FFmpeg
avformat.h
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1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVFORMAT_AVFORMAT_H
22 #define AVFORMAT_AVFORMAT_H
23 
24 /**
25  * @file
26  * @ingroup libavf
27  * Main libavformat public API header
28  */
29 
30 /**
31  * @defgroup libavf libavformat
32  * I/O and Muxing/Demuxing Library
33  *
34  * Libavformat (lavf) is a library for dealing with various media container
35  * formats. Its main two purposes are demuxing - i.e. splitting a media file
36  * into component streams, and the reverse process of muxing - writing supplied
37  * data in a specified container format. It also has an @ref lavf_io
38  * "I/O module" which supports a number of protocols for accessing the data (e.g.
39  * file, tcp, http and others).
40  * Unless you are absolutely sure you won't use libavformat's network
41  * capabilities, you should also call avformat_network_init().
42  *
43  * A supported input format is described by an AVInputFormat struct, conversely
44  * an output format is described by AVOutputFormat. You can iterate over all
45  * input/output formats using the av_demuxer_iterate / av_muxer_iterate() functions.
46  * The protocols layer is not part of the public API, so you can only get the names
47  * of supported protocols with the avio_enum_protocols() function.
48  *
49  * Main lavf structure used for both muxing and demuxing is AVFormatContext,
50  * which exports all information about the file being read or written. As with
51  * most Libavformat structures, its size is not part of public ABI, so it cannot be
52  * allocated on stack or directly with av_malloc(). To create an
53  * AVFormatContext, use avformat_alloc_context() (some functions, like
54  * avformat_open_input() might do that for you).
55  *
56  * Most importantly an AVFormatContext contains:
57  * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat
58  * "output" format. It is either autodetected or set by user for input;
59  * always set by user for output.
60  * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all
61  * elementary streams stored in the file. AVStreams are typically referred to
62  * using their index in this array.
63  * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or
64  * set by user for input, always set by user for output (unless you are dealing
65  * with an AVFMT_NOFILE format).
66  *
67  * @section lavf_options Passing options to (de)muxers
68  * It is possible to configure lavf muxers and demuxers using the @ref avoptions
69  * mechanism. Generic (format-independent) libavformat options are provided by
70  * AVFormatContext, they can be examined from a user program by calling
71  * av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass
72  * from avformat_get_class()). Private (format-specific) options are provided by
73  * AVFormatContext.priv_data if and only if AVInputFormat.priv_class /
74  * AVOutputFormat.priv_class of the corresponding format struct is non-NULL.
75  * Further options may be provided by the @ref AVFormatContext.pb "I/O context",
76  * if its AVClass is non-NULL, and the protocols layer. See the discussion on
77  * nesting in @ref avoptions documentation to learn how to access those.
78  *
79  * @section urls
80  * URL strings in libavformat are made of a scheme/protocol, a ':', and a
81  * scheme specific string. URLs without a scheme and ':' used for local files
82  * are supported but deprecated. "file:" should be used for local files.
83  *
84  * It is important that the scheme string is not taken from untrusted
85  * sources without checks.
86  *
87  * Note that some schemes/protocols are quite powerful, allowing access to
88  * both local and remote files, parts of them, concatenations of them, local
89  * audio and video devices and so on.
90  *
91  * @{
92  *
93  * @defgroup lavf_decoding Demuxing
94  * @{
95  * Demuxers read a media file and split it into chunks of data (@em packets). A
96  * @ref AVPacket "packet" contains one or more encoded frames which belongs to a
97  * single elementary stream. In the lavf API this process is represented by the
98  * avformat_open_input() function for opening a file, av_read_frame() for
99  * reading a single packet and finally avformat_close_input(), which does the
100  * cleanup.
101  *
102  * @section lavf_decoding_open Opening a media file
103  * The minimum information required to open a file is its URL, which
104  * is passed to avformat_open_input(), as in the following code:
105  * @code
106  * const char *url = "file:in.mp3";
107  * AVFormatContext *s = NULL;
108  * int ret = avformat_open_input(&s, url, NULL, NULL);
109  * if (ret < 0)
110  * abort();
111  * @endcode
112  * The above code attempts to allocate an AVFormatContext, open the
113  * specified file (autodetecting the format) and read the header, exporting the
114  * information stored there into s. Some formats do not have a header or do not
115  * store enough information there, so it is recommended that you call the
116  * avformat_find_stream_info() function which tries to read and decode a few
117  * frames to find missing information.
118  *
119  * In some cases you might want to preallocate an AVFormatContext yourself with
120  * avformat_alloc_context() and do some tweaking on it before passing it to
121  * avformat_open_input(). One such case is when you want to use custom functions
122  * for reading input data instead of lavf internal I/O layer.
123  * To do that, create your own AVIOContext with avio_alloc_context(), passing
124  * your reading callbacks to it. Then set the @em pb field of your
125  * AVFormatContext to newly created AVIOContext.
126  *
127  * Since the format of the opened file is in general not known until after
128  * avformat_open_input() has returned, it is not possible to set demuxer private
129  * options on a preallocated context. Instead, the options should be passed to
130  * avformat_open_input() wrapped in an AVDictionary:
131  * @code
132  * AVDictionary *options = NULL;
133  * av_dict_set(&options, "video_size", "640x480", 0);
134  * av_dict_set(&options, "pixel_format", "rgb24", 0);
135  *
136  * if (avformat_open_input(&s, url, NULL, &options) < 0)
137  * abort();
138  * av_dict_free(&options);
139  * @endcode
140  * This code passes the private options 'video_size' and 'pixel_format' to the
141  * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it
142  * cannot know how to interpret raw video data otherwise. If the format turns
143  * out to be something different than raw video, those options will not be
144  * recognized by the demuxer and therefore will not be applied. Such unrecognized
145  * options are then returned in the options dictionary (recognized options are
146  * consumed). The calling program can handle such unrecognized options as it
147  * wishes, e.g.
148  * @code
149  * AVDictionaryEntry *e;
150  * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
151  * fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key);
152  * abort();
153  * }
154  * @endcode
155  *
156  * After you have finished reading the file, you must close it with
157  * avformat_close_input(). It will free everything associated with the file.
158  *
159  * @section lavf_decoding_read Reading from an opened file
160  * Reading data from an opened AVFormatContext is done by repeatedly calling
161  * av_read_frame() on it. Each call, if successful, will return an AVPacket
162  * containing encoded data for one AVStream, identified by
163  * AVPacket.stream_index. This packet may be passed straight into the libavcodec
164  * decoding functions avcodec_send_packet() or avcodec_decode_subtitle2() if the
165  * caller wishes to decode the data.
166  *
167  * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be
168  * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for
169  * pts/dts, 0 for duration) if the stream does not provide them. The timing
170  * information will be in AVStream.time_base units, i.e. it has to be
171  * multiplied by the timebase to convert them to seconds.
172  *
173  * A packet returned by av_read_frame() is always reference-counted,
174  * i.e. AVPacket.buf is set and the user may keep it indefinitely.
175  * The packet must be freed with av_packet_unref() when it is no
176  * longer needed.
177  *
178  * @section lavf_decoding_seek Seeking
179  * @}
180  *
181  * @defgroup lavf_encoding Muxing
182  * @{
183  * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write
184  * it into files or other output bytestreams in the specified container format.
185  *
186  * The main API functions for muxing are avformat_write_header() for writing the
187  * file header, av_write_frame() / av_interleaved_write_frame() for writing the
188  * packets and av_write_trailer() for finalizing the file.
189  *
190  * At the beginning of the muxing process, the caller must first call
191  * avformat_alloc_context() to create a muxing context. The caller then sets up
192  * the muxer by filling the various fields in this context:
193  *
194  * - The @ref AVFormatContext.oformat "oformat" field must be set to select the
195  * muxer that will be used.
196  * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb
197  * "pb" field must be set to an opened IO context, either returned from
198  * avio_open2() or a custom one.
199  * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must
200  * be created with the avformat_new_stream() function. The caller should fill
201  * the @ref AVStream.codecpar "stream codec parameters" information, such as the
202  * codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id
203  * "id" and other parameters (e.g. width / height, the pixel or sample format,
204  * etc.) as known. The @ref AVStream.time_base "stream timebase" should
205  * be set to the timebase that the caller desires to use for this stream (note
206  * that the timebase actually used by the muxer can be different, as will be
207  * described later).
208  * - It is advised to manually initialize only the relevant fields in
209  * AVCodecParameters, rather than using @ref avcodec_parameters_copy() during
210  * remuxing: there is no guarantee that the codec context values remain valid
211  * for both input and output format contexts.
212  * - The caller may fill in additional information, such as @ref
213  * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream"
214  * metadata, @ref AVFormatContext.chapters "chapters", @ref
215  * AVFormatContext.programs "programs", etc. as described in the
216  * AVFormatContext documentation. Whether such information will actually be
217  * stored in the output depends on what the container format and the muxer
218  * support.
219  *
220  * When the muxing context is fully set up, the caller must call
221  * avformat_write_header() to initialize the muxer internals and write the file
222  * header. Whether anything actually is written to the IO context at this step
223  * depends on the muxer, but this function must always be called. Any muxer
224  * private options must be passed in the options parameter to this function.
225  *
226  * The data is then sent to the muxer by repeatedly calling av_write_frame() or
227  * av_interleaved_write_frame() (consult those functions' documentation for
228  * discussion on the difference between them; only one of them may be used with
229  * a single muxing context, they should not be mixed). Do note that the timing
230  * information on the packets sent to the muxer must be in the corresponding
231  * AVStream's timebase. That timebase is set by the muxer (in the
232  * avformat_write_header() step) and may be different from the timebase
233  * requested by the caller.
234  *
235  * Once all the data has been written, the caller must call av_write_trailer()
236  * to flush any buffered packets and finalize the output file, then close the IO
237  * context (if any) and finally free the muxing context with
238  * avformat_free_context().
239  * @}
240  *
241  * @defgroup lavf_io I/O Read/Write
242  * @{
243  * @section lavf_io_dirlist Directory listing
244  * The directory listing API makes it possible to list files on remote servers.
245  *
246  * Some of possible use cases:
247  * - an "open file" dialog to choose files from a remote location,
248  * - a recursive media finder providing a player with an ability to play all
249  * files from a given directory.
250  *
251  * @subsection lavf_io_dirlist_open Opening a directory
252  * At first, a directory needs to be opened by calling avio_open_dir()
253  * supplied with a URL and, optionally, ::AVDictionary containing
254  * protocol-specific parameters. The function returns zero or positive
255  * integer and allocates AVIODirContext on success.
256  *
257  * @code
258  * AVIODirContext *ctx = NULL;
259  * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) {
260  * fprintf(stderr, "Cannot open directory.\n");
261  * abort();
262  * }
263  * @endcode
264  *
265  * This code tries to open a sample directory using smb protocol without
266  * any additional parameters.
267  *
268  * @subsection lavf_io_dirlist_read Reading entries
269  * Each directory's entry (i.e. file, another directory, anything else
270  * within ::AVIODirEntryType) is represented by AVIODirEntry.
271  * Reading consecutive entries from an opened AVIODirContext is done by
272  * repeatedly calling avio_read_dir() on it. Each call returns zero or
273  * positive integer if successful. Reading can be stopped right after the
274  * NULL entry has been read -- it means there are no entries left to be
275  * read. The following code reads all entries from a directory associated
276  * with ctx and prints their names to standard output.
277  * @code
278  * AVIODirEntry *entry = NULL;
279  * for (;;) {
280  * if (avio_read_dir(ctx, &entry) < 0) {
281  * fprintf(stderr, "Cannot list directory.\n");
282  * abort();
283  * }
284  * if (!entry)
285  * break;
286  * printf("%s\n", entry->name);
287  * avio_free_directory_entry(&entry);
288  * }
289  * @endcode
290  * @}
291  *
292  * @defgroup lavf_codec Demuxers
293  * @{
294  * @defgroup lavf_codec_native Native Demuxers
295  * @{
296  * @}
297  * @defgroup lavf_codec_wrappers External library wrappers
298  * @{
299  * @}
300  * @}
301  * @defgroup lavf_protos I/O Protocols
302  * @{
303  * @}
304  * @defgroup lavf_internal Internal
305  * @{
306  * @}
307  * @}
308  */
309 
310 #include <time.h>
311 #include <stdio.h> /* FILE */
312 #include "libavcodec/avcodec.h"
313 #include "libavutil/dict.h"
314 #include "libavutil/log.h"
315 
316 #include "avio.h"
317 #include "libavformat/version.h"
318 
319 struct AVFormatContext;
320 
321 struct AVDeviceInfoList;
323 
324 /**
325  * @defgroup metadata_api Public Metadata API
326  * @{
327  * @ingroup libavf
328  * The metadata API allows libavformat to export metadata tags to a client
329  * application when demuxing. Conversely it allows a client application to
330  * set metadata when muxing.
331  *
332  * Metadata is exported or set as pairs of key/value strings in the 'metadata'
333  * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
334  * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
335  * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
336  * exported by demuxers isn't checked to be valid UTF-8 in most cases.
337  *
338  * Important concepts to keep in mind:
339  * - Keys are unique; there can never be 2 tags with the same key. This is
340  * also meant semantically, i.e., a demuxer should not knowingly produce
341  * several keys that are literally different but semantically identical.
