avformat.h source code [include/libavformat/avformat.h]

1	/*
2	* copyright (c) 2001 Fabrice Bellard
3	*
4	* This file is part of FFmpeg.
5	*
6	* FFmpeg is free software; you can redistribute it and/or
7	* modify it under the terms of the GNU Lesser General Public
8	* License as published by the Free Software Foundation; either
9	* version 2.1 of the License, or (at your option) any later version.
10	*
11	* FFmpeg is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14	* Lesser General Public License for more details.
15	*
16	* You should have received a copy of the GNU Lesser General Public
17	* License along with FFmpeg; if not, write to the Free Software
18	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19	*/
20
21	#ifndef AVFORMAT_AVFORMAT_H
22	#define AVFORMAT_AVFORMAT_H
23
24	/**
25	* @file
26	* @ingroup libavf
27	* Main libavformat public API header
28	*/
29
30	/**
31	* @defgroup libavf libavformat
32	* I/O and Muxing/Demuxing Library
33	*
34	* Libavformat (lavf) is a library for dealing with various media container
35	* formats. Its main two purposes are demuxing - i.e. splitting a media file
36	* into component streams, and the reverse process of muxing - writing supplied
37	* data in a specified container format. It also has an @ref lavf_io
38	* "I/O module" which supports a number of protocols for accessing the data (e.g.
39	* file, tcp, http and others).
40	* Unless you are absolutely sure you won't use libavformat's network
41	* capabilities, you should also call avformat_network_init().
42	*
43	* A supported input format is described by an AVInputFormat struct, conversely
44	* an output format is described by AVOutputFormat. You can iterate over all
45	* input/output formats using the av_demuxer_iterate / av_muxer_iterate() functions.
46	* The protocols layer is not part of the public API, so you can only get the names
47	* of supported protocols with the avio_enum_protocols() function.
48	*
49	* Main lavf structure used for both muxing and demuxing is AVFormatContext,
50	* which exports all information about the file being read or written. As with
51	* most Libavformat structures, its size is not part of public ABI, so it cannot be
52	* allocated on stack or directly with av_malloc(). To create an
53	* AVFormatContext, use avformat_alloc_context() (some functions, like
54	* avformat_open_input() might do that for you).
55	*
56	* Most importantly an AVFormatContext contains:
57	* @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat
58	* "output" format. It is either autodetected or set by user for input;
59	* always set by user for output.
60	* @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all
61	* elementary streams stored in the file. AVStreams are typically referred to
62	* using their index in this array.
63	* @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or
64	* set by user for input, always set by user for output (unless you are dealing
65	* with an AVFMT_NOFILE format).
66	*
67	* @section lavf_options Passing options to (de)muxers
68	* It is possible to configure lavf muxers and demuxers using the @ref avoptions
69	* mechanism. Generic (format-independent) libavformat options are provided by
70	* AVFormatContext, they can be examined from a user program by calling
71	* av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass
72	* from avformat_get_class()). Private (format-specific) options are provided by
73	* AVFormatContext.priv_data if and only if AVInputFormat.priv_class /
74	* AVOutputFormat.priv_class of the corresponding format struct is non-NULL.
75	* Further options may be provided by the @ref AVFormatContext.pb "I/O context",
76	* if its AVClass is non-NULL, and the protocols layer. See the discussion on
77	* nesting in @ref avoptions documentation to learn how to access those.
78	*
79	* @section urls
80	* URL strings in libavformat are made of a scheme/protocol, a ':', and a
81	* scheme specific string. URLs without a scheme and ':' used for local files
82	* are supported but deprecated. "file:" should be used for local files.
83	*
84	* It is important that the scheme string is not taken from untrusted
85	* sources without checks.
86	*
87	* Note that some schemes/protocols are quite powerful, allowing access to
88	* both local and remote files, parts of them, concatenations of them, local
89	* audio and video devices and so on.
90	*
91	* @{
92	*
93	* @defgroup lavf_decoding Demuxing
94	* @{
95	* Demuxers read a media file and split it into chunks of data (@em packets). A
96	* @ref AVPacket "packet" contains one or more encoded frames which belongs to a
97	* single elementary stream. In the lavf API this process is represented by the
98	* avformat_open_input() function for opening a file, av_read_frame() for
99	* reading a single packet and finally avformat_close_input(), which does the
100	* cleanup.
101	*
102	* @section lavf_decoding_open Opening a media file
103	* The minimum information required to open a file is its URL, which
104	* is passed to avformat_open_input(), as in the following code:
105	* @code
106	* const char *url = "file:in.mp3";
107	* AVFormatContext *s = NULL;
108	* int ret = avformat_open_input(&s, url, NULL, NULL);
109	* if (ret < 0)
110	* abort();
111	* @endcode
112	* The above code attempts to allocate an AVFormatContext, open the
113	* specified file (autodetecting the format) and read the header, exporting the
114	* information stored there into s. Some formats do not have a header or do not
115	* store enough information there, so it is recommended that you call the
116	* avformat_find_stream_info() function which tries to read and decode a few
117	* frames to find missing information.
118	*
119	* In some cases you might want to preallocate an AVFormatContext yourself with
120	* avformat_alloc_context() and do some tweaking on it before passing it to
121	* avformat_open_input(). One such case is when you want to use custom functions
122	* for reading input data instead of lavf internal I/O layer.
123	* To do that, create your own AVIOContext with avio_alloc_context(), passing
124	* your reading callbacks to it. Then set the @em pb field of your
125	* AVFormatContext to newly created AVIOContext.
126	*
127	* Since the format of the opened file is in general not known until after
128	* avformat_open_input() has returned, it is not possible to set demuxer private
129	* options on a preallocated context. Instead, the options should be passed to
130	* avformat_open_input() wrapped in an AVDictionary:
131	* @code
132	* AVDictionary *options = NULL;
133	* av_dict_set(&options, "video_size", "640x480", 0);
134	* av_dict_set(&options, "pixel_format", "rgb24", 0);
135	*
136	* if (avformat_open_input(&s, url, NULL, &options) < 0)
137	* abort();
138	* av_dict_free(&options);
139	* @endcode
140	* This code passes the private options 'video_size' and 'pixel_format' to the
141	* demuxer. They would be necessary for e.g. the rawvideo demuxer, since it
142	* cannot know how to interpret raw video data otherwise. If the format turns
143	* out to be something different than raw video, those options will not be
144	* recognized by the demuxer and therefore will not be applied. Such unrecognized
145	* options are then returned in the options dictionary (recognized options are
146	* consumed). The calling program can handle such unrecognized options as it
147	* wishes, e.g.
148	* @code
149	* AVDictionaryEntry *e;
150	* if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
151	* fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key);
152	* abort();
153	* }
154	* @endcode
155	*
156	* After you have finished reading the file, you must close it with
157	* avformat_close_input(). It will free everything associated with the file.
158	*
159	* @section lavf_decoding_read Reading from an opened file
160	* Reading data from an opened AVFormatContext is done by repeatedly calling
161	* av_read_frame() on it. Each call, if successful, will return an AVPacket
162	* containing encoded data for one AVStream, identified by
163	* AVPacket.stream_index. This packet may be passed straight into the libavcodec
164	* decoding functions avcodec_send_packet() or avcodec_decode_subtitle2() if the
165	* caller wishes to decode the data.
166	*
167	* AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be
168	* set if known. They may also be unset (i.e. AV_NOPTS_VALUE for
169	* pts/dts, 0 for duration) if the stream does not provide them. The timing
170	* information will be in AVStream.time_base units, i.e. it has to be
171	* multiplied by the timebase to convert them to seconds.
172	*
173	* A packet returned by av_read_frame() is always reference-counted,
174	* i.e. AVPacket.buf is set and the user may keep it indefinitely.
175	* The packet must be freed with av_packet_unref() when it is no
176	* longer needed.
177	*
178	* @section lavf_decoding_seek Seeking
179	* @}
180	*
181	* @defgroup lavf_encoding Muxing
182	* @{
183	* Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write
184	* it into files or other output bytestreams in the specified container format.
185	*
186	* The main API functions for muxing are avformat_write_header() for writing the
187	* file header, av_write_frame() / av_interleaved_write_frame() for writing the
188	* packets and av_write_trailer() for finalizing the file.
189	*
190	* At the beginning of the muxing process, the caller must first call
191	* avformat_alloc_context() to create a muxing context. The caller then sets up
192	* the muxer by filling the various fields in this context:
193	*
194	* - The @ref AVFormatContext.oformat "oformat" field must be set to select the
195	* muxer that will be used.
196	* - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb
197	* "pb" field must be set to an opened IO context, either returned from
198	* avio_open2() or a custom one.
199	* - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must
200	* be created with the avformat_new_stream() function. The caller should fill
201	* the @ref AVStream.codecpar "stream codec parameters" information, such as the
202	* codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id
203	* "id" and other parameters (e.g. width / height, the pixel or sample format,
204	* etc.) as known. The @ref AVStream.time_base "stream timebase" should
205	* be set to the timebase that the caller desires to use for this stream (note
206	* that the timebase actually used by the muxer can be different, as will be
207	* described later).
208	* - It is advised to manually initialize only the relevant fields in
209	* AVCodecParameters, rather than using @ref avcodec_parameters_copy() during
210	* remuxing: there is no guarantee that the codec context values remain valid
211	* for both input and output format contexts.
212	* - The caller may fill in additional information, such as @ref
213	* AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream"
214	* metadata, @ref AVFormatContext.chapters "chapters", @ref
215	* AVFormatContext.programs "programs", etc. as described in the
216	* AVFormatContext documentation. Whether such information will actually be
217	* stored in the output depends on what the container format and the muxer
218	* support.
219	*
220	* When the muxing context is fully set up, the caller must call
221	* avformat_write_header() to initialize the muxer internals and write the file
222	* header. Whether anything actually is written to the IO context at this step
223	* depends on the muxer, but this function must always be called. Any muxer
224	* private options must be passed in the options parameter to this function.
225	*
226	* The data is then sent to the muxer by repeatedly calling av_write_frame() or
227	* av_interleaved_write_frame() (consult those functions' documentation for
228	* discussion on the difference between them; only one of them may be used with
229	* a single muxing context, they should not be mixed). Do note that the timing
230	* information on the packets sent to the muxer must be in the corresponding
231	* AVStream's timebase. That timebase is set by the muxer (in the
232	* avformat_write_header() step) and may be different from the timebase
233	* requested by the caller.
234	*
235	* Once all the data has been written, the caller must call av_write_trailer()
236	* to flush any buffered packets and finalize the output file, then close the IO
237	* context (if any) and finally free the muxing context with
238	* avformat_free_context().
239	* @}
240	*
241	* @defgroup lavf_io I/O Read/Write
242	* @{
243	* @section lavf_io_dirlist Directory listing
244	* The directory listing API makes it possible to list files on remote servers.
245	*
246	* Some of possible use cases:
247	* - an "open file" dialog to choose files from a remote location,
248	* - a recursive media finder providing a player with an ability to play all
249	* files from a given directory.
250	*
251	* @subsection lavf_io_dirlist_open Opening a directory
252	* At first, a directory needs to be opened by calling avio_open_dir()
253	* supplied with a URL and, optionally, ::AVDictionary containing
254	* protocol-specific parameters. The function returns zero or positive
255	* integer and allocates AVIODirContext on success.
256	*
257	* @code
258	* AVIODirContext *ctx = NULL;
259	* if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) {
260	* fprintf(stderr, "Cannot open directory.\n");
261	* abort();
262	* }
263	* @endcode
264	*
265	* This code tries to open a sample directory using smb protocol without
266	* any additional parameters.
267	*
268	* @subsection lavf_io_dirlist_read Reading entries
269	* Each directory's entry (i.e. file, another directory, anything else
270	* within ::AVIODirEntryType) is represented by AVIODirEntry.
271	* Reading consecutive entries from an opened AVIODirContext is done by
272	* repeatedly calling avio_read_dir() on it. Each call returns zero or
273	* positive integer if successful. Reading can be stopped right after the
274	* NULL entry has been read -- it means there are no entries left to be
275	* read. The following code reads all entries from a directory associated
276	* with ctx and prints their names to standard output.
277	* @code
278	* AVIODirEntry *entry = NULL;
279	* for (;;) {
280	* if (avio_read_dir(ctx, &entry) < 0) {
281	* fprintf(stderr, "Cannot list directory.\n");
282	* abort();
283	* }
284	* if (!entry)
285	* break;
286	* printf("%s\n", entry->name);
287	* avio_free_directory_entry(&entry);
288	* }
289	* @endcode
290	* @}
291	*
292	* @defgroup lavf_codec Demuxers
293	* @{
294	* @defgroup lavf_codec_native Native Demuxers
295	* @{
296	* @}
297	* @defgroup lavf_codec_wrappers External library wrappers
298	* @{
299	* @}
300	* @}
301	* @defgroup lavf_protos I/O Protocols
302	* @{
303	* @}
304	* @defgroup lavf_internal Internal
305	* @{
306	* @}
307	* @}
308	*/
309
310	#include <stdio.h> /* FILE */
311
312	#include "libavcodec/codec_par.h"
313	#include "libavcodec/defs.h"
314	#include "libavcodec/packet.h"
315
316	#include "libavutil/dict.h"
317	#include "libavutil/log.h"
318
319	#include "avio.h"
320	#include "libavformat/version_major.h"
321	#ifndef HAVE_AV_CONFIG_H
322	/ When included as part of the ffmpeg build, only include the major version*
323	* to avoid unnecessary rebuilds. When included externally, keep including
324	* the full version information. */
325	#include "libavformat/version.h"
326
327	#include "libavutil/frame.h"
328	#include "libavcodec/codec.h"
329	#endif
330
331	struct AVFormatContext;
332	struct AVFrame;
333
334	/**
335	* @defgroup metadata_api Public Metadata API
336	* @{
337	* @ingroup libavf
338	* The metadata API allows libavformat to export metadata tags to a client
339	* application when demuxing. Conversely it allows a client application to
340	* set metadata when muxing.
