FFmpeg
avformat.h
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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  * AVDictionaryEntry *e;
150  * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
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 
312 #include "libavcodec/codec_par.h"
313 #include "libavcodec/defs.h"
314 #include "libavcodec/packet.h"
315 
316 #include "libavutil/dict.h"
317 #include "libavutil/log.h"
318 
319 #include "avio.h"
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. */
325 #include "libavformat/version.h"
326 
327 #include "libavutil/frame.h"
328 #include "libavcodec/codec.h"
329 #endif
330 
331 struct AVFormatContext;
332 struct AVFrame;
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 
446 struct AVCodecTag;
447 
448 /**
449  * This structure contains the data a format has to probe a file.
450  */
451 typedef struct AVProbeData {
452  const char *filename;
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 */
455  const char *mime_type; /**< mime_type, when known. */
456 } AVProbeData;
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 75 ///< score for file 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  * - demuxers: will not be selected automatically by probing, must be specified
474  * explicitly.
475  */
476 #define AVFMT_EXPERIMENTAL 0x0004
477 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
478 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
479 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
480 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
481 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
482 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
483 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
484 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
485 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
486 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
487 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
488 #if FF_API_ALLOW_FLUSH
489 #define AVFMT_ALLOW_FLUSH 0x10000 /**< @deprecated: Just send a NULL packet if you want to flush a muxer. */
490 #endif
491 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
492  increasing timestamps, but they must
493  still be monotonic */
494 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
495  timestamps. If not set the timestamp
496  will be shifted in av_write_frame and
497  av_interleaved_write_frame so they
498  start from 0.
499  The user or muxer can override this through
500  AVFormatContext.avoid_negative_ts
501  */
502 
503 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
504 
505 /**
506  * @addtogroup lavf_encoding
507  * @{
508  */
509 typedef struct AVOutputFormat {
510  const char *name;
511  /**
512  * Descriptive name for the format, meant to be more human-readable
513  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
514  * to define it.
515  */
516  const char *long_name;
517  const char *mime_type;
518  const char *extensions; /**< comma-separated filename extensions */
519  /* output support */
520  enum AVCodecID audio_codec; /**< default audio codec */
521  enum AVCodecID video_codec; /**< default video codec */
522  enum AVCodecID subtitle_codec; /**< default subtitle codec */
523  /**
524  * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER,
525  * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
526  * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS,
527  * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
528  */
529  int flags;
530 
531  /**
532  * List of supported codec_id-codec_tag pairs, ordered by "better
533  * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
534  */
535  const struct AVCodecTag * const *codec_tag;
536 
537 
538  const AVClass *priv_class; ///< AVClass for the private context
540 /**
541  * @}
542  */
543 
544 /**
545  * @addtogroup lavf_decoding
546  * @{
547  */
548 typedef struct AVInputFormat {
549  /**
550  * A comma separated list of short names for the format. New names
551  * may be appended with a minor bump.
552  */
553  const char *name;
554 
555  /**
556  * Descriptive name for the format, meant to be more human-readable
557  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
558  * to define it.
559  */
560  const char *long_name;
561 
562  /**
563  * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
564  * AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
565  * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
566  */
567  int flags;
568 
569  /**
570  * If extensions are defined, then no probe is done. You should
571  * usually not use extension format guessing because it is not
572  * reliable enough
573  */
574  const char *extensions;
575 
576  const struct AVCodecTag * const *codec_tag;
577 
578  const AVClass *priv_class; ///< AVClass for the private context
579 
580  /**
581  * Comma-separated list of mime types.
582  * It is used check for matching mime types while probing.
583  * @see av_probe_input_format2
584  */
585  const char *mime_type;
586 } AVInputFormat;
587 /**
588  * @}
589  */
590 
593  AVSTREAM_PARSE_FULL, /**< full parsing and repack */
594  AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
595  AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
596  AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
597  AVSTREAM_PARSE_FULL_RAW, /**< full parsing and repack with timestamp and position generation by parser for raw
598  this assumes that each packet in the file contains no demuxer level headers and
599  just codec level data, otherwise position generation would fail */
600 };
601 
602 typedef struct AVIndexEntry {
603  int64_t pos;
604  int64_t timestamp; /**<
605  * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
606  * when seeking to this entry. That means preferable PTS on keyframe based formats.
607  * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
608  * is known
609  */
610 #define AVINDEX_KEYFRAME 0x0001
611 #define AVINDEX_DISCARD_FRAME 0x0002 /**
612  * Flag is used to indicate which frame should be discarded after decoding.
613  */
614  int flags:2;
615  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).
616  int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
617 } AVIndexEntry;
618 
619 /**
620  * The stream should be chosen by default among other streams of the same type,
621  * unless the user has explicitly specified otherwise.
622  */
623 #define AV_DISPOSITION_DEFAULT (1 << 0)
624 /**
625  * The stream is not in original language.
626  *
627  * @note AV_DISPOSITION_ORIGINAL is the inverse of this disposition. At most
628  * one of them should be set in properly tagged streams.
629  * @note This disposition may apply to any stream type, not just audio.
630  */
631 #define AV_DISPOSITION_DUB (1 << 1)
632 /**
633  * The stream is in original language.
634  *
635  * @see the notes for AV_DISPOSITION_DUB
636  */
637 #define AV_DISPOSITION_ORIGINAL (1 << 2)
638 /**
639  * The stream is a commentary track.
640  */
641 #define AV_DISPOSITION_COMMENT (1 << 3)
642 /**
643  * The stream contains song lyrics.
644  */
645 #define AV_DISPOSITION_LYRICS (1 << 4)
646 /**
647  * The stream contains karaoke audio.
648  */
649 #define AV_DISPOSITION_KARAOKE (1 << 5)
650 
651 /**
652  * Track should be used during playback by default.
653  * Useful for subtitle track that should be displayed
654  * even when user did not explicitly ask for subtitles.
655  */
656 #define AV_DISPOSITION_FORCED (1 << 6)
657 /**
658  * The stream is intended for hearing impaired audiences.
659  */
660 #define AV_DISPOSITION_HEARING_IMPAIRED (1 << 7)
661 /**
662  * The stream is intended for visually impaired audiences.
663  */
664 #define AV_DISPOSITION_VISUAL_IMPAIRED (1 << 8)
665 /**
666  * The audio stream contains music and sound effects without voice.
667  */
668 #define AV_DISPOSITION_CLEAN_EFFECTS (1 << 9)
669 /**
670  * The stream is stored in the file as an attached picture/"cover art" (e.g.
671  * APIC frame in ID3v2). The first (usually only) packet associated with it
672  * will be returned among the first few packets read from the file unless
673  * seeking takes place. It can also be accessed at any time in
674  * AVStream.attached_pic.
675  */
676 #define AV_DISPOSITION_ATTACHED_PIC (1 << 10)
677 /**
678  * The stream is sparse, and contains thumbnail images, often corresponding
679  * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
680  */
681 #define AV_DISPOSITION_TIMED_THUMBNAILS (1 << 11)
682 
683 /**
684  * The stream is intended to be mixed with a spatial audio track. For example,
685  * it could be used for narration or stereo music, and may remain unchanged by
686  * listener head rotation.
687  */
688 #define AV_DISPOSITION_NON_DIEGETIC (1 << 12)
689 
690 /**
691  * The subtitle stream contains captions, providing a transcription and possibly
692  * a translation of audio. Typically intended for hearing-impaired audiences.
693  */
694 #define AV_DISPOSITION_CAPTIONS (1 << 16)
695 /**
696  * The subtitle stream contains a textual description of the video content.
697  * Typically intended for visually-impaired audiences or for the cases where the
698  * video cannot be seen.
699  */
700 #define AV_DISPOSITION_DESCRIPTIONS (1 << 17)
701 /**
702  * The subtitle stream contains time-aligned metadata that is not intended to be
703  * directly presented to the user.
704  */
705 #define AV_DISPOSITION_METADATA (1 << 18)
706 /**
707  * The stream is intended to be mixed with another stream before presentation.
708  * Used for example to signal the stream contains an image part of a HEIF grid,
709  * or for mix_type=0 in mpegts.
710  */
711 #define AV_DISPOSITION_DEPENDENT (1 << 19)
712 /**
713  * The video stream contains still images.
714  */
715 #define AV_DISPOSITION_STILL_IMAGE (1 << 20)
716 
717 /**
718  * @return The AV_DISPOSITION_* flag corresponding to disp or a negative error
719  * code if disp does not correspond to a known stream disposition.
720  */
721 int av_disposition_from_string(const char *disp);
722 
723 /**
724  * @param disposition a combination of AV_DISPOSITION_* values
725  * @return The string description corresponding to the lowest set bit in
726  * disposition. NULL when the lowest set bit does not correspond
727  * to a known disposition or when disposition is 0.
728  */
729 const char *av_disposition_to_string(int disposition);
730 
731 /**
732  * Options for behavior on timestamp wrap detection.
733  */
734 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
735 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
736 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
737 
738 /**
739  * Stream structure.
740  * New fields can be added to the end with minor version bumps.
741  * Removal, reordering and changes to existing fields require a major
742  * version bump.
743  * sizeof(AVStream) must not be used outside libav*.
744  */
745 typedef struct AVStream {
746  /**
747  * A class for @ref avoptions. Set on stream creation.
748  */
750 
751  int index; /**< stream index in AVFormatContext */
752  /**
753  * Format-specific stream ID.
754  * decoding: set by libavformat
755  * encoding: set by the user, replaced by libavformat if left unset
756  */
757  int id;
758 
759  /**
760  * Codec parameters associated with this stream. Allocated and freed by
761  * libavformat in avformat_new_stream() and avformat_free_context()
762  * respectively.
763  *
764  * - demuxing: filled by libavformat on stream creation or in
765  * avformat_find_stream_info()
766  * - muxing: filled by the caller before avformat_write_header()
767  */
769 
770  void *priv_data;
771 
772  /**
773  * This is the fundamental unit of time (in seconds) in terms
774  * of which frame timestamps are represented.
775  *
776  * decoding: set by libavformat
777  * encoding: May be set by the caller before avformat_write_header() to
778  * provide a hint to the muxer about the desired timebase. In
779  * avformat_write_header(), the muxer will overwrite this field
780  * with the timebase that will actually be used for the timestamps
781  * written into the file (which may or may not be related to the
782  * user-provided one, depending on the format).
783  */
785 
786  /**
787  * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
788  * Only set this if you are absolutely 100% sure that the value you set
789  * it to really is the pts of the first frame.
790  * This may be undefined (AV_NOPTS_VALUE).
791  * @note The ASF header does NOT contain a correct start_time the ASF
792  * demuxer must NOT set this.
793  */
794  int64_t start_time;
795 
796  /**
797  * Decoding: duration of the stream, in stream time base.
798  * If a source file does not specify a duration, but does specify
799  * a bitrate, this value will be estimated from bitrate and file size.
800  *
801  * Encoding: May be set by the caller before avformat_write_header() to
802  * provide a hint to the muxer about the estimated duration.
803  */
804  int64_t duration;
805 
806  int64_t nb_frames; ///< number of frames in this stream if known or 0
807 
808  /**
809  * Stream disposition - a combination of AV_DISPOSITION_* flags.
810  * - demuxing: set by libavformat when creating the stream or in
811  * avformat_find_stream_info().
812  * - muxing: may be set by the caller before avformat_write_header().
813  */
815 
816  enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
817 
818  /**
819  * sample aspect ratio (0 if unknown)
820  * - encoding: Set by user.
821  * - decoding: Set by libavformat.
822  */
824 
826 
827  /**
828  * Average framerate
829  *
830  * - demuxing: May be set by libavformat when creating the stream or in
831  * avformat_find_stream_info().
832  * - muxing: May be set by the caller before avformat_write_header().
833  */
835 
836  /**
837  * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
838  * will contain the attached picture.
839  *
840  * decoding: set by libavformat, must not be modified by the caller.
841  * encoding: unused
842  */
844 
845 #if FF_API_AVSTREAM_SIDE_DATA
846  /**
847  * An array of side data that applies to the whole stream (i.e. the
848  * container does not allow it to change between packets).
849  *
850  * There may be no overlap between the side data in this array and side data
851  * in the packets. I.e. a given side data is either exported by the muxer
852  * (demuxing) / set by the caller (muxing) in this array, then it never
853  * appears in the packets, or the side data is exported / sent through
854  * the packets (always in the first packet where the value becomes known or
855  * changes), then it does not appear in this array.
856  *
857  * - demuxing: Set by libavformat when the stream is created.
858  * - muxing: May be set by the caller before avformat_write_header().
859  *
860  * Freed by libavformat in avformat_free_context().
861  *
862  * @deprecated use AVStream's @ref AVCodecParameters.coded_side_data
863  * "codecpar side data".
864  */
866  AVPacketSideData *side_data;
867  /**
868  * The number of elements in the AVStream.side_data array.
869  *
870  * @deprecated use AVStream's @ref AVCodecParameters.nb_coded_side_data
871  * "codecpar side data".
872  */
874  int nb_side_data;
875 #endif
876 
877  /**
878  * Flags indicating events happening on the stream, a combination of
879  * AVSTREAM_EVENT_FLAG_*.
880  *
881  * - demuxing: may be set by the demuxer in avformat_open_input(),
882  * avformat_find_stream_info() and av_read_frame(). Flags must be cleared
883  * by the user once the event has been handled.
884  * - muxing: may be set by the user after avformat_write_header(). to
885  * indicate a user-triggered event. The muxer will clear the flags for
886  * events it has handled in av_[interleaved]_write_frame().
887  */
888  int event_flags;
889 /**
890  * - demuxing: the demuxer read new metadata from the file and updated
891  * AVStream.metadata accordingly
892  * - muxing: the user updated AVStream.metadata and wishes the muxer to write
893  * it into the file
894  */
895 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001
896 /**
897  * - demuxing: new packets for this stream were read from the file. This
898  * event is informational only and does not guarantee that new packets
899  * for this stream will necessarily be returned from av_read_frame().
900  */
901 #define AVSTREAM_EVENT_FLAG_NEW_PACKETS (1 << 1)
902 
903  /**
904  * Real base framerate of the stream.
905  * This is the lowest framerate with which all timestamps can be
906  * represented accurately (it is the least common multiple of all
907  * framerates in the stream). Note, this value is just a guess!
908  * For example, if the time base is 1/90000 and all frames have either
909  * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
910  */
912 
913  /**
914  * Number of bits in timestamps. Used for wrapping control.
915  *
916  * - demuxing: set by libavformat
917  * - muxing: set by libavformat
918  *
919  */
920  int pts_wrap_bits;
921 } AVStream;
922 
923 /**
924  * AVStreamGroupTileGrid holds information on how to combine several
925  * independent images on a single canvas for presentation.
