FFmpeg  2.8.11
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 I/O and Muxing/Demuxing Library
32  * @{
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). Before using lavf, you need to call
40  * av_register_all() to register all compiled muxers, demuxers and protocols.
41  * Unless you are absolutely sure you won't use libavformat's network
42  * capabilities, you should also call avformat_network_init().
43  *
44  * A supported input format is described by an AVInputFormat struct, conversely
45  * an output format is described by AVOutputFormat. You can iterate over all
46  * registered input/output formats using the av_iformat_next() /
47  * av_oformat_next() functions. The protocols layer is not part of the public
48  * API, so you can only get the names of supported protocols with the
49  * avio_enum_protocols() function.
50  *
51  * Main lavf structure used for both muxing and demuxing is AVFormatContext,
52  * which exports all information about the file being read or written. As with
53  * most Libavformat structures, its size is not part of public ABI, so it cannot be
54  * allocated on stack or directly with av_malloc(). To create an
55  * AVFormatContext, use avformat_alloc_context() (some functions, like
56  * avformat_open_input() might do that for you).
57  *
58  * Most importantly an AVFormatContext contains:
59  * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat
60  * "output" format. It is either autodetected or set by user for input;
61  * always set by user for output.
62  * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all
63  * elementary streams stored in the file. AVStreams are typically referred to
64  * using their index in this array.
65  * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or
66  * set by user for input, always set by user for output (unless you are dealing
67  * with an AVFMT_NOFILE format).
68  *
69  * @section lavf_options Passing options to (de)muxers
70  * It is possible to configure lavf muxers and demuxers using the @ref avoptions
71  * mechanism. Generic (format-independent) libavformat options are provided by
72  * AVFormatContext, they can be examined from a user program by calling
73  * av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass
74  * from avformat_get_class()). Private (format-specific) options are provided by
75  * AVFormatContext.priv_data if and only if AVInputFormat.priv_class /
76  * AVOutputFormat.priv_class of the corresponding format struct is non-NULL.
77  * Further options may be provided by the @ref AVFormatContext.pb "I/O context",
78  * if its AVClass is non-NULL, and the protocols layer. See the discussion on
79  * nesting in @ref avoptions documentation to learn how to access those.
80  *
81  * @section urls
82  * URL strings in libavformat are made of a scheme/protocol, a ':', and a
83  * scheme specific string. URLs without a scheme and ':' used for local files
84  * are supported but deprecated. "file:" should be used for local files.
85  *
86  * It is important that the scheme string is not taken from untrusted
87  * sources without checks.
88  *
89  * Note that some schemes/protocols are quite powerful, allowing access to
90  * both local and remote files, parts of them, concatenations of them, local
91  * audio and video devices and so on.
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_decode_video2(), avcodec_decode_audio4() or
165  * avcodec_decode_subtitle2() if the 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  * If AVPacket.buf is set on the returned packet, then the packet is
174  * allocated dynamically and the user may keep it indefinitely.
175  * Otherwise, if AVPacket.buf is NULL, the packet data is backed by a
176  * static storage somewhere inside the demuxer and the packet is only valid
177  * until the next av_read_frame() call or closing the file. If the caller
178  * requires a longer lifetime, av_dup_packet() will make an av_malloc()ed copy
179  * of it.
180  * In both cases, the packet must be freed with av_free_packet() when it is no
181  * longer needed.
182  *
183  * @section lavf_decoding_seek Seeking
184  * @}
185  *
186  * @defgroup lavf_encoding Muxing
187  * @{
188  * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write
189  * it into files or other output bytestreams in the specified container format.
190  *
191  * The main API functions for muxing are avformat_write_header() for writing the
192  * file header, av_write_frame() / av_interleaved_write_frame() for writing the
193  * packets and av_write_trailer() for finalizing the file.
194  *
195  * At the beginning of the muxing process, the caller must first call
196  * avformat_alloc_context() to create a muxing context. The caller then sets up
197  * the muxer by filling the various fields in this context:
198  *
199  * - The @ref AVFormatContext.oformat "oformat" field must be set to select the
200  * muxer that will be used.
201  * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb
202  * "pb" field must be set to an opened IO context, either returned from
203  * avio_open2() or a custom one.
204  * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must
205  * be created with the avformat_new_stream() function. The caller should fill
206  * the @ref AVStream.codec "stream codec context" information, such as the
207  * codec @ref AVCodecContext.codec_type "type", @ref AVCodecContext.codec_id
208  * "id" and other parameters (e.g. width / height, the pixel or sample format,
209  * etc.) as known. The @ref AVStream.time_base "stream timebase" should
210  * be set to the timebase that the caller desires to use for this stream (note
211  * that the timebase actually used by the muxer can be different, as will be
212  * described later).
213  * - It is advised to manually initialize only the relevant fields in
214  * AVCodecContext, rather than using @ref avcodec_copy_context() during
215  * remuxing: there is no guarantee that the codec context values remain valid
216  * for both input and output format contexts.
217  * - The caller may fill in additional information, such as @ref
218  * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream"
219  * metadata, @ref AVFormatContext.chapters "chapters", @ref
220  * AVFormatContext.programs "programs", etc. as described in the
221  * AVFormatContext documentation. Whether such information will actually be
222  * stored in the output depends on what the container format and the muxer
223  * support.
224  *
225  * When the muxing context is fully set up, the caller must call
226  * avformat_write_header() to initialize the muxer internals and write the file
227  * header. Whether anything actually is written to the IO context at this step
228  * depends on the muxer, but this function must always be called. Any muxer
229  * private options must be passed in the options parameter to this function.
230  *
231  * The data is then sent to the muxer by repeatedly calling av_write_frame() or
232  * av_interleaved_write_frame() (consult those functions' documentation for
233  * discussion on the difference between them; only one of them may be used with
234  * a single muxing context, they should not be mixed). Do note that the timing
235  * information on the packets sent to the muxer must be in the corresponding
236  * AVStream's timebase. That timebase is set by the muxer (in the
237  * avformat_write_header() step) and may be different from the timebase
238  * requested by the caller.
239  *
240  * Once all the data has been written, the caller must call av_write_trailer()
241  * to flush any buffered packets and finalize the output file, then close the IO
242  * context (if any) and finally free the muxing context with
243  * avformat_free_context().
244  * @}
245  *
246  * @defgroup lavf_io I/O Read/Write
247  * @{
248  * @section lavf_io_dirlist Directory listing
249  * The directory listing API makes it possible to list files on remote servers.
250  *
251  * Some of possible use cases:
252  * - an "open file" dialog to choose files from a remote location,
253  * - a recursive media finder providing a player with an ability to play all
254  * files from a given directory.
255  *
256  * @subsection lavf_io_dirlist_open Opening a directory
257  * At first, a directory needs to be opened by calling avio_open_dir()
258  * supplied with a URL and, optionally, ::AVDictionary containing
259  * protocol-specific parameters. The function returns zero or positive
260  * integer and allocates AVIODirContext on success.
261  *
262  * @code
263  * AVIODirContext *ctx = NULL;
264  * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) {
265  * fprintf(stderr, "Cannot open directory.\n");
266  * abort();
267  * }
268  * @endcode
269  *
270  * This code tries to open a sample directory using smb protocol without
271  * any additional parameters.
272  *
273  * @subsection lavf_io_dirlist_read Reading entries
274  * Each directory's entry (i.e. file, another directory, anything else
275  * within ::AVIODirEntryType) is represented by AVIODirEntry.
276  * Reading consecutive entries from an opened AVIODirContext is done by
277  * repeatedly calling avio_read_dir() on it. Each call returns zero or
278  * positive integer if successful. Reading can be stopped right after the
279  * NULL entry has been read -- it means there are no entries left to be
280  * read. The following code reads all entries from a directory associated
281  * with ctx and prints their names to standard output.
282  * @code
283  * AVIODirEntry *entry = NULL;
284  * for (;;) {
285  * if (avio_read_dir(ctx, &entry) < 0) {
286  * fprintf(stderr, "Cannot list directory.\n");
287  * abort();
288  * }
289  * if (!entry)
290  * break;
291  * printf("%s\n", entry->name);
292  * avio_free_directory_entry(&entry);
293  * }
294  * @endcode
295  * @}
296  *
297  * @defgroup lavf_codec Demuxers
298  * @{
299  * @defgroup lavf_codec_native Native Demuxers
300  * @{
301  * @}
302  * @defgroup lavf_codec_wrappers External library wrappers
303  * @{
304  * @}
305  * @}
306  * @defgroup lavf_protos I/O Protocols
307  * @{
308  * @}
309  * @defgroup lavf_internal Internal
310  * @{
311  * @}
312  * @}
313  *
314  */
315 
316 #include <time.h>
317 #include <stdio.h> /* FILE */
318 #include "libavcodec/avcodec.h"
319 #include "libavutil/dict.h"
320 #include "libavutil/log.h"
321 
322 #include "avio.h"
323 #include "libavformat/version.h"
324 
325 struct AVFormatContext;
326 
327 struct AVDeviceInfoList;
329 
330 /**
331  * @defgroup metadata_api Public Metadata API
332  * @{
333  * @ingroup libavf
334  * The metadata API allows libavformat to export metadata tags to a client
335  * application when demuxing. Conversely it allows a client application to
336  * set metadata when muxing.
337  *
338  * Metadata is exported or set as pairs of key/value strings in the 'metadata'
339  * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
340  * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
341  * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
342  * exported by demuxers isn't checked to be valid UTF-8 in most cases.
343  *
344  * Important concepts to keep in mind:
345  * - Keys are unique; there can never be 2 tags with the same key. This is
346  * also meant semantically, i.e., a demuxer should not knowingly produce
347  * several keys that are literally different but semantically identical.
348  * E.g., key=Author5, key=Author6. In this example, all authors must be
349  * placed in the same tag.
350  * - Metadata is flat, not hierarchical; there are no subtags. If you
351  * want to store, e.g., the email address of the child of producer Alice
352  * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
353  * - Several modifiers can be applied to the tag name. This is done by
354  * appending a dash character ('-') and the modifier name in the order
355  * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
356  * - language -- a tag whose value is localized for a particular language
357  * is appended with the ISO 639-2/B 3-letter language code.
358  * For example: Author-ger=Michael, Author-eng=Mike
359  * The original/default language is in the unqualified "Author" tag.
360  * A demuxer should set a default if it sets any translated tag.
361  * - sorting -- a modified version of a tag that should be used for
362  * sorting will have '-sort' appended. E.g. artist="The Beatles",
363  * artist-sort="Beatles, The".
364  * - Some protocols and demuxers support metadata updates. After a successful
365  * call to av_read_packet(), AVFormatContext.event_flags or AVStream.event_flags
366  * will be updated to indicate if metadata changed. In order to detect metadata
367  * changes on a stream, you need to loop through all streams in the AVFormatContext
368  * and check their individual event_flags.
369  *
370  * - Demuxers attempt to export metadata in a generic format, however tags
371  * with no generic equivalents are left as they are stored in the container.
372  * Follows a list of generic tag names:
373  *
374  @verbatim
375  album -- name of the set this work belongs to
376  album_artist -- main creator of the set/album, if different from artist.
377  e.g. "Various Artists" for compilation albums.
378  artist -- main creator of the work
379  comment -- any additional description of the file.
380  composer -- who composed the work, if different from artist.
381  copyright -- name of copyright holder.
382  creation_time-- date when the file was created, preferably in ISO 8601.
383  date -- date when the work was created, preferably in ISO 8601.
384  disc -- number of a subset, e.g. disc in a multi-disc collection.
385  encoder -- name/settings of the software/hardware that produced the file.
386  encoded_by -- person/group who created the file.
387  filename -- original name of the file.
388  genre -- <self-evident>.
