FFmpeg
avformat.h
Go to the documentation of this file.
1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVFORMAT_AVFORMAT_H
22 #define AVFORMAT_AVFORMAT_H
23 
24 /**
25  * @file
26  * @ingroup libavf
27  * Main libavformat public API header
28  */
29 
30 /**
31  * @defgroup libavf libavformat
32  * I/O and Muxing/Demuxing Library
33  *
34  * Libavformat (lavf) is a library for dealing with various media container
35  * formats. Its main two purposes are demuxing - i.e. splitting a media file
36  * into component streams, and the reverse process of muxing - writing supplied
37  * data in a specified container format. It also has an @ref lavf_io
38  * "I/O module" which supports a number of protocols for accessing the data (e.g.
39  * file, tcp, http and others).
40  * Unless you are absolutely sure you won't use libavformat's network
41  * capabilities, you should also call avformat_network_init().
42  *
43  * A supported input format is described by an AVInputFormat struct, conversely
44  * an output format is described by AVOutputFormat. You can iterate over all
45  * input/output formats using the av_demuxer_iterate / av_muxer_iterate() functions.
46  * The protocols layer is not part of the public API, so you can only get the names
47  * of supported protocols with the avio_enum_protocols() function.
48  *
49  * Main lavf structure used for both muxing and demuxing is AVFormatContext,
50  * which exports all information about the file being read or written. As with
51  * most Libavformat structures, its size is not part of public ABI, so it cannot be
52  * allocated on stack or directly with av_malloc(). To create an
53  * AVFormatContext, use avformat_alloc_context() (some functions, like
54  * avformat_open_input() might do that for you).
55  *
56  * Most importantly an AVFormatContext contains:
57  * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat
58  * "output" format. It is either autodetected or set by user for input;
59  * always set by user for output.
60  * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all
61  * elementary streams stored in the file. AVStreams are typically referred to
62  * using their index in this array.
63  * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or
64  * set by user for input, always set by user for output (unless you are dealing
65  * with an AVFMT_NOFILE format).
66  *
67  * @section lavf_options Passing options to (de)muxers
68  * It is possible to configure lavf muxers and demuxers using the @ref avoptions
69  * mechanism. Generic (format-independent) libavformat options are provided by
70  * AVFormatContext, they can be examined from a user program by calling
71  * av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass
72  * from avformat_get_class()). Private (format-specific) options are provided by
73  * AVFormatContext.priv_data if and only if AVInputFormat.priv_class /
74  * AVOutputFormat.priv_class of the corresponding format struct is non-NULL.
75  * Further options may be provided by the @ref AVFormatContext.pb "I/O context",
76  * if its AVClass is non-NULL, and the protocols layer. See the discussion on
77  * nesting in @ref avoptions documentation to learn how to access those.
78  *
79  * @section urls
80  * URL strings in libavformat are made of a scheme/protocol, a ':', and a
81  * scheme specific string. URLs without a scheme and ':' used for local files
82  * are supported but deprecated. "file:" should be used for local files.
83  *
84  * It is important that the scheme string is not taken from untrusted
85  * sources without checks.
86  *
87  * Note that some schemes/protocols are quite powerful, allowing access to
88  * both local and remote files, parts of them, concatenations of them, local
89  * audio and video devices and so on.
90  *
91  * @{
92  *
93  * @defgroup lavf_decoding Demuxing
94  * @{
95  * Demuxers read a media file and split it into chunks of data (@em packets). A
96  * @ref AVPacket "packet" contains one or more encoded frames which belongs to a
97  * single elementary stream. In the lavf API this process is represented by the
98  * avformat_open_input() function for opening a file, av_read_frame() for
99  * reading a single packet and finally avformat_close_input(), which does the
100  * cleanup.
101  *
102  * @section lavf_decoding_open Opening a media file
103  * The minimum information required to open a file is its URL, which
104  * is passed to avformat_open_input(), as in the following code:
105  * @code
106  * const char *url = "file:in.mp3";
107  * AVFormatContext *s = NULL;
108  * int ret = avformat_open_input(&s, url, NULL, NULL);
109  * if (ret < 0)
110  * abort();
111  * @endcode
112  * The above code attempts to allocate an AVFormatContext, open the
113  * specified file (autodetecting the format) and read the header, exporting the
114  * information stored there into s. Some formats do not have a header or do not
115  * store enough information there, so it is recommended that you call the
116  * avformat_find_stream_info() function which tries to read and decode a few
117  * frames to find missing information.
118  *
119  * In some cases you might want to preallocate an AVFormatContext yourself with
120  * avformat_alloc_context() and do some tweaking on it before passing it to
121  * avformat_open_input(). One such case is when you want to use custom functions
122  * for reading input data instead of lavf internal I/O layer.
123  * To do that, create your own AVIOContext with avio_alloc_context(), passing
124  * your reading callbacks to it. Then set the @em pb field of your
125  * AVFormatContext to newly created AVIOContext.
126  *
127  * Since the format of the opened file is in general not known until after
128  * avformat_open_input() has returned, it is not possible to set demuxer private
129  * options on a preallocated context. Instead, the options should be passed to
130  * avformat_open_input() wrapped in an AVDictionary:
131  * @code
132  * AVDictionary *options = NULL;
133  * av_dict_set(&options, "video_size", "640x480", 0);
134  * av_dict_set(&options, "pixel_format", "rgb24", 0);
135  *
136  * if (avformat_open_input(&s, url, NULL, &options) < 0)
137  * abort();
138  * av_dict_free(&options);
139  * @endcode
140  * This code passes the private options 'video_size' and 'pixel_format' to the
141  * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it
142  * cannot know how to interpret raw video data otherwise. If the format turns
143  * out to be something different than raw video, those options will not be
144  * recognized by the demuxer and therefore will not be applied. Such unrecognized
145  * options are then returned in the options dictionary (recognized options are
146  * consumed). The calling program can handle such unrecognized options as it
147  * wishes, e.g.
148  * @code
149  * AVDictionaryEntry *e;
150  * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
151  * fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key);
152  * abort();
153  * }
154  * @endcode
155  *
156  * After you have finished reading the file, you must close it with
157  * avformat_close_input(). It will free everything associated with the file.
158  *
159  * @section lavf_decoding_read Reading from an opened file
160  * Reading data from an opened AVFormatContext is done by repeatedly calling
161  * av_read_frame() on it. Each call, if successful, will return an AVPacket
162  * containing encoded data for one AVStream, identified by
163  * AVPacket.stream_index. This packet may be passed straight into the libavcodec
164  * decoding functions avcodec_send_packet() or avcodec_decode_subtitle2() if the
165  * caller wishes to decode the data.
166  *
167  * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be
168  * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for
169  * pts/dts, 0 for duration) if the stream does not provide them. The timing
170  * information will be in AVStream.time_base units, i.e. it has to be
171  * multiplied by the timebase to convert them to seconds.
172  *
173  * If AVPacket.buf is set on the returned packet, then the packet is
174  * allocated dynamically and the user may keep it indefinitely.
175  * Otherwise, if AVPacket.buf is NULL, the packet data is backed by a
176  * static storage somewhere inside the demuxer and the packet is only valid
177  * until the next av_read_frame() call or closing the file. If the caller
178  * requires a longer lifetime, av_packet_make_refcounted() will ensure that
179  * the data is reference counted, copying the data if necessary.
180  * In both cases, the packet must be freed with av_packet_unref() when it is no
181  * longer needed.
182  *
183  * @section lavf_decoding_seek Seeking
184  * @}
185  *
186  * @defgroup lavf_encoding Muxing
187  * @{
188  * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write
189  * it into files or other output bytestreams in the specified container format.
190  *
191  * The main API functions for muxing are avformat_write_header() for writing the
192  * file header, av_write_frame() / av_interleaved_write_frame() for writing the
193  * packets and av_write_trailer() for finalizing the file.
194  *
195  * At the beginning of the muxing process, the caller must first call
196  * avformat_alloc_context() to create a muxing context. The caller then sets up
197  * the muxer by filling the various fields in this context:
198  *
199  * - The @ref AVFormatContext.oformat "oformat" field must be set to select the
200  * muxer that will be used.
201  * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb
202  * "pb" field must be set to an opened IO context, either returned from
203  * avio_open2() or a custom one.
204  * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must
205  * be created with the avformat_new_stream() function. The caller should fill
206  * the @ref AVStream.codecpar "stream codec parameters" information, such as the
207  * codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id
208  * "id" and other parameters (e.g. width / height, the pixel or sample format,
209  * etc.) as known. The @ref AVStream.time_base "stream timebase" should
210  * be set to the timebase that the caller desires to use for this stream (note
211  * that the timebase actually used by the muxer can be different, as will be
212  * described later).
213  * - It is advised to manually initialize only the relevant fields in
214  * AVCodecParameters, rather than using @ref avcodec_parameters_copy() during
215  * remuxing: there is no guarantee that the codec context values remain valid
216  * for both input and output format contexts.
217  * - The caller may fill in additional information, such as @ref
218  * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream"
219  * metadata, @ref AVFormatContext.chapters "chapters", @ref
220  * AVFormatContext.programs "programs", etc. as described in the
221  * AVFormatContext documentation. Whether such information will actually be
222  * stored in the output depends on what the container format and the muxer
223  * support.
224  *
225  * When the muxing context is fully set up, the caller must call
226  * avformat_write_header() to initialize the muxer internals and write the file
227  * header. Whether anything actually is written to the IO context at this step
228  * depends on the muxer, but this function must always be called. Any muxer
229  * private options must be passed in the options parameter to this function.
230  *
231  * The data is then sent to the muxer by repeatedly calling av_write_frame() or
232  * av_interleaved_write_frame() (consult those functions' documentation for
233  * discussion on the difference between them; only one of them may be used with
234  * a single muxing context, they should not be mixed). Do note that the timing
235  * information on the packets sent to the muxer must be in the corresponding
236  * AVStream's timebase. That timebase is set by the muxer (in the
237  * avformat_write_header() step) and may be different from the timebase
238  * requested by the caller.
239  *
240  * Once all the data has been written, the caller must call av_write_trailer()
241  * to flush any buffered packets and finalize the output file, then close the IO
242  * context (if any) and finally free the muxing context with
243  * avformat_free_context().
244  * @}
245  *
246  * @defgroup lavf_io I/O Read/Write
247  * @{
248  * @section lavf_io_dirlist Directory listing
249  * The directory listing API makes it possible to list files on remote servers.
250  *
251  * Some of possible use cases:
252  * - an "open file" dialog to choose files from a remote location,
253  * - a recursive media finder providing a player with an ability to play all
254  * files from a given directory.
255  *
256  * @subsection lavf_io_dirlist_open Opening a directory
257  * At first, a directory needs to be opened by calling avio_open_dir()
258  * supplied with a URL and, optionally, ::AVDictionary containing
259  * protocol-specific parameters. The function returns zero or positive
260  * integer and allocates AVIODirContext on success.
261  *
262  * @code
263  * AVIODirContext *ctx = NULL;
264  * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) {
265  * fprintf(stderr, "Cannot open directory.\n");
266  * abort();
267  * }
268  * @endcode
269  *
270  * This code tries to open a sample directory using smb protocol without
271  * any additional parameters.
272  *
273  * @subsection lavf_io_dirlist_read Reading entries
274  * Each directory's entry (i.e. file, another directory, anything else
275  * within ::AVIODirEntryType) is represented by AVIODirEntry.
276  * Reading consecutive entries from an opened AVIODirContext is done by
277  * repeatedly calling avio_read_dir() on it. Each call returns zero or
278  * positive integer if successful. Reading can be stopped right after the
279  * NULL entry has been read -- it means there are no entries left to be
280  * read. The following code reads all entries from a directory associated
281  * with ctx and prints their names to standard output.
282  * @code
283  * AVIODirEntry *entry = NULL;
284  * for (;;) {
285  * if (avio_read_dir(ctx, &entry) < 0) {
286  * fprintf(stderr, "Cannot list directory.\n");
287  * abort();
288  * }
289  * if (!entry)
290  * break;
291  * printf("%s\n", entry->name);
292  * avio_free_directory_entry(&entry);
293  * }
294  * @endcode
295  * @}
296  *
297  * @defgroup lavf_codec Demuxers
298  * @{
299  * @defgroup lavf_codec_native Native Demuxers
300  * @{
301  * @}
302  * @defgroup lavf_codec_wrappers External library wrappers
303  * @{
304  * @}
305  * @}
306  * @defgroup lavf_protos I/O Protocols
307  * @{
308  * @}
309  * @defgroup lavf_internal Internal
310  * @{
311  * @}
312  * @}
313  */
314 
315 #include <time.h>
316 #include <stdio.h> /* FILE */
317 #include "libavcodec/avcodec.h"
318 #include "libavutil/dict.h"
319 #include "libavutil/log.h"
320 
321 #include "avio.h"
322 #include "libavformat/version.h"
323 
324 struct AVFormatContext;
325 
326 struct AVDeviceInfoList;
328 
329 /**
330  * @defgroup metadata_api Public Metadata API
331  * @{
332  * @ingroup libavf
333  * The metadata API allows libavformat to export metadata tags to a client
334  * application when demuxing. Conversely it allows a client application to
335  * set metadata when muxing.
336  *
337  * Metadata is exported or set as pairs of key/value strings in the 'metadata'
338  * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
339  * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
340  * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
341  * exported by demuxers isn't checked to be valid UTF-8 in most cases.
