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 <time.h>
311 #include <stdio.h> /* FILE */
312 
313 #include "libavcodec/codec.h"
314 #include "libavcodec/codec_par.h"
315 #include "libavcodec/defs.h"
316 #include "libavcodec/packet.h"
317 
318 #include "libavutil/dict.h"
319 #include "libavutil/log.h"
320 
321 #include "avio.h"
323 #ifndef HAVE_AV_CONFIG_H
324 /* When included as part of the ffmpeg build, only include the major version
325  * to avoid unnecessary rebuilds. When included externally, keep including
326  * the full version information. */
327 #include "libavformat/version.h"
328 #endif
329 
330 struct AVFormatContext;
331 struct AVStream;
332 
333 struct AVDeviceInfoList;
335 
336 /**
337  * @defgroup metadata_api Public Metadata API
338  * @{
339  * @ingroup libavf
340  * The metadata API allows libavformat to export metadata tags to a client
341  * application when demuxing. Conversely it allows a client application to
342  * set metadata when muxing.
343  *
344  * Metadata is exported or set as pairs of key/value strings in the 'metadata'
345  * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
346  * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
347  * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
348  * exported by demuxers isn't checked to be valid UTF-8 in most cases.
349  *
350  * Important concepts to keep in mind:
351  * - Keys are unique; there can never be 2 tags with the same key. This is
352  * also meant semantically, i.e., a demuxer should not knowingly produce
353  * several keys that are literally different but semantically identical.
354  * E.g., key=Author5, key=Author6. In this example, all authors must be
355  * placed in the same tag.
356  * - Metadata is flat, not hierarchical; there are no subtags. If you
357  * want to store, e.g., the email address of the child of producer Alice
358  * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
359  * - Several modifiers can be applied to the tag name. This is done by
360  * appending a dash character ('-') and the modifier name in the order
361  * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
362  * - language -- a tag whose value is localized for a particular language
363  * is appended with the ISO 639-2/B 3-letter language code.
364  * For example: Author-ger=Michael, Author-eng=Mike
365  * The original/default language is in the unqualified "Author" tag.
366  * A demuxer should set a default if it sets any translated tag.
367  * - sorting -- a modified version of a tag that should be used for
368  * sorting will have '-sort' appended. E.g. artist="The Beatles",
369  * artist-sort="Beatles, The".
370  * - Some protocols and demuxers support metadata updates. After a successful
371  * call to av_read_frame(), AVFormatContext.event_flags or AVStream.event_flags
372  * will be updated to indicate if metadata changed. In order to detect metadata
373  * changes on a stream, you need to loop through all streams in the AVFormatContext
374  * and check their individual event_flags.
375  *
376  * - Demuxers attempt to export metadata in a generic format, however tags
377  * with no generic equivalents are left as they are stored in the container.
378  * Follows a list of generic tag names:
379  *
380  @verbatim
381  album -- name of the set this work belongs to
382  album_artist -- main creator of the set/album, if different from artist.
383  e.g. "Various Artists" for compilation albums.
384  artist -- main creator of the work
385  comment -- any additional description of the file.
386  composer -- who composed the work, if different from artist.
387  copyright -- name of copyright holder.
388  creation_time-- date when the file was created, preferably in ISO 8601.
389  date -- date when the work was created, preferably in ISO 8601.
390  disc -- number of a subset, e.g. disc in a multi-disc collection.
391  encoder -- name/settings of the software/hardware that produced the file.
392  encoded_by -- person/group who created the file.
393  filename -- original name of the file.
394  genre -- <self-evident>.
395  language -- main language in which the work is performed, preferably
396  in ISO 639-2 format. Multiple languages can be specified by
397  separating them with commas.
398  performer -- artist who performed the work, if different from artist.
399  E.g for "Also sprach Zarathustra", artist would be "Richard
400  Strauss" and performer "London Philharmonic Orchestra".
401  publisher -- name of the label/publisher.
402  service_name -- name of the service in broadcasting (channel name).
403  service_provider -- name of the service provider in broadcasting.
404  title -- name of the work.
405  track -- number of this work in the set, can be in form current/total.
406  variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
407  @endverbatim
408  *
409  * Look in the examples section for an application example how to use the Metadata API.
410  *
411  * @}
412  */
413 
414 /* packet functions */
415 
416 
417 /**
418  * Allocate and read the payload of a packet and initialize its
419  * fields with default values.
420  *
421  * @param s associated IO context
422  * @param pkt packet
423  * @param size desired payload size
424  * @return >0 (read size) if OK, AVERROR_xxx otherwise
425  */
427 
428 
429 /**
430  * Read data and append it to the current content of the AVPacket.
431  * If pkt->size is 0 this is identical to av_get_packet.
432  * Note that this uses av_grow_packet and thus involves a realloc
433  * which is inefficient. Thus this function should only be used
434  * when there is no reasonable way to know (an upper bound of)
435  * the final size.
436  *
437  * @param s associated IO context
438  * @param pkt packet
439  * @param size amount of data to read
440  * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
441  * will not be lost even if an error occurs.
442  */
444 
445 /*************************************************/
446 /* input/output formats */
447 
448 struct AVCodecTag;
449 
450 /**
451  * This structure contains the data a format has to probe a file.
452  */
453 typedef struct AVProbeData {
454  const char *filename;
455  unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
456  int buf_size; /**< Size of buf except extra allocated bytes */
457  const char *mime_type; /**< mime_type, when known. */
458 } AVProbeData;
459 
460 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
461 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
462 
463 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
464 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type
465 #define AVPROBE_SCORE_MAX 100 ///< maximum score
466 
467 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
468 
469 /// Demuxer will use avio_open, no opened file should be provided by the caller.
470 #define AVFMT_NOFILE 0x0001
471 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
472 /**
473  * The muxer/demuxer is experimental and should be used with caution.
474  *
475  * - demuxers: will not be selected automatically by probing, must be specified
476  * explicitly.
477  */
478 #define AVFMT_EXPERIMENTAL 0x0004
479 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
480 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
481 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
482 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
483 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
484 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
485 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
486 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
487 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
488 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
489 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
490 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
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, AVFMT_ALLOW_FLUSH,
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
539 
540  /*****************************************************************
541  * No fields below this line are part of the public API. They
542  * may not be used outside of libavformat and can be changed and
543  * removed at will.
544  * New public fields should be added right above.
545  *****************************************************************
546  */
547  /**
548  * size of private data so that it can be allocated in the wrapper
549  */
551 
552  /**
553  * Internal flags. See FF_FMT_FLAG_* in internal.h.
554  */
556 
558  /**
559  * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
560  * pkt can be NULL in order to flush data buffered in the muxer.
561  * When flushing, return 0 if there still is more data to flush,
562  * or 1 if everything was flushed and there is no more buffered
563  * data.
564  */
567  /**
568  * A format-specific function for interleavement.
569  * If unset, packets will be interleaved by dts.
570  *
571  * @param s An AVFormatContext for output. pkt will be added to
572  * resp. taken from its packet buffer.
573  * @param[in,out] pkt A packet to be interleaved if has_packet is set;
574  * also used to return packets. If no packet is returned
575  * (e.g. on error), pkt is blank on return.
576  * @param flush 1 if no further packets are available as input and
577  * all remaining packets should be output.
578  * @param has_packet If set, pkt contains a packet to be interleaved
579  * on input; otherwise pkt is blank on input.
580  * @return 1 if a packet was output, 0 if no packet could be output,
581  * < 0 if an error occurred
582  */
584  int flush, int has_packet);
585  /**
586  * Test if the given codec can be stored in this container.
587  *
588  * @return 1 if the codec is supported, 0 if it is not.
589  * A negative number if unknown.
590  * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
591  */
592  int (*query_codec)(enum AVCodecID id, int std_compliance);
593 
594  void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
595  int64_t *dts, int64_t *wall);
596  /**
597  * Allows sending messages from application to device.
598  */
600  void *data, size_t data_size);
601 
602  /**
603  * Write an uncoded AVFrame.
604  *
605  * See av_write_uncoded_frame() for details.
606  *
607  * The library will free *frame afterwards, but the muxer can prevent it
608  * by setting the pointer to NULL.
609  */
610  int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
611  AVFrame **frame, unsigned flags);
612  /**
613  * Returns device list with it properties.
614  * @see avdevice_list_devices() for more details.
615  */
616  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
617  enum AVCodecID data_codec; /**< default data codec */
618  /**
619  * Initialize format. May allocate data here, and set any AVFormatContext or
620  * AVStream parameters that need to be set before packets are sent.
621  * This method must not write output.
622  *
623  * Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure
624  *
625  * Any allocations made here must be freed in deinit().
626  */
627  int (*init)(struct AVFormatContext *);
628  /**
629  * Deinitialize format. If present, this is called whenever the muxer is being
630  * destroyed, regardless of whether or not the header has been written.
631  *
632  * If a trailer is being written, this is called after write_trailer().
633  *
634  * This is called if init() fails as well.
635  */
636  void (*deinit)(struct AVFormatContext *);
637  /**
638  * Set up any necessary bitstream filtering and extract any extra data needed
639  * for the global header.
640  *
641  * @note pkt might have been directly forwarded by a meta-muxer; therefore
642  * pkt->stream_index as well as the pkt's timebase might be invalid.
643  * Return 0 if more packets from this stream must be checked; 1 if not.
644  */
645  int (*check_bitstream)(struct AVFormatContext *s, struct AVStream *st,
646  const AVPacket *pkt);
648 /**
649  * @}
650  */
651 
652 /**
653  * @addtogroup lavf_decoding
654  * @{
655  */
656 typedef struct AVInputFormat {
657  /**
658  * A comma separated list of short names for the format. New names
659  * may be appended with a minor bump.
660  */
661  const char *name;
662 
663  /**
664  * Descriptive name for the format, meant to be more human-readable
665  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
666  * to define it.
667  */
668  const char *long_name;
669 
670  /**
671  * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
672  * AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
673  * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
674  */
675  int flags;
676 
677  /**
678  * If extensions are defined, then no probe is done. You should
679  * usually not use extension format guessing because it is not
680  * reliable enough
681  */
682  const char *extensions;
683 
684  const struct AVCodecTag * const *codec_tag;
685 
686  const AVClass *priv_class; ///< AVClass for the private context
687 
688  /**
689  * Comma-separated list of mime types.
690  * It is used check for matching mime types while probing.
691  * @see av_probe_input_format2
692  */
693  const char *mime_type;
694 
695  /*****************************************************************
696  * No fields below this line are part of the public API. They
697  * may not be used outside of libavformat and can be changed and
698  * removed at will.
699  * New public fields should be added right above.
700  *****************************************************************
701  */
702  /**
703  * Raw demuxers store their codec ID here.
704  */
706 
707  /**
708  * Size of private data so that it can be allocated in the wrapper.
709  */
711 
712  /**
713  * Internal flags. See FF_FMT_FLAG_* in internal.h.
714  */
716 
717  /**
718  * Tell if a given file has a chance of being parsed as this format.
719  * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
720  * big so you do not have to check for that unless you need more.
721  */
723 
724  /**
725  * Read the format header and initialize the AVFormatContext
726  * structure. Return 0 if OK. 'avformat_new_stream' should be
727  * called to create new streams.
728  */
730 
731  /**
732  * Read one packet and put it in 'pkt'. pts and flags are also
733  * set. 'avformat_new_stream' can be called only if the flag
734  * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
735  * background thread).
736  * @return 0 on success, < 0 on error.
737  * Upon returning an error, pkt must be unreferenced by the caller.
738  */
740 
741  /**
742  * Close the stream. The AVFormatContext and AVStreams are not
743  * freed by this function
744  */
746 
747  /**
748  * Seek to a given timestamp relative to the frames in
749  * stream component stream_index.
750  * @param stream_index Must not be -1.
751  * @param flags Selects which direction should be preferred if no exact
752  * match is available.
753  * @return >= 0 on success (but not necessarily the new offset)
754  */
756  int stream_index, int64_t timestamp, int flags);
757 
758  /**
759  * Get the next timestamp in stream[stream_index].time_base units.
760  * @return the timestamp or AV_NOPTS_VALUE if an error occurred
761  */
762  int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
763  int64_t *pos, int64_t pos_limit);
764 
765  /**
766  * Start/resume playing - only meaningful if using a network-based format
767  * (RTSP).
768  */
770 
771  /**
772  * Pause playing - only meaningful if using a network-based format
773  * (RTSP).
774  */
776 
777  /**
778  * Seek to timestamp ts.
779  * Seeking will be done so that the point from which all active streams
780  * can be presented successfully will be closest to ts and within min/max_ts.
781  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
782  */
783  int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
784 
785  /**
786  * Returns device list with it properties.
787  * @see avdevice_list_devices() for more details.
788  */
789  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
790 
791 } AVInputFormat;
792 /**
793  * @}
794  */
795 
798  AVSTREAM_PARSE_FULL, /**< full parsing and repack */
799  AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
800  AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
801  AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
802  AVSTREAM_PARSE_FULL_RAW, /**< full parsing and repack with timestamp and position generation by parser for raw
803  this assumes that each packet in the file contains no demuxer level headers and
804  just codec level data, otherwise position generation would fail */
805 };
806 
807 typedef struct AVIndexEntry {
808  int64_t pos;
809  int64_t timestamp; /**<
810  * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
811  * when seeking to this entry. That means preferable PTS on keyframe based formats.
