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	* const AVDictionaryEntry *e;
150	* if ((e = av_dict_iterate(options, NULL))) {
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	disc_subtitle-- title of a subset, e.g. disc subtitle in a multi-disc collection.
390	encoder -- name/settings of the software/hardware that produced the file.
391	encoded_by -- person/group who created the file.
392	filename -- original name of the file.
393	genre -- <self-evident>.
394	language -- main language in which the work is performed, preferably
395	in ISO 639-2 format. Multiple languages can be specified by
396	separating them with commas.
397	performer -- artist who performed the work, if different from artist.
398	E.g for "Also sprach Zarathustra", artist would be "Richard
399	Strauss" and performer "London Philharmonic Orchestra".
400	publisher -- name of the label/publisher.
401	service_name -- name of the service in broadcasting (channel name).
402	service_provider -- name of the service provider in broadcasting.
403	title -- name of the work.
404	track -- number of this work in the set, can be in form current/total.
405	variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
406	@endverbatim
407	*
408	* Look in the examples section for an application example how to use the Metadata API.
409	*
410	* @}
411	*/
412
413	/ packet functions /
414
415
416	/**
417	* Allocate and read the payload of a packet and initialize its
418	* fields with default values.
419	*
420	* @param s associated IO context
421	* @param pkt packet
422	* @param size desired payload size
423	* @return >0 (read size) if OK, AVERROR_xxx otherwise
424	*/
425	int av_get_packet(AVIOContext s, AVPacket pkt, int size);
426
427
428	/**
429	* Read data and append it to the current content of the AVPacket.
430	* If pkt->size is 0 this is identical to av_get_packet.
431	* Note that this uses av_grow_packet and thus involves a realloc
432	* which is inefficient. Thus this function should only be used
433	* when there is no reasonable way to know (an upper bound of)
434	* the final size.
435	*
436	* @param s associated IO context
437	* @param pkt packet
438	* @param size amount of data to read
439	* @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
440	* will not be lost even if an error occurs.
441	*/
442	int av_append_packet(AVIOContext s, AVPacket pkt, int size);
443
444	/***********************************************/
445	/ input/output formats /
446
447	struct AVCodecTag;
448
449	/**
450	* This structure contains the data a format has to probe a file.
451	*/
452	typedef struct AVProbeData {
453	const char *filename;
454	unsigned char buf; /*< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. /*
455	int buf_size; /< Size of buf except extra allocated bytes /*
456	const char mime_type; /*< mime_type, when known. /*
457	} AVProbeData;
458
459	#define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
460	#define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
461
462	#define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
463	#define AVPROBE_SCORE_MIME_BONUS 30 ///< score added for matching mime type
464	#define AVPROBE_SCORE_MAX 100 ///< maximum score
465
466	#define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
467
468	/// Demuxer will use avio_open, no opened file should be provided by the caller.
469	#define AVFMT_NOFILE 0x0001
470	#define AVFMT_NEEDNUMBER 0x0002 /*< Needs '%d' in filename. /
471	/**
472	* The muxer/demuxer is experimental and should be used with caution.
473	*
474	* It will not be selected automatically, and must be specified 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	#define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
489	increasing timestamps, but they must
490	still be monotonic */
491	#define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
492	timestamps. If not set the timestamp
493	will be shifted in av_write_frame and
494	av_interleaved_write_frame so they
495	start from 0.
496	The user or muxer can override this through
497	AVFormatContext.avoid_negative_ts
498	*/
499	#define AVFMT_FIXED_FRAMESIZE 0x80000 /*< Format wants @ref AVCodecParameters.frame_size "fixed size audio frames." /
500
501	#define AVFMT_SEEK_TO_PTS 0x4000000 /*< Seeking is based on PTS /
502
503	/**
504	* @addtogroup lavf_encoding
505	* @{
506	*/
507	typedef struct AVOutputFormat {
508	const char *name;
509	/**
510	* Descriptive name for the format, meant to be more human-readable
511	* than name. You should use the NULL_IF_CONFIG_SMALL() macro
512	* to define it.
513	*/
514	const char *long_name;
515	const char *mime_type;
516	const char extensions; /*< comma-separated filename extensions /*
517	/ output support /
518	enum AVCodecID audio_codec; /< default audio codec /*
519	enum AVCodecID video_codec; /< default video codec /*
520	enum AVCodecID subtitle_codec; /< default subtitle codec /*
521	/**
522	* can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_EXPERIMENTAL,
523	* AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
524	* AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS,
525	* AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE, AVFMT_FIXED_FRAMESIZE
526	*/
527	int flags;
528
529	/**
530	* List of supported codec_id-codec_tag pairs, ordered by "better
531	* choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
532	*/
533	const struct AVCodecTag * const *codec_tag;
534
535
536	const AVClass priv_class; ///< AVClass for the private context*
537	} AVOutputFormat;
538	/**
539	* @}
540	*/
541
542	/**
543	* @addtogroup lavf_decoding
544	* @{
545	*/
546	typedef struct AVInputFormat {
547	/**
548	* A comma separated list of short names for the format. New names
549	* may be appended with a minor bump.
550	*/
551	const char *name;
552
553	/**
554	* Descriptive name for the format, meant to be more human-readable
555	* than name. You should use the NULL_IF_CONFIG_SMALL() macro
556	* to define it.
557	*/
558	const char *long_name;
559
560	/**
561	* Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_EXPERIMENTAL,
562	* AVFMT_SHOW_IDS, AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX,
563	* AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH, AVFMT_NOGENSEARCH,
564	* AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
565	*/
566	int flags;
567
568	/**
569	* If extensions are defined, then no probe is done. You should
570	* usually not use extension format guessing because it is not
571	* reliable enough
572	*/
573	const char *extensions;
574
575	const struct AVCodecTag * const *codec_tag;
576
577	const AVClass priv_class; ///< AVClass for the private context*
578
579	/**
580	* Comma-separated list of mime types.
581	* It is used check for matching mime types while probing.
582	* @see av_probe_input_format2
583	*/
584	const char *mime_type;
585	} AVInputFormat;
586	/**
587	* @}
588	*/
589
590	enum AVStreamParseType {
591	AVSTREAM_PARSE_NONE,
592	AVSTREAM_PARSE_FULL, /< full parsing and repack /*
593	AVSTREAM_PARSE_HEADERS, /< Only parse headers, do not repack. /*
594	AVSTREAM_PARSE_TIMESTAMPS, /< full parsing and interpolation of timestamps for frames not starting on a packet boundary /*
595	AVSTREAM_PARSE_FULL_ONCE, /< full parsing and repack of the first frame only, only implemented for H.264 currently /*
596	AVSTREAM_PARSE_FULL_RAW, /< full parsing and repack with timestamp and position generation by parser for raw
597	this assumes that each packet in the file contains no demuxer level headers and
598	just codec level data, otherwise position generation would fail /*
599	};
600
601	typedef struct AVIndexEntry {
602	int64_t pos;
603	int64_t timestamp; /<
604	* Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
605	* when seeking to this entry. That means preferable PTS on keyframe based formats.
606	* But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
607	* is known
608	*/
609	#define AVINDEX_KEYFRAME 0x0001
610	#define AVINDEX_DISCARD_FRAME 0x0002 /**
611	* Flag is used to indicate which frame should be discarded after decoding.
612	*/
613	int flags:`2`;
614	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).
615	int min_distance; /< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. /*
616	} AVIndexEntry;
617
618	/**
619	* The stream should be chosen by default among other streams of the same type,
620	* unless the user has explicitly specified otherwise.
621	*/
622	#define AV_DISPOSITION_DEFAULT (1 << 0)
623	/**
624	* The stream is not in original language.
625	*
626	* @note AV_DISPOSITION_ORIGINAL is the inverse of this disposition. At most
627	* one of them should be set in properly tagged streams.
628	* @note This disposition may apply to any stream type, not just audio.
629	*/
630	#define AV_DISPOSITION_DUB (1 << 1)
631	/**
632	* The stream is in original language.
633	*
634	* @see the notes for AV_DISPOSITION_DUB
635	*/
636	#define AV_DISPOSITION_ORIGINAL (1 << 2)
637	/**
638	* The stream is a commentary track.
639	*/
640	#define AV_DISPOSITION_COMMENT (1 << 3)
641	/**
642	* The stream contains song lyrics.
643	*/
644	#define AV_DISPOSITION_LYRICS (1 << 4)
645	/**
646	* The stream contains karaoke audio.
647	*/
648	#define AV_DISPOSITION_KARAOKE (1 << 5)
649
650	/**
651	* Track should be used during playback by default.
652	* Useful for subtitle track that should be displayed
653	* even when user did not explicitly ask for subtitles.
654	*/
655	#define AV_DISPOSITION_FORCED (1 << 6)
656	/**
657	* The stream is intended for hearing impaired audiences.
658	*/
659	#define AV_DISPOSITION_HEARING_IMPAIRED (1 << 7)
660	/**
661	* The stream is intended for visually impaired audiences.
662	*/
663	#define AV_DISPOSITION_VISUAL_IMPAIRED (1 << 8)
664	/**
665	* The audio stream contains music and sound effects without voice.
666	*/
667	#define AV_DISPOSITION_CLEAN_EFFECTS (1 << 9)
668	/**
669	* The stream is stored in the file as an attached picture/"cover art" (e.g.
670	* APIC frame in ID3v2). The first (usually only) packet associated with it
671	* will be returned among the first few packets read from the file unless
672	* seeking takes place. It can also be accessed at any time in
673	* AVStream.attached_pic.
674	*/
675	#define AV_DISPOSITION_ATTACHED_PIC (1 << 10)
676	/**
677	* The stream is sparse, and contains thumbnail images, often corresponding
678	* to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
679	*/
680	#define AV_DISPOSITION_TIMED_THUMBNAILS (1 << 11)
681
682	/**
683	* The stream is intended to be mixed with a spatial audio track. For example,
684	* it could be used for narration or stereo music, and may remain unchanged by
685	* listener head rotation.
686	*/
687	#define AV_DISPOSITION_NON_DIEGETIC (1 << 12)
688
689	/**
690	* The subtitle stream contains captions, providing a transcription and possibly
691	* a translation of audio. Typically intended for hearing-impaired audiences.
692	*/
693	#define AV_DISPOSITION_CAPTIONS (1 << 16)
694	/**
695	* The subtitle stream contains a textual description of the video content.
696	* Typically intended for visually-impaired audiences or for the cases where the
697	* video cannot be seen.
698	*/
699	#define AV_DISPOSITION_DESCRIPTIONS (1 << 17)
700	/**
701	* The subtitle stream contains time-aligned metadata that is not intended to be
702	* directly presented to the user.
703	*/
704	#define AV_DISPOSITION_METADATA (1 << 18)
705	/**
706	* The stream is intended to be mixed with another stream before presentation.
707	* Used for example to signal the stream contains an image part of a HEIF grid,
708	* or for mix_type=0 in mpegts.
709	*/
710	#define AV_DISPOSITION_DEPENDENT (1 << 19)
711	/**
712	* The video stream contains still images.
713	*/
714	#define AV_DISPOSITION_STILL_IMAGE (1 << 20)
715	/**
716	* The video stream contains multiple layers, e.g. stereoscopic views (cf. H.264
717	* Annex G/H, or HEVC Annex F).
718	*/
719	#define AV_DISPOSITION_MULTILAYER (1 << 21)
720
721	/**
722	* @return The AV_DISPOSITION_* flag corresponding to disp or a negative error
723	* code if disp does not correspond to a known stream disposition.
724	*/
725	int av_disposition_from_string(const char *disp);
726
727	/**
728	* @param disposition a combination of AV_DISPOSITION_* values
729	* @return The string description corresponding to the lowest set bit in
730	* disposition. NULL when the lowest set bit does not correspond
731	* to a known disposition or when disposition is 0.
732	*/
733	const char av_disposition_to_string(int* disposition);
734
735	/**
736	* Options for behavior on timestamp wrap detection.
737	*/
738	#define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
739	#define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
740	#define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
741
742	/**
743	* Stream structure.
744	* New fields can be added to the end with minor version bumps.
745	* Removal, reordering and changes to existing fields require a major
746	* version bump.
747	* sizeof(AVStream) must not be used outside libav*.
748	*/
749	typedef struct AVStream {
750	/**
751	* A class for @ref avoptions. Set on stream creation.
752	*/
753	const AVClass *av_class;
754
755	int index; /< stream index in AVFormatContext /*
756	/**
757	* Format-specific stream ID.