926  *
927  * The output should be a @ref AVStreamGroupTileGrid.background "background"
928  * colored @ref AVStreamGroupTileGrid.coded_width "coded_width" x
929  * @ref AVStreamGroupTileGrid.coded_height "coded_height" canvas where a
930  * @ref AVStreamGroupTileGrid.nb_tiles "nb_tiles" amount of tiles are placed in
931  * the order they appear in the @ref AVStreamGroupTileGrid.offsets "offsets"
932  * array, at the exact offset described for them. In particular, if two or more
933  * tiles overlap, the image with higher index in the
934  * @ref AVStreamGroupTileGrid.offsets "offsets" array takes priority.
935  * Note that a single image may be used multiple times, i.e. multiple entries
936  * in @ref AVStreamGroupTileGrid.offsets "offsets" may have the same value of
937  * idx.
938  *
939  * The following is an example of a simple grid with 3 rows and 4 columns:
940  *
941  * +---+---+---+---+
942  * | 0 | 1 | 2 | 3 |
943  * +---+---+---+---+
944  * | 4 | 5 | 6 | 7 |
945  * +---+---+---+---+
946  * | 8 | 9 |10 |11 |
947  * +---+---+---+---+
948  *
949  * Assuming all tiles have a dimension of 512x512, the
950  * @ref AVStreamGroupTileGrid.offsets "offset" of the topleft pixel of
951  * the first @ref AVStreamGroup.streams "stream" in the group is "0,0", the
952  * @ref AVStreamGroupTileGrid.offsets "offset" of the topleft pixel of
953  * the second @ref AVStreamGroup.streams "stream" in the group is "512,0", the
954  * @ref AVStreamGroupTileGrid.offsets "offset" of the topleft pixel of
955  * the fifth @ref AVStreamGroup.streams "stream" in the group is "0,512", the
956  * @ref AVStreamGroupTileGrid.offsets "offset", of the topleft pixel of
957  * the sixth @ref AVStreamGroup.streams "stream" in the group is "512,512",
958  * etc.
959  *
960  * The following is an example of a canvas with overlaping tiles:
961  *
962  * +-----------+
963  * | %%%%% |
964  * |***%%3%%@@@|
965  * |**0%%%%%2@@|
966  * |***##1@@@@@|
967  * | ##### |
968  * +-----------+
969  *
970  * Assuming a canvas with size 1024x1024 and all tiles with a dimension of
971  * 512x512, a possible @ref AVStreamGroupTileGrid.offsets "offset" for the
972  * topleft pixel of the first @ref AVStreamGroup.streams "stream" in the group
973  * would be 0x256, the @ref AVStreamGroupTileGrid.offsets "offset" for the
974  * topleft pixel of the second @ref AVStreamGroup.streams "stream" in the group
975  * would be 256x512, the @ref AVStreamGroupTileGrid.offsets "offset" for the
976  * topleft pixel of the third @ref AVStreamGroup.streams "stream" in the group
977  * would be 512x256, and the @ref AVStreamGroupTileGrid.offsets "offset" for
978  * the topleft pixel of the fourth @ref AVStreamGroup.streams "stream" in the
979  * group would be 256x0.
980  *
981  * sizeof(AVStreamGroupTileGrid) is not a part of the ABI and may only be
982  * allocated by avformat_stream_group_create().
983  */
984 typedef struct AVStreamGroupTileGrid {
985  const AVClass *av_class;
986 
987  /**
988  * Amount of tiles in the grid.
989  *
990  * Must be > 0.
991  */
992  unsigned int nb_tiles;
993 
994  /**
995  * Width of the canvas.
996  *
997  * Must be > 0.
998  */
999  int coded_width;
1000  /**
1001  * Width of the canvas.
1002  *
1003  * Must be > 0.
1004  */
1005  int coded_height;
1006 
1007  /**
1008  * An @ref nb_tiles sized array of offsets in pixels from the topleft edge
1009  * of the canvas, indicating where each stream should be placed.
1010  * It must be allocated with the av_malloc() family of functions.
1011  *
1012  * - demuxing: set by libavformat, must not be modified by the caller.
1013  * - muxing: set by the caller before avformat_write_header().
1014  *
1015  * Freed by libavformat in avformat_free_context().
1016  */
1017  struct {
1018  /**
1019  * Index of the stream in the group this tile references.
1020  *
1021  * Must be < @ref AVStreamGroup.nb_streams "nb_streams".
1022  */
1023  unsigned int idx;
1024  /**
1025  * Offset in pixels from the left edge of the canvas where the tile
1026  * should be placed.
1027  */
1028  int horizontal;
1029  /**
1030  * Offset in pixels from the top edge of the canvas where the tile
1031  * should be placed.
1032  */
1033  int vertical;
1034  } *offsets;
1035 
1036  /**
1037  * The pixel value per channel in RGBA format used if no pixel of any tile
1038  * is located at a particular pixel location.
1039  *
1040  * @see av_image_fill_color().
1041  * @see av_parse_color().
1042  */
1043  uint8_t background[4];
1044 
1045  /**
1046  * Offset in pixels from the left edge of the canvas where the actual image
1047  * meant for presentation starts.
1048  *
1049  * This field must be >= 0 and < @ref coded_width.
1050  */
1051  int horizontal_offset;
1052  /**
1053  * Offset in pixels from the top edge of the canvas where the actual image
1054  * meant for presentation starts.
1055  *
1056  * This field must be >= 0 and < @ref coded_height.
1057  */
1058  int vertical_offset;
1059 
1060  /**
1061  * Width of the final image for presentation.
1062  *
1063  * Must be > 0 and <= (@ref coded_width - @ref horizontal_offset).
1064  * When it's not equal to (@ref coded_width - @ref horizontal_offset), the
1065  * result of (@ref coded_width - width - @ref horizontal_offset) is the
1066  * amount amount of pixels to be cropped from the right edge of the
1067  * final image before presentation.
1068  */
1069  int width;
1070  /**
1071  * Height of the final image for presentation.
1072  *
1073  * Must be > 0 and <= (@ref coded_height - @ref vertical_offset).
1074  * When it's not equal to (@ref coded_height - @ref vertical_offset), the
1075  * result of (@ref coded_height - height - @ref vertical_offset) is the
1076  * amount amount of pixels to be cropped from the bottom edge of the
1077  * final image before presentation.
1078  */
1079  int height;
1087 };
1088 
1089 struct AVIAMFAudioElement;
1091 
1092 typedef struct AVStreamGroup {
1093  /**
1094  * A class for @ref avoptions. Set by avformat_stream_group_create().
1095  */
1097 
1098  void *priv_data;
1099 
1100  /**
1101  * Group index in AVFormatContext.
1102  */
1103  unsigned int index;
1104 
1105  /**
1106  * Group type-specific group ID.
1107  *
1108  * decoding: set by libavformat
1109  * encoding: may set by the user
1110  */
1111  int64_t id;
1112 
1113  /**
1114  * Group type
1115  *
1116  * decoding: set by libavformat on group creation
1117  * encoding: set by avformat_stream_group_create()
1118  */
1120 
1121  /**
1122  * Group type-specific parameters
1123  */
1124  union {
1128  } params;
1129 
1130  /**
1131  * Metadata that applies to the whole group.
1132  *
1133  * - demuxing: set by libavformat on group creation
1134  * - muxing: may be set by the caller before avformat_write_header()
1135  *
1136  * Freed by libavformat in avformat_free_context().
1137  */
1139 
1140  /**
1141  * Number of elements in AVStreamGroup.streams.
1142  *
1143  * Set by avformat_stream_group_add_stream() must not be modified by any other code.
1144  */
1145  unsigned int nb_streams;
1146 
1147  /**
1148  * A list of streams in the group. New entries are created with
1149  * avformat_stream_group_add_stream().
1150  *
1151  * - demuxing: entries are created by libavformat on group creation.
1152  * If AVFMTCTX_NOHEADER is set in ctx_flags, then new entries may also
1153  * appear in av_read_frame().
1154  * - muxing: entries are created by the user before avformat_write_header().
1155  *
1156  * Freed by libavformat in avformat_free_context().
1157  */
1158  AVStream **streams;
1159 
1160  /**
1161  * Stream group disposition - a combination of AV_DISPOSITION_* flags.
1162  * This field currently applies to all defined AVStreamGroupParamsType.
1163  *
1164  * - demuxing: set by libavformat when creating the group or in
1165  * avformat_find_stream_info().
1166  * - muxing: may be set by the caller before avformat_write_header().
1167  */
1168  int disposition;
1169 } AVStreamGroup;
1170 
1172 
1173 #define AV_PROGRAM_RUNNING 1
1174 
1175 /**
1176  * New fields can be added to the end with minor version bumps.
1177  * Removal, reordering and changes to existing fields require a major
1178  * version bump.
1179  * sizeof(AVProgram) must not be used outside libav*.
1180  */
1181 typedef struct AVProgram {
1182  int id;
1183  int flags;
1184  enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1185  unsigned int *stream_index;
1186  unsigned int nb_stream_indexes;
1190  int pmt_pid;
1191  int pcr_pid;
1192  int pmt_version;
1193 
1194  /*****************************************************************
1195  * All fields below this line are not part of the public API. They
1196  * may not be used outside of libavformat and can be changed and
1197  * removed at will.
1198  * New public fields should be added right above.
1199  *****************************************************************
1200  */
1201  int64_t start_time;
1202  int64_t end_time;
1204  int64_t pts_wrap_reference; ///< reference dts for wrap detection
1205  int pts_wrap_behavior; ///< behavior on wrap detection
1207 
1208 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1209  (streams are added dynamically) */
1210 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely
1211  not seekable, and attempts to call the
1212  seek function will fail. For some
1213  network protocols (e.g. HLS), this can
1214  change dynamically at runtime. */
1216 typedef struct AVChapter {
1217  int64_t id; ///< unique ID to identify the chapter
1218  AVRational time_base; ///< time base in which the start/end timestamps are specified
1219  int64_t start, end; ///< chapter start/end time in time_base units
1221 } AVChapter;
1222 
1223 
1224 /**
1225  * Callback used by devices to communicate with application.
1226  */
1227 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1228  void *data, size_t data_size);
1229 
1230 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
1232 
1233 /**
1234  * The duration of a video can be estimated through various ways, and this enum can be used
1235  * to know how the duration was estimated.
1236  */
1238  AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1239  AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1240  AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1241 };
1242 
1243 /**
1244  * Format I/O context.
1245  * New fields can be added to the end with minor version bumps.
1246  * Removal, reordering and changes to existing fields require a major
1247  * version bump.
1248  * sizeof(AVFormatContext) must not be used outside libav*, use
1249  * avformat_alloc_context() to create an AVFormatContext.
1250  *
1251  * Fields can be accessed through AVOptions (av_opt*),
1252  * the name string used matches the associated command line parameter name and
1253  * can be found in libavformat/options_table.h.
1254  * The AVOption/command line parameter names differ in some cases from the C
1255  * structure field names for historic reasons or brevity.
1256  */
1257 typedef struct AVFormatContext {
1258  /**
1259  * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1260  * Exports (de)muxer private options if they exist.
1261  */
1262  const AVClass *av_class;
1263 
1264  /**
1265  * The input container format.
1266  *
1267  * Demuxing only, set by avformat_open_input().
1268  */
1269  const struct AVInputFormat *iformat;
1270 
1271  /**
1272  * The output container format.
1273  *
1274  * Muxing only, must be set by the caller before avformat_write_header().
1275  */
1276  const struct AVOutputFormat *oformat;
1277 
1278  /**
1279  * Format private data. This is an AVOptions-enabled struct
1280  * if and only if iformat/oformat.priv_class is not NULL.
1281  *
1282  * - muxing: set by avformat_write_header()
1283  * - demuxing: set by avformat_open_input()
1284  */
1285  void *priv_data;
1286 
1287  /**
1288  * I/O context.
1289  *
1290  * - demuxing: either set by the user before avformat_open_input() (then
1291  * the user must close it manually) or set by avformat_open_input().
1292  * - muxing: set by the user before avformat_write_header(). The caller must
1293  * take care of closing / freeing the IO context.
1294  *
1295  * Do NOT set this field if AVFMT_NOFILE flag is set in
1296  * iformat/oformat.flags. In such a case, the (de)muxer will handle
1297  * I/O in some other way and this field will be NULL.
1298  */
1299  AVIOContext *pb;
1300 
1301  /* stream info */
1302  /**
1303  * Flags signalling stream properties. A combination of AVFMTCTX_*.
1304  * Set by libavformat.
1305  */
1306  int ctx_flags;
1307 
1308  /**
1309  * Number of elements in AVFormatContext.streams.
1310  *
1311  * Set by avformat_new_stream(), must not be modified by any other code.
1312  */
1313  unsigned int nb_streams;
1314  /**
1315  * A list of all streams in the file. New streams are created with
1316  * avformat_new_stream().
1317  *
1318  * - demuxing: streams are created by libavformat in avformat_open_input().
1319  * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1320  * appear in av_read_frame().
1321  * - muxing: streams are created by the user before avformat_write_header().
1322  *
1323  * Freed by libavformat in avformat_free_context().
1324  */
1325  AVStream **streams;
1326 
1327  /**
1328  * Number of elements in AVFormatContext.stream_groups.
1329  *
1330  * Set by avformat_stream_group_create(), must not be modified by any other code.
1331  */
1332  unsigned int nb_stream_groups;
1333  /**
1334  * A list of all stream groups in the file. New groups are created with
1335  * avformat_stream_group_create(), and filled with avformat_stream_group_add_stream().
1336  *
1337  * - demuxing: groups may be created by libavformat in avformat_open_input().
1338  * If AVFMTCTX_NOHEADER is set in ctx_flags, then new groups may also
1339  * appear in av_read_frame().
1340  * - muxing: groups may be created by the user before avformat_write_header().
1341  *
1342  * Freed by libavformat in avformat_free_context().
1343  */
1345 
1346  /**
1347  * Number of chapters in AVChapter array.
1348  * When muxing, chapters are normally written in the file header,
1349  * so nb_chapters should normally be initialized before write_header
1350  * is called. Some muxers (e.g. mov and mkv) can also write chapters
1351  * in the trailer. To write chapters in the trailer, nb_chapters
1352  * must be zero when write_header is called and non-zero when
1353  * write_trailer is called.
1354  * - muxing: set by user
1355  * - demuxing: set by libavformat
1356  */
1357  unsigned int nb_chapters;
1358  AVChapter **chapters;
1359 
1360  /**
1361  * input or output URL. Unlike the old filename field, this field has no
1362  * length restriction.
1363  *
1364  * - demuxing: set by avformat_open_input(), initialized to an empty
1365  * string if url parameter was NULL in avformat_open_input().
1366  * - muxing: may be set by the caller before calling avformat_write_header()
1367  * (or avformat_init_output() if that is called first) to a string
1368  * which is freeable by av_free(). Set to an empty string if it
1369  * was NULL in avformat_init_output().
1370  *
1371  * Freed by libavformat in avformat_free_context().
1372  */
1373  char *url;
1374 
1375  /**
1376  * Position of the first frame of the component, in
1377  * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1378  * It is deduced from the AVStream values.
1379  *
1380  * Demuxing only, set by libavformat.
1381  */
1382  int64_t start_time;
1383 
1384  /**
1385  * Duration of the stream, in AV_TIME_BASE fractional
1386  * seconds. Only set this value if you know none of the individual stream
1387  * durations and also do not set any of them. This is deduced from the
1388  * AVStream values if not set.
