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  * If AVPacket.buf is set on the returned packet, then the packet is
174  * allocated dynamically and the user may keep it indefinitely.
175  * Otherwise, if AVPacket.buf is NULL, the packet data is backed by a
176  * static storage somewhere inside the demuxer and the packet is only valid
177  * until the next av_read_frame() call or closing the file. If the caller
178  * requires a longer lifetime, av_packet_make_refcounted() will ensure that
179  * the data is reference counted, copying the data if necessary.
180  * In both cases, the packet must be freed with av_packet_unref() when it is no
181  * longer needed.
182  *
183  * @section lavf_decoding_seek Seeking
184  * @}
185  *
186  * @defgroup lavf_encoding Muxing
187  * @{
188  * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write
189  * it into files or other output bytestreams in the specified container format.
190  *
191  * The main API functions for muxing are avformat_write_header() for writing the
192  * file header, av_write_frame() / av_interleaved_write_frame() for writing the
193  * packets and av_write_trailer() for finalizing the file.
194  *
195  * At the beginning of the muxing process, the caller must first call
196  * avformat_alloc_context() to create a muxing context. The caller then sets up
197  * the muxer by filling the various fields in this context:
198  *
199  * - The @ref AVFormatContext.oformat "oformat" field must be set to select the
200  * muxer that will be used.
201  * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb
202  * "pb" field must be set to an opened IO context, either returned from
203  * avio_open2() or a custom one.
204  * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must
205  * be created with the avformat_new_stream() function. The caller should fill
206  * the @ref AVStream.codecpar "stream codec parameters" information, such as the
207  * codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id
208  * "id" and other parameters (e.g. width / height, the pixel or sample format,
209  * etc.) as known. The @ref AVStream.time_base "stream timebase" should
210  * be set to the timebase that the caller desires to use for this stream (note
211  * that the timebase actually used by the muxer can be different, as will be
212  * described later).
213  * - It is advised to manually initialize only the relevant fields in
214  * AVCodecParameters, rather than using @ref avcodec_parameters_copy() during
215  * remuxing: there is no guarantee that the codec context values remain valid
216  * for both input and output format contexts.
217  * - The caller may fill in additional information, such as @ref
218  * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream"
219  * metadata, @ref AVFormatContext.chapters "chapters", @ref
220  * AVFormatContext.programs "programs", etc. as described in the
221  * AVFormatContext documentation. Whether such information will actually be
222  * stored in the output depends on what the container format and the muxer
223  * support.
224  *
225  * When the muxing context is fully set up, the caller must call
226  * avformat_write_header() to initialize the muxer internals and write the file
227  * header. Whether anything actually is written to the IO context at this step
228  * depends on the muxer, but this function must always be called. Any muxer
229  * private options must be passed in the options parameter to this function.
230  *
231  * The data is then sent to the muxer by repeatedly calling av_write_frame() or
232  * av_interleaved_write_frame() (consult those functions' documentation for
233  * discussion on the difference between them; only one of them may be used with
234  * a single muxing context, they should not be mixed). Do note that the timing
235  * information on the packets sent to the muxer must be in the corresponding
236  * AVStream's timebase. That timebase is set by the muxer (in the
237  * avformat_write_header() step) and may be different from the timebase
238  * requested by the caller.
239  *
240  * Once all the data has been written, the caller must call av_write_trailer()
241  * to flush any buffered packets and finalize the output file, then close the IO
242  * context (if any) and finally free the muxing context with
243  * avformat_free_context().
244  * @}
245  *
246  * @defgroup lavf_io I/O Read/Write
247  * @{
248  * @section lavf_io_dirlist Directory listing
249  * The directory listing API makes it possible to list files on remote servers.
250  *
251  * Some of possible use cases:
252  * - an "open file" dialog to choose files from a remote location,
253  * - a recursive media finder providing a player with an ability to play all
254  * files from a given directory.
255  *
256  * @subsection lavf_io_dirlist_open Opening a directory
257  * At first, a directory needs to be opened by calling avio_open_dir()
258  * supplied with a URL and, optionally, ::AVDictionary containing
259  * protocol-specific parameters. The function returns zero or positive
260  * integer and allocates AVIODirContext on success.
261  *
262  * @code
263  * AVIODirContext *ctx = NULL;
264  * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) {
265  * fprintf(stderr, "Cannot open directory.\n");
266  * abort();
267  * }
268  * @endcode
269  *
270  * This code tries to open a sample directory using smb protocol without
271  * any additional parameters.
272  *
273  * @subsection lavf_io_dirlist_read Reading entries
274  * Each directory's entry (i.e. file, another directory, anything else
275  * within ::AVIODirEntryType) is represented by AVIODirEntry.
276  * Reading consecutive entries from an opened AVIODirContext is done by
277  * repeatedly calling avio_read_dir() on it. Each call returns zero or
278  * positive integer if successful. Reading can be stopped right after the
279  * NULL entry has been read -- it means there are no entries left to be
280  * read. The following code reads all entries from a directory associated
281  * with ctx and prints their names to standard output.
282  * @code
283  * AVIODirEntry *entry = NULL;
284  * for (;;) {
285  * if (avio_read_dir(ctx, &entry) < 0) {
286  * fprintf(stderr, "Cannot list directory.\n");
287  * abort();
288  * }
289  * if (!entry)
290  * break;
291  * printf("%s\n", entry->name);
292  * avio_free_directory_entry(&entry);
293  * }
294  * @endcode
295  * @}
296  *
297  * @defgroup lavf_codec Demuxers
298  * @{
299  * @defgroup lavf_codec_native Native Demuxers
300  * @{
301  * @}
302  * @defgroup lavf_codec_wrappers External library wrappers
303  * @{
304  * @}
305  * @}
306  * @defgroup lavf_protos I/O Protocols
307  * @{
308  * @}
309  * @defgroup lavf_internal Internal
310  * @{
311  * @}
312  * @}
313  */
314 
315 #include <time.h>
316 #include <stdio.h> /* FILE */
317 #include "libavcodec/avcodec.h"
318 #include "libavutil/dict.h"
319 #include "libavutil/log.h"
320 
321 #include "avio.h"
322 #include "libavformat/version.h"
323 
324 struct AVFormatContext;
325 
326 struct AVDeviceInfoList;
328 
329 /**
330  * @defgroup metadata_api Public Metadata API
331  * @{
332  * @ingroup libavf
333  * The metadata API allows libavformat to export metadata tags to a client
334  * application when demuxing. Conversely it allows a client application to
335  * set metadata when muxing.
336  *
337  * Metadata is exported or set as pairs of key/value strings in the 'metadata'
338  * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
339  * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
340  * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
341  * exported by demuxers isn't checked to be valid UTF-8 in most cases.
342  *
343  * Important concepts to keep in mind:
344  * - Keys are unique; there can never be 2 tags with the same key. This is
345  * also meant semantically, i.e., a demuxer should not knowingly produce
346  * several keys that are literally different but semantically identical.
347  * E.g., key=Author5, key=Author6. In this example, all authors must be
348  * placed in the same tag.
349  * - Metadata is flat, not hierarchical; there are no subtags. If you
350  * want to store, e.g., the email address of the child of producer Alice
351  * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
352  * - Several modifiers can be applied to the tag name. This is done by
353  * appending a dash character ('-') and the modifier name in the order
354  * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
355  * - language -- a tag whose value is localized for a particular language
356  * is appended with the ISO 639-2/B 3-letter language code.
357  * For example: Author-ger=Michael, Author-eng=Mike
358  * The original/default language is in the unqualified "Author" tag.
359  * A demuxer should set a default if it sets any translated tag.
360  * - sorting -- a modified version of a tag that should be used for
361  * sorting will have '-sort' appended. E.g. artist="The Beatles",
362  * artist-sort="Beatles, The".
363  * - Some protocols and demuxers support metadata updates. After a successful
364  * call to av_read_packet(), AVFormatContext.event_flags or AVStream.event_flags
365  * will be updated to indicate if metadata changed. In order to detect metadata
366  * changes on a stream, you need to loop through all streams in the AVFormatContext
367  * and check their individual event_flags.
368  *
369  * - Demuxers attempt to export metadata in a generic format, however tags
370  * with no generic equivalents are left as they are stored in the container.
371  * Follows a list of generic tag names:
372  *
373  @verbatim
374  album -- name of the set this work belongs to
375  album_artist -- main creator of the set/album, if different from artist.
376  e.g. "Various Artists" for compilation albums.
377  artist -- main creator of the work
378  comment -- any additional description of the file.
379  composer -- who composed the work, if different from artist.
380  copyright -- name of copyright holder.
381  creation_time-- date when the file was created, preferably in ISO 8601.
382  date -- date when the work was created, preferably in ISO 8601.
383  disc -- number of a subset, e.g. disc in a multi-disc collection.
384  encoder -- name/settings of the software/hardware that produced the file.
385  encoded_by -- person/group who created the file.
386  filename -- original name of the file.
387  genre -- <self-evident>.
388  language -- main language in which the work is performed, preferably
389  in ISO 639-2 format. Multiple languages can be specified by
390  separating them with commas.
391  performer -- artist who performed the work, if different from artist.
392  E.g for "Also sprach Zarathustra", artist would be "Richard
393  Strauss" and performer "London Philharmonic Orchestra".
394  publisher -- name of the label/publisher.
395  service_name -- name of the service in broadcasting (channel name).
396  service_provider -- name of the service provider in broadcasting.
397  title -- name of the work.
398  track -- number of this work in the set, can be in form current/total.
399  variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
400  @endverbatim
401  *
402  * Look in the examples section for an application example how to use the Metadata API.
403  *
404  * @}
405  */
406 
407 /* packet functions */
408 
409 
410 /**
411  * Allocate and read the payload of a packet and initialize its
412  * fields with default values.
413  *
414  * @param s associated IO context
415  * @param pkt packet
416  * @param size desired payload size
417  * @return >0 (read size) if OK, AVERROR_xxx otherwise
418  */
420 
421 
422 /**
423  * Read data and append it to the current content of the AVPacket.
424  * If pkt->size is 0 this is identical to av_get_packet.
425  * Note that this uses av_grow_packet and thus involves a realloc
426  * which is inefficient. Thus this function should only be used
427  * when there is no reasonable way to know (an upper bound of)
428  * the final size.
429  *
430  * @param s associated IO context
431  * @param pkt packet
432  * @param size amount of data to read
433  * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
434  * will not be lost even if an error occurs.
435  */
437 
438 /*************************************************/
439 /* input/output formats */
440 
441 struct AVCodecTag;
442 
443 /**
444  * This structure contains the data a format has to probe a file.
445  */
446 typedef struct AVProbeData {
447  const char *filename;
448  unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
449  int buf_size; /**< Size of buf except extra allocated bytes */
450  const char *mime_type; /**< mime_type, when known. */
451 } AVProbeData;
452 
453 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
454 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
455 
456 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
457 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type
458 #define AVPROBE_SCORE_MAX 100 ///< maximum score
459 
460 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
461 
462 /// Demuxer will use avio_open, no opened file should be provided by the caller.
463 #define AVFMT_NOFILE 0x0001
464 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
465 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
466 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
467 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
468 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
469 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
470 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
471 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
472 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
473 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
474 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
475 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
476 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
477 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
478  increasing timestamps, but they must
479  still be monotonic */
480 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
481  timestamps. If not set the timestamp
482  will be shifted in av_write_frame and
483  av_interleaved_write_frame so they
484  start from 0.
485  The user or muxer can override this through
486  AVFormatContext.avoid_negative_ts
487  */
488 
489 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
490 
491 /**
492  * @addtogroup lavf_encoding
493  * @{
494  */
495 typedef struct AVOutputFormat {
496  const char *name;
497  /**
498  * Descriptive name for the format, meant to be more human-readable
499  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
500  * to define it.
501  */
502  const char *long_name;
503  const char *mime_type;
504  const char *extensions; /**< comma-separated filename extensions */
505  /* output support */
506  enum AVCodecID audio_codec; /**< default audio codec */
507  enum AVCodecID video_codec; /**< default video codec */
508  enum AVCodecID subtitle_codec; /**< default subtitle codec */
509  /**
510  * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER,
511  * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
512  * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
513  * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
514  */
515  int flags;
517  /**
518  * List of supported codec_id-codec_tag pairs, ordered by "better
519  * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
520  */
521  const struct AVCodecTag * const *codec_tag;
522 
523 
524  const AVClass *priv_class; ///< AVClass for the private context
525 
526  /*****************************************************************
527  * No fields below this line are part of the public API. They
528  * may not be used outside of libavformat and can be changed and
529  * removed at will.
530  * New public fields should be added right above.
531  *****************************************************************
532  */
533  /**
534  * The ff_const59 define is not part of the public API and will
535  * be removed without further warning.
536  */
537 #if FF_API_AVIOFORMAT
538 #define ff_const59
539 #else
540 #define ff_const59 const
541 #endif
543  /**
544  * size of private data so that it can be allocated in the wrapper
545  */
546  int priv_data_size;
547 
548  int (*write_header)(struct AVFormatContext *);
549  /**
550  * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
551  * pkt can be NULL in order to flush data buffered in the muxer.
552  * When flushing, return 0 if there still is more data to flush,
553  * or 1 if everything was flushed and there is no more buffered
554  * data.
555  */
558  /**
559  * Currently only used to set pixel format if not YUV420P.