342  * E.g., key=Author5, key=Author6. In this example, all authors must be
343  * placed in the same tag.
344  * - Metadata is flat, not hierarchical; there are no subtags. If you
345  * want to store, e.g., the email address of the child of producer Alice
346  * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
347  * - Several modifiers can be applied to the tag name. This is done by
348  * appending a dash character ('-') and the modifier name in the order
349  * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
350  * - language -- a tag whose value is localized for a particular language
351  * is appended with the ISO 639-2/B 3-letter language code.
352  * For example: Author-ger=Michael, Author-eng=Mike
353  * The original/default language is in the unqualified "Author" tag.
354  * A demuxer should set a default if it sets any translated tag.
355  * - sorting -- a modified version of a tag that should be used for
356  * sorting will have '-sort' appended. E.g. artist="The Beatles",
357  * artist-sort="Beatles, The".
358  * - Some protocols and demuxers support metadata updates. After a successful
359  * call to av_read_frame(), AVFormatContext.event_flags or AVStream.event_flags
360  * will be updated to indicate if metadata changed. In order to detect metadata
361  * changes on a stream, you need to loop through all streams in the AVFormatContext
362  * and check their individual event_flags.
363  *
364  * - Demuxers attempt to export metadata in a generic format, however tags
365  * with no generic equivalents are left as they are stored in the container.
366  * Follows a list of generic tag names:
367  *
368  @verbatim
369  album -- name of the set this work belongs to
370  album_artist -- main creator of the set/album, if different from artist.
371  e.g. "Various Artists" for compilation albums.
372  artist -- main creator of the work
373  comment -- any additional description of the file.
374  composer -- who composed the work, if different from artist.
375  copyright -- name of copyright holder.
376  creation_time-- date when the file was created, preferably in ISO 8601.
377  date -- date when the work was created, preferably in ISO 8601.
378  disc -- number of a subset, e.g. disc in a multi-disc collection.
379  encoder -- name/settings of the software/hardware that produced the file.
380  encoded_by -- person/group who created the file.
381  filename -- original name of the file.
382  genre -- <self-evident>.
383  language -- main language in which the work is performed, preferably
384  in ISO 639-2 format. Multiple languages can be specified by
385  separating them with commas.
386  performer -- artist who performed the work, if different from artist.
387  E.g for "Also sprach Zarathustra", artist would be "Richard
388  Strauss" and performer "London Philharmonic Orchestra".
389  publisher -- name of the label/publisher.
390  service_name -- name of the service in broadcasting (channel name).
391  service_provider -- name of the service provider in broadcasting.
392  title -- name of the work.
393  track -- number of this work in the set, can be in form current/total.
394  variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
395  @endverbatim
396  *
397  * Look in the examples section for an application example how to use the Metadata API.
398  *
399  * @}
400  */
401 
402 /* packet functions */
403 
404 
405 /**
406  * Allocate and read the payload of a packet and initialize its
407  * fields with default values.
408  *
409  * @param s associated IO context
410  * @param pkt packet
411  * @param size desired payload size
412  * @return >0 (read size) if OK, AVERROR_xxx otherwise
413  */
415 
416 
417 /**
418  * Read data and append it to the current content of the AVPacket.
419  * If pkt->size is 0 this is identical to av_get_packet.
420  * Note that this uses av_grow_packet and thus involves a realloc
421  * which is inefficient. Thus this function should only be used
422  * when there is no reasonable way to know (an upper bound of)
423  * the final size.
424  *
425  * @param s associated IO context
426  * @param pkt packet
427  * @param size amount of data to read
428  * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
429  * will not be lost even if an error occurs.
430  */
432 
433 /*************************************************/
434 /* input/output formats */
435 
436 struct AVCodecTag;
437 
438 /**
439  * This structure contains the data a format has to probe a file.
440  */
441 typedef struct AVProbeData {
442  const char *filename;
443  unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
444  int buf_size; /**< Size of buf except extra allocated bytes */
445  const char *mime_type; /**< mime_type, when known. */
446 } AVProbeData;
447 
448 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
449 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
450 
451 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
452 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type
453 #define AVPROBE_SCORE_MAX 100 ///< maximum score
454 
455 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
456 
457 /// Demuxer will use avio_open, no opened file should be provided by the caller.
458 #define AVFMT_NOFILE 0x0001
459 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
460 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
461 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
462 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
463 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
464 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
465 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
466 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
467 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
468 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
469 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
470 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
471 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
472 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
473  increasing timestamps, but they must
474  still be monotonic */
475 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
476  timestamps. If not set the timestamp
477  will be shifted in av_write_frame and
478  av_interleaved_write_frame so they
479  start from 0.
480  The user or muxer can override this through
481  AVFormatContext.avoid_negative_ts
482  */
483 
484 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
485 
486 /**
487  * @addtogroup lavf_encoding
488  * @{
489  */
490 typedef struct AVOutputFormat {
491  const char *name;
492  /**
493  * Descriptive name for the format, meant to be more human-readable
494  * than name. You should use the NULL_IF_CONFIG_SMALL() macro
495  * to define it.
496  */
497  const char *long_name;
498  const char *mime_type;
499  const char *extensions; /**< comma-separated filename extensions */
500  /* output support */
501  enum AVCodecID audio_codec; /**< default audio codec */
502  enum AVCodecID video_codec; /**< default video codec */
503  enum AVCodecID subtitle_codec; /**< default subtitle codec */
504  /**
505  * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER,
506  * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
507  * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
508  * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
509  */
510  int flags;
512  /**
513  * List of supported codec_id-codec_tag pairs, ordered by "better
514  * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
515  */
516  const struct AVCodecTag * const *codec_tag;
517 
518 
519  const AVClass *priv_class; ///< AVClass for the private context
520 
521  /*****************************************************************
522  * No fields below this line are part of the public API. They
523  * may not be used outside of libavformat and can be changed and
524  * removed at will.
525  * New public fields should be added right above.
526  *****************************************************************
527  */
528  /**
529  * The ff_const59 define is not part of the public API and will
530  * be removed without further warning.
531  */
532 #if FF_API_AVIOFORMAT
533 #define ff_const59
534 #else
535 #define ff_const59 const
536 #endif
537 #if FF_API_NEXT
538  ff_const59 struct AVOutputFormat *next;
539 #endif
540  /**
541  * size of private data so that it can be allocated in the wrapper
542  */
543  int priv_data_size;
545  int (*write_header)(struct AVFormatContext *);
546  /**
547  * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
548  * pkt can be NULL in order to flush data buffered in the muxer.
549  * When flushing, return 0 if there still is more data to flush,
550  * or 1 if everything was flushed and there is no more buffered
551  * data.
552  */
555  /**
556  * A format-specific function for interleavement.
557  * If unset, packets will be interleaved by dts.
558  */
560  AVPacket *in, int flush);
561  /**
562  * Test if the given codec can be stored in this container.
563  *
564  * @return 1 if the codec is supported, 0 if it is not.
565  * A negative number if unknown.
566  * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
567  */
568  int (*query_codec)(enum AVCodecID id, int std_compliance);
569 
570  void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
571  int64_t *dts, int64_t *wall);
572  /**
573  * Allows sending messages from application to device.
574  */
575  int (*control_message)(struct AVFormatContext *s, int type,
576  void *data, size_t data_size);
578  /**
579  * Write an uncoded AVFrame.
580  *
581  * See av_write_uncoded_frame() for details.
582  *
583  * The library will free *frame afterwards, but the muxer can prevent it
584  * by setting the pointer to NULL.
585  */
586  int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
587  AVFrame **frame, unsigned flags);
588  /**
589  * Returns device list with it properties.
590  * @see avdevice_list_devices() for more details.
591  */
592  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
593 #if LIBAVFORMAT_VERSION_MAJOR < 59
594  /**
595  * Initialize device capabilities submodule.
596  * @see avdevice_capabilities_create() for more details.
597  */
598  int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
599  /**
600  * Free device capabilities submodule.
601  * @see avdevice_capabilities_free() for more details.
602  */
603  int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
604 #endif
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  */
686 #if FF_API_NEXT
687  ff_const59 struct AVInputFormat *next;
688 #endif
689 
690  /**
691  * Raw demuxers store their codec ID here.
692  */
693  int raw_codec_id;
694 
695  /**
696  * Size of private data so that it can be allocated in the wrapper.
697  */
698  int priv_data_size;
699 
700  /**
701  * Tell if a given file has a chance of being parsed as this format.
702  * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
703  * big so you do not have to check for that unless you need more.
704  */
705  int (*read_probe)(const AVProbeData *);
706 
707  /**
708  * Read the format header and initialize the AVFormatContext
709  * structure. Return 0 if OK. 'avformat_new_stream' should be
710  * called to create new streams.
711  */
712  int (*read_header)(struct AVFormatContext *);
713 
714  /**
715  * Read one packet and put it in 'pkt'. pts and flags are also
716  * set. 'avformat_new_stream' can be called only if the flag
717  * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
718  * background thread).
719  * @return 0 on success, < 0 on error.
720  * Upon returning an error, pkt must be unreferenced by the caller.
721  */
722  int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
723 
724  /**
725  * Close the stream. The AVFormatContext and AVStreams are not
726  * freed by this function
727  */
728  int (*read_close)(struct AVFormatContext *);
729 
730  /**
731  * Seek to a given timestamp relative to the frames in
732  * stream component stream_index.
733  * @param stream_index Must not be -1.
734  * @param flags Selects which direction should be preferred if no exact
735  * match is available.
736  * @return >= 0 on success (but not necessarily the new offset)
737  */
738  int (*read_seek)(struct AVFormatContext *,
739  int stream_index, int64_t timestamp, int flags);
740 
741  /**
742  * Get the next timestamp in stream[stream_index].time_base units.
743  * @return the timestamp or AV_NOPTS_VALUE if an error occurred
744  */
745  int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
746  int64_t *pos, int64_t pos_limit);
748  /**
749  * Start/resume playing - only meaningful if using a network-based format
750  * (RTSP).
751  */
752  int (*read_play)(struct AVFormatContext *);
753 
754  /**
755  * Pause playing - only meaningful if using a network-based format
756  * (RTSP).
757  */
758  int (*read_pause)(struct AVFormatContext *);
759 
760  /**
761  * Seek to timestamp ts.
762  * Seeking will be done so that the point from which all active streams
763  * can be presented successfully will be closest to ts and within min/max_ts.
764  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
765  */
766  int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
768  /**
769  * Returns device list with it properties.
770  * @see avdevice_list_devices() for more details.
771  */
772  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
773 
774 #if LIBAVFORMAT_VERSION_MAJOR < 59
775  /**
776  * Initialize device capabilities submodule.
777  * @see avdevice_capabilities_create() for more details.
778  */
779  int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
780 
781  /**
782  * Free device capabilities submodule.
783  * @see avdevice_capabilities_free() for more details.
784  */
785  int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
786 #endif
787 } AVInputFormat;
788 /**
789  * @}
790  */
791 
792 enum AVStreamParseType {
794  AVSTREAM_PARSE_FULL, /**< full parsing and repack */
795  AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
796  AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
797  AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
798  AVSTREAM_PARSE_FULL_RAW, /**< full parsing and repack with timestamp and position generation by parser for raw
799  this assumes that each packet in the file contains no demuxer level headers and
800  just codec level data, otherwise position generation would fail */
801 };
803 typedef struct AVIndexEntry {
804  int64_t pos;
805  int64_t timestamp; /**<
806  * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
807  * when seeking to this entry. That means preferable PTS on keyframe based formats.
808  * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
809  * is known
810  */
811 #define AVINDEX_KEYFRAME 0x0001
812 #define AVINDEX_DISCARD_FRAME 0x0002 /**
813  * Flag is used to indicate which frame should be discarded after decoding.
814  */
815  int flags:2;
816  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).
817  int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
818 } AVIndexEntry;
819 
820 #define AV_DISPOSITION_DEFAULT 0x0001
821 #define AV_DISPOSITION_DUB 0x0002
822 #define AV_DISPOSITION_ORIGINAL 0x0004
823 #define AV_DISPOSITION_COMMENT 0x0008
824 #define AV_DISPOSITION_LYRICS 0x0010
825 #define AV_DISPOSITION_KARAOKE 0x0020
827 /**
828  * Track should be used during playback by default.
829  * Useful for subtitle track that should be displayed
830  * even when user did not explicitly ask for subtitles.
831  */
832 #define AV_DISPOSITION_FORCED 0x0040
833 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
834 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
835 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
836 /**
837  * The stream is stored in the file as an attached picture/"cover art" (e.g.
838  * APIC frame in ID3v2). The first (usually only) packet associated with it
839  * will be returned among the first few packets read from the file unless
840  * seeking takes place. It can also be accessed at any time in
841  * AVStream.attached_pic.
842  */
843 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
844 /**
845  * The stream is sparse, and contains thumbnail images, often corresponding
846  * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
847  */
848 #define AV_DISPOSITION_TIMED_THUMBNAILS 0x0800
849 
850 typedef struct AVStreamInternal AVStreamInternal;
851 
852 /**
853  * To specify text track kind (different from subtitles default).