812  * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
813  * is known
814  */
815 #define AVINDEX_KEYFRAME 0x0001
816 #define AVINDEX_DISCARD_FRAME 0x0002 /**
817  * Flag is used to indicate which frame should be discarded after decoding.
818  */
819  int flags:2;
820  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).
821  int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
822 } AVIndexEntry;
823 
824 /**
825  * The stream should be chosen by default among other streams of the same type,
826  * unless the user has explicitly specified otherwise.
827  */
828 #define AV_DISPOSITION_DEFAULT (1 << 0)
829 /**
830  * The stream is not in original language.
831  *
832  * @note AV_DISPOSITION_ORIGINAL is the inverse of this disposition. At most
833  * one of them should be set in properly tagged streams.
834  * @note This disposition may apply to any stream type, not just audio.
835  */
836 #define AV_DISPOSITION_DUB (1 << 1)
837 /**
838  * The stream is in original language.
839  *
840  * @see the notes for AV_DISPOSITION_DUB
841  */
842 #define AV_DISPOSITION_ORIGINAL (1 << 2)
843 /**
844  * The stream is a commentary track.
845  */
846 #define AV_DISPOSITION_COMMENT (1 << 3)
847 /**
848  * The stream contains song lyrics.
849  */
850 #define AV_DISPOSITION_LYRICS (1 << 4)
851 /**
852  * The stream contains karaoke audio.
853  */
854 #define AV_DISPOSITION_KARAOKE (1 << 5)
855 
856 /**
857  * Track should be used during playback by default.
858  * Useful for subtitle track that should be displayed
859  * even when user did not explicitly ask for subtitles.
860  */
861 #define AV_DISPOSITION_FORCED (1 << 6)
862 /**
863  * The stream is intended for hearing impaired audiences.
864  */
865 #define AV_DISPOSITION_HEARING_IMPAIRED (1 << 7)
866 /**
867  * The stream is intended for visually impaired audiences.
868  */
869 #define AV_DISPOSITION_VISUAL_IMPAIRED (1 << 8)
870 /**
871  * The audio stream contains music and sound effects without voice.
872  */
873 #define AV_DISPOSITION_CLEAN_EFFECTS (1 << 9)
874 /**
875  * The stream is stored in the file as an attached picture/"cover art" (e.g.
876  * APIC frame in ID3v2). The first (usually only) packet associated with it
877  * will be returned among the first few packets read from the file unless
878  * seeking takes place. It can also be accessed at any time in
879  * AVStream.attached_pic.
880  */
881 #define AV_DISPOSITION_ATTACHED_PIC (1 << 10)
882 /**
883  * The stream is sparse, and contains thumbnail images, often corresponding
884  * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
885  */
886 #define AV_DISPOSITION_TIMED_THUMBNAILS (1 << 11)
887 
888 /**
889  * The stream is intended to be mixed with a spatial audio track. For example,
890  * it could be used for narration or stereo music, and may remain unchanged by
891  * listener head rotation.
892  */
893 #define AV_DISPOSITION_NON_DIEGETIC (1 << 12)
894 
895 /**
896  * The subtitle stream contains captions, providing a transcription and possibly
897  * a translation of audio. Typically intended for hearing-impaired audiences.
898  */
899 #define AV_DISPOSITION_CAPTIONS (1 << 16)
900 /**
901  * The subtitle stream contains a textual description of the video content.
902  * Typically intended for visually-impaired audiences or for the cases where the
903  * video cannot be seen.
904  */
905 #define AV_DISPOSITION_DESCRIPTIONS (1 << 17)
906 /**
907  * The subtitle stream contains time-aligned metadata that is not intended to be
908  * directly presented to the user.
909  */
910 #define AV_DISPOSITION_METADATA (1 << 18)
911 /**
912  * The audio stream is intended to be mixed with another stream before
913  * presentation.
914  * Corresponds to mix_type=0 in mpegts.
915  */
916 #define AV_DISPOSITION_DEPENDENT (1 << 19)
917 /**
918  * The video stream contains still images.
919  */
920 #define AV_DISPOSITION_STILL_IMAGE (1 << 20)
921 
922 /**
923  * @return The AV_DISPOSITION_* flag corresponding to disp or a negative error
924  * code if disp does not correspond to a known stream disposition.
925  */
926 int av_disposition_from_string(const char *disp);
927 
928 /**
929  * @param disposition a combination of AV_DISPOSITION_* values
930  * @return The string description corresponding to the lowest set bit in
931  * disposition. NULL when the lowest set bit does not correspond
932  * to a known disposition or when disposition is 0.
933  */
934 const char *av_disposition_to_string(int disposition);
935 
936 /**
937  * Options for behavior on timestamp wrap detection.
938  */
939 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
940 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
941 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
942 
943 /**
944  * Stream structure.
945  * New fields can be added to the end with minor version bumps.
946  * Removal, reordering and changes to existing fields require a major
947  * version bump.
948  * sizeof(AVStream) must not be used outside libav*.
949  */
950 typedef struct AVStream {
951 #if FF_API_AVSTREAM_CLASS
952  /**
953  * A class for @ref avoptions. Set on stream creation.
954  */
955  const AVClass *av_class;
956 #endif
957 
958  int index; /**< stream index in AVFormatContext */
959  /**
960  * Format-specific stream ID.
961  * decoding: set by libavformat
962  * encoding: set by the user, replaced by libavformat if left unset
963  */
964  int id;
965 
966  void *priv_data;
967 
968  /**
969  * This is the fundamental unit of time (in seconds) in terms
970  * of which frame timestamps are represented.
971  *
972  * decoding: set by libavformat
973  * encoding: May be set by the caller before avformat_write_header() to
974  * provide a hint to the muxer about the desired timebase. In
975  * avformat_write_header(), the muxer will overwrite this field
976  * with the timebase that will actually be used for the timestamps
977  * written into the file (which may or may not be related to the
978  * user-provided one, depending on the format).
979  */
981 
982  /**
983  * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
984  * Only set this if you are absolutely 100% sure that the value you set
985  * it to really is the pts of the first frame.
986  * This may be undefined (AV_NOPTS_VALUE).
987  * @note The ASF header does NOT contain a correct start_time the ASF
988  * demuxer must NOT set this.
989  */
990  int64_t start_time;
991 
992  /**
993  * Decoding: duration of the stream, in stream time base.
994  * If a source file does not specify a duration, but does specify
995  * a bitrate, this value will be estimated from bitrate and file size.
996  *
997  * Encoding: May be set by the caller before avformat_write_header() to
998  * provide a hint to the muxer about the estimated duration.
999  */
1000  int64_t duration;
1001 
1002  int64_t nb_frames; ///< number of frames in this stream if known or 0
1003 
1004  /**
1005  * Stream disposition - a combination of AV_DISPOSITION_* flags.
1006  * - demuxing: set by libavformat when creating the stream or in
1007  * avformat_find_stream_info().
1008  * - muxing: may be set by the caller before avformat_write_header().
1009  */
1011 
1012  enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
1013 
1014  /**
1015  * sample aspect ratio (0 if unknown)
1016  * - encoding: Set by user.
1017  * - decoding: Set by libavformat.
1018  */
1020 
1022 
1023  /**
1024  * Average framerate
1025  *
1026  * - demuxing: May be set by libavformat when creating the stream or in
1027  * avformat_find_stream_info().
1028  * - muxing: May be set by the caller before avformat_write_header().
1029  */
1031 
1032  /**
1033  * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
1034  * will contain the attached picture.
1035  *
1036  * decoding: set by libavformat, must not be modified by the caller.
1037  * encoding: unused
1038  */
1040 
1041  /**
1042  * An array of side data that applies to the whole stream (i.e. the
1043  * container does not allow it to change between packets).
1044  *
1045  * There may be no overlap between the side data in this array and side data
1046  * in the packets. I.e. a given side data is either exported by the muxer
1047  * (demuxing) / set by the caller (muxing) in this array, then it never
1048  * appears in the packets, or the side data is exported / sent through
1049  * the packets (always in the first packet where the value becomes known or
1050  * changes), then it does not appear in this array.
1051  *
1052  * - demuxing: Set by libavformat when the stream is created.
1053  * - muxing: May be set by the caller before avformat_write_header().
1054  *
1055  * Freed by libavformat in avformat_free_context().
1056  *
1057  * @see av_format_inject_global_side_data()
1058  */
1060  /**
1061  * The number of elements in the AVStream.side_data array.
1062  */
1063  int nb_side_data;
1064 
1065  /**
1066  * Flags indicating events happening on the stream, a combination of
1067  * AVSTREAM_EVENT_FLAG_*.
1068  *
1069  * - demuxing: may be set by the demuxer in avformat_open_input(),
1070  * avformat_find_stream_info() and av_read_frame(). Flags must be cleared
1071  * by the user once the event has been handled.
1072  * - muxing: may be set by the user after avformat_write_header(). to
1073  * indicate a user-triggered event. The muxer will clear the flags for
1074  * events it has handled in av_[interleaved]_write_frame().
1075  */
1076  int event_flags;
1077 /**
1078  * - demuxing: the demuxer read new metadata from the file and updated
1079  * AVStream.metadata accordingly
1080  * - muxing: the user updated AVStream.metadata and wishes the muxer to write
1081  * it into the file
1082  */
1083 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001
1084 /**
1085  * - demuxing: new packets for this stream were read from the file. This
1086  * event is informational only and does not guarantee that new packets
1087  * for this stream will necessarily be returned from av_read_frame().
1088  */
1089 #define AVSTREAM_EVENT_FLAG_NEW_PACKETS (1 << 1)
1090 
1091  /**
1092  * Real base framerate of the stream.
1093  * This is the lowest framerate with which all timestamps can be
1094  * represented accurately (it is the least common multiple of all
1095  * framerates in the stream). Note, this value is just a guess!
1096  * For example, if the time base is 1/90000 and all frames have either
1097  * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
1098  */
1100 
1101  /**
1102  * Codec parameters associated with this stream. Allocated and freed by
1103  * libavformat in avformat_new_stream() and avformat_free_context()
1104  * respectively.
1105  *
1106  * - demuxing: filled by libavformat on stream creation or in
1107  * avformat_find_stream_info()
1108  * - muxing: filled by the caller before avformat_write_header()
1109  */
1111 
1112  /**
1113  * Number of bits in timestamps. Used for wrapping control.
1114  *
1115  * - demuxing: set by libavformat
1116  * - muxing: set by libavformat
1117  *
1118  */
1119  int pts_wrap_bits;
1120 } AVStream;
1121 
1123 
1124 #if FF_API_GET_END_PTS
1125 /**
1126  * Returns the pts of the last muxed packet + its duration
1127  *
1128  * the retuned value is undefined when used with a demuxer.
1129  */
1131 int64_t av_stream_get_end_pts(const AVStream *st);
1132 #endif
1133 
1134 #define AV_PROGRAM_RUNNING 1
1135 
1136 /**
1137  * New fields can be added to the end with minor version bumps.
1138  * Removal, reordering and changes to existing fields require a major
1139  * version bump.
1140  * sizeof(AVProgram) must not be used outside libav*.
1141  */
1142 typedef struct AVProgram {
1143  int id;
1144  int flags;
1145  enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1146  unsigned int *stream_index;
1147  unsigned int nb_stream_indexes;
1151  int pmt_pid;
1152  int pcr_pid;
1153  int pmt_version;
1154 
1155  /*****************************************************************
1156  * All fields below this line are not part of the public API. They
1157  * may not be used outside of libavformat and can be changed and
1158  * removed at will.
1159  * New public fields should be added right above.
1160  *****************************************************************
1161  */
1162  int64_t start_time;
1163  int64_t end_time;
1165  int64_t pts_wrap_reference; ///< reference dts for wrap detection
1166  int pts_wrap_behavior; ///< behavior on wrap detection
1168 
1169 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1170  (streams are added dynamically) */
1171 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely
1172  not seekable, and attempts to call the
1173  seek function will fail. For some
1174  network protocols (e.g. HLS), this can
1175  change dynamically at runtime. */
1177 typedef struct AVChapter {
1178  int64_t id; ///< unique ID to identify the chapter
1179  AVRational time_base; ///< time base in which the start/end timestamps are specified
1180  int64_t start, end; ///< chapter start/end time in time_base units
1182 } AVChapter;
1183 
1184 
1185 /**
1186  * Callback used by devices to communicate with application.
1187  */
1188 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1189  void *data, size_t data_size);
1190 
1191 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
1193 
1194 /**
1195  * The duration of a video can be estimated through various ways, and this enum can be used
1196  * to know how the duration was estimated.
1197  */
1199  AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1200  AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1201  AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1202 };
1203 
1204 /**
1205  * Format I/O context.
1206  * New fields can be added to the end with minor version bumps.
1207  * Removal, reordering and changes to existing fields require a major
1208  * version bump.
1209  * sizeof(AVFormatContext) must not be used outside libav*, use
1210  * avformat_alloc_context() to create an AVFormatContext.
1211  *
1212  * Fields can be accessed through AVOptions (av_opt*),
1213  * the name string used matches the associated command line parameter name and
1214  * can be found in libavformat/options_table.h.
1215  * The AVOption/command line parameter names differ in some cases from the C
1216  * structure field names for historic reasons or brevity.
