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). Before using lavf, you need to call
40 * av_register_all() to register all compiled muxers, demuxers and protocols.
41 * Unless you are absolutely sure you won't use libavformat's network
42 * capabilities, you should also call avformat_network_init().
44 * A supported input format is described by an AVInputFormat struct, conversely
45 * an output format is described by AVOutputFormat. You can iterate over all
46 * registered input/output formats using the av_iformat_next() /
47 * av_oformat_next() functions. The protocols layer is not part of the public
48 * API, so you can only get the names of supported protocols with the
49 * avio_enum_protocols() function.
51 * Main lavf structure used for both muxing and demuxing is AVFormatContext,
52 * which exports all information about the file being read or written. As with
53 * most Libavformat structures, its size is not part of public ABI, so it cannot be
54 * allocated on stack or directly with av_malloc(). To create an
55 * AVFormatContext, use avformat_alloc_context() (some functions, like
56 * avformat_open_input() might do that for you).
58 * Most importantly an AVFormatContext contains:
59 * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat
60 * "output" format. It is either autodetected or set by user for input;
61 * always set by user for output.
62 * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all
63 * elementary streams stored in the file. AVStreams are typically referred to
64 * using their index in this array.
65 * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or
66 * set by user for input, always set by user for output (unless you are dealing
67 * with an AVFMT_NOFILE format).
69 * @section lavf_options Passing options to (de)muxers
70 * It is possible to configure lavf muxers and demuxers using the @ref avoptions
71 * mechanism. Generic (format-independent) libavformat options are provided by
72 * AVFormatContext, they can be examined from a user program by calling
73 * av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass
74 * from avformat_get_class()). Private (format-specific) options are provided by
75 * AVFormatContext.priv_data if and only if AVInputFormat.priv_class /
76 * AVOutputFormat.priv_class of the corresponding format struct is non-NULL.
77 * Further options may be provided by the @ref AVFormatContext.pb "I/O context",
78 * if its AVClass is non-NULL, and the protocols layer. See the discussion on
79 * nesting in @ref avoptions documentation to learn how to access those.
82 * URL strings in libavformat are made of a scheme/protocol, a ':', and a
83 * scheme specific string. URLs without a scheme and ':' used for local files
84 * are supported but deprecated. "file:" should be used for local files.
86 * It is important that the scheme string is not taken from untrusted
87 * sources without checks.
89 * Note that some schemes/protocols are quite powerful, allowing access to
90 * both local and remote files, parts of them, concatenations of them, local
91 * audio and video devices and so on.
95 * @defgroup lavf_decoding Demuxing
97 * Demuxers read a media file and split it into chunks of data (@em packets). A
98 * @ref AVPacket "packet" contains one or more encoded frames which belongs to a
99 * single elementary stream. In the lavf API this process is represented by the
100 * avformat_open_input() function for opening a file, av_read_frame() for
101 * reading a single packet and finally avformat_close_input(), which does the
104 * @section lavf_decoding_open Opening a media file
105 * The minimum information required to open a file is its URL, which
106 * is passed to avformat_open_input(), as in the following code:
108 * const char *url = "file:in.mp3";
109 * AVFormatContext *s = NULL;
110 * int ret = avformat_open_input(&s, url, NULL, NULL);
114 * The above code attempts to allocate an AVFormatContext, open the
115 * specified file (autodetecting the format) and read the header, exporting the
116 * information stored there into s. Some formats do not have a header or do not
117 * store enough information there, so it is recommended that you call the
118 * avformat_find_stream_info() function which tries to read and decode a few
119 * frames to find missing information.
121 * In some cases you might want to preallocate an AVFormatContext yourself with
122 * avformat_alloc_context() and do some tweaking on it before passing it to
123 * avformat_open_input(). One such case is when you want to use custom functions
124 * for reading input data instead of lavf internal I/O layer.
125 * To do that, create your own AVIOContext with avio_alloc_context(), passing
126 * your reading callbacks to it. Then set the @em pb field of your
127 * AVFormatContext to newly created AVIOContext.
129 * Since the format of the opened file is in general not known until after
130 * avformat_open_input() has returned, it is not possible to set demuxer private
131 * options on a preallocated context. Instead, the options should be passed to
132 * avformat_open_input() wrapped in an AVDictionary:
134 * AVDictionary *options = NULL;
135 * av_dict_set(&options, "video_size", "640x480", 0);
136 * av_dict_set(&options, "pixel_format", "rgb24", 0);
138 * if (avformat_open_input(&s, url, NULL, &options) < 0)
140 * av_dict_free(&options);
142 * This code passes the private options 'video_size' and 'pixel_format' to the
143 * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it
144 * cannot know how to interpret raw video data otherwise. If the format turns
145 * out to be something different than raw video, those options will not be
146 * recognized by the demuxer and therefore will not be applied. Such unrecognized
147 * options are then returned in the options dictionary (recognized options are
148 * consumed). The calling program can handle such unrecognized options as it
151 * AVDictionaryEntry *e;
152 * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
153 * fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key);
158 * After you have finished reading the file, you must close it with
159 * avformat_close_input(). It will free everything associated with the file.
161 * @section lavf_decoding_read Reading from an opened file
162 * Reading data from an opened AVFormatContext is done by repeatedly calling
163 * av_read_frame() on it. Each call, if successful, will return an AVPacket
164 * containing encoded data for one AVStream, identified by
165 * AVPacket.stream_index. This packet may be passed straight into the libavcodec
166 * decoding functions avcodec_send_packet() or avcodec_decode_subtitle2() if the
167 * caller wishes to decode the data.
169 * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be
170 * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for
171 * pts/dts, 0 for duration) if the stream does not provide them. The timing
172 * information will be in AVStream.time_base units, i.e. it has to be
173 * multiplied by the timebase to convert them to seconds.
175 * If AVPacket.buf is set on the returned packet, then the packet is
176 * allocated dynamically and the user may keep it indefinitely.
177 * Otherwise, if AVPacket.buf is NULL, the packet data is backed by a
178 * static storage somewhere inside the demuxer and the packet is only valid
179 * until the next av_read_frame() call or closing the file. If the caller
180 * requires a longer lifetime, av_dup_packet() will make an av_malloc()ed copy
182 * In both cases, the packet must be freed with av_packet_unref() when it is no
185 * @section lavf_decoding_seek Seeking
188 * @defgroup lavf_encoding Muxing
190 * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write
191 * it into files or other output bytestreams in the specified container format.
193 * The main API functions for muxing are avformat_write_header() for writing the
194 * file header, av_write_frame() / av_interleaved_write_frame() for writing the
195 * packets and av_write_trailer() for finalizing the file.
197 * At the beginning of the muxing process, the caller must first call
198 * avformat_alloc_context() to create a muxing context. The caller then sets up
199 * the muxer by filling the various fields in this context:
201 * - The @ref AVFormatContext.oformat "oformat" field must be set to select the
202 * muxer that will be used.
203 * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb
204 * "pb" field must be set to an opened IO context, either returned from
205 * avio_open2() or a custom one.
206 * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must
207 * be created with the avformat_new_stream() function. The caller should fill
208 * the @ref AVStream.codecpar "stream codec parameters" information, such as the
209 * codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id
210 * "id" and other parameters (e.g. width / height, the pixel or sample format,
211 * etc.) as known. The @ref AVStream.time_base "stream timebase" should
212 * be set to the timebase that the caller desires to use for this stream (note
213 * that the timebase actually used by the muxer can be different, as will be
215 * - It is advised to manually initialize only the relevant fields in
216 * AVCodecParameters, rather than using @ref avcodec_parameters_copy() during
217 * remuxing: there is no guarantee that the codec context values remain valid
218 * for both input and output format contexts.
219 * - The caller may fill in additional information, such as @ref
220 * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream"
221 * metadata, @ref AVFormatContext.chapters "chapters", @ref
222 * AVFormatContext.programs "programs", etc. as described in the
223 * AVFormatContext documentation. Whether such information will actually be
224 * stored in the output depends on what the container format and the muxer
227 * When the muxing context is fully set up, the caller must call
228 * avformat_write_header() to initialize the muxer internals and write the file
229 * header. Whether anything actually is written to the IO context at this step
230 * depends on the muxer, but this function must always be called. Any muxer
231 * private options must be passed in the options parameter to this function.
233 * The data is then sent to the muxer by repeatedly calling av_write_frame() or
234 * av_interleaved_write_frame() (consult those functions' documentation for
235 * discussion on the difference between them; only one of them may be used with
236 * a single muxing context, they should not be mixed). Do note that the timing
237 * information on the packets sent to the muxer must be in the corresponding
238 * AVStream's timebase. That timebase is set by the muxer (in the
239 * avformat_write_header() step) and may be different from the timebase
240 * requested by the caller.
242 * Once all the data has been written, the caller must call av_write_trailer()
243 * to flush any buffered packets and finalize the output file, then close the IO
244 * context (if any) and finally free the muxing context with
245 * avformat_free_context().
248 * @defgroup lavf_io I/O Read/Write
250 * @section lavf_io_dirlist Directory listing
251 * The directory listing API makes it possible to list files on remote servers.
253 * Some of possible use cases:
254 * - an "open file" dialog to choose files from a remote location,
255 * - a recursive media finder providing a player with an ability to play all
256 * files from a given directory.
258 * @subsection lavf_io_dirlist_open Opening a directory
259 * At first, a directory needs to be opened by calling avio_open_dir()
260 * supplied with a URL and, optionally, ::AVDictionary containing
261 * protocol-specific parameters. The function returns zero or positive
262 * integer and allocates AVIODirContext on success.
265 * AVIODirContext *ctx = NULL;
266 * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) {
267 * fprintf(stderr, "Cannot open directory.\n");
272 * This code tries to open a sample directory using smb protocol without
273 * any additional parameters.
275 * @subsection lavf_io_dirlist_read Reading entries
276 * Each directory's entry (i.e. file, another directory, anything else
277 * within ::AVIODirEntryType) is represented by AVIODirEntry.
278 * Reading consecutive entries from an opened AVIODirContext is done by
279 * repeatedly calling avio_read_dir() on it. Each call returns zero or
280 * positive integer if successful. Reading can be stopped right after the
281 * NULL entry has been read -- it means there are no entries left to be
282 * read. The following code reads all entries from a directory associated
283 * with ctx and prints their names to standard output.
