FFmpeg
avformat.h
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1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVFORMAT_AVFORMAT_H
22 #define AVFORMAT_AVFORMAT_H
23 
24 /**
25  * @file
26  * @ingroup libavf
27  * Main libavformat public API header
28  */
29 
30 /**
31  * @defgroup libavf libavformat
32  * I/O and Muxing/Demuxing Library
33  *
34  * Libavformat (lavf) is a library for dealing with various media container
35  * formats. Its main two purposes are demuxing - i.e. splitting a media file
36  * into component streams, and the reverse process of muxing - writing supplied
37  * data in a specified container format. It also has an @ref lavf_io
38  * "I/O module" which supports a number of protocols for accessing the data (e.g.
39  * file, tcp, http and others).
40  * Unless you are absolutely sure you won't use libavformat's network
41  * capabilities, you should also call avformat_network_init().
42  *
43  * A supported input format is described by an AVInputFormat struct, conversely
44  * an output format is described by AVOutputFormat. You can iterate over all
45  * input/output formats using the av_demuxer_iterate / av_muxer_iterate() functions.
46  * The protocols layer is not part of the public API, so you can only get the names
47  * of supported protocols with the avio_enum_protocols() function.
48  *
49  * Main lavf structure used for both muxing and demuxing is AVFormatContext,
50  * which exports all information about the file being read or written. As with
51  * most Libavformat structures, its size is not part of public ABI, so it cannot be
52  * allocated on stack or directly with av_malloc(). To create an
53  * AVFormatContext, use avformat_alloc_context() (some functions, like
54  * avformat_open_input() might do that for you).
55  *
56  * Most importantly an AVFormatContext contains:
57  * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat
58  * "output" format. It is either autodetected or set by user for input;
59  * always set by user for output.
60  * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all
61  * elementary streams stored in the file. AVStreams are typically referred to
62  * using their index in this array.
63  * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or
64  * set by user for input, always set by user for output (unless you are dealing
65  * with an AVFMT_NOFILE format).
66  *
67  * @section lavf_options Passing options to (de)muxers
68  * It is possible to configure lavf muxers and demuxers using the @ref avoptions
69  * mechanism. Generic (format-independent) libavformat options are provided by
70  * AVFormatContext, they can be examined from a user program by calling
71  * av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass
72  * from avformat_get_class()). Private (format-specific) options are provided by
73  * AVFormatContext.priv_data if and only if AVInputFormat.priv_class /
74  * AVOutputFormat.priv_class of the corresponding format struct is non-NULL.
75  * Further options may be provided by the @ref AVFormatContext.pb "I/O context",
76  * if its AVClass is non-NULL, and the protocols layer. See the discussion on
77  * nesting in @ref avoptions documentation to learn how to access those.
78  *
79  * @section urls
80  * URL strings in libavformat are made of a scheme/protocol, a ':', and a
81  * scheme specific string. URLs without a scheme and ':' used for local files
82  * are supported but deprecated. "file:" should be used for local files.
83  *
84  * It is important that the scheme string is not taken from untrusted
85  * sources without checks.
86  *
87  * Note that some schemes/protocols are quite powerful, allowing access to
88  * both local and remote files, parts of them, concatenations of them, local
89  * audio and video devices and so on.
90  *
91  * @{
92  *
93  * @defgroup lavf_decoding Demuxing
94  * @{
95  * Demuxers read a media file and split it into chunks of data (@em packets). A
96  * @ref AVPacket "packet" contains one or more encoded frames which belongs to a
97  * single elementary stream. In the lavf API this process is represented by the
98  * avformat_open_input() function for opening a file, av_read_frame() for
99  * reading a single packet and finally avformat_close_input(), which does the
100  * cleanup.
101  *
102  * @section lavf_decoding_open Opening a media file
103  * The minimum information required to open a file is its URL, which
104  * is passed to avformat_open_input(), as in the following code:
105  * @code
106  * const char *url = "file:in.mp3";
107  * AVFormatContext *s = NULL;
108  * int ret = avformat_open_input(&s, url, NULL, NULL);
109  * if (ret < 0)
110  * abort();
111  * @endcode
112  * The above code attempts to allocate an AVFormatContext, open the
113  * specified file (autodetecting the format) and read the header, exporting the
114  * information stored there into s. Some formats do not have a header or do not
115  * store enough information there, so it is recommended that you call the
116  * avformat_find_stream_info() function which tries to read and decode a few
117  * frames to find missing information.
118  *
119  * In some cases you might want to preallocate an AVFormatContext yourself with
120  * avformat_alloc_context() and do some tweaking on it before passing it to
121  * avformat_open_input(). One such case is when you want to use custom functions
122  * for reading input data instead of lavf internal I/O layer.
123  * To do that, create your own AVIOContext with avio_alloc_context(), passing
124  * your reading callbacks to it. Then set the @em pb field of your
125  * AVFormatContext to newly created AVIOContext.
126  *
127  * Since the format of the opened file is in general not known until after
128  * avformat_open_input() has returned, it is not possible to set demuxer private
129  * options on a preallocated context. Instead, the options should be passed to
130  * avformat_open_input() wrapped in an AVDictionary:
131  * @code
132  * AVDictionary *options = NULL;
133  * av_dict_set(&options, "video_size", "640x480", 0);
134  * av_dict_set(&options, "pixel_format", "rgb24", 0);
135  *
136  * if (avformat_open_input(&s, url, NULL, &options) < 0)
137  * abort();
138  * av_dict_free(&options);
139  * @endcode
140  * This code passes the private options 'video_size' and 'pixel_format' to the
141  * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it
142  * cannot know how to interpret raw video data otherwise. If the format turns
143  * out to be something different than raw video, those options will not be
144  * recognized by the demuxer and therefore will not be applied. Such unrecognized
145  * options are then returned in the options dictionary (recognized options are
146  * consumed). The calling program can handle such unrecognized options as it
147  * wishes, e.g.
148  * @code
149  * AVDictionaryEntry *e;
150  * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
151  * fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key);
152  * abort();
153  * }
154  * @endcode
155  *
156  * After you have finished reading the file, you must close it with
157  * avformat_close_input(). It will free everything associated with the file.
158  *
159  * @section lavf_decoding_read Reading from an opened file
160  * Reading data from an opened AVFormatContext is done by repeatedly calling
161  * av_read_frame() on it. Each call, if successful, will return an AVPacket
162  * containing encoded data for one AVStream, identified by
163  * AVPacket.stream_index. This packet may be passed straight into the libavcodec
164  * decoding functions avcodec_send_packet() or avcodec_decode_subtitle2() if the
165  * caller wishes to decode the data.
166  *
167  * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be
168  * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for
169  * pts/dts, 0 for duration) if the stream does not provide them. The timing
170  * information will be in AVStream.time_base units, i.e. it has to be
171  * multiplied by the timebase to convert them to seconds.
172  *
173  * A packet returned by av_read_frame() is always reference-counted,
174  * i.e. AVPacket.buf is set and the user may keep it indefinitely.
175  * The packet must be freed with av_packet_unref() when it is no
176  * longer needed.
177  *
178  * @section lavf_decoding_seek Seeking
179  * @}
180  *
181  * @defgroup lavf_encoding Muxing
182  * @{
183  * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write
184  * it into files or other output bytestreams in the specified container format.
185  *
186  * The main API functions for muxing are avformat_write_header() for writing the
187  * file header, av_write_frame() / av_interleaved_write_frame() for writing the
188  * packets and av_write_trailer() for finalizing the file.
189  *
190  * At the beginning of the muxing process, the caller must first call
191  * avformat_alloc_context() to create a muxing context. The caller then sets up
192  * the muxer by filling the various fields in this context:
193  *
194  * - The @ref AVFormatContext.oformat "oformat" field must be set to select the
195  * muxer that will be used.
196  * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb
197  * "pb" field must be set to an opened IO context, either returned from
198  * avio_open2() or a custom one.
199  * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must
200  * be created with the avformat_new_stream() function. The caller should fill
201  * the @ref AVStream.codecpar "stream codec parameters" information, such as the
202  * codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id
203  * "id" and other parameters (e.g. width / height, the pixel or sample format,
204  * etc.) as known. The @ref AVStream.time_base "stream timebase" should
205  * be set to the timebase that the caller desires to use for this stream (note
206  * that the timebase actually used by the muxer can be different, as will be
207  * described later).
208  * - It is advised to manually initialize only the relevant fields in
209  * AVCodecParameters, rather than using @ref avcodec_parameters_copy() during
210  * remuxing: there is no guarantee that the codec context values remain valid
211  * for both input and output format contexts.
212  * - The caller may fill in additional information, such as @ref
213  * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream"
214  * metadata, @ref AVFormatContext.chapters "chapters", @ref
215  * AVFormatContext.programs "programs", etc. as described in the
216  * AVFormatContext documentation. Whether such information will actually be
217  * stored in the output depends on what the container format and the muxer
218  * support.
219  *
220  * When the muxing context is fully set up, the caller must call
221  * avformat_write_header() to initialize the muxer internals and write the file
222  * header. Whether anything actually is written to the IO context at this step
223  * depends on the muxer, but this function must always be called. Any muxer
224  * private options must be passed in the options parameter to this function.
225  *
226  * The data is then sent to the muxer by repeatedly calling av_write_frame() or
227  * av_interleaved_write_frame() (consult those functions' documentation for
228  * discussion on the difference between them; only one of them may be used with
229  * a single muxing context, they should not be mixed). Do note that the timing
230  * information on the packets sent to the muxer must be in the corresponding
231  * AVStream's timebase. That timebase is set by the muxer (in the
232  * avformat_write_header() step) and may be different from the timebase
233  * requested by the caller.
234  *
235  * Once all the data has been written, the caller must call av_write_trailer()
236  * to flush any buffered packets and finalize the output file, then close the IO
237  * context (if any) and finally free the muxing context with
238  * avformat_free_context().
239  * @}
240  *
241  * @defgroup lavf_io I/O Read/Write
242  * @{
243  * @section lavf_io_dirlist Directory listing
244  * The directory listing API makes it possible to list files on remote servers.
245  *
246  * Some of possible use cases:
247  * - an "open file" dialog to choose files from a remote location,
248  * - a recursive media finder providing a player with an ability to play all
249  * files from a given directory.
250  *
251  * @subsection lavf_io_dirlist_open Opening a directory
252  * At first, a directory needs to be opened by calling avio_open_dir()
253  * supplied with a URL and, optionally, ::AVDictionary containing
254  * protocol-specific parameters. The function returns zero or positive
255  * integer and allocates AVIODirContext on success.
256  *
257  * @code
258  * AVIODirContext *ctx = NULL;
259  * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) {
260  * fprintf(stderr, "Cannot open directory.\n");
261  * abort();
262  * }
263  * @endcode
264  *
265  * This code tries to open a sample directory using smb protocol without
266  * any additional parameters.
267  *
268  * @subsection lavf_io_dirlist_read Reading entries
269  * Each directory's entry (i.e. file, another directory, anything else
270  * within ::AVIODirEntryType) is represented by AVIODirEntry.
271  * Reading consecutive entries from an opened AVIODirContext is done by
272  * repeatedly calling avio_read_dir() on it. Each call returns zero or
273  * positive integer if successful. Reading can be stopped right after the
274  * NULL entry has been read -- it means there are no entries left to be
275  * read. The following code reads all entries from a directory associated
276  * with ctx and prints their names to standard output.
277  * @code
278  * AVIODirEntry *entry = NULL;
279  * for (;;) {
280  * if (avio_read_dir(ctx, &entry) < 0) {
281  * fprintf(stderr, "Cannot list directory.\n");
282  * abort();
283  * }
284  * if (!entry)
285  * break;
286  * printf("%s\n", entry->name);
287  * avio_free_directory_entry(&entry);
288  * }
289  * @endcode
290  * @}
291  *
292  * @defgroup lavf_codec Demuxers
293  * @{
294  * @defgroup lavf_codec_native Native Demuxers
295  * @{
296  * @}
297  * @defgroup lavf_codec_wrappers External library wrappers
298  * @{
299  * @}
300  * @}
301  * @defgroup lavf_protos I/O Protocols
302  * @{
303  * @}
304  * @defgroup lavf_internal Internal
305  * @{
306  * @}
307  * @}
308  */
309 
310 #include <time.h>
311 #include <stdio.h> /* FILE */
312 #include "libavcodec/avcodec.h"
313 #include "libavutil/dict.h"
314 #include "libavutil/log.h"
315 
316 #include "avio.h"
317 #include "libavformat/version.h"
318 
319 struct AVFormatContext;
320 
321 struct AVDeviceInfoList;
323 
324 /**
325  * @defgroup metadata_api Public Metadata API
326  * @{
327  * @ingroup libavf
328  * The metadata API allows libavformat to export metadata tags to a client
329  * application when demuxing. Conversely it allows a client application to
330  * set metadata when muxing.
331  *
332  * Metadata is exported or set as pairs of key/value strings in the 'metadata'
333  * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
334  * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
335  * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
336  * exported by demuxers isn't checked to be valid UTF-8 in most cases.
337  *
338  * Important concepts to keep in mind:
339  * - Keys are unique; there can never be 2 tags with the same key. This is
340  * also meant semantically, i.e., a demuxer should not knowingly produce
341  * several keys that are literally different but semantically identical.
342  * E.g., key=Author5, key=Author6. In this example, all authors must be
343  * placed in the same tag.
344  * - Metadata is flat, not hierarchical; there are no subtags. If you
345  * want to store, e.g., the email address of the child of producer Alice
346  * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
347  * - Several modifiers can be applied to the tag name. This is done by
348  * appending a dash character ('-') and the modifier name in the order
349  * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
350  * - language -- a tag whose value is localized for a particular language
351  * is appended with the ISO 639-2/B 3-letter language code.
352  * For example: Author-ger=Michael, Author-eng=Mike
353  * The original/default language is in the unqualified "Author" tag.
354  * A demuxer should set a default if it sets any translated tag.