854  */
855 #define AV_DISPOSITION_CAPTIONS 0x10000
856 #define AV_DISPOSITION_DESCRIPTIONS 0x20000
857 #define AV_DISPOSITION_METADATA 0x40000
858 #define AV_DISPOSITION_DEPENDENT 0x80000 ///< dependent audio stream (mix_type=0 in mpegts)
859 #define AV_DISPOSITION_STILL_IMAGE 0x100000 ///< still images in video stream (still_picture_flag=1 in mpegts)
860 
861 /**
862  * Options for behavior on timestamp wrap detection.
863  */
864 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
865 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
866 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
868 /**
869  * Stream structure.
870  * New fields can be added to the end with minor version bumps.
871  * Removal, reordering and changes to existing fields require a major
872  * version bump.
873  * sizeof(AVStream) must not be used outside libav*.
874  */
875 typedef struct AVStream {
876  int index; /**< stream index in AVFormatContext */
877  /**
878  * Format-specific stream ID.
879  * decoding: set by libavformat
880  * encoding: set by the user, replaced by libavformat if left unset
881  */
882  int id;
883 #if FF_API_LAVF_AVCTX
884  /**
885  * @deprecated use the codecpar struct instead
886  */
888  AVCodecContext *codec;
889 #endif
890  void *priv_data;
892  /**
893  * This is the fundamental unit of time (in seconds) in terms
894  * of which frame timestamps are represented.
895  *
896  * decoding: set by libavformat
897  * encoding: May be set by the caller before avformat_write_header() to
898  * provide a hint to the muxer about the desired timebase. In
899  * avformat_write_header(), the muxer will overwrite this field
900  * with the timebase that will actually be used for the timestamps
901  * written into the file (which may or may not be related to the
902  * user-provided one, depending on the format).
903  */
904  AVRational time_base;
905 
906  /**
907  * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
908  * Only set this if you are absolutely 100% sure that the value you set
909  * it to really is the pts of the first frame.
910  * This may be undefined (AV_NOPTS_VALUE).
911  * @note The ASF header does NOT contain a correct start_time the ASF
912  * demuxer must NOT set this.
913  */
914  int64_t start_time;
915 
916  /**
917  * Decoding: duration of the stream, in stream time base.
918  * If a source file does not specify a duration, but does specify
919  * a bitrate, this value will be estimated from bitrate and file size.
920  *
921  * Encoding: May be set by the caller before avformat_write_header() to
922  * provide a hint to the muxer about the estimated duration.
923  */
924  int64_t duration;
925 
926  int64_t nb_frames; ///< number of frames in this stream if known or 0
927 
928  int disposition; /**< AV_DISPOSITION_* bit field */
929 
930  enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
931 
932  /**
933  * sample aspect ratio (0 if unknown)
934  * - encoding: Set by user.
935  * - decoding: Set by libavformat.
936  */
937  AVRational sample_aspect_ratio;
938 
939  AVDictionary *metadata;
940 
941  /**
942  * Average framerate
943  *
944  * - demuxing: May be set by libavformat when creating the stream or in
945  * avformat_find_stream_info().
946  * - muxing: May be set by the caller before avformat_write_header().
947  */
948  AVRational avg_frame_rate;
949 
950  /**
951  * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
952  * will contain the attached picture.
953  *
954  * decoding: set by libavformat, must not be modified by the caller.
955  * encoding: unused
956  */
957  AVPacket attached_pic;
958 
959  /**
960  * An array of side data that applies to the whole stream (i.e. the
961  * container does not allow it to change between packets).
962  *
963  * There may be no overlap between the side data in this array and side data
964  * in the packets. I.e. a given side data is either exported by the muxer
965  * (demuxing) / set by the caller (muxing) in this array, then it never
966  * appears in the packets, or the side data is exported / sent through
967  * the packets (always in the first packet where the value becomes known or
968  * changes), then it does not appear in this array.
969  *
970  * - demuxing: Set by libavformat when the stream is created.
971  * - muxing: May be set by the caller before avformat_write_header().
972  *
973  * Freed by libavformat in avformat_free_context().
974  *
975  * @see av_format_inject_global_side_data()
976  */
977  AVPacketSideData *side_data;
978  /**
979  * The number of elements in the AVStream.side_data array.
980  */
981  int nb_side_data;
982 
983  /**
984  * Flags indicating events happening on the stream, a combination of
985  * AVSTREAM_EVENT_FLAG_*.
986  *
987  * - demuxing: may be set by the demuxer in avformat_open_input(),
988  * avformat_find_stream_info() and av_read_frame(). Flags must be cleared
989  * by the user once the event has been handled.
990  * - muxing: may be set by the user after avformat_write_header(). to
991  * indicate a user-triggered event. The muxer will clear the flags for
992  * events it has handled in av_[interleaved]_write_frame().
993  */
994  int event_flags;
995 /**
996  * - demuxing: the demuxer read new metadata from the file and updated
997  * AVStream.metadata accordingly
998  * - muxing: the user updated AVStream.metadata and wishes the muxer to write
999  * it into the file
1000  */
1001 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001
1002 /**
1003  * - demuxing: new packets for this stream were read from the file. This
1004  * event is informational only and does not guarantee that new packets
1005  * for this stream will necessarily be returned from av_read_frame().
1006  */
1007 #define AVSTREAM_EVENT_FLAG_NEW_PACKETS (1 << 1)
1008 
1009  /**
1010  * Real base framerate of the stream.
1011  * This is the lowest framerate with which all timestamps can be
1012  * represented accurately (it is the least common multiple of all
1013  * framerates in the stream). Note, this value is just a guess!
1014  * For example, if the time base is 1/90000 and all frames have either
1015  * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
1016  */
1017  AVRational r_frame_rate;
1018 
1019 #if FF_API_LAVF_FFSERVER
1020  /**
1021  * String containing pairs of key and values describing recommended encoder configuration.
1022  * Pairs are separated by ','.
1023  * Keys are separated from values by '='.
1024  *
1025  * @deprecated unused
1026  */
1028  char *recommended_encoder_configuration;
1029 #endif
1030 
1031  /**
1032  * Codec parameters associated with this stream. Allocated and freed by
1033  * libavformat in avformat_new_stream() and avformat_free_context()
1034  * respectively.
1035  *
1036  * - demuxing: filled by libavformat on stream creation or in
1037  * avformat_find_stream_info()
1038  * - muxing: filled by the caller before avformat_write_header()
1039  */
1040  AVCodecParameters *codecpar;
1041 
1042  /*****************************************************************
1043  * All fields below this line are not part of the public API. They
1044  * may not be used outside of libavformat and can be changed and
1045  * removed at will.
1046  * Internal note: be aware that physically removing these fields
1047  * will break ABI. Replace removed fields with dummy fields, and
1048  * add new fields to AVStreamInternal.
1049  *****************************************************************
1050  */
1051 
1052 #if LIBAVFORMAT_VERSION_MAJOR < 59
1053  // kept for ABI compatibility only, do not access in any way
1054  void *unused;
1055 #endif
1056 
1057  int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
1058 
1059  // Timestamp generation support:
1060  /**
1061  * Timestamp corresponding to the last dts sync point.
1062  *
1063  * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
1064  * a DTS is received from the underlying container. Otherwise set to
1065  * AV_NOPTS_VALUE by default.
1066  */
1067  int64_t first_dts;
1068  int64_t cur_dts;
1069  int64_t last_IP_pts;
1070  int last_IP_duration;
1071 
1072  /**
1073  * Number of packets to buffer for codec probing
1074  */
1075  int probe_packets;
1077  /**
1078  * Number of frames that have been demuxed during avformat_find_stream_info()
1079  */
1080  int codec_info_nb_frames;
1081 
1082  /* av_read_frame() support */
1083  enum AVStreamParseType need_parsing;
1085 
1086 #if LIBAVFORMAT_VERSION_MAJOR < 59
1087  // kept for ABI compatibility only, do not access in any way
1088  void *unused7;
1089  AVProbeData unused6;
1090  int64_t unused5[16+1];
1091  void *unused2;
1092  int unused3;
1093  unsigned int unused4;
1094 #endif
1095 
1096  /**
1097  * Stream Identifier
1098  * This is the MPEG-TS stream identifier +1
1099  * 0 means unknown
1100  */
1101  int stream_identifier;
1103 #if LIBAVFORMAT_VERSION_MAJOR < 59
1104  // kept for ABI compatibility only, do not access in any way
1105  int unused8;
1106  int unused9;
1107  int unused10;
1108 #endif
1109 
1110  /**
1111  * An opaque field for libavformat internal usage.
1112  * Must not be accessed in any way by callers.
1113  */
1114  AVStreamInternal *internal;
1117 #if FF_API_FORMAT_GET_SET
1118 /**
1119  * Accessors for some AVStream fields. These used to be provided for ABI
1120  * compatibility, and do not need to be used anymore.
1121  */
1123 AVRational av_stream_get_r_frame_rate(const AVStream *s);
1125 void av_stream_set_r_frame_rate(AVStream *s, AVRational r);
1126 #if FF_API_LAVF_FFSERVER
1128 char* av_stream_get_recommended_encoder_configuration(const AVStream *s);
1130 void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration);
1131 #endif
1132 #endif
1133 
1135 
1136 /**
1137  * Returns the pts of the last muxed packet + its duration
1138  *
1139  * the retuned value is undefined when used with a demuxer.
1140  */
1141 int64_t av_stream_get_end_pts(const AVStream *st);
1142 
1143 #define AV_PROGRAM_RUNNING 1
1144 
1145 /**
1146  * New fields can be added to the end with minor version bumps.
1147  * Removal, reordering and changes to existing fields require a major
1148  * version bump.
1149  * sizeof(AVProgram) must not be used outside libav*.
1150  */
1151 typedef struct AVProgram {
1152  int id;
1153  int flags;
1154  enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1155  unsigned int *stream_index;
1156  unsigned int nb_stream_indexes;
1157  AVDictionary *metadata;
1158 
1159  int program_num;
1160  int pmt_pid;
1161  int pcr_pid;
1162  int pmt_version;
1164  /*****************************************************************
1165  * All fields below this line are not part of the public API. They
1166  * may not be used outside of libavformat and can be changed and
1167  * removed at will.
1168  * New public fields should be added right above.
1169  *****************************************************************
1170  */
1171  int64_t start_time;
1172  int64_t end_time;
1173 
1174  int64_t pts_wrap_reference; ///< reference dts for wrap detection
1175  int pts_wrap_behavior; ///< behavior on wrap detection
1176 } AVProgram;
1177 
1178 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1179  (streams are added dynamically) */
1180 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely
1181  not seekable, and attempts to call the
1182  seek function will fail. For some
1183  network protocols (e.g. HLS), this can
1184  change dynamically at runtime. */
1185 
1186 typedef struct AVChapter {
1187  int id; ///< unique ID to identify the chapter
1188  AVRational time_base; ///< time base in which the start/end timestamps are specified
1189  int64_t start, end; ///< chapter start/end time in time_base units
1190  AVDictionary *metadata;
1191 } AVChapter;
1192 
1193 
1194 /**
1195  * Callback used by devices to communicate with application.
1196  */
1197 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1198  void *data, size_t data_size);
1199 
1200 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
1203 /**
1204  * The duration of a video can be estimated through various ways, and this enum can be used
1205  * to know how the duration was estimated.
1206  */
1208  AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1209  AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1210  AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1211 };
1212 
1213 typedef struct AVFormatInternal AVFormatInternal;
1215 /**
1216  * Format I/O context.
1217  * New fields can be added to the end with minor version bumps.
1218  * Removal, reordering and changes to existing fields require a major
1219  * version bump.
1220  * sizeof(AVFormatContext) must not be used outside libav*, use
1221  * avformat_alloc_context() to create an AVFormatContext.
1222  *
1223  * Fields can be accessed through AVOptions (av_opt*),
1224  * the name string used matches the associated command line parameter name and
1225  * can be found in libavformat/options_table.h.
1226  * The AVOption/command line parameter names differ in some cases from the C
1227  * structure field names for historic reasons or brevity.
1228  */
1229 typedef struct AVFormatContext {
1230  /**
1231  * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1232  * Exports (de)muxer private options if they exist.
1233  */
1234  const AVClass *av_class;
1235 
1236  /**
1237  * The input container format.
1238  *
1239  * Demuxing only, set by avformat_open_input().
1240  */
1242 
1243  /**
1244  * The output container format.
1245  *
1246  * Muxing only, must be set by the caller before avformat_write_header().
1247  */
1248  ff_const59 struct AVOutputFormat *oformat;
1249 
1250  /**
1251  * Format private data. This is an AVOptions-enabled struct
1252  * if and only if iformat/oformat.priv_class is not NULL.
1253  *
1254  * - muxing: set by avformat_write_header()
1255  * - demuxing: set by avformat_open_input()
1256  */
1257  void *priv_data;
1258 
1259  /**
1260  * I/O context.
1261  *
1262  * - demuxing: either set by the user before avformat_open_input() (then
1263  * the user must close it manually) or set by avformat_open_input().
1264  * - muxing: set by the user before avformat_write_header(). The caller must
1265  * take care of closing / freeing the IO context.
1266  *
1267  * Do NOT set this field if AVFMT_NOFILE flag is set in
1268  * iformat/oformat.flags. In such a case, the (de)muxer will handle
1269  * I/O in some other way and this field will be NULL.