342  *
343  * Important concepts to keep in mind:
344  * - Keys are unique; there can never be 2 tags with the same key. This is
345  * also meant semantically, i.e., a demuxer should not knowingly produce
346  * several keys that are literally different but semantically identical.
347  * E.g., key=Author5, key=Author6. In this example, all authors must be
348  * placed in the same tag.
349  * - Metadata is flat, not hierarchical; there are no subtags. If you
350  * want to store, e.g., the email address of the child of producer Alice
351  * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
352  * - Several modifiers can be applied to the tag name. This is done by
353  * appending a dash character ('-') and the modifier name in the order
354  * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
355  * - language -- a tag whose value is localized for a particular language
356  * is appended with the ISO 639-2/B 3-letter language code.
357  * For example: Author-ger=Michael, Author-eng=Mike
358  * The original/default language is in the unqualified "Author" tag.
359  * A demuxer should set a default if it sets any translated tag.
360  * - sorting -- a modified version of a tag that should be used for
361  * sorting will have '-sort' appended. E.g. artist="The Beatles",
362  * artist-sort="Beatles, The".
363  * - Some protocols and demuxers support metadata updates. After a successful
364  * call to av_read_packet(), AVFormatContext.event_flags or AVStream.event_flags
365  * will be updated to indicate if metadata changed. In order to detect metadata
366  * changes on a stream, you need to loop through all streams in the AVFormatContext
367  * and check their individual event_flags.
368  *
369  * - Demuxers attempt to export metadata in a generic format, however tags
370  * with no generic equivalents are left as they are stored in the container.
371  * Follows a list of generic tag names:
372  *
373  @verbatim
374  album -- name of the set this work belongs to
375  album_artist -- main creator of the set/album, if different from artist.
376  e.g. "Various Artists" for compilation albums.
377  artist -- main creator of the work
378  comment -- any additional description of the file.
379  composer -- who composed the work, if different from artist.
380  copyright -- name of copyright holder.
381  creation_time-- date when the file was created, preferably in ISO 8601.
382  date -- date when the work was created, preferably in ISO 8601.
383  disc -- number of a subset, e.g. disc in a multi-disc collection.
384  encoder -- name/settings of the software/hardware that produced the file.
385  encoded_by -- person/group who created the file.
386  filename -- original name of the file.
387  genre -- <self-evident>.
388  language -- main language in which the work is performed, preferably
389  in ISO 639-2 format. Multiple languages can be specified by
390  separating them with commas.
391  performer -- artist who performed the work, if different from artist.
392  E.g for "Also sprach Zarathustra", artist would be "Richard
393  Strauss" and performer "London Philharmonic Orchestra".
394  publisher -- name of the label/publisher.
395  service_name -- name of the service in broadcasting (channel name).
396  service_provider -- name of the service provider in broadcasting.
397  title -- name of the work.
398  track -- number of this work in the set, can be in form current/total.
399  variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
400  @endverbatim
401  *
402  * Look in the examples section for an application example how to use the Metadata API.
403  *
404  * @}
405  */
406 
407 /* packet functions */
408 
409 
410 /**
411  * Allocate and read the payload of a packet and initialize its
412  * fields with default values.
413  *
414  * @param s associated IO context
415  * @param pkt packet
416  * @param size desired payload size
417  * @return >0 (read size) if OK, AVERROR_xxx otherwise
418  */
420 
421 
422 /**
423  * Read data and append it to the current content of the AVPacket.
424  * If pkt->size is 0 this is identical to av_get_packet.
425  * Note that this uses av_grow_packet and thus involves a realloc
426  * which is inefficient. Thus this function should only be used
427  * when there is no reasonable way to know (an upper bound of)
428  * the final size.
429  *
430  * @param s associated IO context
431  * @param pkt packet
432  * @param size amount of data to read
433  * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
434  * will not be lost even if an error occurs.
435  */
437 
438 /*************************************************/
439 /* input/output formats */
440 
441 struct AVCodecTag;
442 
443 /**
444  * This structure contains the data a format has to probe a file.
445  */
446 typedef struct AVProbeData {
447  const char *filename;
448  unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
449  int buf_size; /**< Size of buf except extra allocated bytes */
450  const char *mime_type; /**< mime_type, when known. */
451 } AVProbeData;
452 
453 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
454 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
455 
456 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
457 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type
458 #define AVPROBE_SCORE_MAX 100 ///< maximum score
459 
460 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
461 
462 /// Demuxer will use avio_open, no opened file should be provided by the caller.
463 #define AVFMT_NOFILE 0x0001
464 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
465 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
466 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
467 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
468 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
469 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
470 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
471 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
472 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
473 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
474 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
475 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
476 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
477 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
478  increasing timestamps, but they must
479  still be monotonic */
480 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
481  timestamps. If not set the timestamp
482  will be shifted in av_write_frame and
483  av_interleaved_write_frame so they
484  start from 0.
485  The user or muxer can override this through
486  AVFormatContext.avoid_negative_ts
487  */
488 
489 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
490 
491 /**
492  * @addtogroup lavf_encoding
493  * @{
494  */
495 typedef struct AVOutputFormat {
496  const char *name;
497  /**
498  * Descriptive name for the format, meant to be more human-readable
499  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
500  * to define it.
501  */
502  const char *long_name;
503  const char *mime_type;
504  const char *extensions; /**< comma-separated filename extensions */
505  /* output support */
506  enum AVCodecID audio_codec; /**< default audio codec */
507  enum AVCodecID video_codec; /**< default video codec */
508  enum AVCodecID subtitle_codec; /**< default subtitle codec */
509  /**
510  * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER,
511  * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
512  * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
513  * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
514  */
515  int flags;
517  /**
518  * List of supported codec_id-codec_tag pairs, ordered by "better
519  * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
520  */
521  const struct AVCodecTag * const *codec_tag;
522 
523 
524  const AVClass *priv_class; ///< AVClass for the private context
525 
526  /*****************************************************************
527  * No fields below this line are part of the public API. They
528  * may not be used outside of libavformat and can be changed and
529  * removed at will.
530  * New public fields should be added right above.
531  *****************************************************************
532  */
533  /**
534  * The ff_const59 define is not part of the public API and will
535  * be removed without further warning.
536  */
537 #if FF_API_AVIOFORMAT
538 #define ff_const59
539 #else
540 #define ff_const59 const
541 #endif
543  /**
544  * size of private data so that it can be allocated in the wrapper
545  */
546  int priv_data_size;
547 
548  int (*write_header)(struct AVFormatContext *);
549  /**
550  * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
551  * pkt can be NULL in order to flush data buffered in the muxer.
552  * When flushing, return 0 if there still is more data to flush,
553  * or 1 if everything was flushed and there is no more buffered
554  * data.
555  */
558  /**
559  * Currently only used to set pixel format if not YUV420P.
560  */
562  AVPacket *in, int flush);
563  /**
564  * Test if the given codec can be stored in this container.
565  *
566  * @return 1 if the codec is supported, 0 if it is not.
567  * A negative number if unknown.
568  * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
569  */
570  int (*query_codec)(enum AVCodecID id, int std_compliance);
571 
572  void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
573  int64_t *dts, int64_t *wall);
574  /**
575  * Allows sending messages from application to device.
576  */
577  int (*control_message)(struct AVFormatContext *s, int type,
578  void *data, size_t data_size);
580  /**
581  * Write an uncoded AVFrame.
582  *
583  * See av_write_uncoded_frame() for details.
584  *
585  * The library will free *frame afterwards, but the muxer can prevent it
586  * by setting the pointer to NULL.
587  */
588  int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
589  AVFrame **frame, unsigned flags);
590  /**
591  * Returns device list with it properties.
592  * @see avdevice_list_devices() for more details.
593  */
594  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
595  /**
596  * Initialize device capabilities submodule.
597  * @see avdevice_capabilities_create() for more details.
598  */
599  int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
600  /**
601  * Free device capabilities submodule.
602  * @see avdevice_capabilities_free() for more details.
603  */
604  int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
605  enum AVCodecID data_codec; /**< default data codec */
606  /**
607  * Initialize format. May allocate data here, and set any AVFormatContext or
608  * AVStream parameters that need to be set before packets are sent.
609  * This method must not write output.
610  *
611  * Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure
612  *
613  * Any allocations made here must be freed in deinit().
614  */
615  int (*init)(struct AVFormatContext *);
616  /**
617  * Deinitialize format. If present, this is called whenever the muxer is being
618  * destroyed, regardless of whether or not the header has been written.
619  *
620  * If a trailer is being written, this is called after write_trailer().
621  *
622  * This is called if init() fails as well.
623  */
624  void (*deinit)(struct AVFormatContext *);
625  /**
626  * Set up any necessary bitstream filtering and extract any extra data needed
627  * for the global header.
628  * Return 0 if more packets from this stream must be checked; 1 if not.
629  */
630  int (*check_bitstream)(struct AVFormatContext *, const AVPacket *pkt);
632 /**
633  * @}
634  */
635 
636 /**
637  * @addtogroup lavf_decoding
638  * @{
639  */
640 typedef struct AVInputFormat {
641  /**
642  * A comma separated list of short names for the format. New names
643  * may be appended with a minor bump.
644  */
645  const char *name;
646 
647  /**
648  * Descriptive name for the format, meant to be more human-readable
649  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
650  * to define it.
651  */
652  const char *long_name;
653 
654  /**
655  * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
656  * AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
657  * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
658  */
659  int flags;
660 
661  /**
662  * If extensions are defined, then no probe is done. You should
663  * usually not use extension format guessing because it is not
664  * reliable enough
665  */
666  const char *extensions;
667 
668  const struct AVCodecTag * const *codec_tag;
669 
670  const AVClass *priv_class; ///< AVClass for the private context
671 
672  /**
673  * Comma-separated list of mime types.
674  * It is used check for matching mime types while probing.
675  * @see av_probe_input_format2
676  */
677  const char *mime_type;
678 
679  /*****************************************************************
680  * No fields below this line are part of the public API. They
681  * may not be used outside of libavformat and can be changed and
682  * removed at will.
683  * New public fields should be added right above.
684  *****************************************************************
685  */
687 
688  /**
689  * Raw demuxers store their codec ID here.
690  */
691  int raw_codec_id;
692 
693  /**
694  * Size of private data so that it can be allocated in the wrapper.
695  */
696  int priv_data_size;
697 
698  /**
699  * Tell if a given file has a chance of being parsed as this format.
700  * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
701  * big so you do not have to check for that unless you need more.
702  */
703  int (*read_probe)(const AVProbeData *);
704 
705  /**
706  * Read the format header and initialize the AVFormatContext
707  * structure. Return 0 if OK. 'avformat_new_stream' should be
708  * called to create new streams.
709  */
710  int (*read_header)(struct AVFormatContext *);
711 
712  /**
713  * Read one packet and put it in 'pkt'. pts and flags are also
714  * set. 'avformat_new_stream' can be called only if the flag
715  * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
716  * background thread).
717  * @return 0 on success, < 0 on error.
718  * Upon returning an error, pkt must be unreferenced by the caller.
719  */
720  int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
721 
722  /**
723  * Close the stream. The AVFormatContext and AVStreams are not
724  * freed by this function
725  */
726  int (*read_close)(struct AVFormatContext *);
727 
728  /**
729  * Seek to a given timestamp relative to the frames in
730  * stream component stream_index.
731  * @param stream_index Must not be -1.
732  * @param flags Selects which direction should be preferred if no exact
733  * match is available.
734  * @return >= 0 on success (but not necessarily the new offset)
735  */
736  int (*read_seek)(struct AVFormatContext *,
737  int stream_index, int64_t timestamp, int flags);
738 
739  /**
740  * Get the next timestamp in stream[stream_index].time_base units.
741  * @return the timestamp or AV_NOPTS_VALUE if an error occurred
742  */
743  int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
744  int64_t *pos, int64_t pos_limit);
746  /**
747  * Start/resume playing - only meaningful if using a network-based format
748  * (RTSP).
749  */
750  int (*read_play)(struct AVFormatContext *);
751 
752  /**
753  * Pause playing - only meaningful if using a network-based format
754  * (RTSP).
755  */
756  int (*read_pause)(struct AVFormatContext *);
757 
758  /**
759  * Seek to timestamp ts.
760  * Seeking will be done so that the point from which all active streams
761  * can be presented successfully will be closest to ts and within min/max_ts.
762  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
763  */
764  int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
766  /**
767  * Returns device list with it properties.
768  * @see avdevice_list_devices() for more details.
769  */
770  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
771 
772  /**
773  * Initialize device capabilities submodule.
774  * @see avdevice_capabilities_create() for more details.
775  */
776  int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
777 
778  /**
779  * Free device capabilities submodule.
780  * @see avdevice_capabilities_free() for more details.
781  */
782  int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
783 } AVInputFormat;
784 /**
785  * @}
786  */
787 
788 enum AVStreamParseType {
790  AVSTREAM_PARSE_FULL, /**< full parsing and repack */
791  AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
792  AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
793  AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
794  AVSTREAM_PARSE_FULL_RAW, /**< full parsing and repack with timestamp and position generation by parser for raw
795  this assumes that each packet in the file contains no demuxer level headers and
796  just codec level data, otherwise position generation would fail */
797 };
799 typedef struct AVIndexEntry {
800  int64_t pos;
801  int64_t timestamp; /**<
802  * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
803  * when seeking to this entry. That means preferable PTS on keyframe based formats.
804  * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
805  * is known
806  */
807 #define AVINDEX_KEYFRAME 0x0001
808 #define AVINDEX_DISCARD_FRAME 0x0002 /**
809  * Flag is used to indicate which frame should be discarded after decoding.
