2 * copyright (c) 2001 Fabrice Bellard
4 * This file is part of Libav.
6 * Libav 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 * Libav 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 Libav; 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 Libav 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 * Lavf allows to configure 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
178 * @defgroup lavf_io I/O Read/Write
182 * @defgroup lavf_codec Demuxers
184 * @defgroup lavf_codec_native Native Demuxers
187 * @defgroup lavf_codec_wrappers External library wrappers
191 * @defgroup lavf_protos I/O Protocols
194 * @defgroup lavf_internal Internal
202 #include <stdio.h> /* FILE */
203 #include "libavcodec/avcodec.h"
204 #include "libavutil/dict.h"
205 #include "libavutil/log.h"
208 #include "libavformat/version.h"
210 struct AVFormatContext;
214 * @defgroup metadata_api Public Metadata API
217 * The metadata API allows libavformat to export metadata tags to a client
218 * application when demuxing. Conversely it allows a client application to
219 * set metadata when muxing.
221 * Metadata is exported or set as pairs of key/value strings in the 'metadata'
222 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
223 * using the @ref lavu_dict "AVDictionary" API. Like all strings in Libav,
224 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
225 * exported by demuxers isn't checked to be valid UTF-8 in most cases.
227 * Important concepts to keep in mind:
228 * - Keys are unique; there can never be 2 tags with the same key. This is
229 * also meant semantically, i.e., a demuxer should not knowingly produce
230 * several keys that are literally different but semantically identical.
231 * E.g., key=Author5, key=Author6. In this example, all authors must be
232 * placed in the same tag.
233 * - Metadata is flat, not hierarchical; there are no subtags. If you
234 * want to store, e.g., the email address of the child of producer Alice
235 * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
236 * - Several modifiers can be applied to the tag name. This is done by
237 * appending a dash character ('-') and the modifier name in the order
238 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
239 * - language -- a tag whose value is localized for a particular language
240 * is appended with the ISO 639-2/B 3-letter language code.
241 * For example: Author-ger=Michael, Author-eng=Mike
242 * The original/default language is in the unqualified "Author" tag.
243 * A demuxer should set a default if it sets any translated tag.
244 * - sorting -- a modified version of a tag that should be used for
245 * sorting will have '-sort' appended. E.g. artist="The Beatles",
246 * artist-sort="Beatles, The".
248 * - Demuxers attempt to export metadata in a generic format, however tags
249 * with no generic equivalents are left as they are stored in the container.
250 * Follows a list of generic tag names:
253 album -- name of the set this work belongs to
254 album_artist -- main creator of the set/album, if different from artist.
255 e.g. "Various Artists" for compilation albums.
256 artist -- main creator of the work
257 comment -- any additional description of the file.
258 composer -- who composed the work, if different from artist.
259 copyright -- name of copyright holder.
260 creation_time-- date when the file was created, preferably in ISO 8601.
261 date -- date when the work was created, preferably in ISO 8601.
262 disc -- number of a subset, e.g. disc in a multi-disc collection.
263 encoder -- name/settings of the software/hardware that produced the file.
264 encoded_by -- person/group who created the file.
265 filename -- original name of the file.
266 genre -- <self-evident>.
267 language -- main language in which the work is performed, preferably
268 in ISO 639-2 format. Multiple languages can be specified by
269 separating them with commas.
270 performer -- artist who performed the work, if different from artist.
271 E.g for "Also sprach Zarathustra", artist would be "Richard
272 Strauss" and performer "London Philharmonic Orchestra".
273 publisher -- name of the label/publisher.
274 service_name -- name of the service in broadcasting (channel name).
275 service_provider -- name of the service provider in broadcasting.
276 title -- name of the work.
277 track -- number of this work in the set, can be in form current/total.
278 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
281 * Look in the examples section for an application example how to use the Metadata API.
286 /* packet functions */
290 * Allocate and read the payload of a packet and initialize its
291 * fields with default values.
294 * @param size desired payload size
295 * @return >0 (read size) if OK, AVERROR_xxx otherwise
297 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
301 * Read data and append it to the current content of the AVPacket.
302 * If pkt->size is 0 this is identical to av_get_packet.
303 * Note that this uses av_grow_packet and thus involves a realloc
304 * which is inefficient. Thus this function should only be used
305 * when there is no reasonable way to know (an upper bound of)
309 * @param size amount of data to read
310 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
311 * will not be lost even if an error occurs.