560  */
562  AVPacket *in, int flush);
563  /**
564  * Test if the given codec can be stored in this container.
565  *
566  * @return 1 if the codec is supported, 0 if it is not.
567  * A negative number if unknown.
568  * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
569  */
570  int (*query_codec)(enum AVCodecID id, int std_compliance);
571 
572  void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
573  int64_t *dts, int64_t *wall);
574  /**
575  * Allows sending messages from application to device.
576  */
577  int (*control_message)(struct AVFormatContext *s, int type,
578  void *data, size_t data_size);
580  /**
581  * Write an uncoded AVFrame.
582  *
583  * See av_write_uncoded_frame() for details.
584  *
585  * The library will free *frame afterwards, but the muxer can prevent it
586  * by setting the pointer to NULL.
587  */
588  int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
589  AVFrame **frame, unsigned flags);
590  /**
591  * Returns device list with it properties.
592  * @see avdevice_list_devices() for more details.
593  */
594  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
595  /**
596  * Initialize device capabilities submodule.
597  * @see avdevice_capabilities_create() for more details.
598  */
599  int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
600  /**
601  * Free device capabilities submodule.
602  * @see avdevice_capabilities_free() for more details.
603  */
604  int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
605  enum AVCodecID data_codec; /**< default data codec */
606  /**
607  * Initialize format. May allocate data here, and set any AVFormatContext or
608  * AVStream parameters that need to be set before packets are sent.
609  * This method must not write output.
610  *
611  * Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure
612  *
613  * Any allocations made here must be freed in deinit().
614  */
615  int (*init)(struct AVFormatContext *);
616  /**
617  * Deinitialize format. If present, this is called whenever the muxer is being
618  * destroyed, regardless of whether or not the header has been written.
619  *
620  * If a trailer is being written, this is called after write_trailer().
621  *
622  * This is called if init() fails as well.
623  */
624  void (*deinit)(struct AVFormatContext *);
625  /**
626  * Set up any necessary bitstream filtering and extract any extra data needed
627  * for the global header.
628  * Return 0 if more packets from this stream must be checked; 1 if not.
629  */
630  int (*check_bitstream)(struct AVFormatContext *, const AVPacket *pkt);
632 /**
633  * @}
634  */
635 
636 /**
637  * @addtogroup lavf_decoding
638  * @{
639  */
640 typedef struct AVInputFormat {
641  /**
642  * A comma separated list of short names for the format. New names
643  * may be appended with a minor bump.
644  */
645  const char *name;
646 
647  /**
648  * Descriptive name for the format, meant to be more human-readable
649  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
650  * to define it.
651  */
652  const char *long_name;
653 
654  /**
655  * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
656  * AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
657  * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
658  */
659  int flags;
660 
661  /**
662  * If extensions are defined, then no probe is done. You should
663  * usually not use extension format guessing because it is not
664  * reliable enough
665  */
666  const char *extensions;
667 
668  const struct AVCodecTag * const *codec_tag;
669 
670  const AVClass *priv_class; ///< AVClass for the private context
671 
672  /**
673  * Comma-separated list of mime types.
674  * It is used check for matching mime types while probing.
675  * @see av_probe_input_format2
676  */
677  const char *mime_type;
678 
679  /*****************************************************************
680  * No fields below this line are part of the public API. They
681  * may not be used outside of libavformat and can be changed and
682  * removed at will.
683  * New public fields should be added right above.
684  *****************************************************************
685  */
687 
688  /**
689  * Raw demuxers store their codec ID here.
690  */
691  int raw_codec_id;
692 
693  /**
694  * Size of private data so that it can be allocated in the wrapper.
695  */
696  int priv_data_size;
697 
698  /**
699  * Tell if a given file has a chance of being parsed as this format.
700  * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
701  * big so you do not have to check for that unless you need more.
702  */
703  int (*read_probe)(const AVProbeData *);
704 
705  /**
706  * Read the format header and initialize the AVFormatContext
707  * structure. Return 0 if OK. 'avformat_new_stream' should be
708  * called to create new streams.
709  */
710  int (*read_header)(struct AVFormatContext *);
711 
712  /**
713  * Read one packet and put it in 'pkt'. pts and flags are also
714  * set. 'avformat_new_stream' can be called only if the flag
715  * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
716  * background thread).
717  * @return 0 on success, < 0 on error.
718  * When returning an error, pkt must not have been allocated
719  * or must be freed before returning
720  */
721  int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
722 
723  /**
724  * Close the stream. The AVFormatContext and AVStreams are not
725  * freed by this function
726  */
727  int (*read_close)(struct AVFormatContext *);
728 
729  /**
730  * Seek to a given timestamp relative to the frames in
731  * stream component stream_index.
732  * @param stream_index Must not be -1.
733  * @param flags Selects which direction should be preferred if no exact
734  * match is available.
735  * @return >= 0 on success (but not necessarily the new offset)
736  */
737  int (*read_seek)(struct AVFormatContext *,
738  int stream_index, int64_t timestamp, int flags);
739 
740  /**
741  * Get the next timestamp in stream[stream_index].time_base units.
742  * @return the timestamp or AV_NOPTS_VALUE if an error occurred
743  */
744  int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
745  int64_t *pos, int64_t pos_limit);
747  /**
748  * Start/resume playing - only meaningful if using a network-based format
749  * (RTSP).
750  */
751  int (*read_play)(struct AVFormatContext *);
752 
753  /**
754  * Pause playing - only meaningful if using a network-based format
755  * (RTSP).
756  */
757  int (*read_pause)(struct AVFormatContext *);
758 
759  /**
760  * Seek to timestamp ts.
761  * Seeking will be done so that the point from which all active streams
762  * can be presented successfully will be closest to ts and within min/max_ts.
763  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
764  */
765  int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
767  /**
768  * Returns device list with it properties.
769  * @see avdevice_list_devices() for more details.
770  */
771  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
772 
773  /**
774  * Initialize device capabilities submodule.
775  * @see avdevice_capabilities_create() for more details.
776  */
777  int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
778 
779  /**
780  * Free device capabilities submodule.
781  * @see avdevice_capabilities_free() for more details.
782  */
783  int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
784 } AVInputFormat;
785 /**
786  * @}
787  */
788 
789 enum AVStreamParseType {
791  AVSTREAM_PARSE_FULL, /**< full parsing and repack */
792  AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
793  AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
794  AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
795  AVSTREAM_PARSE_FULL_RAW, /**< full parsing and repack with timestamp and position generation by parser for raw
796  this assumes that each packet in the file contains no demuxer level headers and
797  just codec level data, otherwise position generation would fail */
798 };
800 typedef struct AVIndexEntry {
801  int64_t pos;
802  int64_t timestamp; /**<
803  * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
804  * when seeking to this entry. That means preferable PTS on keyframe based formats.
805  * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
806  * is known
807  */
808 #define AVINDEX_KEYFRAME 0x0001
809 #define AVINDEX_DISCARD_FRAME 0x0002 /**
810  * Flag is used to indicate which frame should be discarded after decoding.
811  */
812  int flags:2;
813  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).
814  int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
815 } AVIndexEntry;
816 
817 #define AV_DISPOSITION_DEFAULT 0x0001
818 #define AV_DISPOSITION_DUB 0x0002
819 #define AV_DISPOSITION_ORIGINAL 0x0004
820 #define AV_DISPOSITION_COMMENT 0x0008
821 #define AV_DISPOSITION_LYRICS 0x0010
822 #define AV_DISPOSITION_KARAOKE 0x0020
824 /**
825  * Track should be used during playback by default.
826  * Useful for subtitle track that should be displayed
827  * even when user did not explicitly ask for subtitles.
828  */
829 #define AV_DISPOSITION_FORCED 0x0040
830 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
831 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
832 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
833 /**
834  * The stream is stored in the file as an attached picture/"cover art" (e.g.
835  * APIC frame in ID3v2). The first (usually only) packet associated with it
836  * will be returned among the first few packets read from the file unless
837  * seeking takes place. It can also be accessed at any time in
838  * AVStream.attached_pic.
839  */
840 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
841 /**
842  * The stream is sparse, and contains thumbnail images, often corresponding
843  * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
844  */
845 #define AV_DISPOSITION_TIMED_THUMBNAILS 0x0800
846 
847 typedef struct AVStreamInternal AVStreamInternal;
848 
849 /**
850  * To specify text track kind (different from subtitles default).
851  */
852 #define AV_DISPOSITION_CAPTIONS 0x10000
853 #define AV_DISPOSITION_DESCRIPTIONS 0x20000
854 #define AV_DISPOSITION_METADATA 0x40000
855 #define AV_DISPOSITION_DEPENDENT 0x80000 ///< dependent audio stream (mix_type=0 in mpegts)
856 #define AV_DISPOSITION_STILL_IMAGE 0x100000 ///< still images in video stream (still_picture_flag=1 in mpegts)
857 
858 /**
859  * Options for behavior on timestamp wrap detection.
860  */
861 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
862 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
863 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
865 /**
866  * Stream structure.
867  * New fields can be added to the end with minor version bumps.
868  * Removal, reordering and changes to existing fields require a major
869  * version bump.
870  * sizeof(AVStream) must not be used outside libav*.
871  */
872 typedef struct AVStream {
873  int index; /**< stream index in AVFormatContext */
874  /**
875  * Format-specific stream ID.
876  * decoding: set by libavformat
877  * encoding: set by the user, replaced by libavformat if left unset
878  */
879  int id;
880 #if FF_API_LAVF_AVCTX
881  /**
882  * @deprecated use the codecpar struct instead
883  */
885  AVCodecContext *codec;
886 #endif
887  void *priv_data;
889  /**
890  * This is the fundamental unit of time (in seconds) in terms
891  * of which frame timestamps are represented.
892  *
893  * decoding: set by libavformat
894  * encoding: May be set by the caller before avformat_write_header() to
895  * provide a hint to the muxer about the desired timebase. In
896  * avformat_write_header(), the muxer will overwrite this field
897  * with the timebase that will actually be used for the timestamps
898  * written into the file (which may or may not be related to the
899  * user-provided one, depending on the format).
900  */
901  AVRational time_base;
902 
903  /**
904  * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
905  * Only set this if you are absolutely 100% sure that the value you set
906  * it to really is the pts of the first frame.
907  * This may be undefined (AV_NOPTS_VALUE).
908  * @note The ASF header does NOT contain a correct start_time the ASF
909  * demuxer must NOT set this.
910  */
911  int64_t start_time;
912 
913  /**
914  * Decoding: duration of the stream, in stream time base.
915  * If a source file does not specify a duration, but does specify
916  * a bitrate, this value will be estimated from bitrate and file size.
917  *
918  * Encoding: May be set by the caller before avformat_write_header() to
919  * provide a hint to the muxer about the estimated duration.
920  */
921  int64_t duration;
922 
923  int64_t nb_frames; ///< number of frames in this stream if known or 0
924 
925  int disposition; /**< AV_DISPOSITION_* bit field */
926 
927  enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
928 
929  /**
930  * sample aspect ratio (0 if unknown)
931  * - encoding: Set by user.
932  * - decoding: Set by libavformat.
933  */
934  AVRational sample_aspect_ratio;
935 
936  AVDictionary *metadata;
937 
938  /**
939  * Average framerate
940  *
941  * - demuxing: May be set by libavformat when creating the stream or in
942  * avformat_find_stream_info().
943  * - muxing: May be set by the caller before avformat_write_header().
944  */
945  AVRational avg_frame_rate;
946 
947  /**
948  * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
949  * will contain the attached picture.
950  *
951  * decoding: set by libavformat, must not be modified by the caller.
952  * encoding: unused
953  */
954  AVPacket attached_pic;
955 
956  /**
957  * An array of side data that applies to the whole stream (i.e. the
958  * container does not allow it to change between packets).
959  *
960  * There may be no overlap between the side data in this array and side data
961  * in the packets. I.e. a given side data is either exported by the muxer
962  * (demuxing) / set by the caller (muxing) in this array, then it never
963  * appears in the packets, or the side data is exported / sent through
964  * the packets (always in the first packet where the value becomes known or
965  * changes), then it does not appear in this array.
966  *
967  * - demuxing: Set by libavformat when the stream is created.
968  * - muxing: May be set by the caller before avformat_write_header().
969  *
970  * Freed by libavformat in avformat_free_context().
971  *
972  * @see av_format_inject_global_side_data()
973  */
974  AVPacketSideData *side_data;
975  /**
976  * The number of elements in the AVStream.side_data array.
977  */
978  int nb_side_data;
979 
980  /**
981  * Flags for the user to detect events happening on the stream. Flags must
982  * be cleared by the user once the event has been handled.
983  * A combination of AVSTREAM_EVENT_FLAG_*.
984  */
985  int event_flags;
986 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
988  /**
989  * Real base framerate of the stream.
990  * This is the lowest framerate with which all timestamps can be
991  * represented accurately (it is the least common multiple of all
992  * framerates in the stream). Note, this value is just a guess!
993  * For example, if the time base is 1/90000 and all frames have either
994  * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
995  */
996  AVRational r_frame_rate;
997 
998 #if FF_API_LAVF_FFSERVER
999  /**
1000  * String containing pairs of key and values describing recommended encoder configuration.
1001  * Pairs are separated by ','.
1002  * Keys are separated from values by '='.
1003  *
1004  * @deprecated unused
1005  */
1007  char *recommended_encoder_configuration;
1008 #endif
1009 
1010  /**
1011  * Codec parameters associated with this stream. Allocated and freed by
1012  * libavformat in avformat_new_stream() and avformat_free_context()
1013  * respectively.