285 * AVIODirEntry *entry = NULL;
287 * if (avio_read_dir(ctx, &entry) < 0) {
288 * fprintf(stderr, "Cannot list directory.\n");
293 * printf("%s\n", entry->name);
294 * avio_free_directory_entry(&entry);
299 * @defgroup lavf_codec Demuxers
301 * @defgroup lavf_codec_native Native Demuxers
304 * @defgroup lavf_codec_wrappers External library wrappers
308 * @defgroup lavf_protos I/O Protocols
311 * @defgroup lavf_internal Internal
318 #include <stdio.h> /* FILE */
319 #include "libavcodec/avcodec.h"
320 #include "libavutil/dict.h"
321 #include "libavutil/log.h"
324 #include "libavformat/version.h"
326 struct AVFormatContext;
328 struct AVDeviceInfoList;
329 struct AVDeviceCapabilitiesQuery;
332 * @defgroup metadata_api Public Metadata API
335 * The metadata API allows libavformat to export metadata tags to a client
336 * application when demuxing. Conversely it allows a client application to
337 * set metadata when muxing.
339 * Metadata is exported or set as pairs of key/value strings in the 'metadata'
340 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
341 * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
342 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
343 * exported by demuxers isn't checked to be valid UTF-8 in most cases.
345 * Important concepts to keep in mind:
346 * - Keys are unique; there can never be 2 tags with the same key. This is
347 * also meant semantically, i.e., a demuxer should not knowingly produce
348 * several keys that are literally different but semantically identical.
349 * E.g., key=Author5, key=Author6. In this example, all authors must be
350 * placed in the same tag.
351 * - Metadata is flat, not hierarchical; there are no subtags. If you
352 * want to store, e.g., the email address of the child of producer Alice
353 * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
354 * - Several modifiers can be applied to the tag name. This is done by
355 * appending a dash character ('-') and the modifier name in the order
356 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
357 * - language -- a tag whose value is localized for a particular language
358 * is appended with the ISO 639-2/B 3-letter language code.
359 * For example: Author-ger=Michael, Author-eng=Mike
360 * The original/default language is in the unqualified "Author" tag.
361 * A demuxer should set a default if it sets any translated tag.
362 * - sorting -- a modified version of a tag that should be used for
363 * sorting will have '-sort' appended. E.g. artist="The Beatles",
364 * artist-sort="Beatles, The".
365 * - Some protocols and demuxers support metadata updates. After a successful
366 * call to av_read_packet(), AVFormatContext.event_flags or AVStream.event_flags
367 * will be updated to indicate if metadata changed. In order to detect metadata
368 * changes on a stream, you need to loop through all streams in the AVFormatContext
369 * and check their individual event_flags.
371 * - Demuxers attempt to export metadata in a generic format, however tags
372 * with no generic equivalents are left as they are stored in the container.
373 * Follows a list of generic tag names:
376 album -- name of the set this work belongs to
377 album_artist -- main creator of the set/album, if different from artist.
378 e.g. "Various Artists" for compilation albums.
379 artist -- main creator of the work
380 comment -- any additional description of the file.
381 composer -- who composed the work, if different from artist.
382 copyright -- name of copyright holder.
383 creation_time-- date when the file was created, preferably in ISO 8601.
384 date -- date when the work was created, preferably in ISO 8601.
385 disc -- number of a subset, e.g. disc in a multi-disc collection.
386 encoder -- name/settings of the software/hardware that produced the file.
387 encoded_by -- person/group who created the file.
388 filename -- original name of the file.
389 genre -- <self-evident>.
390 language -- main language in which the work is performed, preferably
391 in ISO 639-2 format. Multiple languages can be specified by
392 separating them with commas.
393 performer -- artist who performed the work, if different from artist.
394 E.g for "Also sprach Zarathustra", artist would be "Richard
395 Strauss" and performer "London Philharmonic Orchestra".
396 publisher -- name of the label/publisher.
397 service_name -- name of the service in broadcasting (channel name).
398 service_provider -- name of the service provider in broadcasting.
399 title -- name of the work.
400 track -- number of this work in the set, can be in form current/total.
401 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
404 * Look in the examples section for an application example how to use the Metadata API.
409 /* packet functions */
413 * Allocate and read the payload of a packet and initialize its
414 * fields with default values.
416 * @param s associated IO context
418 * @param size desired payload size
419 * @return >0 (read size) if OK, AVERROR_xxx otherwise
421 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
425 * Read data and append it to the current content of the AVPacket.
426 * If pkt->size is 0 this is identical to av_get_packet.
427 * Note that this uses av_grow_packet and thus involves a realloc
428 * which is inefficient. Thus this function should only be used
429 * when there is no reasonable way to know (an upper bound of)
432 * @param s associated IO context
434 * @param size amount of data to read
435 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
436 * will not be lost even if an error occurs.
438 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
441 /*************************************************/
442 /* fractional numbers for exact pts handling */
445 * The exact value of the fractional number is: 'val + num / den'.
446 * num is assumed to be 0 <= num < den.
448 typedef struct AVFrac {
449 int64_t val, num, den;
453 /*************************************************/
454 /* input/output formats */
459 * This structure contains the data a format has to probe a file.
461 typedef struct AVProbeData {
462 const char *filename;
463 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
464 int buf_size; /**< Size of buf except extra allocated bytes */
465 const char *mime_type; /**< mime_type, when known. */
468 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
469 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
471 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
472 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type
473 #define AVPROBE_SCORE_MAX 100 ///< maximum score
475 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
477 /// Demuxer will use avio_open, no opened file should be provided by the caller.
478 #define AVFMT_NOFILE 0x0001
479 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
480 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
481 #if FF_API_LAVF_FMT_RAWPICTURE
482 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
483 raw picture data. @deprecated Not used anymore */
485 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
486 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
487 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
488 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
489 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
490 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
491 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
492 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
493 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
494 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
495 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
496 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
497 increasing timestamps, but they must
498 still be monotonic */
499 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
500 timestamps. If not set the timestamp
501 will be shifted in av_write_frame and
502 av_interleaved_write_frame so they
504 The user or muxer can override this through
505 AVFormatContext.avoid_negative_ts
508 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
511 * @addtogroup lavf_encoding
514 typedef struct AVOutputFormat {
517 * Descriptive name for the format, meant to be more human-readable
518 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
521 const char *long_name;
522 const char *mime_type;
523 const char *extensions; /**< comma-separated filename extensions */
525 enum AVCodecID audio_codec; /**< default audio codec */
526 enum AVCodecID video_codec; /**< default video codec */
527 enum AVCodecID subtitle_codec; /**< default subtitle codec */
529 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER,
530 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
531 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
532 * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
537 * List of supported codec_id-codec_tag pairs, ordered by "better
538 * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
540 const struct AVCodecTag * const *codec_tag;
543 const AVClass *priv_class; ///< AVClass for the private context
545 /*****************************************************************
546 * No fields below this line are part of the public API. They
547 * may not be used outside of libavformat and can be changed and
549 * New public fields should be added right above.
550 *****************************************************************
552 struct AVOutputFormat *next;
554 * size of private data so that it can be allocated in the wrapper
558 int (*write_header)(struct AVFormatContext *);
560 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
561 * pkt can be NULL in order to flush data buffered in the muxer.
562 * When flushing, return 0 if there still is more data to flush,
563 * or 1 if everything was flushed and there is no more buffered
566 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
567 int (*write_trailer)(struct AVFormatContext *);
569 * Currently only used to set pixel format if not YUV420P.
571 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
572 AVPacket *in, int flush);
574 * Test if the given codec can be stored in this container.
576 * @return 1 if the codec is supported, 0 if it is not.
577 * A negative number if unknown.
578 * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
580 int (*query_codec)(enum AVCodecID id, int std_compliance);
582 void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
583 int64_t *dts, int64_t *wall);
585 * Allows sending messages from application to device.
587 int (*control_message)(struct AVFormatContext *s, int type,
588 void *data, size_t data_size);
591 * Write an uncoded AVFrame.
593 * See av_write_uncoded_frame() for details.
595 * The library will free *frame afterwards, but the muxer can prevent it
596 * by setting the pointer to NULL.
598 int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
599 AVFrame **frame, unsigned flags);
601 * Returns device list with it properties.
602 * @see avdevice_list_devices() for more details.
604 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
606 * Initialize device capabilities submodule.
607 * @see avdevice_capabilities_create() for more details.
609 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
611 * Free device capabilities submodule.
612 * @see avdevice_capabilities_free() for more details.
614 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
615 enum AVCodecID data_codec; /**< default data codec */
617 * Initialize format. May allocate data here, and set any AVFormatContext or
618 * AVStream parameters that need to be set before packets are sent.
619 * This method must not write output.
621 * Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure
623 * Any allocations made here must be freed in deinit().
625 int (*init)(struct AVFormatContext *);
627 * Deinitialize format. If present, this is called whenever the muxer is being
628 * destroyed, regardless of whether or not the header has been written.
630 * If a trailer is being written, this is called after write_trailer().
632 * This is called if init() fails as well.
634 void (*deinit)(struct AVFormatContext *);
636 * Set up any necessary bitstream filtering and extract any extra data needed
637 * for the global header.
638 * Return 0 if more packets from this stream must be checked; 1 if not.
640 int (*check_bitstream)(struct AVFormatContext *, const AVPacket *pkt);
647 * @addtogroup lavf_decoding
650 typedef struct AVInputFormat {
652 * A comma separated list of short names for the format. New names
653 * may be appended with a minor bump.
658 * Descriptive name for the format, meant to be more human-readable
659 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
662 const char *long_name;
665 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
666 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
667 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
672 * If extensions are defined, then no probe is done. You should
673 * usually not use extension format guessing because it is not
676 const char *extensions;
678 const struct AVCodecTag * const *codec_tag;
680 const AVClass *priv_class; ///< AVClass for the private context
683 * Comma-separated list of mime types.
684 * It is used check for matching mime types while probing.
685 * @see av_probe_input_format2
687 const char *mime_type;
689 /*****************************************************************
690 * No fields below this line are part of the public API. They
691 * may not be used outside of libavformat and can be changed and
693 * New public fields should be added right above.
694 *****************************************************************
696 struct AVInputFormat *next;
699 * Raw demuxers store their codec ID here.
704 * Size of private data so that it can be allocated in the wrapper.