313 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
315 /*************************************************/
316 /* fractional numbers for exact pts handling */
319 * The exact value of the fractional number is: 'val + num / den'.
320 * num is assumed to be 0 <= num < den.
322 typedef struct AVFrac {
323 int64_t val, num, den;
326 /*************************************************/
327 /* input/output formats */
332 * This structure contains the data a format has to probe a file.
334 typedef struct AVProbeData {
335 const char *filename;
336 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
337 int buf_size; /**< Size of buf except extra allocated bytes */
340 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
341 #define AVPROBE_SCORE_MAX 100 ///< maximum score
343 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
345 /// Demuxer will use avio_open, no opened file should be provided by the caller.
346 #define AVFMT_NOFILE 0x0001
347 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
348 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
349 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
351 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
352 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
353 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
354 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
355 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
356 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
357 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
358 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
359 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
360 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
361 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
362 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
363 increasing timestamps, but they must
364 still be monotonic */
365 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
366 timestamps. If not set the timestamp
367 will be shifted in av_write_frame and
368 av_interleaved_write_frame so they
372 * @addtogroup lavf_encoding
375 typedef struct AVOutputFormat {
378 * Descriptive name for the format, meant to be more human-readable
379 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
382 const char *long_name;
383 const char *mime_type;
384 const char *extensions; /**< comma-separated filename extensions */
386 enum AVCodecID audio_codec; /**< default audio codec */
387 enum AVCodecID video_codec; /**< default video codec */
388 enum AVCodecID subtitle_codec; /**< default subtitle codec */
390 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
391 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
392 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
398 * List of supported codec_id-codec_tag pairs, ordered by "better
399 * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
401 const struct AVCodecTag * const *codec_tag;
404 const AVClass *priv_class; ///< AVClass for the private context
406 /*****************************************************************
407 * No fields below this line are part of the public API. They
408 * may not be used outside of libavformat and can be changed and
410 * New public fields should be added right above.
411 *****************************************************************
413 struct AVOutputFormat *next;
415 * size of private data so that it can be allocated in the wrapper
419 int (*write_header)(struct AVFormatContext *);
421 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
422 * pkt can be NULL in order to flush data buffered in the muxer.
423 * When flushing, return 0 if there still is more data to flush,
424 * or 1 if everything was flushed and there is no more buffered
427 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
428 int (*write_trailer)(struct AVFormatContext *);
430 * Currently only used to set pixel format if not YUV420P.
432 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
433 AVPacket *in, int flush);
435 * Test if the given codec can be stored in this container.
437 * @return 1 if the codec is supported, 0 if it is not.
438 * A negative number if unknown.
440 int (*query_codec)(enum AVCodecID id, int std_compliance);
447 * @addtogroup lavf_decoding
450 typedef struct AVInputFormat {
452 * A comma separated list of short names for the format. New names
453 * may be appended with a minor bump.
458 * Descriptive name for the format, meant to be more human-readable
459 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
462 const char *long_name;
465 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
466 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
467 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK.
472 * If extensions are defined, then no probe is done. You should
473 * usually not use extension format guessing because it is not
476 const char *extensions;
478 const struct AVCodecTag * const *codec_tag;
480 const AVClass *priv_class; ///< AVClass for the private context
482 /*****************************************************************
483 * No fields below this line are part of the public API. They
484 * may not be used outside of libavformat and can be changed and
486 * New public fields should be added right above.
487 *****************************************************************
489 struct AVInputFormat *next;
492 * Raw demuxers store their codec ID here.
497 * Size of private data so that it can be allocated in the wrapper.
502 * Tell if a given file has a chance of being parsed as this format.
503 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
504 * big so you do not have to check for that unless you need more.
506 int (*read_probe)(AVProbeData *);
509 * Read the format header and initialize the AVFormatContext
510 * structure. Return 0 if OK. Only used in raw format right
511 * now. 'avformat_new_stream' should be called to create new streams.
513 int (*read_header)(struct AVFormatContext *);
516 * Read one packet and put it in 'pkt'. pts and flags are also
517 * set. 'avformat_new_stream' can be called only if the flag
518 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
519 * background thread).
520 * @return 0 on success, < 0 on error.
521 * When returning an error, pkt must not have been allocated
522 * or must be freed before returning
524 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
527 * Close the stream. The AVFormatContext and AVStreams are not
528 * freed by this function
530 int (*read_close)(struct AVFormatContext *);
533 * Seek to a given timestamp relative to the frames in
534 * stream component stream_index.
535 * @param stream_index Must not be -1.