758	* decoding: set by libavformat
759	* encoding: set by the user, replaced by libavformat if left unset
760	*/
761	int id;
762
763	/**
764	* Codec parameters associated with this stream. Allocated and freed by
765	* libavformat in avformat_new_stream() and avformat_free_context()
766	* respectively.
767	*
768	* - demuxing: filled by libavformat on stream creation or in
769	* avformat_find_stream_info()
770	* - muxing: filled by the caller before avformat_write_header()
771	*/
772	AVCodecParameters *codecpar;
773
774	void *priv_data;
775
776	/**
777	* This is the fundamental unit of time (in seconds) in terms
778	* of which frame timestamps are represented.
779	*
780	* decoding: set by libavformat
781	* encoding: May be set by the caller before avformat_write_header() to
782	* provide a hint to the muxer about the desired timebase. In
783	* avformat_write_header(), the muxer will overwrite this field
784	* with the timebase that will actually be used for the timestamps
785	* written into the file (which may or may not be related to the
786	* user-provided one, depending on the format).
787	*/
788	AVRational time_base;
789
790	/**
791	* Decoding: pts of the first frame of the stream in presentation order, in stream time base.
792	* Only set this if you are absolutely 100% sure that the value you set
793	* it to really is the pts of the first frame.
794	* This may be undefined (AV_NOPTS_VALUE).
795	* @note The ASF header does NOT contain a correct start_time the ASF
796	* demuxer must NOT set this.
797	*/
798	int64_t start_time;
799
800	/**
801	* Decoding: duration of the stream, in stream time base.
802	* If a source file does not specify a duration, but does specify
803	* a bitrate, this value will be estimated from bitrate and file size.
804	*
805	* Encoding: May be set by the caller before avformat_write_header() to
806	* provide a hint to the muxer about the estimated duration.
807	*/
808	int64_t duration;
809
810	int64_t nb_frames; ///< number of frames in this stream if known or 0
811
812	/**
813	* Stream disposition - a combination of AV_DISPOSITION_* flags.
814	* - demuxing: set by libavformat when creating the stream or in
815	* avformat_find_stream_info().
816	* - muxing: may be set by the caller before avformat_write_header().
817	*/
818	int disposition;
819
820	enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
821
822	/**
823	* sample aspect ratio (0 if unknown)
824	* - encoding: Set by user.
825	* - decoding: Set by libavformat.
826	*/
827	AVRational sample_aspect_ratio;
828
829	AVDictionary *metadata;
830
831	/**
832	* Average framerate
833	*
834	* - demuxing: May be set by libavformat when creating the stream or in
835	* avformat_find_stream_info().
836	* - muxing: May be set by the caller before avformat_write_header().
837	*/
838	AVRational avg_frame_rate;
839
840	/**
841	* For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
842	* will contain the attached picture.
843	*
844	* decoding: set by libavformat, must not be modified by the caller.
845	* encoding: unused
846	*/
847	AVPacket attached_pic;
848
849	/**
850	* Flags indicating events happening on the stream, a combination of
851	* AVSTREAM_EVENT_FLAG_*.
852	*
853	* - demuxing: may be set by the demuxer in avformat_open_input(),
854	* avformat_find_stream_info() and av_read_frame(). Flags must be cleared
855	* by the user once the event has been handled.
856	* - muxing: may be set by the user after avformat_write_header(). to
857	* indicate a user-triggered event. The muxer will clear the flags for
858	* events it has handled in av_[interleaved]_write_frame().
859	*/
860	int event_flags;
861	/**
862	* - demuxing: the demuxer read new metadata from the file and updated
863	* AVStream.metadata accordingly
864	* - muxing: the user updated AVStream.metadata and wishes the muxer to write
865	* it into the file
866	*/
867	#define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001
868	/**
869	* - demuxing: new packets for this stream were read from the file. This
870	* event is informational only and does not guarantee that new packets
871	* for this stream will necessarily be returned from av_read_frame().
872	*/
873	#define AVSTREAM_EVENT_FLAG_NEW_PACKETS (1 << 1)
874
875	/**
876	* Real base framerate of the stream.
877	* This is the lowest framerate with which all timestamps can be
878	* represented accurately (it is the least common multiple of all
879	* framerates in the stream). Note, this value is just a guess!
880	* For example, if the time base is 1/90000 and all frames have either
881	* approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
882	*/
883	AVRational r_frame_rate;
884
885	/**
886	* Number of bits in timestamps. Used for wrapping control.
887	*
888	* - demuxing: set by libavformat
889	* - muxing: set by libavformat
890	*
891	*/
892	int pts_wrap_bits;
893	} AVStream;
894
895	/**
896	* AVStreamGroupTileGrid holds information on how to combine several
897	* independent images on a single canvas for presentation.
898	*
899	* The output should be a @ref AVStreamGroupTileGrid.background "background"
900	* colored @ref AVStreamGroupTileGrid.coded_width "coded_width" x
901	* @ref AVStreamGroupTileGrid.coded_height "coded_height" canvas where a
902	* @ref AVStreamGroupTileGrid.nb_tiles "nb_tiles" amount of tiles are placed in
903	* the order they appear in the @ref AVStreamGroupTileGrid.offsets "offsets"
904	* array, at the exact offset described for them. In particular, if two or more
905	* tiles overlap, the image with higher index in the
906	* @ref AVStreamGroupTileGrid.offsets "offsets" array takes priority.
907	* Note that a single image may be used multiple times, i.e. multiple entries
908	* in @ref AVStreamGroupTileGrid.offsets "offsets" may have the same value of
909	* idx.
910	*
911	* The following is an example of a simple grid with 3 rows and 4 columns:
912	*
913	* +---+---+---+---+
914	* \| 0 \| 1 \| 2 \| 3 \|
915	* +---+---+---+---+
916	* \| 4 \| 5 \| 6 \| 7 \|
917	* +---+---+---+---+
918	* \| 8 \| 9 \|10 \|11 \|
919	* +---+---+---+---+
920	*
921	* Assuming all tiles have a dimension of 512x512, the
922	* @ref AVStreamGroupTileGrid.offsets "offset" of the topleft pixel of
923	* the first @ref AVStreamGroup.streams "stream" in the group is "0,0", the
924	* @ref AVStreamGroupTileGrid.offsets "offset" of the topleft pixel of
925	* the second @ref AVStreamGroup.streams "stream" in the group is "512,0", the
926	* @ref AVStreamGroupTileGrid.offsets "offset" of the topleft pixel of
927	* the fifth @ref AVStreamGroup.streams "stream" in the group is "0,512", the
928	* @ref AVStreamGroupTileGrid.offsets "offset", of the topleft pixel of
929	* the sixth @ref AVStreamGroup.streams "stream" in the group is "512,512",
930	* etc.
931	*
932	* The following is an example of a canvas with overlapping tiles:
933	*
934	* +-----------+
935	* \| %%%%% \|
936	* \|***%%3%%@@@\|
937	* \|**0%%%%%2@@\|
938	* \|***##1@@@@@\|
939	* \| ##### \|
940	* +-----------+
941	*
942	* Assuming a canvas with size 1024x1024 and all tiles with a dimension of
943	* 512x512, a possible @ref AVStreamGroupTileGrid.offsets "offset" for the
944	* topleft pixel of the first @ref AVStreamGroup.streams "stream" in the group
945	* would be 0x256, the @ref AVStreamGroupTileGrid.offsets "offset" for the
946	* topleft pixel of the second @ref AVStreamGroup.streams "stream" in the group
947	* would be 256x512, the @ref AVStreamGroupTileGrid.offsets "offset" for the
948	* topleft pixel of the third @ref AVStreamGroup.streams "stream" in the group
949	* would be 512x256, and the @ref AVStreamGroupTileGrid.offsets "offset" for
950	* the topleft pixel of the fourth @ref AVStreamGroup.streams "stream" in the
951	* group would be 256x0.
952	*
953	* sizeof(AVStreamGroupTileGrid) is not a part of the ABI and may only be
954	* allocated by avformat_stream_group_create().
955	*/
956	typedef struct AVStreamGroupTileGrid {
957	const AVClass *av_class;
958
959	/**
960	* Amount of tiles in the grid.
961	*
962	* Must be > 0.
963	*/
964	unsigned int nb_tiles;
965
966	/**
967	* Width of the canvas.
968	*
969	* Must be > 0.
970	*/
971	int coded_width;
972	/**
973	* Width of the canvas.
974	*
975	* Must be > 0.
976	*/
977	int coded_height;
978
979	/**
980	* An @ref nb_tiles sized array of offsets in pixels from the topleft edge
981	* of the canvas, indicating where each stream should be placed.
982	* It must be allocated with the av_malloc() family of functions.
983	*
984	* - demuxing: set by libavformat, must not be modified by the caller.
985	* - muxing: set by the caller before avformat_write_header().
986	*
987	* Freed by libavformat in avformat_free_context().
988	*/
989	struct {
990	/**
991	* Index of the stream in the group this tile references.
992	*
993	* Must be < @ref AVStreamGroup.nb_streams "nb_streams".
994	*/
995	unsigned int idx;
996	/**
997	* Offset in pixels from the left edge of the canvas where the tile
998	* should be placed.
999	*/
1000	int horizontal;
1001	/**
1002	* Offset in pixels from the top edge of the canvas where the tile
1003	* should be placed.
1004	*/
1005	int vertical;
1006	} *offsets;
1007
1008	/**
1009	* The pixel value per channel in RGBA format used if no pixel of any tile
1010	* is located at a particular pixel location.
1011	*
1012	* @see av_image_fill_color().
1013	* @see av_parse_color().
1014	*/
1015	uint8_t background[`4`];
1016
1017	/**
1018	* Offset in pixels from the left edge of the canvas where the actual image
1019	* meant for presentation starts.
1020	*
1021	* This field must be >= 0 and < @ref coded_width.
1022	*/
1023	int horizontal_offset;
1024	/**
1025	* Offset in pixels from the top edge of the canvas where the actual image
1026	* meant for presentation starts.
1027	*
1028	* This field must be >= 0 and < @ref coded_height.
1029	*/
1030	int vertical_offset;
1031
1032	/**
1033	* Width of the final image for presentation.
1034	*
1035	* Must be > 0 and <= (@ref coded_width - @ref horizontal_offset).
1036	* When it's not equal to (@ref coded_width - @ref horizontal_offset), the
1037	* result of (@ref coded_width - width - @ref horizontal_offset) is the
1038	* amount amount of pixels to be cropped from the right edge of the
1039	* final image before presentation.
1040	*/
1041	int width;
1042	/**
1043	* Height of the final image for presentation.
1044	*
1045	* Must be > 0 and <= (@ref coded_height - @ref vertical_offset).
1046	* When it's not equal to (@ref coded_height - @ref vertical_offset), the
1047	* result of (@ref coded_height - height - @ref vertical_offset) is the
1048	* amount amount of pixels to be cropped from the bottom edge of the
1049	* final image before presentation.
1050	*/
1051	int height;
1052
1053	/**
1054	* Additional data associated with the grid.
1055	*
1056	* Should be allocated with av_packet_side_data_new() or
1057	* av_packet_side_data_add(), and will be freed by avformat_free_context().
1058	*/
1059	AVPacketSideData *coded_side_data;
1060
1061	/**
1062	* Amount of entries in @ref coded_side_data.
1063	*/
1064	int nb_coded_side_data;
1065	} AVStreamGroupTileGrid;
1066
1067	/**
1068	* AVStreamGroupLayeredVideo is meant to define the relation between a base
1069	* layer video stream and a separate enhancement layer stream that together
1070	* form a single layered video presentation (for example a video stream and a
1071	* data stream containing LCEVC enhancement layer NALUs, or Dolby Vision
1072	* Profile 7 dual-layer encoding).
1073	*
1074	* The enhancement layer stream is identified by @ref el_index.
1075	*/
1076	typedef struct AVStreamGroupLayeredVideo {
1077	const AVClass *av_class;
1078
1079	/**
1080	* Index of the enhancement layer stream in AVStreamGroup.
1081	*/
1082	#if FF_API_LCEVC_STRUCT
1083	union {
1084	#endif
1085	unsigned int el_index;
1086	#if FF_API_LCEVC_STRUCT
1087	/**
1088	* Alias for @ref el_index, kept for backward compatibility.
1089	*/
1090	attribute_deprecated
1091	unsigned int lcevc_index;
1092	};
1093	#endif
1094	/**
1095	* Width of the final stream for presentation.
1096	*/
1097	int width;
1098	/**
1099	* Height of the final image for presentation.