810  */
811  int flags:2;
812  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).
813  int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
814 } AVIndexEntry;
815 
816 #define AV_DISPOSITION_DEFAULT 0x0001
817 #define AV_DISPOSITION_DUB 0x0002
818 #define AV_DISPOSITION_ORIGINAL 0x0004
819 #define AV_DISPOSITION_COMMENT 0x0008
820 #define AV_DISPOSITION_LYRICS 0x0010
821 #define AV_DISPOSITION_KARAOKE 0x0020
823 /**
824  * Track should be used during playback by default.
825  * Useful for subtitle track that should be displayed
826  * even when user did not explicitly ask for subtitles.
827  */
828 #define AV_DISPOSITION_FORCED 0x0040
829 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
830 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
831 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
832 /**
833  * The stream is stored in the file as an attached picture/"cover art" (e.g.
834  * APIC frame in ID3v2). The first (usually only) packet associated with it
835  * will be returned among the first few packets read from the file unless
836  * seeking takes place. It can also be accessed at any time in
837  * AVStream.attached_pic.
838  */
839 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
840 /**
841  * The stream is sparse, and contains thumbnail images, often corresponding
842  * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
843  */
844 #define AV_DISPOSITION_TIMED_THUMBNAILS 0x0800
845 
846 typedef struct AVStreamInternal AVStreamInternal;
847 
848 /**
849  * To specify text track kind (different from subtitles default).
850  */
851 #define AV_DISPOSITION_CAPTIONS 0x10000
852 #define AV_DISPOSITION_DESCRIPTIONS 0x20000
853 #define AV_DISPOSITION_METADATA 0x40000
854 #define AV_DISPOSITION_DEPENDENT 0x80000 ///< dependent audio stream (mix_type=0 in mpegts)
855 #define AV_DISPOSITION_STILL_IMAGE 0x100000 ///< still images in video stream (still_picture_flag=1 in mpegts)
856 
857 /**
858  * Options for behavior on timestamp wrap detection.
859  */
860 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
861 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
862 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
864 /**
865  * Stream structure.
866  * New fields can be added to the end with minor version bumps.
867  * Removal, reordering and changes to existing fields require a major
868  * version bump.
869  * sizeof(AVStream) must not be used outside libav*.
870  */
871 typedef struct AVStream {
872  int index; /**< stream index in AVFormatContext */
873  /**
874  * Format-specific stream ID.
875  * decoding: set by libavformat
876  * encoding: set by the user, replaced by libavformat if left unset
877  */
878  int id;
879 #if FF_API_LAVF_AVCTX
880  /**
881  * @deprecated use the codecpar struct instead
882  */
884  AVCodecContext *codec;
885 #endif
886  void *priv_data;
888  /**
889  * This is the fundamental unit of time (in seconds) in terms
890  * of which frame timestamps are represented.
891  *
892  * decoding: set by libavformat
893  * encoding: May be set by the caller before avformat_write_header() to
894  * provide a hint to the muxer about the desired timebase. In
895  * avformat_write_header(), the muxer will overwrite this field
896  * with the timebase that will actually be used for the timestamps
897  * written into the file (which may or may not be related to the
898  * user-provided one, depending on the format).
899  */
900  AVRational time_base;
901 
902  /**
903  * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
904  * Only set this if you are absolutely 100% sure that the value you set
905  * it to really is the pts of the first frame.
906  * This may be undefined (AV_NOPTS_VALUE).
907  * @note The ASF header does NOT contain a correct start_time the ASF
908  * demuxer must NOT set this.
909  */
910  int64_t start_time;
911 
912  /**
913  * Decoding: duration of the stream, in stream time base.
914  * If a source file does not specify a duration, but does specify
915  * a bitrate, this value will be estimated from bitrate and file size.
916  *
917  * Encoding: May be set by the caller before avformat_write_header() to
918  * provide a hint to the muxer about the estimated duration.
919  */
920  int64_t duration;
921 
922  int64_t nb_frames; ///< number of frames in this stream if known or 0
923 
924  int disposition; /**< AV_DISPOSITION_* bit field */
925 
926  enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
927 
928  /**
929  * sample aspect ratio (0 if unknown)
930  * - encoding: Set by user.
931  * - decoding: Set by libavformat.
932  */
933  AVRational sample_aspect_ratio;
934 
935  AVDictionary *metadata;
936 
937  /**
938  * Average framerate
939  *
940  * - demuxing: May be set by libavformat when creating the stream or in
941  * avformat_find_stream_info().
942  * - muxing: May be set by the caller before avformat_write_header().
943  */
944  AVRational avg_frame_rate;
945 
946  /**
947  * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
948  * will contain the attached picture.
949  *
950  * decoding: set by libavformat, must not be modified by the caller.
951  * encoding: unused
952  */
953  AVPacket attached_pic;
954 
955  /**
956  * An array of side data that applies to the whole stream (i.e. the
957  * container does not allow it to change between packets).
958  *
959  * There may be no overlap between the side data in this array and side data
960  * in the packets. I.e. a given side data is either exported by the muxer
961  * (demuxing) / set by the caller (muxing) in this array, then it never
962  * appears in the packets, or the side data is exported / sent through
963  * the packets (always in the first packet where the value becomes known or
964  * changes), then it does not appear in this array.
965  *
966  * - demuxing: Set by libavformat when the stream is created.
967  * - muxing: May be set by the caller before avformat_write_header().
968  *
969  * Freed by libavformat in avformat_free_context().
970  *
971  * @see av_format_inject_global_side_data()
972  */
973  AVPacketSideData *side_data;
974  /**
975  * The number of elements in the AVStream.side_data array.
976  */
977  int nb_side_data;
978 
979  /**
980  * Flags for the user to detect events happening on the stream. Flags must
981  * be cleared by the user once the event has been handled.
982  * A combination of AVSTREAM_EVENT_FLAG_*.
983  */
984  int event_flags;
985 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
987  /**
988  * Real base framerate of the stream.
989  * This is the lowest framerate with which all timestamps can be
990  * represented accurately (it is the least common multiple of all
991  * framerates in the stream). Note, this value is just a guess!
992  * For example, if the time base is 1/90000 and all frames have either
993  * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
994  */
995  AVRational r_frame_rate;
996 
997 #if FF_API_LAVF_FFSERVER
998  /**
999  * String containing pairs of key and values describing recommended encoder configuration.
1000  * Pairs are separated by ','.
1001  * Keys are separated from values by '='.
1002  *
1003  * @deprecated unused
1004  */
1006  char *recommended_encoder_configuration;
1007 #endif
1008 
1009  /**
1010  * Codec parameters associated with this stream. Allocated and freed by
1011  * libavformat in avformat_new_stream() and avformat_free_context()
1012  * respectively.
1013  *
1014  * - demuxing: filled by libavformat on stream creation or in
1015  * avformat_find_stream_info()
1016  * - muxing: filled by the caller before avformat_write_header()
1017  */
1018  AVCodecParameters *codecpar;
1019 
1020  /*****************************************************************
1021  * All fields below this line are not part of the public API. They
1022  * may not be used outside of libavformat and can be changed and
1023  * removed at will.
1024  * Internal note: be aware that physically removing these fields
1025  * will break ABI. Replace removed fields with dummy fields, and
1026  * add new fields to AVStreamInternal.
1027  *****************************************************************
1028  */
1029 
1030 #define MAX_STD_TIMEBASES (30*12+30+3+6)
1031  /**
1032  * Stream information used internally by avformat_find_stream_info()
1033  */
1034  struct {
1035  int64_t last_dts;
1036  int64_t duration_gcd;
1037  int duration_count;
1038  int64_t rfps_duration_sum;
1039  double (*duration_error)[2][MAX_STD_TIMEBASES];
1040  int64_t codec_info_duration;
1041  int64_t codec_info_duration_fields;
1042  int frame_delay_evidence;
1043 
1044  /**
1045  * 0 -> decoder has not been searched for yet.
1046  * >0 -> decoder found
1047  * <0 -> decoder with codec_id == -found_decoder has not been found
1048  */
1049  int found_decoder;
1051  int64_t last_duration;
1052 
1053  /**
1054  * Those are used for average framerate estimation.
1055  */
1056  int64_t fps_first_dts;
1057  int fps_first_dts_idx;
1058  int64_t fps_last_dts;
1059  int fps_last_dts_idx;
1061  } *info;
1062 
1063  int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
1064 
1065  // Timestamp generation support:
1066  /**
1067  * Timestamp corresponding to the last dts sync point.
1068  *
1069  * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
1070  * a DTS is received from the underlying container. Otherwise set to
1071  * AV_NOPTS_VALUE by default.
1072  */
1073  int64_t first_dts;
1074  int64_t cur_dts;
1075  int64_t last_IP_pts;
1076  int last_IP_duration;
1077 
1078  /**
1079  * Number of packets to buffer for codec probing
1080  */
1081  int probe_packets;
1083  /**
1084  * Number of frames that have been demuxed during avformat_find_stream_info()
1085  */
1086  int codec_info_nb_frames;
1087 
1088  /* av_read_frame() support */
1089  enum AVStreamParseType need_parsing;
1091 
1092  /**
1093  * last packet in packet_buffer for this stream when muxing.
1094  */
1095  struct AVPacketList *last_in_packet_buffer;
1096  AVProbeData probe_data;
1097 #define MAX_REORDER_DELAY 16
1098  int64_t pts_buffer[MAX_REORDER_DELAY+1];
1100  AVIndexEntry *index_entries; /**< Only used if the format does not
1101  support seeking natively. */
1102  int nb_index_entries;
1103  unsigned int index_entries_allocated_size;
1105  /**
1106  * Stream Identifier
1107  * This is the MPEG-TS stream identifier +1
1108  * 0 means unknown
1109  */
1110  int stream_identifier;
1112  /**
1113  * Details of the MPEG-TS program which created this stream.
1114  */
1115  int program_num;
1116  int pmt_version;
1117  int pmt_stream_idx;
1118 
1119  int64_t interleaver_chunk_size;
1120  int64_t interleaver_chunk_duration;
1121 
1122  /**
1123  * stream probing state
1124  * -1 -> probing finished
1125  * 0 -> no probing requested
1126  * rest -> perform probing with request_probe being the minimum score to accept.
1127  * NOT PART OF PUBLIC API
1128  */
1129  int request_probe;
1130  /**
1131  * Indicates that everything up to the next keyframe
1132  * should be discarded.
1133  */
1134  int skip_to_keyframe;
1135 
1136  /**
1137  * Number of samples to skip at the start of the frame decoded from the next packet.
1138  */
1139  int skip_samples;
1140 
1141  /**
1142  * If not 0, the number of samples that should be skipped from the start of
1143  * the stream (the samples are removed from packets with pts==0, which also
1144  * assumes negative timestamps do not happen).
1145  * Intended for use with formats such as mp3 with ad-hoc gapless audio
1146  * support.
1147  */
1148  int64_t start_skip_samples;
1149 
1150  /**
1151  * If not 0, the first audio sample that should be discarded from the stream.
1152  * This is broken by design (needs global sample count), but can't be
1153  * avoided for broken by design formats such as mp3 with ad-hoc gapless
1154  * audio support.
1155  */
1156  int64_t first_discard_sample;
1158  /**
1159  * The sample after last sample that is intended to be discarded after
1160  * first_discard_sample. Works on frame boundaries only. Used to prevent
1161  * early EOF if the gapless info is broken (considered concatenated mp3s).
1162  */
1163  int64_t last_discard_sample;
1164 
1165  /**
1166  * Number of internally decoded frames, used internally in libavformat, do not access
1167  * its lifetime differs from info which is why it is not in that structure.
1168  */
1169  int nb_decoded_frames;
1170 
1171  /**
1172  * Timestamp offset added to timestamps before muxing
1173  * NOT PART OF PUBLIC API
1174  */
1175  int64_t mux_ts_offset;
1176 
1177  /**
1178  * Internal data to check for wrapping of the time stamp
1179  */
1180  int64_t pts_wrap_reference;
1181 
1182  /**
1183  * Options for behavior, when a wrap is detected.
1184  *
1185  * Defined by AV_PTS_WRAP_ values.
1186  *
1187  * If correction is enabled, there are two possibilities:
1188  * If the first time stamp is near the wrap point, the wrap offset
1189  * will be subtracted, which will create negative time stamps.
1190  * Otherwise the offset will be added.
1191  */
1192  int pts_wrap_behavior;
1193 
1194  /**
1195  * Internal data to prevent doing update_initial_durations() twice
1196  */
1197  int update_initial_durations_done;
1198 
1199  /**
1200  * Internal data to generate dts from pts
1201  */
1202  int64_t pts_reorder_error[MAX_REORDER_DELAY+1];
1203  uint8_t pts_reorder_error_count[MAX_REORDER_DELAY+1];
1204 
1205  /**
1206  * Internal data to analyze DTS and detect faulty mpeg streams
1207  */
1208  int64_t last_dts_for_order_check;
1209  uint8_t dts_ordered;
1210  uint8_t dts_misordered;
1212  /**
1213  * Internal data to inject global side data
1214  */
1215  int inject_global_side_data;
1216 
1217  /**
1218  * display aspect ratio (0 if unknown)
1219  * - encoding: unused
1220  * - decoding: Set by libavformat to calculate sample_aspect_ratio internally
1221  */
1222  AVRational display_aspect_ratio;
1223 
1224  /**
1225  * An opaque field for libavformat internal usage.
1226  * Must not be accessed in any way by callers.