536 * @param flags Selects which direction should be preferred if no exact
537 * match is available.
538 * @return >= 0 on success (but not necessarily the new offset)
540 int (*read_seek)(struct AVFormatContext *,
541 int stream_index, int64_t timestamp, int flags);
544 * Get the next timestamp in stream[stream_index].time_base units.
545 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
547 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
548 int64_t *pos, int64_t pos_limit);
551 * Start/resume playing - only meaningful if using a network-based format
554 int (*read_play)(struct AVFormatContext *);
557 * Pause playing - only meaningful if using a network-based format
560 int (*read_pause)(struct AVFormatContext *);
563 * Seek to timestamp ts.
564 * Seeking will be done so that the point from which all active streams
565 * can be presented successfully will be closest to ts and within min/max_ts.
566 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
568 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
574 enum AVStreamParseType {
576 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
577 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
578 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
579 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
582 typedef struct AVIndexEntry {
585 #define AVINDEX_KEYFRAME 0x0001
587 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).
588 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
591 #define AV_DISPOSITION_DEFAULT 0x0001
592 #define AV_DISPOSITION_DUB 0x0002
593 #define AV_DISPOSITION_ORIGINAL 0x0004
594 #define AV_DISPOSITION_COMMENT 0x0008
595 #define AV_DISPOSITION_LYRICS 0x0010
596 #define AV_DISPOSITION_KARAOKE 0x0020
599 * Track should be used during playback by default.
600 * Useful for subtitle track that should be displayed
601 * even when user did not explicitly ask for subtitles.
603 #define AV_DISPOSITION_FORCED 0x0040
604 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
605 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
606 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
608 * The stream is stored in the file as an attached picture/"cover art" (e.g.
609 * APIC frame in ID3v2). The single packet associated with it will be returned
610 * among the first few packets read from the file unless seeking takes place.
611 * It can also be accessed at any time in AVStream.attached_pic.
613 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
617 * New fields can be added to the end with minor version bumps.
618 * Removal, reordering and changes to existing fields require a major
620 * sizeof(AVStream) must not be used outside libav*.
622 typedef struct AVStream {
623 int index; /**< stream index in AVFormatContext */
625 * Format-specific stream ID.
626 * decoding: set by libavformat
627 * encoding: set by the user, replaced by libavformat if left unset
631 * Codec context associated with this stream. Allocated and freed by
634 * - decoding: The demuxer exports codec information stored in the headers
636 * - encoding: The user sets codec information, the muxer writes it to the
637 * output. Mandatory fields as specified in AVCodecContext
638 * documentation must be set even if this AVCodecContext is
639 * not actually used for encoding.
641 AVCodecContext *codec;
645 * encoding: pts generation when outputting stream
650 * This is the fundamental unit of time (in seconds) in terms
651 * of which frame timestamps are represented.
653 * decoding: set by libavformat
654 * encoding: set by libavformat in avformat_write_header. The muxer may use the
655 * user-provided value of @ref AVCodecContext.time_base "codec->time_base"
658 AVRational time_base;
661 * Decoding: pts of the first frame of the stream, in stream time base.
662 * Only set this if you are absolutely 100% sure that the value you set
663 * it to really is the pts of the first frame.
664 * This may be undefined (AV_NOPTS_VALUE).
669 * Decoding: duration of the stream, in stream time base.
670 * If a source file does not specify a duration, but does specify
671 * a bitrate, this value will be estimated from bitrate and file size.
675 int64_t nb_frames; ///< number of frames in this stream if known or 0
677 int disposition; /**< AV_DISPOSITION_* bit field */
679 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
682 * sample aspect ratio (0 if unknown)
683 * - encoding: Set by user.
684 * - decoding: Set by libavformat.
686 AVRational sample_aspect_ratio;
688 AVDictionary *metadata;
693 AVRational avg_frame_rate;
696 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
697 * will contain the attached picture.
699 * decoding: set by libavformat, must not be modified by the caller.
702 AVPacket attached_pic;
704 /*****************************************************************
705 * All fields below this line are not part of the public API. They
706 * may not be used outside of libavformat and can be changed and
708 * New public fields should be added right above.
709 *****************************************************************
713 * Stream information used internally by av_find_stream_info()
715 #define MAX_STD_TIMEBASES (60*12+5)
717 int nb_decoded_frames;
721 * Those are used for average framerate estimation.
