1 /*
2 * copyright (c) 2001 Fabrice Bellard
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #ifndef AVFORMAT_AVFORMAT_H
22 #define AVFORMAT_AVFORMAT_H
23
24 /**
25 * @file
26 * @ingroup libavf
27 * Main libavformat public API header
28 */
29
30 /**
31 * @defgroup libavf libavformat
32 * I/O and Muxing/Demuxing Library
33 *
34 * Libavformat (lavf) is a library for dealing with various media container
35 * formats. Its main two purposes are demuxing - i.e. splitting a media file
36 * into component streams, and the reverse process of muxing - writing supplied
37 * data in a specified container format. It also has an @ref lavf_io
38 * "I/O module" which supports a number of protocols for accessing the data (e.g.
39 * file, tcp, http and others).
40 * Unless you are absolutely sure you won't use libavformat's network
41 * capabilities, you should also call avformat_network_init().
42 *
43 * A supported input format is described by an AVInputFormat struct, conversely
44 * an output format is described by AVOutputFormat. You can iterate over all
45 * input/output formats using the av_demuxer_iterate / av_muxer_iterate() functions.
46 * The protocols layer is not part of the public API, so you can only get the names
47 * of supported protocols with the avio_enum_protocols() function.
48 *
49 * Main lavf structure used for both muxing and demuxing is AVFormatContext,
50 * which exports all information about the file being read or written. As with
51 * most Libavformat structures, its size is not part of public ABI, so it cannot be
52 * allocated on stack or directly with av_malloc(). To create an
53 * AVFormatContext, use avformat_alloc_context() (some functions, like
54 * avformat_open_input() might do that for you).
55 *
56 * Most importantly an AVFormatContext contains:
57 * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat
58 * "output" format. It is either autodetected or set by user for input;
59 * always set by user for output.
60 * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all
61 * elementary streams stored in the file. AVStreams are typically referred to
62 * using their index in this array.
63 * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or
64 * set by user for input, always set by user for output (unless you are dealing
65 * with an AVFMT_NOFILE format).
66 *
67 * @section lavf_options Passing options to (de)muxers
68 * It is possible to configure lavf muxers and demuxers using the @ref avoptions
69 * mechanism. Generic (format-independent) libavformat options are provided by
70 * AVFormatContext, they can be examined from a user program by calling
71 * av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass
72 * from avformat_get_class()). Private (format-specific) options are provided by
73 * AVFormatContext.priv_data if and only if AVInputFormat.priv_class /
74 * AVOutputFormat.priv_class of the corresponding format struct is non-NULL.
75 * Further options may be provided by the @ref AVFormatContext.pb "I/O context",
76 * if its AVClass is non-NULL, and the protocols layer. See the discussion on
77 * nesting in @ref avoptions documentation to learn how to access those.
78 *
79 * @section urls
80 * URL strings in libavformat are made of a scheme/protocol, a ':', and a
81 * scheme specific string. URLs without a scheme and ':' used for local files
82 * are supported but deprecated. "file:" should be used for local files.
83 *
84 * It is important that the scheme string is not taken from untrusted
85 * sources without checks.
86 *
87 * Note that some schemes/protocols are quite powerful, allowing access to
88 * both local and remote files, parts of them, concatenations of them, local
89 * audio and video devices and so on.
90 *
91 * @{
92 *
93 * @defgroup lavf_decoding Demuxing
94 * @{
95 * Demuxers read a media file and split it into chunks of data (@em packets). A
96 * @ref AVPacket "packet" contains one or more encoded frames which belongs to a
97 * single elementary stream. In the lavf API this process is represented by the
98 * avformat_open_input() function for opening a file, av_read_frame() for
99 * reading a single packet and finally avformat_close_input(), which does the
100 * cleanup.
101 *
102 * @section lavf_decoding_open Opening a media file
103 * The minimum information required to open a file is its URL, which
104 * is passed to avformat_open_input(), as in the following code:
105 * @code
106 * const char *url = "file:in.mp3";
107 * AVFormatContext *s = NULL;
108 * int ret = avformat_open_input(&s, url, NULL, NULL);
109 * if (ret < 0)
110 * abort();
111 * @endcode
112 * The above code attempts to allocate an AVFormatContext, open the
113 * specified file (autodetecting the format) and read the header, exporting the
114 * information stored there into s. Some formats do not have a header or do not
115 * store enough information there, so it is recommended that you call the
116 * avformat_find_stream_info() function which tries to read and decode a few
117 * frames to find missing information.
118 *
119 * In some cases you might want to preallocate an AVFormatContext yourself with
120 * avformat_alloc_context() and do some tweaking on it before passing it to
121 * avformat_open_input(). One such case is when you want to use custom functions
122 * for reading input data instead of lavf internal I/O layer.
123 * To do that, create your own AVIOContext with avio_alloc_context(), passing
124 * your reading callbacks to it. Then set the @em pb field of your
125 * AVFormatContext to newly created AVIOContext.
126 *
127 * Since the format of the opened file is in general not known until after
128 * avformat_open_input() has returned, it is not possible to set demuxer private
129 * options on a preallocated context. Instead, the options should be passed to
130 * avformat_open_input() wrapped in an AVDictionary:
131 * @code
132 * AVDictionary *options = NULL;
133 * av_dict_set(&options, "video_size", "640x480", 0);
134 * av_dict_set(&options, "pixel_format", "rgb24", 0);
135 *
136 * if (avformat_open_input(&s, url, NULL, &options) < 0)
137 * abort();
138 * av_dict_free(&options);
139 * @endcode
140 * This code passes the private options 'video_size' and 'pixel_format' to the
141 * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it
142 * cannot know how to interpret raw video data otherwise. If the format turns
143 * out to be something different than raw video, those options will not be
144 * recognized by the demuxer and therefore will not be applied. Such unrecognized
145 * options are then returned in the options dictionary (recognized options are
146 * consumed). The calling program can handle such unrecognized options as it
147 * wishes, e.g.
148 * @code
149 * const AVDictionaryEntry *e;
150 * if ((e = av_dict_iterate(options, NULL))) {
151 * fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key);
152 * abort();
153 * }
154 * @endcode
155 *
156 * After you have finished reading the file, you must close it with
157 * avformat_close_input(). It will free everything associated with the file.
158 *
159 * @section lavf_decoding_read Reading from an opened file
160 * Reading data from an opened AVFormatContext is done by repeatedly calling
161 * av_read_frame() on it. Each call, if successful, will return an AVPacket
162 * containing encoded data for one AVStream, identified by
163 * AVPacket.stream_index. This packet may be passed straight into the libavcodec
164 * decoding functions avcodec_send_packet() or avcodec_decode_subtitle2() if the
165 * caller wishes to decode the data.
166 *
167 * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be
168 * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for
169 * pts/dts, 0 for duration) if the stream does not provide them. The timing
170 * information will be in AVStream.time_base units, i.e. it has to be
171 * multiplied by the timebase to convert them to seconds.
172 *
173 * A packet returned by av_read_frame() is always reference-counted,
174 * i.e. AVPacket.buf is set and the user may keep it indefinitely.
175 * The packet must be freed with av_packet_unref() when it is no
176 * longer needed.
177 *
178 * @section lavf_decoding_seek Seeking
179 * @}
180 *
181 * @defgroup lavf_encoding Muxing
182 * @{
183 * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write
184 * it into files or other output bytestreams in the specified container format.
185 *
186 * The main API functions for muxing are avformat_write_header() for writing the
187 * file header, av_write_frame() / av_interleaved_write_frame() for writing the
188 * packets and av_write_trailer() for finalizing the file.
189 *
190 * At the beginning of the muxing process, the caller must first call
191 * avformat_alloc_context() to create a muxing context. The caller then sets up
192 * the muxer by filling the various fields in this context:
193 *
194 * - The @ref AVFormatContext.oformat "oformat" field must be set to select the
195 * muxer that will be used.
196 * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb
197 * "pb" field must be set to an opened IO context, either returned from
198 * avio_open2() or a custom one.
199 * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must
200 * be created with the avformat_new_stream() function. The caller should fill
201 * the @ref AVStream.codecpar "stream codec parameters" information, such as the
202 * codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id
203 * "id" and other parameters (e.g. width / height, the pixel or sample format,
204 * etc.) as known. The @ref AVStream.time_base "stream timebase" should
205 * be set to the timebase that the caller desires to use for this stream (note
206 * that the timebase actually used by the muxer can be different, as will be
207 * described later).
208 * - It is advised to manually initialize only the relevant fields in
209 * AVCodecParameters, rather than using @ref avcodec_parameters_copy() during
210 * remuxing: there is no guarantee that the codec context values remain valid
211 * for both input and output format contexts.
212 * - The caller may fill in additional information, such as @ref
213 * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream"
214 * metadata, @ref AVFormatContext.chapters "chapters", @ref
215 * AVFormatContext.programs "programs", etc. as described in the
216 * AVFormatContext documentation. Whether such information will actually be
217 * stored in the output depends on what the container format and the muxer
218 * support.
219 *
220 * When the muxing context is fully set up, the caller must call
221 * avformat_write_header() to initialize the muxer internals and write the file
222 * header. Whether anything actually is written to the IO context at this step
223 * depends on the muxer, but this function must always be called. Any muxer
224 * private options must be passed in the options parameter to this function.
225 *
226 * The data is then sent to the muxer by repeatedly calling av_write_frame() or
227 * av_interleaved_write_frame() (consult those functions' documentation for
228 * discussion on the difference between them; only one of them may be used with
229 * a single muxing context, they should not be mixed). Do note that the timing
230 * information on the packets sent to the muxer must be in the corresponding
231 * AVStream's timebase. That timebase is set by the muxer (in the
232 * avformat_write_header() step) and may be different from the timebase
233 * requested by the caller.
234 *
235 * Once all the data has been written, the caller must call av_write_trailer()
236 * to flush any buffered packets and finalize the output file, then close the IO
237 * context (if any) and finally free the muxing context with
238 * avformat_free_context().
239 * @}
240 *
241 * @defgroup lavf_io I/O Read/Write
242 * @{
243 * @section lavf_io_dirlist Directory listing
244 * The directory listing API makes it possible to list files on remote servers.
245 *
246 * Some of possible use cases:
247 * - an "open file" dialog to choose files from a remote location,
248 * - a recursive media finder providing a player with an ability to play all
249 * files from a given directory.
250 *
251 * @subsection lavf_io_dirlist_open Opening a directory
252 * At first, a directory needs to be opened by calling avio_open_dir()
253 * supplied with a URL and, optionally, ::AVDictionary containing
254 * protocol-specific parameters. The function returns zero or positive
255 * integer and allocates AVIODirContext on success.
256 *
257 * @code
258 * AVIODirContext *ctx = NULL;
259 * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) {
260 * fprintf(stderr, "Cannot open directory.\n");
261 * abort();
262 * }
263 * @endcode
264 *
265 * This code tries to open a sample directory using smb protocol without
266 * any additional parameters.
267 *
268 * @subsection lavf_io_dirlist_read Reading entries
269 * Each directory's entry (i.e. file, another directory, anything else
270 * within ::AVIODirEntryType) is represented by AVIODirEntry.
271 * Reading consecutive entries from an opened AVIODirContext is done by
272 * repeatedly calling avio_read_dir() on it. Each call returns zero or
273 * positive integer if successful. Reading can be stopped right after the
274 * NULL entry has been read -- it means there are no entries left to be
275 * read. The following code reads all entries from a directory associated
276 * with ctx and prints their names to standard output.