1227  */
1228  AVStreamInternal *internal;
1229 } AVStream;
1230 
1231 #if FF_API_FORMAT_GET_SET
1232 /**
1233  * Accessors for some AVStream fields. These used to be provided for ABI
1234  * compatibility, and do not need to be used anymore.
1235  */
1237 AVRational av_stream_get_r_frame_rate(const AVStream *s);
1239 void av_stream_set_r_frame_rate(AVStream *s, AVRational r);
1240 #if FF_API_LAVF_FFSERVER
1242 char* av_stream_get_recommended_encoder_configuration(const AVStream *s);
1244 void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration);
1245 #endif
1246 #endif
1247 
1249 
1250 /**
1251  * Returns the pts of the last muxed packet + its duration
1252  *
1253  * the retuned value is undefined when used with a demuxer.
1254  */
1255 int64_t av_stream_get_end_pts(const AVStream *st);
1256 
1257 #define AV_PROGRAM_RUNNING 1
1258 
1259 /**
1260  * New fields can be added to the end with minor version bumps.
1261  * Removal, reordering and changes to existing fields require a major
1262  * version bump.
1263  * sizeof(AVProgram) must not be used outside libav*.
1264  */
1265 typedef struct AVProgram {
1266  int id;
1267  int flags;
1268  enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1269  unsigned int *stream_index;
1270  unsigned int nb_stream_indexes;
1271  AVDictionary *metadata;
1272 
1273  int program_num;
1274  int pmt_pid;
1275  int pcr_pid;
1276  int pmt_version;
1278  /*****************************************************************
1279  * All fields below this line are not part of the public API. They
1280  * may not be used outside of libavformat and can be changed and
1281  * removed at will.
1282  * New public fields should be added right above.
1283  *****************************************************************
1284  */
1285  int64_t start_time;
1286  int64_t end_time;
1287 
1288  int64_t pts_wrap_reference; ///< reference dts for wrap detection
1289  int pts_wrap_behavior; ///< behavior on wrap detection
1290 } AVProgram;
1291 
1292 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1293  (streams are added dynamically) */
1294 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely
1295  not seekable, and attempts to call the
1296  seek function will fail. For some
1297  network protocols (e.g. HLS), this can
1298  change dynamically at runtime. */
1299 
1300 typedef struct AVChapter {
1301  int id; ///< unique ID to identify the chapter
1302  AVRational time_base; ///< time base in which the start/end timestamps are specified
1303  int64_t start, end; ///< chapter start/end time in time_base units
1304  AVDictionary *metadata;
1305 } AVChapter;
1306 
1307 
1308 /**
1309  * Callback used by devices to communicate with application.
1310  */
1311 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1312  void *data, size_t data_size);
1313 
1314 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
1317 /**
1318  * The duration of a video can be estimated through various ways, and this enum can be used
1319  * to know how the duration was estimated.
1320  */
1322  AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1323  AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1324  AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1325 };
1326 
1327 typedef struct AVFormatInternal AVFormatInternal;
1329 /**
1330  * Format I/O context.
1331  * New fields can be added to the end with minor version bumps.
1332  * Removal, reordering and changes to existing fields require a major
1333  * version bump.
1334  * sizeof(AVFormatContext) must not be used outside libav*, use
1335  * avformat_alloc_context() to create an AVFormatContext.
1336  *
1337  * Fields can be accessed through AVOptions (av_opt*),
1338  * the name string used matches the associated command line parameter name and
1339  * can be found in libavformat/options_table.h.
1340  * The AVOption/command line parameter names differ in some cases from the C
1341  * structure field names for historic reasons or brevity.
1342  */
1343 typedef struct AVFormatContext {
1344  /**
1345  * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1346  * Exports (de)muxer private options if they exist.
1347  */
1348  const AVClass *av_class;
1349 
1350  /**
1351  * The input container format.
1352  *
1353  * Demuxing only, set by avformat_open_input().
1354  */
1356 
1357  /**
1358  * The output container format.
1359  *
1360  * Muxing only, must be set by the caller before avformat_write_header().
1361  */
1362  ff_const59 struct AVOutputFormat *oformat;
1363 
1364  /**
1365  * Format private data. This is an AVOptions-enabled struct
1366  * if and only if iformat/oformat.priv_class is not NULL.
1367  *
1368  * - muxing: set by avformat_write_header()
1369  * - demuxing: set by avformat_open_input()
1370  */
1371  void *priv_data;
1372 
1373  /**
1374  * I/O context.
1375  *
1376  * - demuxing: either set by the user before avformat_open_input() (then
1377  * the user must close it manually) or set by avformat_open_input().
1378  * - muxing: set by the user before avformat_write_header(). The caller must
1379  * take care of closing / freeing the IO context.
1380  *
1381  * Do NOT set this field if AVFMT_NOFILE flag is set in
1382  * iformat/oformat.flags. In such a case, the (de)muxer will handle
1383  * I/O in some other way and this field will be NULL.
1384  */
1386 
1387  /* stream info */
1388  /**
1389  * Flags signalling stream properties. A combination of AVFMTCTX_*.
1390  * Set by libavformat.
1391  */
1392  int ctx_flags;
1393 
1394  /**
1395  * Number of elements in AVFormatContext.streams.
1396  *
1397  * Set by avformat_new_stream(), must not be modified by any other code.
1398  */
1399  unsigned int nb_streams;
1400  /**
1401  * A list of all streams in the file. New streams are created with
1402  * avformat_new_stream().
1403  *
1404  * - demuxing: streams are created by libavformat in avformat_open_input().
1405  * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1406  * appear in av_read_frame().
1407  * - muxing: streams are created by the user before avformat_write_header().
1408  *
1409  * Freed by libavformat in avformat_free_context().
1410  */
1411  AVStream **streams;
1412 
1413 #if FF_API_FORMAT_FILENAME
1414  /**
1415  * input or output filename
1416  *
1417  * - demuxing: set by avformat_open_input()
1418  * - muxing: may be set by the caller before avformat_write_header()
1419  *
1420  * @deprecated Use url instead.
1421  */
1423  char filename[1024];
1424 #endif
1426  /**
1427  * input or output URL. Unlike the old filename field, this field has no
1428  * length restriction.
1429  *
1430  * - demuxing: set by avformat_open_input(), initialized to an empty
1431  * string if url parameter was NULL in avformat_open_input().
1432  * - muxing: may be set by the caller before calling avformat_write_header()
1433  * (or avformat_init_output() if that is called first) to a string
1434  * which is freeable by av_free(). Set to an empty string if it
1435  * was NULL in avformat_init_output().
1436  *
1437  * Freed by libavformat in avformat_free_context().
1438  */
1439  char *url;
1440 
1441  /**
1442  * Position of the first frame of the component, in
1443  * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1444  * It is deduced from the AVStream values.
1445  *
1446  * Demuxing only, set by libavformat.
1447  */
1448  int64_t start_time;
1449 
1450  /**
1451  * Duration of the stream, in AV_TIME_BASE fractional
1452  * seconds. Only set this value if you know none of the individual stream
1453  * durations and also do not set any of them. This is deduced from the
1454  * AVStream values if not set.
1455  *
1456  * Demuxing only, set by libavformat.
1457  */
1458  int64_t duration;
1459 
1460  /**
1461  * Total stream bitrate in bit/s, 0 if not
1462  * available. Never set it directly if the file_size and the
1463  * duration are known as FFmpeg can compute it automatically.
1464  */
1465  int64_t bit_rate;
1466 
1467  unsigned int packet_size;
1468  int max_delay;
1469 
1470  /**
1471  * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1472  * Set by the user before avformat_open_input() / avformat_write_header().
1473  */
1474  int flags;
1475 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1476 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1477 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1478 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1479 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1480 #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
1481 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1482 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1483 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1484 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1485 /**
1486  * When muxing, try to avoid writing any random/volatile data to the output.
1487  * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1488  *
1489  * This flag is mainly intended for testing.
1490  */
1491 #define AVFMT_FLAG_BITEXACT 0x0400
1492 #if FF_API_LAVF_MP4A_LATM
1493 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Deprecated, does nothing.
1494 #endif
1495 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1496 #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)
1497 #if FF_API_LAVF_KEEPSIDE_FLAG
1498 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Deprecated, does nothing.
1499 #endif
1500 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1501 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
1502 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
1503 
1504  /**
1505  * Maximum size of the data read from input for determining
1506  * the input container format.
1507  * Demuxing only, set by the caller before avformat_open_input().
1508  */
1509  int64_t probesize;
1511  /**
1512  * Maximum duration (in AV_TIME_BASE units) of the data read
1513  * from input in avformat_find_stream_info().
1514  * Demuxing only, set by the caller before avformat_find_stream_info().
1515  * Can be set to 0 to let avformat choose using a heuristic.
1516  */
1517  int64_t max_analyze_duration;
1518 
1519  const uint8_t *key;
1520  int keylen;
1521 
1522  unsigned int nb_programs;
1523  AVProgram **programs;
1524 
1525  /**
1526  * Forced video codec_id.
1527  * Demuxing: Set by user.
1528  */
1529  enum AVCodecID video_codec_id;
1530 
1531  /**
1532  * Forced audio codec_id.
1533  * Demuxing: Set by user.
1534  */
1535  enum AVCodecID audio_codec_id;
1537  /**
1538  * Forced subtitle codec_id.
1539  * Demuxing: Set by user.
1540  */
1541  enum AVCodecID subtitle_codec_id;
1542 
1543  /**
1544  * Maximum amount of memory in bytes to use for the index of each stream.
1545  * If the index exceeds this size, entries will be discarded as
1546  * needed to maintain a smaller size. This can lead to slower or less
1547  * accurate seeking (depends on demuxer).
1548  * Demuxers for which a full in-memory index is mandatory will ignore
1549  * this.
1550  * - muxing: unused
1551  * - demuxing: set by user
1552  */
1553  unsigned int max_index_size;
1554 
1555  /**
1556  * Maximum amount of memory in bytes to use for buffering frames
1557  * obtained from realtime capture devices.
1558  */
1559  unsigned int max_picture_buffer;
1560 
1561  /**
1562  * Number of chapters in AVChapter array.
1563  * When muxing, chapters are normally written in the file header,
1564  * so nb_chapters should normally be initialized before write_header
1565  * is called. Some muxers (e.g. mov and mkv) can also write chapters
1566  * in the trailer. To write chapters in the trailer, nb_chapters
1567  * must be zero when write_header is called and non-zero when
1568  * write_trailer is called.
1569  * - muxing: set by user
1570  * - demuxing: set by libavformat
1571  */
1572  unsigned int nb_chapters;
1573  AVChapter **chapters;
1574 
1575  /**
1576  * Metadata that applies to the whole file.
1577  *
1578  * - demuxing: set by libavformat in avformat_open_input()
1579  * - muxing: may be set by the caller before avformat_write_header()
1580  *
1581  * Freed by libavformat in avformat_free_context().
1582  */
1583  AVDictionary *metadata;
1584 
1585  /**
1586  * Start time of the stream in real world time, in microseconds
1587  * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1588  * stream was captured at this real world time.
1589  * - muxing: Set by the caller before avformat_write_header(). If set to
1590  * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1591  * be used.
1592  * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1593  * the value may become known after some number of frames
1594  * have been received.
1595  */
1596  int64_t start_time_realtime;
1598  /**
1599  * The number of frames used for determining the framerate in
1600  * avformat_find_stream_info().
1601  * Demuxing only, set by the caller before avformat_find_stream_info().
1602  */
1603  int fps_probe_size;
1604 
1605  /**
1606  * Error recognition; higher values will detect more errors but may
1607  * misdetect some more or less valid parts as errors.
1608  * Demuxing only, set by the caller before avformat_open_input().
1609  */
1610  int error_recognition;
1611 
1612  /**
1613  * Custom interrupt callbacks for the I/O layer.
1614  *
1615  * demuxing: set by the user before avformat_open_input().
1616  * muxing: set by the user before avformat_write_header()
1617  * (mainly useful for AVFMT_NOFILE formats). The callback
1618  * should also be passed to avio_open2() if it's used to
1619  * open the file.
1620  */
1621  AVIOInterruptCB interrupt_callback;
1622 
1623  /**
1624  * Flags to enable debugging.
1625  */
1626  int debug;
1627 #define FF_FDEBUG_TS 0x0001
1628 
1629  /**
1630  * Maximum buffering duration for interleaving.
1631  *
1632  * To ensure all the streams are interleaved correctly,
1633  * av_interleaved_write_frame() will wait until it has at least one packet
1634  * for each stream before actually writing any packets to the output file.
1635  * When some streams are "sparse" (i.e. there are large gaps between
1636  * successive packets), this can result in excessive buffering.
1637  *
1638  * This field specifies the maximum difference between the timestamps of the
1639  * first and the last packet in the muxing queue, above which libavformat
1640  * will output a packet regardless of whether it has queued a packet for all
1641  * the streams.
1642  *
1643  * Muxing only, set by the caller before avformat_write_header().
1644  */
1645  int64_t max_interleave_delta;
1646 
1647  /**
1648  * Allow non-standard and experimental extension
1649  * @see AVCodecContext.strict_std_compliance
1650  */
1651  int strict_std_compliance;
1652 
1653  /**
1654  * Flags for the user to detect events happening on the file. Flags must
1655  * be cleared by the user once the event has been handled.
1656  * A combination of AVFMT_EVENT_FLAG_*.
1657  */
1658  int event_flags;
1659 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
1660 
1661  /**
1662  * Maximum number of packets to read while waiting for the first timestamp.