1100	*/
1101	int height;
1102	} AVStreamGroupLayeredVideo;
1103
1104	#if FF_API_LCEVC_STRUCT
1105	/**
1106	* Alias kept for backward compatibility.
1107	*
1108	* AVStreamGroupLCEVC was renamed to @ref AVStreamGroupLayeredVideo.
1109	*/
1110	#define AVStreamGroupLCEVC AVStreamGroupLayeredVideo
1111	#endif
1112
1113	/**
1114	* AVStreamGroupTREF is meant to define the relation between video, audio,
1115	* or subtitle streams, and a data stream containing metadata.
1116	*
1117	* No more than one stream of @ref AVCodecParameters.codec_type "codec_type"
1118	* AVMEDIA_TYPE_DATA shall be present.
1119	*/
1120	typedef struct AVStreamGroupTREF {
1121	const AVClass *av_class;
1122
1123	/**
1124	* Index of the metadata stream in the AVStreamGroup.
1125	*/
1126	unsigned int metadata_index;
1127	} AVStreamGroupTREF;
1128
1129	enum AVStreamGroupParamsType {
1130	AV_STREAM_GROUP_PARAMS_NONE,
1131	AV_STREAM_GROUP_PARAMS_IAMF_AUDIO_ELEMENT,
1132	AV_STREAM_GROUP_PARAMS_IAMF_MIX_PRESENTATION,
1133	AV_STREAM_GROUP_PARAMS_TILE_GRID,
1134	AV_STREAM_GROUP_PARAMS_LCEVC,
1135	AV_STREAM_GROUP_PARAMS_TREF,
1136	AV_STREAM_GROUP_PARAMS_DOLBY_VISION,
1137	};
1138
1139	struct AVIAMFAudioElement;
1140	struct AVIAMFMixPresentation;
1141
1142	typedef struct AVStreamGroup {
1143	/**
1144	* A class for @ref avoptions. Set by avformat_stream_group_create().
1145	*/
1146	const AVClass *av_class;
1147
1148	void *priv_data;
1149
1150	/**
1151	* Group index in AVFormatContext.
1152	*/
1153	unsigned int index;
1154
1155	/**
1156	* Group type-specific group ID.
1157	*
1158	* decoding: set by libavformat
1159	* encoding: may set by the user
1160	*/
1161	int64_t id;
1162
1163	/**
1164	* Group type
1165	*
1166	* decoding: set by libavformat on group creation
1167	* encoding: set by avformat_stream_group_create()
1168	*/
1169	enum AVStreamGroupParamsType type;
1170
1171	/**
1172	* Group type-specific parameters
1173	*/
1174	union {
1175	struct AVIAMFAudioElement *iamf_audio_element;
1176	struct AVIAMFMixPresentation *iamf_mix_presentation;
1177	struct AVStreamGroupTileGrid *tile_grid;
1178	struct AVStreamGroupLayeredVideo *layered_video;
1179	#if FF_API_LCEVC_STRUCT
1180	/**
1181	* deprecated, use layered_video.
1182	*/
1183	attribute_deprecated
1184	struct AVStreamGroupLCEVC *lcevc;
1185	#endif
1186	struct AVStreamGroupTREF *tref;
1187	} params;
1188
1189	/**
1190	* Metadata that applies to the whole group.
1191	*
1192	* - demuxing: set by libavformat on group creation
1193	* - muxing: may be set by the caller before avformat_write_header()
1194	*
1195	* Freed by libavformat in avformat_free_context().
1196	*/
1197	AVDictionary *metadata;
1198
1199	/**
1200	* Number of elements in AVStreamGroup.streams.
1201	*
1202	* Set by avformat_stream_group_add_stream() must not be modified by any other code.
1203	*/
1204	unsigned int nb_streams;
1205
1206	/**
1207	* A list of streams in the group. New entries are created with
1208	* avformat_stream_group_add_stream().
1209	*
1210	* - demuxing: entries are created by libavformat on group creation.
1211	* If AVFMTCTX_NOHEADER is set in ctx_flags, then new entries may also
1212	* appear in av_read_frame().
1213	* - muxing: entries are created by the user before avformat_write_header().
1214	*
1215	* Freed by libavformat in avformat_free_context().
1216	*/
1217	AVStream **streams;
1218
1219	/**
1220	* Stream group disposition - a combination of AV_DISPOSITION_* flags.
1221	* This field currently applies to all defined AVStreamGroupParamsType.
1222	*
1223	* - demuxing: set by libavformat when creating the group or in
1224	* avformat_find_stream_info().
1225	* - muxing: may be set by the caller before avformat_write_header().
1226	*/
1227	int disposition;
1228	} AVStreamGroup;
1229
1230	struct AVCodecParserContext av_stream_get_parser(const* AVStream *s);
1231
1232	// Chromium: We use the internal field first_dts vvv
1233	int64_t av_stream_get_first_dts(const AVStream *st);
1234	// Chromium: We use the internal field first_dts ^^^
1235
1236	#define AV_PROGRAM_RUNNING 1
1237
1238	/**
1239	* New fields can be added to the end with minor version bumps.
1240	* Removal, reordering and changes to existing fields require a major
1241	* version bump.
1242	* sizeof(AVProgram) must not be used outside libav*.
1243	*/
1244	typedef struct AVProgram {
1245	int id;
1246	int flags;
1247	enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1248	unsigned int *stream_index;
1249	unsigned int nb_stream_indexes;
1250	AVDictionary *metadata;
1251
1252	int program_num;
1253	int pmt_pid;
1254	int pcr_pid;
1255	int pmt_version;
1256
1257	/*****************************************************************
1258	* All fields below this line are not part of the public API. They
1259	* may not be used outside of libavformat and can be changed and
1260	* removed at will.
1261	* New public fields should be added right above.
1262	*****************************************************************
1263	*/
1264	int64_t start_time;
1265	int64_t end_time;
1266
1267	int64_t pts_wrap_reference; ///< reference dts for wrap detection
1268	int pts_wrap_behavior; ///< behavior on wrap detection
1269	} AVProgram;
1270
1271	#define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1272	(streams are added dynamically) */
1273	#define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely
1274	not seekable, and attempts to call the
1275	seek function will fail. For some
1276	network protocols (e.g. HLS), this can
1277	change dynamically at runtime. */
1278
1279	typedef struct AVChapter {
1280	int64_t id; ///< unique ID to identify the chapter
1281	AVRational time_base; ///< time base in which the start/end timestamps are specified
1282	int64_t start, end; ///< chapter start/end time in time_base units
1283	AVDictionary *metadata;
1284	} AVChapter;
1285
1286
1287	/**
1288	* Callback used by devices to communicate with application.
1289	*/
1290	typedef int (av_format_control_message)(struct* AVFormatContext s, int* type,
1291	void *data, size_t data_size);
1292
1293	typedef int (AVOpenCallback)(struct* AVFormatContext s, AVIOContext pb, const* char url, int* flags,
1294	const AVIOInterruptCB int_cb, AVDictionary *options);
1295
1296	/**
1297	* The duration of a video can be estimated through various ways, and this enum can be used
1298	* to know how the duration was estimated.
1299	*/
1300	enum AVDurationEstimationMethod {
1301	AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1302	AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1303	AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1304	};
1305
1306	/**
1307	* Format I/O context.
1308	* New fields can be added to the end with minor version bumps.
1309	* Removal, reordering and changes to existing fields require a major
1310	* version bump.
1311	* sizeof(AVFormatContext) must not be used outside libav*, use
1312	* avformat_alloc_context() to create an AVFormatContext.
1313	*
1314	* Fields can be accessed through AVOptions (av_opt*),
1315	* the name string used matches the associated command line parameter name and
1316	* can be found in libavformat/options_table.h.
1317	* The AVOption/command line parameter names differ in some cases from the C
1318	* structure field names for historic reasons or brevity.
1319	*/
1320	typedef struct AVFormatContext {
1321	/**
1322	* A class for logging and @ref avoptions. Set by avformat_alloc_context().
1323	* Exports (de)muxer private options if they exist.
1324	*/
1325	const AVClass *av_class;
1326
1327	/**
1328	* The input container format.
1329	*
1330	* Demuxing only, set by avformat_open_input().
1331	*/
1332	const struct AVInputFormat *iformat;
1333
1334	/**
1335	* The output container format.
1336	*
1337	* Muxing only, must be set by the caller before avformat_write_header().
1338	*/
1339	const struct AVOutputFormat *oformat;
1340
1341	/**
1342	* Format private data. This is an AVOptions-enabled struct
1343	* if and only if iformat/oformat.priv_class is not NULL.
1344	*
1345	* - muxing: set by avformat_write_header()
1346	* - demuxing: set by avformat_open_input()
1347	*/
1348	void *priv_data;
1349
1350	/**
1351	* I/O context.
1352	*
1353	* - demuxing: either set by the user before avformat_open_input() (then
1354	* the user must close it manually) or set by avformat_open_input().
1355	* - muxing: set by the user before avformat_write_header(). The caller must
1356	* take care of closing / freeing the IO context.
1357	*
1358	* Do NOT set this field if AVFMT_NOFILE flag is set in
1359	* iformat/oformat.flags. In such a case, the (de)muxer will handle
1360	* I/O in some other way and this field will be NULL.
1361	*/
1362	AVIOContext *pb;
1363
1364	/ stream info /
1365	/**
1366	* Flags signalling stream properties. A combination of AVFMTCTX_*.
1367	* Set by libavformat.
1368	*/
1369	int ctx_flags;
1370
1371	/**
1372	* Number of elements in AVFormatContext.streams.
1373	*
1374	* Set by avformat_new_stream(), must not be modified by any other code.
1375	*/
1376	unsigned int nb_streams;
1377	/**
1378	* A list of all streams in the file. New streams are created with
1379	* avformat_new_stream().
1380	*
1381	* - demuxing: streams are created by libavformat in avformat_open_input().
1382	* If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1383	* appear in av_read_frame().
1384	* - muxing: streams are created by the user before avformat_write_header().
1385	*
1386	* Freed by libavformat in avformat_free_context().
1387	*/
1388	AVStream **streams;
1389
1390	/**
1391	* Number of elements in AVFormatContext.stream_groups.
1392	*
1393	* Set by avformat_stream_group_create(), must not be modified by any other code.
1394	*/
1395	unsigned int nb_stream_groups;
1396	/**
1397	* A list of all stream groups in the file. New groups are created with
1398	* avformat_stream_group_create(), and filled with avformat_stream_group_add_stream().
1399	*
1400	* - demuxing: groups may be created by libavformat in avformat_open_input().
1401	* If AVFMTCTX_NOHEADER is set in ctx_flags, then new groups may also
1402	* appear in av_read_frame().
1403	* - muxing: groups may be created by the user before avformat_write_header().
1404	*
1405	* Freed by libavformat in avformat_free_context().
1406	*/
1407	AVStreamGroup **stream_groups;
1408
1409	/**
1410	* Number of chapters in AVChapter array.
1411	* When muxing, chapters are normally written in the file header,
1412	* so nb_chapters should normally be initialized before write_header
1413	* is called. Some muxers (e.g. mov and mkv) can also write chapters
1414	* in the trailer. To write chapters in the trailer, nb_chapters
1415	* must be zero when write_header is called and non-zero when
1416	* write_trailer is called.
1417	* - muxing: set by user
1418	* - demuxing: set by libavformat
1419	*/
1420	unsigned int nb_chapters;
1421	AVChapter **chapters;
1422
1423	/**
1424	* input or output URL. Unlike the old filename field, this field has no
1425	* length restriction.
1426	*
1427	* - demuxing: set by avformat_open_input(), initialized to an empty
1428	* string if url parameter was NULL in avformat_open_input().
1429	* - muxing: may be set by the caller before calling avformat_write_header()
1430	* (or avformat_init_output() if that is called first) to a string
1431	* which is freeable by av_free(). Set to an empty string if it
1432	* was NULL in avformat_init_output().
1433	*
1434	* Freed by libavformat in avformat_free_context().
1435	*/
1436	char *url;
1437
1438	/**
1439	* Position of the first frame of the component, in
1440	* AV_TIME_BASE fractional seconds. NEVER set this value directly:
1441	* It is deduced from the AVStream values.
1442	*
1443	* Demuxing only, set by libavformat.
1444	*/
1445	int64_t start_time;
1446
1447	/**
1448	* Duration of the stream, in AV_TIME_BASE fractional
1449	* seconds. Only set this value if you know none of the individual stream
1450	* durations and also do not set any of them. This is deduced from the
1451	* AVStream values if not set.
1452	*
1453	* Demuxing only, set by libavformat.