355  * - sorting -- a modified version of a tag that should be used for
356  * sorting will have '-sort' appended. E.g. artist="The Beatles",
357  * artist-sort="Beatles, The".
358  * - Some protocols and demuxers support metadata updates. After a successful
359  * call to av_read_frame(), AVFormatContext.event_flags or AVStream.event_flags
360  * will be updated to indicate if metadata changed. In order to detect metadata
361  * changes on a stream, you need to loop through all streams in the AVFormatContext
362  * and check their individual event_flags.
363  *
364  * - Demuxers attempt to export metadata in a generic format, however tags
365  * with no generic equivalents are left as they are stored in the container.
366  * Follows a list of generic tag names:
367  *
368  @verbatim
369  album -- name of the set this work belongs to
370  album_artist -- main creator of the set/album, if different from artist.
371  e.g. "Various Artists" for compilation albums.
372  artist -- main creator of the work
373  comment -- any additional description of the file.
374  composer -- who composed the work, if different from artist.
375  copyright -- name of copyright holder.
376  creation_time-- date when the file was created, preferably in ISO 8601.
377  date -- date when the work was created, preferably in ISO 8601.
378  disc -- number of a subset, e.g. disc in a multi-disc collection.
379  encoder -- name/settings of the software/hardware that produced the file.
380  encoded_by -- person/group who created the file.
381  filename -- original name of the file.
382  genre -- <self-evident>.
383  language -- main language in which the work is performed, preferably
384  in ISO 639-2 format. Multiple languages can be specified by
385  separating them with commas.
386  performer -- artist who performed the work, if different from artist.
387  E.g for "Also sprach Zarathustra", artist would be "Richard
388  Strauss" and performer "London Philharmonic Orchestra".
389  publisher -- name of the label/publisher.
390  service_name -- name of the service in broadcasting (channel name).
391  service_provider -- name of the service provider in broadcasting.
392  title -- name of the work.
393  track -- number of this work in the set, can be in form current/total.
394  variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
395  @endverbatim
396  *
397  * Look in the examples section for an application example how to use the Metadata API.
398  *
399  * @}
400  */
401 
402 /* packet functions */
403 
404 
405 /**
406  * Allocate and read the payload of a packet and initialize its
407  * fields with default values.
408  *
409  * @param s associated IO context
410  * @param pkt packet
411  * @param size desired payload size
412  * @return >0 (read size) if OK, AVERROR_xxx otherwise
413  */
415 
416 
417 /**
418  * Read data and append it to the current content of the AVPacket.
419  * If pkt->size is 0 this is identical to av_get_packet.
420  * Note that this uses av_grow_packet and thus involves a realloc
421  * which is inefficient. Thus this function should only be used
422  * when there is no reasonable way to know (an upper bound of)
423  * the final size.
424  *
425  * @param s associated IO context
426  * @param pkt packet
427  * @param size amount of data to read
428  * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
429  * will not be lost even if an error occurs.
430  */
432 
433 /*************************************************/
434 /* input/output formats */
435 
436 struct AVCodecTag;
437 
438 /**
439  * This structure contains the data a format has to probe a file.
440  */
441 typedef struct AVProbeData {
442  const char *filename;
443  unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
444  int buf_size; /**< Size of buf except extra allocated bytes */
445  const char *mime_type; /**< mime_type, when known. */
446 } AVProbeData;
447 
448 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
449 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
450 
451 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
452 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type
453 #define AVPROBE_SCORE_MAX 100 ///< maximum score
454 
455 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
456 
457 /// Demuxer will use avio_open, no opened file should be provided by the caller.
458 #define AVFMT_NOFILE 0x0001
459 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
460 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
461 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
462 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
463 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
464 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
465 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
466 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
467 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
468 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
469 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
470 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
471 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
472 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
473  increasing timestamps, but they must
474  still be monotonic */
475 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
476  timestamps. If not set the timestamp
477  will be shifted in av_write_frame and
478  av_interleaved_write_frame so they
479  start from 0.
480  The user or muxer can override this through
481  AVFormatContext.avoid_negative_ts
482  */
483 
484 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
485 
486 /**
487  * @addtogroup lavf_encoding
488  * @{
489  */
490 typedef struct AVOutputFormat {
491  const char *name;
492  /**
493  * Descriptive name for the format, meant to be more human-readable
494  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
495  * to define it.
496  */
497  const char *long_name;
498  const char *mime_type;
499  const char *extensions; /**< comma-separated filename extensions */
500  /* output support */
501  enum AVCodecID audio_codec; /**< default audio codec */
502  enum AVCodecID video_codec; /**< default video codec */
503  enum AVCodecID subtitle_codec; /**< default subtitle codec */
504  /**
505  * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER,
506  * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
507  * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
508  * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
509  */
510  int flags;
512  /**
513  * List of supported codec_id-codec_tag pairs, ordered by "better
514  * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
515  */
516  const struct AVCodecTag * const *codec_tag;
517 
518 
519  const AVClass *priv_class; ///< AVClass for the private context
520 
521  /*****************************************************************
522  * No fields below this line are part of the public API. They
523  * may not be used outside of libavformat and can be changed and
524  * removed at will.
525  * New public fields should be added right above.
526  *****************************************************************
527  */
528  /**
529  * The ff_const59 define is not part of the public API and will
530  * be removed without further warning.
531  */
532 #if FF_API_AVIOFORMAT
533 #define ff_const59
534 #else
535 #define ff_const59 const
536 #endif
537 #if FF_API_NEXT
538  ff_const59 struct AVOutputFormat *next;
539 #endif
540  /**
541  * size of private data so that it can be allocated in the wrapper
542  */
543  int priv_data_size;
545  int (*write_header)(struct AVFormatContext *);
546  /**
547  * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
548  * pkt can be NULL in order to flush data buffered in the muxer.
549  * When flushing, return 0 if there still is more data to flush,
550  * or 1 if everything was flushed and there is no more buffered
551  * data.
552  */
555  /**
556  * A format-specific function for interleavement.
557  * If unset, packets will be interleaved by dts.
558  */
560  AVPacket *in, int flush);
561  /**
562  * Test if the given codec can be stored in this container.
563  *
564  * @return 1 if the codec is supported, 0 if it is not.
565  * A negative number if unknown.
566  * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
567  */
568  int (*query_codec)(enum AVCodecID id, int std_compliance);
569 
570  void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
571  int64_t *dts, int64_t *wall);
572  /**
573  * Allows sending messages from application to device.
574  */
575  int (*control_message)(struct AVFormatContext *s, int type,
576  void *data, size_t data_size);
578  /**
579  * Write an uncoded AVFrame.
580  *
581  * See av_write_uncoded_frame() for details.
582  *
583  * The library will free *frame afterwards, but the muxer can prevent it
584  * by setting the pointer to NULL.
585  */
586  int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
587  AVFrame **frame, unsigned flags);
588  /**
589  * Returns device list with it properties.
590  * @see avdevice_list_devices() for more details.
591  */
592  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
593  /**
594  * Initialize device capabilities submodule.
595  * @see avdevice_capabilities_create() for more details.
596  */
597  int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
598  /**
599  * Free device capabilities submodule.
600  * @see avdevice_capabilities_free() for more details.
601  */
602  int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
603  enum AVCodecID data_codec; /**< default data codec */
604  /**
605  * Initialize format. May allocate data here, and set any AVFormatContext or
606  * AVStream parameters that need to be set before packets are sent.
607  * This method must not write output.
608  *
609  * Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure
610  *
611  * Any allocations made here must be freed in deinit().
612  */
613  int (*init)(struct AVFormatContext *);
614  /**
615  * Deinitialize format. If present, this is called whenever the muxer is being
616  * destroyed, regardless of whether or not the header has been written.
617  *
618  * If a trailer is being written, this is called after write_trailer().
619  *
620  * This is called if init() fails as well.
621  */
622  void (*deinit)(struct AVFormatContext *);
623  /**
624  * Set up any necessary bitstream filtering and extract any extra data needed
625  * for the global header.
626  * Return 0 if more packets from this stream must be checked; 1 if not.
627  */
628  int (*check_bitstream)(struct AVFormatContext *, const AVPacket *pkt);
630 /**
631  * @}
632  */
633 
634 /**
635  * @addtogroup lavf_decoding
636  * @{
637  */
638 typedef struct AVInputFormat {
639  /**
640  * A comma separated list of short names for the format. New names
641  * may be appended with a minor bump.
642  */
643  const char *name;
644 
645  /**
646  * Descriptive name for the format, meant to be more human-readable
647  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
648  * to define it.
649  */
650  const char *long_name;
651 
652  /**
653  * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
654  * AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
655  * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
656  */
657  int flags;
658 
659  /**
660  * If extensions are defined, then no probe is done. You should
661  * usually not use extension format guessing because it is not
662  * reliable enough
663  */
664  const char *extensions;
665 
666  const struct AVCodecTag * const *codec_tag;
667 
668  const AVClass *priv_class; ///< AVClass for the private context
669 
670  /**
671  * Comma-separated list of mime types.
672  * It is used check for matching mime types while probing.
673  * @see av_probe_input_format2
674  */
675  const char *mime_type;
676 
677  /*****************************************************************
678  * No fields below this line are part of the public API. They
679  * may not be used outside of libavformat and can be changed and
680  * removed at will.
681  * New public fields should be added right above.
682  *****************************************************************
683  */
684 #if FF_API_NEXT
685  ff_const59 struct AVInputFormat *next;
686 #endif
687 
688  /**
689  * Raw demuxers store their codec ID here.
690  */
691  int raw_codec_id;
692 
693  /**
694  * Size of private data so that it can be allocated in the wrapper.
695  */
696  int priv_data_size;
697 
698  /**
699  * Tell if a given file has a chance of being parsed as this format.
700  * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
701  * big so you do not have to check for that unless you need more.
702  */
703  int (*read_probe)(const AVProbeData *);
704 
705  /**
706  * Read the format header and initialize the AVFormatContext
707  * structure. Return 0 if OK. 'avformat_new_stream' should be
708  * called to create new streams.
709  */
710  int (*read_header)(struct AVFormatContext *);
711 
712  /**
713  * Read one packet and put it in 'pkt'. pts and flags are also
714  * set. 'avformat_new_stream' can be called only if the flag
715  * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
716  * background thread).
717  * @return 0 on success, < 0 on error.
718  * Upon returning an error, pkt must be unreferenced by the caller.
719  */
720  int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
721 
722  /**
723  * Close the stream. The AVFormatContext and AVStreams are not
724  * freed by this function
725  */
726  int (*read_close)(struct AVFormatContext *);
727 
728  /**
729  * Seek to a given timestamp relative to the frames in
730  * stream component stream_index.
731  * @param stream_index Must not be -1.
732  * @param flags Selects which direction should be preferred if no exact
733  * match is available.
734  * @return >= 0 on success (but not necessarily the new offset)
735  */
736  int (*read_seek)(struct AVFormatContext *,
737  int stream_index, int64_t timestamp, int flags);
738 
739  /**
740  * Get the next timestamp in stream[stream_index].time_base units.
741  * @return the timestamp or AV_NOPTS_VALUE if an error occurred
742  */
743  int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
744  int64_t *pos, int64_t pos_limit);
746  /**
747  * Start/resume playing - only meaningful if using a network-based format
748  * (RTSP).
749  */
750  int (*read_play)(struct AVFormatContext *);
751 
752  /**
753  * Pause playing - only meaningful if using a network-based format
754  * (RTSP).
755  */
756  int (*read_pause)(struct AVFormatContext *);
757 
758  /**
759  * Seek to timestamp ts.
760  * Seeking will be done so that the point from which all active streams
761  * can be presented successfully will be closest to ts and within min/max_ts.
762  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
763  */
764  int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
766  /**
767  * Returns device list with it properties.
768  * @see avdevice_list_devices() for more details.
769  */
770  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
771 
772  /**
773  * Initialize device capabilities submodule.
774  * @see avdevice_capabilities_create() for more details.
775  */
776  int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
777 
778  /**
779  * Free device capabilities submodule.
780  * @see avdevice_capabilities_free() for more details.
781  */
782  int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
783 } AVInputFormat;
784 /**
785  * @}
786  */
787 
788 enum AVStreamParseType {
790  AVSTREAM_PARSE_FULL, /**< full parsing and repack */
791  AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
792  AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
793  AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
794  AVSTREAM_PARSE_FULL_RAW, /**< full parsing and repack with timestamp and position generation by parser for raw
795  this assumes that each packet in the file contains no demuxer level headers and
796  just codec level data, otherwise position generation would fail */
797 };
799 typedef struct AVIndexEntry {
800  int64_t pos;
801  int64_t timestamp; /**<
802  * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
803  * when seeking to this entry. That means preferable PTS on keyframe based formats.
804  * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
805  * is known
806  */
807 #define AVINDEX_KEYFRAME 0x0001
808 #define AVINDEX_DISCARD_FRAME 0x0002 /**
809  * Flag is used to indicate which frame should be discarded after decoding.
810  */
811  int flags:2;
812  int size:30; //Yeah, trying to keep the size of this small to reduce memory requirements (it is 24 vs. 32 bytes due to possible 8-byte alignment).
813  int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
814 } AVIndexEntry;
815 
816 #define AV_DISPOSITION_DEFAULT 0x0001
817 #define AV_DISPOSITION_DUB 0x0002
818 #define AV_DISPOSITION_ORIGINAL 0x0004
819 #define AV_DISPOSITION_COMMENT 0x0008
820 #define AV_DISPOSITION_LYRICS 0x0010
821 #define AV_DISPOSITION_KARAOKE 0x0020
823 /**
824  * Track should be used during playback by default.
825  * Useful for subtitle track that should be displayed
826  * even when user did not explicitly ask for subtitles.
827  */
828 #define AV_DISPOSITION_FORCED 0x0040
829 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
830 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
831 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
832 /**
833  * The stream is stored in the file as an attached picture/"cover art" (e.g.
