2 * copyright (c) 2001 Fabrice Bellard
4 * This file is part of FFmpeg.
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.
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.
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
21 #ifndef AVFORMAT_AVFORMAT_H
22 #define AVFORMAT_AVFORMAT_H
27 * Main libavformat public API header
31 * @defgroup libavf libavformat
32 * I/O and Muxing/Demuxing Library
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().
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.
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).
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).
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.
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.
84 * It is important that the scheme string is not taken from untrusted
85 * sources without checks.
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.
93 * @defgroup lavf_decoding Demuxing
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
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:
106 * const char *url = "file:in.mp3";
107 * AVFormatContext *s = NULL;
108 * int ret = avformat_open_input(&s, url, NULL, NULL);
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.
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.
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:
132 * AVDictionary *options = NULL;
133 * av_dict_set(&options, "video_size", "640x480", 0);
134 * av_dict_set(&options, "pixel_format", "rgb24", 0);
136 * if (avformat_open_input(&s, url, NULL, &options) < 0)
138 * av_dict_free(&options);
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
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);
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.
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.
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.
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
178 * @section lavf_decoding_seek Seeking
181 * @defgroup lavf_encoding Muxing
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.
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.
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:
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
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
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.
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.
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().
241 * @defgroup lavf_io I/O Read/Write
243 * @section lavf_io_dirlist Directory listing
244 * The directory listing API makes it possible to list files on remote servers.
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.
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.
258 * AVIODirContext *ctx = NULL;
259 * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) {
260 * fprintf(stderr, "Cannot open directory.\n");
265 * This code tries to open a sample directory using smb protocol without
266 * any additional parameters.
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.
278 * AVIODirEntry *entry = NULL;
280 * if (avio_read_dir(ctx, &entry) < 0) {
281 * fprintf(stderr, "Cannot list directory.\n");
286 * printf("%s\n", entry->name);
287 * avio_free_directory_entry(&entry);
292 * @defgroup lavf_codec Demuxers
294 * @defgroup lavf_codec_native Native Demuxers
297 * @defgroup lavf_codec_wrappers External library wrappers
301 * @defgroup lavf_protos I/O Protocols
304 * @defgroup lavf_internal Internal
311 #include <stdio.h> /* FILE */
312 #include "libavcodec/avcodec.h"
313 #include "libavutil/dict.h"
314 #include "libavutil/log.h"
317 #include "libavformat/version.h"
319 struct AVFormatContext;
321 struct AVDeviceInfoList;
322 struct AVDeviceCapabilitiesQuery;
325 * @defgroup metadata_api Public Metadata API
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.
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.
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.
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:
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
397 * Look in the examples section for an application example how to use the Metadata API.
402 /* packet functions */
406 * Allocate and read the payload of a packet and initialize its
407 * fields with default values.
409 * @param s associated IO context
411 * @param size desired payload size
412 * @return >0 (read size) if OK, AVERROR_xxx otherwise
414 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
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)
425 * @param s associated IO context
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.
431 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
433 /*************************************************/
434 /* input/output formats */
439 * This structure contains the data a format has to probe a file.
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. */
448 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
449 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
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
455 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
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
480 The user or muxer can override this through
481 AVFormatContext.avoid_negative_ts
484 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
487 * @addtogroup lavf_encoding
490 typedef struct AVOutputFormat {
493 * Descriptive name for the format, meant to be more human-readable
494 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
497 const char *long_name;
498 const char *mime_type;
499 const char *extensions; /**< comma-separated filename extensions */
501 enum AVCodecID audio_codec; /**< default audio codec */
502 enum AVCodecID video_codec; /**< default video codec */
503 enum AVCodecID subtitle_codec; /**< default subtitle codec */
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
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.
516 const struct AVCodecTag * const *codec_tag;
519 const AVClass *priv_class; ///< AVClass for the private context
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
525 * New public fields should be added right above.
526 *****************************************************************
529 * The ff_const59 define is not part of the public API and will
530 * be removed without further warning.
532 #if FF_API_AVIOFORMAT
535 #define ff_const59 const
538 ff_const59 struct AVOutputFormat *next;
541 * size of private data so that it can be allocated in the wrapper
545 int (*write_header)(struct AVFormatContext *);
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
553 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
554 int (*write_trailer)(struct AVFormatContext *);
556 * A format-specific function for interleavement.
557 * If unset, packets will be interleaved by dts.
559 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
560 AVPacket *in, int flush);
562 * Test if the given codec can be stored in this container.
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
568 int (*query_codec)(enum AVCodecID id, int std_compliance);
570 void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
571 int64_t *dts, int64_t *wall);
573 * Allows sending messages from application to device.
575 int (*control_message)(struct AVFormatContext *s, int type,
576 void *data, size_t data_size);
579 * Write an uncoded AVFrame.
581 * See av_write_uncoded_frame() for details.
583 * The library will free *frame afterwards, but the muxer can prevent it
584 * by setting the pointer to NULL.
586 int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
587 AVFrame **frame, unsigned flags);
589 * Returns device list with it properties.
590 * @see avdevice_list_devices() for more details.
592 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
594 * Initialize device capabilities submodule.
595 * @see avdevice_capabilities_create() for more details.
597 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
599 * Free device capabilities submodule.
600 * @see avdevice_capabilities_free() for more details.
602 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
603 enum AVCodecID data_codec; /**< default data codec */
605 * Initialize format. May allocate data here, and set any AVFormatContext or
606 * AVStream parameters that need to be set before packets are sent.
607 * This method must not write output.
609 * Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure
611 * Any allocations made here must be freed in deinit().
613 int (*init)(struct AVFormatContext *);
615 * Deinitialize format. If present, this is called whenever the muxer is being
616 * destroyed, regardless of whether or not the header has been written.
618 * If a trailer is being written, this is called after write_trailer().
620 * This is called if init() fails as well.
622 void (*deinit)(struct AVFormatContext *);
624 * Set up any necessary bitstream filtering and extract any extra data needed
625 * for the global header.
626 * Return 0 if more packets from this stream must be checked; 1 if not.
628 int (*check_bitstream)(struct AVFormatContext *, const AVPacket *pkt);
635 * @addtogroup lavf_decoding
638 typedef struct AVInputFormat {
640 * A comma separated list of short names for the format. New names
641 * may be appended with a minor bump.
646 * Descriptive name for the format, meant to be more human-readable
647 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
650 const char *long_name;
653 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
654 * AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
655 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
660 * If extensions are defined, then no probe is done. You should
661 * usually not use extension format guessing because it is not
664 const char *extensions;
666 const struct AVCodecTag * const *codec_tag;
668 const AVClass *priv_class; ///< AVClass for the private context
671 * Comma-separated list of mime types.
672 * It is used check for matching mime types while probing.
673 * @see av_probe_input_format2
675 const char *mime_type;
677 /*****************************************************************
678 * No fields below this line are part of the public API. They
679 * may not be used outside of libavformat and can be changed and
681 * New public fields should be added right above.
682 *****************************************************************
685 ff_const59 struct AVInputFormat *next;
689 * Raw demuxers store their codec ID here.
694 * Size of private data so that it can be allocated in the wrapper.
699 * Tell if a given file has a chance of being parsed as this format.
700 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
701 * big so you do not have to check for that unless you need more.
703 int (*read_probe)(const AVProbeData *);
706 * Read the format header and initialize the AVFormatContext
707 * structure. Return 0 if OK. 'avformat_new_stream' should be
708 * called to create new streams.
710 int (*read_header)(struct AVFormatContext *);
713 * Read one packet and put it in 'pkt'. pts and flags are also
714 * set. 'avformat_new_stream' can be called only if the flag
715 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
716 * background thread).
717 * @return 0 on success, < 0 on error.
718 * Upon returning an error, pkt must be unreferenced by the caller.
720 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
723 * Close the stream. The AVFormatContext and AVStreams are not
724 * freed by this function
726 int (*read_close)(struct AVFormatContext *);
729 * Seek to a given timestamp relative to the frames in
730 * stream component stream_index.
731 * @param stream_index Must not be -1.
732 * @param flags Selects which direction should be preferred if no exact
733 * match is available.
734 * @return >= 0 on success (but not necessarily the new offset)
736 int (*read_seek)(struct AVFormatContext *,
737 int stream_index, int64_t timestamp, int flags);
740 * Get the next timestamp in stream[stream_index].time_base units.
741 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
743 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
744 int64_t *pos, int64_t pos_limit);
747 * Start/resume playing - only meaningful if using a network-based format
750 int (*read_play)(struct AVFormatContext *);
753 * Pause playing - only meaningful if using a network-based format
756 int (*read_pause)(struct AVFormatContext *);
759 * Seek to timestamp ts.
760 * Seeking will be done so that the point from which all active streams
761 * can be presented successfully will be closest to ts and within min/max_ts.
762 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
764 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
767 * Returns device list with it properties.
768 * @see avdevice_list_devices() for more details.
770 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
773 * Initialize device capabilities submodule.
774 * @see avdevice_capabilities_create() for more details.
776 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
779 * Free device capabilities submodule.
