FFmpeg  4.0
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  *
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17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVFORMAT_AVFORMAT_H
22 #define AVFORMAT_AVFORMAT_H
23 
24 /**
25  * @file
26  * @ingroup libavf
27  * Main libavformat public API header
28  */
29 
30 /**
31  * @defgroup libavf libavformat
32  * I/O and Muxing/Demuxing Library
33  *
34  * Libavformat (lavf) is a library for dealing with various media container
35  * formats. Its main two purposes are demuxing - i.e. splitting a media file
36  * into component streams, and the reverse process of muxing - writing supplied
37  * data in a specified container format. It also has an @ref lavf_io
38  * "I/O module" which supports a number of protocols for accessing the data (e.g.
39  * file, tcp, http and others). 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  * @{
94  *
95  * @defgroup lavf_decoding Demuxing
96  * @{
97  * Demuxers read a media file and split it into chunks of data (@em packets). A
98  * @ref AVPacket "packet" contains one or more encoded frames which belongs to a
99  * single elementary stream. In the lavf API this process is represented by the
100  * avformat_open_input() function for opening a file, av_read_frame() for
101  * reading a single packet and finally avformat_close_input(), which does the
102  * cleanup.
103  *
104  * @section lavf_decoding_open Opening a media file
105  * The minimum information required to open a file is its URL, which
106  * is passed to avformat_open_input(), as in the following code:
107  * @code
108  * const char *url = "file:in.mp3";
109  * AVFormatContext *s = NULL;
110  * int ret = avformat_open_input(&s, url, NULL, NULL);
111  * if (ret < 0)
112  * abort();
113  * @endcode
114  * The above code attempts to allocate an AVFormatContext, open the
115  * specified file (autodetecting the format) and read the header, exporting the
116  * information stored there into s. Some formats do not have a header or do not
117  * store enough information there, so it is recommended that you call the
118  * avformat_find_stream_info() function which tries to read and decode a few
119  * frames to find missing information.
120  *
121  * In some cases you might want to preallocate an AVFormatContext yourself with
122  * avformat_alloc_context() and do some tweaking on it before passing it to
123  * avformat_open_input(). One such case is when you want to use custom functions
124  * for reading input data instead of lavf internal I/O layer.
125  * To do that, create your own AVIOContext with avio_alloc_context(), passing
126  * your reading callbacks to it. Then set the @em pb field of your
127  * AVFormatContext to newly created AVIOContext.
128  *
129  * Since the format of the opened file is in general not known until after
130  * avformat_open_input() has returned, it is not possible to set demuxer private
131  * options on a preallocated context. Instead, the options should be passed to
132  * avformat_open_input() wrapped in an AVDictionary:
133  * @code
134  * AVDictionary *options = NULL;
135  * av_dict_set(&options, "video_size", "640x480", 0);
136  * av_dict_set(&options, "pixel_format", "rgb24", 0);
137  *
138  * if (avformat_open_input(&s, url, NULL, &options) < 0)
139  * abort();
140  * av_dict_free(&options);
141  * @endcode
142  * This code passes the private options 'video_size' and 'pixel_format' to the
143  * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it
144  * cannot know how to interpret raw video data otherwise. If the format turns
145  * out to be something different than raw video, those options will not be
146  * recognized by the demuxer and therefore will not be applied. Such unrecognized
147  * options are then returned in the options dictionary (recognized options are
148  * consumed). The calling program can handle such unrecognized options as it
149  * wishes, e.g.
150  * @code
151  * AVDictionaryEntry *e;
152  * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
153  * fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key);
154  * abort();
155  * }
156  * @endcode
157  *
158  * After you have finished reading the file, you must close it with
159  * avformat_close_input(). It will free everything associated with the file.
160  *
161  * @section lavf_decoding_read Reading from an opened file
162  * Reading data from an opened AVFormatContext is done by repeatedly calling
163  * av_read_frame() on it. Each call, if successful, will return an AVPacket
164  * containing encoded data for one AVStream, identified by
165  * AVPacket.stream_index. This packet may be passed straight into the libavcodec
166  * decoding functions avcodec_send_packet() or avcodec_decode_subtitle2() if the
167  * caller wishes to decode the data.
168  *
169  * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be
170  * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for
171  * pts/dts, 0 for duration) if the stream does not provide them. The timing
172  * information will be in AVStream.time_base units, i.e. it has to be
173  * multiplied by the timebase to convert them to seconds.
174  *
175  * If AVPacket.buf is set on the returned packet, then the packet is
176  * allocated dynamically and the user may keep it indefinitely.
177  * Otherwise, if AVPacket.buf is NULL, the packet data is backed by a
178  * static storage somewhere inside the demuxer and the packet is only valid
179  * until the next av_read_frame() call or closing the file. If the caller
180  * requires a longer lifetime, av_dup_packet() will make an av_malloc()ed copy
181  * of it.
182  * In both cases, the packet must be freed with av_packet_unref() when it is no
183  * longer needed.
184  *
185  * @section lavf_decoding_seek Seeking
186  * @}
187  *
188  * @defgroup lavf_encoding Muxing
189  * @{
190  * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write
191  * it into files or other output bytestreams in the specified container format.
192  *
193  * The main API functions for muxing are avformat_write_header() for writing the
194  * file header, av_write_frame() / av_interleaved_write_frame() for writing the
195  * packets and av_write_trailer() for finalizing the file.
196  *
197  * At the beginning of the muxing process, the caller must first call
198  * avformat_alloc_context() to create a muxing context. The caller then sets up
199  * the muxer by filling the various fields in this context:
200  *
201  * - The @ref AVFormatContext.oformat "oformat" field must be set to select the
202  * muxer that will be used.
203  * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb
204  * "pb" field must be set to an opened IO context, either returned from
205  * avio_open2() or a custom one.
206  * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must
207  * be created with the avformat_new_stream() function. The caller should fill
208  * the @ref AVStream.codecpar "stream codec parameters" information, such as the
209  * codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id
210  * "id" and other parameters (e.g. width / height, the pixel or sample format,
211  * etc.) as known. The @ref AVStream.time_base "stream timebase" should
212  * be set to the timebase that the caller desires to use for this stream (note
213  * that the timebase actually used by the muxer can be different, as will be
214  * described later).
215  * - It is advised to manually initialize only the relevant fields in
216  * AVCodecParameters, rather than using @ref avcodec_parameters_copy() during
217  * remuxing: there is no guarantee that the codec context values remain valid
218  * for both input and output format contexts.
219  * - The caller may fill in additional information, such as @ref
220  * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream"
221  * metadata, @ref AVFormatContext.chapters "chapters", @ref
222  * AVFormatContext.programs "programs", etc. as described in the
223  * AVFormatContext documentation. Whether such information will actually be
224  * stored in the output depends on what the container format and the muxer
225  * support.
226  *
227  * When the muxing context is fully set up, the caller must call
228  * avformat_write_header() to initialize the muxer internals and write the file
229  * header. Whether anything actually is written to the IO context at this step
230  * depends on the muxer, but this function must always be called. Any muxer
231  * private options must be passed in the options parameter to this function.
232  *
233  * The data is then sent to the muxer by repeatedly calling av_write_frame() or
234  * av_interleaved_write_frame() (consult those functions' documentation for
235  * discussion on the difference between them; only one of them may be used with
236  * a single muxing context, they should not be mixed). Do note that the timing
237  * information on the packets sent to the muxer must be in the corresponding
238  * AVStream's timebase. That timebase is set by the muxer (in the
239  * avformat_write_header() step) and may be different from the timebase
240  * requested by the caller.
241  *
242  * Once all the data has been written, the caller must call av_write_trailer()
243  * to flush any buffered packets and finalize the output file, then close the IO
244  * context (if any) and finally free the muxing context with
245  * avformat_free_context().
246  * @}
247  *
248  * @defgroup lavf_io I/O Read/Write
249  * @{
250  * @section lavf_io_dirlist Directory listing
251  * The directory listing API makes it possible to list files on remote servers.
252  *
253  * Some of possible use cases:
254  * - an "open file" dialog to choose files from a remote location,
255  * - a recursive media finder providing a player with an ability to play all
256  * files from a given directory.
257  *
258  * @subsection lavf_io_dirlist_open Opening a directory
259  * At first, a directory needs to be opened by calling avio_open_dir()
260  * supplied with a URL and, optionally, ::AVDictionary containing
261  * protocol-specific parameters. The function returns zero or positive
262  * integer and allocates AVIODirContext on success.
263  *
264  * @code
265  * AVIODirContext *ctx = NULL;
266  * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) {
267  * fprintf(stderr, "Cannot open directory.\n");
268  * abort();
269  * }
270  * @endcode
271  *
272  * This code tries to open a sample directory using smb protocol without
273  * any additional parameters.
274  *
275  * @subsection lavf_io_dirlist_read Reading entries
276  * Each directory's entry (i.e. file, another directory, anything else
277  * within ::AVIODirEntryType) is represented by AVIODirEntry.
278  * Reading consecutive entries from an opened AVIODirContext is done by
279  * repeatedly calling avio_read_dir() on it. Each call returns zero or
280  * positive integer if successful. Reading can be stopped right after the
281  * NULL entry has been read -- it means there are no entries left to be
282  * read. The following code reads all entries from a directory associated
283  * with ctx and prints their names to standard output.
284  * @code
285  * AVIODirEntry *entry = NULL;
286  * for (;;) {
287  * if (avio_read_dir(ctx, &entry) < 0) {
288  * fprintf(stderr, "Cannot list directory.\n");
289  * abort();
290  * }
291  * if (!entry)
292  * break;
293  * printf("%s\n", entry->name);
294  * avio_free_directory_entry(&entry);
295  * }
296  * @endcode
297  * @}
298  *
299  * @defgroup lavf_codec Demuxers
300  * @{
301  * @defgroup lavf_codec_native Native Demuxers
302  * @{
303  * @}
304  * @defgroup lavf_codec_wrappers External library wrappers
305  * @{
306  * @}
307  * @}
308  * @defgroup lavf_protos I/O Protocols
309  * @{
310  * @}
311  * @defgroup lavf_internal Internal
312  * @{
313  * @}
314  * @}
315  */
316 
317 #include <time.h>
318 #include <stdio.h> /* FILE */
319 #include "libavcodec/avcodec.h"
320 #include "libavutil/dict.h"
321 #include "libavutil/log.h"
322 
323 #include "avio.h"
324 #include "libavformat/version.h"
325 
326 struct AVFormatContext;
327 
328 struct AVDeviceInfoList;
330 
331 /**
332  * @defgroup metadata_api Public Metadata API
333  * @{
334  * @ingroup libavf
335  * The metadata API allows libavformat to export metadata tags to a client
336  * application when demuxing. Conversely it allows a client application to
337  * set metadata when muxing.
338  *
339  * Metadata is exported or set as pairs of key/value strings in the 'metadata'
340  * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
341  * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
342  * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
343  * exported by demuxers isn't checked to be valid UTF-8 in most cases.
344  *
345  * Important concepts to keep in mind:
346  * - Keys are unique; there can never be 2 tags with the same key. This is
347  * also meant semantically, i.e., a demuxer should not knowingly produce
348  * several keys that are literally different but semantically identical.
349  * E.g., key=Author5, key=Author6. In this example, all authors must be
350  * placed in the same tag.
351  * - Metadata is flat, not hierarchical; there are no subtags. If you
352  * want to store, e.g., the email address of the child of producer Alice
353  * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
354  * - Several modifiers can be applied to the tag name. This is done by
355  * appending a dash character ('-') and the modifier name in the order
356  * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
357  * - language -- a tag whose value is localized for a particular language
358  * is appended with the ISO 639-2/B 3-letter language code.
359  * For example: Author-ger=Michael, Author-eng=Mike
360  * The original/default language is in the unqualified "Author" tag.
361  * A demuxer should set a default if it sets any translated tag.
362  * - sorting -- a modified version of a tag that should be used for
363  * sorting will have '-sort' appended. E.g. artist="The Beatles",
364  * artist-sort="Beatles, The".
365  * - Some protocols and demuxers support metadata updates. After a successful
366  * call to av_read_packet(), AVFormatContext.event_flags or AVStream.event_flags
367  * will be updated to indicate if metadata changed. In order to detect metadata
368  * changes on a stream, you need to loop through all streams in the AVFormatContext
369  * and check their individual event_flags.
370  *
371  * - Demuxers attempt to export metadata in a generic format, however tags
372  * with no generic equivalents are left as they are stored in the container.
373  * Follows a list of generic tag names:
374  *
375  @verbatim
376  album -- name of the set this work belongs to
377  album_artist -- main creator of the set/album, if different from artist.
378  e.g. "Various Artists" for compilation albums.
379  artist -- main creator of the work
380  comment -- any additional description of the file.
381  composer -- who composed the work, if different from artist.
382  copyright -- name of copyright holder.
383  creation_time-- date when the file was created, preferably in ISO 8601.
384  date -- date when the work was created, preferably in ISO 8601.
385  disc -- number of a subset, e.g. disc in a multi-disc collection.
386  encoder -- name/settings of the software/hardware that produced the file.
387  encoded_by -- person/group who created the file.
388  filename -- original name of the file.
389  genre -- <self-evident>.
390  language -- main language in which the work is performed, preferably
391  in ISO 639-2 format. Multiple languages can be specified by
392  separating them with commas.
393  performer -- artist who performed the work, if different from artist.
394  E.g for "Also sprach Zarathustra", artist would be "Richard
395  Strauss" and performer "London Philharmonic Orchestra".
396  publisher -- name of the label/publisher.
397  service_name -- name of the service in broadcasting (channel name).