709 * Tell if a given file has a chance of being parsed as this format.
710 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
711 * big so you do not have to check for that unless you need more.
713 int (*read_probe)(AVProbeData *);
716 * Read the format header and initialize the AVFormatContext
717 * structure. Return 0 if OK. 'avformat_new_stream' should be
718 * called to create new streams.
720 int (*read_header)(struct AVFormatContext *);
723 * Read one packet and put it in 'pkt'. pts and flags are also
724 * set. 'avformat_new_stream' can be called only if the flag
725 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
726 * background thread).
727 * @return 0 on success, < 0 on error.
728 * When returning an error, pkt must not have been allocated
729 * or must be freed before returning
731 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
734 * Close the stream. The AVFormatContext and AVStreams are not
735 * freed by this function
737 int (*read_close)(struct AVFormatContext *);
740 * Seek to a given timestamp relative to the frames in
741 * stream component stream_index.
742 * @param stream_index Must not be -1.
743 * @param flags Selects which direction should be preferred if no exact
744 * match is available.
745 * @return >= 0 on success (but not necessarily the new offset)
747 int (*read_seek)(struct AVFormatContext *,
748 int stream_index, int64_t timestamp, int flags);
751 * Get the next timestamp in stream[stream_index].time_base units.
752 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
754 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
755 int64_t *pos, int64_t pos_limit);
758 * Start/resume playing - only meaningful if using a network-based format
761 int (*read_play)(struct AVFormatContext *);
764 * Pause playing - only meaningful if using a network-based format
767 int (*read_pause)(struct AVFormatContext *);
770 * Seek to timestamp ts.
771 * Seeking will be done so that the point from which all active streams
772 * can be presented successfully will be closest to ts and within min/max_ts.
773 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
775 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
778 * Returns device list with it properties.
779 * @see avdevice_list_devices() for more details.
781 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
784 * Initialize device capabilities submodule.
785 * @see avdevice_capabilities_create() for more details.
787 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
790 * Free device capabilities submodule.
791 * @see avdevice_capabilities_free() for more details.
793 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
799 enum AVStreamParseType {
801 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
802 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
803 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
804 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
805 AVSTREAM_PARSE_FULL_RAW=MKTAG(0,'R','A','W'), /**< full parsing and repack with timestamp and position generation by parser for raw
806 this assumes that each packet in the file contains no demuxer level headers and
807 just codec level data, otherwise position generation would fail */
810 typedef struct AVIndexEntry {
812 int64_t timestamp; /**<
813 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
814 * when seeking to this entry. That means preferable PTS on keyframe based formats.
815 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
818 #define AVINDEX_KEYFRAME 0x0001
819 #define AVINDEX_DISCARD_FRAME 0x0002 /**
820 * Flag is used to indicate which frame should be discarded after decoding.
823 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).
824 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
827 #define AV_DISPOSITION_DEFAULT 0x0001
828 #define AV_DISPOSITION_DUB 0x0002
829 #define AV_DISPOSITION_ORIGINAL 0x0004
830 #define AV_DISPOSITION_COMMENT 0x0008
831 #define AV_DISPOSITION_LYRICS 0x0010
832 #define AV_DISPOSITION_KARAOKE 0x0020
835 * Track should be used during playback by default.
836 * Useful for subtitle track that should be displayed
837 * even when user did not explicitly ask for subtitles.
839 #define AV_DISPOSITION_FORCED 0x0040
840 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
841 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
842 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
844 * The stream is stored in the file as an attached picture/"cover art" (e.g.
845 * APIC frame in ID3v2). The first (usually only) packet associated with it
846 * will be returned among the first few packets read from the file unless
847 * seeking takes place. It can also be accessed at any time in
848 * AVStream.attached_pic.
850 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
852 * The stream is sparse, and contains thumbnail images, often corresponding
853 * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
855 #define AV_DISPOSITION_TIMED_THUMBNAILS 0x0800
857 typedef struct AVStreamInternal AVStreamInternal;
860 * To specify text track kind (different from subtitles default).
862 #define AV_DISPOSITION_CAPTIONS 0x10000
863 #define AV_DISPOSITION_DESCRIPTIONS 0x20000
864 #define AV_DISPOSITION_METADATA 0x40000
867 * Options for behavior on timestamp wrap detection.
869 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
870 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
871 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
875 * New fields can be added to the end with minor version bumps.
876 * Removal, reordering and changes to existing fields require a major
878 * sizeof(AVStream) must not be used outside libav*.
880 typedef struct AVStream {
881 int index; /**< stream index in AVFormatContext */
883 * Format-specific stream ID.
884 * decoding: set by libavformat
885 * encoding: set by the user, replaced by libavformat if left unset
888 #if FF_API_LAVF_AVCTX
890 * @deprecated use the codecpar struct instead
893 AVCodecContext *codec;
899 * @deprecated this field is unused
906 * This is the fundamental unit of time (in seconds) in terms
907 * of which frame timestamps are represented.
909 * decoding: set by libavformat
910 * encoding: May be set by the caller before avformat_write_header() to
911 * provide a hint to the muxer about the desired timebase. In
912 * avformat_write_header(), the muxer will overwrite this field
913 * with the timebase that will actually be used for the timestamps
914 * written into the file (which may or may not be related to the
915 * user-provided one, depending on the format).
917 AVRational time_base;
920 * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
921 * Only set this if you are absolutely 100% sure that the value you set
922 * it to really is the pts of the first frame.
923 * This may be undefined (AV_NOPTS_VALUE).
924 * @note The ASF header does NOT contain a correct start_time the ASF
925 * demuxer must NOT set this.
930 * Decoding: duration of the stream, in stream time base.
931 * If a source file does not specify a duration, but does specify
932 * a bitrate, this value will be estimated from bitrate and file size.
934 * Encoding: May be set by the caller before avformat_write_header() to
935 * provide a hint to the muxer about the estimated duration.
939 int64_t nb_frames; ///< number of frames in this stream if known or 0
941 int disposition; /**< AV_DISPOSITION_* bit field */
943 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
946 * sample aspect ratio (0 if unknown)
947 * - encoding: Set by user.
948 * - decoding: Set by libavformat.
950 AVRational sample_aspect_ratio;
952 AVDictionary *metadata;
957 * - demuxing: May be set by libavformat when creating the stream or in
958 * avformat_find_stream_info().
959 * - muxing: May be set by the caller before avformat_write_header().
961 AVRational avg_frame_rate;
964 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
965 * will contain the attached picture.
967 * decoding: set by libavformat, must not be modified by the caller.
970 AVPacket attached_pic;
973 * An array of side data that applies to the whole stream (i.e. the
974 * container does not allow it to change between packets).
976 * There may be no overlap between the side data in this array and side data
977 * in the packets. I.e. a given side data is either exported by the muxer
978 * (demuxing) / set by the caller (muxing) in this array, then it never
979 * appears in the packets, or the side data is exported / sent through
980 * the packets (always in the first packet where the value becomes known or
981 * changes), then it does not appear in this array.
983 * - demuxing: Set by libavformat when the stream is created.
984 * - muxing: May be set by the caller before avformat_write_header().
986 * Freed by libavformat in avformat_free_context().
988 * @see av_format_inject_global_side_data()
990 AVPacketSideData *side_data;
992 * The number of elements in the AVStream.side_data array.
997 * Flags for the user to detect events happening on the stream. Flags must
998 * be cleared by the user once the event has been handled.
999 * A combination of AVSTREAM_EVENT_FLAG_*.
1002 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
1004 /*****************************************************************
1005 * All fields below this line are not part of the public API. They
1006 * may not be used outside of libavformat and can be changed and
1008 * New public fields should be added right above.
1009 *****************************************************************
1013 * Stream information used internally by avformat_find_stream_info()
1015 #define MAX_STD_TIMEBASES (30*12+30+3+6)
1018 int64_t duration_gcd;
1020 int64_t rfps_duration_sum;
1021 double (*duration_error)[2][MAX_STD_TIMEBASES];
1022 int64_t codec_info_duration;
1023 int64_t codec_info_duration_fields;
1026 * 0 -> decoder has not been searched for yet.
1027 * >0 -> decoder found
1028 * <0 -> decoder with codec_id == -found_decoder has not been found
1032 int64_t last_duration;
1035 * Those are used for average framerate estimation.
1037 int64_t fps_first_dts;
1038 int fps_first_dts_idx;
1039 int64_t fps_last_dts;
1040 int fps_last_dts_idx;
1044 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
1046 // Timestamp generation support:
1048 * Timestamp corresponding to the last dts sync point.
1050 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
1051 * a DTS is received from the underlying container. Otherwise set to
1052 * AV_NOPTS_VALUE by default.
1056 int64_t last_IP_pts;
1057 int last_IP_duration;
1060 * Number of packets to buffer for codec probing
1065 * Number of frames that have been demuxed during avformat_find_stream_info()
1067 int codec_info_nb_frames;
1069 /* av_read_frame() support */
1070 enum AVStreamParseType need_parsing;
1071 struct AVCodecParserContext *parser;
1074 * last packet in packet_buffer for this stream when muxing.
1076 struct AVPacketList *last_in_packet_buffer;
1077 AVProbeData probe_data;
1078 #define MAX_REORDER_DELAY 16
1079 int64_t pts_buffer[MAX_REORDER_DELAY+1];
1081 AVIndexEntry *index_entries; /**< Only used if the format does not
1082 support seeking natively. */
1083 int nb_index_entries;
1084 unsigned int index_entries_allocated_size;
1087 * Real base framerate of the stream.
1088 * This is the lowest framerate with which all timestamps can be
1089 * represented accurately (it is the least common multiple of all
1090 * framerates in the stream). Note, this value is just a guess!
1091 * For example, if the time base is 1/90000 and all frames have either
1092 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
1094 * Code outside avformat should access this field using:
1095 * av_stream_get/set_r_frame_rate(stream)
1097 AVRational r_frame_rate;
1101 * This is the MPEG-TS stream identifier +1
1104 int stream_identifier;
1106 int64_t interleaver_chunk_size;
1107 int64_t interleaver_chunk_duration;
1110 * stream probing state
1111 * -1 -> probing finished
1112 * 0 -> no probing requested
1113 * rest -> perform probing with request_probe being the minimum score to accept.
1114 * NOT PART OF PUBLIC API
1118 * Indicates that everything up to the next keyframe
1119 * should be discarded.