1014  *
1015  * - demuxing: filled by libavformat on stream creation or in
1016  * avformat_find_stream_info()
1017  * - muxing: filled by the caller before avformat_write_header()
1018  */
1019  AVCodecParameters *codecpar;
1020 
1021  /*****************************************************************
1022  * All fields below this line are not part of the public API. They
1023  * may not be used outside of libavformat and can be changed and
1024  * removed at will.
1025  * Internal note: be aware that physically removing these fields
1026  * will break ABI. Replace removed fields with dummy fields, and
1027  * add new fields to AVStreamInternal.
1028  *****************************************************************
1029  */
1030 
1031 #define MAX_STD_TIMEBASES (30*12+30+3+6)
1032  /**
1033  * Stream information used internally by avformat_find_stream_info()
1034  */
1035  struct {
1036  int64_t last_dts;
1037  int64_t duration_gcd;
1038  int duration_count;
1039  int64_t rfps_duration_sum;
1040  double (*duration_error)[2][MAX_STD_TIMEBASES];
1041  int64_t codec_info_duration;
1042  int64_t codec_info_duration_fields;
1043  int frame_delay_evidence;
1044 
1045  /**
1046  * 0 -> decoder has not been searched for yet.
1047  * >0 -> decoder found
1048  * <0 -> decoder with codec_id == -found_decoder has not been found
1049  */
1050  int found_decoder;
1052  int64_t last_duration;
1053 
1054  /**
1055  * Those are used for average framerate estimation.
1056  */
1057  int64_t fps_first_dts;
1058  int fps_first_dts_idx;
1059  int64_t fps_last_dts;
1060  int fps_last_dts_idx;
1062  } *info;
1063 
1064  int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
1065 
1066  // Timestamp generation support:
1067  /**
1068  * Timestamp corresponding to the last dts sync point.
1069  *
1070  * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
1071  * a DTS is received from the underlying container. Otherwise set to
1072  * AV_NOPTS_VALUE by default.
1073  */
1074  int64_t first_dts;
1075  int64_t cur_dts;
1076  int64_t last_IP_pts;
1077  int last_IP_duration;
1078 
1079  /**
1080  * Number of packets to buffer for codec probing
1081  */
1082  int probe_packets;
1084  /**
1085  * Number of frames that have been demuxed during avformat_find_stream_info()
1086  */
1087  int codec_info_nb_frames;
1088 
1089  /* av_read_frame() support */
1090  enum AVStreamParseType need_parsing;
1092 
1093  /**
1094  * last packet in packet_buffer for this stream when muxing.
1095  */
1096  struct AVPacketList *last_in_packet_buffer;
1097  AVProbeData probe_data;
1098 #define MAX_REORDER_DELAY 16
1099  int64_t pts_buffer[MAX_REORDER_DELAY+1];
1101  AVIndexEntry *index_entries; /**< Only used if the format does not
1102  support seeking natively. */
1103  int nb_index_entries;
1104  unsigned int index_entries_allocated_size;
1106  /**
1107  * Stream Identifier
1108  * This is the MPEG-TS stream identifier +1
1109  * 0 means unknown
1110  */
1111  int stream_identifier;
1113  /**
1114  * Details of the MPEG-TS program which created this stream.
1115  */
1116  int program_num;
1117  int pmt_version;
1118  int pmt_stream_idx;
1119 
1120  int64_t interleaver_chunk_size;
1121  int64_t interleaver_chunk_duration;
1122 
1123  /**
1124  * stream probing state
1125  * -1 -> probing finished
1126  * 0 -> no probing requested
1127  * rest -> perform probing with request_probe being the minimum score to accept.
1128  * NOT PART OF PUBLIC API
1129  */
1130  int request_probe;
1131  /**
1132  * Indicates that everything up to the next keyframe
1133  * should be discarded.
1134  */
1135  int skip_to_keyframe;
1136 
1137  /**
1138  * Number of samples to skip at the start of the frame decoded from the next packet.
1139  */
1140  int skip_samples;
1141 
1142  /**
1143  * If not 0, the number of samples that should be skipped from the start of
1144  * the stream (the samples are removed from packets with pts==0, which also
1145  * assumes negative timestamps do not happen).
1146  * Intended for use with formats such as mp3 with ad-hoc gapless audio
1147  * support.
1148  */
1149  int64_t start_skip_samples;
1150 
1151  /**
1152  * If not 0, the first audio sample that should be discarded from the stream.
1153  * This is broken by design (needs global sample count), but can't be
1154  * avoided for broken by design formats such as mp3 with ad-hoc gapless
1155  * audio support.
1156  */
1157  int64_t first_discard_sample;
1159  /**
1160  * The sample after last sample that is intended to be discarded after
1161  * first_discard_sample. Works on frame boundaries only. Used to prevent
1162  * early EOF if the gapless info is broken (considered concatenated mp3s).
1163  */
1164  int64_t last_discard_sample;
1165 
1166  /**
1167  * Number of internally decoded frames, used internally in libavformat, do not access
1168  * its lifetime differs from info which is why it is not in that structure.
1169  */
1170  int nb_decoded_frames;
1171 
1172  /**
1173  * Timestamp offset added to timestamps before muxing
1174  * NOT PART OF PUBLIC API
1175  */
1176  int64_t mux_ts_offset;
1177 
1178  /**
1179  * Internal data to check for wrapping of the time stamp
1180  */
1181  int64_t pts_wrap_reference;
1182 
1183  /**
1184  * Options for behavior, when a wrap is detected.
1185  *
1186  * Defined by AV_PTS_WRAP_ values.
1187  *
1188  * If correction is enabled, there are two possibilities:
1189  * If the first time stamp is near the wrap point, the wrap offset
1190  * will be subtracted, which will create negative time stamps.
1191  * Otherwise the offset will be added.
1192  */
1193  int pts_wrap_behavior;
1194 
1195  /**
1196  * Internal data to prevent doing update_initial_durations() twice
1197  */
1198  int update_initial_durations_done;
1199 
1200  /**
1201  * Internal data to generate dts from pts
1202  */
1203  int64_t pts_reorder_error[MAX_REORDER_DELAY+1];
1204  uint8_t pts_reorder_error_count[MAX_REORDER_DELAY+1];
1205 
1206  /**
1207  * Internal data to analyze DTS and detect faulty mpeg streams
1208  */
1209  int64_t last_dts_for_order_check;
1210  uint8_t dts_ordered;
1211  uint8_t dts_misordered;
1213  /**
1214  * Internal data to inject global side data
1215  */
1216  int inject_global_side_data;
1217 
1218  /**
1219  * display aspect ratio (0 if unknown)
1220  * - encoding: unused
1221  * - decoding: Set by libavformat to calculate sample_aspect_ratio internally
1222  */
1223  AVRational display_aspect_ratio;
1224 
1225  /**
1226  * An opaque field for libavformat internal usage.
1227  * Must not be accessed in any way by callers.
1228  */
1229  AVStreamInternal *internal;
1230 } AVStream;
1231 
1232 #if FF_API_FORMAT_GET_SET
1233 /**
1234  * Accessors for some AVStream fields. These used to be provided for ABI
1235  * compatibility, and do not need to be used anymore.
1236  */
1238 AVRational av_stream_get_r_frame_rate(const AVStream *s);
1240 void av_stream_set_r_frame_rate(AVStream *s, AVRational r);
1241 #if FF_API_LAVF_FFSERVER
1243 char* av_stream_get_recommended_encoder_configuration(const AVStream *s);
1245 void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration);
1246 #endif
1247 #endif
1248 
1250 
1251 /**
1252  * Returns the pts of the last muxed packet + its duration
1253  *
1254  * the retuned value is undefined when used with a demuxer.
1255  */
1256 int64_t av_stream_get_end_pts(const AVStream *st);
1257 
1258 #define AV_PROGRAM_RUNNING 1
1259 
1260 /**
1261  * New fields can be added to the end with minor version bumps.
1262  * Removal, reordering and changes to existing fields require a major
1263  * version bump.
1264  * sizeof(AVProgram) must not be used outside libav*.
1265  */
1266 typedef struct AVProgram {
1267  int id;
1268  int flags;
1269  enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1270  unsigned int *stream_index;
1271  unsigned int nb_stream_indexes;
1272  AVDictionary *metadata;
1273 
1274  int program_num;
1275  int pmt_pid;
1276  int pcr_pid;
1277  int pmt_version;
1279  /*****************************************************************
1280  * All fields below this line are not part of the public API. They
1281  * may not be used outside of libavformat and can be changed and
1282  * removed at will.
1283  * New public fields should be added right above.
1284  *****************************************************************
1285  */
1286  int64_t start_time;
1287  int64_t end_time;
1288 
1289  int64_t pts_wrap_reference; ///< reference dts for wrap detection
1290  int pts_wrap_behavior; ///< behavior on wrap detection
1291 } AVProgram;
1292 
1293 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1294  (streams are added dynamically) */
1295 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely
1296  not seekable, and attempts to call the
1297  seek function will fail. For some
1298  network protocols (e.g. HLS), this can
1299  change dynamically at runtime. */
1300 
1301 typedef struct AVChapter {
1302  int id; ///< unique ID to identify the chapter
1303  AVRational time_base; ///< time base in which the start/end timestamps are specified
1304  int64_t start, end; ///< chapter start/end time in time_base units
1305  AVDictionary *metadata;
1306 } AVChapter;
1307 
1308 
1309 /**
1310  * Callback used by devices to communicate with application.
1311  */
1312 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1313  void *data, size_t data_size);
1314 
1315 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
1318 /**
1319  * The duration of a video can be estimated through various ways, and this enum can be used
1320  * to know how the duration was estimated.
1321  */
1323  AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1324  AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1325  AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1326 };
1327 
1328 typedef struct AVFormatInternal AVFormatInternal;
1330 /**
1331  * Format I/O context.
1332  * New fields can be added to the end with minor version bumps.
1333  * Removal, reordering and changes to existing fields require a major
1334  * version bump.
1335  * sizeof(AVFormatContext) must not be used outside libav*, use
1336  * avformat_alloc_context() to create an AVFormatContext.
1337  *
1338  * Fields can be accessed through AVOptions (av_opt*),
1339  * the name string used matches the associated command line parameter name and
1340  * can be found in libavformat/options_table.h.
1341  * The AVOption/command line parameter names differ in some cases from the C
1342  * structure field names for historic reasons or brevity.
1343  */
1344 typedef struct AVFormatContext {
1345  /**
1346  * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1347  * Exports (de)muxer private options if they exist.
1348  */
1349  const AVClass *av_class;
1350 
1351  /**
1352  * The input container format.
1353  *
1354  * Demuxing only, set by avformat_open_input().
1355  */
1357 
1358  /**
1359  * The output container format.
1360  *
1361  * Muxing only, must be set by the caller before avformat_write_header().
1362  */
1363  ff_const59 struct AVOutputFormat *oformat;
1364 
1365  /**
1366  * Format private data. This is an AVOptions-enabled struct
1367  * if and only if iformat/oformat.priv_class is not NULL.
1368  *
1369  * - muxing: set by avformat_write_header()
1370  * - demuxing: set by avformat_open_input()
1371  */
1372  void *priv_data;
1373 
1374  /**
1375  * I/O context.
1376  *
1377  * - demuxing: either set by the user before avformat_open_input() (then
1378  * the user must close it manually) or set by avformat_open_input().
1379  * - muxing: set by the user before avformat_write_header(). The caller must
1380  * take care of closing / freeing the IO context.
1381  *
1382  * Do NOT set this field if AVFMT_NOFILE flag is set in
1383  * iformat/oformat.flags. In such a case, the (de)muxer will handle
1384  * I/O in some other way and this field will be NULL.
1385  */
1387 
1388  /* stream info */
1389  /**
1390  * Flags signalling stream properties. A combination of AVFMTCTX_*.
1391  * Set by libavformat.
1392  */
1393  int ctx_flags;
1394 
1395  /**
1396  * Number of elements in AVFormatContext.streams.
1397  *
1398  * Set by avformat_new_stream(), must not be modified by any other code.
1399  */
1400  unsigned int nb_streams;
1401  /**
1402  * A list of all streams in the file. New streams are created with
1403  * avformat_new_stream().
1404  *
1405  * - demuxing: streams are created by libavformat in avformat_open_input().
1406  * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1407  * appear in av_read_frame().
1408  * - muxing: streams are created by the user before avformat_write_header().
1409  *
1410  * Freed by libavformat in avformat_free_context().
1411  */
1412  AVStream **streams;
1413 
1414 #if FF_API_FORMAT_FILENAME
1415  /**
1416  * input or output filename
1417  *
1418  * - demuxing: set by avformat_open_input()
1419  * - muxing: may be set by the caller before avformat_write_header()
1420  *
1421  * @deprecated Use url instead.
1422  */
1424  char filename[1024];
1425 #endif
1427  /**
1428  * input or output URL. Unlike the old filename field, this field has no
1429  * length restriction.
1430  *
1431  * - demuxing: set by avformat_open_input(), initialized to an empty
1432  * string if url parameter was NULL in avformat_open_input().
1433  * - muxing: may be set by the caller before calling avformat_write_header()
1434  * (or avformat_init_output() if that is called first) to a string
1435  * which is freeable by av_free(). Set to an empty string if it
1436  * was NULL in avformat_init_output().