398  service_provider -- name of the service provider in broadcasting.
399  title -- name of the work.
400  track -- number of this work in the set, can be in form current/total.
401  variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
402  @endverbatim
403  *
404  * Look in the examples section for an application example how to use the Metadata API.
405  *
406  * @}
407  */
408 
409 /* packet functions */
410 
411 
412 /**
413  * Allocate and read the payload of a packet and initialize its
414  * fields with default values.
415  *
416  * @param s associated IO context
417  * @param pkt packet
418  * @param size desired payload size
419  * @return >0 (read size) if OK, AVERROR_xxx otherwise
420  */
422 
423 
424 /**
425  * Read data and append it to the current content of the AVPacket.
426  * If pkt->size is 0 this is identical to av_get_packet.
427  * Note that this uses av_grow_packet and thus involves a realloc
428  * which is inefficient. Thus this function should only be used
429  * when there is no reasonable way to know (an upper bound of)
430  * the final size.
431  *
432  * @param s associated IO context
433  * @param pkt packet
434  * @param size amount of data to read
435  * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
436  * will not be lost even if an error occurs.
437  */
439 
440 /*************************************************/
441 /* input/output formats */
442 
443 struct AVCodecTag;
444 
445 /**
446  * This structure contains the data a format has to probe a file.
447  */
448 typedef struct AVProbeData {
449  const char *filename;
450  unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
451  int buf_size; /**< Size of buf except extra allocated bytes */
452  const char *mime_type; /**< mime_type, when known. */
453 } AVProbeData;
454 
455 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
456 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
457 
458 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
459 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type
460 #define AVPROBE_SCORE_MAX 100 ///< maximum score
461 
462 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
463 
464 /// Demuxer will use avio_open, no opened file should be provided by the caller.
465 #define AVFMT_NOFILE 0x0001
466 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
467 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
468 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
469 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
470 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
471 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
472 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
473 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
474 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
475 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
476 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
477 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
478 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
479 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
480  increasing timestamps, but they must
481  still be monotonic */
482 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
483  timestamps. If not set the timestamp
484  will be shifted in av_write_frame and
485  av_interleaved_write_frame so they
486  start from 0.
487  The user or muxer can override this through
488  AVFormatContext.avoid_negative_ts
489  */
490 
491 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
492 
493 /**
494  * @addtogroup lavf_encoding
495  * @{
496  */
497 typedef struct AVOutputFormat {
498  const char *name;
499  /**
500  * Descriptive name for the format, meant to be more human-readable
501  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
502  * to define it.
503  */
504  const char *long_name;
505  const char *mime_type;
506  const char *extensions; /**< comma-separated filename extensions */
507  /* output support */
508  enum AVCodecID audio_codec; /**< default audio codec */
509  enum AVCodecID video_codec; /**< default video codec */
510  enum AVCodecID subtitle_codec; /**< default subtitle codec */
511  /**
512  * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER,
513  * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
514  * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
515  * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
516  */
517  int flags;
519  /**
520  * List of supported codec_id-codec_tag pairs, ordered by "better
521  * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
522  */
523  const struct AVCodecTag * const *codec_tag;
524 
525 
526  const AVClass *priv_class; ///< AVClass for the private context
527 
528  /*****************************************************************
529  * No fields below this line are part of the public API. They
530  * may not be used outside of libavformat and can be changed and
531  * removed at will.
532  * New public fields should be added right above.
533  *****************************************************************
534  */
536  /**
537  * size of private data so that it can be allocated in the wrapper
538  */
539  int priv_data_size;
540 
541  int (*write_header)(struct AVFormatContext *);
542  /**
543  * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
544  * pkt can be NULL in order to flush data buffered in the muxer.
545  * When flushing, return 0 if there still is more data to flush,
546  * or 1 if everything was flushed and there is no more buffered
547  * data.
548  */
551  /**
552  * Currently only used to set pixel format if not YUV420P.
553  */
555  AVPacket *in, int flush);
556  /**
557  * Test if the given codec can be stored in this container.
558  *
559  * @return 1 if the codec is supported, 0 if it is not.
560  * A negative number if unknown.
561  * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
562  */
563  int (*query_codec)(enum AVCodecID id, int std_compliance);
564 
565  void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
566  int64_t *dts, int64_t *wall);
567  /**
568  * Allows sending messages from application to device.
569  */
570  int (*control_message)(struct AVFormatContext *s, int type,
571  void *data, size_t data_size);
573  /**
574  * Write an uncoded AVFrame.
575  *
576  * See av_write_uncoded_frame() for details.
577  *
578  * The library will free *frame afterwards, but the muxer can prevent it
579  * by setting the pointer to NULL.
580  */
581  int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
582  AVFrame **frame, unsigned flags);
583  /**
584  * Returns device list with it properties.
585  * @see avdevice_list_devices() for more details.
586  */
587  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
588  /**
589  * Initialize device capabilities submodule.
590  * @see avdevice_capabilities_create() for more details.
591  */
592  int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
593  /**
594  * Free device capabilities submodule.
595  * @see avdevice_capabilities_free() for more details.
596  */
597  int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
598  enum AVCodecID data_codec; /**< default data codec */
599  /**
600  * Initialize format. May allocate data here, and set any AVFormatContext or
601  * AVStream parameters that need to be set before packets are sent.
602  * This method must not write output.
603  *
604  * Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure
605  *
606  * Any allocations made here must be freed in deinit().
607  */
608  int (*init)(struct AVFormatContext *);
609  /**
610  * Deinitialize format. If present, this is called whenever the muxer is being
611  * destroyed, regardless of whether or not the header has been written.
612  *
613  * If a trailer is being written, this is called after write_trailer().
614  *
615  * This is called if init() fails as well.
616  */
617  void (*deinit)(struct AVFormatContext *);
618  /**
619  * Set up any necessary bitstream filtering and extract any extra data needed
620  * for the global header.
621  * Return 0 if more packets from this stream must be checked; 1 if not.
622  */
623  int (*check_bitstream)(struct AVFormatContext *, const AVPacket *pkt);
625 /**
626  * @}
627  */
628 
629 /**
630  * @addtogroup lavf_decoding
631  * @{
632  */
633 typedef struct AVInputFormat {
634  /**
635  * A comma separated list of short names for the format. New names
636  * may be appended with a minor bump.
637  */
638  const char *name;
639 
640  /**
641  * Descriptive name for the format, meant to be more human-readable
642  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
643  * to define it.
644  */
645  const char *long_name;
646 
647  /**
648  * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
649  * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
650  * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
651  */
652  int flags;
653 
654  /**
655  * If extensions are defined, then no probe is done. You should
656  * usually not use extension format guessing because it is not
657  * reliable enough
658  */
659  const char *extensions;
660 
661  const struct AVCodecTag * const *codec_tag;
662 
663  const AVClass *priv_class; ///< AVClass for the private context
664 
665  /**
666  * Comma-separated list of mime types.
667  * It is used check for matching mime types while probing.
668  * @see av_probe_input_format2
669  */
670  const char *mime_type;
671 
672  /*****************************************************************
673  * No fields below this line are part of the public API. They
674  * may not be used outside of libavformat and can be changed and
675  * removed at will.
676  * New public fields should be added right above.
677  *****************************************************************
678  */
680 
681  /**
682  * Raw demuxers store their codec ID here.
683  */
684  int raw_codec_id;
685 
686  /**
687  * Size of private data so that it can be allocated in the wrapper.
688  */
689  int priv_data_size;
690 
691  /**
692  * Tell if a given file has a chance of being parsed as this format.
693  * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
694  * big so you do not have to check for that unless you need more.
695  */
696  int (*read_probe)(AVProbeData *);
697 
698  /**
699  * Read the format header and initialize the AVFormatContext
700  * structure. Return 0 if OK. 'avformat_new_stream' should be
701  * called to create new streams.
702  */
703  int (*read_header)(struct AVFormatContext *);
704 
705  /**
706  * Read one packet and put it in 'pkt'. pts and flags are also
707  * set. 'avformat_new_stream' can be called only if the flag
708  * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
709  * background thread).
710  * @return 0 on success, < 0 on error.
711  * When returning an error, pkt must not have been allocated
712  * or must be freed before returning
713  */
714  int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
715 
716  /**
717  * Close the stream. The AVFormatContext and AVStreams are not
718  * freed by this function
719  */
720  int (*read_close)(struct AVFormatContext *);
721 
722  /**
723  * Seek to a given timestamp relative to the frames in
724  * stream component stream_index.
725  * @param stream_index Must not be -1.
726  * @param flags Selects which direction should be preferred if no exact
727  * match is available.
728  * @return >= 0 on success (but not necessarily the new offset)
729  */
730  int (*read_seek)(struct AVFormatContext *,
731  int stream_index, int64_t timestamp, int flags);
732 
733  /**
734  * Get the next timestamp in stream[stream_index].time_base units.
735  * @return the timestamp or AV_NOPTS_VALUE if an error occurred
736  */
737  int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
738  int64_t *pos, int64_t pos_limit);
740  /**
741  * Start/resume playing - only meaningful if using a network-based format
742  * (RTSP).
743  */
744  int (*read_play)(struct AVFormatContext *);
745 
746  /**
747  * Pause playing - only meaningful if using a network-based format
748  * (RTSP).
749  */
750  int (*read_pause)(struct AVFormatContext *);
751 
752  /**
753  * Seek to timestamp ts.
754  * Seeking will be done so that the point from which all active streams
755  * can be presented successfully will be closest to ts and within min/max_ts.
756  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
757  */
758  int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
760  /**
761  * Returns device list with it properties.
762  * @see avdevice_list_devices() for more details.
763  */
764  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
765 
766  /**
767  * Initialize device capabilities submodule.
768  * @see avdevice_capabilities_create() for more details.
769  */
770  int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
771 
772  /**
773  * Free device capabilities submodule.
774  * @see avdevice_capabilities_free() for more details.
775  */
776  int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
777 } AVInputFormat;
778 /**
779  * @}
780  */
781 
782 enum AVStreamParseType {
784  AVSTREAM_PARSE_FULL, /**< full parsing and repack */
785  AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
786  AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
787  AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
788  AVSTREAM_PARSE_FULL_RAW, /**< full parsing and repack with timestamp and position generation by parser for raw
789  this assumes that each packet in the file contains no demuxer level headers and
790  just codec level data, otherwise position generation would fail */
791 };
793 typedef struct AVIndexEntry {
794  int64_t pos;
795  int64_t timestamp; /**<
796  * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
797  * when seeking to this entry. That means preferable PTS on keyframe based formats.
798  * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
799  * is known
800  */
801 #define AVINDEX_KEYFRAME 0x0001
802 #define AVINDEX_DISCARD_FRAME 0x0002 /**
803  * Flag is used to indicate which frame should be discarded after decoding.
804  */
805  int flags:2;
806  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).
807  int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
808 } AVIndexEntry;
809 
810 #define AV_DISPOSITION_DEFAULT 0x0001
811 #define AV_DISPOSITION_DUB 0x0002
812 #define AV_DISPOSITION_ORIGINAL 0x0004
813 #define AV_DISPOSITION_COMMENT 0x0008
814 #define AV_DISPOSITION_LYRICS 0x0010
815 #define AV_DISPOSITION_KARAOKE 0x0020
817 /**
818  * Track should be used during playback by default.
819  * Useful for subtitle track that should be displayed
820  * even when user did not explicitly ask for subtitles.
821  */
822 #define AV_DISPOSITION_FORCED 0x0040
823 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
824 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
825 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
826 /**
827  * The stream is stored in the file as an attached picture/"cover art" (e.g.
828  * APIC frame in ID3v2). The first (usually only) packet associated with it
829  * will be returned among the first few packets read from the file unless
830  * seeking takes place. It can also be accessed at any time in
831  * AVStream.attached_pic.
832  */
833 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
834 /**
835  * The stream is sparse, and contains thumbnail images, often corresponding
836  * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
837  */
838 #define AV_DISPOSITION_TIMED_THUMBNAILS 0x0800
839 
840 typedef struct AVStreamInternal AVStreamInternal;
841 
842 /**
843  * To specify text track kind (different from subtitles default).
844  */
845 #define AV_DISPOSITION_CAPTIONS 0x10000
846 #define AV_DISPOSITION_DESCRIPTIONS 0x20000
847 #define AV_DISPOSITION_METADATA 0x40000
848 #define AV_DISPOSITION_DEPENDENT 0x80000 ///< dependent audio stream (mix_type=0 in mpegts)
849 
850 /**
851  * Options for behavior on timestamp wrap detection.
852  */
853 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
854 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
855 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
857 /**
858  * Stream structure.
859  * New fields can be added to the end with minor version bumps.
860  * Removal, reordering and changes to existing fields require a major
861  * version bump.
862  * sizeof(AVStream) must not be used outside libav*.
863  */
864 typedef struct AVStream {
865  int index; /**< stream index in AVFormatContext */
866  /**
867  * Format-specific stream ID.
868  * decoding: set by libavformat
869  * encoding: set by the user, replaced by libavformat if left unset
870  */
871  int id;
872 #if FF_API_LAVF_AVCTX
873  /**
874  * @deprecated use the codecpar struct instead
875  */
877  AVCodecContext *codec;
878 #endif
879  void *priv_data;
881  /**
882  * This is the fundamental unit of time (in seconds) in terms
883  * of which frame timestamps are represented.
884  *
885  * decoding: set by libavformat
886  * encoding: May be set by the caller before avformat_write_header() to
887  * provide a hint to the muxer about the desired timebase. In
888  * avformat_write_header(), the muxer will overwrite this field
889  * with the timebase that will actually be used for the timestamps
890  * written into the file (which may or may not be related to the
891  * user-provided one, depending on the format).