1121 int skip_to_keyframe;
1124 * Number of samples to skip at the start of the frame decoded from the next packet.
1129 * If not 0, the number of samples that should be skipped from the start of
1130 * the stream (the samples are removed from packets with pts==0, which also
1131 * assumes negative timestamps do not happen).
1132 * Intended for use with formats such as mp3 with ad-hoc gapless audio
1135 int64_t start_skip_samples;
1138 * If not 0, the first audio sample that should be discarded from the stream.
1139 * This is broken by design (needs global sample count), but can't be
1140 * avoided for broken by design formats such as mp3 with ad-hoc gapless
1143 int64_t first_discard_sample;
1146 * The sample after last sample that is intended to be discarded after
1147 * first_discard_sample. Works on frame boundaries only. Used to prevent
1148 * early EOF if the gapless info is broken (considered concatenated mp3s).
1150 int64_t last_discard_sample;
1153 * Number of internally decoded frames, used internally in libavformat, do not access
1154 * its lifetime differs from info which is why it is not in that structure.
1156 int nb_decoded_frames;
1159 * Timestamp offset added to timestamps before muxing
1160 * NOT PART OF PUBLIC API
1162 int64_t mux_ts_offset;
1165 * Internal data to check for wrapping of the time stamp
1167 int64_t pts_wrap_reference;
1170 * Options for behavior, when a wrap is detected.
1172 * Defined by AV_PTS_WRAP_ values.
1174 * If correction is enabled, there are two possibilities:
1175 * If the first time stamp is near the wrap point, the wrap offset
1176 * will be subtracted, which will create negative time stamps.
1177 * Otherwise the offset will be added.
1179 int pts_wrap_behavior;
1182 * Internal data to prevent doing update_initial_durations() twice
1184 int update_initial_durations_done;
1187 * Internal data to generate dts from pts
1189 int64_t pts_reorder_error[MAX_REORDER_DELAY+1];
1190 uint8_t pts_reorder_error_count[MAX_REORDER_DELAY+1];
1193 * Internal data to analyze DTS and detect faulty mpeg streams
1195 int64_t last_dts_for_order_check;
1196 uint8_t dts_ordered;
1197 uint8_t dts_misordered;
1200 * Internal data to inject global side data
1202 int inject_global_side_data;
1205 * String containing paris of key and values describing recommended encoder configuration.
1206 * Paris are separated by ','.
1207 * Keys are separated from values by '='.
1209 char *recommended_encoder_configuration;
1212 * display aspect ratio (0 if unknown)
1213 * - encoding: unused
1214 * - decoding: Set by libavformat to calculate sample_aspect_ratio internally
1216 AVRational display_aspect_ratio;
1218 struct FFFrac *priv_pts;
1221 * An opaque field for libavformat internal usage.
1222 * Must not be accessed in any way by callers.
1224 AVStreamInternal *internal;
1227 * Codec parameters associated with this stream. Allocated and freed by
1228 * libavformat in avformat_new_stream() and avformat_free_context()
1231 * - demuxing: filled by libavformat on stream creation or in
1232 * avformat_find_stream_info()
1233 * - muxing: filled by the caller before avformat_write_header()
1235 AVCodecParameters *codecpar;
1238 AVRational av_stream_get_r_frame_rate(const AVStream *s);
1239 void av_stream_set_r_frame_rate(AVStream *s, AVRational r);
1240 struct AVCodecParserContext *av_stream_get_parser(const AVStream *s);
1241 char* av_stream_get_recommended_encoder_configuration(const AVStream *s);
1242 void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration);
1245 * Returns the pts of the last muxed packet + its duration
1247 * the retuned value is undefined when used with a demuxer.
1249 int64_t av_stream_get_end_pts(const AVStream *st);
1251 #define AV_PROGRAM_RUNNING 1
1254 * New fields can be added to the end with minor version bumps.
1255 * Removal, reordering and changes to existing fields require a major
1257 * sizeof(AVProgram) must not be used outside libav*.
1259 typedef struct AVProgram {
1262 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1263 unsigned int *stream_index;
1264 unsigned int nb_stream_indexes;
1265 AVDictionary *metadata;
1271 /*****************************************************************
1272 * All fields below this line are not part of the public API. They
1273 * may not be used outside of libavformat and can be changed and
1275 * New public fields should be added right above.
1276 *****************************************************************
1281 int64_t pts_wrap_reference; ///< reference dts for wrap detection
1282 int pts_wrap_behavior; ///< behavior on wrap detection
1285 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1286 (streams are added dynamically) */
1288 typedef struct AVChapter {
1289 int id; ///< unique ID to identify the chapter
1290 AVRational time_base; ///< time base in which the start/end timestamps are specified
1291 int64_t start, end; ///< chapter start/end time in time_base units
1292 AVDictionary *metadata;
1297 * Callback used by devices to communicate with application.
1299 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1300 void *data, size_t data_size);
1302 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
1303 const AVIOInterruptCB *int_cb, AVDictionary **options);
1306 * The duration of a video can be estimated through various ways, and this enum can be used
1307 * to know how the duration was estimated.
1309 enum AVDurationEstimationMethod {
1310 AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1311 AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1312 AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1315 typedef struct AVFormatInternal AVFormatInternal;
1318 * Format I/O context.
1319 * New fields can be added to the end with minor version bumps.
1320 * Removal, reordering and changes to existing fields require a major
1322 * sizeof(AVFormatContext) must not be used outside libav*, use
1323 * avformat_alloc_context() to create an AVFormatContext.
1325 * Fields can be accessed through AVOptions (av_opt*),
1326 * the name string used matches the associated command line parameter name and
1327 * can be found in libavformat/options_table.h.
1328 * The AVOption/command line parameter names differ in some cases from the C
1329 * structure field names for historic reasons or brevity.
1331 typedef struct AVFormatContext {
1333 * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1334 * Exports (de)muxer private options if they exist.
1336 const AVClass *av_class;
1339 * The input container format.
1341 * Demuxing only, set by avformat_open_input().
1343 struct AVInputFormat *iformat;
1346 * The output container format.
1348 * Muxing only, must be set by the caller before avformat_write_header().
1350 struct AVOutputFormat *oformat;
1353 * Format private data. This is an AVOptions-enabled struct
1354 * if and only if iformat/oformat.priv_class is not NULL.
1356 * - muxing: set by avformat_write_header()
1357 * - demuxing: set by avformat_open_input()
1364 * - demuxing: either set by the user before avformat_open_input() (then
1365 * the user must close it manually) or set by avformat_open_input().
1366 * - muxing: set by the user before avformat_write_header(). The caller must
1367 * take care of closing / freeing the IO context.
1369 * Do NOT set this field if AVFMT_NOFILE flag is set in
1370 * iformat/oformat.flags. In such a case, the (de)muxer will handle
1371 * I/O in some other way and this field will be NULL.
1377 * Flags signalling stream properties. A combination of AVFMTCTX_*.
1378 * Set by libavformat.
1383 * Number of elements in AVFormatContext.streams.
1385 * Set by avformat_new_stream(), must not be modified by any other code.
1387 unsigned int nb_streams;
1389 * A list of all streams in the file. New streams are created with
1390 * avformat_new_stream().
1392 * - demuxing: streams are created by libavformat in avformat_open_input().
1393 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1394 * appear in av_read_frame().
1395 * - muxing: streams are created by the user before avformat_write_header().
1397 * Freed by libavformat in avformat_free_context().
1402 * input or output filename
1404 * - demuxing: set by avformat_open_input()
1405 * - muxing: may be set by the caller before avformat_write_header()
1407 char filename[1024];
1410 * Position of the first frame of the component, in
1411 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1412 * It is deduced from the AVStream values.
1414 * Demuxing only, set by libavformat.
1419 * Duration of the stream, in AV_TIME_BASE fractional
1420 * seconds. Only set this value if you know none of the individual stream
1421 * durations and also do not set any of them. This is deduced from the
1422 * AVStream values if not set.
1424 * Demuxing only, set by libavformat.
1429 * Total stream bitrate in bit/s, 0 if not
1430 * available. Never set it directly if the file_size and the
1431 * duration are known as FFmpeg can compute it automatically.
1435 unsigned int packet_size;
1439 * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1440 * Set by the user before avformat_open_input() / avformat_write_header().
1443 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1444 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1445 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1446 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1447 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1448 #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
1449 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1450 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1451 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1452 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1454 * When muxing, try to avoid writing any random/volatile data to the output.
1455 * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1457 * This flag is mainly intended for testing.
1459 #define AVFMT_FLAG_BITEXACT 0x0400
1460 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload
1461 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1462 #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)
1463 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Don't merge side data but keep it separate.
1464 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1465 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops.
1466 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Wait for packet data before writing a header, and add bitstream filters as requested by the muxer
1469 * Maximum size of the data read from input for determining
1470 * the input container format.
1471 * Demuxing only, set by the caller before avformat_open_input().
1476 * Maximum duration (in AV_TIME_BASE units) of the data read
1477 * from input in avformat_find_stream_info().
1478 * Demuxing only, set by the caller before avformat_find_stream_info().
1479 * Can be set to 0 to let avformat choose using a heuristic.
1481 int64_t max_analyze_duration;
1486 unsigned int nb_programs;
1487 AVProgram **programs;
1490 * Forced video codec_id.
1491 * Demuxing: Set by user.
1493 enum AVCodecID video_codec_id;
1496 * Forced audio codec_id.
1497 * Demuxing: Set by user.
1499 enum AVCodecID audio_codec_id;
1502 * Forced subtitle codec_id.
1503 * Demuxing: Set by user.
1505 enum AVCodecID subtitle_codec_id;
1508 * Maximum amount of memory in bytes to use for the index of each stream.
1509 * If the index exceeds this size, entries will be discarded as
1510 * needed to maintain a smaller size. This can lead to slower or less
1511 * accurate seeking (depends on demuxer).
1512 * Demuxers for which a full in-memory index is mandatory will ignore
1515 * - demuxing: set by user
1517 unsigned int max_index_size;
1520 * Maximum amount of memory in bytes to use for buffering frames
1521 * obtained from realtime capture devices.
1523 unsigned int max_picture_buffer;
1526 * Number of chapters in AVChapter array.
