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 
313 #include "libavcodec/codec.h"
314 #include "libavcodec/codec_par.h"
315 #include "libavcodec/defs.h"
316 #include "libavcodec/packet.h"
317 
318 #include "libavutil/dict.h"
319 #include "libavutil/log.h"
320 
321 #include "avio.h"
322 #include "libavformat/version.h"
323 
324 struct AVFormatContext;
325 struct AVStream;
326 
327 struct AVDeviceInfoList;
329 
330 /**
331  * @defgroup metadata_api Public Metadata API
332  * @{
333  * @ingroup libavf
334  * The metadata API allows libavformat to export metadata tags to a client
335  * application when demuxing. Conversely it allows a client application to
336  * set metadata when muxing.
337  *
338  * Metadata is exported or set as pairs of key/value strings in the 'metadata'
339  * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
340  * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
341  * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
342  * exported by demuxers isn't checked to be valid UTF-8 in most cases.
343  *
344  * Important concepts to keep in mind:
345  * - Keys are unique; there can never be 2 tags with the same key. This is
346  * also meant semantically, i.e., a demuxer should not knowingly produce
347  * several keys that are literally different but semantically identical.
348  * E.g., key=Author5, key=Author6. In this example, all authors must be
349  * placed in the same tag.
350  * - Metadata is flat, not hierarchical; there are no subtags. If you
351  * want to store, e.g., the email address of the child of producer Alice
352  * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
353  * - Several modifiers can be applied to the tag name. This is done by
354  * appending a dash character ('-') and the modifier name in the order
355  * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
356  * - language -- a tag whose value is localized for a particular language
357  * is appended with the ISO 639-2/B 3-letter language code.
358  * For example: Author-ger=Michael, Author-eng=Mike
359  * The original/default language is in the unqualified "Author" tag.
360  * A demuxer should set a default if it sets any translated tag.
361  * - sorting -- a modified version of a tag that should be used for
362  * sorting will have '-sort' appended. E.g. artist="The Beatles",
363  * artist-sort="Beatles, The".
364  * - Some protocols and demuxers support metadata updates. After a successful
365  * call to av_read_frame(), AVFormatContext.event_flags or AVStream.event_flags
366  * will be updated to indicate if metadata changed. In order to detect metadata
367  * changes on a stream, you need to loop through all streams in the AVFormatContext
368  * and check their individual event_flags.
369  *
370  * - Demuxers attempt to export metadata in a generic format, however tags
371  * with no generic equivalents are left as they are stored in the container.
372  * Follows a list of generic tag names:
373  *
374  @verbatim
375  album -- name of the set this work belongs to
376  album_artist -- main creator of the set/album, if different from artist.
377  e.g. "Various Artists" for compilation albums.
378  artist -- main creator of the work
379  comment -- any additional description of the file.
380  composer -- who composed the work, if different from artist.
381  copyright -- name of copyright holder.
382  creation_time-- date when the file was created, preferably in ISO 8601.
383  date -- date when the work was created, preferably in ISO 8601.
384  disc -- number of a subset, e.g. disc in a multi-disc collection.
385  encoder -- name/settings of the software/hardware that produced the file.
386  encoded_by -- person/group who created the file.
387  filename -- original name of the file.
388  genre -- <self-evident>.
389  language -- main language in which the work is performed, preferably
390  in ISO 639-2 format. Multiple languages can be specified by
391  separating them with commas.
392  performer -- artist who performed the work, if different from artist.
393  E.g for "Also sprach Zarathustra", artist would be "Richard
394  Strauss" and performer "London Philharmonic Orchestra".
395  publisher -- name of the label/publisher.
396  service_name -- name of the service in broadcasting (channel name).
397  service_provider -- name of the service provider in broadcasting.
398  title -- name of the work.
399  track -- number of this work in the set, can be in form current/total.
400  variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
401  @endverbatim
402  *
403  * Look in the examples section for an application example how to use the Metadata API.
404  *
405  * @}
406  */
407 
408 /* packet functions */
409 
410 
411 /**
412  * Allocate and read the payload of a packet and initialize its
413  * fields with default values.
414  *
415  * @param s associated IO context
416  * @param pkt packet
417  * @param size desired payload size
418  * @return >0 (read size) if OK, AVERROR_xxx otherwise
419  */
421 
422 
423 /**
424  * Read data and append it to the current content of the AVPacket.
425  * If pkt->size is 0 this is identical to av_get_packet.
426  * Note that this uses av_grow_packet and thus involves a realloc
427  * which is inefficient. Thus this function should only be used
428  * when there is no reasonable way to know (an upper bound of)
429  * the final size.
430  *
431  * @param s associated IO context
432  * @param pkt packet
433  * @param size amount of data to read
434  * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
435  * will not be lost even if an error occurs.
436  */
438 
439 /*************************************************/
440 /* input/output formats */
441 
442 struct AVCodecTag;
443 
444 /**
445  * This structure contains the data a format has to probe a file.
446  */
447 typedef struct AVProbeData {
448  const char *filename;
449  unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
450  int buf_size; /**< Size of buf except extra allocated bytes */
451  const char *mime_type; /**< mime_type, when known. */
452 } AVProbeData;
453 
454 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
455 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
456 
457 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
458 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type
459 #define AVPROBE_SCORE_MAX 100 ///< maximum score
460 
461 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
462 
463 /// Demuxer will use avio_open, no opened file should be provided by the caller.
464 #define AVFMT_NOFILE 0x0001
465 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
466 /**
467  * The muxer/demuxer is experimental and should be used with caution.
468  *
469  * - demuxers: will not be selected automatically by probing, must be specified
470  * explicitly.
471  */
472 #define AVFMT_EXPERIMENTAL 0x0004
473 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
474 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
475 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
476 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
477 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
478 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
479 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
480 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
481 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
482 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
483 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
484 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
485 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
486  increasing timestamps, but they must
487  still be monotonic */
488 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
489  timestamps. If not set the timestamp
490  will be shifted in av_write_frame and
491  av_interleaved_write_frame so they
492  start from 0.
493  The user or muxer can override this through
494  AVFormatContext.avoid_negative_ts
495  */
496 
497 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
498 
499 /**
500  * @addtogroup lavf_encoding
501  * @{
502  */
503 typedef struct AVOutputFormat {
504  const char *name;
505  /**
506  * Descriptive name for the format, meant to be more human-readable
507  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
508  * to define it.
509  */
510  const char *long_name;
511  const char *mime_type;
512  const char *extensions; /**< comma-separated filename extensions */
513  /* output support */
514  enum AVCodecID audio_codec; /**< default audio codec */
515  enum AVCodecID video_codec; /**< default video codec */
516  enum AVCodecID subtitle_codec; /**< default subtitle codec */
517  /**
518  * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER,
519  * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
520  * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
521  * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
522  */
523  int flags;
524 
525  /**
526  * List of supported codec_id-codec_tag pairs, ordered by "better
527  * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
528  */
529  const struct AVCodecTag * const *codec_tag;
530 
531 
532  const AVClass *priv_class; ///< AVClass for the private context
533 
534  /*****************************************************************
535  * No fields below this line are part of the public API. They
536  * may not be used outside of libavformat and can be changed and
537  * removed at will.
538  * New public fields should be added right above.
539  *****************************************************************
540  */
541  /**
542  * size of private data so that it can be allocated in the wrapper
543  */
545 
546  /**
547  * Internal flags. See FF_FMT_FLAG_* in internal.h.
548  */
550 
552  /**
553  * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
554  * pkt can be NULL in order to flush data buffered in the muxer.
555  * When flushing, return 0 if there still is more data to flush,
556  * or 1 if everything was flushed and there is no more buffered
557  * data.
558  */
561  /**
562  * A format-specific function for interleavement.
563  * If unset, packets will be interleaved by dts.
564  *
565  * @param s An AVFormatContext for output. pkt will be added to
566  * resp. taken from its packet buffer.
567  * @param[in,out] pkt A packet to be interleaved if has_packet is set;
568  * also used to return packets. If no packet is returned
569  * (e.g. on error), pkt is blank on return.
570  * @param flush 1 if no further packets are available as input and
571  * all remaining packets should be output.
572  * @param has_packet If set, pkt contains a packet to be interleaved
573  * on input; otherwise pkt is blank on input.
574  * @return 1 if a packet was output, 0 if no packet could be output,
575  * < 0 if an error occurred
576  */
578  int flush, int has_packet);
579  /**
580  * Test if the given codec can be stored in this container.
581  *
582  * @return 1 if the codec is supported, 0 if it is not.
583  * A negative number if unknown.
584  * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
585  */
586  int (*query_codec)(enum AVCodecID id, int std_compliance);
587 
588  void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
589  int64_t *dts, int64_t *wall);
590  /**
591  * Allows sending messages from application to device.
592  */
594  void *data, size_t data_size);
595 
596  /**
597  * Write an uncoded AVFrame.
598  *
599  * See av_write_uncoded_frame() for details.
600  *
601  * The library will free *frame afterwards, but the muxer can prevent it
602  * by setting the pointer to NULL.
603  */
604  int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
605  AVFrame **frame, unsigned flags);
606  /**
607  * Returns device list with it properties.
608  * @see avdevice_list_devices() for more details.
609  */
610  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
611  enum AVCodecID data_codec; /**< default data codec */
612  /**
613  * Initialize format. May allocate data here, and set any AVFormatContext or
614  * AVStream parameters that need to be set before packets are sent.
615  * This method must not write output.
616  *
617  * Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure
618  *
619  * Any allocations made here must be freed in deinit().
620  */
621  int (*init)(struct AVFormatContext *);
622  /**
623  * Deinitialize format. If present, this is called whenever the muxer is being
624  * destroyed, regardless of whether or not the header has been written.
625  *
626  * If a trailer is being written, this is called after write_trailer().
627  *
628  * This is called if init() fails as well.
629  */
630  void (*deinit)(struct AVFormatContext *);
631  /**
632  * Set up any necessary bitstream filtering and extract any extra data needed
633  * for the global header.
634  *
635  * @note pkt might have been directly forwarded by a meta-muxer; therefore
636  * pkt->stream_index as well as the pkt's timebase might be invalid.
637  * Return 0 if more packets from this stream must be checked; 1 if not.
638  */
639  int (*check_bitstream)(struct AVFormatContext *s, struct AVStream *st,
640  const AVPacket *pkt);
642 /**
643  * @}
644  */
645 
646 /**
647  * @addtogroup lavf_decoding
648  * @{
649  */
650 typedef struct AVInputFormat {
651  /**
652  * A comma separated list of short names for the format. New names
653  * may be appended with a minor bump.
654  */
655  const char *name;
656 
657  /**
658  * Descriptive name for the format, meant to be more human-readable
659  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
660  * to define it.
661  */
662  const char *long_name;
663 
664  /**
665  * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
666  * AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
667  * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
668  */
669  int flags;
670 
671  /**
672  * If extensions are defined, then no probe is done. You should
673  * usually not use extension format guessing because it is not
674  * reliable enough
675  */
676  const char *extensions;
677 
678  const struct AVCodecTag * const *codec_tag;
679 
680  const AVClass *priv_class; ///< AVClass for the private context
681 
682  /**
683  * Comma-separated list of mime types.
684  * It is used check for matching mime types while probing.
685  * @see av_probe_input_format2
686  */
687  const char *mime_type;
688 
689  /*****************************************************************
690  * No fields below this line are part of the public API. They
691  * may not be used outside of libavformat and can be changed and
692  * removed at will.
693  * New public fields should be added right above.
694  *****************************************************************
695  */
696  /**
697  * Raw demuxers store their codec ID here.
698  */
700 
701  /**
702  * Size of private data so that it can be allocated in the wrapper.
703  */
705 
706  /**
707  * Internal flags. See FF_FMT_FLAG_* in internal.h.
708  */
710 
711  /**
712  * Tell if a given file has a chance of being parsed as this format.
713  * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
714  * big so you do not have to check for that unless you need more.
715  */
717 
718  /**
719  * Read the format header and initialize the AVFormatContext
720  * structure. Return 0 if OK. 'avformat_new_stream' should be
721  * called to create new streams.
722  */
724 
725  /**
726  * Read one packet and put it in 'pkt'. pts and flags are also
727  * set. 'avformat_new_stream' can be called only if the flag
728  * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
729  * background thread).
730  * @return 0 on success, < 0 on error.
731  * Upon returning an error, pkt must be unreferenced by the caller.
732  */
734 
735  /**
736  * Close the stream. The AVFormatContext and AVStreams are not
737  * freed by this function
738  */
740 
741  /**
742  * Seek to a given timestamp relative to the frames in
743  * stream component stream_index.
744  * @param stream_index Must not be -1.
745  * @param flags Selects which direction should be preferred if no exact
746  * match is available.
747  * @return >= 0 on success (but not necessarily the new offset)
748  */
750  int stream_index, int64_t timestamp, int flags);
751 
752  /**
753  * Get the next timestamp in stream[stream_index].time_base units.
754  * @return the timestamp or AV_NOPTS_VALUE if an error occurred
755  */
756  int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
757  int64_t *pos, int64_t pos_limit);
758 
759  /**
760  * Start/resume playing - only meaningful if using a network-based format
761  * (RTSP).
762  */
764 
765  /**
766  * Pause playing - only meaningful if using a network-based format
767  * (RTSP).
768  */
770 
771  /**
772  * Seek to timestamp ts.
773  * Seeking will be done so that the point from which all active streams
774  * can be presented successfully will be closest to ts and within min/max_ts.
775  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
776  */
777  int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
778 
779  /**
780  * Returns device list with it properties.
781  * @see avdevice_list_devices() for more details.
782  */
783  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
784 
785 } AVInputFormat;
786 /**
787  * @}
788  */
789 
792  AVSTREAM_PARSE_FULL, /**< full parsing and repack */
793  AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
794  AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
795  AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
796  AVSTREAM_PARSE_FULL_RAW, /**< full parsing and repack with timestamp and position generation by parser for raw
797  this assumes that each packet in the file contains no demuxer level headers and
798  just codec level data, otherwise position generation would fail */
799 };
800 
801 typedef struct AVIndexEntry {
802  int64_t pos;
803  int64_t timestamp; /**<
804  * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
805  * when seeking to this entry. That means preferable PTS on keyframe based formats.