723 int64_t fps_first_dts;
724 int fps_first_dts_idx;
725 int64_t fps_last_dts;
726 int fps_last_dts_idx;
730 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
732 // Timestamp generation support:
734 * Timestamp corresponding to the last dts sync point.
736 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
737 * a DTS is received from the underlying container. Otherwise set to
738 * AV_NOPTS_VALUE by default.
740 int64_t reference_dts;
744 int last_IP_duration;
747 * Number of packets to buffer for codec probing
749 #define MAX_PROBE_PACKETS 2500
753 * Number of frames that have been demuxed during av_find_stream_info()
755 int codec_info_nb_frames;
757 /* av_read_frame() support */
758 enum AVStreamParseType need_parsing;
759 struct AVCodecParserContext *parser;
762 * last packet in packet_buffer for this stream when muxing.
764 struct AVPacketList *last_in_packet_buffer;
765 AVProbeData probe_data;
766 #define MAX_REORDER_DELAY 16
767 int64_t pts_buffer[MAX_REORDER_DELAY+1];
769 AVIndexEntry *index_entries; /**< Only used if the format does not
770 support seeking natively. */
771 int nb_index_entries;
772 unsigned int index_entries_allocated_size;
775 #define AV_PROGRAM_RUNNING 1
778 * New fields can be added to the end with minor version bumps.
779 * Removal, reordering and changes to existing fields require a major
781 * sizeof(AVProgram) must not be used outside libav*.
783 typedef struct AVProgram {
786 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
787 unsigned int *stream_index;
788 unsigned int nb_stream_indexes;
789 AVDictionary *metadata;
792 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
793 (streams are added dynamically) */
795 typedef struct AVChapter {
796 int id; ///< unique ID to identify the chapter
797 AVRational time_base; ///< time base in which the start/end timestamps are specified
798 int64_t start, end; ///< chapter start/end time in time_base units
799 AVDictionary *metadata;
803 * Format I/O context.
804 * New fields can be added to the end with minor version bumps.
805 * Removal, reordering and changes to existing fields require a major
807 * sizeof(AVFormatContext) must not be used outside libav*, use
808 * avformat_alloc_context() to create an AVFormatContext.
810 typedef struct AVFormatContext {
812 * A class for logging and AVOptions. Set by avformat_alloc_context().
813 * Exports (de)muxer private options if they exist.
815 const AVClass *av_class;
818 * Can only be iformat or oformat, not both at the same time.
820 * decoding: set by avformat_open_input().
821 * encoding: set by the user.
823 struct AVInputFormat *iformat;
824 struct AVOutputFormat *oformat;
827 * Format private data. This is an AVOptions-enabled struct
828 * if and only if iformat/oformat.priv_class is not NULL.
835 * decoding: either set by the user before avformat_open_input() (then
836 * the user must close it manually) or set by avformat_open_input().
837 * encoding: set by the user.
839 * Do NOT set this field if AVFMT_NOFILE flag is set in
840 * iformat/oformat.flags. In such a case, the (de)muxer will handle
841 * I/O in some other way and this field will be NULL.
846 int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
849 * A list of all streams in the file. New streams are created with
850 * avformat_new_stream().
852 * decoding: streams are created by libavformat in avformat_open_input().
853 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
854 * appear in av_read_frame().
855 * encoding: streams are created by the user before avformat_write_header().
857 unsigned int nb_streams;
860 char filename[1024]; /**< input or output filename */
863 * Decoding: position of the first frame of the component, in
864 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
865 * It is deduced from the AVStream values.
870 * Decoding: duration of the stream, in AV_TIME_BASE fractional
871 * seconds. Only set this value if you know none of the individual stream
872 * durations and also do not set any of them. This is deduced from the
873 * AVStream values if not set.
878 * Decoding: total stream bitrate in bit/s, 0 if not
879 * available. Never set it directly if the file_size and the
880 * duration are known as Libav can compute it automatically.
884 unsigned int packet_size;
888 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
889 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
890 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
891 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
892 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
893 #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
894 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
895 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
896 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
897 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
900 * decoding: size of data to probe; encoding: unused.
902 unsigned int probesize;
905 * decoding: maximum time (in AV_TIME_BASE units) during which the input should
906 * be analyzed in avformat_find_stream_info().
908 int max_analyze_duration;
913 unsigned int nb_programs;
914 AVProgram **programs;
917 * Forced video codec_id.
918 * Demuxing: Set by user.
920 enum AVCodecID video_codec_id;
923 * Forced audio codec_id.
924 * Demuxing: Set by user.
