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 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.
81 * @defgroup lavf_decoding Demuxing
83 * Demuxers read a media file and split it into chunks of data (@em packets). A
84 * @ref AVPacket "packet" contains one or more encoded frames which belongs to a
85 * single elementary stream. In the lavf API this process is represented by the
86 * avformat_open_input() function for opening a file, av_read_frame() for
87 * reading a single packet and finally avformat_close_input(), which does the
90 * @section lavf_decoding_open Opening a media file
91 * The minimum information required to open a file is its URL or filename, which
92 * is passed to avformat_open_input(), as in the following code:
94 * const char *url = "in.mp3";
95 * AVFormatContext *s = NULL;
96 * int ret = avformat_open_input(&s, url, NULL, NULL);
100 * The above code attempts to allocate an AVFormatContext, open the
101 * specified file (autodetecting the format) and read the header, exporting the
102 * information stored there into s. Some formats do not have a header or do not
103 * store enough information there, so it is recommended that you call the
104 * avformat_find_stream_info() function which tries to read and decode a few
105 * frames to find missing information.
107 * In some cases you might want to preallocate an AVFormatContext yourself with
108 * avformat_alloc_context() and do some tweaking on it before passing it to
109 * avformat_open_input(). One such case is when you want to use custom functions
110 * for reading input data instead of lavf internal I/O layer.
111 * To do that, create your own AVIOContext with avio_alloc_context(), passing
112 * your reading callbacks to it. Then set the @em pb field of your
113 * AVFormatContext to newly created AVIOContext.
115 * Since the format of the opened file is in general not known until after
116 * avformat_open_input() has returned, it is not possible to set demuxer private
117 * options on a preallocated context. Instead, the options should be passed to
118 * avformat_open_input() wrapped in an AVDictionary:
120 * AVDictionary *options = NULL;
121 * av_dict_set(&options, "video_size", "640x480", 0);
122 * av_dict_set(&options, "pixel_format", "rgb24", 0);
124 * if (avformat_open_input(&s, url, NULL, &options) < 0)
126 * av_dict_free(&options);
128 * This code passes the private options 'video_size' and 'pixel_format' to the
129 * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it
130 * cannot know how to interpret raw video data otherwise. If the format turns
131 * out to be something different than raw video, those options will not be
132 * recognized by the demuxer and therefore will not be applied. Such unrecognized
133 * options are then returned in the options dictionary (recognized options are
134 * consumed). The calling program can handle such unrecognized options as it
137 * AVDictionaryEntry *e;
138 * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
139 * fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key);
144 * After you have finished reading the file, you must close it with
145 * avformat_close_input(). It will free everything associated with the file.
147 * @section lavf_decoding_read Reading from an opened file
148 * Reading data from an opened AVFormatContext is done by repeatedly calling
149 * av_read_frame() on it. Each call, if successful, will return an AVPacket
150 * containing encoded data for one AVStream, identified by
151 * AVPacket.stream_index. This packet may be passed straight into the libavcodec
152 * decoding functions avcodec_decode_video2(), avcodec_decode_audio4() or
153 * avcodec_decode_subtitle2() if the caller wishes to decode the data.
155 * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be
156 * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for
157 * pts/dts, 0 for duration) if the stream does not provide them. The timing
158 * information will be in AVStream.time_base units, i.e. it has to be
159 * multiplied by the timebase to convert them to seconds.
161 * If AVPacket.buf is set on the returned packet, then the packet is
162 * allocated dynamically and the user may keep it indefinitely.
163 * Otherwise, if AVPacket.buf is NULL, the packet data is backed by a
164 * static storage somewhere inside the demuxer and the packet is only valid
165 * until the next av_read_frame() call or closing the file. If the caller
166 * requires a longer lifetime, av_dup_packet() will make an av_malloc()ed copy
168 * In both cases, the packet must be freed with av_free_packet() when it is no
171 * @section lavf_decoding_seek Seeking
174 * @defgroup lavf_encoding Muxing
176 * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write
177 * it into files or other output bytestreams in the specified container format.
179 * The main API functions for muxing are avformat_write_header() for writing the
180 * file header, av_write_frame() / av_interleaved_write_frame() for writing the
181 * packets and av_write_trailer() for finalizing the file.
183 * At the beginning of the muxing process, the caller must first call
184 * avformat_alloc_context() to create a muxing context. The caller then sets up
185 * the muxer by filling the various fields in this context:
187 * - The @ref AVFormatContext.oformat "oformat" field must be set to select the
188 * muxer that will be used.
189 * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb
190 * "pb" field must be set to an opened IO context, either returned from
191 * avio_open2() or a custom one.
192 * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must
193 * be created with the avformat_new_stream() function. The caller should fill
194 * the @ref AVStream.codec "stream codec context" information, such as the
195 * codec @ref AVCodecContext.codec_type "type", @ref AVCodecContext.codec_id
196 * "id" and other parameters (e.g. width / height, the pixel or sample format,
197 * etc.) as known. The @ref AVStream.time_base "stream timebase" should
198 * be set to the timebase that the caller desires to use for this stream (note
199 * that the timebase actually used by the muxer can be different, as will be
201 * - It is advised to manually initialize only the relevant fields in
202 * AVCodecContext, rather than using @ref avcodec_copy_context() during
203 * remuxing: there is no guarantee that the codec context values remain valid
204 * for both input and output format contexts.
205 * - The caller may fill in additional information, such as @ref
206 * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream"
207 * metadata, @ref AVFormatContext.chapters "chapters", @ref
208 * AVFormatContext.programs "programs", etc. as described in the
209 * AVFormatContext documentation. Whether such information will actually be
210 * stored in the output depends on what the container format and the muxer
213 * When the muxing context is fully set up, the caller must call
214 * avformat_write_header() to initialize the muxer internals and write the file
215 * header. Whether anything actually is written to the IO context at this step
216 * depends on the muxer, but this function must always be called. Any muxer
217 * private options must be passed in the options parameter to this function.
219 * The data is then sent to the muxer by repeatedly calling av_write_frame() or
220 * av_interleaved_write_frame() (consult those functions' documentation for
221 * discussion on the difference between them; only one of them may be used with
222 * a single muxing context, they should not be mixed). Do note that the timing
223 * information on the packets sent to the muxer must be in the corresponding
224 * AVStream's timebase. That timebase is set by the muxer (in the
225 * avformat_write_header() step) and may be different from the timebase
226 * requested by the caller.
228 * Once all the data has been written, the caller must call av_write_trailer()
229 * to flush any buffered packets and finalize the output file, then close the IO
230 * context (if any) and finally free the muxing context with
231 * avformat_free_context().
234 * @defgroup lavf_io I/O Read/Write
236 * @section lavf_io_dirlist Directory listing
237 * The directory listing API makes it possible to list files on remote servers.
239 * Some of possible use cases:
240 * - an "open file" dialog to choose files from a remote location,
241 * - a recursive media finder providing a player with an ability to play all
242 * files from a given directory.
244 * @subsection lavf_io_dirlist_open Opening a directory
245 * At first, a directory needs to be opened by calling avio_open_dir()
246 * supplied with a URL and, optionally, ::AVDictionary containing
247 * protocol-specific parameters. The function returns zero or positive
248 * integer and allocates AVIODirContext on success.
251 * AVIODirContext *ctx = NULL;
252 * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) {
253 * fprintf(stderr, "Cannot open directory.\n");
258 * This code tries to open a sample directory using smb protocol without
259 * any additional parameters.
261 * @subsection lavf_io_dirlist_read Reading entries
262 * Each directory's entry (i.e. file, another directory, anything else
263 * within ::AVIODirEntryType) is represented by AVIODirEntry.
264 * Reading consecutive entries from an opened AVIODirContext is done by
265 * repeatedly calling avio_read_dir() on it. Each call returns zero or
266 * positive integer if successful. Reading can be stopped right after the
267 * NULL entry has been read -- it means there are no entries left to be
268 * read. The following code reads all entries from a directory associated
269 * with ctx and prints their names to standard output.
271 * AVIODirEntry *entry = NULL;
273 * if (avio_read_dir(ctx, &entry) < 0) {
274 * fprintf(stderr, "Cannot list directory.\n");
279 * printf("%s\n", entry->name);
280 * avio_free_directory_entry(&entry);
285 * @defgroup lavf_codec Demuxers
287 * @defgroup lavf_codec_native Native Demuxers
290 * @defgroup lavf_codec_wrappers External library wrappers
294 * @defgroup lavf_protos I/O Protocols
297 * @defgroup lavf_internal Internal
305 #include <stdio.h> /* FILE */
306 #include "libavcodec/avcodec.h"
307 #include "libavutil/dict.h"
308 #include "libavutil/log.h"
311 #include "libavformat/version.h"
313 struct AVFormatContext;
315 struct AVDeviceInfoList;
316 struct AVDeviceCapabilitiesQuery;
319 * @defgroup metadata_api Public Metadata API
322 * The metadata API allows libavformat to export metadata tags to a client
323 * application when demuxing. Conversely it allows a client application to
324 * set metadata when muxing.