806  * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
807  * is known
808  */
809 #define AVINDEX_KEYFRAME 0x0001
810 #define AVINDEX_DISCARD_FRAME 0x0002 /**
811  * Flag is used to indicate which frame should be discarded after decoding.
812  */
813  int flags:2;
814  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).
815  int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
816 } AVIndexEntry;
817 
818 /**
819  * The stream should be chosen by default among other streams of the same type,
820  * unless the user has explicitly specified otherwise.
821  */
822 #define AV_DISPOSITION_DEFAULT (1 << 0)
823 /**
824  * The stream is not in original language.
825  *
826  * @note AV_DISPOSITION_ORIGINAL is the inverse of this disposition. At most
827  * one of them should be set in properly tagged streams.
828  * @note This disposition may apply to any stream type, not just audio.
829  */
830 #define AV_DISPOSITION_DUB (1 << 1)
831 /**
832  * The stream is in original language.
833  *
834  * @see the notes for AV_DISPOSITION_DUB
835  */
836 #define AV_DISPOSITION_ORIGINAL (1 << 2)
837 /**
838  * The stream is a commentary track.
839  */
840 #define AV_DISPOSITION_COMMENT (1 << 3)
841 /**
842  * The stream contains song lyrics.
843  */
844 #define AV_DISPOSITION_LYRICS (1 << 4)
845 /**
846  * The stream contains karaoke audio.
847  */
848 #define AV_DISPOSITION_KARAOKE (1 << 5)
849 
850 /**
851  * Track should be used during playback by default.
852  * Useful for subtitle track that should be displayed
853  * even when user did not explicitly ask for subtitles.
854  */
855 #define AV_DISPOSITION_FORCED (1 << 6)
856 /**
857  * The stream is intended for hearing impaired audiences.
858  */
859 #define AV_DISPOSITION_HEARING_IMPAIRED (1 << 7)
860 /**
861  * The stream is intended for visually impaired audiences.
862  */
863 #define AV_DISPOSITION_VISUAL_IMPAIRED (1 << 8)
864 /**
865  * The audio stream contains music and sound effects without voice.
866  */
867 #define AV_DISPOSITION_CLEAN_EFFECTS (1 << 9)
868 /**
869  * The stream is stored in the file as an attached picture/"cover art" (e.g.
870  * APIC frame in ID3v2). The first (usually only) packet associated with it
871  * will be returned among the first few packets read from the file unless
872  * seeking takes place. It can also be accessed at any time in
873  * AVStream.attached_pic.
874  */
875 #define AV_DISPOSITION_ATTACHED_PIC (1 << 10)
876 /**
877  * The stream is sparse, and contains thumbnail images, often corresponding
878  * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
879  */
880 #define AV_DISPOSITION_TIMED_THUMBNAILS (1 << 11)
881 
882 /**
883  * The subtitle stream contains captions, providing a transcription and possibly
884  * a translation of audio. Typically intended for hearing-impaired audiences.
885  */
886 #define AV_DISPOSITION_CAPTIONS (1 << 16)
887 /**
888  * The subtitle stream contains a textual description of the video content.
889  * Typically intended for visually-impaired audiences or for the cases where the
890  * video cannot be seen.
891  */
892 #define AV_DISPOSITION_DESCRIPTIONS (1 << 17)
893 /**
894  * The subtitle stream contains time-aligned metadata that is not intended to be
895  * directly presented to the user.
896  */
897 #define AV_DISPOSITION_METADATA (1 << 18)
898 /**
899  * The audio stream is intended to be mixed with another stream before
900  * presentation.
901  * Corresponds to mix_type=0 in mpegts.
902  */
903 #define AV_DISPOSITION_DEPENDENT (1 << 19)
904 /**
905  * The video stream contains still images.
906  */
907 #define AV_DISPOSITION_STILL_IMAGE (1 << 20)
908 
909 /**
910  * @return The AV_DISPOSITION_* flag corresponding to disp or a negative error
911  * code if disp does not correspond to a known stream disposition.
912  */
913 int av_disposition_from_string(const char *disp);
914 
915 /**
916  * @param disposition a combination of AV_DISPOSITION_* values
917  * @return The string description corresponding to the lowest set bit in
918  * disposition. NULL when the lowest set bit does not correspond
919  * to a known disposition or when disposition is 0.
920  */
921 const char *av_disposition_to_string(int disposition);
922 
923 /**
924  * Options for behavior on timestamp wrap detection.
925  */
926 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
927 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
928 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
929 
930 /**
931  * Stream structure.
932  * New fields can be added to the end with minor version bumps.
933  * Removal, reordering and changes to existing fields require a major
934  * version bump.
935  * sizeof(AVStream) must not be used outside libav*.
936  */
937 typedef struct AVStream {
938 #if FF_API_AVSTREAM_CLASS
939  /**
940  * A class for @ref avoptions. Set on stream creation.
941  */
942  const AVClass *av_class;
943 #endif
944 
945  int index; /**< stream index in AVFormatContext */
946  /**
947  * Format-specific stream ID.
948  * decoding: set by libavformat
949  * encoding: set by the user, replaced by libavformat if left unset
950  */
951  int id;
952 
953  void *priv_data;
954 
955  /**
956  * This is the fundamental unit of time (in seconds) in terms
957  * of which frame timestamps are represented.
958  *
959  * decoding: set by libavformat
960  * encoding: May be set by the caller before avformat_write_header() to
961  * provide a hint to the muxer about the desired timebase. In
962  * avformat_write_header(), the muxer will overwrite this field
963  * with the timebase that will actually be used for the timestamps
964  * written into the file (which may or may not be related to the
965  * user-provided one, depending on the format).
966  */
968 
969  /**
970  * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
971  * Only set this if you are absolutely 100% sure that the value you set
972  * it to really is the pts of the first frame.
973  * This may be undefined (AV_NOPTS_VALUE).
974  * @note The ASF header does NOT contain a correct start_time the ASF
975  * demuxer must NOT set this.
976  */
977  int64_t start_time;
978 
979  /**
980  * Decoding: duration of the stream, in stream time base.
981  * If a source file does not specify a duration, but does specify
982  * a bitrate, this value will be estimated from bitrate and file size.
983  *
984  * Encoding: May be set by the caller before avformat_write_header() to
985  * provide a hint to the muxer about the estimated duration.
986  */
987  int64_t duration;
988 
989  int64_t nb_frames; ///< number of frames in this stream if known or 0
990 
991  /**
992  * Stream disposition - a combination of AV_DISPOSITION_* flags.
993  * - demuxing: set by libavformat when creating the stream or in
994  * avformat_find_stream_info().
995  * - muxing: may be set by the caller before avformat_write_header().
996  */
998 
999  enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
1000 
1001  /**
1002  * sample aspect ratio (0 if unknown)
1003  * - encoding: Set by user.
1004  * - decoding: Set by libavformat.
1005  */
1007 
1009 
1010  /**
1011  * Average framerate
1012  *
1013  * - demuxing: May be set by libavformat when creating the stream or in
1014  * avformat_find_stream_info().
1015  * - muxing: May be set by the caller before avformat_write_header().
1016  */
1018 
1019  /**
1020  * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
1021  * will contain the attached picture.
1022  *
1023  * decoding: set by libavformat, must not be modified by the caller.
1024  * encoding: unused
1025  */
1027 
1028  /**
1029  * An array of side data that applies to the whole stream (i.e. the
1030  * container does not allow it to change between packets).
1031  *
1032  * There may be no overlap between the side data in this array and side data
1033  * in the packets. I.e. a given side data is either exported by the muxer
1034  * (demuxing) / set by the caller (muxing) in this array, then it never
1035  * appears in the packets, or the side data is exported / sent through
1036  * the packets (always in the first packet where the value becomes known or
1037  * changes), then it does not appear in this array.
1038  *
1039  * - demuxing: Set by libavformat when the stream is created.
1040  * - muxing: May be set by the caller before avformat_write_header().
1041  *
1042  * Freed by libavformat in avformat_free_context().
1043  *
1044  * @see av_format_inject_global_side_data()
1045  */
1047  /**
1048  * The number of elements in the AVStream.side_data array.
1049  */
1050  int nb_side_data;
1051 
1052  /**
1053  * Flags indicating events happening on the stream, a combination of
1054  * AVSTREAM_EVENT_FLAG_*.
1055  *
1056  * - demuxing: may be set by the demuxer in avformat_open_input(),
1057  * avformat_find_stream_info() and av_read_frame(). Flags must be cleared
1058  * by the user once the event has been handled.
1059  * - muxing: may be set by the user after avformat_write_header(). to
1060  * indicate a user-triggered event. The muxer will clear the flags for
1061  * events it has handled in av_[interleaved]_write_frame().
1062  */
1063  int event_flags;
1064 /**
1065  * - demuxing: the demuxer read new metadata from the file and updated
1066  * AVStream.metadata accordingly
1067  * - muxing: the user updated AVStream.metadata and wishes the muxer to write
1068  * it into the file
1069  */
1070 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001
1071 /**
1072  * - demuxing: new packets for this stream were read from the file. This
1073  * event is informational only and does not guarantee that new packets
1074  * for this stream will necessarily be returned from av_read_frame().
1075  */
1076 #define AVSTREAM_EVENT_FLAG_NEW_PACKETS (1 << 1)
1077 
1078  /**
1079  * Real base framerate of the stream.
1080  * This is the lowest framerate with which all timestamps can be
1081  * represented accurately (it is the least common multiple of all
1082  * framerates in the stream). Note, this value is just a guess!
1083  * For example, if the time base is 1/90000 and all frames have either
1084  * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
1085  */
1087 
1088  /**
1089  * Codec parameters associated with this stream. Allocated and freed by
1090  * libavformat in avformat_new_stream() and avformat_free_context()
1091  * respectively.
1092  *
1093  * - demuxing: filled by libavformat on stream creation or in
1094  * avformat_find_stream_info()
1095  * - muxing: filled by the caller before avformat_write_header()
1096  */
1098 
1099  /**
1100  * Number of bits in timestamps. Used for wrapping control.
1101  *
1102  * - demuxing: set by libavformat
1103  * - muxing: set by libavformat
1104  *
1105  */
1106  int pts_wrap_bits;
1107 } AVStream;
1108 
1110 
1111 /**
1112  * Returns the pts of the last muxed packet + its duration
1113  *
1114  * the retuned value is undefined when used with a demuxer.
1115  */
1116 int64_t av_stream_get_end_pts(const AVStream *st);
1117 
1118 #define AV_PROGRAM_RUNNING 1
1119 
1120 /**
1121  * New fields can be added to the end with minor version bumps.
1122  * Removal, reordering and changes to existing fields require a major
1123  * version bump.
1124  * sizeof(AVProgram) must not be used outside libav*.
1125  */
1126 typedef struct AVProgram {
1127  int id;
1128  int flags;
1129  enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1130  unsigned int *stream_index;
1131  unsigned int nb_stream_indexes;
1135  int pmt_pid;
1136  int pcr_pid;
1137  int pmt_version;
1138 
1139  /*****************************************************************
1140  * All fields below this line are not part of the public API. They
1141  * may not be used outside of libavformat and can be changed and
1142  * removed at will.
1143  * New public fields should be added right above.
1144  *****************************************************************
1145  */
1146  int64_t start_time;
1147  int64_t end_time;
1149  int64_t pts_wrap_reference; ///< reference dts for wrap detection
1150  int pts_wrap_behavior; ///< behavior on wrap detection
1152 
1153 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1154  (streams are added dynamically) */
1155 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely
1156  not seekable, and attempts to call the
1157  seek function will fail. For some
1158  network protocols (e.g. HLS), this can
1159  change dynamically at runtime. */
1161 typedef struct AVChapter {
1162  int64_t id; ///< unique ID to identify the chapter
1163  AVRational time_base; ///< time base in which the start/end timestamps are specified
1164  int64_t start, end; ///< chapter start/end time in time_base units
1166 } AVChapter;
1167 
1168 
1169 /**
1170  * Callback used by devices to communicate with application.
1171  */
1172 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1173  void *data, size_t data_size);
1174 
1175 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
1177 
1178 /**
1179  * The duration of a video can be estimated through various ways, and this enum can be used
1180  * to know how the duration was estimated.
1181  */
1183  AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1184  AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1185  AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1186 };
1187 
1188 /**
1189  * Format I/O context.
1190  * New fields can be added to the end with minor version bumps.
1191  * Removal, reordering and changes to existing fields require a major
1192  * version bump.
1193  * sizeof(AVFormatContext) must not be used outside libav*, use
1194  * avformat_alloc_context() to create an AVFormatContext.
1195  *
1196  * Fields can be accessed through AVOptions (av_opt*),
1197  * the name string used matches the associated command line parameter name and
1198  * can be found in libavformat/options_table.h.
1199  * The AVOption/command line parameter names differ in some cases from the C
1200  * structure field names for historic reasons or brevity.
1201  */
1202 typedef struct AVFormatContext {
1203  /**
1204  * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1205  * Exports (de)muxer private options if they exist.
1206  */
1207  const AVClass *av_class;
1208 
1209  /**
1210  * The input container format.
1211  *
1212  * Demuxing only, set by avformat_open_input().
1213  */
1214  const struct AVInputFormat *iformat;
1215 
1216  /**
1217  * The output container format.
1218  *
1219  * Muxing only, must be set by the caller before avformat_write_header().
1220  */
1221  const struct AVOutputFormat *oformat;
1222 
1223  /**
1224  * Format private data. This is an AVOptions-enabled struct
1225  * if and only if iformat/oformat.priv_class is not NULL.
1226  *
1227  * - muxing: set by avformat_write_header()
1228  * - demuxing: set by avformat_open_input()
1229  */
1230  void *priv_data;
1231 
1232  /**
1233  * I/O context.
1234  *
1235  * - demuxing: either set by the user before avformat_open_input() (then
1236  * the user must close it manually) or set by avformat_open_input().
1237  * - muxing: set by the user before avformat_write_header(). The caller must
1238  * take care of closing / freeing the IO context.