1527 * When muxing, chapters are normally written in the file header,
1528 * so nb_chapters should normally be initialized before write_header
1529 * is called. Some muxers (e.g. mov and mkv) can also write chapters
1530 * in the trailer. To write chapters in the trailer, nb_chapters
1531 * must be zero when write_header is called and non-zero when
1532 * write_trailer is called.
1533 * - muxing: set by user
1534 * - demuxing: set by libavformat
1536 unsigned int nb_chapters;
1537 AVChapter **chapters;
1540 * Metadata that applies to the whole file.
1542 * - demuxing: set by libavformat in avformat_open_input()
1543 * - muxing: may be set by the caller before avformat_write_header()
1545 * Freed by libavformat in avformat_free_context().
1547 AVDictionary *metadata;
1550 * Start time of the stream in real world time, in microseconds
1551 * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1552 * stream was captured at this real world time.
1553 * - muxing: Set by the caller before avformat_write_header(). If set to
1554 * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1556 * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1557 * the value may become known after some number of frames
1558 * have been received.
1560 int64_t start_time_realtime;
1563 * The number of frames used for determining the framerate in
1564 * avformat_find_stream_info().
1565 * Demuxing only, set by the caller before avformat_find_stream_info().
1570 * Error recognition; higher values will detect more errors but may
1571 * misdetect some more or less valid parts as errors.
1572 * Demuxing only, set by the caller before avformat_open_input().
1574 int error_recognition;
1577 * Custom interrupt callbacks for the I/O layer.
1579 * demuxing: set by the user before avformat_open_input().
1580 * muxing: set by the user before avformat_write_header()
1581 * (mainly useful for AVFMT_NOFILE formats). The callback
1582 * should also be passed to avio_open2() if it's used to
1585 AVIOInterruptCB interrupt_callback;
1588 * Flags to enable debugging.
1591 #define FF_FDEBUG_TS 0x0001
1594 * Maximum buffering duration for interleaving.
1596 * To ensure all the streams are interleaved correctly,
1597 * av_interleaved_write_frame() will wait until it has at least one packet
1598 * for each stream before actually writing any packets to the output file.
1599 * When some streams are "sparse" (i.e. there are large gaps between
1600 * successive packets), this can result in excessive buffering.
1602 * This field specifies the maximum difference between the timestamps of the
1603 * first and the last packet in the muxing queue, above which libavformat
1604 * will output a packet regardless of whether it has queued a packet for all
1607 * Muxing only, set by the caller before avformat_write_header().
1609 int64_t max_interleave_delta;
1612 * Allow non-standard and experimental extension
1613 * @see AVCodecContext.strict_std_compliance
1615 int strict_std_compliance;
1618 * Flags for the user to detect events happening on the file. Flags must
1619 * be cleared by the user once the event has been handled.
1620 * A combination of AVFMT_EVENT_FLAG_*.
1623 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
1626 * Maximum number of packets to read while waiting for the first timestamp.
1632 * Avoid negative timestamps during muxing.
1633 * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1634 * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use)
1635 * - muxing: Set by user
1636 * - demuxing: unused
1638 int avoid_negative_ts;
1639 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1640 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1641 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1644 * Transport stream id.
1645 * This will be moved into demuxer private options. Thus no API/ABI compatibility
1650 * Audio preload in microseconds.
1651 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1652 * - encoding: Set by user via AVOptions (NO direct access)
1653 * - decoding: unused
1658 * Max chunk time in microseconds.
1659 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1660 * - encoding: Set by user via AVOptions (NO direct access)
1661 * - decoding: unused
1663 int max_chunk_duration;
1666 * Max chunk size in bytes
1667 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1668 * - encoding: Set by user via AVOptions (NO direct access)
1669 * - decoding: unused
1674 * forces the use of wallclock timestamps as pts/dts of packets
1675 * This has undefined results in the presence of B frames.
1676 * - encoding: unused
1677 * - decoding: Set by user via AVOptions (NO direct access)
1679 int use_wallclock_as_timestamps;
1682 * avio flags, used to force AVIO_FLAG_DIRECT.
1683 * - encoding: unused
1684 * - decoding: Set by user via AVOptions (NO direct access)
1689 * The duration field can be estimated through various ways, and this field can be used
1690 * to know how the duration was estimated.
1691 * - encoding: unused
1692 * - decoding: Read by user via AVOptions (NO direct access)
1694 enum AVDurationEstimationMethod duration_estimation_method;
1697 * Skip initial bytes when opening stream
1698 * - encoding: unused
1699 * - decoding: Set by user via AVOptions (NO direct access)
1701 int64_t skip_initial_bytes;
1704 * Correct single timestamp overflows
1705 * - encoding: unused
1706 * - decoding: Set by user via AVOptions (NO direct access)
1708 unsigned int correct_ts_overflow;
1711 * Force seeking to any (also non key) frames.
1712 * - encoding: unused
1713 * - decoding: Set by user via AVOptions (NO direct access)
1718 * Flush the I/O context after each packet.
1719 * - encoding: Set by user via AVOptions (NO direct access)
1720 * - decoding: unused
1725 * format probing score.
1726 * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1728 * - encoding: unused
1729 * - decoding: set by avformat, read by user via av_format_get_probe_score() (NO direct access)
1734 * number of bytes to read maximally to identify format.
1735 * - encoding: unused
1736 * - decoding: set by user through AVOPtions (NO direct access)
1738 int format_probesize;
1741 * ',' separated list of allowed decoders.
1742 * If NULL then all are allowed
1743 * - encoding: unused
1744 * - decoding: set by user through AVOptions (NO direct access)
1746 char *codec_whitelist;
1749 * ',' separated list of allowed demuxers.
1750 * If NULL then all are allowed
1751 * - encoding: unused
1752 * - decoding: set by user through AVOptions (NO direct access)
1754 char *format_whitelist;
1757 * An opaque field for libavformat internal usage.
1758 * Must not be accessed in any way by callers.
1760 AVFormatInternal *internal;
1763 * IO repositioned flag.
1764 * This is set by avformat when the underlaying IO context read pointer
1765 * is repositioned, for example when doing byte based seeking.
1766 * Demuxers can use the flag to detect such changes.
1768 int io_repositioned;
1771 * Forced video codec.
1772 * This allows forcing a specific decoder, even when there are multiple with
1773 * the same codec_id.
1774 * Demuxing: Set by user via av_format_set_video_codec (NO direct access).
1776 AVCodec *video_codec;
1779 * Forced audio codec.
1780 * This allows forcing a specific decoder, even when there are multiple with
1781 * the same codec_id.
1782 * Demuxing: Set by user via av_format_set_audio_codec (NO direct access).
1784 AVCodec *audio_codec;
1787 * Forced subtitle codec.
1788 * This allows forcing a specific decoder, even when there are multiple with
1789 * the same codec_id.
1790 * Demuxing: Set by user via av_format_set_subtitle_codec (NO direct access).
1792 AVCodec *subtitle_codec;
1795 * Forced data codec.
1796 * This allows forcing a specific decoder, even when there are multiple with
1797 * the same codec_id.
1798 * Demuxing: Set by user via av_format_set_data_codec (NO direct access).
1800 AVCodec *data_codec;
1803 * Number of bytes to be written as padding in a metadata header.
1805 * Muxing: Set by user via av_format_set_metadata_header_padding.
1807 int metadata_header_padding;
1811 * This is a place for some private data of the user.
1816 * Callback used by devices to communicate with application.
1818 av_format_control_message control_message_cb;
1821 * Output timestamp offset, in microseconds.
1822 * Muxing: set by user via AVOptions (NO direct access)
1824 int64_t output_ts_offset;
1827 * dump format separator.
1828 * can be ", " or "\n " or anything else
1829 * Code outside libavformat should access this field using AVOptions
1830 * (NO direct access).
1831 * - muxing: Set by user.
1832 * - demuxing: Set by user.
1834 uint8_t *dump_separator;
1837 * Forced Data codec_id.
1838 * Demuxing: Set by user.
1840 enum AVCodecID data_codec_id;
1842 #if FF_API_OLD_OPEN_CALLBACKS
1844 * Called to open further IO contexts when needed for demuxing.
1846 * This can be set by the user application to perform security checks on
1847 * the URLs before opening them.
1848 * The function should behave like avio_open2(), AVFormatContext is provided
1849 * as contextual information and to reach AVFormatContext.opaque.
1851 * If NULL then some simple checks are used together with avio_open2().
1853 * Must not be accessed directly from outside avformat.
1854 * @See av_format_set_open_cb()
1856 * Demuxing: Set by user.
1858 * @deprecated Use io_open and io_close.
1860 attribute_deprecated
1861 int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options);
1865 * ',' separated list of allowed protocols.
1866 * - encoding: unused
1867 * - decoding: set by user through AVOptions (NO direct access)
1869 char *protocol_whitelist;
1872 * A callback for opening new IO streams.
1874 * Whenever a muxer or a demuxer needs to open an IO stream (typically from
1875 * avformat_open_input() for demuxers, but for certain formats can happen at
1876 * other times as well), it will call this callback to obtain an IO context.
1878 * @param s the format context
1879 * @param pb on success, the newly opened IO context should be returned here
1880 * @param url the url to open
1881 * @param flags a combination of AVIO_FLAG_*
1882 * @param options a dictionary of additional options, with the same
1883 * semantics as in avio_open2()
1884 * @return 0 on success, a negative AVERROR code on failure
1886 * @note Certain muxers and demuxers do nesting, i.e. they open one or more
1887 * additional internal format contexts. Thus the AVFormatContext pointer
1888 * passed to this callback may be different from the one facing the caller.
1889 * It will, however, have the same 'opaque' field.
1891 int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url,
1892 int flags, AVDictionary **options);
1895 * A callback for closing the streams opened with AVFormatContext.io_open().
1897 void (*io_close)(struct AVFormatContext *s, AVIOContext *pb);
1900 * ',' separated list of disallowed protocols.
1901 * - encoding: unused
1902 * - decoding: set by user through AVOptions (NO direct access)
1904 char *protocol_blacklist;
1907 * The maximum number of streams.