834  * APIC frame in ID3v2). The first (usually only) packet associated with it
835  * will be returned among the first few packets read from the file unless
836  * seeking takes place. It can also be accessed at any time in
837  * AVStream.attached_pic.
838  */
839 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
840 /**
841  * The stream is sparse, and contains thumbnail images, often corresponding
842  * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
843  */
844 #define AV_DISPOSITION_TIMED_THUMBNAILS 0x0800
845 
846 typedef struct AVStreamInternal AVStreamInternal;
847 
848 /**
849  * To specify text track kind (different from subtitles default).
850  */
851 #define AV_DISPOSITION_CAPTIONS 0x10000
852 #define AV_DISPOSITION_DESCRIPTIONS 0x20000
853 #define AV_DISPOSITION_METADATA 0x40000
854 #define AV_DISPOSITION_DEPENDENT 0x80000 ///< dependent audio stream (mix_type=0 in mpegts)
855 #define AV_DISPOSITION_STILL_IMAGE 0x100000 ///< still images in video stream (still_picture_flag=1 in mpegts)
856 
857 /**
858  * Options for behavior on timestamp wrap detection.
859  */
860 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
861 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
862 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
864 /**
865  * Stream structure.
866  * New fields can be added to the end with minor version bumps.
867  * Removal, reordering and changes to existing fields require a major
868  * version bump.
869  * sizeof(AVStream) must not be used outside libav*.
870  */
871 typedef struct AVStream {
872  int index; /**< stream index in AVFormatContext */
873  /**
874  * Format-specific stream ID.
875  * decoding: set by libavformat
876  * encoding: set by the user, replaced by libavformat if left unset
877  */
878  int id;
879 #if FF_API_LAVF_AVCTX
880  /**
881  * @deprecated use the codecpar struct instead
882  */
884  AVCodecContext *codec;
885 #endif
886  void *priv_data;
888  /**
889  * This is the fundamental unit of time (in seconds) in terms
890  * of which frame timestamps are represented.
891  *
892  * decoding: set by libavformat
893  * encoding: May be set by the caller before avformat_write_header() to
894  * provide a hint to the muxer about the desired timebase. In
895  * avformat_write_header(), the muxer will overwrite this field
896  * with the timebase that will actually be used for the timestamps
897  * written into the file (which may or may not be related to the
898  * user-provided one, depending on the format).
899  */
900  AVRational time_base;
901 
902  /**
903  * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
904  * Only set this if you are absolutely 100% sure that the value you set
905  * it to really is the pts of the first frame.
906  * This may be undefined (AV_NOPTS_VALUE).
907  * @note The ASF header does NOT contain a correct start_time the ASF
908  * demuxer must NOT set this.
909  */
910  int64_t start_time;
911 
912  /**
913  * Decoding: duration of the stream, in stream time base.
914  * If a source file does not specify a duration, but does specify
915  * a bitrate, this value will be estimated from bitrate and file size.
916  *
917  * Encoding: May be set by the caller before avformat_write_header() to
918  * provide a hint to the muxer about the estimated duration.
919  */
920  int64_t duration;
921 
922  int64_t nb_frames; ///< number of frames in this stream if known or 0
923 
924  int disposition; /**< AV_DISPOSITION_* bit field */
925 
926  enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
927 
928  /**
929  * sample aspect ratio (0 if unknown)
930  * - encoding: Set by user.
931  * - decoding: Set by libavformat.
932  */
933  AVRational sample_aspect_ratio;
934 
935  AVDictionary *metadata;
936 
937  /**
938  * Average framerate
939  *
940  * - demuxing: May be set by libavformat when creating the stream or in
941  * avformat_find_stream_info().
942  * - muxing: May be set by the caller before avformat_write_header().
943  */
944  AVRational avg_frame_rate;
945 
946  /**
947  * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
948  * will contain the attached picture.
949  *
950  * decoding: set by libavformat, must not be modified by the caller.
951  * encoding: unused
952  */
953  AVPacket attached_pic;
954 
955  /**
956  * An array of side data that applies to the whole stream (i.e. the
957  * container does not allow it to change between packets).
958  *
959  * There may be no overlap between the side data in this array and side data
960  * in the packets. I.e. a given side data is either exported by the muxer
961  * (demuxing) / set by the caller (muxing) in this array, then it never
962  * appears in the packets, or the side data is exported / sent through
963  * the packets (always in the first packet where the value becomes known or
964  * changes), then it does not appear in this array.
965  *
966  * - demuxing: Set by libavformat when the stream is created.
967  * - muxing: May be set by the caller before avformat_write_header().
968  *
969  * Freed by libavformat in avformat_free_context().
970  *
971  * @see av_format_inject_global_side_data()
972  */
973  AVPacketSideData *side_data;
974  /**
975  * The number of elements in the AVStream.side_data array.
976  */
977  int nb_side_data;
978 
979  /**
980  * Flags indicating events happening on the stream, a combination of
981  * AVSTREAM_EVENT_FLAG_*.
982  *
983  * - demuxing: may be set by the demuxer in avformat_open_input(),
984  * avformat_find_stream_info() and av_read_frame(). Flags must be cleared
985  * by the user once the event has been handled.
986  * - muxing: may be set by the user after avformat_write_header(). to
987  * indicate a user-triggered event. The muxer will clear the flags for
988  * events it has handled in av_[interleaved]_write_frame().
989  */
990  int event_flags;
991 /**
992  * - demuxing: the demuxer read new metadata from the file and updated
993  * AVStream.metadata accordingly
994  * - muxing: the user updated AVStream.metadata and wishes the muxer to write
995  * it into the file
996  */
997 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001
998 /**
999  * - demuxing: new packets for this stream were read from the file. This
1000  * event is informational only and does not guarantee that new packets
1001  * for this stream will necessarily be returned from av_read_frame().
1002  */
1003 #define AVSTREAM_EVENT_FLAG_NEW_PACKETS (1 << 1)
1004 
1005  /**
1006  * Real base framerate of the stream.
1007  * This is the lowest framerate with which all timestamps can be
1008  * represented accurately (it is the least common multiple of all
1009  * framerates in the stream). Note, this value is just a guess!
1010  * For example, if the time base is 1/90000 and all frames have either
1011  * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
1012  */
1013  AVRational r_frame_rate;
1014 
1015 #if FF_API_LAVF_FFSERVER
1016  /**
1017  * String containing pairs of key and values describing recommended encoder configuration.
1018  * Pairs are separated by ','.
1019  * Keys are separated from values by '='.
1020  *
1021  * @deprecated unused
1022  */
1024  char *recommended_encoder_configuration;
1025 #endif
1026 
1027  /**
1028  * Codec parameters associated with this stream. Allocated and freed by
1029  * libavformat in avformat_new_stream() and avformat_free_context()
1030  * respectively.
1031  *
1032  * - demuxing: filled by libavformat on stream creation or in
1033  * avformat_find_stream_info()
1034  * - muxing: filled by the caller before avformat_write_header()
1035  */
1036  AVCodecParameters *codecpar;
1037 
1038  /*****************************************************************
1039  * All fields below this line are not part of the public API. They
1040  * may not be used outside of libavformat and can be changed and
1041  * removed at will.
1042  * Internal note: be aware that physically removing these fields
1043  * will break ABI. Replace removed fields with dummy fields, and
1044  * add new fields to AVStreamInternal.
1045  *****************************************************************
1046  */
1047 
1048 #if LIBAVFORMAT_VERSION_MAJOR < 59
1049  // kept for ABI compatibility only, do not access in any way
1050  void *unused;
1051 #endif
1052 
1053  int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
1054 
1055  // Timestamp generation support:
1056  /**
1057  * Timestamp corresponding to the last dts sync point.
1058  *
1059  * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
1060  * a DTS is received from the underlying container. Otherwise set to
1061  * AV_NOPTS_VALUE by default.
1062  */
1063  int64_t first_dts;
1064  int64_t cur_dts;
1065  int64_t last_IP_pts;
1066  int last_IP_duration;
1067 
1068  /**
1069  * Number of packets to buffer for codec probing
1070  */
1071  int probe_packets;
1073  /**
1074  * Number of frames that have been demuxed during avformat_find_stream_info()
1075  */
1076  int codec_info_nb_frames;
1077 
1078  /* av_read_frame() support */
1079  enum AVStreamParseType need_parsing;
1081 
1082 #if LIBAVFORMAT_VERSION_MAJOR < 59
1083  // kept for ABI compatibility only, do not access in any way
1084  void *unused7;
1085  AVProbeData unused6;
1086  int64_t unused5[16+1];
1087  void *unused2;
1088  int unused3;
1089  unsigned int unused4;
1090 #endif
1091 
1092  /**
1093  * Stream Identifier
1094  * This is the MPEG-TS stream identifier +1
1095  * 0 means unknown
1096  */
1097  int stream_identifier;
1099  /**
1100  * Details of the MPEG-TS program which created this stream.
1101  */
1102  int program_num;
1103  int pmt_version;
1104  int pmt_stream_idx;
1105 
1106  /**
1107  * An opaque field for libavformat internal usage.
1108  * Must not be accessed in any way by callers.
1109  */
1110  AVStreamInternal *internal;
1113 #if FF_API_FORMAT_GET_SET
1114 /**
1115  * Accessors for some AVStream fields. These used to be provided for ABI
1116  * compatibility, and do not need to be used anymore.
1117  */
1119 AVRational av_stream_get_r_frame_rate(const AVStream *s);
1121 void av_stream_set_r_frame_rate(AVStream *s, AVRational r);
1122 #if FF_API_LAVF_FFSERVER
1124 char* av_stream_get_recommended_encoder_configuration(const AVStream *s);
1126 void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration);
1127 #endif
1128 #endif
1129 
1131 
1132 /**
1133  * Returns the pts of the last muxed packet + its duration
1134  *
1135  * the retuned value is undefined when used with a demuxer.
1136  */
1137 int64_t av_stream_get_end_pts(const AVStream *st);
1138 
1139 #define AV_PROGRAM_RUNNING 1
1140 
1141 /**
1142  * New fields can be added to the end with minor version bumps.
1143  * Removal, reordering and changes to existing fields require a major
1144  * version bump.
1145  * sizeof(AVProgram) must not be used outside libav*.
1146  */
1147 typedef struct AVProgram {
1148  int id;
1149  int flags;
1150  enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1151  unsigned int *stream_index;
1152  unsigned int nb_stream_indexes;
1153  AVDictionary *metadata;
1154 
1155  int program_num;
1156  int pmt_pid;
1157  int pcr_pid;
1158  int pmt_version;
1160  /*****************************************************************
1161  * All fields below this line are not part of the public API. They
1162  * may not be used outside of libavformat and can be changed and
1163  * removed at will.
1164  * New public fields should be added right above.
1165  *****************************************************************
1166  */
1167  int64_t start_time;
1168  int64_t end_time;
1169 
1170  int64_t pts_wrap_reference; ///< reference dts for wrap detection
1171  int pts_wrap_behavior; ///< behavior on wrap detection
1172 } AVProgram;
1173 
1174 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1175  (streams are added dynamically) */
1176 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely
1177  not seekable, and attempts to call the
1178  seek function will fail. For some
1179  network protocols (e.g. HLS), this can
1180  change dynamically at runtime. */
1181 
1182 typedef struct AVChapter {
1183  int id; ///< unique ID to identify the chapter
1184  AVRational time_base; ///< time base in which the start/end timestamps are specified
1185  int64_t start, end; ///< chapter start/end time in time_base units
1186  AVDictionary *metadata;
1187 } AVChapter;
1188 
1189 
1190 /**
1191  * Callback used by devices to communicate with application.
1192  */
1193 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1194  void *data, size_t data_size);
1195 
1196 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
1199 /**
1200  * The duration of a video can be estimated through various ways, and this enum can be used
1201  * to know how the duration was estimated.
1202  */
1204  AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1205  AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1206  AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1207 };
1208 
1209 typedef struct AVFormatInternal AVFormatInternal;
1211 /**
1212  * Format I/O context.
1213  * New fields can be added to the end with minor version bumps.
1214  * Removal, reordering and changes to existing fields require a major
1215  * version bump.
1216  * sizeof(AVFormatContext) must not be used outside libav*, use
1217  * avformat_alloc_context() to create an AVFormatContext.
1218  *
1219  * Fields can be accessed through AVOptions (av_opt*),
1220  * the name string used matches the associated command line parameter name and
1221  * can be found in libavformat/options_table.h.
1222  * The AVOption/command line parameter names differ in some cases from the C
1223  * structure field names for historic reasons or brevity.
1224  */
1225 typedef struct AVFormatContext {
1226  /**
1227  * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1228  * Exports (de)muxer private options if they exist.
1229  */
1230  const AVClass *av_class;
1231 
1232  /**
1233  * The input container format.
1234  *
1235  * Demuxing only, set by avformat_open_input().
1236  */
1238 
1239  /**
1240  * The output container format.
1241  *
1242  * Muxing only, must be set by the caller before avformat_write_header().
1243  */
1244  ff_const59 struct AVOutputFormat *oformat;
1245 
1246  /**
1247  * Format private data. This is an AVOptions-enabled struct
1248  * if and only if iformat/oformat.priv_class is not NULL.
1249  *
1250  * - muxing: set by avformat_write_header()
1251  * - demuxing: set by avformat_open_input()
1252  */
1253  void *priv_data;
1254 
1255  /**
1256  * I/O context.
1257  *
1258  * - demuxing: either set by the user before avformat_open_input() (then
1259  * the user must close it manually) or set by avformat_open_input().
1260  * - muxing: set by the user before avformat_write_header(). The caller must
1261  * take care of closing / freeing the IO context.
1262  *
1263  * Do NOT set this field if AVFMT_NOFILE flag is set in
1264  * iformat/oformat.flags. In such a case, the (de)muxer will handle
1265  * I/O in some other way and this field will be NULL.
1266  */
1268 
1269  /* stream info */
1270  /**
1271  * Flags signalling stream properties. A combination of AVFMTCTX_*.
1272  * Set by libavformat.