926 enum AVCodecID audio_codec_id;
929 * Forced subtitle codec_id.
930 * Demuxing: Set by user.
932 enum AVCodecID subtitle_codec_id;
935 * Maximum amount of memory in bytes to use for the index of each stream.
936 * If the index exceeds this size, entries will be discarded as
937 * needed to maintain a smaller size. This can lead to slower or less
938 * accurate seeking (depends on demuxer).
939 * Demuxers for which a full in-memory index is mandatory will ignore
942 * demuxing: set by user
944 unsigned int max_index_size;
947 * Maximum amount of memory in bytes to use for buffering frames
948 * obtained from realtime capture devices.
950 unsigned int max_picture_buffer;
953 * Number of chapters in AVChapter array.
954 * When muxing, chapters are normally written in the file header,
955 * so nb_chapters should normally be initialized before write_header
956 * is called. Some muxers (e.g. mov and mkv) can also write chapters
957 * in the trailer. To write chapters in the trailer, nb_chapters
958 * must be zero when write_header is called and non-zero when
959 * write_trailer is called.
960 * muxing : set by user
961 * demuxing: set by libavformat
963 unsigned int nb_chapters;
964 AVChapter **chapters;
966 AVDictionary *metadata;
969 * Start time of the stream in real world time, in microseconds
970 * since the unix epoch (00:00 1st January 1970). That is, pts=0
971 * in the stream was captured at this real world time.
972 * - encoding: Set by user.
973 * - decoding: Unused.
975 int64_t start_time_realtime;
978 * decoding: number of frames used to probe fps
983 * Error recognition; higher values will detect more errors but may
984 * misdetect some more or less valid parts as errors.
986 * - decoding: Set by user.
988 int error_recognition;
991 * Custom interrupt callbacks for the I/O layer.
993 * decoding: set by the user before avformat_open_input().
994 * encoding: set by the user before avformat_write_header()
995 * (mainly useful for AVFMT_NOFILE formats). The callback
996 * should also be passed to avio_open2() if it's used to
999 AVIOInterruptCB interrupt_callback;
1002 * Flags to enable debugging.
1005 #define FF_FDEBUG_TS 0x0001
1006 /*****************************************************************
1007 * All fields below this line are not part of the public API. They
1008 * may not be used outside of libavformat and can be changed and
1010 * New public fields should be added right above.
1011 *****************************************************************
1015 * This buffer is only needed when packets were already buffered but
1016 * not decoded, for example to get the codec parameters in MPEG
1019 struct AVPacketList *packet_buffer;
1020 struct AVPacketList *packet_buffer_end;
1022 /* av_seek_frame() support */
1023 int64_t data_offset; /**< offset of the first packet */
1026 * Raw packets from the demuxer, prior to parsing and decoding.
1027 * This buffer is used for buffering packets until the codec can
1028 * be identified, as parsing cannot be done without knowing the
1031 struct AVPacketList *raw_packet_buffer;
1032 struct AVPacketList *raw_packet_buffer_end;
1034 * Packets split by the parser get queued here.
1036 struct AVPacketList *parse_queue;
1037 struct AVPacketList *parse_queue_end;
1039 * Remaining size available for raw_packet_buffer, in bytes.
1041 #define RAW_PACKET_BUFFER_SIZE 2500000
1042 int raw_packet_buffer_remaining_size;
1045 * Offset to remap timestamps to be non-negative.
1046 * Expressed in timebase units.
1051 * Timebase for the timestamp offset.
1053 AVRational offset_timebase;
1057 typedef struct AVPacketList {
1059 struct AVPacketList *next;
1064 * @defgroup lavf_core Core functions
1067 * Functions for querying libavformat capabilities, allocating core structures,
1073 * Return the LIBAVFORMAT_VERSION_INT constant.
1075 unsigned avformat_version(void);
1078 * Return the libavformat build-time configuration.
1080 const char *avformat_configuration(void);
1083 * Return the libavformat license.
1085 const char *avformat_license(void);
1088 * Initialize libavformat and register all the muxers, demuxers and
1089 * protocols. If you do not call this function, then you can select
1090 * exactly which formats you want to support.
1092 * @see av_register_input_format()
1093 * @see av_register_output_format()
1094 * @see av_register_protocol()
1096 void av_register_all(void);
1098 void av_register_input_format(AVInputFormat *format);
1099 void av_register_output_format(AVOutputFormat *format);
1102 * Do global initialization of network components. This is optional,
1103 * but recommended, since it avoids the overhead of implicitly
1104 * doing the setup for each session.