892  */
893  AVRational time_base;
894 
895  /**
896  * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
897  * Only set this if you are absolutely 100% sure that the value you set
898  * it to really is the pts of the first frame.
899  * This may be undefined (AV_NOPTS_VALUE).
900  * @note The ASF header does NOT contain a correct start_time the ASF
901  * demuxer must NOT set this.
902  */
903  int64_t start_time;
904 
905  /**
906  * Decoding: duration of the stream, in stream time base.
907  * If a source file does not specify a duration, but does specify
908  * a bitrate, this value will be estimated from bitrate and file size.
909  *
910  * Encoding: May be set by the caller before avformat_write_header() to
911  * provide a hint to the muxer about the estimated duration.
912  */
913  int64_t duration;
914 
915  int64_t nb_frames; ///< number of frames in this stream if known or 0
916 
917  int disposition; /**< AV_DISPOSITION_* bit field */
918 
919  enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
920 
921  /**
922  * sample aspect ratio (0 if unknown)
923  * - encoding: Set by user.
924  * - decoding: Set by libavformat.
925  */
926  AVRational sample_aspect_ratio;
927 
928  AVDictionary *metadata;
929 
930  /**
931  * Average framerate
932  *
933  * - demuxing: May be set by libavformat when creating the stream or in
934  * avformat_find_stream_info().
935  * - muxing: May be set by the caller before avformat_write_header().
936  */
937  AVRational avg_frame_rate;
938 
939  /**
940  * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
941  * will contain the attached picture.
942  *
943  * decoding: set by libavformat, must not be modified by the caller.
944  * encoding: unused
945  */
946  AVPacket attached_pic;
947 
948  /**
949  * An array of side data that applies to the whole stream (i.e. the
950  * container does not allow it to change between packets).
951  *
952  * There may be no overlap between the side data in this array and side data
953  * in the packets. I.e. a given side data is either exported by the muxer
954  * (demuxing) / set by the caller (muxing) in this array, then it never
955  * appears in the packets, or the side data is exported / sent through
956  * the packets (always in the first packet where the value becomes known or
957  * changes), then it does not appear in this array.
958  *
959  * - demuxing: Set by libavformat when the stream is created.
960  * - muxing: May be set by the caller before avformat_write_header().
961  *
962  * Freed by libavformat in avformat_free_context().
963  *
964  * @see av_format_inject_global_side_data()
965  */
966  AVPacketSideData *side_data;
967  /**
968  * The number of elements in the AVStream.side_data array.
969  */
970  int nb_side_data;
971 
972  /**
973  * Flags for the user to detect events happening on the stream. Flags must
974  * be cleared by the user once the event has been handled.
975  * A combination of AVSTREAM_EVENT_FLAG_*.
976  */
977  int event_flags;
978 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
980  /**
981  * Real base framerate of the stream.
982  * This is the lowest framerate with which all timestamps can be
983  * represented accurately (it is the least common multiple of all
984  * framerates in the stream). Note, this value is just a guess!
985  * For example, if the time base is 1/90000 and all frames have either
986  * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
987  */
988  AVRational r_frame_rate;
989 
990 #if FF_API_LAVF_FFSERVER
991  /**
992  * String containing pairs of key and values describing recommended encoder configuration.
993  * Pairs are separated by ','.
994  * Keys are separated from values by '='.
995  *
996  * @deprecated unused
997  */
999  char *recommended_encoder_configuration;
1000 #endif
1001 
1002  /**
1003  * Codec parameters associated with this stream. Allocated and freed by
1004  * libavformat in avformat_new_stream() and avformat_free_context()
1005  * respectively.
1006  *
1007  * - demuxing: filled by libavformat on stream creation or in
1008  * avformat_find_stream_info()
1009  * - muxing: filled by the caller before avformat_write_header()
1010  */
1011  AVCodecParameters *codecpar;
1012 
1013  /*****************************************************************
1014  * All fields below this line are not part of the public API. They
1015  * may not be used outside of libavformat and can be changed and
1016  * removed at will.
1017  * Internal note: be aware that physically removing these fields
1018  * will break ABI. Replace removed fields with dummy fields, and
1019  * add new fields to AVStreamInternal.
1020  *****************************************************************
1021  */
1022 
1023 #define MAX_STD_TIMEBASES (30*12+30+3+6)
1024  /**
1025  * Stream information used internally by avformat_find_stream_info()
1026  */
1027  struct {
1028  int64_t last_dts;
1029  int64_t duration_gcd;
1030  int duration_count;
1031  int64_t rfps_duration_sum;
1032  double (*duration_error)[2][MAX_STD_TIMEBASES];
1033  int64_t codec_info_duration;
1034  int64_t codec_info_duration_fields;
1035  int frame_delay_evidence;
1036 
1037  /**
1038  * 0 -> decoder has not been searched for yet.
1039  * >0 -> decoder found
1040  * <0 -> decoder with codec_id == -found_decoder has not been found
1041  */
1042  int found_decoder;
1044  int64_t last_duration;
1045 
1046  /**
1047  * Those are used for average framerate estimation.
1048  */
1049  int64_t fps_first_dts;
1050  int fps_first_dts_idx;
1051  int64_t fps_last_dts;
1052  int fps_last_dts_idx;
1054  } *info;
1055 
1056  int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
1057 
1058  // Timestamp generation support:
1059  /**
1060  * Timestamp corresponding to the last dts sync point.
1061  *
1062  * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
1063  * a DTS is received from the underlying container. Otherwise set to
1064  * AV_NOPTS_VALUE by default.
1065  */
1066  int64_t first_dts;
1067  int64_t cur_dts;
1068  int64_t last_IP_pts;
1069  int last_IP_duration;
1070 
1071  /**
1072  * Number of packets to buffer for codec probing
1073  */
1074  int probe_packets;
1076  /**
1077  * Number of frames that have been demuxed during avformat_find_stream_info()
1078  */
1079  int codec_info_nb_frames;
1080 
1081  /* av_read_frame() support */
1082  enum AVStreamParseType need_parsing;
1084 
1085  /**
1086  * last packet in packet_buffer for this stream when muxing.
1087  */
1088  struct AVPacketList *last_in_packet_buffer;
1089  AVProbeData probe_data;
1090 #define MAX_REORDER_DELAY 16
1091  int64_t pts_buffer[MAX_REORDER_DELAY+1];
1093  AVIndexEntry *index_entries; /**< Only used if the format does not
1094  support seeking natively. */
1095  int nb_index_entries;
1096  unsigned int index_entries_allocated_size;
1098  /**
1099  * Stream Identifier
1100  * This is the MPEG-TS stream identifier +1
1101  * 0 means unknown
1102  */
1103  int stream_identifier;
1105  int64_t interleaver_chunk_size;
1106  int64_t interleaver_chunk_duration;
1107 
1108  /**
1109  * stream probing state
1110  * -1 -> probing finished
1111  * 0 -> no probing requested
1112  * rest -> perform probing with request_probe being the minimum score to accept.
1113  * NOT PART OF PUBLIC API
1114  */
1115  int request_probe;
1116  /**
1117  * Indicates that everything up to the next keyframe
1118  * should be discarded.
1119  */
1120  int skip_to_keyframe;
1121 
1122  /**
1123  * Number of samples to skip at the start of the frame decoded from the next packet.
1124  */
1125  int skip_samples;
1126 
1127  /**
1128  * If not 0, the number of samples that should be skipped from the start of
1129  * the stream (the samples are removed from packets with pts==0, which also
1130  * assumes negative timestamps do not happen).
1131  * Intended for use with formats such as mp3 with ad-hoc gapless audio
1132  * support.
1133  */
1134  int64_t start_skip_samples;
1135 
1136  /**
1137  * If not 0, the first audio sample that should be discarded from the stream.
1138  * This is broken by design (needs global sample count), but can't be
1139  * avoided for broken by design formats such as mp3 with ad-hoc gapless
1140  * audio support.
1141  */
1142  int64_t first_discard_sample;
1144  /**
1145  * The sample after last sample that is intended to be discarded after
1146  * first_discard_sample. Works on frame boundaries only. Used to prevent
1147  * early EOF if the gapless info is broken (considered concatenated mp3s).
1148  */
1149  int64_t last_discard_sample;
1150 
1151  /**
1152  * Number of internally decoded frames, used internally in libavformat, do not access
1153  * its lifetime differs from info which is why it is not in that structure.
1154  */
1155  int nb_decoded_frames;
1156 
1157  /**
1158  * Timestamp offset added to timestamps before muxing
1159  * NOT PART OF PUBLIC API
1160  */
1161  int64_t mux_ts_offset;
1162 
1163  /**
1164  * Internal data to check for wrapping of the time stamp
1165  */
1166  int64_t pts_wrap_reference;
1167 
1168  /**
1169  * Options for behavior, when a wrap is detected.
1170  *
1171  * Defined by AV_PTS_WRAP_ values.
1172  *
1173  * If correction is enabled, there are two possibilities:
1174  * If the first time stamp is near the wrap point, the wrap offset
1175  * will be subtracted, which will create negative time stamps.
1176  * Otherwise the offset will be added.
1177  */
1178  int pts_wrap_behavior;
1179 
1180  /**
1181  * Internal data to prevent doing update_initial_durations() twice
1182  */
1183  int update_initial_durations_done;
1184 
1185  /**
1186  * Internal data to generate dts from pts
1187  */
1188  int64_t pts_reorder_error[MAX_REORDER_DELAY+1];
1189  uint8_t pts_reorder_error_count[MAX_REORDER_DELAY+1];
1190 
1191  /**
1192  * Internal data to analyze DTS and detect faulty mpeg streams
1193  */
1194  int64_t last_dts_for_order_check;
1195  uint8_t dts_ordered;
1196  uint8_t dts_misordered;
1198  /**
1199  * Internal data to inject global side data
1200  */
1201  int inject_global_side_data;
1202 
1203  /**
1204  * display aspect ratio (0 if unknown)
1205  * - encoding: unused
1206  * - decoding: Set by libavformat to calculate sample_aspect_ratio internally
1207  */
1208  AVRational display_aspect_ratio;
1209 
1210  /**
1211  * An opaque field for libavformat internal usage.
1212  * Must not be accessed in any way by callers.
1213  */
1214  AVStreamInternal *internal;
1215 } AVStream;
1216 
1217 #if FF_API_FORMAT_GET_SET
1218 /**
1219  * Accessors for some AVStream fields. These used to be provided for ABI
1220  * compatibility, and do not need to be used anymore.
1221  */
1223 AVRational av_stream_get_r_frame_rate(const AVStream *s);
1225 void av_stream_set_r_frame_rate(AVStream *s, AVRational r);
1226 #if FF_API_LAVF_FFSERVER
1228 char* av_stream_get_recommended_encoder_configuration(const AVStream *s);
1230 void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration);
1231 #endif
1232 #endif
1233 
1235 
1236 /**
1237  * Returns the pts of the last muxed packet + its duration
1238  *
1239  * the retuned value is undefined when used with a demuxer.
1240  */
1241 int64_t av_stream_get_end_pts(const AVStream *st);
1242 
1243 #define AV_PROGRAM_RUNNING 1
1244 
1245 /**
1246  * New fields can be added to the end with minor version bumps.
1247  * Removal, reordering and changes to existing fields require a major
1248  * version bump.
1249  * sizeof(AVProgram) must not be used outside libav*.
1250  */
1251 typedef struct AVProgram {
1252  int id;
1253  int flags;
1254  enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1255  unsigned int *stream_index;
1256  unsigned int nb_stream_indexes;
1257  AVDictionary *metadata;
1258 
1259  int program_num;
1260  int pmt_pid;
1261  int pcr_pid;
1263  /*****************************************************************
1264  * All fields below this line are not part of the public API. They
1265  * may not be used outside of libavformat and can be changed and
1266  * removed at will.
1267  * New public fields should be added right above.
1268  *****************************************************************
1269  */
1270  int64_t start_time;
1271  int64_t end_time;
1272 
1273  int64_t pts_wrap_reference; ///< reference dts for wrap detection
1274  int pts_wrap_behavior; ///< behavior on wrap detection
1275 } AVProgram;
1276 
1277 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1278  (streams are added dynamically) */
1279 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely
1280  not seekable, and attempts to call the
1281  seek function will fail. For some
1282  network protocols (e.g. HLS), this can
1283  change dynamically at runtime. */
1284 
1285 typedef struct AVChapter {
1286  int id; ///< unique ID to identify the chapter
1287  AVRational time_base; ///< time base in which the start/end timestamps are specified
1288  int64_t start, end; ///< chapter start/end time in time_base units
1289  AVDictionary *metadata;
1290 } AVChapter;
1291 
1292 
1293 /**
1294  * Callback used by devices to communicate with application.
1295  */
1296 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1297  void *data, size_t data_size);
1298 
1299 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
1302 /**
1303  * The duration of a video can be estimated through various ways, and this enum can be used
1304  * to know how the duration was estimated.
1305  */
1307  AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1308  AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1309  AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1310 };
1311 
1312 typedef struct AVFormatInternal AVFormatInternal;
1314 /**
1315  * Format I/O context.
1316  * New fields can be added to the end with minor version bumps.
1317  * Removal, reordering and changes to existing fields require a major
1318  * version bump.
1319  * sizeof(AVFormatContext) must not be used outside libav*, use
1320  * avformat_alloc_context() to create an AVFormatContext.
1321  *
1322  * Fields can be accessed through AVOptions (av_opt*),
1323  * the name string used matches the associated command line parameter name and
1324  * can be found in libavformat/options_table.h.