780 * @see avdevice_capabilities_free() for more details.
782 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
788 enum AVStreamParseType {
790 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
791 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
792 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
793 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
794 AVSTREAM_PARSE_FULL_RAW, /**< full parsing and repack with timestamp and position generation by parser for raw
795 this assumes that each packet in the file contains no demuxer level headers and
796 just codec level data, otherwise position generation would fail */
799 typedef struct AVIndexEntry {
801 int64_t timestamp; /**<
802 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
803 * when seeking to this entry. That means preferable PTS on keyframe based formats.
804 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
807 #define AVINDEX_KEYFRAME 0x0001
808 #define AVINDEX_DISCARD_FRAME 0x0002 /**
809 * Flag is used to indicate which frame should be discarded after decoding.
812 int size:30; //Yeah, trying to keep the size of this small to reduce memory requirements (it is 24 vs. 32 bytes due to possible 8-byte alignment).
813 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
816 #define AV_DISPOSITION_DEFAULT 0x0001
817 #define AV_DISPOSITION_DUB 0x0002
818 #define AV_DISPOSITION_ORIGINAL 0x0004
819 #define AV_DISPOSITION_COMMENT 0x0008
820 #define AV_DISPOSITION_LYRICS 0x0010
821 #define AV_DISPOSITION_KARAOKE 0x0020
824 * Track should be used during playback by default.
825 * Useful for subtitle track that should be displayed
826 * even when user did not explicitly ask for subtitles.
828 #define AV_DISPOSITION_FORCED 0x0040
829 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
830 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
831 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
833 * The stream is stored in the file as an attached picture/"cover art" (e.g.
834 * APIC frame in ID3v2). The first (usually only) packet associated with it
835 * will be returned among the first few packets read from the file unless
836 * seeking takes place. It can also be accessed at any time in
837 * AVStream.attached_pic.
839 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
841 * The stream is sparse, and contains thumbnail images, often corresponding
842 * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
844 #define AV_DISPOSITION_TIMED_THUMBNAILS 0x0800
846 typedef struct AVStreamInternal AVStreamInternal;
849 * To specify text track kind (different from subtitles default).
851 #define AV_DISPOSITION_CAPTIONS 0x10000
852 #define AV_DISPOSITION_DESCRIPTIONS 0x20000
853 #define AV_DISPOSITION_METADATA 0x40000
854 #define AV_DISPOSITION_DEPENDENT 0x80000 ///< dependent audio stream (mix_type=0 in mpegts)
855 #define AV_DISPOSITION_STILL_IMAGE 0x100000 ///< still images in video stream (still_picture_flag=1 in mpegts)
858 * Options for behavior on timestamp wrap detection.
860 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
861 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
862 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
866 * New fields can be added to the end with minor version bumps.
867 * Removal, reordering and changes to existing fields require a major
869 * sizeof(AVStream) must not be used outside libav*.
871 typedef struct AVStream {
872 int index; /**< stream index in AVFormatContext */
874 * Format-specific stream ID.
875 * decoding: set by libavformat
876 * encoding: set by the user, replaced by libavformat if left unset
879 #if FF_API_LAVF_AVCTX
881 * @deprecated use the codecpar struct instead
884 AVCodecContext *codec;
889 * This is the fundamental unit of time (in seconds) in terms
890 * of which frame timestamps are represented.
892 * decoding: set by libavformat
893 * encoding: May be set by the caller before avformat_write_header() to
894 * provide a hint to the muxer about the desired timebase. In
895 * avformat_write_header(), the muxer will overwrite this field
896 * with the timebase that will actually be used for the timestamps
897 * written into the file (which may or may not be related to the
898 * user-provided one, depending on the format).
900 AVRational time_base;
903 * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
904 * Only set this if you are absolutely 100% sure that the value you set
905 * it to really is the pts of the first frame.
906 * This may be undefined (AV_NOPTS_VALUE).
907 * @note The ASF header does NOT contain a correct start_time the ASF
908 * demuxer must NOT set this.
913 * Decoding: duration of the stream, in stream time base.
914 * If a source file does not specify a duration, but does specify
915 * a bitrate, this value will be estimated from bitrate and file size.
917 * Encoding: May be set by the caller before avformat_write_header() to
918 * provide a hint to the muxer about the estimated duration.
922 int64_t nb_frames; ///< number of frames in this stream if known or 0
924 int disposition; /**< AV_DISPOSITION_* bit field */
926 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
929 * sample aspect ratio (0 if unknown)
930 * - encoding: Set by user.
931 * - decoding: Set by libavformat.
933 AVRational sample_aspect_ratio;
935 AVDictionary *metadata;
940 * - demuxing: May be set by libavformat when creating the stream or in
941 * avformat_find_stream_info().
942 * - muxing: May be set by the caller before avformat_write_header().
944 AVRational avg_frame_rate;
947 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
948 * will contain the attached picture.
950 * decoding: set by libavformat, must not be modified by the caller.
953 AVPacket attached_pic;
956 * An array of side data that applies to the whole stream (i.e. the
957 * container does not allow it to change between packets).
959 * There may be no overlap between the side data in this array and side data
960 * in the packets. I.e. a given side data is either exported by the muxer
961 * (demuxing) / set by the caller (muxing) in this array, then it never
962 * appears in the packets, or the side data is exported / sent through
963 * the packets (always in the first packet where the value becomes known or
964 * changes), then it does not appear in this array.
966 * - demuxing: Set by libavformat when the stream is created.
967 * - muxing: May be set by the caller before avformat_write_header().
969 * Freed by libavformat in avformat_free_context().
971 * @see av_format_inject_global_side_data()
973 AVPacketSideData *side_data;
975 * The number of elements in the AVStream.side_data array.
980 * Flags for the user to detect events happening on the stream. Flags must
981 * be cleared by the user once the event has been handled.
982 * A combination of AVSTREAM_EVENT_FLAG_*.
985 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
988 * Real base framerate of the stream.
989 * This is the lowest framerate with which all timestamps can be
990 * represented accurately (it is the least common multiple of all
991 * framerates in the stream). Note, this value is just a guess!
992 * For example, if the time base is 1/90000 and all frames have either
993 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
995 AVRational r_frame_rate;
997 #if FF_API_LAVF_FFSERVER
999 * String containing pairs of key and values describing recommended encoder configuration.
1000 * Pairs are separated by ','.
1001 * Keys are separated from values by '='.
1003 * @deprecated unused
1005 attribute_deprecated
1006 char *recommended_encoder_configuration;
1010 * Codec parameters associated with this stream. Allocated and freed by
1011 * libavformat in avformat_new_stream() and avformat_free_context()
1014 * - demuxing: filled by libavformat on stream creation or in
1015 * avformat_find_stream_info()
1016 * - muxing: filled by the caller before avformat_write_header()
1018 AVCodecParameters *codecpar;
1020 /*****************************************************************
1021 * All fields below this line are not part of the public API. They
1022 * may not be used outside of libavformat and can be changed and
1024 * Internal note: be aware that physically removing these fields
1025 * will break ABI. Replace removed fields with dummy fields, and
1026 * add new fields to AVStreamInternal.
1027 *****************************************************************
1030 #define MAX_STD_TIMEBASES (30*12+30+3+6)
1032 * Stream information used internally by avformat_find_stream_info()
1036 int64_t duration_gcd;
1038 int64_t rfps_duration_sum;
1039 double (*duration_error)[2][MAX_STD_TIMEBASES];
1040 int64_t codec_info_duration;
1041 int64_t codec_info_duration_fields;
1042 int frame_delay_evidence;
1045 * 0 -> decoder has not been searched for yet.
1046 * >0 -> decoder found
1047 * <0 -> decoder with codec_id == -found_decoder has not been found
1051 int64_t last_duration;
1054 * Those are used for average framerate estimation.
1056 int64_t fps_first_dts;
1057 int fps_first_dts_idx;
1058 int64_t fps_last_dts;
1059 int fps_last_dts_idx;
1063 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
1065 // Timestamp generation support:
1067 * Timestamp corresponding to the last dts sync point.
1069 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
1070 * a DTS is received from the underlying container. Otherwise set to
1071 * AV_NOPTS_VALUE by default.
1075 int64_t last_IP_pts;
1076 int last_IP_duration;
1079 * Number of packets to buffer for codec probing
1084 * Number of frames that have been demuxed during avformat_find_stream_info()
1086 int codec_info_nb_frames;
1088 /* av_read_frame() support */
1089 enum AVStreamParseType need_parsing;
1090 struct AVCodecParserContext *parser;
1093 * last packet in packet_buffer for this stream when muxing.
1095 struct AVPacketList *last_in_packet_buffer;
1096 AVProbeData probe_data;
1097 #define MAX_REORDER_DELAY 16
1098 int64_t pts_buffer[MAX_REORDER_DELAY+1];
1100 AVIndexEntry *index_entries; /**< Only used if the format does not
1101 support seeking natively. */
1102 int nb_index_entries;
1103 unsigned int index_entries_allocated_size;
1107 * This is the MPEG-TS stream identifier +1
1110 int stream_identifier;
1113 * Details of the MPEG-TS program which created this stream.