1270  */
1272 
1273  /* stream info */
1274  /**
1275  * Flags signalling stream properties. A combination of AVFMTCTX_*.
1276  * Set by libavformat.
1277  */
1278  int ctx_flags;
1279 
1280  /**
1281  * Number of elements in AVFormatContext.streams.
1282  *
1283  * Set by avformat_new_stream(), must not be modified by any other code.
1284  */
1285  unsigned int nb_streams;
1286  /**
1287  * A list of all streams in the file. New streams are created with
1288  * avformat_new_stream().
1289  *
1290  * - demuxing: streams are created by libavformat in avformat_open_input().
1291  * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1292  * appear in av_read_frame().
1293  * - muxing: streams are created by the user before avformat_write_header().
1294  *
1295  * Freed by libavformat in avformat_free_context().
1296  */
1297  AVStream **streams;
1298 
1299 #if FF_API_FORMAT_FILENAME
1300  /**
1301  * input or output filename
1302  *
1303  * - demuxing: set by avformat_open_input()
1304  * - muxing: may be set by the caller before avformat_write_header()
1305  *
1306  * @deprecated Use url instead.
1307  */
1309  char filename[1024];
1310 #endif
1312  /**
1313  * input or output URL. Unlike the old filename field, this field has no
1314  * length restriction.
1315  *
1316  * - demuxing: set by avformat_open_input(), initialized to an empty
1317  * string if url parameter was NULL in avformat_open_input().
1318  * - muxing: may be set by the caller before calling avformat_write_header()
1319  * (or avformat_init_output() if that is called first) to a string
1320  * which is freeable by av_free(). Set to an empty string if it
1321  * was NULL in avformat_init_output().
1322  *
1323  * Freed by libavformat in avformat_free_context().
1324  */
1325  char *url;
1326 
1327  /**
1328  * Position of the first frame of the component, in
1329  * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1330  * It is deduced from the AVStream values.
1331  *
1332  * Demuxing only, set by libavformat.
1333  */
1334  int64_t start_time;
1335 
1336  /**
1337  * Duration of the stream, in AV_TIME_BASE fractional
1338  * seconds. Only set this value if you know none of the individual stream
1339  * durations and also do not set any of them. This is deduced from the
1340  * AVStream values if not set.
1341  *
1342  * Demuxing only, set by libavformat.
1343  */
1344  int64_t duration;
1345 
1346  /**
1347  * Total stream bitrate in bit/s, 0 if not
1348  * available. Never set it directly if the file_size and the
1349  * duration are known as FFmpeg can compute it automatically.
1350  */
1351  int64_t bit_rate;
1352 
1353  unsigned int packet_size;
1354  int max_delay;
1355 
1356  /**
1357  * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1358  * Set by the user before avformat_open_input() / avformat_write_header().
1359  */
1360  int flags;
1361 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1362 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1363 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1364 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1365 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1366 #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
1367 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1368 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1369 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1370 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1371 /**
1372  * When muxing, try to avoid writing any random/volatile data to the output.
1373  * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1374  *
1375  * This flag is mainly intended for testing.
1376  */
1377 #define AVFMT_FLAG_BITEXACT 0x0400
1378 #if FF_API_LAVF_MP4A_LATM
1379 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Deprecated, does nothing.
1380 #endif
1381 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1382 #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)
1383 #if FF_API_LAVF_KEEPSIDE_FLAG
1384 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Deprecated, does nothing.
1385 #endif
1386 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1387 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
1388 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
1389 
1390  /**
1391  * Maximum size of the data read from input for determining
1392  * the input container format.
1393  * Demuxing only, set by the caller before avformat_open_input().
1394  */
1395  int64_t probesize;
1397  /**
1398  * Maximum duration (in AV_TIME_BASE units) of the data read
1399  * from input in avformat_find_stream_info().
1400  * Demuxing only, set by the caller before avformat_find_stream_info().
1401  * Can be set to 0 to let avformat choose using a heuristic.
1402  */
1403  int64_t max_analyze_duration;
1404 
1405  const uint8_t *key;
1406  int keylen;
1407 
1408  unsigned int nb_programs;
1409  AVProgram **programs;
1410 
1411  /**
1412  * Forced video codec_id.
1413  * Demuxing: Set by user.
1414  */
1415  enum AVCodecID video_codec_id;
1416 
1417  /**
1418  * Forced audio codec_id.
1419  * Demuxing: Set by user.
1420  */
1421  enum AVCodecID audio_codec_id;
1423  /**
1424  * Forced subtitle codec_id.
1425  * Demuxing: Set by user.
1426  */
1427  enum AVCodecID subtitle_codec_id;
1428 
1429  /**
1430  * Maximum amount of memory in bytes to use for the index of each stream.
1431  * If the index exceeds this size, entries will be discarded as
1432  * needed to maintain a smaller size. This can lead to slower or less
1433  * accurate seeking (depends on demuxer).
1434  * Demuxers for which a full in-memory index is mandatory will ignore
1435  * this.
1436  * - muxing: unused
1437  * - demuxing: set by user
1438  */
1439  unsigned int max_index_size;
1440 
1441  /**
1442  * Maximum amount of memory in bytes to use for buffering frames
1443  * obtained from realtime capture devices.
1444  */
1445  unsigned int max_picture_buffer;
1446 
1447  /**
1448  * Number of chapters in AVChapter array.
1449  * When muxing, chapters are normally written in the file header,
1450  * so nb_chapters should normally be initialized before write_header
1451  * is called. Some muxers (e.g. mov and mkv) can also write chapters
1452  * in the trailer. To write chapters in the trailer, nb_chapters
1453  * must be zero when write_header is called and non-zero when
1454  * write_trailer is called.
1455  * - muxing: set by user
1456  * - demuxing: set by libavformat
1457  */
1458  unsigned int nb_chapters;
1459  AVChapter **chapters;
1460 
1461  /**
1462  * Metadata that applies to the whole file.
1463  *
1464  * - demuxing: set by libavformat in avformat_open_input()
1465  * - muxing: may be set by the caller before avformat_write_header()
1466  *
1467  * Freed by libavformat in avformat_free_context().
1468  */
1469  AVDictionary *metadata;
1470 
1471  /**
1472  * Start time of the stream in real world time, in microseconds
1473  * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1474  * stream was captured at this real world time.
1475  * - muxing: Set by the caller before avformat_write_header(). If set to
1476  * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1477  * be used.
1478  * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1479  * the value may become known after some number of frames
1480  * have been received.
1481  */
1482  int64_t start_time_realtime;
1484  /**
1485  * The number of frames used for determining the framerate in
1486  * avformat_find_stream_info().
1487  * Demuxing only, set by the caller before avformat_find_stream_info().
1488  */
1489  int fps_probe_size;
1490 
1491  /**
1492  * Error recognition; higher values will detect more errors but may
1493  * misdetect some more or less valid parts as errors.
1494  * Demuxing only, set by the caller before avformat_open_input().
1495  */
1496  int error_recognition;
1497 
1498  /**
1499  * Custom interrupt callbacks for the I/O layer.
1500  *
1501  * demuxing: set by the user before avformat_open_input().
1502  * muxing: set by the user before avformat_write_header()
1503  * (mainly useful for AVFMT_NOFILE formats). The callback
1504  * should also be passed to avio_open2() if it's used to
1505  * open the file.
1506  */
1507  AVIOInterruptCB interrupt_callback;
1508 
1509  /**
1510  * Flags to enable debugging.
1511  */
1512  int debug;
1513 #define FF_FDEBUG_TS 0x0001
1514 
1515  /**
1516  * Maximum buffering duration for interleaving.
1517  *
1518  * To ensure all the streams are interleaved correctly,
1519  * av_interleaved_write_frame() will wait until it has at least one packet
1520  * for each stream before actually writing any packets to the output file.
1521  * When some streams are "sparse" (i.e. there are large gaps between
1522  * successive packets), this can result in excessive buffering.
1523  *
1524  * This field specifies the maximum difference between the timestamps of the
1525  * first and the last packet in the muxing queue, above which libavformat
1526  * will output a packet regardless of whether it has queued a packet for all
1527  * the streams.
1528  *
1529  * Muxing only, set by the caller before avformat_write_header().
1530  */
1531  int64_t max_interleave_delta;
1532 
1533  /**
1534  * Allow non-standard and experimental extension
1535  * @see AVCodecContext.strict_std_compliance
1536  */
1537  int strict_std_compliance;
1538 
1539  /**
1540  * Flags indicating events happening on the file, a combination of
1541  * AVFMT_EVENT_FLAG_*.
1542  *
1543  * - demuxing: may be set by the demuxer in avformat_open_input(),
1544  * avformat_find_stream_info() and av_read_frame(). Flags must be cleared
1545  * by the user once the event has been handled.
1546  * - muxing: may be set by the user after avformat_write_header() to
1547  * indicate a user-triggered event. The muxer will clear the flags for
1548  * events it has handled in av_[interleaved]_write_frame().
1549  */
1550  int event_flags;
1551 /**
1552  * - demuxing: the demuxer read new metadata from the file and updated
1553  * AVFormatContext.metadata accordingly
1554  * - muxing: the user updated AVFormatContext.metadata and wishes the muxer to
1555  * write it into the file
1556  */
1557 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001
1558 
1559  /**
1560  * Maximum number of packets to read while waiting for the first timestamp.
1561  * Decoding only.
1562  */
1563  int max_ts_probe;
1565  /**
1566  * Avoid negative timestamps during muxing.
1567  * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1568  * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use)
1569  * - muxing: Set by user
1570  * - demuxing: unused
1571  */
1572  int avoid_negative_ts;
1573 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1574 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1575 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1576 
1577  /**
1578  * Transport stream id.
1579  * This will be moved into demuxer private options. Thus no API/ABI compatibility
1580  */
1581  int ts_id;
1582 
1583  /**
1584  * Audio preload in microseconds.
1585  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1586  * - encoding: Set by user
1587  * - decoding: unused
1588  */
1589  int audio_preload;
1590 
1591  /**
1592  * Max chunk time in microseconds.
1593  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1594  * - encoding: Set by user
1595  * - decoding: unused
1596  */
1597  int max_chunk_duration;
1598 
1599  /**
1600  * Max chunk size in bytes
1601  * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1602  * - encoding: Set by user
1603  * - decoding: unused
1604  */
1605  int max_chunk_size;
1606 
1607  /**
1608  * forces the use of wallclock timestamps as pts/dts of packets
1609  * This has undefined results in the presence of B frames.
1610  * - encoding: unused
1611  * - decoding: Set by user
1612  */
1613  int use_wallclock_as_timestamps;
1614 
1615  /**
1616  * avio flags, used to force AVIO_FLAG_DIRECT.
1617  * - encoding: unused
1618  * - decoding: Set by user
1619  */
1620  int avio_flags;
1621 
1622  /**
1623  * The duration field can be estimated through various ways, and this field can be used
1624  * to know how the duration was estimated.
1625  * - encoding: unused
1626  * - decoding: Read by user
1627  */
1628  enum AVDurationEstimationMethod duration_estimation_method;
1629 
1630  /**
1631  * Skip initial bytes when opening stream
1632  * - encoding: unused
1633  * - decoding: Set by user
1634  */
1635  int64_t skip_initial_bytes;
1636 
1637  /**
1638  * Correct single timestamp overflows
1639  * - encoding: unused
1640  * - decoding: Set by user
1641  */
1642  unsigned int correct_ts_overflow;
1643 
1644  /**
1645  * Force seeking to any (also non key) frames.
1646  * - encoding: unused
1647  * - decoding: Set by user
1648  */
1649  int seek2any;
1650 
1651  /**
1652  * Flush the I/O context after each packet.
1653  * - encoding: Set by user
1654  * - decoding: unused
1655  */
1656  int flush_packets;
1657 
1658  /**
1659  * format probing score.
1660  * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1661  * the format.
1662  * - encoding: unused
1663  * - decoding: set by avformat, read by user
1664  */
1665  int probe_score;
1666 
1667  /**
1668  * number of bytes to read maximally to identify format.
1669  * - encoding: unused
1670  * - decoding: set by user
1671  */
1672  int format_probesize;
1673 
1674  /**
1675  * ',' separated list of allowed decoders.
1676  * If NULL then all are allowed
1677  * - encoding: unused
1678  * - decoding: set by user
1679  */
1680  char *codec_whitelist;
1681 
1682  /**
1683  * ',' separated list of allowed demuxers.
1684  * If NULL then all are allowed
1685  * - encoding: unused
1686  * - decoding: set by user
1687  */
1688  char *format_whitelist;
1689 
1690  /**
1691  * An opaque field for libavformat internal usage.
1692  * Must not be accessed in any way by callers.
1693  */
1694  AVFormatInternal *internal;
1695 
1696  /**
1697  * IO repositioned flag.
1698  * This is set by avformat when the underlaying IO context read pointer
1699  * is repositioned, for example when doing byte based seeking.
1700  * Demuxers can use the flag to detect such changes.
1701  */
1702  int io_repositioned;
1703 
1704  /**
1705  * Forced video codec.
1706  * This allows forcing a specific decoder, even when there are multiple with
1707  * the same codec_id.
1708  * Demuxing: Set by user
1709  */
1711 
1712  /**
1713  * Forced audio codec.
1714  * This allows forcing a specific decoder, even when there are multiple with
1715  * the same codec_id.