1389  *
1390  * Demuxing only, set by libavformat.
1391  */
1392  int64_t duration;
1393 
1394  /**
1395  * Total stream bitrate in bit/s, 0 if not
1396  * available. Never set it directly if the file_size and the
1397  * duration are known as FFmpeg can compute it automatically.
1398  */
1399  int64_t bit_rate;
1401  unsigned int packet_size;
1402  int max_delay;
1403 
1404  /**
1405  * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1406  * Set by the user before avformat_open_input() / avformat_write_header().
1407  */
1408  int flags;
1409 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1410 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1411 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1412 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1413 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1414 #define AVFMT_FLAG_NOPARSE 0x0020 ///< Do not use AVParsers, you also must set AVFMT_FLAG_NOFILLIN as the fillin 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
1415 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1416 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1417 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1418 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1419 /**
1420  * When muxing, try to avoid writing any random/volatile data to the output.
1421  * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1422  *
1423  * This flag is mainly intended for testing.
1424  */
1425 #define AVFMT_FLAG_BITEXACT 0x0400
1426 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1427 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1428 #if FF_API_LAVF_SHORTEST
1429 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
1430 #endif
1431 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
1432 
1433  /**
1434  * Maximum number of bytes read from input in order to determine stream
1435  * properties. Used when reading the global header and in
1436  * avformat_find_stream_info().
1437  *
1438  * Demuxing only, set by the caller before avformat_open_input().
1439  *
1440  * @note this is \e not used for determining the \ref AVInputFormat
1441  * "input format"
1442  * @see format_probesize
1443  */
1444  int64_t probesize;
1445 
1446  /**
1447  * Maximum duration (in AV_TIME_BASE units) of the data read
1448  * from input in avformat_find_stream_info().
1449  * Demuxing only, set by the caller before avformat_find_stream_info().
1450  * Can be set to 0 to let avformat choose using a heuristic.
1451  */
1454  const uint8_t *key;
1455  int keylen;
1457  unsigned int nb_programs;
1458  AVProgram **programs;
1459 
1460  /**
1461  * Forced video codec_id.
1462  * Demuxing: Set by user.
1463  */
1465 
1466  /**
1467  * Forced audio codec_id.
1468  * Demuxing: Set by user.
1469  */
1471 
1472  /**
1473  * Forced subtitle codec_id.
1474  * Demuxing: Set by user.
1475  */
1477 
1478  /**
1479  * Forced Data codec_id.
1480  * Demuxing: Set by user.
1481  */
1482  enum AVCodecID data_codec_id;
1483 
1484  /**
1485  * Metadata that applies to the whole file.
1486  *
1487  * - demuxing: set by libavformat in avformat_open_input()
1488  * - muxing: may be set by the caller before avformat_write_header()
1489  *
1490  * Freed by libavformat in avformat_free_context().
1491  */
1493 
1494  /**
1495  * Start time of the stream in real world time, in microseconds
1496  * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1497  * stream was captured at this real world time.
1498  * - muxing: Set by the caller before avformat_write_header(). If set to
1499  * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1500  * be used.
1501  * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1502  * the value may become known after some number of frames
1503  * have been received.
1504  */
1505  int64_t start_time_realtime;
1506 
1507  /**
1508  * The number of frames used for determining the framerate in
1509  * avformat_find_stream_info().
1510  * Demuxing only, set by the caller before avformat_find_stream_info().
1511  */
1512  int fps_probe_size;
1513 
1514  /**
1515  * Error recognition; higher values will detect more errors but may
1516  * misdetect some more or less valid parts as errors.
1517  * Demuxing only, set by the caller before avformat_open_input().
1518  */
1519  int error_recognition;
1520 
1521  /**
1522  * Custom interrupt callbacks for the I/O layer.
1523  *
1524  * demuxing: set by the user before avformat_open_input().
1525  * muxing: set by the user before avformat_write_header()
1526  * (mainly useful for AVFMT_NOFILE formats). The callback
1527  * should also be passed to avio_open2() if it's used to
1528  * open the file.
1529  */
1531 
1532  /**
1533  * Flags to enable debugging.
1534  */
1535  int debug;
1536 #define FF_FDEBUG_TS 0x0001
1537 
1538  /**
1539  * The maximum number of streams.
1540  * - encoding: unused
1541  * - decoding: set by user
1542  */
1543  int max_streams;
1544 
1545  /**
1546  * Maximum amount of memory in bytes to use for the index of each stream.
1547  * If the index exceeds this size, entries will be discarded as
1548  * needed to maintain a smaller size. This can lead to slower or less
1549  * accurate seeking (depends on demuxer).
1550  * Demuxers for which a full in-memory index is mandatory will ignore
1551  * this.
1552  * - muxing: unused
1553  * - demuxing: set by user
1554  */
1555  unsigned int max_index_size;
1556 
1557  /**
1558  * Maximum amount of memory in bytes to use for buffering frames
1559  * obtained from realtime capture devices.
1560  */
1561  unsigned int max_picture_buffer;
1562 
1563  /**
1564  * Maximum buffering duration for interleaving.
1565  *
1566  * To ensure all the streams are interleaved correctly,
1567  * av_interleaved_write_frame() will wait until it has at least one packet
1568  * for each stream before actually writing any packets to the output file.
1569  * When some streams are "sparse" (i.e. there are large gaps between
1570  * successive packets), this can result in excessive buffering.
1571  *
1572  * This field specifies the maximum difference between the timestamps of the
1573  * first and the last packet in the muxing queue, above which libavformat
1574  * will output a packet regardless of whether it has queued a packet for all
1575  * the streams.
1576  *
1577  * Muxing only, set by the caller before avformat_write_header().
1578  */
1579  int64_t max_interleave_delta;
1580 
1581  /**
1582  * Maximum number of packets to read while waiting for the first timestamp.
1583  * Decoding only.
1584  */
1585  int max_ts_probe;
1586 
1587  /**
1588  * Max chunk time in microseconds.
1589  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1590  * - encoding: Set by user
1591  * - decoding: unused
1592  */
1593  int max_chunk_duration;
1594 
1595  /**
1596  * Max chunk size in bytes
1597  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1598  * - encoding: Set by user
1599  * - decoding: unused
1600  */
1601  int max_chunk_size;
1602 
1603  /**
1604  * Maximum number of packets that can be probed
1605  * - encoding: unused
1606  * - decoding: set by user
1607  */
1608  int max_probe_packets;
1609 
1610  /**
1611  * Allow non-standard and experimental extension
1612  * @see AVCodecContext.strict_std_compliance
1613  */
1615 
1616  /**
1617  * Flags indicating events happening on the file, a combination of
1618  * AVFMT_EVENT_FLAG_*.
1619  *
1620  * - demuxing: may be set by the demuxer in avformat_open_input(),
1621  * avformat_find_stream_info() and av_read_frame(). Flags must be cleared
1622  * by the user once the event has been handled.
1623  * - muxing: may be set by the user after avformat_write_header() to
1624  * indicate a user-triggered event. The muxer will clear the flags for
1625  * events it has handled in av_[interleaved]_write_frame().
1626  */
1627  int event_flags;
1628 /**
1629  * - demuxing: the demuxer read new metadata from the file and updated
1630  * AVFormatContext.metadata accordingly
1631  * - muxing: the user updated AVFormatContext.metadata and wishes the muxer to
1632  * write it into the file
1633  */
1634 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001
1635 
1636 
1637  /**
1638  * Avoid negative timestamps during muxing.
1639  * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1640  * Note, this works better when using av_interleaved_write_frame().
1641  * - muxing: Set by user
1642  * - demuxing: unused
1643  */
1645 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1646 #define AVFMT_AVOID_NEG_TS_DISABLED 0 ///< Do not shift timestamps even when they are negative.
1647 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1648 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1649 
1650  /**
1651  * Audio preload in microseconds.
1652  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1653  * - encoding: Set by user
1654  * - decoding: unused
1655  */
1656  int audio_preload;
1657 
1658  /**
1659  * forces the use of wallclock timestamps as pts/dts of packets
1660  * This has undefined results in the presence of B frames.
1661  * - encoding: unused
1662  * - decoding: Set by user
1663  */
1665 
1666  /**
1667  * Skip duration calcuation in estimate_timings_from_pts.
1668  * - encoding: unused
1669  * - decoding: set by user
1670  *
1671  * @see duration_probesize
1672  */
1674 
1675  /**
1676  * avio flags, used to force AVIO_FLAG_DIRECT.
1677  * - encoding: unused
1678  * - decoding: Set by user
1679  */
1680  int avio_flags;
1681 
1682  /**
1683  * The duration field can be estimated through various ways, and this field can be used
1684  * to know how the duration was estimated.
1685  * - encoding: unused
1686  * - decoding: Read by user
1687  */
1689 
1690  /**
1691  * Skip initial bytes when opening stream
1692  * - encoding: unused
1693  * - decoding: Set by user
1694  */
1695  int64_t skip_initial_bytes;
1696 
1697  /**
1698  * Correct single timestamp overflows
1699  * - encoding: unused
1700  * - decoding: Set by user
1701  */
1702  unsigned int correct_ts_overflow;
1703 
1704  /**
1705  * Force seeking to any (also non key) frames.
1706  * - encoding: unused
1707  * - decoding: Set by user
1708  */
1709  int seek2any;
1710 
1711  /**
1712  * Flush the I/O context after each packet.
1713  * - encoding: Set by user
1714  * - decoding: unused
1715  */
1716  int flush_packets;
1717 
1718  /**
1719  * format probing score.
1720  * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1721  * the format.
1722  * - encoding: unused
1723  * - decoding: set by avformat, read by user
1724  */
1725  int probe_score;
1726 
1727  /**
1728  * Maximum number of bytes read from input in order to identify the
1729  * \ref AVInputFormat "input format". Only used when the format is not set
1730  * explicitly by the caller.
1731  *
1732  * Demuxing only, set by the caller before avformat_open_input().
1733  *
1734  * @see probesize
1735  */
1736  int format_probesize;
1737 
1738  /**
1739  * ',' separated list of allowed decoders.
1740  * If NULL then all are allowed
1741  * - encoding: unused
1742  * - decoding: set by user
1743  */
1744  char *codec_whitelist;
1745 
1746  /**
1747  * ',' separated list of allowed demuxers.
1748  * If NULL then all are allowed
1749  * - encoding: unused
1750  * - decoding: set by user
1751  */
1752  char *format_whitelist;
1753 
1754  /**
1755  * ',' separated list of allowed protocols.
1756  * - encoding: unused
1757  * - decoding: set by user
1758  */
1759  char *protocol_whitelist;
1760 
1761  /**
1762  * ',' separated list of disallowed protocols.
1763  * - encoding: unused
1764  * - decoding: set by user
1765  */
1766  char *protocol_blacklist;
1767 
1768  /**
1769  * IO repositioned flag.
1770  * This is set by avformat when the underlaying IO context read pointer
1771  * is repositioned, for example when doing byte based seeking.
1772  * Demuxers can use the flag to detect such changes.
1773  */
1774  int io_repositioned;
1775 
1776  /**
1777  * Forced video codec.
1778  * This allows forcing a specific decoder, even when there are multiple with
1779  * the same codec_id.
1780  * Demuxing: Set by user
1781  */
1782  const struct AVCodec *video_codec;
1783 
1784  /**
1785  * Forced audio codec.
1786  * This allows forcing a specific decoder, even when there are multiple with
1787  * the same codec_id.
1788  * Demuxing: Set by user
1789  */
1790  const struct AVCodec *audio_codec;
1791 
1792  /**
1793  * Forced subtitle codec.
1794  * This allows forcing a specific decoder, even when there are multiple with
1795  * the same codec_id.
1796  * Demuxing: Set by user
1797  */
1798  const struct AVCodec *subtitle_codec;
1799 
1800  /**
1801  * Forced data codec.
1802  * This allows forcing a specific decoder, even when there are multiple with
1803  * the same codec_id.
1804  * Demuxing: Set by user
1805  */
1806  const struct AVCodec *data_codec;
1807 
1808  /**
1809  * Number of bytes to be written as padding in a metadata header.
1810  * Demuxing: Unused.
1811  * Muxing: Set by user.
1812  */
1814 
1815  /**
1816  * User data.
1817  * This is a place for some private data of the user.
1818  */
1819  void *opaque;
1820 
1821  /**
1822  * Callback used by devices to communicate with application.
1823  */
1825 
1826  /**
1827  * Output timestamp offset, in microseconds.
1828  * Muxing: set by user
1829  */
1830  int64_t output_ts_offset;
1831 
1832  /**
1833  * dump format separator.
1834  * can be ", " or "\n " or anything else
1835  * - muxing: Set by user.
1836  * - demuxing: Set by user.
1837  */
1838  uint8_t *dump_separator;
1839 
1840  /**
1841  * A callback for opening new IO streams.
1842  *
1843  * Whenever a muxer or a demuxer needs to open an IO stream (typically from
1844  * avformat_open_input() for demuxers, but for certain formats can happen at
1845  * other times as well), it will call this callback to obtain an IO context.
1846  *
1847  * @param s the format context
1848  * @param pb on success, the newly opened IO context should be returned here
1849  * @param url the url to open
1850  * @param flags a combination of AVIO_FLAG_*
1851  * @param options a dictionary of additional options, with the same
1852  * semantics as in avio_open2()
1853  * @return 0 on success, a negative AVERROR code on failure
1854  *
1855  * @note Certain muxers and demuxers do nesting, i.e. they open one or more
1856  * additional internal format contexts. Thus the AVFormatContext pointer
1857  * passed to this callback may be different from the one facing the caller.
1858  * It will, however, have the same 'opaque' field.
1859  */
1860  int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url,
1861  int flags, AVDictionary **options);
1862 
1863  /**
1864  * A callback for closing the streams opened with AVFormatContext.io_open().
1865  *
1866  * Using this is preferred over io_close, because this can return an error.
1867  * Therefore this callback is used instead of io_close by the generic
1868  * libavformat code if io_close is NULL or the default.
1869  *
1870  * @param s the format context
1871  * @param pb IO context to be closed and freed
1872  * @return 0 on success, a negative AVERROR code on failure
1873  */
1874  int (*io_close2)(struct AVFormatContext *s, AVIOContext *pb);
1875 
1876  /**
1877  * Maximum number of bytes read from input in order to determine stream durations
1878  * when using estimate_timings_from_pts in avformat_find_stream_info().
1879  * Demuxing only, set by the caller before avformat_find_stream_info().
1880  * Can be set to 0 to let avformat choose using a heuristic.
1881  *
1882  * @see skip_estimate_duration_from_pts
1883  */
1884  int64_t duration_probesize;
1885 } AVFormatContext;
1886 
1887 /**
1888  * This function will cause global side data to be injected in the next packet
1889  * of each stream as well as after any subsequent seek.