1217  */
1218 typedef struct AVFormatContext {
1219  /**
1220  * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1221  * Exports (de)muxer private options if they exist.
1222  */
1223  const AVClass *av_class;
1224 
1225  /**
1226  * The input container format.
1227  *
1228  * Demuxing only, set by avformat_open_input().
1229  */
1230  const struct AVInputFormat *iformat;
1231 
1232  /**
1233  * The output container format.
1234  *
1235  * Muxing only, must be set by the caller before avformat_write_header().
1236  */
1237  const struct AVOutputFormat *oformat;
1238 
1239  /**
1240  * Format private data. This is an AVOptions-enabled struct
1241  * if and only if iformat/oformat.priv_class is not NULL.
1242  *
1243  * - muxing: set by avformat_write_header()
1244  * - demuxing: set by avformat_open_input()
1245  */
1246  void *priv_data;
1247 
1248  /**
1249  * I/O context.
1250  *
1251  * - demuxing: either set by the user before avformat_open_input() (then
1252  * the user must close it manually) or set by avformat_open_input().
1253  * - muxing: set by the user before avformat_write_header(). The caller must
1254  * take care of closing / freeing the IO context.
1255  *
1256  * Do NOT set this field if AVFMT_NOFILE flag is set in
1257  * iformat/oformat.flags. In such a case, the (de)muxer will handle
1258  * I/O in some other way and this field will be NULL.
1259  */
1260  AVIOContext *pb;
1261 
1262  /* stream info */
1263  /**
1264  * Flags signalling stream properties. A combination of AVFMTCTX_*.
1265  * Set by libavformat.
1266  */
1267  int ctx_flags;
1268 
1269  /**
1270  * Number of elements in AVFormatContext.streams.
1271  *
1272  * Set by avformat_new_stream(), must not be modified by any other code.
1273  */
1274  unsigned int nb_streams;
1275  /**
1276  * A list of all streams in the file. New streams are created with
1277  * avformat_new_stream().
1278  *
1279  * - demuxing: streams are created by libavformat in avformat_open_input().
1280  * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1281  * appear in av_read_frame().
1282  * - muxing: streams are created by the user before avformat_write_header().
1283  *
1284  * Freed by libavformat in avformat_free_context().
1285  */
1286  AVStream **streams;
1287 
1288  /**
1289  * input or output URL. Unlike the old filename field, this field has no
1290  * length restriction.
1291  *
1292  * - demuxing: set by avformat_open_input(), initialized to an empty
1293  * string if url parameter was NULL in avformat_open_input().
1294  * - muxing: may be set by the caller before calling avformat_write_header()
1295  * (or avformat_init_output() if that is called first) to a string
1296  * which is freeable by av_free(). Set to an empty string if it
1297  * was NULL in avformat_init_output().
1298  *
1299  * Freed by libavformat in avformat_free_context().
1300  */
1301  char *url;
1302 
1303  /**
1304  * Position of the first frame of the component, in
1305  * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1306  * It is deduced from the AVStream values.
1307  *
1308  * Demuxing only, set by libavformat.
1309  */
1310  int64_t start_time;
1311 
1312  /**
1313  * Duration of the stream, in AV_TIME_BASE fractional
1314  * seconds. Only set this value if you know none of the individual stream
1315  * durations and also do not set any of them. This is deduced from the
1316  * AVStream values if not set.
1317  *
1318  * Demuxing only, set by libavformat.
1319  */
1320  int64_t duration;
1321 
1322  /**
1323  * Total stream bitrate in bit/s, 0 if not
1324  * available. Never set it directly if the file_size and the
1325  * duration are known as FFmpeg can compute it automatically.
1326  */
1327  int64_t bit_rate;
1329  unsigned int packet_size;
1330  int max_delay;
1331 
1332  /**
1333  * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1334  * Set by the user before avformat_open_input() / avformat_write_header().
1335  */
1336  int flags;
1337 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1338 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1339 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1340 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1341 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1342 #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
1343 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1344 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1345 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1346 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1347 /**
1348  * When muxing, try to avoid writing any random/volatile data to the output.
1349  * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1350  *
1351  * This flag is mainly intended for testing.
1352  */
1353 #define AVFMT_FLAG_BITEXACT 0x0400
1354 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1355 #if FF_API_LAVF_PRIV_OPT
1356 #define AVFMT_FLAG_PRIV_OPT 0x20000 ///< Enable use of private options by delaying codec open (deprecated, does nothing)
1357 #endif
1358 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1359 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
1360 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
1361 
1362  /**
1363  * Maximum number of bytes read from input in order to determine stream
1364  * properties. Used when reading the global header and in
1365  * avformat_find_stream_info().
1366  *
1367  * Demuxing only, set by the caller before avformat_open_input().
1368  *
1369  * @note this is \e not used for determining the \ref AVInputFormat
1370  * "input format"
1371  * @sa format_probesize
1372  */
1373  int64_t probesize;
1374 
1375  /**
1376  * Maximum duration (in AV_TIME_BASE units) of the data read
1377  * from input in avformat_find_stream_info().
1378  * Demuxing only, set by the caller before avformat_find_stream_info().
1379  * Can be set to 0 to let avformat choose using a heuristic.
1380  */
1383  const uint8_t *key;
1384  int keylen;
1386  unsigned int nb_programs;
1387  AVProgram **programs;
1388 
1389  /**
1390  * Forced video codec_id.
1391  * Demuxing: Set by user.
1392  */
1394 
1395  /**
1396  * Forced audio codec_id.
1397  * Demuxing: Set by user.
1398  */
1400 
1401  /**
1402  * Forced subtitle codec_id.
1403  * Demuxing: Set by user.
1404  */
1406 
1407  /**
1408  * Maximum amount of memory in bytes to use for the index of each stream.
1409  * If the index exceeds this size, entries will be discarded as
1410  * needed to maintain a smaller size. This can lead to slower or less
1411  * accurate seeking (depends on demuxer).
1412  * Demuxers for which a full in-memory index is mandatory will ignore
1413  * this.
1414  * - muxing: unused
1415  * - demuxing: set by user
1416  */
1417  unsigned int max_index_size;
1418 
1419  /**
1420  * Maximum amount of memory in bytes to use for buffering frames
1421  * obtained from realtime capture devices.
1422  */
1423  unsigned int max_picture_buffer;
1424 
1425  /**
1426  * Number of chapters in AVChapter array.
1427  * When muxing, chapters are normally written in the file header,
1428  * so nb_chapters should normally be initialized before write_header
1429  * is called. Some muxers (e.g. mov and mkv) can also write chapters
1430  * in the trailer. To write chapters in the trailer, nb_chapters
1431  * must be zero when write_header is called and non-zero when
1432  * write_trailer is called.
1433  * - muxing: set by user
1434  * - demuxing: set by libavformat
1435  */
1436  unsigned int nb_chapters;
1437  AVChapter **chapters;
1438 
1439  /**
1440  * Metadata that applies to the whole file.
1441  *
1442  * - demuxing: set by libavformat in avformat_open_input()
1443  * - muxing: may be set by the caller before avformat_write_header()
1444  *
1445  * Freed by libavformat in avformat_free_context().
1446  */
1448 
1449  /**
1450  * Start time of the stream in real world time, in microseconds
1451  * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1452  * stream was captured at this real world time.
1453  * - muxing: Set by the caller before avformat_write_header(). If set to
1454  * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1455  * be used.
1456  * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1457  * the value may become known after some number of frames
1458  * have been received.
1459  */
1460  int64_t start_time_realtime;
1461 
1462  /**
1463  * The number of frames used for determining the framerate in
1464  * avformat_find_stream_info().
1465  * Demuxing only, set by the caller before avformat_find_stream_info().
1466  */
1467  int fps_probe_size;
1468 
1469  /**
1470  * Error recognition; higher values will detect more errors but may
1471  * misdetect some more or less valid parts as errors.
1472  * Demuxing only, set by the caller before avformat_open_input().
1473  */
1474  int error_recognition;
1475 
1476  /**
1477  * Custom interrupt callbacks for the I/O layer.
1478  *
1479  * demuxing: set by the user before avformat_open_input().
1480  * muxing: set by the user before avformat_write_header()
1481  * (mainly useful for AVFMT_NOFILE formats). The callback
1482  * should also be passed to avio_open2() if it's used to
1483  * open the file.
1484  */
1486 
1487  /**
1488  * Flags to enable debugging.
1489  */
1490  int debug;
1491 #define FF_FDEBUG_TS 0x0001
1492 
1493  /**
1494  * Maximum buffering duration for interleaving.
1495  *
1496  * To ensure all the streams are interleaved correctly,
1497  * av_interleaved_write_frame() will wait until it has at least one packet
1498  * for each stream before actually writing any packets to the output file.
1499  * When some streams are "sparse" (i.e. there are large gaps between
1500  * successive packets), this can result in excessive buffering.
1501  *
1502  * This field specifies the maximum difference between the timestamps of the
1503  * first and the last packet in the muxing queue, above which libavformat
1504  * will output a packet regardless of whether it has queued a packet for all
1505  * the streams.
1506  *
1507  * Muxing only, set by the caller before avformat_write_header().
1508  */
1509  int64_t max_interleave_delta;
1510 
1511  /**
1512  * Allow non-standard and experimental extension
1513  * @see AVCodecContext.strict_std_compliance
1514  */
1516 
1517  /**
1518  * Flags indicating events happening on the file, a combination of
1519  * AVFMT_EVENT_FLAG_*.
1520  *
1521  * - demuxing: may be set by the demuxer in avformat_open_input(),
1522  * avformat_find_stream_info() and av_read_frame(). Flags must be cleared
1523  * by the user once the event has been handled.
1524  * - muxing: may be set by the user after avformat_write_header() to
1525  * indicate a user-triggered event. The muxer will clear the flags for
1526  * events it has handled in av_[interleaved]_write_frame().
1527  */
1528  int event_flags;
1529 /**
1530  * - demuxing: the demuxer read new metadata from the file and updated
1531  * AVFormatContext.metadata accordingly
1532  * - muxing: the user updated AVFormatContext.metadata and wishes the muxer to
1533  * write it into the file
1534  */
1535 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001
1536 
1537  /**
1538  * Maximum number of packets to read while waiting for the first timestamp.
1539  * Decoding only.
1540  */
1541  int max_ts_probe;
1542 
1543  /**
1544  * Avoid negative timestamps during muxing.
1545  * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1546  * Note, this works better when using av_interleaved_write_frame().
1547  * - muxing: Set by user
1548  * - demuxing: unused
1549  */
1551 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1552 #define AVFMT_AVOID_NEG_TS_DISABLED 0 ///< Do not shift timestamps even when they are negative.
1553 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1554 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1555 
1556  /**
1557  * Transport stream id.
1558  * This will be moved into demuxer private options. Thus no API/ABI compatibility
1559  */
1560  int ts_id;
1561 
1562  /**
1563  * Audio preload in microseconds.
1564  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1565  * - encoding: Set by user
1566  * - decoding: unused
1567  */
1568  int audio_preload;
1569 
1570  /**
1571  * Max chunk time in microseconds.
1572  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1573  * - encoding: Set by user
1574  * - decoding: unused
1575  */
1576  int max_chunk_duration;
1577 
1578  /**
1579  * Max chunk size in bytes
1580  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1581  * - encoding: Set by user
1582  * - decoding: unused
1583  */
1584  int max_chunk_size;
1585 
1586  /**
1587  * forces the use of wallclock timestamps as pts/dts of packets
1588  * This has undefined results in the presence of B frames.
1589  * - encoding: unused
1590  * - decoding: Set by user
1591  */
1593 
1594  /**
1595  * avio flags, used to force AVIO_FLAG_DIRECT.
1596  * - encoding: unused
1597  * - decoding: Set by user
1598  */
1599  int avio_flags;
1600 
1601  /**
1602  * The duration field can be estimated through various ways, and this field can be used
1603  * to know how the duration was estimated.
1604  * - encoding: unused
1605  * - decoding: Read by user
1606  */
1608 
1609  /**
1610  * Skip initial bytes when opening stream
1611  * - encoding: unused
1612  * - decoding: Set by user
1613  */
1614  int64_t skip_initial_bytes;
1615 
1616  /**
1617  * Correct single timestamp overflows
1618  * - encoding: unused
1619  * - decoding: Set by user
1620  */
1621  unsigned int correct_ts_overflow;
1622 
1623  /**
1624  * Force seeking to any (also non key) frames.
1625  * - encoding: unused
1626  * - decoding: Set by user
1627  */
1628  int seek2any;
1629 
1630  /**
1631  * Flush the I/O context after each packet.
1632  * - encoding: Set by user
1633  * - decoding: unused
1634  */
1635  int flush_packets;
1636 
1637  /**
1638  * format probing score.
1639  * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1640  * the format.
1641  * - encoding: unused
1642  * - decoding: set by avformat, read by user
1643  */
1644  int probe_score;
1645 
1646  /**
1647  * Maximum number of bytes read from input in order to identify the
1648  * \ref AVInputFormat "input format". Only used when the format is not set
1649  * explicitly by the caller.
1650  *
1651  * Demuxing only, set by the caller before avformat_open_input().
1652  *
1653  * @sa probesize
1654  */
1655  int format_probesize;
1656 
1657  /**
1658  * ',' separated list of allowed decoders.