1325  * The AVOption/command line parameter names differ in some cases from the C
1326  * structure field names for historic reasons or brevity.
1327  */
1328 typedef struct AVFormatContext {
1329  /**
1330  * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1331  * Exports (de)muxer private options if they exist.
1332  */
1333  const AVClass *av_class;
1334 
1335  /**
1336  * The input container format.
1337  *
1338  * Demuxing only, set by avformat_open_input().
1339  */
1340  struct AVInputFormat *iformat;
1341 
1342  /**
1343  * The output container format.
1344  *
1345  * Muxing only, must be set by the caller before avformat_write_header().
1346  */
1347  struct AVOutputFormat *oformat;
1348 
1349  /**
1350  * Format private data. This is an AVOptions-enabled struct
1351  * if and only if iformat/oformat.priv_class is not NULL.
1352  *
1353  * - muxing: set by avformat_write_header()
1354  * - demuxing: set by avformat_open_input()
1355  */
1356  void *priv_data;
1357 
1358  /**
1359  * I/O context.
1360  *
1361  * - demuxing: either set by the user before avformat_open_input() (then
1362  * the user must close it manually) or set by avformat_open_input().
1363  * - muxing: set by the user before avformat_write_header(). The caller must
1364  * take care of closing / freeing the IO context.
1365  *
1366  * Do NOT set this field if AVFMT_NOFILE flag is set in
1367  * iformat/oformat.flags. In such a case, the (de)muxer will handle
1368  * I/O in some other way and this field will be NULL.
1369  */
1371 
1372  /* stream info */
1373  /**
1374  * Flags signalling stream properties. A combination of AVFMTCTX_*.
1375  * Set by libavformat.
1376  */
1377  int ctx_flags;
1378 
1379  /**
1380  * Number of elements in AVFormatContext.streams.
1381  *
1382  * Set by avformat_new_stream(), must not be modified by any other code.
1383  */
1384  unsigned int nb_streams;
1385  /**
1386  * A list of all streams in the file. New streams are created with
1387  * avformat_new_stream().
1388  *
1389  * - demuxing: streams are created by libavformat in avformat_open_input().
1390  * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1391  * appear in av_read_frame().
1392  * - muxing: streams are created by the user before avformat_write_header().
1393  *
1394  * Freed by libavformat in avformat_free_context().
1395  */
1396  AVStream **streams;
1397 
1398 #if FF_API_FORMAT_FILENAME
1399  /**
1400  * input or output filename
1401  *
1402  * - demuxing: set by avformat_open_input()
1403  * - muxing: may be set by the caller before avformat_write_header()
1404  *
1405  * @deprecated Use url instead.
1406  */
1408  char filename[1024];
1409 #endif
1411  /**
1412  * input or output URL. Unlike the old filename field, this field has no
1413  * length restriction.
1414  *
1415  * - demuxing: set by avformat_open_input(), initialized to an empty
1416  * string if url parameter was NULL in avformat_open_input().
1417  * - muxing: may be set by the caller before calling avformat_write_header()
1418  * (or avformat_init_output() if that is called first) to a string
1419  * which is freeable by av_free(). Set to an empty string if it
1420  * was NULL in avformat_init_output().
1421  *
1422  * Freed by libavformat in avformat_free_context().
1423  */
1424  char *url;
1425 
1426  /**
1427  * Position of the first frame of the component, in
1428  * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1429  * It is deduced from the AVStream values.
1430  *
1431  * Demuxing only, set by libavformat.
1432  */
1433  int64_t start_time;
1434 
1435  /**
1436  * Duration of the stream, in AV_TIME_BASE fractional
1437  * seconds. Only set this value if you know none of the individual stream
1438  * durations and also do not set any of them. This is deduced from the
1439  * AVStream values if not set.
1440  *
1441  * Demuxing only, set by libavformat.
1442  */
1443  int64_t duration;
1444 
1445  /**
1446  * Total stream bitrate in bit/s, 0 if not
1447  * available. Never set it directly if the file_size and the
1448  * duration are known as FFmpeg can compute it automatically.
1449  */
1450  int64_t bit_rate;
1451 
1452  unsigned int packet_size;
1453  int max_delay;
1454 
1455  /**
1456  * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1457  * Set by the user before avformat_open_input() / avformat_write_header().
1458  */
1459  int flags;
1460 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1461 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1462 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1463 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1464 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1465 #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
1466 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1467 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1468 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1469 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1470 /**
1471  * When muxing, try to avoid writing any random/volatile data to the output.
1472  * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1473  *
1474  * This flag is mainly intended for testing.
1475  */
1476 #define AVFMT_FLAG_BITEXACT 0x0400
1477 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload
1478 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1479 #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)
1480 #if FF_API_LAVF_KEEPSIDE_FLAG
1481 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Deprecated, does nothing.
1482 #endif
1483 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1484 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
1485 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
1486 
1487  /**
1488  * Maximum size of the data read from input for determining
1489  * the input container format.
1490  * Demuxing only, set by the caller before avformat_open_input().
1491  */
1492  int64_t probesize;
1494  /**
1495  * Maximum duration (in AV_TIME_BASE units) of the data read
1496  * from input in avformat_find_stream_info().
1497  * Demuxing only, set by the caller before avformat_find_stream_info().
1498  * Can be set to 0 to let avformat choose using a heuristic.
1499  */
1500  int64_t max_analyze_duration;
1501 
1502  const uint8_t *key;
1503  int keylen;
1504 
1505  unsigned int nb_programs;
1506  AVProgram **programs;
1507 
1508  /**
1509  * Forced video codec_id.
1510  * Demuxing: Set by user.
1511  */
1512  enum AVCodecID video_codec_id;
1513 
1514  /**
1515  * Forced audio codec_id.
1516  * Demuxing: Set by user.
1517  */
1518  enum AVCodecID audio_codec_id;
1520  /**
1521  * Forced subtitle codec_id.
1522  * Demuxing: Set by user.
1523  */
1524  enum AVCodecID subtitle_codec_id;
1525 
1526  /**
1527  * Maximum amount of memory in bytes to use for the index of each stream.
1528  * If the index exceeds this size, entries will be discarded as
1529  * needed to maintain a smaller size. This can lead to slower or less
1530  * accurate seeking (depends on demuxer).
1531  * Demuxers for which a full in-memory index is mandatory will ignore
1532  * this.
1533  * - muxing: unused
1534  * - demuxing: set by user
1535  */
1536  unsigned int max_index_size;
1537 
1538  /**
1539  * Maximum amount of memory in bytes to use for buffering frames
1540  * obtained from realtime capture devices.
1541  */
1542  unsigned int max_picture_buffer;
1543 
1544  /**
1545  * Number of chapters in AVChapter array.
1546  * When muxing, chapters are normally written in the file header,
1547  * so nb_chapters should normally be initialized before write_header
1548  * is called. Some muxers (e.g. mov and mkv) can also write chapters
1549  * in the trailer. To write chapters in the trailer, nb_chapters
1550  * must be zero when write_header is called and non-zero when
1551  * write_trailer is called.
1552  * - muxing: set by user
1553  * - demuxing: set by libavformat
1554  */
1555  unsigned int nb_chapters;
1556  AVChapter **chapters;
1557 
1558  /**
1559  * Metadata that applies to the whole file.
1560  *
1561  * - demuxing: set by libavformat in avformat_open_input()
1562  * - muxing: may be set by the caller before avformat_write_header()
1563  *
1564  * Freed by libavformat in avformat_free_context().
1565  */
1566  AVDictionary *metadata;
1567 
1568  /**
1569  * Start time of the stream in real world time, in microseconds
1570  * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1571  * stream was captured at this real world time.
1572  * - muxing: Set by the caller before avformat_write_header(). If set to
1573  * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1574  * be used.
1575  * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1576  * the value may become known after some number of frames
1577  * have been received.
1578  */
1579  int64_t start_time_realtime;
1581  /**
1582  * The number of frames used for determining the framerate in
1583  * avformat_find_stream_info().
1584  * Demuxing only, set by the caller before avformat_find_stream_info().
1585  */
1586  int fps_probe_size;
1587 
1588  /**
1589  * Error recognition; higher values will detect more errors but may
1590  * misdetect some more or less valid parts as errors.
1591  * Demuxing only, set by the caller before avformat_open_input().
1592  */
1593  int error_recognition;
1594 
1595  /**
1596  * Custom interrupt callbacks for the I/O layer.
1597  *
1598  * demuxing: set by the user before avformat_open_input().
1599  * muxing: set by the user before avformat_write_header()
1600  * (mainly useful for AVFMT_NOFILE formats). The callback
1601  * should also be passed to avio_open2() if it's used to
1602  * open the file.
1603  */
1604  AVIOInterruptCB interrupt_callback;
1605 
1606  /**
1607  * Flags to enable debugging.
1608  */
1609  int debug;
1610 #define FF_FDEBUG_TS 0x0001
1611 
1612  /**
1613  * Maximum buffering duration for interleaving.
1614  *
1615  * To ensure all the streams are interleaved correctly,
1616  * av_interleaved_write_frame() will wait until it has at least one packet
1617  * for each stream before actually writing any packets to the output file.
1618  * When some streams are "sparse" (i.e. there are large gaps between
1619  * successive packets), this can result in excessive buffering.
1620  *
1621  * This field specifies the maximum difference between the timestamps of the
1622  * first and the last packet in the muxing queue, above which libavformat
1623  * will output a packet regardless of whether it has queued a packet for all
1624  * the streams.
1625  *
1626  * Muxing only, set by the caller before avformat_write_header().
1627  */
1628  int64_t max_interleave_delta;
1629 
1630  /**
1631  * Allow non-standard and experimental extension
1632  * @see AVCodecContext.strict_std_compliance
1633  */
1634  int strict_std_compliance;
1635 
1636  /**
1637  * Flags for the user to detect events happening on the file. Flags must
1638  * be cleared by the user once the event has been handled.
1639  * A combination of AVFMT_EVENT_FLAG_*.
1640  */
1641  int event_flags;
1642 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
1643 
1644  /**
1645  * Maximum number of packets to read while waiting for the first timestamp.
1646  * Decoding only.
1647  */
1648  int max_ts_probe;
1649 
1650  /**
1651  * Avoid negative timestamps during muxing.
1652  * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1653  * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use)
1654  * - muxing: Set by user
1655  * - demuxing: unused
1656  */
1657  int avoid_negative_ts;
1658 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1659 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1660 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1661 
1662  /**
1663  * Transport stream id.
1664  * This will be moved into demuxer private options. Thus no API/ABI compatibility
1665  */
1666  int ts_id;
1667 
1668  /**
1669  * Audio preload in microseconds.
1670  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1671  * - encoding: Set by user
1672  * - decoding: unused
1673  */
1674  int audio_preload;
1675 
1676  /**
1677  * Max chunk time in microseconds.
1678  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1679  * - encoding: Set by user
1680  * - decoding: unused
1681  */
1682  int max_chunk_duration;
1683 
1684  /**
1685  * Max chunk size in bytes
1686  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1687  * - encoding: Set by user
1688  * - decoding: unused
1689  */
1690  int max_chunk_size;
1691 
1692  /**
1693  * forces the use of wallclock timestamps as pts/dts of packets
1694  * This has undefined results in the presence of B frames.
1695  * - encoding: unused
1696  * - decoding: Set by user
1697  */
1698  int use_wallclock_as_timestamps;
1699 
1700  /**
1701  * avio flags, used to force AVIO_FLAG_DIRECT.
1702  * - encoding: unused
1703  * - decoding: Set by user
1704  */
1705  int avio_flags;
1706 
1707  /**
1708  * The duration field can be estimated through various ways, and this field can be used
1709  * to know how the duration was estimated.
1710  * - encoding: unused
1711  * - decoding: Read by user
1712  */
1713  enum AVDurationEstimationMethod duration_estimation_method;
1714 
1715  /**
1716  * Skip initial bytes when opening stream
1717  * - encoding: unused
1718  * - decoding: Set by user
1719  */
1720  int64_t skip_initial_bytes;
1721 
1722  /**
1723  * Correct single timestamp overflows
1724  * - encoding: unused
1725  * - decoding: Set by user
1726  */
1727  unsigned int correct_ts_overflow;
1728 
1729  /**
1730  * Force seeking to any (also non key) frames.
1731  * - encoding: unused
1732  * - decoding: Set by user
1733  */
1734  int seek2any;
1735 
1736  /**
1737  * Flush the I/O context after each packet.
1738  * - encoding: Set by user
1739  * - decoding: unused
1740  */
1741  int flush_packets;
1742 
1743  /**
1744  * format probing score.
1745  * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1746  * the format.
1747  * - encoding: unused
1748  * - decoding: set by avformat, read by user
1749  */
1750  int probe_score;
1751 
1752  /**
1753  * number of bytes to read maximally to identify format.
1754  * - encoding: unused
1755  * - decoding: set by user
1756  */
1757  int format_probesize;
1758 
1759  /**
1760  * ',' separated list of allowed decoders.
1761  * If NULL then all are allowed
1762  * - encoding: unused
1763  * - decoding: set by user
1764  */
1765  char *codec_whitelist;
1766 
1767  /**
1768  * ',' separated list of allowed demuxers.
1769  * If NULL then all are allowed
1770  * - encoding: unused
1771  * - decoding: set by user
1772  */
1773  char *format_whitelist;
1774 
1775  /**
1776  * An opaque field for libavformat internal usage.
1777  * Must not be accessed in any way by callers.
1778  */
1779  AVFormatInternal *internal;
1780 
1781  /**
1782  * IO repositioned flag.