1454	*/
1455	int64_t duration;
1456
1457	/**
1458	* Total stream bitrate in bit/s, 0 if not
1459	* available. Never set it directly if the file_size and the
1460	* duration are known as FFmpeg can compute it automatically.
1461	*/
1462	int64_t bit_rate;
1463
1464	unsigned int packet_size;
1465	int max_delay;
1466
1467	/**
1468	* Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1469	* Set by the user before avformat_open_input() / avformat_write_header().
1470	*/
1471	int flags;
1472	#define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1473	#define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1474	#define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1475	#define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1476	#define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1477	#define AVFMT_FLAG_NOPARSE 0x0020 ///< Do not use AVParsers, you also must set AVFMT_FLAG_NOFILLIN as the filling 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
1478	#define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1479	#define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1480	#define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1481	#define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1482	/**
1483	* When muxing, try to avoid writing any random/volatile data to the output.
1484	* This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1485	*
1486	* This flag is mainly intended for testing.
1487	*/
1488	#define AVFMT_FLAG_BITEXACT 0x0400
1489	#define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1490	#define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1491	#define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
1492
1493	/**
1494	* Maximum number of bytes read from input in order to determine stream
1495	* properties. Used when reading the global header and in
1496	* avformat_find_stream_info().
1497	*
1498	* Demuxing only, set by the caller before avformat_open_input().
1499	*
1500	* @note this is \e not used for determining the \ref AVInputFormat
1501	* "input format"
1502	* @see format_probesize
1503	*/
1504	int64_t probesize;
1505
1506	/**
1507	* Maximum duration (in AV_TIME_BASE units) of the data read
1508	* from input in avformat_find_stream_info().
1509	* Demuxing only, set by the caller before avformat_find_stream_info().
1510	* Can be set to 0 to let avformat choose using a heuristic.
1511	*/
1512	int64_t max_analyze_duration;
1513
1514	const uint8_t *key;
1515	int keylen;
1516
1517	unsigned int nb_programs;
1518	AVProgram **programs;
1519
1520	/**
1521	* Forced video codec_id.
1522	* Demuxing: Set by user.
1523	*/
1524	enum AVCodecID video_codec_id;
1525
1526	/**
1527	* Forced audio codec_id.
1528	* Demuxing: Set by user.
1529	*/
1530	enum AVCodecID audio_codec_id;
1531
1532	/**
1533	* Forced subtitle codec_id.
1534	* Demuxing: Set by user.
1535	*/
1536	enum AVCodecID subtitle_codec_id;
1537
1538	/**
1539	* Forced Data codec_id.
1540	* Demuxing: Set by user.
1541	*/
1542	enum AVCodecID data_codec_id;
1543
1544	/**
1545	* Metadata that applies to the whole file.
1546	*
1547	* - demuxing: set by libavformat in avformat_open_input()
1548	* - muxing: may be set by the caller before avformat_write_header()
1549	*
1550	* Freed by libavformat in avformat_free_context().
1551	*/
1552	AVDictionary *metadata;
1553
1554	/**
1555	* Start time of the stream in real world time, in microseconds
1556	* since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1557	* stream was captured at this real world time.
1558	* - muxing: Set by the caller before avformat_write_header(). If set to
1559	* either 0 or AV_NOPTS_VALUE, then the current wall-time will
1560	* be used.
1561	* - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1562	* the value may become known after some number of frames
1563	* have been received.
1564	*/
1565	int64_t start_time_realtime;
1566
1567	/**
1568	* The number of frames used for determining the framerate in
1569	* avformat_find_stream_info().
1570	* Demuxing only, set by the caller before avformat_find_stream_info().
1571	*/
1572	int fps_probe_size;
1573
1574	/**
1575	* Error recognition; higher values will detect more errors but may
1576	* misdetect some more or less valid parts as errors.
1577	* Demuxing only, set by the caller before avformat_open_input().
1578	*/
1579	int error_recognition;
1580
1581	/**
1582	* Custom interrupt callbacks for the I/O layer.
1583	*
1584	* demuxing: set by the user before avformat_open_input().
1585	* muxing: set by the user before avformat_write_header()
1586	* (mainly useful for AVFMT_NOFILE formats). The callback
1587	* should also be passed to avio_open2() if it's used to
1588	* open the file.
1589	*/
1590	AVIOInterruptCB interrupt_callback;
1591
1592	/**
1593	* Flags to enable debugging.
1594	*/
1595	int debug;
1596	#define AV_FDEBUG_TS 0x0001
1597	#define AV_FDEBUG_ID3V2 0x0002
1598
1599	#if FF_API_FDEBUG_TS
1600	#define FF_FDEBUG_TS AV_FDEBUG_TS
1601	#endif
1602
1603	/**
1604	* The maximum number of streams.
1605	* - encoding: unused
1606	* - decoding: set by user
1607	*/
1608	int max_streams;
1609
1610	/**
1611	* Maximum amount of memory in bytes to use for the index of each stream.
1612	* If the index exceeds this size, entries will be discarded as
1613	* needed to maintain a smaller size. This can lead to slower or less
1614	* accurate seeking (depends on demuxer).
1615	* Demuxers for which a full in-memory index is mandatory will ignore
1616	* this.
1617	* - muxing: unused
1618	* - demuxing: set by user
1619	*/
1620	unsigned int max_index_size;
1621
1622	/**
1623	* Maximum amount of memory in bytes to use for buffering frames
1624	* obtained from realtime capture devices.
1625	*/
1626	unsigned int max_picture_buffer;
1627
1628	/**
1629	* Maximum buffering duration for interleaving.
1630	*
1631	* To ensure all the streams are interleaved correctly,
1632	* av_interleaved_write_frame() will wait until it has at least one packet
1633	* for each stream before actually writing any packets to the output file.
1634	* When some streams are "sparse" (i.e. there are large gaps between
1635	* successive packets), this can result in excessive buffering.
1636	*
1637	* This field specifies the maximum difference between the timestamps of the
1638	* first and the last packet in the muxing queue, above which libavformat
1639	* will output a packet regardless of whether it has queued a packet for all
1640	* the streams.
1641	*
1642	* Muxing only, set by the caller before avformat_write_header().
1643	*/
1644	int64_t max_interleave_delta;
1645
1646	/**
1647	* Maximum number of packets to read while waiting for the first timestamp.
1648	* Decoding only.
1649	*/
1650	int max_ts_probe;
1651
1652	/**
1653	* Max chunk time in microseconds.
1654	* Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1655	* - encoding: Set by user
1656	* - decoding: unused
1657	*/
1658	int max_chunk_duration;
1659
1660	/**
1661	* Max chunk size in bytes
1662	* Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1663	* - encoding: Set by user
1664	* - decoding: unused
1665	*/
1666	int max_chunk_size;
1667
1668	/**
1669	* Maximum number of packets that can be probed
1670	* - encoding: unused
1671	* - decoding: set by user
1672	*/
1673	int max_probe_packets;
1674
1675	/**
1676	* Allow non-standard and experimental extension
1677	* @see AVCodecContext.strict_std_compliance
1678	*/
1679	int strict_std_compliance;
1680
1681	/**
1682	* Flags indicating events happening on the file, a combination of
1683	* AVFMT_EVENT_FLAG_*.
1684	*
1685	* - demuxing: may be set by the demuxer in avformat_open_input(),
1686	* avformat_find_stream_info() and av_read_frame(). Flags must be cleared
1687	* by the user once the event has been handled.
1688	* - muxing: may be set by the user after avformat_write_header() to
1689	* indicate a user-triggered event. The muxer will clear the flags for
1690	* events it has handled in av_[interleaved]_write_frame().
1691	*/
1692	int event_flags;
1693	/**
1694	* - demuxing: the demuxer read new metadata from the file and updated
1695	* AVFormatContext.metadata accordingly
1696	* - muxing: the user updated AVFormatContext.metadata and wishes the muxer to
1697	* write it into the file
1698	*/
1699	#define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001
1700
1701
1702	/**
1703	* Avoid negative timestamps during muxing.
1704	* Any value of the AVFMT_AVOID_NEG_TS_* constants.
1705	* Note, this works better when using av_interleaved_write_frame().
1706	* - muxing: Set by user
1707	* - demuxing: unused
1708	*/
1709	int avoid_negative_ts;
1710	#define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1711	#define AVFMT_AVOID_NEG_TS_DISABLED 0 ///< Do not shift timestamps even when they are negative.
1712	#define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1713	#define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1714
1715	/**
1716	* Audio preload in microseconds.
1717	* Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1718	* - encoding: Set by user
1719	* - decoding: unused
1720	*/
1721	int audio_preload;
1722
1723	/**
1724	* forces the use of wallclock timestamps as pts/dts of packets
1725	* This has undefined results in the presence of B frames.
1726	* - encoding: unused
1727	* - decoding: Set by user
1728	*/
1729	int use_wallclock_as_timestamps;
1730
1731	/**
1732	* Skip duration calculation in estimate_timings_from_pts.
1733	* - encoding: unused
1734	* - decoding: set by user
1735	*
1736	* @see duration_probesize
1737	*/
1738	int skip_estimate_duration_from_pts;
1739
1740	/**
1741	* avio flags, used to force AVIO_FLAG_DIRECT.
1742	* - encoding: unused
1743	* - decoding: Set by user
1744	*/
1745	int avio_flags;
1746
1747	/**
1748	* The duration field can be estimated through various ways, and this field can be used
1749	* to know how the duration was estimated.
1750	* - encoding: unused
1751	* - decoding: Read by user
1752	*/
1753	enum AVDurationEstimationMethod duration_estimation_method;
1754
1755	/**
1756	* Skip initial bytes when opening stream
1757	* - encoding: unused
1758	* - decoding: Set by user
1759	*/
1760	int64_t skip_initial_bytes;
1761
1762	/**
1763	* Correct single timestamp overflows
1764	* - encoding: unused
1765	* - decoding: Set by user
1766	*/
1767	unsigned int correct_ts_overflow;
1768
1769	/**
1770	* Force seeking to any (also non key) frames.
1771	* - encoding: unused
1772	* - decoding: Set by user
1773	*/
1774	int seek2any;
1775
1776	/**
1777	* Flush the I/O context after each packet.
1778	* - encoding: Set by user
1779	* - decoding: unused
1780	*/
1781	int flush_packets;
1782
1783	/**
1784	* format probing score.
1785	* The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1786	* the format.
1787	* - encoding: unused
1788	* - decoding: set by avformat, read by user
1789	*/
1790	int probe_score;
1791
1792	/**
1793	* Maximum number of bytes read from input in order to identify the
1794	* \ref AVInputFormat "input format". Only used when the format is not set
1795	* explicitly by the caller.
1796	*
1797	* Demuxing only, set by the caller before avformat_open_input().
1798	*
1799	* @see probesize
1800	*/
1801	int format_probesize;
1802
1803	/**
1804	* ',' separated list of allowed decoders.
1805	* If NULL then all are allowed
1806	* - encoding: unused
1807	* - decoding: set by user
1808	*/
1809	char *codec_whitelist;
1810
1811	/**
1812	* ',' separated list of allowed demuxers.
1813	* If NULL then all are allowed
1814	* - encoding: unused
1815	* - decoding: set by user
1816	*/
1817	char *format_whitelist;
1818
1819	/**
1820	* ',' separated list of allowed protocols.
1821	* - encoding: unused
1822	* - decoding: set by user
1823	*/
1824	char *protocol_whitelist;
1825
1826	/**
1827	* ',' separated list of disallowed protocols.
1828	* - encoding: unused
1829	* - decoding: set by user
1830	*/
1831	char *protocol_blacklist;
1832
1833	/**
1834	* IO repositioned flag.
1835	* This is set by avformat when the underlying IO context read pointer
1836	* is repositioned, for example when doing byte based seeking.
1837	* Demuxers can use the flag to detect such changes.
1838	*/
1839	int io_repositioned;
1840
1841	/**
1842	* Forced video codec.
1843	* This allows forcing a specific decoder, even when there are multiple with
1844	* the same codec_id.
1845	* Demuxing: Set by user
1846	*/
1847	const struct AVCodec *video_codec;
1848
1849	/**
1850	* Forced audio codec.
1851	* This allows forcing a specific decoder, even when there are multiple with
1852	* the same codec_id.
1853	* Demuxing: Set by user
1854	*/
1855	const struct AVCodec *audio_codec;
1856
1857	/**
1858	* Forced subtitle codec.
1859	* This allows forcing a specific decoder, even when there are multiple with
1860	* the same codec_id.