1106 * Calling this function will become mandatory if using network
1107 * protocols at some major version bump.
1109 int avformat_network_init(void);
1112 * Undo the initialization done by avformat_network_init.
1114 int avformat_network_deinit(void);
1117 * If f is NULL, returns the first registered input format,
1118 * if f is non-NULL, returns the next registered input format after f
1119 * or NULL if f is the last one.
1121 AVInputFormat *av_iformat_next(AVInputFormat *f);
1124 * If f is NULL, returns the first registered output format,
1125 * if f is non-NULL, returns the next registered output format after f
1126 * or NULL if f is the last one.
1128 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1131 * Allocate an AVFormatContext.
1132 * avformat_free_context() can be used to free the context and everything
1133 * allocated by the framework within it.
1135 AVFormatContext *avformat_alloc_context(void);
1138 * Free an AVFormatContext and all its streams.
1139 * @param s context to free
1141 void avformat_free_context(AVFormatContext *s);
1144 * Get the AVClass for AVFormatContext. It can be used in combination with
1145 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1147 * @see av_opt_find().
1149 const AVClass *avformat_get_class(void);
1152 * Add a new stream to a media file.
1154 * When demuxing, it is called by the demuxer in read_header(). If the
1155 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1156 * be called in read_packet().
1158 * When muxing, should be called by the user before avformat_write_header().
1160 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1161 * will be initialized to use this codec. This is needed for e.g. codec-specific
1162 * defaults to be set, so codec should be provided if it is known.
1164 * @return newly created stream or NULL on error.
1166 AVStream *avformat_new_stream(AVFormatContext *s, AVCodec *c);
1168 AVProgram *av_new_program(AVFormatContext *s, int id);
1176 * @addtogroup lavf_decoding
1181 * Find AVInputFormat based on the short name of the input format.
1183 AVInputFormat *av_find_input_format(const char *short_name);
1186 * Guess the file format.
1188 * @param is_opened Whether the file is already opened; determines whether
1189 * demuxers with or without AVFMT_NOFILE are probed.
1191 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1194 * Guess the file format.
1196 * @param is_opened Whether the file is already opened; determines whether
1197 * demuxers with or without AVFMT_NOFILE are probed.
1198 * @param score_max A probe score larger that this is required to accept a
1199 * detection, the variable is set to the actual detection
1201 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1202 * to retry with a larger probe buffer.
1204 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1207 * Probe a bytestream to determine the input format. Each time a probe returns
1208 * with a score that is too low, the probe buffer size is increased and another
1209 * attempt is made. When the maximum probe size is reached, the input format
1210 * with the highest score is returned.
1212 * @param pb the bytestream to probe
1213 * @param fmt the input format is put here
1214 * @param filename the filename of the stream
1215 * @param logctx the log context
1216 * @param offset the offset within the bytestream to probe from
1217 * @param max_probe_size the maximum probe buffer size (zero for default)
1218 * @return 0 in case of success, a negative value corresponding to an
1219 * AVERROR code otherwise
1221 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1222 const char *filename, void *logctx,
1223 unsigned int offset, unsigned int max_probe_size);
1226 * Open an input stream and read the header. The codecs are not opened.
1227 * The stream must be closed with avformat_close_input().
1229 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1230 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1231 * function and written into ps.
1232 * Note that a user-supplied AVFormatContext will be freed on failure.
1233 * @param filename Name of the stream to open.
1234 * @param fmt If non-NULL, this parameter forces a specific input format.
1235 * Otherwise the format is autodetected.
1236 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1237 * On return this parameter will be destroyed and replaced with a dict containing
1238 * options that were not found. May be NULL.
1240 * @return 0 on success, a negative AVERROR on failure.
1242 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1244 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1247 * Read packets of a media file to get stream information. This
1248 * is useful for file formats with no headers such as MPEG. This
1249 * function also computes the real framerate in case of MPEG-2 repeat
1251 * The logical file position is not changed by this function;
1252 * examined packets may be buffered for later processing.
1254 * @param ic media file handle
1255 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1256 * dictionaries, where i-th member contains options for
1257 * codec corresponding to i-th stream.
1258 * On return each dictionary will be filled with options that were not found.
1259 * @return >=0 if OK, AVERROR_xxx on error
1261 * @note this function isn't guaranteed to open all the codecs, so
1262 * options being non-empty at return is a perfectly normal behavior.
1264 * @todo Let the user decide somehow what information is needed so that
1265 * we do not waste time getting stuff the user does not need.