1659  * If NULL then all are allowed
1660  * - encoding: unused
1661  * - decoding: set by user
1662  */
1663  char *codec_whitelist;
1664 
1665  /**
1666  * ',' separated list of allowed demuxers.
1667  * If NULL then all are allowed
1668  * - encoding: unused
1669  * - decoding: set by user
1670  */
1671  char *format_whitelist;
1672 
1673  /**
1674  * IO repositioned flag.
1675  * This is set by avformat when the underlaying IO context read pointer
1676  * is repositioned, for example when doing byte based seeking.
1677  * Demuxers can use the flag to detect such changes.
1678  */
1679  int io_repositioned;
1680 
1681  /**
1682  * Forced video codec.
1683  * This allows forcing a specific decoder, even when there are multiple with
1684  * the same codec_id.
1685  * Demuxing: Set by user
1686  */
1687  const AVCodec *video_codec;
1688 
1689  /**
1690  * Forced audio codec.
1691  * This allows forcing a specific decoder, even when there are multiple with
1692  * the same codec_id.
1693  * Demuxing: Set by user
1694  */
1695  const AVCodec *audio_codec;
1696 
1697  /**
1698  * Forced subtitle codec.
1699  * This allows forcing a specific decoder, even when there are multiple with
1700  * the same codec_id.
1701  * Demuxing: Set by user
1702  */
1703  const AVCodec *subtitle_codec;
1704 
1705  /**
1706  * Forced data codec.
1707  * This allows forcing a specific decoder, even when there are multiple with
1708  * the same codec_id.
1709  * Demuxing: Set by user
1710  */
1711  const AVCodec *data_codec;
1712 
1713  /**
1714  * Number of bytes to be written as padding in a metadata header.
1715  * Demuxing: Unused.
1716  * Muxing: Set by user via av_format_set_metadata_header_padding.
1717  */
1719 
1720  /**
1721  * User data.
1722  * This is a place for some private data of the user.
1723  */
1724  void *opaque;
1725 
1726  /**
1727  * Callback used by devices to communicate with application.
1728  */
1730 
1731  /**
1732  * Output timestamp offset, in microseconds.
1733  * Muxing: set by user
1734  */
1735  int64_t output_ts_offset;
1736 
1737  /**
1738  * dump format separator.
1739  * can be ", " or "\n " or anything else
1740  * - muxing: Set by user.
1741  * - demuxing: Set by user.
1742  */
1743  uint8_t *dump_separator;
1744 
1745  /**
1746  * Forced Data codec_id.
1747  * Demuxing: Set by user.
1748  */
1749  enum AVCodecID data_codec_id;
1750 
1751  /**
1752  * ',' separated list of allowed protocols.
1753  * - encoding: unused
1754  * - decoding: set by user
1755  */
1756  char *protocol_whitelist;
1757 
1758  /**
1759  * A callback for opening new IO streams.
1760  *
1761  * Whenever a muxer or a demuxer needs to open an IO stream (typically from
1762  * avformat_open_input() for demuxers, but for certain formats can happen at
1763  * other times as well), it will call this callback to obtain an IO context.
1764  *
1765  * @param s the format context
1766  * @param pb on success, the newly opened IO context should be returned here
1767  * @param url the url to open
1768  * @param flags a combination of AVIO_FLAG_*
1769  * @param options a dictionary of additional options, with the same
1770  * semantics as in avio_open2()
1771  * @return 0 on success, a negative AVERROR code on failure
1772  *
1773  * @note Certain muxers and demuxers do nesting, i.e. they open one or more
1774  * additional internal format contexts. Thus the AVFormatContext pointer
1775  * passed to this callback may be different from the one facing the caller.
1776  * It will, however, have the same 'opaque' field.
1777  */
1778  int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url,
1779  int flags, AVDictionary **options);
1780 
1781  /**
1782  * A callback for closing the streams opened with AVFormatContext.io_open().
1783  */
1784  void (*io_close)(struct AVFormatContext *s, AVIOContext *pb);
1785 
1786  /**
1787  * ',' separated list of disallowed protocols.
1788  * - encoding: unused
1789  * - decoding: set by user
1790  */
1791  char *protocol_blacklist;
1792 
1793  /**
1794  * The maximum number of streams.
1795  * - encoding: unused
1796  * - decoding: set by user
1797  */
1798  int max_streams;
1799 
1800  /**
1801  * Skip duration calcuation in estimate_timings_from_pts.
1802  * - encoding: unused
1803  * - decoding: set by user
1804  */
1806 
1807  /**
1808  * Maximum number of packets that can be probed
1809  * - encoding: unused
1810  * - decoding: set by user
1811  */
1812  int max_probe_packets;
1813 
1814  /**
1815  * A callback for closing the streams opened with AVFormatContext.io_open().
1816  *
1817  * Using this is preferred over io_close, because this can return an error.
1818  * Therefore this callback is used instead of io_close by the generic
1819  * libavformat code if io_close is NULL or the default.
1820  *
1821  * @param s the format context
1822  * @param pb IO context to be closed and freed
1823  * @return 0 on success, a negative AVERROR code on failure
1824  */
1825  int (*io_close2)(struct AVFormatContext *s, AVIOContext *pb);
1826 } AVFormatContext;
1827 
1828 /**
1829  * This function will cause global side data to be injected in the next packet
1830  * of each stream as well as after any subsequent seek.
1831  */
1833 
1834 /**
1835  * Returns the method used to set ctx->duration.
1836  *
1837  * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1838  */
1840 
1841 /**
1842  * @defgroup lavf_core Core functions
1843  * @ingroup libavf
1844  *
1845  * Functions for querying libavformat capabilities, allocating core structures,
1846  * etc.
1847  * @{
1848  */
1849 
1850 /**
1851  * Return the LIBAVFORMAT_VERSION_INT constant.
1852  */
1853 unsigned avformat_version(void);
1854 
1855 /**
1856  * Return the libavformat build-time configuration.
1857  */
1858 const char *avformat_configuration(void);
1859 
1860 /**
1861  * Return the libavformat license.
1862  */
1863 const char *avformat_license(void);
1864 
1865 /**
1866  * Do global initialization of network libraries. This is optional,
1867  * and not recommended anymore.
1868  *
1869  * This functions only exists to work around thread-safety issues
1870  * with older GnuTLS or OpenSSL libraries. If libavformat is linked
1871  * to newer versions of those libraries, or if you do not use them,
1872  * calling this function is unnecessary. Otherwise, you need to call
1873  * this function before any other threads using them are started.
1874  *
1875  * This function will be deprecated once support for older GnuTLS and
1876  * OpenSSL libraries is removed, and this function has no purpose
1877  * anymore.
1878  */
1879 int avformat_network_init(void);
1880 
1881 /**
1882  * Undo the initialization done by avformat_network_init. Call it only
1883  * once for each time you called avformat_network_init.
1884  */
1885 int avformat_network_deinit(void);
1886 
1887 /**
1888  * Iterate over all registered muxers.
1889  *
1890  * @param opaque a pointer where libavformat will store the iteration state. Must
1891  * point to NULL to start the iteration.
1892  *
1893  * @return the next registered muxer or NULL when the iteration is
1894  * finished
1895  */
1896 const AVOutputFormat *av_muxer_iterate(void **opaque);
1897 
1898 /**
1899  * Iterate over all registered demuxers.
1900  *
1901  * @param opaque a pointer where libavformat will store the iteration state.
1902  * Must point to NULL to start the iteration.
1903  *
1904  * @return the next registered demuxer or NULL when the iteration is
1905  * finished
1906  */
1907 const AVInputFormat *av_demuxer_iterate(void **opaque);
1908 
1909 /**
1910  * Allocate an AVFormatContext.
1911  * avformat_free_context() can be used to free the context and everything
1912  * allocated by the framework within it.
1913  */
1915 
1916 /**
1917  * Free an AVFormatContext and all its streams.
1918  * @param s context to free
1919  */
1921 
1922 /**
1923  * Get the AVClass for AVFormatContext. It can be used in combination with
1924  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1925  *
1926  * @see av_opt_find().
1927  */
1928 const AVClass *avformat_get_class(void);
1929 
1930 /**
1931  * Get the AVClass for AVStream. It can be used in combination with
1932  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1933  *
1934  * @see av_opt_find().
1935  */
1936 const AVClass *av_stream_get_class(void);
1937 
1938 /**
1939  * Add a new stream to a media file.
1940  *
1941  * When demuxing, it is called by the demuxer in read_header(). If the
1942  * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1943  * be called in read_packet().
1944  *
1945  * When muxing, should be called by the user before avformat_write_header().
1946  *
1947  * User is required to call avformat_free_context() to clean up the allocation
1948  * by avformat_new_stream().
1949  *
1950  * @param s media file handle
1951  * @param c unused, does nothing
1952  *
1953  * @return newly created stream or NULL on error.
1954  */
1956 
1957 /**
1958  * Wrap an existing array as stream side data.
1959  *
1960  * @param st stream
1961  * @param type side information type
1962  * @param data the side data array. It must be allocated with the av_malloc()
1963  * family of functions. The ownership of the data is transferred to
1964  * st.
1965  * @param size side information size
1966  *
1967  * @return zero on success, a negative AVERROR code on failure. On failure,
1968  * the stream is unchanged and the data remains owned by the caller.
1969  */
1971  uint8_t *data, size_t size);
1972 
1973 /**
1974  * Allocate new information from stream.
1975  *
1976  * @param stream stream
1977  * @param type desired side information type
1978  * @param size side information size
1979  *
1980  * @return pointer to fresh allocated data or NULL otherwise
1981  */
1982 uint8_t *av_stream_new_side_data(AVStream *stream,
1983  enum AVPacketSideDataType type, size_t size);
1984 /**
1985  * Get side information from stream.
1986  *
1987  * @param stream stream
1988  * @param type desired side information type
1989  * @param size If supplied, *size will be set to the size of the side data
1990  * or to zero if the desired side data is not present.
1991  *
1992  * @return pointer to data if present or NULL otherwise
1993  */
1994 uint8_t *av_stream_get_side_data(const AVStream *stream,
1995  enum AVPacketSideDataType type, size_t *size);
1996 
1998 
1999 /**
2000  * @}
2001  */
2002 
2003 
2004 /**
2005  * Allocate an AVFormatContext for an output format.
2006  * avformat_free_context() can be used to free the context and
2007  * everything allocated by the framework within it.
2008  *
2009  * @param ctx pointee is set to the created format context,
2010  * or to NULL in case of failure
2011  * @param oformat format to use for allocating the context, if NULL
2012  * format_name and filename are used instead
2013  * @param format_name the name of output format to use for allocating the
2014  * context, if NULL filename is used instead
2015  * @param filename the name of the filename to use for allocating the
2016  * context, may be NULL
2017  *
2018  * @return >= 0 in case of success, a negative AVERROR code in case of
2019  * failure
2020  */
2022  const char *format_name, const char *filename);
2023 
2024 /**
2025  * @addtogroup lavf_decoding
2026  * @{
2027  */
2028 
2029 /**
2030  * Find AVInputFormat based on the short name of the input format.
2031  */
2032 const AVInputFormat *av_find_input_format(const char *short_name);
2033 
2034 /**
2035  * Guess the file format.
2036  *
2037  * @param pd data to be probed
2038  * @param is_opened Whether the file is already opened; determines whether
2039  * demuxers with or without AVFMT_NOFILE are probed.
2040  */
2041 const AVInputFormat *av_probe_input_format(const AVProbeData *pd, int is_opened);
2042 
2043 /**
2044  * Guess the file format.
2045  *
2046  * @param pd data to be probed
2047  * @param is_opened Whether the file is already opened; determines whether
2048  * demuxers with or without AVFMT_NOFILE are probed.
2049  * @param score_max A probe score larger that this is required to accept a
2050  * detection, the variable is set to the actual detection
2051  * score afterwards.
2052  * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2053  * to retry with a larger probe buffer.
2054  */
2056  int is_opened, int *score_max);
2057 
2058 /**
2059  * Guess the file format.
2060  *
2061  * @param is_opened Whether the file is already opened; determines whether
2062  * demuxers with or without AVFMT_NOFILE are probed.
2063  * @param score_ret The score of the best detection.
2064  */
2066  int is_opened, int *score_ret);
2067 
2068 /**
2069  * Probe a bytestream to determine the input format. Each time a probe returns
2070  * with a score that is too low, the probe buffer size is increased and another
2071  * attempt is made. When the maximum probe size is reached, the input format
2072  * with the highest score is returned.
2073  *
2074  * @param pb the bytestream to probe
2075  * @param fmt the input format is put here
2076  * @param url the url of the stream
2077  * @param logctx the log context
2078  * @param offset the offset within the bytestream to probe from
2079  * @param max_probe_size the maximum probe buffer size (zero for default)
2080  *
2081  * @return the score in case of success, a negative value corresponding to an
2082  * the maximal score is AVPROBE_SCORE_MAX
2083  * AVERROR code otherwise
2084  */
2086  const char *url, void *logctx,
2087  unsigned int offset, unsigned int max_probe_size);
2088 
2089 /**
2090  * Like av_probe_input_buffer2() but returns 0 on success
2091  */
2093  const char *url, void *logctx,
2094  unsigned int offset, unsigned int max_probe_size);
2095 
2096 /**
2097  * Open an input stream and read the header. The codecs are not opened.