1437  *
1438  * Freed by libavformat in avformat_free_context().
1439  */
1440  char *url;
1441 
1442  /**
1443  * Position of the first frame of the component, in
1444  * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1445  * It is deduced from the AVStream values.
1446  *
1447  * Demuxing only, set by libavformat.
1448  */
1449  int64_t start_time;
1450 
1451  /**
1452  * Duration of the stream, in AV_TIME_BASE fractional
1453  * seconds. Only set this value if you know none of the individual stream
1454  * durations and also do not set any of them. This is deduced from the
1455  * AVStream values if not set.
1456  *
1457  * Demuxing only, set by libavformat.
1458  */
1459  int64_t duration;
1460 
1461  /**
1462  * Total stream bitrate in bit/s, 0 if not
1463  * available. Never set it directly if the file_size and the
1464  * duration are known as FFmpeg can compute it automatically.
1465  */
1466  int64_t bit_rate;
1467 
1468  unsigned int packet_size;
1469  int max_delay;
1470 
1471  /**
1472  * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1473  * Set by the user before avformat_open_input() / avformat_write_header().
1474  */
1475  int flags;
1476 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1477 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1478 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1479 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1480 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1481 #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
1482 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1483 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1484 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1485 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1486 /**
1487  * When muxing, try to avoid writing any random/volatile data to the output.
1488  * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1489  *
1490  * This flag is mainly intended for testing.
1491  */
1492 #define AVFMT_FLAG_BITEXACT 0x0400
1493 #if FF_API_LAVF_MP4A_LATM
1494 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Deprecated, does nothing.
1495 #endif
1496 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1497 #define AVFMT_FLAG_PRIV_OPT 0x20000 ///< Enable use of private options by delaying codec open (this could be made default once all code is converted)
1498 #if FF_API_LAVF_KEEPSIDE_FLAG
1499 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Deprecated, does nothing.
1500 #endif
1501 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1502 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
1503 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
1504 
1505  /**
1506  * Maximum size of the data read from input for determining
1507  * the input container format.
1508  * Demuxing only, set by the caller before avformat_open_input().
1509  */
1510  int64_t probesize;
1512  /**
1513  * Maximum duration (in AV_TIME_BASE units) of the data read
1514  * from input in avformat_find_stream_info().
1515  * Demuxing only, set by the caller before avformat_find_stream_info().
1516  * Can be set to 0 to let avformat choose using a heuristic.
1517  */
1518  int64_t max_analyze_duration;
1519 
1520  const uint8_t *key;
1521  int keylen;
1522 
1523  unsigned int nb_programs;
1524  AVProgram **programs;
1525 
1526  /**
1527  * Forced video codec_id.
1528  * Demuxing: Set by user.
1529  */
1530  enum AVCodecID video_codec_id;
1531 
1532  /**
1533  * Forced audio codec_id.
1534  * Demuxing: Set by user.
1535  */
1536  enum AVCodecID audio_codec_id;
1538  /**
1539  * Forced subtitle codec_id.
1540  * Demuxing: Set by user.
1541  */
1542  enum AVCodecID subtitle_codec_id;
1543 
1544  /**
1545  * Maximum amount of memory in bytes to use for the index of each stream.
1546  * If the index exceeds this size, entries will be discarded as
1547  * needed to maintain a smaller size. This can lead to slower or less
1548  * accurate seeking (depends on demuxer).
1549  * Demuxers for which a full in-memory index is mandatory will ignore
1550  * this.
1551  * - muxing: unused
1552  * - demuxing: set by user
1553  */
1554  unsigned int max_index_size;
1555 
1556  /**
1557  * Maximum amount of memory in bytes to use for buffering frames
1558  * obtained from realtime capture devices.
1559  */
1560  unsigned int max_picture_buffer;
1561 
1562  /**
1563  * Number of chapters in AVChapter array.
1564  * When muxing, chapters are normally written in the file header,
1565  * so nb_chapters should normally be initialized before write_header
1566  * is called. Some muxers (e.g. mov and mkv) can also write chapters
1567  * in the trailer. To write chapters in the trailer, nb_chapters
1568  * must be zero when write_header is called and non-zero when
1569  * write_trailer is called.
1570  * - muxing: set by user
1571  * - demuxing: set by libavformat
1572  */
1573  unsigned int nb_chapters;
1574  AVChapter **chapters;
1575 
1576  /**
1577  * Metadata that applies to the whole file.
1578  *
1579  * - demuxing: set by libavformat in avformat_open_input()
1580  * - muxing: may be set by the caller before avformat_write_header()
1581  *
1582  * Freed by libavformat in avformat_free_context().
1583  */
1584  AVDictionary *metadata;
1585 
1586  /**
1587  * Start time of the stream in real world time, in microseconds
1588  * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1589  * stream was captured at this real world time.
1590  * - muxing: Set by the caller before avformat_write_header(). If set to
1591  * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1592  * be used.
1593  * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1594  * the value may become known after some number of frames
1595  * have been received.
1596  */
1597  int64_t start_time_realtime;
1599  /**
1600  * The number of frames used for determining the framerate in
1601  * avformat_find_stream_info().
1602  * Demuxing only, set by the caller before avformat_find_stream_info().
1603  */
1604  int fps_probe_size;
1605 
1606  /**
1607  * Error recognition; higher values will detect more errors but may
1608  * misdetect some more or less valid parts as errors.
1609  * Demuxing only, set by the caller before avformat_open_input().
1610  */
1611  int error_recognition;
1612 
1613  /**
1614  * Custom interrupt callbacks for the I/O layer.
1615  *
1616  * demuxing: set by the user before avformat_open_input().
1617  * muxing: set by the user before avformat_write_header()
1618  * (mainly useful for AVFMT_NOFILE formats). The callback
1619  * should also be passed to avio_open2() if it's used to
1620  * open the file.
1621  */
1622  AVIOInterruptCB interrupt_callback;
1623 
1624  /**
1625  * Flags to enable debugging.
1626  */
1627  int debug;
1628 #define FF_FDEBUG_TS 0x0001
1629 
1630  /**
1631  * Maximum buffering duration for interleaving.
1632  *
1633  * To ensure all the streams are interleaved correctly,
1634  * av_interleaved_write_frame() will wait until it has at least one packet
1635  * for each stream before actually writing any packets to the output file.
1636  * When some streams are "sparse" (i.e. there are large gaps between
1637  * successive packets), this can result in excessive buffering.
1638  *
1639  * This field specifies the maximum difference between the timestamps of the
1640  * first and the last packet in the muxing queue, above which libavformat
1641  * will output a packet regardless of whether it has queued a packet for all
1642  * the streams.
1643  *
1644  * Muxing only, set by the caller before avformat_write_header().
1645  */
1646  int64_t max_interleave_delta;
1647 
1648  /**
1649  * Allow non-standard and experimental extension
1650  * @see AVCodecContext.strict_std_compliance
1651  */
1652  int strict_std_compliance;
1653 
1654  /**
1655  * Flags for the user to detect events happening on the file. Flags must
1656  * be cleared by the user once the event has been handled.
1657  * A combination of AVFMT_EVENT_FLAG_*.
1658  */
1659  int event_flags;
1660 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
1661 
1662  /**
1663  * Maximum number of packets to read while waiting for the first timestamp.
1664  * Decoding only.
1665  */
1666  int max_ts_probe;
1667 
1668  /**
1669  * Avoid negative timestamps during muxing.
1670  * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1671  * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use)
1672  * - muxing: Set by user
1673  * - demuxing: unused
1674  */
1675  int avoid_negative_ts;
1676 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1677 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1678 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1679 
1680  /**
1681  * Transport stream id.
1682  * This will be moved into demuxer private options. Thus no API/ABI compatibility
1683  */
1684  int ts_id;
1685 
1686  /**
1687  * Audio preload in microseconds.
1688  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1689  * - encoding: Set by user
1690  * - decoding: unused
1691  */
1692  int audio_preload;
1693 
1694  /**
1695  * Max chunk time in microseconds.
1696  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1697  * - encoding: Set by user
1698  * - decoding: unused
1699  */
1700  int max_chunk_duration;
1701 
1702  /**
1703  * Max chunk size in bytes
1704  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1705  * - encoding: Set by user
1706  * - decoding: unused
1707  */
1708  int max_chunk_size;
1709 
1710  /**
1711  * forces the use of wallclock timestamps as pts/dts of packets
1712  * This has undefined results in the presence of B frames.
1713  * - encoding: unused
1714  * - decoding: Set by user
1715  */
1716  int use_wallclock_as_timestamps;
1717 
1718  /**
1719  * avio flags, used to force AVIO_FLAG_DIRECT.
1720  * - encoding: unused
1721  * - decoding: Set by user
1722  */
1723  int avio_flags;
1724 
1725  /**
1726  * The duration field can be estimated through various ways, and this field can be used
1727  * to know how the duration was estimated.
1728  * - encoding: unused
1729  * - decoding: Read by user
1730  */
1731  enum AVDurationEstimationMethod duration_estimation_method;
1732 
1733  /**
1734  * Skip initial bytes when opening stream
1735  * - encoding: unused
1736  * - decoding: Set by user
1737  */
1738  int64_t skip_initial_bytes;
1739 
1740  /**
1741  * Correct single timestamp overflows
1742  * - encoding: unused
1743  * - decoding: Set by user
1744  */
1745  unsigned int correct_ts_overflow;
1746 
1747  /**
1748  * Force seeking to any (also non key) frames.
1749  * - encoding: unused
1750  * - decoding: Set by user
1751  */
1752  int seek2any;
1753 
1754  /**
1755  * Flush the I/O context after each packet.
1756  * - encoding: Set by user
1757  * - decoding: unused
1758  */
1759  int flush_packets;
1760 
1761  /**
1762  * format probing score.
1763  * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1764  * the format.
1765  * - encoding: unused
1766  * - decoding: set by avformat, read by user
1767  */
1768  int probe_score;
1769 
1770  /**
1771  * number of bytes to read maximally to identify format.
1772  * - encoding: unused
1773  * - decoding: set by user
1774  */
1775  int format_probesize;
1776 
1777  /**
1778  * ',' separated list of allowed decoders.
1779  * If NULL then all are allowed
1780  * - encoding: unused
1781  * - decoding: set by user
1782  */
1783  char *codec_whitelist;
1784 
1785  /**
1786  * ',' separated list of allowed demuxers.
1787  * If NULL then all are allowed
1788  * - encoding: unused
1789  * - decoding: set by user
1790  */
1791  char *format_whitelist;
1792 
1793  /**
1794  * An opaque field for libavformat internal usage.
1795  * Must not be accessed in any way by callers.
1796  */
1797  AVFormatInternal *internal;
1798 
1799  /**
1800  * IO repositioned flag.
1801  * This is set by avformat when the underlaying IO context read pointer
1802  * is repositioned, for example when doing byte based seeking.
1803  * Demuxers can use the flag to detect such changes.
1804  */
1805  int io_repositioned;
1806 
1807  /**
1808  * Forced video codec.
1809  * This allows forcing a specific decoder, even when there are multiple with
1810  * the same codec_id.
1811  * Demuxing: Set by user
1812  */
1814 
1815  /**
1816  * Forced audio codec.
1817  * This allows forcing a specific decoder, even when there are multiple with
1818  * the same codec_id.
1819  * Demuxing: Set by user
1820  */
1822 
1823  /**
1824  * Forced subtitle codec.
1825  * This allows forcing a specific decoder, even when there are multiple with
1826  * the same codec_id.
1827  * Demuxing: Set by user
1828  */
1830 
1831  /**
1832  * Forced data codec.
1833  * This allows forcing a specific decoder, even when there are multiple with
1834  * the same codec_id.
1835  * Demuxing: Set by user
1836  */
1838 
1839  /**
1840  * Number of bytes to be written as padding in a metadata header.
1841  * Demuxing: Unused.
1842  * Muxing: Set by user via av_format_set_metadata_header_padding.
1843  */
1844  int metadata_header_padding;
1845 
1846  /**
1847  * User data.
1848  * This is a place for some private data of the user.
1849  */
1850  void *opaque;
1852  /**
1853  * Callback used by devices to communicate with application.
1854  */
1855  av_format_control_message control_message_cb;
1856 
1857  /**
1858  * Output timestamp offset, in microseconds.
1859  * Muxing: set by user
1860  */
1861  int64_t output_ts_offset;
1862 
1863  /**
1864  * dump format separator.
1865  * can be ", " or "\n " or anything else
1866  * - muxing: Set by user.
1867  * - demuxing: Set by user.
1868  */
1869  uint8_t *dump_separator;
1870 
1871  /**
1872  * Forced Data codec_id.
1873  * Demuxing: Set by user.
1874  */
1875  enum AVCodecID data_codec_id;
1876 
1877 #if FF_API_OLD_OPEN_CALLBACKS
1878  /**
1879  * Called to open further IO contexts when needed for demuxing.
1880  *
1881  * This can be set by the user application to perform security checks on
1882  * the URLs before opening them.
1883  * The function should behave like avio_open2(), AVFormatContext is provided
1884  * as contextual information and to reach AVFormatContext.opaque.
1885  *
1886  * If NULL then some simple checks are used together with avio_open2().
1887  *
1888  * Must not be accessed directly from outside avformat.
1889  * @See av_format_set_open_cb()
1890  *
1891  * Demuxing: Set by user.
1892  *
1893  * @deprecated Use io_open and io_close.