341	*
342	* Metadata is exported or set as pairs of key/value strings in the 'metadata'
343	* fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
344	* using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
345	* metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
346	* exported by demuxers isn't checked to be valid UTF-8 in most cases.
347	*
348	* Important concepts to keep in mind:
349	* - Keys are unique; there can never be 2 tags with the same key. This is
350	* also meant semantically, i.e., a demuxer should not knowingly produce
351	* several keys that are literally different but semantically identical.
352	* E.g., key=Author5, key=Author6. In this example, all authors must be
353	* placed in the same tag.
354	* - Metadata is flat, not hierarchical; there are no subtags. If you
355	* want to store, e.g., the email address of the child of producer Alice
356	* and actor Bob, that could have key=alice_and_bobs_childs_email_address.
357	* - Several modifiers can be applied to the tag name. This is done by
358	* appending a dash character ('-') and the modifier name in the order
359	* they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
360	* - language -- a tag whose value is localized for a particular language
361	* is appended with the ISO 639-2/B 3-letter language code.
362	* For example: Author-ger=Michael, Author-eng=Mike
363	* The original/default language is in the unqualified "Author" tag.
364	* A demuxer should set a default if it sets any translated tag.
365	* - sorting -- a modified version of a tag that should be used for
366	* sorting will have '-sort' appended. E.g. artist="The Beatles",
367	* artist-sort="Beatles, The".
368	* - Some protocols and demuxers support metadata updates. After a successful
369	* call to av_read_frame(), AVFormatContext.event_flags or AVStream.event_flags
370	* will be updated to indicate if metadata changed. In order to detect metadata
371	* changes on a stream, you need to loop through all streams in the AVFormatContext
372	* and check their individual event_flags.
373	*
374	* - Demuxers attempt to export metadata in a generic format, however tags
375	* with no generic equivalents are left as they are stored in the container.
376	* Follows a list of generic tag names:
377	*
378	@verbatim
379	album -- name of the set this work belongs to
380	album_artist -- main creator of the set/album, if different from artist.
381	e.g. "Various Artists" for compilation albums.
382	artist -- main creator of the work
383	comment -- any additional description of the file.
384	composer -- who composed the work, if different from artist.
385	copyright -- name of copyright holder.
386	creation_time-- date when the file was created, preferably in ISO 8601.
387	date -- date when the work was created, preferably in ISO 8601.
388	disc -- number of a subset, e.g. disc in a multi-disc collection.
389	encoder -- name/settings of the software/hardware that produced the file.
390	encoded_by -- person/group who created the file.
391	filename -- original name of the file.
392	genre -- <self-evident>.
393	language -- main language in which the work is performed, preferably
394	in ISO 639-2 format. Multiple languages can be specified by
395	separating them with commas.
396	performer -- artist who performed the work, if different from artist.
397	E.g for "Also sprach Zarathustra", artist would be "Richard
398	Strauss" and performer "London Philharmonic Orchestra".
399	publisher -- name of the label/publisher.
400	service_name -- name of the service in broadcasting (channel name).
401	service_provider -- name of the service provider in broadcasting.
402	title -- name of the work.
403	track -- number of this work in the set, can be in form current/total.
404	variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
405	@endverbatim
406	*
407	* Look in the examples section for an application example how to use the Metadata API.
408	*
409	* @}
410	*/
411
412	/ packet functions /
413
414
415	/**
416	* Allocate and read the payload of a packet and initialize its
417	* fields with default values.
418	*
419	* @param s associated IO context
420	* @param pkt packet
421	* @param size desired payload size
422	* @return >0 (read size) if OK, AVERROR_xxx otherwise
423	*/
424	int av_get_packet(AVIOContext s, AVPacket pkt, int size);
425
426
427	/**
428	* Read data and append it to the current content of the AVPacket.
429	* If pkt->size is 0 this is identical to av_get_packet.
430	* Note that this uses av_grow_packet and thus involves a realloc
431	* which is inefficient. Thus this function should only be used
432	* when there is no reasonable way to know (an upper bound of)
433	* the final size.
434	*
435	* @param s associated IO context
436	* @param pkt packet
437	* @param size amount of data to read
438	* @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
439	* will not be lost even if an error occurs.
440	*/
441	int av_append_packet(AVIOContext s, AVPacket pkt, int size);
442
443	/***********************************************/
444	/ input/output formats /
445
446	struct AVCodecTag;
447
448	/**
449	* This structure contains the data a format has to probe a file.
450	*/
451	typedef struct AVProbeData {
452	const char *filename;
453	unsigned char buf; /*< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. /*
454	int buf_size; /< Size of buf except extra allocated bytes /*
455	const char mime_type; /*< mime_type, when known. /*
456	} AVProbeData;
457
458	#define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
459	#define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
460
461	#define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
462	#define AVPROBE_SCORE_MIME 75 ///< score for file mime type
463	#define AVPROBE_SCORE_MAX 100 ///< maximum score
464
465	#define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
466
467	/// Demuxer will use avio_open, no opened file should be provided by the caller.
468	#define AVFMT_NOFILE 0x0001
469	#define AVFMT_NEEDNUMBER 0x0002 /*< Needs '%d' in filename. /
470	/**
471	* The muxer/demuxer is experimental and should be used with caution.
472	*
473	* - demuxers: will not be selected automatically by probing, must be specified
474	* explicitly.
475	*/
476	#define AVFMT_EXPERIMENTAL 0x0004
477	#define AVFMT_SHOW_IDS 0x0008 /*< Show format stream IDs numbers. /
478	#define AVFMT_GLOBALHEADER 0x0040 /*< Format wants global header. /
479	#define AVFMT_NOTIMESTAMPS 0x0080 /*< Format does not need / have any timestamps. /
480	#define AVFMT_GENERIC_INDEX 0x0100 /*< Use generic index building code. /
481	#define AVFMT_TS_DISCONT 0x0200 /*< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps /
482	#define AVFMT_VARIABLE_FPS 0x0400 /*< Format allows variable fps. /
483	#define AVFMT_NODIMENSIONS 0x0800 /*< Format does not need width/height /
484	#define AVFMT_NOSTREAMS 0x1000 /*< Format does not require any streams /
485	#define AVFMT_NOBINSEARCH 0x2000 /*< Format does not allow to fall back on binary search via read_timestamp /
486	#define AVFMT_NOGENSEARCH 0x4000 /*< Format does not allow to fall back on generic search /
487	#define AVFMT_NO_BYTE_SEEK 0x8000 /*< Format does not allow seeking by bytes /
488	#if FF_API_ALLOW_FLUSH
489	#define AVFMT_ALLOW_FLUSH 0x10000 /*< @deprecated: Just send a NULL packet if you want to flush a muxer. /
490	#endif
491	#define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
492	increasing timestamps, but they must
493	still be monotonic */
494	#define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
495	timestamps. If not set the timestamp
496	will be shifted in av_write_frame and
497	av_interleaved_write_frame so they
498	start from 0.
499	The user or muxer can override this through
500	AVFormatContext.avoid_negative_ts
501	*/
502
503	#define AVFMT_SEEK_TO_PTS 0x4000000 /*< Seeking is based on PTS /
504
505	/**
506	* @addtogroup lavf_encoding
507	* @{
508	*/
509	typedef struct AVOutputFormat {
510	const char *name;
511	/**
512	* Descriptive name for the format, meant to be more human-readable
513	* than name. You should use the NULL_IF_CONFIG_SMALL() macro
514	* to define it.
515	*/
516	const char *long_name;
517	const char *mime_type;
518	const char extensions; /*< comma-separated filename extensions /*
519	/ output support /
520	enum AVCodecID audio_codec; /< default audio codec /*
521	enum AVCodecID video_codec; /< default video codec /*
522	enum AVCodecID subtitle_codec; /< default subtitle codec /*
523	/**
524	* can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER,
525	* AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
526	* AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS,
527	* AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
528	*/
529	int flags;
530
531	/**
532	* List of supported codec_id-codec_tag pairs, ordered by "better
533	* choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
534	*/
535	const struct AVCodecTag * const *codec_tag;
536
537
538	const AVClass priv_class; ///< AVClass for the private context*
539	} AVOutputFormat;
540	/**
541	* @}
542	*/
543
544	/**
545	* @addtogroup lavf_decoding
546	* @{
547	*/
548	typedef struct AVInputFormat {
549	/**
550	* A comma separated list of short names for the format. New names
551	* may be appended with a minor bump.
552	*/
553	const char *name;
554
555	/**
556	* Descriptive name for the format, meant to be more human-readable
557	* than name. You should use the NULL_IF_CONFIG_SMALL() macro
558	* to define it.
559	*/
560	const char *long_name;
561
562	/**
563	* Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
564	* AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
565	* AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
566	*/
567	int flags;
568
569	/**
570	* If extensions are defined, then no probe is done. You should
571	* usually not use extension format guessing because it is not
572	* reliable enough
573	*/
574	const char *extensions;
575
576	const struct AVCodecTag * const *codec_tag;
577
578	const AVClass priv_class; ///< AVClass for the private context*
579
580	/**
581	* Comma-separated list of mime types.
582	* It is used check for matching mime types while probing.
583	* @see av_probe_input_format2
584	*/
585	const char *mime_type;
586	} AVInputFormat;
587	/**
588	* @}
589	*/
590
591	enum AVStreamParseType {
592	AVSTREAM_PARSE_NONE,
593	AVSTREAM_PARSE_FULL, /< full parsing and repack /*
594	AVSTREAM_PARSE_HEADERS, /< Only parse headers, do not repack. /*
595	AVSTREAM_PARSE_TIMESTAMPS, /< full parsing and interpolation of timestamps for frames not starting on a packet boundary /*
596	AVSTREAM_PARSE_FULL_ONCE, /< full parsing and repack of the first frame only, only implemented for H.264 currently /*
597	AVSTREAM_PARSE_FULL_RAW, /< full parsing and repack with timestamp and position generation by parser for raw
598	this assumes that each packet in the file contains no demuxer level headers and
599	just codec level data, otherwise position generation would fail /*
600	};
601
602	typedef struct AVIndexEntry {
603	int64_t pos;
604	int64_t timestamp; /<
605	* Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
606	* when seeking to this entry. That means preferable PTS on keyframe based formats.
607	* But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
608	* is known
609	*/
610	#define AVINDEX_KEYFRAME 0x0001
611	#define AVINDEX_DISCARD_FRAME 0x0002 /**
612	* Flag is used to indicate which frame should be discarded after decoding.
613	*/
614	int flags:`2`;
615	int size:`30`; //Yeah, trying to keep the size of this small to reduce memory requirements (it is 24 vs. 32 bytes due to possible 8-byte alignment).
616	int min_distance; /< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. /*
617	} AVIndexEntry;
618
619	/**
620	* The stream should be chosen by default among other streams of the same type,
621	* unless the user has explicitly specified otherwise.
622	*/
623	#define AV_DISPOSITION_DEFAULT (1 << 0)
624	/**
625	* The stream is not in original language.
626	*
627	* @note AV_DISPOSITION_ORIGINAL is the inverse of this disposition. At most
628	* one of them should be set in properly tagged streams.
629	* @note This disposition may apply to any stream type, not just audio.
630	*/
631	#define AV_DISPOSITION_DUB (1 << 1)
632	/**
633	* The stream is in original language.
634	*
635	* @see the notes for AV_DISPOSITION_DUB
636	*/
637	#define AV_DISPOSITION_ORIGINAL (1 << 2)
638	/**
639	* The stream is a commentary track.
640	*/
641	#define AV_DISPOSITION_COMMENT (1 << 3)
642	/**
643	* The stream contains song lyrics.
644	*/
645	#define AV_DISPOSITION_LYRICS (1 << 4)
646	/**
647	* The stream contains karaoke audio.
648	*/
649	#define AV_DISPOSITION_KARAOKE (1 << 5)
650
651	/**
652	* Track should be used during playback by default.
653	* Useful for subtitle track that should be displayed
654	* even when user did not explicitly ask for subtitles.
655	*/
656	#define AV_DISPOSITION_FORCED (1 << 6)
657	/**
658	* The stream is intended for hearing impaired audiences.
659	*/
660	#define AV_DISPOSITION_HEARING_IMPAIRED (1 << 7)
661	/**
662	* The stream is intended for visually impaired audiences.
663	*/
664	#define AV_DISPOSITION_VISUAL_IMPAIRED (1 << 8)
665	/**
666	* The audio stream contains music and sound effects without voice.
667	*/
668	#define AV_DISPOSITION_CLEAN_EFFECTS (1 << 9)
669	/**
670	* The stream is stored in the file as an attached picture/"cover art" (e.g.
671	* APIC frame in ID3v2). The first (usually only) packet associated with it
672	* will be returned among the first few packets read from the file unless
673	* seeking takes place. It can also be accessed at any time in
674	* AVStream.attached_pic.
675	*/
676	#define AV_DISPOSITION_ATTACHED_PIC (1 << 10)
677	/**
678	* The stream is sparse, and contains thumbnail images, often corresponding
679	* to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
680	*/
681	#define AV_DISPOSITION_TIMED_THUMBNAILS (1 << 11)
682
683	/**
684	* The stream is intended to be mixed with a spatial audio track. For example,
685	* it could be used for narration or stereo music, and may remain unchanged by
686	* listener head rotation.
687	*/
688	#define AV_DISPOSITION_NON_DIEGETIC (1 << 12)
689
690	/**
691	* The subtitle stream contains captions, providing a transcription and possibly
692	* a translation of audio. Typically intended for hearing-impaired audiences.
693	*/
694	#define AV_DISPOSITION_CAPTIONS (1 << 16)
695	/**
696	* The subtitle stream contains a textual description of the video content.
697	* Typically intended for visually-impaired audiences or for the cases where the
698	* video cannot be seen.
699	*/
700	#define AV_DISPOSITION_DESCRIPTIONS (1 << 17)
701	/**
702	* The subtitle stream contains time-aligned metadata that is not intended to be
703	* directly presented to the user.
704	*/
705	#define AV_DISPOSITION_METADATA (1 << 18)
706	/**
707	* The stream is intended to be mixed with another stream before presentation.