1273  */
1274  int ctx_flags;
1275 
1276  /**
1277  * Number of elements in AVFormatContext.streams.
1278  *
1279  * Set by avformat_new_stream(), must not be modified by any other code.
1280  */
1281  unsigned int nb_streams;
1282  /**
1283  * A list of all streams in the file. New streams are created with
1284  * avformat_new_stream().
1285  *
1286  * - demuxing: streams are created by libavformat in avformat_open_input().
1287  * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1288  * appear in av_read_frame().
1289  * - muxing: streams are created by the user before avformat_write_header().
1290  *
1291  * Freed by libavformat in avformat_free_context().
1292  */
1293  AVStream **streams;
1294 
1295 #if FF_API_FORMAT_FILENAME
1296  /**
1297  * input or output filename
1298  *
1299  * - demuxing: set by avformat_open_input()
1300  * - muxing: may be set by the caller before avformat_write_header()
1301  *
1302  * @deprecated Use url instead.
1303  */
1305  char filename[1024];
1306 #endif
1308  /**
1309  * input or output URL. Unlike the old filename field, this field has no
1310  * length restriction.
1311  *
1312  * - demuxing: set by avformat_open_input(), initialized to an empty
1313  * string if url parameter was NULL in avformat_open_input().
1314  * - muxing: may be set by the caller before calling avformat_write_header()
1315  * (or avformat_init_output() if that is called first) to a string
1316  * which is freeable by av_free(). Set to an empty string if it
1317  * was NULL in avformat_init_output().
1318  *
1319  * Freed by libavformat in avformat_free_context().
1320  */
1321  char *url;
1322 
1323  /**
1324  * Position of the first frame of the component, in
1325  * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1326  * It is deduced from the AVStream values.
1327  *
1328  * Demuxing only, set by libavformat.
1329  */
1330  int64_t start_time;
1331 
1332  /**
1333  * Duration of the stream, in AV_TIME_BASE fractional
1334  * seconds. Only set this value if you know none of the individual stream
1335  * durations and also do not set any of them. This is deduced from the
1336  * AVStream values if not set.
1337  *
1338  * Demuxing only, set by libavformat.
1339  */
1340  int64_t duration;
1341 
1342  /**
1343  * Total stream bitrate in bit/s, 0 if not
1344  * available. Never set it directly if the file_size and the
1345  * duration are known as FFmpeg can compute it automatically.
1346  */
1347  int64_t bit_rate;
1348 
1349  unsigned int packet_size;
1350  int max_delay;
1351 
1352  /**
1353  * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1354  * Set by the user before avformat_open_input() / avformat_write_header().
1355  */
1356  int flags;
1357 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1358 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1359 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1360 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1361 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1362 #define AVFMT_FLAG_NOPARSE 0x0020 ///< Do not use AVParsers, you also must set AVFMT_FLAG_NOFILLIN as the fillin code works on frames and no parsing -> no frames. Also seeking to frames can not work if parsing to find frame boundaries has been disabled
1363 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1364 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1365 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1366 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1367 /**
1368  * When muxing, try to avoid writing any random/volatile data to the output.
1369  * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1370  *
1371  * This flag is mainly intended for testing.
1372  */
1373 #define AVFMT_FLAG_BITEXACT 0x0400
1374 #if FF_API_LAVF_MP4A_LATM
1375 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Deprecated, does nothing.
1376 #endif
1377 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1378 #define AVFMT_FLAG_PRIV_OPT 0x20000 ///< Enable use of private options by delaying codec open (this could be made default once all code is converted)
1379 #if FF_API_LAVF_KEEPSIDE_FLAG
1380 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Deprecated, does nothing.
1381 #endif
1382 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1383 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
1384 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
1385 
1386  /**
1387  * Maximum size of the data read from input for determining
1388  * the input container format.
1389  * Demuxing only, set by the caller before avformat_open_input().
1390  */
1391  int64_t probesize;
1393  /**
1394  * Maximum duration (in AV_TIME_BASE units) of the data read
1395  * from input in avformat_find_stream_info().
1396  * Demuxing only, set by the caller before avformat_find_stream_info().
1397  * Can be set to 0 to let avformat choose using a heuristic.
1398  */
1399  int64_t max_analyze_duration;
1400 
1401  const uint8_t *key;
1402  int keylen;
1403 
1404  unsigned int nb_programs;
1405  AVProgram **programs;
1406 
1407  /**
1408  * Forced video codec_id.
1409  * Demuxing: Set by user.
1410  */
1411  enum AVCodecID video_codec_id;
1412 
1413  /**
1414  * Forced audio codec_id.
1415  * Demuxing: Set by user.
1416  */
1417  enum AVCodecID audio_codec_id;
1419  /**
1420  * Forced subtitle codec_id.
1421  * Demuxing: Set by user.
1422  */
1423  enum AVCodecID subtitle_codec_id;
1424 
1425  /**
1426  * Maximum amount of memory in bytes to use for the index of each stream.
1427  * If the index exceeds this size, entries will be discarded as
1428  * needed to maintain a smaller size. This can lead to slower or less
1429  * accurate seeking (depends on demuxer).
1430  * Demuxers for which a full in-memory index is mandatory will ignore
1431  * this.
1432  * - muxing: unused
1433  * - demuxing: set by user
1434  */
1435  unsigned int max_index_size;
1436 
1437  /**
1438  * Maximum amount of memory in bytes to use for buffering frames
1439  * obtained from realtime capture devices.
1440  */
1441  unsigned int max_picture_buffer;
1442 
1443  /**
1444  * Number of chapters in AVChapter array.
1445  * When muxing, chapters are normally written in the file header,
1446  * so nb_chapters should normally be initialized before write_header
1447  * is called. Some muxers (e.g. mov and mkv) can also write chapters
1448  * in the trailer. To write chapters in the trailer, nb_chapters
1449  * must be zero when write_header is called and non-zero when
1450  * write_trailer is called.
1451  * - muxing: set by user
1452  * - demuxing: set by libavformat
1453  */
1454  unsigned int nb_chapters;
1455  AVChapter **chapters;
1456 
1457  /**
1458  * Metadata that applies to the whole file.
1459  *
1460  * - demuxing: set by libavformat in avformat_open_input()
1461  * - muxing: may be set by the caller before avformat_write_header()
1462  *
1463  * Freed by libavformat in avformat_free_context().
1464  */
1465  AVDictionary *metadata;
1466 
1467  /**
1468  * Start time of the stream in real world time, in microseconds
1469  * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1470  * stream was captured at this real world time.
1471  * - muxing: Set by the caller before avformat_write_header(). If set to
1472  * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1473  * be used.
1474  * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1475  * the value may become known after some number of frames
1476  * have been received.
1477  */
1478  int64_t start_time_realtime;
1480  /**
1481  * The number of frames used for determining the framerate in
1482  * avformat_find_stream_info().
1483  * Demuxing only, set by the caller before avformat_find_stream_info().
1484  */
1485  int fps_probe_size;
1486 
1487  /**
1488  * Error recognition; higher values will detect more errors but may
1489  * misdetect some more or less valid parts as errors.
1490  * Demuxing only, set by the caller before avformat_open_input().
1491  */
1492  int error_recognition;
1493 
1494  /**
1495  * Custom interrupt callbacks for the I/O layer.
1496  *
1497  * demuxing: set by the user before avformat_open_input().
1498  * muxing: set by the user before avformat_write_header()
1499  * (mainly useful for AVFMT_NOFILE formats). The callback
1500  * should also be passed to avio_open2() if it's used to
1501  * open the file.
1502  */
1503  AVIOInterruptCB interrupt_callback;
1504 
1505  /**
1506  * Flags to enable debugging.
1507  */
1508  int debug;
1509 #define FF_FDEBUG_TS 0x0001
1510 
1511  /**
1512  * Maximum buffering duration for interleaving.
1513  *
1514  * To ensure all the streams are interleaved correctly,
1515  * av_interleaved_write_frame() will wait until it has at least one packet
1516  * for each stream before actually writing any packets to the output file.
1517  * When some streams are "sparse" (i.e. there are large gaps between
1518  * successive packets), this can result in excessive buffering.
1519  *
1520  * This field specifies the maximum difference between the timestamps of the
1521  * first and the last packet in the muxing queue, above which libavformat
1522  * will output a packet regardless of whether it has queued a packet for all
1523  * the streams.
1524  *
1525  * Muxing only, set by the caller before avformat_write_header().
1526  */
1527  int64_t max_interleave_delta;
1528 
1529  /**
1530  * Allow non-standard and experimental extension
1531  * @see AVCodecContext.strict_std_compliance
1532  */
1533  int strict_std_compliance;
1534 
1535  /**
1536  * Flags indicating events happening on the file, a combination of
1537  * AVFMT_EVENT_FLAG_*.
1538  *
1539  * - demuxing: may be set by the demuxer in avformat_open_input(),
1540  * avformat_find_stream_info() and av_read_frame(). Flags must be cleared
1541  * by the user once the event has been handled.
1542  * - muxing: may be set by the user after avformat_write_header() to
1543  * indicate a user-triggered event. The muxer will clear the flags for
1544  * events it has handled in av_[interleaved]_write_frame().
1545  */
1546  int event_flags;
1547 /**
1548  * - demuxing: the demuxer read new metadata from the file and updated
1549  * AVFormatContext.metadata accordingly
1550  * - muxing: the user updated AVFormatContext.metadata and wishes the muxer to
1551  * write it into the file
1552  */
1553 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001
1554 
1555  /**
1556  * Maximum number of packets to read while waiting for the first timestamp.
1557  * Decoding only.
1558  */
1559  int max_ts_probe;
1561  /**
1562  * Avoid negative timestamps during muxing.
1563  * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1564  * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use)
1565  * - muxing: Set by user
1566  * - demuxing: unused
1567  */
1568  int avoid_negative_ts;
1569 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1570 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1571 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1572 
1573  /**
1574  * Transport stream id.
1575  * This will be moved into demuxer private options. Thus no API/ABI compatibility
1576  */
1577  int ts_id;
1578 
1579  /**
1580  * Audio preload in microseconds.
1581  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1582  * - encoding: Set by user
1583  * - decoding: unused
1584  */
1585  int audio_preload;
1586 
1587  /**
1588  * Max chunk time in microseconds.
1589  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1590  * - encoding: Set by user
1591  * - decoding: unused
1592  */
1593  int max_chunk_duration;
1594 
1595  /**
1596  * Max chunk size in bytes
1597  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1598  * - encoding: Set by user
1599  * - decoding: unused
1600  */
1601  int max_chunk_size;
1602 
1603  /**
1604  * forces the use of wallclock timestamps as pts/dts of packets
1605  * This has undefined results in the presence of B frames.
1606  * - encoding: unused
1607  * - decoding: Set by user
1608  */
1609  int use_wallclock_as_timestamps;
1610 
1611  /**
1612  * avio flags, used to force AVIO_FLAG_DIRECT.
1613  * - encoding: unused
1614  * - decoding: Set by user
1615  */
1616  int avio_flags;
1617 
1618  /**
1619  * The duration field can be estimated through various ways, and this field can be used
1620  * to know how the duration was estimated.
1621  * - encoding: unused
1622  * - decoding: Read by user
1623  */
1624  enum AVDurationEstimationMethod duration_estimation_method;
1625 
1626  /**
1627  * Skip initial bytes when opening stream
1628  * - encoding: unused
1629  * - decoding: Set by user
1630  */
1631  int64_t skip_initial_bytes;
1632 
1633  /**
1634  * Correct single timestamp overflows
1635  * - encoding: unused
1636  * - decoding: Set by user
1637  */
1638  unsigned int correct_ts_overflow;
1639 
1640  /**
1641  * Force seeking to any (also non key) frames.
1642  * - encoding: unused
1643  * - decoding: Set by user
1644  */
1645  int seek2any;
1646 
1647  /**
1648  * Flush the I/O context after each packet.
1649  * - encoding: Set by user
1650  * - decoding: unused
1651  */
1652  int flush_packets;
1653 
1654  /**
1655  * format probing score.
1656  * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1657  * the format.
1658  * - encoding: unused
1659  * - decoding: set by avformat, read by user
1660  */
1661  int probe_score;
1662 
1663  /**
1664  * number of bytes to read maximally to identify format.
1665  * - encoding: unused
1666  * - decoding: set by user
1667  */
1668  int format_probesize;
1669 
1670  /**
1671  * ',' separated list of allowed decoders.
1672  * If NULL then all are allowed
1673  * - encoding: unused
1674  * - decoding: set by user
1675  */
1676  char *codec_whitelist;
1677 
1678  /**
1679  * ',' separated list of allowed demuxers.
1680  * If NULL then all are allowed
1681  * - encoding: unused
1682  * - decoding: set by user
1683  */
1684  char *format_whitelist;
1685 
1686  /**
1687  * An opaque field for libavformat internal usage.
1688  * Must not be accessed in any way by callers.
1689  */
1690  AVFormatInternal *internal;
1691 
1692  /**
1693  * IO repositioned flag.
1694  * This is set by avformat when the underlaying IO context read pointer
1695  * is repositioned, for example when doing byte based seeking.
1696  * Demuxers can use the flag to detect such changes.
1697  */
1698  int io_repositioned;
1699 
1700  /**
1701  * Forced video codec.
1702  * This allows forcing a specific decoder, even when there are multiple with
1703  * the same codec_id.
1704  * Demuxing: Set by user
1705  */
1707 
1708  /**
1709  * Forced audio codec.
1710  * This allows forcing a specific decoder, even when there are multiple with
1711  * the same codec_id.
1712  * Demuxing: Set by user
1713  */
1715 
1716  /**
1717  * Forced subtitle codec.
1718  * This allows forcing a specific decoder, even when there are multiple with
1719  * the same codec_id.
1720  * Demuxing: Set by user
1721  */
1723 
1724  /**
1725  * Forced data codec.
1726  * This allows forcing a specific decoder, even when there are multiple with
1727  * the same codec_id.
1728  * Demuxing: Set by user
1729  */
1731 
1732  /**
1733  * Number of bytes to be written as padding in a metadata header.