326 * Metadata is exported or set as pairs of key/value strings in the 'metadata'
327 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
328 * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
329 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
330 * exported by demuxers isn't checked to be valid UTF-8 in most cases.
332 * Important concepts to keep in mind:
333 * - Keys are unique; there can never be 2 tags with the same key. This is
334 * also meant semantically, i.e., a demuxer should not knowingly produce
335 * several keys that are literally different but semantically identical.
336 * E.g., key=Author5, key=Author6. In this example, all authors must be
337 * placed in the same tag.
338 * - Metadata is flat, not hierarchical; there are no subtags. If you
339 * want to store, e.g., the email address of the child of producer Alice
340 * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
341 * - Several modifiers can be applied to the tag name. This is done by
342 * appending a dash character ('-') and the modifier name in the order
343 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
344 * - language -- a tag whose value is localized for a particular language
345 * is appended with the ISO 639-2/B 3-letter language code.
346 * For example: Author-ger=Michael, Author-eng=Mike
347 * The original/default language is in the unqualified "Author" tag.
348 * A demuxer should set a default if it sets any translated tag.
349 * - sorting -- a modified version of a tag that should be used for
350 * sorting will have '-sort' appended. E.g. artist="The Beatles",
351 * artist-sort="Beatles, The".
352 * - Some protocols and demuxers support metadata updates. After a successful
353 * call to av_read_packet(), AVFormatContext.event_flags or AVStream.event_flags
354 * will be updated to indicate if metadata changed. In order to detect metadata
355 * changes on a stream, you need to loop through all streams in the AVFormatContext
356 * and check their individual event_flags.
358 * - Demuxers attempt to export metadata in a generic format, however tags
359 * with no generic equivalents are left as they are stored in the container.
360 * Follows a list of generic tag names:
363 album -- name of the set this work belongs to
364 album_artist -- main creator of the set/album, if different from artist.
365 e.g. "Various Artists" for compilation albums.
366 artist -- main creator of the work
367 comment -- any additional description of the file.
368 composer -- who composed the work, if different from artist.
369 copyright -- name of copyright holder.
370 creation_time-- date when the file was created, preferably in ISO 8601.
371 date -- date when the work was created, preferably in ISO 8601.
372 disc -- number of a subset, e.g. disc in a multi-disc collection.
373 encoder -- name/settings of the software/hardware that produced the file.
374 encoded_by -- person/group who created the file.
375 filename -- original name of the file.
376 genre -- <self-evident>.
377 language -- main language in which the work is performed, preferably
378 in ISO 639-2 format. Multiple languages can be specified by
379 separating them with commas.
380 performer -- artist who performed the work, if different from artist.
381 E.g for "Also sprach Zarathustra", artist would be "Richard
382 Strauss" and performer "London Philharmonic Orchestra".
383 publisher -- name of the label/publisher.
384 service_name -- name of the service in broadcasting (channel name).
385 service_provider -- name of the service provider in broadcasting.
386 title -- name of the work.
387 track -- number of this work in the set, can be in form current/total.
388 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
391 * Look in the examples section for an application example how to use the Metadata API.
396 /* packet functions */
400 * Allocate and read the payload of a packet and initialize its
401 * fields with default values.
403 * @param s associated IO context
405 * @param size desired payload size
406 * @return >0 (read size) if OK, AVERROR_xxx otherwise
408 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
412 * Read data and append it to the current content of the AVPacket.
413 * If pkt->size is 0 this is identical to av_get_packet.
414 * Note that this uses av_grow_packet and thus involves a realloc
415 * which is inefficient. Thus this function should only be used
416 * when there is no reasonable way to know (an upper bound of)
419 * @param s associated IO context
421 * @param size amount of data to read
422 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
423 * will not be lost even if an error occurs.
425 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
428 /*************************************************/
429 /* fractional numbers for exact pts handling */
432 * The exact value of the fractional number is: 'val + num / den'.
433 * num is assumed to be 0 <= num < den.
435 typedef struct AVFrac {
436 int64_t val, num, den;
440 /*************************************************/
441 /* input/output formats */
446 * This structure contains the data a format has to probe a file.
448 typedef struct AVProbeData {
449 const char *filename;
450 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
451 int buf_size; /**< Size of buf except extra allocated bytes */
452 const char *mime_type; /**< mime_type, when known. */
455 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
456 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
458 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
459 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type
460 #define AVPROBE_SCORE_MAX 100 ///< maximum score
462 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
464 /// Demuxer will use avio_open, no opened file should be provided by the caller.
465 #define AVFMT_NOFILE 0x0001
466 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
467 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
468 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
470 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
471 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
472 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
473 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
474 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
475 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
476 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
477 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
478 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
479 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
480 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
481 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
482 increasing timestamps, but they must
483 still be monotonic */
484 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
485 timestamps. If not set the timestamp
486 will be shifted in av_write_frame and
487 av_interleaved_write_frame so they
489 The user or muxer can override this through
490 AVFormatContext.avoid_negative_ts
493 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
496 * @addtogroup lavf_encoding
499 typedef struct AVOutputFormat {
502 * Descriptive name for the format, meant to be more human-readable
503 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
506 const char *long_name;
507 const char *mime_type;
508 const char *extensions; /**< comma-separated filename extensions */
510 enum AVCodecID audio_codec; /**< default audio codec */
511 enum AVCodecID video_codec; /**< default video codec */
512 enum AVCodecID subtitle_codec; /**< default subtitle codec */
514 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
515 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
516 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
522 * List of supported codec_id-codec_tag pairs, ordered by "better
523 * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
525 const struct AVCodecTag * const *codec_tag;
528 const AVClass *priv_class; ///< AVClass for the private context
530 /*****************************************************************
531 * No fields below this line are part of the public API. They
532 * may not be used outside of libavformat and can be changed and
534 * New public fields should be added right above.
535 *****************************************************************
537 struct AVOutputFormat *next;
539 * size of private data so that it can be allocated in the wrapper
543 int (*write_header)(struct AVFormatContext *);
545 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
546 * pkt can be NULL in order to flush data buffered in the muxer.
547 * When flushing, return 0 if there still is more data to flush,
548 * or 1 if everything was flushed and there is no more buffered
551 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
552 int (*write_trailer)(struct AVFormatContext *);
554 * Currently only used to set pixel format if not YUV420P.
556 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
557 AVPacket *in, int flush);
559 * Test if the given codec can be stored in this container.
561 * @return 1 if the codec is supported, 0 if it is not.
562 * A negative number if unknown.
563 * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
565 int (*query_codec)(enum AVCodecID id, int std_compliance);
567 void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
568 int64_t *dts, int64_t *wall);
570 * Allows sending messages from application to device.
572 int (*control_message)(struct AVFormatContext *s, int type,
573 void *data, size_t data_size);
576 * Write an uncoded AVFrame.
578 * See av_write_uncoded_frame() for details.
580 * The library will free *frame afterwards, but the muxer can prevent it
581 * by setting the pointer to NULL.
583 int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
584 AVFrame **frame, unsigned flags);
586 * Returns device list with it properties.
587 * @see avdevice_list_devices() for more details.
589 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
591 * Initialize device capabilities submodule.
592 * @see avdevice_capabilities_create() for more details.
594 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
596 * Free device capabilities submodule.
597 * @see avdevice_capabilities_free() for more details.
599 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
600 enum AVCodecID data_codec; /**< default data codec */
607 * @addtogroup lavf_decoding
610 typedef struct AVInputFormat {
612 * A comma separated list of short names for the format. New names
613 * may be appended with a minor bump.
618 * Descriptive name for the format, meant to be more human-readable
619 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
622 const char *long_name;
625 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
626 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
627 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
632 * If extensions are defined, then no probe is done. You should
633 * usually not use extension format guessing because it is not
636 const char *extensions;
638 const struct AVCodecTag * const *codec_tag;
640 const AVClass *priv_class; ///< AVClass for the private context
643 * Comma-separated list of mime types.
644 * It is used check for matching mime types while probing.
645 * @see av_probe_input_format2
647 const char *mime_type;
649 /*****************************************************************
650 * No fields below this line are part of the public API. They
651 * may not be used outside of libavformat and can be changed and
653 * New public fields should be added right above.
654 *****************************************************************
656 struct AVInputFormat *next;
659 * Raw demuxers store their codec ID here.
664 * Size of private data so that it can be allocated in the wrapper.
669 * Tell if a given file has a chance of being parsed as this format.
670 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
671 * big so you do not have to check for that unless you need more.
673 int (*read_probe)(AVProbeData *);
676 * Read the format header and initialize the AVFormatContext
677 * structure. Return 0 if OK. 'avformat_new_stream' should be
678 * called to create new streams.
680 int (*read_header)(struct AVFormatContext *);
683 * Read one packet and put it in 'pkt'. pts and flags are also
684 * set. 'avformat_new_stream' can be called only if the flag
685 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
686 * background thread).
687 * @return 0 on success, < 0 on error.
688 * When returning an error, pkt must not have been allocated
689 * or must be freed before returning
691 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
694 * Close the stream. The AVFormatContext and AVStreams are not
695 * freed by this function
697 int (*read_close)(struct AVFormatContext *);
700 * Seek to a given timestamp relative to the frames in
701 * stream component stream_index.