389  language -- main language in which the work is performed, preferably
390  in ISO 639-2 format. Multiple languages can be specified by
391  separating them with commas.
392  performer -- artist who performed the work, if different from artist.
393  E.g for "Also sprach Zarathustra", artist would be "Richard
394  Strauss" and performer "London Philharmonic Orchestra".
395  publisher -- name of the label/publisher.
396  service_name -- name of the service in broadcasting (channel name).
397  service_provider -- name of the service provider in broadcasting.
398  title -- name of the work.
399  track -- number of this work in the set, can be in form current/total.
400  variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
401  @endverbatim
402  *
403  * Look in the examples section for an application example how to use the Metadata API.
404  *
405  * @}
406  */
407 
408 /* packet functions */
409 
410 
411 /**
412  * Allocate and read the payload of a packet and initialize its
413  * fields with default values.
414  *
415  * @param s associated IO context
416  * @param pkt packet
417  * @param size desired payload size
418  * @return >0 (read size) if OK, AVERROR_xxx otherwise
419  */
420 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
421 
422 
423 /**
424  * Read data and append it to the current content of the AVPacket.
425  * If pkt->size is 0 this is identical to av_get_packet.
426  * Note that this uses av_grow_packet and thus involves a realloc
427  * which is inefficient. Thus this function should only be used
428  * when there is no reasonable way to know (an upper bound of)
429  * the final size.
430  *
431  * @param s associated IO context
432  * @param pkt packet
433  * @param size amount of data to read
434  * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
435  * will not be lost even if an error occurs.
436  */
437 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
438 
439 #if FF_API_LAVF_FRAC
440 /*************************************************/
441 /* fractional numbers for exact pts handling */
442 
443 /**
444  * The exact value of the fractional number is: 'val + num / den'.
445  * num is assumed to be 0 <= num < den.
446  */
447 typedef struct AVFrac {
448  int64_t val, num, den;
449 } AVFrac;
450 #endif
451 
452 /*************************************************/
453 /* input/output formats */
454 
455 struct AVCodecTag;
456 
457 /**
458  * This structure contains the data a format has to probe a file.
459  */
460 typedef struct AVProbeData {
461  const char *filename;
462  unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
463  int buf_size; /**< Size of buf except extra allocated bytes */
464  const char *mime_type; /**< mime_type, when known. */
465 } AVProbeData;
466 
467 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
468 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
469 
470 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
471 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type
472 #define AVPROBE_SCORE_MAX 100 ///< maximum score
473 
474 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
475 
476 /// Demuxer will use avio_open, no opened file should be provided by the caller.
477 #define AVFMT_NOFILE 0x0001
478 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
479 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
480 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
481  raw picture data. */
482 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
483 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
484 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
485 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
486 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
487 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
488 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
489 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
490 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
491 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
492 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
493 #if LIBAVFORMAT_VERSION_MAJOR <= 54
494 #define AVFMT_TS_NONSTRICT 0x8020000 //we try to be compatible to the ABIs of ffmpeg and major forks
495 #else
496 #define AVFMT_TS_NONSTRICT 0x20000
497 #endif
498  /**< Format does not require strictly
499  increasing timestamps, but they must
500  still be monotonic */
501 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
502  timestamps. If not set the timestamp
503  will be shifted in av_write_frame and
504  av_interleaved_write_frame so they
505  start from 0.
506  The user or muxer can override this through
507  AVFormatContext.avoid_negative_ts
508  */
509 
510 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
511 
512 /**
513  * @addtogroup lavf_encoding
514  * @{
515  */
516 typedef struct AVOutputFormat {
517  const char *name;
518  /**
519  * Descriptive name for the format, meant to be more human-readable
520  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
521  * to define it.
522  */
523  const char *long_name;
524  const char *mime_type;
525  const char *extensions; /**< comma-separated filename extensions */
526  /* output support */
527  enum AVCodecID audio_codec; /**< default audio codec */
528  enum AVCodecID video_codec; /**< default video codec */
529  enum AVCodecID subtitle_codec; /**< default subtitle codec */
530  /**
531  * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
532  * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
533  * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
534  * AVFMT_TS_NONSTRICT
535  */
536  int flags;
538  /**
539  * List of supported codec_id-codec_tag pairs, ordered by "better
540  * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
541  */
542  const struct AVCodecTag * const *codec_tag;
543 
545  const AVClass *priv_class; ///< AVClass for the private context
546 
547  /*****************************************************************
548  * No fields below this line are part of the public API. They
549  * may not be used outside of libavformat and can be changed and
550  * removed at will.
551  * New public fields should be added right above.
552  *****************************************************************
553  */
554  struct AVOutputFormat *next;
555  /**
556  * size of private data so that it can be allocated in the wrapper
557  */
558  int priv_data_size;
559 
560  int (*write_header)(struct AVFormatContext *);
561  /**
562  * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
563  * pkt can be NULL in order to flush data buffered in the muxer.
564  * When flushing, return 0 if there still is more data to flush,
565  * or 1 if everything was flushed and there is no more buffered
566  * data.
567  */
568  int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
569  int (*write_trailer)(struct AVFormatContext *);
570  /**
571  * Currently only used to set pixel format if not YUV420P.
572  */
573  int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
574  AVPacket *in, int flush);
575  /**
576  * Test if the given codec can be stored in this container.
577  *
578  * @return 1 if the codec is supported, 0 if it is not.
579  * A negative number if unknown.
580  * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
581  */
582  int (*query_codec)(enum AVCodecID id, int std_compliance);
583 
584  void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
585  int64_t *dts, int64_t *wall);
586  /**
587  * Allows sending messages from application to device.
588  */
589  int (*control_message)(struct AVFormatContext *s, int type,
590  void *data, size_t data_size);
591 
592  /**
593  * Write an uncoded AVFrame.
594  *
595  * See av_write_uncoded_frame() for details.
596  *
597  * The library will free *frame afterwards, but the muxer can prevent it
598  * by setting the pointer to NULL.
599  */
600  int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
601  AVFrame **frame, unsigned flags);
602  /**
603  * Returns device list with it properties.
604  * @see avdevice_list_devices() for more details.
605  */
606  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
607  /**
608  * Initialize device capabilities submodule.
609  * @see avdevice_capabilities_create() for more details.
610  */
611  int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
612  /**
613  * Free device capabilities submodule.
614  * @see avdevice_capabilities_free() for more details.
615  */
616  int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
617  enum AVCodecID data_codec; /**< default data codec */
619 /**
620  * @}
621  */
622 
623 /**
624  * @addtogroup lavf_decoding
625  * @{
626  */
627 typedef struct AVInputFormat {
628  /**
629  * A comma separated list of short names for the format. New names
630  * may be appended with a minor bump.
631  */
632  const char *name;
633 
634  /**
635  * Descriptive name for the format, meant to be more human-readable
636  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
637  * to define it.
638  */
639  const char *long_name;
641  /**
642  * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
643  * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
644  * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
645  */
646  int flags;
648  /**
649  * If extensions are defined, then no probe is done. You should
650  * usually not use extension format guessing because it is not
651  * reliable enough
652  */
653  const char *extensions;
655  const struct AVCodecTag * const *codec_tag;
656 
657  const AVClass *priv_class; ///< AVClass for the private context
658 
659  /**
660  * Comma-separated list of mime types.
661  * It is used check for matching mime types while probing.
662  * @see av_probe_input_format2
663  */
664  const char *mime_type;
666  /*****************************************************************
667  * No fields below this line are part of the public API. They
668  * may not be used outside of libavformat and can be changed and
669  * removed at will.
670  * New public fields should be added right above.
671  *****************************************************************
672  */
673  struct AVInputFormat *next;
674 
675  /**
676  * Raw demuxers store their codec ID here.
677  */
678  int raw_codec_id;
679 
680  /**
681  * Size of private data so that it can be allocated in the wrapper.
682  */
683  int priv_data_size;
684 
685  /**
686  * Tell if a given file has a chance of being parsed as this format.
687  * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
688  * big so you do not have to check for that unless you need more.
689  */
690  int (*read_probe)(AVProbeData *);
692  /**
693  * Read the format header and initialize the AVFormatContext
694  * structure. Return 0 if OK. 'avformat_new_stream' should be
695  * called to create new streams.
696  */
697  int (*read_header)(struct AVFormatContext *);
699  /**
700  * Read one packet and put it in 'pkt'. pts and flags are also
701  * set. 'avformat_new_stream' can be called only if the flag
702  * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
703  * background thread).
704  * @return 0 on success, < 0 on error.
705  * When returning an error, pkt must not have been allocated
706  * or must be freed before returning
707  */
708  int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
709 
710  /**
711  * Close the stream. The AVFormatContext and AVStreams are not
712  * freed by this function
713  */
714  int (*read_close)(struct AVFormatContext *);
715 
716  /**
717  * Seek to a given timestamp relative to the frames in
718  * stream component stream_index.
719  * @param stream_index Must not be -1.
720  * @param flags Selects which direction should be preferred if no exact
721  * match is available.
722  * @return >= 0 on success (but not necessarily the new offset)
723  */
724  int (*read_seek)(struct AVFormatContext *,
725  int stream_index, int64_t timestamp, int flags);
726 
727  /**
728  * Get the next timestamp in stream[stream_index].time_base units.
729  * @return the timestamp or AV_NOPTS_VALUE if an error occurred
730  */
731  int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
732  int64_t *pos, int64_t pos_limit);
733 
734  /**
735  * Start/resume playing - only meaningful if using a network-based format
736  * (RTSP).
737  */
738  int (*read_play)(struct AVFormatContext *);
740  /**
741  * Pause playing - only meaningful if using a network-based format
742  * (RTSP).
743  */
744  int (*read_pause)(struct AVFormatContext *);
745 
746  /**
747  * Seek to timestamp ts.
748  * Seeking will be done so that the point from which all active streams
749  * can be presented successfully will be closest to ts and within min/max_ts.
750  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
751  */
752  int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
753 
754  /**
755  * Returns device list with it properties.
756  * @see avdevice_list_devices() for more details.
757  */
758  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
759 
760  /**
761  * Initialize device capabilities submodule.
762  * @see avdevice_capabilities_create() for more details.
763  */
764  int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
765 
766  /**
767  * Free device capabilities submodule.
768  * @see avdevice_capabilities_free() for more details.
769  */
770  int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
771 } AVInputFormat;
772 /**
773  * @}
774  */
775 
776 enum AVStreamParseType {
778  AVSTREAM_PARSE_FULL, /**< full parsing and repack */
779  AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
780  AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
781  AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
782  AVSTREAM_PARSE_FULL_RAW=MKTAG(0,'R','A','W'), /**< full parsing and repack with timestamp and position generation by parser for raw
783  this assumes that each packet in the file contains no demuxer level headers and
784  just codec level data, otherwise position generation would fail */
785 };
787 typedef struct AVIndexEntry {
788  int64_t pos;
789  int64_t timestamp; /**<
790  * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
791  * when seeking to this entry. That means preferable PTS on keyframe based formats.
792  * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
793  * is known
794  */
795 #define AVINDEX_KEYFRAME 0x0001
796  int flags:2;
797  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).
798  int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
799 } AVIndexEntry;
800 
801 #define AV_DISPOSITION_DEFAULT 0x0001
802 #define AV_DISPOSITION_DUB 0x0002
803 #define AV_DISPOSITION_ORIGINAL 0x0004
804 #define AV_DISPOSITION_COMMENT 0x0008
805 #define AV_DISPOSITION_LYRICS 0x0010
806 #define AV_DISPOSITION_KARAOKE 0x0020
807 
808 /**
809  * Track should be used during playback by default.
810  * Useful for subtitle track that should be displayed
811  * even when user did not explicitly ask for subtitles.