1267 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1270 * Find the "best" stream in the file.
1271 * The best stream is determined according to various heuristics as the most
1272 * likely to be what the user expects.
1273 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1274 * default decoder for the stream's codec; streams for which no decoder can
1275 * be found are ignored.
1277 * @param ic media file handle
1278 * @param type stream type: video, audio, subtitles, etc.
1279 * @param wanted_stream_nb user-requested stream number,
1280 * or -1 for automatic selection
1281 * @param related_stream try to find a stream related (eg. in the same
1282 * program) to this one, or -1 if none
1283 * @param decoder_ret if non-NULL, returns the decoder for the
1285 * @param flags flags; none are currently defined
1286 * @return the non-negative stream number in case of success,
1287 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
1289 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
1290 * @note If av_find_best_stream returns successfully and decoder_ret is not
1291 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
1293 int av_find_best_stream(AVFormatContext *ic,
1294 enum AVMediaType type,
1295 int wanted_stream_nb,
1297 AVCodec **decoder_ret,
1301 * Return the next frame of a stream.
1302 * This function returns what is stored in the file, and does not validate
1303 * that what is there are valid frames for the decoder. It will split what is
1304 * stored in the file into frames and return one for each call. It will not
1305 * omit invalid data between valid frames so as to give the decoder the maximum
1306 * information possible for decoding.
1308 * If pkt->buf is NULL, then the packet is valid until the next
1309 * av_read_frame() or until avformat_close_input(). Otherwise the packet
1310 * is valid indefinitely. In both cases the packet must be freed with
1311 * av_free_packet when it is no longer needed. For video, the packet contains
1312 * exactly one frame. For audio, it contains an integer number of frames if each
1313 * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
1314 * have a variable size (e.g. MPEG audio), then it contains one frame.
1316 * pkt->pts, pkt->dts and pkt->duration are always set to correct
1317 * values in AVStream.time_base units (and guessed if the format cannot
1318 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
1319 * has B-frames, so it is better to rely on pkt->dts if you do not
1320 * decompress the payload.
1322 * @return 0 if OK, < 0 on error or end of file
1324 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
1327 * Seek to the keyframe at timestamp.
1328 * 'timestamp' in 'stream_index'.
1329 * @param stream_index If stream_index is (-1), a default
1330 * stream is selected, and timestamp is automatically converted
1331 * from AV_TIME_BASE units to the stream specific time_base.
1332 * @param timestamp Timestamp in AVStream.time_base units
1333 * or, if no stream is specified, in AV_TIME_BASE units.
1334 * @param flags flags which select direction and seeking mode
1335 * @return >= 0 on success
1337 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
1341 * Seek to timestamp ts.
1342 * Seeking will be done so that the point from which all active streams
1343 * can be presented successfully will be closest to ts and within min/max_ts.
1344 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
1346 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
1347 * are the file position (this may not be supported by all demuxers).
1348 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
1349 * in the stream with stream_index (this may not be supported by all demuxers).
1350 * Otherwise all timestamps are in units of the stream selected by stream_index
1351 * or if stream_index is -1, in AV_TIME_BASE units.
1352 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
1353 * keyframes (this may not be supported by all demuxers).
1355 * @param stream_index index of the stream which is used as time base reference
1356 * @param min_ts smallest acceptable timestamp
1357 * @param ts target timestamp
1358 * @param max_ts largest acceptable timestamp
1359 * @param flags flags
1360 * @return >=0 on success, error code otherwise
1362 * @note This is part of the new seek API which is still under construction.
1363 * Thus do not use this yet. It may change at any time, do not expect
1364 * ABI compatibility yet!
1366 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
1369 * Start playing a network-based stream (e.g. RTSP stream) at the
1372 int av_read_play(AVFormatContext *s);
1375 * Pause a network-based stream (e.g. RTSP stream).
1377 * Use av_read_play() to resume it.
1379 int av_read_pause(AVFormatContext *s);
1382 * Close an opened input AVFormatContext. Free it and all its contents
1383 * and set *s to NULL.
1385 void avformat_close_input(AVFormatContext **s);
1390 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
1391 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
1392 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
1393 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
1396 * @addtogroup lavf_encoding
1400 * Allocate the stream private data and write the stream header to
1401 * an output media file.
1403 * @param s Media file handle, must be allocated with avformat_alloc_context().
1404 * Its oformat field must be set to the desired output format;
1405 * Its pb field must be set to an already opened AVIOContext.