1908 * - encoding: unused
1909 * - decoding: set by user through AVOptions (NO direct access)
1914 int av_format_get_probe_score(const AVFormatContext *s);
1915 AVCodec * av_format_get_video_codec(const AVFormatContext *s);
1916 void av_format_set_video_codec(AVFormatContext *s, AVCodec *c);
1917 AVCodec * av_format_get_audio_codec(const AVFormatContext *s);
1918 void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c);
1919 AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s);
1920 void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c);
1921 AVCodec * av_format_get_data_codec(const AVFormatContext *s);
1922 void av_format_set_data_codec(AVFormatContext *s, AVCodec *c);
1923 int av_format_get_metadata_header_padding(const AVFormatContext *s);
1924 void av_format_set_metadata_header_padding(AVFormatContext *s, int c);
1925 void * av_format_get_opaque(const AVFormatContext *s);
1926 void av_format_set_opaque(AVFormatContext *s, void *opaque);
1927 av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s);
1928 void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback);
1929 #if FF_API_OLD_OPEN_CALLBACKS
1930 attribute_deprecated AVOpenCallback av_format_get_open_cb(const AVFormatContext *s);
1931 attribute_deprecated void av_format_set_open_cb(AVFormatContext *s, AVOpenCallback callback);
1935 * This function will cause global side data to be injected in the next packet
1936 * of each stream as well as after any subsequent seek.
1938 void av_format_inject_global_side_data(AVFormatContext *s);
1941 * Returns the method used to set ctx->duration.
1943 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1945 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
1947 typedef struct AVPacketList {
1949 struct AVPacketList *next;
1954 * @defgroup lavf_core Core functions
1957 * Functions for querying libavformat capabilities, allocating core structures,
1963 * Return the LIBAVFORMAT_VERSION_INT constant.
1965 unsigned avformat_version(void);
1968 * Return the libavformat build-time configuration.
1970 const char *avformat_configuration(void);
1973 * Return the libavformat license.
1975 const char *avformat_license(void);
1978 * Initialize libavformat and register all the muxers, demuxers and
1979 * protocols. If you do not call this function, then you can select
1980 * exactly which formats you want to support.
1982 * @see av_register_input_format()
1983 * @see av_register_output_format()
1985 void av_register_all(void);
1987 void av_register_input_format(AVInputFormat *format);
1988 void av_register_output_format(AVOutputFormat *format);
1991 * Do global initialization of network components. This is optional,
1992 * but recommended, since it avoids the overhead of implicitly
1993 * doing the setup for each session.
1995 * Calling this function will become mandatory if using network
1996 * protocols at some major version bump.
1998 int avformat_network_init(void);
2001 * Undo the initialization done by avformat_network_init.
2003 int avformat_network_deinit(void);
2006 * If f is NULL, returns the first registered input format,
2007 * if f is non-NULL, returns the next registered input format after f
2008 * or NULL if f is the last one.
2010 AVInputFormat *av_iformat_next(const AVInputFormat *f);
2013 * If f is NULL, returns the first registered output format,
2014 * if f is non-NULL, returns the next registered output format after f
2015 * or NULL if f is the last one.
2017 AVOutputFormat *av_oformat_next(const AVOutputFormat *f);
2020 * Allocate an AVFormatContext.
2021 * avformat_free_context() can be used to free the context and everything
2022 * allocated by the framework within it.
2024 AVFormatContext *avformat_alloc_context(void);
2027 * Free an AVFormatContext and all its streams.
2028 * @param s context to free
2030 void avformat_free_context(AVFormatContext *s);
2033 * Get the AVClass for AVFormatContext. It can be used in combination with
2034 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2036 * @see av_opt_find().
2038 const AVClass *avformat_get_class(void);
2041 * Add a new stream to a media file.
2043 * When demuxing, it is called by the demuxer in read_header(). If the
2044 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2045 * be called in read_packet().
2047 * When muxing, should be called by the user before avformat_write_header().
2049 * User is required to call avcodec_close() and avformat_free_context() to
2050 * clean up the allocation by avformat_new_stream().
2052 * @param s media file handle
2053 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
2054 * will be initialized to use this codec. This is needed for e.g. codec-specific
2055 * defaults to be set, so codec should be provided if it is known.
2057 * @return newly created stream or NULL on error.
2059 AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c);
2062 * Wrap an existing array as stream side data.
2065 * @param type side information type
2066 * @param data the side data array. It must be allocated with the av_malloc()
2067 * family of functions. The ownership of the data is transferred to
2069 * @param size side information size
2070 * @return zero on success, a negative AVERROR code on failure. On failure,
2071 * the stream is unchanged and the data remains owned by the caller.
2073 int av_stream_add_side_data(AVStream *st, enum AVPacketSideDataType type,
2074 uint8_t *data, size_t size);
2077 * Allocate new information from stream.
2079 * @param stream stream
2080 * @param type desired side information type
2081 * @param size side information size
2082 * @return pointer to fresh allocated data or NULL otherwise
2084 uint8_t *av_stream_new_side_data(AVStream *stream,
2085 enum AVPacketSideDataType type, int size);
2087 * Get side information from stream.
2089 * @param stream stream
2090 * @param type desired side information type
2091 * @param size pointer for side information size to store (optional)
2092 * @return pointer to data if present or NULL otherwise
2094 #if FF_API_NOCONST_GET_SIDE_DATA
2095 uint8_t *av_stream_get_side_data(AVStream *stream,
2096 enum AVPacketSideDataType type, int *size);
2098 uint8_t *av_stream_get_side_data(const AVStream *stream,
2099 enum AVPacketSideDataType type, int *size);
2102 AVProgram *av_new_program(AVFormatContext *s, int id);
2110 * Allocate an AVFormatContext for an output format.
2111 * avformat_free_context() can be used to free the context and
2112 * everything allocated by the framework within it.
2114 * @param *ctx is set to the created format context, or to NULL in
2116 * @param oformat format to use for allocating the context, if NULL
2117 * format_name and filename are used instead
2118 * @param format_name the name of output format to use for allocating the
2119 * context, if NULL filename is used instead
2120 * @param filename the name of the filename to use for allocating the
2121 * context, may be NULL
2122 * @return >= 0 in case of success, a negative AVERROR code in case of
2125 int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat,
2126 const char *format_name, const char *filename);
2129 * @addtogroup lavf_decoding
2134 * Find AVInputFormat based on the short name of the input format.
2136 AVInputFormat *av_find_input_format(const char *short_name);
2139 * Guess the file format.
2141 * @param pd data to be probed
2142 * @param is_opened Whether the file is already opened; determines whether
2143 * demuxers with or without AVFMT_NOFILE are probed.
2145 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
2148 * Guess the file format.
2150 * @param pd data to be probed
2151 * @param is_opened Whether the file is already opened; determines whether
2152 * demuxers with or without AVFMT_NOFILE are probed.
2153 * @param score_max A probe score larger that this is required to accept a
2154 * detection, the variable is set to the actual detection
2156 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2157 * to retry with a larger probe buffer.
2159 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
2162 * Guess the file format.
2164 * @param is_opened Whether the file is already opened; determines whether
2165 * demuxers with or without AVFMT_NOFILE are probed.
2166 * @param score_ret The score of the best detection.
2168 AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
2171 * Probe a bytestream to determine the input format. Each time a probe returns
2172 * with a score that is too low, the probe buffer size is increased and another
2173 * attempt is made. When the maximum probe size is reached, the input format
2174 * with the highest score is returned.
2176 * @param pb the bytestream to probe
2177 * @param fmt the input format is put here
2178 * @param url the url of the stream
2179 * @param logctx the log context
2180 * @param offset the offset within the bytestream to probe from
2181 * @param max_probe_size the maximum probe buffer size (zero for default)
2182 * @return the score in case of success, a negative value corresponding to an
2183 * the maximal score is AVPROBE_SCORE_MAX
2184 * AVERROR code otherwise
2186 int av_probe_input_buffer2(AVIOContext *pb, AVInputFormat **fmt,
2187 const char *url, void *logctx,
2188 unsigned int offset, unsigned int max_probe_size);
2191 * Like av_probe_input_buffer2() but returns 0 on success
2193 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
2194 const char *url, void *logctx,
2195 unsigned int offset, unsigned int max_probe_size);
2198 * Open an input stream and read the header. The codecs are not opened.
2199 * The stream must be closed with avformat_close_input().
2201 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
2202 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
2203 * function and written into ps.
2204 * Note that a user-supplied AVFormatContext will be freed on failure.
2205 * @param url URL of the stream to open.
2206 * @param fmt If non-NULL, this parameter forces a specific input format.
2207 * Otherwise the format is autodetected.
2208 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
2209 * On return this parameter will be destroyed and replaced with a dict containing
2210 * options that were not found. May be NULL.
2212 * @return 0 on success, a negative AVERROR on failure.
2214 * @note If you want to use custom IO, preallocate the format context and set its pb field.
2216 int avformat_open_input(AVFormatContext **ps, const char *url, AVInputFormat *fmt, AVDictionary **options);
2218 attribute_deprecated
2219 int av_demuxer_open(AVFormatContext *ic);
2222 * Read packets of a media file to get stream information. This
2223 * is useful for file formats with no headers such as MPEG. This
2224 * function also computes the real framerate in case of MPEG-2 repeat
2226 * The logical file position is not changed by this function;
2227 * examined packets may be buffered for later processing.
2229 * @param ic media file handle
2230 * @param options If non-NULL, an ic.nb_streams long array of pointers to
2231 * dictionaries, where i-th member contains options for
2232 * codec corresponding to i-th stream.
2233 * On return each dictionary will be filled with options that were not found.
2234 * @return >=0 if OK, AVERROR_xxx on error
2236 * @note this function isn't guaranteed to open all the codecs, so
2237 * options being non-empty at return is a perfectly normal behavior.
2239 * @todo Let the user decide somehow what information is needed so that
2240 * we do not waste time getting stuff the user does not need.
2242 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
2245 * Find the programs which belong to a given stream.
2247 * @param ic media file handle
2248 * @param last the last found program, the search will start after this
2249 * program, or from the beginning if it is NULL
2250 * @param s stream index
2251 * @return the next program which belongs to s, NULL if no program is found or
2252 * the last program is not among the programs of ic.
2254 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s);
2256 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
2259 * Find the "best" stream in the file.
2260 * The best stream is determined according to various heuristics as the most
2261 * likely to be what the user expects.
2262 * If the decoder parameter is non-NULL, av_find_best_stream will find the
2263 * default decoder for the stream's codec; streams for which no decoder can
2264 * be found are ignored.