1119 int64_t interleaver_chunk_size;
1120 int64_t interleaver_chunk_duration;
1123 * stream probing state
1124 * -1 -> probing finished
1125 * 0 -> no probing requested
1126 * rest -> perform probing with request_probe being the minimum score to accept.
1130 * Indicates that everything up to the next keyframe
1131 * should be discarded.
1133 int skip_to_keyframe;
1136 * Number of samples to skip at the start of the frame decoded from the next packet.
1141 * If not 0, the number of samples that should be skipped from the start of
1142 * the stream (the samples are removed from packets with pts==0, which also
1143 * assumes negative timestamps do not happen).
1144 * Intended for use with formats such as mp3 with ad-hoc gapless audio
1147 int64_t start_skip_samples;
1150 * If not 0, the first audio sample that should be discarded from the stream.
1151 * This is broken by design (needs global sample count), but can't be
1152 * avoided for broken by design formats such as mp3 with ad-hoc gapless
1155 int64_t first_discard_sample;
1158 * The sample after last sample that is intended to be discarded after
1159 * first_discard_sample. Works on frame boundaries only. Used to prevent
1160 * early EOF if the gapless info is broken (considered concatenated mp3s).
1162 int64_t last_discard_sample;
1165 * Number of internally decoded frames, used internally in libavformat, do not access
1166 * its lifetime differs from info which is why it is not in that structure.
1168 int nb_decoded_frames;
1171 * Timestamp offset added to timestamps before muxing
1173 int64_t mux_ts_offset;
1176 * Internal data to check for wrapping of the time stamp
1178 int64_t pts_wrap_reference;
1181 * Options for behavior, when a wrap is detected.
1183 * Defined by AV_PTS_WRAP_ values.
1185 * If correction is enabled, there are two possibilities:
1186 * If the first time stamp is near the wrap point, the wrap offset
1187 * will be subtracted, which will create negative time stamps.
1188 * Otherwise the offset will be added.
1190 int pts_wrap_behavior;
1193 * Internal data to prevent doing update_initial_durations() twice
1195 int update_initial_durations_done;
1198 * Internal data to generate dts from pts
1200 int64_t pts_reorder_error[MAX_REORDER_DELAY+1];
1201 uint8_t pts_reorder_error_count[MAX_REORDER_DELAY+1];
1204 * Internal data to analyze DTS and detect faulty mpeg streams
1206 int64_t last_dts_for_order_check;
1207 uint8_t dts_ordered;
1208 uint8_t dts_misordered;
1211 * Internal data to inject global side data
1213 int inject_global_side_data;
1216 * display aspect ratio (0 if unknown)
1217 * - encoding: unused
1218 * - decoding: Set by libavformat to calculate sample_aspect_ratio internally
1220 AVRational display_aspect_ratio;
1223 * An opaque field for libavformat internal usage.
1224 * Must not be accessed in any way by callers.
1226 AVStreamInternal *internal;
1229 #if FF_API_FORMAT_GET_SET
1231 * Accessors for some AVStream fields. These used to be provided for ABI
1232 * compatibility, and do not need to be used anymore.
1234 attribute_deprecated
1235 AVRational av_stream_get_r_frame_rate(const AVStream *s);
1236 attribute_deprecated
1237 void av_stream_set_r_frame_rate(AVStream *s, AVRational r);
1238 #if FF_API_LAVF_FFSERVER
1239 attribute_deprecated
1240 char* av_stream_get_recommended_encoder_configuration(const AVStream *s);
1241 attribute_deprecated
1242 void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration);
1246 struct AVCodecParserContext *av_stream_get_parser(const AVStream *s);
1249 * Returns the pts of the last muxed packet + its duration
1251 * the retuned value is undefined when used with a demuxer.
1253 int64_t av_stream_get_end_pts(const AVStream *st);
1255 #define AV_PROGRAM_RUNNING 1
1258 * New fields can be added to the end with minor version bumps.
1259 * Removal, reordering and changes to existing fields require a major
1261 * sizeof(AVProgram) must not be used outside libav*.
1263 typedef struct AVProgram {
1266 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1267 unsigned int *stream_index;
1268 unsigned int nb_stream_indexes;
1269 AVDictionary *metadata;
1276 /*****************************************************************
1277 * All fields below this line are not part of the public API. They
1278 * may not be used outside of libavformat and can be changed and
1280 * New public fields should be added right above.
1281 *****************************************************************
1286 int64_t pts_wrap_reference; ///< reference dts for wrap detection
1287 int pts_wrap_behavior; ///< behavior on wrap detection
1290 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1291 (streams are added dynamically) */
1292 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely
1293 not seekable, and attempts to call the
1294 seek function will fail. For some
1295 network protocols (e.g. HLS), this can
1296 change dynamically at runtime. */
1298 typedef struct AVChapter {
1299 int id; ///< unique ID to identify the chapter
1300 AVRational time_base; ///< time base in which the start/end timestamps are specified
1301 int64_t start, end; ///< chapter start/end time in time_base units
1302 AVDictionary *metadata;
1307 * Callback used by devices to communicate with application.
1309 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1310 void *data, size_t data_size);
1312 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
1313 const AVIOInterruptCB *int_cb, AVDictionary **options);
1316 * The duration of a video can be estimated through various ways, and this enum can be used
1317 * to know how the duration was estimated.
1319 enum AVDurationEstimationMethod {
1320 AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1321 AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1322 AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1325 typedef struct AVFormatInternal AVFormatInternal;
1328 * Format I/O context.
1329 * New fields can be added to the end with minor version bumps.
1330 * Removal, reordering and changes to existing fields require a major
1332 * sizeof(AVFormatContext) must not be used outside libav*, use
1333 * avformat_alloc_context() to create an AVFormatContext.
1335 * Fields can be accessed through AVOptions (av_opt*),
1336 * the name string used matches the associated command line parameter name and
1337 * can be found in libavformat/options_table.h.
1338 * The AVOption/command line parameter names differ in some cases from the C
1339 * structure field names for historic reasons or brevity.
1341 typedef struct AVFormatContext {
1343 * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1344 * Exports (de)muxer private options if they exist.
1346 const AVClass *av_class;
1349 * The input container format.
1351 * Demuxing only, set by avformat_open_input().
1353 ff_const59 struct AVInputFormat *iformat;
1356 * The output container format.
1358 * Muxing only, must be set by the caller before avformat_write_header().
1360 ff_const59 struct AVOutputFormat *oformat;
1363 * Format private data. This is an AVOptions-enabled struct
1364 * if and only if iformat/oformat.priv_class is not NULL.
1366 * - muxing: set by avformat_write_header()
1367 * - demuxing: set by avformat_open_input()
1374 * - demuxing: either set by the user before avformat_open_input() (then
1375 * the user must close it manually) or set by avformat_open_input().
1376 * - muxing: set by the user before avformat_write_header(). The caller must
1377 * take care of closing / freeing the IO context.
1379 * Do NOT set this field if AVFMT_NOFILE flag is set in
1380 * iformat/oformat.flags. In such a case, the (de)muxer will handle
1381 * I/O in some other way and this field will be NULL.
1387 * Flags signalling stream properties. A combination of AVFMTCTX_*.
1388 * Set by libavformat.
1393 * Number of elements in AVFormatContext.streams.
1395 * Set by avformat_new_stream(), must not be modified by any other code.
1397 unsigned int nb_streams;
1399 * A list of all streams in the file. New streams are created with
1400 * avformat_new_stream().
1402 * - demuxing: streams are created by libavformat in avformat_open_input().
1403 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1404 * appear in av_read_frame().
1405 * - muxing: streams are created by the user before avformat_write_header().
1407 * Freed by libavformat in avformat_free_context().
1411 #if FF_API_FORMAT_FILENAME
1413 * input or output filename
1415 * - demuxing: set by avformat_open_input()
1416 * - muxing: may be set by the caller before avformat_write_header()
1418 * @deprecated Use url instead.
1420 attribute_deprecated
1421 char filename[1024];
1425 * input or output URL. Unlike the old filename field, this field has no
1426 * length restriction.
1428 * - demuxing: set by avformat_open_input(), initialized to an empty
1429 * string if url parameter was NULL in avformat_open_input().
1430 * - muxing: may be set by the caller before calling avformat_write_header()
1431 * (or avformat_init_output() if that is called first) to a string
1432 * which is freeable by av_free(). Set to an empty string if it
1433 * was NULL in avformat_init_output().
1435 * Freed by libavformat in avformat_free_context().
1440 * Position of the first frame of the component, in
1441 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1442 * It is deduced from the AVStream values.
1444 * Demuxing only, set by libavformat.
1449 * Duration of the stream, in AV_TIME_BASE fractional
1450 * seconds. Only set this value if you know none of the individual stream
1451 * durations and also do not set any of them. This is deduced from the
1452 * AVStream values if not set.
1454 * Demuxing only, set by libavformat.
1459 * Total stream bitrate in bit/s, 0 if not
1460 * available. Never set it directly if the file_size and the
1461 * duration are known as FFmpeg can compute it automatically.