812  */
813 #define AV_DISPOSITION_FORCED 0x0040
814 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
815 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
816 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
817 /**
818  * The stream is stored in the file as an attached picture/"cover art" (e.g.
819  * APIC frame in ID3v2). The single packet associated with it will be returned
820  * among the first few packets read from the file unless seeking takes place.
821  * It can also be accessed at any time in AVStream.attached_pic.
822  */
823 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
825 /**
826  * To specify text track kind (different from subtitles default).
827  */
828 #define AV_DISPOSITION_CAPTIONS 0x10000
829 #define AV_DISPOSITION_DESCRIPTIONS 0x20000
830 #define AV_DISPOSITION_METADATA 0x40000
832 /**
833  * Options for behavior on timestamp wrap detection.
834  */
835 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
836 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
837 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
839 /**
840  * Stream structure.
841  * New fields can be added to the end with minor version bumps.
842  * Removal, reordering and changes to existing fields require a major
843  * version bump.
844  * sizeof(AVStream) must not be used outside libav*.
845  */
846 typedef struct AVStream {
847  int index; /**< stream index in AVFormatContext */
848  /**
849  * Format-specific stream ID.
850  * decoding: set by libavformat
851  * encoding: set by the user, replaced by libavformat if left unset
852  */
853  int id;
854  /**
855  * Codec context associated with this stream. Allocated and freed by
856  * libavformat.
857  *
858  * - decoding: The demuxer exports codec information stored in the headers
859  * here.
860  * - encoding: The user sets codec information, the muxer writes it to the
861  * output. Mandatory fields as specified in AVCodecContext
862  * documentation must be set even if this AVCodecContext is
863  * not actually used for encoding.
864  */
865  AVCodecContext *codec;
866  void *priv_data;
867 
868 #if FF_API_LAVF_FRAC
869  /**
870  * @deprecated this field is unused
871  */
873  struct AVFrac pts;
874 #endif
875 
876  /**
877  * This is the fundamental unit of time (in seconds) in terms
878  * of which frame timestamps are represented.
879  *
880  * decoding: set by libavformat
881  * encoding: May be set by the caller before avformat_write_header() to
882  * provide a hint to the muxer about the desired timebase. In
883  * avformat_write_header(), the muxer will overwrite this field
884  * with the timebase that will actually be used for the timestamps
885  * written into the file (which may or may not be related to the
886  * user-provided one, depending on the format).
887  */
888  AVRational time_base;
889 
890  /**
891  * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
892  * Only set this if you are absolutely 100% sure that the value you set
893  * it to really is the pts of the first frame.
894  * This may be undefined (AV_NOPTS_VALUE).
895  * @note The ASF header does NOT contain a correct start_time the ASF
896  * demuxer must NOT set this.
897  */
898  int64_t start_time;
899 
900  /**
901  * Decoding: duration of the stream, in stream time base.
902  * If a source file does not specify a duration, but does specify
903  * a bitrate, this value will be estimated from bitrate and file size.
904  */
905  int64_t duration;
907  int64_t nb_frames; ///< number of frames in this stream if known or 0
908 
909  int disposition; /**< AV_DISPOSITION_* bit field */
910 
911  enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
912 
913  /**
914  * sample aspect ratio (0 if unknown)
915  * - encoding: Set by user.
916  * - decoding: Set by libavformat.
917  */
918  AVRational sample_aspect_ratio;
920  AVDictionary *metadata;
921 
922  /**
923  * Average framerate
924  *
925  * - demuxing: May be set by libavformat when creating the stream or in
926  * avformat_find_stream_info().
927  * - muxing: May be set by the caller before avformat_write_header().
928  */
929  AVRational avg_frame_rate;
930 
931  /**
932  * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
933  * will contain the attached picture.
934  *
935  * decoding: set by libavformat, must not be modified by the caller.
936  * encoding: unused
937  */
938  AVPacket attached_pic;
939 
940  /**
941  * An array of side data that applies to the whole stream (i.e. the
942  * container does not allow it to change between packets).
943  *
944  * There may be no overlap between the side data in this array and side data
945  * in the packets. I.e. a given side data is either exported by the muxer
946  * (demuxing) / set by the caller (muxing) in this array, then it never
947  * appears in the packets, or the side data is exported / sent through
948  * the packets (always in the first packet where the value becomes known or
949  * changes), then it does not appear in this array.
950  *
951  * - demuxing: Set by libavformat when the stream is created.
952  * - muxing: May be set by the caller before avformat_write_header().
953  *
954  * Freed by libavformat in avformat_free_context().
955  *
956  * @see av_format_inject_global_side_data()
957  */
958  AVPacketSideData *side_data;
959  /**
960  * The number of elements in the AVStream.side_data array.
961  */
962  int nb_side_data;
963 
964  /**
965  * Flags for the user to detect events happening on the stream. Flags must
966  * be cleared by the user once the event has been handled.
967  * A combination of AVSTREAM_EVENT_FLAG_*.
968  */
969  int event_flags;
970 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
971 
972  /*****************************************************************
973  * All fields below this line are not part of the public API. They
974  * may not be used outside of libavformat and can be changed and
975  * removed at will.
976  * New public fields should be added right above.
977  *****************************************************************
978  */
979 
980  /**
981  * Stream information used internally by av_find_stream_info()
982  */
983 #define MAX_STD_TIMEBASES (30*12+30+3+6)
984  struct {
985  int64_t last_dts;
986  int64_t duration_gcd;
987  int duration_count;
988  int64_t rfps_duration_sum;
989  double (*duration_error)[2][MAX_STD_TIMEBASES];
990  int64_t codec_info_duration;
991  int64_t codec_info_duration_fields;
992 
993  /**
994  * 0 -> decoder has not been searched for yet.
995  * >0 -> decoder found
996  * <0 -> decoder with codec_id == -found_decoder has not been found
997  */
998  int found_decoder;
1000  int64_t last_duration;
1001 
1002  /**
1003  * Those are used for average framerate estimation.
1004  */
1005  int64_t fps_first_dts;
1006  int fps_first_dts_idx;
1007  int64_t fps_last_dts;
1008  int fps_last_dts_idx;
1009 
1010  } *info;
1011 
1012  int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
1014  // Timestamp generation support:
1015  /**
1016  * Timestamp corresponding to the last dts sync point.
1017  *
1018  * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
1019  * a DTS is received from the underlying container. Otherwise set to
1020  * AV_NOPTS_VALUE by default.
1021  */
1022  int64_t first_dts;
1023  int64_t cur_dts;
1024  int64_t last_IP_pts;
1025  int last_IP_duration;
1026 
1027  /**
1028  * Number of packets to buffer for codec probing
1029  */
1030  int probe_packets;
1032  /**
1033  * Number of frames that have been demuxed during av_find_stream_info()
1034  */
1035  int codec_info_nb_frames;
1036 
1037  /* av_read_frame() support */
1038  enum AVStreamParseType need_parsing;
1039  struct AVCodecParserContext *parser;
1040 
1041  /**
1042  * last packet in packet_buffer for this stream when muxing.
1043  */
1044  struct AVPacketList *last_in_packet_buffer;
1045  AVProbeData probe_data;
1046 #define MAX_REORDER_DELAY 16
1047  int64_t pts_buffer[MAX_REORDER_DELAY+1];
1048 
1049  AVIndexEntry *index_entries; /**< Only used if the format does not
1050  support seeking natively. */
1051  int nb_index_entries;
1052  unsigned int index_entries_allocated_size;
1054  /**
1055  * Real base framerate of the stream.
1056  * This is the lowest framerate with which all timestamps can be
1057  * represented accurately (it is the least common multiple of all
1058  * framerates in the stream). Note, this value is just a guess!
1059  * For example, if the time base is 1/90000 and all frames have either
1060  * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
1061  *
1062  * Code outside avformat should access this field using:
1063  * av_stream_get/set_r_frame_rate(stream)
1064  */
1065  AVRational r_frame_rate;
1066 
1067  /**
1068  * Stream Identifier
1069  * This is the MPEG-TS stream identifier +1
1070  * 0 means unknown
1071  */
1072  int stream_identifier;
1074  int64_t interleaver_chunk_size;
1075  int64_t interleaver_chunk_duration;
1076 
1077  /**
1078  * stream probing state
1079  * -1 -> probing finished
1080  * 0 -> no probing requested
1081  * rest -> perform probing with request_probe being the minimum score to accept.
1082  * NOT PART OF PUBLIC API
1083  */
1084  int request_probe;
1085  /**
1086  * Indicates that everything up to the next keyframe
1087  * should be discarded.
1088  */
1089  int skip_to_keyframe;
1090 
1091  /**
1092  * Number of samples to skip at the start of the frame decoded from the next packet.
1093  */
1094  int skip_samples;
1095 
1096  /**
1097  * If not 0, the number of samples that should be skipped from the start of
1098  * the stream (the samples are removed from packets with pts==0, which also
1099  * assumes negative timestamps do not happen).
1100  * Intended for use with formats such as mp3 with ad-hoc gapless audio
1101  * support.
1102  */
1103  int64_t start_skip_samples;
1104 
1105  /**
1106  * If not 0, the first audio sample that should be discarded from the stream.
1107  * This is broken by design (needs global sample count), but can't be
1108  * avoided for broken by design formats such as mp3 with ad-hoc gapless
1109  * audio support.
1110  */
1111  int64_t first_discard_sample;
1112 
1113  /**
1114  * The sample after last sample that is intended to be discarded after
1115  * first_discard_sample. Works on frame boundaries only. Used to prevent
1116  * early EOF if the gapless info is broken (considered concatenated mp3s).
1117  */
1118  int64_t last_discard_sample;
1120  /**
1121  * Number of internally decoded frames, used internally in libavformat, do not access
1122  * its lifetime differs from info which is why it is not in that structure.
1123  */
1124  int nb_decoded_frames;
1125 
1126  /**
1127  * Timestamp offset added to timestamps before muxing
1128  * NOT PART OF PUBLIC API
1129  */
1130  int64_t mux_ts_offset;
1131 
1132  /**
1133  * Internal data to check for wrapping of the time stamp
1134  */
1135  int64_t pts_wrap_reference;
1136 
1137  /**
1138  * Options for behavior, when a wrap is detected.
1139  *
1140  * Defined by AV_PTS_WRAP_ values.
1141  *
1142  * If correction is enabled, there are two possibilities:
1143  * If the first time stamp is near the wrap point, the wrap offset
1144  * will be subtracted, which will create negative time stamps.
1145  * Otherwise the offset will be added.
1146  */
1147  int pts_wrap_behavior;
1148 
1149  /**
1150  * Internal data to prevent doing update_initial_durations() twice
1151  */
1152  int update_initial_durations_done;
1153 
1154  /**
1155  * Internal data to generate dts from pts
1156  */
1157  int64_t pts_reorder_error[MAX_REORDER_DELAY+1];
1158  uint8_t pts_reorder_error_count[MAX_REORDER_DELAY+1];
1159 
1160  /**
1161  * Internal data to analyze DTS and detect faulty mpeg streams
1162  */
1163  int64_t last_dts_for_order_check;
1164  uint8_t dts_ordered;
1165  uint8_t dts_misordered;
1167  /**
1168  * Internal data to inject global side data
1169  */
1170  int inject_global_side_data;
1172  /**
1173  * String containing paris of key and values describing recommended encoder configuration.
1174  * Paris are separated by ','.
1175  * Keys are separated from values by '='.
1176  */
1177  char *recommended_encoder_configuration;
1179  /**
1180  * display aspect ratio (0 if unknown)
1181  * - encoding: unused
1182  * - decoding: Set by libavformat to calculate sample_aspect_ratio internally
1183  */
1184  AVRational display_aspect_ratio;
1186  struct FFFrac *priv_pts;
1187 } AVStream;
1188 
1193 void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration);
1195 /**
1196  * Returns the pts of the last muxed packet + its duration
1197  *
1198  * the retuned value is undefined when used with a demuxer.