1734  * Demuxing: Unused.
1735  * Muxing: Set by user via av_format_set_metadata_header_padding.
1736  */
1737  int metadata_header_padding;
1738 
1739  /**
1740  * User data.
1741  * This is a place for some private data of the user.
1742  */
1743  void *opaque;
1745  /**
1746  * Callback used by devices to communicate with application.
1747  */
1748  av_format_control_message control_message_cb;
1749 
1750  /**
1751  * Output timestamp offset, in microseconds.
1752  * Muxing: set by user
1753  */
1754  int64_t output_ts_offset;
1755 
1756  /**
1757  * dump format separator.
1758  * can be ", " or "\n " or anything else
1759  * - muxing: Set by user.
1760  * - demuxing: Set by user.
1761  */
1762  uint8_t *dump_separator;
1763 
1764  /**
1765  * Forced Data codec_id.
1766  * Demuxing: Set by user.
1767  */
1768  enum AVCodecID data_codec_id;
1769 
1770 #if FF_API_OLD_OPEN_CALLBACKS
1771  /**
1772  * Called to open further IO contexts when needed for demuxing.
1773  *
1774  * This can be set by the user application to perform security checks on
1775  * the URLs before opening them.
1776  * The function should behave like avio_open2(), AVFormatContext is provided
1777  * as contextual information and to reach AVFormatContext.opaque.
1778  *
1779  * If NULL then some simple checks are used together with avio_open2().
1780  *
1781  * Must not be accessed directly from outside avformat.
1782  * @See av_format_set_open_cb()
1783  *
1784  * Demuxing: Set by user.
1785  *
1786  * @deprecated Use io_open and io_close.
1787  */
1789  int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options);
1790 #endif
1791 
1792  /**
1793  * ',' separated list of allowed protocols.
1794  * - encoding: unused
1795  * - decoding: set by user
1796  */
1797  char *protocol_whitelist;
1798 
1799  /**
1800  * A callback for opening new IO streams.
1801  *
1802  * Whenever a muxer or a demuxer needs to open an IO stream (typically from
1803  * avformat_open_input() for demuxers, but for certain formats can happen at
1804  * other times as well), it will call this callback to obtain an IO context.
1805  *
1806  * @param s the format context
1807  * @param pb on success, the newly opened IO context should be returned here
1808  * @param url the url to open
1809  * @param flags a combination of AVIO_FLAG_*
1810  * @param options a dictionary of additional options, with the same
1811  * semantics as in avio_open2()
1812  * @return 0 on success, a negative AVERROR code on failure
1813  *
1814  * @note Certain muxers and demuxers do nesting, i.e. they open one or more
1815  * additional internal format contexts. Thus the AVFormatContext pointer
1816  * passed to this callback may be different from the one facing the caller.
1817  * It will, however, have the same 'opaque' field.
1818  */
1819  int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url,
1820  int flags, AVDictionary **options);
1821 
1822  /**
1823  * A callback for closing the streams opened with AVFormatContext.io_open().
1824  */
1825  void (*io_close)(struct AVFormatContext *s, AVIOContext *pb);
1826 
1827  /**
1828  * ',' separated list of disallowed protocols.
1829  * - encoding: unused
1830  * - decoding: set by user
1831  */
1832  char *protocol_blacklist;
1834  /**
1835  * The maximum number of streams.
1836  * - encoding: unused
1837  * - decoding: set by user
1838  */
1840 
1841  /**
1842  * Skip duration calcuation in estimate_timings_from_pts.
1843  * - encoding: unused
1844  * - decoding: set by user
1845  */
1847 
1848  /**
1849  * Maximum number of packets that can be probed
1850  * - encoding: unused
1851  * - decoding: set by user
1852  */
1854 } AVFormatContext;
1855 
1856 #if FF_API_FORMAT_GET_SET
1857 /**
1858  * Accessors for some AVFormatContext fields. These used to be provided for ABI
1859  * compatibility, and do not need to be used anymore.
1860  */
1862 int av_format_get_probe_score(const AVFormatContext *s);
1864 AVCodec * av_format_get_video_codec(const AVFormatContext *s);
1866 void av_format_set_video_codec(AVFormatContext *s, AVCodec *c);
1868 AVCodec * av_format_get_audio_codec(const AVFormatContext *s);
1870 void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c);
1872 AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s);
1874 void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c);
1876 AVCodec * av_format_get_data_codec(const AVFormatContext *s);
1878 void av_format_set_data_codec(AVFormatContext *s, AVCodec *c);
1880 int av_format_get_metadata_header_padding(const AVFormatContext *s);
1882 void av_format_set_metadata_header_padding(AVFormatContext *s, int c);
1884 void * av_format_get_opaque(const AVFormatContext *s);
1886 void av_format_set_opaque(AVFormatContext *s, void *opaque);
1888 av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s);
1890 void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback);
1891 #if FF_API_OLD_OPEN_CALLBACKS
1892 attribute_deprecated AVOpenCallback av_format_get_open_cb(const AVFormatContext *s);
1893 attribute_deprecated void av_format_set_open_cb(AVFormatContext *s, AVOpenCallback callback);
1894 #endif
1895 #endif
1896 
1897 /**
1898  * This function will cause global side data to be injected in the next packet
1899  * of each stream as well as after any subsequent seek.
1900  */
1902 
1903 /**
1904  * Returns the method used to set ctx->duration.
1905  *
1906  * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1907  */
1909 
1910 /**
1911  * @defgroup lavf_core Core functions
1912  * @ingroup libavf
1913  *
1914  * Functions for querying libavformat capabilities, allocating core structures,
1915  * etc.
1916  * @{
1917  */
1918 
1919 /**
1920  * Return the LIBAVFORMAT_VERSION_INT constant.
1921  */
1922 unsigned avformat_version(void);
1923 
1924 /**
1925  * Return the libavformat build-time configuration.
1926  */
1927 const char *avformat_configuration(void);
1928 
1929 /**
1930  * Return the libavformat license.
1931  */
1932 const char *avformat_license(void);
1933 
1934 #if FF_API_NEXT
1935 /**
1936  * Initialize libavformat and register all the muxers, demuxers and
1937  * protocols. If you do not call this function, then you can select
1938  * exactly which formats you want to support.
1939  *
1940  * @see av_register_input_format()
1941  * @see av_register_output_format()
1942  */
1944 void av_register_all(void);
1945 
1947 void av_register_input_format(AVInputFormat *format);
1949 void av_register_output_format(AVOutputFormat *format);
1950 #endif
1951 
1952 /**
1953  * Do global initialization of network libraries. This is optional,
1954  * and not recommended anymore.
1955  *
1956  * This functions only exists to work around thread-safety issues
1957  * with older GnuTLS or OpenSSL libraries. If libavformat is linked
1958  * to newer versions of those libraries, or if you do not use them,
1959  * calling this function is unnecessary. Otherwise, you need to call
1960  * this function before any other threads using them are started.
1961  *
1962  * This function will be deprecated once support for older GnuTLS and
1963  * OpenSSL libraries is removed, and this function has no purpose
1964  * anymore.
1965  */
1966 int avformat_network_init(void);
1967 
1968 /**
1969  * Undo the initialization done by avformat_network_init. Call it only
1970  * once for each time you called avformat_network_init.
1971  */
1972 int avformat_network_deinit(void);
1973 
1974 #if FF_API_NEXT
1975 /**
1976  * If f is NULL, returns the first registered input format,
1977  * if f is non-NULL, returns the next registered input format after f
1978  * or NULL if f is the last one.
1979  */
1981 AVInputFormat *av_iformat_next(const AVInputFormat *f);
1982 
1983 /**
1984  * If f is NULL, returns the first registered output format,
1985  * if f is non-NULL, returns the next registered output format after f
1986  * or NULL if f is the last one.
1987  */
1989 AVOutputFormat *av_oformat_next(const AVOutputFormat *f);
1990 #endif
1991 
1992 /**
1993  * Iterate over all registered muxers.
1994  *
1995  * @param opaque a pointer where libavformat will store the iteration state. Must
1996  * point to NULL to start the iteration.
1997  *
1998  * @return the next registered muxer or NULL when the iteration is
1999  * finished
2000  */
2001 const AVOutputFormat *av_muxer_iterate(void **opaque);
2002 
2003 /**
2004  * Iterate over all registered demuxers.
2005  *
2006  * @param opaque a pointer where libavformat will store the iteration state. Must
2007  * point to NULL to start the iteration.
2008  *
2009  * @return the next registered demuxer or NULL when the iteration is
2010  * finished
2011  */
2012 const AVInputFormat *av_demuxer_iterate(void **opaque);
2013 
2014 /**
2015  * Allocate an AVFormatContext.
2016  * avformat_free_context() can be used to free the context and everything
2017  * allocated by the framework within it.
2018  */
2020 
2021 /**
2022  * Free an AVFormatContext and all its streams.
2023  * @param s context to free
2024  */
2026 
2027 /**
2028  * Get the AVClass for AVFormatContext. It can be used in combination with
2029  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2030  *
2031  * @see av_opt_find().
2032  */
2033 const AVClass *avformat_get_class(void);
2034 
2035 /**
2036  * Add a new stream to a media file.
2037  *
2038  * When demuxing, it is called by the demuxer in read_header(). If the
2039  * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2040  * be called in read_packet().
2041  *
2042  * When muxing, should be called by the user before avformat_write_header().
2043  *
2044  * User is required to call avcodec_close() and avformat_free_context() to
2045  * clean up the allocation by avformat_new_stream().
2046  *
2047  * @param s media file handle
2048  * @param c If non-NULL, the AVCodecContext corresponding to the new stream
2049  * will be initialized to use this codec. This is needed for e.g. codec-specific
2050  * defaults to be set, so codec should be provided if it is known.
2051  *
2052  * @return newly created stream or NULL on error.
2053  */
2055 
2056 /**
2057  * Wrap an existing array as stream side data.
2058  *
2059  * @param st stream
2060  * @param type side information type
2061  * @param data the side data array. It must be allocated with the av_malloc()
2062  * family of functions. The ownership of the data is transferred to
2063  * st.
2064  * @param size side information size
2065  * @return zero on success, a negative AVERROR code on failure. On failure,
2066  * the stream is unchanged and the data remains owned by the caller.
2067  */
2069  uint8_t *data, size_t size);
2070 
2071 /**
2072  * Allocate new information from stream.
2073  *
2074  * @param stream stream
2075  * @param type desired side information type
2076  * @param size side information size
2077  * @return pointer to fresh allocated data or NULL otherwise
2078  */
2080  enum AVPacketSideDataType type, int size);
2081 /**
2082  * Get side information from stream.
2083  *
2084  * @param stream stream
2085  * @param type desired side information type
2086  * @param size If supplied, *size will be set to the size of the side data
2087  * or to zero if the desired side data is not present.
2088  * @return pointer to data if present or NULL otherwise
2089  */
2091  enum AVPacketSideDataType type, int *size);
2092 
2094 
2095 /**
2096  * @}
2097  */
2098 
2099 
2100 /**
2101  * Allocate an AVFormatContext for an output format.
2102  * avformat_free_context() can be used to free the context and
2103  * everything allocated by the framework within it.
2104  *
2105  * @param *ctx is set to the created format context, or to NULL in
2106  * case of failure
2107  * @param oformat format to use for allocating the context, if NULL
2108  * format_name and filename are used instead
2109  * @param format_name the name of output format to use for allocating the
2110  * context, if NULL filename is used instead
2111  * @param filename the name of the filename to use for allocating the
2112  * context, may be NULL
2113  * @return >= 0 in case of success, a negative AVERROR code in case of
2114  * failure
2115  */
2117  const char *format_name, const char *filename);
2118 
2119 /**
2120  * @addtogroup lavf_decoding
2121  * @{
2122  */
2123 
2124 /**
2125  * Find AVInputFormat based on the short name of the input format.
2126  */
2127 ff_const59 AVInputFormat *av_find_input_format(const char *short_name);
2128 
2129 /**
2130  * Guess the file format.
2131  *
2132  * @param pd data to be probed
2133  * @param is_opened Whether the file is already opened; determines whether
2134  * demuxers with or without AVFMT_NOFILE are probed.
2135  */
2137 
2138 /**
2139  * Guess the file format.
2140  *
2141  * @param pd data to be probed
2142  * @param is_opened Whether the file is already opened; determines whether
2143  * demuxers with or without AVFMT_NOFILE are probed.
2144  * @param score_max A probe score larger that this is required to accept a
2145  * detection, the variable is set to the actual detection
2146  * score afterwards.
2147  * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2148  * to retry with a larger probe buffer.
2149  */
2150 ff_const59 AVInputFormat *av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max);
2151 
2152 /**
2153  * Guess the file format.
2154  *
2155  * @param is_opened Whether the file is already opened; determines whether
2156  * demuxers with or without AVFMT_NOFILE are probed.
2157  * @param score_ret The score of the best detection.
2158  */
2159 ff_const59 AVInputFormat *av_probe_input_format3(ff_const59 AVProbeData *pd, int is_opened, int *score_ret);
2160 
2161 /**
2162  * Probe a bytestream to determine the input format. Each time a probe returns
2163  * with a score that is too low, the probe buffer size is increased and another
2164  * attempt is made. When the maximum probe size is reached, the input format
2165  * with the highest score is returned.
2166  *
2167  * @param pb the bytestream to probe
2168  * @param fmt the input format is put here
2169  * @param url the url of the stream
2170  * @param logctx the log context
2171  * @param offset the offset within the bytestream to probe from
2172  * @param max_probe_size the maximum probe buffer size (zero for default)
2173  * @return the score in case of success, a negative value corresponding to an
2174  * the maximal score is AVPROBE_SCORE_MAX
2175  * AVERROR code otherwise
2176  */
2178  const char *url, void *logctx,
2179  unsigned int offset, unsigned int max_probe_size);
2180 
2181 /**
2182  * Like av_probe_input_buffer2() but returns 0 on success
2183  */
2185  const char *url, void *logctx,
2186  unsigned int offset, unsigned int max_probe_size);
2187 
2188 /**
2189  * Open an input stream and read the header. The codecs are not opened.