1716  * Demuxing: Set by user
1717  */
1719 
1720  /**
1721  * Forced subtitle codec.
1722  * This allows forcing a specific decoder, even when there are multiple with
1723  * the same codec_id.
1724  * Demuxing: Set by user
1725  */
1727 
1728  /**
1729  * Forced data codec.
1730  * This allows forcing a specific decoder, even when there are multiple with
1731  * the same codec_id.
1732  * Demuxing: Set by user
1733  */
1735 
1736  /**
1737  * Number of bytes to be written as padding in a metadata header.
1738  * Demuxing: Unused.
1739  * Muxing: Set by user via av_format_set_metadata_header_padding.
1740  */
1741  int metadata_header_padding;
1742 
1743  /**
1744  * User data.
1745  * This is a place for some private data of the user.
1746  */
1747  void *opaque;
1749  /**
1750  * Callback used by devices to communicate with application.
1751  */
1752  av_format_control_message control_message_cb;
1753 
1754  /**
1755  * Output timestamp offset, in microseconds.
1756  * Muxing: set by user
1757  */
1758  int64_t output_ts_offset;
1759 
1760  /**
1761  * dump format separator.
1762  * can be ", " or "\n " or anything else
1763  * - muxing: Set by user.
1764  * - demuxing: Set by user.
1765  */
1766  uint8_t *dump_separator;
1767 
1768  /**
1769  * Forced Data codec_id.
1770  * Demuxing: Set by user.
1771  */
1772  enum AVCodecID data_codec_id;
1773 
1774 #if FF_API_OLD_OPEN_CALLBACKS
1775  /**
1776  * Called to open further IO contexts when needed for demuxing.
1777  *
1778  * This can be set by the user application to perform security checks on
1779  * the URLs before opening them.
1780  * The function should behave like avio_open2(), AVFormatContext is provided
1781  * as contextual information and to reach AVFormatContext.opaque.
1782  *
1783  * If NULL then some simple checks are used together with avio_open2().
1784  *
1785  * Must not be accessed directly from outside avformat.
1786  * @See av_format_set_open_cb()
1787  *
1788  * Demuxing: Set by user.
1789  *
1790  * @deprecated Use io_open and io_close.
1791  */
1793  int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options);
1794 #endif
1795 
1796  /**
1797  * ',' separated list of allowed protocols.
1798  * - encoding: unused
1799  * - decoding: set by user
1800  */
1801  char *protocol_whitelist;
1802 
1803  /**
1804  * A callback for opening new IO streams.
1805  *
1806  * Whenever a muxer or a demuxer needs to open an IO stream (typically from
1807  * avformat_open_input() for demuxers, but for certain formats can happen at
1808  * other times as well), it will call this callback to obtain an IO context.
1809  *
1810  * @param s the format context
1811  * @param pb on success, the newly opened IO context should be returned here
1812  * @param url the url to open
1813  * @param flags a combination of AVIO_FLAG_*
1814  * @param options a dictionary of additional options, with the same
1815  * semantics as in avio_open2()
1816  * @return 0 on success, a negative AVERROR code on failure
1817  *
1818  * @note Certain muxers and demuxers do nesting, i.e. they open one or more
1819  * additional internal format contexts. Thus the AVFormatContext pointer
1820  * passed to this callback may be different from the one facing the caller.
1821  * It will, however, have the same 'opaque' field.
1822  */
1823  int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url,
1824  int flags, AVDictionary **options);
1825 
1826  /**
1827  * A callback for closing the streams opened with AVFormatContext.io_open().
1828  */
1829  void (*io_close)(struct AVFormatContext *s, AVIOContext *pb);
1830 
1831  /**
1832  * ',' separated list of disallowed protocols.
1833  * - encoding: unused
1834  * - decoding: set by user
1835  */
1836  char *protocol_blacklist;
1838  /**
1839  * The maximum number of streams.
1840  * - encoding: unused
1841  * - decoding: set by user
1842  */
1844 
1845  /**
1846  * Skip duration calcuation in estimate_timings_from_pts.
1847  * - encoding: unused
1848  * - decoding: set by user
1849  */
1851 
1852  /**
1853  * Maximum number of packets that can be probed
1854  * - encoding: unused
1855  * - decoding: set by user
1856  */
1858 } AVFormatContext;
1859 
1860 #if FF_API_FORMAT_GET_SET
1861 /**
1862  * Accessors for some AVFormatContext fields. These used to be provided for ABI
1863  * compatibility, and do not need to be used anymore.
1864  */
1866 int av_format_get_probe_score(const AVFormatContext *s);
1868 AVCodec * av_format_get_video_codec(const AVFormatContext *s);
1870 void av_format_set_video_codec(AVFormatContext *s, AVCodec *c);
1872 AVCodec * av_format_get_audio_codec(const AVFormatContext *s);
1874 void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c);
1876 AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s);
1878 void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c);
1880 AVCodec * av_format_get_data_codec(const AVFormatContext *s);
1882 void av_format_set_data_codec(AVFormatContext *s, AVCodec *c);
1884 int av_format_get_metadata_header_padding(const AVFormatContext *s);
1886 void av_format_set_metadata_header_padding(AVFormatContext *s, int c);
1888 void * av_format_get_opaque(const AVFormatContext *s);
1890 void av_format_set_opaque(AVFormatContext *s, void *opaque);
1892 av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s);
1894 void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback);
1895 #if FF_API_OLD_OPEN_CALLBACKS
1896 attribute_deprecated AVOpenCallback av_format_get_open_cb(const AVFormatContext *s);
1897 attribute_deprecated void av_format_set_open_cb(AVFormatContext *s, AVOpenCallback callback);
1898 #endif
1899 #endif
1900 
1901 /**
1902  * This function will cause global side data to be injected in the next packet
1903  * of each stream as well as after any subsequent seek.
1904  */
1906 
1907 /**
1908  * Returns the method used to set ctx->duration.
1909  *
1910  * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1911  */
1913 
1914 /**
1915  * @defgroup lavf_core Core functions
1916  * @ingroup libavf
1917  *
1918  * Functions for querying libavformat capabilities, allocating core structures,
1919  * etc.
1920  * @{
1921  */
1922 
1923 /**
1924  * Return the LIBAVFORMAT_VERSION_INT constant.
1925  */
1926 unsigned avformat_version(void);
1927 
1928 /**
1929  * Return the libavformat build-time configuration.
1930  */
1931 const char *avformat_configuration(void);
1932 
1933 /**
1934  * Return the libavformat license.
1935  */
1936 const char *avformat_license(void);
1937 
1938 #if FF_API_NEXT
1939 /**
1940  * Initialize libavformat and register all the muxers, demuxers and
1941  * protocols. If you do not call this function, then you can select
1942  * exactly which formats you want to support.
1943  *
1944  * @see av_register_input_format()
1945  * @see av_register_output_format()
1946  */
1948 void av_register_all(void);
1949 
1951 void av_register_input_format(AVInputFormat *format);
1953 void av_register_output_format(AVOutputFormat *format);
1954 #endif
1955 
1956 /**
1957  * Do global initialization of network libraries. This is optional,
1958  * and not recommended anymore.
1959  *
1960  * This functions only exists to work around thread-safety issues
1961  * with older GnuTLS or OpenSSL libraries. If libavformat is linked
1962  * to newer versions of those libraries, or if you do not use them,
1963  * calling this function is unnecessary. Otherwise, you need to call
1964  * this function before any other threads using them are started.
1965  *
1966  * This function will be deprecated once support for older GnuTLS and
1967  * OpenSSL libraries is removed, and this function has no purpose
1968  * anymore.
1969  */
1970 int avformat_network_init(void);
1971 
1972 /**
1973  * Undo the initialization done by avformat_network_init. Call it only
1974  * once for each time you called avformat_network_init.
1975  */
1976 int avformat_network_deinit(void);
1977 
1978 #if FF_API_NEXT
1979 /**
1980  * If f is NULL, returns the first registered input format,
1981  * if f is non-NULL, returns the next registered input format after f
1982  * or NULL if f is the last one.
1983  */
1985 AVInputFormat *av_iformat_next(const AVInputFormat *f);
1986 
1987 /**
1988  * If f is NULL, returns the first registered output format,
1989  * if f is non-NULL, returns the next registered output format after f
1990  * or NULL if f is the last one.
1991  */
1993 AVOutputFormat *av_oformat_next(const AVOutputFormat *f);
1994 #endif
1995 
1996 /**
1997  * Iterate over all registered muxers.
1998  *
1999  * @param opaque a pointer where libavformat will store the iteration state. Must
2000  * point to NULL to start the iteration.
2001  *
2002  * @return the next registered muxer or NULL when the iteration is
2003  * finished
2004  */
2005 const AVOutputFormat *av_muxer_iterate(void **opaque);
2006 
2007 /**
2008  * Iterate over all registered demuxers.
2009  *
2010  * @param opaque a pointer where libavformat will store the iteration state. Must
2011  * point to NULL to start the iteration.
2012  *
2013  * @return the next registered demuxer or NULL when the iteration is
2014  * finished
2015  */
2016 const AVInputFormat *av_demuxer_iterate(void **opaque);
2017 
2018 /**
2019  * Allocate an AVFormatContext.
2020  * avformat_free_context() can be used to free the context and everything
2021  * allocated by the framework within it.
2022  */
2024 
2025 /**
2026  * Free an AVFormatContext and all its streams.
2027  * @param s context to free
2028  */
2030 
2031 /**
2032  * Get the AVClass for AVFormatContext. It can be used in combination with
2033  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2034  *
2035  * @see av_opt_find().
2036  */
2037 const AVClass *avformat_get_class(void);
2038 
2039 /**
2040  * Add a new stream to a media file.
2041  *
2042  * When demuxing, it is called by the demuxer in read_header(). If the
2043  * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2044  * be called in read_packet().
2045  *
2046  * When muxing, should be called by the user before avformat_write_header().
2047  *
2048  * User is required to call avcodec_close() and avformat_free_context() to
2049  * clean up the allocation by avformat_new_stream().
2050  *
2051  * @param s media file handle
2052  * @param c If non-NULL, the AVCodecContext corresponding to the new stream
2053  * will be initialized to use this codec. This is needed for e.g. codec-specific
2054  * defaults to be set, so codec should be provided if it is known.
2055  *
2056  * @return newly created stream or NULL on error.
2057  */
2059 
2060 /**
2061  * Wrap an existing array as stream side data.
2062  *
2063  * @param st stream
2064  * @param type side information type
2065  * @param data the side data array. It must be allocated with the av_malloc()
2066  * family of functions. The ownership of the data is transferred to
2067  * st.
2068  * @param size side information size
2069  * @return zero on success, a negative AVERROR code on failure. On failure,
2070  * the stream is unchanged and the data remains owned by the caller.
2071  */
2073  uint8_t *data, size_t size);
2074 
2075 /**
2076  * Allocate new information from stream.
2077  *
2078  * @param stream stream
2079  * @param type desired side information type
2080  * @param size side information size
2081  * @return pointer to fresh allocated data or NULL otherwise
2082  */
2084  enum AVPacketSideDataType type, int size);
2085 /**
2086  * Get side information from stream.
2087  *
2088  * @param stream stream
2089  * @param type desired side information type
2090  * @param size If supplied, *size will be set to the size of the side data
2091  * or to zero if the desired side data is not present.
2092  * @return pointer to data if present or NULL otherwise
2093  */
2095  enum AVPacketSideDataType type, int *size);
2096 
2098 
2099 /**
2100  * @}
2101  */
2102 
2103 
2104 /**
2105  * Allocate an AVFormatContext for an output format.
2106  * avformat_free_context() can be used to free the context and
2107  * everything allocated by the framework within it.
2108  *
2109  * @param *ctx is set to the created format context, or to NULL in
2110  * case of failure
2111  * @param oformat format to use for allocating the context, if NULL
2112  * format_name and filename are used instead
2113  * @param format_name the name of output format to use for allocating the
2114  * context, if NULL filename is used instead
2115  * @param filename the name of the filename to use for allocating the
2116  * context, may be NULL
2117  * @return >= 0 in case of success, a negative AVERROR code in case of
2118  * failure
2119  */
2121  const char *format_name, const char *filename);
2122 
2123 /**
2124  * @addtogroup lavf_decoding
2125  * @{
2126  */
2127 
2128 /**
2129  * Find AVInputFormat based on the short name of the input format.
2130  */
2131 ff_const59 AVInputFormat *av_find_input_format(const char *short_name);
2132 
2133 /**
2134  * Guess the file format.
2135  *
2136  * @param pd data to be probed
2137  * @param is_opened Whether the file is already opened; determines whether
2138  * demuxers with or without AVFMT_NOFILE are probed.
2139  */
2141 
2142 /**
2143  * Guess the file format.
2144  *
2145  * @param pd data to be probed
2146  * @param is_opened Whether the file is already opened; determines whether
2147  * demuxers with or without AVFMT_NOFILE are probed.
2148  * @param score_max A probe score larger that this is required to accept a
2149  * detection, the variable is set to the actual detection
2150  * score afterwards.
2151  * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2152  * to retry with a larger probe buffer.
2153  */
2154 ff_const59 AVInputFormat *av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max);
2155 
2156 /**
2157  * Guess the file format.