1890  *
1891  * @note global side data is always available in every AVStream's
1892  * @ref AVCodecParameters.coded_side_data "codecpar side data" array, and
1893  * in a @ref AVCodecContext.coded_side_data "decoder's side data" array if
1894  * initialized with said stream's codecpar.
1895  * @see av_packet_side_data_get()
1896  */
1898 
1899 #if FF_API_GET_DUR_ESTIMATE_METHOD
1900 /**
1901  * Returns the method used to set ctx->duration.
1902  *
1903  * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1904  * @deprecated duration_estimation_method is public and can be read directly.
1905  */
1907 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
1908 #endif
1909 
1910 /**
1911  * @defgroup lavf_core Core functions
1912  * @ingroup libavf
1913  *
1914  * Functions for querying libavformat capabilities, allocating core structures,
1915  * etc.
1916  * @{
1917  */
1918 
1919 /**
1920  * Return the LIBAVFORMAT_VERSION_INT constant.
1921  */
1922 unsigned avformat_version(void);
1923 
1924 /**
1925  * Return the libavformat build-time configuration.
1926  */
1927 const char *avformat_configuration(void);
1928 
1929 /**
1930  * Return the libavformat license.
1931  */
1932 const char *avformat_license(void);
1933 
1934 /**
1935  * Do global initialization of network libraries. This is optional,
1936  * and not recommended anymore.
1937  *
1938  * This functions only exists to work around thread-safety issues
1939  * with older GnuTLS or OpenSSL libraries. If libavformat is linked
1940  * to newer versions of those libraries, or if you do not use them,
1941  * calling this function is unnecessary. Otherwise, you need to call
1942  * this function before any other threads using them are started.
1943  *
1944  * This function will be deprecated once support for older GnuTLS and
1945  * OpenSSL libraries is removed, and this function has no purpose
1946  * anymore.
1947  */
1948 int avformat_network_init(void);
1949 
1950 /**
1951  * Undo the initialization done by avformat_network_init. Call it only
1952  * once for each time you called avformat_network_init.
1953  */
1954 int avformat_network_deinit(void);
1955 
1956 /**
1957  * Iterate over all registered muxers.
1958  *
1959  * @param opaque a pointer where libavformat will store the iteration state. Must
1960  * point to NULL to start the iteration.
1961  *
1962  * @return the next registered muxer or NULL when the iteration is
1963  * finished
1964  */
1965 const AVOutputFormat *av_muxer_iterate(void **opaque);
1966 
1967 /**
1968  * Iterate over all registered demuxers.
1969  *
1970  * @param opaque a pointer where libavformat will store the iteration state.
1971  * Must point to NULL to start the iteration.
1972  *
1973  * @return the next registered demuxer or NULL when the iteration is
1974  * finished
1975  */
1976 const AVInputFormat *av_demuxer_iterate(void **opaque);
1977 
1978 /**
1979  * Allocate an AVFormatContext.
1980  * avformat_free_context() can be used to free the context and everything
1981  * allocated by the framework within it.
1982  */
1984 
1985 /**
1986  * Free an AVFormatContext and all its streams.
1987  * @param s context to free
1988  */
1990 
1991 /**
1992  * Get the AVClass for AVFormatContext. It can be used in combination with
1993  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1994  *
1995  * @see av_opt_find().
1996  */
1997 const AVClass *avformat_get_class(void);
1998 
1999 /**
2000  * Get the AVClass for AVStream. It can be used in combination with
2001  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2002  *
2003  * @see av_opt_find().
2004  */
2005 const AVClass *av_stream_get_class(void);
2006 
2007 /**
2008  * Get the AVClass for AVStreamGroup. It can be used in combination with
2009  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2010  *
2011  * @see av_opt_find().
2012  */
2013 const AVClass *av_stream_group_get_class(void);
2014 
2015 /**
2016  * @return a string identifying the stream group type, or NULL if unknown
2017  */
2019 
2020 /**
2021  * Add a new empty stream group to a media file.
2022  *
2023  * When demuxing, it may be called by the demuxer in read_header(). If the
2024  * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2025  * be called in read_packet().
2026  *
2027  * When muxing, may be called by the user before avformat_write_header().
2028  *
2029  * User is required to call avformat_free_context() to clean up the allocation
2030  * by avformat_stream_group_create().
2031  *
2032  * New streams can be added to the group with avformat_stream_group_add_stream().
2033  *
2034  * @param s media file handle
2035  *
2036  * @return newly created group or NULL on error.
2037  * @see avformat_new_stream, avformat_stream_group_add_stream.
2038  */
2041  AVDictionary **options);
2042 
2043 /**
2044  * Add a new stream to a media file.
2045  *
2046  * When demuxing, it is called by the demuxer in read_header(). If the
2047  * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2048  * be called in read_packet().
2049  *
2050  * When muxing, should be called by the user before avformat_write_header().
2051  *
2052  * User is required to call avformat_free_context() to clean up the allocation
2053  * by avformat_new_stream().
2054  *
2055  * @param s media file handle
2056  * @param c unused, does nothing
2057  *
2058  * @return newly created stream or NULL on error.
2059  */
2061 
2062 /**
2063  * Add an already allocated stream to a stream group.
2064  *
2065  * When demuxing, it may be called by the demuxer in read_header(). If the
2066  * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2067  * be called in read_packet().
2068  *
2069  * When muxing, may be called by the user before avformat_write_header() after
2070  * having allocated a new group with avformat_stream_group_create() and stream with
2071  * avformat_new_stream().
2072  *
2073  * User is required to call avformat_free_context() to clean up the allocation
2074  * by avformat_stream_group_add_stream().
2075  *
2076  * @param stg stream group belonging to a media file.
2077  * @param st stream in the media file to add to the group.
2078  *
2079  * @retval 0 success
2080  * @retval AVERROR(EEXIST) the stream was already in the group
2081  * @retval "another negative error code" legitimate errors
2082  *
2083  * @see avformat_new_stream, avformat_stream_group_create.
2084  */
2086 
2087 #if FF_API_AVSTREAM_SIDE_DATA
2088 /**
2089  * Wrap an existing array as stream side data.
2090  *
2091  * @param st stream
2092  * @param type side information type
2093  * @param data the side data array. It must be allocated with the av_malloc()
2094  * family of functions. The ownership of the data is transferred to
2095  * st.
2096  * @param size side information size
2097  *
2098  * @return zero on success, a negative AVERROR code on failure. On failure,
2099  * the stream is unchanged and the data remains owned by the caller.
2100  * @deprecated use av_packet_side_data_add() with the stream's
2101  * @ref AVCodecParameters.coded_side_data "codecpar side data"
2102  */
2104 int av_stream_add_side_data(AVStream *st, enum AVPacketSideDataType type,
2105  uint8_t *data, size_t size);
2106 
2107 /**
2108  * Allocate new information from stream.
2109  *
2110  * @param stream stream
2111  * @param type desired side information type
2112  * @param size side information size
2113  *
2114  * @return pointer to fresh allocated data or NULL otherwise
2115  * @deprecated use av_packet_side_data_new() with the stream's
2116  * @ref AVCodecParameters.coded_side_data "codecpar side data"
2117  */
2119 uint8_t *av_stream_new_side_data(AVStream *stream,
2120  enum AVPacketSideDataType type, size_t size);
2121 /**
2122  * Get side information from stream.
2123  *
2124  * @param stream stream
2125  * @param type desired side information type
2126  * @param size If supplied, *size will be set to the size of the side data
2127  * or to zero if the desired side data is not present.
2128  *
2129  * @return pointer to data if present or NULL otherwise
2130  * @deprecated use av_packet_side_data_get() with the stream's
2131  * @ref AVCodecParameters.coded_side_data "codecpar side data"
2132  */
2134 uint8_t *av_stream_get_side_data(const AVStream *stream,
2135  enum AVPacketSideDataType type, size_t *size);
2136 #endif
2137 
2139 
2140 /**
2141  * @}
2142  */
2143 
2144 
2145 /**
2146  * Allocate an AVFormatContext for an output format.
2147  * avformat_free_context() can be used to free the context and
2148  * everything allocated by the framework within it.
2149  *
2150  * @param ctx pointee is set to the created format context,
2151  * or to NULL in case of failure
2152  * @param oformat format to use for allocating the context, if NULL
2153  * format_name and filename are used instead
2154  * @param format_name the name of output format to use for allocating the
2155  * context, if NULL filename is used instead
2156  * @param filename the name of the filename to use for allocating the
2157  * context, may be NULL
2158  *
2159  * @return >= 0 in case of success, a negative AVERROR code in case of
2160  * failure
2161  */
2163  const char *format_name, const char *filename);
2164 
2165 /**
2166  * @addtogroup lavf_decoding
2167  * @{
2168  */
2169 
2170 /**
2171  * Find AVInputFormat based on the short name of the input format.
2172  */
2173 const AVInputFormat *av_find_input_format(const char *short_name);
2174 
2175 /**
2176  * Guess the file format.
2177  *
2178  * @param pd data to be probed
2179  * @param is_opened Whether the file is already opened; determines whether
2180  * demuxers with or without AVFMT_NOFILE are probed.
2181  */
2182 const AVInputFormat *av_probe_input_format(const AVProbeData *pd, int is_opened);
2183 
2184 /**
2185  * Guess the file format.
2186  *
2187  * @param pd data to be probed
2188  * @param is_opened Whether the file is already opened; determines whether
2189  * demuxers with or without AVFMT_NOFILE are probed.
2190  * @param score_max A probe score larger that this is required to accept a
2191  * detection, the variable is set to the actual detection
2192  * score afterwards.
2193  * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2194  * to retry with a larger probe buffer.
2195  */
2197  int is_opened, int *score_max);
2198 
2199 /**
2200  * Guess the file format.
2201  *
2202  * @param is_opened Whether the file is already opened; determines whether
2203  * demuxers with or without AVFMT_NOFILE are probed.
2204  * @param score_ret The score of the best detection.
2205  */
2207  int is_opened, int *score_ret);
2208 
2209 /**
2210  * Probe a bytestream to determine the input format. Each time a probe returns
2211  * with a score that is too low, the probe buffer size is increased and another
2212  * attempt is made. When the maximum probe size is reached, the input format
2213  * with the highest score is returned.
2214  *
2215  * @param pb the bytestream to probe
2216  * @param fmt the input format is put here
2217  * @param url the url of the stream
2218  * @param logctx the log context
2219  * @param offset the offset within the bytestream to probe from
2220  * @param max_probe_size the maximum probe buffer size (zero for default)
2221  *
2222  * @return the score in case of success, a negative value corresponding to an
2223  * the maximal score is AVPROBE_SCORE_MAX
2224  * AVERROR code otherwise
2225  */
2227  const char *url, void *logctx,
2228  unsigned int offset, unsigned int max_probe_size);
2229 
2230 /**
2231  * Like av_probe_input_buffer2() but returns 0 on success
2232  */
2234  const char *url, void *logctx,
2235  unsigned int offset, unsigned int max_probe_size);
2236 
2237 /**
2238  * Open an input stream and read the header. The codecs are not opened.
2239  * The stream must be closed with avformat_close_input().
2240  *
2241  * @param ps Pointer to user-supplied AVFormatContext (allocated by
2242  * avformat_alloc_context). May be a pointer to NULL, in
2243  * which case an AVFormatContext is allocated by this
2244  * function and written into ps.
2245  * Note that a user-supplied AVFormatContext will be freed
2246  * on failure.
2247  * @param url URL of the stream to open.
2248  * @param fmt If non-NULL, this parameter forces a specific input format.
2249  * Otherwise the format is autodetected.
2250  * @param options A dictionary filled with AVFormatContext and demuxer-private
2251  * options.
2252  * On return this parameter will be destroyed and replaced with
2253  * a dict containing options that were not found. May be NULL.
2254  *
2255  * @return 0 on success, a negative AVERROR on failure.
2256  *
2257  * @note If you want to use custom IO, preallocate the format context and set its pb field.
2258  */
2259 int avformat_open_input(AVFormatContext **ps, const char *url,
2260  const AVInputFormat *fmt, AVDictionary **options);
2261 
2262 /**
2263  * Read packets of a media file to get stream information. This
2264  * is useful for file formats with no headers such as MPEG. This
2265  * function also computes the real framerate in case of MPEG-2 repeat
2266  * frame mode.
2267  * The logical file position is not changed by this function;
2268  * examined packets may be buffered for later processing.
2269  *
2270  * @param ic media file handle
2271  * @param options If non-NULL, an ic.nb_streams long array of pointers to
2272  * dictionaries, where i-th member contains options for
2273  * codec corresponding to i-th stream.
2274  * On return each dictionary will be filled with options that were not found.
2275  * @return >=0 if OK, AVERROR_xxx on error
2276  *
2277  * @note this function isn't guaranteed to open all the codecs, so
2278  * options being non-empty at return is a perfectly normal behavior.
2279  *
2280  * @todo Let the user decide somehow what information is needed so that
2281  * we do not waste time getting stuff the user does not need.
2282  */
2284 
2285 /**
2286  * Find the programs which belong to a given stream.
2287  *
2288  * @param ic media file handle
2289  * @param last the last found program, the search will start after this
2290  * program, or from the beginning if it is NULL
2291  * @param s stream index
2292  *
2293  * @return the next program which belongs to s, NULL if no program is found or
2294  * the last program is not among the programs of ic.
2295  */
2297 
2298 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
2299 
2300 /**
2301  * Find the "best" stream in the file.
2302  * The best stream is determined according to various heuristics as the most
2303  * likely to be what the user expects.
2304  * If the decoder parameter is non-NULL, av_find_best_stream will find the
2305  * default decoder for the stream's codec; streams for which no decoder can
2306  * be found are ignored.
2307  *
2308  * @param ic media file handle
2309  * @param type stream type: video, audio, subtitles, etc.
2310  * @param wanted_stream_nb user-requested stream number,
2311  * or -1 for automatic selection
2312  * @param related_stream try to find a stream related (eg. in the same
2313  * program) to this one, or -1 if none
2314  * @param decoder_ret if non-NULL, returns the decoder for the
2315  * selected stream
2316  * @param flags flags; none are currently defined
2317  *
2318  * @return the non-negative stream number in case of success,
2319  * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2320  * could be found,
2321  * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2322  *
2323  * @note If av_find_best_stream returns successfully and decoder_ret is not
2324  * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2325  */
2327  enum AVMediaType type,
2328  int wanted_stream_nb,
2329  int related_stream,
2330  const struct AVCodec **decoder_ret,
2331  int flags);
2332 
2333 /**
2334  * Return the next frame of a stream.
2335  * This function returns what is stored in the file, and does not validate
2336  * that what is there are valid frames for the decoder. It will split what is
2337  * stored in the file into frames and return one for each call. It will not
2338  * omit invalid data between valid frames so as to give the decoder the maximum
2339  * information possible for decoding.
2340  *
2341  * On success, the returned packet is reference-counted (pkt->buf is set) and
2342  * valid indefinitely. The packet must be freed with av_packet_unref() when
2343  * it is no longer needed. For video, the packet contains exactly one frame.