1199  */
1200 int64_t av_stream_get_end_pts(const AVStream *st);
1201 
1202 #define AV_PROGRAM_RUNNING 1
1203 
1204 /**
1205  * New fields can be added to the end with minor version bumps.
1206  * Removal, reordering and changes to existing fields require a major
1207  * version bump.
1208  * sizeof(AVProgram) must not be used outside libav*.
1209  */
1210 typedef struct AVProgram {
1211  int id;
1212  int flags;
1213  enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1214  unsigned int *stream_index;
1215  unsigned int nb_stream_indexes;
1216  AVDictionary *metadata;
1217 
1218  int program_num;
1219  int pmt_pid;
1220  int pcr_pid;
1222  /*****************************************************************
1223  * All fields below this line are not part of the public API. They
1224  * may not be used outside of libavformat and can be changed and
1225  * removed at will.
1226  * New public fields should be added right above.
1227  *****************************************************************
1228  */
1229  int64_t start_time;
1230  int64_t end_time;
1231 
1232  int64_t pts_wrap_reference; ///< reference dts for wrap detection
1233  int pts_wrap_behavior; ///< behavior on wrap detection
1234 } AVProgram;
1235 
1236 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1237  (streams are added dynamically) */
1239 typedef struct AVChapter {
1240  int id; ///< unique ID to identify the chapter
1241  AVRational time_base; ///< time base in which the start/end timestamps are specified
1242  int64_t start, end; ///< chapter start/end time in time_base units
1243  AVDictionary *metadata;
1245 
1246 
1247 /**
1248  * Callback used by devices to communicate with application.
1249  */
1250 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1251  void *data, size_t data_size);
1253 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
1254  const AVIOInterruptCB *int_cb, AVDictionary **options);
1255 
1256 /**
1257  * The duration of a video can be estimated through various ways, and this enum can be used
1258  * to know how the duration was estimated.
1259  */
1261  AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1262  AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1263  AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1264 };
1265 
1266 typedef struct AVFormatInternal AVFormatInternal;
1267 
1268 /**
1269  * Format I/O context.
1270  * New fields can be added to the end with minor version bumps.
1271  * Removal, reordering and changes to existing fields require a major
1272  * version bump.
1273  * sizeof(AVFormatContext) must not be used outside libav*, use
1274  * avformat_alloc_context() to create an AVFormatContext.
1275  */
1276 typedef struct AVFormatContext {
1277  /**
1278  * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1279  * Exports (de)muxer private options if they exist.
1280  */
1281  const AVClass *av_class;
1282 
1283  /**
1284  * The input container format.
1285  *
1286  * Demuxing only, set by avformat_open_input().
1287  */
1288  struct AVInputFormat *iformat;
1289 
1290  /**
1291  * The output container format.
1292  *
1293  * Muxing only, must be set by the caller before avformat_write_header().
1294  */
1295  struct AVOutputFormat *oformat;
1296 
1297  /**
1298  * Format private data. This is an AVOptions-enabled struct
1299  * if and only if iformat/oformat.priv_class is not NULL.
1300  *
1301  * - muxing: set by avformat_write_header()
1302  * - demuxing: set by avformat_open_input()
1303  */
1304  void *priv_data;
1305 
1306  /**
1307  * I/O context.
1308  *
1309  * - demuxing: either set by the user before avformat_open_input() (then
1310  * the user must close it manually) or set by avformat_open_input().
1311  * - muxing: set by the user before avformat_write_header(). The caller must
1312  * take care of closing / freeing the IO context.
1313  *
1314  * Do NOT set this field if AVFMT_NOFILE flag is set in
1315  * iformat/oformat.flags. In such a case, the (de)muxer will handle
1316  * I/O in some other way and this field will be NULL.
1317  */
1318  AVIOContext *pb;
1319 
1320  /* stream info */
1321  /**
1322  * Flags signalling stream properties. A combination of AVFMTCTX_*.
1323  * Set by libavformat.
1324  */
1325  int ctx_flags;
1326 
1327  /**
1328  * Number of elements in AVFormatContext.streams.
1329  *
1330  * Set by avformat_new_stream(), must not be modified by any other code.
1331  */
1332  unsigned int nb_streams;
1333  /**
1334  * A list of all streams in the file. New streams are created with
1335  * avformat_new_stream().
1336  *
1337  * - demuxing: streams are created by libavformat in avformat_open_input().
1338  * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1339  * appear in av_read_frame().
1340  * - muxing: streams are created by the user before avformat_write_header().
1341  *
1342  * Freed by libavformat in avformat_free_context().
1343  */
1344  AVStream **streams;
1345 
1346  /**
1347  * input or output filename
1348  *
1349  * - demuxing: set by avformat_open_input()
1350  * - muxing: may be set by the caller before avformat_write_header()
1351  */
1352  char filename[1024];
1354  /**
1355  * Position of the first frame of the component, in
1356  * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1357  * It is deduced from the AVStream values.
1358  *
1359  * Demuxing only, set by libavformat.
1360  */
1361  int64_t start_time;
1362 
1363  /**
1364  * Duration of the stream, in AV_TIME_BASE fractional
1365  * seconds. Only set this value if you know none of the individual stream
1366  * durations and also do not set any of them. This is deduced from the
1367  * AVStream values if not set.
1368  *
1369  * Demuxing only, set by libavformat.
1370  */
1371  int64_t duration;
1372 
1373  /**
1374  * Total stream bitrate in bit/s, 0 if not
1375  * available. Never set it directly if the file_size and the
1376  * duration are known as FFmpeg can compute it automatically.
1377  */
1378  int bit_rate;
1379 
1380  unsigned int packet_size;
1381  int max_delay;
1382 
1383  /**
1384  * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1385  * Set by the user before avformat_open_input() / avformat_write_header().
1386  */
1387  int flags;
1388 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1389 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1390 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1391 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1392 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1393 #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
1394 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1395 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1396 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1397 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1398 /**
1399  * When muxing, try to avoid writing any random/volatile data to the output.
1400  * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1401  *
1402  * This flag is mainly intended for testing.
1403  */
1404 #define AVFMT_FLAG_BITEXACT 0x0400
1405 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload
1406 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1407 #define AVFMT_FLAG_PRIV_OPT 0x20000 ///< Enable use of private options by delaying codec open (this could be made default once all code is converted)
1408 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Don't merge side data but keep it separate.
1409 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1410 
1411 #if FF_API_PROBESIZE_32
1412  /**
1413  * @deprecated deprecated in favor of probesize2
1414  */
1415  unsigned int probesize;
1417  /**
1418  * @deprecated deprecated in favor of max_analyze_duration2
1419  */
1421  int max_analyze_duration;
1422 #endif
1423 
1424  const uint8_t *key;
1425  int keylen;
1426 
1427  unsigned int nb_programs;
1428  AVProgram **programs;
1429 
1430  /**
1431  * Forced video codec_id.
1432  * Demuxing: Set by user.
1433  */
1434  enum AVCodecID video_codec_id;
1435 
1436  /**
1437  * Forced audio codec_id.
1438  * Demuxing: Set by user.
1439  */
1440  enum AVCodecID audio_codec_id;
1441 
1442  /**
1443  * Forced subtitle codec_id.
1444  * Demuxing: Set by user.
1445  */
1446  enum AVCodecID subtitle_codec_id;
1447 
1448  /**
1449  * Maximum amount of memory in bytes to use for the index of each stream.
1450  * If the index exceeds this size, entries will be discarded as
1451  * needed to maintain a smaller size. This can lead to slower or less
1452  * accurate seeking (depends on demuxer).
1453  * Demuxers for which a full in-memory index is mandatory will ignore
1454  * this.
1455  * - muxing: unused
1456  * - demuxing: set by user
1457  */
1458  unsigned int max_index_size;
1459 
1460  /**
1461  * Maximum amount of memory in bytes to use for buffering frames
1462  * obtained from realtime capture devices.
1463  */
1464  unsigned int max_picture_buffer;
1465 
1466  /**
1467  * Number of chapters in AVChapter array.
1468  * When muxing, chapters are normally written in the file header,
1469  * so nb_chapters should normally be initialized before write_header
1470  * is called. Some muxers (e.g. mov and mkv) can also write chapters
1471  * in the trailer. To write chapters in the trailer, nb_chapters
1472  * must be zero when write_header is called and non-zero when
1473  * write_trailer is called.
1474  * - muxing: set by user
1475  * - demuxing: set by libavformat
1476  */
1477  unsigned int nb_chapters;
1478  AVChapter **chapters;
1479 
1480  /**
1481  * Metadata that applies to the whole file.
1482  *
1483  * - demuxing: set by libavformat in avformat_open_input()
1484  * - muxing: may be set by the caller before avformat_write_header()
1485  *
1486  * Freed by libavformat in avformat_free_context().
1487  */
1488  AVDictionary *metadata;
1489 
1490  /**
1491  * Start time of the stream in real world time, in microseconds
1492  * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1493  * stream was captured at this real world time.
1494  * - muxing: Set by the caller before avformat_write_header(). If set to
1495  * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1496  * be used.
1497  * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1498  * the value may become known after some number of frames
1499  * have been received.
1500  */
1501  int64_t start_time_realtime;
1502 
1503  /**
1504  * The number of frames used for determining the framerate in
1505  * avformat_find_stream_info().
1506  * Demuxing only, set by the caller before avformat_find_stream_info().
1507  */
1508  int fps_probe_size;
1509 
1510  /**
1511  * Error recognition; higher values will detect more errors but may
1512  * misdetect some more or less valid parts as errors.
1513  * Demuxing only, set by the caller before avformat_open_input().
1514  */
1515  int error_recognition;
1516 
1517  /**
1518  * Custom interrupt callbacks for the I/O layer.
1519  *
1520  * demuxing: set by the user before avformat_open_input().
1521  * muxing: set by the user before avformat_write_header()
1522  * (mainly useful for AVFMT_NOFILE formats). The callback
1523  * should also be passed to avio_open2() if it's used to
1524  * open the file.
1525  */
1526  AVIOInterruptCB interrupt_callback;
1527 
1528  /**
1529  * Flags to enable debugging.
1530  */
1531  int debug;
1532 #define FF_FDEBUG_TS 0x0001
1533 
1534  /**
1535  * Maximum buffering duration for interleaving.
1536  *
1537  * To ensure all the streams are interleaved correctly,
1538  * av_interleaved_write_frame() will wait until it has at least one packet
1539  * for each stream before actually writing any packets to the output file.
1540  * When some streams are "sparse" (i.e. there are large gaps between
1541  * successive packets), this can result in excessive buffering.
1542  *
1543  * This field specifies the maximum difference between the timestamps of the
1544  * first and the last packet in the muxing queue, above which libavformat
1545  * will output a packet regardless of whether it has queued a packet for all
1546  * the streams.
1547  *
1548  * Muxing only, set by the caller before avformat_write_header().
1549  */
1550  int64_t max_interleave_delta;
1551 
1552  /**
1553  * Allow non-standard and experimental extension
1554  * @see AVCodecContext.strict_std_compliance
1555  */
1556  int strict_std_compliance;
1557 
1558  /**
1559  * Flags for the user to detect events happening on the file. Flags must
1560  * be cleared by the user once the event has been handled.
1561  * A combination of AVFMT_EVENT_FLAG_*.
1562  */
1563  int event_flags;
1564 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
1566  /**
1567  * Maximum number of packets to read while waiting for the first timestamp.
1568  * Decoding only.
1569  */
1570  int max_ts_probe;
1571 
1572  /**
1573  * Avoid negative timestamps during muxing.
1574  * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1575  * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use)
1576  * - muxing: Set by user
1577  * - demuxing: unused
1578  */
1579  int avoid_negative_ts;
1580 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1581 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1582 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1583 
1584  /**
1585  * Transport stream id.