1783  * This is set by avformat when the underlaying IO context read pointer
1784  * is repositioned, for example when doing byte based seeking.
1785  * Demuxers can use the flag to detect such changes.
1786  */
1787  int io_repositioned;
1788 
1789  /**
1790  * Forced video codec.
1791  * This allows forcing a specific decoder, even when there are multiple with
1792  * the same codec_id.
1793  * Demuxing: Set by user
1794  */
1796 
1797  /**
1798  * Forced audio codec.
1799  * This allows forcing a specific decoder, even when there are multiple with
1800  * the same codec_id.
1801  * Demuxing: Set by user
1802  */
1804 
1805  /**
1806  * Forced subtitle codec.
1807  * This allows forcing a specific decoder, even when there are multiple with
1808  * the same codec_id.
1809  * Demuxing: Set by user
1810  */
1812 
1813  /**
1814  * Forced data codec.
1815  * This allows forcing a specific decoder, even when there are multiple with
1816  * the same codec_id.
1817  * Demuxing: Set by user
1818  */
1820 
1821  /**
1822  * Number of bytes to be written as padding in a metadata header.
1823  * Demuxing: Unused.
1824  * Muxing: Set by user via av_format_set_metadata_header_padding.
1825  */
1826  int metadata_header_padding;
1827 
1828  /**
1829  * User data.
1830  * This is a place for some private data of the user.
1831  */
1832  void *opaque;
1834  /**
1835  * Callback used by devices to communicate with application.
1836  */
1837  av_format_control_message control_message_cb;
1838 
1839  /**
1840  * Output timestamp offset, in microseconds.
1841  * Muxing: set by user
1842  */
1843  int64_t output_ts_offset;
1844 
1845  /**
1846  * dump format separator.
1847  * can be ", " or "\n " or anything else
1848  * - muxing: Set by user.
1849  * - demuxing: Set by user.
1850  */
1851  uint8_t *dump_separator;
1852 
1853  /**
1854  * Forced Data codec_id.
1855  * Demuxing: Set by user.
1856  */
1857  enum AVCodecID data_codec_id;
1858 
1859 #if FF_API_OLD_OPEN_CALLBACKS
1860  /**
1861  * Called to open further IO contexts when needed for demuxing.
1862  *
1863  * This can be set by the user application to perform security checks on
1864  * the URLs before opening them.
1865  * The function should behave like avio_open2(), AVFormatContext is provided
1866  * as contextual information and to reach AVFormatContext.opaque.
1867  *
1868  * If NULL then some simple checks are used together with avio_open2().
1869  *
1870  * Must not be accessed directly from outside avformat.
1871  * @See av_format_set_open_cb()
1872  *
1873  * Demuxing: Set by user.
1874  *
1875  * @deprecated Use io_open and io_close.
1876  */
1878  int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options);
1879 #endif
1880 
1881  /**
1882  * ',' separated list of allowed protocols.
1883  * - encoding: unused
1884  * - decoding: set by user
1885  */
1886  char *protocol_whitelist;
1887 
1888  /**
1889  * A callback for opening new IO streams.
1890  *
1891  * Whenever a muxer or a demuxer needs to open an IO stream (typically from
1892  * avformat_open_input() for demuxers, but for certain formats can happen at
1893  * other times as well), it will call this callback to obtain an IO context.
1894  *
1895  * @param s the format context
1896  * @param pb on success, the newly opened IO context should be returned here
1897  * @param url the url to open
1898  * @param flags a combination of AVIO_FLAG_*
1899  * @param options a dictionary of additional options, with the same
1900  * semantics as in avio_open2()
1901  * @return 0 on success, a negative AVERROR code on failure
1902  *
1903  * @note Certain muxers and demuxers do nesting, i.e. they open one or more
1904  * additional internal format contexts. Thus the AVFormatContext pointer
1905  * passed to this callback may be different from the one facing the caller.
1906  * It will, however, have the same 'opaque' field.
1907  */
1908  int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url,
1909  int flags, AVDictionary **options);
1910 
1911  /**
1912  * A callback for closing the streams opened with AVFormatContext.io_open().
1913  */
1914  void (*io_close)(struct AVFormatContext *s, AVIOContext *pb);
1915 
1916  /**
1917  * ',' separated list of disallowed protocols.
1918  * - encoding: unused
1919  * - decoding: set by user
1920  */
1921  char *protocol_blacklist;
1923  /**
1924  * The maximum number of streams.
1925  * - encoding: unused
1926  * - decoding: set by user
1927  */
1929 } AVFormatContext;
1930 
1931 #if FF_API_FORMAT_GET_SET
1932 /**
1933  * Accessors for some AVFormatContext fields. These used to be provided for ABI
1934  * compatibility, and do not need to be used anymore.
1935  */
1937 int av_format_get_probe_score(const AVFormatContext *s);
1939 AVCodec * av_format_get_video_codec(const AVFormatContext *s);
1941 void av_format_set_video_codec(AVFormatContext *s, AVCodec *c);
1943 AVCodec * av_format_get_audio_codec(const AVFormatContext *s);
1945 void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c);
1947 AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s);
1949 void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c);
1951 AVCodec * av_format_get_data_codec(const AVFormatContext *s);
1953 void av_format_set_data_codec(AVFormatContext *s, AVCodec *c);
1955 int av_format_get_metadata_header_padding(const AVFormatContext *s);
1957 void av_format_set_metadata_header_padding(AVFormatContext *s, int c);
1959 void * av_format_get_opaque(const AVFormatContext *s);
1961 void av_format_set_opaque(AVFormatContext *s, void *opaque);
1963 av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s);
1965 void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback);
1966 #if FF_API_OLD_OPEN_CALLBACKS
1967 attribute_deprecated AVOpenCallback av_format_get_open_cb(const AVFormatContext *s);
1968 attribute_deprecated void av_format_set_open_cb(AVFormatContext *s, AVOpenCallback callback);
1969 #endif
1970 #endif
1971 
1972 /**
1973  * This function will cause global side data to be injected in the next packet
1974  * of each stream as well as after any subsequent seek.
1975  */
1977 
1978 /**
1979  * Returns the method used to set ctx->duration.
1980  *
1981  * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1982  */
1984 
1985 typedef struct AVPacketList {
1986  AVPacket pkt;
1987  struct AVPacketList *next;
1988 } AVPacketList;
1989 
1990 
1991 /**
1992  * @defgroup lavf_core Core functions
1993  * @ingroup libavf
1994  *
1995  * Functions for querying libavformat capabilities, allocating core structures,
1996  * etc.
1997  * @{
1998  */
2000 /**
2001  * Return the LIBAVFORMAT_VERSION_INT constant.
2002  */
2003 unsigned avformat_version(void);
2004 
2005 /**
2006  * Return the libavformat build-time configuration.
2007  */
2008 const char *avformat_configuration(void);
2009 
2010 /**
2011  * Return the libavformat license.
2012  */
2013 const char *avformat_license(void);
2014 
2015 #if FF_API_NEXT
2016 /**
2017  * Initialize libavformat and register all the muxers, demuxers and
2018  * protocols. If you do not call this function, then you can select
2019  * exactly which formats you want to support.
2020  *
2021  * @see av_register_input_format()
2022  * @see av_register_output_format()
2023  */
2025 void av_register_all(void);
2026 
2028 void av_register_input_format(AVInputFormat *format);
2030 void av_register_output_format(AVOutputFormat *format);
2031 #endif
2032 
2033 /**
2034  * Do global initialization of network libraries. This is optional,
2035  * and not recommended anymore.
2036  *
2037  * This functions only exists to work around thread-safety issues
2038  * with older GnuTLS or OpenSSL libraries. If libavformat is linked
2039  * to newer versions of those libraries, or if you do not use them,
2040  * calling this function is unnecessary. Otherwise, you need to call
2041  * this function before any other threads using them are started.
2042  *
2043  * This function will be deprecated once support for older GnuTLS and
2044  * OpenSSL libraries is removed, and this function has no purpose
2045  * anymore.
2046  */
2047 int avformat_network_init(void);
2048 
2049 /**
2050  * Undo the initialization done by avformat_network_init. Call it only
2051  * once for each time you called avformat_network_init.
2052  */
2053 int avformat_network_deinit(void);
2054 
2055 #if FF_API_NEXT
2056 /**
2057  * If f is NULL, returns the first registered input format,
2058  * if f is non-NULL, returns the next registered input format after f
2059  * or NULL if f is the last one.
2060  */
2062 AVInputFormat *av_iformat_next(const AVInputFormat *f);
2063 
2064 /**
2065  * If f is NULL, returns the first registered output format,
2066  * if f is non-NULL, returns the next registered output format after f
2067  * or NULL if f is the last one.
2068  */
2070 AVOutputFormat *av_oformat_next(const AVOutputFormat *f);
2071 #endif
2072 
2073 /**
2074  * Iterate over all registered muxers.
2075  *
2076  * @param opaque a pointer where libavformat will store the iteration state. Must
2077  * point to NULL to start the iteration.
2078  *
2079  * @return the next registered muxer or NULL when the iteration is
2080  * finished
2081  */
2082 const AVOutputFormat *av_muxer_iterate(void **opaque);
2083 
2084 /**
2085  * Iterate over all registered demuxers.
2086  *
2087  * @param opaque a pointer where libavformat will store the iteration state. Must
2088  * point to NULL to start the iteration.
2089  *
2090  * @return the next registered demuxer or NULL when the iteration is
2091  * finished
2092  */
2093 const AVInputFormat *av_demuxer_iterate(void **opaque);
2094 
2095 /**
2096  * Allocate an AVFormatContext.
2097  * avformat_free_context() can be used to free the context and everything
2098  * allocated by the framework within it.
2099  */
2101 
2102 /**
2103  * Free an AVFormatContext and all its streams.
2104  * @param s context to free
2105  */
2107 
2108 /**
2109  * Get the AVClass for AVFormatContext. It can be used in combination with
2110  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2111  *
2112  * @see av_opt_find().
2113  */
2114 const AVClass *avformat_get_class(void);
2115 
2116 /**
2117  * Add a new stream to a media file.
2118  *
2119  * When demuxing, it is called by the demuxer in read_header(). If the
2120  * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2121  * be called in read_packet().
2122  *
2123  * When muxing, should be called by the user before avformat_write_header().
2124  *
2125  * User is required to call avcodec_close() and avformat_free_context() to
2126  * clean up the allocation by avformat_new_stream().
2127  *
2128  * @param s media file handle
2129  * @param c If non-NULL, the AVCodecContext corresponding to the new stream
2130  * will be initialized to use this codec. This is needed for e.g. codec-specific
2131  * defaults to be set, so codec should be provided if it is known.
2132  *
2133  * @return newly created stream or NULL on error.
2134  */
2136 
2137 /**
2138  * Wrap an existing array as stream side data.
2139  *
2140  * @param st stream
2141  * @param type side information type
2142  * @param data the side data array. It must be allocated with the av_malloc()
2143  * family of functions. The ownership of the data is transferred to
2144  * st.
2145  * @param size side information size
2146  * @return zero on success, a negative AVERROR code on failure. On failure,
2147  * the stream is unchanged and the data remains owned by the caller.
2148  */
2150  uint8_t *data, size_t size);
2151 
2152 /**
2153  * Allocate new information from stream.
2154  *
2155  * @param stream stream
2156  * @param type desired side information type
2157  * @param size side information size
2158  * @return pointer to fresh allocated data or NULL otherwise
2159  */
2161  enum AVPacketSideDataType type, int size);
2162 /**
2163  * Get side information from stream.
2164  *
2165  * @param stream stream
2166  * @param type desired side information type
2167  * @param size pointer for side information size to store (optional)
2168  * @return pointer to data if present or NULL otherwise
2169  */
2171  enum AVPacketSideDataType type, int *size);
2172 
2174 
2175 /**
2176  * @}
2177  */
2178 
2179 
2180 /**
2181  * Allocate an AVFormatContext for an output format.
2182  * avformat_free_context() can be used to free the context and
2183  * everything allocated by the framework within it.
2184  *
2185  * @param *ctx is set to the created format context, or to NULL in
2186  * case of failure
2187  * @param oformat format to use for allocating the context, if NULL
2188  * format_name and filename are used instead
2189  * @param format_name the name of output format to use for allocating the
2190  * context, if NULL filename is used instead
2191  * @param filename the name of the filename to use for allocating the
2192  * context, may be NULL
2193  * @return >= 0 in case of success, a negative AVERROR code in case of
2194  * failure
2195  */
2197  const char *format_name, const char *filename);
2198 
2199 /**
2200  * @addtogroup lavf_decoding
2201  * @{
2202  */
2203 
2204 /**
2205  * Find AVInputFormat based on the short name of the input format.
2206  */
2207 AVInputFormat *av_find_input_format(const char *short_name);
2208 
2209 /**
2210  * Guess the file format.
2211  *
2212  * @param pd data to be probed
2213  * @param is_opened Whether the file is already opened; determines whether
2214  * demuxers with or without AVFMT_NOFILE are probed.
2215  */
2216 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
2217 
2218 /**
2219  * Guess the file format.
2220  *
2221  * @param pd data to be probed
2222  * @param is_opened Whether the file is already opened; determines whether
2223  * demuxers with or without AVFMT_NOFILE are probed.
2224  * @param score_max A probe score larger that this is required to accept a
2225  * detection, the variable is set to the actual detection
2226  * score afterwards.
2227  * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2228  * to retry with a larger probe buffer.
2229  */
2230 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
2231 
2232 /**
2233  * Guess the file format.
2234  *
2235  * @param is_opened Whether the file is already opened; determines whether
2236  * demuxers with or without AVFMT_NOFILE are probed.