1663  * Decoding only.
1664  */
1665  int max_ts_probe;
1666 
1667  /**
1668  * Avoid negative timestamps during muxing.
1669  * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1670  * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use)
1671  * - muxing: Set by user
1672  * - demuxing: unused
1673  */
1674  int avoid_negative_ts;
1675 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1676 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1677 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1678 
1679  /**
1680  * Transport stream id.
1681  * This will be moved into demuxer private options. Thus no API/ABI compatibility
1682  */
1683  int ts_id;
1684 
1685  /**
1686  * Audio preload in microseconds.
1687  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1688  * - encoding: Set by user
1689  * - decoding: unused
1690  */
1691  int audio_preload;
1692 
1693  /**
1694  * Max chunk time in microseconds.
1695  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1696  * - encoding: Set by user
1697  * - decoding: unused
1698  */
1699  int max_chunk_duration;
1700 
1701  /**
1702  * Max chunk size in bytes
1703  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1704  * - encoding: Set by user
1705  * - decoding: unused
1706  */
1707  int max_chunk_size;
1708 
1709  /**
1710  * forces the use of wallclock timestamps as pts/dts of packets
1711  * This has undefined results in the presence of B frames.
1712  * - encoding: unused
1713  * - decoding: Set by user
1714  */
1715  int use_wallclock_as_timestamps;
1716 
1717  /**
1718  * avio flags, used to force AVIO_FLAG_DIRECT.
1719  * - encoding: unused
1720  * - decoding: Set by user
1721  */
1722  int avio_flags;
1723 
1724  /**
1725  * The duration field can be estimated through various ways, and this field can be used
1726  * to know how the duration was estimated.
1727  * - encoding: unused
1728  * - decoding: Read by user
1729  */
1730  enum AVDurationEstimationMethod duration_estimation_method;
1731 
1732  /**
1733  * Skip initial bytes when opening stream
1734  * - encoding: unused
1735  * - decoding: Set by user
1736  */
1737  int64_t skip_initial_bytes;
1738 
1739  /**
1740  * Correct single timestamp overflows
1741  * - encoding: unused
1742  * - decoding: Set by user
1743  */
1744  unsigned int correct_ts_overflow;
1745 
1746  /**
1747  * Force seeking to any (also non key) frames.
1748  * - encoding: unused
1749  * - decoding: Set by user
1750  */
1751  int seek2any;
1752 
1753  /**
1754  * Flush the I/O context after each packet.
1755  * - encoding: Set by user
1756  * - decoding: unused
1757  */
1758  int flush_packets;
1759 
1760  /**
1761  * format probing score.
1762  * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1763  * the format.
1764  * - encoding: unused
1765  * - decoding: set by avformat, read by user
1766  */
1767  int probe_score;
1768 
1769  /**
1770  * number of bytes to read maximally to identify format.
1771  * - encoding: unused
1772  * - decoding: set by user
1773  */
1774  int format_probesize;
1775 
1776  /**
1777  * ',' separated list of allowed decoders.
1778  * If NULL then all are allowed
1779  * - encoding: unused
1780  * - decoding: set by user
1781  */
1782  char *codec_whitelist;
1783 
1784  /**
1785  * ',' separated list of allowed demuxers.
1786  * If NULL then all are allowed
1787  * - encoding: unused
1788  * - decoding: set by user
1789  */
1790  char *format_whitelist;
1791 
1792  /**
1793  * An opaque field for libavformat internal usage.
1794  * Must not be accessed in any way by callers.
1795  */
1796  AVFormatInternal *internal;
1797 
1798  /**
1799  * IO repositioned flag.
1800  * This is set by avformat when the underlaying IO context read pointer
1801  * is repositioned, for example when doing byte based seeking.
1802  * Demuxers can use the flag to detect such changes.
1803  */
1804  int io_repositioned;
1805 
1806  /**
1807  * Forced video codec.
1808  * This allows forcing a specific decoder, even when there are multiple with
1809  * the same codec_id.
1810  * Demuxing: Set by user
1811  */
1813 
1814  /**
1815  * Forced audio codec.
1816  * This allows forcing a specific decoder, even when there are multiple with
1817  * the same codec_id.
1818  * Demuxing: Set by user
1819  */
1821 
1822  /**
1823  * Forced subtitle codec.
1824  * This allows forcing a specific decoder, even when there are multiple with
1825  * the same codec_id.
1826  * Demuxing: Set by user
1827  */
1829 
1830  /**
1831  * Forced data codec.
1832  * This allows forcing a specific decoder, even when there are multiple with
1833  * the same codec_id.
1834  * Demuxing: Set by user
1835  */
1837 
1838  /**
1839  * Number of bytes to be written as padding in a metadata header.
1840  * Demuxing: Unused.
1841  * Muxing: Set by user via av_format_set_metadata_header_padding.
1842  */
1843  int metadata_header_padding;
1844 
1845  /**
1846  * User data.
1847  * This is a place for some private data of the user.
1848  */
1849  void *opaque;
1851  /**
1852  * Callback used by devices to communicate with application.
1853  */
1854  av_format_control_message control_message_cb;
1855 
1856  /**
1857  * Output timestamp offset, in microseconds.
1858  * Muxing: set by user
1859  */
1860  int64_t output_ts_offset;
1861 
1862  /**
1863  * dump format separator.
1864  * can be ", " or "\n " or anything else
1865  * - muxing: Set by user.
1866  * - demuxing: Set by user.
1867  */
1868  uint8_t *dump_separator;
1869 
1870  /**
1871  * Forced Data codec_id.
1872  * Demuxing: Set by user.
1873  */
1874  enum AVCodecID data_codec_id;
1875 
1876 #if FF_API_OLD_OPEN_CALLBACKS
1877  /**
1878  * Called to open further IO contexts when needed for demuxing.
1879  *
1880  * This can be set by the user application to perform security checks on
1881  * the URLs before opening them.
1882  * The function should behave like avio_open2(), AVFormatContext is provided
1883  * as contextual information and to reach AVFormatContext.opaque.
1884  *
1885  * If NULL then some simple checks are used together with avio_open2().
1886  *
1887  * Must not be accessed directly from outside avformat.
1888  * @See av_format_set_open_cb()
1889  *
1890  * Demuxing: Set by user.
1891  *
1892  * @deprecated Use io_open and io_close.
1893  */
1895  int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options);
1896 #endif
1897 
1898  /**
1899  * ',' separated list of allowed protocols.
1900  * - encoding: unused
1901  * - decoding: set by user
1902  */
1903  char *protocol_whitelist;
1904 
1905  /**
1906  * A callback for opening new IO streams.
1907  *
1908  * Whenever a muxer or a demuxer needs to open an IO stream (typically from
1909  * avformat_open_input() for demuxers, but for certain formats can happen at
1910  * other times as well), it will call this callback to obtain an IO context.
1911  *
1912  * @param s the format context
1913  * @param pb on success, the newly opened IO context should be returned here
1914  * @param url the url to open
1915  * @param flags a combination of AVIO_FLAG_*
1916  * @param options a dictionary of additional options, with the same
1917  * semantics as in avio_open2()
1918  * @return 0 on success, a negative AVERROR code on failure
1919  *
1920  * @note Certain muxers and demuxers do nesting, i.e. they open one or more
1921  * additional internal format contexts. Thus the AVFormatContext pointer
1922  * passed to this callback may be different from the one facing the caller.
1923  * It will, however, have the same 'opaque' field.
1924  */
1925  int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url,
1926  int flags, AVDictionary **options);
1927 
1928  /**
1929  * A callback for closing the streams opened with AVFormatContext.io_open().
1930  */
1931  void (*io_close)(struct AVFormatContext *s, AVIOContext *pb);
1932 
1933  /**
1934  * ',' separated list of disallowed protocols.
1935  * - encoding: unused
1936  * - decoding: set by user
1937  */
1938  char *protocol_blacklist;
1940  /**
1941  * The maximum number of streams.
1942  * - encoding: unused
1943  * - decoding: set by user
1944  */
1946 
1947  /**
1948  * Skip duration calcuation in estimate_timings_from_pts.
1949  * - encoding: unused
1950  * - decoding: set by user
1951  */
1953 
1954  /**
1955  * Maximum number of packets that can be probed
1956  * - encoding: unused
1957  * - decoding: set by user
1958  */
1960 } AVFormatContext;
1961 
1962 #if FF_API_FORMAT_GET_SET
1963 /**
1964  * Accessors for some AVFormatContext fields. These used to be provided for ABI
1965  * compatibility, and do not need to be used anymore.
1966  */
1968 int av_format_get_probe_score(const AVFormatContext *s);
1970 AVCodec * av_format_get_video_codec(const AVFormatContext *s);
1972 void av_format_set_video_codec(AVFormatContext *s, AVCodec *c);
1974 AVCodec * av_format_get_audio_codec(const AVFormatContext *s);
1976 void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c);
1978 AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s);
1980 void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c);
1982 AVCodec * av_format_get_data_codec(const AVFormatContext *s);
1984 void av_format_set_data_codec(AVFormatContext *s, AVCodec *c);
1986 int av_format_get_metadata_header_padding(const AVFormatContext *s);
1988 void av_format_set_metadata_header_padding(AVFormatContext *s, int c);
1990 void * av_format_get_opaque(const AVFormatContext *s);
1992 void av_format_set_opaque(AVFormatContext *s, void *opaque);
1994 av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s);
1996 void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback);
1997 #if FF_API_OLD_OPEN_CALLBACKS
1998 attribute_deprecated AVOpenCallback av_format_get_open_cb(const AVFormatContext *s);
1999 attribute_deprecated void av_format_set_open_cb(AVFormatContext *s, AVOpenCallback callback);
2000 #endif
2001 #endif
2002 
2003 /**
2004  * This function will cause global side data to be injected in the next packet
2005  * of each stream as well as after any subsequent seek.
2006  */
2008 
2009 /**
2010  * Returns the method used to set ctx->duration.
2011  *
2012  * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
2013  */
2015 
2016 typedef struct AVPacketList {
2017  AVPacket pkt;
2018  struct AVPacketList *next;
2019 } AVPacketList;
2020 
2021 
2022 /**
2023  * @defgroup lavf_core Core functions
2024  * @ingroup libavf
2025  *
2026  * Functions for querying libavformat capabilities, allocating core structures,
2027  * etc.
2028  * @{
2029  */
2031 /**
2032  * Return the LIBAVFORMAT_VERSION_INT constant.
2033  */
2034 unsigned avformat_version(void);
2035 
2036 /**
2037  * Return the libavformat build-time configuration.
2038  */
2039 const char *avformat_configuration(void);
2040 
2041 /**
2042  * Return the libavformat license.
2043  */
2044 const char *avformat_license(void);
2045 
2046 #if FF_API_NEXT
2047 /**
2048  * Initialize libavformat and register all the muxers, demuxers and
2049  * protocols. If you do not call this function, then you can select
2050  * exactly which formats you want to support.
2051  *
2052  * @see av_register_input_format()
2053  * @see av_register_output_format()
2054  */
2056 void av_register_all(void);
2057 
2059 void av_register_input_format(AVInputFormat *format);
2061 void av_register_output_format(AVOutputFormat *format);
2062 #endif
2063 
2064 /**
2065  * Do global initialization of network libraries. This is optional,
2066  * and not recommended anymore.
2067  *
2068  * This functions only exists to work around thread-safety issues
2069  * with older GnuTLS or OpenSSL libraries. If libavformat is linked
2070  * to newer versions of those libraries, or if you do not use them,
2071  * calling this function is unnecessary. Otherwise, you need to call
2072  * this function before any other threads using them are started.
2073  *
2074  * This function will be deprecated once support for older GnuTLS and
2075  * OpenSSL libraries is removed, and this function has no purpose
2076  * anymore.
2077  */
2078 int avformat_network_init(void);
2079 
2080 /**
2081  * Undo the initialization done by avformat_network_init. Call it only
2082  * once for each time you called avformat_network_init.
2083  */
2084 int avformat_network_deinit(void);
2085 
2086 #if FF_API_NEXT
2087 /**
2088  * If f is NULL, returns the first registered input format,
2089  * if f is non-NULL, returns the next registered input format after f
2090  * or NULL if f is the last one.
2091  */
2093 AVInputFormat *av_iformat_next(const AVInputFormat *f);
2094 
2095 /**
2096  * If f is NULL, returns the first registered output format,
2097  * if f is non-NULL, returns the next registered output format after f
2098  * or NULL if f is the last one.
2099  */
2101 AVOutputFormat *av_oformat_next(const AVOutputFormat *f);
2102 #endif
2103 
2104 /**
2105  * Iterate over all registered muxers.
2106  *
2107  * @param opaque a pointer where libavformat will store the iteration state. Must
2108  * point to NULL to start the iteration.
2109  *
2110  * @return the next registered muxer or NULL when the iteration is
2111  * finished
2112  */
2113 const AVOutputFormat *av_muxer_iterate(void **opaque);
2114 
2115 /**
2116  * Iterate over all registered demuxers.
2117  *
2118  * @param opaque a pointer where libavformat will store the iteration state. Must
2119  * point to NULL to start the iteration.
2120  *
2121  * @return the next registered demuxer or NULL when the iteration is
2122  * finished
2123  */
2124 const AVInputFormat *av_demuxer_iterate(void **opaque);
2125 
2126 /**
2127  * Allocate an AVFormatContext.
2128  * avformat_free_context() can be used to free the context and everything
2129  * allocated by the framework within it.