1861	* Demuxing: Set by user
1862	*/
1863	const struct AVCodec *subtitle_codec;
1864
1865	/**
1866	* Forced data codec.
1867	* This allows forcing a specific decoder, even when there are multiple with
1868	* the same codec_id.
1869	* Demuxing: Set by user
1870	*/
1871	const struct AVCodec *data_codec;
1872
1873	/**
1874	* Number of bytes to be written as padding in a metadata header.
1875	* Demuxing: Unused.
1876	* Muxing: Set by user.
1877	*/
1878	int metadata_header_padding;
1879
1880	/**
1881	* User data.
1882	* This is a place for some private data of the user.
1883	*/
1884	void *opaque;
1885
1886	/**
1887	* Callback used by devices to communicate with application.
1888	*/
1889	av_format_control_message control_message_cb;
1890
1891	/**
1892	* Output timestamp offset, in microseconds.
1893	* Muxing: set by user
1894	*/
1895	int64_t output_ts_offset;
1896
1897	/**
1898	* dump format separator.
1899	* can be ", " or "\n " or anything else
1900	* - muxing: Set by user.
1901	* - demuxing: Set by user.
1902	*/
1903	uint8_t *dump_separator;
1904
1905	/**
1906	* A callback for opening new IO streams.
1907	*
1908	* Whenever a muxer or a demuxer needs to open an IO stream (typically from
1909	* avformat_open_input() for demuxers, but for certain formats can happen at
1910	* other times as well), it will call this callback to obtain an IO context.
1911	*
1912	* @param s the format context
1913	* @param pb on success, the newly opened IO context should be returned here
1914	* @param url the url to open
1915	* @param flags a combination of AVIO_FLAG_*
1916	* @param options a dictionary of additional options, with the same
1917	* semantics as in avio_open2()
1918	* @return 0 on success, a negative AVERROR code on failure
1919	*
1920	* @note Certain muxers and demuxers do nesting, i.e. they open one or more
1921	* additional internal format contexts. Thus the AVFormatContext pointer
1922	* passed to this callback may be different from the one facing the caller.
1923	* It will, however, have the same 'opaque' field.
1924	*/
1925	int (io_open)(struct* AVFormatContext s, AVIOContext pb, const* char *url,
1926	int flags, AVDictionary **options);
1927
1928	/**
1929	* A callback for closing the streams opened with AVFormatContext.io_open().
1930	*
1931	* @param s the format context
1932	* @param pb IO context to be closed and freed
1933	* @return 0 on success, a negative AVERROR code on failure
1934	*/
1935	int (io_close2)(struct* AVFormatContext s, AVIOContext pb);
1936
1937	/**
1938	* Maximum number of bytes read from input in order to determine stream durations
1939	* when using estimate_timings_from_pts in avformat_find_stream_info().
1940	* Demuxing only, set by the caller before avformat_find_stream_info().
1941	* Can be set to 0 to let avformat choose using a heuristic.
1942	*
1943	* @see skip_estimate_duration_from_pts
1944	*/
1945	int64_t duration_probesize;
1946
1947	/**
1948	* Name of this format context, only used for logging purposes.
1949	*/
1950	char *name;
1951	} AVFormatContext;
1952
1953	/**
1954	* @defgroup lavf_core Core functions
1955	* @ingroup libavf
1956	*
1957	* Functions for querying libavformat capabilities, allocating core structures,
1958	* etc.
1959	* @{
1960	*/
1961
1962	/**
1963	* Return the LIBAVFORMAT_VERSION_INT constant.
1964	*/
1965	unsigned avformat_version(void);
1966
1967	/**
1968	* Return the libavformat build-time configuration.
1969	*/
1970	const char avformat_configuration(void*);
1971
1972	/**
1973	* Return the libavformat license.
1974	*/
1975	const char avformat_license(void*);
1976
1977	/**
1978	* Do global initialization of network libraries. This is optional,
1979	* and not recommended anymore.
1980	*
1981	* This functions only exists to work around thread-safety issues
1982	* with older GnuTLS or OpenSSL libraries. If libavformat is linked
1983	* to newer versions of those libraries, or if you do not use them,
1984	* calling this function is unnecessary. Otherwise, you need to call
1985	* this function before any other threads using them are started.
1986	*
1987	* This function will be deprecated once support for older GnuTLS and
1988	* OpenSSL libraries is removed, and this function has no purpose
1989	* anymore.
1990	*/
1991	int avformat_network_init(void);
1992
1993	/**
1994	* Undo the initialization done by avformat_network_init. Call it only
1995	* once for each time you called avformat_network_init.
1996	*/
1997	int avformat_network_deinit(void);
1998
1999	/**
2000	* Iterate over all registered muxers.
2001	*
2002	* @param opaque a pointer where libavformat will store the iteration state. Must
2003	* point to NULL to start the iteration.
2004	*
2005	* @return the next registered muxer or NULL when the iteration is
2006	* finished
2007	*/
2008	const AVOutputFormat av_muxer_iterate(void* **opaque);
2009
2010	/**
2011	* Iterate over all registered demuxers.
2012	*
2013	* @param opaque a pointer where libavformat will store the iteration state.
2014	* Must point to NULL to start the iteration.
2015	*
2016	* @return the next registered demuxer or NULL when the iteration is
2017	* finished
2018	*/
2019	const AVInputFormat av_demuxer_iterate(void* **opaque);
2020
2021	/**
2022	* Allocate an AVFormatContext.
2023	* avformat_free_context() can be used to free the context and everything
2024	* allocated by the framework within it.
2025	*/
2026	AVFormatContext avformat_alloc_context(void*);
2027
2028	/**
2029	* Free an AVFormatContext and all its streams.
2030	* @param s context to free
2031	*/
2032	void avformat_free_context(AVFormatContext *s);
2033
2034	/**
2035	* Get the AVClass for AVFormatContext. It can be used in combination with
2036	* AV_OPT_SEARCH_FAKE_OBJ for examining options.
2037	*
2038	* @see av_opt_find().
2039	*/
2040	const AVClass avformat_get_class(void*);
2041
2042	/**
2043	* Get the AVClass for AVStream. It can be used in combination with
2044	* AV_OPT_SEARCH_FAKE_OBJ for examining options.
2045	*
2046	* @see av_opt_find().
2047	*/
2048	const AVClass av_stream_get_class(void*);
2049
2050	/**
2051	* Get the AVClass for AVStreamGroup. It can be used in combination with
2052	* AV_OPT_SEARCH_FAKE_OBJ for examining options.
2053	*
2054	* @see av_opt_find().
2055	*/
2056	const AVClass av_stream_group_get_class(void*);
2057
2058	/**
2059	* @return a string identifying the stream group type, or NULL if unknown
2060	*/
2061	const char avformat_stream_group_name(enum* AVStreamGroupParamsType type);
2062
2063	/**
2064	* Add a new empty stream group to a media file.
2065	*
2066	* When demuxing, it may be called by the demuxer in read_header(). If the
2067	* flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2068	* be called in read_packet().
2069	*
2070	* When muxing, may be called by the user before avformat_write_header().
2071	*
2072	* User is required to call avformat_free_context() to clean up the allocation
2073	* by avformat_stream_group_create().
2074	*
2075	* New streams can be added to the group with avformat_stream_group_add_stream().
2076	*
2077	* @param s media file handle
2078	*
2079	* @return newly created group or NULL on error.
2080	* @see avformat_new_stream, avformat_stream_group_add_stream.
2081	*/
2082	AVStreamGroup avformat_stream_group_create(AVFormatContext s,
2083	enum AVStreamGroupParamsType type,
2084	AVDictionary **options);
2085
2086	/**
2087	* Add a new stream to a media file.
2088	*
2089	* When demuxing, it is called by the demuxer in read_header(). If the
2090	* flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2091	* be called in read_packet().
2092	*
2093	* When muxing, should be called by the user before avformat_write_header().
2094	*
2095	* User is required to call avformat_free_context() to clean up the allocation
2096	* by avformat_new_stream().
2097	*
2098	* @param s media file handle
2099	* @param c unused, does nothing
2100	*
2101	* @return newly created stream or NULL on error.
2102	*/
2103	AVStream avformat_new_stream(AVFormatContext s, const struct AVCodec *c);
2104
2105	/**
2106	* Add an already allocated stream to a stream group.
2107	*
2108	* When demuxing, it may be called by the demuxer in read_header(). If the
2109	* flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2110	* be called in read_packet().
2111	*
2112	* When muxing, may be called by the user before avformat_write_header() after
2113	* having allocated a new group with avformat_stream_group_create() and stream with
2114	* avformat_new_stream().
2115	*
2116	* User is required to call avformat_free_context() to clean up the allocation
2117	* by avformat_stream_group_add_stream().
2118	*
2119	* @param stg stream group belonging to a media file.
2120	* @param st stream in the media file to add to the group.
2121	*
2122	* @retval 0 success
2123	* @retval AVERROR(EEXIST) the stream was already in the group
2124	* @retval "another negative error code" legitimate errors
2125	*
2126	* @see avformat_new_stream, avformat_stream_group_create.
2127	*/
2128	int avformat_stream_group_add_stream(AVStreamGroup stg, AVStream st);
2129
2130	AVProgram av_new_program(AVFormatContext s, int id);
2131
2132
2133	#define AVFMT_PROGCOPY_MATCH_BY_ID (1 << 0) ///< match streams using stream id
2134	#define AVFMT_PROGCOPY_MATCH_BY_INDEX (1 << 1) ///< match streams using stream index
2135	#define AVFMT_PROGCOPY_OVERWRITE (1 << 8) ///< overwrite pre-existing program having same ID
2136
2137	/**
2138	* Copy an AVProgram from one AVFormatContext to another.
2139	*
2140	* Streams in the destination context whose designated attribute match the attribute of
2141	* the streams in the source AVProgram index are added to the stream index of the copied
2142	* AVProgram. The attribute is designated using AVFMT_PROGCOPY_MATCH_ flags.
2143	*
2144	* If a new program has to be added, the function expects and requires any existing buffer
2145	* holding the array of pointers to AVPrograms in the destination context to have its size
2146	* be a power-of-two value. This should be the case if all earlier programs were created
2147	* using av_new_program or this function.
2148	*
2149	* @param dst pointer to the target muxer context
2150	* @param src pointer to the source muxer context
2151	* @param progid ID of the program to be copied
2152	* @param flags combination of flags which determine how streams are matched and
2153	* whether pre-existing AVProgram in target is overwritten.
2154	* If no match condition is set, streams will be matched by ids if
2155	* all source stream ids are non-zero and unique, else by index.
2156	*
2157	* @return >= 0 in case of success, Error EEXIST if target already has program with same ID
2158	* and overwrite flag isn't set, else a negative AVERROR code in case of other
2159	* failures.
2160	*/
2161	int av_program_copy(AVFormatContext dst, const* AVFormatContext src, int* progid, int flags);
2162
2163	/**
2164	* @}
2165	*/
2166
2167
2168	/**
2169	* Allocate an AVFormatContext for an output format.
2170	* avformat_free_context() can be used to free the context and
2171	* everything allocated by the framework within it.
2172	*
2173	* @param ctx pointee is set to the created format context,
2174	* or to NULL in case of failure
2175	* @param oformat format to use for allocating the context, if NULL
2176	* format_name and filename are used instead
2177	* @param format_name the name of output format to use for allocating the
2178	* context, if NULL filename is used instead
2179	* @param filename the name of the filename to use for allocating the
2180	* context, may be NULL
2181	*
2182	* @return >= 0 in case of success, a negative AVERROR code in case of
2183	* failure
2184	*/
2185	int avformat_alloc_output_context2(AVFormatContext *ctx, const* AVOutputFormat *oformat,
2186	const char format_name, const* char *filename);
2187
2188	/**
2189	* @addtogroup lavf_decoding
2190	* @{
2191	*/
2192
2193	/**
2194	* Find AVInputFormat based on the short name of the input format.
2195	*/
2196	const AVInputFormat av_find_input_format(const* char *short_name);
2197
2198	/**
2199	* Guess the file format.
2200	*
2201	* @param pd data to be probed
2202	* @param is_opened Whether the file is already opened; determines whether
2203	* demuxers with or without AVFMT_NOFILE are probed.
2204	*/
2205	const AVInputFormat av_probe_input_format(const* AVProbeData pd, int* is_opened);
2206
2207	/**
2208	* Guess the file format.
2209	*
2210	* @param pd data to be probed
2211	* @param is_opened Whether the file is already opened; determines whether
2212	* demuxers with or without AVFMT_NOFILE are probed.