277 * @code
278 * AVIODirEntry *entry = NULL;
279 * for (;;) {
280 * if (avio_read_dir(ctx, &entry) < 0) {
281 * fprintf(stderr, "Cannot list directory.\n");
282 * abort();
283 * }
284 * if (!entry)
285 * break;
286 * printf("%s\n", entry->name);
287 * avio_free_directory_entry(&entry);
288 * }
289 * @endcode
290 * @}
291 *
292 * @defgroup lavf_codec Demuxers
293 * @{
294 * @defgroup lavf_codec_native Native Demuxers
295 * @{
296 * @}
297 * @defgroup lavf_codec_wrappers External library wrappers
298 * @{
299 * @}
300 * @}
301 * @defgroup lavf_protos I/O Protocols
302 * @{
303 * @}
304 * @defgroup lavf_internal Internal
305 * @{
306 * @}
307 * @}
308 */
309
310 #include <stdio.h> /* FILE */
311
315
318
321 #ifndef HAVE_AV_CONFIG_H
322 /* When included as part of the ffmpeg build, only include the major version
323 * to avoid unnecessary rebuilds. When included externally, keep including
324 * the full version information. */
326
329 #endif
330
333
334 /**
335 * @defgroup metadata_api Public Metadata API
336 * @{
337 * @ingroup libavf
338 * The metadata API allows libavformat to export metadata tags to a client
339 * application when demuxing. Conversely it allows a client application to
340 * set metadata when muxing.
341 *
342 * Metadata is exported or set as pairs of key/value strings in the 'metadata'
343 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
344 * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
345 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
346 * exported by demuxers isn't checked to be valid UTF-8 in most cases.
347 *
348 * Important concepts to keep in mind:
349 * - Keys are unique; there can never be 2 tags with the same key. This is
350 * also meant semantically, i.e., a demuxer should not knowingly produce
351 * several keys that are literally different but semantically identical.
352 * E.g., key=Author5, key=Author6. In this example, all authors must be
353 * placed in the same tag.
354 * - Metadata is flat, not hierarchical; there are no subtags. If you
355 * want to store, e.g., the email address of the child of producer Alice
356 * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
357 * - Several modifiers can be applied to the tag name. This is done by
358 * appending a dash character ('-') and the modifier name in the order
359 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
360 * - language -- a tag whose value is localized for a particular language
361 * is appended with the ISO 639-2/B 3-letter language code.
362 * For example: Author-ger=Michael, Author-eng=Mike
363 * The original/default language is in the unqualified "Author" tag.
364 * A demuxer should set a default if it sets any translated tag.
365 * - sorting -- a modified version of a tag that should be used for
366 * sorting will have '-sort' appended. E.g. artist="The Beatles",
367 * artist-sort="Beatles, The".
368 * - Some protocols and demuxers support metadata updates. After a successful
369 * call to av_read_frame(), AVFormatContext.event_flags or AVStream.event_flags
370 * will be updated to indicate if metadata changed. In order to detect metadata
371 * changes on a stream, you need to loop through all streams in the AVFormatContext
372 * and check their individual event_flags.
373 *
374 * - Demuxers attempt to export metadata in a generic format, however tags
375 * with no generic equivalents are left as they are stored in the container.
376 * Follows a list of generic tag names:
377 *
378 @verbatim
379 album -- name of the set this work belongs to
380 album_artist -- main creator of the set/album, if different from artist.
381 e.g. "Various Artists" for compilation albums.
382 artist -- main creator of the work
383 comment -- any additional description of the file.
384 composer -- who composed the work, if different from artist.
385 copyright -- name of copyright holder.
386 creation_time-- date when the file was created, preferably in ISO 8601.
387 date -- date when the work was created, preferably in ISO 8601.
388 disc -- number of a subset, e.g. disc in a multi-disc collection.
389 encoder -- name/settings of the software/hardware that produced the file.
390 encoded_by -- person/group who created the file.
391 filename -- original name of the file.
392 genre -- <self-evident>.
393 language -- main language in which the work is performed, preferably
394 in ISO 639-2 format. Multiple languages can be specified by
395 separating them with commas.
396 performer -- artist who performed the work, if different from artist.
397 E.g for "Also sprach Zarathustra", artist would be "Richard
398 Strauss" and performer "London Philharmonic Orchestra".
399 publisher -- name of the label/publisher.
400 service_name -- name of the service in broadcasting (channel name).
401 service_provider -- name of the service provider in broadcasting.
402 title -- name of the work.
403 track -- number of this work in the set, can be in form current/total.
404 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
405 @endverbatim
406 *
407 * Look in the examples section for an application example how to use the Metadata API.
408 *
409 * @}
410 */
411
412 /* packet functions */
413
414
415 /**
416 * Allocate and read the payload of a packet and initialize its
417 * fields with default values.
418 *
419 * @param s associated IO context
420 * @param pkt packet
421 * @param size desired payload size
422 * @return >0 (read size) if OK, AVERROR_xxx otherwise
423 */
425
426
427 /**
428 * Read data and append it to the current content of the AVPacket.
429 * If pkt->size is 0 this is identical to av_get_packet.
430 * Note that this uses av_grow_packet and thus involves a realloc
431 * which is inefficient. Thus this function should only be used
432 * when there is no reasonable way to know (an upper bound of)
433 * the final size.
434 *
435 * @param s associated IO context
436 * @param pkt packet
437 * @param size amount of data to read
438 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
439 * will not be lost even if an error occurs.
440 */
442
443 /*************************************************/
444 /* input/output formats */
445
447
448 /**
449 * This structure contains the data a format has to probe a file.
450 */
453 unsigned char *
buf;
/**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
454 int buf_size;
/**< Size of buf except extra allocated bytes */
457
458 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
459 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
460
461 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
462 #define AVPROBE_SCORE_MIME_BONUS 30
///< score added for matching mime type
463 #define AVPROBE_SCORE_MAX 100
///< maximum score
464
465 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
466
467 /// Demuxer will use avio_open, no opened file should be provided by the caller.
468 #define AVFMT_NOFILE 0x0001
469 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
470 /**
471 * The muxer/demuxer is experimental and should be used with caution.
472 *
473 * It will not be selected automatically, and must be specified explicitly.
474 */
475 #define AVFMT_EXPERIMENTAL 0x0004
476 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
477 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
478 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
479 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
480 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
481 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
482 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
483 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
484 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
485 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
486 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
487 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
488 increasing timestamps, but they must
489 still be monotonic */
490 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
491 timestamps. If not set the timestamp
492 will be shifted in av_write_frame and
493 av_interleaved_write_frame so they
494 start from 0.
495 The user or muxer can override this through
496 AVFormatContext.avoid_negative_ts
497 */
498
499 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
500
501 /**
502 * @addtogroup lavf_encoding
503 * @{
504 */
507 /**
508 * Descriptive name for the format, meant to be more human-readable
509 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
510 * to define it.
511 */
514 const char *
extensions;
/**< comma-separated filename extensions */
515 /* output support */
519 /**
520 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER,
521 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
522 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS,
523 * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
524 */
526
527 /**
528 * List of supported codec_id-codec_tag pairs, ordered by "better
529 * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
530 */
532
533
536 /**
537 * @}
538 */
539
540 /**
541 * @addtogroup lavf_decoding
542 * @{
543 */
545 /**
546 * A comma separated list of short names for the format. New names
547 * may be appended with a minor bump.
548 */
550
551 /**
552 * Descriptive name for the format, meant to be more human-readable
553 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
554 * to define it.
555 */
557
558 /**
559 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
560 * AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
561 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
562 */
564
565 /**
566 * If extensions are defined, then no probe is done. You should
567 * usually not use extension format guessing because it is not
568 * reliable enough
569 */
571
573
575
576 /**
577 * Comma-separated list of mime types.
578 * It is used check for matching mime types while probing.
579 * @see av_probe_input_format2
580 */
583 /**
584 * @}
585 */
586
594 this assumes that each packet in the file contains no demuxer level headers and
595 just codec level data, otherwise position generation would fail */
596 };
597
601 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
602 * when seeking to this entry. That means preferable PTS on keyframe based formats.
603 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
604 * is known
605 */
606 #define AVINDEX_KEYFRAME 0x0001
607 #define AVINDEX_DISCARD_FRAME 0x0002 /**
608 * Flag is used to indicate which frame should be discarded after decoding.
611 int size:30;
//Yeah, trying to keep the size of this small to reduce memory requirements (it is 24 vs. 32 bytes due to possible 8-byte alignment).
612 int min_distance;
/**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
614
615 /**
616 * The stream should be chosen by default among other streams of the same type,
617 * unless the user has explicitly specified otherwise.
618 */
619 #define AV_DISPOSITION_DEFAULT (1 << 0)
620 /**
621 * The stream is not in original language.
622 *
623 * @note AV_DISPOSITION_ORIGINAL is the inverse of this disposition. At most
624 * one of them should be set in properly tagged streams.
625 * @note This disposition may apply to any stream type, not just audio.
626 */
627 #define AV_DISPOSITION_DUB (1 << 1)
628 /**
629 * The stream is in original language.
630 *
631 * @see the notes for AV_DISPOSITION_DUB
632 */
633 #define AV_DISPOSITION_ORIGINAL (1 << 2)
634 /**
635 * The stream is a commentary track.
636 */
637 #define AV_DISPOSITION_COMMENT (1 << 3)
638 /**
639 * The stream contains song lyrics.
640 */
641 #define AV_DISPOSITION_LYRICS (1 << 4)
642 /**
643 * The stream contains karaoke audio.
644 */
645 #define AV_DISPOSITION_KARAOKE (1 << 5)
646
647 /**
648 * Track should be used during playback by default.
649 * Useful for subtitle track that should be displayed
650 * even when user did not explicitly ask for subtitles.
651 */
652 #define AV_DISPOSITION_FORCED (1 << 6)
653 /**
654 * The stream is intended for hearing impaired audiences.
655 */
656 #define AV_DISPOSITION_HEARING_IMPAIRED (1 << 7)
657 /**
658 * The stream is intended for visually impaired audiences.
659 */
660 #define AV_DISPOSITION_VISUAL_IMPAIRED (1 << 8)
661 /**
662 * The audio stream contains music and sound effects without voice.
663 */
664 #define AV_DISPOSITION_CLEAN_EFFECTS (1 << 9)
665 /**
666 * The stream is stored in the file as an attached picture/"cover art" (e.g.
667 * APIC frame in ID3v2). The first (usually only) packet associated with it
668 * will be returned among the first few packets read from the file unless
669 * seeking takes place. It can also be accessed at any time in
670 * AVStream.attached_pic.
671 */
672 #define AV_DISPOSITION_ATTACHED_PIC (1 << 10)
673 /**
674 * The stream is sparse, and contains thumbnail images, often corresponding
675 * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
676 */
677 #define AV_DISPOSITION_TIMED_THUMBNAILS (1 << 11)
678
679 /**
680 * The stream is intended to be mixed with a spatial audio track. For example,
681 * it could be used for narration or stereo music, and may remain unchanged by
682 * listener head rotation.
683 */
684 #define AV_DISPOSITION_NON_DIEGETIC (1 << 12)
685
686 /**
687 * The subtitle stream contains captions, providing a transcription and possibly
688 * a translation of audio. Typically intended for hearing-impaired audiences.