2266 * @param ic media file handle
2267 * @param type stream type: video, audio, subtitles, etc.
2268 * @param wanted_stream_nb user-requested stream number,
2269 * or -1 for automatic selection
2270 * @param related_stream try to find a stream related (eg. in the same
2271 * program) to this one, or -1 if none
2272 * @param decoder_ret if non-NULL, returns the decoder for the
2274 * @param flags flags; none are currently defined
2275 * @return the non-negative stream number in case of success,
2276 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2278 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2279 * @note If av_find_best_stream returns successfully and decoder_ret is not
2280 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2282 int av_find_best_stream(AVFormatContext *ic,
2283 enum AVMediaType type,
2284 int wanted_stream_nb,
2286 AVCodec **decoder_ret,
2290 * Return the next frame of a stream.
2291 * This function returns what is stored in the file, and does not validate
2292 * that what is there are valid frames for the decoder. It will split what is
2293 * stored in the file into frames and return one for each call. It will not
2294 * omit invalid data between valid frames so as to give the decoder the maximum
2295 * information possible for decoding.
2297 * If pkt->buf is NULL, then the packet is valid until the next
2298 * av_read_frame() or until avformat_close_input(). Otherwise the packet
2299 * is valid indefinitely. In both cases the packet must be freed with
2300 * av_packet_unref when it is no longer needed. For video, the packet contains
2301 * exactly one frame. For audio, it contains an integer number of frames if each
2302 * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
2303 * have a variable size (e.g. MPEG audio), then it contains one frame.
2305 * pkt->pts, pkt->dts and pkt->duration are always set to correct
2306 * values in AVStream.time_base units (and guessed if the format cannot
2307 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2308 * has B-frames, so it is better to rely on pkt->dts if you do not
2309 * decompress the payload.
2311 * @return 0 if OK, < 0 on error or end of file
2313 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
2316 * Seek to the keyframe at timestamp.
2317 * 'timestamp' in 'stream_index'.
2319 * @param s media file handle
2320 * @param stream_index If stream_index is (-1), a default
2321 * stream is selected, and timestamp is automatically converted
2322 * from AV_TIME_BASE units to the stream specific time_base.
2323 * @param timestamp Timestamp in AVStream.time_base units
2324 * or, if no stream is specified, in AV_TIME_BASE units.
2325 * @param flags flags which select direction and seeking mode
2326 * @return >= 0 on success
2328 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2332 * Seek to timestamp ts.
2333 * Seeking will be done so that the point from which all active streams
2334 * can be presented successfully will be closest to ts and within min/max_ts.
2335 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2337 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2338 * are the file position (this may not be supported by all demuxers).
2339 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2340 * in the stream with stream_index (this may not be supported by all demuxers).
2341 * Otherwise all timestamps are in units of the stream selected by stream_index
2342 * or if stream_index is -1, in AV_TIME_BASE units.
2343 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2344 * keyframes (this may not be supported by all demuxers).
2345 * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2347 * @param s media file handle
2348 * @param stream_index index of the stream which is used as time base reference
2349 * @param min_ts smallest acceptable timestamp
2350 * @param ts target timestamp
2351 * @param max_ts largest acceptable timestamp
2352 * @param flags flags
2353 * @return >=0 on success, error code otherwise
2355 * @note This is part of the new seek API which is still under construction.
2356 * Thus do not use this yet. It may change at any time, do not expect
2357 * ABI compatibility yet!
2359 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2362 * Discard all internally buffered data. This can be useful when dealing with
2363 * discontinuities in the byte stream. Generally works only with formats that
2364 * can resync. This includes headerless formats like MPEG-TS/TS but should also
2365 * work with NUT, Ogg and in a limited way AVI for example.
2367 * The set of streams, the detected duration, stream parameters and codecs do
2368 * not change when calling this function. If you want a complete reset, it's
2369 * better to open a new AVFormatContext.
2371 * This does not flush the AVIOContext (s->pb). If necessary, call
2372 * avio_flush(s->pb) before calling this function.
2374 * @param s media file handle
2375 * @return >=0 on success, error code otherwise
2377 int avformat_flush(AVFormatContext *s);
2380 * Start playing a network-based stream (e.g. RTSP stream) at the
2383 int av_read_play(AVFormatContext *s);
2386 * Pause a network-based stream (e.g. RTSP stream).
2388 * Use av_read_play() to resume it.
2390 int av_read_pause(AVFormatContext *s);
2393 * Close an opened input AVFormatContext. Free it and all its contents
2394 * and set *s to NULL.
2396 void avformat_close_input(AVFormatContext **s);
2401 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2402 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2403 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2404 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2407 * @addtogroup lavf_encoding
2411 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header
2412 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output
2415 * Allocate the stream private data and write the stream header to
2416 * an output media file.
2418 * @param s Media file handle, must be allocated with avformat_alloc_context().
2419 * Its oformat field must be set to the desired output format;
2420 * Its pb field must be set to an already opened AVIOContext.
2421 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2422 * On return this parameter will be destroyed and replaced with a dict containing
2423 * options that were not found. May be NULL.
2425 * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init,
2426 * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init,
2427 * negative AVERROR on failure.
2429 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2431 av_warn_unused_result
2432 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
2435 * Allocate the stream private data and initialize the codec, but do not write the header.
2436 * May optionally be used before avformat_write_header to initialize stream parameters
2437 * before actually writing the header.
2438 * If using this function, do not pass the same options to avformat_write_header.
2440 * @param s Media file handle, must be allocated with avformat_alloc_context().
2441 * Its oformat field must be set to the desired output format;
2442 * Its pb field must be set to an already opened AVIOContext.
2443 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2444 * On return this parameter will be destroyed and replaced with a dict containing
2445 * options that were not found. May be NULL.
2447 * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec requires avformat_write_header to fully initialize,
2448 * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec has been fully initialized,
2449 * negative AVERROR on failure.
2451 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2453 av_warn_unused_result
2454 int avformat_init_output(AVFormatContext *s, AVDictionary **options);
2457 * Write a packet to an output media file.
2459 * This function passes the packet directly to the muxer, without any buffering
2460 * or reordering. The caller is responsible for correctly interleaving the
2461 * packets if the format requires it. Callers that want libavformat to handle
2462 * the interleaving should call av_interleaved_write_frame() instead of this
2465 * @param s media file handle
2466 * @param pkt The packet containing the data to be written. Note that unlike
2467 * av_interleaved_write_frame(), this function does not take
2468 * ownership of the packet passed to it (though some muxers may make
2469 * an internal reference to the input packet).
2471 * This parameter can be NULL (at any time, not just at the end), in
2472 * order to immediately flush data buffered within the muxer, for
2473 * muxers that buffer up data internally before writing it to the
2476 * Packet's @ref AVPacket.stream_index "stream_index" field must be
2477 * set to the index of the corresponding stream in @ref
2478 * AVFormatContext.streams "s->streams".
2480 * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2481 * must be set to correct values in the stream's timebase (unless the
2482 * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2483 * they can be set to AV_NOPTS_VALUE).
2484 * The dts for subsequent packets passed to this function must be strictly
2485 * increasing when compared in their respective timebases (unless the
2486 * output format is flagged with the AVFMT_TS_NONSTRICT, then they
2487 * merely have to be nondecreasing). @ref AVPacket.duration
2488 * "duration") should also be set if known.
2489 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2491 * @see av_interleaved_write_frame()
2493 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
2496 * Write a packet to an output media file ensuring correct interleaving.
2498 * This function will buffer the packets internally as needed to make sure the
2499 * packets in the output file are properly interleaved in the order of
2500 * increasing dts. Callers doing their own interleaving should call
2501 * av_write_frame() instead of this function.
2503 * Using this function instead of av_write_frame() can give muxers advance
2504 * knowledge of future packets, improving e.g. the behaviour of the mp4
2505 * muxer for VFR content in fragmenting mode.
2507 * @param s media file handle
2508 * @param pkt The packet containing the data to be written.
2510 * If the packet is reference-counted, this function will take
2511 * ownership of this reference and unreference it later when it sees
2513 * The caller must not access the data through this reference after
2514 * this function returns. If the packet is not reference-counted,
2515 * libavformat will make a copy.
2517 * This parameter can be NULL (at any time, not just at the end), to
2518 * flush the interleaving queues.
2520 * Packet's @ref AVPacket.stream_index "stream_index" field must be
2521 * set to the index of the corresponding stream in @ref
2522 * AVFormatContext.streams "s->streams".
2524 * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2525 * must be set to correct values in the stream's timebase (unless the
2526 * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2527 * they can be set to AV_NOPTS_VALUE).
2528 * The dts for subsequent packets in one stream must be strictly
2529 * increasing (unless the output format is flagged with the
2530 * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2531 * @ref AVPacket.duration "duration") should also be set if known.
2533 * @return 0 on success, a negative AVERROR on error. Libavformat will always
2534 * take care of freeing the packet, even if this function fails.
2536 * @see av_write_frame(), AVFormatContext.max_interleave_delta
2538 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
2541 * Write an uncoded frame to an output media file.
2543 * The frame must be correctly interleaved according to the container
2544 * specification; if not, then av_interleaved_write_frame() must be used.
2546 * See av_interleaved_write_frame() for details.
2548 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2552 * Write an uncoded frame to an output media file.
2554 * If the muxer supports it, this function makes it possible to write an AVFrame
2555 * structure directly, without encoding it into a packet.
2556 * It is mostly useful for devices and similar special muxers that use raw
2557 * video or PCM data and will not serialize it into a byte stream.
2559 * To test whether it is possible to use it with a given muxer and stream,
2560 * use av_write_uncoded_frame_query().
2562 * The caller gives up ownership of the frame and must not access it
2565 * @return >=0 for success, a negative code on error
2567 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
2571 * Test whether a muxer supports uncoded frame.
2573 * @return >=0 if an uncoded frame can be written to that muxer and stream,
2576 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2579 * Write the stream trailer to an output media file and free the
2580 * file private data.
2582 * May only be called after a successful call to avformat_write_header.
2584 * @param s media file handle
2585 * @return 0 if OK, AVERROR_xxx on error
2587 int av_write_trailer(AVFormatContext *s);
2590 * Return the output format in the list of registered output formats
2591 * which best matches the provided parameters, or return NULL if
2592 * there is no match.