708	* Used for example to signal the stream contains an image part of a HEIF grid,
709	* or for mix_type=0 in mpegts.
710	*/
711	#define AV_DISPOSITION_DEPENDENT (1 << 19)
712	/**
713	* The video stream contains still images.
714	*/
715	#define AV_DISPOSITION_STILL_IMAGE (1 << 20)
716
717	/**
718	* @return The AV_DISPOSITION_* flag corresponding to disp or a negative error
719	* code if disp does not correspond to a known stream disposition.
720	*/
721	int av_disposition_from_string(const char *disp);
722
723	/**
724	* @param disposition a combination of AV_DISPOSITION_* values
725	* @return The string description corresponding to the lowest set bit in
726	* disposition. NULL when the lowest set bit does not correspond
727	* to a known disposition or when disposition is 0.
728	*/
729	const char av_disposition_to_string(int* disposition);
730
731	/**
732	* Options for behavior on timestamp wrap detection.
733	*/
734	#define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
735	#define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
736	#define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
737
738	/**
739	* Stream structure.
740	* New fields can be added to the end with minor version bumps.
741	* Removal, reordering and changes to existing fields require a major
742	* version bump.
743	* sizeof(AVStream) must not be used outside libav*.
744	*/
745	typedef struct AVStream {
746	/**
747	* A class for @ref avoptions. Set on stream creation.
748	*/
749	const AVClass *av_class;
750
751	int index; /< stream index in AVFormatContext /*
752	/**
753	* Format-specific stream ID.
754	* decoding: set by libavformat
755	* encoding: set by the user, replaced by libavformat if left unset
756	*/
757	int id;
758
759	/**
760	* Codec parameters associated with this stream. Allocated and freed by
761	* libavformat in avformat_new_stream() and avformat_free_context()
762	* respectively.
763	*
764	* - demuxing: filled by libavformat on stream creation or in
765	* avformat_find_stream_info()
766	* - muxing: filled by the caller before avformat_write_header()
767	*/
768	AVCodecParameters *codecpar;
769
770	void *priv_data;
771
772	/**
773	* This is the fundamental unit of time (in seconds) in terms
774	* of which frame timestamps are represented.
775	*
776	* decoding: set by libavformat
777	* encoding: May be set by the caller before avformat_write_header() to
778	* provide a hint to the muxer about the desired timebase. In
779	* avformat_write_header(), the muxer will overwrite this field
780	* with the timebase that will actually be used for the timestamps
781	* written into the file (which may or may not be related to the
782	* user-provided one, depending on the format).
783	*/
784	AVRational time_base;
785
786	/**
787	* Decoding: pts of the first frame of the stream in presentation order, in stream time base.
788	* Only set this if you are absolutely 100% sure that the value you set
789	* it to really is the pts of the first frame.
790	* This may be undefined (AV_NOPTS_VALUE).
791	* @note The ASF header does NOT contain a correct start_time the ASF
792	* demuxer must NOT set this.
793	*/
794	int64_t start_time;
795
796	/**
797	* Decoding: duration of the stream, in stream time base.
798	* If a source file does not specify a duration, but does specify
799	* a bitrate, this value will be estimated from bitrate and file size.
800	*
801	* Encoding: May be set by the caller before avformat_write_header() to
802	* provide a hint to the muxer about the estimated duration.
803	*/
804	int64_t duration;
805
806	int64_t nb_frames; ///< number of frames in this stream if known or 0
807
808	/**
809	* Stream disposition - a combination of AV_DISPOSITION_* flags.
810	* - demuxing: set by libavformat when creating the stream or in
811	* avformat_find_stream_info().
812	* - muxing: may be set by the caller before avformat_write_header().
813	*/
814	int disposition;
815
816	enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
817
818	/**
819	* sample aspect ratio (0 if unknown)
820	* - encoding: Set by user.
821	* - decoding: Set by libavformat.
822	*/
823	AVRational sample_aspect_ratio;
824
825	AVDictionary *metadata;
826
827	/**
828	* Average framerate
829	*
830	* - demuxing: May be set by libavformat when creating the stream or in
831	* avformat_find_stream_info().
832	* - muxing: May be set by the caller before avformat_write_header().
833	*/
834	AVRational avg_frame_rate;
835
836	/**
837	* For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
838	* will contain the attached picture.
839	*
840	* decoding: set by libavformat, must not be modified by the caller.
841	* encoding: unused
842	*/
843	AVPacket attached_pic;
844
845	#if FF_API_AVSTREAM_SIDE_DATA
846	/**
847	* An array of side data that applies to the whole stream (i.e. the
848	* container does not allow it to change between packets).
849	*
850	* There may be no overlap between the side data in this array and side data
851	* in the packets. I.e. a given side data is either exported by the muxer
852	* (demuxing) / set by the caller (muxing) in this array, then it never
853	* appears in the packets, or the side data is exported / sent through
854	* the packets (always in the first packet where the value becomes known or
855	* changes), then it does not appear in this array.
856	*
857	* - demuxing: Set by libavformat when the stream is created.
858	* - muxing: May be set by the caller before avformat_write_header().
859	*
860	* Freed by libavformat in avformat_free_context().
861	*
862	* @deprecated use AVStream's @ref AVCodecParameters.coded_side_data
863	* "codecpar side data".
864	*/
865	attribute_deprecated
866	AVPacketSideData *side_data;
867	/**
868	* The number of elements in the AVStream.side_data array.
869	*
870	* @deprecated use AVStream's @ref AVCodecParameters.nb_coded_side_data
871	* "codecpar side data".
872	*/
873	attribute_deprecated
874	int nb_side_data;
875	#endif
876
877	/**
878	* Flags indicating events happening on the stream, a combination of
879	* AVSTREAM_EVENT_FLAG_*.
880	*
881	* - demuxing: may be set by the demuxer in avformat_open_input(),
882	* avformat_find_stream_info() and av_read_frame(). Flags must be cleared
883	* by the user once the event has been handled.
884	* - muxing: may be set by the user after avformat_write_header(). to
885	* indicate a user-triggered event. The muxer will clear the flags for
886	* events it has handled in av_[interleaved]_write_frame().
887	*/
888	int event_flags;
889	/**
890	* - demuxing: the demuxer read new metadata from the file and updated
891	* AVStream.metadata accordingly
892	* - muxing: the user updated AVStream.metadata and wishes the muxer to write
893	* it into the file
894	*/
895	#define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001
896	/**
897	* - demuxing: new packets for this stream were read from the file. This
898	* event is informational only and does not guarantee that new packets
899	* for this stream will necessarily be returned from av_read_frame().
900	*/
901	#define AVSTREAM_EVENT_FLAG_NEW_PACKETS (1 << 1)
902
903	/**
904	* Real base framerate of the stream.
905	* This is the lowest framerate with which all timestamps can be
906	* represented accurately (it is the least common multiple of all
907	* framerates in the stream). Note, this value is just a guess!
908	* For example, if the time base is 1/90000 and all frames have either
909	* approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
910	*/
911	AVRational r_frame_rate;
912
913	/**
914	* Number of bits in timestamps. Used for wrapping control.
915	*
916	* - demuxing: set by libavformat
917	* - muxing: set by libavformat
918	*
919	*/
920	int pts_wrap_bits;
921	} AVStream;
922
923	/**
924	* AVStreamGroupTileGrid holds information on how to combine several
925	* independent images on a single canvas for presentation.
926	*
927	* The output should be a @ref AVStreamGroupTileGrid.background "background"
928	* colored @ref AVStreamGroupTileGrid.coded_width "coded_width" x
929	* @ref AVStreamGroupTileGrid.coded_height "coded_height" canvas where a
930	* @ref AVStreamGroupTileGrid.nb_tiles "nb_tiles" amount of tiles are placed in
931	* the order they appear in the @ref AVStreamGroupTileGrid.offsets "offsets"
932	* array, at the exact offset described for them. In particular, if two or more
933	* tiles overlap, the image with higher index in the
934	* @ref AVStreamGroupTileGrid.offsets "offsets" array takes priority.
935	* Note that a single image may be used multiple times, i.e. multiple entries
936	* in @ref AVStreamGroupTileGrid.offsets "offsets" may have the same value of
937	* idx.
938	*
939	* The following is an example of a simple grid with 3 rows and 4 columns:
940	*
941	* +---+---+---+---+
942	* \| 0 \| 1 \| 2 \| 3 \|
943	* +---+---+---+---+
944	* \| 4 \| 5 \| 6 \| 7 \|
945	* +---+---+---+---+
946	* \| 8 \| 9 \|10 \|11 \|
947	* +---+---+---+---+
948	*
949	* Assuming all tiles have a dimension of 512x512, the
950	* @ref AVStreamGroupTileGrid.offsets "offset" of the topleft pixel of
951	* the first @ref AVStreamGroup.streams "stream" in the group is "0,0", the
952	* @ref AVStreamGroupTileGrid.offsets "offset" of the topleft pixel of
953	* the second @ref AVStreamGroup.streams "stream" in the group is "512,0", the
954	* @ref AVStreamGroupTileGrid.offsets "offset" of the topleft pixel of
955	* the fifth @ref AVStreamGroup.streams "stream" in the group is "0,512", the
956	* @ref AVStreamGroupTileGrid.offsets "offset", of the topleft pixel of
957	* the sixth @ref AVStreamGroup.streams "stream" in the group is "512,512",
958	* etc.
959	*
960	* The following is an example of a canvas with overlaping tiles:
961	*
962	* +-----------+
963	* \| %%%%% \|
964	* \|***%%3%%@@@\|
965	* \|**0%%%%%2@@\|
966	* \|***##1@@@@@\|
967	* \| ##### \|
968	* +-----------+
969	*
970	* Assuming a canvas with size 1024x1024 and all tiles with a dimension of
971	* 512x512, a possible @ref AVStreamGroupTileGrid.offsets "offset" for the
972	* topleft pixel of the first @ref AVStreamGroup.streams "stream" in the group
973	* would be 0x256, the @ref AVStreamGroupTileGrid.offsets "offset" for the
974	* topleft pixel of the second @ref AVStreamGroup.streams "stream" in the group
975	* would be 256x512, the @ref AVStreamGroupTileGrid.offsets "offset" for the
976	* topleft pixel of the third @ref AVStreamGroup.streams "stream" in the group
977	* would be 512x256, and the @ref AVStreamGroupTileGrid.offsets "offset" for
978	* the topleft pixel of the fourth @ref AVStreamGroup.streams "stream" in the
979	* group would be 256x0.
980	*
981	* sizeof(AVStreamGroupTileGrid) is not a part of the ABI and may only be
982	* allocated by avformat_stream_group_create().
983	*/
984	typedef struct AVStreamGroupTileGrid {
985	const AVClass *av_class;
986
987	/**
988	* Amount of tiles in the grid.
989	*
990	* Must be > 0.
991	*/
992	unsigned int nb_tiles;
993
994	/**
995	* Width of the canvas.
996	*
997	* Must be > 0.
998	*/
999	int coded_width;
1000	/**
1001	* Width of the canvas.
1002	*
1003	* Must be > 0.
1004	*/
1005	int coded_height;
1006
1007	/**
1008	* An @ref nb_tiles sized array of offsets in pixels from the topleft edge
1009	* of the canvas, indicating where each stream should be placed.
1010	* It must be allocated with the av_malloc() family of functions.
1011	*
1012	* - demuxing: set by libavformat, must not be modified by the caller.
1013	* - muxing: set by the caller before avformat_write_header().
1014	*
1015	* Freed by libavformat in avformat_free_context().
1016	*/
1017	struct {
1018	/**
1019	* Index of the stream in the group this tile references.
1020	*
1021	* Must be < @ref AVStreamGroup.nb_streams "nb_streams".
1022	*/
1023	unsigned int idx;
1024	/**
1025	* Offset in pixels from the left edge of the canvas where the tile
1026	* should be placed.
1027	*/
1028	int horizontal;
1029	/**
1030	* Offset in pixels from the top edge of the canvas where the tile
1031	* should be placed.
1032	*/
1033	int vertical;
1034	} *offsets;
1035
1036	/**
1037	* The pixel value per channel in RGBA format used if no pixel of any tile
1038	* is located at a particular pixel location.
1039	*
1040	* @see av_image_fill_color().
1041	* @see av_parse_color().
1042	*/
1043	uint8_t background[`4`];
1044
1045	/**
1046	* Offset in pixels from the left edge of the canvas where the actual image
1047	* meant for presentation starts.
1048	*
1049	* This field must be >= 0 and < @ref coded_width.
1050	*/
1051	int horizontal_offset;
1052	/**
1053	* Offset in pixels from the top edge of the canvas where the actual image
1054	* meant for presentation starts.
1055	*
1056	* This field must be >= 0 and < @ref coded_height.
1057	*/
1058	int vertical_offset;
1059
1060	/**
1061	* Width of the final image for presentation.
1062	*
1063	* Must be > 0 and <= (@ref coded_width - @ref horizontal_offset).
1064	* When it's not equal to (@ref coded_width - @ref horizontal_offset), the
1065	* result of (@ref coded_width - width - @ref horizontal_offset) is the
1066	* amount amount of pixels to be cropped from the right edge of the
1067	* final image before presentation.
1068	*/
1069	int width;
1070	/**
1071	* Height of the final image for presentation.
1072	*
1073	* Must be > 0 and <= (@ref coded_height - @ref vertical_offset).
1074	* When it's not equal to (@ref coded_height - @ref vertical_offset), the
1075	* result of (@ref coded_height - height - @ref vertical_offset) is the
1076	* amount amount of pixels to be cropped from the bottom edge of the
1077	* final image before presentation.
1078	*/
1079	int height;
1080	} AVStreamGroupTileGrid;
1081
1082	enum AVStreamGroupParamsType {
1083	AV_STREAM_GROUP_PARAMS_NONE,
1084	AV_STREAM_GROUP_PARAMS_IAMF_AUDIO_ELEMENT,
1085	AV_STREAM_GROUP_PARAMS_IAMF_MIX_PRESENTATION,
1086	AV_STREAM_GROUP_PARAMS_TILE_GRID,
1087	};
1088
1089	struct AVIAMFAudioElement;
1090	struct AVIAMFMixPresentation;
1091
1092	typedef struct AVStreamGroup {
1093	/**
1094	* A class for @ref avoptions. Set by avformat_stream_group_create().