1586  * This will be moved into demuxer private options. Thus no API/ABI compatibility
1587  */
1588  int ts_id;
1590  /**
1591  * Audio preload in microseconds.
1592  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1593  * - encoding: Set by user via AVOptions (NO direct access)
1594  * - decoding: unused
1595  */
1596  int audio_preload;
1598  /**
1599  * Max chunk time in microseconds.
1600  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1601  * - encoding: Set by user via AVOptions (NO direct access)
1602  * - decoding: unused
1603  */
1604  int max_chunk_duration;
1606  /**
1607  * Max chunk size in bytes
1608  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1609  * - encoding: Set by user via AVOptions (NO direct access)
1610  * - decoding: unused
1611  */
1612  int max_chunk_size;
1614  /**
1615  * forces the use of wallclock timestamps as pts/dts of packets
1616  * This has undefined results in the presence of B frames.
1617  * - encoding: unused
1618  * - decoding: Set by user via AVOptions (NO direct access)
1619  */
1620  int use_wallclock_as_timestamps;
1622  /**
1623  * avio flags, used to force AVIO_FLAG_DIRECT.
1624  * - encoding: unused
1625  * - decoding: Set by user via AVOptions (NO direct access)
1626  */
1627  int avio_flags;
1628 
1629  /**
1630  * The duration field can be estimated through various ways, and this field can be used
1631  * to know how the duration was estimated.
1632  * - encoding: unused
1633  * - decoding: Read by user via AVOptions (NO direct access)
1634  */
1635  enum AVDurationEstimationMethod duration_estimation_method;
1637  /**
1638  * Skip initial bytes when opening stream
1639  * - encoding: unused
1640  * - decoding: Set by user via AVOptions (NO direct access)
1641  */
1642  int64_t skip_initial_bytes;
1643 
1644  /**
1645  * Correct single timestamp overflows
1646  * - encoding: unused
1647  * - decoding: Set by user via AVOptions (NO direct access)
1648  */
1649  unsigned int correct_ts_overflow;
1650 
1651  /**
1652  * Force seeking to any (also non key) frames.
1653  * - encoding: unused
1654  * - decoding: Set by user via AVOptions (NO direct access)
1655  */
1656  int seek2any;
1657 
1658  /**
1659  * Flush the I/O context after each packet.
1660  * - encoding: Set by user via AVOptions (NO direct access)
1661  * - decoding: unused
1662  */
1663  int flush_packets;
1664 
1665  /**
1666  * format probing score.
1667  * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1668  * the format.
1669  * - encoding: unused
1670  * - decoding: set by avformat, read by user via av_format_get_probe_score() (NO direct access)
1671  */
1672  int probe_score;
1673 
1674  /**
1675  * number of bytes to read maximally to identify format.
1676  * - encoding: unused
1677  * - decoding: set by user through AVOPtions (NO direct access)
1678  */
1679  int format_probesize;
1680 
1681  /**
1682  * ',' separated list of allowed decoders.
1683  * If NULL then all are allowed
1684  * - encoding: unused
1685  * - decoding: set by user through AVOptions (NO direct access)
1686  */
1687  char *codec_whitelist;
1689  /**
1690  * ',' separated list of allowed demuxers.
1691  * If NULL then all are allowed
1692  * - encoding: unused
1693  * - decoding: set by user through AVOptions (NO direct access)
1694  */
1695  char *format_whitelist;
1697  /**
1698  * An opaque field for libavformat internal usage.
1699  * Must not be accessed in any way by callers.
1700  */
1701  AVFormatInternal *internal;
1702 
1703  /**
1704  * IO repositioned flag.
1705  * This is set by avformat when the underlaying IO context read pointer
1706  * is repositioned, for example when doing byte based seeking.
1707  * Demuxers can use the flag to detect such changes.
1708  */
1709  int io_repositioned;
1711  /**
1712  * Forced video codec.
1713  * This allows forcing a specific decoder, even when there are multiple with
1714  * the same codec_id.
1715  * Demuxing: Set by user via av_format_set_video_codec (NO direct access).
1716  */
1719  /**
1720  * Forced audio codec.
1721  * This allows forcing a specific decoder, even when there are multiple with
1722  * the same codec_id.
1723  * Demuxing: Set by user via av_format_set_audio_codec (NO direct access).
1724  */
1727  /**
1728  * Forced subtitle codec.
1729  * This allows forcing a specific decoder, even when there are multiple with
1730  * the same codec_id.
1731  * Demuxing: Set by user via av_format_set_subtitle_codec (NO direct access).
1732  */
1735  /**
1736  * Forced data codec.
1737  * This allows forcing a specific decoder, even when there are multiple with
1738  * the same codec_id.
1739  * Demuxing: Set by user via av_format_set_data_codec (NO direct access).
1740  */
1743  /**
1744  * Number of bytes to be written as padding in a metadata header.
1745  * Demuxing: Unused.
1746  * Muxing: Set by user via av_format_set_metadata_header_padding.
1747  */
1748  int metadata_header_padding;
1749 
1750  /**
1751  * User data.
1752  * This is a place for some private data of the user.
1753  * Mostly usable with control_message_cb or any future callbacks in device's context.
1754  */
1755  void *opaque;
1756 
1757  /**
1758  * Callback used by devices to communicate with application.
1759  */
1760  av_format_control_message control_message_cb;
1761 
1762  /**
1763  * Output timestamp offset, in microseconds.
1764  * Muxing: set by user via AVOptions (NO direct access)
1765  */
1766  int64_t output_ts_offset;
1767 
1768  /**
1769  * Maximum duration (in AV_TIME_BASE units) of the data read
1770  * from input in avformat_find_stream_info().
1771  * Demuxing only, set by the caller before avformat_find_stream_info()
1772  * via AVOptions (NO direct access).
1773  * Can be set to 0 to let avformat choose using a heuristic.
1774  */
1775 #if FF_API_PROBESIZE_32
1776  int64_t max_analyze_duration2;
1777 #else
1778  int64_t max_analyze_duration;
1779 #endif
1780 
1781  /**
1782  * Maximum size of the data read from input for determining
1783  * the input container format.
1784  * Demuxing only, set by the caller before avformat_open_input()
1785  * via AVOptions (NO direct access).
1786  */
1787 #if FF_API_PROBESIZE_32
1788  int64_t probesize2;
1789 #else
1790  int64_t probesize;
1791 #endif
1792 
1793  /**
1794  * dump format separator.
1795  * can be ", " or "\n " or anything else
1796  * Code outside libavformat should access this field using AVOptions
1797  * (NO direct access).
1798  * - muxing: Set by user.
1799  * - demuxing: Set by user.
1800  */
1801  uint8_t *dump_separator;
1802 
1803  /**
1804  * Forced Data codec_id.
1805  * Demuxing: Set by user.
1806  */
1807  enum AVCodecID data_codec_id;
1808 
1809  /**
1810  * Called to open further IO contexts when needed for demuxing.
1811  *
1812  * This can be set by the user application to perform security checks on
1813  * the URLs before opening them.
1814  * The function should behave like avio_open2(), AVFormatContext is provided
1815  * as contextual information and to reach AVFormatContext.opaque.
1816  *
1817  * If NULL then some simple checks are used together with avio_open2().
1818  *
1819  * Must not be accessed directly from outside avformat.
1820  * @See av_format_set_open_cb()
1821  *
1822  * Demuxing: Set by user.
1823  */
1824  int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options);
1825 
1826  /**
1827  * The maximum number of streams.
1828  * - encoding: unused
1829  * - decoding: set by user through AVOptions (NO direct access)
1830  */
1831  int max_streams;
1832 } AVFormatContext;
1845 void * av_format_get_opaque(const AVFormatContext *s);
1851 
1852 /**
1853  * This function will cause global side data to be injected in the next packet
1854  * of each stream as well as after any subsequent seek.
1855  */
1857 
1858 /**
1859  * Returns the method used to set ctx->duration.
1860  *
1861  * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1862  */
1864 
1865 typedef struct AVPacketList {
1866  AVPacket pkt;
1867  struct AVPacketList *next;
1868 } AVPacketList;
1869 
1870 
1871 /**
1872  * @defgroup lavf_core Core functions
1873  * @ingroup libavf
1874  *
1875  * Functions for querying libavformat capabilities, allocating core structures,
1876  * etc.
1877  * @{
1878  */
1879 
1880 /**
1881  * Return the LIBAVFORMAT_VERSION_INT constant.
1882  */
1883 unsigned avformat_version(void);
1884 
1885 /**
1886  * Return the libavformat build-time configuration.
1887  */
1888 const char *avformat_configuration(void);
1889 
1890 /**
1891  * Return the libavformat license.
1892  */
1893 const char *avformat_license(void);
1894 
1895 /**
1896  * Initialize libavformat and register all the muxers, demuxers and
1897  * protocols. If you do not call this function, then you can select
1898  * exactly which formats you want to support.
1899  *
1900  * @see av_register_input_format()
1901  * @see av_register_output_format()
1902  */
1903 void av_register_all(void);
1904 
1907 
1908 /**
1909  * Do global initialization of network components. This is optional,
1910  * but recommended, since it avoids the overhead of implicitly
1911  * doing the setup for each session.
1912  *
1913  * Calling this function will become mandatory if using network
1914  * protocols at some major version bump.
1915  */
1916 int avformat_network_init(void);
1917 
1918 /**
1919  * Undo the initialization done by avformat_network_init.
1920  */
1921 int avformat_network_deinit(void);
1922 
1923 /**
1924  * If f is NULL, returns the first registered input format,
1925  * if f is non-NULL, returns the next registered input format after f
1926  * or NULL if f is the last one.
1927  */
1929 
1930 /**
1931  * If f is NULL, returns the first registered output format,
1932  * if f is non-NULL, returns the next registered output format after f
1933  * or NULL if f is the last one.
1934  */
1936 
1937 /**
1938  * Allocate an AVFormatContext.
1939  * avformat_free_context() can be used to free the context and everything
1940  * allocated by the framework within it.
1941  */
1943 
1944 /**
1945  * Free an AVFormatContext and all its streams.
1946  * @param s context to free
1947  */
1949 
1950 /**
1951  * Get the AVClass for AVFormatContext. It can be used in combination with
1952  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1953  *
1954  * @see av_opt_find().
1955  */
1956 const AVClass *avformat_get_class(void);
1957 
1958 /**
1959  * Add a new stream to a media file.
1960  *
1961  * When demuxing, it is called by the demuxer in read_header(). If the
1962  * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1963  * be called in read_packet().
1964  *
1965  * When muxing, should be called by the user before avformat_write_header().
1966  *
1967  * User is required to call avcodec_close() and avformat_free_context() to
1968  * clean up the allocation by avformat_new_stream().
1969  *
1970  * @param s media file handle
1971  * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1972  * will be initialized to use this codec. This is needed for e.g. codec-specific
1973  * defaults to be set, so codec should be provided if it is known.
1974  *
1975  * @return newly created stream or NULL on error.
1976  */
1978 
1979 /**
1980  * Get side information from stream.
1981  *
1982  * @param stream stream
1983  * @param type desired side information type
1984  * @param size pointer for side information size to store (optional)
1985  * @return pointer to data if present or NULL otherwise
1986  */
1987 uint8_t *av_stream_get_side_data(AVStream *stream,
1988  enum AVPacketSideDataType type, int *size);
1989 
1991 
1992 /**
1993  * @}
1994  */
1995 
1996 
1997 /**
1998  * Allocate an AVFormatContext for an output format.
1999  * avformat_free_context() can be used to free the context and
2000  * everything allocated by the framework within it.