2098  * The stream must be closed with avformat_close_input().
2099  *
2100  * @param ps Pointer to user-supplied AVFormatContext (allocated by
2101  * avformat_alloc_context). May be a pointer to NULL, in
2102  * which case an AVFormatContext is allocated by this
2103  * function and written into ps.
2104  * Note that a user-supplied AVFormatContext will be freed
2105  * on failure.
2106  * @param url URL of the stream to open.
2107  * @param fmt If non-NULL, this parameter forces a specific input format.
2108  * Otherwise the format is autodetected.
2109  * @param options A dictionary filled with AVFormatContext and demuxer-private
2110  * options.
2111  * On return this parameter will be destroyed and replaced with
2112  * a dict containing options that were not found. May be NULL.
2113  *
2114  * @return 0 on success, a negative AVERROR on failure.
2115  *
2116  * @note If you want to use custom IO, preallocate the format context and set its pb field.
2117  */
2118 int avformat_open_input(AVFormatContext **ps, const char *url,
2119  const AVInputFormat *fmt, AVDictionary **options);
2120 
2121 /**
2122  * Read packets of a media file to get stream information. This
2123  * is useful for file formats with no headers such as MPEG. This
2124  * function also computes the real framerate in case of MPEG-2 repeat
2125  * frame mode.
2126  * The logical file position is not changed by this function;
2127  * examined packets may be buffered for later processing.
2128  *
2129  * @param ic media file handle
2130  * @param options If non-NULL, an ic.nb_streams long array of pointers to
2131  * dictionaries, where i-th member contains options for
2132  * codec corresponding to i-th stream.
2133  * On return each dictionary will be filled with options that were not found.
2134  * @return >=0 if OK, AVERROR_xxx on error
2135  *
2136  * @note this function isn't guaranteed to open all the codecs, so
2137  * options being non-empty at return is a perfectly normal behavior.
2138  *
2139  * @todo Let the user decide somehow what information is needed so that
2140  * we do not waste time getting stuff the user does not need.
2141  */
2143 
2144 /**
2145  * Find the programs which belong to a given stream.
2146  *
2147  * @param ic media file handle
2148  * @param last the last found program, the search will start after this
2149  * program, or from the beginning if it is NULL
2150  * @param s stream index
2151  *
2152  * @return the next program which belongs to s, NULL if no program is found or
2153  * the last program is not among the programs of ic.
2154  */
2156 
2157 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
2158 
2159 /**
2160  * Find the "best" stream in the file.
2161  * The best stream is determined according to various heuristics as the most
2162  * likely to be what the user expects.
2163  * If the decoder parameter is non-NULL, av_find_best_stream will find the
2164  * default decoder for the stream's codec; streams for which no decoder can
2165  * be found are ignored.
2166  *
2167  * @param ic media file handle
2168  * @param type stream type: video, audio, subtitles, etc.
2169  * @param wanted_stream_nb user-requested stream number,
2170  * or -1 for automatic selection
2171  * @param related_stream try to find a stream related (eg. in the same
2172  * program) to this one, or -1 if none
2173  * @param decoder_ret if non-NULL, returns the decoder for the
2174  * selected stream
2175  * @param flags flags; none are currently defined
2176  *
2177  * @return the non-negative stream number in case of success,
2178  * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2179  * could be found,
2180  * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2181  *
2182  * @note If av_find_best_stream returns successfully and decoder_ret is not
2183  * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2184  */
2186  enum AVMediaType type,
2187  int wanted_stream_nb,
2188  int related_stream,
2189  const AVCodec **decoder_ret,
2190  int flags);
2191 
2192 /**
2193  * Return the next frame of a stream.
2194  * This function returns what is stored in the file, and does not validate
2195  * that what is there are valid frames for the decoder. It will split what is
2196  * stored in the file into frames and return one for each call. It will not
2197  * omit invalid data between valid frames so as to give the decoder the maximum
2198  * information possible for decoding.
2199  *
2200  * On success, the returned packet is reference-counted (pkt->buf is set) and
2201  * valid indefinitely. The packet must be freed with av_packet_unref() when
2202  * it is no longer needed. For video, the packet contains exactly one frame.
2203  * For audio, it contains an integer number of frames if each frame has
2204  * a known fixed size (e.g. PCM or ADPCM data). If the audio frames have
2205  * a variable size (e.g. MPEG audio), then it contains one frame.
2206  *
2207  * pkt->pts, pkt->dts and pkt->duration are always set to correct
2208  * values in AVStream.time_base units (and guessed if the format cannot
2209  * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2210  * has B-frames, so it is better to rely on pkt->dts if you do not
2211  * decompress the payload.
2212  *
2213  * @return 0 if OK, < 0 on error or end of file. On error, pkt will be blank
2214  * (as if it came from av_packet_alloc()).
2215  *
2216  * @note pkt will be initialized, so it may be uninitialized, but it must not
2217  * contain data that needs to be freed.
2218  */
2220 
2221 /**
2222  * Seek to the keyframe at timestamp.
2223  * 'timestamp' in 'stream_index'.
2224  *
2225  * @param s media file handle
2226  * @param stream_index If stream_index is (-1), a default stream is selected,
2227  * and timestamp is automatically converted from
2228  * AV_TIME_BASE units to the stream specific time_base.
2229  * @param timestamp Timestamp in AVStream.time_base units or, if no stream
2230  * is specified, in AV_TIME_BASE units.
2231  * @param flags flags which select direction and seeking mode
2232  *
2233  * @return >= 0 on success
2234  */
2235 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2236  int flags);
2237 
2238 /**
2239  * Seek to timestamp ts.
2240  * Seeking will be done so that the point from which all active streams
2241  * can be presented successfully will be closest to ts and within min/max_ts.
2242  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2243  *
2244  * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2245  * are the file position (this may not be supported by all demuxers).
2246  * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2247  * in the stream with stream_index (this may not be supported by all demuxers).
2248  * Otherwise all timestamps are in units of the stream selected by stream_index
2249  * or if stream_index is -1, in AV_TIME_BASE units.
2250  * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2251  * keyframes (this may not be supported by all demuxers).
2252  * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2253  *
2254  * @param s media file handle
2255  * @param stream_index index of the stream which is used as time base reference
2256  * @param min_ts smallest acceptable timestamp
2257  * @param ts target timestamp
2258  * @param max_ts largest acceptable timestamp
2259  * @param flags flags
2260  * @return >=0 on success, error code otherwise
2261  *
2262  * @note This is part of the new seek API which is still under construction.
2263  */
2264 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2265 
2266 /**
2267  * Discard all internally buffered data. This can be useful when dealing with
2268  * discontinuities in the byte stream. Generally works only with formats that
2269  * can resync. This includes headerless formats like MPEG-TS/TS but should also
2270  * work with NUT, Ogg and in a limited way AVI for example.
2271  *
2272  * The set of streams, the detected duration, stream parameters and codecs do
2273  * not change when calling this function. If you want a complete reset, it's
2274  * better to open a new AVFormatContext.
2275  *
2276  * This does not flush the AVIOContext (s->pb). If necessary, call
2277  * avio_flush(s->pb) before calling this function.
2278  *
2279  * @param s media file handle
2280  * @return >=0 on success, error code otherwise
2281  */
2283 
2284 /**
2285  * Start playing a network-based stream (e.g. RTSP stream) at the
2286  * current position.
2287  */
2289 
2290 /**
2291  * Pause a network-based stream (e.g. RTSP stream).
2292  *
2293  * Use av_read_play() to resume it.
2294  */
2296 
2297 /**
2298  * Close an opened input AVFormatContext. Free it and all its contents
2299  * and set *s to NULL.
2300  */
2302 /**
2303  * @}
2304  */
2306 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2307 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2308 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2309 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2310 
2311 /**
2312  * @addtogroup lavf_encoding
2313  * @{
2314  */
2316 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2317 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2318 
2319 /**
2320  * Allocate the stream private data and write the stream header to
2321  * an output media file.
2322  *
2323  * @param s Media file handle, must be allocated with
2324  * avformat_alloc_context().
2325  * Its \ref AVFormatContext.oformat "oformat" field must be set
2326  * to the desired output format;
2327  * Its \ref AVFormatContext.pb "pb" field must be set to an
2328  * already opened ::AVIOContext.
2329  * @param options An ::AVDictionary filled with AVFormatContext and
2330  * muxer-private options.
2331  * On return this parameter will be destroyed and replaced with
2332  * a dict containing options that were not found. May be NULL.
2333  *
2334  * @retval AVSTREAM_INIT_IN_WRITE_HEADER On success, if the codec had not already been
2335  * fully initialized in avformat_init_output().
2336  * @retval AVSTREAM_INIT_IN_INIT_OUTPUT On success, if the codec had already been fully
2337  * initialized in avformat_init_output().
2338  * @retval AVERROR A negative AVERROR on failure.
2339  *
2340  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2341  */
2344 
2345 /**
2346  * Allocate the stream private data and initialize the codec, but do not write the header.
2347  * May optionally be used before avformat_write_header() to initialize stream parameters
2348  * before actually writing the header.
2349  * If using this function, do not pass the same options to avformat_write_header().
2350  *
2351  * @param s Media file handle, must be allocated with
2352  * avformat_alloc_context().
2353  * Its \ref AVFormatContext.oformat "oformat" field must be set
2354  * to the desired output format;
2355  * Its \ref AVFormatContext.pb "pb" field must be set to an
2356  * already opened ::AVIOContext.
2357  * @param options An ::AVDictionary filled with AVFormatContext and
2358  * muxer-private options.
2359  * On return this parameter will be destroyed and replaced with
2360  * a dict containing options that were not found. May be NULL.
2361  *
2362  * @retval AVSTREAM_INIT_IN_WRITE_HEADER On success, if the codec requires
2363  * avformat_write_header to fully initialize.
2364  * @retval AVSTREAM_INIT_IN_INIT_OUTPUT On success, if the codec has been fully
2365  * initialized.
2366  * @retval AVERROR Anegative AVERROR on failure.
2367  *
2368  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2369  */
2372 
2373 /**
2374  * Write a packet to an output media file.
2375  *
2376  * This function passes the packet directly to the muxer, without any buffering
2377  * or reordering. The caller is responsible for correctly interleaving the
2378  * packets if the format requires it. Callers that want libavformat to handle
2379  * the interleaving should call av_interleaved_write_frame() instead of this
2380  * function.
2381  *
2382  * @param s media file handle
2383  * @param pkt The packet containing the data to be written. Note that unlike
2384  * av_interleaved_write_frame(), this function does not take
2385  * ownership of the packet passed to it (though some muxers may make
2386  * an internal reference to the input packet).
2387  * <br>
2388  * This parameter can be NULL (at any time, not just at the end), in
2389  * order to immediately flush data buffered within the muxer, for
2390  * muxers that buffer up data internally before writing it to the
2391  * output.
2392  * <br>
2393  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2394  * set to the index of the corresponding stream in @ref
2395  * AVFormatContext.streams "s->streams".
2396  * <br>
2397  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2398  * must be set to correct values in the stream's timebase (unless the
2399  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2400  * they can be set to AV_NOPTS_VALUE).
2401  * The dts for subsequent packets passed to this function must be strictly
2402  * increasing when compared in their respective timebases (unless the
2403  * output format is flagged with the AVFMT_TS_NONSTRICT, then they
2404  * merely have to be nondecreasing). @ref AVPacket.duration
2405  * "duration") should also be set if known.
2406  * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2407  *
2408  * @see av_interleaved_write_frame()
2409  */
2411 
2412 /**
2413  * Write a packet to an output media file ensuring correct interleaving.
2414  *
2415  * This function will buffer the packets internally as needed to make sure the
2416  * packets in the output file are properly interleaved, usually ordered by
2417  * increasing dts. Callers doing their own interleaving should call
2418  * av_write_frame() instead of this function.
2419  *
2420  * Using this function instead of av_write_frame() can give muxers advance
2421  * knowledge of future packets, improving e.g. the behaviour of the mp4
2422  * muxer for VFR content in fragmenting mode.
2423  *
2424  * @param s media file handle
2425  * @param pkt The packet containing the data to be written.
2426  * <br>
2427  * If the packet is reference-counted, this function will take
2428  * ownership of this reference and unreference it later when it sees
2429  * fit. If the packet is not reference-counted, libavformat will
2430  * make a copy.
2431  * The returned packet will be blank (as if returned from
2432  * av_packet_alloc()), even on error.
2433  * <br>
2434  * This parameter can be NULL (at any time, not just at the end), to
2435  * flush the interleaving queues.
2436  * <br>
2437  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2438  * set to the index of the corresponding stream in @ref
2439  * AVFormatContext.streams "s->streams".
2440  * <br>
2441  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2442  * must be set to correct values in the stream's timebase (unless the
2443  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2444  * they can be set to AV_NOPTS_VALUE).
2445  * The dts for subsequent packets in one stream must be strictly
2446  * increasing (unless the output format is flagged with the
2447  * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2448  * @ref AVPacket.duration "duration" should also be set if known.
2449  *
2450  * @return 0 on success, a negative AVERROR on error.
2451  *
2452  * @see av_write_frame(), AVFormatContext.max_interleave_delta
2453  */
2455 
2456 /**
2457  * Write an uncoded frame to an output media file.
2458  *
2459  * The frame must be correctly interleaved according to the container
2460  * specification; if not, av_interleaved_write_uncoded_frame() must be used.