1465 unsigned int packet_size;
1469 * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1470 * Set by the user before avformat_open_input() / avformat_write_header().
1473 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1474 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1475 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1476 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1477 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1478 #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
1479 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1480 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1481 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1482 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1484 * When muxing, try to avoid writing any random/volatile data to the output.
1485 * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1487 * This flag is mainly intended for testing.
1489 #define AVFMT_FLAG_BITEXACT 0x0400
1490 #if FF_API_LAVF_MP4A_LATM
1491 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Deprecated, does nothing.
1493 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1494 #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)
1495 #if FF_API_LAVF_KEEPSIDE_FLAG
1496 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Deprecated, does nothing.
1498 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1499 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
1500 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer
1503 * Maximum size of the data read from input for determining
1504 * the input container format.
1505 * Demuxing only, set by the caller before avformat_open_input().
1510 * Maximum duration (in AV_TIME_BASE units) of the data read
1511 * from input in avformat_find_stream_info().
1512 * Demuxing only, set by the caller before avformat_find_stream_info().
1513 * Can be set to 0 to let avformat choose using a heuristic.
1515 int64_t max_analyze_duration;
1520 unsigned int nb_programs;
1521 AVProgram **programs;
1524 * Forced video codec_id.
1525 * Demuxing: Set by user.
1527 enum AVCodecID video_codec_id;
1530 * Forced audio codec_id.
1531 * Demuxing: Set by user.
1533 enum AVCodecID audio_codec_id;
1536 * Forced subtitle codec_id.
1537 * Demuxing: Set by user.
1539 enum AVCodecID subtitle_codec_id;
1542 * Maximum amount of memory in bytes to use for the index of each stream.
1543 * If the index exceeds this size, entries will be discarded as
1544 * needed to maintain a smaller size. This can lead to slower or less
1545 * accurate seeking (depends on demuxer).
1546 * Demuxers for which a full in-memory index is mandatory will ignore
1549 * - demuxing: set by user
1551 unsigned int max_index_size;
1554 * Maximum amount of memory in bytes to use for buffering frames
1555 * obtained from realtime capture devices.
1557 unsigned int max_picture_buffer;
1560 * Number of chapters in AVChapter array.
1561 * When muxing, chapters are normally written in the file header,
1562 * so nb_chapters should normally be initialized before write_header
1563 * is called. Some muxers (e.g. mov and mkv) can also write chapters
1564 * in the trailer. To write chapters in the trailer, nb_chapters
1565 * must be zero when write_header is called and non-zero when
1566 * write_trailer is called.
1567 * - muxing: set by user
1568 * - demuxing: set by libavformat
1570 unsigned int nb_chapters;
1571 AVChapter **chapters;
1574 * Metadata that applies to the whole file.
1576 * - demuxing: set by libavformat in avformat_open_input()
1577 * - muxing: may be set by the caller before avformat_write_header()
1579 * Freed by libavformat in avformat_free_context().
1581 AVDictionary *metadata;
1584 * Start time of the stream in real world time, in microseconds
1585 * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1586 * stream was captured at this real world time.
1587 * - muxing: Set by the caller before avformat_write_header(). If set to
1588 * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1590 * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1591 * the value may become known after some number of frames
1592 * have been received.
1594 int64_t start_time_realtime;
1597 * The number of frames used for determining the framerate in
1598 * avformat_find_stream_info().
1599 * Demuxing only, set by the caller before avformat_find_stream_info().
1604 * Error recognition; higher values will detect more errors but may
1605 * misdetect some more or less valid parts as errors.
1606 * Demuxing only, set by the caller before avformat_open_input().
1608 int error_recognition;
1611 * Custom interrupt callbacks for the I/O layer.
1613 * demuxing: set by the user before avformat_open_input().
1614 * muxing: set by the user before avformat_write_header()
1615 * (mainly useful for AVFMT_NOFILE formats). The callback
1616 * should also be passed to avio_open2() if it's used to
1619 AVIOInterruptCB interrupt_callback;
1622 * Flags to enable debugging.
1625 #define FF_FDEBUG_TS 0x0001
1628 * Maximum buffering duration for interleaving.
1630 * To ensure all the streams are interleaved correctly,
1631 * av_interleaved_write_frame() will wait until it has at least one packet
1632 * for each stream before actually writing any packets to the output file.
1633 * When some streams are "sparse" (i.e. there are large gaps between
1634 * successive packets), this can result in excessive buffering.
1636 * This field specifies the maximum difference between the timestamps of the
1637 * first and the last packet in the muxing queue, above which libavformat
1638 * will output a packet regardless of whether it has queued a packet for all
1641 * Muxing only, set by the caller before avformat_write_header().
1643 int64_t max_interleave_delta;
1646 * Allow non-standard and experimental extension
1647 * @see AVCodecContext.strict_std_compliance
1649 int strict_std_compliance;
1652 * Flags for the user to detect events happening on the file. Flags must
1653 * be cleared by the user once the event has been handled.
1654 * A combination of AVFMT_EVENT_FLAG_*.
1657 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
1660 * Maximum number of packets to read while waiting for the first timestamp.
1666 * Avoid negative timestamps during muxing.
1667 * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1668 * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use)
1669 * - muxing: Set by user
1670 * - demuxing: unused
1672 int avoid_negative_ts;
1673 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1674 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1675 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1678 * Transport stream id.
1679 * This will be moved into demuxer private options. Thus no API/ABI compatibility
1684 * Audio preload in microseconds.
1685 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1686 * - encoding: Set by user
1687 * - decoding: unused
1692 * Max chunk time in microseconds.
1693 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1694 * - encoding: Set by user
1695 * - decoding: unused
1697 int max_chunk_duration;
1700 * Max chunk size in bytes
1701 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1702 * - encoding: Set by user
1703 * - decoding: unused
1708 * forces the use of wallclock timestamps as pts/dts of packets
1709 * This has undefined results in the presence of B frames.
1710 * - encoding: unused
1711 * - decoding: Set by user
1713 int use_wallclock_as_timestamps;
1716 * avio flags, used to force AVIO_FLAG_DIRECT.
1717 * - encoding: unused
1718 * - decoding: Set by user
1723 * The duration field can be estimated through various ways, and this field can be used
1724 * to know how the duration was estimated.
1725 * - encoding: unused
1726 * - decoding: Read by user
1728 enum AVDurationEstimationMethod duration_estimation_method;
1731 * Skip initial bytes when opening stream
1732 * - encoding: unused
1733 * - decoding: Set by user
1735 int64_t skip_initial_bytes;
1738 * Correct single timestamp overflows
1739 * - encoding: unused
1740 * - decoding: Set by user
1742 unsigned int correct_ts_overflow;
1745 * Force seeking to any (also non key) frames.
1746 * - encoding: unused
1747 * - decoding: Set by user
1752 * Flush the I/O context after each packet.
1753 * - encoding: Set by user
1754 * - decoding: unused
1759 * format probing score.
1760 * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1762 * - encoding: unused
1763 * - decoding: set by avformat, read by user
1768 * number of bytes to read maximally to identify format.
1769 * - encoding: unused
1770 * - decoding: set by user
1772 int format_probesize;
1775 * ',' separated list of allowed decoders.
1776 * If NULL then all are allowed
1777 * - encoding: unused
1778 * - decoding: set by user
1780 char *codec_whitelist;
1783 * ',' separated list of allowed demuxers.
1784 * If NULL then all are allowed
1785 * - encoding: unused
1786 * - decoding: set by user
1788 char *format_whitelist;
1791 * An opaque field for libavformat internal usage.
1792 * Must not be accessed in any way by callers.
1794 AVFormatInternal *internal;
1797 * IO repositioned flag.
1798 * This is set by avformat when the underlaying IO context read pointer
1799 * is repositioned, for example when doing byte based seeking.
1800 * Demuxers can use the flag to detect such changes.
1802 int io_repositioned;
1805 * Forced video codec.
1806 * This allows forcing a specific decoder, even when there are multiple with
1807 * the same codec_id.
1808 * Demuxing: Set by user
1810 AVCodec *video_codec;
1813 * Forced audio codec.
1814 * This allows forcing a specific decoder, even when there are multiple with
1815 * the same codec_id.
1816 * Demuxing: Set by user
1818 AVCodec *audio_codec;
1821 * Forced subtitle codec.
1822 * This allows forcing a specific decoder, even when there are multiple with
1823 * the same codec_id.
1824 * Demuxing: Set by user
1826 AVCodec *subtitle_codec;
1829 * Forced data codec.
1830 * This allows forcing a specific decoder, even when there are multiple with
1831 * the same codec_id.
1832 * Demuxing: Set by user
1834 AVCodec *data_codec;
1837 * Number of bytes to be written as padding in a metadata header.
1839 * Muxing: Set by user via av_format_set_metadata_header_padding.
1841 int metadata_header_padding;
1845 * This is a place for some private data of the user.
1850 * Callback used by devices to communicate with application.
1852 av_format_control_message control_message_cb;
1855 * Output timestamp offset, in microseconds.