702 * @param stream_index Must not be -1.
703 * @param flags Selects which direction should be preferred if no exact
704 * match is available.
705 * @return >= 0 on success (but not necessarily the new offset)
707 int (*read_seek)(struct AVFormatContext *,
708 int stream_index, int64_t timestamp, int flags);
711 * Get the next timestamp in stream[stream_index].time_base units.
712 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
714 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
715 int64_t *pos, int64_t pos_limit);
718 * Start/resume playing - only meaningful if using a network-based format
721 int (*read_play)(struct AVFormatContext *);
724 * Pause playing - only meaningful if using a network-based format
727 int (*read_pause)(struct AVFormatContext *);
730 * Seek to timestamp ts.
731 * Seeking will be done so that the point from which all active streams
732 * can be presented successfully will be closest to ts and within min/max_ts.
733 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
735 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
738 * Returns device list with it properties.
739 * @see avdevice_list_devices() for more details.
741 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
744 * Initialize device capabilities submodule.
745 * @see avdevice_capabilities_create() for more details.
747 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
750 * Free device capabilities submodule.
751 * @see avdevice_capabilities_free() for more details.
753 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
759 enum AVStreamParseType {
761 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
762 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
763 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
764 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
765 AVSTREAM_PARSE_FULL_RAW=MKTAG(0,'R','A','W'), /**< full parsing and repack with timestamp and position generation by parser for raw
766 this assumes that each packet in the file contains no demuxer level headers and
767 just codec level data, otherwise position generation would fail */
770 typedef struct AVIndexEntry {
772 int64_t timestamp; /**<
773 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
774 * when seeking to this entry. That means preferable PTS on keyframe based formats.
775 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
778 #define AVINDEX_KEYFRAME 0x0001
780 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).
781 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
784 #define AV_DISPOSITION_DEFAULT 0x0001
785 #define AV_DISPOSITION_DUB 0x0002
786 #define AV_DISPOSITION_ORIGINAL 0x0004
787 #define AV_DISPOSITION_COMMENT 0x0008
788 #define AV_DISPOSITION_LYRICS 0x0010
789 #define AV_DISPOSITION_KARAOKE 0x0020
792 * Track should be used during playback by default.
793 * Useful for subtitle track that should be displayed
794 * even when user did not explicitly ask for subtitles.
796 #define AV_DISPOSITION_FORCED 0x0040
797 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
798 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
799 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
801 * The stream is stored in the file as an attached picture/"cover art" (e.g.
802 * APIC frame in ID3v2). The single packet associated with it will be returned
803 * among the first few packets read from the file unless seeking takes place.
804 * It can also be accessed at any time in AVStream.attached_pic.
806 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
809 * To specify text track kind (different from subtitles default).
811 #define AV_DISPOSITION_CAPTIONS 0x10000
812 #define AV_DISPOSITION_DESCRIPTIONS 0x20000
813 #define AV_DISPOSITION_METADATA 0x40000
816 * Options for behavior on timestamp wrap detection.
818 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
819 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
820 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
824 * New fields can be added to the end with minor version bumps.
825 * Removal, reordering and changes to existing fields require a major
827 * sizeof(AVStream) must not be used outside libav*.
829 typedef struct AVStream {
830 int index; /**< stream index in AVFormatContext */
832 * Format-specific stream ID.
833 * decoding: set by libavformat
834 * encoding: set by the user, replaced by libavformat if left unset
838 * Codec context associated with this stream. Allocated and freed by
841 * - decoding: The demuxer exports codec information stored in the headers
843 * - encoding: The user sets codec information, the muxer writes it to the
844 * output. Mandatory fields as specified in AVCodecContext
845 * documentation must be set even if this AVCodecContext is
846 * not actually used for encoding.
848 AVCodecContext *codec;
853 * @deprecated this field is unused
860 * This is the fundamental unit of time (in seconds) in terms
861 * of which frame timestamps are represented.
863 * decoding: set by libavformat
864 * encoding: May be set by the caller before avformat_write_header() to
865 * provide a hint to the muxer about the desired timebase. In
866 * avformat_write_header(), the muxer will overwrite this field
867 * with the timebase that will actually be used for the timestamps
868 * written into the file (which may or may not be related to the
869 * user-provided one, depending on the format).
871 AVRational time_base;
874 * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
875 * Only set this if you are absolutely 100% sure that the value you set
876 * it to really is the pts of the first frame.
877 * This may be undefined (AV_NOPTS_VALUE).
878 * @note The ASF header does NOT contain a correct start_time the ASF
879 * demuxer must NOT set this.
884 * Decoding: duration of the stream, in stream time base.
885 * If a source file does not specify a duration, but does specify
886 * a bitrate, this value will be estimated from bitrate and file size.
890 int64_t nb_frames; ///< number of frames in this stream if known or 0
892 int disposition; /**< AV_DISPOSITION_* bit field */
894 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
897 * sample aspect ratio (0 if unknown)
898 * - encoding: Set by user.
899 * - decoding: Set by libavformat.
901 AVRational sample_aspect_ratio;
903 AVDictionary *metadata;
908 * - demuxing: May be set by libavformat when creating the stream or in
909 * avformat_find_stream_info().
910 * - muxing: May be set by the caller before avformat_write_header().
912 AVRational avg_frame_rate;
915 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
916 * will contain the attached picture.
918 * decoding: set by libavformat, must not be modified by the caller.
921 AVPacket attached_pic;
924 * An array of side data that applies to the whole stream (i.e. the
925 * container does not allow it to change between packets).
927 * There may be no overlap between the side data in this array and side data
928 * in the packets. I.e. a given side data is either exported by the muxer
929 * (demuxing) / set by the caller (muxing) in this array, then it never
930 * appears in the packets, or the side data is exported / sent through
931 * the packets (always in the first packet where the value becomes known or
932 * changes), then it does not appear in this array.
934 * - demuxing: Set by libavformat when the stream is created.
935 * - muxing: May be set by the caller before avformat_write_header().
937 * Freed by libavformat in avformat_free_context().
939 * @see av_format_inject_global_side_data()
941 AVPacketSideData *side_data;
943 * The number of elements in the AVStream.side_data array.
948 * Flags for the user to detect events happening on the stream. Flags must
949 * be cleared by the user once the event has been handled.
950 * A combination of AVSTREAM_EVENT_FLAG_*.
953 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
955 /*****************************************************************
956 * All fields below this line are not part of the public API. They
957 * may not be used outside of libavformat and can be changed and
959 * New public fields should be added right above.
960 *****************************************************************
964 * Stream information used internally by av_find_stream_info()
966 #define MAX_STD_TIMEBASES (30*12+7+6)
969 int64_t duration_gcd;
971 int64_t rfps_duration_sum;
972 double (*duration_error)[2][MAX_STD_TIMEBASES];
973 int64_t codec_info_duration;
974 int64_t codec_info_duration_fields;
977 * 0 -> decoder has not been searched for yet.
978 * >0 -> decoder found
979 * <0 -> decoder with codec_id == -found_decoder has not been found
983 int64_t last_duration;
986 * Those are used for average framerate estimation.
988 int64_t fps_first_dts;
989 int fps_first_dts_idx;
990 int64_t fps_last_dts;
991 int fps_last_dts_idx;
995 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
997 // Timestamp generation support:
999 * Timestamp corresponding to the last dts sync point.
1001 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
1002 * a DTS is received from the underlying container. Otherwise set to
1003 * AV_NOPTS_VALUE by default.
1007 int64_t last_IP_pts;
1008 int last_IP_duration;
1011 * Number of packets to buffer for codec probing
1016 * Number of frames that have been demuxed during av_find_stream_info()
1018 int codec_info_nb_frames;
1020 /* av_read_frame() support */
1021 enum AVStreamParseType need_parsing;
1022 struct AVCodecParserContext *parser;
1025 * last packet in packet_buffer for this stream when muxing.
1027 struct AVPacketList *last_in_packet_buffer;
1028 AVProbeData probe_data;
1029 #define MAX_REORDER_DELAY 16
1030 int64_t pts_buffer[MAX_REORDER_DELAY+1];
1032 AVIndexEntry *index_entries; /**< Only used if the format does not
1033 support seeking natively. */
1034 int nb_index_entries;
1035 unsigned int index_entries_allocated_size;
1038 * Real base framerate of the stream.
1039 * This is the lowest framerate with which all timestamps can be
1040 * represented accurately (it is the least common multiple of all
1041 * framerates in the stream). Note, this value is just a guess!
1042 * For example, if the time base is 1/90000 and all frames have either
1043 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
1045 * Code outside avformat should access this field using:
1046 * av_stream_get/set_r_frame_rate(stream)
1048 AVRational r_frame_rate;
1052 * This is the MPEG-TS stream identifier +1
1055 int stream_identifier;
1057 int64_t interleaver_chunk_size;
1058 int64_t interleaver_chunk_duration;
1061 * stream probing state
1062 * -1 -> probing finished
1063 * 0 -> no probing requested
1064 * rest -> perform probing with request_probe being the minimum score to accept.