2461  *
2462  * See av_interleaved_write_uncoded_frame() for details.
2463  */
2464 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2465  AVFrame *frame);
2466 
2467 /**
2468  * Write an uncoded frame to an output media file.
2469  *
2470  * If the muxer supports it, this function makes it possible to write an AVFrame
2471  * structure directly, without encoding it into a packet.
2472  * It is mostly useful for devices and similar special muxers that use raw
2473  * video or PCM data and will not serialize it into a byte stream.
2474  *
2475  * To test whether it is possible to use it with a given muxer and stream,
2476  * use av_write_uncoded_frame_query().
2477  *
2478  * The caller gives up ownership of the frame and must not access it
2479  * afterwards.
2480  *
2481  * @return >=0 for success, a negative code on error
2482  */
2484  AVFrame *frame);
2485 
2486 /**
2487  * Test whether a muxer supports uncoded frame.
2488  *
2489  * @return >=0 if an uncoded frame can be written to that muxer and stream,
2490  * <0 if not
2491  */
2492 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2493 
2494 /**
2495  * Write the stream trailer to an output media file and free the
2496  * file private data.
2497  *
2498  * May only be called after a successful call to avformat_write_header.
2499  *
2500  * @param s media file handle
2501  * @return 0 if OK, AVERROR_xxx on error
2502  */
2504 
2505 /**
2506  * Return the output format in the list of registered output formats
2507  * which best matches the provided parameters, or return NULL if
2508  * there is no match.
2509  *
2510  * @param short_name if non-NULL checks if short_name matches with the
2511  * names of the registered formats
2512  * @param filename if non-NULL checks if filename terminates with the
2513  * extensions of the registered formats
2514  * @param mime_type if non-NULL checks if mime_type matches with the
2515  * MIME type of the registered formats
2516  */
2517 const AVOutputFormat *av_guess_format(const char *short_name,
2518  const char *filename,
2519  const char *mime_type);
2520 
2521 /**
2522  * Guess the codec ID based upon muxer and filename.
2523  */
2524 enum AVCodecID av_guess_codec(const AVOutputFormat *fmt, const char *short_name,
2525  const char *filename, const char *mime_type,
2526  enum AVMediaType type);
2527 
2528 /**
2529  * Get timing information for the data currently output.
2530  * The exact meaning of "currently output" depends on the format.
2531  * It is mostly relevant for devices that have an internal buffer and/or
2532  * work in real time.
2533  * @param s media file handle
2534  * @param stream stream in the media file
2535  * @param[out] dts DTS of the last packet output for the stream, in stream
2536  * time_base units
2537  * @param[out] wall absolute time when that packet whas output,
2538  * in microsecond
2539  * @retval 0 Success
2540  * @retval AVERROR(ENOSYS) The format does not support it
2541  *
2542  * @note Some formats or devices may not allow to measure dts and wall
2543  * atomically.
2544  */
2545 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2546  int64_t *dts, int64_t *wall);
2547 
2548 
2549 /**
2550  * @}
2551  */
2552 
2553 
2554 /**
2555  * @defgroup lavf_misc Utility functions
2556  * @ingroup libavf
2557  * @{
2558  *
2559  * Miscellaneous utility functions related to both muxing and demuxing
2560  * (or neither).
2561  */
2562 
2563 /**
2564  * Send a nice hexadecimal dump of a buffer to the specified file stream.
2565  *
2566  * @param f The file stream pointer where the dump should be sent to.
2567  * @param buf buffer
2568  * @param size buffer size
2569  *
2570  * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2571  */
2572 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2573 
2574 /**
2575  * Send a nice hexadecimal dump of a buffer to the log.
2576  *
2577  * @param avcl A pointer to an arbitrary struct of which the first field is a
2578  * pointer to an AVClass struct.
2579  * @param level The importance level of the message, lower values signifying
2580  * higher importance.
2581  * @param buf buffer
2582  * @param size buffer size
2583  *
2584  * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2585  */
2586 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2587 
2588 /**
2589  * Send a nice dump of a packet to the specified file stream.
2590  *
2591  * @param f The file stream pointer where the dump should be sent to.
2592  * @param pkt packet to dump
2593  * @param dump_payload True if the payload must be displayed, too.
2594  * @param st AVStream that the packet belongs to
2595  */
2596 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2597 
2598 
2599 /**
2600  * Send a nice dump of a packet to the log.
2601  *
2602  * @param avcl A pointer to an arbitrary struct of which the first field is a
2603  * pointer to an AVClass struct.
2604  * @param level The importance level of the message, lower values signifying
2605  * higher importance.
2606  * @param pkt packet to dump
2607  * @param dump_payload True if the payload must be displayed, too.
2608  * @param st AVStream that the packet belongs to
2609  */
2610 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2611  const AVStream *st);
2612 
2613 /**
2614  * Get the AVCodecID for the given codec tag tag.
2615  * If no codec id is found returns AV_CODEC_ID_NONE.
2616  *
2617  * @param tags list of supported codec_id-codec_tag pairs, as stored
2618  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2619  * @param tag codec tag to match to a codec ID
2620  */
2621 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2622 
2623 /**
2624  * Get the codec tag for the given codec id id.
2625  * If no codec tag is found returns 0.
2626  *
2627  * @param tags list of supported codec_id-codec_tag pairs, as stored
2628  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2629  * @param id codec ID to match to a codec tag
2630  */
2631 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2632 
2633 /**
2634  * Get the codec tag for the given codec id.
2635  *
2636  * @param tags list of supported codec_id - codec_tag pairs, as stored
2637  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2638  * @param id codec id that should be searched for in the list
2639  * @param tag A pointer to the found tag
2640  * @return 0 if id was not found in tags, > 0 if it was found
2641  */
2642 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2643  unsigned int *tag);
2644 
2646 
2647 /**
2648  * Get the index for a specific timestamp.
2649  *
2650  * @param st stream that the timestamp belongs to
2651  * @param timestamp timestamp to retrieve the index for
2652  * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2653  * to the timestamp which is <= the requested one, if backward
2654  * is 0, then it will be >=
2655  * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2656  * @return < 0 if no such timestamp could be found
2657  */
2658 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2659 
2660 /**
2661  * Get the index entry count for the given AVStream.
2662  *
2663  * @param st stream
2664  * @return the number of index entries in the stream
2665  */
2667 
2668 /**
2669  * Get the AVIndexEntry corresponding to the given index.
2670  *
2671  * @param st Stream containing the requested AVIndexEntry.
2672  * @param idx The desired index.
2673  * @return A pointer to the requested AVIndexEntry if it exists, NULL otherwise.
2674  *
2675  * @note The pointer returned by this function is only guaranteed to be valid
2676  * until any function that takes the stream or the parent AVFormatContext
2677  * as input argument is called.
2678  */
2679 const AVIndexEntry *avformat_index_get_entry(AVStream *st, int idx);
2680 
2681 /**
2682  * Get the AVIndexEntry corresponding to the given timestamp.
2683  *
2684  * @param st Stream containing the requested AVIndexEntry.
2685  * @param wanted_timestamp Timestamp to retrieve the index entry for.
2686  * @param flags If AVSEEK_FLAG_BACKWARD then the returned entry will correspond
2687  * to the timestamp which is <= the requested one, if backward
2688  * is 0, then it will be >=
2689  * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise.
2690  * @return A pointer to the requested AVIndexEntry if it exists, NULL otherwise.
2691  *
2692  * @note The pointer returned by this function is only guaranteed to be valid
2693  * until any function that takes the stream or the parent AVFormatContext
2694  * as input argument is called.
2695  */
2697  int64_t wanted_timestamp,
2698  int flags);
2699 /**
2700  * Add an index entry into a sorted list. Update the entry if the list
2701  * already contains it.
2702  *
2703  * @param timestamp timestamp in the time base of the given stream
2704  */
2705 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2706  int size, int distance, int flags);
2707 
2708 
2709 /**
2710  * Split a URL string into components.
2711  *
2712  * The pointers to buffers for storing individual components may be null,
2713  * in order to ignore that component. Buffers for components not found are
2714  * set to empty strings. If the port is not found, it is set to a negative
2715  * value.
2716  *
2717  * @param proto the buffer for the protocol
2718  * @param proto_size the size of the proto buffer
2719  * @param authorization the buffer for the authorization
2720  * @param authorization_size the size of the authorization buffer
2721  * @param hostname the buffer for the host name
2722  * @param hostname_size the size of the hostname buffer
2723  * @param port_ptr a pointer to store the port number in
2724  * @param path the buffer for the path
2725  * @param path_size the size of the path buffer
2726  * @param url the URL to split
2727  */
2728 void av_url_split(char *proto, int proto_size,
2729  char *authorization, int authorization_size,
2730  char *hostname, int hostname_size,
2731  int *port_ptr,
2732  char *path, int path_size,
2733  const char *url);
2734 
2735 
2736 /**
2737  * Print detailed information about the input or output format, such as
2738  * duration, bitrate, streams, container, programs, metadata, side data,
2739  * codec and time base.
2740  *
2741  * @param ic the context to analyze
2742  * @param index index of the stream to dump information about
2743  * @param url the URL to print, such as source or destination file
2744  * @param is_output Select whether the specified context is an input(0) or output(1)
2745  */
2747  int index,
2748  const char *url,
2749  int is_output);
2751 
2752 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
2753 
2754 /**
2755  * Return in 'buf' the path with '%d' replaced by a number.
2756  *
2757  * Also handles the '%0nd' format where 'n' is the total number
2758  * of digits and '%%'.
2759  *
2760  * @param buf destination buffer
2761  * @param buf_size destination buffer size
2762  * @param path numbered sequence string
2763  * @param number frame number
2764  * @param flags AV_FRAME_FILENAME_FLAGS_*
2765  * @return 0 if OK, -1 on format error
2766  */
2767 int av_get_frame_filename2(char *buf, int buf_size,
2768  const char *path, int number, int flags);
2769 
2770 int av_get_frame_filename(char *buf, int buf_size,
2771  const char *path, int number);
2772 
2773 /**
2774  * Check whether filename actually is a numbered sequence generator.
2775  *
2776  * @param filename possible numbered sequence string
2777  * @return 1 if a valid numbered sequence string, 0 otherwise
2778  */
2779 int av_filename_number_test(const char *filename);
2780 
2781 /**
2782  * Generate an SDP for an RTP session.
2783  *
2784  * Note, this overwrites the id values of AVStreams in the muxer contexts
2785  * for getting unique dynamic payload types.
2786  *
2787  * @param ac array of AVFormatContexts describing the RTP streams. If the
2788  * array is composed by only one context, such context can contain
2789  * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2790  * all the contexts in the array (an AVCodecContext per RTP stream)
2791  * must contain only one AVStream.
2792  * @param n_files number of AVCodecContexts contained in ac
2793  * @param buf buffer where the SDP will be stored (must be allocated by
2794  * the caller)
2795  * @param size the size of the buffer
2796  * @return 0 if OK, AVERROR_xxx on error
2797  */
2798 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2799 
2800 /**
2801  * Return a positive value if the given filename has one of the given
2802  * extensions, 0 otherwise.
2803  *
2804  * @param filename file name to check against the given extensions
2805  * @param extensions a comma-separated list of filename extensions
2806  */
2807 int av_match_ext(const char *filename, const char *extensions);
2808 
2809 /**
2810  * Test if the given container can store a codec.
2811  *
2812  * @param ofmt container to check for compatibility
2813  * @param codec_id codec to potentially store in container
2814  * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2815  *
2816  * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2817  * A negative number if this information is not available.
2818  */
2820  int std_compliance);
2821 
2822 /**
2823  * @defgroup riff_fourcc RIFF FourCCs
2824  * @{
2825  * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2826  * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2827  * following code:
2828  * @code
2829  * uint32_t tag = MKTAG('H', '2', '6', '4');
2830  * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2831  * enum AVCodecID id = av_codec_get_id(table, tag);
2832  * @endcode
2833  */
2834 /**
2835  * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2836  */
2837 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2838 /**
2839  * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2840  */
2841 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2842 /**
2843  * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2844  */
2845 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2846 /**
2847  * @return the table mapping MOV FourCCs for audio to AVCodecID.
2848  */
2849 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2850 
2851 /**
2852  * @}
2853  */
2854 
2855 /**
2856  * Guess the sample aspect ratio of a frame, based on both the stream and the
2857  * frame aspect ratio.
2858  *
2859  * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2860  * is set by the demuxer, these two may not be equal. This function tries to
2861  * return the value that you should use if you would like to display the frame.
2862  *
2863  * Basic logic is to use the stream aspect ratio if it is set to something sane
2864  * otherwise use the frame aspect ratio. This way a container setting, which is
2865  * usually easy to modify can override the coded value in the frames.
2866  *
2867  * @param format the format context which the stream is part of
2868  * @param stream the stream which the frame is part of
2869  * @param frame the frame with the aspect ratio to be determined
2870  * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2871  */
2873 
2874 /**
2875  * Guess the frame rate, based on both the container and codec information.
2876  *
2877  * @param ctx the format context which the stream is part of
2878  * @param stream the stream which the frame is part of
2879  * @param frame the frame for which the frame rate should be determined, may be NULL
2880  * @return the guessed (valid) frame rate, 0/1 if no idea
2881  */
2883 
2884 /**
2885  * Check if the stream st contained in s is matched by the stream specifier
2886  * spec.