1239  *
1240  * Do NOT set this field if AVFMT_NOFILE flag is set in
1241  * iformat/oformat.flags. In such a case, the (de)muxer will handle
1242  * I/O in some other way and this field will be NULL.
1243  */
1244  AVIOContext *pb;
1245 
1246  /* stream info */
1247  /**
1248  * Flags signalling stream properties. A combination of AVFMTCTX_*.
1249  * Set by libavformat.
1250  */
1251  int ctx_flags;
1252 
1253  /**
1254  * Number of elements in AVFormatContext.streams.
1255  *
1256  * Set by avformat_new_stream(), must not be modified by any other code.
1257  */
1258  unsigned int nb_streams;
1259  /**
1260  * A list of all streams in the file. New streams are created with
1261  * avformat_new_stream().
1262  *
1263  * - demuxing: streams are created by libavformat in avformat_open_input().
1264  * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1265  * appear in av_read_frame().
1266  * - muxing: streams are created by the user before avformat_write_header().
1267  *
1268  * Freed by libavformat in avformat_free_context().
1269  */
1270  AVStream **streams;
1271 
1272  /**
1273  * input or output URL. Unlike the old filename field, this field has no
1274  * length restriction.
1275  *
1276  * - demuxing: set by avformat_open_input(), initialized to an empty
1277  * string if url parameter was NULL in avformat_open_input().
1278  * - muxing: may be set by the caller before calling avformat_write_header()
1279  * (or avformat_init_output() if that is called first) to a string
1280  * which is freeable by av_free(). Set to an empty string if it
1281  * was NULL in avformat_init_output().
1282  *
1283  * Freed by libavformat in avformat_free_context().
1284  */
1285  char *url;
1286 
1287  /**
1288  * Position of the first frame of the component, in
1289  * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1290  * It is deduced from the AVStream values.
1291  *
1292  * Demuxing only, set by libavformat.
1293  */
1294  int64_t start_time;
1295 
1296  /**
1297  * Duration of the stream, in AV_TIME_BASE fractional
1298  * seconds. Only set this value if you know none of the individual stream
1299  * durations and also do not set any of them. This is deduced from the
1300  * AVStream values if not set.
1301  *
1302  * Demuxing only, set by libavformat.
1303  */
1304  int64_t duration;
1305 
1306  /**
1307  * Total stream bitrate in bit/s, 0 if not
1308  * available. Never set it directly if the file_size and the
1309  * duration are known as FFmpeg can compute it automatically.
1310  */
1311  int64_t bit_rate;
1313  unsigned int packet_size;
1314  int max_delay;
1315 
1316  /**
1317  * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1318  * Set by the user before avformat_open_input() / avformat_write_header().
1319  */
1320  int flags;
1321 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1322 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1323 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1324 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1325 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1326 #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
1327 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1328 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1329 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1330 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1331 /**
1332  * When muxing, try to avoid writing any random/volatile data to the output.
1333  * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1334  *
1335  * This flag is mainly intended for testing.
1336  */
1337 #define AVFMT_FLAG_BITEXACT 0x0400
1338 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1339 #if FF_API_LAVF_PRIV_OPT
1340 #define AVFMT_FLAG_PRIV_OPT 0x20000 ///< Enable use of private options by delaying codec open (deprecated, does nothing)
1341 #endif
1342 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1343 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
1344 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
1345 
1346  /**
1347  * Maximum number of bytes read from input in order to determine stream
1348  * properties. Used when reading the global header and in
1349  * avformat_find_stream_info().
1350  *
1351  * Demuxing only, set by the caller before avformat_open_input().
1352  *
1353  * @note this is \e not used for determining the \ref AVInputFormat
1354  * "input format"
1355  * @sa format_probesize
1356  */
1357  int64_t probesize;
1358 
1359  /**
1360  * Maximum duration (in AV_TIME_BASE units) of the data read
1361  * from input in avformat_find_stream_info().
1362  * Demuxing only, set by the caller before avformat_find_stream_info().
1363  * Can be set to 0 to let avformat choose using a heuristic.
1364  */
1367  const uint8_t *key;
1368  int keylen;
1370  unsigned int nb_programs;
1371  AVProgram **programs;
1372 
1373  /**
1374  * Forced video codec_id.
1375  * Demuxing: Set by user.
1376  */
1378 
1379  /**
1380  * Forced audio codec_id.
1381  * Demuxing: Set by user.
1382  */
1384 
1385  /**
1386  * Forced subtitle codec_id.
1387  * Demuxing: Set by user.
1388  */
1390 
1391  /**
1392  * Maximum amount of memory in bytes to use for the index of each stream.
1393  * If the index exceeds this size, entries will be discarded as
1394  * needed to maintain a smaller size. This can lead to slower or less
1395  * accurate seeking (depends on demuxer).
1396  * Demuxers for which a full in-memory index is mandatory will ignore
1397  * this.
1398  * - muxing: unused
1399  * - demuxing: set by user
1400  */
1401  unsigned int max_index_size;
1402 
1403  /**
1404  * Maximum amount of memory in bytes to use for buffering frames
1405  * obtained from realtime capture devices.
1406  */
1407  unsigned int max_picture_buffer;
1408 
1409  /**
1410  * Number of chapters in AVChapter array.
1411  * When muxing, chapters are normally written in the file header,
1412  * so nb_chapters should normally be initialized before write_header
1413  * is called. Some muxers (e.g. mov and mkv) can also write chapters
1414  * in the trailer. To write chapters in the trailer, nb_chapters
1415  * must be zero when write_header is called and non-zero when
1416  * write_trailer is called.
1417  * - muxing: set by user
1418  * - demuxing: set by libavformat
1419  */
1420  unsigned int nb_chapters;
1421  AVChapter **chapters;
1422 
1423  /**
1424  * Metadata that applies to the whole file.
1425  *
1426  * - demuxing: set by libavformat in avformat_open_input()
1427  * - muxing: may be set by the caller before avformat_write_header()
1428  *
1429  * Freed by libavformat in avformat_free_context().
1430  */
1432 
1433  /**
1434  * Start time of the stream in real world time, in microseconds
1435  * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1436  * stream was captured at this real world time.
1437  * - muxing: Set by the caller before avformat_write_header(). If set to
1438  * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1439  * be used.
1440  * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1441  * the value may become known after some number of frames
1442  * have been received.
1443  */
1444  int64_t start_time_realtime;
1445 
1446  /**
1447  * The number of frames used for determining the framerate in
1448  * avformat_find_stream_info().
1449  * Demuxing only, set by the caller before avformat_find_stream_info().
1450  */
1451  int fps_probe_size;
1452 
1453  /**
1454  * Error recognition; higher values will detect more errors but may
1455  * misdetect some more or less valid parts as errors.
1456  * Demuxing only, set by the caller before avformat_open_input().
1457  */
1458  int error_recognition;
1459 
1460  /**
1461  * Custom interrupt callbacks for the I/O layer.
1462  *
1463  * demuxing: set by the user before avformat_open_input().
1464  * muxing: set by the user before avformat_write_header()
1465  * (mainly useful for AVFMT_NOFILE formats). The callback
1466  * should also be passed to avio_open2() if it's used to
1467  * open the file.
1468  */
1470 
1471  /**
1472  * Flags to enable debugging.
1473  */
1474  int debug;
1475 #define FF_FDEBUG_TS 0x0001
1476 
1477  /**
1478  * Maximum buffering duration for interleaving.
1479  *
1480  * To ensure all the streams are interleaved correctly,
1481  * av_interleaved_write_frame() will wait until it has at least one packet
1482  * for each stream before actually writing any packets to the output file.
1483  * When some streams are "sparse" (i.e. there are large gaps between
1484  * successive packets), this can result in excessive buffering.
1485  *
1486  * This field specifies the maximum difference between the timestamps of the
1487  * first and the last packet in the muxing queue, above which libavformat
1488  * will output a packet regardless of whether it has queued a packet for all
1489  * the streams.
1490  *
1491  * Muxing only, set by the caller before avformat_write_header().
1492  */
1493  int64_t max_interleave_delta;
1494 
1495  /**
1496  * Allow non-standard and experimental extension
1497  * @see AVCodecContext.strict_std_compliance
1498  */
1500 
1501  /**
1502  * Flags indicating events happening on the file, a combination of
1503  * AVFMT_EVENT_FLAG_*.
1504  *
1505  * - demuxing: may be set by the demuxer in avformat_open_input(),
1506  * avformat_find_stream_info() and av_read_frame(). Flags must be cleared
1507  * by the user once the event has been handled.
1508  * - muxing: may be set by the user after avformat_write_header() to
1509  * indicate a user-triggered event. The muxer will clear the flags for
1510  * events it has handled in av_[interleaved]_write_frame().
1511  */
1512  int event_flags;
1513 /**
1514  * - demuxing: the demuxer read new metadata from the file and updated
1515  * AVFormatContext.metadata accordingly
1516  * - muxing: the user updated AVFormatContext.metadata and wishes the muxer to
1517  * write it into the file
1518  */
1519 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001
1520 
1521  /**
1522  * Maximum number of packets to read while waiting for the first timestamp.
1523  * Decoding only.
1524  */
1525  int max_ts_probe;
1526 
1527  /**
1528  * Avoid negative timestamps during muxing.
1529  * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1530  * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use)
1531  * - muxing: Set by user
1532  * - demuxing: unused
1533  */
1535 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1536 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1537 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1538 
1539  /**
1540  * Transport stream id.
1541  * This will be moved into demuxer private options. Thus no API/ABI compatibility
1542  */
1543  int ts_id;
1544 
1545  /**
1546  * Audio preload in microseconds.
1547  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1548  * - encoding: Set by user
1549  * - decoding: unused
1550  */
1551  int audio_preload;
1552 
1553  /**
1554  * Max chunk time in microseconds.
1555  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1556  * - encoding: Set by user
1557  * - decoding: unused
1558  */
1559  int max_chunk_duration;
1560 
1561  /**
1562  * Max chunk size in bytes
1563  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1564  * - encoding: Set by user
1565  * - decoding: unused
1566  */
1567  int max_chunk_size;
1568 
1569  /**
1570  * forces the use of wallclock timestamps as pts/dts of packets
1571  * This has undefined results in the presence of B frames.
1572  * - encoding: unused
1573  * - decoding: Set by user
1574  */
1576 
1577  /**
1578  * avio flags, used to force AVIO_FLAG_DIRECT.
1579  * - encoding: unused
1580  * - decoding: Set by user
1581  */
1582  int avio_flags;
1583 
1584  /**
1585  * The duration field can be estimated through various ways, and this field can be used
1586  * to know how the duration was estimated.
1587  * - encoding: unused
1588  * - decoding: Read by user
1589  */
1591 
1592  /**
1593  * Skip initial bytes when opening stream
1594  * - encoding: unused
1595  * - decoding: Set by user
1596  */
1597  int64_t skip_initial_bytes;
1598 
1599  /**
1600  * Correct single timestamp overflows
1601  * - encoding: unused
1602  * - decoding: Set by user
1603  */
1604  unsigned int correct_ts_overflow;
1605 
1606  /**
1607  * Force seeking to any (also non key) frames.
1608  * - encoding: unused
1609  * - decoding: Set by user
1610  */
1611  int seek2any;
1612 
1613  /**
1614  * Flush the I/O context after each packet.
1615  * - encoding: Set by user
1616  * - decoding: unused
1617  */
1618  int flush_packets;
1619 
1620  /**
1621  * format probing score.
1622  * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1623  * the format.
1624  * - encoding: unused
1625  * - decoding: set by avformat, read by user
1626  */
1627  int probe_score;
1628 
1629  /**
1630  * Maximum number of bytes read from input in order to identify the
1631  * \ref AVInputFormat "input format". Only used when the format is not set
1632  * explicitly by the caller.
1633  *
1634  * Demuxing only, set by the caller before avformat_open_input().
1635  *
1636  * @sa probesize
1637  */
1638  int format_probesize;
1639 
1640  /**
1641  * ',' separated list of allowed decoders.
1642  * If NULL then all are allowed
1643  * - encoding: unused
1644  * - decoding: set by user
1645  */
1646  char *codec_whitelist;
1647 
1648  /**
1649  * ',' separated list of allowed demuxers.
1650  * If NULL then all are allowed
1651  * - encoding: unused
1652  * - decoding: set by user
1653  */
1654  char *format_whitelist;
1655 
1656  /**
1657  * IO repositioned flag.
1658  * This is set by avformat when the underlaying IO context read pointer
1659  * is repositioned, for example when doing byte based seeking.
1660  * Demuxers can use the flag to detect such changes.
1661  */
1662  int io_repositioned;
1663 
1664  /**
1665  * Forced video codec.
1666  * This allows forcing a specific decoder, even when there are multiple with
1667  * the same codec_id.
1668  * Demuxing: Set by user
1669  */
1670  const AVCodec *video_codec;
1671 
1672  /**
1673  * Forced audio codec.
1674  * This allows forcing a specific decoder, even when there are multiple with
1675  * the same codec_id.
1676  * Demuxing: Set by user
1677  */
1678  const AVCodec *audio_codec;
1679 
1680  /**
1681  * Forced subtitle codec.
1682  * This allows forcing a specific decoder, even when there are multiple with
1683  * the same codec_id.
1684  * Demuxing: Set by user
1685  */
1686  const AVCodec *subtitle_codec;
1687 
1688  /**
1689  * Forced data codec.
1690  * This allows forcing a specific decoder, even when there are multiple with
1691  * the same codec_id.
1692  * Demuxing: Set by user
1693  */
1694  const AVCodec *data_codec;
1695 
1696  /**
1697  * Number of bytes to be written as padding in a metadata header.
1698  * Demuxing: Unused.
1699  * Muxing: Set by user via av_format_set_metadata_header_padding.
1700  */
1702 
1703  /**
1704  * User data.
1705  * This is a place for some private data of the user.
1706  */
1707  void *opaque;
1708 
1709  /**
1710  * Callback used by devices to communicate with application.
1711  */
1713 
1714  /**
1715  * Output timestamp offset, in microseconds.
1716  * Muxing: set by user
1717  */
1718  int64_t output_ts_offset;
1719 
1720  /**
1721  * dump format separator.