1894  */
1896  int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options);
1897 #endif
1898 
1899  /**
1900  * ',' separated list of allowed protocols.
1901  * - encoding: unused
1902  * - decoding: set by user
1903  */
1904  char *protocol_whitelist;
1905 
1906  /**
1907  * A callback for opening new IO streams.
1908  *
1909  * Whenever a muxer or a demuxer needs to open an IO stream (typically from
1910  * avformat_open_input() for demuxers, but for certain formats can happen at
1911  * other times as well), it will call this callback to obtain an IO context.
1912  *
1913  * @param s the format context
1914  * @param pb on success, the newly opened IO context should be returned here
1915  * @param url the url to open
1916  * @param flags a combination of AVIO_FLAG_*
1917  * @param options a dictionary of additional options, with the same
1918  * semantics as in avio_open2()
1919  * @return 0 on success, a negative AVERROR code on failure
1920  *
1921  * @note Certain muxers and demuxers do nesting, i.e. they open one or more
1922  * additional internal format contexts. Thus the AVFormatContext pointer
1923  * passed to this callback may be different from the one facing the caller.
1924  * It will, however, have the same 'opaque' field.
1925  */
1926  int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url,
1927  int flags, AVDictionary **options);
1928 
1929  /**
1930  * A callback for closing the streams opened with AVFormatContext.io_open().
1931  */
1932  void (*io_close)(struct AVFormatContext *s, AVIOContext *pb);
1933 
1934  /**
1935  * ',' separated list of disallowed protocols.
1936  * - encoding: unused
1937  * - decoding: set by user
1938  */
1939  char *protocol_blacklist;
1941  /**
1942  * The maximum number of streams.
1943  * - encoding: unused
1944  * - decoding: set by user
1945  */
1947 
1948  /**
1949  * Skip duration calcuation in estimate_timings_from_pts.
1950  * - encoding: unused
1951  * - decoding: set by user
1952  */
1954 } AVFormatContext;
1955 
1956 #if FF_API_FORMAT_GET_SET
1957 /**
1958  * Accessors for some AVFormatContext fields. These used to be provided for ABI
1959  * compatibility, and do not need to be used anymore.
1960  */
1962 int av_format_get_probe_score(const AVFormatContext *s);
1964 AVCodec * av_format_get_video_codec(const AVFormatContext *s);
1966 void av_format_set_video_codec(AVFormatContext *s, AVCodec *c);
1968 AVCodec * av_format_get_audio_codec(const AVFormatContext *s);
1970 void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c);
1972 AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s);
1974 void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c);
1976 AVCodec * av_format_get_data_codec(const AVFormatContext *s);
1978 void av_format_set_data_codec(AVFormatContext *s, AVCodec *c);
1980 int av_format_get_metadata_header_padding(const AVFormatContext *s);
1982 void av_format_set_metadata_header_padding(AVFormatContext *s, int c);
1984 void * av_format_get_opaque(const AVFormatContext *s);
1986 void av_format_set_opaque(AVFormatContext *s, void *opaque);
1988 av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s);
1990 void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback);
1991 #if FF_API_OLD_OPEN_CALLBACKS
1992 attribute_deprecated AVOpenCallback av_format_get_open_cb(const AVFormatContext *s);
1993 attribute_deprecated void av_format_set_open_cb(AVFormatContext *s, AVOpenCallback callback);
1994 #endif
1995 #endif
1996 
1997 /**
1998  * This function will cause global side data to be injected in the next packet
1999  * of each stream as well as after any subsequent seek.
2000  */
2002 
2003 /**
2004  * Returns the method used to set ctx->duration.
2005  *
2006  * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
2007  */
2009 
2010 typedef struct AVPacketList {
2011  AVPacket pkt;
2012  struct AVPacketList *next;
2013 } AVPacketList;
2014 
2015 
2016 /**
2017  * @defgroup lavf_core Core functions
2018  * @ingroup libavf
2019  *
2020  * Functions for querying libavformat capabilities, allocating core structures,
2021  * etc.
2022  * @{
2023  */
2025 /**
2026  * Return the LIBAVFORMAT_VERSION_INT constant.
2027  */
2028 unsigned avformat_version(void);
2029 
2030 /**
2031  * Return the libavformat build-time configuration.
2032  */
2033 const char *avformat_configuration(void);
2034 
2035 /**
2036  * Return the libavformat license.
2037  */
2038 const char *avformat_license(void);
2039 
2040 #if FF_API_NEXT
2041 /**
2042  * Initialize libavformat and register all the muxers, demuxers and
2043  * protocols. If you do not call this function, then you can select
2044  * exactly which formats you want to support.
2045  *
2046  * @see av_register_input_format()
2047  * @see av_register_output_format()
2048  */
2050 void av_register_all(void);
2051 
2053 void av_register_input_format(AVInputFormat *format);
2055 void av_register_output_format(AVOutputFormat *format);
2056 #endif
2057 
2058 /**
2059  * Do global initialization of network libraries. This is optional,
2060  * and not recommended anymore.
2061  *
2062  * This functions only exists to work around thread-safety issues
2063  * with older GnuTLS or OpenSSL libraries. If libavformat is linked
2064  * to newer versions of those libraries, or if you do not use them,
2065  * calling this function is unnecessary. Otherwise, you need to call
2066  * this function before any other threads using them are started.
2067  *
2068  * This function will be deprecated once support for older GnuTLS and
2069  * OpenSSL libraries is removed, and this function has no purpose
2070  * anymore.
2071  */
2072 int avformat_network_init(void);
2073 
2074 /**
2075  * Undo the initialization done by avformat_network_init. Call it only
2076  * once for each time you called avformat_network_init.
2077  */
2078 int avformat_network_deinit(void);
2079 
2080 #if FF_API_NEXT
2081 /**
2082  * If f is NULL, returns the first registered input format,
2083  * if f is non-NULL, returns the next registered input format after f
2084  * or NULL if f is the last one.
2085  */
2087 AVInputFormat *av_iformat_next(const AVInputFormat *f);
2088 
2089 /**
2090  * If f is NULL, returns the first registered output format,
2091  * if f is non-NULL, returns the next registered output format after f
2092  * or NULL if f is the last one.
2093  */
2095 AVOutputFormat *av_oformat_next(const AVOutputFormat *f);
2096 #endif
2097 
2098 /**
2099  * Iterate over all registered muxers.
2100  *
2101  * @param opaque a pointer where libavformat will store the iteration state. Must
2102  * point to NULL to start the iteration.
2103  *
2104  * @return the next registered muxer or NULL when the iteration is
2105  * finished
2106  */
2107 const AVOutputFormat *av_muxer_iterate(void **opaque);
2108 
2109 /**
2110  * Iterate over all registered demuxers.
2111  *
2112  * @param opaque a pointer where libavformat will store the iteration state. Must
2113  * point to NULL to start the iteration.
2114  *
2115  * @return the next registered demuxer or NULL when the iteration is
2116  * finished
2117  */
2118 const AVInputFormat *av_demuxer_iterate(void **opaque);
2119 
2120 /**
2121  * Allocate an AVFormatContext.
2122  * avformat_free_context() can be used to free the context and everything
2123  * allocated by the framework within it.
2124  */
2126 
2127 /**
2128  * Free an AVFormatContext and all its streams.
2129  * @param s context to free
2130  */
2132 
2133 /**
2134  * Get the AVClass for AVFormatContext. It can be used in combination with
2135  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2136  *
2137  * @see av_opt_find().
2138  */
2139 const AVClass *avformat_get_class(void);
2140 
2141 /**
2142  * Add a new stream to a media file.
2143  *
2144  * When demuxing, it is called by the demuxer in read_header(). If the
2145  * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2146  * be called in read_packet().
2147  *
2148  * When muxing, should be called by the user before avformat_write_header().
2149  *
2150  * User is required to call avcodec_close() and avformat_free_context() to
2151  * clean up the allocation by avformat_new_stream().
2152  *
2153  * @param s media file handle
2154  * @param c If non-NULL, the AVCodecContext corresponding to the new stream
2155  * will be initialized to use this codec. This is needed for e.g. codec-specific
2156  * defaults to be set, so codec should be provided if it is known.
2157  *
2158  * @return newly created stream or NULL on error.
2159  */
2161 
2162 /**
2163  * Wrap an existing array as stream side data.
2164  *
2165  * @param st stream
2166  * @param type side information type
2167  * @param data the side data array. It must be allocated with the av_malloc()
2168  * family of functions. The ownership of the data is transferred to
2169  * st.
2170  * @param size side information size
2171  * @return zero on success, a negative AVERROR code on failure. On failure,
2172  * the stream is unchanged and the data remains owned by the caller.
2173  */
2175  uint8_t *data, size_t size);
2176 
2177 /**
2178  * Allocate new information from stream.
2179  *
2180  * @param stream stream
2181  * @param type desired side information type
2182  * @param size side information size
2183  * @return pointer to fresh allocated data or NULL otherwise
2184  */
2186  enum AVPacketSideDataType type, int size);
2187 /**
2188  * Get side information from stream.
2189  *
2190  * @param stream stream
2191  * @param type desired side information type
2192  * @param size pointer for side information size to store (optional)
2193  * @return pointer to data if present or NULL otherwise
2194  */
2196  enum AVPacketSideDataType type, int *size);
2197 
2199 
2200 /**
2201  * @}
2202  */
2203 
2204 
2205 /**
2206  * Allocate an AVFormatContext for an output format.
2207  * avformat_free_context() can be used to free the context and
2208  * everything allocated by the framework within it.
2209  *
2210  * @param *ctx is set to the created format context, or to NULL in
2211  * case of failure
2212  * @param oformat format to use for allocating the context, if NULL
2213  * format_name and filename are used instead
2214  * @param format_name the name of output format to use for allocating the
2215  * context, if NULL filename is used instead
2216  * @param filename the name of the filename to use for allocating the
2217  * context, may be NULL
2218  * @return >= 0 in case of success, a negative AVERROR code in case of
2219  * failure
2220  */
2222  const char *format_name, const char *filename);
2223 
2224 /**
2225  * @addtogroup lavf_decoding
2226  * @{
2227  */
2228 
2229 /**
2230  * Find AVInputFormat based on the short name of the input format.
2231  */
2232 ff_const59 AVInputFormat *av_find_input_format(const char *short_name);
2233 
2234 /**
2235  * Guess the file format.
2236  *
2237  * @param pd data to be probed
2238  * @param is_opened Whether the file is already opened; determines whether
2239  * demuxers with or without AVFMT_NOFILE are probed.
2240  */
2242 
2243 /**
2244  * Guess the file format.
2245  *
2246  * @param pd data to be probed
2247  * @param is_opened Whether the file is already opened; determines whether
2248  * demuxers with or without AVFMT_NOFILE are probed.
2249  * @param score_max A probe score larger that this is required to accept a
2250  * detection, the variable is set to the actual detection
2251  * score afterwards.
2252  * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2253  * to retry with a larger probe buffer.
2254  */
2255 ff_const59 AVInputFormat *av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max);
2256 
2257 /**
2258  * Guess the file format.
2259  *
2260  * @param is_opened Whether the file is already opened; determines whether
2261  * demuxers with or without AVFMT_NOFILE are probed.
2262  * @param score_ret The score of the best detection.
2263  */
2264 ff_const59 AVInputFormat *av_probe_input_format3(ff_const59 AVProbeData *pd, int is_opened, int *score_ret);
2265 
2266 /**
2267  * Probe a bytestream to determine the input format. Each time a probe returns
2268  * with a score that is too low, the probe buffer size is increased and another
2269  * attempt is made. When the maximum probe size is reached, the input format
2270  * with the highest score is returned.
2271  *
2272  * @param pb the bytestream to probe
2273  * @param fmt the input format is put here
2274  * @param url the url of the stream
2275  * @param logctx the log context
2276  * @param offset the offset within the bytestream to probe from
2277  * @param max_probe_size the maximum probe buffer size (zero for default)
2278  * @return the score in case of success, a negative value corresponding to an
2279  * the maximal score is AVPROBE_SCORE_MAX
2280  * AVERROR code otherwise
2281  */
2283  const char *url, void *logctx,
2284  unsigned int offset, unsigned int max_probe_size);
2285 
2286 /**
2287  * Like av_probe_input_buffer2() but returns 0 on success
2288  */
2290  const char *url, void *logctx,
2291  unsigned int offset, unsigned int max_probe_size);
2292 
2293 /**
2294  * Open an input stream and read the header. The codecs are not opened.
2295  * The stream must be closed with avformat_close_input().
2296  *
2297  * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
2298  * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
2299  * function and written into ps.
2300  * Note that a user-supplied AVFormatContext will be freed on failure.
2301  * @param url URL of the stream to open.
2302  * @param fmt If non-NULL, this parameter forces a specific input format.
2303  * Otherwise the format is autodetected.
2304  * @param options A dictionary filled with AVFormatContext and demuxer-private options.
2305  * On return this parameter will be destroyed and replaced with a dict containing
2306  * options that were not found. May be NULL.
2307  *
2308  * @return 0 on success, a negative AVERROR on failure.
2309  *
2310  * @note If you want to use custom IO, preallocate the format context and set its pb field.
2311  */
2313 
2316 
2317 /**
2318  * Read packets of a media file to get stream information. This
2319  * is useful for file formats with no headers such as MPEG. This
2320  * function also computes the real framerate in case of MPEG-2 repeat
2321  * frame mode.