1065 * NOT PART OF PUBLIC API
1069 * Indicates that everything up to the next keyframe
1070 * should be discarded.
1072 int skip_to_keyframe;
1075 * Number of samples to skip at the start of the frame decoded from the next packet.
1080 * If not 0, the number of samples that should be skipped from the start of
1081 * the stream (the samples are removed from packets with pts==0, which also
1082 * assumes negative timestamps do not happen).
1083 * Intended for use with formats such as mp3 with ad-hoc gapless audio
1086 int64_t start_skip_samples;
1089 * If not 0, the first audio sample that should be discarded from the stream.
1090 * This is broken by design (needs global sample count), but can't be
1091 * avoided for broken by design formats such as mp3 with ad-hoc gapless
1094 int64_t first_discard_sample;
1097 * The sample after last sample that is intended to be discarded after
1098 * first_discard_sample. Works on frame boundaries only. Used to prevent
1099 * early EOF if the gapless info is broken (considered concatenated mp3s).
1101 int64_t last_discard_sample;
1104 * Number of internally decoded frames, used internally in libavformat, do not access
1105 * its lifetime differs from info which is why it is not in that structure.
1107 int nb_decoded_frames;
1110 * Timestamp offset added to timestamps before muxing
1111 * NOT PART OF PUBLIC API
1113 int64_t mux_ts_offset;
1116 * Internal data to check for wrapping of the time stamp
1118 int64_t pts_wrap_reference;
1121 * Options for behavior, when a wrap is detected.
1123 * Defined by AV_PTS_WRAP_ values.
1125 * If correction is enabled, there are two possibilities:
1126 * If the first time stamp is near the wrap point, the wrap offset
1127 * will be subtracted, which will create negative time stamps.
1128 * Otherwise the offset will be added.
1130 int pts_wrap_behavior;
1133 * Internal data to prevent doing update_initial_durations() twice
1135 int update_initial_durations_done;
1138 * Internal data to generate dts from pts
1140 int64_t pts_reorder_error[MAX_REORDER_DELAY+1];
1141 uint8_t pts_reorder_error_count[MAX_REORDER_DELAY+1];
1144 * Internal data to analyze DTS and detect faulty mpeg streams
1146 int64_t last_dts_for_order_check;
1147 uint8_t dts_ordered;
1148 uint8_t dts_misordered;
1151 * Internal data to inject global side data
1153 int inject_global_side_data;
1156 * String containing paris of key and values describing recommended encoder configuration.
1157 * Paris are separated by ','.
1158 * Keys are separated from values by '='.
1160 char *recommended_encoder_configuration;
1163 * display aspect ratio (0 if unknown)
1164 * - encoding: unused
1165 * - decoding: Set by libavformat to calculate sample_aspect_ratio internally
1167 AVRational display_aspect_ratio;
1169 struct FFFrac *priv_pts;
1172 AVRational av_stream_get_r_frame_rate(const AVStream *s);
1173 void av_stream_set_r_frame_rate(AVStream *s, AVRational r);
1174 struct AVCodecParserContext *av_stream_get_parser(const AVStream *s);
1175 char* av_stream_get_recommended_encoder_configuration(const AVStream *s);
1176 void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration);
1179 * Returns the pts of the last muxed packet + its duration
1181 * the retuned value is undefined when used with a demuxer.
1183 int64_t av_stream_get_end_pts(const AVStream *st);
1185 #define AV_PROGRAM_RUNNING 1
1188 * New fields can be added to the end with minor version bumps.
1189 * Removal, reordering and changes to existing fields require a major
1191 * sizeof(AVProgram) must not be used outside libav*.
1193 typedef struct AVProgram {
1196 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1197 unsigned int *stream_index;
1198 unsigned int nb_stream_indexes;
1199 AVDictionary *metadata;
1205 /*****************************************************************
1206 * All fields below this line are not part of the public API. They
1207 * may not be used outside of libavformat and can be changed and
1209 * New public fields should be added right above.
1210 *****************************************************************
1215 int64_t pts_wrap_reference; ///< reference dts for wrap detection
1216 int pts_wrap_behavior; ///< behavior on wrap detection
1219 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1220 (streams are added dynamically) */
1222 typedef struct AVChapter {
1223 int id; ///< unique ID to identify the chapter
1224 AVRational time_base; ///< time base in which the start/end timestamps are specified
1225 int64_t start, end; ///< chapter start/end time in time_base units
1226 AVDictionary *metadata;
1231 * Callback used by devices to communicate with application.
1233 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1234 void *data, size_t data_size);
1236 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags,
1237 const AVIOInterruptCB *int_cb, AVDictionary **options);
1240 * The duration of a video can be estimated through various ways, and this enum can be used
1241 * to know how the duration was estimated.
1243 enum AVDurationEstimationMethod {
1244 AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1245 AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1246 AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1249 typedef struct AVFormatInternal AVFormatInternal;
1252 * Format I/O context.
1253 * New fields can be added to the end with minor version bumps.
1254 * Removal, reordering and changes to existing fields require a major
1256 * sizeof(AVFormatContext) must not be used outside libav*, use
1257 * avformat_alloc_context() to create an AVFormatContext.
1259 typedef struct AVFormatContext {
1261 * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1262 * Exports (de)muxer private options if they exist.
1264 const AVClass *av_class;
1267 * The input container format.
1269 * Demuxing only, set by avformat_open_input().
1271 struct AVInputFormat *iformat;
1274 * The output container format.
1276 * Muxing only, must be set by the caller before avformat_write_header().
1278 struct AVOutputFormat *oformat;
1281 * Format private data. This is an AVOptions-enabled struct
1282 * if and only if iformat/oformat.priv_class is not NULL.
1284 * - muxing: set by avformat_write_header()
1285 * - demuxing: set by avformat_open_input()
1292 * - demuxing: either set by the user before avformat_open_input() (then
1293 * the user must close it manually) or set by avformat_open_input().
1294 * - muxing: set by the user before avformat_write_header(). The caller must
1295 * take care of closing / freeing the IO context.
1297 * Do NOT set this field if AVFMT_NOFILE flag is set in
1298 * iformat/oformat.flags. In such a case, the (de)muxer will handle
1299 * I/O in some other way and this field will be NULL.
1305 * Flags signalling stream properties. A combination of AVFMTCTX_*.
1306 * Set by libavformat.
1311 * Number of elements in AVFormatContext.streams.
1313 * Set by avformat_new_stream(), must not be modified by any other code.
1315 unsigned int nb_streams;
1317 * A list of all streams in the file. New streams are created with
1318 * avformat_new_stream().
1320 * - demuxing: streams are created by libavformat in avformat_open_input().
1321 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1322 * appear in av_read_frame().
1323 * - muxing: streams are created by the user before avformat_write_header().
1325 * Freed by libavformat in avformat_free_context().
1330 * input or output filename
1332 * - demuxing: set by avformat_open_input()
1333 * - muxing: may be set by the caller before avformat_write_header()
1335 char filename[1024];
1338 * Position of the first frame of the component, in
1339 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1340 * It is deduced from the AVStream values.
1342 * Demuxing only, set by libavformat.
1347 * Duration of the stream, in AV_TIME_BASE fractional
1348 * seconds. Only set this value if you know none of the individual stream
1349 * durations and also do not set any of them. This is deduced from the
1350 * AVStream values if not set.
1352 * Demuxing only, set by libavformat.
1357 * Total stream bitrate in bit/s, 0 if not
1358 * available. Never set it directly if the file_size and the
1359 * duration are known as FFmpeg can compute it automatically.
1361 #if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
1367 unsigned int packet_size;
1371 * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1372 * Set by the user before avformat_open_input() / avformat_write_header().
1375 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1376 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1377 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1378 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1379 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1380 #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
1381 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1382 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1383 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1384 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1386 * When muxing, try to avoid writing any random/volatile data to the output.
1387 * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1389 * This flag is mainly intended for testing.
1391 #define AVFMT_FLAG_BITEXACT 0x0400
1392 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload
1393 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1394 #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)
1395 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Don't merge side data but keep it separate.
1396 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats
1398 #if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
1400 * @deprecated deprecated in favor of probesize2
1402 unsigned int probesize;
1405 * @deprecated deprecated in favor of max_analyze_duration2
1407 attribute_deprecated
1408 int max_analyze_duration;
1414 unsigned int nb_programs;
1415 AVProgram **programs;
1418 * Forced video codec_id.
1419 * Demuxing: Set by user.
1421 enum AVCodecID video_codec_id;
1424 * Forced audio codec_id.
1425 * Demuxing: Set by user.
1427 enum AVCodecID audio_codec_id;
1430 * Forced subtitle codec_id.
1431 * Demuxing: Set by user.
1433 enum AVCodecID subtitle_codec_id;
1436 * Maximum amount of memory in bytes to use for the index of each stream.
1437 * If the index exceeds this size, entries will be discarded as
1438 * needed to maintain a smaller size. This can lead to slower or less
1439 * accurate seeking (depends on demuxer).