1095	*/
1096	const AVClass *av_class;
1097
1098	void *priv_data;
1099
1100	/**
1101	* Group index in AVFormatContext.
1102	*/
1103	unsigned int index;
1104
1105	/**
1106	* Group type-specific group ID.
1107	*
1108	* decoding: set by libavformat
1109	* encoding: may set by the user
1110	*/
1111	int64_t id;
1112
1113	/**
1114	* Group type
1115	*
1116	* decoding: set by libavformat on group creation
1117	* encoding: set by avformat_stream_group_create()
1118	*/
1119	enum AVStreamGroupParamsType type;
1120
1121	/**
1122	* Group type-specific parameters
1123	*/
1124	union {
1125	struct AVIAMFAudioElement *iamf_audio_element;
1126	struct AVIAMFMixPresentation *iamf_mix_presentation;
1127	struct AVStreamGroupTileGrid *tile_grid;
1128	} params;
1129
1130	/**
1131	* Metadata that applies to the whole group.
1132	*
1133	* - demuxing: set by libavformat on group creation
1134	* - muxing: may be set by the caller before avformat_write_header()
1135	*
1136	* Freed by libavformat in avformat_free_context().
1137	*/
1138	AVDictionary *metadata;
1139
1140	/**
1141	* Number of elements in AVStreamGroup.streams.
1142	*
1143	* Set by avformat_stream_group_add_stream() must not be modified by any other code.
1144	*/
1145	unsigned int nb_streams;
1146
1147	/**
1148	* A list of streams in the group. New entries are created with
1149	* avformat_stream_group_add_stream().
1150	*
1151	* - demuxing: entries are created by libavformat on group creation.
1152	* If AVFMTCTX_NOHEADER is set in ctx_flags, then new entries may also
1153	* appear in av_read_frame().
1154	* - muxing: entries are created by the user before avformat_write_header().
1155	*
1156	* Freed by libavformat in avformat_free_context().
1157	*/
1158	AVStream **streams;
1159
1160	/**
1161	* Stream group disposition - a combination of AV_DISPOSITION_* flags.
1162	* This field currently applies to all defined AVStreamGroupParamsType.
1163	*
1164	* - demuxing: set by libavformat when creating the group or in
1165	* avformat_find_stream_info().
1166	* - muxing: may be set by the caller before avformat_write_header().
1167	*/
1168	int disposition;
1169	} AVStreamGroup;
1170
1171	struct AVCodecParserContext av_stream_get_parser(const* AVStream *s);
1172
1173	// Chromium: We use the internal field first_dts vvv
1174	int64_t av_stream_get_first_dts(const AVStream *st);
1175	// Chromium: We use the internal field first_dts ^^^
1176
1177	#define AV_PROGRAM_RUNNING 1
1178
1179	/**
1180	* New fields can be added to the end with minor version bumps.
1181	* Removal, reordering and changes to existing fields require a major
1182	* version bump.
1183	* sizeof(AVProgram) must not be used outside libav*.
1184	*/
1185	typedef struct AVProgram {
1186	int id;
1187	int flags;
1188	enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1189	unsigned int *stream_index;
1190	unsigned int nb_stream_indexes;
1191	AVDictionary *metadata;
1192
1193	int program_num;
1194	int pmt_pid;
1195	int pcr_pid;
1196	int pmt_version;
1197
1198	/*****************************************************************
1199	* All fields below this line are not part of the public API. They
1200	* may not be used outside of libavformat and can be changed and
1201	* removed at will.
1202	* New public fields should be added right above.
1203	*****************************************************************
1204	*/
1205	int64_t start_time;
1206	int64_t end_time;
1207
1208	int64_t pts_wrap_reference; ///< reference dts for wrap detection
1209	int pts_wrap_behavior; ///< behavior on wrap detection
1210	} AVProgram;
1211
1212	#define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1213	(streams are added dynamically) */
1214	#define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely
1215	not seekable, and attempts to call the
1216	seek function will fail. For some
1217	network protocols (e.g. HLS), this can
1218	change dynamically at runtime. */
1219
1220	typedef struct AVChapter {
1221	int64_t id; ///< unique ID to identify the chapter
1222	AVRational time_base; ///< time base in which the start/end timestamps are specified
1223	int64_t start, end; ///< chapter start/end time in time_base units
1224	AVDictionary *metadata;
1225	} AVChapter;
1226
1227
1228	/**
1229	* Callback used by devices to communicate with application.
1230	*/
1231	typedef int (av_format_control_message)(struct* AVFormatContext s, int* type,
1232	void *data, size_t data_size);
1233
1234	typedef int (AVOpenCallback)(struct* AVFormatContext s, AVIOContext pb, const* char url, int* flags,
1235	const AVIOInterruptCB int_cb, AVDictionary *options);
1236
1237	/**
1238	* The duration of a video can be estimated through various ways, and this enum can be used
1239	* to know how the duration was estimated.
1240	*/
1241	enum AVDurationEstimationMethod {
1242	AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1243	AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1244	AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1245	};
1246
1247	/**
1248	* Format I/O context.
1249	* New fields can be added to the end with minor version bumps.
1250	* Removal, reordering and changes to existing fields require a major
1251	* version bump.
1252	* sizeof(AVFormatContext) must not be used outside libav*, use
1253	* avformat_alloc_context() to create an AVFormatContext.
1254	*
1255	* Fields can be accessed through AVOptions (av_opt*),
1256	* the name string used matches the associated command line parameter name and
1257	* can be found in libavformat/options_table.h.
1258	* The AVOption/command line parameter names differ in some cases from the C
1259	* structure field names for historic reasons or brevity.
1260	*/
1261	typedef struct AVFormatContext {
1262	/**
1263	* A class for logging and @ref avoptions. Set by avformat_alloc_context().
1264	* Exports (de)muxer private options if they exist.
1265	*/
1266	const AVClass *av_class;
1267
1268	/**
1269	* The input container format.
1270	*
1271	* Demuxing only, set by avformat_open_input().
1272	*/
1273	const struct AVInputFormat *iformat;
1274
1275	/**
1276	* The output container format.
1277	*
1278	* Muxing only, must be set by the caller before avformat_write_header().
1279	*/
1280	const struct AVOutputFormat *oformat;
1281
1282	/**
1283	* Format private data. This is an AVOptions-enabled struct
1284	* if and only if iformat/oformat.priv_class is not NULL.
1285	*
1286	* - muxing: set by avformat_write_header()
1287	* - demuxing: set by avformat_open_input()
1288	*/
1289	void *priv_data;
1290
1291	/**
1292	* I/O context.
1293	*
1294	* - demuxing: either set by the user before avformat_open_input() (then
1295	* the user must close it manually) or set by avformat_open_input().
1296	* - muxing: set by the user before avformat_write_header(). The caller must
1297	* take care of closing / freeing the IO context.
1298	*
1299	* Do NOT set this field if AVFMT_NOFILE flag is set in
1300	* iformat/oformat.flags. In such a case, the (de)muxer will handle
1301	* I/O in some other way and this field will be NULL.
1302	*/
1303	AVIOContext *pb;
1304
1305	/ stream info /
1306	/**
1307	* Flags signalling stream properties. A combination of AVFMTCTX_*.
1308	* Set by libavformat.
1309	*/
1310	int ctx_flags;
1311
1312	/**
1313	* Number of elements in AVFormatContext.streams.
1314	*
1315	* Set by avformat_new_stream(), must not be modified by any other code.
1316	*/
1317	unsigned int nb_streams;
1318	/**
1319	* A list of all streams in the file. New streams are created with
1320	* avformat_new_stream().
1321	*
1322	* - demuxing: streams are created by libavformat in avformat_open_input().
1323	* If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1324	* appear in av_read_frame().
1325	* - muxing: streams are created by the user before avformat_write_header().
1326	*
1327	* Freed by libavformat in avformat_free_context().
1328	*/
1329	AVStream **streams;
1330
1331	/**
1332	* Number of elements in AVFormatContext.stream_groups.
1333	*
1334	* Set by avformat_stream_group_create(), must not be modified by any other code.
1335	*/
1336	unsigned int nb_stream_groups;
1337	/**
1338	* A list of all stream groups in the file. New groups are created with
1339	* avformat_stream_group_create(), and filled with avformat_stream_group_add_stream().
1340	*
1341	* - demuxing: groups may be created by libavformat in avformat_open_input().
1342	* If AVFMTCTX_NOHEADER is set in ctx_flags, then new groups may also
1343	* appear in av_read_frame().
1344	* - muxing: groups may be created by the user before avformat_write_header().
1345	*
1346	* Freed by libavformat in avformat_free_context().
1347	*/
1348	AVStreamGroup **stream_groups;
1349
1350	/**
1351	* Number of chapters in AVChapter array.
1352	* When muxing, chapters are normally written in the file header,
1353	* so nb_chapters should normally be initialized before write_header
1354	* is called. Some muxers (e.g. mov and mkv) can also write chapters
1355	* in the trailer. To write chapters in the trailer, nb_chapters
1356	* must be zero when write_header is called and non-zero when
1357	* write_trailer is called.
1358	* - muxing: set by user
1359	* - demuxing: set by libavformat
1360	*/
1361	unsigned int nb_chapters;
1362	AVChapter **chapters;
1363
1364	/**
1365	* input or output URL. Unlike the old filename field, this field has no
1366	* length restriction.
1367	*
1368	* - demuxing: set by avformat_open_input(), initialized to an empty
1369	* string if url parameter was NULL in avformat_open_input().
1370	* - muxing: may be set by the caller before calling avformat_write_header()
1371	* (or avformat_init_output() if that is called first) to a string
1372	* which is freeable by av_free(). Set to an empty string if it
1373	* was NULL in avformat_init_output().
1374	*
1375	* Freed by libavformat in avformat_free_context().
1376	*/
1377	char *url;
1378
1379	/**
1380	* Position of the first frame of the component, in
1381	* AV_TIME_BASE fractional seconds. NEVER set this value directly:
1382	* It is deduced from the AVStream values.
1383	*
1384	* Demuxing only, set by libavformat.
1385	*/
1386	int64_t start_time;
1387
1388	/**
1389	* Duration of the stream, in AV_TIME_BASE fractional
1390	* seconds. Only set this value if you know none of the individual stream
1391	* durations and also do not set any of them. This is deduced from the
1392	* AVStream values if not set.
1393	*
1394	* Demuxing only, set by libavformat.
1395	*/
1396	int64_t duration;
1397
1398	/**
1399	* Total stream bitrate in bit/s, 0 if not
1400	* available. Never set it directly if the file_size and the
1401	* duration are known as FFmpeg can compute it automatically.
1402	*/
1403	int64_t bit_rate;
1404
1405	unsigned int packet_size;
1406	int max_delay;
1407
1408	/**
1409	* Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1410	* Set by the user before avformat_open_input() / avformat_write_header().
1411	*/
1412	int flags;
1413	#define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1414	#define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1415	#define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1416	#define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1417	#define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1418	#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
1419	#define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1420	#define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1421	#define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1422	#define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1423	/**
1424	* When muxing, try to avoid writing any random/volatile data to the output.
1425	* This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1426	*
1427	* This flag is mainly intended for testing.
1428	*/
1429	#define AVFMT_FLAG_BITEXACT 0x0400
1430	#define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1431	#define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1432	#if FF_API_LAVF_SHORTEST
1433	#define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
1434	#endif
1435	#define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
1436
1437	/**
1438	* Maximum number of bytes read from input in order to determine stream
1439	* properties. Used when reading the global header and in
1440	* avformat_find_stream_info().
1441	*
1442	* Demuxing only, set by the caller before avformat_open_input().
1443	*
1444	* @note this is \e not used for determining the \ref AVInputFormat
1445	* "input format"
1446	* @sa format_probesize
1447	*/
1448	int64_t probesize;
1449
1450	/**
1451	* Maximum duration (in AV_TIME_BASE units) of the data read
1452	* from input in avformat_find_stream_info().
1453	* Demuxing only, set by the caller before avformat_find_stream_info().
1454	* Can be set to 0 to let avformat choose using a heuristic.
1455	*/
1456	int64_t max_analyze_duration;
1457
1458	const uint8_t *key;
1459	int keylen;
1460
1461	unsigned int nb_programs;
1462	AVProgram **programs;
1463
1464	/**
1465	* Forced video codec_id.
1466	* Demuxing: Set by user.
1467	*/
1468	enum AVCodecID video_codec_id;
1469
1470	/**
1471	* Forced audio codec_id.
1472	* Demuxing: Set by user.
1473	*/
1474	enum AVCodecID audio_codec_id;
1475
1476	/**
1477	* Forced subtitle codec_id.
1478	* Demuxing: Set by user.
1479	*/
1480	enum AVCodecID subtitle_codec_id;
1481
1482	/**
1483	* Forced Data codec_id.
1484	* Demuxing: Set by user.
1485	*/
1486	enum AVCodecID data_codec_id;
1487
1488	/**
1489	* Metadata that applies to the whole file.
1490	*
1491	* - demuxing: set by libavformat in avformat_open_input()
1492	* - muxing: may be set by the caller before avformat_write_header()
1493	*
1494	* Freed by libavformat in avformat_free_context().
1495	*/
1496	AVDictionary *metadata;
1497
1498	/**
1499	* Start time of the stream in real world time, in microseconds
1500	* since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1501	* stream was captured at this real world time.
1502	* - muxing: Set by the caller before avformat_write_header(). If set to
1503	* either 0 or AV_NOPTS_VALUE, then the current wall-time will
1504	* be used.
1505	* - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1506	* the value may become known after some number of frames
1507	* have been received.
1508	*/
1509	int64_t start_time_realtime;
1510
1511	/**
1512	* The number of frames used for determining the framerate in
1513	* avformat_find_stream_info().
1514	* Demuxing only, set by the caller before avformat_find_stream_info().