689 */
690 #define AV_DISPOSITION_CAPTIONS (1 << 16)
691 /**
692 * The subtitle stream contains a textual description of the video content.
693 * Typically intended for visually-impaired audiences or for the cases where the
694 * video cannot be seen.
695 */
696 #define AV_DISPOSITION_DESCRIPTIONS (1 << 17)
697 /**
698 * The subtitle stream contains time-aligned metadata that is not intended to be
699 * directly presented to the user.
700 */
701 #define AV_DISPOSITION_METADATA (1 << 18)
702 /**
703 * The stream is intended to be mixed with another stream before presentation.
704 * Used for example to signal the stream contains an image part of a HEIF grid,
705 * or for mix_type=0 in mpegts.
706 */
707 #define AV_DISPOSITION_DEPENDENT (1 << 19)
708 /**
709 * The video stream contains still images.
710 */
711 #define AV_DISPOSITION_STILL_IMAGE (1 << 20)
712 /**
713 * The video stream contains multiple layers, e.g. stereoscopic views (cf. H.264
714 * Annex G/H, or HEVC Annex F).
715 */
716 #define AV_DISPOSITION_MULTILAYER (1 << 21)
717
718 /**
719 * @return The AV_DISPOSITION_* flag corresponding to disp or a negative error
720 * code if disp does not correspond to a known stream disposition.
721 */
723
724 /**
725 * @param disposition a combination of AV_DISPOSITION_* values
726 * @return The string description corresponding to the lowest set bit in
727 * disposition. NULL when the lowest set bit does not correspond
728 * to a known disposition or when disposition is 0.
729 */
731
732 /**
733 * Options for behavior on timestamp wrap detection.
735 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
736 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
737 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
738
739 /**
740 * Stream structure.
741 * New fields can be added to the end with minor version bumps.
742 * Removal, reordering and changes to existing fields require a major
743 * version bump.
744 * sizeof(AVStream) must not be used outside libav*.
745 */
747 /**
748 * A class for @ref avoptions. Set on stream creation.
749 */
751
752 int index;
/**< stream index in AVFormatContext */
753 /**
754 * Format-specific stream ID.
755 * decoding: set by libavformat
756 * encoding: set by the user, replaced by libavformat if left unset
757 */
759
760 /**
761 * Codec parameters associated with this stream. Allocated and freed by
762 * libavformat in avformat_new_stream() and avformat_free_context()
763 * respectively.
764 *
765 * - demuxing: filled by libavformat on stream creation or in
766 * avformat_find_stream_info()
767 * - muxing: filled by the caller before avformat_write_header()
768 */
770
772
773 /**
774 * This is the fundamental unit of time (in seconds) in terms
775 * of which frame timestamps are represented.
776 *
777 * decoding: set by libavformat
778 * encoding: May be set by the caller before avformat_write_header() to
779 * provide a hint to the muxer about the desired timebase. In
780 * avformat_write_header(), the muxer will overwrite this field
781 * with the timebase that will actually be used for the timestamps
782 * written into the file (which may or may not be related to the
783 * user-provided one, depending on the format).
784 */
786
787 /**
788 * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
789 * Only set this if you are absolutely 100% sure that the value you set
790 * it to really is the pts of the first frame.
791 * This may be undefined (AV_NOPTS_VALUE).
792 * @note The ASF header does NOT contain a correct start_time the ASF
793 * demuxer must NOT set this.
794 */
796
797 /**
798 * Decoding: duration of the stream, in stream time base.
799 * If a source file does not specify a duration, but does specify
800 * a bitrate, this value will be estimated from bitrate and file size.
801 *
802 * Encoding: May be set by the caller before avformat_write_header() to
803 * provide a hint to the muxer about the estimated duration.
804 */
806
808
809 /**
810 * Stream disposition - a combination of AV_DISPOSITION_* flags.
811 * - demuxing: set by libavformat when creating the stream or in
812 * avformat_find_stream_info().
813 * - muxing: may be set by the caller before avformat_write_header().
814 */
816
817 enum AVDiscard discard;
///< Selects which packets can be discarded at will and do not need to be demuxed.
818
819 /**
820 * sample aspect ratio (0 if unknown)
821 * - encoding: Set by user.
822 * - decoding: Set by libavformat.
823 */
825
827
828 /**
829 * Average framerate
830 *
831 * - demuxing: May be set by libavformat when creating the stream or in
832 * avformat_find_stream_info().
833 * - muxing: May be set by the caller before avformat_write_header().
834 */
836
837 /**
838 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
839 * will contain the attached picture.
840 *
841 * decoding: set by libavformat, must not be modified by the caller.
843 */
845
846 /**
847 * Flags indicating events happening on the stream, a combination of
848 * AVSTREAM_EVENT_FLAG_*.
849 *
850 * - demuxing: may be set by the demuxer in avformat_open_input(),
851 * avformat_find_stream_info() and av_read_frame(). Flags must be cleared
852 * by the user once the event has been handled.
853 * - muxing: may be set by the user after avformat_write_header(). to
854 * indicate a user-triggered event. The muxer will clear the flags for
855 * events it has handled in av_[interleaved]_write_frame().
856 */
858 /**
859 * - demuxing: the demuxer read new metadata from the file and updated
860 * AVStream.metadata accordingly
861 * - muxing: the user updated AVStream.metadata and wishes the muxer to write
863 */
864 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001
865 /**
866 * - demuxing: new packets for this stream were read from the file. This
867 * event is informational only and does not guarantee that new packets
868 * for this stream will necessarily be returned from av_read_frame().
869 */
870 #define AVSTREAM_EVENT_FLAG_NEW_PACKETS (1 << 1)
871
872 /**
873 * Real base framerate of the stream.
874 * This is the lowest framerate with which all timestamps can be
875 * represented accurately (it is the least common multiple of all
876 * framerates in the stream). Note, this value is just a guess!
877 * For example, if the time base is 1/90000 and all frames have either
878 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
879 */
881
882 /**
883 * Number of bits in timestamps. Used for wrapping control.
884 *
885 * - demuxing: set by libavformat
886 * - muxing: set by libavformat
888 */
891
892 /**
893 * AVStreamGroupTileGrid holds information on how to combine several
894 * independent images on a single canvas for presentation.
895 *
896 * The output should be a @ref AVStreamGroupTileGrid.background "background"
897 * colored @ref AVStreamGroupTileGrid.coded_width "coded_width" x
898 * @ref AVStreamGroupTileGrid.coded_height "coded_height" canvas where a
899 * @ref AVStreamGroupTileGrid.nb_tiles "nb_tiles" amount of tiles are placed in
900 * the order they appear in the @ref AVStreamGroupTileGrid.offsets "offsets"
901 * array, at the exact offset described for them. In particular, if two or more
902 * tiles overlap, the image with higher index in the
903 * @ref AVStreamGroupTileGrid.offsets "offsets" array takes priority.
904 * Note that a single image may be used multiple times, i.e. multiple entries
905 * in @ref AVStreamGroupTileGrid.offsets "offsets" may have the same value of
906 * idx.
907 *
908 * The following is an example of a simple grid with 3 rows and 4 columns:
909 *
910 * +---+---+---+---+
911 * | 0 | 1 | 2 | 3 |
912 * +---+---+---+---+
913 * | 4 | 5 | 6 | 7 |
914 * +---+---+---+---+
915 * | 8 | 9 |10 |11 |
916 * +---+---+---+---+
917 *
918 * Assuming all tiles have a dimension of 512x512, the
919 * @ref AVStreamGroupTileGrid.offsets "offset" of the topleft pixel of
920 * the first @ref AVStreamGroup.streams "stream" in the group is "0,0", the
921 * @ref AVStreamGroupTileGrid.offsets "offset" of the topleft pixel of
922 * the second @ref AVStreamGroup.streams "stream" in the group is "512,0", the
923 * @ref AVStreamGroupTileGrid.offsets "offset" of the topleft pixel of
924 * the fifth @ref AVStreamGroup.streams "stream" in the group is "0,512", the
925 * @ref AVStreamGroupTileGrid.offsets "offset", of the topleft pixel of
926 * the sixth @ref AVStreamGroup.streams "stream" in the group is "512,512",
927 * etc.
928 *
929 * The following is an example of a canvas with overlapping tiles:
930 *
931 * +-----------+
932 * | %%%%% |
933 * |***%%3%%@@@|
934 * |**0%%%%%2@@|
935 * |***##1@@@@@|
936 * | ##### |
937 * +-----------+
938 *
939 * Assuming a canvas with size 1024x1024 and all tiles with a dimension of
940 * 512x512, a possible @ref AVStreamGroupTileGrid.offsets "offset" for the
941 * topleft pixel of the first @ref AVStreamGroup.streams "stream" in the group
942 * would be 0x256, the @ref AVStreamGroupTileGrid.offsets "offset" for the
943 * topleft pixel of the second @ref AVStreamGroup.streams "stream" in the group
944 * would be 256x512, the @ref AVStreamGroupTileGrid.offsets "offset" for the
945 * topleft pixel of the third @ref AVStreamGroup.streams "stream" in the group
946 * would be 512x256, and the @ref AVStreamGroupTileGrid.offsets "offset" for
947 * the topleft pixel of the fourth @ref AVStreamGroup.streams "stream" in the
948 * group would be 256x0.
949 *
950 * sizeof(AVStreamGroupTileGrid) is not a part of the ABI and may only be
951 * allocated by avformat_stream_group_create().
955
956 /**
957 * Amount of tiles in the grid.
958 *
960 */
962
963 /**
964 * Width of the canvas.
965 *
967 */
969 /**
970 * Width of the canvas.
971 *
973 */
975
976 /**
977 * An @ref nb_tiles sized array of offsets in pixels from the topleft edge
978 * of the canvas, indicating where each stream should be placed.
979 * It must be allocated with the av_malloc() family of functions.
980 *
981 * - demuxing: set by libavformat, must not be modified by the caller.
982 * - muxing: set by the caller before avformat_write_header().
983 *
984 * Freed by libavformat in avformat_free_context().
985 */
986 struct {
987 /**
988 * Index of the stream in the group this tile references.
989 *
990 * Must be < @ref AVStreamGroup.nb_streams "nb_streams".
991 */
993 /**
994 * Offset in pixels from the left edge of the canvas where the tile
996 */
998 /**
999 * Offset in pixels from the top edge of the canvas where the tile
1001 */
1004
1005 /**
1006 * The pixel value per channel in RGBA format used if no pixel of any tile
1007 * is located at a particular pixel location.
1008 *
1009 * @see av_image_fill_color().
1010 * @see av_parse_color().
1011 */
1013
1014 /**
1015 * Offset in pixels from the left edge of the canvas where the actual image
1016 * meant for presentation starts.
1017 *
1018 * This field must be >= 0 and < @ref coded_width.
1019 */
1021 /**
1022 * Offset in pixels from the top edge of the canvas where the actual image
1023 * meant for presentation starts.
1024 *
1025 * This field must be >= 0 and < @ref coded_height.
1026 */
1028
1029 /**
1030 * Width of the final image for presentation.
1031 *
1032 * Must be > 0 and <= (@ref coded_width - @ref horizontal_offset).
1033 * When it's not equal to (@ref coded_width - @ref horizontal_offset), the
1034 * result of (@ref coded_width - width - @ref horizontal_offset) is the
1035 * amount amount of pixels to be cropped from the right edge of the
1036 * final image before presentation.