2001  *
2002  * @param *ctx is set to the created format context, or to NULL in
2003  * case of failure
2004  * @param oformat format to use for allocating the context, if NULL
2005  * format_name and filename are used instead
2006  * @param format_name the name of output format to use for allocating the
2007  * context, if NULL filename is used instead
2008  * @param filename the name of the filename to use for allocating the
2009  * context, may be NULL
2010  * @return >= 0 in case of success, a negative AVERROR code in case of
2011  * failure
2012  */
2014  const char *format_name, const char *filename);
2015 
2016 /**
2017  * @addtogroup lavf_decoding
2018  * @{
2019  */
2020 
2021 /**
2022  * Find AVInputFormat based on the short name of the input format.
2023  */
2024 AVInputFormat *av_find_input_format(const char *short_name);
2025 
2026 /**
2027  * Guess the file format.
2028  *
2029  * @param pd data to be probed
2030  * @param is_opened Whether the file is already opened; determines whether
2031  * demuxers with or without AVFMT_NOFILE are probed.
2032  */
2033 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
2034 
2035 /**
2036  * Guess the file format.
2037  *
2038  * @param pd data to be probed
2039  * @param is_opened Whether the file is already opened; determines whether
2040  * demuxers with or without AVFMT_NOFILE are probed.
2041  * @param score_max A probe score larger that this is required to accept a
2042  * detection, the variable is set to the actual detection
2043  * score afterwards.
2044  * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2045  * to retry with a larger probe buffer.
2046  */
2047 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
2048 
2049 /**
2050  * Guess the file format.
2051  *
2052  * @param is_opened Whether the file is already opened; determines whether
2053  * demuxers with or without AVFMT_NOFILE are probed.
2054  * @param score_ret The score of the best detection.
2055  */
2056 AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
2057 
2058 /**
2059  * Probe a bytestream to determine the input format. Each time a probe returns
2060  * with a score that is too low, the probe buffer size is increased and another
2061  * attempt is made. When the maximum probe size is reached, the input format
2062  * with the highest score is returned.
2063  *
2064  * @param pb the bytestream to probe
2065  * @param fmt the input format is put here
2066  * @param url the url of the stream
2067  * @param logctx the log context
2068  * @param offset the offset within the bytestream to probe from
2069  * @param max_probe_size the maximum probe buffer size (zero for default)
2070  * @return the score in case of success, a negative value corresponding to an
2071  * the maximal score is AVPROBE_SCORE_MAX
2072  * AVERROR code otherwise
2073  */
2075  const char *url, void *logctx,
2076  unsigned int offset, unsigned int max_probe_size);
2077 
2078 /**
2079  * Like av_probe_input_buffer2() but returns 0 on success
2080  */
2082  const char *url, void *logctx,
2083  unsigned int offset, unsigned int max_probe_size);
2084 
2085 /**
2086  * Open an input stream and read the header. The codecs are not opened.
2087  * The stream must be closed with avformat_close_input().
2088  *
2089  * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
2090  * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
2091  * function and written into ps.
2092  * Note that a user-supplied AVFormatContext will be freed on failure.
2093  * @param url URL of the stream to open.
2094  * @param fmt If non-NULL, this parameter forces a specific input format.
2095  * Otherwise the format is autodetected.
2096  * @param options A dictionary filled with AVFormatContext and demuxer-private options.
2097  * On return this parameter will be destroyed and replaced with a dict containing
2098  * options that were not found. May be NULL.
2099  *
2100  * @return 0 on success, a negative AVERROR on failure.
2101  *
2102  * @note If you want to use custom IO, preallocate the format context and set its pb field.
2103  */
2104 int avformat_open_input(AVFormatContext **ps, const char *url, AVInputFormat *fmt, AVDictionary **options);
2105 
2108 
2109 /**
2110  * Read packets of a media file to get stream information. This
2111  * is useful for file formats with no headers such as MPEG. This
2112  * function also computes the real framerate in case of MPEG-2 repeat
2113  * frame mode.
2114  * The logical file position is not changed by this function;
2115  * examined packets may be buffered for later processing.
2116  *
2117  * @param ic media file handle
2118  * @param options If non-NULL, an ic.nb_streams long array of pointers to
2119  * dictionaries, where i-th member contains options for
2120  * codec corresponding to i-th stream.
2121  * On return each dictionary will be filled with options that were not found.
2122  * @return >=0 if OK, AVERROR_xxx on error
2123  *
2124  * @note this function isn't guaranteed to open all the codecs, so
2125  * options being non-empty at return is a perfectly normal behavior.
2126  *
2127  * @todo Let the user decide somehow what information is needed so that
2128  * we do not waste time getting stuff the user does not need.
2129  */
2131 
2132 /**
2133  * Find the programs which belong to a given stream.
2134  *
2135  * @param ic media file handle
2136  * @param last the last found program, the search will start after this
2137  * program, or from the beginning if it is NULL
2138  * @param s stream index
2139  * @return the next program which belongs to s, NULL if no program is found or
2140  * the last program is not among the programs of ic.
2141  */
2143 
2144 /**
2145  * Find the "best" stream in the file.
2146  * The best stream is determined according to various heuristics as the most
2147  * likely to be what the user expects.
2148  * If the decoder parameter is non-NULL, av_find_best_stream will find the
2149  * default decoder for the stream's codec; streams for which no decoder can
2150  * be found are ignored.
2151  *
2152  * @param ic media file handle
2153  * @param type stream type: video, audio, subtitles, etc.
2154  * @param wanted_stream_nb user-requested stream number,
2155  * or -1 for automatic selection
2156  * @param related_stream try to find a stream related (eg. in the same
2157  * program) to this one, or -1 if none
2158  * @param decoder_ret if non-NULL, returns the decoder for the
2159  * selected stream
2160  * @param flags flags; none are currently defined
2161  * @return the non-negative stream number in case of success,
2162  * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2163  * could be found,
2164  * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2165  * @note If av_find_best_stream returns successfully and decoder_ret is not
2166  * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2167  */
2169  enum AVMediaType type,
2170  int wanted_stream_nb,
2171  int related_stream,
2172  AVCodec **decoder_ret,
2173  int flags);
2174 
2175 /**
2176  * Return the next frame of a stream.
2177  * This function returns what is stored in the file, and does not validate
2178  * that what is there are valid frames for the decoder. It will split what is
2179  * stored in the file into frames and return one for each call. It will not
2180  * omit invalid data between valid frames so as to give the decoder the maximum
2181  * information possible for decoding.
2182  *
2183  * If pkt->buf is NULL, then the packet is valid until the next
2184  * av_read_frame() or until avformat_close_input(). Otherwise the packet
2185  * is valid indefinitely. In both cases the packet must be freed with
2186  * av_free_packet when it is no longer needed. For video, the packet contains
2187  * exactly one frame. For audio, it contains an integer number of frames if each
2188  * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
2189  * have a variable size (e.g. MPEG audio), then it contains one frame.
2190  *
2191  * pkt->pts, pkt->dts and pkt->duration are always set to correct
2192  * values in AVStream.time_base units (and guessed if the format cannot
2193  * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2194  * has B-frames, so it is better to rely on pkt->dts if you do not
2195  * decompress the payload.
2196  *
2197  * @return 0 if OK, < 0 on error or end of file
2198  */
2200 
2201 /**
2202  * Seek to the keyframe at timestamp.
2203  * 'timestamp' in 'stream_index'.
2204  *
2205  * @param s media file handle
2206  * @param stream_index If stream_index is (-1), a default
2207  * stream is selected, and timestamp is automatically converted
2208  * from AV_TIME_BASE units to the stream specific time_base.
2209  * @param timestamp Timestamp in AVStream.time_base units
2210  * or, if no stream is specified, in AV_TIME_BASE units.
2211  * @param flags flags which select direction and seeking mode
2212  * @return >= 0 on success
2213  */
2214 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2215  int flags);
2216 
2217 /**
2218  * Seek to timestamp ts.
2219  * Seeking will be done so that the point from which all active streams
2220  * can be presented successfully will be closest to ts and within min/max_ts.
2221  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2222  *
2223  * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2224  * are the file position (this may not be supported by all demuxers).
2225  * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2226  * in the stream with stream_index (this may not be supported by all demuxers).
2227  * Otherwise all timestamps are in units of the stream selected by stream_index
2228  * or if stream_index is -1, in AV_TIME_BASE units.
2229  * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2230  * keyframes (this may not be supported by all demuxers).
2231  * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2232  *
2233  * @param s media file handle
2234  * @param stream_index index of the stream which is used as time base reference
2235  * @param min_ts smallest acceptable timestamp
2236  * @param ts target timestamp
2237  * @param max_ts largest acceptable timestamp
2238  * @param flags flags
2239  * @return >=0 on success, error code otherwise
2240  *
2241  * @note This is part of the new seek API which is still under construction.
2242  * Thus do not use this yet. It may change at any time, do not expect
2243  * ABI compatibility yet!
2244  */
2245 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2246 
2247 /**
2248  * Discard all internally buffered data. This can be useful when dealing with
2249  * discontinuities in the byte stream. Generally works only with formats that
2250  * can resync. This includes headerless formats like MPEG-TS/TS but should also
2251  * work with NUT, Ogg and in a limited way AVI for example.
2252  *
2253  * The set of streams, the detected duration, stream parameters and codecs do
2254  * not change when calling this function. If you want a complete reset, it's
2255  * better to open a new AVFormatContext.
2256  *
2257  * This does not flush the AVIOContext (s->pb). If necessary, call
2258  * avio_flush(s->pb) before calling this function.
2259  *
2260  * @param s media file handle
2261  * @return >=0 on success, error code otherwise
2262  */
2264 
2265 /**
2266  * Start playing a network-based stream (e.g. RTSP stream) at the
2267  * current position.
2268  */
2270 
2271 /**
2272  * Pause a network-based stream (e.g. RTSP stream).
2273  *
2274  * Use av_read_play() to resume it.
2275  */
2277 
2278 /**
2279  * Close an opened input AVFormatContext. Free it and all its contents
2280  * and set *s to NULL.
2281  */
2283 /**
2284  * @}
2285  */
2286 
2287 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2288 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2289 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2290 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2291 
2292 /**
2293  * @addtogroup lavf_encoding
2294  * @{
2295  */
2296 /**
2297  * Allocate the stream private data and write the stream header to
2298  * an output media file.
2299  *
2300  * @param s Media file handle, must be allocated with avformat_alloc_context().
2301  * Its oformat field must be set to the desired output format;
2302  * Its pb field must be set to an already opened AVIOContext.
2303  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2304  * On return this parameter will be destroyed and replaced with a dict containing
2305  * options that were not found. May be NULL.
2306  *
2307  * @return 0 on success, negative AVERROR on failure.
2308  *
2309  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
2310  */
2312 
2313 /**
2314  * Write a packet to an output media file.
2315  *
2316  * This function passes the packet directly to the muxer, without any buffering
2317  * or reordering. The caller is responsible for correctly interleaving the
2318  * packets if the format requires it. Callers that want libavformat to handle
2319  * the interleaving should call av_interleaved_write_frame() instead of this
2320  * function.
2321  *
2322  * @param s media file handle
2323  * @param pkt The packet containing the data to be written. Note that unlike
2324  * av_interleaved_write_frame(), this function does not take
2325  * ownership of the packet passed to it (though some muxers may make
2326  * an internal reference to the input packet).
2327  * <br>
2328  * This parameter can be NULL (at any time, not just at the end), in
2329  * order to immediately flush data buffered within the muxer, for
2330  * muxers that buffer up data internally before writing it to the
2331  * output.
2332  * <br>
2333  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2334  * set to the index of the corresponding stream in @ref
2335  * AVFormatContext.streams "s->streams". It is very strongly
2336  * recommended that timing information (@ref AVPacket.pts "pts", @ref
2337  * AVPacket.dts "dts", @ref AVPacket.duration "duration") is set to
2338  * correct values.