2594 * @param short_name if non-NULL checks if short_name matches with the
2595 * names of the registered formats
2596 * @param filename if non-NULL checks if filename terminates with the
2597 * extensions of the registered formats
2598 * @param mime_type if non-NULL checks if mime_type matches with the
2599 * MIME type of the registered formats
2601 AVOutputFormat *av_guess_format(const char *short_name,
2602 const char *filename,
2603 const char *mime_type);
2606 * Guess the codec ID based upon muxer and filename.
2608 enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
2609 const char *filename, const char *mime_type,
2610 enum AVMediaType type);
2613 * Get timing information for the data currently output.
2614 * The exact meaning of "currently output" depends on the format.
2615 * It is mostly relevant for devices that have an internal buffer and/or
2616 * work in real time.
2617 * @param s media file handle
2618 * @param stream stream in the media file
2619 * @param[out] dts DTS of the last packet output for the stream, in stream
2621 * @param[out] wall absolute time when that packet whas output,
2623 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
2624 * Note: some formats or devices may not allow to measure dts and wall
2627 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2628 int64_t *dts, int64_t *wall);
2637 * @defgroup lavf_misc Utility functions
2641 * Miscellaneous utility functions related to both muxing and demuxing
2646 * Send a nice hexadecimal dump of a buffer to the specified file stream.
2648 * @param f The file stream pointer where the dump should be sent to.
2650 * @param size buffer size
2652 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2654 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2657 * Send a nice hexadecimal dump of a buffer to the log.
2659 * @param avcl A pointer to an arbitrary struct of which the first field is a
2660 * pointer to an AVClass struct.
2661 * @param level The importance level of the message, lower values signifying
2662 * higher importance.
2664 * @param size buffer size
2666 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2668 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2671 * Send a nice dump of a packet to the specified file stream.
2673 * @param f The file stream pointer where the dump should be sent to.
2674 * @param pkt packet to dump
2675 * @param dump_payload True if the payload must be displayed, too.
2676 * @param st AVStream that the packet belongs to
2678 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2682 * Send a nice dump of a packet to the log.
2684 * @param avcl A pointer to an arbitrary struct of which the first field is a
2685 * pointer to an AVClass struct.
2686 * @param level The importance level of the message, lower values signifying
2687 * higher importance.
2688 * @param pkt packet to dump
2689 * @param dump_payload True if the payload must be displayed, too.
2690 * @param st AVStream that the packet belongs to
2692 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2693 const AVStream *st);
2696 * Get the AVCodecID for the given codec tag tag.
2697 * If no codec id is found returns AV_CODEC_ID_NONE.
2699 * @param tags list of supported codec_id-codec_tag pairs, as stored
2700 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2701 * @param tag codec tag to match to a codec ID
2703 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2706 * Get the codec tag for the given codec id id.
2707 * If no codec tag is found returns 0.
2709 * @param tags list of supported codec_id-codec_tag pairs, as stored
2710 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2711 * @param id codec ID to match to a codec tag
2713 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2716 * Get the codec tag for the given codec id.
2718 * @param tags list of supported codec_id - codec_tag pairs, as stored
2719 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2720 * @param id codec id that should be searched for in the list
2721 * @param tag A pointer to the found tag
2722 * @return 0 if id was not found in tags, > 0 if it was found
2724 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2727 int av_find_default_stream_index(AVFormatContext *s);
2730 * Get the index for a specific timestamp.
2732 * @param st stream that the timestamp belongs to
2733 * @param timestamp timestamp to retrieve the index for
2734 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2735 * to the timestamp which is <= the requested one, if backward
2736 * is 0, then it will be >=
2737 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2738 * @return < 0 if no such timestamp could be found
2740 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2743 * Add an index entry into a sorted list. Update the entry if the list
2744 * already contains it.
2746 * @param timestamp timestamp in the time base of the given stream
2748 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2749 int size, int distance, int flags);
2753 * Split a URL string into components.
2755 * The pointers to buffers for storing individual components may be null,
2756 * in order to ignore that component. Buffers for components not found are
2757 * set to empty strings. If the port is not found, it is set to a negative
2760 * @param proto the buffer for the protocol
2761 * @param proto_size the size of the proto buffer
2762 * @param authorization the buffer for the authorization
2763 * @param authorization_size the size of the authorization buffer
2764 * @param hostname the buffer for the host name
2765 * @param hostname_size the size of the hostname buffer
2766 * @param port_ptr a pointer to store the port number in
2767 * @param path the buffer for the path
2768 * @param path_size the size of the path buffer
2769 * @param url the URL to split
2771 void av_url_split(char *proto, int proto_size,
2772 char *authorization, int authorization_size,
2773 char *hostname, int hostname_size,
2775 char *path, int path_size,
2780 * Print detailed information about the input or output format, such as
2781 * duration, bitrate, streams, container, programs, metadata, side data,
2782 * codec and time base.
2784 * @param ic the context to analyze
2785 * @param index index of the stream to dump information about
2786 * @param url the URL to print, such as source or destination file
2787 * @param is_output Select whether the specified context is an input(0) or output(1)
2789 void av_dump_format(AVFormatContext *ic,
2795 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d
2798 * Return in 'buf' the path with '%d' replaced by a number.
2800 * Also handles the '%0nd' format where 'n' is the total number
2801 * of digits and '%%'.
2803 * @param buf destination buffer
2804 * @param buf_size destination buffer size
2805 * @param path numbered sequence string
2806 * @param number frame number
2807 * @param flags AV_FRAME_FILENAME_FLAGS_*
2808 * @return 0 if OK, -1 on format error
2810 int av_get_frame_filename2(char *buf, int buf_size,
2811 const char *path, int number, int flags);
2813 int av_get_frame_filename(char *buf, int buf_size,
2814 const char *path, int number);
2817 * Check whether filename actually is a numbered sequence generator.
2819 * @param filename possible numbered sequence string
2820 * @return 1 if a valid numbered sequence string, 0 otherwise
2822 int av_filename_number_test(const char *filename);
2825 * Generate an SDP for an RTP session.
2827 * Note, this overwrites the id values of AVStreams in the muxer contexts
2828 * for getting unique dynamic payload types.
2830 * @param ac array of AVFormatContexts describing the RTP streams. If the
2831 * array is composed by only one context, such context can contain
2832 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2833 * all the contexts in the array (an AVCodecContext per RTP stream)
2834 * must contain only one AVStream.
2835 * @param n_files number of AVCodecContexts contained in ac
2836 * @param buf buffer where the SDP will be stored (must be allocated by
2838 * @param size the size of the buffer
2839 * @return 0 if OK, AVERROR_xxx on error
2841 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2844 * Return a positive value if the given filename has one of the given
2845 * extensions, 0 otherwise.
2847 * @param filename file name to check against the given extensions
2848 * @param extensions a comma-separated list of filename extensions
2850 int av_match_ext(const char *filename, const char *extensions);
2853 * Test if the given container can store a codec.
2855 * @param ofmt container to check for compatibility
2856 * @param codec_id codec to potentially store in container
2857 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2859 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2860 * A negative number if this information is not available.
2862 int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id,
2863 int std_compliance);
2866 * @defgroup riff_fourcc RIFF FourCCs
2868 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2869 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2872 * uint32_t tag = MKTAG('H', '2', '6', '4');
2873 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2874 * enum AVCodecID id = av_codec_get_id(table, tag);
2878 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2880 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2882 * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2884 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2886 * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2888 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2890 * @return the table mapping MOV FourCCs for audio to AVCodecID.
2892 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2899 * Guess the sample aspect ratio of a frame, based on both the stream and the
2900 * frame aspect ratio.
2902 * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2903 * is set by the demuxer, these two may not be equal. This function tries to
2904 * return the value that you should use if you would like to display the frame.
2906 * Basic logic is to use the stream aspect ratio if it is set to something sane
2907 * otherwise use the frame aspect ratio. This way a container setting, which is
2908 * usually easy to modify can override the coded value in the frames.
2910 * @param format the format context which the stream is part of
2911 * @param stream the stream which the frame is part of
2912 * @param frame the frame with the aspect ratio to be determined
2913 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2915 AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame);
2918 * Guess the frame rate, based on both the container and codec information.
2920 * @param ctx the format context which the stream is part of
2921 * @param stream the stream which the frame is part of
2922 * @param frame the frame for which the frame rate should be determined, may be NULL
2923 * @return the guessed (valid) frame rate, 0/1 if no idea
2925 AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame);
2928 * Check if the stream st contained in s is matched by the stream specifier
2931 * See the "stream specifiers" chapter in the documentation for the syntax
2934 * @return >0 if st is matched by spec;
2935 * 0 if st is not matched by spec;
2936 * AVERROR code if spec is invalid
2938 * @note A stream specifier can match several streams in the format.
2940 int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st,
2943 int avformat_queue_attached_pictures(AVFormatContext *s);
2946 * Apply a list of bitstream filters to a packet.
2948 * @param codec AVCodecContext, usually from an AVStream
2949 * @param pkt the packet to apply filters to. If, on success, the returned
2950 * packet has size == 0 and side_data_elems == 0, it indicates that
2951 * the packet should be dropped
2952 * @param bsfc a NULL-terminated list of filters to apply
2953 * @return >=0 on success;
2954 * AVERROR code on failure
2957 attribute_deprecated
2958 int av_apply_bitstream_filters(AVCodecContext *codec, AVPacket *pkt,
2959 AVBitStreamFilterContext *bsfc);
2962 enum AVTimebaseSource {
2963 AVFMT_TBCF_AUTO = -1,
2966 #if FF_API_R_FRAME_RATE
2967 AVFMT_TBCF_R_FRAMERATE,
2972 * Transfer internal timing information from one stream to another.
2974 * This function is useful when doing stream copy.
2976 * @param ofmt target output format for ost
2977 * @param ost output stream which needs timings copy and adjustments
2978 * @param ist reference input stream to copy timings from
2979 * @param copy_tb define from where the stream codec timebase needs to be imported
2981 int avformat_transfer_internal_stream_timing_info(const AVOutputFormat *ofmt,
2982 AVStream *ost, const AVStream *ist,
2983 enum AVTimebaseSource copy_tb);
2986 * Get the internal codec timebase from a stream.
2988 * @param st input stream to extract the timebase from
2990 AVRational av_stream_get_codec_timebase(const AVStream *st);
2996 #endif /* AVFORMAT_AVFORMAT_H */