1515	*/
1516	int fps_probe_size;
1517
1518	/**
1519	* Error recognition; higher values will detect more errors but may
1520	* misdetect some more or less valid parts as errors.
1521	* Demuxing only, set by the caller before avformat_open_input().
1522	*/
1523	int error_recognition;
1524
1525	/**
1526	* Custom interrupt callbacks for the I/O layer.
1527	*
1528	* demuxing: set by the user before avformat_open_input().
1529	* muxing: set by the user before avformat_write_header()
1530	* (mainly useful for AVFMT_NOFILE formats). The callback
1531	* should also be passed to avio_open2() if it's used to
1532	* open the file.
1533	*/
1534	AVIOInterruptCB interrupt_callback;
1535
1536	/**
1537	* Flags to enable debugging.
1538	*/
1539	int debug;
1540	#define FF_FDEBUG_TS 0x0001
1541
1542	/**
1543	* The maximum number of streams.
1544	* - encoding: unused
1545	* - decoding: set by user
1546	*/
1547	int max_streams;
1548
1549	/**
1550	* Maximum amount of memory in bytes to use for the index of each stream.
1551	* If the index exceeds this size, entries will be discarded as
1552	* needed to maintain a smaller size. This can lead to slower or less
1553	* accurate seeking (depends on demuxer).
1554	* Demuxers for which a full in-memory index is mandatory will ignore
1555	* this.
1556	* - muxing: unused
1557	* - demuxing: set by user
1558	*/
1559	unsigned int max_index_size;
1560
1561	/**
1562	* Maximum amount of memory in bytes to use for buffering frames
1563	* obtained from realtime capture devices.
1564	*/
1565	unsigned int max_picture_buffer;
1566
1567	/**
1568	* Maximum buffering duration for interleaving.
1569	*
1570	* To ensure all the streams are interleaved correctly,
1571	* av_interleaved_write_frame() will wait until it has at least one packet
1572	* for each stream before actually writing any packets to the output file.
1573	* When some streams are "sparse" (i.e. there are large gaps between
1574	* successive packets), this can result in excessive buffering.
1575	*
1576	* This field specifies the maximum difference between the timestamps of the
1577	* first and the last packet in the muxing queue, above which libavformat
1578	* will output a packet regardless of whether it has queued a packet for all
1579	* the streams.
1580	*
1581	* Muxing only, set by the caller before avformat_write_header().
1582	*/
1583	int64_t max_interleave_delta;
1584
1585	/**
1586	* Maximum number of packets to read while waiting for the first timestamp.
1587	* Decoding only.
1588	*/
1589	int max_ts_probe;
1590
1591	/**
1592	* Max chunk time in microseconds.
1593	* Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1594	* - encoding: Set by user
1595	* - decoding: unused
1596	*/
1597	int max_chunk_duration;
1598
1599	/**
1600	* Max chunk size in bytes
1601	* Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1602	* - encoding: Set by user
1603	* - decoding: unused
1604	*/
1605	int max_chunk_size;
1606
1607	/**
1608	* Maximum number of packets that can be probed
1609	* - encoding: unused
1610	* - decoding: set by user
1611	*/
1612	int max_probe_packets;
1613
1614	/**
1615	* Allow non-standard and experimental extension
1616	* @see AVCodecContext.strict_std_compliance
1617	*/
1618	int strict_std_compliance;
1619
1620	/**
1621	* Flags indicating events happening on the file, a combination of
1622	* AVFMT_EVENT_FLAG_*.
1623	*
1624	* - demuxing: may be set by the demuxer in avformat_open_input(),
1625	* avformat_find_stream_info() and av_read_frame(). Flags must be cleared
1626	* by the user once the event has been handled.
1627	* - muxing: may be set by the user after avformat_write_header() to
1628	* indicate a user-triggered event. The muxer will clear the flags for
1629	* events it has handled in av_[interleaved]_write_frame().
1630	*/
1631	int event_flags;
1632	/**
1633	* - demuxing: the demuxer read new metadata from the file and updated
1634	* AVFormatContext.metadata accordingly
1635	* - muxing: the user updated AVFormatContext.metadata and wishes the muxer to
1636	* write it into the file
1637	*/
1638	#define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001
1639
1640
1641	/**
1642	* Avoid negative timestamps during muxing.
1643	* Any value of the AVFMT_AVOID_NEG_TS_* constants.
1644	* Note, this works better when using av_interleaved_write_frame().
1645	* - muxing: Set by user
1646	* - demuxing: unused
1647	*/
1648	int avoid_negative_ts;
1649	#define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1650	#define AVFMT_AVOID_NEG_TS_DISABLED 0 ///< Do not shift timestamps even when they are negative.
1651	#define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1652	#define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1653
1654	/**
1655	* Audio preload in microseconds.
1656	* Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1657	* - encoding: Set by user
1658	* - decoding: unused
1659	*/
1660	int audio_preload;
1661
1662	/**
1663	* forces the use of wallclock timestamps as pts/dts of packets
1664	* This has undefined results in the presence of B frames.
1665	* - encoding: unused
1666	* - decoding: Set by user
1667	*/
1668	int use_wallclock_as_timestamps;
1669
1670	/**
1671	* Skip duration calcuation in estimate_timings_from_pts.
1672	* - encoding: unused
1673	* - decoding: set by user
1674	*/
1675	int skip_estimate_duration_from_pts;
1676
1677	/**
1678	* avio flags, used to force AVIO_FLAG_DIRECT.
1679	* - encoding: unused
1680	* - decoding: Set by user
1681	*/
1682	int avio_flags;
1683
1684	/**
1685	* The duration field can be estimated through various ways, and this field can be used
1686	* to know how the duration was estimated.
1687	* - encoding: unused
1688	* - decoding: Read by user
1689	*/
1690	enum AVDurationEstimationMethod duration_estimation_method;
1691
1692	/**
1693	* Skip initial bytes when opening stream
1694	* - encoding: unused
1695	* - decoding: Set by user
1696	*/
1697	int64_t skip_initial_bytes;
1698
1699	/**
1700	* Correct single timestamp overflows
1701	* - encoding: unused
1702	* - decoding: Set by user
1703	*/
1704	unsigned int correct_ts_overflow;
1705
1706	/**
1707	* Force seeking to any (also non key) frames.
1708	* - encoding: unused
1709	* - decoding: Set by user
1710	*/
1711	int seek2any;
1712
1713	/**
1714	* Flush the I/O context after each packet.
1715	* - encoding: Set by user
1716	* - decoding: unused
1717	*/
1718	int flush_packets;
1719
1720	/**
1721	* format probing score.
1722	* The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1723	* the format.
1724	* - encoding: unused
1725	* - decoding: set by avformat, read by user
1726	*/
1727	int probe_score;
1728
1729	/**
1730	* Maximum number of bytes read from input in order to identify the
1731	* \ref AVInputFormat "input format". Only used when the format is not set
1732	* explicitly by the caller.
1733	*
1734	* Demuxing only, set by the caller before avformat_open_input().
1735	*
1736	* @sa probesize
1737	*/
1738	int format_probesize;
1739
1740	/**
1741	* ',' separated list of allowed decoders.
1742	* If NULL then all are allowed
1743	* - encoding: unused
1744	* - decoding: set by user
1745	*/
1746	char *codec_whitelist;
1747
1748	/**
1749	* ',' separated list of allowed demuxers.
1750	* If NULL then all are allowed
1751	* - encoding: unused
1752	* - decoding: set by user
1753	*/
1754	char *format_whitelist;
1755
1756	/**
1757	* ',' separated list of allowed protocols.
1758	* - encoding: unused
1759	* - decoding: set by user
1760	*/
1761	char *protocol_whitelist;
1762
1763	/**
1764	* ',' separated list of disallowed protocols.
1765	* - encoding: unused
1766	* - decoding: set by user
1767	*/
1768	char *protocol_blacklist;
1769
1770	/**
1771	* IO repositioned flag.
1772	* This is set by avformat when the underlaying IO context read pointer
1773	* is repositioned, for example when doing byte based seeking.
1774	* Demuxers can use the flag to detect such changes.
1775	*/
1776	int io_repositioned;
1777
1778	/**
1779	* Forced video codec.
1780	* This allows forcing a specific decoder, even when there are multiple with
1781	* the same codec_id.
1782	* Demuxing: Set by user
1783	*/
1784	const struct AVCodec *video_codec;
1785
1786	/**
1787	* Forced audio codec.
1788	* This allows forcing a specific decoder, even when there are multiple with
1789	* the same codec_id.
1790	* Demuxing: Set by user
1791	*/
1792	const struct AVCodec *audio_codec;
1793
1794	/**
1795	* Forced subtitle codec.
1796	* This allows forcing a specific decoder, even when there are multiple with
1797	* the same codec_id.
1798	* Demuxing: Set by user
1799	*/
1800	const struct AVCodec *subtitle_codec;
1801
1802	/**
1803	* Forced data codec.
1804	* This allows forcing a specific decoder, even when there are multiple with
1805	* the same codec_id.
1806	* Demuxing: Set by user
1807	*/
1808	const struct AVCodec *data_codec;
1809
1810	/**
1811	* Number of bytes to be written as padding in a metadata header.
1812	* Demuxing: Unused.
1813	* Muxing: Set by user.
1814	*/
1815	int metadata_header_padding;
1816
1817	/**
1818	* User data.
1819	* This is a place for some private data of the user.
1820	*/
1821	void *opaque;
1822
1823	/**
1824	* Callback used by devices to communicate with application.
1825	*/
1826	av_format_control_message control_message_cb;
1827
1828	/**
1829	* Output timestamp offset, in microseconds.
1830	* Muxing: set by user
1831	*/
1832	int64_t output_ts_offset;
1833
1834	/**
1835	* dump format separator.
1836	* can be ", " or "\n " or anything else
1837	* - muxing: Set by user.
1838	* - demuxing: Set by user.
1839	*/
1840	uint8_t *dump_separator;
1841
1842	/**
1843	* A callback for opening new IO streams.
1844	*
1845	* Whenever a muxer or a demuxer needs to open an IO stream (typically from
1846	* avformat_open_input() for demuxers, but for certain formats can happen at
1847	* other times as well), it will call this callback to obtain an IO context.
1848	*
1849	* @param s the format context
1850	* @param pb on success, the newly opened IO context should be returned here
1851	* @param url the url to open
1852	* @param flags a combination of AVIO_FLAG_*
1853	* @param options a dictionary of additional options, with the same
1854	* semantics as in avio_open2()
1855	* @return 0 on success, a negative AVERROR code on failure
1856	*
1857	* @note Certain muxers and demuxers do nesting, i.e. they open one or more
1858	* additional internal format contexts. Thus the AVFormatContext pointer
1859	* passed to this callback may be different from the one facing the caller.
1860	* It will, however, have the same 'opaque' field.
1861	*/
1862	int (io_open)(struct* AVFormatContext s, AVIOContext pb, const* char *url,
1863	int flags, AVDictionary **options);
1864
1865	/**
1866	* A callback for closing the streams opened with AVFormatContext.io_open().
1867	*
1868	* Using this is preferred over io_close, because this can return an error.
1869	* Therefore this callback is used instead of io_close by the generic
1870	* libavformat code if io_close is NULL or the default.
1871	*
1872	* @param s the format context
1873	* @param pb IO context to be closed and freed
1874	* @return 0 on success, a negative AVERROR code on failure
1875	*/
1876	int (io_close2)(struct* AVFormatContext s, AVIOContext pb);
1877	} AVFormatContext;
1878
1879	/**
1880	* This function will cause global side data to be injected in the next packet
1881	* of each stream as well as after any subsequent seek.
1882	*
1883	* @note global side data is always available in every AVStream's
1884	* @ref AVCodecParameters.coded_side_data "codecpar side data" array, and
1885	* in a @ref AVCodecContext.coded_side_data "decoder's side data" array if
1886	* initialized with said stream's codecpar.
1887	* @see av_packet_side_data_get()
1888	*/
1889	void av_format_inject_global_side_data(AVFormatContext *s);
1890
1891	#if FF_API_GET_DUR_ESTIMATE_METHOD
1892	/**
1893	* Returns the method used to set ctx->duration.
1894	*
1895	* @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1896	* @deprecated duration_estimation_method is public and can be read directly.
1897	*/
1898	attribute_deprecated
1899	enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
1900	#endif
1901
1902	/**
1903	* @defgroup lavf_core Core functions
1904	* @ingroup libavf
1905	*
1906	* Functions for querying libavformat capabilities, allocating core structures,
1907	* etc.
1908	* @{
1909	*/
1910
1911	/**
1912	* Return the LIBAVFORMAT_VERSION_INT constant.
1913	*/
1914	unsigned avformat_version(void);
1915
1916	/**
1917	* Return the libavformat build-time configuration.
1918	*/
1919	const char avformat_configuration(void*);
1920
1921	/**
1922	* Return the libavformat license.
1923	*/
1924	const char avformat_license(void*);
1925
1926	/**
1927	* Do global initialization of network libraries. This is optional,
1928	* and not recommended anymore.
1929	*
1930	* This functions only exists to work around thread-safety issues
1931	* with older GnuTLS or OpenSSL libraries. If libavformat is linked
1932	* to newer versions of those libraries, or if you do not use them,
1933	* calling this function is unnecessary. Otherwise, you need to call
1934	* this function before any other threads using them are started.
1935	*
1936	* This function will be deprecated once support for older GnuTLS and
1937	* OpenSSL libraries is removed, and this function has no purpose
1938	* anymore.
1939	*/
1940	int avformat_network_init(void);
1941
1942	/**
1943	* Undo the initialization done by avformat_network_init. Call it only
1944	* once for each time you called avformat_network_init.
1945	*/
1946	int avformat_network_deinit(void);
1947
1948	/**
1949	* Iterate over all registered muxers.
1950	*
1951	* @param opaque a pointer where libavformat will store the iteration state. Must
1952	* point to NULL to start the iteration.
1953	*
1954	* @return the next registered muxer or NULL when the iteration is
1955	* finished
1956	*/
1957	const AVOutputFormat av_muxer_iterate(void* **opaque);
1958
1959	/**
1960	* Iterate over all registered demuxers.