2130  */
2132 
2133 /**
2134  * Free an AVFormatContext and all its streams.
2135  * @param s context to free
2136  */
2138 
2139 /**
2140  * Get the AVClass for AVFormatContext. It can be used in combination with
2141  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2142  *
2143  * @see av_opt_find().
2144  */
2145 const AVClass *avformat_get_class(void);
2146 
2147 /**
2148  * Add a new stream to a media file.
2149  *
2150  * When demuxing, it is called by the demuxer in read_header(). If the
2151  * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2152  * be called in read_packet().
2153  *
2154  * When muxing, should be called by the user before avformat_write_header().
2155  *
2156  * User is required to call avcodec_close() and avformat_free_context() to
2157  * clean up the allocation by avformat_new_stream().
2158  *
2159  * @param s media file handle
2160  * @param c If non-NULL, the AVCodecContext corresponding to the new stream
2161  * will be initialized to use this codec. This is needed for e.g. codec-specific
2162  * defaults to be set, so codec should be provided if it is known.
2163  *
2164  * @return newly created stream or NULL on error.
2165  */
2167 
2168 /**
2169  * Wrap an existing array as stream side data.
2170  *
2171  * @param st stream
2172  * @param type side information type
2173  * @param data the side data array. It must be allocated with the av_malloc()
2174  * family of functions. The ownership of the data is transferred to
2175  * st.
2176  * @param size side information size
2177  * @return zero on success, a negative AVERROR code on failure. On failure,
2178  * the stream is unchanged and the data remains owned by the caller.
2179  */
2181  uint8_t *data, size_t size);
2182 
2183 /**
2184  * Allocate new information from stream.
2185  *
2186  * @param stream stream
2187  * @param type desired side information type
2188  * @param size side information size
2189  * @return pointer to fresh allocated data or NULL otherwise
2190  */
2192  enum AVPacketSideDataType type, int size);
2193 /**
2194  * Get side information from stream.
2195  *
2196  * @param stream stream
2197  * @param type desired side information type
2198  * @param size pointer for side information size to store (optional)
2199  * @return pointer to data if present or NULL otherwise
2200  */
2202  enum AVPacketSideDataType type, int *size);
2203 
2205 
2206 /**
2207  * @}
2208  */
2209 
2210 
2211 /**
2212  * Allocate an AVFormatContext for an output format.
2213  * avformat_free_context() can be used to free the context and
2214  * everything allocated by the framework within it.
2215  *
2216  * @param *ctx is set to the created format context, or to NULL in
2217  * case of failure
2218  * @param oformat format to use for allocating the context, if NULL
2219  * format_name and filename are used instead
2220  * @param format_name the name of output format to use for allocating the
2221  * context, if NULL filename is used instead
2222  * @param filename the name of the filename to use for allocating the
2223  * context, may be NULL
2224  * @return >= 0 in case of success, a negative AVERROR code in case of
2225  * failure
2226  */
2228  const char *format_name, const char *filename);
2229 
2230 /**
2231  * @addtogroup lavf_decoding
2232  * @{
2233  */
2234 
2235 /**
2236  * Find AVInputFormat based on the short name of the input format.
2237  */
2238 ff_const59 AVInputFormat *av_find_input_format(const char *short_name);
2239 
2240 /**
2241  * Guess the file format.
2242  *
2243  * @param pd data to be probed
2244  * @param is_opened Whether the file is already opened; determines whether
2245  * demuxers with or without AVFMT_NOFILE are probed.
2246  */
2248 
2249 /**
2250  * Guess the file format.
2251  *
2252  * @param pd data to be probed
2253  * @param is_opened Whether the file is already opened; determines whether
2254  * demuxers with or without AVFMT_NOFILE are probed.
2255  * @param score_max A probe score larger that this is required to accept a
2256  * detection, the variable is set to the actual detection
2257  * score afterwards.
2258  * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2259  * to retry with a larger probe buffer.
2260  */
2261 ff_const59 AVInputFormat *av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max);
2262 
2263 /**
2264  * Guess the file format.
2265  *
2266  * @param is_opened Whether the file is already opened; determines whether
2267  * demuxers with or without AVFMT_NOFILE are probed.
2268  * @param score_ret The score of the best detection.
2269  */
2270 ff_const59 AVInputFormat *av_probe_input_format3(ff_const59 AVProbeData *pd, int is_opened, int *score_ret);
2271 
2272 /**
2273  * Probe a bytestream to determine the input format. Each time a probe returns
2274  * with a score that is too low, the probe buffer size is increased and another
2275  * attempt is made. When the maximum probe size is reached, the input format
2276  * with the highest score is returned.
2277  *
2278  * @param pb the bytestream to probe
2279  * @param fmt the input format is put here
2280  * @param url the url of the stream
2281  * @param logctx the log context
2282  * @param offset the offset within the bytestream to probe from
2283  * @param max_probe_size the maximum probe buffer size (zero for default)
2284  * @return the score in case of success, a negative value corresponding to an
2285  * the maximal score is AVPROBE_SCORE_MAX
2286  * AVERROR code otherwise
2287  */
2289  const char *url, void *logctx,
2290  unsigned int offset, unsigned int max_probe_size);
2291 
2292 /**
2293  * Like av_probe_input_buffer2() but returns 0 on success
2294  */
2296  const char *url, void *logctx,
2297  unsigned int offset, unsigned int max_probe_size);
2298 
2299 /**
2300  * Open an input stream and read the header. The codecs are not opened.
2301  * The stream must be closed with avformat_close_input().
2302  *
2303  * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
2304  * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
2305  * function and written into ps.
2306  * Note that a user-supplied AVFormatContext will be freed on failure.
2307  * @param url URL of the stream to open.
2308  * @param fmt If non-NULL, this parameter forces a specific input format.
2309  * Otherwise the format is autodetected.
2310  * @param options A dictionary filled with AVFormatContext and demuxer-private options.
2311  * On return this parameter will be destroyed and replaced with a dict containing
2312  * options that were not found. May be NULL.
2313  *
2314  * @return 0 on success, a negative AVERROR on failure.
2315  *
2316  * @note If you want to use custom IO, preallocate the format context and set its pb field.
2317  */
2319 
2322 
2323 /**
2324  * Read packets of a media file to get stream information. This
2325  * is useful for file formats with no headers such as MPEG. This
2326  * function also computes the real framerate in case of MPEG-2 repeat
2327  * frame mode.
2328  * The logical file position is not changed by this function;
2329  * examined packets may be buffered for later processing.
2330  *
2331  * @param ic media file handle
2332  * @param options If non-NULL, an ic.nb_streams long array of pointers to
2333  * dictionaries, where i-th member contains options for
2334  * codec corresponding to i-th stream.
2335  * On return each dictionary will be filled with options that were not found.
2336  * @return >=0 if OK, AVERROR_xxx on error
2337  *
2338  * @note this function isn't guaranteed to open all the codecs, so
2339  * options being non-empty at return is a perfectly normal behavior.
2340  *
2341  * @todo Let the user decide somehow what information is needed so that
2342  * we do not waste time getting stuff the user does not need.
2343  */
2345 
2346 /**
2347  * Find the programs which belong to a given stream.
2348  *
2349  * @param ic media file handle
2350  * @param last the last found program, the search will start after this
2351  * program, or from the beginning if it is NULL
2352  * @param s stream index
2353  * @return the next program which belongs to s, NULL if no program is found or
2354  * the last program is not among the programs of ic.
2355  */
2357 
2358 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
2359 
2360 /**
2361  * Find the "best" stream in the file.
2362  * The best stream is determined according to various heuristics as the most
2363  * likely to be what the user expects.
2364  * If the decoder parameter is non-NULL, av_find_best_stream will find the
2365  * default decoder for the stream's codec; streams for which no decoder can
2366  * be found are ignored.
2367  *
2368  * @param ic media file handle
2369  * @param type stream type: video, audio, subtitles, etc.
2370  * @param wanted_stream_nb user-requested stream number,
2371  * or -1 for automatic selection
2372  * @param related_stream try to find a stream related (eg. in the same
2373  * program) to this one, or -1 if none
2374  * @param decoder_ret if non-NULL, returns the decoder for the
2375  * selected stream
2376  * @param flags flags; none are currently defined
2377  * @return the non-negative stream number in case of success,
2378  * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2379  * could be found,
2380  * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2381  * @note If av_find_best_stream returns successfully and decoder_ret is not
2382  * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2383  */
2385  enum AVMediaType type,
2386  int wanted_stream_nb,
2387  int related_stream,
2388  AVCodec **decoder_ret,
2389  int flags);
2390 
2391 /**
2392  * Return the next frame of a stream.
2393  * This function returns what is stored in the file, and does not validate
2394  * that what is there are valid frames for the decoder. It will split what is
2395  * stored in the file into frames and return one for each call. It will not
2396  * omit invalid data between valid frames so as to give the decoder the maximum
2397  * information possible for decoding.
2398  *
2399  * If pkt->buf is NULL, then the packet is valid until the next
2400  * av_read_frame() or until avformat_close_input(). Otherwise the packet
2401  * is valid indefinitely. In both cases the packet must be freed with
2402  * av_packet_unref when it is no longer needed. For video, the packet contains
2403  * exactly one frame. For audio, it contains an integer number of frames if each
2404  * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
2405  * have a variable size (e.g. MPEG audio), then it contains one frame.
2406  *
2407  * pkt->pts, pkt->dts and pkt->duration are always set to correct
2408  * values in AVStream.time_base units (and guessed if the format cannot
2409  * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2410  * has B-frames, so it is better to rely on pkt->dts if you do not
2411  * decompress the payload.
2412  *
2413  * @return 0 if OK, < 0 on error or end of file
2414  */
2416 
2417 /**
2418  * Seek to the keyframe at timestamp.
2419  * 'timestamp' in 'stream_index'.
2420  *
2421  * @param s media file handle
2422  * @param stream_index If stream_index is (-1), a default
2423  * stream is selected, and timestamp is automatically converted
2424  * from AV_TIME_BASE units to the stream specific time_base.
2425  * @param timestamp Timestamp in AVStream.time_base units
2426  * or, if no stream is specified, in AV_TIME_BASE units.
2427  * @param flags flags which select direction and seeking mode
2428  * @return >= 0 on success
2429  */
2430 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2431  int flags);
2432 
2433 /**
2434  * Seek to timestamp ts.
2435  * Seeking will be done so that the point from which all active streams
2436  * can be presented successfully will be closest to ts and within min/max_ts.
2437  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2438  *
2439  * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2440  * are the file position (this may not be supported by all demuxers).
2441  * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2442  * in the stream with stream_index (this may not be supported by all demuxers).
2443  * Otherwise all timestamps are in units of the stream selected by stream_index
2444  * or if stream_index is -1, in AV_TIME_BASE units.
2445  * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2446  * keyframes (this may not be supported by all demuxers).
2447  * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2448  *
2449  * @param s media file handle
2450  * @param stream_index index of the stream which is used as time base reference
2451  * @param min_ts smallest acceptable timestamp
2452  * @param ts target timestamp
2453  * @param max_ts largest acceptable timestamp
2454  * @param flags flags
2455  * @return >=0 on success, error code otherwise
2456  *
2457  * @note This is part of the new seek API which is still under construction.
2458  * Thus do not use this yet. It may change at any time, do not expect
2459  * ABI compatibility yet!
2460  */
2461 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2462 
2463 /**
2464  * Discard all internally buffered data. This can be useful when dealing with
2465  * discontinuities in the byte stream. Generally works only with formats that
2466  * can resync. This includes headerless formats like MPEG-TS/TS but should also
2467  * work with NUT, Ogg and in a limited way AVI for example.
2468  *
2469  * The set of streams, the detected duration, stream parameters and codecs do
2470  * not change when calling this function. If you want a complete reset, it's
2471  * better to open a new AVFormatContext.
2472  *
2473  * This does not flush the AVIOContext (s->pb). If necessary, call
2474  * avio_flush(s->pb) before calling this function.
2475  *
2476  * @param s media file handle
2477  * @return >=0 on success, error code otherwise
2478  */
2480 
2481 /**
2482  * Start playing a network-based stream (e.g. RTSP stream) at the
2483  * current position.
2484  */
2486 
2487 /**
2488  * Pause a network-based stream (e.g. RTSP stream).
2489  *
2490  * Use av_read_play() to resume it.
2491  */
2493 
2494 /**
2495  * Close an opened input AVFormatContext. Free it and all its contents
2496  * and set *s to NULL.
2497  */
2499 /**
2500  * @}
2501  */
2502 
2503 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2504 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2505 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2506 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2507 
2508 /**
2509  * @addtogroup lavf_encoding
2510  * @{
2511  */
2512 
2513 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2514 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2515 
2516 /**
2517  * Allocate the stream private data and write the stream header to
2518  * an output media file.
2519  *
2520  * @param s Media file handle, must be allocated with avformat_alloc_context().
2521  * Its oformat field must be set to the desired output format;
2522  * Its pb field must be set to an already opened AVIOContext.
2523  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2524  * On return this parameter will be destroyed and replaced with a dict containing
2525  * options that were not found. May be NULL.
2526  *
2527  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init,
2528  * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init,
2529  * negative AVERROR on failure.
2530  *
2531  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2532  */
2535 
2536 /**
2537  * Allocate the stream private data and initialize the codec, but do not write the header.
2538  * May optionally be used before avformat_write_header to initialize stream parameters
2539  * before actually writing the header.
2540  * If using this function, do not pass the same options to avformat_write_header.
2541  *
2542  * @param s Media file handle, must be allocated with avformat_alloc_context().