2344  * For audio, it contains an integer number of frames if each frame has
2345  * a known fixed size (e.g. PCM or ADPCM data). If the audio frames have
2346  * a variable size (e.g. MPEG audio), then it contains one frame.
2347  *
2348  * pkt->pts, pkt->dts and pkt->duration are always set to correct
2349  * values in AVStream.time_base units (and guessed if the format cannot
2350  * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2351  * has B-frames, so it is better to rely on pkt->dts if you do not
2352  * decompress the payload.
2353  *
2354  * @return 0 if OK, < 0 on error or end of file. On error, pkt will be blank
2355  * (as if it came from av_packet_alloc()).
2356  *
2357  * @note pkt will be initialized, so it may be uninitialized, but it must not
2358  * contain data that needs to be freed.
2359  */
2361 
2362 /**
2363  * Seek to the keyframe at timestamp.
2364  * 'timestamp' in 'stream_index'.
2365  *
2366  * @param s media file handle
2367  * @param stream_index If stream_index is (-1), a default stream is selected,
2368  * and timestamp is automatically converted from
2369  * AV_TIME_BASE units to the stream specific time_base.
2370  * @param timestamp Timestamp in AVStream.time_base units or, if no stream
2371  * is specified, in AV_TIME_BASE units.
2372  * @param flags flags which select direction and seeking mode
2373  *
2374  * @return >= 0 on success
2375  */
2376 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2377  int flags);
2378 
2379 /**
2380  * Seek to timestamp ts.
2381  * Seeking will be done so that the point from which all active streams
2382  * can be presented successfully will be closest to ts and within min/max_ts.
2383  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2384  *
2385  * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2386  * are the file position (this may not be supported by all demuxers).
2387  * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2388  * in the stream with stream_index (this may not be supported by all demuxers).
2389  * Otherwise all timestamps are in units of the stream selected by stream_index
2390  * or if stream_index is -1, in AV_TIME_BASE units.
2391  * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2392  * keyframes (this may not be supported by all demuxers).
2393  * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2394  *
2395  * @param s media file handle
2396  * @param stream_index index of the stream which is used as time base reference
2397  * @param min_ts smallest acceptable timestamp
2398  * @param ts target timestamp
2399  * @param max_ts largest acceptable timestamp
2400  * @param flags flags
2401  * @return >=0 on success, error code otherwise
2402  *
2403  * @note This is part of the new seek API which is still under construction.
2404  */
2405 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2406 
2407 /**
2408  * Discard all internally buffered data. This can be useful when dealing with
2409  * discontinuities in the byte stream. Generally works only with formats that
2410  * can resync. This includes headerless formats like MPEG-TS/TS but should also
2411  * work with NUT, Ogg and in a limited way AVI for example.
2412  *
2413  * The set of streams, the detected duration, stream parameters and codecs do
2414  * not change when calling this function. If you want a complete reset, it's
2415  * better to open a new AVFormatContext.
2416  *
2417  * This does not flush the AVIOContext (s->pb). If necessary, call
2418  * avio_flush(s->pb) before calling this function.
2419  *
2420  * @param s media file handle
2421  * @return >=0 on success, error code otherwise
2422  */
2424 
2425 /**
2426  * Start playing a network-based stream (e.g. RTSP stream) at the
2427  * current position.
2428  */
2430 
2431 /**
2432  * Pause a network-based stream (e.g. RTSP stream).
2433  *
2434  * Use av_read_play() to resume it.
2435  */
2437 
2438 /**
2439  * Close an opened input AVFormatContext. Free it and all its contents
2440  * and set *s to NULL.
2441  */
2443 /**
2444  * @}
2445  */
2447 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2448 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2449 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2450 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2451 
2452 /**
2453  * @addtogroup lavf_encoding
2454  * @{
2455  */
2457 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2458 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2459 
2460 /**
2461  * Allocate the stream private data and write the stream header to
2462  * an output media file.
2463  *
2464  * @param s Media file handle, must be allocated with
2465  * avformat_alloc_context().
2466  * Its \ref AVFormatContext.oformat "oformat" field must be set
2467  * to the desired output format;
2468  * Its \ref AVFormatContext.pb "pb" field must be set to an
2469  * already opened ::AVIOContext.
2470  * @param options An ::AVDictionary filled with AVFormatContext and
2471  * muxer-private options.
2472  * On return this parameter will be destroyed and replaced with
2473  * a dict containing options that were not found. May be NULL.
2474  *
2475  * @retval AVSTREAM_INIT_IN_WRITE_HEADER On success, if the codec had not already been
2476  * fully initialized in avformat_init_output().
2477  * @retval AVSTREAM_INIT_IN_INIT_OUTPUT On success, if the codec had already been fully
2478  * initialized in avformat_init_output().
2479  * @retval AVERROR A negative AVERROR on failure.
2480  *
2481  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2482  */
2485 
2486 /**
2487  * Allocate the stream private data and initialize the codec, but do not write the header.
2488  * May optionally be used before avformat_write_header() to initialize stream parameters
2489  * before actually writing the header.
2490  * If using this function, do not pass the same options to avformat_write_header().
2491  *
2492  * @param s Media file handle, must be allocated with
2493  * avformat_alloc_context().
2494  * Its \ref AVFormatContext.oformat "oformat" field must be set
2495  * to the desired output format;
2496  * Its \ref AVFormatContext.pb "pb" field must be set to an
2497  * already opened ::AVIOContext.
2498  * @param options An ::AVDictionary filled with AVFormatContext and
2499  * muxer-private options.
2500  * On return this parameter will be destroyed and replaced with
2501  * a dict containing options that were not found. May be NULL.
2502  *
2503  * @retval AVSTREAM_INIT_IN_WRITE_HEADER On success, if the codec requires
2504  * avformat_write_header to fully initialize.
2505  * @retval AVSTREAM_INIT_IN_INIT_OUTPUT On success, if the codec has been fully
2506  * initialized.
2507  * @retval AVERROR Anegative AVERROR on failure.
2508  *
2509  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2510  */
2513 
2514 /**
2515  * Write a packet to an output media file.
2516  *
2517  * This function passes the packet directly to the muxer, without any buffering
2518  * or reordering. The caller is responsible for correctly interleaving the
2519  * packets if the format requires it. Callers that want libavformat to handle
2520  * the interleaving should call av_interleaved_write_frame() instead of this
2521  * function.
2522  *
2523  * @param s media file handle
2524  * @param pkt The packet containing the data to be written. Note that unlike
2525  * av_interleaved_write_frame(), this function does not take
2526  * ownership of the packet passed to it (though some muxers may make
2527  * an internal reference to the input packet).
2528  * <br>
2529  * This parameter can be NULL (at any time, not just at the end), in
2530  * order to immediately flush data buffered within the muxer, for
2531  * muxers that buffer up data internally before writing it to the
2532  * output.
2533  * <br>
2534  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2535  * set to the index of the corresponding stream in @ref
2536  * AVFormatContext.streams "s->streams".
2537  * <br>
2538  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2539  * must be set to correct values in the stream's timebase (unless the
2540  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2541  * they can be set to AV_NOPTS_VALUE).
2542  * The dts for subsequent packets passed to this function must be strictly
2543  * increasing when compared in their respective timebases (unless the
2544  * output format is flagged with the AVFMT_TS_NONSTRICT, then they
2545  * merely have to be nondecreasing). @ref AVPacket.duration
2546  * "duration") should also be set if known.
2547  * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2548  *
2549  * @see av_interleaved_write_frame()
2550  */
2552 
2553 /**
2554  * Write a packet to an output media file ensuring correct interleaving.
2555  *
2556  * This function will buffer the packets internally as needed to make sure the
2557  * packets in the output file are properly interleaved, usually ordered by
2558  * increasing dts. Callers doing their own interleaving should call
2559  * av_write_frame() instead of this function.
2560  *
2561  * Using this function instead of av_write_frame() can give muxers advance
2562  * knowledge of future packets, improving e.g. the behaviour of the mp4
2563  * muxer for VFR content in fragmenting mode.
2564  *
2565  * @param s media file handle
2566  * @param pkt The packet containing the data to be written.
2567  * <br>
2568  * If the packet is reference-counted, this function will take
2569  * ownership of this reference and unreference it later when it sees
2570  * fit. If the packet is not reference-counted, libavformat will
2571  * make a copy.
2572  * The returned packet will be blank (as if returned from
2573  * av_packet_alloc()), even on error.
2574  * <br>
2575  * This parameter can be NULL (at any time, not just at the end), to
2576  * flush the interleaving queues.
2577  * <br>
2578  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2579  * set to the index of the corresponding stream in @ref
2580  * AVFormatContext.streams "s->streams".
2581  * <br>
2582  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2583  * must be set to correct values in the stream's timebase (unless the
2584  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2585  * they can be set to AV_NOPTS_VALUE).
2586  * The dts for subsequent packets in one stream must be strictly
2587  * increasing (unless the output format is flagged with the
2588  * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2589  * @ref AVPacket.duration "duration" should also be set if known.
2590  *
2591  * @return 0 on success, a negative AVERROR on error.
2592  *
2593  * @see av_write_frame(), AVFormatContext.max_interleave_delta
2594  */
2596 
2597 /**
2598  * Write an uncoded frame to an output media file.
2599  *
2600  * The frame must be correctly interleaved according to the container
2601  * specification; if not, av_interleaved_write_uncoded_frame() must be used.
2602  *
2603  * See av_interleaved_write_uncoded_frame() for details.
2604  */
2605 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2606  struct AVFrame *frame);
2607 
2608 /**
2609  * Write an uncoded frame to an output media file.
2610  *
2611  * If the muxer supports it, this function makes it possible to write an AVFrame
2612  * structure directly, without encoding it into a packet.
2613  * It is mostly useful for devices and similar special muxers that use raw
2614  * video or PCM data and will not serialize it into a byte stream.
2615  *
2616  * To test whether it is possible to use it with a given muxer and stream,
2617  * use av_write_uncoded_frame_query().
2618  *
2619  * The caller gives up ownership of the frame and must not access it
2620  * afterwards.
2621  *
2622  * @return >=0 for success, a negative code on error
2623  */
2625  struct AVFrame *frame);
2626 
2627 /**
2628  * Test whether a muxer supports uncoded frame.
2629  *
2630  * @return >=0 if an uncoded frame can be written to that muxer and stream,
2631  * <0 if not
2632  */
2633 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2634 
2635 /**
2636  * Write the stream trailer to an output media file and free the
2637  * file private data.
2638  *
2639  * May only be called after a successful call to avformat_write_header.
2640  *
2641  * @param s media file handle
2642  * @return 0 if OK, AVERROR_xxx on error
2643  */
2645 
2646 /**
2647  * Return the output format in the list of registered output formats
2648  * which best matches the provided parameters, or return NULL if
2649  * there is no match.
2650  *
2651  * @param short_name if non-NULL checks if short_name matches with the
2652  * names of the registered formats
2653  * @param filename if non-NULL checks if filename terminates with the
2654  * extensions of the registered formats
2655  * @param mime_type if non-NULL checks if mime_type matches with the
2656  * MIME type of the registered formats
2657  */
2658 const AVOutputFormat *av_guess_format(const char *short_name,
2659  const char *filename,
2660  const char *mime_type);
2661 
2662 /**
2663  * Guess the codec ID based upon muxer and filename.
2664  */
2665 enum AVCodecID av_guess_codec(const AVOutputFormat *fmt, const char *short_name,
2666  const char *filename, const char *mime_type,
2667  enum AVMediaType type);
2668 
2669 /**
2670  * Get timing information for the data currently output.
2671  * The exact meaning of "currently output" depends on the format.
2672  * It is mostly relevant for devices that have an internal buffer and/or
2673  * work in real time.
2674  * @param s media file handle
2675  * @param stream stream in the media file
2676  * @param[out] dts DTS of the last packet output for the stream, in stream
2677  * time_base units
2678  * @param[out] wall absolute time when that packet whas output,
2679  * in microsecond
2680  * @retval 0 Success
2681  * @retval AVERROR(ENOSYS) The format does not support it
2682  *
2683  * @note Some formats or devices may not allow to measure dts and wall
2684  * atomically.
2685  */
2686 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2687  int64_t *dts, int64_t *wall);
2688 
2689 
2690 /**
2691  * @}
2692  */
2693 
2694 
2695 /**
2696  * @defgroup lavf_misc Utility functions
2697  * @ingroup libavf
2698  * @{
2699  *
2700  * Miscellaneous utility functions related to both muxing and demuxing
2701  * (or neither).
2702  */
2703 
2704 /**
2705  * Send a nice hexadecimal dump of a buffer to the specified file stream.
2706  *
2707  * @param f The file stream pointer where the dump should be sent to.
2708  * @param buf buffer
2709  * @param size buffer size
2710  *
2711  * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2712  */
2713 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2714 
2715 /**
2716  * Send a nice hexadecimal dump of a buffer to the log.
2717  *
2718  * @param avcl A pointer to an arbitrary struct of which the first field is a
2719  * pointer to an AVClass struct.
2720  * @param level The importance level of the message, lower values signifying
2721  * higher importance.
2722  * @param buf buffer
2723  * @param size buffer size
2724  *
2725  * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2726  */
2727 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2728 
2729 /**
2730  * Send a nice dump of a packet to the specified file stream.
2731  *
2732  * @param f The file stream pointer where the dump should be sent to.
2733  * @param pkt packet to dump
2734  * @param dump_payload True if the payload must be displayed, too.
2735  * @param st AVStream that the packet belongs to
2736  */
2737 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2738 
2739 
2740 /**
2741  * Send a nice dump of a packet to the log.
2742  *
2743  * @param avcl A pointer to an arbitrary struct of which the first field is a
2744  * pointer to an AVClass struct.
2745  * @param level The importance level of the message, lower values signifying
2746  * higher importance.
2747  * @param pkt packet to dump
2748  * @param dump_payload True if the payload must be displayed, too.
2749  * @param st AVStream that the packet belongs to
2750  */
2751 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2752  const AVStream *st);
2753 
2754 /**
2755  * Get the AVCodecID for the given codec tag tag.
2756  * If no codec id is found returns AV_CODEC_ID_NONE.
2757  *
2758  * @param tags list of supported codec_id-codec_tag pairs, as stored
2759  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2760  * @param tag codec tag to match to a codec ID
2761  */
2762 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2763 
2764 /**
2765  * Get the codec tag for the given codec id id.
2766  * If no codec tag is found returns 0.
2767  *
2768  * @param tags list of supported codec_id-codec_tag pairs, as stored
2769  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2770  * @param id codec ID to match to a codec tag
2771  */
2772 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2773 
2774 /**
2775  * Get the codec tag for the given codec id.
2776  *
2777  * @param tags list of supported codec_id - codec_tag pairs, as stored
2778  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2779  * @param id codec id that should be searched for in the list
2780  * @param tag A pointer to the found tag
2781  * @return 0 if id was not found in tags, > 0 if it was found
2782  */
2783 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2784  unsigned int *tag);
2785 
2787 
2788 /**
2789  * Get the index for a specific timestamp.