1722  * can be ", " or "\n " or anything else
1723  * - muxing: Set by user.
1724  * - demuxing: Set by user.
1725  */
1726  uint8_t *dump_separator;
1727 
1728  /**
1729  * Forced Data codec_id.
1730  * Demuxing: Set by user.
1731  */
1732  enum AVCodecID data_codec_id;
1733 
1734  /**
1735  * ',' separated list of allowed protocols.
1736  * - encoding: unused
1737  * - decoding: set by user
1738  */
1739  char *protocol_whitelist;
1740 
1741  /**
1742  * A callback for opening new IO streams.
1743  *
1744  * Whenever a muxer or a demuxer needs to open an IO stream (typically from
1745  * avformat_open_input() for demuxers, but for certain formats can happen at
1746  * other times as well), it will call this callback to obtain an IO context.
1747  *
1748  * @param s the format context
1749  * @param pb on success, the newly opened IO context should be returned here
1750  * @param url the url to open
1751  * @param flags a combination of AVIO_FLAG_*
1752  * @param options a dictionary of additional options, with the same
1753  * semantics as in avio_open2()
1754  * @return 0 on success, a negative AVERROR code on failure
1755  *
1756  * @note Certain muxers and demuxers do nesting, i.e. they open one or more
1757  * additional internal format contexts. Thus the AVFormatContext pointer
1758  * passed to this callback may be different from the one facing the caller.
1759  * It will, however, have the same 'opaque' field.
1760  */
1761  int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url,
1762  int flags, AVDictionary **options);
1763 
1764  /**
1765  * A callback for closing the streams opened with AVFormatContext.io_open().
1766  */
1767  void (*io_close)(struct AVFormatContext *s, AVIOContext *pb);
1768 
1769  /**
1770  * ',' separated list of disallowed protocols.
1771  * - encoding: unused
1772  * - decoding: set by user
1773  */
1774  char *protocol_blacklist;
1775 
1776  /**
1777  * The maximum number of streams.
1778  * - encoding: unused
1779  * - decoding: set by user
1780  */
1781  int max_streams;
1782 
1783  /**
1784  * Skip duration calcuation in estimate_timings_from_pts.
1785  * - encoding: unused
1786  * - decoding: set by user
1787  */
1789 
1790  /**
1791  * Maximum number of packets that can be probed
1792  * - encoding: unused
1793  * - decoding: set by user
1794  */
1795  int max_probe_packets;
1796 
1797  /**
1798  * A callback for closing the streams opened with AVFormatContext.io_open().
1799  *
1800  * Using this is preferred over io_close, because this can return an error.
1801  * Therefore this callback is used instead of io_close by the generic
1802  * libavformat code if io_close is NULL or the default.
1803  *
1804  * @param s the format context
1805  * @param pb IO context to be closed and freed
1806  * @return 0 on success, a negative AVERROR code on failure
1807  */
1808  int (*io_close2)(struct AVFormatContext *s, AVIOContext *pb);
1809 } AVFormatContext;
1810 
1811 /**
1812  * This function will cause global side data to be injected in the next packet
1813  * of each stream as well as after any subsequent seek.
1814  */
1816 
1817 /**
1818  * Returns the method used to set ctx->duration.
1819  *
1820  * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1821  */
1823 
1824 /**
1825  * @defgroup lavf_core Core functions
1826  * @ingroup libavf
1827  *
1828  * Functions for querying libavformat capabilities, allocating core structures,
1829  * etc.
1830  * @{
1831  */
1832 
1833 /**
1834  * Return the LIBAVFORMAT_VERSION_INT constant.
1835  */
1836 unsigned avformat_version(void);
1837 
1838 /**
1839  * Return the libavformat build-time configuration.
1840  */
1841 const char *avformat_configuration(void);
1842 
1843 /**
1844  * Return the libavformat license.
1845  */
1846 const char *avformat_license(void);
1847 
1848 /**
1849  * Do global initialization of network libraries. This is optional,
1850  * and not recommended anymore.
1851  *
1852  * This functions only exists to work around thread-safety issues
1853  * with older GnuTLS or OpenSSL libraries. If libavformat is linked
1854  * to newer versions of those libraries, or if you do not use them,
1855  * calling this function is unnecessary. Otherwise, you need to call
1856  * this function before any other threads using them are started.
1857  *
1858  * This function will be deprecated once support for older GnuTLS and
1859  * OpenSSL libraries is removed, and this function has no purpose
1860  * anymore.
1861  */
1862 int avformat_network_init(void);
1863 
1864 /**
1865  * Undo the initialization done by avformat_network_init. Call it only
1866  * once for each time you called avformat_network_init.
1867  */
1868 int avformat_network_deinit(void);
1869 
1870 /**
1871  * Iterate over all registered muxers.
1872  *
1873  * @param opaque a pointer where libavformat will store the iteration state. Must
1874  * point to NULL to start the iteration.
1875  *
1876  * @return the next registered muxer or NULL when the iteration is
1877  * finished
1878  */
1879 const AVOutputFormat *av_muxer_iterate(void **opaque);
1880 
1881 /**
1882  * Iterate over all registered demuxers.
1883  *
1884  * @param opaque a pointer where libavformat will store the iteration state. Must
1885  * point to NULL to start the iteration.
1886  *
1887  * @return the next registered demuxer or NULL when the iteration is
1888  * finished
1889  */
1890 const AVInputFormat *av_demuxer_iterate(void **opaque);
1891 
1892 /**
1893  * Allocate an AVFormatContext.
1894  * avformat_free_context() can be used to free the context and everything
1895  * allocated by the framework within it.
1896  */
1898 
1899 /**
1900  * Free an AVFormatContext and all its streams.
1901  * @param s context to free
1902  */
1904 
1905 /**
1906  * Get the AVClass for AVFormatContext. It can be used in combination with
1907  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1908  *
1909  * @see av_opt_find().
1910  */
1911 const AVClass *avformat_get_class(void);
1912 
1913 /**
1914  * Get the AVClass for AVStream. It can be used in combination with
1915  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1916  *
1917  * @see av_opt_find().
1918  */
1919 const AVClass *av_stream_get_class(void);
1920 
1921 /**
1922  * Add a new stream to a media file.
1923  *
1924  * When demuxing, it is called by the demuxer in read_header(). If the
1925  * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1926  * be called in read_packet().
1927  *
1928  * When muxing, should be called by the user before avformat_write_header().
1929  *
1930  * User is required to call avformat_free_context() to clean up the allocation
1931  * by avformat_new_stream().
1932  *
1933  * @param s media file handle
1934  * @param c unused, does nothing
1935  *
1936  * @return newly created stream or NULL on error.
1937  */
1939 
1940 /**
1941  * Wrap an existing array as stream side data.
1942  *
1943  * @param st stream
1944  * @param type side information type
1945  * @param data the side data array. It must be allocated with the av_malloc()
1946  * family of functions. The ownership of the data is transferred to
1947  * st.
1948  * @param size side information size
1949  * @return zero on success, a negative AVERROR code on failure. On failure,
1950  * the stream is unchanged and the data remains owned by the caller.
1951  */
1953  uint8_t *data, size_t size);
1954 
1955 /**
1956  * Allocate new information from stream.
1957  *
1958  * @param stream stream
1959  * @param type desired side information type
1960  * @param size side information size
1961  * @return pointer to fresh allocated data or NULL otherwise
1962  */
1963 uint8_t *av_stream_new_side_data(AVStream *stream,
1964  enum AVPacketSideDataType type, size_t size);
1965 /**
1966  * Get side information from stream.
1967  *
1968  * @param stream stream
1969  * @param type desired side information type
1970  * @param size If supplied, *size will be set to the size of the side data
1971  * or to zero if the desired side data is not present.
1972  * @return pointer to data if present or NULL otherwise
1973  */
1974 uint8_t *av_stream_get_side_data(const AVStream *stream,
1975  enum AVPacketSideDataType type, size_t *size);
1976 
1978 
1979 /**
1980  * @}
1981  */
1982 
1983 
1984 /**
1985  * Allocate an AVFormatContext for an output format.
1986  * avformat_free_context() can be used to free the context and
1987  * everything allocated by the framework within it.
1988  *
1989  * @param *ctx is set to the created format context, or to NULL in
1990  * case of failure
1991  * @param oformat format to use for allocating the context, if NULL
1992  * format_name and filename are used instead
1993  * @param format_name the name of output format to use for allocating the
1994  * context, if NULL filename is used instead
1995  * @param filename the name of the filename to use for allocating the
1996  * context, may be NULL
1997  * @return >= 0 in case of success, a negative AVERROR code in case of
1998  * failure
1999  */
2001  const char *format_name, const char *filename);
2002 
2003 /**
2004  * @addtogroup lavf_decoding
2005  * @{
2006  */
2007 
2008 /**
2009  * Find AVInputFormat based on the short name of the input format.
2010  */
2011 const AVInputFormat *av_find_input_format(const char *short_name);
2012 
2013 /**
2014  * Guess the file format.
2015  *
2016  * @param pd data to be probed
2017  * @param is_opened Whether the file is already opened; determines whether
2018  * demuxers with or without AVFMT_NOFILE are probed.
2019  */
2020 const AVInputFormat *av_probe_input_format(const AVProbeData *pd, int is_opened);
2021 
2022 /**
2023  * Guess the file format.
2024  *
2025  * @param pd data to be probed
2026  * @param is_opened Whether the file is already opened; determines whether
2027  * demuxers with or without AVFMT_NOFILE are probed.
2028  * @param score_max A probe score larger that this is required to accept a
2029  * detection, the variable is set to the actual detection
2030  * score afterwards.
2031  * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2032  * to retry with a larger probe buffer.
2033  */
2035  int is_opened, int *score_max);
2036 
2037 /**
2038  * Guess the file format.
2039  *
2040  * @param is_opened Whether the file is already opened; determines whether
2041  * demuxers with or without AVFMT_NOFILE are probed.
2042  * @param score_ret The score of the best detection.
2043  */
2045  int is_opened, int *score_ret);
2046 
2047 /**
2048  * Probe a bytestream to determine the input format. Each time a probe returns
2049  * with a score that is too low, the probe buffer size is increased and another
2050  * attempt is made. When the maximum probe size is reached, the input format
2051  * with the highest score is returned.
2052  *
2053  * @param pb the bytestream to probe
2054  * @param fmt the input format is put here
2055  * @param url the url of the stream
2056  * @param logctx the log context
2057  * @param offset the offset within the bytestream to probe from
2058  * @param max_probe_size the maximum probe buffer size (zero for default)
2059  * @return the score in case of success, a negative value corresponding to an
2060  * the maximal score is AVPROBE_SCORE_MAX
2061  * AVERROR code otherwise
2062  */
2064  const char *url, void *logctx,
2065  unsigned int offset, unsigned int max_probe_size);
2066 
2067 /**
2068  * Like av_probe_input_buffer2() but returns 0 on success
2069  */
2071  const char *url, void *logctx,
2072  unsigned int offset, unsigned int max_probe_size);
2073 
2074 /**
2075  * Open an input stream and read the header. The codecs are not opened.
2076  * The stream must be closed with avformat_close_input().
2077  *
2078  * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
2079  * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
2080  * function and written into ps.
2081  * Note that a user-supplied AVFormatContext will be freed on failure.
2082  * @param url URL of the stream to open.
2083  * @param fmt If non-NULL, this parameter forces a specific input format.
2084  * Otherwise the format is autodetected.
2085  * @param options A dictionary filled with AVFormatContext and demuxer-private options.
2086  * On return this parameter will be destroyed and replaced with a dict containing
2087  * options that were not found. May be NULL.
2088  *
2089  * @return 0 on success, a negative AVERROR on failure.
2090  *
2091  * @note If you want to use custom IO, preallocate the format context and set its pb field.
2092  */
2093 int avformat_open_input(AVFormatContext **ps, const char *url,
2094  const AVInputFormat *fmt, AVDictionary **options);
2095 
2096 /**
2097  * Read packets of a media file to get stream information. This
2098  * is useful for file formats with no headers such as MPEG. This
2099  * function also computes the real framerate in case of MPEG-2 repeat
2100  * frame mode.
2101  * The logical file position is not changed by this function;
2102  * examined packets may be buffered for later processing.
2103  *
2104  * @param ic media file handle
2105  * @param options If non-NULL, an ic.nb_streams long array of pointers to
2106  * dictionaries, where i-th member contains options for
2107  * codec corresponding to i-th stream.
2108  * On return each dictionary will be filled with options that were not found.
2109  * @return >=0 if OK, AVERROR_xxx on error
2110  *
2111  * @note this function isn't guaranteed to open all the codecs, so
2112  * options being non-empty at return is a perfectly normal behavior.
2113  *
2114  * @todo Let the user decide somehow what information is needed so that
2115  * we do not waste time getting stuff the user does not need.
2116  */
2118 
2119 /**
2120  * Find the programs which belong to a given stream.
2121  *
2122  * @param ic media file handle
2123  * @param last the last found program, the search will start after this
2124  * program, or from the beginning if it is NULL
2125  * @param s stream index
2126  * @return the next program which belongs to s, NULL if no program is found or
2127  * the last program is not among the programs of ic.
2128  */
2130 
2131 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
2132 
2133 /**
2134  * Find the "best" stream in the file.
2135  * The best stream is determined according to various heuristics as the most
2136  * likely to be what the user expects.
2137  * If the decoder parameter is non-NULL, av_find_best_stream will find the
2138  * default decoder for the stream's codec; streams for which no decoder can
2139  * be found are ignored.
2140  *
2141  * @param ic media file handle
2142  * @param type stream type: video, audio, subtitles, etc.
2143  * @param wanted_stream_nb user-requested stream number,
2144  * or -1 for automatic selection
2145  * @param related_stream try to find a stream related (eg. in the same
2146  * program) to this one, or -1 if none
2147  * @param decoder_ret if non-NULL, returns the decoder for the
2148  * selected stream
2149  * @param flags flags; none are currently defined
2150  * @return the non-negative stream number in case of success,
2151  * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2152  * could be found,
2153  * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2154  * @note If av_find_best_stream returns successfully and decoder_ret is not
2155  * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2156  */
2158  enum AVMediaType type,
2159  int wanted_stream_nb,
2160  int related_stream,
2161  const AVCodec **decoder_ret,
2162  int flags);
2163 
2164 /**
2165  * Return the next frame of a stream.