2339  * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2340  *
2341  * @see av_interleaved_write_frame()
2342  */
2344 
2345 /**
2346  * Write a packet to an output media file ensuring correct interleaving.
2347  *
2348  * This function will buffer the packets internally as needed to make sure the
2349  * packets in the output file are properly interleaved in the order of
2350  * increasing dts. Callers doing their own interleaving should call
2351  * av_write_frame() instead of this function.
2352  *
2353  * @param s media file handle
2354  * @param pkt The packet containing the data to be written.
2355  * <br>
2356  * If the packet is reference-counted, this function will take
2357  * ownership of this reference and unreference it later when it sees
2358  * fit.
2359  * The caller must not access the data through this reference after
2360  * this function returns. If the packet is not reference-counted,
2361  * libavformat will make a copy.
2362  * <br>
2363  * This parameter can be NULL (at any time, not just at the end), to
2364  * flush the interleaving queues.
2365  * <br>
2366  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2367  * set to the index of the corresponding stream in @ref
2368  * AVFormatContext.streams "s->streams". It is very strongly
2369  * recommended that timing information (@ref AVPacket.pts "pts", @ref
2370  * AVPacket.dts "dts", @ref AVPacket.duration "duration") is set to
2371  * correct values.
2372  *
2373  * @return 0 on success, a negative AVERROR on error. Libavformat will always
2374  * take care of freeing the packet, even if this function fails.
2375  *
2376  * @see av_write_frame(), AVFormatContext.max_interleave_delta
2377  */
2379 
2380 /**
2381  * Write a uncoded frame to an output media file.
2382  *
2383  * The frame must be correctly interleaved according to the container
2384  * specification; if not, then av_interleaved_write_frame() must be used.
2385  *
2386  * See av_interleaved_write_frame() for details.
2387  */
2388 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2389  AVFrame *frame);
2390 
2391 /**
2392  * Write a uncoded frame to an output media file.
2393  *
2394  * If the muxer supports it, this function makes it possible to write an AVFrame
2395  * structure directly, without encoding it into a packet.
2396  * It is mostly useful for devices and similar special muxers that use raw
2397  * video or PCM data and will not serialize it into a byte stream.
2398  *
2399  * To test whether it is possible to use it with a given muxer and stream,
2400  * use av_write_uncoded_frame_query().
2401  *
2402  * The caller gives up ownership of the frame and must not access it
2403  * afterwards.
2404  *
2405  * @return >=0 for success, a negative code on error
2406  */
2407 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
2408  AVFrame *frame);
2409 
2410 /**
2411  * Test whether a muxer supports uncoded frame.
2412  *
2413  * @return >=0 if an uncoded frame can be written to that muxer and stream,
2414  * <0 if not
2415  */
2416 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2417 
2418 /**
2419  * Write the stream trailer to an output media file and free the
2420  * file private data.
2421  *
2422  * May only be called after a successful call to avformat_write_header.
2423  *
2424  * @param s media file handle
2425  * @return 0 if OK, AVERROR_xxx on error
2426  */
2428 
2429 /**
2430  * Return the output format in the list of registered output formats
2431  * which best matches the provided parameters, or return NULL if
2432  * there is no match.
2433  *
2434  * @param short_name if non-NULL checks if short_name matches with the
2435  * names of the registered formats
2436  * @param filename if non-NULL checks if filename terminates with the
2437  * extensions of the registered formats
2438  * @param mime_type if non-NULL checks if mime_type matches with the
2439  * MIME type of the registered formats
2440  */
2441 AVOutputFormat *av_guess_format(const char *short_name,
2442  const char *filename,
2443  const char *mime_type);
2444 
2445 /**
2446  * Guess the codec ID based upon muxer and filename.
2447  */
2448 enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
2449  const char *filename, const char *mime_type,
2450  enum AVMediaType type);
2451 
2452 /**
2453  * Get timing information for the data currently output.
2454  * The exact meaning of "currently output" depends on the format.
2455  * It is mostly relevant for devices that have an internal buffer and/or
2456  * work in real time.
2457  * @param s media file handle
2458  * @param stream stream in the media file
2459  * @param[out] dts DTS of the last packet output for the stream, in stream
2460  * time_base units
2461  * @param[out] wall absolute time when that packet whas output,
2462  * in microsecond
2463  * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
2464  * Note: some formats or devices may not allow to measure dts and wall
2465  * atomically.
2466  */
2467 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2468  int64_t *dts, int64_t *wall);
2469 
2470 
2471 /**
2472  * @}
2473  */
2474 
2475 
2476 /**
2477  * @defgroup lavf_misc Utility functions
2478  * @ingroup libavf
2479  * @{
2480  *
2481  * Miscellaneous utility functions related to both muxing and demuxing
2482  * (or neither).
2483  */
2484 
2485 /**
2486  * Send a nice hexadecimal dump of a buffer to the specified file stream.
2487  *
2488  * @param f The file stream pointer where the dump should be sent to.
2489  * @param buf buffer
2490  * @param size buffer size
2491  *
2492  * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2493  */
2494 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2495 
2496 /**
2497  * Send a nice hexadecimal dump of a buffer to the log.
2498  *
2499  * @param avcl A pointer to an arbitrary struct of which the first field is a
2500  * pointer to an AVClass struct.
2501  * @param level The importance level of the message, lower values signifying
2502  * higher importance.
2503  * @param buf buffer
2504  * @param size buffer size
2505  *
2506  * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2507  */
2508 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2509 
2510 /**
2511  * Send a nice dump of a packet to the specified file stream.
2512  *
2513  * @param f The file stream pointer where the dump should be sent to.
2514  * @param pkt packet to dump
2515  * @param dump_payload True if the payload must be displayed, too.
2516  * @param st AVStream that the packet belongs to
2517  */
2518 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2519 
2520 
2521 /**
2522  * Send a nice dump of a packet to the log.
2523  *
2524  * @param avcl A pointer to an arbitrary struct of which the first field is a
2525  * pointer to an AVClass struct.
2526  * @param level The importance level of the message, lower values signifying
2527  * higher importance.
2528  * @param pkt packet to dump
2529  * @param dump_payload True if the payload must be displayed, too.
2530  * @param st AVStream that the packet belongs to
2531  */
2532 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2533  const AVStream *st);
2534 
2535 /**
2536  * Get the AVCodecID for the given codec tag tag.
2537  * If no codec id is found returns AV_CODEC_ID_NONE.
2538  *
2539  * @param tags list of supported codec_id-codec_tag pairs, as stored
2540  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2541  * @param tag codec tag to match to a codec ID
2542  */
2543 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2544 
2545 /**
2546  * Get the codec tag for the given codec id id.
2547  * If no codec tag is found returns 0.
2548  *
2549  * @param tags list of supported codec_id-codec_tag pairs, as stored
2550  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2551  * @param id codec ID to match to a codec tag
2552  */
2553 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2554 
2555 /**
2556  * Get the codec tag for the given codec id.
2557  *
2558  * @param tags list of supported codec_id - codec_tag pairs, as stored
2559  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2560  * @param id codec id that should be searched for in the list
2561  * @param tag A pointer to the found tag
2562  * @return 0 if id was not found in tags, > 0 if it was found
2563  */
2564 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2565  unsigned int *tag);
2566 
2568 
2569 /**
2570  * Get the index for a specific timestamp.
2571  *
2572  * @param st stream that the timestamp belongs to
2573  * @param timestamp timestamp to retrieve the index for
2574  * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2575  * to the timestamp which is <= the requested one, if backward
2576  * is 0, then it will be >=
2577  * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2578  * @return < 0 if no such timestamp could be found
2579  */
2580 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2581 
2582 /**
2583  * Add an index entry into a sorted list. Update the entry if the list
2584  * already contains it.
2585  *
2586  * @param timestamp timestamp in the time base of the given stream
2587  */
2588 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2589  int size, int distance, int flags);
2590 
2591 
2592 /**
2593  * Split a URL string into components.
2594  *
2595  * The pointers to buffers for storing individual components may be null,
2596  * in order to ignore that component. Buffers for components not found are
2597  * set to empty strings. If the port is not found, it is set to a negative
2598  * value.
2599  *
2600  * @param proto the buffer for the protocol
2601  * @param proto_size the size of the proto buffer
2602  * @param authorization the buffer for the authorization
2603  * @param authorization_size the size of the authorization buffer
2604  * @param hostname the buffer for the host name
2605  * @param hostname_size the size of the hostname buffer
2606  * @param port_ptr a pointer to store the port number in
2607  * @param path the buffer for the path
2608  * @param path_size the size of the path buffer
2609  * @param url the URL to split
2610  */
2611 void av_url_split(char *proto, int proto_size,
2612  char *authorization, int authorization_size,
2613  char *hostname, int hostname_size,
2614  int *port_ptr,
2615  char *path, int path_size,
2616  const char *url);
2617 
2618 
2619 /**
2620  * Print detailed information about the input or output format, such as
2621  * duration, bitrate, streams, container, programs, metadata, side data,
2622  * codec and time base.
2623  *
2624  * @param ic the context to analyze
2625  * @param index index of the stream to dump information about
2626  * @param url the URL to print, such as source or destination file
2627  * @param is_output Select whether the specified context is an input(0) or output(1)
2628  */
2630  int index,
2631  const char *url,
2632  int is_output);
2633 
2634 /**
2635  * Return in 'buf' the path with '%d' replaced by a number.
2636  *
2637  * Also handles the '%0nd' format where 'n' is the total number
2638  * of digits and '%%'.
2639  *
2640  * @param buf destination buffer
2641  * @param buf_size destination buffer size
2642  * @param path numbered sequence string
2643  * @param number frame number
2644  * @return 0 if OK, -1 on format error
2645  */
2646 int av_get_frame_filename(char *buf, int buf_size,
2647  const char *path, int number);
2648 
2649 /**
2650  * Check whether filename actually is a numbered sequence generator.
2651  *
2652  * @param filename possible numbered sequence string
2653  * @return 1 if a valid numbered sequence string, 0 otherwise
2654  */
2655 int av_filename_number_test(const char *filename);
2656 
2657 /**
2658  * Generate an SDP for an RTP session.
2659  *
2660  * Note, this overwrites the id values of AVStreams in the muxer contexts
2661  * for getting unique dynamic payload types.
2662  *
2663  * @param ac array of AVFormatContexts describing the RTP streams. If the
2664  * array is composed by only one context, such context can contain
2665  * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2666  * all the contexts in the array (an AVCodecContext per RTP stream)
2667  * must contain only one AVStream.
2668  * @param n_files number of AVCodecContexts contained in ac
2669  * @param buf buffer where the SDP will be stored (must be allocated by
2670  * the caller)
2671  * @param size the size of the buffer
2672  * @return 0 if OK, AVERROR_xxx on error
2673  */
2674 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2675 
2676 /**
2677  * Return a positive value if the given filename has one of the given
2678  * extensions, 0 otherwise.
2679  *
2680  * @param filename file name to check against the given extensions
2681  * @param extensions a comma-separated list of filename extensions
2682  */
2683 int av_match_ext(const char *filename, const char *extensions);
2684 
2685 /**
2686  * Test if the given container can store a codec.
2687  *
2688  * @param ofmt container to check for compatibility
2689  * @param codec_id codec to potentially store in container
2690  * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2691  *
2692  * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2693  * A negative number if this information is not available.
2694  */
2695 int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id,
2696  int std_compliance);
2697 
2698 /**
2699  * @defgroup riff_fourcc RIFF FourCCs
2700  * @{
2701  * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2702  * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2703  * following code:
2704  * @code
2705  * uint32_t tag = MKTAG('H', '2', '6', '4');
2706  * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2707  * enum AVCodecID id = av_codec_get_id(table, tag);
2708  * @endcode
2709  */
2710 /**
2711  * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2712  */
2713 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2714 /**
2715  * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2716  */
2717 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2718 /**
2719  * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2720  */
2721 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2722 /**
2723  * @return the table mapping MOV FourCCs for audio to AVCodecID.