2190  * The stream must be closed with avformat_close_input().
2191  *
2192  * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
2193  * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
2194  * function and written into ps.
2195  * Note that a user-supplied AVFormatContext will be freed on failure.
2196  * @param url URL of the stream to open.
2197  * @param fmt If non-NULL, this parameter forces a specific input format.
2198  * Otherwise the format is autodetected.
2199  * @param options A dictionary filled with AVFormatContext and demuxer-private options.
2200  * On return this parameter will be destroyed and replaced with a dict containing
2201  * options that were not found. May be NULL.
2202  *
2203  * @return 0 on success, a negative AVERROR on failure.
2204  *
2205  * @note If you want to use custom IO, preallocate the format context and set its pb field.
2206  */
2208 
2211 
2212 /**
2213  * Read packets of a media file to get stream information. This
2214  * is useful for file formats with no headers such as MPEG. This
2215  * function also computes the real framerate in case of MPEG-2 repeat
2216  * frame mode.
2217  * The logical file position is not changed by this function;
2218  * examined packets may be buffered for later processing.
2219  *
2220  * @param ic media file handle
2221  * @param options If non-NULL, an ic.nb_streams long array of pointers to
2222  * dictionaries, where i-th member contains options for
2223  * codec corresponding to i-th stream.
2224  * On return each dictionary will be filled with options that were not found.
2225  * @return >=0 if OK, AVERROR_xxx on error
2226  *
2227  * @note this function isn't guaranteed to open all the codecs, so
2228  * options being non-empty at return is a perfectly normal behavior.
2229  *
2230  * @todo Let the user decide somehow what information is needed so that
2231  * we do not waste time getting stuff the user does not need.
2232  */
2234 
2235 /**
2236  * Find the programs which belong to a given stream.
2237  *
2238  * @param ic media file handle
2239  * @param last the last found program, the search will start after this
2240  * program, or from the beginning if it is NULL
2241  * @param s stream index
2242  * @return the next program which belongs to s, NULL if no program is found or
2243  * the last program is not among the programs of ic.
2244  */
2246 
2247 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
2248 
2249 /**
2250  * Find the "best" stream in the file.
2251  * The best stream is determined according to various heuristics as the most
2252  * likely to be what the user expects.
2253  * If the decoder parameter is non-NULL, av_find_best_stream will find the
2254  * default decoder for the stream's codec; streams for which no decoder can
2255  * be found are ignored.
2256  *
2257  * @param ic media file handle
2258  * @param type stream type: video, audio, subtitles, etc.
2259  * @param wanted_stream_nb user-requested stream number,
2260  * or -1 for automatic selection
2261  * @param related_stream try to find a stream related (eg. in the same
2262  * program) to this one, or -1 if none
2263  * @param decoder_ret if non-NULL, returns the decoder for the
2264  * selected stream
2265  * @param flags flags; none are currently defined
2266  * @return the non-negative stream number in case of success,
2267  * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2268  * could be found,
2269  * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2270  * @note If av_find_best_stream returns successfully and decoder_ret is not
2271  * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2272  */
2274  enum AVMediaType type,
2275  int wanted_stream_nb,
2276  int related_stream,
2277  AVCodec **decoder_ret,
2278  int flags);
2279 
2280 /**
2281  * Return the next frame of a stream.
2282  * This function returns what is stored in the file, and does not validate
2283  * that what is there are valid frames for the decoder. It will split what is
2284  * stored in the file into frames and return one for each call. It will not
2285  * omit invalid data between valid frames so as to give the decoder the maximum
2286  * information possible for decoding.
2287  *
2288  * On success, the returned packet is reference-counted (pkt->buf is set) and
2289  * valid indefinitely. The packet must be freed with av_packet_unref() when
2290  * it is no longer needed. For video, the packet contains exactly one frame.
2291  * For audio, it contains an integer number of frames if each frame has
2292  * a known fixed size (e.g. PCM or ADPCM data). If the audio frames have
2293  * a variable size (e.g. MPEG audio), then it contains one frame.
2294  *
2295  * pkt->pts, pkt->dts and pkt->duration are always set to correct
2296  * values in AVStream.time_base units (and guessed if the format cannot
2297  * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2298  * has B-frames, so it is better to rely on pkt->dts if you do not
2299  * decompress the payload.
2300  *
2301  * @return 0 if OK, < 0 on error or end of file. On error, pkt will be blank
2302  * (as if it came from av_packet_alloc()).
2303  *
2304  * @note pkt will be initialized, so it may be uninitialized, but it must not
2305  * contain data that needs to be freed.
2306  */
2308 
2309 /**
2310  * Seek to the keyframe at timestamp.
2311  * 'timestamp' in 'stream_index'.
2312  *
2313  * @param s media file handle
2314  * @param stream_index If stream_index is (-1), a default
2315  * stream is selected, and timestamp is automatically converted
2316  * from AV_TIME_BASE units to the stream specific time_base.
2317  * @param timestamp Timestamp in AVStream.time_base units
2318  * or, if no stream is specified, in AV_TIME_BASE units.
2319  * @param flags flags which select direction and seeking mode
2320  * @return >= 0 on success
2321  */
2322 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2323  int flags);
2324 
2325 /**
2326  * Seek to timestamp ts.
2327  * Seeking will be done so that the point from which all active streams
2328  * can be presented successfully will be closest to ts and within min/max_ts.
2329  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2330  *
2331  * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2332  * are the file position (this may not be supported by all demuxers).
2333  * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2334  * in the stream with stream_index (this may not be supported by all demuxers).
2335  * Otherwise all timestamps are in units of the stream selected by stream_index
2336  * or if stream_index is -1, in AV_TIME_BASE units.
2337  * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2338  * keyframes (this may not be supported by all demuxers).
2339  * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2340  *
2341  * @param s media file handle
2342  * @param stream_index index of the stream which is used as time base reference
2343  * @param min_ts smallest acceptable timestamp
2344  * @param ts target timestamp
2345  * @param max_ts largest acceptable timestamp
2346  * @param flags flags
2347  * @return >=0 on success, error code otherwise
2348  *
2349  * @note This is part of the new seek API which is still under construction.
2350  */
2351 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2352 
2353 /**
2354  * Discard all internally buffered data. This can be useful when dealing with
2355  * discontinuities in the byte stream. Generally works only with formats that
2356  * can resync. This includes headerless formats like MPEG-TS/TS but should also
2357  * work with NUT, Ogg and in a limited way AVI for example.
2358  *
2359  * The set of streams, the detected duration, stream parameters and codecs do
2360  * not change when calling this function. If you want a complete reset, it's
2361  * better to open a new AVFormatContext.
2362  *
2363  * This does not flush the AVIOContext (s->pb). If necessary, call
2364  * avio_flush(s->pb) before calling this function.
2365  *
2366  * @param s media file handle
2367  * @return >=0 on success, error code otherwise
2368  */
2370 
2371 /**
2372  * Start playing a network-based stream (e.g. RTSP stream) at the
2373  * current position.
2374  */
2376 
2377 /**
2378  * Pause a network-based stream (e.g. RTSP stream).
2379  *
2380  * Use av_read_play() to resume it.
2381  */
2383 
2384 /**
2385  * Close an opened input AVFormatContext. Free it and all its contents
2386  * and set *s to NULL.
2387  */
2389 /**
2390  * @}
2391  */
2392 
2393 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2394 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2395 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2396 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2397 
2398 /**
2399  * @addtogroup lavf_encoding
2400  * @{
2401  */
2402 
2403 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2404 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2405 
2406 /**
2407  * Allocate the stream private data and write the stream header to
2408  * an output media file.
2409  *
2410  * @param s Media file handle, must be allocated with avformat_alloc_context().
2411  * Its oformat field must be set to the desired output format;
2412  * Its pb field must be set to an already opened AVIOContext.
2413  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2414  * On return this parameter will be destroyed and replaced with a dict containing
2415  * options that were not found. May be NULL.
2416  *
2417  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init,
2418  * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init,
2419  * negative AVERROR on failure.
2420  *
2421  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2422  */
2425 
2426 /**
2427  * Allocate the stream private data and initialize the codec, but do not write the header.
2428  * May optionally be used before avformat_write_header to initialize stream parameters
2429  * before actually writing the header.
2430  * If using this function, do not pass the same options to avformat_write_header.
2431  *
2432  * @param s Media file handle, must be allocated with avformat_alloc_context().
2433  * Its oformat field must be set to the desired output format;
2434  * Its pb field must be set to an already opened AVIOContext.
2435  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2436  * On return this parameter will be destroyed and replaced with a dict containing
2437  * options that were not found. May be NULL.
2438  *
2439  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec requires avformat_write_header to fully initialize,
2440  * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec has been fully initialized,
2441  * negative AVERROR on failure.
2442  *
2443  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2444  */
2447 
2448 /**
2449  * Write a packet to an output media file.
2450  *
2451  * This function passes the packet directly to the muxer, without any buffering
2452  * or reordering. The caller is responsible for correctly interleaving the
2453  * packets if the format requires it. Callers that want libavformat to handle
2454  * the interleaving should call av_interleaved_write_frame() instead of this
2455  * function.
2456  *
2457  * @param s media file handle
2458  * @param pkt The packet containing the data to be written. Note that unlike
2459  * av_interleaved_write_frame(), this function does not take
2460  * ownership of the packet passed to it (though some muxers may make
2461  * an internal reference to the input packet).
2462  * <br>
2463  * This parameter can be NULL (at any time, not just at the end), in
2464  * order to immediately flush data buffered within the muxer, for
2465  * muxers that buffer up data internally before writing it to the
2466  * output.
2467  * <br>
2468  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2469  * set to the index of the corresponding stream in @ref
2470  * AVFormatContext.streams "s->streams".
2471  * <br>
2472  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2473  * must be set to correct values in the stream's timebase (unless the
2474  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2475  * they can be set to AV_NOPTS_VALUE).
2476  * The dts for subsequent packets passed to this function must be strictly
2477  * increasing when compared in their respective timebases (unless the
2478  * output format is flagged with the AVFMT_TS_NONSTRICT, then they
2479  * merely have to be nondecreasing). @ref AVPacket.duration
2480  * "duration") should also be set if known.
2481  * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2482  *
2483  * @see av_interleaved_write_frame()
2484  */
2486 
2487 /**
2488  * Write a packet to an output media file ensuring correct interleaving.
2489  *
2490  * This function will buffer the packets internally as needed to make sure the
2491  * packets in the output file are properly interleaved in the order of
2492  * increasing dts. Callers doing their own interleaving should call
2493  * av_write_frame() instead of this function.
2494  *
2495  * Using this function instead of av_write_frame() can give muxers advance
2496  * knowledge of future packets, improving e.g. the behaviour of the mp4
2497  * muxer for VFR content in fragmenting mode.
2498  *
2499  * @param s media file handle
2500  * @param pkt The packet containing the data to be written.
2501  * <br>
2502  * If the packet is reference-counted, this function will take
2503  * ownership of this reference and unreference it later when it sees
2504  * fit.
2505  * The caller must not access the data through this reference after
2506  * this function returns. If the packet is not reference-counted,
2507  * libavformat will make a copy.
2508  * <br>
2509  * This parameter can be NULL (at any time, not just at the end), to
2510  * flush the interleaving queues.
2511  * <br>
2512  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2513  * set to the index of the corresponding stream in @ref
2514  * AVFormatContext.streams "s->streams".
2515  * <br>
2516  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2517  * must be set to correct values in the stream's timebase (unless the
2518  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2519  * they can be set to AV_NOPTS_VALUE).
2520  * The dts for subsequent packets in one stream must be strictly
2521  * increasing (unless the output format is flagged with the
2522  * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2523  * @ref AVPacket.duration "duration") should also be set if known.
2524  *
2525  * @return 0 on success, a negative AVERROR on error. Libavformat will always
2526  * take care of freeing the packet, even if this function fails.
2527  *
2528  * @see av_write_frame(), AVFormatContext.max_interleave_delta
2529  */
2531 
2532 /**
2533  * Write an uncoded frame to an output media file.
2534  *
2535  * The frame must be correctly interleaved according to the container
2536  * specification; if not, av_interleaved_write_uncoded_frame() must be used.
2537  *
2538  * See av_interleaved_write_uncoded_frame() for details.
2539  */
2540 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2541  AVFrame *frame);
2542 
2543 /**
2544  * Write an uncoded frame to an output media file.
2545  *
2546  * If the muxer supports it, this function makes it possible to write an AVFrame
2547  * structure directly, without encoding it into a packet.
2548  * It is mostly useful for devices and similar special muxers that use raw
2549  * video or PCM data and will not serialize it into a byte stream.
2550  *
2551  * To test whether it is possible to use it with a given muxer and stream,
2552  * use av_write_uncoded_frame_query().
2553  *
2554  * The caller gives up ownership of the frame and must not access it
2555  * afterwards.
2556  *
2557  * @return >=0 for success, a negative code on error
2558  */
2559 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
2560  AVFrame *frame);
2561 
2562 /**
2563  * Test whether a muxer supports uncoded frame.
2564  *
2565  * @return >=0 if an uncoded frame can be written to that muxer and stream,
2566  * <0 if not
2567  */
2568 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2569 
2570 /**
2571  * Write the stream trailer to an output media file and free the
2572  * file private data.
2573  *
2574  * May only be called after a successful call to avformat_write_header.
2575  *
2576  * @param s media file handle
2577  * @return 0 if OK, AVERROR_xxx on error
2578  */
2580 
2581 /**
2582  * Return the output format in the list of registered output formats
2583  * which best matches the provided parameters, or return NULL if
2584  * there is no match.