2166  * This function returns what is stored in the file, and does not validate
2167  * that what is there are valid frames for the decoder. It will split what is
2168  * stored in the file into frames and return one for each call. It will not
2169  * omit invalid data between valid frames so as to give the decoder the maximum
2170  * information possible for decoding.
2171  *
2172  * On success, the returned packet is reference-counted (pkt->buf is set) and
2173  * valid indefinitely. The packet must be freed with av_packet_unref() when
2174  * it is no longer needed. For video, the packet contains exactly one frame.
2175  * For audio, it contains an integer number of frames if each frame has
2176  * a known fixed size (e.g. PCM or ADPCM data). If the audio frames have
2177  * a variable size (e.g. MPEG audio), then it contains one frame.
2178  *
2179  * pkt->pts, pkt->dts and pkt->duration are always set to correct
2180  * values in AVStream.time_base units (and guessed if the format cannot
2181  * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2182  * has B-frames, so it is better to rely on pkt->dts if you do not
2183  * decompress the payload.
2184  *
2185  * @return 0 if OK, < 0 on error or end of file. On error, pkt will be blank
2186  * (as if it came from av_packet_alloc()).
2187  *
2188  * @note pkt will be initialized, so it may be uninitialized, but it must not
2189  * contain data that needs to be freed.
2190  */
2192 
2193 /**
2194  * Seek to the keyframe at timestamp.
2195  * 'timestamp' in 'stream_index'.
2196  *
2197  * @param s media file handle
2198  * @param stream_index If stream_index is (-1), a default
2199  * stream is selected, and timestamp is automatically converted
2200  * from AV_TIME_BASE units to the stream specific time_base.
2201  * @param timestamp Timestamp in AVStream.time_base units
2202  * or, if no stream is specified, in AV_TIME_BASE units.
2203  * @param flags flags which select direction and seeking mode
2204  * @return >= 0 on success
2205  */
2206 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2207  int flags);
2208 
2209 /**
2210  * Seek to timestamp ts.
2211  * Seeking will be done so that the point from which all active streams
2212  * can be presented successfully will be closest to ts and within min/max_ts.
2213  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2214  *
2215  * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2216  * are the file position (this may not be supported by all demuxers).
2217  * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2218  * in the stream with stream_index (this may not be supported by all demuxers).
2219  * Otherwise all timestamps are in units of the stream selected by stream_index
2220  * or if stream_index is -1, in AV_TIME_BASE units.
2221  * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2222  * keyframes (this may not be supported by all demuxers).
2223  * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2224  *
2225  * @param s media file handle
2226  * @param stream_index index of the stream which is used as time base reference
2227  * @param min_ts smallest acceptable timestamp
2228  * @param ts target timestamp
2229  * @param max_ts largest acceptable timestamp
2230  * @param flags flags
2231  * @return >=0 on success, error code otherwise
2232  *
2233  * @note This is part of the new seek API which is still under construction.
2234  */
2235 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2236 
2237 /**
2238  * Discard all internally buffered data. This can be useful when dealing with
2239  * discontinuities in the byte stream. Generally works only with formats that
2240  * can resync. This includes headerless formats like MPEG-TS/TS but should also
2241  * work with NUT, Ogg and in a limited way AVI for example.
2242  *
2243  * The set of streams, the detected duration, stream parameters and codecs do
2244  * not change when calling this function. If you want a complete reset, it's
2245  * better to open a new AVFormatContext.
2246  *
2247  * This does not flush the AVIOContext (s->pb). If necessary, call
2248  * avio_flush(s->pb) before calling this function.
2249  *
2250  * @param s media file handle
2251  * @return >=0 on success, error code otherwise
2252  */
2254 
2255 /**
2256  * Start playing a network-based stream (e.g. RTSP stream) at the
2257  * current position.
2258  */
2260 
2261 /**
2262  * Pause a network-based stream (e.g. RTSP stream).
2263  *
2264  * Use av_read_play() to resume it.
2265  */
2267 
2268 /**
2269  * Close an opened input AVFormatContext. Free it and all its contents
2270  * and set *s to NULL.
2271  */
2273 /**
2274  * @}
2275  */
2277 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2278 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2279 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2280 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2281 
2282 /**
2283  * @addtogroup lavf_encoding
2284  * @{
2285  */
2287 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2288 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2289 
2290 /**
2291  * Allocate the stream private data and write the stream header to
2292  * an output media file.
2293  *
2294  * @param s Media file handle, must be allocated with avformat_alloc_context().
2295  * Its oformat field must be set to the desired output format;
2296  * Its pb field must be set to an already opened AVIOContext.
2297  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2298  * On return this parameter will be destroyed and replaced with a dict containing
2299  * options that were not found. May be NULL.
2300  *
2301  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init,
2302  * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init,
2303  * negative AVERROR on failure.
2304  *
2305  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2306  */
2309 
2310 /**
2311  * Allocate the stream private data and initialize the codec, but do not write the header.
2312  * May optionally be used before avformat_write_header to initialize stream parameters
2313  * before actually writing the header.
2314  * If using this function, do not pass the same options to avformat_write_header.
2315  *
2316  * @param s Media file handle, must be allocated with avformat_alloc_context().
2317  * Its oformat field must be set to the desired output format;
2318  * Its pb field must be set to an already opened AVIOContext.
2319  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2320  * On return this parameter will be destroyed and replaced with a dict containing
2321  * options that were not found. May be NULL.
2322  *
2323  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec requires avformat_write_header to fully initialize,
2324  * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec has been fully initialized,
2325  * negative AVERROR on failure.
2326  *
2327  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2328  */
2331 
2332 /**
2333  * Write a packet to an output media file.
2334  *
2335  * This function passes the packet directly to the muxer, without any buffering
2336  * or reordering. The caller is responsible for correctly interleaving the
2337  * packets if the format requires it. Callers that want libavformat to handle
2338  * the interleaving should call av_interleaved_write_frame() instead of this
2339  * function.
2340  *
2341  * @param s media file handle
2342  * @param pkt The packet containing the data to be written. Note that unlike
2343  * av_interleaved_write_frame(), this function does not take
2344  * ownership of the packet passed to it (though some muxers may make
2345  * an internal reference to the input packet).
2346  * <br>
2347  * This parameter can be NULL (at any time, not just at the end), in
2348  * order to immediately flush data buffered within the muxer, for
2349  * muxers that buffer up data internally before writing it to the
2350  * output.
2351  * <br>
2352  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2353  * set to the index of the corresponding stream in @ref
2354  * AVFormatContext.streams "s->streams".
2355  * <br>
2356  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2357  * must be set to correct values in the stream's timebase (unless the
2358  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2359  * they can be set to AV_NOPTS_VALUE).
2360  * The dts for subsequent packets passed to this function must be strictly
2361  * increasing when compared in their respective timebases (unless the
2362  * output format is flagged with the AVFMT_TS_NONSTRICT, then they
2363  * merely have to be nondecreasing). @ref AVPacket.duration
2364  * "duration") should also be set if known.
2365  * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2366  *
2367  * @see av_interleaved_write_frame()
2368  */
2370 
2371 /**
2372  * Write a packet to an output media file ensuring correct interleaving.
2373  *
2374  * This function will buffer the packets internally as needed to make sure the
2375  * packets in the output file are properly interleaved, usually ordered by
2376  * increasing dts. Callers doing their own interleaving should call
2377  * av_write_frame() instead of this function.
2378  *
2379  * Using this function instead of av_write_frame() can give muxers advance
2380  * knowledge of future packets, improving e.g. the behaviour of the mp4
2381  * muxer for VFR content in fragmenting mode.
2382  *
2383  * @param s media file handle
2384  * @param pkt The packet containing the data to be written.
2385  * <br>
2386  * If the packet is reference-counted, this function will take
2387  * ownership of this reference and unreference it later when it sees
2388  * fit. If the packet is not reference-counted, libavformat will
2389  * make a copy.
2390  * The returned packet will be blank (as if returned from
2391  * av_packet_alloc()), even on error.
2392  * <br>
2393  * This parameter can be NULL (at any time, not just at the end), to
2394  * flush the interleaving queues.
2395  * <br>
2396  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2397  * set to the index of the corresponding stream in @ref
2398  * AVFormatContext.streams "s->streams".
2399  * <br>
2400  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2401  * must be set to correct values in the stream's timebase (unless the
2402  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2403  * they can be set to AV_NOPTS_VALUE).
2404  * The dts for subsequent packets in one stream must be strictly
2405  * increasing (unless the output format is flagged with the
2406  * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2407  * @ref AVPacket.duration "duration" should also be set if known.
2408  *
2409  * @return 0 on success, a negative AVERROR on error.
2410  *
2411  * @see av_write_frame(), AVFormatContext.max_interleave_delta
2412  */
2414 
2415 /**
2416  * Write an uncoded frame to an output media file.
2417  *
2418  * The frame must be correctly interleaved according to the container
2419  * specification; if not, av_interleaved_write_uncoded_frame() must be used.
2420  *
2421  * See av_interleaved_write_uncoded_frame() for details.
2422  */
2423 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2424  AVFrame *frame);
2425 
2426 /**
2427  * Write an uncoded frame to an output media file.
2428  *
2429  * If the muxer supports it, this function makes it possible to write an AVFrame
2430  * structure directly, without encoding it into a packet.
2431  * It is mostly useful for devices and similar special muxers that use raw
2432  * video or PCM data and will not serialize it into a byte stream.
2433  *
2434  * To test whether it is possible to use it with a given muxer and stream,
2435  * use av_write_uncoded_frame_query().
2436  *
2437  * The caller gives up ownership of the frame and must not access it
2438  * afterwards.
2439  *
2440  * @return >=0 for success, a negative code on error
2441  */
2443  AVFrame *frame);
2444 
2445 /**
2446  * Test whether a muxer supports uncoded frame.
2447  *
2448  * @return >=0 if an uncoded frame can be written to that muxer and stream,
2449  * <0 if not
2450  */
2451 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2452 
2453 /**
2454  * Write the stream trailer to an output media file and free the
2455  * file private data.
2456  *
2457  * May only be called after a successful call to avformat_write_header.
2458  *
2459  * @param s media file handle
2460  * @return 0 if OK, AVERROR_xxx on error
2461  */
2463 
2464 /**
2465  * Return the output format in the list of registered output formats
2466  * which best matches the provided parameters, or return NULL if
2467  * there is no match.
2468  *
2469  * @param short_name if non-NULL checks if short_name matches with the
2470  * names of the registered formats
2471  * @param filename if non-NULL checks if filename terminates with the
2472  * extensions of the registered formats
2473  * @param mime_type if non-NULL checks if mime_type matches with the
2474  * MIME type of the registered formats
2475  */
2476 const AVOutputFormat *av_guess_format(const char *short_name,
2477  const char *filename,
2478  const char *mime_type);
2479 
2480 /**
2481  * Guess the codec ID based upon muxer and filename.
2482  */
2483 enum AVCodecID av_guess_codec(const AVOutputFormat *fmt, const char *short_name,
2484  const char *filename, const char *mime_type,
2485  enum AVMediaType type);
2486 
2487 /**
2488  * Get timing information for the data currently output.
2489  * The exact meaning of "currently output" depends on the format.
2490  * It is mostly relevant for devices that have an internal buffer and/or
2491  * work in real time.
2492  * @param s media file handle
2493  * @param stream stream in the media file
2494  * @param[out] dts DTS of the last packet output for the stream, in stream
2495  * time_base units
2496  * @param[out] wall absolute time when that packet whas output,
2497  * in microsecond
2498  * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
2499  * Note: some formats or devices may not allow to measure dts and wall
2500  * atomically.
2501  */
2502 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2503  int64_t *dts, int64_t *wall);
2504 
2505 
2506 /**
2507  * @}
2508  */
2509 
2510 
2511 /**
2512  * @defgroup lavf_misc Utility functions
2513  * @ingroup libavf
2514  * @{
2515  *
2516  * Miscellaneous utility functions related to both muxing and demuxing
2517  * (or neither).
2518  */
2519 
2520 /**
2521  * Send a nice hexadecimal dump of a buffer to the specified file stream.
2522  *
2523  * @param f The file stream pointer where the dump should be sent to.
2524  * @param buf buffer
2525  * @param size buffer size
2526  *
2527  * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2528  */
2529 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2530 
2531 /**
2532  * Send a nice hexadecimal dump of a buffer to the log.
2533  *
2534  * @param avcl A pointer to an arbitrary struct of which the first field is a
2535  * pointer to an AVClass struct.
2536  * @param level The importance level of the message, lower values signifying
2537  * higher importance.
2538  * @param buf buffer
2539  * @param size buffer size
2540  *
2541  * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2542  */
2543 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2544 
2545 /**
2546  * Send a nice dump of a packet to the specified file stream.
2547  *
2548  * @param f The file stream pointer where the dump should be sent to.
2549  * @param pkt packet to dump
2550  * @param dump_payload True if the payload must be displayed, too.
2551  * @param st AVStream that the packet belongs to
2552  */
2553 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2554 
2555 
2556 /**
2557  * Send a nice dump of a packet to the log.
2558  *
2559  * @param avcl A pointer to an arbitrary struct of which the first field is a
2560  * pointer to an AVClass struct.
2561  * @param level The importance level of the message, lower values signifying
2562  * higher importance.
2563  * @param pkt packet to dump
2564  * @param dump_payload True if the payload must be displayed, too.
2565  * @param st AVStream that the packet belongs to
2566  */
2567 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2568  const AVStream *st);
2569 
2570 /**
2571  * Get the AVCodecID for the given codec tag tag.
2572  * If no codec id is found returns AV_CODEC_ID_NONE.
2573  *
2574  * @param tags list of supported codec_id-codec_tag pairs, as stored
2575  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2576  * @param tag codec tag to match to a codec ID
2577  */
2578 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2579 
2580 /**
2581  * Get the codec tag for the given codec id id.
2582  * If no codec tag is found returns 0.
