_probe(const AVProbeData *p)
Definition: aadec.c:338
FFStream::need_parsing
enum AVStreamParseType need_parsing
Definition: internal.h:386
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
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVSEEK_FLAG_BACKWARD
#define AVSEEK_FLAG_BACKWARD
Definition: avformat.h:2304
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:540
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
result
and forward the result(frame or status change) to the corresponding input. If nothing is possible
AVStream::time_base
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avformat.h:978
NULL
#define NULL
Definition: coverity.c:32
read_probe
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:453
AVCodecParameters::ch_layout
AVChannelLayout ch_layout
Audio only.
Definition: codec_par.h:213
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:178
AV_WB32
#define AV_WB32(p, v)
Definition: intreadwrite.h:419
av_rescale_rnd
int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd)
Rescale a 64-bit integer with specified rounding.
Definition: mathematics.c:58
AVIOContext
Bytestream IO Context.
Definition: avio.h:166
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
get_second_size
static int get_second_size(char *codec_name)
Definition: aadec.c:58
FFStream
Definition: internal.h:196
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
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
MP3_FRAME_SIZE
#define MP3_FRAME_SIZE
Definition: aadec.c:41
offset
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 offset
Definition: writing_filters.txt:86
AADemuxContext::current_chapter_size
int64_t current_chapter_size
Definition: aadec.c:52
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
TEA_BLOCK_SIZE
#define TEA_BLOCK_SIZE
Definition: aadec.c:38
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:185
aa_read_header
static int aa_read_header(AVFormatContext *s)
Definition: aadec.c:73
OFFSET
#define OFFSET(x)
Definition: aadec.c:358
AV_ROUND_DOWN
@ AV_ROUND_DOWN
Round toward -infinity.
Definition: mathematics.h:82
MAX_TOC_ENTRIES
#define MAX_TOC_ENTRIES
Definition: aadec.c:36
AV_OPT_FLAG_DECODING_PARAM
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:282
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
ret
ret
Definition: filter_design.txt:187
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
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
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:71
av_tea_init
void av_tea_init(AVTEA *ctx, const uint8_t key[16], int rounds)
Initialize an AVTEA context.
Definition: tea.c:42
pos
unsigned int pos
Definition: spdifenc.c:412
avformat.h
dict.h
AADemuxContext::chapter_idx
int chapter_idx
Definition: aadec.c:49
av_tea_alloc
struct AVTEA * av_tea_alloc(void)
Allocate an AVTEA context To free the struct: av_free(ptr)
Definition: tea.c:35
AVFMT_NOGENSEARCH
#define AVFMT_NOGENSEARCH
Format does not allow to fall back on generic search.
Definition: avformat.h:488
AVSTREAM_PARSE_FULL_RAW
@ AVSTREAM_PARSE_FULL_RAW
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:802
AADemuxContext::seek_offset
int seek_offset
Definition: aadec.c:55
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:349
AADemuxContext::file_key
uint8_t file_key[16]
Definition: aadec.c:51
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
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
av_strlcpy
size_t av_strlcpy(char *dst, const char *src, size_t size)
Copy the string src to dst, but no more than size - 1 bytes, and null-terminate dst.
Definition: avstring.c:86
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
AV_WN64
#define AV_WN64(p, v)
Definition: intreadwrite.h:380
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
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
avstring.h
AADemuxContext::content_start
int64_t content_start
Definition: aadec.c:53
CHAPTER_HEADER_SIZE
#define CHAPTER_HEADER_SIZE
Definition: aadec.c:39
AADemuxContext::current_codec_second_size
int current_codec_second_size
Definition: aadec.c:48
AADemuxContext
Definition: aadec.c:43
AVTEA
Definition: tea.c:30
ff_aa_demuxer
const AVInputFormat ff_aa_demuxer
Definition: aadec.c:374
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:377