1037 */
1039 /**
1040 * Height of the final image for presentation.
1041 *
1042 * Must be > 0 and <= (@ref coded_height - @ref vertical_offset).
1043 * When it's not equal to (@ref coded_height - @ref vertical_offset), the
1044 * result of (@ref coded_height - height - @ref vertical_offset) is the
1045 * amount amount of pixels to be cropped from the bottom edge of the
1046 * final image before presentation.
1047 */
1049
1050 /**
1051 * Additional data associated with the grid.
1052 *
1053 * Should be allocated with av_packet_side_data_new() or
1054 * av_packet_side_data_add(), and will be freed by avformat_free_context().
1055 */
1057
1058 /**
1059 * Amount of entries in @ref coded_side_data.
1060 */
1063
1064 /**
1065 * AVStreamGroupLCEVC is meant to define the relation between video streams
1066 * and a data stream containing LCEVC enhancement layer NALUs.
1067 *
1068 * No more than one stream of @ref AVCodecParameters.codec_type "codec_type"
1069 * AVMEDIA_TYPE_DATA shall be present, and it must be of
1070 * @ref AVCodecParameters.codec_id "codec_id" AV_CODEC_ID_LCEVC.
1074
1075 /**
1076 * Index of the LCEVC data stream in AVStreamGroup.
1077 */
1079 /**
1080 * Width of the final stream for presentation.
1081 */
1083 /**
1084 * Height of the final image for presentation.
1085 */
1095 };
1096
1099
1101 /**
1102 * A class for @ref avoptions. Set by avformat_stream_group_create().
1103 */
1105
1107
1108 /**
1109 * Group index in AVFormatContext.
1110 */
1112
1113 /**
1114 * Group type-specific group ID.
1115 *
1116 * decoding: set by libavformat
1117 * encoding: may set by the user
1118 */
1120
1121 /**
1122 * Group type
1123 *
1124 * decoding: set by libavformat on group creation
1125 * encoding: set by avformat_stream_group_create()
1126 */
1128
1129 /**
1130 * Group type-specific parameters
1138
1139 /**
1140 * Metadata that applies to the whole group.
1141 *
1142 * - demuxing: set by libavformat on group creation
1143 * - muxing: may be set by the caller before avformat_write_header()
1144 *
1145 * Freed by libavformat in avformat_free_context().
1146 */
1148
1149 /**
1150 * Number of elements in AVStreamGroup.streams.
1151 *
1152 * Set by avformat_stream_group_add_stream() must not be modified by any other code.
1153 */
1155
1156 /**
1157 * A list of streams in the group. New entries are created with
1158 * avformat_stream_group_add_stream().
1159 *
1160 * - demuxing: entries are created by libavformat on group creation.
1161 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new entries may also
1162 * appear in av_read_frame().
1163 * - muxing: entries are created by the user before avformat_write_header().
1164 *
1165 * Freed by libavformat in avformat_free_context().
1166 */
1168
1169 /**
1170 * Stream group disposition - a combination of AV_DISPOSITION_* flags.
1171 * This field currently applies to all defined AVStreamGroupParamsType.
1172 *
1173 * - demuxing: set by libavformat when creating the group or in
1174 * avformat_find_stream_info().
1175 * - muxing: may be set by the caller before avformat_write_header().
1176 */
1179
1181
1182 #define AV_PROGRAM_RUNNING 1
1183
1184 /**
1185 * New fields can be added to the end with minor version bumps.
1186 * Removal, reordering and changes to existing fields require a major
1187 * version bump.
1188 * sizeof(AVProgram) must not be used outside libav*.
1202
1203 /*****************************************************************
1204 * All fields below this line are not part of the public API. They
1205 * may not be used outside of libavformat and can be changed and
1206 * removed at will.
1207 * New public fields should be added right above.
1208 *****************************************************************
1216
1217 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1218 (streams are added dynamically) */
1219 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely
1220 not seekable, and attempts to call the
1221 seek function will fail. For some
1222 network protocols (e.g. HLS), this can
1223 change dynamically at runtime. */
1231
1232
1233 /**
1234 * Callback used by devices to communicate with application.
1235 */
1238
1241
1242 /**
1243 * The duration of a video can be estimated through various ways, and this enum can be used
1244 * to know how the duration was estimated.
1250 };
1251
1252 /**
1253 * Format I/O context.
1254 * New fields can be added to the end with minor version bumps.
1255 * Removal, reordering and changes to existing fields require a major
1256 * version bump.
1257 * sizeof(AVFormatContext) must not be used outside libav*, use
1258 * avformat_alloc_context() to create an AVFormatContext.
1259 *
1260 * Fields can be accessed through AVOptions (av_opt*),
1261 * the name string used matches the associated command line parameter name and
1262 * can be found in libavformat/options_table.h.
1263 * The AVOption/command line parameter names differ in some cases from the C
1264 * structure field names for historic reasons or brevity.
1265 */
1267 /**
1268 * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1269 * Exports (de)muxer private options if they exist.
1270 */
1272
1273 /**
1274 * The input container format.
1275 *
1276 * Demuxing only, set by avformat_open_input().
1277 */
1279
1280 /**
1281 * The output container format.
1282 *
1283 * Muxing only, must be set by the caller before avformat_write_header().
1284 */
1286
1287 /**
1288 * Format private data. This is an AVOptions-enabled struct
1289 * if and only if iformat/oformat.priv_class is not NULL.
1290 *
1291 * - muxing: set by avformat_write_header()
1292 * - demuxing: set by avformat_open_input()
1293 */
1295
1296 /**
1297 * I/O context.
1298 *
1299 * - demuxing: either set by the user before avformat_open_input() (then
1300 * the user must close it manually) or set by avformat_open_input().
1301 * - muxing: set by the user before avformat_write_header(). The caller must
1302 * take care of closing / freeing the IO context.
1303 *
1304 * Do NOT set this field if AVFMT_NOFILE flag is set in
1305 * iformat/oformat.flags. In such a case, the (de)muxer will handle
1306 * I/O in some other way and this field will be NULL.
1307 */
1309
1310 /* stream info */
1311 /**
1312 * Flags signalling stream properties. A combination of AVFMTCTX_*.
1313 * Set by libavformat.
1314 */
1316
1317 /**
1318 * Number of elements in AVFormatContext.streams.
1319 *
1320 * Set by avformat_new_stream(), must not be modified by any other code.
1321 */
1323 /**
1324 * A list of all streams in the file. New streams are created with
1325 * avformat_new_stream().
1326 *
1327 * - demuxing: streams are created by libavformat in avformat_open_input().
1328 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1329 * appear in av_read_frame().
1330 * - muxing: streams are created by the user before avformat_write_header().
1331 *
1332 * Freed by libavformat in avformat_free_context().
1333 */
1335
1336 /**
1337 * Number of elements in AVFormatContext.stream_groups.
1338 *
1339 * Set by avformat_stream_group_create(), must not be modified by any other code.
1340 */
1342 /**
1343 * A list of all stream groups in the file. New groups are created with
1344 * avformat_stream_group_create(), and filled with avformat_stream_group_add_stream().
1345 *
1346 * - demuxing: groups may be created by libavformat in avformat_open_input().
1347 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new groups may also
1348 * appear in av_read_frame().
1349 * - muxing: groups may be created by the user before avformat_write_header().
1350 *
1351 * Freed by libavformat in avformat_free_context().
1352 */
1354
1355 /**
1356 * Number of chapters in AVChapter array.
1357 * When muxing, chapters are normally written in the file header,
1358 * so nb_chapters should normally be initialized before write_header
1359 * is called. Some muxers (e.g. mov and mkv) can also write chapters
1360 * in the trailer. To write chapters in the trailer, nb_chapters
1361 * must be zero when write_header is called and non-zero when
1362 * write_trailer is called.
1363 * - muxing: set by user
1364 * - demuxing: set by libavformat
1368
1369 /**
1370 * input or output URL. Unlike the old filename field, this field has no
1371 * length restriction.
1372 *
1373 * - demuxing: set by avformat_open_input(), initialized to an empty
1374 * string if url parameter was NULL in avformat_open_input().
1375 * - muxing: may be set by the caller before calling avformat_write_header()
1376 * (or avformat_init_output() if that is called first) to a string
1377 * which is freeable by av_free(). Set to an empty string if it
1378 * was NULL in avformat_init_output().
1379 *
1380 * Freed by libavformat in avformat_free_context().
1381 */
1383
1384 /**
1385 * Position of the first frame of the component, in
1386 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1387 * It is deduced from the AVStream values.
1388 *
1389 * Demuxing only, set by libavformat.
1390 */
1392
1393 /**
1394 * Duration of the stream, in AV_TIME_BASE fractional
1395 * seconds. Only set this value if you know none of the individual stream
1396 * durations and also do not set any of them. This is deduced from the
1397 * AVStream values if not set.
1398 *
1399 * Demuxing only, set by libavformat.
1400 */
1402
1403 /**
1404 * Total stream bitrate in bit/s, 0 if not
1405 * available. Never set it directly if the file_size and the
1406 * duration are known as FFmpeg can compute it automatically.
1407 */
1412
1413 /**
1414 * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1415 * Set by the user before avformat_open_input() / avformat_write_header().
1418 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1419 #define AVFMT_FLAG_IGNIDX 0x0002
///< Ignore index.
1420 #define AVFMT_FLAG_NONBLOCK 0x0004
///< Do not block when reading packets from input.
1421 #define AVFMT_FLAG_IGNDTS 0x0008
///< Ignore DTS on frames that contain both DTS & PTS
1422 #define AVFMT_FLAG_NOFILLIN 0x0010
///< Do not infer any values from other values, just return what is stored in the container
1423 #define AVFMT_FLAG_NOPARSE 0x0020
///< Do not use AVParsers, you also must set AVFMT_FLAG_NOFILLIN as the filling code works on frames and no parsing -> no frames. Also seeking to frames can not work if parsing to find frame boundaries has been disabled
1424 #define AVFMT_FLAG_NOBUFFER 0x0040
///< Do not buffer frames when possible
1425 #define AVFMT_FLAG_CUSTOM_IO 0x0080
///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1426 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1427 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1428 /**
1429 * When muxing, try to avoid writing any random/volatile data to the output.
1430 * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1431 *
1432 * This flag is mainly intended for testing.
1434 #define AVFMT_FLAG_BITEXACT 0x0400
1435 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1436 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1437 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
1438
1439 /**
1440 * Maximum number of bytes read from input in order to determine stream
1441 * properties. Used when reading the global header and in
1442 * avformat_find_stream_info().
1443 *
1444 * Demuxing only, set by the caller before avformat_open_input().
1445 *
1446 * @note this is \e not used for determining the \ref AVInputFormat
1447 * "input format"
1448 * @see format_probesize
1449 */
1451
1452 /**
1453 * Maximum duration (in AV_TIME_BASE units) of the data read
1454 * from input in avformat_find_stream_info().
1455 * Demuxing only, set by the caller before avformat_find_stream_info().
1456 * Can be set to 0 to let avformat choose using a heuristic.
1457 */
1465
1466 /**
1467 * Forced video codec_id.
1468 * Demuxing: Set by user.
1469 */
1471
1472 /**
1473 * Forced audio codec_id.
1474 * Demuxing: Set by user.