2724  */
2725 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2726 
2727 /**
2728  * @}
2729  */
2730 
2731 /**
2732  * Guess the sample aspect ratio of a frame, based on both the stream and the
2733  * frame aspect ratio.
2734  *
2735  * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2736  * is set by the demuxer, these two may not be equal. This function tries to
2737  * return the value that you should use if you would like to display the frame.
2738  *
2739  * Basic logic is to use the stream aspect ratio if it is set to something sane
2740  * otherwise use the frame aspect ratio. This way a container setting, which is
2741  * usually easy to modify can override the coded value in the frames.
2742  *
2743  * @param format the format context which the stream is part of
2744  * @param stream the stream which the frame is part of
2745  * @param frame the frame with the aspect ratio to be determined
2746  * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2747  */
2749 
2750 /**
2751  * Guess the frame rate, based on both the container and codec information.
2752  *
2753  * @param ctx the format context which the stream is part of
2754  * @param stream the stream which the frame is part of
2755  * @param frame the frame for which the frame rate should be determined, may be NULL
2756  * @return the guessed (valid) frame rate, 0/1 if no idea
2757  */
2759 
2760 /**
2761  * Check if the stream st contained in s is matched by the stream specifier
2762  * spec.
2763  *
2764  * See the "stream specifiers" chapter in the documentation for the syntax
2765  * of spec.
2766  *
2767  * @return >0 if st is matched by spec;
2768  * 0 if st is not matched by spec;
2769  * AVERROR code if spec is invalid
2770  *
2771  * @note A stream specifier can match several streams in the format.
2772  */
2774  const char *spec);
2775 
2777 
2778 
2779 /**
2780  * @}
2781  */
2782 
2783 #endif /* AVFORMAT_AVFORMAT_H */
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.
full parsing and interpolation of timestamps for frames not starting on a packet boundary ...
Definition: avformat.h:788
Bytestream IO Context.
Definition: avio.h:111
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.
Buffered I/O operations.
AVPacketSideDataType
Definition: avcodec.h:1224
attribute_deprecated int av_demuxer_open(AVFormatContext *ic)
This structure describes decoded (raw) audio or video data.
Definition: frame.h:171
AVCodec * av_format_get_video_codec(const AVFormatContext *s)
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
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.
int avformat_write_header(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and write the stream header to an output media file.
int av_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file.
const char * filename
Definition: avformat.h:461
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...
enum AVCodecID video_codec
default video codec
Definition: avformat.h:536
void av_stream_set_r_frame_rate(AVStream *s, AVRational r)
uint8_t * av_stream_get_side_data(AVStream *stream, enum AVPacketSideDataType type, int *size)
Get side information from stream.
int av_get_output_timestamp(struct AVFormatContext *s, int stream, int64_t *dts, int64_t *wall)
Get timing information for the data currently output.
AVInputFormat * av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret)
Guess the file format.
static AVPacket pkt
int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index)
Test whether a muxer supports uncoded frame.
int priv_data_size
Size of private data so that it can be allocated in the wrapper.
Definition: avformat.h:691
AVCodec.
Definition: avcodec.h:3472
void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c)
enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext *ctx)
Returns the method used to set ctx->duration.
Format I/O context.
Definition: avformat.h:1285
AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame)
Guess the frame rate, based on both the container and codec information.
const struct AVCodecTag * avformat_get_mov_audio_tags(void)
Public dictionary API.
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS, AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH, AVFMT_TS_NONSTRICT
Definition: avformat.h:544
const struct AVCodecTag * avformat_get_riff_video_tags(void)
enum AVCodecID av_codec_get_id(const struct AVCodecTag *const *tags, unsigned int tag)
Get the AVCodecID for the given codec tag tag.
unsigned avformat_version(void)
Return the LIBAVFORMAT_VERSION_INT constant.
const char * avformat_license(void)
Return the libavformat license.
struct AVFormatInternal AVFormatInternal
Definition: avformat.h:1275
int priv_data_size
size of private data so that it can be allocated in the wrapper
Definition: avformat.h:566
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.
AVDurationEstimationMethod
The duration of a video can be estimated through various ways, and this enum can be used to know how ...
Definition: avformat.h:1269
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
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.
static AVFrame * frame
AVFormatContext * avformat_alloc_context(void)
Allocate an AVFormatContext.
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.
const char * avformat_configuration(void)
Return the libavformat build-time configuration.
#define MAX_REORDER_DELAY
Definition: avformat.h:1054
int flags
Flags modifying the (de)muxer behaviour.
Definition: avformat.h:1396
AVProgram * av_new_program(AVFormatContext *s, int id)
int avformat_network_init(void)
Do global initialization of network components.
const struct AVCodecTag * avformat_get_riff_audio_tags(void)
int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
Generate an SDP for an RTP session.
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.
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.
const AVClass * avformat_get_class(void)
Get the AVClass for AVFormatContext.
int av_probe_input_buffer2(AVIOContext *pb, AVInputFormat **fmt, const char *url, void *logctx, unsigned int offset, unsigned int max_probe_size)
Probe a bytestream to determine the input format.
AVCodec * av_format_get_audio_codec(const AVFormatContext *s)
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:790
Duration estimated from bitrate (less accurate)
Definition: avformat.h:1272
int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
Read data and append it to the current content of the AVPacket.
const struct AVCodecTag * avformat_get_mov_video_tags(void)
int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output 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, streams, container, programs, metadata, side data, codec and time base.
Callback for checking whether to abort blocking functions.
Definition: avio.h:50
int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type, int wanted_stream_nb, int related_stream, AVCodec **decoder_ret, int flags)
Find the "best" stream in the file.
int av_probe_input_buffer(AVIOContext *pb, 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.
AVProgram * av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s)
Find the programs which belong to a given stream.
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: avcodec.h:102
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
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.
struct AVCodecParser * parser
Definition: avcodec.h:4541
void av_format_set_data_codec(AVFormatContext *s, AVCodec *c)
AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s)
struct AVCodecParserContext * av_stream_get_parser(const AVStream *s)
struct AVDictionary AVDictionary
Definition: dict.h:91
int av_read_play(AVFormatContext *s)
Start playing a network-based stream (e.g.
New fields can be added to the end with minor version bumps.
Definition: avformat.h:1218
Libavcodec external API header.
AVInputFormat * av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max)
Guess the file format.
void * opaque
User data.
Definition: avformat.h:1764
Only parse headers, do not repack.
Definition: avformat.h:787
int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id, int std_compliance)
Test if the given container can store a codec.
const char * mime_type
mime_type, when known.
Definition: avformat.h:464
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:463
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:462
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...
void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration)
int av_read_pause(AVFormatContext *s)
Pause a network-based stream (e.g.
AVInputFormat * av_find_input_format(const char *short_name)
Find AVInputFormat based on the short name of the input format.
int(* write_header)(struct AVFormatContext *)
Definition: avformat.h:568
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:1259
enum AVCodecID av_guess_codec(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.
int max_streams
The maximum number of streams.
Definition: avformat.h:1840
int av_find_default_stream_index(AVFormatContext *s)
void av_format_set_opaque(AVFormatContext *s, void *opaque)
Duration estimated from a stream with a known duration.
Definition: avformat.h:1271
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...
void av_register_input_format(AVInputFormat *format)
void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c)
Libavformat version macros.
int(* AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Definition: avformat.h:1262
AVOutputFormat * av_oformat_next(const AVOutputFormat *f)
If f is NULL, returns the first registered output format, if f is non-NULL, returns the next register...
void * av_format_get_opaque(const AVFormatContext *s)
int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
Return in &#39;buf&#39; the path with &#39;d&#39; replaced by a number.
int av_format_get_probe_score(const AVFormatContext *s)
Stream structure.
Definition: avformat.h:854
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
int avformat_queue_attached_pictures(AVFormatContext *s)
void av_register_output_format(AVOutputFormat *format)
int avformat_network_deinit(void)
Undo the initialization done by avformat_network_init.
struct AVOutputFormat * next
Definition: avformat.h:562
AVIOContext * pb
I/O context.
Definition: avformat.h:1327
main external API structure.
Definition: avcodec.h:1502
int av_filename_number_test(const char *filename)
Check whether filename actually is a numbered sequence generator.
void av_format_set_video_codec(AVFormatContext *s, AVCodec *c)
Describe the class of an AVClass context structure.
Definition: log.h:67
enum AVCodecID subtitle_codec
default subtitle codec
Definition: avformat.h:537
rational number numerator/denominator
Definition: rational.h:43
AVRational av_stream_get_r_frame_rate(const AVStream *s)
AVMediaType
Definition: avutil.h:191
void av_format_set_open_cb(AVFormatContext *s, AVOpenCallback callback)
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
This structure contains the data a format has to probe a file.
Definition: avformat.h:460
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
List of devices.
Definition: avdevice.h:459
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.
full parsing and repack of the first frame only, only implemented for H.264 currently ...
Definition: avformat.h:789
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:686
static int64_t pts
Global timestamp for the audio frames.
av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s)
#define attribute_deprecated
Definition: attributes.h:86
Duration accurately estimated from PTSes.
Definition: avformat.h:1270
int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Seek to the keyframe at timestamp.
AVOpenCallback av_format_get_open_cb(const AVFormatContext *s)
full parsing and repack
Definition: avformat.h:786
int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index, AVFrame *frame)
Write a uncoded frame to an output media file.
struct AVPacketList * next
Definition: avformat.h:1876
enum AVCodecID data_codec
default data codec
Definition: avformat.h:625
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
AVStreamParseType
Definition: avformat.h:784
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
int av_write_uncoded_frame(AVFormatContext *s, int stream_index, AVFrame *frame)
Write a uncoded frame to an output media file.
int(* read_header)(struct AVFormatContext *)
Read the format header and initialize the AVFormatContext structure.
Definition: avformat.h:705
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:535
void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback)
int avformat_open_input(AVFormatContext **ps, const char *url, AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
AVDiscard
Definition: avcodec.h:680
int av_format_get_metadata_header_padding(const AVFormatContext *s)
char * av_stream_get_recommended_encoder_configuration(const AVStream *s)
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
int avformat_flush(AVFormatContext *s)
Discard all internally buffered data.
void av_format_set_metadata_header_padding(AVFormatContext *s, int c)
int(* read_probe)(AVProbeData *)
Tell if a given file has a chance of being parsed as this format.
Definition: avformat.h:698
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.
struct AVInputFormat * next
Definition: avformat.h:681
AVCodec * av_format_get_data_codec(const AVFormatContext *s)
#define MKTAG(a, b, c, d)
Definition: common.h:341
unsigned int av_codec_get_tag(const struct AVCodecTag *const *tags, enum AVCodecID id)
Get the codec tag for the given codec id id.
AVInputFormat * av_probe_input_format(AVProbeData *pd, int is_opened)
Guess the file format.
Following API allows user to probe device capabilities (supported codecs, pixel formats, sample formats, resolutions, channel counts, etc).
Definition: avdevice.h:399
This structure stores compressed data.
Definition: avcodec.h:1400
void av_register_all(void)
Initialize libavformat and register all the muxers, demuxers and protocols.
#define MAX_STD_TIMEBASES
Stream information used internally by av_find_stream_info()
Definition: avformat.h:991
int64_t av_stream_get_end_pts(const AVStream *st)
Returns the pts of the last muxed packet + its duration.
AVInputFormat * av_iformat_next(const AVInputFormat *f)
If f is NULL, returns the first registered input format, if f is non-NULL, returns the next registere...