2887  *
2888  * See the "stream specifiers" chapter in the documentation for the syntax
2889  * of spec.
2890  *
2891  * @return >0 if st is matched by spec;
2892  * 0 if st is not matched by spec;
2893  * AVERROR code if spec is invalid
2894  *
2895  * @note A stream specifier can match several streams in the format.
2896  */
2898  const char *spec);
2899 
2906 #if FF_API_R_FRAME_RATE
2907  AVFMT_TBCF_R_FRAMERATE,
2908 #endif
2909 };
2910 
2911 /**
2912  * Transfer internal timing information from one stream to another.
2913  *
2914  * This function is useful when doing stream copy.
2915  *
2916  * @param ofmt target output format for ost
2917  * @param ost output stream which needs timings copy and adjustments
2918  * @param ist reference input stream to copy timings from
2919  * @param copy_tb define from where the stream codec timebase needs to be imported
2920  */
2922  AVStream *ost, const AVStream *ist,
2923  enum AVTimebaseSource copy_tb);
2924 
2925 /**
2926  * Get the internal codec timebase from a stream.
2927  *
2928  * @param st input stream to extract the timebase from
2929  */
2931 
2932 /**
2933  * @}
2934  */
2935 
2936 #endif /* AVFORMAT_AVFORMAT_H */
avformat_get_riff_video_tags
const struct AVCodecTag * avformat_get_riff_video_tags(void)
Definition: riff.c:633
AVFormatContext::control_message_cb
av_format_control_message control_message_cb
Callback used by devices to communicate with application.
Definition: avformat.h:1727
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:112
AVCodec
AVCodec.
Definition: codec.h:204
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.
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:1186
level
uint8_t level
Definition: svq3.c:204
av_fmt_ctx_get_duration_estimation_method
enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext *ctx)
Returns the method used to set ctx->duration.
Definition: options.c:192
AVFMT_DURATION_FROM_BITRATE
@ AVFMT_DURATION_FROM_BITRATE
Duration estimated from bitrate (less accurate)
Definition: avformat.h:1199
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:1179
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: options.c:237
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:227
AVInputFormat::raw_codec_id
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:705
AVProgram::nb_stream_indexes
unsigned int nb_stream_indexes
Definition: avformat.h:1145
AVFormatContext::max_chunk_duration
int max_chunk_duration
Max chunk time in microseconds.
Definition: avformat.h:1574
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:1415
AVFormatContext::nb_chapters
unsigned int nb_chapters
Number of chapters in AVChapter array.
Definition: avformat.h:1434
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:54
AVStream::priv_data
void * priv_data
Definition: avformat.h:964
AVStream::discard
enum AVDiscard discard
Selects which packets can be discarded at will and do not need to be demuxed.
Definition: avformat.h:1010
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:362
AVFormatContext::audio_preload
int audio_preload
Audio preload in microseconds.
Definition: avformat.h:1566
AVFormatContext::protocol_blacklist
char * protocol_blacklist
',' separated list of disallowed protocols.
Definition: avformat.h:1789
AVDeviceCapabilitiesQuery
Following API allows user to probe device capabilities (supported codecs, pixel formats,...
Definition: avdevice.h:407
AVFMT_TBCF_DECODER
@ AVFMT_TBCF_DECODER
Definition: avformat.h:2902
AVProgram::pmt_version
int pmt_version
Definition: avformat.h:1151
avformat_get_class
const AVClass * avformat_get_class(void)
Get the AVClass for AVFormatContext.
Definition: options.c:197
AVFMT_TBCF_AUTO
@ AVFMT_TBCF_AUTO
Definition: avformat.h:2901
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1284
AVPacketSideData
Definition: packet.h:315
AVFormatContext::strict_std_compliance
int strict_std_compliance
Allow non-standard and experimental extension.
Definition: avformat.h:1513
av_disposition_to_string
const char * av_disposition_to_string(int disposition)
Definition: options.c:334
av_write_uncoded_frame
int av_write_uncoded_frame(AVFormatContext *s, int stream_index, AVFrame *frame)
Write an uncoded frame to an output media file.
Definition: mux.c:1440
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:294
AVFormatContext::max_interleave_delta
int64_t max_interleave_delta
Maximum buffering duration for interleaving.
Definition: avformat.h:1507
AVStream::avg_frame_rate
AVRational avg_frame_rate
Average framerate.
Definition: avformat.h:1028
AVChapter::start
int64_t start
Definition: avformat.h:1178
data
const char data[16]
Definition: mxf.c:146
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:1605
AVFMT_TBCF_DEMUXER
@ AVFMT_TBCF_DEMUXER
Definition: avformat.h:2903
AVOutputFormat::deinit
void(* deinit)(struct AVFormatContext *)
Deinitialize format.
Definition: avformat.h:636
AVFormatContext::programs
AVProgram ** programs
Definition: avformat.h:1385
AVOutputFormat::write_packet
int(* write_packet)(struct AVFormatContext *, AVPacket *pkt)
Write a packet.
Definition: avformat.h:565
AVDictionary
Definition: dict.c:32
AVProgram::flags
int flags
Definition: avformat.h:1142
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:456
AVFormatContext::probesize
int64_t probesize
Maximum number of bytes read from input in order to determine stream properties.
Definition: avformat.h:1371
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:1452
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:429
av_read_frame
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: demux.c:1439
AVFormatContext::video_codec_id
enum AVCodecID video_codec_id
Forced video codec_id.
Definition: avformat.h:1391
AVOutputFormat::write_trailer
int(* write_trailer)(struct AVFormatContext *)
Definition: avformat.h:566
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:261
av_get_frame_filename
int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
Definition: utils.c:352
ost
static AVStream * ost
Definition: vaapi_transcode.c:45
AVIndexEntry
Definition: avformat.h:807
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:1149
AVInputFormat::long_name
const char * long_name
Descriptive name for the format, meant to be more human-readable than name.
Definition: avformat.h:668
av_filename_number_test
int av_filename_number_test(const char *filename)
Check whether filename actually is a numbered sequence generator.
Definition: utils.c:125
av_find_best_stream
int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type, int wanted_stream_nb, int related_stream, const AVCodec **decoder_ret, int flags)
Find the "best" stream in the file.
Definition: avformat.c:413
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:369
AVFormatContext::interrupt_callback
AVIOInterruptCB interrupt_callback
Custom interrupt callbacks for the I/O layer.
Definition: avformat.h:1483
AVFormatContext::flush_packets
int flush_packets
Flush the I/O context after each packet.
Definition: avformat.h:1633
avformat_get_mov_video_tags
const struct AVCodecTag * avformat_get_mov_video_tags(void)
Definition: isom_tags.c:349
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:1421
av_add_index_entry
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
Definition: seek.c:120
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:801
avformat_version
unsigned avformat_version(void)
Return the LIBAVFORMAT_VERSION_INT constant.
Definition: version.c:30
AVStreamParseType
AVStreamParseType
Definition: avformat.h:796
AVProgram::discard
enum AVDiscard discard
selects which program to discard and which to feed to the caller
Definition: avformat.h:1143
AVChapter
Definition: avformat.h:1175
AVFormatContext::dump_separator
uint8_t * dump_separator
dump format separator.
Definition: avformat.h:1741
AVFMT_DURATION_FROM_PTS
@ AVFMT_DURATION_FROM_PTS
Duration accurately estimated from PTSes.
Definition: avformat.h:1197
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
av_new_program
AVProgram * av_new_program(AVFormatContext *s, int id)
Definition: avformat.c:304
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:998
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:130
codec.h
avformat_network_init
int avformat_network_init(void)
Do global initialization of network libraries.
Definition: utils.c:557
AVFormatContext::event_flags
int event_flags
Flags indicating events happening on the file, a combination of AVFMT_EVENT_FLAG_*.
Definition: avformat.h:1526
AVStream::attached_pic
AVPacket attached_pic
For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet will contain the attached pictu...
Definition: avformat.h:1037
avformat_get_riff_audio_tags
const struct AVCodecTag * avformat_get_riff_audio_tags(void)
Definition: riff.c:638
AVFormatContext::bit_rate
int64_t bit_rate
Total stream bitrate in bit/s, 0 if not available.
Definition: avformat.h:1325
AVFormatContext::max_ts_probe
int max_ts_probe
Maximum number of packets to read while waiting for the first timestamp.
Definition: avformat.h:1539
AVFormatContext::format_whitelist
char * format_whitelist
',' separated list of allowed demuxers.
Definition: avformat.h:1669
AVFormatContext::format_probesize
int format_probesize
Maximum number of bytes read from input in order to identify the input format.
Definition: avformat.h:1653
av_guess_sample_aspect_ratio
AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame)
Guess the sample aspect ratio of a frame, based on both the stream and the frame aspect ratio.
Definition: avformat.c:655
pkt
AVPacket * pkt
Definition: movenc.c:59
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:247
AVFormatContext::metadata
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1445
AVInputFormat
Definition: avformat.h:656
AVProbeData::mime_type
const char * mime_type
mime_type, when known.
Definition: avformat.h:457
AVInputFormat::extensions
const char * extensions
If extensions are defined, then no probe is done.
Definition: avformat.h:682
AVFormatContext::subtitle_codec
const AVCodec * subtitle_codec
Forced subtitle codec.
Definition: avformat.h:1701
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:629
AVCodecTag
Definition: internal.h:49
AVFormatContext::ctx_flags
int ctx_flags
Flags signalling stream properties.
Definition: avformat.h:1265
AVOutputFormat::data_codec
enum AVCodecID data_codec
default data codec
Definition: avformat.h:617
AVProgram::id
int id
Definition: avformat.h:1141
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:221
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:43
AVChapter::end
int64_t end
chapter start/end time in time_base units
Definition: avformat.h:1178
s
#define s(width, name)
Definition: cbs_vp9.c:256
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:636
AVFormatContext::flags
int flags
Flags modifying the (de)muxer behaviour.
Definition: avformat.h:1334
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:1384
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:661
AVFormatContext::iformat
const struct AVInputFormat * iformat
The input container format.
Definition: avformat.h:1228
AVFormatContext::chapters
AVChapter ** chapters
Definition: avformat.h:1435
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:455
AVIndexEntry::size
int size
Definition: avformat.h:818
AVProbeData::filename
const char * filename
Definition: avformat.h:454
AVOpenCallback
int(* AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Definition: avformat.h:1189
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:40
AVIndexEntry::timestamp
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
Definition: avformat.h:809
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:1733
AVInputFormat::mime_type
const char * mime_type
Comma-separated list of mime types.
Definition: avformat.h:693
av_read_play
int av_read_play(AVFormatContext *s)
Start playing a network-based stream (e.g.
Definition: demux_utils.c:202
ctx
AVFormatContext * ctx
Definition: movenc.c:48
av_class
static const AVClass av_class
Definition: options.c:152
avformat_flush
int avformat_flush(AVFormatContext *s)
Discard all internally buffered data.
Definition: seek.c:752
AVOutputFormat::init
int(* init)(struct AVFormatContext *)
Initialize format.
Definition: avformat.h:627
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:819
av_interleaved_write_uncoded_frame
int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index, AVFrame *frame)
Write an uncoded frame to an output media file.
Definition: mux.c:1446
codec_id
enum AVCodecID codec_id
Definition: vaapi_decode.c:388
AVProgram::start_time
int64_t start_time
Definition: avformat.h:1160
AVFormatContext::opaque
void * opaque
User data.
Definition: avformat.h:1722
AVFormatContext::probe_score
int probe_score
format probing score.
Definition: avformat.h:1642
AVOutputFormat::get_output_timestamp
void(* get_output_timestamp)(struct AVFormatContext *s, int stream, int64_t *dts, int64_t *wall)
Definition: avformat.h:594
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:450
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:1379
AVFormatContext::correct_ts_overflow
unsigned int correct_ts_overflow
Correct single timestamp overflows.
Definition: avformat.h:1619
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:209
AVOutputFormat::write_header
int(* write_header)(struct AVFormatContext *)
Definition: avformat.h:557
AVFormatContext
Format I/O context.
Definition: avformat.h:1216
AVFormatContext::audio_codec_id
enum AVCodecID audio_codec_id
Forced audio codec_id.
Definition: avformat.h:1397
av_probe_input_format
const AVInputFormat * av_probe_input_format(const AVProbeData *pd, int is_opened)
Guess the file format.
Definition: format.c:221
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1108
AVInputFormat::codec_tag
const struct AVCodecTag *const * codec_tag
Definition: avformat.h:684
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
AVStream::time_base
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avformat.h:978
AVFormatContext::max_streams
int max_streams
The maximum number of streams.
Definition: avformat.h:1796
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:1465
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:1198
AVFormatContext::protocol_whitelist
char * protocol_whitelist
',' separated list of allowed protocols.
Definition: avformat.h:1754
AVOutputFormat::get_device_list
int(* get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list)
Returns device list with it properties.
Definition: avformat.h:616
AVOutputFormat::long_name
const char * long_name
Descriptive name for the format, meant to be more human-readable than name.
Definition: avformat.h:516
av_stream_add_side_data
int av_stream_add_side_data(AVStream *st, enum AVPacketSideDataType type, uint8_t *data, size_t size)
Wrap an existing array as stream side data.