1961	*
1962	* @param opaque a pointer where libavformat will store the iteration state.
1963	* Must point to NULL to start the iteration.
1964	*
1965	* @return the next registered demuxer or NULL when the iteration is
1966	* finished
1967	*/
1968	const AVInputFormat av_demuxer_iterate(void* **opaque);
1969
1970	/**
1971	* Allocate an AVFormatContext.
1972	* avformat_free_context() can be used to free the context and everything
1973	* allocated by the framework within it.
1974	*/
1975	AVFormatContext avformat_alloc_context(void*);
1976
1977	/**
1978	* Free an AVFormatContext and all its streams.
1979	* @param s context to free
1980	*/
1981	void avformat_free_context(AVFormatContext *s);
1982
1983	/**
1984	* Get the AVClass for AVFormatContext. It can be used in combination with
1985	* AV_OPT_SEARCH_FAKE_OBJ for examining options.
1986	*
1987	* @see av_opt_find().
1988	*/
1989	const AVClass avformat_get_class(void*);
1990
1991	/**
1992	* Get the AVClass for AVStream. It can be used in combination with
1993	* AV_OPT_SEARCH_FAKE_OBJ for examining options.
1994	*
1995	* @see av_opt_find().
1996	*/
1997	const AVClass av_stream_get_class(void*);
1998
1999	/**
2000	* Get the AVClass for AVStreamGroup. It can be used in combination with
2001	* AV_OPT_SEARCH_FAKE_OBJ for examining options.
2002	*
2003	* @see av_opt_find().
2004	*/
2005	const AVClass av_stream_group_get_class(void*);
2006
2007	/**
2008	* @return a string identifying the stream group type, or NULL if unknown
2009	*/
2010	const char avformat_stream_group_name(enum* AVStreamGroupParamsType type);
2011
2012	/**
2013	* Add a new empty stream group to a media file.
2014	*
2015	* When demuxing, it may be called by the demuxer in read_header(). If the
2016	* flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2017	* be called in read_packet().
2018	*
2019	* When muxing, may be called by the user before avformat_write_header().
2020	*
2021	* User is required to call avformat_free_context() to clean up the allocation
2022	* by avformat_stream_group_create().
2023	*
2024	* New streams can be added to the group with avformat_stream_group_add_stream().
2025	*
2026	* @param s media file handle
2027	*
2028	* @return newly created group or NULL on error.
2029	* @see avformat_new_stream, avformat_stream_group_add_stream.
2030	*/
2031	AVStreamGroup avformat_stream_group_create(AVFormatContext s,
2032	enum AVStreamGroupParamsType type,
2033	AVDictionary **options);
2034
2035	/**
2036	* Add a new stream to a media file.
2037	*
2038	* When demuxing, it is called by the demuxer in read_header(). If the
2039	* flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2040	* be called in read_packet().
2041	*
2042	* When muxing, should be called by the user before avformat_write_header().
2043	*
2044	* User is required to call avformat_free_context() to clean up the allocation
2045	* by avformat_new_stream().
2046	*
2047	* @param s media file handle
2048	* @param c unused, does nothing
2049	*
2050	* @return newly created stream or NULL on error.
2051	*/
2052	AVStream avformat_new_stream(AVFormatContext s, const struct AVCodec *c);
2053
2054	/**
2055	* Add an already allocated stream to a stream group.
2056	*
2057	* When demuxing, it may be called by the demuxer in read_header(). If the
2058	* flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2059	* be called in read_packet().
2060	*
2061	* When muxing, may be called by the user before avformat_write_header() after
2062	* having allocated a new group with avformat_stream_group_create() and stream with
2063	* avformat_new_stream().
2064	*
2065	* User is required to call avformat_free_context() to clean up the allocation
2066	* by avformat_stream_group_add_stream().
2067	*
2068	* @param stg stream group belonging to a media file.
2069	* @param st stream in the media file to add to the group.
2070	*
2071	* @retval 0 success
2072	* @retval AVERROR(EEXIST) the stream was already in the group
2073	* @retval "another negative error code" legitimate errors
2074	*
2075	* @see avformat_new_stream, avformat_stream_group_create.
2076	*/
2077	int avformat_stream_group_add_stream(AVStreamGroup stg, AVStream st);
2078
2079	#if FF_API_AVSTREAM_SIDE_DATA
2080	/**
2081	* Wrap an existing array as stream side data.
2082	*
2083	* @param st stream
2084	* @param type side information type
2085	* @param data the side data array. It must be allocated with the av_malloc()
2086	* family of functions. The ownership of the data is transferred to
2087	* st.
2088	* @param size side information size
2089	*
2090	* @return zero on success, a negative AVERROR code on failure. On failure,
2091	* the stream is unchanged and the data remains owned by the caller.
2092	* @deprecated use av_packet_side_data_add() with the stream's
2093	* @ref AVCodecParameters.coded_side_data "codecpar side data"
2094	*/
2095	attribute_deprecated
2096	int av_stream_add_side_data(AVStream st, enum* AVPacketSideDataType type,
2097	uint8_t *data, size_t size);
2098
2099	/**
2100	* Allocate new information from stream.
2101	*
2102	* @param stream stream
2103	* @param type desired side information type
2104	* @param size side information size
2105	*
2106	* @return pointer to fresh allocated data or NULL otherwise
2107	* @deprecated use av_packet_side_data_new() with the stream's
2108	* @ref AVCodecParameters.coded_side_data "codecpar side data"
2109	*/
2110	attribute_deprecated
2111	uint8_t av_stream_new_side_data(AVStream stream,
2112	enum AVPacketSideDataType type, size_t size);
2113	/**
2114	* Get side information from stream.
2115	*
2116	* @param stream stream
2117	* @param type desired side information type
2118	* @param size If supplied, *size will be set to the size of the side data
2119	* or to zero if the desired side data is not present.
2120	*
2121	* @return pointer to data if present or NULL otherwise
2122	* @deprecated use av_packet_side_data_get() with the stream's
2123	* @ref AVCodecParameters.coded_side_data "codecpar side data"
2124	*/
2125	attribute_deprecated
2126	uint8_t av_stream_get_side_data(const* AVStream *stream,
2127	enum AVPacketSideDataType type, size_t *size);
2128	#endif
2129
2130	AVProgram av_new_program(AVFormatContext s, int id);
2131
2132	/**
2133	* @}
2134	*/
2135
2136
2137	/**
2138	* Allocate an AVFormatContext for an output format.
2139	* avformat_free_context() can be used to free the context and
2140	* everything allocated by the framework within it.
2141	*
2142	* @param ctx pointee is set to the created format context,
2143	* or to NULL in case of failure
2144	* @param oformat format to use for allocating the context, if NULL
2145	* format_name and filename are used instead
2146	* @param format_name the name of output format to use for allocating the
2147	* context, if NULL filename is used instead
2148	* @param filename the name of the filename to use for allocating the
2149	* context, may be NULL
2150	*
2151	* @return >= 0 in case of success, a negative AVERROR code in case of
2152	* failure
2153	*/
2154	int avformat_alloc_output_context2(AVFormatContext *ctx, const* AVOutputFormat *oformat,
2155	const char format_name, const* char *filename);
2156
2157	/**
2158	* @addtogroup lavf_decoding
2159	* @{
2160	*/
2161
2162	/**
2163	* Find AVInputFormat based on the short name of the input format.
2164	*/
2165	const AVInputFormat av_find_input_format(const* char *short_name);
2166
2167	/**
2168	* Guess the file format.
2169	*
2170	* @param pd data to be probed
2171	* @param is_opened Whether the file is already opened; determines whether
2172	* demuxers with or without AVFMT_NOFILE are probed.
2173	*/
2174	const AVInputFormat av_probe_input_format(const* AVProbeData pd, int* is_opened);
2175
2176	/**
2177	* Guess the file format.
2178	*
2179	* @param pd data to be probed
2180	* @param is_opened Whether the file is already opened; determines whether
2181	* demuxers with or without AVFMT_NOFILE are probed.
2182	* @param score_max A probe score larger that this is required to accept a
2183	* detection, the variable is set to the actual detection
2184	* score afterwards.
2185	* If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2186	* to retry with a larger probe buffer.
2187	*/
2188	const AVInputFormat av_probe_input_format2(const* AVProbeData *pd,
2189	int is_opened, int *score_max);
2190
2191	/**
2192	* Guess the file format.
2193	*
2194	* @param is_opened Whether the file is already opened; determines whether
2195	* demuxers with or without AVFMT_NOFILE are probed.
2196	* @param score_ret The score of the best detection.
2197	*/
2198	const AVInputFormat av_probe_input_format3(const* AVProbeData *pd,
2199	int is_opened, int *score_ret);
2200
2201	/**
2202	* Probe a bytestream to determine the input format. Each time a probe returns
2203	* with a score that is too low, the probe buffer size is increased and another
2204	* attempt is made. When the maximum probe size is reached, the input format
2205	* with the highest score is returned.
2206	*
2207	* @param pb the bytestream to probe
2208	* @param fmt the input format is put here
2209	* @param url the url of the stream
2210	* @param logctx the log context
2211	* @param offset the offset within the bytestream to probe from
2212	* @param max_probe_size the maximum probe buffer size (zero for default)
2213	*
2214	* @return the score in case of success, a negative value corresponding to an
2215	* the maximal score is AVPROBE_SCORE_MAX
2216	* AVERROR code otherwise
2217	*/
2218	int av_probe_input_buffer2(AVIOContext pb, const* AVInputFormat **fmt,
2219	const char url, void* *logctx,
2220	unsigned int offset, unsigned int max_probe_size);
2221
2222	/**
2223	* Like av_probe_input_buffer2() but returns 0 on success
2224	*/
2225	int av_probe_input_buffer(AVIOContext pb, const* AVInputFormat **fmt,
2226	const char url, void* *logctx,
2227	unsigned int offset, unsigned int max_probe_size);
2228
2229	/**
2230	* Open an input stream and read the header. The codecs are not opened.
2231	* The stream must be closed with avformat_close_input().
2232	*
2233	* @param ps Pointer to user-supplied AVFormatContext (allocated by
2234	* avformat_alloc_context). May be a pointer to NULL, in
2235	* which case an AVFormatContext is allocated by this
2236	* function and written into ps.
2237	* Note that a user-supplied AVFormatContext will be freed
2238	* on failure.
2239	* @param url URL of the stream to open.
2240	* @param fmt If non-NULL, this parameter forces a specific input format.
2241	* Otherwise the format is autodetected.
2242	* @param options A dictionary filled with AVFormatContext and demuxer-private
2243	* options.
2244	* On return this parameter will be destroyed and replaced with
2245	* a dict containing options that were not found. May be NULL.
2246	*
2247	* @return 0 on success, a negative AVERROR on failure.
2248	*
2249	* @note If you want to use custom IO, preallocate the format context and set its pb field.
2250	*/
2251	int avformat_open_input(AVFormatContext *ps, const* char *url,
2252	const AVInputFormat fmt, AVDictionary *options);
2253
2254	/**
2255	* Read packets of a media file to get stream information. This
2256	* is useful for file formats with no headers such as MPEG. This
2257	* function also computes the real framerate in case of MPEG-2 repeat
2258	* frame mode.
2259	* The logical file position is not changed by this function;
2260	* examined packets may be buffered for later processing.
2261	*
2262	* @param ic media file handle
2263	* @param options If non-NULL, an ic.nb_streams long array of pointers to
2264	* dictionaries, where i-th member contains options for
2265	* codec corresponding to i-th stream.
2266	* On return each dictionary will be filled with options that were not found.
2267	* @return >=0 if OK, AVERROR_xxx on error
2268	*
2269	* @note this function isn't guaranteed to open all the codecs, so
2270	* options being non-empty at return is a perfectly normal behavior.
2271	*
2272	* @todo Let the user decide somehow what information is needed so that
2273	* we do not waste time getting stuff the user does not need.
2274	*/
2275	int avformat_find_stream_info(AVFormatContext ic, AVDictionary *options);
2276
2277	/**
2278	* Find the programs which belong to a given stream.
2279	*
2280	* @param ic media file handle
2281	* @param last the last found program, the search will start after this
2282	* program, or from the beginning if it is NULL
2283	* @param s stream index
2284	*
2285	* @return the next program which belongs to s, NULL if no program is found or
2286	* the last program is not among the programs of ic.
2287	*/
2288	AVProgram av_find_program_from_stream(AVFormatContext ic, AVProgram last, int* s);
2289
2290	void av_program_add_stream_index(AVFormatContext ac, int* progid, unsigned int idx);
2291
2292	/**
2293	* Find the "best" stream in the file.
2294	* The best stream is determined according to various heuristics as the most
2295	* likely to be what the user expects.
2296	* If the decoder parameter is non-NULL, av_find_best_stream will find the
2297	* default decoder for the stream's codec; streams for which no decoder can
2298	* be found are ignored.
2299	*
2300	* @param ic media file handle
2301	* @param type stream type: video, audio, subtitles, etc.
2302	* @param wanted_stream_nb user-requested stream number,
2303	* or -1 for automatic selection
2304	* @param related_stream try to find a stream related (eg. in the same
2305	* program) to this one, or -1 if none
2306	* @param decoder_ret if non-NULL, returns the decoder for the
2307	* selected stream
2308	* @param flags flags; none are currently defined
2309	*
2310	* @return the non-negative stream number in case of success,
2311	* AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2312	* could be found,
2313	* AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2314	*
2315	* @note If av_find_best_stream returns successfully and decoder_ret is not
2316	* NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2317	*/
2318	int av_find_best_stream(AVFormatContext *ic,
2319	enum AVMediaType type,
2320	int wanted_stream_nb,
2321	int related_stream,
2322	const struct AVCodec **decoder_ret,
2323	int flags);
2324
2325	/**
2326	* Return the next frame of a stream.
2327	* This function returns what is stored in the file, and does not validate
2328	* that what is there are valid frames for the decoder. It will split what is
2329	* stored in the file into frames and return one for each call. It will not
2330	* omit invalid data between valid frames so as to give the decoder the maximum
2331	* information possible for decoding.