1856 * Muxing: set by user
1858 int64_t output_ts_offset;
1861 * dump format separator.
1862 * can be ", " or "\n " or anything else
1863 * - muxing: Set by user.
1864 * - demuxing: Set by user.
1866 uint8_t *dump_separator;
1869 * Forced Data codec_id.
1870 * Demuxing: Set by user.
1872 enum AVCodecID data_codec_id;
1874 #if FF_API_OLD_OPEN_CALLBACKS
1876 * Called to open further IO contexts when needed for demuxing.
1878 * This can be set by the user application to perform security checks on
1879 * the URLs before opening them.
1880 * The function should behave like avio_open2(), AVFormatContext is provided
1881 * as contextual information and to reach AVFormatContext.opaque.
1883 * If NULL then some simple checks are used together with avio_open2().
1885 * Must not be accessed directly from outside avformat.
1886 * @See av_format_set_open_cb()
1888 * Demuxing: Set by user.
1890 * @deprecated Use io_open and io_close.
1892 attribute_deprecated
1893 int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options);
1897 * ',' separated list of allowed protocols.
1898 * - encoding: unused
1899 * - decoding: set by user
1901 char *protocol_whitelist;
1904 * A callback for opening new IO streams.
1906 * Whenever a muxer or a demuxer needs to open an IO stream (typically from
1907 * avformat_open_input() for demuxers, but for certain formats can happen at
1908 * other times as well), it will call this callback to obtain an IO context.
1910 * @param s the format context
1911 * @param pb on success, the newly opened IO context should be returned here
1912 * @param url the url to open
1913 * @param flags a combination of AVIO_FLAG_*
1914 * @param options a dictionary of additional options, with the same
1915 * semantics as in avio_open2()
1916 * @return 0 on success, a negative AVERROR code on failure
1918 * @note Certain muxers and demuxers do nesting, i.e. they open one or more
1919 * additional internal format contexts. Thus the AVFormatContext pointer
1920 * passed to this callback may be different from the one facing the caller.
1921 * It will, however, have the same 'opaque' field.
1923 int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url,
1924 int flags, AVDictionary **options);
1927 * A callback for closing the streams opened with AVFormatContext.io_open().
1929 void (*io_close)(struct AVFormatContext *s, AVIOContext *pb);
1932 * ',' separated list of disallowed protocols.
1933 * - encoding: unused
1934 * - decoding: set by user
1936 char *protocol_blacklist;
1939 * The maximum number of streams.
1940 * - encoding: unused
1941 * - decoding: set by user
1946 * Skip duration calcuation in estimate_timings_from_pts.
1947 * - encoding: unused
1948 * - decoding: set by user
1950 int skip_estimate_duration_from_pts;
1953 * Maximum number of packets that can be probed
1954 * - encoding: unused
1955 * - decoding: set by user
1957 int max_probe_packets;
1960 #if FF_API_FORMAT_GET_SET
1962 * Accessors for some AVFormatContext fields. These used to be provided for ABI
1963 * compatibility, and do not need to be used anymore.
1965 attribute_deprecated
1966 int av_format_get_probe_score(const AVFormatContext *s);
1967 attribute_deprecated
1968 AVCodec * av_format_get_video_codec(const AVFormatContext *s);
1969 attribute_deprecated
1970 void av_format_set_video_codec(AVFormatContext *s, AVCodec *c);
1971 attribute_deprecated
1972 AVCodec * av_format_get_audio_codec(const AVFormatContext *s);
1973 attribute_deprecated
1974 void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c);
1975 attribute_deprecated
1976 AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s);
1977 attribute_deprecated
1978 void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c);
1979 attribute_deprecated
1980 AVCodec * av_format_get_data_codec(const AVFormatContext *s);
1981 attribute_deprecated
1982 void av_format_set_data_codec(AVFormatContext *s, AVCodec *c);
1983 attribute_deprecated
1984 int av_format_get_metadata_header_padding(const AVFormatContext *s);
1985 attribute_deprecated
1986 void av_format_set_metadata_header_padding(AVFormatContext *s, int c);
1987 attribute_deprecated
1988 void * av_format_get_opaque(const AVFormatContext *s);
1989 attribute_deprecated
1990 void av_format_set_opaque(AVFormatContext *s, void *opaque);
1991 attribute_deprecated
1992 av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s);
1993 attribute_deprecated
1994 void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback);
1995 #if FF_API_OLD_OPEN_CALLBACKS
1996 attribute_deprecated AVOpenCallback av_format_get_open_cb(const AVFormatContext *s);
1997 attribute_deprecated void av_format_set_open_cb(AVFormatContext *s, AVOpenCallback callback);
2002 * This function will cause global side data to be injected in the next packet
2003 * of each stream as well as after any subsequent seek.
2005 void av_format_inject_global_side_data(AVFormatContext *s);
2008 * Returns the method used to set ctx->duration.
2010 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
2012 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
2015 * @defgroup lavf_core Core functions
2018 * Functions for querying libavformat capabilities, allocating core structures,
2024 * Return the LIBAVFORMAT_VERSION_INT constant.
2026 unsigned avformat_version(void);
2029 * Return the libavformat build-time configuration.
2031 const char *avformat_configuration(void);
2034 * Return the libavformat license.
2036 const char *avformat_license(void);
2040 * Initialize libavformat and register all the muxers, demuxers and
2041 * protocols. If you do not call this function, then you can select
2042 * exactly which formats you want to support.
2044 * @see av_register_input_format()
2045 * @see av_register_output_format()
2047 attribute_deprecated
2048 void av_register_all(void);
2050 attribute_deprecated
2051 void av_register_input_format(AVInputFormat *format);
2052 attribute_deprecated
2053 void av_register_output_format(AVOutputFormat *format);
2057 * Do global initialization of network libraries. This is optional,
2058 * and not recommended anymore.
2060 * This functions only exists to work around thread-safety issues
2061 * with older GnuTLS or OpenSSL libraries. If libavformat is linked
2062 * to newer versions of those libraries, or if you do not use them,
2063 * calling this function is unnecessary. Otherwise, you need to call
2064 * this function before any other threads using them are started.
2066 * This function will be deprecated once support for older GnuTLS and
2067 * OpenSSL libraries is removed, and this function has no purpose
2070 int avformat_network_init(void);
2073 * Undo the initialization done by avformat_network_init. Call it only
2074 * once for each time you called avformat_network_init.
2076 int avformat_network_deinit(void);
2080 * If f is NULL, returns the first registered input format,
2081 * if f is non-NULL, returns the next registered input format after f
2082 * or NULL if f is the last one.
2084 attribute_deprecated
2085 AVInputFormat *av_iformat_next(const AVInputFormat *f);
2088 * If f is NULL, returns the first registered output format,
2089 * if f is non-NULL, returns the next registered output format after f
2090 * or NULL if f is the last one.
2092 attribute_deprecated
2093 AVOutputFormat *av_oformat_next(const AVOutputFormat *f);
2097 * Iterate over all registered muxers.
2099 * @param opaque a pointer where libavformat will store the iteration state. Must
2100 * point to NULL to start the iteration.
2102 * @return the next registered muxer or NULL when the iteration is
2105 const AVOutputFormat *av_muxer_iterate(void **opaque);
2108 * Iterate over all registered demuxers.
2110 * @param opaque a pointer where libavformat will store the iteration state. Must
2111 * point to NULL to start the iteration.
2113 * @return the next registered demuxer or NULL when the iteration is
2116 const AVInputFormat *av_demuxer_iterate(void **opaque);
2119 * Allocate an AVFormatContext.
2120 * avformat_free_context() can be used to free the context and everything
2121 * allocated by the framework within it.
2123 AVFormatContext *avformat_alloc_context(void);
2126 * Free an AVFormatContext and all its streams.
2127 * @param s context to free
2129 void avformat_free_context(AVFormatContext *s);
2132 * Get the AVClass for AVFormatContext. It can be used in combination with
2133 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2135 * @see av_opt_find().
2137 const AVClass *avformat_get_class(void);
2140 * Add a new stream to a media file.
2142 * When demuxing, it is called by the demuxer in read_header(). If the
2143 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2144 * be called in read_packet().
2146 * When muxing, should be called by the user before avformat_write_header().
2148 * User is required to call avcodec_close() and avformat_free_context() to
2149 * clean up the allocation by avformat_new_stream().
2151 * @param s media file handle
2152 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
2153 * will be initialized to use this codec. This is needed for e.g. codec-specific
2154 * defaults to be set, so codec should be provided if it is known.
2156 * @return newly created stream or NULL on error.
2158 AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c);
2161 * Wrap an existing array as stream side data.
2164 * @param type side information type
2165 * @param data the side data array. It must be allocated with the av_malloc()
2166 * family of functions. The ownership of the data is transferred to
2168 * @param size side information size
2169 * @return zero on success, a negative AVERROR code on failure. On failure,
2170 * the stream is unchanged and the data remains owned by the caller.
2172 int av_stream_add_side_data(AVStream *st, enum AVPacketSideDataType type,
2173 uint8_t *data, size_t size);
2176 * Allocate new information from stream.