2583  *
2584  * @param tags list of supported codec_id-codec_tag pairs, as stored
2585  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2586  * @param id codec ID to match to a codec tag
2587  */
2588 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2589 
2590 /**
2591  * Get the codec tag for the given codec id.
2592  *
2593  * @param tags list of supported codec_id - codec_tag pairs, as stored
2594  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2595  * @param id codec id that should be searched for in the list
2596  * @param tag A pointer to the found tag
2597  * @return 0 if id was not found in tags, > 0 if it was found
2598  */
2599 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2600  unsigned int *tag);
2601 
2603 
2604 /**
2605  * Get the index for a specific timestamp.
2606  *
2607  * @param st stream that the timestamp belongs to
2608  * @param timestamp timestamp to retrieve the index for
2609  * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2610  * to the timestamp which is <= the requested one, if backward
2611  * is 0, then it will be >=
2612  * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2613  * @return < 0 if no such timestamp could be found
2614  */
2615 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2616 
2617 /**
2618  * Get the index entry count for the given AVStream.
2619  *
2620  * @param st stream
2621  * @return the number of index entries in the stream
2622  */
2624 
2625 /**
2626  * Get the AVIndexEntry corresponding to the given index.
2627  *
2628  * @param st Stream containing the requested AVIndexEntry.
2629  * @param idx The desired index.
2630  * @return A pointer to the requested AVIndexEntry if it exists, NULL otherwise.
2631  *
2632  * @note The pointer returned by this function is only guaranteed to be valid
2633  * until any function that takes the stream or the parent AVFormatContext
2634  * as input argument is called.
2635  */
2636 const AVIndexEntry *avformat_index_get_entry(AVStream *st, int idx);
2637 
2638 /**
2639  * Get the AVIndexEntry corresponding to the given timestamp.
2640  *
2641  * @param st Stream containing the requested AVIndexEntry.
2642  * @param timestamp Timestamp to retrieve the index entry for.
2643  * @param flags If AVSEEK_FLAG_BACKWARD then the returned entry will correspond
2644  * to the timestamp which is <= the requested one, if backward
2645  * is 0, then it will be >=
2646  * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise.
2647  * @return A pointer to the requested AVIndexEntry if it exists, NULL otherwise.
2648  *
2649  * @note The pointer returned by this function is only guaranteed to be valid
2650  * until any function that takes the stream or the parent AVFormatContext
2651  * as input argument is called.
2652  */
2654  int64_t wanted_timestamp,
2655  int flags);
2656 /**
2657  * Add an index entry into a sorted list. Update the entry if the list
2658  * already contains it.
2659  *
2660  * @param timestamp timestamp in the time base of the given stream
2661  */
2662 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2663  int size, int distance, int flags);
2664 
2665 
2666 /**
2667  * Split a URL string into components.
2668  *
2669  * The pointers to buffers for storing individual components may be null,
2670  * in order to ignore that component. Buffers for components not found are
2671  * set to empty strings. If the port is not found, it is set to a negative
2672  * value.
2673  *
2674  * @param proto the buffer for the protocol
2675  * @param proto_size the size of the proto buffer
2676  * @param authorization the buffer for the authorization
2677  * @param authorization_size the size of the authorization buffer
2678  * @param hostname the buffer for the host name
2679  * @param hostname_size the size of the hostname buffer
2680  * @param port_ptr a pointer to store the port number in
2681  * @param path the buffer for the path
2682  * @param path_size the size of the path buffer
2683  * @param url the URL to split
2684  */
2685 void av_url_split(char *proto, int proto_size,
2686  char *authorization, int authorization_size,
2687  char *hostname, int hostname_size,
2688  int *port_ptr,
2689  char *path, int path_size,
2690  const char *url);
2691 
2692 
2693 /**
2694  * Print detailed information about the input or output format, such as
2695  * duration, bitrate, streams, container, programs, metadata, side data,
2696  * codec and time base.
2697  *
2698  * @param ic the context to analyze
2699  * @param index index of the stream to dump information about
2700  * @param url the URL to print, such as source or destination file
2701  * @param is_output Select whether the specified context is an input(0) or output(1)
2702  */
2704  int index,
2705  const char *url,
2706  int is_output);
2708 
2709 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
2710 
2711 /**
2712  * Return in 'buf' the path with '%d' replaced by a number.
2713  *
2714  * Also handles the '%0nd' format where 'n' is the total number
2715  * of digits and '%%'.
2716  *
2717  * @param buf destination buffer
2718  * @param buf_size destination buffer size
2719  * @param path numbered sequence string
2720  * @param number frame number
2721  * @param flags AV_FRAME_FILENAME_FLAGS_*
2722  * @return 0 if OK, -1 on format error
2723  */
2724 int av_get_frame_filename2(char *buf, int buf_size,
2725  const char *path, int number, int flags);
2726 
2727 int av_get_frame_filename(char *buf, int buf_size,
2728  const char *path, int number);
2729 
2730 /**
2731  * Check whether filename actually is a numbered sequence generator.
2732  *
2733  * @param filename possible numbered sequence string
2734  * @return 1 if a valid numbered sequence string, 0 otherwise
2735  */
2736 int av_filename_number_test(const char *filename);
2737 
2738 /**
2739  * Generate an SDP for an RTP session.
2740  *
2741  * Note, this overwrites the id values of AVStreams in the muxer contexts
2742  * for getting unique dynamic payload types.
2743  *
2744  * @param ac array of AVFormatContexts describing the RTP streams. If the
2745  * array is composed by only one context, such context can contain
2746  * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2747  * all the contexts in the array (an AVCodecContext per RTP stream)
2748  * must contain only one AVStream.
2749  * @param n_files number of AVCodecContexts contained in ac
2750  * @param buf buffer where the SDP will be stored (must be allocated by
2751  * the caller)
2752  * @param size the size of the buffer
2753  * @return 0 if OK, AVERROR_xxx on error
2754  */
2755 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2756 
2757 /**
2758  * Return a positive value if the given filename has one of the given
2759  * extensions, 0 otherwise.
2760  *
2761  * @param filename file name to check against the given extensions
2762  * @param extensions a comma-separated list of filename extensions
2763  */
2764 int av_match_ext(const char *filename, const char *extensions);
2765 
2766 /**
2767  * Test if the given container can store a codec.
2768  *
2769  * @param ofmt container to check for compatibility
2770  * @param codec_id codec to potentially store in container
2771  * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2772  *
2773  * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2774  * A negative number if this information is not available.
2775  */
2777  int std_compliance);
2778 
2779 /**
2780  * @defgroup riff_fourcc RIFF FourCCs
2781  * @{
2782  * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2783  * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2784  * following code:
2785  * @code
2786  * uint32_t tag = MKTAG('H', '2', '6', '4');
2787  * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2788  * enum AVCodecID id = av_codec_get_id(table, tag);
2789  * @endcode
2790  */
2791 /**
2792  * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2793  */
2794 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2795 /**
2796  * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2797  */
2798 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2799 /**
2800  * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2801  */
2802 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2803 /**
2804  * @return the table mapping MOV FourCCs for audio to AVCodecID.
2805  */
2806 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2807 
2808 /**
2809  * @}
2810  */
2811 
2812 /**
2813  * Guess the sample aspect ratio of a frame, based on both the stream and the
2814  * frame aspect ratio.
2815  *
2816  * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2817  * is set by the demuxer, these two may not be equal. This function tries to
2818  * return the value that you should use if you would like to display the frame.
2819  *
2820  * Basic logic is to use the stream aspect ratio if it is set to something sane
2821  * otherwise use the frame aspect ratio. This way a container setting, which is
2822  * usually easy to modify can override the coded value in the frames.
2823  *
2824  * @param format the format context which the stream is part of
2825  * @param stream the stream which the frame is part of
2826  * @param frame the frame with the aspect ratio to be determined
2827  * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2828  */
2830 
2831 /**
2832  * Guess the frame rate, based on both the container and codec information.
2833  *
2834  * @param ctx the format context which the stream is part of
2835  * @param stream the stream which the frame is part of
2836  * @param frame the frame for which the frame rate should be determined, may be NULL
2837  * @return the guessed (valid) frame rate, 0/1 if no idea
2838  */
2840 
2841 /**
2842  * Check if the stream st contained in s is matched by the stream specifier
2843  * spec.
2844  *
2845  * See the "stream specifiers" chapter in the documentation for the syntax
2846  * of spec.
2847  *
2848  * @return >0 if st is matched by spec;
2849  * 0 if st is not matched by spec;
2850  * AVERROR code if spec is invalid
2851  *
2852  * @note A stream specifier can match several streams in the format.
2853  */
2855  const char *spec);
2856 
2863 #if FF_API_R_FRAME_RATE
2864  AVFMT_TBCF_R_FRAMERATE,
2865 #endif
2866 };
2867 
2868 /**
2869  * Transfer internal timing information from one stream to another.
2870  *
2871  * This function is useful when doing stream copy.
2872  *
2873  * @param ofmt target output format for ost
2874  * @param ost output stream which needs timings copy and adjustments
2875  * @param ist reference input stream to copy timings from
2876  * @param copy_tb define from where the stream codec timebase needs to be imported
2877  */
2879  AVStream *ost, const AVStream *ist,
2880  enum AVTimebaseSource copy_tb);
2881 
2882 /**
2883  * Get the internal codec timebase from a stream.
2884  *
2885  * @param st input stream to extract the timebase from
2886  */
2888 
2889 /**
2890  * @}
2891  */
2892 
2893 #endif /* AVFORMAT_AVFORMAT_H */
avformat_get_riff_video_tags
const struct AVCodecTag * avformat_get_riff_video_tags(void)
Definition: riff.c:622
AVFormatContext::control_message_cb
av_format_control_message control_message_cb
Callback used by devices to communicate with application.
Definition: avformat.h:1710
ost
OutputStream * ost
Definition: ffmpeg_filter.c:160
av_pkt_dump2
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:111
AVCodec
AVCodec.
Definition: codec.h:202
av_codec_get_id
enum AVCodecID av_codec_get_id(const struct AVCodecTag *const *tags, unsigned int tag)
Get the AVCodecID for the given codec tag tag.
av_format_control_message
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:1170
level
uint8_t level
Definition: svq3.c:202
av_fmt_ctx_get_duration_estimation_method
enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext *ctx)
Returns the method used to set ctx->duration.
Definition: options.c:183
AVFMT_DURATION_FROM_BITRATE
@ AVFMT_DURATION_FROM_BITRATE
Duration estimated from bitrate (less accurate)
Definition: avformat.h:1183
AVOutputFormat::extensions
const char * extensions
comma-separated filename extensions
Definition: avformat.h:512
AVOutputFormat::name
const char * name
Definition: avformat.h:504
AVChapter::metadata
AVDictionary * metadata
Definition: avformat.h:1163
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:768
av_probe_input_buffer2
int av_probe_input_buffer2(AVIOContext *pb, const 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:225
AVInputFormat::raw_codec_id
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:699
AVProgram::nb_stream_indexes
unsigned int nb_stream_indexes
Definition: avformat.h:1129
AVFormatContext::max_chunk_duration
int max_chunk_duration
Max chunk time in microseconds.
Definition: avformat.h:1557
AVFormatContext::max_index_size
unsigned int max_index_size
Maximum amount of memory in bytes to use for the index of each stream.
Definition: avformat.h:1399
AVFormatContext::nb_chapters
unsigned int nb_chapters
Number of chapters in AVChapter array.
Definition: avformat.h:1418
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
AVStream::priv_data
void * priv_data
Definition: avformat.h:951
AVStream::discard
enum AVDiscard discard
Selects which packets can be discarded at will and do not need to be demuxed.
Definition: avformat.h:997
av_find_program_from_stream
AVProgram * av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s)
Find the programs which belong to a given stream.
Definition: utils.c:485
AVFormatContext::audio_preload
int audio_preload
Audio preload in microseconds.
Definition: avformat.h:1549
AVFormatContext::protocol_blacklist
char * protocol_blacklist
',' separated list of disallowed protocols.
Definition: avformat.h:1772
AVDeviceCapabilitiesQuery
Following API allows user to probe device capabilities (supported codecs, pixel formats,...
Definition: avdevice.h:401
AVFMT_TBCF_DECODER
@ AVFMT_TBCF_DECODER
Definition: avformat.h:2859
AVProgram::pmt_version
int pmt_version
Definition: avformat.h:1135
avformat_get_class
const AVClass * avformat_get_class(void)
Get the AVClass for AVFormatContext.
Definition: options.c:188
AVFMT_TBCF_AUTO
@ AVFMT_TBCF_AUTO
Definition: avformat.h:2858
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:317
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1268
index
fg index
Definition: ffmpeg_filter.c:167
AVPacketSideData
Definition: packet.h:314
AVFormatContext::strict_std_compliance
int strict_std_compliance
Allow non-standard and experimental extension.
Definition: avformat.h:1497
av_disposition_to_string
const char * av_disposition_to_string(int disposition)
Definition: utils.c:2023
av_write_uncoded_frame
int av_write_uncoded_frame(AVFormatContext *s, int stream_index, AVFrame *frame)
Write an uncoded frame to an output media file.
Definition: mux.c:1379
av_get_frame_filename2
int av_get_frame_filename2(char *buf, int buf_size, const char *path, int number, int flags)
Return in 'buf' the path with 'd' replaced by a number.
Definition: utils.c:986
AVFormatContext::max_interleave_delta
int64_t max_interleave_delta
Maximum buffering duration for interleaving.
Definition: avformat.h:1491
ist
ifilter ist
Definition: ffmpeg_filter.c:177
AVStream::avg_frame_rate
AVRational avg_frame_rate
Average framerate.
Definition: avformat.h:1015
AVChapter::start
int64_t start
Definition: avformat.h:1162
data
const char data[16]
Definition: mxf.c:143
AVFormatContext::duration_estimation_method
enum AVDurationEstimationMethod duration_estimation_method
The duration field can be estimated through various ways, and this field can be used to know how the ...
Definition: avformat.h:1588
AVFMT_TBCF_DEMUXER
@ AVFMT_TBCF_DEMUXER
Definition: avformat.h:2860
AVOutputFormat::deinit
void(* deinit)(struct AVFormatContext *)
Deinitialize format.