2543  * Its oformat field must be set to the desired output format;
2544  * Its pb field must be set to an already opened AVIOContext.
2545  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2546  * On return this parameter will be destroyed and replaced with a dict containing
2547  * options that were not found. May be NULL.
2548  *
2549  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec requires avformat_write_header to fully initialize,
2550  * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec has been fully initialized,
2551  * negative AVERROR on failure.
2552  *
2553  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2554  */
2557 
2558 /**
2559  * Write a packet to an output media file.
2560  *
2561  * This function passes the packet directly to the muxer, without any buffering
2562  * or reordering. The caller is responsible for correctly interleaving the
2563  * packets if the format requires it. Callers that want libavformat to handle
2564  * the interleaving should call av_interleaved_write_frame() instead of this
2565  * function.
2566  *
2567  * @param s media file handle
2568  * @param pkt The packet containing the data to be written. Note that unlike
2569  * av_interleaved_write_frame(), this function does not take
2570  * ownership of the packet passed to it (though some muxers may make
2571  * an internal reference to the input packet).
2572  * <br>
2573  * This parameter can be NULL (at any time, not just at the end), in
2574  * order to immediately flush data buffered within the muxer, for
2575  * muxers that buffer up data internally before writing it to the
2576  * output.
2577  * <br>
2578  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2579  * set to the index of the corresponding stream in @ref
2580  * AVFormatContext.streams "s->streams".
2581  * <br>
2582  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2583  * must be set to correct values in the stream's timebase (unless the
2584  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2585  * they can be set to AV_NOPTS_VALUE).
2586  * The dts for subsequent packets passed to this function must be strictly
2587  * increasing when compared in their respective timebases (unless the
2588  * output format is flagged with the AVFMT_TS_NONSTRICT, then they
2589  * merely have to be nondecreasing). @ref AVPacket.duration
2590  * "duration") should also be set if known.
2591  * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2592  *
2593  * @see av_interleaved_write_frame()
2594  */
2596 
2597 /**
2598  * Write a packet to an output media file ensuring correct interleaving.
2599  *
2600  * This function will buffer the packets internally as needed to make sure the
2601  * packets in the output file are properly interleaved in the order of
2602  * increasing dts. Callers doing their own interleaving should call
2603  * av_write_frame() instead of this function.
2604  *
2605  * Using this function instead of av_write_frame() can give muxers advance
2606  * knowledge of future packets, improving e.g. the behaviour of the mp4
2607  * muxer for VFR content in fragmenting mode.
2608  *
2609  * @param s media file handle
2610  * @param pkt The packet containing the data to be written.
2611  * <br>
2612  * If the packet is reference-counted, this function will take
2613  * ownership of this reference and unreference it later when it sees
2614  * fit.
2615  * The caller must not access the data through this reference after
2616  * this function returns. If the packet is not reference-counted,
2617  * libavformat will make a copy.
2618  * <br>
2619  * This parameter can be NULL (at any time, not just at the end), to
2620  * flush the interleaving queues.
2621  * <br>
2622  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2623  * set to the index of the corresponding stream in @ref
2624  * AVFormatContext.streams "s->streams".
2625  * <br>
2626  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2627  * must be set to correct values in the stream's timebase (unless the
2628  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2629  * they can be set to AV_NOPTS_VALUE).
2630  * The dts for subsequent packets in one stream must be strictly
2631  * increasing (unless the output format is flagged with the
2632  * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2633  * @ref AVPacket.duration "duration") should also be set if known.
2634  *
2635  * @return 0 on success, a negative AVERROR on error. Libavformat will always
2636  * take care of freeing the packet, even if this function fails.
2637  *
2638  * @see av_write_frame(), AVFormatContext.max_interleave_delta
2639  */
2641 
2642 /**
2643  * Write an uncoded frame to an output media file.
2644  *
2645  * The frame must be correctly interleaved according to the container
2646  * specification; if not, then av_interleaved_write_frame() must be used.
2647  *
2648  * See av_interleaved_write_frame() for details.
2649  */
2650 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2651  AVFrame *frame);
2652 
2653 /**
2654  * Write an uncoded frame to an output media file.
2655  *
2656  * If the muxer supports it, this function makes it possible to write an AVFrame
2657  * structure directly, without encoding it into a packet.
2658  * It is mostly useful for devices and similar special muxers that use raw
2659  * video or PCM data and will not serialize it into a byte stream.
2660  *
2661  * To test whether it is possible to use it with a given muxer and stream,
2662  * use av_write_uncoded_frame_query().
2663  *
2664  * The caller gives up ownership of the frame and must not access it
2665  * afterwards.
2666  *
2667  * @return >=0 for success, a negative code on error
2668  */
2669 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
2670  AVFrame *frame);
2671 
2672 /**
2673  * Test whether a muxer supports uncoded frame.
2674  *
2675  * @return >=0 if an uncoded frame can be written to that muxer and stream,
2676  * <0 if not
2677  */
2678 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2679 
2680 /**
2681  * Write the stream trailer to an output media file and free the
2682  * file private data.
2683  *
2684  * May only be called after a successful call to avformat_write_header.
2685  *
2686  * @param s media file handle
2687  * @return 0 if OK, AVERROR_xxx on error
2688  */
2690 
2691 /**
2692  * Return the output format in the list of registered output formats
2693  * which best matches the provided parameters, or return NULL if
2694  * there is no match.
2695  *
2696  * @param short_name if non-NULL checks if short_name matches with the
2697  * names of the registered formats
2698  * @param filename if non-NULL checks if filename terminates with the
2699  * extensions of the registered formats
2700  * @param mime_type if non-NULL checks if mime_type matches with the
2701  * MIME type of the registered formats
2702  */
2703 ff_const59 AVOutputFormat *av_guess_format(const char *short_name,
2704  const char *filename,
2705  const char *mime_type);
2706 
2707 /**
2708  * Guess the codec ID based upon muxer and filename.
2709  */
2710 enum AVCodecID av_guess_codec(ff_const59 AVOutputFormat *fmt, const char *short_name,
2711  const char *filename, const char *mime_type,
2712  enum AVMediaType type);
2713 
2714 /**
2715  * Get timing information for the data currently output.
2716  * The exact meaning of "currently output" depends on the format.
2717  * It is mostly relevant for devices that have an internal buffer and/or
2718  * work in real time.
2719  * @param s media file handle
2720  * @param stream stream in the media file
2721  * @param[out] dts DTS of the last packet output for the stream, in stream
2722  * time_base units
2723  * @param[out] wall absolute time when that packet whas output,
2724  * in microsecond
2725  * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
2726  * Note: some formats or devices may not allow to measure dts and wall
2727  * atomically.
2728  */
2729 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2730  int64_t *dts, int64_t *wall);
2731 
2732 
2733 /**
2734  * @}
2735  */
2736 
2737 
2738 /**
2739  * @defgroup lavf_misc Utility functions
2740  * @ingroup libavf
2741  * @{
2742  *
2743  * Miscellaneous utility functions related to both muxing and demuxing
2744  * (or neither).
2745  */
2746 
2747 /**
2748  * Send a nice hexadecimal dump of a buffer to the specified file stream.
2749  *
2750  * @param f The file stream pointer where the dump should be sent to.
2751  * @param buf buffer
2752  * @param size buffer size
2753  *
2754  * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2755  */
2756 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2757 
2758 /**
2759  * Send a nice hexadecimal dump of a buffer to the log.
2760  *
2761  * @param avcl A pointer to an arbitrary struct of which the first field is a
2762  * pointer to an AVClass struct.
2763  * @param level The importance level of the message, lower values signifying
2764  * higher importance.
2765  * @param buf buffer
2766  * @param size buffer size
2767  *
2768  * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2769  */
2770 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2771 
2772 /**
2773  * Send a nice dump of a packet to the specified file stream.
2774  *
2775  * @param f The file stream pointer where the dump should be sent to.
2776  * @param pkt packet to dump
2777  * @param dump_payload True if the payload must be displayed, too.
2778  * @param st AVStream that the packet belongs to
2779  */
2780 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2781 
2782 
2783 /**
2784  * Send a nice dump of a packet to the log.
2785  *
2786  * @param avcl A pointer to an arbitrary struct of which the first field is a
2787  * pointer to an AVClass struct.
2788  * @param level The importance level of the message, lower values signifying
2789  * higher importance.
2790  * @param pkt packet to dump
2791  * @param dump_payload True if the payload must be displayed, too.
2792  * @param st AVStream that the packet belongs to
2793  */
2794 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2795  const AVStream *st);
2796 
2797 /**
2798  * Get the AVCodecID for the given codec tag tag.
2799  * If no codec id is found returns AV_CODEC_ID_NONE.
2800  *
2801  * @param tags list of supported codec_id-codec_tag pairs, as stored
2802  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2803  * @param tag codec tag to match to a codec ID
2804  */
2805 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2806 
2807 /**
2808  * Get the codec tag for the given codec id id.
2809  * If no codec tag is found returns 0.
2810  *
2811  * @param tags list of supported codec_id-codec_tag pairs, as stored
2812  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2813  * @param id codec ID to match to a codec tag
2814  */
2815 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2816 
2817 /**
2818  * Get the codec tag for the given codec id.
2819  *
2820  * @param tags list of supported codec_id - codec_tag pairs, as stored
2821  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2822  * @param id codec id that should be searched for in the list
2823  * @param tag A pointer to the found tag
2824  * @return 0 if id was not found in tags, > 0 if it was found
2825  */
2826 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2827  unsigned int *tag);
2828 
2830 
2831 /**
2832  * Get the index for a specific timestamp.
2833  *
2834  * @param st stream that the timestamp belongs to
2835  * @param timestamp timestamp to retrieve the index for
2836  * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2837  * to the timestamp which is <= the requested one, if backward
2838  * is 0, then it will be >=
2839  * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2840  * @return < 0 if no such timestamp could be found
2841  */
2842 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2843 
2844 /**
2845  * Add an index entry into a sorted list. Update the entry if the list
2846  * already contains it.
2847  *
2848  * @param timestamp timestamp in the time base of the given stream
2849  */
2850 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2851  int size, int distance, int flags);
2852 
2853 
2854 /**
2855  * Split a URL string into components.
2856  *
2857  * The pointers to buffers for storing individual components may be null,
2858  * in order to ignore that component. Buffers for components not found are
2859  * set to empty strings. If the port is not found, it is set to a negative
2860  * value.
2861  *
2862  * @param proto the buffer for the protocol
2863  * @param proto_size the size of the proto buffer
2864  * @param authorization the buffer for the authorization
2865  * @param authorization_size the size of the authorization buffer
2866  * @param hostname the buffer for the host name
2867  * @param hostname_size the size of the hostname buffer
2868  * @param port_ptr a pointer to store the port number in
2869  * @param path the buffer for the path
2870  * @param path_size the size of the path buffer
2871  * @param url the URL to split
2872  */
2873 void av_url_split(char *proto, int proto_size,
2874  char *authorization, int authorization_size,
2875  char *hostname, int hostname_size,
2876  int *port_ptr,
2877  char *path, int path_size,
2878  const char *url);
2879 
2880 
2881 /**
2882  * Print detailed information about the input or output format, such as
2883  * duration, bitrate, streams, container, programs, metadata, side data,
2884  * codec and time base.
2885  *
2886  * @param ic the context to analyze
2887  * @param index index of the stream to dump information about
2888  * @param url the URL to print, such as source or destination file
2889  * @param is_output Select whether the specified context is an input(0) or output(1)
2890  */
2892  int index,
2893  const char *url,
2894  int is_output);
2895 
2896 
2897 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
2898 
2899 /**
2900  * Return in 'buf' the path with '%d' replaced by a number.
2901  *
2902  * Also handles the '%0nd' format where 'n' is the total number
2903  * of digits and '%%'.
2904  *
2905  * @param buf destination buffer
2906  * @param buf_size destination buffer size
2907  * @param path numbered sequence string
2908  * @param number frame number
2909  * @param flags AV_FRAME_FILENAME_FLAGS_*
2910  * @return 0 if OK, -1 on format error
2911  */
2912 int av_get_frame_filename2(char *buf, int buf_size,
2913  const char *path, int number, int flags);
2914 
2915 int av_get_frame_filename(char *buf, int buf_size,
2916  const char *path, int number);
2917 
2918 /**
2919  * Check whether filename actually is a numbered sequence generator.
2920  *
2921  * @param filename possible numbered sequence string
2922  * @return 1 if a valid numbered sequence string, 0 otherwise
2923  */
2924 int av_filename_number_test(const char *filename);
2925 
2926 /**
2927  * Generate an SDP for an RTP session.
2928  *
2929  * Note, this overwrites the id values of AVStreams in the muxer contexts
2930  * for getting unique dynamic payload types.
2931  *
2932  * @param ac array of AVFormatContexts describing the RTP streams. If the
2933  * array is composed by only one context, such context can contain
2934  * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2935  * all the contexts in the array (an AVCodecContext per RTP stream)
2936  * must contain only one AVStream.
2937  * @param n_files number of AVCodecContexts contained in ac
2938  * @param buf buffer where the SDP will be stored (must be allocated by
2939  * the caller)
2940  * @param size the size of the buffer
2941  * @return 0 if OK, AVERROR_xxx on error
2942  */
2943 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2944 
2945 /**
2946  * Return a positive value if the given filename has one of the given
2947  * extensions, 0 otherwise.