2332	*
2333	* On success, the returned packet is reference-counted (pkt->buf is set) and
2334	* valid indefinitely. The packet must be freed with av_packet_unref() when
2335	* it is no longer needed. For video, the packet contains exactly one frame.
2336	* For audio, it contains an integer number of frames if each frame has
2337	* a known fixed size (e.g. PCM or ADPCM data). If the audio frames have
2338	* a variable size (e.g. MPEG audio), then it contains one frame.
2339	*
2340	* pkt->pts, pkt->dts and pkt->duration are always set to correct
2341	* values in AVStream.time_base units (and guessed if the format cannot
2342	* provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2343	* has B-frames, so it is better to rely on pkt->dts if you do not
2344	* decompress the payload.
2345	*
2346	* @return 0 if OK, < 0 on error or end of file. On error, pkt will be blank
2347	* (as if it came from av_packet_alloc()).
2348	*
2349	* @note pkt will be initialized, so it may be uninitialized, but it must not
2350	* contain data that needs to be freed.
2351	*/
2352	int av_read_frame(AVFormatContext s, AVPacket pkt);
2353
2354	/**
2355	* Seek to the keyframe at timestamp.
2356	* 'timestamp' in 'stream_index'.
2357	*
2358	* @param s media file handle
2359	* @param stream_index If stream_index is (-1), a default stream is selected,
2360	* and timestamp is automatically converted from
2361	* AV_TIME_BASE units to the stream specific time_base.
2362	* @param timestamp Timestamp in AVStream.time_base units or, if no stream
2363	* is specified, in AV_TIME_BASE units.
2364	* @param flags flags which select direction and seeking mode
2365	*
2366	* @return >= 0 on success
2367	*/
2368	int av_seek_frame(AVFormatContext s, int* stream_index, int64_t timestamp,
2369	int flags);
2370
2371	/**
2372	* Seek to timestamp ts.
2373	* Seeking will be done so that the point from which all active streams
2374	* can be presented successfully will be closest to ts and within min/max_ts.
2375	* Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2376	*
2377	* If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2378	* are the file position (this may not be supported by all demuxers).
2379	* If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2380	* in the stream with stream_index (this may not be supported by all demuxers).
2381	* Otherwise all timestamps are in units of the stream selected by stream_index
2382	* or if stream_index is -1, in AV_TIME_BASE units.
2383	* If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2384	* keyframes (this may not be supported by all demuxers).
2385	* If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2386	*
2387	* @param s media file handle
2388	* @param stream_index index of the stream which is used as time base reference
2389	* @param min_ts smallest acceptable timestamp
2390	* @param ts target timestamp
2391	* @param max_ts largest acceptable timestamp
2392	* @param flags flags
2393	* @return >=0 on success, error code otherwise
2394	*
2395	* @note This is part of the new seek API which is still under construction.
2396	*/
2397	int avformat_seek_file(AVFormatContext s, int* stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2398
2399	/**
2400	* Discard all internally buffered data. This can be useful when dealing with
2401	* discontinuities in the byte stream. Generally works only with formats that
2402	* can resync. This includes headerless formats like MPEG-TS/TS but should also
2403	* work with NUT, Ogg and in a limited way AVI for example.
2404	*
2405	* The set of streams, the detected duration, stream parameters and codecs do
2406	* not change when calling this function. If you want a complete reset, it's
2407	* better to open a new AVFormatContext.
2408	*
2409	* This does not flush the AVIOContext (s->pb). If necessary, call
2410	* avio_flush(s->pb) before calling this function.
2411	*
2412	* @param s media file handle
2413	* @return >=0 on success, error code otherwise
2414	*/
2415	int avformat_flush(AVFormatContext *s);
2416
2417	/**
2418	* Start playing a network-based stream (e.g. RTSP stream) at the
2419	* current position.
2420	*/
2421	int av_read_play(AVFormatContext *s);
2422
2423	/**
2424	* Pause a network-based stream (e.g. RTSP stream).
2425	*
2426	* Use av_read_play() to resume it.
2427	*/
2428	int av_read_pause(AVFormatContext *s);
2429
2430	/**
2431	* Close an opened input AVFormatContext. Free it and all its contents
2432	* and set *s to NULL.
2433	*/
2434	void avformat_close_input(AVFormatContext **s);
2435	/**
2436	* @}
2437	*/
2438
2439	#define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2440	#define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2441	#define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2442	#define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2443
2444	/**
2445	* @addtogroup lavf_encoding
2446	* @{
2447	*/
2448
2449	#define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2450	#define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2451
2452	/**
2453	* Allocate the stream private data and write the stream header to
2454	* an output media file.
2455	*
2456	* @param s Media file handle, must be allocated with
2457	* avformat_alloc_context().
2458	* Its \ref AVFormatContext.oformat "oformat" field must be set
2459	* to the desired output format;
2460	* Its \ref AVFormatContext.pb "pb" field must be set to an
2461	* already opened ::AVIOContext.
2462	* @param options An ::AVDictionary filled with AVFormatContext and
2463	* muxer-private options.
2464	* On return this parameter will be destroyed and replaced with
2465	* a dict containing options that were not found. May be NULL.
2466	*
2467	* @retval AVSTREAM_INIT_IN_WRITE_HEADER On success, if the codec had not already been
2468	* fully initialized in avformat_init_output().
2469	* @retval AVSTREAM_INIT_IN_INIT_OUTPUT On success, if the codec had already been fully
2470	* initialized in avformat_init_output().
2471	* @retval AVERROR A negative AVERROR on failure.
2472	*
2473	* @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2474	*/
2475	av_warn_unused_result
2476	int avformat_write_header(AVFormatContext s, AVDictionary *options);
2477
2478	/**
2479	* Allocate the stream private data and initialize the codec, but do not write the header.
2480	* May optionally be used before avformat_write_header() to initialize stream parameters
2481	* before actually writing the header.
2482	* If using this function, do not pass the same options to avformat_write_header().
2483	*
2484	* @param s Media file handle, must be allocated with
2485	* avformat_alloc_context().
2486	* Its \ref AVFormatContext.oformat "oformat" field must be set
2487	* to the desired output format;
2488	* Its \ref AVFormatContext.pb "pb" field must be set to an
2489	* already opened ::AVIOContext.
2490	* @param options An ::AVDictionary filled with AVFormatContext and
2491	* muxer-private options.
2492	* On return this parameter will be destroyed and replaced with
2493	* a dict containing options that were not found. May be NULL.
2494	*
2495	* @retval AVSTREAM_INIT_IN_WRITE_HEADER On success, if the codec requires
2496	* avformat_write_header to fully initialize.
2497	* @retval AVSTREAM_INIT_IN_INIT_OUTPUT On success, if the codec has been fully
2498	* initialized.
2499	* @retval AVERROR Anegative AVERROR on failure.
2500	*
2501	* @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2502	*/
2503	av_warn_unused_result
2504	int avformat_init_output(AVFormatContext s, AVDictionary *options);
2505
2506	/**
2507	* Write a packet to an output media file.
2508	*
2509	* This function passes the packet directly to the muxer, without any buffering
2510	* or reordering. The caller is responsible for correctly interleaving the
2511	* packets if the format requires it. Callers that want libavformat to handle
2512	* the interleaving should call av_interleaved_write_frame() instead of this
2513	* function.
2514	*
2515	* @param s media file handle
2516	* @param pkt The packet containing the data to be written. Note that unlike
2517	* av_interleaved_write_frame(), this function does not take
2518	* ownership of the packet passed to it (though some muxers may make
2519	* an internal reference to the input packet).
2520	* <br>
2521	* This parameter can be NULL (at any time, not just at the end), in
2522	* order to immediately flush data buffered within the muxer, for
2523	* muxers that buffer up data internally before writing it to the
2524	* output.
2525	* <br>
2526	* Packet's @ref AVPacket.stream_index "stream_index" field must be
2527	* set to the index of the corresponding stream in @ref
2528	* AVFormatContext.streams "s->streams".
2529	* <br>
2530	* The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2531	* must be set to correct values in the stream's timebase (unless the
2532	* output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2533	* they can be set to AV_NOPTS_VALUE).
2534	* The dts for subsequent packets passed to this function must be strictly
2535	* increasing when compared in their respective timebases (unless the
2536	* output format is flagged with the AVFMT_TS_NONSTRICT, then they
2537	* merely have to be nondecreasing). @ref AVPacket.duration
2538	* "duration") should also be set if known.
2539	* @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2540	*
2541	* @see av_interleaved_write_frame()
2542	*/
2543	int av_write_frame(AVFormatContext s, AVPacket pkt);
2544
2545	/**
2546	* Write a packet to an output media file ensuring correct interleaving.
2547	*
2548	* This function will buffer the packets internally as needed to make sure the
2549	* packets in the output file are properly interleaved, usually ordered by
2550	* increasing dts. Callers doing their own interleaving should call
2551	* av_write_frame() instead of this function.
2552	*
2553	* Using this function instead of av_write_frame() can give muxers advance
2554	* knowledge of future packets, improving e.g. the behaviour of the mp4
2555	* muxer for VFR content in fragmenting mode.
2556	*
2557	* @param s media file handle
2558	* @param pkt The packet containing the data to be written.
2559	* <br>
2560	* If the packet is reference-counted, this function will take
2561	* ownership of this reference and unreference it later when it sees
2562	* fit. If the packet is not reference-counted, libavformat will
2563	* make a copy.
2564	* The returned packet will be blank (as if returned from
2565	* av_packet_alloc()), even on error.
2566	* <br>
2567	* This parameter can be NULL (at any time, not just at the end), to
2568	* flush the interleaving queues.
2569	* <br>
2570	* Packet's @ref AVPacket.stream_index "stream_index" field must be
2571	* set to the index of the corresponding stream in @ref
2572	* AVFormatContext.streams "s->streams".
2573	* <br>
2574	* The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2575	* must be set to correct values in the stream's timebase (unless the
2576	* output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2577	* they can be set to AV_NOPTS_VALUE).
2578	* The dts for subsequent packets in one stream must be strictly
2579	* increasing (unless the output format is flagged with the
2580	* AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2581	* @ref AVPacket.duration "duration" should also be set if known.
2582	*
2583	* @return 0 on success, a negative AVERROR on error.
2584	*
2585	* @see av_write_frame(), AVFormatContext.max_interleave_delta
2586	*/
2587	int av_interleaved_write_frame(AVFormatContext s, AVPacket pkt);
2588
2589	/**
2590	* Write an uncoded frame to an output media file.
2591	*
2592	* The frame must be correctly interleaved according to the container
2593	* specification; if not, av_interleaved_write_uncoded_frame() must be used.
2594	*
2595	* See av_interleaved_write_uncoded_frame() for details.
2596	*/
2597	int av_write_uncoded_frame(AVFormatContext s, int* stream_index,
2598	struct AVFrame *frame);
2599
2600	/**
2601	* Write an uncoded frame to an output media file.
2602	*
2603	* If the muxer supports it, this function makes it possible to write an AVFrame
2604	* structure directly, without encoding it into a packet.
2605	* It is mostly useful for devices and similar special muxers that use raw
2606	* video or PCM data and will not serialize it into a byte stream.
2607	*
2608	* To test whether it is possible to use it with a given muxer and stream,
2609	* use av_write_uncoded_frame_query().
2610	*
2611	* The caller gives up ownership of the frame and must not access it
2612	* afterwards.
2613	*
2614	* @return >=0 for success, a negative code on error
2615	*/
2616	int av_interleaved_write_uncoded_frame(AVFormatContext s, int* stream_index,
2617	struct AVFrame *frame);
2618
2619	/**
2620	* Test whether a muxer supports uncoded frame.
2621	*
2622	* @return >=0 if an uncoded frame can be written to that muxer and stream,
2623	* <0 if not
2624	*/
2625	int av_write_uncoded_frame_query(AVFormatContext s, int* stream_index);
2626
2627	/**
2628	* Write the stream trailer to an output media file and free the
2629	* file private data.
2630	*
2631	* May only be called after a successful call to avformat_write_header.
2632	*
2633	* @param s media file handle
2634	* @return 0 if OK, AVERROR_xxx on error
2635	*/
2636	int av_write_trailer(AVFormatContext *s);
2637
2638	/**
2639	* Return the output format in the list of registered output formats
2640	* which best matches the provided parameters, or return NULL if
2641	* there is no match.
2642	*
2643	* @param short_name if non-NULL checks if short_name matches with the
2644	* names of the registered formats
2645	* @param filename if non-NULL checks if filename terminates with the
2646	* extensions of the registered formats
2647	* @param mime_type if non-NULL checks if mime_type matches with the
2648	* MIME type of the registered formats
2649	*/
2650	const AVOutputFormat av_guess_format(const* char *short_name,
2651	const char *filename,
2652	const char *mime_type);
2653
2654	/**
2655	* Guess the codec ID based upon muxer and filename.
2656	*/
2657	enum AVCodecID av_guess_codec(const AVOutputFormat fmt, const* char *short_name,
2658	const char filename, const* char *mime_type,
2659	enum AVMediaType type);
2660
2661	/**
2662	* Get timing information for the data currently output.
2663	* The exact meaning of "currently output" depends on the format.
2664	* It is mostly relevant for devices that have an internal buffer and/or
2665	* work in real time.
2666	* @param s media file handle
2667	* @param stream stream in the media file
2668	* @param[out] dts DTS of the last packet output for the stream, in stream
2669	* time_base units
2670	* @param[out] wall absolute time when that packet whas output,
2671	* in microsecond
2672	* @retval 0 Success
2673	* @retval AVERROR(ENOSYS) The format does not support it
2674	*
2675	* @note Some formats or devices may not allow to measure dts and wall
2676	* atomically.
2677	*/
2678	int av_get_output_timestamp(struct AVFormatContext s, int* stream,
2679	int64_t dts, int64_t wall);
2680
2681
2682	/**
2683	* @}
2684	*/
2685
2686
2687	/**
2688	* @defgroup lavf_misc Utility functions
2689	* @ingroup libavf
2690	* @{
2691	*
2692	* Miscellaneous utility functions related to both muxing and demuxing
2693	* (or neither).