2585  *
2586  * @param short_name if non-NULL checks if short_name matches with the
2587  * names of the registered formats
2588  * @param filename if non-NULL checks if filename terminates with the
2589  * extensions of the registered formats
2590  * @param mime_type if non-NULL checks if mime_type matches with the
2591  * MIME type of the registered formats
2592  */
2593 ff_const59 AVOutputFormat *av_guess_format(const char *short_name,
2594  const char *filename,
2595  const char *mime_type);
2596 
2597 /**
2598  * Guess the codec ID based upon muxer and filename.
2599  */
2600 enum AVCodecID av_guess_codec(ff_const59 AVOutputFormat *fmt, const char *short_name,
2601  const char *filename, const char *mime_type,
2602  enum AVMediaType type);
2603 
2604 /**
2605  * Get timing information for the data currently output.
2606  * The exact meaning of "currently output" depends on the format.
2607  * It is mostly relevant for devices that have an internal buffer and/or
2608  * work in real time.
2609  * @param s media file handle
2610  * @param stream stream in the media file
2611  * @param[out] dts DTS of the last packet output for the stream, in stream
2612  * time_base units
2613  * @param[out] wall absolute time when that packet whas output,
2614  * in microsecond
2615  * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
2616  * Note: some formats or devices may not allow to measure dts and wall
2617  * atomically.
2618  */
2619 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2620  int64_t *dts, int64_t *wall);
2621 
2622 
2623 /**
2624  * @}
2625  */
2626 
2627 
2628 /**
2629  * @defgroup lavf_misc Utility functions
2630  * @ingroup libavf
2631  * @{
2632  *
2633  * Miscellaneous utility functions related to both muxing and demuxing
2634  * (or neither).
2635  */
2636 
2637 /**
2638  * Send a nice hexadecimal dump of a buffer to the specified file stream.
2639  *
2640  * @param f The file stream pointer where the dump should be sent to.
2641  * @param buf buffer
2642  * @param size buffer size
2643  *
2644  * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2645  */
2646 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2647 
2648 /**
2649  * Send a nice hexadecimal dump of a buffer to the log.
2650  *
2651  * @param avcl A pointer to an arbitrary struct of which the first field is a
2652  * pointer to an AVClass struct.
2653  * @param level The importance level of the message, lower values signifying
2654  * higher importance.
2655  * @param buf buffer
2656  * @param size buffer size
2657  *
2658  * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2659  */
2660 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2661 
2662 /**
2663  * Send a nice dump of a packet to the specified file stream.
2664  *
2665  * @param f The file stream pointer where the dump should be sent to.
2666  * @param pkt packet to dump
2667  * @param dump_payload True if the payload must be displayed, too.
2668  * @param st AVStream that the packet belongs to
2669  */
2670 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2671 
2672 
2673 /**
2674  * Send a nice dump of a packet to the log.
2675  *
2676  * @param avcl A pointer to an arbitrary struct of which the first field is a
2677  * pointer to an AVClass struct.
2678  * @param level The importance level of the message, lower values signifying
2679  * higher importance.
2680  * @param pkt packet to dump
2681  * @param dump_payload True if the payload must be displayed, too.
2682  * @param st AVStream that the packet belongs to
2683  */
2684 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2685  const AVStream *st);
2686 
2687 /**
2688  * Get the AVCodecID for the given codec tag tag.
2689  * If no codec id is found returns AV_CODEC_ID_NONE.
2690  *
2691  * @param tags list of supported codec_id-codec_tag pairs, as stored
2692  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2693  * @param tag codec tag to match to a codec ID
2694  */
2695 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2696 
2697 /**
2698  * Get the codec tag for the given codec id id.
2699  * If no codec tag is found returns 0.
2700  *
2701  * @param tags list of supported codec_id-codec_tag pairs, as stored
2702  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2703  * @param id codec ID to match to a codec tag
2704  */
2705 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2706 
2707 /**
2708  * Get the codec tag for the given codec id.
2709  *
2710  * @param tags list of supported codec_id - codec_tag pairs, as stored
2711  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2712  * @param id codec id that should be searched for in the list
2713  * @param tag A pointer to the found tag
2714  * @return 0 if id was not found in tags, > 0 if it was found
2715  */
2716 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2717  unsigned int *tag);
2718 
2720 
2721 /**
2722  * Get the index for a specific timestamp.
2723  *
2724  * @param st stream that the timestamp belongs to
2725  * @param timestamp timestamp to retrieve the index for
2726  * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2727  * to the timestamp which is <= the requested one, if backward
2728  * is 0, then it will be >=
2729  * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2730  * @return < 0 if no such timestamp could be found
2731  */
2732 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2733 
2734 /**
2735  * Add an index entry into a sorted list. Update the entry if the list
2736  * already contains it.
2737  *
2738  * @param timestamp timestamp in the time base of the given stream
2739  */
2740 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2741  int size, int distance, int flags);
2742 
2743 
2744 /**
2745  * Split a URL string into components.
2746  *
2747  * The pointers to buffers for storing individual components may be null,
2748  * in order to ignore that component. Buffers for components not found are
2749  * set to empty strings. If the port is not found, it is set to a negative
2750  * value.
2751  *
2752  * @param proto the buffer for the protocol
2753  * @param proto_size the size of the proto buffer
2754  * @param authorization the buffer for the authorization
2755  * @param authorization_size the size of the authorization buffer
2756  * @param hostname the buffer for the host name
2757  * @param hostname_size the size of the hostname buffer
2758  * @param port_ptr a pointer to store the port number in
2759  * @param path the buffer for the path
2760  * @param path_size the size of the path buffer
2761  * @param url the URL to split
2762  */
2763 void av_url_split(char *proto, int proto_size,
2764  char *authorization, int authorization_size,
2765  char *hostname, int hostname_size,
2766  int *port_ptr,
2767  char *path, int path_size,
2768  const char *url);
2769 
2770 
2771 /**
2772  * Print detailed information about the input or output format, such as
2773  * duration, bitrate, streams, container, programs, metadata, side data,
2774  * codec and time base.
2775  *
2776  * @param ic the context to analyze
2777  * @param index index of the stream to dump information about
2778  * @param url the URL to print, such as source or destination file
2779  * @param is_output Select whether the specified context is an input(0) or output(1)
2780  */
2782  int index,
2783  const char *url,
2784  int is_output);
2785 
2786 
2787 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
2788 
2789 /**
2790  * Return in 'buf' the path with '%d' replaced by a number.
2791  *
2792  * Also handles the '%0nd' format where 'n' is the total number
2793  * of digits and '%%'.
2794  *
2795  * @param buf destination buffer
2796  * @param buf_size destination buffer size
2797  * @param path numbered sequence string
2798  * @param number frame number
2799  * @param flags AV_FRAME_FILENAME_FLAGS_*
2800  * @return 0 if OK, -1 on format error
2801  */
2802 int av_get_frame_filename2(char *buf, int buf_size,
2803  const char *path, int number, int flags);
2804 
2805 int av_get_frame_filename(char *buf, int buf_size,
2806  const char *path, int number);
2807 
2808 /**
2809  * Check whether filename actually is a numbered sequence generator.
2810  *
2811  * @param filename possible numbered sequence string
2812  * @return 1 if a valid numbered sequence string, 0 otherwise
2813  */
2814 int av_filename_number_test(const char *filename);
2815 
2816 /**
2817  * Generate an SDP for an RTP session.
2818  *
2819  * Note, this overwrites the id values of AVStreams in the muxer contexts
2820  * for getting unique dynamic payload types.
2821  *
2822  * @param ac array of AVFormatContexts describing the RTP streams. If the
2823  * array is composed by only one context, such context can contain
2824  * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2825  * all the contexts in the array (an AVCodecContext per RTP stream)
2826  * must contain only one AVStream.
2827  * @param n_files number of AVCodecContexts contained in ac
2828  * @param buf buffer where the SDP will be stored (must be allocated by
2829  * the caller)
2830  * @param size the size of the buffer
2831  * @return 0 if OK, AVERROR_xxx on error
2832  */
2833 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2834 
2835 /**
2836  * Return a positive value if the given filename has one of the given
2837  * extensions, 0 otherwise.
2838  *
2839  * @param filename file name to check against the given extensions
2840  * @param extensions a comma-separated list of filename extensions
2841  */
2842 int av_match_ext(const char *filename, const char *extensions);
2843 
2844 /**
2845  * Test if the given container can store a codec.
2846  *
2847  * @param ofmt container to check for compatibility
2848  * @param codec_id codec to potentially store in container
2849  * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2850  *
2851  * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2852  * A negative number if this information is not available.
2853  */
2855  int std_compliance);
2856 
2857 /**
2858  * @defgroup riff_fourcc RIFF FourCCs
2859  * @{
2860  * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2861  * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2862  * following code:
2863  * @code
2864  * uint32_t tag = MKTAG('H', '2', '6', '4');
2865  * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2866  * enum AVCodecID id = av_codec_get_id(table, tag);
2867  * @endcode
2868  */
2869 /**
2870  * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2871  */
2872 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2873 /**
2874  * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2875  */
2876 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2877 /**
2878  * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2879  */
2880 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2881 /**
2882  * @return the table mapping MOV FourCCs for audio to AVCodecID.
2883  */
2884 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2885 
2886 /**
2887  * @}
2888  */
2889 
2890 /**
2891  * Guess the sample aspect ratio of a frame, based on both the stream and the
2892  * frame aspect ratio.
2893  *
2894  * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2895  * is set by the demuxer, these two may not be equal. This function tries to
2896  * return the value that you should use if you would like to display the frame.
2897  *
2898  * Basic logic is to use the stream aspect ratio if it is set to something sane
2899  * otherwise use the frame aspect ratio. This way a container setting, which is
2900  * usually easy to modify can override the coded value in the frames.
2901  *
2902  * @param format the format context which the stream is part of
2903  * @param stream the stream which the frame is part of
2904  * @param frame the frame with the aspect ratio to be determined
2905  * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2906  */
2908 
2909 /**
2910  * Guess the frame rate, based on both the container and codec information.
2911  *
2912  * @param ctx the format context which the stream is part of
2913  * @param stream the stream which the frame is part of
2914  * @param frame the frame for which the frame rate should be determined, may be NULL
2915  * @return the guessed (valid) frame rate, 0/1 if no idea
2916  */
2918 
2919 /**
2920  * Check if the stream st contained in s is matched by the stream specifier
2921  * spec.
2922  *
2923  * See the "stream specifiers" chapter in the documentation for the syntax
2924  * of spec.
2925  *
2926  * @return >0 if st is matched by spec;
2927  * 0 if st is not matched by spec;
2928  * AVERROR code if spec is invalid
2929  *
2930  * @note A stream specifier can match several streams in the format.
2931  */
2933  const char *spec);
2934 
2936 
2937 #if FF_API_OLD_BSF
2938 /**
2939  * Apply a list of bitstream filters to a packet.
2940  *
2941  * @param codec AVCodecContext, usually from an AVStream
2942  * @param pkt the packet to apply filters to. If, on success, the returned
2943  * packet has size == 0 and side_data_elems == 0, it indicates that
2944  * the packet should be dropped
2945  * @param bsfc a NULL-terminated list of filters to apply
2946  * @return >=0 on success;
2947  * AVERROR code on failure
2948  */
2950 int av_apply_bitstream_filters(AVCodecContext *codec, AVPacket *pkt,
2951  AVBitStreamFilterContext *bsfc);
2952 #endif
2953 
2954 enum AVTimebaseSource {
2955  AVFMT_TBCF_AUTO = -1,
2958 #if FF_API_R_FRAME_RATE
2959  AVFMT_TBCF_R_FRAMERATE,
2960 #endif
2961 };
2962 
2963 /**
2964  * Transfer internal timing information from one stream to another.
2965  *
2966  * This function is useful when doing stream copy.
2967  *
2968  * @param ofmt target output format for ost
2969  * @param ost output stream which needs timings copy and adjustments
2970  * @param ist reference input stream to copy timings from
2971  * @param copy_tb define from where the stream codec timebase needs to be imported
2972  */
2974  AVStream *ost, const AVStream *ist,
2975  enum AVTimebaseSource copy_tb);
2976 
2977 /**
2978  * Get the internal codec timebase from a stream.
2979  *
2980  * @param st input stream to extract the timebase from
2981  */
2983 
2984 /**
2985  * @}
2986  */
2987 
2988 #endif /* AVFORMAT_AVFORMAT_H */
void av_url_split(char *proto, int proto_size, char *authorization, int authorization_size, char *hostname, int hostname_size, int *port_ptr, char *path, int path_size, const char *url)
Split a URL string into components.
Definition: utils.c:4725
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:703
int(* io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, AVDictionary **options)
A callback for opening new IO streams.
Definition: avformat.h:1833
full parsing and interpolation of timestamps for frames not starting on a packet boundary ...
Definition: avformat.h:801
Bytestream IO Context.
Definition: avio.h:161
void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st)
Send a nice dump of a packet to the specified file stream.
Definition: dump.c:110
Buffered I/O operations.
AVPacketSideDataType
Definition: packet.h:40
attribute_deprecated int av_demuxer_open(AVFormatContext *ic)
Definition: utils.c:390
This structure describes decoded (raw) audio or video data.
Definition: frame.h:314
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
Definition: mux.c:1236
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
static void flush(AVCodecContext *avctx)
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
Definition: utils.c:1984
int av_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file.
Definition: mux.c:1190
const char * filename
Definition: avformat.h:442
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame)
Guess the sample aspect ratio of a frame, based on both the stream and the frame aspect ratio...
Definition: utils.c:5045
enum AVCodecID video_codec
default video codec
Definition: avformat.h:511
GLint GLenum type
Definition: opengl_enc.c:104
int av_get_output_timestamp(struct AVFormatContext *s, int stream, int64_t *dts, int64_t *wall)
Get timing information for the data currently output.
Definition: mux.c:1296
int avformat_open_input(AVFormatContext **ps, const char *url, ff_const59 AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: utils.c:500
const char * key
static AVPacket pkt
int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index)
Test whether a muxer supports uncoded frame.