2178 * @param stream stream
2179 * @param type desired side information type
2180 * @param size side information size
2181 * @return pointer to fresh allocated data or NULL otherwise
2183 uint8_t *av_stream_new_side_data(AVStream *stream,
2184 enum AVPacketSideDataType type, int size);
2186 * Get side information from stream.
2188 * @param stream stream
2189 * @param type desired side information type
2190 * @param size If supplied, *size will be set to the size of the side data
2191 * or to zero if the desired side data is not present.
2192 * @return pointer to data if present or NULL otherwise
2194 uint8_t *av_stream_get_side_data(const AVStream *stream,
2195 enum AVPacketSideDataType type, int *size);
2197 AVProgram *av_new_program(AVFormatContext *s, int id);
2205 * Allocate an AVFormatContext for an output format.
2206 * avformat_free_context() can be used to free the context and
2207 * everything allocated by the framework within it.
2209 * @param *ctx is set to the created format context, or to NULL in
2211 * @param oformat format to use for allocating the context, if NULL
2212 * format_name and filename are used instead
2213 * @param format_name the name of output format to use for allocating the
2214 * context, if NULL filename is used instead
2215 * @param filename the name of the filename to use for allocating the
2216 * context, may be NULL
2217 * @return >= 0 in case of success, a negative AVERROR code in case of
2220 int avformat_alloc_output_context2(AVFormatContext **ctx, ff_const59 AVOutputFormat *oformat,
2221 const char *format_name, const char *filename);
2224 * @addtogroup lavf_decoding
2229 * Find AVInputFormat based on the short name of the input format.
2231 ff_const59 AVInputFormat *av_find_input_format(const char *short_name);
2234 * Guess the file format.
2236 * @param pd data to be probed
2237 * @param is_opened Whether the file is already opened; determines whether
2238 * demuxers with or without AVFMT_NOFILE are probed.
2240 ff_const59 AVInputFormat *av_probe_input_format(ff_const59 AVProbeData *pd, int is_opened);
2243 * Guess the file format.
2245 * @param pd data to be probed
2246 * @param is_opened Whether the file is already opened; determines whether
2247 * demuxers with or without AVFMT_NOFILE are probed.
2248 * @param score_max A probe score larger that this is required to accept a
2249 * detection, the variable is set to the actual detection
2251 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2252 * to retry with a larger probe buffer.
2254 ff_const59 AVInputFormat *av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max);
2257 * Guess the file format.
2259 * @param is_opened Whether the file is already opened; determines whether
2260 * demuxers with or without AVFMT_NOFILE are probed.
2261 * @param score_ret The score of the best detection.
2263 ff_const59 AVInputFormat *av_probe_input_format3(ff_const59 AVProbeData *pd, int is_opened, int *score_ret);
2266 * Probe a bytestream to determine the input format. Each time a probe returns
2267 * with a score that is too low, the probe buffer size is increased and another
2268 * attempt is made. When the maximum probe size is reached, the input format
2269 * with the highest score is returned.
2271 * @param pb the bytestream to probe
2272 * @param fmt the input format is put here
2273 * @param url the url of the stream
2274 * @param logctx the log context
2275 * @param offset the offset within the bytestream to probe from
2276 * @param max_probe_size the maximum probe buffer size (zero for default)
2277 * @return the score in case of success, a negative value corresponding to an
2278 * the maximal score is AVPROBE_SCORE_MAX
2279 * AVERROR code otherwise
2281 int av_probe_input_buffer2(AVIOContext *pb, ff_const59 AVInputFormat **fmt,
2282 const char *url, void *logctx,
2283 unsigned int offset, unsigned int max_probe_size);
2286 * Like av_probe_input_buffer2() but returns 0 on success
2288 int av_probe_input_buffer(AVIOContext *pb, ff_const59 AVInputFormat **fmt,
2289 const char *url, void *logctx,
2290 unsigned int offset, unsigned int max_probe_size);
2293 * Open an input stream and read the header. The codecs are not opened.
2294 * The stream must be closed with avformat_close_input().
2296 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
2297 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
2298 * function and written into ps.
2299 * Note that a user-supplied AVFormatContext will be freed on failure.
2300 * @param url URL of the stream to open.
2301 * @param fmt If non-NULL, this parameter forces a specific input format.
2302 * Otherwise the format is autodetected.
2303 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
2304 * On return this parameter will be destroyed and replaced with a dict containing
2305 * options that were not found. May be NULL.
2307 * @return 0 on success, a negative AVERROR on failure.
2309 * @note If you want to use custom IO, preallocate the format context and set its pb field.
2311 int avformat_open_input(AVFormatContext **ps, const char *url, ff_const59 AVInputFormat *fmt, AVDictionary **options);
2313 attribute_deprecated
2314 int av_demuxer_open(AVFormatContext *ic);
2317 * Read packets of a media file to get stream information. This
2318 * is useful for file formats with no headers such as MPEG. This
2319 * function also computes the real framerate in case of MPEG-2 repeat
2321 * The logical file position is not changed by this function;
2322 * examined packets may be buffered for later processing.
2324 * @param ic media file handle
2325 * @param options If non-NULL, an ic.nb_streams long array of pointers to
2326 * dictionaries, where i-th member contains options for
2327 * codec corresponding to i-th stream.
2328 * On return each dictionary will be filled with options that were not found.
2329 * @return >=0 if OK, AVERROR_xxx on error
2331 * @note this function isn't guaranteed to open all the codecs, so
2332 * options being non-empty at return is a perfectly normal behavior.
2334 * @todo Let the user decide somehow what information is needed so that
2335 * we do not waste time getting stuff the user does not need.
2337 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
2340 * Find the programs which belong to a given stream.
2342 * @param ic media file handle
2343 * @param last the last found program, the search will start after this
2344 * program, or from the beginning if it is NULL
2345 * @param s stream index
2346 * @return the next program which belongs to s, NULL if no program is found or
2347 * the last program is not among the programs of ic.
2349 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s);
2351 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
2354 * Find the "best" stream in the file.
2355 * The best stream is determined according to various heuristics as the most
2356 * likely to be what the user expects.
2357 * If the decoder parameter is non-NULL, av_find_best_stream will find the
2358 * default decoder for the stream's codec; streams for which no decoder can
2359 * be found are ignored.
2361 * @param ic media file handle
2362 * @param type stream type: video, audio, subtitles, etc.
2363 * @param wanted_stream_nb user-requested stream number,
2364 * or -1 for automatic selection
2365 * @param related_stream try to find a stream related (eg. in the same
2366 * program) to this one, or -1 if none
2367 * @param decoder_ret if non-NULL, returns the decoder for the
2369 * @param flags flags; none are currently defined
2370 * @return the non-negative stream number in case of success,
2371 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2373 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2374 * @note If av_find_best_stream returns successfully and decoder_ret is not
2375 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2377 int av_find_best_stream(AVFormatContext *ic,
2378 enum AVMediaType type,
2379 int wanted_stream_nb,
2381 AVCodec **decoder_ret,
2385 * Return the next frame of a stream.
2386 * This function returns what is stored in the file, and does not validate
2387 * that what is there are valid frames for the decoder. It will split what is
2388 * stored in the file into frames and return one for each call. It will not
2389 * omit invalid data between valid frames so as to give the decoder the maximum
2390 * information possible for decoding.
2392 * On success, the returned packet is reference-counted (pkt->buf is set) and
2393 * valid indefinitely. The packet must be freed with av_packet_unref() when
2394 * it is no longer needed. For video, the packet contains exactly one frame.
2395 * For audio, it contains an integer number of frames if each frame has
2396 * a known fixed size (e.g. PCM or ADPCM data). If the audio frames have
2397 * a variable size (e.g. MPEG audio), then it contains one frame.
2399 * pkt->pts, pkt->dts and pkt->duration are always set to correct
2400 * values in AVStream.time_base units (and guessed if the format cannot
2401 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2402 * has B-frames, so it is better to rely on pkt->dts if you do not
2403 * decompress the payload.
2405 * @return 0 if OK, < 0 on error or end of file. On error, pkt will be blank
2406 * (as if it came from av_packet_alloc()).
2408 * @note pkt will be initialized, so it may be uninitialized, but it must not
2409 * contain data that needs to be freed.
2411 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
2414 * Seek to the keyframe at timestamp.
2415 * 'timestamp' in 'stream_index'.
2417 * @param s media file handle
2418 * @param stream_index If stream_index is (-1), a default
2419 * stream is selected, and timestamp is automatically converted
2420 * from AV_TIME_BASE units to the stream specific time_base.
2421 * @param timestamp Timestamp in AVStream.time_base units
2422 * or, if no stream is specified, in AV_TIME_BASE units.
2423 * @param flags flags which select direction and seeking mode
2424 * @return >= 0 on success
2426 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2430 * Seek to timestamp ts.
2431 * Seeking will be done so that the point from which all active streams
2432 * can be presented successfully will be closest to ts and within min/max_ts.
2433 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2435 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2436 * are the file position (this may not be supported by all demuxers).
2437 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2438 * in the stream with stream_index (this may not be supported by all demuxers).