2213	* @param score_max A probe score larger that this is required to accept a
2214	* detection, the variable is set to the actual detection
2215	* score afterwards.
2216	* If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2217	* to retry with a larger probe buffer.
2218	*/
2219	const AVInputFormat av_probe_input_format2(const* AVProbeData *pd,
2220	int is_opened, int *score_max);
2221
2222	/**
2223	* Guess the file format.
2224	*
2225	* @param is_opened Whether the file is already opened; determines whether
2226	* demuxers with or without AVFMT_NOFILE are probed.
2227	* @param score_ret The score of the best detection.
2228	*/
2229	const AVInputFormat av_probe_input_format3(const* AVProbeData *pd,
2230	int is_opened, int *score_ret);
2231
2232	/**
2233	* Probe a bytestream to determine the input format. Each time a probe returns
2234	* with a score that is too low, the probe buffer size is increased and another
2235	* attempt is made. When the maximum probe size is reached, the input format
2236	* with the highest score is returned.
2237	*
2238	* @param pb the bytestream to probe
2239	* @param fmt the input format is put here
2240	* @param url the url of the stream
2241	* @param logctx the log context
2242	* @param offset the offset within the bytestream to probe from
2243	* @param max_probe_size the maximum probe buffer size (zero for default)
2244	*
2245	* @return the score in case of success, a negative value corresponding to an
2246	* the maximal score is AVPROBE_SCORE_MAX
2247	* AVERROR code otherwise
2248	*/
2249	int av_probe_input_buffer2(AVIOContext pb, const* AVInputFormat **fmt,
2250	const char url, void* *logctx,
2251	unsigned int offset, unsigned int max_probe_size);
2252
2253	/**
2254	* Like av_probe_input_buffer2() but returns 0 on success
2255	*/
2256	int av_probe_input_buffer(AVIOContext pb, const* AVInputFormat **fmt,
2257	const char url, void* *logctx,
2258	unsigned int offset, unsigned int max_probe_size);
2259
2260	/**
2261	* Open an input stream and read the header. The codecs are not opened.
2262	* The stream must be closed with avformat_close_input().
2263	*
2264	* @param ps Pointer to user-supplied AVFormatContext (allocated by
2265	* avformat_alloc_context). May be a pointer to NULL, in
2266	* which case an AVFormatContext is allocated by this
2267	* function and written into ps.
2268	* Note that a user-supplied AVFormatContext will be freed
2269	* on failure and its pointer set to NULL.
2270	* @param url URL of the stream to open.
2271	* @param fmt If non-NULL, this parameter forces a specific input format.
2272	* Otherwise the format is autodetected.
2273	* @param options A dictionary filled with AVFormatContext and demuxer-private
2274	* options.
2275	* On return this parameter will be destroyed and replaced with
2276	* a dict containing options that were not found. May be NULL.
2277	*
2278	* @return 0 on success; on failure: frees ps, sets its pointer to NULL,
2279	* and returns a negative AVERROR.
2280	*
2281	* @note If you want to use custom IO, preallocate the format context and set its pb field.
2282	*/
2283	int avformat_open_input(AVFormatContext *ps, const* char *url,
2284	const AVInputFormat fmt, AVDictionary *options);
2285
2286	/**
2287	* Read packets of a media file to get stream information. This
2288	* is useful for file formats with no headers such as MPEG. This
2289	* function also computes the real framerate in case of MPEG-2 repeat
2290	* frame mode.
2291	* The logical file position is not changed by this function;
2292	* examined packets may be buffered for later processing.
2293	*
2294	* @param ic media file handle
2295	* @param options If non-NULL, an ic.nb_streams long array of pointers to
2296	* dictionaries, where i-th member contains options for
2297	* codec corresponding to i-th stream.
2298	* On return each dictionary will be filled with options that were not found.
2299	* @return >=0 if OK, AVERROR_xxx on error
2300	*
2301	* @note this function isn't guaranteed to open all the codecs, so
2302	* options being non-empty at return is a perfectly normal behavior.
2303	*
2304	* @todo Let the user decide somehow what information is needed so that
2305	* we do not waste time getting stuff the user does not need.
2306	*/
2307	int avformat_find_stream_info(AVFormatContext ic, AVDictionary *options);
2308
2309	/**
2310	* Find the programs which belong to a given stream.
2311	*
2312	* @param ic media file handle
2313	* @param last the last found program, the search will start after this
2314	* program, or from the beginning if it is NULL
2315	* @param s stream index
2316	*
2317	* @return the next program which belongs to s, NULL if no program is found or
2318	* the last program is not among the programs of ic.
2319	*/
2320	AVProgram av_find_program_from_stream(AVFormatContext ic, AVProgram last, int* s);
2321
2322	void av_program_add_stream_index(AVFormatContext ac, int* progid, unsigned int idx);
2323
2324	/**
2325	* Add the supplied index of a stream to the AVProgram with matching id.
2326	*
2327	* @param ac the format context which contains the target AVProgram
2328	* @param progid the ID of the AVProgram whose stream index is to be updated
2329	* @param idx the index of the stream to be added
2330	*
2331	* @return >=0 upon successful addition or if index was already present,
2332	* AVERROR if no matching program is found or stream index is invalid or
2333	* the stream index array reallocation failed.
2334	*/
2335	int av_program_add_stream_index2(AVFormatContext ac, int* progid, unsigned int idx);
2336
2337	/**
2338	* Find the "best" stream in the file.
2339	* The best stream is determined according to various heuristics as the most
2340	* likely to be what the user expects.
2341	* If the decoder parameter is non-NULL, av_find_best_stream will find the
2342	* default decoder for the stream's codec; streams for which no decoder can
2343	* be found are ignored.
2344	*
2345	* @param ic media file handle
2346	* @param type stream type: video, audio, subtitles, etc.
2347	* @param wanted_stream_nb user-requested stream number,
2348	* or -1 for automatic selection
2349	* @param related_stream try to find a stream related (eg. in the same
2350	* program) to this one, or -1 if none
2351	* @param decoder_ret if non-NULL, returns the decoder for the
2352	* selected stream
2353	* @param flags flags; none are currently defined
2354	*
2355	* @return the non-negative stream number in case of success,
2356	* AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2357	* could be found,
2358	* AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2359	*
2360	* @note If av_find_best_stream returns successfully and decoder_ret is not
2361	* NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2362	*/
2363	int av_find_best_stream(AVFormatContext *ic,
2364	enum AVMediaType type,
2365	int wanted_stream_nb,
2366	int related_stream,
2367	const struct AVCodec **decoder_ret,
2368	int flags);
2369
2370	/**
2371	* Return the next frame of a stream.
2372	* This function returns what is stored in the file, and does not validate
2373	* that what is there are valid frames for the decoder. It will split what is
2374	* stored in the file into frames and return one for each call. It will not
2375	* omit invalid data between valid frames so as to give the decoder the maximum
2376	* information possible for decoding.
2377	*
2378	* On success, the returned packet is reference-counted (pkt->buf is set) and
2379	* valid indefinitely. The packet must be freed with av_packet_unref() when
2380	* it is no longer needed. For video, the packet contains exactly one frame.
2381	* For audio, it contains an integer number of frames if each frame has
2382	* a known fixed size (e.g. PCM or ADPCM data). If the audio frames have
2383	* a variable size (e.g. MPEG audio), then it contains one frame.
2384	*
2385	* pkt->pts, pkt->dts and pkt->duration are always set to correct
2386	* values in AVStream.time_base units (and guessed if the format cannot
2387	* provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2388	* has B-frames, so it is better to rely on pkt->dts if you do not
2389	* decompress the payload.
2390	*
2391	* @return 0 if OK, < 0 on error or end of file. On error, pkt will be blank
2392	* (as if it came from av_packet_alloc()).
2393	*
2394	* @note pkt will be initialized, so it may be uninitialized, but it must not
2395	* contain data that needs to be freed.
2396	*/
2397	int av_read_frame(AVFormatContext s, AVPacket pkt);
2398
2399	/**
2400	* Seek to the keyframe at timestamp.
2401	* 'timestamp' in 'stream_index'.
2402	*
2403	* @param s media file handle
2404	* @param stream_index If stream_index is (-1), a default stream is selected,
2405	* and timestamp is automatically converted from
2406	* AV_TIME_BASE units to the stream specific time_base.
2407	* @param timestamp Timestamp in AVStream.time_base units or, if no stream
2408	* is specified, in AV_TIME_BASE units.
2409	* @param flags flags which select direction and seeking mode
2410	*
2411	* @return >= 0 on success
2412	*/
2413	int av_seek_frame(AVFormatContext s, int* stream_index, int64_t timestamp,
2414	int flags);
2415
2416	/**
2417	* Seek to timestamp ts.
2418	* Seeking will be done so that the point from which all active streams
2419	* can be presented successfully will be closest to ts and within min/max_ts.
2420	* Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2421	*
2422	* If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2423	* are the file position (this may not be supported by all demuxers).
2424	* If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2425	* in the stream with stream_index (this may not be supported by all demuxers).
2426	* Otherwise all timestamps are in units of the stream selected by stream_index
2427	* or if stream_index is -1, in AV_TIME_BASE units.
2428	* If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2429	* keyframes (this may not be supported by all demuxers).
2430	* If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2431	*
2432	* @param s media file handle
2433	* @param stream_index index of the stream which is used as time base reference
2434	* @param min_ts smallest acceptable timestamp
2435	* @param ts target timestamp
2436	* @param max_ts largest acceptable timestamp
2437	* @param flags flags
2438	* @return >=0 on success, error code otherwise
2439	*
2440	* @note This is part of the new seek API which is still under construction.
2441	*/
2442	int avformat_seek_file(AVFormatContext s, int* stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2443
2444	/**
2445	* Discard all internally buffered data. This can be useful when dealing with
2446	* discontinuities in the byte stream. Generally works only with formats that
2447	* can resync. This includes headerless formats like MPEG-TS/TS but should also
2448	* work with NUT, Ogg and in a limited way AVI for example.
2449	*
2450	* The set of streams, the detected duration, stream parameters and codecs do
2451	* not change when calling this function. If you want a complete reset, it's
2452	* better to open a new AVFormatContext.
2453	*
2454	* This does not flush the AVIOContext (s->pb). If necessary, call
2455	* avio_flush(s->pb) before calling this function.
2456	*
2457	* @param s media file handle
2458	* @return >=0 on success, error code otherwise
2459	*/
2460	int avformat_flush(AVFormatContext *s);
2461
2462	/**
2463	* Start playing a network-based stream (e.g. RTSP stream) at the
2464	* current position.
2465	*/
2466	int av_read_play(AVFormatContext *s);
2467
2468	/**
2469	* Pause a network-based stream (e.g. RTSP stream).
2470	*
2471	* Use av_read_play() to resume it.
2472	*/
2473	int av_read_pause(AVFormatContext *s);
2474
2475	/**
2476	* Command IDs that can be sent to the demuxer
2477	*
2478	* The following commands can be sent to a demuxer
2479	* using ::avformat_send_command.
2480	*/
2481	enum AVFormatCommandID {
2482	/**
2483	* Send a RTSP `SET_PARAMETER` request to the server
2484	*
2485	* Sends an SET_PARAMETER RTSP command to the server,
2486	* with a data payload of type ::AVRTSPCommandRequest,
2487	* ownership of it and its data remains with the caller.
2488	*
2489	* A reply retrieved is of type ::AVRTSPResponse and it
2490	* and its contents must be freed by the caller.
2491	*/
2492	AVFORMAT_COMMAND_RTSP_SET_PARAMETER,
2493	};
2494
2495	typedef struct AVRTSPCommandRequest {
2496	/**
2497	* Headers sent in the request to the server
2498	*/
2499	AVDictionary *headers;
2500
2501	/**
2502	* Body payload size
2503	*/
2504	size_t body_len;
2505
2506	/**
2507	* Body payload
2508	*/
2509	char *body;
2510	} AVRTSPCommandRequest;
2511
2512	typedef struct AVRTSPResponse {
2513	/**
2514	* Response status code from server
2515	*/
2516	int status_code;
2517
2518	/**
2519	* Reason phrase from the server, describing the
2520	* status in a human-readable way.
2521	*/
2522	char *reason;
2523
2524	/**
2525	* Body payload size
2526	*/
2527	size_t body_len;
2528
2529	/**
2530	* Body payload
2531	*/
2532	unsigned char *body;
2533	} AVRTSPResponse;
2534
2535	/**
2536	* Send a command to the demuxer
2537	*
2538	* Sends the specified command and (depending on the command)
2539	* optionally a command-specific payload to the demuxer to handle.