Definition: mux.c:1388
int av_probe_input_buffer(AVIOContext *pb, ff_const59 AVInputFormat **fmt, const char *url, void *logctx, unsigned int offset, unsigned int max_probe_size)
Like av_probe_input_buffer2() but returns 0 on success.
Definition: format.c:312
int priv_data_size
Size of private data so that it can be allocated in the wrapper.
Definition: avformat.h:705
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample format(the sample packing is implied by the sample format) and sample rate.The lists are not just lists
AVCodec.
Definition: codec.h:190
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext *ctx)
Returns the method used to set ctx->duration.
Definition: options.c:232
Format I/O context.
Definition: avformat.h:1239
AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame)
Guess the frame rate, based on both the container and codec information.
Definition: utils.c:5068
static int query_codec(enum AVCodecID id, int std_compliance)
Definition: img2enc.c:229
const struct AVCodecTag * avformat_get_mov_audio_tags(void)
Definition: isom.c:796
Public dictionary API.
static int64_t start_time
Definition: ffplay.c:332
uint8_t
static int nb_streams
Definition: ffprobe.c:282
const struct AVCodecTag * avformat_get_riff_video_tags(void)
Definition: riff.c:609
enum AVCodecID av_codec_get_id(const struct AVCodecTag *const *tags, unsigned int tag)
Get the AVCodecID for the given codec tag tag.
unsigned avformat_version(void)
Return the LIBAVFORMAT_VERSION_INT constant.
Definition: utils.c:62
const char * avformat_license(void)
Return the libavformat license.
Definition: utils.c:73
int avformat_transfer_internal_stream_timing_info(const AVOutputFormat *ofmt, AVStream *ost, const AVStream *ist, enum AVTimebaseSource copy_tb)
Transfer internal timing information from one stream to another.
Definition: utils.c:5704
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
#define f(width, name)
Definition: cbs_vp9.c:255
int priv_data_size
size of private data so that it can be allocated in the wrapper
Definition: avformat.h:552
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:92
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st, const char *spec)
Check if the stream st contained in s is matched by the stream specifier spec.
Definition: utils.c:5252
AVDurationEstimationMethod
The duration of a video can be estimated through various ways, and this enum can be used to know how ...
Definition: avformat.h:1217
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4453
uint8_t * av_stream_get_side_data(const AVStream *stream, enum AVPacketSideDataType type, int *size)
Get side information from stream.
Definition: utils.c:5431
int64_t duration
Definition: movenc.c:63
int av_codec_get_tag2(const struct AVCodecTag *const *tags, enum AVCodecID id, unsigned int *tag)
Get the codec tag for the given codec id.
AVFormatContext * avformat_alloc_context(void)
Allocate an AVFormatContext.
Definition: options.c:211
void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload, const AVStream *st)
Send a nice dump of a packet to the log.
Definition: dump.c:115
const char * avformat_configuration(void)
Return the libavformat build-time configuration.
Definition: utils.c:68
AVProgram * av_new_program(AVFormatContext *s, int id)
Definition: utils.c:4551
char * protocol_whitelist
&#39;,&#39; separated list of allowed protocols.
Definition: avformat.h:1811
uint32_t tag
Definition: movenc.c:1597
int avformat_network_init(void)
Do global initialization of network libraries.
Definition: utils.c:4982
const struct AVCodecTag * avformat_get_riff_audio_tags(void)
Definition: riff.c:614
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
Generate an SDP for an RTP session.
Definition: sdp.c:846
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:305
int av_match_ext(const char *filename, const char *extensions)
Return a positive value if the given filename has one of the given extensions, 0 otherwise.
Definition: format.c:38
const AVClass * avformat_get_class(void)
Get the AVClass for AVFormatContext.
Definition: options.c:237
ptrdiff_t size
Definition: opengl_enc.c:100
static int interleave_packet(AVFormatContext *s, AVPacket *out, AVPacket *in, int flush)
Interleave an AVPacket correctly so it can be muxed.
Definition: mux.c:1067
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:803
Duration estimated from bitrate (less accurate)
Definition: avformat.h:1220
int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
Read data and append it to the current content of the AVPacket.
Definition: utils.c:315
const AVOutputFormat * av_muxer_iterate(void **opaque)
Iterate over all registered muxers.
Definition: allformats.c:535
const struct AVCodecTag * avformat_get_mov_video_tags(void)
Definition: isom.c:791
void av_dump_format(AVFormatContext *ic, int index, const char *url, int is_output)
Print detailed information about the input or output format, such as duration, bitrate, streams, container, programs, metadata, side data, codec and time base.
Definition: dump.c:640
Callback for checking whether to abort blocking functions.
Definition: avio.h:58
int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type, int wanted_stream_nb, int related_stream, AVCodec **decoder_ret, int flags)
Find the "best" stream in the file.
Definition: utils.c:4176
#define ff_const59
The ff_const59 define is not part of the public API and will be removed without further warning...
Definition: avformat.h:544
AVRational av_stream_get_codec_timebase(const AVStream *st)
Get the internal codec timebase from a stream.
Definition: utils.c:5776
ff_const59 AVInputFormat * av_probe_input_format(ff_const59 AVProbeData *pd, int is_opened)
Guess the file format.
Definition: format.c:216
AVProgram * av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s)
Find the programs which belong to a given stream.
Definition: utils.c:4159
ff_const59 AVInputFormat * av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max)
Guess the file format.
Definition: format.c:205
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:46
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:2101
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:490
void av_hex_dump(FILE *f, const uint8_t *buf, int size)
Send a nice hexadecimal dump of a buffer to the specified file stream.
Definition: dump.c:76
struct AVCodecParser * parser
Definition: avcodec.h:3367
char * url
input or output URL.
Definition: avformat.h:1335
const char * r
Definition: vf_curves.c:114
unsigned int pos
Definition: spdifenc.c:410
struct AVCodecParserContext * av_stream_get_parser(const AVStream *s)
Definition: utils.c:145
int av_read_play(AVFormatContext *s)
Start playing a network-based stream (e.g.
Definition: utils.c:4244
ff_const59 AVInputFormat * av_find_input_format(const char *short_name)
Find AVInputFormat based on the short name of the input format.
Definition: format.c:118
int avformat_alloc_output_context2(AVFormatContext **ctx, ff_const59 AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
Definition: mux.c:135
int skip_estimate_duration_from_pts
Skip duration calcuation in estimate_timings_from_pts.
Definition: avformat.h:1860
New fields can be added to the end with minor version bumps.
Definition: avformat.h:1156
void * opaque
User data.
Definition: avformat.h:1757
Only parse headers, do not repack.
Definition: avformat.h:800
int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id, int std_compliance)
Test if the given container can store a codec.
Definition: utils.c:4964
static float distance(float x, float y, int band)
const char * mime_type
mime_type, when known.
Definition: avformat.h:445
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
void av_format_inject_global_side_data(AVFormatContext *s)
This function will cause global side data to be injected in the next packet of each stream as well as...
Definition: utils.c:150
int av_read_pause(AVFormatContext *s)
Pause a network-based stream (e.g.
Definition: utils.c:4253
static void callback(void *priv_data, int index, uint8_t *buf, int buf_size, int64_t time, enum dshowDeviceType devtype)
Definition: dshow.c:161
av_warn_unused_result int avformat_write_header(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and write the stream header to an output media file.
Definition: mux.c:505
void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx)
int(* av_format_control_message)(struct AVFormatContext *s, int type, void *data, size_t data_size)
Callback used by devices to communicate with application.
Definition: avformat.h:1207
int av_stream_add_side_data(AVStream *st, enum AVPacketSideDataType type, uint8_t *data, size_t size)
Wrap an existing array as stream side data.
Definition: utils.c:5448
int max_streams
The maximum number of streams.
Definition: avformat.h:1853
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
int av_find_default_stream_index(AVFormatContext *s)
Definition: utils.c:1825
static int write_trailer(AVFormatContext *s1)
Definition: v4l2enc.c:98
enum AVCodecID av_guess_codec(ff_const59 AVOutputFormat *fmt, const char *short_name, const char *filename, const char *mime_type, enum AVMediaType type)
Guess the codec ID based upon muxer and filename.
Definition: format.c:87
Duration estimated from a stream with a known duration.
Definition: avformat.h:1219
AVFormatContext * ctx
Definition: movenc.c:48
ff_const59 AVInputFormat * av_probe_input_format3(ff_const59 AVProbeData *pd, int is_opened, int *score_ret)
Guess the file format.
Definition: format.c:128
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
#define s(width, name)
Definition: cbs_vp9.c:257
uint8_t * av_stream_new_side_data(AVStream *stream, enum AVPacketSideDataType type, int size)
Allocate new information from stream.
Definition: utils.c:5484
enum AVCodecID codec_id
Definition: vaapi_decode.c:369
Libavformat version macros.
int(* AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Definition: avformat.h:1210
av_warn_unused_result int avformat_init_output(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and initialize the codec, but do not write the header.
Definition: mux.c:485
const AVInputFormat * av_demuxer_iterate(void **opaque)
Iterate over all registered demuxers.
Definition: allformats.c:552
int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
Definition: utils.c:4720
ff_const59 struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1258
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
Stream structure.
Definition: avformat.h:880
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
int avformat_queue_attached_pictures(AVFormatContext *s)
Definition: utils.c:442
int avformat_network_deinit(void)
Undo the initialization done by avformat_network_init.
Definition: utils.c:4994
static AVInputFormat * iformat
Definition: ffprobe.c:259
Libavcodec external API header.
int av_probe_input_buffer2(AVIOContext *pb, ff_const59 AVInputFormat **fmt, const char *url, void *logctx, unsigned int offset, unsigned int max_probe_size)
Probe a bytestream to determine the input format.
Definition: format.c:222
AVIOContext * pb
I/O context.
Definition: avformat.h:1281
main external API structure.
Definition: avcodec.h:531
int av_filename_number_test(const char *filename)
Check whether filename actually is a numbered sequence generator.
Definition: utils.c:322
int av_get_frame_filename2(char *buf, int buf_size, const char *path, int number, int flags)
Return in &#39;buf&#39; the path with &#39;d&#39; replaced by a number.
Definition: utils.c:4665
void(* io_close)(struct AVFormatContext *s, AVIOContext *pb)
A callback for closing the streams opened with AVFormatContext.io_open().
Definition: avformat.h:1839
static const AVClass av_class
Definition: options.c:134
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(const int16_t *) pi >> 8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(const int32_t *) pi >> 24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31))))#define SET_CONV_FUNC_GROUP(ofmt, ifmt) static void set_generic_function(AudioConvert *ac){}void ff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, int sample_rate, int apply_map){AudioConvert *ac;int in_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) return NULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method!=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt) > 2){ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc){av_free(ac);return NULL;}return ac;}in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar){ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar?ac->channels:1;}else if(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;else ac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);return ac;}int ff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){int use_generic=1;int len=in->nb_samples;int p;if(ac->dc){av_log(ac->avr, AV_LOG_TRACE,"%d samples - audio_convert: %s to %s (dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));return ff_convert_dither(ac-> in
Describe the class of an AVClass context structure.
Definition: log.h:67
int index
Definition: gxfenc.c:89
enum AVCodecID subtitle_codec
default subtitle codec
Definition: avformat.h:512
ff_const59 AVOutputFormat * av_guess_format(const char *short_name, const char *filename, const char *mime_type)
Return the output format in the list of registered output formats which best matches the provided par...
Definition: format.c:51
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVMediaType
Definition: avutil.h:199
int max_probe_packets
Maximum number of packets that can be probed.
Definition: avformat.h:1867
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: utils.c:4382
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1712
List of devices.
Definition: avdevice.h:460
AVTimebaseSource
Definition: avformat.h:2968
int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Seek to timestamp ts.
Definition: utils.c:2482
full parsing and repack of the first frame only, only implemented for H.264 currently ...
Definition: avformat.h:802
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:700
#define flags(name, subs,...)
Definition: cbs_av1.c:560
static int format_name(const char *buf, char **s, int index, const char *varname)
Definition: hlsenc.c:1896
uint8_t level
Definition: svq3.c:205
#define attribute_deprecated
Definition: attributes.h:100
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
Duration accurately estimated from PTSes.
Definition: avformat.h:1218
#define av_warn_unused_result
Definition: attributes.h:62
int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Seek to the keyframe at timestamp.
Definition: utils.c:2459
full parsing and repack
Definition: avformat.h:799
static AVStream * ost
int
const OptionDef options[]
Definition: ffmpeg_opt.c:3400
int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index, AVFrame *frame)
Write an uncoded frame to an output media file.
Definition: mux.c:1382
enum AVCodecID data_codec
default data codec
Definition: avformat.h:612
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: utils.c:3547
AVStreamParseType
Definition: avformat.h:797
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:4425
int av_write_uncoded_frame(AVFormatContext *s, int stream_index, AVFrame *frame)
Write an uncoded frame to an output media file.
Definition: mux.c:1376
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:510
static int check_bitstream(AVFormatContext *s, AVStream *st, AVPacket *pkt)
Definition: mux.c:1075
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:346
AVDiscard
Definition: avcodec.h:227
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
Definition: mux.c:1251
char * protocol_blacklist
&#39;,&#39; separated list of disallowed protocols.
Definition: avformat.h:1846
int avformat_flush(AVFormatContext *s)
Discard all internally buffered data.
Definition: utils.c:2539
FILE * out
Definition: movenc.c:54
int copy_tb
Definition: ffmpeg_opt.c:164
void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size)
Send a nice hexadecimal dump of a buffer to the log.
Definition: dump.c:81
unsigned int av_codec_get_tag(const struct AVCodecTag *const *tags, enum AVCodecID id)
Get the codec tag for the given codec id id.
enum AVCodecID id
Following API allows user to probe device capabilities (supported codecs, pixel formats, sample formats, resolutions, channel counts, etc).
Definition: avdevice.h:400
This structure stores compressed data.
Definition: packet.h:340
int64_t av_stream_get_end_pts(const AVStream *st)
Returns the pts of the last muxed packet + its duration.
Definition: utils.c:137
const char * name
Definition: opengl_enc.c:102