2237  * @param score_ret The score of the best detection.
2238  */
2239 AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
2240 
2241 /**
2242  * Probe a bytestream to determine the input format. Each time a probe returns
2243  * with a score that is too low, the probe buffer size is increased and another
2244  * attempt is made. When the maximum probe size is reached, the input format
2245  * with the highest score is returned.
2246  *
2247  * @param pb the bytestream to probe
2248  * @param fmt the input format is put here
2249  * @param url the url of the stream
2250  * @param logctx the log context
2251  * @param offset the offset within the bytestream to probe from
2252  * @param max_probe_size the maximum probe buffer size (zero for default)
2253  * @return the score in case of success, a negative value corresponding to an
2254  * the maximal score is AVPROBE_SCORE_MAX
2255  * AVERROR code otherwise
2256  */
2258  const char *url, void *logctx,
2259  unsigned int offset, unsigned int max_probe_size);
2260 
2261 /**
2262  * Like av_probe_input_buffer2() but returns 0 on success
2263  */
2265  const char *url, void *logctx,
2266  unsigned int offset, unsigned int max_probe_size);
2267 
2268 /**
2269  * Open an input stream and read the header. The codecs are not opened.
2270  * The stream must be closed with avformat_close_input().
2271  *
2272  * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
2273  * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
2274  * function and written into ps.
2275  * Note that a user-supplied AVFormatContext will be freed on failure.
2276  * @param url URL of the stream to open.
2277  * @param fmt If non-NULL, this parameter forces a specific input format.
2278  * Otherwise the format is autodetected.
2279  * @param options A dictionary filled with AVFormatContext and demuxer-private options.
2280  * On return this parameter will be destroyed and replaced with a dict containing
2281  * options that were not found. May be NULL.
2282  *
2283  * @return 0 on success, a negative AVERROR on failure.
2284  *
2285  * @note If you want to use custom IO, preallocate the format context and set its pb field.
2286  */
2288 
2291 
2292 /**
2293  * Read packets of a media file to get stream information. This
2294  * is useful for file formats with no headers such as MPEG. This
2295  * function also computes the real framerate in case of MPEG-2 repeat
2296  * frame mode.
2297  * The logical file position is not changed by this function;
2298  * examined packets may be buffered for later processing.
2299  *
2300  * @param ic media file handle
2301  * @param options If non-NULL, an ic.nb_streams long array of pointers to
2302  * dictionaries, where i-th member contains options for
2303  * codec corresponding to i-th stream.
2304  * On return each dictionary will be filled with options that were not found.
2305  * @return >=0 if OK, AVERROR_xxx on error
2306  *
2307  * @note this function isn't guaranteed to open all the codecs, so
2308  * options being non-empty at return is a perfectly normal behavior.
2309  *
2310  * @todo Let the user decide somehow what information is needed so that
2311  * we do not waste time getting stuff the user does not need.
2312  */
2314 
2315 /**
2316  * Find the programs which belong to a given stream.
2317  *
2318  * @param ic media file handle
2319  * @param last the last found program, the search will start after this
2320  * program, or from the beginning if it is NULL
2321  * @param s stream index
2322  * @return the next program which belongs to s, NULL if no program is found or
2323  * the last program is not among the programs of ic.
2324  */
2326 
2327 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
2328 
2329 /**
2330  * Find the "best" stream in the file.
2331  * The best stream is determined according to various heuristics as the most
2332  * likely to be what the user expects.
2333  * If the decoder parameter is non-NULL, av_find_best_stream will find the
2334  * default decoder for the stream's codec; streams for which no decoder can
2335  * be found are ignored.
2336  *
2337  * @param ic media file handle
2338  * @param type stream type: video, audio, subtitles, etc.
2339  * @param wanted_stream_nb user-requested stream number,
2340  * or -1 for automatic selection
2341  * @param related_stream try to find a stream related (eg. in the same
2342  * program) to this one, or -1 if none
2343  * @param decoder_ret if non-NULL, returns the decoder for the
2344  * selected stream
2345  * @param flags flags; none are currently defined
2346  * @return the non-negative stream number in case of success,
2347  * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2348  * could be found,
2349  * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2350  * @note If av_find_best_stream returns successfully and decoder_ret is not
2351  * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2352  */
2354  enum AVMediaType type,
2355  int wanted_stream_nb,
2356  int related_stream,
2357  AVCodec **decoder_ret,
2358  int flags);
2359 
2360 /**
2361  * Return the next frame of a stream.
2362  * This function returns what is stored in the file, and does not validate
2363  * that what is there are valid frames for the decoder. It will split what is
2364  * stored in the file into frames and return one for each call. It will not
2365  * omit invalid data between valid frames so as to give the decoder the maximum
2366  * information possible for decoding.
2367  *
2368  * If pkt->buf is NULL, then the packet is valid until the next
2369  * av_read_frame() or until avformat_close_input(). Otherwise the packet
2370  * is valid indefinitely. In both cases the packet must be freed with
2371  * av_packet_unref when it is no longer needed. For video, the packet contains
2372  * exactly one frame. For audio, it contains an integer number of frames if each
2373  * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
2374  * have a variable size (e.g. MPEG audio), then it contains one frame.
2375  *
2376  * pkt->pts, pkt->dts and pkt->duration are always set to correct
2377  * values in AVStream.time_base units (and guessed if the format cannot
2378  * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2379  * has B-frames, so it is better to rely on pkt->dts if you do not
2380  * decompress the payload.
2381  *
2382  * @return 0 if OK, < 0 on error or end of file
2383  */
2385 
2386 /**
2387  * Seek to the keyframe at timestamp.
2388  * 'timestamp' in 'stream_index'.
2389  *
2390  * @param s media file handle
2391  * @param stream_index If stream_index is (-1), a default
2392  * stream is selected, and timestamp is automatically converted
2393  * from AV_TIME_BASE units to the stream specific time_base.
2394  * @param timestamp Timestamp in AVStream.time_base units
2395  * or, if no stream is specified, in AV_TIME_BASE units.
2396  * @param flags flags which select direction and seeking mode
2397  * @return >= 0 on success
2398  */
2399 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2400  int flags);
2401 
2402 /**
2403  * Seek to timestamp ts.
2404  * Seeking will be done so that the point from which all active streams
2405  * can be presented successfully will be closest to ts and within min/max_ts.
2406  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2407  *
2408  * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2409  * are the file position (this may not be supported by all demuxers).
2410  * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2411  * in the stream with stream_index (this may not be supported by all demuxers).
2412  * Otherwise all timestamps are in units of the stream selected by stream_index
2413  * or if stream_index is -1, in AV_TIME_BASE units.
2414  * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2415  * keyframes (this may not be supported by all demuxers).
2416  * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2417  *
2418  * @param s media file handle
2419  * @param stream_index index of the stream which is used as time base reference
2420  * @param min_ts smallest acceptable timestamp
2421  * @param ts target timestamp
2422  * @param max_ts largest acceptable timestamp
2423  * @param flags flags
2424  * @return >=0 on success, error code otherwise
2425  *
2426  * @note This is part of the new seek API which is still under construction.
2427  * Thus do not use this yet. It may change at any time, do not expect
2428  * ABI compatibility yet!
2429  */
2430 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2431 
2432 /**
2433  * Discard all internally buffered data. This can be useful when dealing with
2434  * discontinuities in the byte stream. Generally works only with formats that
2435  * can resync. This includes headerless formats like MPEG-TS/TS but should also
2436  * work with NUT, Ogg and in a limited way AVI for example.
2437  *
2438  * The set of streams, the detected duration, stream parameters and codecs do
2439  * not change when calling this function. If you want a complete reset, it's
2440  * better to open a new AVFormatContext.
2441  *
2442  * This does not flush the AVIOContext (s->pb). If necessary, call
2443  * avio_flush(s->pb) before calling this function.
2444  *
2445  * @param s media file handle
2446  * @return >=0 on success, error code otherwise
2447  */
2449 
2450 /**
2451  * Start playing a network-based stream (e.g. RTSP stream) at the
2452  * current position.
2453  */
2455 
2456 /**
2457  * Pause a network-based stream (e.g. RTSP stream).
2458  *
2459  * Use av_read_play() to resume it.
2460  */
2462 
2463 /**
2464  * Close an opened input AVFormatContext. Free it and all its contents
2465  * and set *s to NULL.
2466  */
2468 /**
2469  * @}
2470  */
2471 
2472 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2473 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2474 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2475 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2476 
2477 /**
2478  * @addtogroup lavf_encoding
2479  * @{
2480  */
2481 
2482 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2483 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2484 
2485 /**
2486  * Allocate the stream private data and write the stream header to
2487  * an output media file.
2488  *
2489  * @param s Media file handle, must be allocated with avformat_alloc_context().
2490  * Its oformat field must be set to the desired output format;
2491  * Its pb field must be set to an already opened AVIOContext.
2492  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2493  * On return this parameter will be destroyed and replaced with a dict containing
2494  * options that were not found. May be NULL.
2495  *
2496  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init,
2497  * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init,
2498  * negative AVERROR on failure.
2499  *
2500  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2501  */
2504 
2505 /**
2506  * Allocate the stream private data and initialize the codec, but do not write the header.
2507  * May optionally be used before avformat_write_header to initialize stream parameters
2508  * before actually writing the header.
2509  * If using this function, do not pass the same options to avformat_write_header.
2510  *
2511  * @param s Media file handle, must be allocated with avformat_alloc_context().
2512  * Its oformat field must be set to the desired output format;
2513  * Its pb field must be set to an already opened AVIOContext.
2514  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2515  * On return this parameter will be destroyed and replaced with a dict containing
2516  * options that were not found. May be NULL.
2517  *
2518  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec requires avformat_write_header to fully initialize,
2519  * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec has been fully initialized,
2520  * negative AVERROR on failure.
2521  *
2522  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2523  */
2526 
2527 /**
2528  * Write a packet to an output media file.
2529  *
2530  * This function passes the packet directly to the muxer, without any buffering
2531  * or reordering. The caller is responsible for correctly interleaving the
2532  * packets if the format requires it. Callers that want libavformat to handle
2533  * the interleaving should call av_interleaved_write_frame() instead of this
2534  * function.
2535  *
2536  * @param s media file handle
2537  * @param pkt The packet containing the data to be written. Note that unlike
2538  * av_interleaved_write_frame(), this function does not take
2539  * ownership of the packet passed to it (though some muxers may make
2540  * an internal reference to the input packet).
2541  * <br>
2542  * This parameter can be NULL (at any time, not just at the end), in
2543  * order to immediately flush data buffered within the muxer, for
2544  * muxers that buffer up data internally before writing it to the
2545  * output.
2546  * <br>
2547  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2548  * set to the index of the corresponding stream in @ref
2549  * AVFormatContext.streams "s->streams".
2550  * <br>
2551  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2552  * must be set to correct values in the stream's timebase (unless the
2553  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2554  * they can be set to AV_NOPTS_VALUE).
2555  * The dts for subsequent packets passed to this function must be strictly
2556  * increasing when compared in their respective timebases (unless the
2557  * output format is flagged with the AVFMT_TS_NONSTRICT, then they
2558  * merely have to be nondecreasing). @ref AVPacket.duration
2559  * "duration") should also be set if known.
2560  * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2561  *
2562  * @see av_interleaved_write_frame()
2563  */
2565 
2566 /**
2567  * Write a packet to an output media file ensuring correct interleaving.
2568  *
2569  * This function will buffer the packets internally as needed to make sure the
2570  * packets in the output file are properly interleaved in the order of
2571  * increasing dts. Callers doing their own interleaving should call
2572  * av_write_frame() instead of this function.
2573  *
2574  * Using this function instead of av_write_frame() can give muxers advance
2575  * knowledge of future packets, improving e.g. the behaviour of the mp4
2576  * muxer for VFR content in fragmenting mode.
2577  *
2578  * @param s media file handle
2579  * @param pkt The packet containing the data to be written.
2580  * <br>
2581  * If the packet is reference-counted, this function will take
2582  * ownership of this reference and unreference it later when it sees
2583  * fit.
2584  * The caller must not access the data through this reference after
2585  * this function returns. If the packet is not reference-counted,
2586  * libavformat will make a copy.
2587  * <br>
2588  * This parameter can be NULL (at any time, not just at the end), to
2589  * flush the interleaving queues.
2590  * <br>
2591  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2592  * set to the index of the corresponding stream in @ref
2593  * AVFormatContext.streams "s->streams".
2594  * <br>
2595  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2596  * must be set to correct values in the stream's timebase (unless the
2597  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2598  * they can be set to AV_NOPTS_VALUE).
2599  * The dts for subsequent packets in one stream must be strictly
2600  * increasing (unless the output format is flagged with the
2601  * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2602  * @ref AVPacket.duration "duration") should also be set if known.
2603  *
2604  * @return 0 on success, a negative AVERROR on error. Libavformat will always
2605  * take care of freeing the packet, even if this function fails.
2606  *
2607  * @see av_write_frame(), AVFormatContext.max_interleave_delta
2608  */
2610 
2611 /**
2612  * Write an uncoded frame to an output media file.
2613  *
2614  * The frame must be correctly interleaved according to the container
2615  * specification; if not, then av_interleaved_write_frame() must be used.
2616  *
2617  * See av_interleaved_write_frame() for details.
2618  */
2619 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2620  AVFrame *frame);
2621 
2622 /**
2623  * Write an uncoded frame to an output media file.
2624  *
2625  * If the muxer supports it, this function makes it possible to write an AVFrame
2626  * structure directly, without encoding it into a packet.
2627  * It is mostly useful for devices and similar special muxers that use raw
2628  * video or PCM data and will not serialize it into a byte stream.