Definition: avformat.c:155
AVSTREAM_PARSE_NONE
@ AVSTREAM_PARSE_NONE
Definition: avformat.h:797
AVInputFormat::read_probe
int(* read_probe)(const AVProbeData *)
Tell if a given file has a chance of being parsed as this format.
Definition: avformat.h:722
AVIndexEntry::flags
int flags
Definition: avformat.h:817
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1258
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:1196
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:453
AVProgram::stream_index
unsigned int * stream_index
Definition: avformat.h:1144
AVStream::metadata
AVDictionary * metadata
Definition: avformat.h:1019
time.h
AVFormatContext::skip_estimate_duration_from_pts
int skip_estimate_duration_from_pts
Skip duration calcuation in estimate_timings_from_pts.
Definition: avformat.h:1803
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:1192
AVFormatContext::audio_codec
const AVCodec * audio_codec
Forced audio codec.
Definition: avformat.h:1693
index
int index
Definition: gxfenc.c:89
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
AVStream::nb_frames
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:1000
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:49
AVFormatContext::nb_streams
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1272
AVFormatContext::metadata_header_padding
int metadata_header_padding
Number of bytes to be written as padding in a metadata header.
Definition: avformat.h:1716
AVOutputFormat::flags
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:529
AVInputFormat::flags_internal
int flags_internal
Internal flags.
Definition: avformat.h:715
AVFormatContext::data_codec
const AVCodec * data_codec
Forced data codec.
Definition: avformat.h:1709
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:2416
f
f
Definition: af_crystalizer.c:122
AVIOContext
Bytestream IO Context.
Definition: avio.h:166
AVProgram::pts_wrap_reference
int64_t pts_wrap_reference
reference dts for wrap detection
Definition: avformat.h:1163
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:611
avformat_alloc_context
AVFormatContext * avformat_alloc_context(void)
Allocate an AVFormatContext.
Definition: options.c:164
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:1161
AVFormatContext::url
char * url
input or output URL.
Definition: avformat.h:1299
size
int size
Definition: twinvq_data.h:10344
avio.h
copy_tb
int copy_tb
Definition: ffmpeg_opt.c:78
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:659
AVStream::event_flags
int event_flags
Flags indicating events happening on the stream, a combination of AVSTREAM_EVENT_FLAG_*.
Definition: avformat.h:1074
av_guess_frame_rate
AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame)
Guess the frame rate, based on both the container and codec information.
Definition: avformat.c:678
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:757
AVProgram::pts_wrap_behavior
int pts_wrap_behavior
behavior on wrap detection
Definition: avformat.h:1164
AVTimebaseSource
AVTimebaseSource
Definition: avformat.h:2900
av_demuxer_iterate
const AVInputFormat * av_demuxer_iterate(void **opaque)
Iterate over all registered demuxers.
Definition: allformats.c:576
AVProgram::program_num
int program_num
Definition: avformat.h:1148
AVStream::sample_aspect_ratio
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown)
Definition: avformat.h:1017
AVFormatContext::keylen
int keylen
Definition: avformat.h:1382
attribute_deprecated
#define attribute_deprecated
Definition: attributes.h:104
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:911
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
AVPacketSideDataType
AVPacketSideDataType
Definition: packet.h:41
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:317
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:1612
AVOutputFormat::interleave_packet
int(* interleave_packet)(struct AVFormatContext *s, AVPacket *pkt, int flush, int has_packet)
A format-specific function for interleavement.
Definition: avformat.h:583
AVStream::side_data
AVPacketSideData * side_data
An array of side data that applies to the whole stream (i.e.
Definition: avformat.h:1057
av_warn_unused_result
#define av_warn_unused_result
Definition: attributes.h:64
AVOutputFormat::flags_internal
int flags_internal
Internal flags.
Definition: avformat.h:555
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:1472
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:1254
av_disposition_from_string
int av_disposition_from_string(const char *disp)
Definition: options.c:326
log.h
AVOutputFormat
Definition: avformat.h:509
AVChapter::id
int64_t id
unique ID to identify the chapter
Definition: avformat.h:1176
packet.h
AVInputFormat::priv_data_size
int priv_data_size
Size of private data so that it can be allocated in the wrapper.
Definition: avformat.h:710
avformat_get_mov_audio_tags
const struct AVCodecTag * avformat_get_mov_audio_tags(void)
Definition: isom_tags.c:354
AVProgram::metadata
AVDictionary * metadata
Definition: avformat.h:1146
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:252
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:1302
AVFormatContext::codec_whitelist
char * codec_whitelist
',' separated list of allowed decoders.
Definition: avformat.h:1661
AVFormatContext::avoid_negative_ts
int avoid_negative_ts
Avoid negative timestamps during muxing.
Definition: avformat.h:1548
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:357
av_find_default_stream_index
int av_find_default_stream_index(AVFormatContext *s)
Definition: avformat.c:377
AVFormatContext::max_delay
int max_delay
Definition: avformat.h:1328
AVFormatContext::io_repositioned
int io_repositioned
IO repositioned flag.
Definition: avformat.h:1677
AVProgram
New fields can be added to the end with minor version bumps.
Definition: avformat.h:1140
av_read_pause
int av_read_pause(AVFormatContext *s)
Pause a network-based stream (e.g.
Definition: demux_utils.c:211
AVInputFormat::read_packet
int(* read_packet)(struct AVFormatContext *, AVPacket *pkt)
Read one packet and put it in 'pkt'.
Definition: avformat.h:739
int_cb
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:492
AVOutputFormat::control_message
int(* control_message)(struct AVFormatContext *s, int type, void *data, size_t data_size)
Allows sending messages from application to device.
Definition: avformat.h:599
av_get_packet
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:102
AVCodecParserContext
Definition: avcodec.h:2800
AVInputFormat::get_device_list
int(* get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list)
Returns device list with it properties.
Definition: avformat.h:789
AVInputFormat::read_seek
int(* read_seek)(struct AVFormatContext *, int stream_index, int64_t timestamp, int flags)
Seek to a given timestamp relative to the frames in stream component stream_index.
Definition: avformat.h:755
version.h
AVStream::disposition
int disposition
Stream disposition - a combination of AV_DISPOSITION_* flags.
Definition: avformat.h:1008
tag
uint32_t tag
Definition: movenc.c:1647
AVStream::id
int id
Format-specific stream ID.
Definition: avformat.h:962
AVStream
Stream structure.
Definition: avformat.h:948
AVFormatContext::ts_id
int ts_id
Transport stream id.
Definition: avformat.h:1558
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:83
AVFormatContext::oformat
const struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1235
AVDeviceInfoList
List of devices.
Definition: avdevice.h:473
AVStream::nb_side_data
int nb_side_data
The number of elements in the AVStream.side_data array.
Definition: avformat.h:1061
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:118
AVSTREAM_PARSE_HEADERS
@ AVSTREAM_PARSE_HEADERS
Only parse headers, do not repack.
Definition: avformat.h:799
AVFormatContext::av_class
const AVClass * av_class
A class for logging and AVOptions.
Definition: avformat.h:1221
pos
unsigned int pos
Definition: spdifenc.c:412
av_stream_get_side_data
uint8_t * av_stream_get_side_data(const AVStream *stream, enum AVPacketSideDataType type, size_t *size)
Get side information from stream.
Definition: avformat.c:140
AVOutputFormat::write_uncoded_frame
int(* write_uncoded_frame)(struct AVFormatContext *, int stream_index, AVFrame **frame, unsigned flags)
Write an uncoded AVFrame.
Definition: avformat.h:610
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:89
id
enum AVCodecID id
Definition: dts2pts_bsf.c:362
avformat_network_deinit
int avformat_network_deinit(void)
Undo the initialization done by avformat_network_init.
Definition: utils.c:569
AVFormatContext::debug
int debug
Flags to enable debugging.
Definition: avformat.h:1488
AVFormatContext::data_codec_id
enum AVCodecID data_codec_id
Forced Data codec_id.
Definition: avformat.h:1747
AVStream::index
int index
stream index in AVFormatContext
Definition: avformat.h:956
AVInputFormat::read_seek2
int(* read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Seek to timestamp ts.
Definition: avformat.h:783
av_muxer_iterate
const AVOutputFormat * av_muxer_iterate(void **opaque)
Iterate over all registered muxers.
Definition: allformats.c:557
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:699
format_name
static int format_name(const char *buf, char **s, int index, const char *varname)
Definition: hlsenc.c:1932
AVInputFormat::read_close
int(* read_close)(struct AVFormatContext *)
Close the stream.
Definition: avformat.h:745
AVFormatContext::seek2any
int seek2any
Force seeking to any (also non key) frames.
Definition: avformat.h:1626
AVInputFormat::flags
int flags
Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:675
AVInputFormat::read_pause
int(* read_pause)(struct AVFormatContext *)
Pause playing - only meaningful if using a network-based format (RTSP).
Definition: avformat.h:775
defs.h
avformat_free_context
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: avformat.c:95
AVFormatContext::io_close
void(* io_close)(struct AVFormatContext *s, AVIOContext *pb)
A callback for closing the streams opened with AVFormatContext.io_open().
Definition: avformat.h:1782
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:1097
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:1776
AVIndexEntry::pos
int64_t pos
Definition: avformat.h:808
AVSTREAM_PARSE_FULL_RAW
@ AVSTREAM_PARSE_FULL_RAW
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:802
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:120
AVFormatContext::duration
int64_t duration
Duration of the stream, in AV_TIME_BASE fractional seconds.
Definition: avformat.h:1318
avformat_license
const char * avformat_license(void)
Return the libavformat license.
Definition: version.c:41
AVFormatContext::packet_size
unsigned int packet_size
Definition: avformat.h:1327
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:53
flush
void(* flush)(AVBSFContext *ctx)
Definition: dts2pts_bsf.c:365
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:1458
avformat_configuration
const char * avformat_configuration(void)
Return the libavformat build-time configuration.
Definition: version.c:36
AVFormatContext::max_probe_packets
int max_probe_packets
Maximum number of packets that can be probed.
Definition: avformat.h:1810
codec_par.h
AVPacket
This structure stores compressed data.
Definition: packet.h:351
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:1590
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:1239
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:1823
av_stream_new_side_data
uint8_t * av_stream_new_side_data(AVStream *stream, enum AVPacketSideDataType type, size_t size)
Allocate new information from stream.
Definition: avformat.c:190
distance
static float distance(float x, float y, int band)
Definition: nellymoserenc.c:230
AVSTREAM_PARSE_FULL
@ AVSTREAM_PARSE_FULL
full parsing and repack
Definition: avformat.h:798
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
AVInputFormat::read_timestamp
int64_t(* read_timestamp)(struct AVFormatContext *s, int stream_index, int64_t *pos, int64_t pos_limit)
Get the next timestamp in stream[stream_index].time_base units.
Definition: avformat.h:762
AVFormatContext::start_time
int64_t start_time
Position of the first frame of the component, in AV_TIME_BASE fractional seconds.
Definition: avformat.h:1308
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:117
AVStream::start_time
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base.
Definition: avformat.h:988
av_stream_get_class
const AVClass * av_stream_get_class(void)
Get the AVClass for AVStream.
Definition: options.c:232
AVSTREAM_PARSE_TIMESTAMPS
@ AVSTREAM_PARSE_TIMESTAMPS
full parsing and interpolation of timestamps for frames not starting on a packet boundary
Definition: avformat.h:800
AVFormatContext::avio_flags
int avio_flags
avio flags, used to force AVIO_FLAG_DIRECT.
Definition: avformat.h:1597
AVOutputFormat::query_codec
int(* query_codec)(enum AVCodecID id, int std_compliance)
Test if the given codec can be stored in this container.
Definition: avformat.h:592
AVDiscard
AVDiscard
Definition: defs.h:67
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:91
AVStream::pts_wrap_bits
int pts_wrap_bits
Number of bits in timestamps.
Definition: avformat.h:1117
AVInputFormat::read_header
int(* read_header)(struct AVFormatContext *)
Read the format header and initialize the AVFormatContext structure.
Definition: avformat.h:729
AVChapter::time_base
AVRational time_base
time base in which the start/end timestamps are specified
Definition: avformat.h:1177
int
int
Definition: ffmpeg_filter.c:156
AVFormatContext::priv_data
void * priv_data
Format private data.
Definition: avformat.h:1244
AVProgram::pcr_pid
int pcr_pid
Definition: avformat.h:1150
AVFormatContext::key
const uint8_t * key
Definition: avformat.h:1381
AVOutputFormat::check_bitstream
int(* check_bitstream)(struct AVFormatContext *s, struct AVStream *st, const AVPacket *pkt)
Set up any necessary bitstream filtering and extract any extra data needed for the global header.
Definition: avformat.h:645
AVInputFormat::priv_class
const AVClass * priv_class
AVClass for the private context.
Definition: avformat.h:686
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:1582
av_index_search_timestamp
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: seek.c:240
AVFormatContext::video_codec
const AVCodec * video_codec
Forced video codec.
Definition: avformat.h:1685
AVInputFormat::read_play
int(* read_play)(struct AVFormatContext *)
Start/resume playing - only meaningful if using a network-based format (RTSP).
Definition: avformat.h:769
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:1403
AVOutputFormat::priv_data_size
int priv_data_size
size of private data so that it can be allocated in the wrapper
Definition: avformat.h:550
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:78