1440 * Demuxers for which a full in-memory index is mandatory will ignore
1443 * - demuxing: set by user
1445 unsigned int max_index_size;
1448 * Maximum amount of memory in bytes to use for buffering frames
1449 * obtained from realtime capture devices.
1451 unsigned int max_picture_buffer;
1454 * Number of chapters in AVChapter array.
1455 * When muxing, chapters are normally written in the file header,
1456 * so nb_chapters should normally be initialized before write_header
1457 * is called. Some muxers (e.g. mov and mkv) can also write chapters
1458 * in the trailer. To write chapters in the trailer, nb_chapters
1459 * must be zero when write_header is called and non-zero when
1460 * write_trailer is called.
1461 * - muxing: set by user
1462 * - demuxing: set by libavformat
1464 unsigned int nb_chapters;
1465 AVChapter **chapters;
1468 * Metadata that applies to the whole file.
1470 * - demuxing: set by libavformat in avformat_open_input()
1471 * - muxing: may be set by the caller before avformat_write_header()
1473 * Freed by libavformat in avformat_free_context().
1475 AVDictionary *metadata;
1478 * Start time of the stream in real world time, in microseconds
1479 * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1480 * stream was captured at this real world time.
1481 * - muxing: Set by the caller before avformat_write_header(). If set to
1482 * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1484 * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1485 * the value may become known after some number of frames
1486 * have been received.
1488 int64_t start_time_realtime;
1491 * The number of frames used for determining the framerate in
1492 * avformat_find_stream_info().
1493 * Demuxing only, set by the caller before avformat_find_stream_info().
1498 * Error recognition; higher values will detect more errors but may
1499 * misdetect some more or less valid parts as errors.
1500 * Demuxing only, set by the caller before avformat_open_input().
1502 int error_recognition;
1505 * Custom interrupt callbacks for the I/O layer.
1507 * demuxing: set by the user before avformat_open_input().
1508 * muxing: set by the user before avformat_write_header()
1509 * (mainly useful for AVFMT_NOFILE formats). The callback
1510 * should also be passed to avio_open2() if it's used to
1513 AVIOInterruptCB interrupt_callback;
1516 * Flags to enable debugging.
1519 #define FF_FDEBUG_TS 0x0001
1522 * Maximum buffering duration for interleaving.
1524 * To ensure all the streams are interleaved correctly,
1525 * av_interleaved_write_frame() will wait until it has at least one packet
1526 * for each stream before actually writing any packets to the output file.
1527 * When some streams are "sparse" (i.e. there are large gaps between
1528 * successive packets), this can result in excessive buffering.
1530 * This field specifies the maximum difference between the timestamps of the
1531 * first and the last packet in the muxing queue, above which libavformat
1532 * will output a packet regardless of whether it has queued a packet for all
1535 * Muxing only, set by the caller before avformat_write_header().
1537 int64_t max_interleave_delta;
1540 * Allow non-standard and experimental extension
1541 * @see AVCodecContext.strict_std_compliance
1543 int strict_std_compliance;
1546 * Flags for the user to detect events happening on the file. Flags must
1547 * be cleared by the user once the event has been handled.
1548 * A combination of AVFMT_EVENT_FLAG_*.
1551 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
1554 * Maximum number of packets to read while waiting for the first timestamp.
1560 * Avoid negative timestamps during muxing.
1561 * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1562 * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use)
1563 * - muxing: Set by user
1564 * - demuxing: unused
1566 int avoid_negative_ts;
1567 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1568 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1569 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1572 * Transport stream id.
1573 * This will be moved into demuxer private options. Thus no API/ABI compatibility
1578 * Audio preload in microseconds.
1579 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1580 * - encoding: Set by user via AVOptions (NO direct access)
1581 * - decoding: unused
1586 * Max chunk time in microseconds.
1587 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1588 * - encoding: Set by user via AVOptions (NO direct access)
1589 * - decoding: unused
1591 int max_chunk_duration;
1594 * Max chunk size in bytes
1595 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1596 * - encoding: Set by user via AVOptions (NO direct access)
1597 * - decoding: unused
1602 * forces the use of wallclock timestamps as pts/dts of packets
1603 * This has undefined results in the presence of B frames.
1604 * - encoding: unused
1605 * - decoding: Set by user via AVOptions (NO direct access)
1607 int use_wallclock_as_timestamps;
1610 * avio flags, used to force AVIO_FLAG_DIRECT.
1611 * - encoding: unused
1612 * - decoding: Set by user via AVOptions (NO direct access)
1617 * The duration field can be estimated through various ways, and this field can be used
1618 * to know how the duration was estimated.
1619 * - encoding: unused
1620 * - decoding: Read by user via AVOptions (NO direct access)
1622 enum AVDurationEstimationMethod duration_estimation_method;
1625 * Skip initial bytes when opening stream
1626 * - encoding: unused
1627 * - decoding: Set by user via AVOptions (NO direct access)
1629 int64_t skip_initial_bytes;
1632 * Correct single timestamp overflows
1633 * - encoding: unused
1634 * - decoding: Set by user via AVOptions (NO direct access)
1636 unsigned int correct_ts_overflow;
1639 * Force seeking to any (also non key) frames.
1640 * - encoding: unused
1641 * - decoding: Set by user via AVOptions (NO direct access)
1646 * Flush the I/O context after each packet.
1647 * - encoding: Set by user via AVOptions (NO direct access)
1648 * - decoding: unused
1653 * format probing score.
1654 * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1656 * - encoding: unused
1657 * - decoding: set by avformat, read by user via av_format_get_probe_score() (NO direct access)
1662 * number of bytes to read maximally to identify format.
1663 * - encoding: unused
1664 * - decoding: set by user through AVOPtions (NO direct access)
1666 int format_probesize;
1669 * ',' separated list of allowed decoders.
1670 * If NULL then all are allowed
1671 * - encoding: unused
1672 * - decoding: set by user through AVOptions (NO direct access)
1674 char *codec_whitelist;
1677 * ',' separated list of allowed demuxers.
1678 * If NULL then all are allowed
1679 * - encoding: unused
1680 * - decoding: set by user through AVOptions (NO direct access)
1682 char *format_whitelist;
1685 * An opaque field for libavformat internal usage.
1686 * Must not be accessed in any way by callers.
1688 AVFormatInternal *internal;
1691 * IO repositioned flag.
1692 * This is set by avformat when the underlaying IO context read pointer
1693 * is repositioned, for example when doing byte based seeking.
1694 * Demuxers can use the flag to detect such changes.
1696 int io_repositioned;
1699 * Forced video codec.
1700 * This allows forcing a specific decoder, even when there are multiple with
1701 * the same codec_id.
1702 * Demuxing: Set by user via av_format_set_video_codec (NO direct access).
1704 AVCodec *video_codec;
1707 * Forced audio codec.
1708 * This allows forcing a specific decoder, even when there are multiple with
1709 * the same codec_id.
1710 * Demuxing: Set by user via av_format_set_audio_codec (NO direct access).
1712 AVCodec *audio_codec;
1715 * Forced subtitle codec.
1716 * This allows forcing a specific decoder, even when there are multiple with
1717 * the same codec_id.
1718 * Demuxing: Set by user via av_format_set_subtitle_codec (NO direct access).
1720 AVCodec *subtitle_codec;
1723 * Forced data codec.
1724 * This allows forcing a specific decoder, even when there are multiple with
1725 * the same codec_id.
1726 * Demuxing: Set by user via av_format_set_data_codec (NO direct access).
1728 AVCodec *data_codec;
1731 * Number of bytes to be written as padding in a metadata header.
1733 * Muxing: Set by user via av_format_set_metadata_header_padding.
1735 int metadata_header_padding;
1739 * This is a place for some private data of the user.
1740 * Mostly usable with control_message_cb or any future callbacks in device's context.
1745 * Callback used by devices to communicate with application.
1747 av_format_control_message control_message_cb;
1750 * Output timestamp offset, in microseconds.
1751 * Muxing: set by user via AVOptions (NO direct access)
1753 int64_t output_ts_offset;
1756 * Maximum duration (in AV_TIME_BASE units) of the data read
1757 * from input in avformat_find_stream_info().
1758 * Demuxing only, set by the caller before avformat_find_stream_info()
1759 * via AVOptions (NO direct access).
1760 * Can be set to 0 to let avformat choose using a heuristic.
1762 #if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
1763 int64_t max_analyze_duration2;
1765 int64_t max_analyze_duration;
1769 * Maximum size of the data read from input for determining
1770 * the input container format.
1771 * Demuxing only, set by the caller before avformat_open_input()
1772 * via AVOptions (NO direct access).
1774 #if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
1781 * dump format separator.
1782 * can be ", " or "\n " or anything else
1783 * Code outside libavformat should access this field using AVOptions
1784 * (NO direct access).
1785 * - muxing: Set by user.
1786 * - demuxing: Set by user.
1788 uint8_t *dump_separator;
1791 * Forced Data codec_id.
1792 * Demuxing: Set by user.
1794 enum AVCodecID data_codec_id;
1797 * Called to open further IO contexts when needed for demuxing.