2629  *
2630  * To test whether it is possible to use it with a given muxer and stream,
2631  * use av_write_uncoded_frame_query().
2632  *
2633  * The caller gives up ownership of the frame and must not access it
2634  * afterwards.
2635  *
2636  * @return >=0 for success, a negative code on error
2637  */
2638 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
2639  AVFrame *frame);
2640 
2641 /**
2642  * Test whether a muxer supports uncoded frame.
2643  *
2644  * @return >=0 if an uncoded frame can be written to that muxer and stream,
2645  * <0 if not
2646  */
2647 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2648 
2649 /**
2650  * Write the stream trailer to an output media file and free the
2651  * file private data.
2652  *
2653  * May only be called after a successful call to avformat_write_header.
2654  *
2655  * @param s media file handle
2656  * @return 0 if OK, AVERROR_xxx on error
2657  */
2659 
2660 /**
2661  * Return the output format in the list of registered output formats
2662  * which best matches the provided parameters, or return NULL if
2663  * there is no match.
2664  *
2665  * @param short_name if non-NULL checks if short_name matches with the
2666  * names of the registered formats
2667  * @param filename if non-NULL checks if filename terminates with the
2668  * extensions of the registered formats
2669  * @param mime_type if non-NULL checks if mime_type matches with the
2670  * MIME type of the registered formats
2671  */
2672 AVOutputFormat *av_guess_format(const char *short_name,
2673  const char *filename,
2674  const char *mime_type);
2675 
2676 /**
2677  * Guess the codec ID based upon muxer and filename.
2678  */
2679 enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
2680  const char *filename, const char *mime_type,
2681  enum AVMediaType type);
2682 
2683 /**
2684  * Get timing information for the data currently output.
2685  * The exact meaning of "currently output" depends on the format.
2686  * It is mostly relevant for devices that have an internal buffer and/or
2687  * work in real time.
2688  * @param s media file handle
2689  * @param stream stream in the media file
2690  * @param[out] dts DTS of the last packet output for the stream, in stream
2691  * time_base units
2692  * @param[out] wall absolute time when that packet whas output,
2693  * in microsecond
2694  * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
2695  * Note: some formats or devices may not allow to measure dts and wall
2696  * atomically.
2697  */
2698 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2699  int64_t *dts, int64_t *wall);
2700 
2701 
2702 /**
2703  * @}
2704  */
2705 
2706 
2707 /**
2708  * @defgroup lavf_misc Utility functions
2709  * @ingroup libavf
2710  * @{
2711  *
2712  * Miscellaneous utility functions related to both muxing and demuxing
2713  * (or neither).
2714  */
2715 
2716 /**
2717  * Send a nice hexadecimal dump of a buffer to the specified file stream.
2718  *
2719  * @param f The file stream pointer where the dump should be sent to.
2720  * @param buf buffer
2721  * @param size buffer size
2722  *
2723  * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2724  */
2725 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2726 
2727 /**
2728  * Send a nice hexadecimal dump of a buffer to the log.
2729  *
2730  * @param avcl A pointer to an arbitrary struct of which the first field is a
2731  * pointer to an AVClass struct.
2732  * @param level The importance level of the message, lower values signifying
2733  * higher importance.
2734  * @param buf buffer
2735  * @param size buffer size
2736  *
2737  * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2738  */
2739 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2740 
2741 /**
2742  * Send a nice dump of a packet to the specified file stream.
2743  *
2744  * @param f The file stream pointer where the dump should be sent to.
2745  * @param pkt packet to dump
2746  * @param dump_payload True if the payload must be displayed, too.
2747  * @param st AVStream that the packet belongs to
2748  */
2749 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2750 
2751 
2752 /**
2753  * Send a nice dump of a packet to the log.
2754  *
2755  * @param avcl A pointer to an arbitrary struct of which the first field is a
2756  * pointer to an AVClass struct.
2757  * @param level The importance level of the message, lower values signifying
2758  * higher importance.
2759  * @param pkt packet to dump
2760  * @param dump_payload True if the payload must be displayed, too.
2761  * @param st AVStream that the packet belongs to
2762  */
2763 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2764  const AVStream *st);
2765 
2766 /**
2767  * Get the AVCodecID for the given codec tag tag.
2768  * If no codec id is found returns AV_CODEC_ID_NONE.
2769  *
2770  * @param tags list of supported codec_id-codec_tag pairs, as stored
2771  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2772  * @param tag codec tag to match to a codec ID
2773  */
2774 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2775 
2776 /**
2777  * Get the codec tag for the given codec id id.
2778  * If no codec tag is found returns 0.
2779  *
2780  * @param tags list of supported codec_id-codec_tag pairs, as stored
2781  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2782  * @param id codec ID to match to a codec tag
2783  */
2784 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2785 
2786 /**
2787  * Get the codec tag for the given codec id.
2788  *
2789  * @param tags list of supported codec_id - codec_tag pairs, as stored
2790  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2791  * @param id codec id that should be searched for in the list
2792  * @param tag A pointer to the found tag
2793  * @return 0 if id was not found in tags, > 0 if it was found
2794  */
2795 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2796  unsigned int *tag);
2797 
2799 
2800 /**
2801  * Get the index for a specific timestamp.
2802  *
2803  * @param st stream that the timestamp belongs to
2804  * @param timestamp timestamp to retrieve the index for
2805  * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2806  * to the timestamp which is <= the requested one, if backward
2807  * is 0, then it will be >=
2808  * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2809  * @return < 0 if no such timestamp could be found
2810  */
2811 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2812 
2813 /**
2814  * Add an index entry into a sorted list. Update the entry if the list
2815  * already contains it.
2816  *
2817  * @param timestamp timestamp in the time base of the given stream
2818  */
2819 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2820  int size, int distance, int flags);
2821 
2822 
2823 /**
2824  * Split a URL string into components.
2825  *
2826  * The pointers to buffers for storing individual components may be null,
2827  * in order to ignore that component. Buffers for components not found are
2828  * set to empty strings. If the port is not found, it is set to a negative
2829  * value.
2830  *
2831  * @param proto the buffer for the protocol
2832  * @param proto_size the size of the proto buffer
2833  * @param authorization the buffer for the authorization
2834  * @param authorization_size the size of the authorization buffer
2835  * @param hostname the buffer for the host name
2836  * @param hostname_size the size of the hostname buffer
2837  * @param port_ptr a pointer to store the port number in
2838  * @param path the buffer for the path
2839  * @param path_size the size of the path buffer
2840  * @param url the URL to split
2841  */
2842 void av_url_split(char *proto, int proto_size,
2843  char *authorization, int authorization_size,
2844  char *hostname, int hostname_size,
2845  int *port_ptr,
2846  char *path, int path_size,
2847  const char *url);
2848 
2849 
2850 /**
2851  * Print detailed information about the input or output format, such as
2852  * duration, bitrate, streams, container, programs, metadata, side data,
2853  * codec and time base.
2854  *
2855  * @param ic the context to analyze
2856  * @param index index of the stream to dump information about
2857  * @param url the URL to print, such as source or destination file
2858  * @param is_output Select whether the specified context is an input(0) or output(1)
2859  */
2861  int index,
2862  const char *url,
2863  int is_output);
2864 
2865 
2866 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
2867 
2868 /**
2869  * Return in 'buf' the path with '%d' replaced by a number.
2870  *
2871  * Also handles the '%0nd' format where 'n' is the total number
2872  * of digits and '%%'.
2873  *
2874  * @param buf destination buffer
2875  * @param buf_size destination buffer size
2876  * @param path numbered sequence string
2877  * @param number frame number
2878  * @param flags AV_FRAME_FILENAME_FLAGS_*
2879  * @return 0 if OK, -1 on format error
2880  */
2881 int av_get_frame_filename2(char *buf, int buf_size,
2882  const char *path, int number, int flags);
2883 
2884 int av_get_frame_filename(char *buf, int buf_size,
2885  const char *path, int number);
2886 
2887 /**
2888  * Check whether filename actually is a numbered sequence generator.
2889  *
2890  * @param filename possible numbered sequence string
2891  * @return 1 if a valid numbered sequence string, 0 otherwise
2892  */
2893 int av_filename_number_test(const char *filename);
2894 
2895 /**
2896  * Generate an SDP for an RTP session.
2897  *
2898  * Note, this overwrites the id values of AVStreams in the muxer contexts
2899  * for getting unique dynamic payload types.
2900  *
2901  * @param ac array of AVFormatContexts describing the RTP streams. If the
2902  * array is composed by only one context, such context can contain
2903  * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2904  * all the contexts in the array (an AVCodecContext per RTP stream)
2905  * must contain only one AVStream.
2906  * @param n_files number of AVCodecContexts contained in ac
2907  * @param buf buffer where the SDP will be stored (must be allocated by
2908  * the caller)
2909  * @param size the size of the buffer
2910  * @return 0 if OK, AVERROR_xxx on error
2911  */
2912 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2913 
2914 /**
2915  * Return a positive value if the given filename has one of the given
2916  * extensions, 0 otherwise.
2917  *
2918  * @param filename file name to check against the given extensions
2919  * @param extensions a comma-separated list of filename extensions
2920  */
2921 int av_match_ext(const char *filename, const char *extensions);
2922 
2923 /**
2924  * Test if the given container can store a codec.
2925  *
2926  * @param ofmt container to check for compatibility
2927  * @param codec_id codec to potentially store in container
2928  * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2929  *
2930  * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2931  * A negative number if this information is not available.
2932  */
2934  int std_compliance);
2935 
2936 /**
2937  * @defgroup riff_fourcc RIFF FourCCs
2938  * @{
2939  * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2940  * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2941  * following code:
2942  * @code
2943  * uint32_t tag = MKTAG('H', '2', '6', '4');
2944  * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2945  * enum AVCodecID id = av_codec_get_id(table, tag);
2946  * @endcode
2947  */
2948 /**
2949  * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2950  */
2951 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2952 /**
2953  * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2954  */
2955 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2956 /**
2957  * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2958  */
2959 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2960 /**
2961  * @return the table mapping MOV FourCCs for audio to AVCodecID.
2962  */
2963 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2964 
2965 /**
2966  * @}
2967  */
2968 
2969 /**
2970  * Guess the sample aspect ratio of a frame, based on both the stream and the
2971  * frame aspect ratio.
2972  *
2973  * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2974  * is set by the demuxer, these two may not be equal. This function tries to
2975  * return the value that you should use if you would like to display the frame.
2976  *
2977  * Basic logic is to use the stream aspect ratio if it is set to something sane
2978  * otherwise use the frame aspect ratio. This way a container setting, which is
2979  * usually easy to modify can override the coded value in the frames.
2980  *
2981  * @param format the format context which the stream is part of
2982  * @param stream the stream which the frame is part of
2983  * @param frame the frame with the aspect ratio to be determined
2984  * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2985  */
2987 
2988 /**
2989  * Guess the frame rate, based on both the container and codec information.
2990  *
2991  * @param ctx the format context which the stream is part of
2992  * @param stream the stream which the frame is part of
2993  * @param frame the frame for which the frame rate should be determined, may be NULL
2994  * @return the guessed (valid) frame rate, 0/1 if no idea
2995  */
2997 
2998 /**
2999  * Check if the stream st contained in s is matched by the stream specifier
3000  * spec.
3001  *
3002  * See the "stream specifiers" chapter in the documentation for the syntax
3003  * of spec.
3004  *
3005  * @return >0 if st is matched by spec;
3006  * 0 if st is not matched by spec;
3007  * AVERROR code if spec is invalid
3008  *
3009  * @note A stream specifier can match several streams in the format.
3010  */
3012  const char *spec);
3013 
3015 
3016 #if FF_API_OLD_BSF
3017 /**
3018  * Apply a list of bitstream filters to a packet.
3019  *
3020  * @param codec AVCodecContext, usually from an AVStream
3021  * @param pkt the packet to apply filters to. If, on success, the returned
3022  * packet has size == 0 and side_data_elems == 0, it indicates that
3023  * the packet should be dropped
3024  * @param bsfc a NULL-terminated list of filters to apply
3025  * @return >=0 on success;
3026  * AVERROR code on failure
3027  */
3029 int av_apply_bitstream_filters(AVCodecContext *codec, AVPacket *pkt,
3030  AVBitStreamFilterContext *bsfc);
3031 #endif
3032 
3033 enum AVTimebaseSource {
3034  AVFMT_TBCF_AUTO = -1,
3037 #if FF_API_R_FRAME_RATE
3038  AVFMT_TBCF_R_FRAMERATE,
3039 #endif
3040 };
3041 
3042 /**
3043  * Transfer internal timing information from one stream to another.
3044  *
3045  * This function is useful when doing stream copy.
3046  *
3047  * @param ofmt target output format for ost
3048  * @param ost output stream which needs timings copy and adjustments
3049  * @param ist reference input stream to copy timings from
3050  * @param copy_tb define from where the stream codec timebase needs to be imported
3051  */
3053  AVStream *ost, const AVStream *ist,
3054  enum AVTimebaseSource copy_tb);
3055 
3056 /**
3057  * Get the internal codec timebase from a stream.
3058  *
3059  * @param st input stream to extract the timebase from
3060  */
3062 
3063 /**
3064  * @}
3065  */
3066 
3067 #endif /* AVFORMAT_AVFORMAT_H */
const char * name
Definition: avisynth_c.h:775
void av_url_split(char *proto, int proto_size, char *authorization, int authorization_size, char *hostname, int hostname_size, int *port_ptr, char *path, int path_size, const char *url)
Split a URL string into components.