1475 */
1477
1478 /**
1479 * Forced subtitle codec_id.
1480 * Demuxing: Set by user.
1481 */
1483
1484 /**
1485 * Forced Data codec_id.
1486 * Demuxing: Set by user.
1487 */
1489
1490 /**
1491 * Metadata that applies to the whole file.
1492 *
1493 * - demuxing: set by libavformat in avformat_open_input()
1494 * - muxing: may be set by the caller before avformat_write_header()
1495 *
1496 * Freed by libavformat in avformat_free_context().
1497 */
1499
1500 /**
1501 * Start time of the stream in real world time, in microseconds
1502 * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1503 * stream was captured at this real world time.
1504 * - muxing: Set by the caller before avformat_write_header(). If set to
1505 * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1506 * be used.
1507 * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1508 * the value may become known after some number of frames
1509 * have been received.
1510 */
1512
1513 /**
1514 * The number of frames used for determining the framerate in
1515 * avformat_find_stream_info().
1516 * Demuxing only, set by the caller before avformat_find_stream_info().
1517 */
1519
1520 /**
1521 * Error recognition; higher values will detect more errors but may
1522 * misdetect some more or less valid parts as errors.
1523 * Demuxing only, set by the caller before avformat_open_input().
1524 */
1526
1527 /**
1528 * Custom interrupt callbacks for the I/O layer.
1529 *
1530 * demuxing: set by the user before avformat_open_input().
1531 * muxing: set by the user before avformat_write_header()
1532 * (mainly useful for AVFMT_NOFILE formats). The callback
1533 * should also be passed to avio_open2() if it's used to
1535 */
1537
1538 /**
1539 * Flags to enable debugging.
1542 #define FF_FDEBUG_TS 0x0001
1543
1544 /**
1545 * The maximum number of streams.
1546 * - encoding: unused
1547 * - decoding: set by user
1548 */
1550
1551 /**
1552 * Maximum amount of memory in bytes to use for the index of each stream.
1553 * If the index exceeds this size, entries will be discarded as
1554 * needed to maintain a smaller size. This can lead to slower or less
1555 * accurate seeking (depends on demuxer).
1556 * Demuxers for which a full in-memory index is mandatory will ignore
1557 * this.
1558 * - muxing: unused
1559 * - demuxing: set by user
1560 */
1562
1563 /**
1564 * Maximum amount of memory in bytes to use for buffering frames
1565 * obtained from realtime capture devices.
1566 */
1568
1569 /**
1570 * Maximum buffering duration for interleaving.
1571 *
1572 * To ensure all the streams are interleaved correctly,
1573 * av_interleaved_write_frame() will wait until it has at least one packet
1574 * for each stream before actually writing any packets to the output file.
1575 * When some streams are "sparse" (i.e. there are large gaps between
1576 * successive packets), this can result in excessive buffering.
1577 *
1578 * This field specifies the maximum difference between the timestamps of the
1579 * first and the last packet in the muxing queue, above which libavformat
1580 * will output a packet regardless of whether it has queued a packet for all
1581 * the streams.
1582 *
1583 * Muxing only, set by the caller before avformat_write_header().
1584 */
1586
1587 /**
1588 * Maximum number of packets to read while waiting for the first timestamp.
1590 */
1592
1593 /**
1594 * Max chunk time in microseconds.
1595 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1596 * - encoding: Set by user
1597 * - decoding: unused
1598 */
1600
1601 /**
1602 * Max chunk size in bytes
1603 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1604 * - encoding: Set by user
1605 * - decoding: unused
1606 */
1608
1609 /**
1610 * Maximum number of packets that can be probed
1611 * - encoding: unused
1612 * - decoding: set by user
1613 */
1615
1616 /**
1617 * Allow non-standard and experimental extension
1618 * @see AVCodecContext.strict_std_compliance
1619 */
1621
1622 /**
1623 * Flags indicating events happening on the file, a combination of
1624 * AVFMT_EVENT_FLAG_*.
1625 *
1626 * - demuxing: may be set by the demuxer in avformat_open_input(),
1627 * avformat_find_stream_info() and av_read_frame(). Flags must be cleared
1628 * by the user once the event has been handled.
1629 * - muxing: may be set by the user after avformat_write_header() to
1630 * indicate a user-triggered event. The muxer will clear the flags for
1631 * events it has handled in av_[interleaved]_write_frame().
1632 */
1634 /**
1635 * - demuxing: the demuxer read new metadata from the file and updated
1636 * AVFormatContext.metadata accordingly
1637 * - muxing: the user updated AVFormatContext.metadata and wishes the muxer to
1638 * write it into the file
1639 */
1640 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001
1641
1642
1643 /**
1644 * Avoid negative timestamps during muxing.
1645 * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1646 * Note, this works better when using av_interleaved_write_frame().
1647 * - muxing: Set by user
1648 * - demuxing: unused
1651 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1652 #define AVFMT_AVOID_NEG_TS_DISABLED 0
///< Do not shift timestamps even when they are negative.
1653 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1654 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1655
1656 /**
1657 * Audio preload in microseconds.
1658 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1659 * - encoding: Set by user
1660 * - decoding: unused
1661 */
1663
1664 /**
1665 * forces the use of wallclock timestamps as pts/dts of packets
1666 * This has undefined results in the presence of B frames.
1667 * - encoding: unused
1668 * - decoding: Set by user
1669 */
1671
1672 /**
1673 * Skip duration calculation in estimate_timings_from_pts.
1674 * - encoding: unused
1675 * - decoding: set by user
1676 *
1677 * @see duration_probesize
1678 */
1680
1681 /**
1682 * avio flags, used to force AVIO_FLAG_DIRECT.
1683 * - encoding: unused
1684 * - decoding: Set by user
1685 */
1687
1688 /**
1689 * The duration field can be estimated through various ways, and this field can be used
1690 * to know how the duration was estimated.
1691 * - encoding: unused
1692 * - decoding: Read by user
1693 */
1695
1696 /**
1697 * Skip initial bytes when opening stream
1698 * - encoding: unused
1699 * - decoding: Set by user
1700 */
1702
1703 /**
1704 * Correct single timestamp overflows
1705 * - encoding: unused
1706 * - decoding: Set by user
1707 */
1709
1710 /**
1711 * Force seeking to any (also non key) frames.
1712 * - encoding: unused
1713 * - decoding: Set by user
1714 */
1716
1717 /**
1718 * Flush the I/O context after each packet.
1719 * - encoding: Set by user
1720 * - decoding: unused
1721 */
1723
1724 /**
1725 * format probing score.
1726 * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1727 * the format.
1728 * - encoding: unused
1729 * - decoding: set by avformat, read by user
1730 */
1732
1733 /**
1734 * Maximum number of bytes read from input in order to identify the
1735 * \ref AVInputFormat "input format". Only used when the format is not set
1736 * explicitly by the caller.
1737 *
1738 * Demuxing only, set by the caller before avformat_open_input().
1739 *
1741 */
1743
1744 /**
1745 * ',' separated list of allowed decoders.
1746 * If NULL then all are allowed
1747 * - encoding: unused
1748 * - decoding: set by user
1749 */
1751
1752 /**
1753 * ',' separated list of allowed demuxers.
1754 * If NULL then all are allowed
1755 * - encoding: unused
1756 * - decoding: set by user
1757 */
1759
1760 /**
1761 * ',' separated list of allowed protocols.
1762 * - encoding: unused
1763 * - decoding: set by user
1764 */
1766
1767 /**
1768 * ',' separated list of disallowed protocols.
1769 * - encoding: unused
1770 * - decoding: set by user
1771 */
1773
1774 /**
1775 * IO repositioned flag.
1776 * This is set by avformat when the underlying IO context read pointer
1777 * is repositioned, for example when doing byte based seeking.
1778 * Demuxers can use the flag to detect such changes.
1779 */
1781
1782 /**
1783 * Forced video codec.
1784 * This allows forcing a specific decoder, even when there are multiple with
1785 * the same codec_id.
1786 * Demuxing: Set by user
1787 */
1789
1790 /**
1791 * Forced audio codec.
1792 * This allows forcing a specific decoder, even when there are multiple with
1793 * the same codec_id.
1794 * Demuxing: Set by user
1795 */
1797
1798 /**
1799 * Forced subtitle codec.
1800 * This allows forcing a specific decoder, even when there are multiple with
1801 * the same codec_id.
1802 * Demuxing: Set by user
1803 */
1805
1806 /**
1807 * Forced data codec.
1808 * This allows forcing a specific decoder, even when there are multiple with
1809 * the same codec_id.
1810 * Demuxing: Set by user
1811 */
1813
1814 /**
1815 * Number of bytes to be written as padding in a metadata header.
1816 * Demuxing: Unused.
1817 * Muxing: Set by user.
1818 */
1820
1821 /**
1822 * User data.
1823 * This is a place for some private data of the user.
1824 */
1826
1827 /**
1828 * Callback used by devices to communicate with application.
1829 */
1831
1832 /**
1833 * Output timestamp offset, in microseconds.
1834 * Muxing: set by user
1835 */
1837
1838 /**
1839 * dump format separator.
1840 * can be ", " or "\n " or anything else
1841 * - muxing: Set by user.
1842 * - demuxing: Set by user.
1843 */
1845
1846 /**
1847 * A callback for opening new IO streams.
1848 *
1849 * Whenever a muxer or a demuxer needs to open an IO stream (typically from
1850 * avformat_open_input() for demuxers, but for certain formats can happen at
1851 * other times as well), it will call this callback to obtain an IO context.
1852 *
1853 * @param s the format context
1854 * @param pb on success, the newly opened IO context should be returned here
1855 * @param url the url to open
1856 * @param flags a combination of AVIO_FLAG_*
1857 * @param options a dictionary of additional options, with the same
1858 * semantics as in avio_open2()
1859 * @return 0 on success, a negative AVERROR code on failure
1860 *
1861 * @note Certain muxers and demuxers do nesting, i.e. they open one or more
1862 * additional internal format contexts. Thus the AVFormatContext pointer
1863 * passed to this callback may be different from the one facing the caller.
1864 * It will, however, have the same 'opaque' field.
1865 */
1868
1869 /**
1870 * A callback for closing the streams opened with AVFormatContext.io_open().
1871 *
1872 * @param s the format context
1873 * @param pb IO context to be closed and freed
1874 * @return 0 on success, a negative AVERROR code on failure
1875 */
1877
1878 /**
1879 * Maximum number of bytes read from input in order to determine stream durations
1880 * when using estimate_timings_from_pts in avformat_find_stream_info().
1881 * Demuxing only, set by the caller before avformat_find_stream_info().
1882 * Can be set to 0 to let avformat choose using a heuristic.
1883 *
1884 * @see skip_estimate_duration_from_pts
1885 */
1888
1889 /**
1890 * @defgroup lavf_core Core functions
1891 * @ingroup libavf
1892 *
1893 * Functions for querying libavformat capabilities, allocating core structures,
1894 * etc.
1895 * @{
1896 */
1897
1898 /**
1899 * Return the LIBAVFORMAT_VERSION_INT constant.
1900 */
1902
1903 /**
1904 * Return the libavformat build-time configuration.
1905 */
1907
1908 /**
1909 * Return the libavformat license.
1910 */
1912
1913 /**
1914 * Do global initialization of network libraries. This is optional,
1915 * and not recommended anymore.