2790  *
2791  * @param st stream that the timestamp belongs to
2792  * @param timestamp timestamp to retrieve the index for
2793  * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2794  * to the timestamp which is <= the requested one, if backward
2795  * is 0, then it will be >=
2796  * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2797  * @return < 0 if no such timestamp could be found
2798  */
2799 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2800 
2801 /**
2802  * Get the index entry count for the given AVStream.
2803  *
2804  * @param st stream
2805  * @return the number of index entries in the stream
2806  */
2808 
2809 /**
2810  * Get the AVIndexEntry corresponding to the given index.
2811  *
2812  * @param st Stream containing the requested AVIndexEntry.
2813  * @param idx The desired index.
2814  * @return A pointer to the requested AVIndexEntry if it exists, NULL otherwise.
2815  *
2816  * @note The pointer returned by this function is only guaranteed to be valid
2817  * until any function that takes the stream or the parent AVFormatContext
2818  * as input argument is called.
2819  */
2820 const AVIndexEntry *avformat_index_get_entry(AVStream *st, int idx);
2821 
2822 /**
2823  * Get the AVIndexEntry corresponding to the given timestamp.
2824  *
2825  * @param st Stream containing the requested AVIndexEntry.
2826  * @param wanted_timestamp Timestamp to retrieve the index entry for.
2827  * @param flags If AVSEEK_FLAG_BACKWARD then the returned entry will correspond
2828  * to the timestamp which is <= the requested one, if backward
2829  * is 0, then it will be >=
2830  * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise.
2831  * @return A pointer to the requested AVIndexEntry if it exists, NULL otherwise.
2832  *
2833  * @note The pointer returned by this function is only guaranteed to be valid
2834  * until any function that takes the stream or the parent AVFormatContext
2835  * as input argument is called.
2836  */
2838  int64_t wanted_timestamp,
2839  int flags);
2840 /**
2841  * Add an index entry into a sorted list. Update the entry if the list
2842  * already contains it.
2843  *
2844  * @param timestamp timestamp in the time base of the given stream
2845  */
2846 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2847  int size, int distance, int flags);
2848 
2849 
2850 /**
2851  * Split a URL string into components.
2852  *
2853  * The pointers to buffers for storing individual components may be null,
2854  * in order to ignore that component. Buffers for components not found are
2855  * set to empty strings. If the port is not found, it is set to a negative
2856  * value.
2857  *
2858  * @param proto the buffer for the protocol
2859  * @param proto_size the size of the proto buffer
2860  * @param authorization the buffer for the authorization
2861  * @param authorization_size the size of the authorization buffer
2862  * @param hostname the buffer for the host name
2863  * @param hostname_size the size of the hostname buffer
2864  * @param port_ptr a pointer to store the port number in
2865  * @param path the buffer for the path
2866  * @param path_size the size of the path buffer
2867  * @param url the URL to split
2868  */
2869 void av_url_split(char *proto, int proto_size,
2870  char *authorization, int authorization_size,
2871  char *hostname, int hostname_size,
2872  int *port_ptr,
2873  char *path, int path_size,
2874  const char *url);
2875 
2876 
2877 /**
2878  * Print detailed information about the input or output format, such as
2879  * duration, bitrate, streams, container, programs, metadata, side data,
2880  * codec and time base.
2881  *
2882  * @param ic the context to analyze
2883  * @param index index of the stream to dump information about
2884  * @param url the URL to print, such as source or destination file
2885  * @param is_output Select whether the specified context is an input(0) or output(1)
2886  */
2888  int index,
2889  const char *url,
2890  int is_output);
2892 
2893 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
2894 
2895 /**
2896  * Return in 'buf' the path with '%d' replaced by a number.
2897  *
2898  * Also handles the '%0nd' format where 'n' is the total number
2899  * of digits and '%%'.
2900  *
2901  * @param buf destination buffer
2902  * @param buf_size destination buffer size
2903  * @param path numbered sequence string
2904  * @param number frame number
2905  * @param flags AV_FRAME_FILENAME_FLAGS_*
2906  * @return 0 if OK, -1 on format error
2907  */
2908 int av_get_frame_filename2(char *buf, int buf_size,
2909  const char *path, int number, int flags);
2910 
2911 int av_get_frame_filename(char *buf, int buf_size,
2912  const char *path, int number);
2913 
2914 /**
2915  * Check whether filename actually is a numbered sequence generator.
2916  *
2917  * @param filename possible numbered sequence string
2918  * @return 1 if a valid numbered sequence string, 0 otherwise
2919  */
2920 int av_filename_number_test(const char *filename);
2921 
2922 /**
2923  * Generate an SDP for an RTP session.
2924  *
2925  * Note, this overwrites the id values of AVStreams in the muxer contexts
2926  * for getting unique dynamic payload types.
2927  *
2928  * @param ac array of AVFormatContexts describing the RTP streams. If the
2929  * array is composed by only one context, such context can contain
2930  * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2931  * all the contexts in the array (an AVCodecContext per RTP stream)
2932  * must contain only one AVStream.
2933  * @param n_files number of AVCodecContexts contained in ac
2934  * @param buf buffer where the SDP will be stored (must be allocated by
2935  * the caller)
2936  * @param size the size of the buffer
2937  * @return 0 if OK, AVERROR_xxx on error
2938  */
2939 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2940 
2941 /**
2942  * Return a positive value if the given filename has one of the given
2943  * extensions, 0 otherwise.
2944  *
2945  * @param filename file name to check against the given extensions
2946  * @param extensions a comma-separated list of filename extensions
2947  */
2948 int av_match_ext(const char *filename, const char *extensions);
2949 
2950 /**
2951  * Test if the given container can store a codec.
2952  *
2953  * @param ofmt container to check for compatibility
2954  * @param codec_id codec to potentially store in container
2955  * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2956  *
2957  * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2958  * A negative number if this information is not available.
2959  */
2961  int std_compliance);
2962 
2963 /**
2964  * @defgroup riff_fourcc RIFF FourCCs
2965  * @{
2966  * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2967  * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2968  * following code:
2969  * @code
2970  * uint32_t tag = MKTAG('H', '2', '6', '4');
2971  * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2972  * enum AVCodecID id = av_codec_get_id(table, tag);
2973  * @endcode
2974  */
2975 /**
2976  * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2977  */
2978 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2979 /**
2980  * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2981  */
2982 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2983 /**
2984  * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2985  */
2986 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2987 /**
2988  * @return the table mapping MOV FourCCs for audio to AVCodecID.
2989  */
2990 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2991 
2992 /**
2993  * @}
2994  */
2995 
2996 /**
2997  * Guess the sample aspect ratio of a frame, based on both the stream and the
2998  * frame aspect ratio.
2999  *
3000  * Since the frame aspect ratio is set by the codec but the stream aspect ratio
3001  * is set by the demuxer, these two may not be equal. This function tries to
3002  * return the value that you should use if you would like to display the frame.
3003  *
3004  * Basic logic is to use the stream aspect ratio if it is set to something sane
3005  * otherwise use the frame aspect ratio. This way a container setting, which is
3006  * usually easy to modify can override the coded value in the frames.
3007  *
3008  * @param format the format context which the stream is part of
3009  * @param stream the stream which the frame is part of
3010  * @param frame the frame with the aspect ratio to be determined
3011  * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
3012  */
3014  struct AVFrame *frame);
3015 
3016 /**
3017  * Guess the frame rate, based on both the container and codec information.
3018  *
3019  * @param ctx the format context which the stream is part of
3020  * @param stream the stream which the frame is part of
3021  * @param frame the frame for which the frame rate should be determined, may be NULL
3022  * @return the guessed (valid) frame rate, 0/1 if no idea
3023  */
3025  struct AVFrame *frame);
3026 
3027 /**
3028  * Check if the stream st contained in s is matched by the stream specifier
3029  * spec.
3030  *
3031  * See the "stream specifiers" chapter in the documentation for the syntax
3032  * of spec.
3033  *
3034  * @return >0 if st is matched by spec;
3035  * 0 if st is not matched by spec;
3036  * AVERROR code if spec is invalid
3037  *
3038  * @note A stream specifier can match several streams in the format.
3039  */
3041  const char *spec);
3042 
3049 #if FF_API_R_FRAME_RATE
3050  AVFMT_TBCF_R_FRAMERATE,
3051 #endif
3052 };
3053 
3054 /**
3055  * Transfer internal timing information from one stream to another.
3056  *
3057  * This function is useful when doing stream copy.
3058  *
3059  * @param ofmt target output format for ost
3060  * @param ost output stream which needs timings copy and adjustments
3061  * @param ist reference input stream to copy timings from
3062  * @param copy_tb define from where the stream codec timebase needs to be imported
3063  */
3065  AVStream *ost, const AVStream *ist,
3066  enum AVTimebaseSource copy_tb);
3067 
3068 /**
3069  * Get the internal codec timebase from a stream.
3070  *
3071  * @param st input stream to extract the timebase from
3072  */
3074 
3075 /**
3076  * @}
3077  */
3078 
3079 #endif /* AVFORMAT_AVFORMAT_H */
avformat_get_riff_video_tags
const struct AVCodecTag * avformat_get_riff_video_tags(void)
Definition: riff.c:638
AVFormatContext::control_message_cb
av_format_control_message control_message_cb
Callback used by devices to communicate with application.
Definition: avformat.h:1822
av_pkt_dump2
void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st)
Send a nice dump of a packet to the specified file stream.
Definition: dump.c:116
AVCodec
AVCodec.
Definition: codec.h:187
AVStreamGroupParamsType
AVStreamGroupParamsType
Definition: avformat.h:1080
av_codec_get_id
enum AVCodecID av_codec_get_id(const struct AVCodecTag *const *tags, unsigned int tag)
Get the AVCodecID for the given codec tag tag.
AVFormatContext::stream_groups
AVStreamGroup ** stream_groups
A list of all stream groups in the file.
Definition: avformat.h:1342
av_format_control_message
int(* av_format_control_message)(struct AVFormatContext *s, int type, void *data, size_t data_size)
Callback used by devices to communicate with application.
Definition: avformat.h:1225
level
uint8_t level
Definition: svq3.c:205
AVStreamGroup::id
int64_t id
Group type-specific group ID.
Definition: avformat.h:1109
AVFMT_DURATION_FROM_BITRATE
@ AVFMT_DURATION_FROM_BITRATE
Duration estimated from bitrate (less accurate)
Definition: avformat.h:1238
AVOutputFormat::extensions
const char * extensions
comma-separated filename extensions
Definition: avformat.h:518
AVOutputFormat::name
const char * name
Definition: avformat.h:510
AVChapter::metadata
AVDictionary * metadata
Definition: avformat.h:1218
AVStreamGroup::tile_grid
struct AVStreamGroupTileGrid * tile_grid
Definition: avformat.h:1125
av_probe_input_buffer2
int av_probe_input_buffer2(AVIOContext *pb, const AVInputFormat **fmt, const char *url, void *logctx, unsigned int offset, unsigned int max_probe_size)
Probe a bytestream to determine the input format.
Definition: format.c:251
AVProgram::nb_stream_indexes
unsigned int nb_stream_indexes
Definition: avformat.h:1184
AVFormatContext::max_chunk_duration
int max_chunk_duration
Max chunk time in microseconds.
Definition: avformat.h:1591
AVFormatContext::max_index_size
unsigned int max_index_size
Maximum amount of memory in bytes to use for the index of each stream.
Definition: avformat.h:1553
AVFormatContext::nb_chapters
unsigned int nb_chapters
Number of chapters in AVChapter array.
Definition: avformat.h:1355
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:47
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
AVStream::priv_data
void * priv_data
Definition: avformat.h:768
AVStreamGroupTileGrid::horizontal_offset
int horizontal_offset
Offset in pixels from the left edge of the canvas where the actual image meant for presentation start...
Definition: avformat.h:1049
AVStream::discard
enum AVDiscard discard
Selects which packets can be discarded at will and do not need to be demuxed.
Definition: avformat.h:814
av_find_program_from_stream
AVProgram * av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s)
Find the programs which belong to a given stream.
Definition: avformat.c:392
AVFormatContext::audio_preload
int audio_preload
Audio preload in microseconds.
Definition: avformat.h:1654
AVFormatContext::protocol_blacklist
char * protocol_blacklist
',' separated list of disallowed protocols.
Definition: avformat.h:1764
AVFMT_TBCF_DECODER
@ AVFMT_TBCF_DECODER
Definition: avformat.h:3045
AVProgram::pmt_version
int pmt_version
Definition: avformat.h:1190
avformat_get_class
const AVClass * avformat_get_class(void)
Get the AVClass for AVFormatContext.
Definition: options.c:197
AVStreamGroup::disposition
int disposition
Stream group disposition - a combination of AV_DISPOSITION_* flags.
Definition: avformat.h:1166
AVFMT_TBCF_AUTO
@ AVFMT_TBCF_AUTO
Definition: avformat.h:3044
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:375
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1323
AVPacketSideData
This structure stores auxiliary information for decoding, presenting, or otherwise processing the cod...
Definition: packet.h:375
AVFormatContext::strict_std_compliance
int strict_std_compliance
Allow non-standard and experimental extension.
Definition: avformat.h:1612
av_disposition_to_string
const char * av_disposition_to_string(int disposition)
Definition: options.c:524
av_get_frame_filename2
int av_get_frame_filename2(char *buf, int buf_size, const char *path, int number, int flags)
Return in 'buf' the path with 'd' replaced by a number.
Definition: utils.c:296
AVFormatContext::max_interleave_delta
int64_t max_interleave_delta
Maximum buffering duration for interleaving.
Definition: avformat.h:1577
AVStream::avg_frame_rate
AVRational avg_frame_rate
Average framerate.
Definition: avformat.h:832
AVStreamGroupTileGrid::vertical_offset
int vertical_offset
Offset in pixels from the top edge of the canvas where the actual image meant for presentation starts...
Definition: avformat.h:1056
AVChapter::start
int64_t start
Definition: avformat.h:1217
data
const char data[16]
Definition: mxf.c:148
AVFormatContext::duration_estimation_method
enum AVDurationEstimationMethod duration_estimation_method
The duration field can be estimated through various ways, and this field can be used to know how the ...
Definition: avformat.h:1686
AVFMT_TBCF_DEMUXER
@ AVFMT_TBCF_DEMUXER
Definition: avformat.h:3046
AVFormatContext::programs
AVProgram ** programs
Definition: avformat.h:1456
AVDictionary
Definition: dict.c:34
AVProgram::flags
int flags
Definition: avformat.h:1181
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:454
AVStreamGroupTileGrid::vertical
int vertical
Offset in pixels from the top edge of the canvas where the tile should be placed.
Definition: avformat.h:1031
AVFormatContext::probesize
int64_t probesize
Maximum number of bytes read from input in order to determine stream properties.
Definition: avformat.h:1442
av_write_uncoded_frame_query
int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index)
Test whether a muxer supports uncoded frame.
Definition: mux.c:1485
avformat_init_output
av_warn_unused_result int avformat_init_output(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and initialize the codec, but do not write the header.
Definition: mux.c:466
av_read_frame
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: demux.c:1526
AVFormatContext::video_codec_id
enum AVCodecID video_codec_id
Forced video codec_id.