2158  *
2159  * @param is_opened Whether the file is already opened; determines whether
2160  * demuxers with or without AVFMT_NOFILE are probed.
2161  * @param score_ret The score of the best detection.
2162  */
2163 ff_const59 AVInputFormat *av_probe_input_format3(ff_const59 AVProbeData *pd, int is_opened, int *score_ret);
2164 
2165 /**
2166  * Probe a bytestream to determine the input format. Each time a probe returns
2167  * with a score that is too low, the probe buffer size is increased and another
2168  * attempt is made. When the maximum probe size is reached, the input format
2169  * with the highest score is returned.
2170  *
2171  * @param pb the bytestream to probe
2172  * @param fmt the input format is put here
2173  * @param url the url of the stream
2174  * @param logctx the log context
2175  * @param offset the offset within the bytestream to probe from
2176  * @param max_probe_size the maximum probe buffer size (zero for default)
2177  * @return the score in case of success, a negative value corresponding to an
2178  * the maximal score is AVPROBE_SCORE_MAX
2179  * AVERROR code otherwise
2180  */
2182  const char *url, void *logctx,
2183  unsigned int offset, unsigned int max_probe_size);
2184 
2185 /**
2186  * Like av_probe_input_buffer2() but returns 0 on success
2187  */
2189  const char *url, void *logctx,
2190  unsigned int offset, unsigned int max_probe_size);
2191 
2192 /**
2193  * Open an input stream and read the header. The codecs are not opened.
2194  * The stream must be closed with avformat_close_input().
2195  *
2196  * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
2197  * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
2198  * function and written into ps.
2199  * Note that a user-supplied AVFormatContext will be freed on failure.
2200  * @param url URL of the stream to open.
2201  * @param fmt If non-NULL, this parameter forces a specific input format.
2202  * Otherwise the format is autodetected.
2203  * @param options A dictionary filled with AVFormatContext and demuxer-private options.
2204  * On return this parameter will be destroyed and replaced with a dict containing
2205  * options that were not found. May be NULL.
2206  *
2207  * @return 0 on success, a negative AVERROR on failure.
2208  *
2209  * @note If you want to use custom IO, preallocate the format context and set its pb field.
2210  */
2212 
2215 
2216 /**
2217  * Read packets of a media file to get stream information. This
2218  * is useful for file formats with no headers such as MPEG. This
2219  * function also computes the real framerate in case of MPEG-2 repeat
2220  * frame mode.
2221  * The logical file position is not changed by this function;
2222  * examined packets may be buffered for later processing.
2223  *
2224  * @param ic media file handle
2225  * @param options If non-NULL, an ic.nb_streams long array of pointers to
2226  * dictionaries, where i-th member contains options for
2227  * codec corresponding to i-th stream.
2228  * On return each dictionary will be filled with options that were not found.
2229  * @return >=0 if OK, AVERROR_xxx on error
2230  *
2231  * @note this function isn't guaranteed to open all the codecs, so
2232  * options being non-empty at return is a perfectly normal behavior.
2233  *
2234  * @todo Let the user decide somehow what information is needed so that
2235  * we do not waste time getting stuff the user does not need.
2236  */
2238 
2239 /**
2240  * Find the programs which belong to a given stream.
2241  *
2242  * @param ic media file handle
2243  * @param last the last found program, the search will start after this
2244  * program, or from the beginning if it is NULL
2245  * @param s stream index
2246  * @return the next program which belongs to s, NULL if no program is found or
2247  * the last program is not among the programs of ic.
2248  */
2250 
2251 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
2252 
2253 /**
2254  * Find the "best" stream in the file.
2255  * The best stream is determined according to various heuristics as the most
2256  * likely to be what the user expects.
2257  * If the decoder parameter is non-NULL, av_find_best_stream will find the
2258  * default decoder for the stream's codec; streams for which no decoder can
2259  * be found are ignored.
2260  *
2261  * @param ic media file handle
2262  * @param type stream type: video, audio, subtitles, etc.
2263  * @param wanted_stream_nb user-requested stream number,
2264  * or -1 for automatic selection
2265  * @param related_stream try to find a stream related (eg. in the same
2266  * program) to this one, or -1 if none
2267  * @param decoder_ret if non-NULL, returns the decoder for the
2268  * selected stream
2269  * @param flags flags; none are currently defined
2270  * @return the non-negative stream number in case of success,
2271  * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2272  * could be found,
2273  * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2274  * @note If av_find_best_stream returns successfully and decoder_ret is not
2275  * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2276  */
2278  enum AVMediaType type,
2279  int wanted_stream_nb,
2280  int related_stream,
2281  AVCodec **decoder_ret,
2282  int flags);
2283 
2284 /**
2285  * Return the next frame of a stream.
2286  * This function returns what is stored in the file, and does not validate
2287  * that what is there are valid frames for the decoder. It will split what is
2288  * stored in the file into frames and return one for each call. It will not
2289  * omit invalid data between valid frames so as to give the decoder the maximum
2290  * information possible for decoding.
2291  *
2292  * On success, the returned packet is reference-counted (pkt->buf is set) and
2293  * valid indefinitely. The packet must be freed with av_packet_unref() when
2294  * it is no longer needed. For video, the packet contains exactly one frame.
2295  * For audio, it contains an integer number of frames if each frame has
2296  * a known fixed size (e.g. PCM or ADPCM data). If the audio frames have
2297  * a variable size (e.g. MPEG audio), then it contains one frame.
2298  *
2299  * pkt->pts, pkt->dts and pkt->duration are always set to correct
2300  * values in AVStream.time_base units (and guessed if the format cannot
2301  * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2302  * has B-frames, so it is better to rely on pkt->dts if you do not
2303  * decompress the payload.
2304  *
2305  * @return 0 if OK, < 0 on error or end of file. On error, pkt will be blank
2306  * (as if it came from av_packet_alloc()).
2307  *
2308  * @note pkt will be initialized, so it may be uninitialized, but it must not
2309  * contain data that needs to be freed.
2310  */
2312 
2313 /**
2314  * Seek to the keyframe at timestamp.
2315  * 'timestamp' in 'stream_index'.
2316  *
2317  * @param s media file handle
2318  * @param stream_index If stream_index is (-1), a default
2319  * stream is selected, and timestamp is automatically converted
2320  * from AV_TIME_BASE units to the stream specific time_base.
2321  * @param timestamp Timestamp in AVStream.time_base units
2322  * or, if no stream is specified, in AV_TIME_BASE units.
2323  * @param flags flags which select direction and seeking mode
2324  * @return >= 0 on success
2325  */
2326 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2327  int flags);
2328 
2329 /**
2330  * Seek to timestamp ts.
2331  * Seeking will be done so that the point from which all active streams
2332  * can be presented successfully will be closest to ts and within min/max_ts.
2333  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2334  *
2335  * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2336  * are the file position (this may not be supported by all demuxers).
2337  * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2338  * in the stream with stream_index (this may not be supported by all demuxers).
2339  * Otherwise all timestamps are in units of the stream selected by stream_index
2340  * or if stream_index is -1, in AV_TIME_BASE units.
2341  * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2342  * keyframes (this may not be supported by all demuxers).
2343  * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2344  *
2345  * @param s media file handle
2346  * @param stream_index index of the stream which is used as time base reference
2347  * @param min_ts smallest acceptable timestamp
2348  * @param ts target timestamp
2349  * @param max_ts largest acceptable timestamp
2350  * @param flags flags
2351  * @return >=0 on success, error code otherwise
2352  *
2353  * @note This is part of the new seek API which is still under construction.
2354  */
2355 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2356 
2357 /**
2358  * Discard all internally buffered data. This can be useful when dealing with
2359  * discontinuities in the byte stream. Generally works only with formats that
2360  * can resync. This includes headerless formats like MPEG-TS/TS but should also
2361  * work with NUT, Ogg and in a limited way AVI for example.
2362  *
2363  * The set of streams, the detected duration, stream parameters and codecs do
2364  * not change when calling this function. If you want a complete reset, it's
2365  * better to open a new AVFormatContext.
2366  *
2367  * This does not flush the AVIOContext (s->pb). If necessary, call
2368  * avio_flush(s->pb) before calling this function.
2369  *
2370  * @param s media file handle
2371  * @return >=0 on success, error code otherwise
2372  */
2374 
2375 /**
2376  * Start playing a network-based stream (e.g. RTSP stream) at the
2377  * current position.
2378  */
2380 
2381 /**
2382  * Pause a network-based stream (e.g. RTSP stream).
2383  *
2384  * Use av_read_play() to resume it.
2385  */
2387 
2388 /**
2389  * Close an opened input AVFormatContext. Free it and all its contents
2390  * and set *s to NULL.
2391  */
2393 /**
2394  * @}
2395  */
2396 
2397 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2398 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2399 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2400 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2401 
2402 /**
2403  * @addtogroup lavf_encoding
2404  * @{
2405  */
2406 
2407 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2408 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2409 
2410 /**
2411  * Allocate the stream private data and write the stream header to
2412  * an output media file.
2413  *
2414  * @param s Media file handle, must be allocated with avformat_alloc_context().
2415  * Its oformat field must be set to the desired output format;
2416  * Its pb field must be set to an already opened AVIOContext.
2417  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2418  * On return this parameter will be destroyed and replaced with a dict containing
2419  * options that were not found. May be NULL.
2420  *
2421  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init,
2422  * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init,
2423  * negative AVERROR on failure.
2424  *
2425  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2426  */
2429 
2430 /**
2431  * Allocate the stream private data and initialize the codec, but do not write the header.
2432  * May optionally be used before avformat_write_header to initialize stream parameters
2433  * before actually writing the header.
2434  * If using this function, do not pass the same options to avformat_write_header.
2435  *
2436  * @param s Media file handle, must be allocated with avformat_alloc_context().
2437  * Its oformat field must be set to the desired output format;
2438  * Its pb field must be set to an already opened AVIOContext.
2439  * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2440  * On return this parameter will be destroyed and replaced with a dict containing
2441  * options that were not found. May be NULL.
2442  *
2443  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec requires avformat_write_header to fully initialize,
2444  * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec has been fully initialized,
2445  * negative AVERROR on failure.
2446  *
2447  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2448  */
2451 
2452 /**
2453  * Write a packet to an output media file.
2454  *
2455  * This function passes the packet directly to the muxer, without any buffering
2456  * or reordering. The caller is responsible for correctly interleaving the
2457  * packets if the format requires it. Callers that want libavformat to handle
2458  * the interleaving should call av_interleaved_write_frame() instead of this
2459  * function.
2460  *
2461  * @param s media file handle
2462  * @param pkt The packet containing the data to be written. Note that unlike
2463  * av_interleaved_write_frame(), this function does not take
2464  * ownership of the packet passed to it (though some muxers may make
2465  * an internal reference to the input packet).
2466  * <br>
2467  * This parameter can be NULL (at any time, not just at the end), in
2468  * order to immediately flush data buffered within the muxer, for
2469  * muxers that buffer up data internally before writing it to the
2470  * output.
2471  * <br>
2472  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2473  * set to the index of the corresponding stream in @ref
2474  * AVFormatContext.streams "s->streams".
2475  * <br>
2476  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2477  * must be set to correct values in the stream's timebase (unless the
2478  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2479  * they can be set to AV_NOPTS_VALUE).
2480  * The dts for subsequent packets passed to this function must be strictly
2481  * increasing when compared in their respective timebases (unless the
2482  * output format is flagged with the AVFMT_TS_NONSTRICT, then they
2483  * merely have to be nondecreasing). @ref AVPacket.duration
2484  * "duration") should also be set if known.
2485  * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2486  *
2487  * @see av_interleaved_write_frame()
2488  */
2490 
2491 /**
2492  * Write a packet to an output media file ensuring correct interleaving.
2493  *
2494  * This function will buffer the packets internally as needed to make sure the
2495  * packets in the output file are properly interleaved in the order of
2496  * increasing dts. Callers doing their own interleaving should call
2497  * av_write_frame() instead of this function.
2498  *
2499  * Using this function instead of av_write_frame() can give muxers advance
2500  * knowledge of future packets, improving e.g. the behaviour of the mp4
2501  * muxer for VFR content in fragmenting mode.
2502  *
2503  * @param s media file handle
2504  * @param pkt The packet containing the data to be written.
2505  * <br>
2506  * If the packet is reference-counted, this function will take
2507  * ownership of this reference and unreference it later when it sees
2508  * fit.
2509  * The caller must not access the data through this reference after
2510  * this function returns. If the packet is not reference-counted,
2511  * libavformat will make a copy.
2512  * <br>
2513  * This parameter can be NULL (at any time, not just at the end), to
2514  * flush the interleaving queues.
2515  * <br>
2516  * Packet's @ref AVPacket.stream_index "stream_index" field must be
2517  * set to the index of the corresponding stream in @ref
2518  * AVFormatContext.streams "s->streams".
2519  * <br>
2520  * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2521  * must be set to correct values in the stream's timebase (unless the
2522  * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2523  * they can be set to AV_NOPTS_VALUE).
2524  * The dts for subsequent packets in one stream must be strictly
2525  * increasing (unless the output format is flagged with the
2526  * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2527  * @ref AVPacket.duration "duration") should also be set if known.