2694	*/
2695
2696	/**
2697	* Send a nice hexadecimal dump of a buffer to the specified file stream.
2698	*
2699	* @param f The file stream pointer where the dump should be sent to.
2700	* @param buf buffer
2701	* @param size buffer size
2702	*
2703	* @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2704	*/
2705	void av_hex_dump(FILE f, const* uint8_t buf, int* size);
2706
2707	/**
2708	* Send a nice hexadecimal dump of a buffer to the log.
2709	*
2710	* @param avcl A pointer to an arbitrary struct of which the first field is a
2711	* pointer to an AVClass struct.
2712	* @param level The importance level of the message, lower values signifying
2713	* higher importance.
2714	* @param buf buffer
2715	* @param size buffer size
2716	*
2717	* @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2718	*/
2719	void av_hex_dump_log(void avcl, int* level, const uint8_t buf, int* size);
2720
2721	/**
2722	* Send a nice dump of a packet to the specified file stream.
2723	*
2724	* @param f The file stream pointer where the dump should be sent to.
2725	* @param pkt packet to dump
2726	* @param dump_payload True if the payload must be displayed, too.
2727	* @param st AVStream that the packet belongs to
2728	*/
2729	void av_pkt_dump2(FILE f, const* AVPacket pkt, int* dump_payload, const AVStream *st);
2730
2731
2732	/**
2733	* Send a nice dump of a packet to the log.
2734	*
2735	* @param avcl A pointer to an arbitrary struct of which the first field is a
2736	* pointer to an AVClass struct.
2737	* @param level The importance level of the message, lower values signifying
2738	* higher importance.
2739	* @param pkt packet to dump
2740	* @param dump_payload True if the payload must be displayed, too.
2741	* @param st AVStream that the packet belongs to
2742	*/
2743	void av_pkt_dump_log2(void avcl, int* level, const AVPacket pkt, int* dump_payload,
2744	const AVStream *st);
2745
2746	/**
2747	* Get the AVCodecID for the given codec tag tag.
2748	* If no codec id is found returns AV_CODEC_ID_NONE.
2749	*
2750	* @param tags list of supported codec_id-codec_tag pairs, as stored
2751	* in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2752	* @param tag codec tag to match to a codec ID
2753	*/
2754	enum AVCodecID av_codec_get_id(const struct AVCodecTag * const tags, unsigned* int tag);
2755
2756	/**
2757	* Get the codec tag for the given codec id id.
2758	* If no codec tag is found returns 0.
2759	*
2760	* @param tags list of supported codec_id-codec_tag pairs, as stored
2761	* in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2762	* @param id codec ID to match to a codec tag
2763	*/
2764	unsigned int av_codec_get_tag(const struct AVCodecTag * const tags, enum* AVCodecID id);
2765
2766	/**
2767	* Get the codec tag for the given codec id.
2768	*
2769	* @param tags list of supported codec_id - codec_tag pairs, as stored
2770	* in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2771	* @param id codec id that should be searched for in the list
2772	* @param tag A pointer to the found tag
2773	* @return 0 if id was not found in tags, > 0 if it was found
2774	*/
2775	int av_codec_get_tag2(const struct AVCodecTag * const tags, enum* AVCodecID id,
2776	unsigned int *tag);
2777
2778	int av_find_default_stream_index(AVFormatContext *s);
2779
2780	/**
2781	* Get the index for a specific timestamp.
2782	*
2783	* @param st stream that the timestamp belongs to
2784	* @param timestamp timestamp to retrieve the index for
2785	* @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2786	* to the timestamp which is <= the requested one, if backward
2787	* is 0, then it will be >=
2788	* if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2789	* @return < 0 if no such timestamp could be found
2790	*/
2791	int av_index_search_timestamp(AVStream st, int64_t timestamp, int* flags);
2792
2793	/**
2794	* Get the index entry count for the given AVStream.
2795	*
2796	* @param st stream
2797	* @return the number of index entries in the stream
2798	*/
2799	int avformat_index_get_entries_count(const AVStream *st);
2800
2801	/**
2802	* Get the AVIndexEntry corresponding to the given index.
2803	*
2804	* @param st Stream containing the requested AVIndexEntry.
2805	* @param idx The desired index.
2806	* @return A pointer to the requested AVIndexEntry if it exists, NULL otherwise.
2807	*
2808	* @note The pointer returned by this function is only guaranteed to be valid
2809	* until any function that takes the stream or the parent AVFormatContext
2810	* as input argument is called.
2811	*/
2812	const AVIndexEntry avformat_index_get_entry(AVStream st, int idx);
2813
2814	/**
2815	* Get the AVIndexEntry corresponding to the given timestamp.
2816	*
2817	* @param st Stream containing the requested AVIndexEntry.
2818	* @param wanted_timestamp Timestamp to retrieve the index entry for.
2819	* @param flags If AVSEEK_FLAG_BACKWARD then the returned entry will correspond
2820	* to the timestamp which is <= the requested one, if backward
2821	* is 0, then it will be >=
2822	* if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise.
2823	* @return A pointer to the requested AVIndexEntry if it exists, NULL otherwise.
2824	*
2825	* @note The pointer returned by this function is only guaranteed to be valid
2826	* until any function that takes the stream or the parent AVFormatContext
2827	* as input argument is called.
2828	*/
2829	const AVIndexEntry avformat_index_get_entry_from_timestamp(AVStream st,
2830	int64_t wanted_timestamp,
2831	int flags);
2832	/**
2833	* Add an index entry into a sorted list. Update the entry if the list
2834	* already contains it.
2835	*
2836	* @param timestamp timestamp in the time base of the given stream
2837	*/
2838	int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2839	int size, int distance, int flags);
2840
2841
2842	/**
2843	* Split a URL string into components.
2844	*
2845	* The pointers to buffers for storing individual components may be null,
2846	* in order to ignore that component. Buffers for components not found are
2847	* set to empty strings. If the port is not found, it is set to a negative
2848	* value.
2849	*
2850	* @param proto the buffer for the protocol
2851	* @param proto_size the size of the proto buffer
2852	* @param authorization the buffer for the authorization
2853	* @param authorization_size the size of the authorization buffer
2854	* @param hostname the buffer for the host name
2855	* @param hostname_size the size of the hostname buffer
2856	* @param port_ptr a pointer to store the port number in
2857	* @param path the buffer for the path
2858	* @param path_size the size of the path buffer
2859	* @param url the URL to split
2860	*/
2861	void av_url_split(char proto, int* proto_size,
2862	char authorization, int* authorization_size,
2863	char hostname, int* hostname_size,
2864	int *port_ptr,
2865	char path, int* path_size,
2866	const char *url);
2867
2868
2869	/**
2870	* Print detailed information about the input or output format, such as
2871	* duration, bitrate, streams, container, programs, metadata, side data,
2872	* codec and time base.
2873	*
2874	* @param ic the context to analyze
2875	* @param index index of the stream to dump information about
2876	* @param url the URL to print, such as source or destination file
2877	* @param is_output Select whether the specified context is an input(0) or output(1)
2878	*/
2879	void av_dump_format(AVFormatContext *ic,
2880	int index,
2881	const char *url,
2882	int is_output);
2883
2884
2885	#define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
2886
2887	/**
2888	* Return in 'buf' the path with '%d' replaced by a number.
2889	*
2890	* Also handles the '%0nd' format where 'n' is the total number
2891	* of digits and '%%'.
2892	*
2893	* @param buf destination buffer
2894	* @param buf_size destination buffer size
2895	* @param path numbered sequence string
2896	* @param number frame number
2897	* @param flags AV_FRAME_FILENAME_FLAGS_*
2898	* @return 0 if OK, -1 on format error
2899	*/
2900	int av_get_frame_filename2(char buf, int* buf_size,
2901	const char path, int* number, int flags);
2902
2903	int av_get_frame_filename(char buf, int* buf_size,
2904	const char path, int* number);
2905
2906	/**
2907	* Check whether filename actually is a numbered sequence generator.
2908	*
2909	* @param filename possible numbered sequence string
2910	* @return 1 if a valid numbered sequence string, 0 otherwise
2911	*/
2912	int av_filename_number_test(const char *filename);
2913
2914	/**
2915	* Generate an SDP for an RTP session.
2916	*
2917	* Note, this overwrites the id values of AVStreams in the muxer contexts
2918	* for getting unique dynamic payload types.
2919	*
2920	* @param ac array of AVFormatContexts describing the RTP streams. If the
2921	* array is composed by only one context, such context can contain
2922	* multiple AVStreams (one AVStream per RTP stream). Otherwise,
2923	* all the contexts in the array (an AVCodecContext per RTP stream)
2924	* must contain only one AVStream.
2925	* @param n_files number of AVCodecContexts contained in ac
2926	* @param buf buffer where the SDP will be stored (must be allocated by
2927	* the caller)
2928	* @param size the size of the buffer
2929	* @return 0 if OK, AVERROR_xxx on error
2930	*/
2931	int av_sdp_create(AVFormatContext ac[], int* n_files, char buf, int* size);
2932
2933	/**
2934	* Return a positive value if the given filename has one of the given
2935	* extensions, 0 otherwise.
2936	*
2937	* @param filename file name to check against the given extensions
2938	* @param extensions a comma-separated list of filename extensions
2939	*/
2940	int av_match_ext(const char filename, const* char *extensions);
2941
2942	/**
2943	* Test if the given container can store a codec.
2944	*
2945	* @param ofmt container to check for compatibility
2946	* @param codec_id codec to potentially store in container
2947	* @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2948	*
2949	* @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2950	* A negative number if this information is not available.
2951	*/
2952	int avformat_query_codec(const AVOutputFormat ofmt, enum* AVCodecID codec_id,
2953	int std_compliance);
2954
2955	/**
2956	* @defgroup riff_fourcc RIFF FourCCs
2957	* @{
2958	* Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2959	* meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2960	* following code:
2961	* @code
2962	* uint32_t tag = MKTAG('H', '2', '6', '4');
2963	* const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2964	* enum AVCodecID id = av_codec_get_id(table, tag);
2965	* @endcode
2966	*/
2967	/**
2968	* @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2969	*/
2970	const struct AVCodecTag avformat_get_riff_video_tags(void*);
2971	/**
2972	* @return the table mapping RIFF FourCCs for audio to AVCodecID.
2973	*/
2974	const struct AVCodecTag avformat_get_riff_audio_tags(void*);
2975	/**
2976	* @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2977	*/
2978	const struct AVCodecTag avformat_get_mov_video_tags(void*);
2979	/**
2980	* @return the table mapping MOV FourCCs for audio to AVCodecID.
2981	*/
2982	const struct AVCodecTag avformat_get_mov_audio_tags(void*);
2983
2984	/**
2985	* @}
2986	*/
2987
2988	/**
2989	* Guess the sample aspect ratio of a frame, based on both the stream and the
2990	* frame aspect ratio.
2991	*
2992	* Since the frame aspect ratio is set by the codec but the stream aspect ratio
2993	* is set by the demuxer, these two may not be equal. This function tries to
2994	* return the value that you should use if you would like to display the frame.
2995	*
2996	* Basic logic is to use the stream aspect ratio if it is set to something sane
2997	* otherwise use the frame aspect ratio. This way a container setting, which is
2998	* usually easy to modify can override the coded value in the frames.
2999	*
3000	* @param format the format context which the stream is part of
3001	* @param stream the stream which the frame is part of
3002	* @param frame the frame with the aspect ratio to be determined
3003	* @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
3004	*/
3005	AVRational av_guess_sample_aspect_ratio(AVFormatContext format, AVStream stream,
3006	struct AVFrame *frame);
3007
3008	/**
3009	* Guess the frame rate, based on both the container and codec information.
3010	*
3011	* @param ctx the format context which the stream is part of
3012	* @param stream the stream which the frame is part of
3013	* @param frame the frame for which the frame rate should be determined, may be NULL
3014	* @return the guessed (valid) frame rate, 0/1 if no idea
3015	*/
3016	AVRational av_guess_frame_rate(AVFormatContext ctx, AVStream stream,
3017	struct AVFrame *frame);
3018
3019	/**
3020	* Check if the stream st contained in s is matched by the stream specifier
3021	* spec.
3022	*
3023	* See the "stream specifiers" chapter in the documentation for the syntax
3024	* of spec.
3025	*
3026	* @return >0 if st is matched by spec;
3027	* 0 if st is not matched by spec;
3028	* AVERROR code if spec is invalid
3029	*
3030	* @note A stream specifier can match several streams in the format.
3031	*/
3032	int avformat_match_stream_specifier(AVFormatContext s, AVStream st,
3033	const char *spec);
3034
3035	int avformat_queue_attached_pictures(AVFormatContext *s);
3036
3037	enum AVTimebaseSource {
3038	AVFMT_TBCF_AUTO = -`1`,
3039	AVFMT_TBCF_DECODER,
3040	AVFMT_TBCF_DEMUXER,
3041	#if FF_API_R_FRAME_RATE
3042	AVFMT_TBCF_R_FRAMERATE,
3043	#endif
3044	};
3045
3046	/**
3047	* Transfer internal timing information from one stream to another.
3048	*
3049	* This function is useful when doing stream copy.
3050	*
3051	* @param ofmt target output format for ost
3052	* @param ost output stream which needs timings copy and adjustments
3053	* @param ist reference input stream to copy timings from
3054	* @param copy_tb define from where the stream codec timebase needs to be imported
3055	*/
3056	int avformat_transfer_internal_stream_timing_info(const AVOutputFormat *ofmt,
3057	AVStream ost, const* AVStream *ist,
3058	enum AVTimebaseSource copy_tb);
3059
3060	/**
3061	* Get the internal codec timebase from a stream.
3062	*
3063	* @param st input stream to extract the timebase from
3064	*/
3065	AVRational av_stream_get_codec_timebase(const AVStream *st);
3066
3067	/**
3068	* @}
3069	*/
3070
3071	#endif /* AVFORMAT_AVFORMAT_H */
3072

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