2439 * Otherwise all timestamps are in units of the stream selected by stream_index
2440 * or if stream_index is -1, in AV_TIME_BASE units.
2441 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2442 * keyframes (this may not be supported by all demuxers).
2443 * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2445 * @param s media file handle
2446 * @param stream_index index of the stream which is used as time base reference
2447 * @param min_ts smallest acceptable timestamp
2448 * @param ts target timestamp
2449 * @param max_ts largest acceptable timestamp
2450 * @param flags flags
2451 * @return >=0 on success, error code otherwise
2453 * @note This is part of the new seek API which is still under construction.
2455 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2458 * Discard all internally buffered data. This can be useful when dealing with
2459 * discontinuities in the byte stream. Generally works only with formats that
2460 * can resync. This includes headerless formats like MPEG-TS/TS but should also
2461 * work with NUT, Ogg and in a limited way AVI for example.
2463 * The set of streams, the detected duration, stream parameters and codecs do
2464 * not change when calling this function. If you want a complete reset, it's
2465 * better to open a new AVFormatContext.
2467 * This does not flush the AVIOContext (s->pb). If necessary, call
2468 * avio_flush(s->pb) before calling this function.
2470 * @param s media file handle
2471 * @return >=0 on success, error code otherwise
2473 int avformat_flush(AVFormatContext *s);
2476 * Start playing a network-based stream (e.g. RTSP stream) at the
2479 int av_read_play(AVFormatContext *s);
2482 * Pause a network-based stream (e.g. RTSP stream).
2484 * Use av_read_play() to resume it.
2486 int av_read_pause(AVFormatContext *s);
2489 * Close an opened input AVFormatContext. Free it and all its contents
2490 * and set *s to NULL.
2492 void avformat_close_input(AVFormatContext **s);
2497 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2498 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2499 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2500 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2503 * @addtogroup lavf_encoding
2507 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2508 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2511 * Allocate the stream private data and write the stream header to
2512 * an output media file.
2514 * @param s Media file handle, must be allocated with avformat_alloc_context().
2515 * Its oformat field must be set to the desired output format;
2516 * Its pb field must be set to an already opened AVIOContext.
2517 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2518 * On return this parameter will be destroyed and replaced with a dict containing
2519 * options that were not found. May be NULL.
2521 * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init,
2522 * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init,
2523 * negative AVERROR on failure.
2525 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2527 av_warn_unused_result
2528 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
2531 * Allocate the stream private data and initialize the codec, but do not write the header.
2532 * May optionally be used before avformat_write_header to initialize stream parameters
2533 * before actually writing the header.
2534 * If using this function, do not pass the same options to avformat_write_header.
2536 * @param s Media file handle, must be allocated with avformat_alloc_context().
2537 * Its oformat field must be set to the desired output format;
2538 * Its pb field must be set to an already opened AVIOContext.
2539 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2540 * On return this parameter will be destroyed and replaced with a dict containing
2541 * options that were not found. May be NULL.
2543 * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec requires avformat_write_header to fully initialize,
2544 * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec has been fully initialized,
2545 * negative AVERROR on failure.
2547 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2549 av_warn_unused_result
2550 int avformat_init_output(AVFormatContext *s, AVDictionary **options);
2553 * Write a packet to an output media file.
2555 * This function passes the packet directly to the muxer, without any buffering
2556 * or reordering. The caller is responsible for correctly interleaving the
2557 * packets if the format requires it. Callers that want libavformat to handle
2558 * the interleaving should call av_interleaved_write_frame() instead of this
2561 * @param s media file handle
2562 * @param pkt The packet containing the data to be written. Note that unlike
2563 * av_interleaved_write_frame(), this function does not take
2564 * ownership of the packet passed to it (though some muxers may make
2565 * an internal reference to the input packet).
2567 * This parameter can be NULL (at any time, not just at the end), in
2568 * order to immediately flush data buffered within the muxer, for
2569 * muxers that buffer up data internally before writing it to the
2572 * Packet's @ref AVPacket.stream_index "stream_index" field must be
2573 * set to the index of the corresponding stream in @ref
2574 * AVFormatContext.streams "s->streams".
2576 * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2577 * must be set to correct values in the stream's timebase (unless the
2578 * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2579 * they can be set to AV_NOPTS_VALUE).
2580 * The dts for subsequent packets passed to this function must be strictly
2581 * increasing when compared in their respective timebases (unless the
2582 * output format is flagged with the AVFMT_TS_NONSTRICT, then they
2583 * merely have to be nondecreasing). @ref AVPacket.duration
2584 * "duration") should also be set if known.
2585 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2587 * @see av_interleaved_write_frame()
2589 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
2592 * Write a packet to an output media file ensuring correct interleaving.
2594 * This function will buffer the packets internally as needed to make sure the
2595 * packets in the output file are properly interleaved in the order of
2596 * increasing dts. Callers doing their own interleaving should call
2597 * av_write_frame() instead of this function.
2599 * Using this function instead of av_write_frame() can give muxers advance
2600 * knowledge of future packets, improving e.g. the behaviour of the mp4
2601 * muxer for VFR content in fragmenting mode.
2603 * @param s media file handle
2604 * @param pkt The packet containing the data to be written.
2606 * If the packet is reference-counted, this function will take
2607 * ownership of this reference and unreference it later when it sees
2609 * The caller must not access the data through this reference after
2610 * this function returns. If the packet is not reference-counted,
2611 * libavformat will make a copy.
2613 * This parameter can be NULL (at any time, not just at the end), to
2614 * flush the interleaving queues.
2616 * Packet's @ref AVPacket.stream_index "stream_index" field must be
2617 * set to the index of the corresponding stream in @ref
2618 * AVFormatContext.streams "s->streams".
2620 * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2621 * must be set to correct values in the stream's timebase (unless the
2622 * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2623 * they can be set to AV_NOPTS_VALUE).
2624 * The dts for subsequent packets in one stream must be strictly
2625 * increasing (unless the output format is flagged with the
2626 * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2627 * @ref AVPacket.duration "duration") should also be set if known.
2629 * @return 0 on success, a negative AVERROR on error. Libavformat will always
2630 * take care of freeing the packet, even if this function fails.
2632 * @see av_write_frame(), AVFormatContext.max_interleave_delta
2634 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
2637 * Write an uncoded frame to an output media file.
2639 * The frame must be correctly interleaved according to the container
2640 * specification; if not, av_interleaved_write_uncoded_frame() must be used.
2642 * See av_interleaved_write_uncoded_frame() for details.
2644 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2648 * Write an uncoded frame to an output media file.
2650 * If the muxer supports it, this function makes it possible to write an AVFrame
2651 * structure directly, without encoding it into a packet.
2652 * It is mostly useful for devices and similar special muxers that use raw
2653 * video or PCM data and will not serialize it into a byte stream.
2655 * To test whether it is possible to use it with a given muxer and stream,
2656 * use av_write_uncoded_frame_query().
2658 * The caller gives up ownership of the frame and must not access it
2661 * @return >=0 for success, a negative code on error
2663 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
2667 * Test whether a muxer supports uncoded frame.
2669 * @return >=0 if an uncoded frame can be written to that muxer and stream,
2672 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2675 * Write the stream trailer to an output media file and free the
2676 * file private data.
2678 * May only be called after a successful call to avformat_write_header.
2680 * @param s media file handle
2681 * @return 0 if OK, AVERROR_xxx on error
2683 int av_write_trailer(AVFormatContext *s);
2686 * Return the output format in the list of registered output formats
2687 * which best matches the provided parameters, or return NULL if
2688 * there is no match.
2690 * @param short_name if non-NULL checks if short_name matches with the
2691 * names of the registered formats
2692 * @param filename if non-NULL checks if filename terminates with the
2693 * extensions of the registered formats
2694 * @param mime_type if non-NULL checks if mime_type matches with the
2695 * MIME type of the registered formats
2697 ff_const59 AVOutputFormat *av_guess_format(const char *short_name,
2698 const char *filename,
2699 const char *mime_type);
2702 * Guess the codec ID based upon muxer and filename.
2704 enum AVCodecID av_guess_codec(ff_const59 AVOutputFormat *fmt, const char *short_name,
2705 const char *filename, const char *mime_type,
2706 enum AVMediaType type);
2709 * Get timing information for the data currently output.
2710 * The exact meaning of "currently output" depends on the format.
2711 * It is mostly relevant for devices that have an internal buffer and/or
2712 * work in real time.
2713 * @param s media file handle
2714 * @param stream stream in the media file
2715 * @param[out] dts DTS of the last packet output for the stream, in stream
2717 * @param[out] wall absolute time when that packet whas output,
2719 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
2720 * Note: some formats or devices may not allow to measure dts and wall
2723 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2724 int64_t *dts, int64_t *wall);
2733 * @defgroup lavf_misc Utility functions
2737 * Miscellaneous utility functions related to both muxing and demuxing
2742 * Send a nice hexadecimal dump of a buffer to the specified file stream.
2744 * @param f The file stream pointer where the dump should be sent to.