1916 *
1917 * This functions only exists to work around thread-safety issues
1918 * with older GnuTLS or OpenSSL libraries. If libavformat is linked
1919 * to newer versions of those libraries, or if you do not use them,
1920 * calling this function is unnecessary. Otherwise, you need to call
1921 * this function before any other threads using them are started.
1922 *
1923 * This function will be deprecated once support for older GnuTLS and
1924 * OpenSSL libraries is removed, and this function has no purpose
1925 * anymore.
1926 */
1928
1929 /**
1930 * Undo the initialization done by avformat_network_init. Call it only
1931 * once for each time you called avformat_network_init.
1932 */
1934
1935 /**
1936 * Iterate over all registered muxers.
1937 *
1938 * @param opaque a pointer where libavformat will store the iteration state. Must
1939 * point to NULL to start the iteration.
1940 *
1941 * @return the next registered muxer or NULL when the iteration is
1942 * finished
1943 */
1945
1946 /**
1947 * Iterate over all registered demuxers.
1948 *
1949 * @param opaque a pointer where libavformat will store the iteration state.
1950 * Must point to NULL to start the iteration.
1951 *
1952 * @return the next registered demuxer or NULL when the iteration is
1953 * finished
1954 */
1956
1957 /**
1958 * Allocate an AVFormatContext.
1959 * avformat_free_context() can be used to free the context and everything
1960 * allocated by the framework within it.
1961 */
1963
1964 /**
1965 * Free an AVFormatContext and all its streams.
1966 * @param s context to free
1967 */
1969
1970 /**
1971 * Get the AVClass for AVFormatContext. It can be used in combination with
1972 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1973 *
1974 * @see av_opt_find().
1975 */
1977
1978 /**
1979 * Get the AVClass for AVStream. It can be used in combination with
1980 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1981 *
1982 * @see av_opt_find().
1983 */
1985
1986 /**
1987 * Get the AVClass for AVStreamGroup. It can be used in combination with
1988 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1989 *
1990 * @see av_opt_find().
1991 */
1993
1994 /**
1995 * @return a string identifying the stream group type, or NULL if unknown
1996 */
1998
1999 /**
2000 * Add a new empty stream group to a media file.
2001 *
2002 * When demuxing, it may be called by the demuxer in read_header(). If the
2003 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2004 * be called in read_packet().
2005 *
2006 * When muxing, may be called by the user before avformat_write_header().
2007 *
2008 * User is required to call avformat_free_context() to clean up the allocation
2009 * by avformat_stream_group_create().
2010 *
2011 * New streams can be added to the group with avformat_stream_group_add_stream().
2012 *
2013 * @param s media file handle
2014 *
2015 * @return newly created group or NULL on error.
2016 * @see avformat_new_stream, avformat_stream_group_add_stream.
2017 */
2021
2022 /**
2023 * Add a new stream to a media file.
2024 *
2025 * When demuxing, it is called by the demuxer in read_header(). If the
2026 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2027 * be called in read_packet().
2028 *
2029 * When muxing, should be called by the user before avformat_write_header().
2030 *
2031 * User is required to call avformat_free_context() to clean up the allocation
2032 * by avformat_new_stream().
2033 *
2034 * @param s media file handle
2035 * @param c unused, does nothing
2036 *
2037 * @return newly created stream or NULL on error.
2038 */
2040
2041 /**
2042 * Add an already allocated stream to a stream group.
2043 *
2044 * When demuxing, it may be called by the demuxer in read_header(). If the
2045 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2046 * be called in read_packet().
2047 *
2048 * When muxing, may be called by the user before avformat_write_header() after
2049 * having allocated a new group with avformat_stream_group_create() and stream with
2050 * avformat_new_stream().
2051 *
2052 * User is required to call avformat_free_context() to clean up the allocation
2053 * by avformat_stream_group_add_stream().
2054 *
2055 * @param stg stream group belonging to a media file.
2056 * @param st stream in the media file to add to the group.
2057 *
2058 * @retval 0 success
2059 * @retval AVERROR(EEXIST) the stream was already in the group
2060 * @retval "another negative error code" legitimate errors
2061 *
2062 * @see avformat_new_stream, avformat_stream_group_create.
2063 */
2065
2067
2068 /**
2069 * @}
2070 */
2071
2072
2073 /**
2074 * Allocate an AVFormatContext for an output format.
2075 * avformat_free_context() can be used to free the context and
2076 * everything allocated by the framework within it.
2077 *
2078 * @param ctx pointee is set to the created format context,
2079 * or to NULL in case of failure
2080 * @param oformat format to use for allocating the context, if NULL
2081 * format_name and filename are used instead
2082 * @param format_name the name of output format to use for allocating the
2083 * context, if NULL filename is used instead
2084 * @param filename the name of the filename to use for allocating the
2085 * context, may be NULL
2086 *
2087 * @return >= 0 in case of success, a negative AVERROR code in case of
2088 * failure
2089 */
2092
2093 /**
2094 * @addtogroup lavf_decoding
2095 * @{
2096 */
2097
2098 /**
2099 * Find AVInputFormat based on the short name of the input format.
2100 */
2102
2103 /**
2104 * Guess the file format.
2105 *
2106 * @param pd data to be probed
2107 * @param is_opened Whether the file is already opened; determines whether
2108 * demuxers with or without AVFMT_NOFILE are probed.
2109 */
2111
2112 /**
2113 * Guess the file format.
2114 *
2115 * @param pd data to be probed
2116 * @param is_opened Whether the file is already opened; determines whether
2117 * demuxers with or without AVFMT_NOFILE are probed.
2118 * @param score_max A probe score larger that this is required to accept a
2119 * detection, the variable is set to the actual detection
2120 * score afterwards.
2121 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2122 * to retry with a larger probe buffer.
2123 */
2125 int is_opened, int *score_max);
2126
2127 /**
2128 * Guess the file format.
2129 *
2130 * @param is_opened Whether the file is already opened; determines whether
2131 * demuxers with or without AVFMT_NOFILE are probed.
2132 * @param score_ret The score of the best detection.
2133 */
2135 int is_opened, int *score_ret);
2136
2137 /**
2138 * Probe a bytestream to determine the input format. Each time a probe returns
2139 * with a score that is too low, the probe buffer size is increased and another
2140 * attempt is made. When the maximum probe size is reached, the input format
2141 * with the highest score is returned.
2142 *
2143 * @param pb the bytestream to probe
2144 * @param fmt the input format is put here
2145 * @param url the url of the stream
2146 * @param logctx the log context
2147 * @param offset the offset within the bytestream to probe from
2148 * @param max_probe_size the maximum probe buffer size (zero for default)
2149 *
2150 * @return the score in case of success, a negative value corresponding to an
2151 * the maximal score is AVPROBE_SCORE_MAX
2152 * AVERROR code otherwise
2153 */
2155 const char *
url,
void *logctx,
2156 unsigned int offset,
unsigned int max_probe_size);
2157
2158 /**
2159 * Like av_probe_input_buffer2() but returns 0 on success
2160 */
2162 const char *
url,
void *logctx,
2163 unsigned int offset,
unsigned int max_probe_size);
2164
2165 /**
2166 * Open an input stream and read the header. The codecs are not opened.
2167 * The stream must be closed with avformat_close_input().
2168 *
2169 * @param ps Pointer to user-supplied AVFormatContext (allocated by
2170 * avformat_alloc_context). May be a pointer to NULL, in
2171 * which case an AVFormatContext is allocated by this
2172 * function and written into ps.
2173 * Note that a user-supplied AVFormatContext will be freed
2174 * on failure and its pointer set to NULL.
2175 * @param url URL of the stream to open.
2176 * @param fmt If non-NULL, this parameter forces a specific input format.
2177 * Otherwise the format is autodetected.
2178 * @param options A dictionary filled with AVFormatContext and demuxer-private
2179 * options.
2180 * On return this parameter will be destroyed and replaced with
2181 * a dict containing options that were not found. May be NULL.
2182 *
2183 * @return 0 on success; on failure: frees ps, sets its pointer to NULL,
2184 * and returns a negative AVERROR.
2185 *
2186 * @note If you want to use custom IO, preallocate the format context and set its pb field.
2187 */
2190
2191 /**
2192 * Read packets of a media file to get stream information. This
2193 * is useful for file formats with no headers such as MPEG. This
2194 * function also computes the real framerate in case of MPEG-2 repeat
2195 * frame mode.
2196 * The logical file position is not changed by this function;
2197 * examined packets may be buffered for later processing.
2198 *
2199 * @param ic media file handle
2200 * @param options If non-NULL, an ic.nb_streams long array of pointers to
2201 * dictionaries, where i-th member contains options for
2202 * codec corresponding to i-th stream.
2203 * On return each dictionary will be filled with options that were not found.
2204 * @return >=0 if OK, AVERROR_xxx on error
2205 *
2206 * @note this function isn't guaranteed to open all the codecs, so
2207 * options being non-empty at return is a perfectly normal behavior.
2208 *
2209 * @todo Let the user decide somehow what information is needed so that
2210 * we do not waste time getting stuff the user does not need.
2211 */
2213
2214 /**
2215 * Find the programs which belong to a given stream.
2216 *
2217 * @param ic media file handle
2218 * @param last the last found program, the search will start after this
2219 * program, or from the beginning if it is NULL
2220 * @param s stream index
2221 *
2222 * @return the next program which belongs to s, NULL if no program is found or
2223 * the last program is not among the programs of ic.
2224 */
2226
2228
2229 /**
2230 * Find the "best" stream in the file.
2231 * The best stream is determined according to various heuristics as the most
2232 * likely to be what the user expects.
2233 * If the decoder parameter is non-NULL, av_find_best_stream will find the
2234 * default decoder for the stream's codec; streams for which no decoder can
2235 * be found are ignored.
2236 *
2237 * @param ic media file handle
2238 * @param type stream type: video, audio, subtitles, etc.
2239 * @param wanted_stream_nb user-requested stream number,
2240 * or -1 for automatic selection
2241 * @param related_stream try to find a stream related (eg. in the same
2242 * program) to this one, or -1 if none
2243 * @param decoder_ret if non-NULL, returns the decoder for the
2244 * selected stream
2245 * @param flags flags; none are currently defined
2246 *
2247 * @return the non-negative stream number in case of success,
2248 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2249 * could be found,
2250 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2251 *
2252 * @note If av_find_best_stream returns successfully and decoder_ret is not
2253 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2254 */
2257 int wanted_stream_nb,
2258 int related_stream,
2259 const struct AVCodec **decoder_ret,
2261
2262 /**
2263 * Return the next frame of a stream.
2264 * This function returns what is stored in the file, and does not validate
2265 * that what is there are valid frames for the decoder. It will split what is
2266 * stored in the file into frames and return one for each call. It will not
2267 * omit invalid data between valid frames so as to give the decoder the maximum
2268 * information possible for decoding.
2269 *
2270 * On success, the returned packet is reference-counted (pkt->buf is set) and
2271 * valid indefinitely. The packet must be freed with av_packet_unref() when
2272 * it is no longer needed. For video, the packet contains exactly one frame.
2273 * For audio, it contains an integer number of frames if each frame has
2274 * a known fixed size (e.g. PCM or ADPCM data). If the audio frames have
2275 * a variable size (e.g. MPEG audio), then it contains one frame.