2322  * The logical file position is not changed by this function;
2323  * examined packets may be buffered for later processing.
2324  *
2325  * @param ic media file handle
2326  * @param options If non-NULL, an ic.nb_streams long array of pointers to
2327  * dictionaries, where i-th member contains options for
2328  * codec corresponding to i-th stream.
2329  * On return each dictionary will be filled with options that were not found.
2330  * @return >=0 if OK, AVERROR_xxx on error
2331  *
2332  * @note this function isn't guaranteed to open all the codecs, so
2333  * options being non-empty at return is a perfectly normal behavior.
2334  *
2335  * @todo Let the user decide somehow what information is needed so that
2336  * we do not waste time getting stuff the user does not need.
2337  */
2339 
2340 /**
2341  * Find the programs which belong to a given stream.
2342  *
2343  * @param ic media file handle
2344  * @param last the last found program, the search will start after this
2345  * program, or from the beginning if it is NULL
2346  * @param s stream index
2347  * @return the next program which belongs to s, NULL if no program is found or
2348  * the last program is not among the programs of ic.
2349  */
2351 
2352 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
2353 
2354 /**
2355  * Find the "best" stream in the file.
2356  * The best stream is determined according to various heuristics as the most
2357  * likely to be what the user expects.
2358  * If the decoder parameter is non-NULL, av_find_best_stream will find the
2359  * default decoder for the stream's codec; streams for which no decoder can
2360  * be found are ignored.
2361  *
2362  * @param ic media file handle
2363  * @param type stream type: video, audio, subtitles, etc.
2364  * @param wanted_stream_nb user-requested stream number,
2365  * or -1 for automatic selection
2366  * @param related_stream try to find a stream related (eg. in the same
2367  * program) to this one, or -1 if none
2368  * @param decoder_ret if non-NULL, returns the decoder for the
2369  * selected stream
2370  * @param flags flags; none are currently defined
2371  * @return the non-negative stream number in case of success,
2372  * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2373  * could be found,
2374  * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2375  * @note If av_find_best_stream returns successfully and decoder_ret is not
2376  * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2377  */
2379  enum AVMediaType type,
2380  int wanted_stream_nb,
2381  int related_stream,
2382  AVCodec **decoder_ret,
2383  int flags);
2384 
2385 /**
2386  * Return the next frame of a stream.
2387  * This function returns what is stored in the file, and does not validate
2388  * that what is there are valid frames for the decoder. It will split what is
2389  * stored in the file into frames and return one for each call. It will not
2390  * omit invalid data between valid frames so as to give the decoder the maximum
2391  * information possible for decoding.
2392  *
2393  * If pkt->buf is NULL, then the packet is valid until the next
2394  * av_read_frame() or until avformat_close_input(). Otherwise the packet
2395  * is valid indefinitely. In both cases the packet must be freed with
2396  * av_packet_unref when it is no longer needed. For video, the packet contains
2397  * exactly one frame. For audio, it contains an integer number of frames if each
2398  * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
2399  * have a variable size (e.g. MPEG audio), then it contains one frame.
2400  *
2401  * pkt->pts, pkt->dts and pkt->duration are always set to correct
2402  * values in AVStream.time_base units (and guessed if the format cannot
2403  * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2404  * has B-frames, so it is better to rely on pkt->dts if you do not
2405  * decompress the payload.
2406  *
2407  * @return 0 if OK, < 0 on error or end of file
2408  */
2410 
2411 /**
2412  * Seek to the keyframe at timestamp.
2413  * 'timestamp' in 'stream_index'.
2414  *
2415  * @param s media file handle
2416  * @param stream_index If stream_index is (-1), a default
2417  * stream is selected, and timestamp is automatically converted
2418  * from AV_TIME_BASE units to the stream specific time_base.
2419  * @param timestamp Timestamp in AVStream.time_base units
2420  * or, if no stream is specified, in AV_TIME_BASE units.
2421  * @param flags flags which select direction and seeking mode
2422  * @return >= 0 on success
2423  */
2424 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2425  int flags);
2426 
2427 /**
2428  * Seek to timestamp ts.
2429  * Seeking will be done so that the point from which all active streams
2430  * can be presented successfully will be closest to ts and within min/max_ts.
2431  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2432  *
2433  * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2434  * are the file position (this may not be supported by all demuxers).
2435  * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2436  * in the stream with stream_index (this may not be supported by all demuxers).
2437  * Otherwise all timestamps are in units of the stream selected by stream_index
2438  * or if stream_index is -1, in AV_TIME_BASE units.
2439  * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2440  * keyframes (this may not be supported by all demuxers).
2441  * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2442  *
2443  * @param s media file handle
2444  * @param stream_index index of the stream which is used as time base reference
2445  * @param min_ts smallest acceptable timestamp
2446  * @param ts target timestamp
2447  * @param max_ts largest acceptable timestamp
2448  * @param flags flags
2449  * @return >=0 on success, error code otherwise
2450  *
2451  * @note This is part of the new seek API which is still under construction.
2452  * Thus do not use this yet. It may change at any time, do not expect
2453  * ABI compatibility yet!
2454  */
2455 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2456 
2457 /**
2458  * Discard all internally buffered data. This can be useful when dealing with
2459  * discontinuities in the byte stream. Generally works only with formats that
2460  * can resync. This includes headerless formats like MPEG-TS/TS but should also
2461  * work with NUT, Ogg and in a limited way AVI for example.
2462  *
2463  * The set of streams, the detected duration, stream parameters and codecs do
2464  * not change when calling this function. If you want a complete reset, it's
2465  * better to open a new AVFormatContext.
2466  *
2467  * This does not flush the AVIOContext (s->pb). If necessary, call
2468  * avio_flush(s->pb) before calling this function.
2469  *
2470  * @param s media file handle
2471  * @return >=0 on success, error code otherwise
2472  */
2474 
2475 /**
2476  * Start playing a network-based stream (e.g. RTSP stream) at the
2477  * current position.
2478  */
2480 
2481 /**
2482  * Pause a network-based stream (e.g. RTSP stream).
2483  *
2484  * Use av_read_play() to resume it.
2485  */
2487 
2488 /**
2489  * Close an opened input AVFormatContext. Free it and all its contents
2490  * and set *s to NULL.
2491  */
2493 /**
2494  * @}
2495  */
2496 
2497 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2498 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2499 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2500 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2501 
2502 /**
2503  * @addtogroup lavf_encoding
2504  * @{
2505  */
2506 
2507 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2508 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2509 
2510 /**
2511  * Allocate the stream private data and write the stream header to
2512  * an output media file.
2513  *
2514  * @param s Media file handle, must be allocated with avformat_alloc_context().
2515  * Its oformat field must be set to the desired output format;
2516  * Its pb field must be set to an already opened AVIOContext.
2517  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2518  * On return this parameter will be destroyed and replaced with a dict containing
2519  * options that were not found. May be NULL.
2520  *
2521  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init,
2522  * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init,
2523  * negative AVERROR on failure.
2524  *
2525  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2526  */
2529 
2530 /**
2531  * Allocate the stream private data and initialize the codec, but do not write the header.
2532  * May optionally be used before avformat_write_header to initialize stream parameters
2533  * before actually writing the header.
2534  * If using this function, do not pass the same options to avformat_write_header.
2535  *
2536  * @param s Media file handle, must be allocated with avformat_alloc_context().
2537  * Its oformat field must be set to the desired output format;
2538  * Its pb field must be set to an already opened AVIOContext.
2539  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2540  * On return this parameter will be destroyed and replaced with a dict containing
2541  * options that were not found. May be NULL.
2542  *
2543  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec requires avformat_write_header to fully initialize,
2544  * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec has been fully initialized,
2545  * negative AVERROR on failure.
2546  *
2547  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2548  */
2551 
2552 /**
2553  * Write a packet to an output media file.
2554  *
2555  * This function passes the packet directly to the muxer, without any buffering
2556  * or reordering. The caller is responsible for correctly interleaving the
2557  * packets if the format requires it. Callers that want libavformat to handle
2558  * the interleaving should call av_interleaved_write_frame() instead of this
2559  * function.
2560  *
2561  * @param s media file handle
2562  * @param pkt The packet containing the data to be written. Note that unlike
2563  * av_interleaved_write_frame(), this function does not take
2564  * ownership of the packet passed to it (though some muxers may make
2565  * an internal reference to the input packet).
2566  * <br>
2567  * This parameter can be NULL (at any time, not just at the end), in
2568  * order to immediately flush data buffered within the muxer, for
2569  * muxers that buffer up data internally before writing it to the
2570  * output.
2571  * <br>
2572  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2573  * set to the index of the corresponding stream in @ref
2574  * AVFormatContext.streams "s->streams".
2575  * <br>
2576  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2577  * must be set to correct values in the stream's timebase (unless the
2578  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2579  * they can be set to AV_NOPTS_VALUE).
2580  * The dts for subsequent packets passed to this function must be strictly
2581  * increasing when compared in their respective timebases (unless the
2582  * output format is flagged with the AVFMT_TS_NONSTRICT, then they
2583  * merely have to be nondecreasing). @ref AVPacket.duration
2584  * "duration") should also be set if known.
2585  * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2586  *
2587  * @see av_interleaved_write_frame()
2588  */
2590 
2591 /**
2592  * Write a packet to an output media file ensuring correct interleaving.
2593  *
2594  * This function will buffer the packets internally as needed to make sure the
2595  * packets in the output file are properly interleaved in the order of
2596  * increasing dts. Callers doing their own interleaving should call
2597  * av_write_frame() instead of this function.
2598  *
2599  * Using this function instead of av_write_frame() can give muxers advance
2600  * knowledge of future packets, improving e.g. the behaviour of the mp4
2601  * muxer for VFR content in fragmenting mode.
2602  *
2603  * @param s media file handle
2604  * @param pkt The packet containing the data to be written.
2605  * <br>
2606  * If the packet is reference-counted, this function will take
2607  * ownership of this reference and unreference it later when it sees
2608  * fit.
2609  * The caller must not access the data through this reference after
2610  * this function returns. If the packet is not reference-counted,
2611  * libavformat will make a copy.
2612  * <br>
2613  * This parameter can be NULL (at any time, not just at the end), to
2614  * flush the interleaving queues.
2615  * <br>
2616  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2617  * set to the index of the corresponding stream in @ref
2618  * AVFormatContext.streams "s->streams".
2619  * <br>
2620  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2621  * must be set to correct values in the stream's timebase (unless the
2622  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2623  * they can be set to AV_NOPTS_VALUE).
2624  * The dts for subsequent packets in one stream must be strictly
2625  * increasing (unless the output format is flagged with the
2626  * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2627  * @ref AVPacket.duration "duration") should also be set if known.
2628  *
2629  * @return 0 on success, a negative AVERROR on error. Libavformat will always
2630  * take care of freeing the packet, even if this function fails.
2631  *
2632  * @see av_write_frame(), AVFormatContext.max_interleave_delta
2633  */
2635 
2636 /**
2637  * Write an uncoded frame to an output media file.
2638  *
2639  * The frame must be correctly interleaved according to the container
2640  * specification; if not, then av_interleaved_write_frame() must be used.
2641  *
2642  * See av_interleaved_write_frame() for details.
2643  */
2644 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2645  AVFrame *frame);
2646 
2647 /**
2648  * Write an uncoded frame to an output media file.
2649  *
2650  * If the muxer supports it, this function makes it possible to write an AVFrame
2651  * structure directly, without encoding it into a packet.
2652  * It is mostly useful for devices and similar special muxers that use raw
2653  * video or PCM data and will not serialize it into a byte stream.
2654  *
2655  * To test whether it is possible to use it with a given muxer and stream,
2656  * use av_write_uncoded_frame_query().
2657  *
2658  * The caller gives up ownership of the frame and must not access it
2659  * afterwards.
2660  *
2661  * @return >=0 for success, a negative code on error
2662  */
2663 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
2664  AVFrame *frame);
2665 
2666 /**
2667  * Test whether a muxer supports uncoded frame.
2668  *
2669  * @return >=0 if an uncoded frame can be written to that muxer and stream,
2670  * <0 if not
2671  */
2672 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2673 
2674 /**
2675  * Write the stream trailer to an output media file and free the
2676  * file private data.
2677  *
2678  * May only be called after a successful call to avformat_write_header.
2679  *
2680  * @param s media file handle
2681  * @return 0 if OK, AVERROR_xxx on error
2682  */
2684 
2685 /**
2686  * Return the output format in the list of registered output formats
2687  * which best matches the provided parameters, or return NULL if
2688  * there is no match.
2689  *
2690  * @param short_name if non-NULL checks if short_name matches with the
2691  * names of the registered formats
2692  * @param filename if non-NULL checks if filename terminates with the
2693  * extensions of the registered formats
2694  * @param mime_type if non-NULL checks if mime_type matches with the
2695  * MIME type of the registered formats
2696  */
2697 ff_const59 AVOutputFormat *av_guess_format(const char *short_name,
2698  const char *filename,
2699  const char *mime_type);
2700 
2701 /**
2702  * Guess the codec ID based upon muxer and filename.
2703  */
2704 enum AVCodecID av_guess_codec(ff_const59 AVOutputFormat *fmt, const char *short_name,
2705  const char *filename, const char *mime_type,
2706  enum AVMediaType type);
2707 
2708 /**
2709  * Get timing information for the data currently output.
2710  * The exact meaning of "currently output" depends on the format.