Definition: avformat.h:630
AVFormatContext::programs
AVProgram ** programs
Definition: avformat.h:1369
AVOutputFormat::write_packet
int(* write_packet)(struct AVFormatContext *, AVPacket *pkt)
Write a packet.
Definition: avformat.h:559
AVDictionary
Definition: dict.c:30
AVProgram::flags
int flags
Definition: avformat.h:1126
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:450
AVFormatContext::probesize
int64_t probesize
Maximum number of bytes read from input in order to determine stream properties.
Definition: avformat.h:1355
av_write_uncoded_frame_query
int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index)
Test whether a muxer supports uncoded frame.
Definition: mux.c:1391
avformat_init_output
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:451
av_read_frame
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: demux.c:1412
AVFormatContext::video_codec_id
enum AVCodecID video_codec_id
Forced video codec_id.
Definition: avformat.h:1375
AVOutputFormat::write_trailer
int(* write_trailer)(struct AVFormatContext *)
Definition: avformat.h:560
avformat_index_get_entry_from_timestamp
const AVIndexEntry * avformat_index_get_entry_from_timestamp(AVStream *st, int64_t wanted_timestamp, int flags)
Get the AVIndexEntry corresponding to the given timestamp.
Definition: seek.c:258
av_get_frame_filename
int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
Definition: utils.c:1044
AVIndexEntry
Definition: avformat.h:801
AVOutputFormat::subtitle_codec
enum AVCodecID subtitle_codec
default subtitle codec
Definition: avformat.h:516
AVIOInterruptCB
Callback for checking whether to abort blocking functions.
Definition: avio.h:58
AVProgram::pmt_pid
int pmt_pid
Definition: avformat.h:1133
AVInputFormat::long_name
const char * long_name
Descriptive name for the format, meant to be more human-readable than name.
Definition: avformat.h:662
av_filename_number_test
int av_filename_number_test(const char *filename)
Check whether filename actually is a numbered sequence generator.
Definition: utils.c:220
av_find_best_stream
int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type, int wanted_stream_nb, int related_stream, const AVCodec **decoder_ret, int flags)
Find the "best" stream in the file.
Definition: utils.c:500
avformat_queue_attached_pictures
int avformat_queue_attached_pictures(AVFormatContext *s)
Definition: utils.c:227
avformat_close_input
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: demux.c:355
AVFormatContext::interrupt_callback
AVIOInterruptCB interrupt_callback
Custom interrupt callbacks for the I/O layer.
Definition: avformat.h:1467
AVFormatContext::flush_packets
int flush_packets
Flush the I/O context after each packet.
Definition: avformat.h:1616
avformat_get_mov_video_tags
const struct AVCodecTag * avformat_get_mov_video_tags(void)
Definition: isom_tags.c:340
AVFormatContext::max_picture_buffer
unsigned int max_picture_buffer
Maximum amount of memory in bytes to use for buffering frames obtained from realtime capture devices.
Definition: avformat.h:1405
av_add_index_entry
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: seek.c:117
AVSTREAM_PARSE_FULL_ONCE
@ AVSTREAM_PARSE_FULL_ONCE
full parsing and repack of the first frame only, only implemented for H.264 currently
Definition: avformat.h:795
avformat_version
unsigned avformat_version(void)
Return the LIBAVFORMAT_VERSION_INT constant.
Definition: utils.c:60
AVStreamParseType
AVStreamParseType
Definition: avformat.h:790
AVProgram::discard
enum AVDiscard discard
selects which program to discard and which to feed to the caller
Definition: avformat.h:1127
AVChapter
Definition: avformat.h:1159
AVFormatContext::dump_separator
uint8_t * dump_separator
dump format separator.
Definition: avformat.h:1724
AVFMT_DURATION_FROM_PTS
@ AVFMT_DURATION_FROM_PTS
Duration accurately estimated from PTSes.
Definition: avformat.h:1181
type
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 type
Definition: writing_filters.txt:86
av_new_program
AVProgram * av_new_program(AVFormatContext *s, int id)
Definition: utils.c:852
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:985
av_codec_get_tag2
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.
av_probe_input_format3
const AVInputFormat * av_probe_input_format3(const AVProbeData *pd, int is_opened, int *score_ret)
Guess the file format.
Definition: format.c:128
codec.h
avformat_network_init
int avformat_network_init(void)
Do global initialization of network libraries.
Definition: utils.c:1301
AVFormatContext::event_flags
int event_flags
Flags indicating events happening on the file, a combination of AVFMT_EVENT_FLAG_*.
Definition: avformat.h:1510
AVStream::attached_pic
AVPacket attached_pic
For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet will contain the attached pictu...
Definition: avformat.h:1024
avformat_get_riff_audio_tags
const struct AVCodecTag * avformat_get_riff_audio_tags(void)
Definition: riff.c:627
AVFormatContext::bit_rate
int64_t bit_rate
Total stream bitrate in bit/s, 0 if not available.
Definition: avformat.h:1309
AVFormatContext::max_ts_probe
int max_ts_probe
Maximum number of packets to read while waiting for the first timestamp.
Definition: avformat.h:1523
AVFormatContext::format_whitelist
char * format_whitelist
',' separated list of allowed demuxers.
Definition: avformat.h:1652
AVFormatContext::format_probesize
int format_probesize
Maximum number of bytes read from input in order to identify the input format.
Definition: avformat.h:1636
av_guess_sample_aspect_ratio
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:1364
pkt
AVPacket * pkt
Definition: movenc.c:59
avformat_index_get_entries_count
int avformat_index_get_entries_count(const AVStream *st)
Get the index entry count for the given AVStream.
Definition: seek.c:244
AVFormatContext::metadata
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1429
AVInputFormat
Definition: avformat.h:650
AVProbeData::mime_type
const char * mime_type
mime_type, when known.
Definition: avformat.h:451
AVInputFormat::extensions
const char * extensions
If extensions are defined, then no probe is done.
Definition: avformat.h:676
AVFormatContext::subtitle_codec
const AVCodec * subtitle_codec
Forced subtitle codec.
Definition: avformat.h:1684
av_dump_format
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,...
Definition: dump.c:621
AVCodecTag
Definition: internal.h:51
AVFormatContext::ctx_flags
int ctx_flags
Flags signalling stream properties.
Definition: avformat.h:1249
AVOutputFormat::data_codec
enum AVCodecID data_codec
default data codec
Definition: avformat.h:611
AVProgram::id
int id
Definition: avformat.h:1125
avformat_open_input
int avformat_open_input(AVFormatContext **ps, const char *url, const AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: demux.c:207
avformat_query_codec
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:1283
AVChapter::end
int64_t end
chapter start/end time in time_base units
Definition: avformat.h:1162
s
#define s(width, name)
Definition: cbs_vp9.c:257
av_seek_frame
int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Seek to the keyframe at timestamp.
Definition: seek.c:633
AVFormatContext::flags
int flags
Flags modifying the (de)muxer behaviour.
Definition: avformat.h:1318
AVFormatContext::nb_programs
unsigned int nb_programs
Definition: avformat.h:1368
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:655
AVFormatContext::iformat
const struct AVInputFormat * iformat
The input container format.
Definition: avformat.h:1212
AVFormatContext::chapters
AVChapter ** chapters
Definition: avformat.h:1419
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:449
AVIndexEntry::size
int size
Definition: avformat.h:812
AVProbeData::filename
const char * filename
Definition: avformat.h:448
AVOpenCallback
int(* AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Definition: avformat.h:1173
av_match_ext
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
AVIndexEntry::timestamp
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
Definition: avformat.h:803
AVOutputFormat::audio_codec
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:514
AVFormatContext::output_ts_offset
int64_t output_ts_offset
Output timestamp offset, in microseconds.
Definition: avformat.h:1716
AVInputFormat::mime_type
const char * mime_type
Comma-separated list of mime types.
Definition: avformat.h:687
av_read_play
int av_read_play(AVFormatContext *s)
Start playing a network-based stream (e.g.
Definition: utils.c:568
ctx
AVFormatContext * ctx
Definition: movenc.c:48
av_class
static const AVClass av_class
Definition: options.c:135
avformat_flush
int avformat_flush(AVFormatContext *s)
Discard all internally buffered data.
Definition: seek.c:749
AVOutputFormat::init
int(* init)(struct AVFormatContext *)
Initialize format.
Definition: avformat.h:621
AVOutputFormat::codec_tag
const struct AVCodecTag *const * codec_tag
List of supported codec_id-codec_tag pairs, ordered by "better choice first".
Definition: avformat.h:529
AVIndexEntry::min_distance
int min_distance
Minimum distance between this and the previous keyframe, used to avoid unneeded searching.
Definition: avformat.h:813
av_interleaved_write_uncoded_frame
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:1385
codec_id
enum AVCodecID codec_id
Definition: vaapi_decode.c:369
AVProgram::start_time
int64_t start_time
Definition: avformat.h:1144
AVFormatContext::opaque
void * opaque
User data.
Definition: avformat.h:1705
AVFormatContext::probe_score
int probe_score
format probing score.
Definition: avformat.h:1625
f
#define f(width, name)
Definition: cbs_vp9.c:255
AVOutputFormat::get_output_timestamp
void(* get_output_timestamp)(struct AVFormatContext *s, int stream, int64_t *dts, int64_t *wall)
Definition: avformat.h:588
avformat_write_header
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:472
AVFormatContext::max_analyze_duration
int64_t max_analyze_duration
Maximum duration (in AV_TIME_BASE units) of the data read from input in avformat_find_stream_info().
Definition: avformat.h:1363
AVFormatContext::correct_ts_overflow
unsigned int correct_ts_overflow
Correct single timestamp overflows.
Definition: avformat.h:1602
av_probe_input_format2
const AVInputFormat * av_probe_input_format2(const AVProbeData *pd, int is_opened, int *score_max)
Guess the file format.
Definition: format.c:207
AVOutputFormat::write_header
int(* write_header)(struct AVFormatContext *)
Definition: avformat.h:551
AVFormatContext
Format I/O context.
Definition: avformat.h:1200
AVFormatContext::audio_codec_id
enum AVCodecID audio_codec_id
Forced audio codec_id.
Definition: avformat.h:1381
av_probe_input_format
const AVInputFormat * av_probe_input_format(const AVProbeData *pd, int is_opened)
Guess the file format.
Definition: format.c:219
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1095
AVInputFormat::codec_tag
const struct AVCodecTag *const * codec_tag
Definition: avformat.h:678
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
AVStream::time_base
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avformat.h:965
flush
static void flush(AVCodecContext *avctx)
Definition: aacdec_template.c:593
AVFormatContext::max_streams
int max_streams
The maximum number of streams.
Definition: avformat.h:1779
AVFormatContext::fps_probe_size
int fps_probe_size
The number of frames used for determining the framerate in avformat_find_stream_info().
Definition: avformat.h:1449
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVFMT_DURATION_FROM_STREAM
@ AVFMT_DURATION_FROM_STREAM
Duration estimated from a stream with a known duration.
Definition: avformat.h:1182
AVFormatContext::protocol_whitelist
char * protocol_whitelist
',' separated list of allowed protocols.
Definition: avformat.h:1737
AVOutputFormat::get_device_list
int(* get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list)
Returns device list with it properties.
Definition: avformat.h:610
AVOutputFormat::long_name
const char * long_name
Descriptive name for the format, meant to be more human-readable than name.
Definition: avformat.h:510
av_stream_add_side_data
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:1736
AVSTREAM_PARSE_NONE
@ AVSTREAM_PARSE_NONE
Definition: avformat.h:791
AVInputFormat::read_probe
int(* read_probe)(const AVProbeData *)
Tell if a given file has a chance of being parsed as this format.
Definition: avformat.h:716
AVIndexEntry::flags
int flags
Definition: avformat.h:811
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1242
AVDurationEstimationMethod
AVDurationEstimationMethod
The duration of a video can be estimated through various ways, and this enum can be used to know how ...
Definition: avformat.h:1180
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:447
AVProgram::stream_index
unsigned int * stream_index
Definition: avformat.h:1128
AVStream::metadata
AVDictionary * metadata
Definition: avformat.h:1006
time.h
AVFormatContext::skip_estimate_duration_from_pts
int skip_estimate_duration_from_pts
Skip duration calcuation in estimate_timings_from_pts.
Definition: avformat.h:1786
AVOutputFormat::priv_class
const AVClass * priv_class
AVClass for the private context.
Definition: avformat.h:532
av_write_frame
int av_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file.
Definition: mux.c:1181
AVFormatContext::audio_codec
const AVCodec * audio_codec
Forced audio codec.
Definition: avformat.h:1676
c
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
AVStream::nb_frames
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:987
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:47
AVFormatContext::nb_streams
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1256
AVFormatContext::metadata_header_padding
int metadata_header_padding
Number of bytes to be written as padding in a metadata header.
Definition: avformat.h:1699
AVOutputFormat::flags
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:523
AVInputFormat::flags_internal
int flags_internal
Internal flags.
Definition: avformat.h:709
AVFormatContext::data_codec
const AVCodec * data_codec
Forced data codec.
Definition: avformat.h:1692
options
const OptionDef options[]
avformat_find_stream_info
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: demux.c:2388
AVIOContext
Bytestream IO Context.
Definition: avio.h:161
AVProgram::pts_wrap_reference
int64_t pts_wrap_reference
reference dts for wrap detection
Definition: avformat.h:1147
AVMediaType
AVMediaType
Definition: avutil.h:199
avformat_match_stream_specifier
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:1542
id
enum AVCodecID id
Definition: extract_extradata_bsf.c:325
avformat_alloc_context
AVFormatContext * avformat_alloc_context(void)
Allocate an AVFormatContext.
Definition: options.c:154
av_codec_get_tag
unsigned int av_codec_get_tag(const struct AVCodecTag *const *tags, enum AVCodecID id)
Get the codec tag for the given codec id id.
AVProgram::end_time
int64_t end_time
Definition: avformat.h:1145
AVFormatContext::url
char * url
input or output URL.