2746 * @param size buffer size
2748 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2750 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2753 * Send a nice hexadecimal dump of a buffer to the log.
2755 * @param avcl A pointer to an arbitrary struct of which the first field is a
2756 * pointer to an AVClass struct.
2757 * @param level The importance level of the message, lower values signifying
2758 * higher importance.
2760 * @param size buffer size
2762 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2764 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2767 * Send a nice dump of a packet to the specified file stream.
2769 * @param f The file stream pointer where the dump should be sent to.
2770 * @param pkt packet to dump
2771 * @param dump_payload True if the payload must be displayed, too.
2772 * @param st AVStream that the packet belongs to
2774 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2778 * Send a nice dump of a packet to the log.
2780 * @param avcl A pointer to an arbitrary struct of which the first field is a
2781 * pointer to an AVClass struct.
2782 * @param level The importance level of the message, lower values signifying
2783 * higher importance.
2784 * @param pkt packet to dump
2785 * @param dump_payload True if the payload must be displayed, too.
2786 * @param st AVStream that the packet belongs to
2788 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2789 const AVStream *st);
2792 * Get the AVCodecID for the given codec tag tag.
2793 * If no codec id is found returns AV_CODEC_ID_NONE.
2795 * @param tags list of supported codec_id-codec_tag pairs, as stored
2796 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2797 * @param tag codec tag to match to a codec ID
2799 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2802 * Get the codec tag for the given codec id id.
2803 * If no codec tag is found returns 0.
2805 * @param tags list of supported codec_id-codec_tag pairs, as stored
2806 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2807 * @param id codec ID to match to a codec tag
2809 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2812 * Get the codec tag for the given codec id.
2814 * @param tags list of supported codec_id - codec_tag pairs, as stored
2815 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2816 * @param id codec id that should be searched for in the list
2817 * @param tag A pointer to the found tag
2818 * @return 0 if id was not found in tags, > 0 if it was found
2820 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2823 int av_find_default_stream_index(AVFormatContext *s);
2826 * Get the index for a specific timestamp.
2828 * @param st stream that the timestamp belongs to
2829 * @param timestamp timestamp to retrieve the index for
2830 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2831 * to the timestamp which is <= the requested one, if backward
2832 * is 0, then it will be >=
2833 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2834 * @return < 0 if no such timestamp could be found
2836 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2839 * Add an index entry into a sorted list. Update the entry if the list
2840 * already contains it.
2842 * @param timestamp timestamp in the time base of the given stream
2844 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2845 int size, int distance, int flags);
2849 * Split a URL string into components.
2851 * The pointers to buffers for storing individual components may be null,
2852 * in order to ignore that component. Buffers for components not found are
2853 * set to empty strings. If the port is not found, it is set to a negative
2856 * @param proto the buffer for the protocol
2857 * @param proto_size the size of the proto buffer
2858 * @param authorization the buffer for the authorization
2859 * @param authorization_size the size of the authorization buffer
2860 * @param hostname the buffer for the host name
2861 * @param hostname_size the size of the hostname buffer
2862 * @param port_ptr a pointer to store the port number in
2863 * @param path the buffer for the path
2864 * @param path_size the size of the path buffer
2865 * @param url the URL to split
2867 void av_url_split(char *proto, int proto_size,
2868 char *authorization, int authorization_size,
2869 char *hostname, int hostname_size,
2871 char *path, int path_size,
2876 * Print detailed information about the input or output format, such as
2877 * duration, bitrate, streams, container, programs, metadata, side data,
2878 * codec and time base.
2880 * @param ic the context to analyze
2881 * @param index index of the stream to dump information about
2882 * @param url the URL to print, such as source or destination file
2883 * @param is_output Select whether the specified context is an input(0) or output(1)
2885 void av_dump_format(AVFormatContext *ic,
2891 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
2894 * Return in 'buf' the path with '%d' replaced by a number.
2896 * Also handles the '%0nd' format where 'n' is the total number
2897 * of digits and '%%'.
2899 * @param buf destination buffer
2900 * @param buf_size destination buffer size
2901 * @param path numbered sequence string
2902 * @param number frame number
2903 * @param flags AV_FRAME_FILENAME_FLAGS_*
2904 * @return 0 if OK, -1 on format error
2906 int av_get_frame_filename2(char *buf, int buf_size,
2907 const char *path, int number, int flags);
2909 int av_get_frame_filename(char *buf, int buf_size,
2910 const char *path, int number);
2913 * Check whether filename actually is a numbered sequence generator.
2915 * @param filename possible numbered sequence string
2916 * @return 1 if a valid numbered sequence string, 0 otherwise
2918 int av_filename_number_test(const char *filename);
2921 * Generate an SDP for an RTP session.
2923 * Note, this overwrites the id values of AVStreams in the muxer contexts
2924 * for getting unique dynamic payload types.
2926 * @param ac array of AVFormatContexts describing the RTP streams. If the
2927 * array is composed by only one context, such context can contain
2928 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2929 * all the contexts in the array (an AVCodecContext per RTP stream)
2930 * must contain only one AVStream.
2931 * @param n_files number of AVCodecContexts contained in ac
2932 * @param buf buffer where the SDP will be stored (must be allocated by
2934 * @param size the size of the buffer
2935 * @return 0 if OK, AVERROR_xxx on error
2937 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2940 * Return a positive value if the given filename has one of the given
2941 * extensions, 0 otherwise.
2943 * @param filename file name to check against the given extensions
2944 * @param extensions a comma-separated list of filename extensions
2946 int av_match_ext(const char *filename, const char *extensions);
2949 * Test if the given container can store a codec.
2951 * @param ofmt container to check for compatibility
2952 * @param codec_id codec to potentially store in container
2953 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2955 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2956 * A negative number if this information is not available.
2958 int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id,
2959 int std_compliance);
2962 * @defgroup riff_fourcc RIFF FourCCs
2964 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2965 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2968 * uint32_t tag = MKTAG('H', '2', '6', '4');
2969 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2970 * enum AVCodecID id = av_codec_get_id(table, tag);
2974 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2976 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2978 * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2980 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2982 * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2984 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2986 * @return the table mapping MOV FourCCs for audio to AVCodecID.
2988 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2995 * Guess the sample aspect ratio of a frame, based on both the stream and the
2996 * frame aspect ratio.
2998 * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2999 * is set by the demuxer, these two may not be equal. This function tries to
3000 * return the value that you should use if you would like to display the frame.
3002 * Basic logic is to use the stream aspect ratio if it is set to something sane
3003 * otherwise use the frame aspect ratio. This way a container setting, which is
3004 * usually easy to modify can override the coded value in the frames.
3006 * @param format the format context which the stream is part of
3007 * @param stream the stream which the frame is part of
3008 * @param frame the frame with the aspect ratio to be determined
3009 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
3011 AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame);
3014 * Guess the frame rate, based on both the container and codec information.
3016 * @param ctx the format context which the stream is part of
3017 * @param stream the stream which the frame is part of
3018 * @param frame the frame for which the frame rate should be determined, may be NULL
3019 * @return the guessed (valid) frame rate, 0/1 if no idea
3021 AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame);
3024 * Check if the stream st contained in s is matched by the stream specifier
3027 * See the "stream specifiers" chapter in the documentation for the syntax
3030 * @return >0 if st is matched by spec;
3031 * 0 if st is not matched by spec;
3032 * AVERROR code if spec is invalid
3034 * @note A stream specifier can match several streams in the format.
3036 int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st,
3039 int avformat_queue_attached_pictures(AVFormatContext *s);
3043 * Apply a list of bitstream filters to a packet.
3045 * @param codec AVCodecContext, usually from an AVStream
3046 * @param pkt the packet to apply filters to. If, on success, the returned
3047 * packet has size == 0 and side_data_elems == 0, it indicates that
3048 * the packet should be dropped
3049 * @param bsfc a NULL-terminated list of filters to apply
3050 * @return >=0 on success;
3051 * AVERROR code on failure
3053 attribute_deprecated
3054 int av_apply_bitstream_filters(AVCodecContext *codec, AVPacket *pkt,
3055 AVBitStreamFilterContext *bsfc);
3058 enum AVTimebaseSource {
3059 AVFMT_TBCF_AUTO = -1,
3062 #if FF_API_R_FRAME_RATE
3063 AVFMT_TBCF_R_FRAMERATE,
3068 * Transfer internal timing information from one stream to another.
3070 * This function is useful when doing stream copy.
3072 * @param ofmt target output format for ost
3073 * @param ost output stream which needs timings copy and adjustments
3074 * @param ist reference input stream to copy timings from
3075 * @param copy_tb define from where the stream codec timebase needs to be imported
3077 int avformat_transfer_internal_stream_timing_info(const AVOutputFormat *ofmt,
3078 AVStream *ost, const AVStream *ist,
3079 enum AVTimebaseSource copy_tb);
3082 * Get the internal codec timebase from a stream.
3084 * @param st input stream to extract the timebase from
3086 AVRational av_stream_get_codec_timebase(const AVStream *st);
3092 #endif /* AVFORMAT_AVFORMAT_H */