2711  * It is mostly relevant for devices that have an internal buffer and/or
2712  * work in real time.
2713  * @param s media file handle
2714  * @param stream stream in the media file
2715  * @param[out] dts DTS of the last packet output for the stream, in stream
2716  * time_base units
2717  * @param[out] wall absolute time when that packet whas output,
2718  * in microsecond
2719  * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
2720  * Note: some formats or devices may not allow to measure dts and wall
2721  * atomically.
2722  */
2723 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2724  int64_t *dts, int64_t *wall);
2725 
2726 
2727 /**
2728  * @}
2729  */
2730 
2731 
2732 /**
2733  * @defgroup lavf_misc Utility functions
2734  * @ingroup libavf
2735  * @{
2736  *
2737  * Miscellaneous utility functions related to both muxing and demuxing
2738  * (or neither).
2739  */
2740 
2741 /**
2742  * Send a nice hexadecimal dump of a buffer to the specified file stream.
2743  *
2744  * @param f The file stream pointer where the dump should be sent to.
2745  * @param buf buffer
2746  * @param size buffer size
2747  *
2748  * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2749  */
2750 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2751 
2752 /**
2753  * Send a nice hexadecimal dump of a buffer to the log.
2754  *
2755  * @param avcl A pointer to an arbitrary struct of which the first field is a
2756  * pointer to an AVClass struct.
2757  * @param level The importance level of the message, lower values signifying
2758  * higher importance.
2759  * @param buf buffer
2760  * @param size buffer size
2761  *
2762  * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2763  */
2764 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2765 
2766 /**
2767  * Send a nice dump of a packet to the specified file stream.
2768  *
2769  * @param f The file stream pointer where the dump should be sent to.
2770  * @param pkt packet to dump
2771  * @param dump_payload True if the payload must be displayed, too.
2772  * @param st AVStream that the packet belongs to
2773  */
2774 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2775 
2776 
2777 /**
2778  * Send a nice dump of a packet to the log.
2779  *
2780  * @param avcl A pointer to an arbitrary struct of which the first field is a
2781  * pointer to an AVClass struct.
2782  * @param level The importance level of the message, lower values signifying
2783  * higher importance.
2784  * @param pkt packet to dump
2785  * @param dump_payload True if the payload must be displayed, too.
2786  * @param st AVStream that the packet belongs to
2787  */
2788 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2789  const AVStream *st);
2790 
2791 /**
2792  * Get the AVCodecID for the given codec tag tag.
2793  * If no codec id is found returns AV_CODEC_ID_NONE.
2794  *
2795  * @param tags list of supported codec_id-codec_tag pairs, as stored
2796  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2797  * @param tag codec tag to match to a codec ID
2798  */
2799 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2800 
2801 /**
2802  * Get the codec tag for the given codec id id.
2803  * If no codec tag is found returns 0.
2804  *
2805  * @param tags list of supported codec_id-codec_tag pairs, as stored
2806  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2807  * @param id codec ID to match to a codec tag
2808  */
2809 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2810 
2811 /**
2812  * Get the codec tag for the given codec id.
2813  *
2814  * @param tags list of supported codec_id - codec_tag pairs, as stored
2815  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2816  * @param id codec id that should be searched for in the list
2817  * @param tag A pointer to the found tag
2818  * @return 0 if id was not found in tags, > 0 if it was found
2819  */
2820 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2821  unsigned int *tag);
2822 
2824 
2825 /**
2826  * Get the index for a specific timestamp.
2827  *
2828  * @param st stream that the timestamp belongs to
2829  * @param timestamp timestamp to retrieve the index for
2830  * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2831  * to the timestamp which is <= the requested one, if backward
2832  * is 0, then it will be >=
2833  * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2834  * @return < 0 if no such timestamp could be found
2835  */
2836 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2837 
2838 /**
2839  * Add an index entry into a sorted list. Update the entry if the list
2840  * already contains it.
2841  *
2842  * @param timestamp timestamp in the time base of the given stream
2843  */
2844 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2845  int size, int distance, int flags);
2846 
2847 
2848 /**
2849  * Split a URL string into components.
2850  *
2851  * The pointers to buffers for storing individual components may be null,
2852  * in order to ignore that component. Buffers for components not found are
2853  * set to empty strings. If the port is not found, it is set to a negative
2854  * value.
2855  *
2856  * @param proto the buffer for the protocol
2857  * @param proto_size the size of the proto buffer
2858  * @param authorization the buffer for the authorization
2859  * @param authorization_size the size of the authorization buffer
2860  * @param hostname the buffer for the host name
2861  * @param hostname_size the size of the hostname buffer
2862  * @param port_ptr a pointer to store the port number in
2863  * @param path the buffer for the path
2864  * @param path_size the size of the path buffer
2865  * @param url the URL to split
2866  */
2867 void av_url_split(char *proto, int proto_size,
2868  char *authorization, int authorization_size,
2869  char *hostname, int hostname_size,
2870  int *port_ptr,
2871  char *path, int path_size,
2872  const char *url);
2873 
2874 
2875 /**
2876  * Print detailed information about the input or output format, such as
2877  * duration, bitrate, streams, container, programs, metadata, side data,
2878  * codec and time base.
2879  *
2880  * @param ic the context to analyze
2881  * @param index index of the stream to dump information about
2882  * @param url the URL to print, such as source or destination file
2883  * @param is_output Select whether the specified context is an input(0) or output(1)
2884  */
2886  int index,
2887  const char *url,
2888  int is_output);
2889 
2890 
2891 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
2892 
2893 /**
2894  * Return in 'buf' the path with '%d' replaced by a number.
2895  *
2896  * Also handles the '%0nd' format where 'n' is the total number
2897  * of digits and '%%'.
2898  *
2899  * @param buf destination buffer
2900  * @param buf_size destination buffer size
2901  * @param path numbered sequence string
2902  * @param number frame number
2903  * @param flags AV_FRAME_FILENAME_FLAGS_*
2904  * @return 0 if OK, -1 on format error
2905  */
2906 int av_get_frame_filename2(char *buf, int buf_size,
2907  const char *path, int number, int flags);
2908 
2909 int av_get_frame_filename(char *buf, int buf_size,
2910  const char *path, int number);
2911 
2912 /**
2913  * Check whether filename actually is a numbered sequence generator.
2914  *
2915  * @param filename possible numbered sequence string
2916  * @return 1 if a valid numbered sequence string, 0 otherwise
2917  */
2918 int av_filename_number_test(const char *filename);
2919 
2920 /**
2921  * Generate an SDP for an RTP session.
2922  *
2923  * Note, this overwrites the id values of AVStreams in the muxer contexts
2924  * for getting unique dynamic payload types.
2925  *
2926  * @param ac array of AVFormatContexts describing the RTP streams. If the
2927  * array is composed by only one context, such context can contain
2928  * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2929  * all the contexts in the array (an AVCodecContext per RTP stream)
2930  * must contain only one AVStream.
2931  * @param n_files number of AVCodecContexts contained in ac
2932  * @param buf buffer where the SDP will be stored (must be allocated by
2933  * the caller)
2934  * @param size the size of the buffer
2935  * @return 0 if OK, AVERROR_xxx on error
2936  */
2937 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2938 
2939 /**
2940  * Return a positive value if the given filename has one of the given
2941  * extensions, 0 otherwise.
2942  *
2943  * @param filename file name to check against the given extensions
2944  * @param extensions a comma-separated list of filename extensions
2945  */
2946 int av_match_ext(const char *filename, const char *extensions);
2947 
2948 /**
2949  * Test if the given container can store a codec.
2950  *
2951  * @param ofmt container to check for compatibility
2952  * @param codec_id codec to potentially store in container
2953  * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2954  *
2955  * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2956  * A negative number if this information is not available.
2957  */
2959  int std_compliance);
2960 
2961 /**
2962  * @defgroup riff_fourcc RIFF FourCCs
2963  * @{
2964  * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2965  * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2966  * following code:
2967  * @code
2968  * uint32_t tag = MKTAG('H', '2', '6', '4');
2969  * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2970  * enum AVCodecID id = av_codec_get_id(table, tag);
2971  * @endcode
2972  */
2973 /**
2974  * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2975  */
2976 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2977 /**
2978  * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2979  */
2980 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2981 /**
2982  * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2983  */
2984 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2985 /**
2986  * @return the table mapping MOV FourCCs for audio to AVCodecID.
2987  */
2988 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2989 
2990 /**
2991  * @}
2992  */
2993 
2994 /**
2995  * Guess the sample aspect ratio of a frame, based on both the stream and the
2996  * frame aspect ratio.
2997  *
2998  * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2999  * is set by the demuxer, these two may not be equal. This function tries to
3000  * return the value that you should use if you would like to display the frame.
3001  *
3002  * Basic logic is to use the stream aspect ratio if it is set to something sane
3003  * otherwise use the frame aspect ratio. This way a container setting, which is
3004  * usually easy to modify can override the coded value in the frames.
3005  *
3006  * @param format the format context which the stream is part of
3007  * @param stream the stream which the frame is part of
3008  * @param frame the frame with the aspect ratio to be determined
3009  * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
3010  */
3012 
3013 /**
3014  * Guess the frame rate, based on both the container and codec information.
3015  *
3016  * @param ctx the format context which the stream is part of
3017  * @param stream the stream which the frame is part of
3018  * @param frame the frame for which the frame rate should be determined, may be NULL
3019  * @return the guessed (valid) frame rate, 0/1 if no idea
3020  */
3022 
3023 /**
3024  * Check if the stream st contained in s is matched by the stream specifier
3025  * spec.
3026  *
3027  * See the "stream specifiers" chapter in the documentation for the syntax
3028  * of spec.
3029  *
3030  * @return >0 if st is matched by spec;
3031  * 0 if st is not matched by spec;
3032  * AVERROR code if spec is invalid
3033  *
3034  * @note A stream specifier can match several streams in the format.
3035  */
3037  const char *spec);
3038 
3040 
3041 #if FF_API_OLD_BSF
3042 /**
3043  * Apply a list of bitstream filters to a packet.
3044  *
3045  * @param codec AVCodecContext, usually from an AVStream
3046  * @param pkt the packet to apply filters to. If, on success, the returned
3047  * packet has size == 0 and side_data_elems == 0, it indicates that
3048  * the packet should be dropped
3049  * @param bsfc a NULL-terminated list of filters to apply
3050  * @return >=0 on success;
3051  * AVERROR code on failure
3052  */
3054 int av_apply_bitstream_filters(AVCodecContext *codec, AVPacket *pkt,
3055  AVBitStreamFilterContext *bsfc);
3056 #endif
3057 
3058 enum AVTimebaseSource {
3059  AVFMT_TBCF_AUTO = -1,
3062 #if FF_API_R_FRAME_RATE
3063  AVFMT_TBCF_R_FRAMERATE,
3064 #endif
3065 };
3066 
3067 /**
3068  * Transfer internal timing information from one stream to another.
3069  *
3070  * This function is useful when doing stream copy.
3071  *
3072  * @param ofmt target output format for ost
3073  * @param ost output stream which needs timings copy and adjustments
3074  * @param ist reference input stream to copy timings from
3075  * @param copy_tb define from where the stream codec timebase needs to be imported
3076  */
3078  AVStream *ost, const AVStream *ist,
3079  enum AVTimebaseSource copy_tb);
3080 
3081 /**
3082  * Get the internal codec timebase from a stream.
3083  *
3084  * @param st input stream to extract the timebase from
3085  */
3087 
3088 /**
3089  * @}
3090  */
3091 
3092 #endif /* AVFORMAT_AVFORMAT_H */
void av_url_split(char *proto, int proto_size, char *authorization, int authorization_size, char *hostname, int hostname_size, int *port_ptr, char *path, int path_size, const char *url)
Split a URL string into components.
Definition: utils.c:4738
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:689
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:1940
full parsing and interpolation of timestamps for frames not starting on a packet boundary ...
Definition: avformat.h:802
Bytestream IO Context.
Definition: avio.h:161
void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st)
Send a nice dump of a packet to the specified file stream.
Definition: dump.c:108
Buffered I/O operations.
AVPacketSideDataType
Definition: avcodec.h:1184
attribute_deprecated int av_demuxer_open(AVFormatContext *ic)
Definition: utils.c:395
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
Definition: mux.c:1192
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
static void flush(AVCodecContext *avctx)
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
Definition: utils.c:2039
int av_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file.
Definition: mux.c:878
const char * fmt
Definition: avisynth_c.h:861
const char * filename
Definition: avformat.h:447
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame)
Guess the sample aspect ratio of a frame, based on both the stream and the frame aspect ratio...
Definition: utils.c:5066
enum AVCodecID video_codec
default video codec
Definition: avformat.h:516
enum AVCodecID codec_id
Definition: qsv.c:72
ff_const59 struct AVInputFormat * next
Definition: avformat.h:695
GLint GLenum type
Definition: opengl_enc.c:104
int av_get_output_timestamp(struct AVFormatContext *s, int stream, int64_t *dts, int64_t *wall)
Get timing information for the data currently output.
Definition: mux.c:1309
int avformat_open_input(AVFormatContext **ps, const char *url, ff_const59 AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: utils.c:537
const char * key
static AVPacket pkt
int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index)
Test whether a muxer supports uncoded frame.