Definition: avformat.h:1462
avformat_index_get_entry_from_timestamp
const AVIndexEntry * avformat_index_get_entry_from_timestamp(AVStream *st, int64_t wanted_timestamp, int flags)
Get the AVIndexEntry corresponding to the given timestamp.
Definition: seek.c:265
av_get_frame_filename
int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
Definition: utils.c:354
ost
static AVStream * ost
Definition: vaapi_transcode.c:42
AVIndexEntry
Definition: avformat.h:602
AVOutputFormat::subtitle_codec
enum AVCodecID subtitle_codec
default subtitle codec
Definition: avformat.h:522
AVIOInterruptCB
Callback for checking whether to abort blocking functions.
Definition: avio.h:59
AVProgram::pmt_pid
int pmt_pid
Definition: avformat.h:1188
AVInputFormat::long_name
const char * long_name
Descriptive name for the format, meant to be more human-readable than name.
Definition: avformat.h:560
av_filename_number_test
int av_filename_number_test(const char *filename)
Check whether filename actually is a numbered sequence generator.
Definition: utils.c:127
avformat_queue_attached_pictures
int avformat_queue_attached_pictures(AVFormatContext *s)
Definition: demux_utils.c:93
avformat_close_input
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: demux.c:363
AVFormatContext::interrupt_callback
AVIOInterruptCB interrupt_callback
Custom interrupt callbacks for the I/O layer.
Definition: avformat.h:1528
AVFormatContext::flush_packets
int flush_packets
Flush the I/O context after each packet.
Definition: avformat.h:1714
AVStreamGroup::av_class
const AVClass * av_class
A class for AVOptions.
Definition: avformat.h:1094
avformat_get_mov_video_tags
const struct AVCodecTag * avformat_get_mov_video_tags(void)
Definition: isom_tags.c:357
AVFormatContext::max_picture_buffer
unsigned int max_picture_buffer
Maximum amount of memory in bytes to use for buffering frames obtained from realtime capture devices.
Definition: avformat.h:1559
AVStreamGroupTileGrid
AVStreamGroupTileGrid holds information on how to combine several independent images on a single canv...
Definition: avformat.h:982
av_add_index_entry
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
Definition: seek.c:121
AVSTREAM_PARSE_FULL_ONCE
@ AVSTREAM_PARSE_FULL_ONCE
full parsing and repack of the first frame only, only implemented for H.264 currently
Definition: avformat.h:596
avformat_version
unsigned avformat_version(void)
Return the LIBAVFORMAT_VERSION_INT constant.
Definition: version.c:31
avformat_stream_group_name
const char * avformat_stream_group_name(enum AVStreamGroupParamsType type)
Definition: avformat.c:324
AVStreamParseType
AVStreamParseType
Definition: avformat.h:591
AVStreamGroupTileGrid::coded_width
int coded_width
Width of the canvas.
Definition: avformat.h:997
AVProgram::discard
enum AVDiscard discard
selects which program to discard and which to feed to the caller
Definition: avformat.h:1182
AVChapter
Definition: avformat.h:1214
AVFormatContext::dump_separator
uint8_t * dump_separator
dump format separator.
Definition: avformat.h:1836
av_stream_group_get_class
const AVClass * av_stream_group_get_class(void)
Get the AVClass for AVStreamGroup.
Definition: options.c:417
AVStreamGroup::params
union AVStreamGroup::@305 params
Group type-specific parameters.
AVFMT_DURATION_FROM_PTS
@ AVFMT_DURATION_FROM_PTS
Duration accurately estimated from PTSes.
Definition: avformat.h:1236
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
AVStreamGroupTileGrid::coded_height
int coded_height
Width of the canvas.
Definition: avformat.h:1003
av_new_program
AVProgram * av_new_program(AVFormatContext *s, int id)
Definition: avformat.c:334
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:802
av_codec_get_tag2
int av_codec_get_tag2(const struct AVCodecTag *const *tags, enum AVCodecID id, unsigned int *tag)
Get the codec tag for the given codec id.
av_probe_input_format3
const AVInputFormat * av_probe_input_format3(const AVProbeData *pd, int is_opened, int *score_ret)
Guess the file format.
Definition: format.c:154
codec.h
avformat_network_init
int avformat_network_init(void)
Do global initialization of network libraries.
Definition: utils.c:559
AVFormatContext::event_flags
int event_flags
Flags indicating events happening on the file, a combination of AVFMT_EVENT_FLAG_*.
Definition: avformat.h:1625
AVStream::attached_pic
AVPacket attached_pic
For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet will contain the attached pictu...
Definition: avformat.h:841
AVStreamGroupTileGrid::av_class
const AVClass * av_class
Definition: avformat.h:983
avformat_get_riff_audio_tags
const struct AVCodecTag * avformat_get_riff_audio_tags(void)
Definition: riff.c:643
AVFormatContext::bit_rate
int64_t bit_rate
Total stream bitrate in bit/s, 0 if not available.
Definition: avformat.h:1397
AVFormatContext::max_ts_probe
int max_ts_probe
Maximum number of packets to read while waiting for the first timestamp.
Definition: avformat.h:1583
AVFormatContext::format_whitelist
char * format_whitelist
',' separated list of allowed demuxers.
Definition: avformat.h:1750
AVFormatContext::format_probesize
int format_probesize
Maximum number of bytes read from input in order to identify the input format.
Definition: avformat.h:1734
pkt
AVPacket * pkt
Definition: movenc.c:60
avformat_index_get_entries_count
int avformat_index_get_entries_count(const AVStream *st)
Get the index entry count for the given AVStream.
Definition: seek.c:251
AVFormatContext::metadata
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1490
AVInputFormat
Definition: avformat.h:548
AVProbeData::mime_type
const char * mime_type
mime_type, when known.
Definition: avformat.h:455
AVInputFormat::extensions
const char * extensions
If extensions are defined, then no probe is done.
Definition: avformat.h:574
av_dump_format
void av_dump_format(AVFormatContext *ic, int index, const char *url, int is_output)
Print detailed information about the input or output format, such as duration, bitrate,...
Definition: dump.c:761
AVCodecTag
Definition: internal.h:42
AVFormatContext::ctx_flags
int ctx_flags
Flags signalling stream properties.
Definition: avformat.h:1304
AVProgram::id
int id
Definition: avformat.h:1180
avformat_open_input
int avformat_open_input(AVFormatContext **ps, const char *url, const AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: demux.c:215
avformat_query_codec
int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id, int std_compliance)
Test if the given container can store a codec.
Definition: mux_utils.c:33
AV_STREAM_GROUP_PARAMS_IAMF_MIX_PRESENTATION
@ AV_STREAM_GROUP_PARAMS_IAMF_MIX_PRESENTATION
Definition: avformat.h:1083
AVChapter::end
int64_t end
chapter start/end time in time_base units
Definition: avformat.h:1217
AVFormatContext::video_codec
const struct AVCodec * video_codec
Forced video codec.
Definition: avformat.h:1780
s
#define s(width, name)
Definition: cbs_vp9.c:198
av_seek_frame
int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Seek to the keyframe at timestamp.
Definition: seek.c:640
AVFormatContext::flags
int flags
Flags modifying the (de)muxer behaviour.
Definition: avformat.h:1406
format
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample format(the sample packing is implied by the sample format) and sample rate. The lists are not just lists
AVFormatContext::nb_programs
unsigned int nb_programs
Definition: avformat.h:1455
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:553
AVFormatContext::iformat
const struct AVInputFormat * iformat
The input container format.
Definition: avformat.h:1267
AVFormatContext::chapters
AVChapter ** chapters
Definition: avformat.h:1356
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:453
AVIndexEntry::size
int size
Definition: avformat.h:613
AVProbeData::filename
const char * filename
Definition: avformat.h:452
AVOpenCallback
int(* AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Definition: avformat.h:1228
av_match_ext
int av_match_ext(const char *filename, const char *extensions)
Return a positive value if the given filename has one of the given extensions, 0 otherwise.
Definition: format.c:41
AVIndexEntry::timestamp
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
Definition: avformat.h:604
AVOutputFormat::audio_codec
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:520
AVFormatContext::output_ts_offset
int64_t output_ts_offset
Output timestamp offset, in microseconds.
Definition: avformat.h:1828
AVInputFormat::mime_type
const char * mime_type
Comma-separated list of mime types.
Definition: avformat.h:585
AVStreamGroup::index
unsigned int index
Group index in AVFormatContext.
Definition: avformat.h:1101
av_read_play
int av_read_play(AVFormatContext *s)
Start playing a network-based stream (e.g.
Definition: demux_utils.c:182
ctx
AVFormatContext * ctx
Definition: movenc.c:49
av_guess_sample_aspect_ratio
AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, struct AVFrame *frame)
Guess the sample aspect ratio of a frame, based on both the stream and the frame aspect ratio.
Definition: avformat.c:727
avformat_flush
int avformat_flush(AVFormatContext *s)
Discard all internally buffered data.
Definition: seek.c:758
AVOutputFormat::codec_tag
const struct AVCodecTag *const * codec_tag
List of supported codec_id-codec_tag pairs, ordered by "better choice first".
Definition: avformat.h:535
version_major.h
AVIndexEntry::min_distance
int min_distance
Minimum distance between this and the previous keyframe, used to avoid unneeded searching.
Definition: avformat.h:614
codec_id
enum AVCodecID codec_id
Definition: vaapi_decode.c:387
AVProgram::start_time
int64_t start_time
Definition: avformat.h:1199
AVFormatContext::opaque
void * opaque
User data.
Definition: avformat.h:1817
AVFormatContext::data_codec
const struct AVCodec * data_codec
Forced data codec.
Definition: avformat.h:1804
AVFormatContext::probe_score
int probe_score
format probing score.
Definition: avformat.h:1723
avformat_write_header
av_warn_unused_result int avformat_write_header(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and write the stream header to an output media file.
Definition: mux.c:487
AVFormatContext::max_analyze_duration
int64_t max_analyze_duration
Maximum duration (in AV_TIME_BASE units) of the data read from input in avformat_find_stream_info().
Definition: avformat.h:1450
AVFormatContext::correct_ts_overflow
unsigned int correct_ts_overflow
Correct single timestamp overflows.
Definition: avformat.h:1700
av_probe_input_format2
const AVInputFormat * av_probe_input_format2(const AVProbeData *pd, int is_opened, int *score_max)
Guess the file format.
Definition: format.c:233
AVFormatContext
Format I/O context.
Definition: avformat.h:1255
AVFormatContext::audio_codec_id
enum AVCodecID audio_codec_id
Forced audio codec_id.
Definition: avformat.h:1468
av_probe_input_format
const AVInputFormat * av_probe_input_format(const AVProbeData *pd, int is_opened)
Guess the file format.
Definition: format.c:245
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:766
AVInputFormat::codec_tag
const struct AVCodecTag *const * codec_tag
Definition: avformat.h:576
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
av_write_uncoded_frame
int av_write_uncoded_frame(AVFormatContext *s, int stream_index, struct AVFrame *frame)
Write an uncoded frame to an output media file.
Definition: mux.c:1473
AVStream::time_base
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avformat.h:782
AVFormatContext::max_streams
int max_streams
The maximum number of streams.
Definition: avformat.h:1541
AVFormatContext::fps_probe_size
int fps_probe_size
The number of frames used for determining the framerate in avformat_find_stream_info().
Definition: avformat.h:1510
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVFMT_DURATION_FROM_STREAM
@ AVFMT_DURATION_FROM_STREAM
Duration estimated from a stream with a known duration.
Definition: avformat.h:1237
AVFormatContext::protocol_whitelist
char * protocol_whitelist
',' separated list of allowed protocols.
Definition: avformat.h:1757
AVOutputFormat::long_name
const char * long_name
Descriptive name for the format, meant to be more human-readable than name.
Definition: avformat.h:516
AVSTREAM_PARSE_NONE
@ AVSTREAM_PARSE_NONE
Definition: avformat.h:592
AVIndexEntry::flags
int flags
Definition: avformat.h:612
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1297
AVDurationEstimationMethod
AVDurationEstimationMethod
The duration of a video can be estimated through various ways, and this enum can be used to know how ...
Definition: avformat.h:1235
AVFormatContext::duration_probesize
int64_t duration_probesize
Maximum number of bytes read from input in order to determine stream durations when using estimate_ti...
Definition: avformat.h:1882
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:451
AVProgram::stream_index
unsigned int * stream_index
Definition: avformat.h:1183
AVStream::metadata
AVDictionary * metadata
Definition: avformat.h:823
AVFormatContext::skip_estimate_duration_from_pts
int skip_estimate_duration_from_pts
Skip duration calcuation in estimate_timings_from_pts.
Definition: avformat.h:1671
AVOutputFormat::priv_class
const AVClass * priv_class
AVClass for the private context.
Definition: avformat.h:538
av_write_frame
int av_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file.
Definition: mux.c:1233
index
int index
Definition: gxfenc.c:90
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AVFormatContext::audio_codec
const struct AVCodec * audio_codec
Forced audio codec.
Definition: avformat.h:1788
AVStream::nb_frames
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:804
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:49
avformat_stream_group_add_stream
int avformat_stream_group_add_stream(AVStreamGroup *stg, AVStream *st)
Add an already allocated stream to a stream group.
Definition: options.c:495
AVFormatContext::nb_streams
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1311
AVFormatContext::metadata_header_padding
int metadata_header_padding
Number of bytes to be written as padding in a metadata header.
Definition: avformat.h:1811
AVOutputFormat::flags
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:529
AV_STREAM_GROUP_PARAMS_TILE_GRID
@ AV_STREAM_GROUP_PARAMS_TILE_GRID
Definition: avformat.h:1084
options
const OptionDef options[]
avformat_find_stream_info
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: demux.c:2503
f
f
Definition: af_crystalizer.c:121
AVIOContext
Bytestream IO Context.
Definition: avio.h:160
AVProgram::pts_wrap_reference
int64_t pts_wrap_reference
reference dts for wrap detection
Definition: avformat.h:1202
AVMediaType
AVMediaType
Definition: avutil.h:199
avformat_match_stream_specifier
int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st, const char *spec)
Check if the stream st contained in s is matched by the stream specifier spec.
Definition: avformat.c:681
av_find_best_stream
int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type, int wanted_stream_nb, int related_stream, const struct AVCodec **decoder_ret, int flags)
Find the "best" stream in the file.
avformat_alloc_context
AVFormatContext * avformat_alloc_context(void)
Allocate an AVFormatContext.
Definition: options.c:161
av_codec_get_tag
unsigned int av_codec_get_tag(const struct AVCodecTag *const *tags, enum AVCodecID id)
Get the codec tag for the given codec id id.
AVProgram::end_time
int64_t end_time
Definition: avformat.h:1200
AVFormatContext::url
char * url
input or output URL.
Definition: avformat.h:1371
size
int size
Definition: twinvq_data.h:10344
avio.h
copy_tb
int copy_tb
Definition: ffmpeg_opt.c:68
avformat_seek_file
int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Seek to timestamp ts.