2276 *
2277 * pkt->pts, pkt->dts and pkt->duration are always set to correct
2278 * values in AVStream.time_base units (and guessed if the format cannot
2279 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2280 * has B-frames, so it is better to rely on pkt->dts if you do not
2281 * decompress the payload.
2282 *
2283 * @return 0 if OK, < 0 on error or end of file. On error, pkt will be blank
2284 * (as if it came from av_packet_alloc()).
2285 *
2286 * @note pkt will be initialized, so it may be uninitialized, but it must not
2287 * contain data that needs to be freed.
2288 */
2290
2291 /**
2292 * Seek to the keyframe at timestamp.
2293 * 'timestamp' in 'stream_index'.
2294 *
2295 * @param s media file handle
2296 * @param stream_index If stream_index is (-1), a default stream is selected,
2297 * and timestamp is automatically converted from
2298 * AV_TIME_BASE units to the stream specific time_base.
2299 * @param timestamp Timestamp in AVStream.time_base units or, if no stream
2300 * is specified, in AV_TIME_BASE units.
2301 * @param flags flags which select direction and seeking mode
2302 *
2303 * @return >= 0 on success
2304 */
2307
2308 /**
2309 * Seek to timestamp ts.
2310 * Seeking will be done so that the point from which all active streams
2311 * can be presented successfully will be closest to ts and within min/max_ts.
2312 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2313 *
2314 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2315 * are the file position (this may not be supported by all demuxers).
2316 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2317 * in the stream with stream_index (this may not be supported by all demuxers).
2318 * Otherwise all timestamps are in units of the stream selected by stream_index
2319 * or if stream_index is -1, in AV_TIME_BASE units.
2320 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2321 * keyframes (this may not be supported by all demuxers).
2322 * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2323 *
2324 * @param s media file handle
2325 * @param stream_index index of the stream which is used as time base reference
2326 * @param min_ts smallest acceptable timestamp
2327 * @param ts target timestamp
2328 * @param max_ts largest acceptable timestamp
2329 * @param flags flags
2330 * @return >=0 on success, error code otherwise
2331 *
2332 * @note This is part of the new seek API which is still under construction.
2333 */
2335
2336 /**
2337 * Discard all internally buffered data. This can be useful when dealing with
2338 * discontinuities in the byte stream. Generally works only with formats that
2339 * can resync. This includes headerless formats like MPEG-TS/TS but should also
2340 * work with NUT, Ogg and in a limited way AVI for example.
2341 *
2342 * The set of streams, the detected duration, stream parameters and codecs do
2343 * not change when calling this function. If you want a complete reset, it's
2344 * better to open a new AVFormatContext.
2345 *
2346 * This does not flush the AVIOContext (s->pb). If necessary, call
2347 * avio_flush(s->pb) before calling this function.
2348 *
2349 * @param s media file handle
2350 * @return >=0 on success, error code otherwise
2351 */
2353
2354 /**
2355 * Start playing a network-based stream (e.g. RTSP stream) at the
2356 * current position.
2357 */
2359
2360 /**
2361 * Pause a network-based stream (e.g. RTSP stream).
2362 *
2363 * Use av_read_play() to resume it.
2364 */
2366
2367 /**
2368 * Close an opened input AVFormatContext. Free it and all its contents
2369 * and set *s to NULL.
2370 */
2372 /**
2373 * @}
2376 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2377 #define AVSEEK_FLAG_BYTE 2
///< seeking based on position in bytes
2378 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2379 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2380
2381 /**
2382 * @addtogroup lavf_encoding
2383 * @{
2386 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2387 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2388
2389 /**
2390 * Allocate the stream private data and write the stream header to
2391 * an output media file.
2392 *
2393 * @param s Media file handle, must be allocated with
2394 * avformat_alloc_context().
2395 * Its \ref AVFormatContext.oformat "oformat" field must be set
2396 * to the desired output format;
2397 * Its \ref AVFormatContext.pb "pb" field must be set to an
2398 * already opened ::AVIOContext.
2399 * @param options An ::AVDictionary filled with AVFormatContext and
2400 * muxer-private options.
2401 * On return this parameter will be destroyed and replaced with
2402 * a dict containing options that were not found. May be NULL.
2403 *
2404 * @retval AVSTREAM_INIT_IN_WRITE_HEADER On success, if the codec had not already been
2405 * fully initialized in avformat_init_output().
2406 * @retval AVSTREAM_INIT_IN_INIT_OUTPUT On success, if the codec had already been fully
2407 * initialized in avformat_init_output().
2408 * @retval AVERROR A negative AVERROR on failure.
2409 *
2410 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2411 */
2414
2415 /**
2416 * Allocate the stream private data and initialize the codec, but do not write the header.
2417 * May optionally be used before avformat_write_header() to initialize stream parameters
2418 * before actually writing the header.
2419 * If using this function, do not pass the same options to avformat_write_header().
2420 *
2421 * @param s Media file handle, must be allocated with
2422 * avformat_alloc_context().
2423 * Its \ref AVFormatContext.oformat "oformat" field must be set
2424 * to the desired output format;
2425 * Its \ref AVFormatContext.pb "pb" field must be set to an
2426 * already opened ::AVIOContext.
2427 * @param options An ::AVDictionary filled with AVFormatContext and
2428 * muxer-private options.
2429 * On return this parameter will be destroyed and replaced with
2430 * a dict containing options that were not found. May be NULL.
2431 *
2432 * @retval AVSTREAM_INIT_IN_WRITE_HEADER On success, if the codec requires
2433 * avformat_write_header to fully initialize.
2434 * @retval AVSTREAM_INIT_IN_INIT_OUTPUT On success, if the codec has been fully
2435 * initialized.
2436 * @retval AVERROR Anegative AVERROR on failure.
2437 *
2438 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2439 */
2442
2443 /**
2444 * Write a packet to an output media file.
2445 *
2446 * This function passes the packet directly to the muxer, without any buffering
2447 * or reordering. The caller is responsible for correctly interleaving the
2448 * packets if the format requires it. Callers that want libavformat to handle
2449 * the interleaving should call av_interleaved_write_frame() instead of this
2450 * function.
2451 *
2452 * @param s media file handle
2453 * @param pkt The packet containing the data to be written. Note that unlike
2454 * av_interleaved_write_frame(), this function does not take
2455 * ownership of the packet passed to it (though some muxers may make
2456 * an internal reference to the input packet).
2457 * <br>
2458 * This parameter can be NULL (at any time, not just at the end), in
2459 * order to immediately flush data buffered within the muxer, for
2460 * muxers that buffer up data internally before writing it to the
2461 * output.
2462 * <br>
2463 * Packet's @ref AVPacket.stream_index "stream_index" field must be
2464 * set to the index of the corresponding stream in @ref
2465 * AVFormatContext.streams "s->streams".
2466 * <br>
2467 * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2468 * must be set to correct values in the stream's timebase (unless the
2469 * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2470 * they can be set to AV_NOPTS_VALUE).
2471 * The dts for subsequent packets passed to this function must be strictly
2472 * increasing when compared in their respective timebases (unless the
2473 * output format is flagged with the AVFMT_TS_NONSTRICT, then they
2474 * merely have to be nondecreasing). @ref AVPacket.duration
2475 * "duration") should also be set if known.
2476 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2477 *
2478 * @see av_interleaved_write_frame()
2479 */
2481
2482 /**
2483 * Write a packet to an output media file ensuring correct interleaving.
2484 *
2485 * This function will buffer the packets internally as needed to make sure the
2486 * packets in the output file are properly interleaved, usually ordered by
2487 * increasing dts. Callers doing their own interleaving should call
2488 * av_write_frame() instead of this function.
2489 *
2490 * Using this function instead of av_write_frame() can give muxers advance
2491 * knowledge of future packets, improving e.g. the behaviour of the mp4
2492 * muxer for VFR content in fragmenting mode.
2493 *
2494 * @param s media file handle
2495 * @param pkt The packet containing the data to be written.
2496 * <br>
2497 * If the packet is reference-counted, this function will take
2498 * ownership of this reference and unreference it later when it sees
2499 * fit. If the packet is not reference-counted, libavformat will
2500 * make a copy.
2501 * The returned packet will be blank (as if returned from
2502 * av_packet_alloc()), even on error.
2503 * <br>
2504 * This parameter can be NULL (at any time, not just at the end), to
2505 * flush the interleaving queues.
2506 * <br>
2507 * Packet's @ref AVPacket.stream_index "stream_index" field must be
2508 * set to the index of the corresponding stream in @ref
2509 * AVFormatContext.streams "s->streams".
2510 * <br>
2511 * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2512 * must be set to correct values in the stream's timebase (unless the
2513 * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2514 * they can be set to AV_NOPTS_VALUE).
2515 * The dts for subsequent packets in one stream must be strictly
2516 * increasing (unless the output format is flagged with the
2517 * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2518 * @ref AVPacket.duration "duration" should also be set if known.
2519 *
2520 * @return 0 on success, a negative AVERROR on error.
2521 *
2522 * @see av_write_frame(), AVFormatContext.max_interleave_delta
2523 */
2525
2526 /**
2527 * Write an uncoded frame to an output media file.
2528 *
2529 * The frame must be correctly interleaved according to the container
2530 * specification; if not, av_interleaved_write_uncoded_frame() must be used.
2531 *
2532 * See av_interleaved_write_uncoded_frame() for details.
2533 */
2536
2537 /**
2538 * Write an uncoded frame to an output media file.
2539 *
2540 * If the muxer supports it, this function makes it possible to write an AVFrame
2541 * structure directly, without encoding it into a packet.
2542 * It is mostly useful for devices and similar special muxers that use raw
2543 * video or PCM data and will not serialize it into a byte stream.
2544 *
2545 * To test whether it is possible to use it with a given muxer and stream,
2546 * use av_write_uncoded_frame_query().
2547 *
2548 * The caller gives up ownership of the frame and must not access it
2549 * afterwards.
2550 *
2551 * @return >=0 for success, a negative code on error
2552 */
2555
2556 /**
2557 * Test whether a muxer supports uncoded frame.
2558 *
2559 * @return >=0 if an uncoded frame can be written to that muxer and stream,
2560 * <0 if not
2561 */
2563
2564 /**
2565 * Write the stream trailer to an output media file and free the
2566 * file private data.
2567 *
2568 * May only be called after a successful call to avformat_write_header.
2569 *
2570 * @param s media file handle
2571 * @return 0 if OK, AVERROR_xxx on error
2572 */
2574
2575 /**
2576 * Return the output format in the list of registered output formats
2577 * which best matches the provided parameters, or return NULL if
2578 * there is no match.
2579 *
2580 * @param short_name if non-NULL checks if short_name matches with the
2581 * names of the registered formats
2582 * @param filename if non-NULL checks if filename terminates with the
2583 * extensions of the registered formats
2584 * @param mime_type if non-NULL checks if mime_type matches with the
2585 * MIME type of the registered formats
2586 */
2588 const char *filename,
2589 const char *mime_type);
2590
2591 /**
2592 * Guess the codec ID based upon muxer and filename.
2593 */
2595 const char *filename, const char *mime_type,
2597
2598 /**
2599 * Get timing information for the data currently output.
2600 * The exact meaning of "currently output" depends on the format.
2601 * It is mostly relevant for devices that have an internal buffer and/or
2602 * work in real time.