Definition: mux.c:1378
int av_probe_input_buffer(AVIOContext *pb, ff_const59 AVInputFormat **fmt, const char *url, void *logctx, unsigned int offset, unsigned int max_probe_size)
Like av_probe_input_buffer2() but returns 0 on success.
Definition: format.c:312
int priv_data_size
Size of private data so that it can be allocated in the wrapper.
Definition: avformat.h:705
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample format(the sample packing is implied by the sample format) and sample rate.The lists are not just lists
AVCodec.
Definition: avcodec.h:3481
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3949
enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext *ctx)
Returns the method used to set ctx->duration.
Definition: options.c:163
Format I/O context.
Definition: avformat.h:1358
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:5089
static int query_codec(enum AVCodecID id, int std_compliance)
Definition: img2enc.c:199
const struct AVCodecTag * avformat_get_mov_audio_tags(void)
Definition: isom.c:668
Public dictionary API.
static int64_t start_time
Definition: ffplay.c:331
uint8_t
static int nb_streams
Definition: ffprobe.c:280
const struct AVCodecTag * avformat_get_riff_video_tags(void)
Definition: riff.c:595
enum AVCodecID av_codec_get_id(const struct AVCodecTag *const *tags, unsigned int tag)
Get the AVCodecID for the given codec tag tag.
unsigned avformat_version(void)
Return the LIBAVFORMAT_VERSION_INT constant.
Definition: utils.c:66
const char * avformat_license(void)
Return the libavformat license.
Definition: utils.c:77
int avformat_transfer_internal_stream_timing_info(const AVOutputFormat *ofmt, AVStream *ost, const AVStream *ist, enum AVTimebaseSource copy_tb)
Transfer internal timing information from one stream to another.
Definition: utils.c:5733
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
#define f(width, name)
Definition: cbs_vp9.c:255
int priv_data_size
size of private data so that it can be allocated in the wrapper
Definition: avformat.h:555
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st, const char *spec)
Check if the stream st contained in s is matched by the stream specifier spec.
Definition: utils.c:5273
AVDurationEstimationMethod
The duration of a video can be estimated through various ways, and this enum can be used to know how ...
Definition: avformat.h:1336
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4465
uint8_t * av_stream_get_side_data(const AVStream *stream, enum AVPacketSideDataType type, int *size)
Get side information from stream.
Definition: utils.c:5453
int64_t duration
Definition: movenc.c:63
int av_codec_get_tag2(const struct AVCodecTag *const *tags, enum AVCodecID id, unsigned int *tag)
Get the codec tag for the given codec id.
AVFormatContext * avformat_alloc_context(void)
Allocate an AVFormatContext.
Definition: options.c:144
void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload, const AVStream *st)
Send a nice dump of a packet to the log.
Definition: dump.c:113
const char * avformat_configuration(void)
Return the libavformat build-time configuration.
Definition: utils.c:72
#define MAX_REORDER_DELAY
Definition: avformat.h:1107
AVProgram * av_new_program(AVFormatContext *s, int id)
Definition: utils.c:4564
char * protocol_whitelist
&#39;,&#39; separated list of allowed protocols.
Definition: avformat.h:1918
uint32_t tag
Definition: movenc.c:1496
int avformat_network_init(void)
Do global initialization of network libraries.
Definition: utils.c:5003
const struct AVCodecTag * avformat_get_riff_audio_tags(void)
Definition: riff.c:600
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
Generate an SDP for an RTP session.
Definition: sdp.c:842
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:310
int av_match_ext(const char *filename, const char *extensions)
Return a positive value if the given filename has one of the given extensions, 0 otherwise.
Definition: format.c:38
const AVClass * avformat_get_class(void)
Get the AVClass for AVFormatContext.
Definition: options.c:168
ptrdiff_t size
Definition: opengl_enc.c:100
static int interleave_packet(AVFormatContext *s, AVPacket *out, AVPacket *in, int flush)
Interleave an AVPacket correctly so it can be muxed.
Definition: mux.c:1181
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:804
Duration estimated from bitrate (less accurate)
Definition: avformat.h:1339
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:320
const AVOutputFormat * av_muxer_iterate(void **opaque)
Iterate over all registered muxers.
Definition: allformats.c:505
const struct AVCodecTag * avformat_get_mov_video_tags(void)
Definition: isom.c:663
void av_dump_format(AVFormatContext *ic, int index, const char *url, int is_output)
Print detailed information about the input or output format, such as duration, bitrate, streams, container, programs, metadata, side data, codec and time base.
Definition: dump.c:575
Callback for checking whether to abort blocking functions.
Definition: avio.h:58
int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type, int wanted_stream_nb, int related_stream, AVCodec **decoder_ret, int flags)
Find the "best" stream in the file.
Definition: utils.c:4192
#define ff_const59
The ff_const59 define is not part of the public API and will be removed without further warning...
Definition: avformat.h:549
AVRational av_stream_get_codec_timebase(const AVStream *st)
Get the internal codec timebase from a stream.
Definition: utils.c:5795
ff_const59 AVInputFormat * av_probe_input_format(ff_const59 AVProbeData *pd, int is_opened)
Guess the file format.
Definition: format.c:216
AVProgram * av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s)
Find the programs which belong to a given stream.
Definition: utils.c:4175
ff_const59 AVInputFormat * av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max)
Guess the file format.
Definition: format.c:205
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: avcodec.h:215
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:2154
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:481
void av_hex_dump(FILE *f, const uint8_t *buf, int size)
Send a nice hexadecimal dump of a buffer to the specified file stream.
Definition: dump.c:74
struct AVCodecParser * parser
Definition: avcodec.h:5110
char * url
input or output URL.
Definition: avformat.h:1454
const char * r
Definition: vf_curves.c:114
struct AVCodecParserContext * av_stream_get_parser(const AVStream *s)
Definition: utils.c:149
int av_read_play(AVFormatContext *s)
Start playing a network-based stream (e.g.
Definition: utils.c:4260
ff_const59 AVInputFormat * av_find_input_format(const char *short_name)
Find AVInputFormat based on the short name of the input format.
Definition: format.c:118
int avformat_alloc_output_context2(AVFormatContext **ctx, ff_const59 AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
Definition: mux.c:148
int skip_estimate_duration_from_pts
Skip duration calcuation in estimate_timings_from_pts.
Definition: avformat.h:1967
New fields can be added to the end with minor version bumps.
Definition: avformat.h:1275
void * opaque
User data.
Definition: avformat.h:1864
Only parse headers, do not repack.
Definition: avformat.h:801
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:4985
static float distance(float x, float y, int band)
const char * mime_type
mime_type, when known.
Definition: avformat.h:450
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:449
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
void av_format_inject_global_side_data(AVFormatContext *s)
This function will cause global side data to be injected in the next packet of each stream as well as...
Definition: utils.c:154
int av_read_pause(AVFormatContext *s)
Pause a network-based stream (e.g.
Definition: utils.c:4269
MIPS optimizations info
Definition: mips.txt:2
static void callback(void *priv_data, int index, uint8_t *buf, int buf_size, int64_t time, enum dshowDeviceType devtype)
Definition: dshow.c:161
av_warn_unused_result int avformat_write_header(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and write the stream header to an output media file.
Definition: mux.c:508
void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx)
int(* av_format_control_message)(struct AVFormatContext *s, int type, void *data, size_t data_size)
Callback used by devices to communicate with application.
Definition: avformat.h:1326
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:5468
int max_streams
The maximum number of streams.
Definition: avformat.h:1960
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
int av_find_default_stream_index(AVFormatContext *s)
Definition: utils.c:1880
static int write_trailer(AVFormatContext *s1)
Definition: v4l2enc.c:94
enum AVCodecID av_guess_codec(ff_const59 AVOutputFormat *fmt, const char *short_name, const char *filename, const char *mime_type, enum AVMediaType type)
Guess the codec ID based upon muxer and filename.
Definition: format.c:87
Duration estimated from a stream with a known duration.
Definition: avformat.h:1338
AVFormatContext * ctx
Definition: movenc.c:48
ff_const59 AVInputFormat * av_probe_input_format3(ff_const59 AVProbeData *pd, int is_opened, int *score_ret)
Guess the file format.
Definition: format.c:128
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
#define s(width, name)
Definition: cbs_vp9.c:257
uint8_t * av_stream_new_side_data(AVStream *stream, enum AVPacketSideDataType type, int size)
Allocate new information from stream.
Definition: utils.c:5504
Libavformat version macros.
int(* AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Definition: avformat.h:1329
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:488
const AVInputFormat * av_demuxer_iterate(void **opaque)
Iterate over all registered demuxers.
Definition: allformats.c:522
int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
Definition: utils.c:4733
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
Stream structure.
Definition: avformat.h:881
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
int avformat_queue_attached_pictures(AVFormatContext *s)
Definition: utils.c:479
int avformat_network_deinit(void)
Undo the initialization done by avformat_network_init.
Definition: utils.c:5015
static AVInputFormat * iformat
Definition: ffprobe.c:257
Libavcodec external API header.
int av_probe_input_buffer2(AVIOContext *pb, ff_const59 AVInputFormat **fmt, const char *url, void *logctx, unsigned int offset, unsigned int max_probe_size)
Probe a bytestream to determine the input format.
Definition: format.c:222
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
main external API structure.
Definition: avcodec.h:1565
int av_filename_number_test(const char *filename)
Check whether filename actually is a numbered sequence generator.
Definition: utils.c:327
int av_get_frame_filename2(char *buf, int buf_size, const char *path, int number, int flags)
Return in &#39;buf&#39; the path with &#39;d&#39; replaced by a number.
Definition: utils.c:4678
void(* io_close)(struct AVFormatContext *s, AVIOContext *pb)
A callback for closing the streams opened with AVFormatContext.io_open().
Definition: avformat.h:1946
static const AVClass av_class
Definition: options.c:134
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(const int16_t *) pi >> 8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(const int32_t *) pi >> 24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31))))#define SET_CONV_FUNC_GROUP(ofmt, ifmt) static void set_generic_function(AudioConvert *ac){}void ff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, int sample_rate, int apply_map){AudioConvert *ac;int in_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) return NULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method!=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt) > 2){ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc){av_free(ac);return NULL;}return ac;}in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar){ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar?ac->channels:1;}else if(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;else ac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);return ac;}int ff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){int use_generic=1;int len=in->nb_samples;int p;if(ac->dc){av_log(ac->avr, AV_LOG_TRACE,"%d samples - audio_convert: %s to %s (dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));return ff_convert_dither(ac-> in
Describe the class of an AVClass context structure.
Definition: log.h:67
int index
Definition: gxfenc.c:89
enum AVCodecID subtitle_codec
default subtitle codec
Definition: avformat.h:517
ff_const59 AVOutputFormat * av_guess_format(const char *short_name, const char *filename, const char *mime_type)
Return the output format in the list of registered output formats which best matches the provided par...
Definition: format.c:51
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVMediaType
Definition: avutil.h:199
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: utils.c:4399
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1768
List of devices.
Definition: avdevice.h:460
AVTimebaseSource
Definition: avformat.h:3072
int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Seek to timestamp ts.
Definition: utils.c:2535
full parsing and repack of the first frame only, only implemented for H.264 currently ...
Definition: avformat.h:803
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:700
#define flags(name, subs,...)
Definition: cbs_av1.c:561
static int format_name(const char *buf, char **s, int index, const char *varname)
Definition: hlsenc.c:1823
uint8_t level
Definition: svq3.c:207
#define attribute_deprecated
Definition: attributes.h:94
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
Duration accurately estimated from PTSes.
Definition: avformat.h:1337
#define av_warn_unused_result
Definition: attributes.h:56
int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Seek to the keyframe at timestamp.
Definition: utils.c:2512
full parsing and repack
Definition: avformat.h:800
static AVStream * ost
int
const OptionDef options[]
Definition: ffmpeg_opt.c:3364
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:1372
struct AVPacketList * next
Definition: avformat.h:2026
enum AVCodecID data_codec
default data codec
Definition: avformat.h:614
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: utils.c:3573
AVStreamParseType
Definition: avformat.h:798
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:4437
int av_write_uncoded_frame(AVFormatContext *s, int stream_index, AVFrame *frame)
Write an uncoded frame to an output media file.
Definition: mux.c:1366
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:515
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:337
AVDiscard
Definition: avcodec.h:802
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
Definition: mux.c:1254
char * protocol_blacklist
&#39;,&#39; separated list of disallowed protocols.
Definition: avformat.h:1953
int avformat_flush(AVFormatContext *s)
Discard all internally buffered data.
Definition: utils.c:2592
FILE * out
Definition: movenc.c:54
void INT64 start
Definition: avisynth_c.h:766
ff_const59 struct AVOutputFormat * next
Definition: avformat.h:551
int copy_tb
Definition: ffmpeg_opt.c:101
void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size)
Send a nice hexadecimal dump of a buffer to the log.
Definition: dump.c:79
unsigned int av_codec_get_tag(const struct AVCodecTag *const *tags, enum AVCodecID id)
Get the codec tag for the given codec id id.
enum AVCodecID id
Following API allows user to probe device capabilities (supported codecs, pixel formats, sample formats, resolutions, channel counts, etc).
Definition: avdevice.h:400
This structure stores compressed data.
Definition: avcodec.h:1454
#define MAX_STD_TIMEBASES
Definition: avformat.h:1040
int64_t av_stream_get_end_pts(const AVStream *st)
Returns the pts of the last muxed packet + its duration.
Definition: utils.c:141
const char * name
Definition: opengl_enc.c:102