2540	*
2541	* @param s Format context, must be allocated with
2542	* ::avformat_alloc_context.
2543	* @param id Identifier of type ::AVFormatCommandID,
2544	* indicating the command to send.
2545	* @param data Command-specific data, allocated by the caller
2546	* and ownership remains with the caller.
2547	* For details what is expected here, consult the
2548	* documentation of the respective ::AVFormatCommandID.
2549	*/
2550	int avformat_send_command(AVFormatContext s, enum* AVFormatCommandID id, void *data);
2551
2552	/**
2553	* Receive a command reply from the demuxer
2554	*
2555	* Retrieves a reply for a previously sent command from the muxer.
2556	*
2557	* @param s Format context, must be allocated with
2558	* ::avformat_alloc_context.
2559	* @param id Identifier of type ::AVFormatCommandID,
2560	* indicating the command for which to retrieve
2561	* the reply.
2562	* @param data_out Pointee is set to the command reply, the actual
2563	* type depends on the command. This is allocated by
2564	* the muxer and must be freed with ::av_free.
2565	* For details on the actual data set here, consult the
2566	* documentation of the respective ::AVFormatCommandID.
2567	*/
2568	int avformat_receive_command_reply(AVFormatContext s, enum* AVFormatCommandID id, void **data_out);
2569
2570	/**
2571	* Close an opened input AVFormatContext. Free it and all its contents
2572	* and set *s to NULL.
2573	*/
2574	void avformat_close_input(AVFormatContext **s);
2575	/**
2576	* @}
2577	*/
2578
2579	#define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2580	#define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2581	#define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2582	#define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2583
2584	/**
2585	* @addtogroup lavf_encoding
2586	* @{
2587	*/
2588
2589	#define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2590	#define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2591
2592	/**
2593	* Allocate the stream private data and write the stream header to
2594	* an output media file.
2595	*
2596	* @param s Media file handle, must be allocated with
2597	* avformat_alloc_context().
2598	* Its \ref AVFormatContext.oformat "oformat" field must be set
2599	* to the desired output format;
2600	* Its \ref AVFormatContext.pb "pb" field must be set to an
2601	* already opened ::AVIOContext.
2602	* @param options An ::AVDictionary filled with AVFormatContext and
2603	* muxer-private options.
2604	* On return this parameter will be destroyed and replaced with
2605	* a dict containing options that were not found. May be NULL.
2606	*
2607	* @retval AVSTREAM_INIT_IN_WRITE_HEADER On success, if the codec had not already been
2608	* fully initialized in avformat_init_output().
2609	* @retval AVSTREAM_INIT_IN_INIT_OUTPUT On success, if the codec had already been fully
2610	* initialized in avformat_init_output().
2611	* @retval AVERROR A negative AVERROR on failure.
2612	*
2613	* @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2614	*/
2615	av_warn_unused_result
2616	int avformat_write_header(AVFormatContext s, AVDictionary *options);
2617
2618	/**
2619	* Allocate the stream private data and initialize the codec, but do not write the header.
2620	* May optionally be used before avformat_write_header() to initialize stream parameters
2621	* before actually writing the header.
2622	* If using this function, do not pass the same options to avformat_write_header().
2623	*
2624	* @param s Media file handle, must be allocated with
2625	* avformat_alloc_context().
2626	* Its \ref AVFormatContext.oformat "oformat" field must be set
2627	* to the desired output format;
2628	* Its \ref AVFormatContext.pb "pb" field must be set to an
2629	* already opened ::AVIOContext.
2630	* @param options An ::AVDictionary filled with AVFormatContext and
2631	* muxer-private options.
2632	* On return this parameter will be destroyed and replaced with
2633	* a dict containing options that were not found. May be NULL.
2634	*
2635	* @retval AVSTREAM_INIT_IN_WRITE_HEADER On success, if the codec requires
2636	* avformat_write_header to fully initialize.
2637	* @retval AVSTREAM_INIT_IN_INIT_OUTPUT On success, if the codec has been fully
2638	* initialized.
2639	* @retval AVERROR Anegative AVERROR on failure.
2640	*
2641	* @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2642	*/
2643	av_warn_unused_result
2644	int avformat_init_output(AVFormatContext s, AVDictionary *options);
2645
2646	/**
2647	* Write a packet to an output media file.
2648	*
2649	* This function passes the packet directly to the muxer, without any buffering
2650	* or reordering. The caller is responsible for correctly interleaving the
2651	* packets if the format requires it. Callers that want libavformat to handle
2652	* the interleaving should call av_interleaved_write_frame() instead of this
2653	* function.
2654	*
2655	* @param s media file handle
2656	* @param pkt The packet containing the data to be written. Note that unlike
2657	* av_interleaved_write_frame(), this function does not take
2658	* ownership of the packet passed to it (though some muxers may make
2659	* an internal reference to the input packet).
2660	* <br>
2661	* This parameter can be NULL (at any time, not just at the end), in
2662	* order to immediately flush data buffered within the muxer, for
2663	* muxers that buffer up data internally before writing it to the
2664	* output.
2665	* <br>
2666	* Packet's @ref AVPacket.stream_index "stream_index" field must be
2667	* set to the index of the corresponding stream in @ref
2668	* AVFormatContext.streams "s->streams".
2669	* <br>
2670	* The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2671	* must be set to correct values in the stream's timebase (unless the
2672	* output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2673	* they can be set to AV_NOPTS_VALUE).
2674	* The dts for subsequent packets passed to this function must be strictly
2675	* increasing when compared in their respective timebases (unless the
2676	* output format is flagged with the AVFMT_TS_NONSTRICT, then they
2677	* merely have to be nondecreasing). @ref AVPacket.duration
2678	* "duration") should also be set if known.
2679	* @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2680	*
2681	* @see av_interleaved_write_frame()
2682	*/
2683	int av_write_frame(AVFormatContext s, AVPacket pkt);
2684
2685	/**
2686	* Write a packet to an output media file ensuring correct interleaving.
2687	*
2688	* This function will buffer the packets internally as needed to make sure the
2689	* packets in the output file are properly interleaved, usually ordered by
2690	* increasing dts. Callers doing their own interleaving should call
2691	* av_write_frame() instead of this function.
2692	*
2693	* Using this function instead of av_write_frame() can give muxers advance
2694	* knowledge of future packets, improving e.g. the behaviour of the mp4
2695	* muxer for VFR content in fragmenting mode.
2696	*
2697	* @param s media file handle
2698	* @param pkt The packet containing the data to be written.
2699	* <br>
2700	* If the packet is reference-counted, this function will take
2701	* ownership of this reference and unreference it later when it sees
2702	* fit. If the packet is not reference-counted, libavformat will
2703	* make a copy.
2704	* The returned packet will be blank (as if returned from
2705	* av_packet_alloc()), even on error.
2706	* <br>
2707	* This parameter can be NULL (at any time, not just at the end), to
2708	* flush the interleaving queues.
2709	* <br>
2710	* Packet's @ref AVPacket.stream_index "stream_index" field must be
2711	* set to the index of the corresponding stream in @ref
2712	* AVFormatContext.streams "s->streams".
2713	* <br>
2714	* The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2715	* must be set to correct values in the stream's timebase (unless the
2716	* output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2717	* they can be set to AV_NOPTS_VALUE).
2718	* The dts for subsequent packets in one stream must be strictly
2719	* increasing (unless the output format is flagged with the
2720	* AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2721	* @ref AVPacket.duration "duration" should also be set if known.
2722	*
2723	* @return 0 on success, a negative AVERROR on error.
2724	*
2725	* @see av_write_frame(), AVFormatContext.max_interleave_delta
2726	*/
2727	int av_interleaved_write_frame(AVFormatContext s, AVPacket pkt);
2728
2729	/**
2730	* Write an uncoded frame to an output media file.
2731	*
2732	* The frame must be correctly interleaved according to the container
2733	* specification; if not, av_interleaved_write_uncoded_frame() must be used.
2734	*
2735	* See av_interleaved_write_uncoded_frame() for details.
2736	*/
2737	int av_write_uncoded_frame(AVFormatContext s, int* stream_index,
2738	struct AVFrame *frame);
2739
2740	/**
2741	* Write an uncoded frame to an output media file.
2742	*
2743	* If the muxer supports it, this function makes it possible to write an AVFrame
2744	* structure directly, without encoding it into a packet.
2745	* It is mostly useful for devices and similar special muxers that use raw
2746	* video or PCM data and will not serialize it into a byte stream.
2747	*
2748	* To test whether it is possible to use it with a given muxer and stream,
2749	* use av_write_uncoded_frame_query().
2750	*
2751	* The caller gives up ownership of the frame and must not access it
2752	* afterwards.
2753	*
2754	* @return >=0 for success, a negative code on error
2755	*/
2756	int av_interleaved_write_uncoded_frame(AVFormatContext s, int* stream_index,
2757	struct AVFrame *frame);
2758
2759	/**
2760	* Test whether a muxer supports uncoded frame.
2761	*
2762	* @return >=0 if an uncoded frame can be written to that muxer and stream,
2763	* <0 if not
2764	*/
2765	int av_write_uncoded_frame_query(AVFormatContext s, int* stream_index);
2766
2767	/**
2768	* Write the stream trailer to an output media file and free the
2769	* file private data.
2770	*
2771	* May only be called after a successful call to avformat_write_header.
2772	*
2773	* @param s media file handle
2774	* @return 0 if OK, AVERROR_xxx on error
2775	*/
2776	int av_write_trailer(AVFormatContext *s);
2777
2778	/**
2779	* Return the output format in the list of registered output formats
2780	* which best matches the provided parameters, or return NULL if
2781	* there is no match.
2782	*
2783	* @param short_name if non-NULL checks if short_name matches with the
2784	* names of the registered formats
2785	* @param filename if non-NULL checks if filename terminates with the
2786	* extensions of the registered formats
2787	* @param mime_type if non-NULL checks if mime_type matches with the
2788	* MIME type of the registered formats
2789	*/
2790	const AVOutputFormat av_guess_format(const* char *short_name,
2791	const char *filename,
2792	const char *mime_type);
2793
2794	/**
2795	* Guess the codec ID based upon muxer and filename.
2796	*/
2797	enum AVCodecID av_guess_codec(const AVOutputFormat fmt, const* char *short_name,
2798	const char filename, const* char *mime_type,
2799	enum AVMediaType type);
2800
2801	/**
2802	* Get timing information for the data currently output.
2803	* The exact meaning of "currently output" depends on the format.
2804	* It is mostly relevant for devices that have an internal buffer and/or
2805	* work in real time.
2806	* @param s media file handle
2807	* @param stream stream in the media file
2808	* @param[out] dts DTS of the last packet output for the stream, in stream
2809	* time_base units
2810	* @param[out] wall absolute time when that packet whas output,
2811	* in microsecond
2812	* @retval 0 Success
2813	* @retval AVERROR(ENOSYS) The format does not support it
2814	*
2815	* @note Some formats or devices may not allow to measure dts and wall
2816	* atomically.
2817	*/
2818	int av_get_output_timestamp(struct AVFormatContext s, int* stream,
2819	int64_t dts, int64_t wall);
2820
2821
2822	/**
2823	* @}
2824	*/
2825
2826
2827	/**
2828	* @defgroup lavf_misc Utility functions
2829	* @ingroup libavf
2830	* @{
2831	*
2832	* Miscellaneous utility functions related to both muxing and demuxing
2833	* (or neither).
2834	*/
2835
2836	/**
2837	* Send a nice hexadecimal dump of a buffer to the specified file stream.
2838	*
2839	* @param f The file stream pointer where the dump should be sent to.
2840	* @param buf buffer
2841	* @param size buffer size
2842	*
2843	* @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2844	*/
2845	void av_hex_dump(FILE f, const* uint8_t buf, int* size);
2846
2847	/**
2848	* Send a nice hexadecimal dump of a buffer to the log.
2849	*
2850	* @param avcl A pointer to an arbitrary struct of which the first field is a
2851	* pointer to an AVClass struct.
2852	* @param level The importance level of the message, lower values signifying
2853	* higher importance.
2854	* @param buf buffer
2855	* @param size buffer size
2856	*
2857	* @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2858	*/
2859	void av_hex_dump_log(void avcl, int* level, const uint8_t buf, int* size);
2860
2861	/**
2862	* Send a nice dump of a packet to the specified file stream.
2863	*
2864	* @param f The file stream pointer where the dump should be sent to.
2865	* @param pkt packet to dump
2866	* @param dump_payload True if the payload must be displayed, too.