1799 * This can be set by the user application to perform security checks on
1800 * the URLs before opening them.
1801 * The function should behave like avio_open2(), AVFormatContext is provided
1802 * as contextual information and to reach AVFormatContext.opaque.
1804 * If NULL then some simple checks are used together with avio_open2().
1806 * Must not be accessed directly from outside avformat.
1807 * @See av_format_set_open_cb()
1809 * Demuxing: Set by user.
1811 int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options);
1814 int av_format_get_probe_score(const AVFormatContext *s);
1815 AVCodec * av_format_get_video_codec(const AVFormatContext *s);
1816 void av_format_set_video_codec(AVFormatContext *s, AVCodec *c);
1817 AVCodec * av_format_get_audio_codec(const AVFormatContext *s);
1818 void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c);
1819 AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s);
1820 void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c);
1821 AVCodec * av_format_get_data_codec(const AVFormatContext *s);
1822 void av_format_set_data_codec(AVFormatContext *s, AVCodec *c);
1823 int av_format_get_metadata_header_padding(const AVFormatContext *s);
1824 void av_format_set_metadata_header_padding(AVFormatContext *s, int c);
1825 void * av_format_get_opaque(const AVFormatContext *s);
1826 void av_format_set_opaque(AVFormatContext *s, void *opaque);
1827 av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s);
1828 void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback);
1829 AVOpenCallback av_format_get_open_cb(const AVFormatContext *s);
1830 void av_format_set_open_cb(AVFormatContext *s, AVOpenCallback callback);
1833 * This function will cause global side data to be injected in the next packet
1834 * of each stream as well as after any subsequent seek.
1836 void av_format_inject_global_side_data(AVFormatContext *s);
1839 * Returns the method used to set ctx->duration.
1841 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1843 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
1845 typedef struct AVPacketList {
1847 struct AVPacketList *next;
1852 * @defgroup lavf_core Core functions
1855 * Functions for querying libavformat capabilities, allocating core structures,
1861 * Return the LIBAVFORMAT_VERSION_INT constant.
1863 unsigned avformat_version(void);
1866 * Return the libavformat build-time configuration.
1868 const char *avformat_configuration(void);
1871 * Return the libavformat license.
1873 const char *avformat_license(void);
1876 * Initialize libavformat and register all the muxers, demuxers and
1877 * protocols. If you do not call this function, then you can select
1878 * exactly which formats you want to support.
1880 * @see av_register_input_format()
1881 * @see av_register_output_format()
1883 void av_register_all(void);
1885 void av_register_input_format(AVInputFormat *format);
1886 void av_register_output_format(AVOutputFormat *format);
1889 * Do global initialization of network components. This is optional,
1890 * but recommended, since it avoids the overhead of implicitly
1891 * doing the setup for each session.
1893 * Calling this function will become mandatory if using network
1894 * protocols at some major version bump.
1896 int avformat_network_init(void);
1899 * Undo the initialization done by avformat_network_init.
1901 int avformat_network_deinit(void);
1904 * If f is NULL, returns the first registered input format,
1905 * if f is non-NULL, returns the next registered input format after f
1906 * or NULL if f is the last one.
1908 AVInputFormat *av_iformat_next(const AVInputFormat *f);
1911 * If f is NULL, returns the first registered output format,
1912 * if f is non-NULL, returns the next registered output format after f
1913 * or NULL if f is the last one.
1915 AVOutputFormat *av_oformat_next(const AVOutputFormat *f);
1918 * Allocate an AVFormatContext.
1919 * avformat_free_context() can be used to free the context and everything
1920 * allocated by the framework within it.
1922 AVFormatContext *avformat_alloc_context(void);
1925 * Free an AVFormatContext and all its streams.
1926 * @param s context to free
1928 void avformat_free_context(AVFormatContext *s);
1931 * Get the AVClass for AVFormatContext. It can be used in combination with
1932 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1934 * @see av_opt_find().
1936 const AVClass *avformat_get_class(void);
1939 * Add a new stream to a media file.
1941 * When demuxing, it is called by the demuxer in read_header(). If the
1942 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1943 * be called in read_packet().
1945 * When muxing, should be called by the user before avformat_write_header().
1947 * User is required to call avcodec_close() and avformat_free_context() to
1948 * clean up the allocation by avformat_new_stream().
1950 * @param s media file handle
1951 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1952 * will be initialized to use this codec. This is needed for e.g. codec-specific
1953 * defaults to be set, so codec should be provided if it is known.
1955 * @return newly created stream or NULL on error.
1957 AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c);
1960 * Get side information from stream.
1962 * @param stream stream
1963 * @param type desired side information type
1964 * @param size pointer for side information size to store (optional)
1965 * @return pointer to data if present or NULL otherwise
1967 uint8_t *av_stream_get_side_data(AVStream *stream,
1968 enum AVPacketSideDataType type, int *size);
1970 AVProgram *av_new_program(AVFormatContext *s, int id);
1978 * Allocate an AVFormatContext for an output format.
1979 * avformat_free_context() can be used to free the context and
1980 * everything allocated by the framework within it.
1982 * @param *ctx is set to the created format context, or to NULL in
1984 * @param oformat format to use for allocating the context, if NULL
1985 * format_name and filename are used instead
1986 * @param format_name the name of output format to use for allocating the
1987 * context, if NULL filename is used instead
1988 * @param filename the name of the filename to use for allocating the
1989 * context, may be NULL
1990 * @return >= 0 in case of success, a negative AVERROR code in case of
1993 int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat,
1994 const char *format_name, const char *filename);
1997 * @addtogroup lavf_decoding
2002 * Find AVInputFormat based on the short name of the input format.
2004 AVInputFormat *av_find_input_format(const char *short_name);
2007 * Guess the file format.
2009 * @param pd data to be probed
2010 * @param is_opened Whether the file is already opened; determines whether
2011 * demuxers with or without AVFMT_NOFILE are probed.
2013 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
2016 * Guess the file format.
2018 * @param pd data to be probed
2019 * @param is_opened Whether the file is already opened; determines whether
2020 * demuxers with or without AVFMT_NOFILE are probed.
2021 * @param score_max A probe score larger that this is required to accept a
2022 * detection, the variable is set to the actual detection
2024 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2025 * to retry with a larger probe buffer.
2027 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
2030 * Guess the file format.
2032 * @param is_opened Whether the file is already opened; determines whether
2033 * demuxers with or without AVFMT_NOFILE are probed.
2034 * @param score_ret The score of the best detection.
2036 AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
2039 * Probe a bytestream to determine the input format. Each time a probe returns
2040 * with a score that is too low, the probe buffer size is increased and another
2041 * attempt is made. When the maximum probe size is reached, the input format
2042 * with the highest score is returned.
2044 * @param pb the bytestream to probe
2045 * @param fmt the input format is put here
2046 * @param filename the filename of the stream
2047 * @param logctx the log context
2048 * @param offset the offset within the bytestream to probe from
2049 * @param max_probe_size the maximum probe buffer size (zero for default)
2050 * @return the score in case of success, a negative value corresponding to an
2051 * the maximal score is AVPROBE_SCORE_MAX
2052 * AVERROR code otherwise
2054 int av_probe_input_buffer2(AVIOContext *pb, AVInputFormat **fmt,
2055 const char *filename, void *logctx,
2056 unsigned int offset, unsigned int max_probe_size);
2059 * Like av_probe_input_buffer2() but returns 0 on success
2061 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
2062 const char *filename, void *logctx,
2063 unsigned int offset, unsigned int max_probe_size);
2066 * Open an input stream and read the header. The codecs are not opened.
2067 * The stream must be closed with avformat_close_input().
2069 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
2070 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
2071 * function and written into ps.
2072 * Note that a user-supplied AVFormatContext will be freed on failure.
2073 * @param filename Name of the stream to open.
2074 * @param fmt If non-NULL, this parameter forces a specific input format.
2075 * Otherwise the format is autodetected.
2076 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
2077 * On return this parameter will be destroyed and replaced with a dict containing
2078 * options that were not found. May be NULL.
2080 * @return 0 on success, a negative AVERROR on failure.
2082 * @note If you want to use custom IO, preallocate the format context and set its pb field.
2084 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
2086 attribute_deprecated
2087 int av_demuxer_open(AVFormatContext *ic);
2090 * Read packets of a media file to get stream information. This
2091 * is useful for file formats with no headers such as MPEG. This
2092 * function also computes the real framerate in case of MPEG-2 repeat
2094 * The logical file position is not changed by this function;
2095 * examined packets may be buffered for later processing.
2097 * @param ic media file handle
2098 * @param options If non-NULL, an ic.nb_streams long array of pointers to
2099 * dictionaries, where i-th member contains options for
2100 * codec corresponding to i-th stream.
2101 * On return each dictionary will be filled with options that were not found.
2102 * @return >=0 if OK, AVERROR_xxx on error
2104 * @note this function isn't guaranteed to open all the codecs, so
2105 * options being non-empty at return is a perfectly normal behavior.
2107 * @todo Let the user decide somehow what information is needed so that
2108 * we do not waste time getting stuff the user does not need.