Definition: avformat.h:1283
size
int size
Definition: twinvq_data.h:10344
avio.h
copy_tb
int copy_tb
Definition: ffmpeg_opt.c:158
avformat_seek_file
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: seek.c:656
AVStream::event_flags
int event_flags
Flags indicating events happening on the stream, a combination of AVSTREAM_EVENT_FLAG_*.
Definition: avformat.h:1061
av_guess_frame_rate
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:1387
av_stream_get_codec_timebase
AVRational av_stream_get_codec_timebase(const AVStream *st)
Get the internal codec timebase from a stream.
Definition: utils.c:1996
format
ofilter format
Definition: ffmpeg_filter.c:172
AVProgram::pts_wrap_behavior
int pts_wrap_behavior
behavior on wrap detection
Definition: avformat.h:1148
AVTimebaseSource
AVTimebaseSource
Definition: avformat.h:2857
av_demuxer_iterate
const AVInputFormat * av_demuxer_iterate(void **opaque)
Iterate over all registered demuxers.
Definition: allformats.c:564
AVProgram::program_num
int program_num
Definition: avformat.h:1132
AVStream::sample_aspect_ratio
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown)
Definition: avformat.h:1004
AVFormatContext::keylen
int keylen
Definition: avformat.h:1366
av_sdp_create
int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
Generate an SDP for an RTP session.
Definition: sdp.c:908
av_format_inject_global_side_data
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:105
offset
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
Definition: writing_filters.txt:86
AVPacketSideDataType
AVPacketSideDataType
Definition: packet.h:40
av_probe_input_buffer
int av_probe_input_buffer(AVIOContext *pb, const 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:315
AVOutputFormat::mime_type
const char * mime_type
Definition: avformat.h:511
AVFormatContext::skip_initial_bytes
int64_t skip_initial_bytes
Skip initial bytes when opening stream.
Definition: avformat.h:1595
AVOutputFormat::interleave_packet
int(* interleave_packet)(struct AVFormatContext *s, AVPacket *pkt, int flush, int has_packet)
A format-specific function for interleavement.
Definition: avformat.h:577
AVStream::side_data
AVPacketSideData * side_data
An array of side data that applies to the whole stream (i.e.
Definition: avformat.h:1044
av_warn_unused_result
#define av_warn_unused_result
Definition: attributes.h:64
AVOutputFormat::flags_internal
int flags_internal
Internal flags.
Definition: avformat.h:549
AVFormatContext::error_recognition
int error_recognition
Error recognition; higher values will detect more errors but may misdetect some more or less valid pa...
Definition: avformat.h:1456
av_write_trailer
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
Definition: mux.c:1243
av_disposition_from_string
int av_disposition_from_string(const char *disp)
Definition: utils.c:2015
log.h
AVOutputFormat
Definition: avformat.h:503
AVChapter::id
int64_t id
unique ID to identify the chapter
Definition: avformat.h:1160
packet.h
AVInputFormat::priv_data_size
int priv_data_size
Size of private data so that it can be allocated in the wrapper.
Definition: avformat.h:704
avformat_get_mov_audio_tags
const struct AVCodecTag * avformat_get_mov_audio_tags(void)
Definition: isom_tags.c:345
AVProgram::metadata
AVDictionary * metadata
Definition: avformat.h:1130
avformat_index_get_entry
const AVIndexEntry * avformat_index_get_entry(AVStream *st, int idx)
Get the AVIndexEntry corresponding to the given index.
Definition: seek.c:249
av_get_output_timestamp
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:1291
AVFormatContext::codec_whitelist
char * codec_whitelist
',' separated list of allowed decoders.
Definition: avformat.h:1644
AVFormatContext::avoid_negative_ts
int avoid_negative_ts
Avoid negative timestamps during muxing.
Definition: avformat.h:1532
av_url_split
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:1049
av_find_default_stream_index
int av_find_default_stream_index(AVFormatContext *s)
Definition: utils.c:309
AVFormatContext::max_delay
int max_delay
Definition: avformat.h:1312
AVFormatContext::io_repositioned
int io_repositioned
IO repositioned flag.
Definition: avformat.h:1660
AVProgram
New fields can be added to the end with minor version bumps.
Definition: avformat.h:1124
av_read_pause
int av_read_pause(AVFormatContext *s)
Pause a network-based stream (e.g.
Definition: utils.c:577
AVInputFormat::read_packet
int(* read_packet)(struct AVFormatContext *, AVPacket *pkt)
Read one packet and put it in 'pkt'.
Definition: avformat.h:733
int_cb
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:513
AVOutputFormat::control_message
int(* control_message)(struct AVFormatContext *s, int type, void *data, size_t data_size)
Allows sending messages from application to device.
Definition: avformat.h:593
av_get_packet
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:197
AVCodecParserContext
Definition: avcodec.h:2773
AVInputFormat::get_device_list
int(* get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list)
Returns device list with it properties.
Definition: avformat.h:783
AVInputFormat::read_seek
int(* read_seek)(struct AVFormatContext *, int stream_index, int64_t timestamp, int flags)
Seek to a given timestamp relative to the frames in stream component stream_index.
Definition: avformat.h:749
version.h
AVStream::disposition
int disposition
Stream disposition - a combination of AV_DISPOSITION_* flags.
Definition: avformat.h:995
tag
uint32_t tag
Definition: movenc.c:1596
AVStream::id
int id
Format-specific stream ID.
Definition: avformat.h:949
AVStream
Stream structure.
Definition: avformat.h:935
AVFormatContext::ts_id
int ts_id
Transport stream id.
Definition: avformat.h:1541
frame
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
Definition: filter_design.txt:264
av_hex_dump_log
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:82
AVFormatContext::oformat
const struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1219
AVDeviceInfoList
List of devices.
Definition: avdevice.h:467
AVStream::nb_side_data
int nb_side_data
The number of elements in the AVStream.side_data array.
Definition: avformat.h:1048
av_append_packet
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:213
AVSTREAM_PARSE_HEADERS
@ AVSTREAM_PARSE_HEADERS
Only parse headers, do not repack.
Definition: avformat.h:793
AVFormatContext::av_class
const AVClass * av_class
A class for logging and AVOptions.
Definition: avformat.h:1205
pos
unsigned int pos
Definition: spdifenc.c:412
av_stream_get_side_data
uint8_t * av_stream_get_side_data(const AVStream *stream, enum AVPacketSideDataType type, size_t *size)
Get side information from stream.
Definition: utils.c:1721
AVOutputFormat::write_uncoded_frame
int(* write_uncoded_frame)(struct AVFormatContext *, int stream_index, AVFrame **frame, unsigned flags)
Write an uncoded AVFrame.
Definition: avformat.h:604
dict.h
av_guess_codec
enum AVCodecID av_guess_codec(const 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
avformat_network_deinit
int avformat_network_deinit(void)
Undo the initialization done by avformat_network_init.
Definition: utils.c:1313
AVFormatContext::debug
int debug
Flags to enable debugging.
Definition: avformat.h:1472
AVFormatContext::data_codec_id
enum AVCodecID data_codec_id
Forced Data codec_id.
Definition: avformat.h:1730
AVStream::index
int index
stream index in AVFormatContext
Definition: avformat.h:943
AVInputFormat::read_seek2
int(* read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Seek to timestamp ts.
Definition: avformat.h:777
av_muxer_iterate
const AVOutputFormat * av_muxer_iterate(void **opaque)
Iterate over all registered muxers.
Definition: allformats.c:545
avformat_transfer_internal_stream_timing_info
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:1938
format_name
static int format_name(const char *buf, char **s, int index, const char *varname)
Definition: hlsenc.c:1926
AVInputFormat::read_close
int(* read_close)(struct AVFormatContext *)
Close the stream.
Definition: avformat.h:739
AVFormatContext::seek2any
int seek2any
Force seeking to any (also non key) frames.
Definition: avformat.h:1609
AVInputFormat::flags
int flags
Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:669
AVInputFormat::read_pause
int(* read_pause)(struct AVFormatContext *)
Pause playing - only meaningful if using a network-based format (RTSP).
Definition: avformat.h:769
av_stream_get_end_pts
int64_t av_stream_get_end_pts(const AVStream *st)
Returns the pts of the last muxed packet + its duration.
Definition: utils.c:87
defs.h
avformat_free_context
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: utils.c:688
AVFormatContext::io_close
void(* io_close)(struct AVFormatContext *s, AVIOContext *pb)
A callback for closing the streams opened with AVFormatContext.io_open().
Definition: avformat.h:1765
AVOutputFormat::video_codec
enum AVCodecID video_codec
default video codec
Definition: avformat.h:515
AVStream::r_frame_rate
AVRational r_frame_rate
Real base framerate of the stream.
Definition: avformat.h:1084
AVFormatContext::io_open
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:1759
AVIndexEntry::pos
int64_t pos
Definition: avformat.h:802
AVSTREAM_PARSE_FULL_RAW
@ AVSTREAM_PARSE_FULL_RAW
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:796
av_find_input_format
const AVInputFormat * av_find_input_format(const char *short_name)
Find AVInputFormat based on the short name of the input format.
Definition: format.c:118
AVFormatContext::duration
int64_t duration
Duration of the stream, in AV_TIME_BASE fractional seconds.
Definition: avformat.h:1302
avformat_license
const char * avformat_license(void)
Return the libavformat license.
Definition: utils.c:71
AVFormatContext::packet_size
unsigned int packet_size
Definition: avformat.h:1311
av_guess_format
const 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
AVFormatContext::start_time_realtime
int64_t start_time_realtime
Start time of the stream in real world time, in microseconds since the Unix epoch (00:00 1st January ...
Definition: avformat.h:1442
avformat_configuration
const char * avformat_configuration(void)
Return the libavformat build-time configuration.
Definition: utils.c:66
AVFormatContext::max_probe_packets
int max_probe_packets
Maximum number of packets that can be probed.
Definition: avformat.h:1793
codec_par.h
AVPacket
This structure stores compressed data.
Definition: packet.h:350
AVFormatContext::use_wallclock_as_timestamps
int use_wallclock_as_timestamps
forces the use of wallclock timestamps as pts/dts of packets This has undefined results in the presen...
Definition: avformat.h:1573
av_interleaved_write_frame
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
Definition: mux.c:1228
AVFormatContext::io_close2
int(* io_close2)(struct AVFormatContext *s, AVIOContext *pb)
A callback for closing the streams opened with AVFormatContext.io_open().
Definition: avformat.h:1806
av_stream_new_side_data
uint8_t * av_stream_new_side_data(AVStream *stream, enum AVPacketSideDataType type, size_t size)
Allocate new information from stream.
Definition: utils.c:1771
distance
static float distance(float x, float y, int band)
Definition: nellymoserenc.c:233
AVSTREAM_PARSE_FULL
@ AVSTREAM_PARSE_FULL
full parsing and repack
Definition: avformat.h:792
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
AVInputFormat::read_timestamp
int64_t(* read_timestamp)(struct AVFormatContext *s, int stream_index, int64_t *pos, int64_t pos_limit)
Get the next timestamp in stream[stream_index].time_base units.
Definition: avformat.h:756
AVFormatContext::start_time
int64_t start_time
Position of the first frame of the component, in AV_TIME_BASE fractional seconds.
Definition: avformat.h:1292
av_stream_get_parser
struct AVCodecParserContext * av_stream_get_parser(const AVStream *s)
Definition: utils.c:95
av_pkt_dump_log2
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:116
AVStream::start_time
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base.
Definition: avformat.h:975
av_stream_get_class
const AVClass * av_stream_get_class(void)
Get the AVClass for AVStream.
Definition: utils.c:763
AVSTREAM_PARSE_TIMESTAMPS
@ AVSTREAM_PARSE_TIMESTAMPS
full parsing and interpolation of timestamps for frames not starting on a packet boundary
Definition: avformat.h:794
AVFormatContext::avio_flags
int avio_flags
avio flags, used to force AVIO_FLAG_DIRECT.
Definition: avformat.h:1580
AVOutputFormat::query_codec
int(* query_codec)(enum AVCodecID id, int std_compliance)
Test if the given codec can be stored in this container.
Definition: avformat.h:586
AVDiscard
AVDiscard
Definition: defs.h:45
avformat_alloc_output_context2
int avformat_alloc_output_context2(AVFormatContext **ctx, const AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
Definition: mux.c:136
AVStream::pts_wrap_bits
int pts_wrap_bits
Number of bits in timestamps.
Definition: avformat.h:1104
AVInputFormat::read_header
int(* read_header)(struct AVFormatContext *)
Read the format header and initialize the AVFormatContext structure.
Definition: avformat.h:723
AVChapter::time_base
AVRational time_base
time base in which the start/end timestamps are specified
Definition: avformat.h:1161
int
int
Definition: ffmpeg_filter.c:153
AVFormatContext::priv_data
void * priv_data
Format private data.
Definition: avformat.h:1228
AVProgram::pcr_pid
int pcr_pid
Definition: avformat.h:1134
AVFormatContext::key
const uint8_t * key
Definition: avformat.h:1365
AVOutputFormat::check_bitstream
int(* check_bitstream)(struct AVFormatContext *s, struct AVStream *st, const AVPacket *pkt)
Set up any necessary bitstream filtering and extract any extra data needed for the global header.
Definition: avformat.h:639
AVInputFormat::priv_class
const AVClass * priv_class
AVClass for the private context.
Definition: avformat.h:680
AVFormatContext::max_chunk_size
int max_chunk_size
Max chunk size in bytes Note, not all formats support this and unpredictable things may happen if it ...
Definition: avformat.h:1565
av_index_search_timestamp
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: seek.c:237
AVFormatContext::video_codec
const AVCodec * video_codec
Forced video codec.
Definition: avformat.h:1668
AVInputFormat::read_play
int(* read_play)(struct AVFormatContext *)
Start/resume playing - only meaningful if using a network-based format (RTSP).
Definition: avformat.h:763
av_program_add_stream_index
void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx)
AVFormatContext::subtitle_codec_id
enum AVCodecID subtitle_codec_id
Forced subtitle codec_id.
Definition: avformat.h:1387
AVOutputFormat::priv_data_size
int priv_data_size
size of private data so that it can be allocated in the wrapper
Definition: avformat.h:544
av_hex_dump
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:77