2603 * @param s media file handle
2604 * @param stream stream in the media file
2605 * @param[out] dts DTS of the last packet output for the stream, in stream
2606 * time_base units
2607 * @param[out] wall absolute time when that packet whas output,
2608 * in microsecond
2609 * @retval 0 Success
2610 * @retval AVERROR(ENOSYS) The format does not support it
2611 *
2612 * @note Some formats or devices may not allow to measure dts and wall
2613 * atomically.
2614 */
2617
2618
2619 /**
2620 * @}
2621 */
2622
2623
2624 /**
2625 * @defgroup lavf_misc Utility functions
2626 * @ingroup libavf
2627 * @{
2628 *
2629 * Miscellaneous utility functions related to both muxing and demuxing
2630 * (or neither).
2631 */
2632
2633 /**
2634 * Send a nice hexadecimal dump of a buffer to the specified file stream.
2635 *
2636 * @param f The file stream pointer where the dump should be sent to.
2637 * @param buf buffer
2638 * @param size buffer size
2639 *
2640 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2641 */
2643
2644 /**
2645 * Send a nice hexadecimal dump of a buffer to the log.
2646 *
2647 * @param avcl A pointer to an arbitrary struct of which the first field is a
2648 * pointer to an AVClass struct.
2649 * @param level The importance level of the message, lower values signifying
2650 * higher importance.
2651 * @param buf buffer
2652 * @param size buffer size
2653 *
2654 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2655 */
2657
2658 /**
2659 * Send a nice dump of a packet to the specified file stream.
2660 *
2661 * @param f The file stream pointer where the dump should be sent to.
2662 * @param pkt packet to dump
2663 * @param dump_payload True if the payload must be displayed, too.
2664 * @param st AVStream that the packet belongs to
2665 */
2667
2668
2669 /**
2670 * Send a nice dump of a packet to the log.
2671 *
2672 * @param avcl A pointer to an arbitrary struct of which the first field is a
2673 * pointer to an AVClass struct.
2674 * @param level The importance level of the message, lower values signifying
2675 * higher importance.
2676 * @param pkt packet to dump
2677 * @param dump_payload True if the payload must be displayed, too.
2678 * @param st AVStream that the packet belongs to
2679 */
2682
2683 /**
2684 * Get the AVCodecID for the given codec tag tag.
2685 * If no codec id is found returns AV_CODEC_ID_NONE.
2686 *
2687 * @param tags list of supported codec_id-codec_tag pairs, as stored
2688 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2689 * @param tag codec tag to match to a codec ID
2690 */
2692
2693 /**
2694 * Get the codec tag for the given codec id id.
2695 * If no codec tag is found returns 0.
2696 *
2697 * @param tags list of supported codec_id-codec_tag pairs, as stored
2698 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2699 * @param id codec ID to match to a codec tag
2700 */
2702
2703 /**
2704 * Get the codec tag for the given codec id.
2705 *
2706 * @param tags list of supported codec_id - codec_tag pairs, as stored
2707 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2708 * @param id codec id that should be searched for in the list
2709 * @param tag A pointer to the found tag
2710 * @return 0 if id was not found in tags, > 0 if it was found
2711 */
2714
2716
2717 /**
2718 * Get the index for a specific timestamp.
2719 *
2720 * @param st stream that the timestamp belongs to
2721 * @param timestamp timestamp to retrieve the index for
2722 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2723 * to the timestamp which is <= the requested one, if backward
2724 * is 0, then it will be >=
2725 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2726 * @return < 0 if no such timestamp could be found
2727 */
2729
2730 /**
2731 * Get the index entry count for the given AVStream.
2732 *
2733 * @param st stream
2734 * @return the number of index entries in the stream
2735 */
2737
2738 /**
2739 * Get the AVIndexEntry corresponding to the given index.
2740 *
2741 * @param st Stream containing the requested AVIndexEntry.
2742 * @param idx The desired index.
2743 * @return A pointer to the requested AVIndexEntry if it exists, NULL otherwise.
2744 *
2745 * @note The pointer returned by this function is only guaranteed to be valid
2746 * until any function that takes the stream or the parent AVFormatContext
2747 * as input argument is called.
2748 */
2750
2751 /**
2752 * Get the AVIndexEntry corresponding to the given timestamp.
2753 *
2754 * @param st Stream containing the requested AVIndexEntry.
2755 * @param wanted_timestamp Timestamp to retrieve the index entry for.
2756 * @param flags If AVSEEK_FLAG_BACKWARD then the returned entry will correspond
2757 * to the timestamp which is <= the requested one, if backward
2758 * is 0, then it will be >=
2759 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise.
2760 * @return A pointer to the requested AVIndexEntry if it exists, NULL otherwise.
2761 *
2762 * @note The pointer returned by this function is only guaranteed to be valid
2763 * until any function that takes the stream or the parent AVFormatContext
2764 * as input argument is called.
2765 */
2769 /**
2770 * Add an index entry into a sorted list. Update the entry if the list
2771 * already contains it.
2772 *
2773 * @param timestamp timestamp in the time base of the given stream
2774 */
2777
2778
2779 /**
2780 * Split a URL string into components.
2781 *
2782 * The pointers to buffers for storing individual components may be null,
2783 * in order to ignore that component. Buffers for components not found are
2784 * set to empty strings. If the port is not found, it is set to a negative
2785 * value.
2786 *
2787 * @param proto the buffer for the protocol
2788 * @param proto_size the size of the proto buffer
2789 * @param authorization the buffer for the authorization
2790 * @param authorization_size the size of the authorization buffer
2791 * @param hostname the buffer for the host name
2792 * @param hostname_size the size of the hostname buffer
2793 * @param port_ptr a pointer to store the port number in
2794 * @param path the buffer for the path
2795 * @param path_size the size of the path buffer
2796 * @param url the URL to split
2797 */
2799 char *authorization, int authorization_size,
2800 char *hostname, int hostname_size,
2801 int *port_ptr,
2802 char *path, int path_size,
2804
2805
2806 /**
2807 * Print detailed information about the input or output format, such as
2808 * duration, bitrate, streams, container, programs, metadata, side data,
2809 * codec and time base.
2810 *
2811 * @param ic the context to analyze
2812 * @param index index of the stream to dump information about
2813 * @param url the URL to print, such as source or destination file
2814 * @param is_output Select whether the specified context is an input(0) or output(1)
2815 */
2819 int is_output);
2822 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
2823 #define AV_FRAME_FILENAME_FLAGS_IGNORE_TRUNCATION 2 ///< Ignore truncated output instead of returning an error
2824
2825 /**
2826 * Return in 'buf' the path with '%d' replaced by a number.
2827 *
2828 * Also handles the '%0nd' format where 'n' is the total number
2829 * of digits and '%%'.
2830 *
2831 * @param buf destination buffer
2832 * @param buf_size destination buffer size
2833 * @param path numbered sequence string
2834 * @param number frame number
2835 * @param flags AV_FRAME_FILENAME_FLAGS_*
2836 * @return 0 if OK, -1 on format error
2837 */
2839 const char *path,
int number,
int flags);
2840
2842 const char *path, int number);
2843
2844 /**
2845 * Check whether filename actually is a numbered sequence generator.
2846 *
2847 * @param filename possible numbered sequence string
2848 * @return 1 if a valid numbered sequence string, 0 otherwise
2849 */
2851
2852 /**
2853 * Generate an SDP for an RTP session.
2854 *
2855 * Note, this overwrites the id values of AVStreams in the muxer contexts
2856 * for getting unique dynamic payload types.
2857 *
2858 * @param ac array of AVFormatContexts describing the RTP streams. If the
2859 * array is composed by only one context, such context can contain
2860 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2861 * all the contexts in the array (an AVCodecContext per RTP stream)
2862 * must contain only one AVStream.
2863 * @param n_files number of AVCodecContexts contained in ac
2864 * @param buf buffer where the SDP will be stored (must be allocated by
2865 * the caller)
2866 * @param size the size of the buffer
2867 * @return 0 if OK, AVERROR_xxx on error
2868 */
2870
2871 /**
2872 * Return a positive value if the given filename has one of the given
2873 * extensions, 0 otherwise.
2874 *
2875 * @param filename file name to check against the given extensions
2876 * @param extensions a comma-separated list of filename extensions
2877 */
2878 int av_match_ext(
const char *filename,
const char *extensions);
2879
2880 /**
2881 * Test if the given container can store a codec.
2882 *
2883 * @param ofmt container to check for compatibility
2884 * @param codec_id codec to potentially store in container
2885 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2886 *
2887 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2888 * A negative number if this information is not available.
2889 */
2891 int std_compliance);
2892
2893 /**
2894 * @defgroup riff_fourcc RIFF FourCCs
2895 * @{
2896 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2897 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2898 * following code:
2899 * @code
2900 * uint32_t tag = MKTAG('H', '2', '6', '4');
2901 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2902 * enum AVCodecID id = av_codec_get_id(table, tag);
2903 * @endcode
2904 */
2905 /**
2906 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2907 */
2909 /**
2910 * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2911 */
2913 /**
2914 * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2915 */
2917 /**
2918 * @return the table mapping MOV FourCCs for audio to AVCodecID.
2919 */
2921
2922 /**
2923 * @}
2924 */
2925
2926 /**
2927 * Guess the sample aspect ratio of a frame, based on both the stream and the
2928 * frame aspect ratio.
2929 *
2930 * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2931 * is set by the demuxer, these two may not be equal. This function tries to
2932 * return the value that you should use if you would like to display the frame.
2933 *
2934 * Basic logic is to use the stream aspect ratio if it is set to something sane
2935 * otherwise use the frame aspect ratio. This way a container setting, which is
2936 * usually easy to modify can override the coded value in the frames.
2937 *
2938 * @param format the format context which the stream is part of
2939 * @param stream the stream which the frame is part of
2940 * @param frame the frame with the aspect ratio to be determined
2941 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2942 */
2945
2946 /**
2947 * Guess the frame rate, based on both the container and codec information.
2948 *
2949 * @param ctx the format context which the stream is part of
2950 * @param stream the stream which the frame is part of
2951 * @param frame the frame for which the frame rate should be determined, may be NULL
2952 * @return the guessed (valid) frame rate, 0/1 if no idea
2953 */
2956
2957 /**
2958 * Check if the stream st contained in s is matched by the stream specifier
2959 * spec.
2960 *
2961 * See the "stream specifiers" chapter in the documentation for the syntax
2962 * of spec.
2963 *
2964 * @return >0 if st is matched by spec;
2965 * 0 if st is not matched by spec;
2966 * AVERROR code if spec is invalid
2967 *
2968 * @note A stream specifier can match several streams in the format.
2969 */
2971 const char *spec);
2972
2974
2975 #if FF_API_INTERNAL_TIMING
2976 enum AVTimebaseSource {
2977 AVFMT_TBCF_AUTO = -1,
2978 AVFMT_TBCF_DECODER,
2979 AVFMT_TBCF_DEMUXER,
2980 #if FF_API_R_FRAME_RATE
2981 AVFMT_TBCF_R_FRAMERATE,
2982 #endif
2983 };
2984
2985 /**
2986 * @deprecated do not call this function
2987 */
2989 int avformat_transfer_internal_stream_timing_info(
const AVOutputFormat *ofmt,
2991 enum AVTimebaseSource
copy_tb);
2992
2993 /**
2994 * @deprecated do not call this function
2995 */
2998 #endif
2999
3000
3001 /**
3002 * @}
3003 */
3004
3005 #endif /* AVFORMAT_AVFORMAT_H */