2948  *
2949  * @param filename file name to check against the given extensions
2950  * @param extensions a comma-separated list of filename extensions
2951  */
2952 int av_match_ext(const char *filename, const char *extensions);
2953 
2954 /**
2955  * Test if the given container can store a codec.
2956  *
2957  * @param ofmt container to check for compatibility
2958  * @param codec_id codec to potentially store in container
2959  * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2960  *
2961  * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2962  * A negative number if this information is not available.
2963  */
2965  int std_compliance);
2966 
2967 /**
2968  * @defgroup riff_fourcc RIFF FourCCs
2969  * @{
2970  * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2971  * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2972  * following code:
2973  * @code
2974  * uint32_t tag = MKTAG('H', '2', '6', '4');
2975  * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2976  * enum AVCodecID id = av_codec_get_id(table, tag);
2977  * @endcode
2978  */
2979 /**
2980  * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2981  */
2982 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2983 /**
2984  * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2985  */
2986 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2987 /**
2988  * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2989  */
2990 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2991 /**
2992  * @return the table mapping MOV FourCCs for audio to AVCodecID.
2993  */
2994 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2995 
2996 /**
2997  * @}
2998  */
2999 
3000 /**
3001  * Guess the sample aspect ratio of a frame, based on both the stream and the
3002  * frame aspect ratio.
3003  *
3004  * Since the frame aspect ratio is set by the codec but the stream aspect ratio
3005  * is set by the demuxer, these two may not be equal. This function tries to
3006  * return the value that you should use if you would like to display the frame.
3007  *
3008  * Basic logic is to use the stream aspect ratio if it is set to something sane
3009  * otherwise use the frame aspect ratio. This way a container setting, which is
3010  * usually easy to modify can override the coded value in the frames.
3011  *
3012  * @param format the format context which the stream is part of
3013  * @param stream the stream which the frame is part of
3014  * @param frame the frame with the aspect ratio to be determined
3015  * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
3016  */
3018 
3019 /**
3020  * Guess the frame rate, based on both the container and codec information.
3021  *
3022  * @param ctx the format context which the stream is part of
3023  * @param stream the stream which the frame is part of
3024  * @param frame the frame for which the frame rate should be determined, may be NULL
3025  * @return the guessed (valid) frame rate, 0/1 if no idea
3026  */
3028 
3029 /**
3030  * Check if the stream st contained in s is matched by the stream specifier
3031  * spec.
3032  *
3033  * See the "stream specifiers" chapter in the documentation for the syntax
3034  * of spec.
3035  *
3036  * @return >0 if st is matched by spec;
3037  * 0 if st is not matched by spec;
3038  * AVERROR code if spec is invalid
3039  *
3040  * @note A stream specifier can match several streams in the format.
3041  */
3043  const char *spec);
3044 
3046 
3047 #if FF_API_OLD_BSF
3048 /**
3049  * Apply a list of bitstream filters to a packet.
3050  *
3051  * @param codec AVCodecContext, usually from an AVStream
3052  * @param pkt the packet to apply filters to. If, on success, the returned
3053  * packet has size == 0 and side_data_elems == 0, it indicates that
3054  * the packet should be dropped
3055  * @param bsfc a NULL-terminated list of filters to apply
3056  * @return >=0 on success;
3057  * AVERROR code on failure
3058  */
3060 int av_apply_bitstream_filters(AVCodecContext *codec, AVPacket *pkt,
3061  AVBitStreamFilterContext *bsfc);
3062 #endif
3063 
3064 enum AVTimebaseSource {
3065  AVFMT_TBCF_AUTO = -1,
3068 #if FF_API_R_FRAME_RATE
3069  AVFMT_TBCF_R_FRAMERATE,
3070 #endif
3071 };
3072 
3073 /**
3074  * Transfer internal timing information from one stream to another.
3075  *
3076  * This function is useful when doing stream copy.
3077  *
3078  * @param ofmt target output format for ost
3079  * @param ost output stream which needs timings copy and adjustments
3080  * @param ist reference input stream to copy timings from
3081  * @param copy_tb define from where the stream codec timebase needs to be imported
3082  */
3084  AVStream *ost, const AVStream *ist,
3085  enum AVTimebaseSource copy_tb);
3086 
3087 /**
3088  * Get the internal codec timebase from a stream.
3089  *
3090  * @param st input stream to extract the timebase from
3091  */
3093 
3094 /**
3095  * @}
3096  */
3097 
3098 #endif /* AVFORMAT_AVFORMAT_H */
void av_url_split(char *proto, int proto_size, char *authorization, int authorization_size, char *hostname, int hostname_size, int *port_ptr, char *path, int path_size, const char *url)
Split a URL string into components.
Definition: utils.c:4774
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:690
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:1939
full parsing and interpolation of timestamps for frames not starting on a packet boundary ...
Definition: avformat.h:801
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:1195
attribute_deprecated int av_demuxer_open(AVFormatContext *ic)
Definition: utils.c:393
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
Definition: mux.c:1199
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
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:2048
int av_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file.
Definition: mux.c:885
const char * fmt
Definition: avisynth_c.h:861
const char * filename
Definition: avformat.h:447
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:5102
enum AVCodecID video_codec
default video codec
Definition: avformat.h:516
ff_const59 struct AVInputFormat * next
Definition: avformat.h:695
GLint GLenum type
Definition: opengl_enc.c:104
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:1312
int avformat_open_input(AVFormatContext **ps, const char *url, ff_const59 AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: utils.c:537
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:1381
int av_probe_input_buffer(AVIOContext *pb, ff_const59 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:312
int priv_data_size
Size of private data so that it can be allocated in the wrapper.
Definition: avformat.h:705
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample format(the sample packing is implied by the sample format) and sample rate.The lists are not just lists
AVCodec.
Definition: avcodec.h:3505
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3973
enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext *ctx)
Returns the method used to set ctx->duration.
Definition: options.c:165
Format I/O context.
Definition: avformat.h:1357
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:5125
static int query_codec(enum AVCodecID id, int std_compliance)
Definition: img2enc.c:219
const struct AVCodecTag * avformat_get_mov_audio_tags(void)
Definition: isom.c:670
Public dictionary API.
static int64_t start_time
Definition: ffplay.c:331
uint8_t
static int nb_streams
Definition: ffprobe.c:281
const struct AVCodecTag * avformat_get_riff_video_tags(void)
Definition: riff.c:604
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:5768
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
#define f(width, name)
Definition: cbs_vp9.c:255
int priv_data_size
size of private data so that it can be allocated in the wrapper
Definition: avformat.h:555
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
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:5309
AVDurationEstimationMethod
The duration of a video can be estimated through various ways, and this enum can be used to know how ...
Definition: avformat.h:1335
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4501
uint8_t * av_stream_get_side_data(const AVStream *stream, enum AVPacketSideDataType type, int *size)
Get side information from stream.
Definition: utils.c:5488
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.
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
#define MAX_REORDER_DELAY
Definition: avformat.h:1106
AVProgram * av_new_program(AVFormatContext *s, int id)
Definition: utils.c:4600
char * protocol_whitelist
&#39;,&#39; separated list of allowed protocols.
Definition: avformat.h:1917
uint32_t tag
Definition: movenc.c:1532
int avformat_network_init(void)
Do global initialization of network libraries.
Definition: utils.c:5039
const struct AVCodecTag * avformat_get_riff_audio_tags(void)
Definition: riff.c:609
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:842
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:308
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:170
ptrdiff_t size
Definition: opengl_enc.c:100
static int interleave_packet(AVFormatContext *s, AVPacket *out, AVPacket *in, int flush)
Interleave an AVPacket correctly so it can be muxed.
Definition: mux.c:1188
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:803
Duration estimated from bitrate (less accurate)
Definition: avformat.h:1338
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:318
const AVOutputFormat * av_muxer_iterate(void **opaque)
Iterate over all registered muxers.
Definition: allformats.c:507
const struct AVCodecTag * avformat_get_mov_video_tags(void)
Definition: isom.c:665
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:578
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:4225
#define ff_const59
The ff_const59 define is not part of the public API and will be removed without further warning...
Definition: avformat.h:549
AVRational av_stream_get_codec_timebase(const AVStream *st)
Get the internal codec timebase from a stream.
Definition: utils.c:5830
ff_const59 AVInputFormat * av_probe_input_format(ff_const59 AVProbeData *pd, int is_opened)
Guess the file format.
Definition: format.c:216
AVProgram * av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s)
Find the programs which belong to a given stream.
Definition: utils.c:4208
ff_const59 AVInputFormat * av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max)
Guess the file format.
Definition: format.c:205
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:2163
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:481
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:5134
char * url
input or output URL.
Definition: avformat.h:1453
const char * r
Definition: vf_curves.c:114
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:4293
ff_const59 AVInputFormat * av_find_input_format(const char *short_name)
Find AVInputFormat based on the short name of the input format.
Definition: format.c:118
int avformat_alloc_output_context2(AVFormatContext **ctx, ff_const59 AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
Definition: mux.c:148
int skip_estimate_duration_from_pts
Skip duration calcuation in estimate_timings_from_pts.
Definition: avformat.h:1966
New fields can be added to the end with minor version bumps.
Definition: avformat.h:1274
void * opaque
User data.
Definition: avformat.h:1863
Only parse headers, do not repack.
Definition: avformat.h:800
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:5021
static float distance(float x, float y, int band)
const char * mime_type
mime_type, when known.
Definition: avformat.h:450
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:449
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
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:4302
MIPS optimizations info
Definition: mips.txt:2
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:516
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:1325
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:5503
int max_streams
The maximum number of streams.
Definition: avformat.h:1959
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
int av_find_default_stream_index(AVFormatContext *s)
Definition: utils.c:1889
static int write_trailer(AVFormatContext *s1)
Definition: v4l2enc.c:94
enum AVCodecID av_guess_codec(ff_const59 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
Duration estimated from a stream with a known duration.
Definition: avformat.h:1337
AVFormatContext * ctx
Definition: movenc.c:48
ff_const59 AVInputFormat * av_probe_input_format3(ff_const59 AVProbeData *pd, int is_opened, int *score_ret)
Guess the file format.
Definition: format.c:128
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
#define s(width, name)
Definition: cbs_vp9.c:257
uint8_t * av_stream_new_side_data(AVStream *stream, enum AVPacketSideDataType type, int size)
Allocate new information from stream.
Definition: utils.c:5539
enum AVCodecID codec_id
Definition: vaapi_decode.c:364
Libavformat version macros.
int(* AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Definition: avformat.h:1328
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:496
const AVInputFormat * av_demuxer_iterate(void **opaque)
Iterate over all registered demuxers.
Definition: allformats.c:524
int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
Definition: utils.c:4769
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
Stream structure.
Definition: avformat.h:880
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:5051
static AVInputFormat * iformat
Definition: ffprobe.c:258
Libavcodec external API header.
int av_probe_input_buffer2(AVIOContext *pb, ff_const59 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
AVIOContext * pb
I/O context.
Definition: avformat.h:1399
main external API structure.
Definition: avcodec.h:1581
int av_filename_number_test(const char *filename)
Check whether filename actually is a numbered sequence generator.
Definition: utils.c:325
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:4714
void(* io_close)(struct AVFormatContext *s, AVIOContext *pb)
A callback for closing the streams opened with AVFormatContext.io_open().
Definition: avformat.h:1945
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)\n", 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:517
ff_const59 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
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVMediaType
Definition: avutil.h:199
int max_probe_packets
Maximum number of packets that can be probed.
Definition: avformat.h:1973
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: utils.c:4432
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1776
List of devices.
Definition: avdevice.h:460
AVTimebaseSource
Definition: avformat.h:3078
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:2544
full parsing and repack of the first frame only, only implemented for H.264 currently ...
Definition: avformat.h:802
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:700
#define flags(name, subs,...)
Definition: cbs_av1.c:561
static int format_name(const char *buf, char **s, int index, const char *varname)
Definition: hlsenc.c:1795
uint8_t level
Definition: svq3.c:207
#define attribute_deprecated
Definition: attributes.h:94
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
Duration accurately estimated from PTSes.
Definition: avformat.h:1336
#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:2521
full parsing and repack
Definition: avformat.h:799
static AVStream * ost
int
const OptionDef options[]
Definition: ffmpeg_opt.c:3374
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:1375
struct AVPacketList * next
Definition: avformat.h:2032
enum AVCodecID data_codec
default data codec
Definition: avformat.h:614
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: utils.c:3599
AVStreamParseType
Definition: avformat.h:797
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:4473
int av_write_uncoded_frame(AVFormatContext *s, int stream_index, AVFrame *frame)
Write an uncoded frame to an output media file.
Definition: mux.c:1369
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:515
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:349
AVDiscard
Definition: avcodec.h:808
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
Definition: mux.c:1261
char * protocol_blacklist
&#39;,&#39; separated list of disallowed protocols.
Definition: avformat.h:1952
int avformat_flush(AVFormatContext *s)
Discard all internally buffered data.
Definition: utils.c:2601
FILE * out
Definition: movenc.c:54
void INT64 start
Definition: avisynth_c.h:766
ff_const59 struct AVOutputFormat * next
Definition: avformat.h:551
int copy_tb
Definition: ffmpeg_opt.c:102
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
unsigned int av_codec_get_tag(const struct AVCodecTag *const *tags, enum AVCodecID id)
Get the codec tag for the given codec id id.
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:1470
#define MAX_STD_TIMEBASES
Definition: avformat.h:1039
int64_t av_stream_get_end_pts(const AVStream *st)
Returns the pts of the last muxed packet + its duration.
Definition: utils.c:141
const char * name
Definition: opengl_enc.c:102