2528  *
2529  * @return 0 on success, a negative AVERROR on error. Libavformat will always
2530  * take care of freeing the packet, even if this function fails.
2531  *
2532  * @see av_write_frame(), AVFormatContext.max_interleave_delta
2533  */
2535 
2536 /**
2537  * Write an uncoded frame to an output media file.
2538  *
2539  * The frame must be correctly interleaved according to the container
2540  * specification; if not, av_interleaved_write_uncoded_frame() must be used.
2541  *
2542  * See av_interleaved_write_uncoded_frame() for details.
2543  */
2544 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2545  AVFrame *frame);
2546 
2547 /**
2548  * Write an uncoded frame to an output media file.
2549  *
2550  * If the muxer supports it, this function makes it possible to write an AVFrame
2551  * structure directly, without encoding it into a packet.
2552  * It is mostly useful for devices and similar special muxers that use raw
2553  * video or PCM data and will not serialize it into a byte stream.
2554  *
2555  * To test whether it is possible to use it with a given muxer and stream,
2556  * use av_write_uncoded_frame_query().
2557  *
2558  * The caller gives up ownership of the frame and must not access it
2559  * afterwards.
2560  *
2561  * @return >=0 for success, a negative code on error
2562  */
2563 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
2564  AVFrame *frame);
2565 
2566 /**
2567  * Test whether a muxer supports uncoded frame.
2568  *
2569  * @return >=0 if an uncoded frame can be written to that muxer and stream,
2570  * <0 if not
2571  */
2572 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2573 
2574 /**
2575  * Write the stream trailer to an output media file and free the
2576  * file private data.
2577  *
2578  * May only be called after a successful call to avformat_write_header.
2579  *
2580  * @param s media file handle
2581  * @return 0 if OK, AVERROR_xxx on error
2582  */
2584 
2585 /**
2586  * Return the output format in the list of registered output formats
2587  * which best matches the provided parameters, or return NULL if
2588  * there is no match.
2589  *
2590  * @param short_name if non-NULL checks if short_name matches with the
2591  * names of the registered formats
2592  * @param filename if non-NULL checks if filename terminates with the
2593  * extensions of the registered formats
2594  * @param mime_type if non-NULL checks if mime_type matches with the
2595  * MIME type of the registered formats
2596  */
2597 ff_const59 AVOutputFormat *av_guess_format(const char *short_name,
2598  const char *filename,
2599  const char *mime_type);
2600 
2601 /**
2602  * Guess the codec ID based upon muxer and filename.
2603  */
2604 enum AVCodecID av_guess_codec(ff_const59 AVOutputFormat *fmt, const char *short_name,
2605  const char *filename, const char *mime_type,
2606  enum AVMediaType type);
2607 
2608 /**
2609  * Get timing information for the data currently output.
2610  * The exact meaning of "currently output" depends on the format.
2611  * It is mostly relevant for devices that have an internal buffer and/or
2612  * work in real time.
2613  * @param s media file handle
2614  * @param stream stream in the media file
2615  * @param[out] dts DTS of the last packet output for the stream, in stream
2616  * time_base units
2617  * @param[out] wall absolute time when that packet whas output,
2618  * in microsecond
2619  * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
2620  * Note: some formats or devices may not allow to measure dts and wall
2621  * atomically.
2622  */
2623 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2624  int64_t *dts, int64_t *wall);
2625 
2626 
2627 /**
2628  * @}
2629  */
2630 
2631 
2632 /**
2633  * @defgroup lavf_misc Utility functions
2634  * @ingroup libavf
2635  * @{
2636  *
2637  * Miscellaneous utility functions related to both muxing and demuxing
2638  * (or neither).
2639  */
2640 
2641 /**
2642  * Send a nice hexadecimal dump of a buffer to the specified file stream.
2643  *
2644  * @param f The file stream pointer where the dump should be sent to.
2645  * @param buf buffer
2646  * @param size buffer size
2647  *
2648  * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2649  */
2650 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2651 
2652 /**
2653  * Send a nice hexadecimal dump of a buffer to the log.
2654  *
2655  * @param avcl A pointer to an arbitrary struct of which the first field is a
2656  * pointer to an AVClass struct.
2657  * @param level The importance level of the message, lower values signifying
2658  * higher importance.
2659  * @param buf buffer
2660  * @param size buffer size
2661  *
2662  * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2663  */
2664 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2665 
2666 /**
2667  * Send a nice dump of a packet to the specified file stream.
2668  *
2669  * @param f The file stream pointer where the dump should be sent to.
2670  * @param pkt packet to dump
2671  * @param dump_payload True if the payload must be displayed, too.
2672  * @param st AVStream that the packet belongs to
2673  */
2674 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2675 
2676 
2677 /**
2678  * Send a nice dump of a packet to the log.
2679  *
2680  * @param avcl A pointer to an arbitrary struct of which the first field is a
2681  * pointer to an AVClass struct.
2682  * @param level The importance level of the message, lower values signifying
2683  * higher importance.
2684  * @param pkt packet to dump
2685  * @param dump_payload True if the payload must be displayed, too.
2686  * @param st AVStream that the packet belongs to
2687  */
2688 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2689  const AVStream *st);
2690 
2691 /**
2692  * Get the AVCodecID for the given codec tag tag.
2693  * If no codec id is found returns AV_CODEC_ID_NONE.
2694  *
2695  * @param tags list of supported codec_id-codec_tag pairs, as stored
2696  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2697  * @param tag codec tag to match to a codec ID
2698  */
2699 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2700 
2701 /**
2702  * Get the codec tag for the given codec id id.
2703  * If no codec tag is found returns 0.
2704  *
2705  * @param tags list of supported codec_id-codec_tag pairs, as stored
2706  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2707  * @param id codec ID to match to a codec tag
2708  */
2709 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2710 
2711 /**
2712  * Get the codec tag for the given codec id.
2713  *
2714  * @param tags list of supported codec_id - codec_tag pairs, as stored
2715  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2716  * @param id codec id that should be searched for in the list
2717  * @param tag A pointer to the found tag
2718  * @return 0 if id was not found in tags, > 0 if it was found
2719  */
2720 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2721  unsigned int *tag);
2722 
2724 
2725 /**
2726  * Get the index for a specific timestamp.
2727  *
2728  * @param st stream that the timestamp belongs to
2729  * @param timestamp timestamp to retrieve the index for
2730  * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2731  * to the timestamp which is <= the requested one, if backward
2732  * is 0, then it will be >=
2733  * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2734  * @return < 0 if no such timestamp could be found
2735  */
2736 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2737 
2738 /**
2739  * Add an index entry into a sorted list. Update the entry if the list
2740  * already contains it.
2741  *
2742  * @param timestamp timestamp in the time base of the given stream
2743  */
2744 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2745  int size, int distance, int flags);
2746 
2747 
2748 /**
2749  * Split a URL string into components.
2750  *
2751  * The pointers to buffers for storing individual components may be null,
2752  * in order to ignore that component. Buffers for components not found are
2753  * set to empty strings. If the port is not found, it is set to a negative
2754  * value.
2755  *
2756  * @param proto the buffer for the protocol
2757  * @param proto_size the size of the proto buffer
2758  * @param authorization the buffer for the authorization
2759  * @param authorization_size the size of the authorization buffer
2760  * @param hostname the buffer for the host name
2761  * @param hostname_size the size of the hostname buffer
2762  * @param port_ptr a pointer to store the port number in
2763  * @param path the buffer for the path
2764  * @param path_size the size of the path buffer
2765  * @param url the URL to split
2766  */
2767 void av_url_split(char *proto, int proto_size,
2768  char *authorization, int authorization_size,
2769  char *hostname, int hostname_size,
2770  int *port_ptr,
2771  char *path, int path_size,
2772  const char *url);
2773 
2774 
2775 /**
2776  * Print detailed information about the input or output format, such as
2777  * duration, bitrate, streams, container, programs, metadata, side data,
2778  * codec and time base.
2779  *
2780  * @param ic the context to analyze
2781  * @param index index of the stream to dump information about
2782  * @param url the URL to print, such as source or destination file
2783  * @param is_output Select whether the specified context is an input(0) or output(1)
2784  */
2786  int index,
2787  const char *url,
2788  int is_output);
2789 
2790 
2791 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
2792 
2793 /**
2794  * Return in 'buf' the path with '%d' replaced by a number.
2795  *
2796  * Also handles the '%0nd' format where 'n' is the total number
2797  * of digits and '%%'.
2798  *
2799  * @param buf destination buffer
2800  * @param buf_size destination buffer size
2801  * @param path numbered sequence string
2802  * @param number frame number
2803  * @param flags AV_FRAME_FILENAME_FLAGS_*
2804  * @return 0 if OK, -1 on format error
2805  */
2806 int av_get_frame_filename2(char *buf, int buf_size,
2807  const char *path, int number, int flags);
2808 
2809 int av_get_frame_filename(char *buf, int buf_size,
2810  const char *path, int number);
2811 
2812 /**
2813  * Check whether filename actually is a numbered sequence generator.
2814  *
2815  * @param filename possible numbered sequence string
2816  * @return 1 if a valid numbered sequence string, 0 otherwise
2817  */
2818 int av_filename_number_test(const char *filename);
2819 
2820 /**
2821  * Generate an SDP for an RTP session.
2822  *
2823  * Note, this overwrites the id values of AVStreams in the muxer contexts
2824  * for getting unique dynamic payload types.
2825  *
2826  * @param ac array of AVFormatContexts describing the RTP streams. If the
2827  * array is composed by only one context, such context can contain
2828  * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2829  * all the contexts in the array (an AVCodecContext per RTP stream)
2830  * must contain only one AVStream.
2831  * @param n_files number of AVCodecContexts contained in ac
2832  * @param buf buffer where the SDP will be stored (must be allocated by
2833  * the caller)
2834  * @param size the size of the buffer
2835  * @return 0 if OK, AVERROR_xxx on error
2836  */
2837 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2838 
2839 /**
2840  * Return a positive value if the given filename has one of the given
2841  * extensions, 0 otherwise.
2842  *
2843  * @param filename file name to check against the given extensions
2844  * @param extensions a comma-separated list of filename extensions
2845  */
2846 int av_match_ext(const char *filename, const char *extensions);
2847 
2848 /**
2849  * Test if the given container can store a codec.
2850  *
2851  * @param ofmt container to check for compatibility
2852  * @param codec_id codec to potentially store in container
2853  * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2854  *
2855  * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2856  * A negative number if this information is not available.
2857  */
2859  int std_compliance);
2860 
2861 /**
2862  * @defgroup riff_fourcc RIFF FourCCs
2863  * @{
2864  * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2865  * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2866  * following code:
2867  * @code
2868  * uint32_t tag = MKTAG('H', '2', '6', '4');
2869  * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2870  * enum AVCodecID id = av_codec_get_id(table, tag);
2871  * @endcode
2872  */
2873 /**
2874  * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2875  */
2876 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2877 /**
2878  * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2879  */
2880 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2881 /**
2882  * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2883  */
2884 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2885 /**
2886  * @return the table mapping MOV FourCCs for audio to AVCodecID.
2887  */
2888 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2889 
2890 /**
2891  * @}
2892  */
2893 
2894 /**
2895  * Guess the sample aspect ratio of a frame, based on both the stream and the
2896  * frame aspect ratio.
2897  *
2898  * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2899  * is set by the demuxer, these two may not be equal. This function tries to
2900  * return the value that you should use if you would like to display the frame.
2901  *
2902  * Basic logic is to use the stream aspect ratio if it is set to something sane
2903  * otherwise use the frame aspect ratio. This way a container setting, which is
2904  * usually easy to modify can override the coded value in the frames.
2905  *
2906  * @param format the format context which the stream is part of
2907  * @param stream the stream which the frame is part of
2908  * @param frame the frame with the aspect ratio to be determined
2909  * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2910  */
2912 
2913 /**
2914  * Guess the frame rate, based on both the container and codec information.
2915  *
2916  * @param ctx the format context which the stream is part of
2917  * @param stream the stream which the frame is part of
2918  * @param frame the frame for which the frame rate should be determined, may be NULL
2919  * @return the guessed (valid) frame rate, 0/1 if no idea
2920  */
2922 
2923 /**
2924  * Check if the stream st contained in s is matched by the stream specifier
2925  * spec.
2926  *
2927  * See the "stream specifiers" chapter in the documentation for the syntax
2928  * of spec.
2929  *
2930  * @return >0 if st is matched by spec;
2931  * 0 if st is not matched by spec;
2932  * AVERROR code if spec is invalid
2933  *
2934  * @note A stream specifier can match several streams in the format.
2935  */
2937  const char *spec);
2938 
2940 
2941 #if FF_API_OLD_BSF
2942 /**
2943  * Apply a list of bitstream filters to a packet.
2944  *
2945  * @param codec AVCodecContext, usually from an AVStream
2946  * @param pkt the packet to apply filters to. If, on success, the returned
2947  * packet has size == 0 and side_data_elems == 0, it indicates that
2948  * the packet should be dropped
2949  * @param bsfc a NULL-terminated list of filters to apply
2950  * @return >=0 on success;
2951  * AVERROR code on failure
2952  */
2954 int av_apply_bitstream_filters(AVCodecContext *codec, AVPacket *pkt,
2955  AVBitStreamFilterContext *bsfc);
2956 #endif
2957 
2958 enum AVTimebaseSource {
2959  AVFMT_TBCF_AUTO = -1,
2962 #if FF_API_R_FRAME_RATE
2963  AVFMT_TBCF_R_FRAMERATE,
2964 #endif
2965 };
2966 
2967 /**
2968  * Transfer internal timing information from one stream to another.