2867	* @param st AVStream that the packet belongs to
2868	*/
2869	void av_pkt_dump2(FILE f, const* AVPacket pkt, int* dump_payload, const AVStream *st);
2870
2871
2872	/**
2873	* Send a nice dump of a packet to the log.
2874	*
2875	* @param avcl A pointer to an arbitrary struct of which the first field is a
2876	* pointer to an AVClass struct.
2877	* @param level The importance level of the message, lower values signifying
2878	* higher importance.
2879	* @param pkt packet to dump
2880	* @param dump_payload True if the payload must be displayed, too.
2881	* @param st AVStream that the packet belongs to
2882	*/
2883	void av_pkt_dump_log2(void avcl, int* level, const AVPacket pkt, int* dump_payload,
2884	const AVStream *st);
2885
2886	/**
2887	* Get the AVCodecID for the given codec tag tag.
2888	* If no codec id is found returns AV_CODEC_ID_NONE.
2889	*
2890	* @param tags list of supported codec_id-codec_tag pairs, as stored
2891	* in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2892	* @param tag codec tag to match to a codec ID
2893	*/
2894	enum AVCodecID av_codec_get_id(const struct AVCodecTag * const tags, unsigned* int tag);
2895
2896	/**
2897	* Get the codec tag for the given codec id id.
2898	* If no codec tag is found returns 0.
2899	*
2900	* @param tags list of supported codec_id-codec_tag pairs, as stored
2901	* in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2902	* @param id codec ID to match to a codec tag
2903	*/
2904	unsigned int av_codec_get_tag(const struct AVCodecTag * const tags, enum* AVCodecID id);
2905
2906	/**
2907	* Get the codec tag for the given codec id.
2908	*
2909	* @param tags list of supported codec_id - codec_tag pairs, as stored
2910	* in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2911	* @param id codec id that should be searched for in the list
2912	* @param tag A pointer to the found tag
2913	* @return 0 if id was not found in tags, > 0 if it was found
2914	*/
2915	int av_codec_get_tag2(const struct AVCodecTag * const tags, enum* AVCodecID id,
2916	unsigned int *tag);
2917
2918	int av_find_default_stream_index(AVFormatContext *s);
2919
2920	/**
2921	* Get the index for a specific timestamp.
2922	*
2923	* @param st stream that the timestamp belongs to
2924	* @param timestamp timestamp to retrieve the index for
2925	* @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2926	* to the timestamp which is <= the requested one, if backward
2927	* is 0, then it will be >=
2928	* if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2929	* @return < 0 if no such timestamp could be found
2930	*/
2931	int av_index_search_timestamp(AVStream st, int64_t timestamp, int* flags);
2932
2933	/**
2934	* Get the index entry count for the given AVStream.
2935	*
2936	* @param st stream
2937	* @return the number of index entries in the stream
2938	*/
2939	int avformat_index_get_entries_count(const AVStream *st);
2940
2941	/**
2942	* Get the AVIndexEntry corresponding to the given index.
2943	*
2944	* @param st Stream containing the requested AVIndexEntry.
2945	* @param idx The desired index.
2946	* @return A pointer to the requested AVIndexEntry if it exists, NULL otherwise.
2947	*
2948	* @note The pointer returned by this function is only guaranteed to be valid
2949	* until any function that takes the stream or the parent AVFormatContext
2950	* as input argument is called.
2951	*/
2952	const AVIndexEntry avformat_index_get_entry(AVStream st, int idx);
2953
2954	/**
2955	* Get the AVIndexEntry corresponding to the given timestamp.
2956	*
2957	* @param st Stream containing the requested AVIndexEntry.
2958	* @param wanted_timestamp Timestamp to retrieve the index entry for.
2959	* @param flags If AVSEEK_FLAG_BACKWARD then the returned entry will correspond
2960	* to the timestamp which is <= the requested one, if backward
2961	* is 0, then it will be >=
2962	* if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise.
2963	* @return A pointer to the requested AVIndexEntry if it exists, NULL otherwise.
2964	*
2965	* @note The pointer returned by this function is only guaranteed to be valid
2966	* until any function that takes the stream or the parent AVFormatContext
2967	* as input argument is called.
2968	*/
2969	const AVIndexEntry avformat_index_get_entry_from_timestamp(AVStream st,
2970	int64_t wanted_timestamp,
2971	int flags);
2972	/**
2973	* Add an index entry into a sorted list. Update the entry if the list
2974	* already contains it.
2975	*
2976	* @param timestamp timestamp in the time base of the given stream
2977	*/
2978	int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2979	int size, int distance, int flags);
2980
2981
2982	/**
2983	* Split a URL string into components.
2984	*
2985	* The pointers to buffers for storing individual components may be null,
2986	* in order to ignore that component. Buffers for components not found are
2987	* set to empty strings. If the port is not found, it is set to a negative
2988	* value.
2989	*
2990	* @param proto the buffer for the protocol
2991	* @param proto_size the size of the proto buffer
2992	* @param authorization the buffer for the authorization
2993	* @param authorization_size the size of the authorization buffer
2994	* @param hostname the buffer for the host name
2995	* @param hostname_size the size of the hostname buffer
2996	* @param port_ptr a pointer to store the port number in
2997	* @param path the buffer for the path
2998	* @param path_size the size of the path buffer
2999	* @param url the URL to split
3000	*/
3001	void av_url_split(char proto, int* proto_size,
3002	char authorization, int* authorization_size,
3003	char hostname, int* hostname_size,
3004	int *port_ptr,
3005	char path, int* path_size,
3006	const char *url);
3007
3008
3009	/**
3010	* Print detailed information about the input or output format, such as
3011	* duration, bitrate, streams, container, programs, metadata, side data,
3012	* codec and time base.
3013	*
3014	* @param ic the context to analyze
3015	* @param index index of the stream to dump information about
3016	* @param url the URL to print, such as source or destination file
3017	* @param is_output Select whether the specified context is an input(0) or output(1)
3018	*/
3019	void av_dump_format(AVFormatContext *ic,
3020	int index,
3021	const char *url,
3022	int is_output);
3023
3024
3025	#define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
3026	#define AV_FRAME_FILENAME_FLAGS_IGNORE_TRUNCATION 2 ///< Ignore truncated output instead of returning an error
3027
3028	/**
3029	* Return in 'buf' the path with '%d' replaced by a number.
3030	*
3031	* Also handles the '%0nd' format where 'n' is the total number
3032	* of digits and '%%'.
3033	*
3034	* @param buf destination buffer
3035	* @param buf_size destination buffer size
3036	* @param path numbered sequence string
3037	* @param number frame number
3038	* @param flags AV_FRAME_FILENAME_FLAGS_*
3039	* @return 0 if OK, -1 on format error
3040	*/
3041	int av_get_frame_filename2(char buf, int* buf_size,
3042	const char path, int* number, int flags);
3043
3044	int av_get_frame_filename(char buf, int* buf_size,
3045	const char path, int* number);
3046
3047	/**
3048	* Check whether filename actually is a numbered sequence generator.
3049	*
3050	* @param filename possible numbered sequence string
3051	* @return 1 if a valid numbered sequence string, 0 otherwise
3052	*/
3053	int av_filename_number_test(const char *filename);
3054
3055	/**
3056	* Generate an SDP for an RTP session.
3057	*
3058	* Note, this overwrites the id values of AVStreams in the muxer contexts
3059	* for getting unique dynamic payload types.
3060	*
3061	* @param ac array of AVFormatContexts describing the RTP streams. If the
3062	* array is composed by only one context, such context can contain
3063	* multiple AVStreams (one AVStream per RTP stream). Otherwise,
3064	* all the contexts in the array (an AVCodecContext per RTP stream)
3065	* must contain only one AVStream.
3066	* @param n_files number of AVCodecContexts contained in ac
3067	* @param buf buffer where the SDP will be stored (must be allocated by
3068	* the caller)
3069	* @param size the size of the buffer
3070	* @return 0 if OK, AVERROR_xxx on error
3071	*/
3072	int av_sdp_create(AVFormatContext ac[], int* n_files, char buf, int* size);
3073
3074	/**
3075	* Return a positive value if the given filename has one of the given
3076	* extensions, 0 otherwise.
3077	*
3078	* @param filename file name to check against the given extensions
3079	* @param extensions a comma-separated list of filename extensions
3080	*/
3081	int av_match_ext(const char filename, const* char *extensions);
3082
3083	/**
3084	* Test if the given container can store a codec.
3085	*
3086	* @param ofmt container to check for compatibility
3087	* @param codec_id codec to potentially store in container
3088	* @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
3089	*
3090	* @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
3091	* A negative number if this information is not available.
3092	*/
3093	int avformat_query_codec(const AVOutputFormat ofmt, enum* AVCodecID codec_id,
3094	int std_compliance);
3095
3096	struct AVBPrint;
3097	/**
3098	* Make a RFC 4281/6381 like string describing a codec for MIME types.
3099	*
3100	* @param par pointer to an AVCodecParameters struct describing the codec
3101	* @param frame_rate an AVRational for the frame rate, for deciding the
3102	* right profile for video codecs. Pass an invalid
3103	* AVRational (1/0) to indicate that it is unknown.
3104	* @param out the AVBPrint to write the output to
3105	* @return <0 on error
3106	*/
3107	int av_mime_codec_str(const AVCodecParameters *par,
3108	AVRational frame_rate, struct AVBPrint *out);
3109
3110	/**
3111	* @defgroup riff_fourcc RIFF FourCCs
3112	* @{
3113	* Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
3114	* meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
3115	* following code:
3116	* @code
3117	* uint32_t tag = MKTAG('H', '2', '6', '4');
3118	* const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
3119	* enum AVCodecID id = av_codec_get_id(table, tag);
3120	* @endcode
3121	*/
3122	/**
3123	* @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
3124	*/
3125	const struct AVCodecTag avformat_get_riff_video_tags(void*);
3126	/**
3127	* @return the table mapping RIFF FourCCs for audio to AVCodecID.
3128	*/
3129	const struct AVCodecTag avformat_get_riff_audio_tags(void*);
3130	/**
3131	* @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
3132	*/
3133	const struct AVCodecTag avformat_get_mov_video_tags(void*);
3134	/**
3135	* @return the table mapping MOV FourCCs for audio to AVCodecID.
3136	*/
3137	const struct AVCodecTag avformat_get_mov_audio_tags(void*);
3138
3139	/**
3140	* @}
3141	*/
3142
3143	/**
3144	* Guess the sample aspect ratio of a frame, based on both the stream and the
3145	* frame aspect ratio.
3146	*
3147	* Since the frame aspect ratio is set by the codec but the stream aspect ratio
3148	* is set by the demuxer, these two may not be equal. This function tries to
3149	* return the value that you should use if you would like to display the frame.
3150	*
3151	* Basic logic is to use the stream aspect ratio if it is set to something sane
3152	* otherwise use the frame aspect ratio. This way a container setting, which is
3153	* usually easy to modify can override the coded value in the frames.
3154	*
3155	* @param format the format context which the stream is part of
3156	* @param stream the stream which the frame is part of
3157	* @param frame the frame with the aspect ratio to be determined
3158	* @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
3159	*/
3160	AVRational av_guess_sample_aspect_ratio(AVFormatContext format, AVStream stream,
3161	struct AVFrame *frame);
3162
3163	/**
3164	* Guess the frame rate, based on both the container and codec information.
3165	*
3166	* @param ctx the format context which the stream is part of
3167	* @param stream the stream which the frame is part of
3168	* @param frame the frame for which the frame rate should be determined, may be NULL
3169	* @return the guessed (valid) frame rate, 0/1 if no idea
3170	*/
3171	AVRational av_guess_frame_rate(AVFormatContext ctx, AVStream stream,
3172	struct AVFrame *frame);
3173
3174	/**
3175	* Check if the stream st contained in s is matched by the stream specifier
3176	* spec.
3177	*
3178	* See the "stream specifiers" chapter in the documentation for the syntax
3179	* of spec.
3180	*
3181	* @return >0 if st is matched by spec;
3182	* 0 if st is not matched by spec;
3183	* AVERROR code if spec is invalid
3184	*
3185	* @note A stream specifier can match several streams in the format.
3186	*/
3187	int avformat_match_stream_specifier(AVFormatContext s, AVStream st,
3188	const char *spec);
3189
3190	int avformat_queue_attached_pictures(AVFormatContext *s);
3191
3192	/**
3193	* @}
3194	*/
3195
3196	#endif /* AVFORMAT_AVFORMAT_H */
3197

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