Definition: utils.c:4691
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:679
int(* io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, AVDictionary **options)
A callback for opening new IO streams.
Definition: avformat.h:1922
full parsing and interpolation of timestamps for frames not starting on a packet boundary ...
Definition: avformat.h:795
const char * s
Definition: avisynth_c.h:768
Bytestream IO Context.
Definition: avio.h:161
void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st)
Send a nice dump of a packet to the specified file stream.
Definition: dump.c:108
Buffered I/O operations.
AVPacketSideDataType
Definition: avcodec.h:1143
static const char * format[]
Definition: af_aiir.c:311
int size
attribute_deprecated int av_demuxer_open(AVFormatContext *ic)
Definition: utils.c:395
This structure describes decoded (raw) audio or video data.
Definition: frame.h:218
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
Definition: mux.c:1185
static void flush(AVCodecContext *avctx)
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
Definition: utils.c:2038
int av_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file.
Definition: mux.c:878
const char * fmt
Definition: avisynth_c.h:769
const char * filename
Definition: avformat.h:449
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame)
Guess the sample aspect ratio of a frame, based on both the stream and the frame aspect ratio...
Definition: utils.c:4985
enum AVCodecID video_codec
default video codec
Definition: avformat.h:518
int av_get_output_timestamp(struct AVFormatContext *s, int stream, int64_t *dts, int64_t *wall)
Get timing information for the data currently output.
Definition: mux.c:1302
AVInputFormat * av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret)
Guess the file format.
Definition: format.c:128
const char * key
static AVPacket pkt
int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index)
Test whether a muxer supports uncoded frame.
Definition: mux.c:1379
int priv_data_size
Size of private data so that it can be allocated in the wrapper.
Definition: avformat.h:698
AVCodec.
Definition: avcodec.h:3408
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3876
enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext *ctx)
Returns the method used to set ctx->duration.
Definition: options.c:163
Format I/O context.
Definition: avformat.h:1342
AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame)
Guess the frame rate, based on both the container and codec information.
Definition: utils.c:5008
static int query_codec(enum AVCodecID id, int std_compliance)
Definition: img2enc.c:198
const struct AVCodecTag * avformat_get_mov_audio_tags(void)
Definition: isom.c:652
Public dictionary API.
static int64_t start_time
Definition: ffplay.c:327
uint8_t
static int nb_streams
Definition: ffprobe.c:276
const struct AVCodecTag * avformat_get_riff_video_tags(void)
Definition: riff.c:576
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.
Definition: utils.c:66
const char * avformat_license(void)
Return the libavformat license.
Definition: utils.c:77
int avformat_transfer_internal_stream_timing_info(const AVOutputFormat *ofmt, AVStream *ost, const AVStream *ist, enum AVTimebaseSource copy_tb)
Transfer internal timing information from one stream to another.
Definition: utils.c:5685
int priv_data_size
size of private data so that it can be allocated in the wrapper
Definition: avformat.h:548
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st, const char *spec)
Check if the stream st contained in s is matched by the stream specifier spec.
Definition: utils.c:5029
AVDurationEstimationMethod
The duration of a video can be estimated through various ways, and this enum can be used to know how ...
Definition: avformat.h:1320
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4441
uint8_t * av_stream_get_side_data(const AVStream *stream, enum AVPacketSideDataType type, int *size)
Get side information from stream.
Definition: utils.c:5405
int64_t duration
Definition: movenc.c:63
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.
Definition: options.c:144
void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload, const AVStream *st)
Send a nice dump of a packet to the log.
Definition: dump.c:113
const char * avformat_configuration(void)
Return the libavformat build-time configuration.
Definition: utils.c:72
const char data[16]
Definition: mxf.c:90
#define MAX_REORDER_DELAY
Definition: avformat.h:1099
AVProgram * av_new_program(AVFormatContext *s, int id)
Definition: utils.c:4540
char * protocol_whitelist
&#39;,&#39; separated list of allowed protocols.
Definition: avformat.h:1900
static int flags
Definition: log.c:55
uint32_t tag
Definition: movenc.c:1455
int avformat_network_init(void)
Do global initialization of network libraries.
Definition: utils.c:4922
const struct AVCodecTag * avformat_get_riff_audio_tags(void)
Definition: riff.c:581
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
Generate an SDP for an RTP session.
Definition: sdp.c:841
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:310
int av_match_ext(const char *filename, const char *extensions)
Return a positive value if the given filename has one of the given extensions, 0 otherwise.
Definition: format.c:38
const AVClass * avformat_get_class(void)
Get the AVClass for AVFormatContext.
Definition: options.c:168
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.
Definition: format.c:222
static int interleave_packet(AVFormatContext *s, AVPacket *out, AVPacket *in, int flush)
Interleave an AVPacket correctly so it can be muxed.
Definition: mux.c:1174
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:797
Duration estimated from bitrate (less accurate)
Definition: avformat.h:1323
int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
Read data and append it to the current content of the AVPacket.
Definition: utils.c:320
const AVOutputFormat * av_muxer_iterate(void **opaque)
Iterate over all registered muxers.
Definition: allformats.c:492
const struct AVCodecTag * avformat_get_mov_video_tags(void)
Definition: isom.c:647
int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
Definition: mux.c:148
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.
Definition: dump.c:561
Callback for checking whether to abort blocking functions.
Definition: avio.h:58
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.
Definition: utils.c:4169
AVRational av_stream_get_codec_timebase(const AVStream *st)
Get the internal codec timebase from a stream.
Definition: utils.c:5747
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.
Definition: format.c:320
AVProgram * av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s)
Find the programs which belong to a given stream.
Definition: utils.c:4152
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: avcodec.h:215
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:2147
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:475
void av_hex_dump(FILE *f, const uint8_t *buf, int size)
Send a nice hexadecimal dump of a buffer to the specified file stream.
Definition: dump.c:74
struct AVCodecParser * parser
Definition: avcodec.h:5034
char * url
input or output URL.
Definition: avformat.h:1438
const char * r
Definition: vf_curves.c:111
struct AVCodecParserContext * av_stream_get_parser(const AVStream *s)
Definition: utils.c:149
int av_read_play(AVFormatContext *s)
Start playing a network-based stream (e.g.
Definition: utils.c:4236
static const uint8_t offset[127][2]
Definition: vf_spp.c:92
New fields can be added to the end with minor version bumps.
Definition: avformat.h:1260
AVInputFormat * av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max)
Guess the file format.
Definition: format.c:205
void * opaque
User data.
Definition: avformat.h:1846
Only parse headers, do not repack.
Definition: avformat.h:794
int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id, int std_compliance)
Test if the given container can store a codec.
Definition: utils.c:4904
static float distance(float x, float y, int band)
const char * mime_type
mime_type, when known.
Definition: avformat.h:452
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:451
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:450
void av_format_inject_global_side_data(AVFormatContext *s)
This function will cause global side data to be injected in the next packet of each stream as well as...
Definition: utils.c:154
int av_read_pause(AVFormatContext *s)
Pause a network-based stream (e.g.
Definition: utils.c:4245
AVInputFormat * av_find_input_format(const char *short_name)
Find AVInputFormat based on the short name of the input format.
Definition: format.c:118
static void callback(void *priv_data, int index, uint8_t *buf, int buf_size, int64_t time, enum dshowDeviceType devtype)
Definition: dshow.c:161
av_warn_unused_result int avformat_write_header(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and write the stream header to an output media file.
Definition: mux.c:508
void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx)
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:1310
int av_stream_add_side_data(AVStream *st, enum AVPacketSideDataType type, uint8_t *data, size_t size)
Wrap an existing array as stream side data.
Definition: utils.c:5420
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
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.
Definition: format.c:87
int max_streams
The maximum number of streams.
Definition: avformat.h:1942
int av_find_default_stream_index(AVFormatContext *s)
Definition: utils.c:1879
static int write_trailer(AVFormatContext *s1)
Definition: v4l2enc.c:94
Duration estimated from a stream with a known duration.
Definition: avformat.h:1322
AVFormatContext * ctx
Definition: movenc.c:48
uint8_t * av_stream_new_side_data(AVStream *stream, enum AVPacketSideDataType type, int size)
Allocate new information from stream.
Definition: utils.c:5456
AVOutputFormat * av_guess_format(const char *short_name, const char *filename, const char *mime_type)
Return the output format in the list of registered output formats which best matches the provided par...
Definition: format.c:51
enum AVCodecID codec_id
Definition: vaapi_decode.c:362
Libavformat version macros.
int(* AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Definition: avformat.h:1313
av_warn_unused_result int avformat_init_output(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and initialize the codec, but do not write the header.
Definition: mux.c:488
const AVInputFormat * av_demuxer_iterate(void **opaque)
Iterate over all registered demuxers.
Definition: allformats.c:509
int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
Definition: utils.c:4686
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
Stream structure.
Definition: avformat.h:873
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
int avformat_queue_attached_pictures(AVFormatContext *s)
Definition: utils.c:479
int avformat_network_deinit(void)
Undo the initialization done by avformat_network_init.
Definition: utils.c:4934
static AVInputFormat * iformat
Definition: ffprobe.c:253
Libavcodec external API header.
struct AVOutputFormat * next
Definition: avformat.h:544
typedef void(RENAME(mix_any_func_type))
AVIOContext * pb
I/O context.
Definition: avformat.h:1384
main external API structure.
Definition: avcodec.h:1518
int av_filename_number_test(const char *filename)
Check whether filename actually is a numbered sequence generator.
Definition: utils.c:327
int av_get_frame_filename2(char *buf, int buf_size, const char *path, int number, int flags)
Return in &#39;buf&#39; the path with &#39;d&#39; replaced by a number.
Definition: utils.c:4631
void(* io_close)(struct AVFormatContext *s, AVIOContext *pb)
A callback for closing the streams opened with AVFormatContext.io_open().
Definition: avformat.h:1928
static const AVClass av_class
Definition: options.c:134
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi - 0x80) *(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi - 0x80) *(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(const int16_t *) pi >> 8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t, *(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t, *(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(const int32_t *) pi >> 24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t, *(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t, *(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31)))) #define SET_CONV_FUNC_GROUP(ofmt, ifmt) static void set_generic_function(AudioConvert *ac) { } void ff_audio_convert_free(AudioConvert **ac) { if(! *ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);} AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, int sample_rate, int apply_map) { AudioConvert *ac;int in_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) return NULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method !=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt) > 2) { ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc) { av_free(ac);return NULL;} return ac;} in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar) { ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar ? ac->channels :1;} else if(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;else ac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);return ac;} int ff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in) { int use_generic=1;int len=in->nb_samples;int p;if(ac->dc) { av_log(ac->avr, AV_LOG_TRACE, "%d samples - audio_convert: %s to %s (dithered)\", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));return ff_convert_dither(ac-> in
Describe the class of an AVClass context structure.
Definition: log.h:67
int index
Definition: gxfenc.c:89
enum AVCodecID subtitle_codec
default subtitle codec
Definition: avformat.h:519
Rational number (pair of numerator and denominator).
Definition: rational.h:58
cl_device_type type
AVMediaType
Definition: avutil.h:199
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: utils.c:4375
This structure contains the data a format has to probe a file.
Definition: avformat.h:448
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1767
List of devices.
Definition: avdevice.h:460
AVTimebaseSource
Definition: avformat.h:3047
int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Seek to timestamp ts.
Definition: utils.c:2528
full parsing and repack of the first frame only, only implemented for H.264 currently ...
Definition: avformat.h:796
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:693
uint8_t level
Definition: svq3.c:207
Duration accurately estimated from PTSes.
Definition: avformat.h:1321
#define av_warn_unused_result
Definition: attributes.h:56
int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Seek to the keyframe at timestamp.
Definition: utils.c:2505
full parsing and repack
Definition: avformat.h:793
static AVStream * ost
int
const OptionDef options[]
Definition: ffmpeg_opt.c:3292
int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index, AVFrame *frame)
Write an uncoded frame to an output media file.
Definition: mux.c:1373
struct AVPacketList * next
Definition: avformat.h:2001
enum AVCodecID data_codec
default data codec
Definition: avformat.h:607
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: utils.c:3550
static double c[64]
AVStreamParseType
Definition: avformat.h:791
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:4413
int av_write_uncoded_frame(AVFormatContext *s, int stream_index, AVFrame *frame)
Write an uncoded frame to an output media file.
Definition: mux.c:1367
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:517
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:337
int avformat_open_input(AVFormatContext **ps, const char *url, AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: utils.c:537
AVDiscard
Definition: avcodec.h:785
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
Definition: mux.c:1247
char * protocol_blacklist
&#39;,&#39; separated list of disallowed protocols.
Definition: avformat.h:1935
int avformat_flush(AVFormatContext *s)
Discard all internally buffered data.
Definition: utils.c:2585
FILE * out
Definition: movenc.c:54
void INT64 start
Definition: avisynth_c.h:690
static int format_name(char *buf, int buf_len, int index)
Definition: hlsenc.c:1744
int copy_tb
Definition: ffmpeg_opt.c:101
void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size)
Send a nice hexadecimal dump of a buffer to the log.
Definition: dump.c:79
struct AVInputFormat * next
Definition: avformat.h:688
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.
Definition: format.c:216
enum AVCodecID id
Following API allows user to probe device capabilities (supported codecs, pixel formats, sample formats, resolutions, channel counts, etc).
Definition: avdevice.h:400
This structure stores compressed data.
Definition: avcodec.h:1407
#define MAX_STD_TIMEBASES
Definition: avformat.h:1032
int64_t av_stream_get_end_pts(const AVStream *st)
Returns the pts of the last muxed packet + its duration.
Definition: utils.c:141