2969  *
2970  * This function is useful when doing stream copy.
2971  *
2972  * @param ofmt target output format for ost
2973  * @param ost output stream which needs timings copy and adjustments
2974  * @param ist reference input stream to copy timings from
2975  * @param copy_tb define from where the stream codec timebase needs to be imported
2976  */
2978  AVStream *ost, const AVStream *ist,
2979  enum AVTimebaseSource copy_tb);
2980 
2981 /**
2982  * Get the internal codec timebase from a stream.
2983  *
2984  * @param st input stream to extract the timebase from
2985  */
2987 
2988 /**
2989  * @}
2990  */
2991 
2992 #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:4759
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:726
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:1837
full parsing and interpolation of timestamps for frames not starting on a packet boundary ...
Definition: avformat.h:805
Bytestream IO Context.
Definition: avio.h:161
void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st)
Send a nice dump of a packet to the specified file stream.
Definition: dump.c:110
Buffered I/O operations.
AVPacketSideDataType
Definition: packet.h:40
attribute_deprecated int av_demuxer_open(AVFormatContext *ic)
Definition: utils.c:395
This structure describes decoded (raw) audio or video data.
Definition: frame.h:314
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
Definition: mux.c:1257
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:1991
int av_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file.
Definition: mux.c:1211
const char * filename
Definition: avformat.h:442
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
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:5079
enum AVCodecID video_codec
default video codec
Definition: avformat.h:511
GLint GLenum type
Definition: opengl_enc.c:104
int av_get_output_timestamp(struct AVFormatContext *s, int stream, int64_t *dts, int64_t *wall)
Get timing information for the data currently output.
Definition: mux.c:1317
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:505
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:1409
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:707
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample format(the sample packing is implied by the sample format) and sample rate.The lists are not just lists
AVCodec.
Definition: codec.h:190
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext *ctx)
Returns the method used to set ctx->duration.
Definition: options.c:232
Format I/O context.
Definition: avformat.h:1243
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:5102
static int query_codec(enum AVCodecID id, int std_compliance)
Definition: img2enc.c:229
const struct AVCodecTag * avformat_get_mov_audio_tags(void)
Definition: isom_tags.c:343
Public dictionary API.
static int64_t start_time
Definition: ffplay.c:332
uint8_t
static int nb_streams
Definition: ffprobe.c:283
const struct AVCodecTag * avformat_get_riff_video_tags(void)
Definition: riff.c:620
enum AVCodecID av_codec_get_id(const struct AVCodecTag *const *tags, unsigned int tag)
Get the AVCodecID for the given codec tag tag.
unsigned avformat_version(void)
Return the LIBAVFORMAT_VERSION_INT constant.
Definition: utils.c:62
const char * avformat_license(void)
Return the libavformat license.
Definition: utils.c:73
int avformat_transfer_internal_stream_timing_info(const AVOutputFormat *ofmt, AVStream *ost, const AVStream *ist, enum AVTimebaseSource copy_tb)
Transfer internal timing information from one stream to another.
Definition: utils.c:5738
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
#define f(width, name)
Definition: cbs_vp9.c:255
int priv_data_size
size of private data so that it can be allocated in the wrapper
Definition: avformat.h:552
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:5286
AVDurationEstimationMethod
The duration of a video can be estimated through various ways, and this enum can be used to know how ...
Definition: avformat.h:1221
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4481
uint8_t * av_stream_get_side_data(const AVStream *stream, enum AVPacketSideDataType type, int *size)
Get side information from stream.
Definition: utils.c:5465
int64_t duration
Definition: movenc.c:63
int av_codec_get_tag2(const struct AVCodecTag *const *tags, enum AVCodecID id, unsigned int *tag)
Get the codec tag for the given codec id.
AVFormatContext * avformat_alloc_context(void)
Allocate an AVFormatContext.
Definition: options.c:211
void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload, const AVStream *st)
Send a nice dump of a packet to the log.
Definition: dump.c:115
const char * avformat_configuration(void)
Return the libavformat build-time configuration.
Definition: utils.c:68
AVProgram * av_new_program(AVFormatContext *s, int id)
Definition: utils.c:4579
char * protocol_whitelist
&#39;,&#39; separated list of allowed protocols.
Definition: avformat.h:1815
uint32_t tag
Definition: movenc.c:1597
int avformat_network_init(void)
Do global initialization of network libraries.
Definition: utils.c:5016
const struct AVCodecTag * avformat_get_riff_audio_tags(void)
Definition: riff.c:625
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
Generate an SDP for an RTP session.
Definition: sdp.c:846
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c: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:237
ptrdiff_t size
Definition: opengl_enc.c:100
static int interleave_packet(AVFormatContext *s, AVPacket *out, AVPacket *in, int flush)
Interleave an AVPacket correctly so it can be muxed.
Definition: mux.c:1086
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:807
Duration estimated from bitrate (less accurate)
Definition: avformat.h:1224
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:539
const struct AVCodecTag * avformat_get_mov_video_tags(void)
Definition: isom_tags.c:338
void av_dump_format(AVFormatContext *ic, int index, const char *url, int is_output)
Print detailed information about the input or output format, such as duration, bitrate, streams, container, programs, metadata, side data, codec and time base.
Definition: dump.c:640
Callback for checking whether to abort blocking functions.
Definition: avio.h:58
int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type, int wanted_stream_nb, int related_stream, AVCodec **decoder_ret, int flags)
Find the "best" stream in the file.
Definition: utils.c:4204
#define ff_const59
The ff_const59 define is not part of the public API and will be removed without further warning...
Definition: avformat.h:544
AVRational av_stream_get_codec_timebase(const AVStream *st)
Get the internal codec timebase from a stream.
Definition: utils.c:5810
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:4187
ff_const59 AVInputFormat * av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max)
Guess the file format.
Definition: format.c:205
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:46
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:2108
const AVIOInterruptCB int_cb
Definition: ffmpeg.c:513
void av_hex_dump(FILE *f, const uint8_t *buf, int size)
Send a nice hexadecimal dump of a buffer to the specified file stream.
Definition: dump.c:76
struct AVCodecParser * parser
Definition: avcodec.h:3338
char * url
input or output URL.
Definition: avformat.h:1339
const char * r
Definition: vf_curves.c:116
unsigned int pos
Definition: spdifenc.c:410
struct AVCodecParserContext * av_stream_get_parser(const AVStream *s)
Definition: utils.c:145
int av_read_play(AVFormatContext *s)
Start playing a network-based stream (e.g.
Definition: utils.c:4272
ff_const59 AVInputFormat * av_find_input_format(const char *short_name)
Find AVInputFormat based on the short name of the input format.
Definition: format.c:118
int avformat_alloc_output_context2(AVFormatContext **ctx, ff_const59 AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
Definition: mux.c:135
int skip_estimate_duration_from_pts
Skip duration calcuation in estimate_timings_from_pts.
Definition: avformat.h:1864
New fields can be added to the end with minor version bumps.
Definition: avformat.h:1160
void * opaque
User data.
Definition: avformat.h:1761
Only parse headers, do not repack.
Definition: avformat.h:804
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:4998
static float distance(float x, float y, int band)
const char * mime_type
mime_type, when known.
Definition: avformat.h:445
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
void av_format_inject_global_side_data(AVFormatContext *s)
This function will cause global side data to be injected in the next packet of each stream as well as...
Definition: utils.c:150
int av_read_pause(AVFormatContext *s)
Pause a network-based stream (e.g.
Definition: utils.c:4281
static void callback(void *priv_data, int index, uint8_t *buf, int buf_size, int64_t time, enum dshowDeviceType devtype)
Definition: dshow.c:161
av_warn_unused_result int avformat_write_header(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and write the stream header to an output media file.
Definition: mux.c:505
void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx)
int(* av_format_control_message)(struct AVFormatContext *s, int type, void *data, size_t data_size)
Callback used by devices to communicate with application.
Definition: avformat.h:1211
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:5482
int max_streams
The maximum number of streams.
Definition: avformat.h:1857
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
int av_find_default_stream_index(AVFormatContext *s)
Definition: utils.c:1832
static int write_trailer(AVFormatContext *s1)
Definition: v4l2enc.c:98
enum AVCodecID av_guess_codec(ff_const59 AVOutputFormat *fmt, const char *short_name, const char *filename, const char *mime_type, enum AVMediaType type)
Guess the codec ID based upon muxer and filename.
Definition: format.c:87
Duration estimated from a stream with a known duration.
Definition: avformat.h:1223
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:5518
enum AVCodecID codec_id
Definition: vaapi_decode.c:369
Libavformat version macros.
int(* AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Definition: avformat.h:1214
av_warn_unused_result int avformat_init_output(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and initialize the codec, but do not write the header.
Definition: mux.c:485
const AVInputFormat * av_demuxer_iterate(void **opaque)
Iterate over all registered demuxers.
Definition: allformats.c:556
int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
Definition: utils.c:4754
ff_const59 struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1262
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
Stream structure.
Definition: avformat.h:884
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:447
int avformat_network_deinit(void)
Undo the initialization done by avformat_network_init.
Definition: utils.c:5028
static AVInputFormat * iformat
Definition: ffprobe.c:260
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:1285
main external API structure.
Definition: avcodec.h:531
int av_filename_number_test(const char *filename)
Check whether filename actually is a numbered sequence generator.
Definition: utils.c: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:4696
void(* io_close)(struct AVFormatContext *s, AVIOContext *pb)
A callback for closing the streams opened with AVFormatContext.io_open().
Definition: avformat.h:1843
static const AVClass av_class
Definition: options.c:134
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(const int16_t *) pi >> 8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(const int32_t *) pi >> 24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31))))#define SET_CONV_FUNC_GROUP(ofmt, ifmt) static void set_generic_function(AudioConvert *ac){}void ff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, int sample_rate, int apply_map){AudioConvert *ac;int in_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) return NULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method!=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt) > 2){ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc){av_free(ac);return NULL;}return ac;}in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar){ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar?ac->channels:1;}else if(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;else ac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);return ac;}int ff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){int use_generic=1;int len=in->nb_samples;int p;if(ac->dc){av_log(ac->avr, AV_LOG_TRACE,"%d samples - audio_convert: %s to %s (dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));return ff_convert_dither(ac-> in
Describe the class of an AVClass context structure.
Definition: log.h:67
int index
Definition: gxfenc.c:89
enum AVCodecID subtitle_codec
default subtitle codec
Definition: avformat.h:512
ff_const59 AVOutputFormat * av_guess_format(const char *short_name, const char *filename, const char *mime_type)
Return the output format in the list of registered output formats which best matches the provided par...
Definition: format.c:51
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVMediaType
Definition: avutil.h:199
int max_probe_packets
Maximum number of packets that can be probed.
Definition: avformat.h:1871
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: utils.c:4410
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1719
List of devices.
Definition: avdevice.h:465
AVTimebaseSource
Definition: avformat.h:2972
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:2489
full parsing and repack of the first frame only, only implemented for H.264 currently ...
Definition: avformat.h:806
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:702
#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:1946
uint8_t level
Definition: svq3.c:206
#define attribute_deprecated
Definition: attributes.h:100
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
Duration accurately estimated from PTSes.
Definition: avformat.h:1222
#define av_warn_unused_result
Definition: attributes.h:62
int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Seek to the keyframe at timestamp.
Definition: utils.c:2466
full parsing and repack
Definition: avformat.h:803
static AVStream * ost
int
const OptionDef options[]
Definition: ffmpeg_opt.c:3424
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:1403
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:3578
AVStreamParseType
Definition: avformat.h:801
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:4453
int av_write_uncoded_frame(AVFormatContext *s, int stream_index, AVFrame *frame)
Write an uncoded frame to an output media file.
Definition: mux.c:1397
enum AVCodecID audio_codec
default audio codec
Definition: avformat.h:510
static int check_bitstream(AVFormatContext *s, AVStream *st, AVPacket *pkt)
Definition: mux.c:1094
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:346
AVDiscard
Definition: avcodec.h:227
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
Definition: mux.c:1272
char * protocol_blacklist
&#39;,&#39; separated list of disallowed protocols.
Definition: avformat.h:1850
int avformat_flush(AVFormatContext *s)
Discard all internally buffered data.
Definition: utils.c:2546
FILE * out
Definition: movenc.c:54
int copy_tb
Definition: ffmpeg_opt.c:165
void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size)
Send a nice hexadecimal dump of a buffer to the log.
Definition: dump.c:81
unsigned int av_codec_get_tag(const struct AVCodecTag *const *tags, enum AVCodecID id)
Get the codec tag for the given codec id id.
enum AVCodecID id
Following API allows user to probe device capabilities (supported codecs, pixel formats, sample formats, resolutions, channel counts, etc).
Definition: avdevice.h:401
This structure stores compressed data.
Definition: packet.h:340
int64_t av_stream_get_end_pts(const AVStream *st)
Returns the pts of the last muxed packet + its duration.
Definition: utils.c:137
const char * name
Definition: opengl_enc.c:102