Definition: seek.c:663
AVStreamGroup::iamf_audio_element
struct AVIAMFAudioElement * iamf_audio_element
Definition: avformat.h:1123
AVStream::event_flags
int event_flags
Flags indicating events happening on the stream, a combination of AVSTREAM_EVENT_FLAG_*.
Definition: avformat.h:886
av_stream_get_codec_timebase
AVRational av_stream_get_codec_timebase(const AVStream *st)
Get the internal codec timebase from a stream.
Definition: avformat.c:848
AVProgram::pts_wrap_behavior
int pts_wrap_behavior
behavior on wrap detection
Definition: avformat.h:1203
AVTimebaseSource
AVTimebaseSource
Definition: avformat.h:3043
av_demuxer_iterate
const AVInputFormat * av_demuxer_iterate(void **opaque)
Iterate over all registered demuxers.
Definition: allformats.c:606
AVProgram::program_num
int program_num
Definition: avformat.h:1187
AVStream::sample_aspect_ratio
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown)
Definition: avformat.h:821
frame.h
AVFormatContext::keylen
int keylen
Definition: avformat.h:1453
attribute_deprecated
#define attribute_deprecated
Definition: attributes.h:104
AVIAMFAudioElement
Information on how to combine one or more audio streams, as defined in section 3.6 of IAMF.
Definition: iamf.h:347
AVStreamGroupTileGrid::nb_tiles
unsigned int nb_tiles
Amount of tiles in the grid.
Definition: avformat.h:990
av_sdp_create
int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
Generate an SDP for an RTP session.
Definition: sdp.c:912
av_format_inject_global_side_data
void av_format_inject_global_side_data(AVFormatContext *s)
This function will cause global side data to be injected in the next packet of each stream as well as...
Definition: demux_utils.c:83
offset
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
Definition: writing_filters.txt:86
av_probe_input_buffer
int av_probe_input_buffer(AVIOContext *pb, const AVInputFormat **fmt, const char *url, void *logctx, unsigned int offset, unsigned int max_probe_size)
Like av_probe_input_buffer2() but returns 0 on success.
Definition: format.c:343
AV_STREAM_GROUP_PARAMS_IAMF_AUDIO_ELEMENT
@ AV_STREAM_GROUP_PARAMS_IAMF_AUDIO_ELEMENT
Definition: avformat.h:1082
AVStreamGroup::streams
AVStream ** streams
A list of streams in the group.
Definition: avformat.h:1156
AVStreamGroup::iamf_mix_presentation
struct AVIAMFMixPresentation * iamf_mix_presentation
Definition: avformat.h:1124
AVOutputFormat::mime_type
const char * mime_type
Definition: avformat.h:517
AVFormatContext::skip_initial_bytes
int64_t skip_initial_bytes
Skip initial bytes when opening stream.
Definition: avformat.h:1693
av_warn_unused_result
#define av_warn_unused_result
Definition: attributes.h:64
AVFormatContext::error_recognition
int error_recognition
Error recognition; higher values will detect more errors but may misdetect some more or less valid pa...
Definition: avformat.h:1517
av_write_trailer
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
Definition: mux.c:1295
av_disposition_from_string
int av_disposition_from_string(const char *disp)
Definition: options.c:516
AVStreamGroupTileGrid::width
int width
Width of the final image for presentation.
Definition: avformat.h:1067
AV_STREAM_GROUP_PARAMS_NONE
@ AV_STREAM_GROUP_PARAMS_NONE
Definition: avformat.h:1081
log.h
AVOutputFormat
Definition: avformat.h:509
AVChapter::id
int64_t id
unique ID to identify the chapter
Definition: avformat.h:1215
packet.h
AVFormatContext::subtitle_codec
const struct AVCodec * subtitle_codec
Forced subtitle codec.
Definition: avformat.h:1796
avformat_get_mov_audio_tags
const struct AVCodecTag * avformat_get_mov_audio_tags(void)
Definition: isom_tags.c:362
AVProgram::metadata
AVDictionary * metadata
Definition: avformat.h:1185
AVIAMFMixPresentation
Information on how to render and mix one or more AVIAMFAudioElement to generate the final audio outpu...
Definition: iamf.h:600
avformat_index_get_entry
const AVIndexEntry * avformat_index_get_entry(AVStream *st, int idx)
Get the AVIndexEntry corresponding to the given index.
Definition: seek.c:256
AVStream::av_class
const AVClass * av_class
A class for AVOptions.
Definition: avformat.h:747
av_get_output_timestamp
int av_get_output_timestamp(struct AVFormatContext *s, int stream, int64_t *dts, int64_t *wall)
Get timing information for the data currently output.
Definition: mux.c:1341
AVFormatContext::codec_whitelist
char * codec_whitelist
',' separated list of allowed decoders.
Definition: avformat.h:1742
AVFormatContext::avoid_negative_ts
int avoid_negative_ts
Avoid negative timestamps during muxing.
Definition: avformat.h:1642
av_url_split
void av_url_split(char *proto, int proto_size, char *authorization, int authorization_size, char *hostname, int hostname_size, int *port_ptr, char *path, int path_size, const char *url)
Split a URL string into components.
Definition: utils.c:359
av_find_default_stream_index
int av_find_default_stream_index(AVFormatContext *s)
Definition: avformat.c:407
AVFormatContext::max_delay
int max_delay
Definition: avformat.h:1400
AVFormatContext::io_repositioned
int io_repositioned
IO repositioned flag.
Definition: avformat.h:1772
AVProgram
New fields can be added to the end with minor version bumps.
Definition: avformat.h:1179
av_read_pause
int av_read_pause(AVFormatContext *s)
Pause a network-based stream (e.g.
Definition: demux_utils.c:191
int_cb
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:306
av_get_packet
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:104
AVStreamGroupTileGrid::horizontal
int horizontal
Offset in pixels from the left edge of the canvas where the tile should be placed.
Definition: avformat.h:1026
AVCodecParserContext
Definition: avcodec.h:2707
version.h
AVStream::disposition
int disposition
Stream disposition - a combination of AV_DISPOSITION_* flags.
Definition: avformat.h:812
tag
uint32_t tag
Definition: movenc.c:1787
AVStream::id
int id
Format-specific stream ID.
Definition: avformat.h:755
AVStream
Stream structure.
Definition: avformat.h:743
av_guess_frame_rate
AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, struct AVFrame *frame)
Guess the frame rate, based on both the container and codec information.
Definition: avformat.c:750
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
av_hex_dump_log
void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size)
Send a nice hexadecimal dump of a buffer to the log.
Definition: dump.c:87
AVFormatContext::oformat
const struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1274
AVStreamGroup::metadata
AVDictionary * metadata
Metadata that applies to the whole group.
Definition: avformat.h:1136
av_append_packet
int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
Read data and append it to the current content of the AVPacket.
Definition: utils.c:120
AVSTREAM_PARSE_HEADERS
@ AVSTREAM_PARSE_HEADERS
Only parse headers, do not repack.
Definition: avformat.h:594
AVFormatContext::av_class
const AVClass * av_class
A class for logging and AVOptions.
Definition: avformat.h:1260
pos
unsigned int pos
Definition: spdifenc.c:414
dict.h
av_guess_codec
enum AVCodecID av_guess_codec(const AVOutputFormat *fmt, const char *short_name, const char *filename, const char *mime_type, enum AVMediaType type)
Guess the codec ID based upon muxer and filename.
Definition: format.c:115
avformat_network_deinit
int avformat_network_deinit(void)
Undo the initialization done by avformat_network_init.
Definition: utils.c:571
AVStreamGroup
Definition: avformat.h:1090
AVFormatContext::debug
int debug
Flags to enable debugging.
Definition: avformat.h:1533
AVFormatContext::data_codec_id
enum AVCodecID data_codec_id
Forced Data codec_id.
Definition: avformat.h:1480
AVStream::index
int index
stream index in AVFormatContext
Definition: avformat.h:749
av_muxer_iterate
const AVOutputFormat * av_muxer_iterate(void **opaque)
Iterate over all registered muxers.
Definition: allformats.c:585
avformat_transfer_internal_stream_timing_info
int avformat_transfer_internal_stream_timing_info(const AVOutputFormat *ofmt, AVStream *ost, const AVStream *ist, enum AVTimebaseSource copy_tb)
Transfer internal timing information from one stream to another.
Definition: avformat.c:773
format_name
static int format_name(const char *buf, char **s, int index, const char *varname)
Definition: hlsenc.c:1942
AVStreamGroup::nb_streams
unsigned int nb_streams
Number of elements in AVStreamGroup.streams.
Definition: avformat.h:1143
AVFormatContext::seek2any
int seek2any
Force seeking to any (also non key) frames.
Definition: avformat.h:1707
AVInputFormat::flags
int flags
Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:567
defs.h
avformat_free_context
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: avformat.c:141
AVOutputFormat::video_codec
enum AVCodecID video_codec
default video codec
Definition: avformat.h:521
AVStream::r_frame_rate
AVRational r_frame_rate
Real base framerate of the stream.
Definition: avformat.h:909
AVFormatContext::io_open
int(* io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, AVDictionary **options)
A callback for opening new IO streams.
Definition: avformat.h:1858
AVIndexEntry::pos
int64_t pos
Definition: avformat.h:603
AVSTREAM_PARSE_FULL_RAW
@ AVSTREAM_PARSE_FULL_RAW
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:597
AVPacketSideDataType
AVPacketSideDataType
Definition: packet.h:41
av_find_input_format
const AVInputFormat * av_find_input_format(const char *short_name)
Find AVInputFormat based on the short name of the input format.
Definition: format.c:144
AVFormatContext::duration
int64_t duration
Duration of the stream, in AV_TIME_BASE fractional seconds.
Definition: avformat.h:1390
avformat_license
const char * avformat_license(void)
Return the libavformat license.
Definition: version.c:42
AVFormatContext::packet_size
unsigned int packet_size
Definition: avformat.h:1399
av_guess_format
const AVOutputFormat * av_guess_format(const char *short_name, const char *filename, const char *mime_type)
Return the output format in the list of registered output formats which best matches the provided par...
Definition: format.c:79
AVStreamGroup::type
enum AVStreamGroupParamsType type
Group type.
Definition: avformat.h:1117
AVFormatContext::start_time_realtime
int64_t start_time_realtime
Start time of the stream in real world time, in microseconds since the Unix epoch (00:00 1st January ...
Definition: avformat.h:1503
avformat_configuration
const char * avformat_configuration(void)
Return the libavformat build-time configuration.
Definition: version.c:37
avformat_stream_group_create
AVStreamGroup * avformat_stream_group_create(AVFormatContext *s, enum AVStreamGroupParamsType type, AVDictionary **options)
Add a new empty stream group to a media file.
Definition: options.c:422
AVFormatContext::nb_stream_groups
unsigned int nb_stream_groups
Number of elements in AVFormatContext.stream_groups.
Definition: avformat.h:1330
AVStreamGroupTileGrid::height
int height
Height of the final image for presentation.
Definition: avformat.h:1077
AVFormatContext::max_probe_packets
int max_probe_packets
Maximum number of packets that can be probed.
Definition: avformat.h:1606
codec_par.h
AVStreamGroupTileGrid::offsets
struct AVStreamGroupTileGrid::@304 * offsets
An nb_tiles sized array of offsets in pixels from the topleft edge of the canvas, indicating where ea...
av_interleaved_write_uncoded_frame
int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index, struct AVFrame *frame)
Write an uncoded frame to an output media file.
Definition: mux.c:1479
AVPacket
This structure stores compressed data.
Definition: packet.h:501
AVFormatContext::use_wallclock_as_timestamps
int use_wallclock_as_timestamps
forces the use of wallclock timestamps as pts/dts of packets This has undefined results in the presen...
Definition: avformat.h:1662
av_interleaved_write_frame
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
Definition: mux.c:1280
AVFormatContext::io_close2
int(* io_close2)(struct AVFormatContext *s, AVIOContext *pb)
A callback for closing the streams opened with AVFormatContext.io_open().
Definition: avformat.h:1872
distance
static float distance(float x, float y, int band)
Definition: nellymoserenc.c:231
AVSTREAM_PARSE_FULL
@ AVSTREAM_PARSE_FULL
full parsing and repack
Definition: avformat.h:593
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
AVFormatContext::start_time
int64_t start_time
Position of the first frame of the component, in AV_TIME_BASE fractional seconds.
Definition: avformat.h:1380
av_stream_get_parser
struct AVCodecParserContext * av_stream_get_parser(const AVStream *s)
Definition: demux_utils.c:32
av_pkt_dump_log2
void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload, const AVStream *st)
Send a nice dump of a packet to the log.
Definition: dump.c:121
AVStream::start_time
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base.
Definition: avformat.h:792
av_stream_get_class
const AVClass * av_stream_get_class(void)
Get the AVClass for AVStream.
Definition: options.c:245
AVSTREAM_PARSE_TIMESTAMPS
@ AVSTREAM_PARSE_TIMESTAMPS
full parsing and interpolation of timestamps for frames not starting on a packet boundary
Definition: avformat.h:595
AVFormatContext::avio_flags
int avio_flags
avio flags, used to force AVIO_FLAG_DIRECT.
Definition: avformat.h:1678
AVDiscard
AVDiscard
Definition: defs.h:210
AVStreamGroupTileGrid::idx
unsigned int idx
Index of the stream in the group this tile references.
Definition: avformat.h:1021
avformat_alloc_output_context2
int avformat_alloc_output_context2(AVFormatContext **ctx, const AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
Definition: mux.c:94
AVStream::pts_wrap_bits
int pts_wrap_bits
Number of bits in timestamps.
Definition: avformat.h:918
AVChapter::time_base
AVRational time_base
time base in which the start/end timestamps are specified
Definition: avformat.h:1216
int
int
Definition: ffmpeg_filter.c:424
AVStreamGroup::priv_data
void * priv_data
Definition: avformat.h:1096
AVFormatContext::priv_data
void * priv_data
Format private data.
Definition: avformat.h:1283
AVProgram::pcr_pid
int pcr_pid
Definition: avformat.h:1189
AVFormatContext::key
const uint8_t * key
Definition: avformat.h:1452
AVInputFormat::priv_class
const AVClass * priv_class
AVClass for the private context.
Definition: avformat.h:578
AVStreamGroupTileGrid::background
uint8_t background[4]
The pixel value per channel in RGBA format used if no pixel of any tile is located at a particular pi...
Definition: avformat.h:1041
AVFormatContext::max_chunk_size
int max_chunk_size
Max chunk size in bytes Note, not all formats support this and unpredictable things may happen if it ...
Definition: avformat.h:1599
av_index_search_timestamp
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: seek.c:244
av_program_add_stream_index
void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx)
AVFormatContext::subtitle_codec_id
enum AVCodecID subtitle_codec_id
Forced subtitle codec_id.
Definition: avformat.h:1474
av_hex_dump
void av_hex_dump(FILE *f, const uint8_t *buf, int size)
Send a nice hexadecimal dump of a buffer to the specified file stream.
Definition: dump.c:82