2110 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
2113 * Find the programs which belong to a given stream.
2115 * @param ic media file handle
2116 * @param last the last found program, the search will start after this
2117 * program, or from the beginning if it is NULL
2118 * @param s stream index
2119 * @return the next program which belongs to s, NULL if no program is found or
2120 * the last program is not among the programs of ic.
2122 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s);
2125 * Find the "best" stream in the file.
2126 * The best stream is determined according to various heuristics as the most
2127 * likely to be what the user expects.
2128 * If the decoder parameter is non-NULL, av_find_best_stream will find the
2129 * default decoder for the stream's codec; streams for which no decoder can
2130 * be found are ignored.
2132 * @param ic media file handle
2133 * @param type stream type: video, audio, subtitles, etc.
2134 * @param wanted_stream_nb user-requested stream number,
2135 * or -1 for automatic selection
2136 * @param related_stream try to find a stream related (eg. in the same
2137 * program) to this one, or -1 if none
2138 * @param decoder_ret if non-NULL, returns the decoder for the
2140 * @param flags flags; none are currently defined
2141 * @return the non-negative stream number in case of success,
2142 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2144 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2145 * @note If av_find_best_stream returns successfully and decoder_ret is not
2146 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2148 int av_find_best_stream(AVFormatContext *ic,
2149 enum AVMediaType type,
2150 int wanted_stream_nb,
2152 AVCodec **decoder_ret,
2156 * Return the next frame of a stream.
2157 * This function returns what is stored in the file, and does not validate
2158 * that what is there are valid frames for the decoder. It will split what is
2159 * stored in the file into frames and return one for each call. It will not
2160 * omit invalid data between valid frames so as to give the decoder the maximum
2161 * information possible for decoding.
2163 * If pkt->buf is NULL, then the packet is valid until the next
2164 * av_read_frame() or until avformat_close_input(). Otherwise the packet
2165 * is valid indefinitely. In both cases the packet must be freed with
2166 * av_free_packet when it is no longer needed. For video, the packet contains
2167 * exactly one frame. For audio, it contains an integer number of frames if each
2168 * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
2169 * have a variable size (e.g. MPEG audio), then it contains one frame.
2171 * pkt->pts, pkt->dts and pkt->duration are always set to correct
2172 * values in AVStream.time_base units (and guessed if the format cannot
2173 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2174 * has B-frames, so it is better to rely on pkt->dts if you do not
2175 * decompress the payload.
2177 * @return 0 if OK, < 0 on error or end of file
2179 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
2182 * Seek to the keyframe at timestamp.
2183 * 'timestamp' in 'stream_index'.
2185 * @param s media file handle
2186 * @param stream_index If stream_index is (-1), a default
2187 * stream is selected, and timestamp is automatically converted
2188 * from AV_TIME_BASE units to the stream specific time_base.
2189 * @param timestamp Timestamp in AVStream.time_base units
2190 * or, if no stream is specified, in AV_TIME_BASE units.
2191 * @param flags flags which select direction and seeking mode
2192 * @return >= 0 on success
2194 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2198 * Seek to timestamp ts.
2199 * Seeking will be done so that the point from which all active streams
2200 * can be presented successfully will be closest to ts and within min/max_ts.
2201 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2203 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2204 * are the file position (this may not be supported by all demuxers).
2205 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2206 * in the stream with stream_index (this may not be supported by all demuxers).
2207 * Otherwise all timestamps are in units of the stream selected by stream_index
2208 * or if stream_index is -1, in AV_TIME_BASE units.
2209 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2210 * keyframes (this may not be supported by all demuxers).
2211 * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2213 * @param s media file handle
2214 * @param stream_index index of the stream which is used as time base reference
2215 * @param min_ts smallest acceptable timestamp
2216 * @param ts target timestamp
2217 * @param max_ts largest acceptable timestamp
2218 * @param flags flags
2219 * @return >=0 on success, error code otherwise
2221 * @note This is part of the new seek API which is still under construction.
2222 * Thus do not use this yet. It may change at any time, do not expect
2223 * ABI compatibility yet!
2225 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2228 * Discard all internally buffered data. This can be useful when dealing with
2229 * discontinuities in the byte stream. Generally works only with formats that
2230 * can resync. This includes headerless formats like MPEG-TS/TS but should also
2231 * work with NUT, Ogg and in a limited way AVI for example.
2233 * The set of streams, the detected duration, stream parameters and codecs do
2234 * not change when calling this function. If you want a complete reset, it's
2235 * better to open a new AVFormatContext.
2237 * This does not flush the AVIOContext (s->pb). If necessary, call
2238 * avio_flush(s->pb) before calling this function.
2240 * @param s media file handle
2241 * @return >=0 on success, error code otherwise
2243 int avformat_flush(AVFormatContext *s);
2246 * Start playing a network-based stream (e.g. RTSP stream) at the
2249 int av_read_play(AVFormatContext *s);
2252 * Pause a network-based stream (e.g. RTSP stream).
2254 * Use av_read_play() to resume it.
2256 int av_read_pause(AVFormatContext *s);
2259 * Close an opened input AVFormatContext. Free it and all its contents
2260 * and set *s to NULL.
2262 void avformat_close_input(AVFormatContext **s);
2267 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2268 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2269 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2270 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2273 * @addtogroup lavf_encoding
2277 * Allocate the stream private data and write the stream header to
2278 * an output media file.
2280 * @param s Media file handle, must be allocated with avformat_alloc_context().
2281 * Its oformat field must be set to the desired output format;
2282 * Its pb field must be set to an already opened AVIOContext.
2283 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2284 * On return this parameter will be destroyed and replaced with a dict containing
2285 * options that were not found. May be NULL.
2287 * @return 0 on success, negative AVERROR on failure.
2289 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
2291 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
2294 * Write a packet to an output media file.
2296 * This function passes the packet directly to the muxer, without any buffering
2297 * or reordering. The caller is responsible for correctly interleaving the
2298 * packets if the format requires it. Callers that want libavformat to handle
2299 * the interleaving should call av_interleaved_write_frame() instead of this
2302 * @param s media file handle
2303 * @param pkt The packet containing the data to be written. Note that unlike
2304 * av_interleaved_write_frame(), this function does not take
2305 * ownership of the packet passed to it (though some muxers may make
2306 * an internal reference to the input packet).
2308 * This parameter can be NULL (at any time, not just at the end), in
2309 * order to immediately flush data buffered within the muxer, for
2310 * muxers that buffer up data internally before writing it to the
2313 * Packet's @ref AVPacket.stream_index "stream_index" field must be
2314 * set to the index of the corresponding stream in @ref
2315 * AVFormatContext.streams "s->streams". It is very strongly
2316 * recommended that timing information (@ref AVPacket.pts "pts", @ref
2317 * AVPacket.dts "dts", @ref AVPacket.duration "duration") is set to
2319 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2321 * @see av_interleaved_write_frame()
2323 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
2326 * Write a packet to an output media file ensuring correct interleaving.
2328 * This function will buffer the packets internally as needed to make sure the
2329 * packets in the output file are properly interleaved in the order of
2330 * increasing dts. Callers doing their own interleaving should call
2331 * av_write_frame() instead of this function.
2333 * @param s media file handle
2334 * @param pkt The packet containing the data to be written.
2336 * If the packet is reference-counted, this function will take
2337 * ownership of this reference and unreference it later when it sees
2339 * The caller must not access the data through this reference after
2340 * this function returns. If the packet is not reference-counted,
2341 * libavformat will make a copy.
2343 * This parameter can be NULL (at any time, not just at the end), to
2344 * flush the interleaving queues.
2346 * Packet's @ref AVPacket.stream_index "stream_index" field must be
2347 * set to the index of the corresponding stream in @ref
2348 * AVFormatContext.streams "s->streams". It is very strongly
2349 * recommended that timing information (@ref AVPacket.pts "pts", @ref
2350 * AVPacket.dts "dts", @ref AVPacket.duration "duration") is set to
2353 * @return 0 on success, a negative AVERROR on error. Libavformat will always
2354 * take care of freeing the packet, even if this function fails.
2356 * @see av_write_frame(), AVFormatContext.max_interleave_delta
2358 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
2361 * Write a uncoded frame to an output media file.
2363 * The frame must be correctly interleaved according to the container
2364 * specification; if not, then av_interleaved_write_frame() must be used.
2366 * See av_interleaved_write_frame() for details.
2368 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2372 * Write a uncoded frame to an output media file.
2374 * If the muxer supports it, this function makes it possible to write an AVFrame
2375 * structure directly, without encoding it into a packet.
2376 * It is mostly useful for devices and similar special muxers that use raw
2377 * video or PCM data and will not serialize it into a byte stream.
2379 * To test whether it is possible to use it with a given muxer and stream,
2380 * use av_write_uncoded_frame_query().
2382 * The caller gives up ownership of the frame and must not access it
2385 * @return >=0 for success, a negative code on error
2387 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
2391 * Test whether a muxer supports uncoded frame.
2393 * @return >=0 if an uncoded frame can be written to that muxer and stream,
2396 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2399 * Write the stream trailer to an output media file and free the
2400 * file private data.
2402 * May only be called after a successful call to avformat_write_header.
2404 * @param s media file handle
2405 * @return 0 if OK, AVERROR_xxx on error
2407 int av_write_trailer(AVFormatContext *s);
2410 * Return the output format in the list of registered output formats
2411 * which best matches the provided parameters, or return NULL if
2412 * there is no match.
2414 * @param short_name if non-NULL checks if short_name matches with the
2415 * names of the registered formats
2416 * @param filename if non-NULL checks if filename terminates with the
2417 * extensions of the registered formats
2418 * @param mime_type if non-NULL checks if mime_type matches with the
2419 * MIME type of the registered formats
2421 AVOutputFormat *av_guess_format(const char *short_name,
2422 const char *filename,
2423 const char *mime_type);
2426 * Guess the codec ID based upon muxer and filename.
2428 enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
2429 const char *filename, const char *mime_type,
2430 enum AVMediaType type);
2433 * Get timing information for the data currently output.
2434 * The exact meaning of "currently output" depends on the format.
2435 * It is mostly relevant for devices that have an internal buffer and/or
2436 * work in real time.
2437 * @param s media file handle
2438 * @param stream stream in the media file
2439 * @param[out] dts DTS of the last packet output for the stream, in stream
2441 * @param[out] wall absolute time when that packet whas output,
2443 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
2444 * Note: some formats or devices may not allow to measure dts and wall
2447 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2448 int64_t *dts, int64_t *wall);
2457 * @defgroup lavf_misc Utility functions
2461 * Miscellaneous utility functions related to both muxing and demuxing
2466 * Send a nice hexadecimal dump of a buffer to the specified file stream.
2468 * @param f The file stream pointer where the dump should be sent to.
2470 * @param size buffer size
2472 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2474 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2477 * Send a nice hexadecimal dump of a buffer to the log.
2479 * @param avcl A pointer to an arbitrary struct of which the first field is a
2480 * pointer to an AVClass struct.
2481 * @param level The importance level of the message, lower values signifying
2482 * higher importance.
2484 * @param size buffer size
2486 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2488 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2491 * Send a nice dump of a packet to the specified file stream.
2493 * @param f The file stream pointer where the dump should be sent to.
2494 * @param pkt packet to dump
2495 * @param dump_payload True if the payload must be displayed, too.
2496 * @param st AVStream that the packet belongs to
2498 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2502 * Send a nice dump of a packet to the log.
2504 * @param avcl A pointer to an arbitrary struct of which the first field is a
2505 * pointer to an AVClass struct.
2506 * @param level The importance level of the message, lower values signifying
2507 * higher importance.
2508 * @param pkt packet to dump
2509 * @param dump_payload True if the payload must be displayed, too.
2510 * @param st AVStream that the packet belongs to
2512 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2513 const AVStream *st);
2516 * Get the AVCodecID for the given codec tag tag.
2517 * If no codec id is found returns AV_CODEC_ID_NONE.
2519 * @param tags list of supported codec_id-codec_tag pairs, as stored
2520 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2521 * @param tag codec tag to match to a codec ID
2523 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2526 * Get the codec tag for the given codec id id.
2527 * If no codec tag is found returns 0.
2529 * @param tags list of supported codec_id-codec_tag pairs, as stored
2530 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2531 * @param id codec ID to match to a codec tag
2533 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2536 * Get the codec tag for the given codec id.
2538 * @param tags list of supported codec_id - codec_tag pairs, as stored
2539 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2540 * @param id codec id that should be searched for in the list
2541 * @param tag A pointer to the found tag
2542 * @return 0 if id was not found in tags, > 0 if it was found
2544 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2547 int av_find_default_stream_index(AVFormatContext *s);
2550 * Get the index for a specific timestamp.
2552 * @param st stream that the timestamp belongs to
2553 * @param timestamp timestamp to retrieve the index for
2554 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2555 * to the timestamp which is <= the requested one, if backward
2556 * is 0, then it will be >=
2557 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2558 * @return < 0 if no such timestamp could be found
2560 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2563 * Add an index entry into a sorted list. Update the entry if the list
2564 * already contains it.
2566 * @param timestamp timestamp in the time base of the given stream
2568 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2569 int size, int distance, int flags);
2573 * Split a URL string into components.
2575 * The pointers to buffers for storing individual components may be null,
2576 * in order to ignore that component. Buffers for components not found are
2577 * set to empty strings. If the port is not found, it is set to a negative
2580 * @param proto the buffer for the protocol
2581 * @param proto_size the size of the proto buffer
2582 * @param authorization the buffer for the authorization
2583 * @param authorization_size the size of the authorization buffer
2584 * @param hostname the buffer for the host name
2585 * @param hostname_size the size of the hostname buffer
2586 * @param port_ptr a pointer to store the port number in
2587 * @param path the buffer for the path
2588 * @param path_size the size of the path buffer
2589 * @param url the URL to split
2591 void av_url_split(char *proto, int proto_size,
2592 char *authorization, int authorization_size,
2593 char *hostname, int hostname_size,
2595 char *path, int path_size,
2600 * Print detailed information about the input or output format, such as
2601 * duration, bitrate, streams, container, programs, metadata, side data,
2602 * codec and time base.
2604 * @param ic the context to analyze
2605 * @param index index of the stream to dump information about
2606 * @param url the URL to print, such as source or destination file
2607 * @param is_output Select whether the specified context is an input(0) or output(1)
2609 void av_dump_format(AVFormatContext *ic,
2615 * Return in 'buf' the path with '%d' replaced by a number.
2617 * Also handles the '%0nd' format where 'n' is the total number
2618 * of digits and '%%'.
2620 * @param buf destination buffer
2621 * @param buf_size destination buffer size
2622 * @param path numbered sequence string
2623 * @param number frame number
2624 * @return 0 if OK, -1 on format error
2626 int av_get_frame_filename(char *buf, int buf_size,
2627 const char *path, int number);
2630 * Check whether filename actually is a numbered sequence generator.
2632 * @param filename possible numbered sequence string
2633 * @return 1 if a valid numbered sequence string, 0 otherwise
2635 int av_filename_number_test(const char *filename);
2638 * Generate an SDP for an RTP session.
2640 * Note, this overwrites the id values of AVStreams in the muxer contexts
2641 * for getting unique dynamic payload types.
2643 * @param ac array of AVFormatContexts describing the RTP streams. If the
2644 * array is composed by only one context, such context can contain
2645 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2646 * all the contexts in the array (an AVCodecContext per RTP stream)
2647 * must contain only one AVStream.
2648 * @param n_files number of AVCodecContexts contained in ac
2649 * @param buf buffer where the SDP will be stored (must be allocated by
2651 * @param size the size of the buffer
2652 * @return 0 if OK, AVERROR_xxx on error
2654 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2657 * Return a positive value if the given filename has one of the given
2658 * extensions, 0 otherwise.
2660 * @param filename file name to check against the given extensions
2661 * @param extensions a comma-separated list of filename extensions
2663 int av_match_ext(const char *filename, const char *extensions);
2666 * Test if the given container can store a codec.
2668 * @param ofmt container to check for compatibility
2669 * @param codec_id codec to potentially store in container
2670 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2672 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2673 * A negative number if this information is not available.
2675 int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id,
2676 int std_compliance);
2679 * @defgroup riff_fourcc RIFF FourCCs
2681 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2682 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2685 * uint32_t tag = MKTAG('H', '2', '6', '4');
2686 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2687 * enum AVCodecID id = av_codec_get_id(table, tag);
2691 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2693 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2695 * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2697 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2699 * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2701 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2703 * @return the table mapping MOV FourCCs for audio to AVCodecID.
2705 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2712 * Guess the sample aspect ratio of a frame, based on both the stream and the
2713 * frame aspect ratio.
2715 * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2716 * is set by the demuxer, these two may not be equal. This function tries to
2717 * return the value that you should use if you would like to display the frame.
2719 * Basic logic is to use the stream aspect ratio if it is set to something sane
2720 * otherwise use the frame aspect ratio. This way a container setting, which is
2721 * usually easy to modify can override the coded value in the frames.
2723 * @param format the format context which the stream is part of
2724 * @param stream the stream which the frame is part of
2725 * @param frame the frame with the aspect ratio to be determined
2726 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2728 AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame);
2731 * Guess the frame rate, based on both the container and codec information.
2733 * @param ctx the format context which the stream is part of
2734 * @param stream the stream which the frame is part of
2735 * @param frame the frame for which the frame rate should be determined, may be NULL
2736 * @return the guessed (valid) frame rate, 0/1 if no idea
2738 AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame);
2741 * Check if the stream st contained in s is matched by the stream specifier
2744 * See the "stream specifiers" chapter in the documentation for the syntax
2747 * @return >0 if st is matched by spec;
2748 * 0 if st is not matched by spec;
2749 * AVERROR code if spec is invalid
2751 * @note A stream specifier can match several streams in the format.
2753 int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st,
2756 int avformat_queue_attached_pictures(AVFormatContext *s);
2763 #endif /* AVFORMAT_AVFORMAT_H */