1406 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
1407 * On return this parameter will be destroyed and replaced with a dict containing
1408 * options that were not found. May be NULL.
1410 * @return 0 on success, negative AVERROR on failure.
1412 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
1414 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
1417 * Write a packet to an output media file.
1419 * The packet shall contain one audio or video frame.
1420 * The packet must be correctly interleaved according to the container
1421 * specification, if not then av_interleaved_write_frame must be used.
1423 * @param s media file handle
1424 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1426 * This can be NULL (at any time, not just at the end), in
1427 * order to immediately flush data buffered within the muxer,
1428 * for muxers that buffer up data internally before writing it
1430 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
1432 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
1435 * Write a packet to an output media file ensuring correct interleaving.
1437 * The packet must contain one audio or video frame.
1438 * If the packets are already correctly interleaved, the application should
1439 * call av_write_frame() instead as it is slightly faster. It is also important
1440 * to keep in mind that completely non-interleaved input will need huge amounts
1441 * of memory to interleave with this, so it is preferable to interleave at the
1444 * @param s media file handle
1445 * @param pkt The packet containing the data to be written. pkt->buf must be set
1446 * to a valid AVBufferRef describing the packet data. Libavformat takes
1447 * ownership of this reference and will unref it when it sees fit. The caller
1448 * must not access the data through this reference after this function returns.
1449 * This can be NULL (at any time, not just at the end), to flush the
1450 * interleaving queues.
1451 * Packet's @ref AVPacket.stream_index "stream_index" field must be set to the
1452 * index of the corresponding stream in @ref AVFormatContext.streams
1454 * It is very strongly recommended that timing information (@ref AVPacket.pts
1455 * "pts", @ref AVPacket.dts "dts" @ref AVPacket.duration "duration") is set to
1458 * @return 0 on success, a negative AVERROR on error.
1460 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
1463 * Write the stream trailer to an output media file and free the
1464 * file private data.
1466 * May only be called after a successful call to avformat_write_header.
1468 * @param s media file handle
1469 * @return 0 if OK, AVERROR_xxx on error
1471 int av_write_trailer(AVFormatContext *s);
1474 * Return the output format in the list of registered output formats
1475 * which best matches the provided parameters, or return NULL if
1476 * there is no match.
1478 * @param short_name if non-NULL checks if short_name matches with the
1479 * names of the registered formats
1480 * @param filename if non-NULL checks if filename terminates with the
1481 * extensions of the registered formats
1482 * @param mime_type if non-NULL checks if mime_type matches with the
1483 * MIME type of the registered formats
1485 AVOutputFormat *av_guess_format(const char *short_name,
1486 const char *filename,
1487 const char *mime_type);
1490 * Guess the codec ID based upon muxer and filename.
1492 enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
1493 const char *filename, const char *mime_type,
1494 enum AVMediaType type);
1502 * @defgroup lavf_misc Utility functions
1506 * Miscellaneous utility functions related to both muxing and demuxing
1511 * Send a nice hexadecimal dump of a buffer to the specified file stream.
1513 * @param f The file stream pointer where the dump should be sent to.
1515 * @param size buffer size
1517 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
1519 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
1522 * Send a nice hexadecimal dump of a buffer to the log.
1524 * @param avcl A pointer to an arbitrary struct of which the first field is a
1525 * pointer to an AVClass struct.
1526 * @param level The importance level of the message, lower values signifying
1527 * higher importance.
1529 * @param size buffer size
1531 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
1533 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
1536 * Send a nice dump of a packet to the specified file stream.
1538 * @param f The file stream pointer where the dump should be sent to.
1539 * @param pkt packet to dump
1540 * @param dump_payload True if the payload must be displayed, too.
1541 * @param st AVStream that the packet belongs to
1543 void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
1547 * Send a nice dump of a packet to the log.
1549 * @param avcl A pointer to an arbitrary struct of which the first field is a
1550 * pointer to an AVClass struct.
1551 * @param level The importance level of the message, lower values signifying
1552 * higher importance.
1553 * @param pkt packet to dump
1554 * @param dump_payload True if the payload must be displayed, too.
1555 * @param st AVStream that the packet belongs to
1557 void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
1561 * Get the AVCodecID for the given codec tag tag.
1562 * If no codec id is found returns AV_CODEC_ID_NONE.
1564 * @param tags list of supported codec_id-codec_tag pairs, as stored
1565 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1567 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
1570 * Get the codec tag for the given codec id id.
1571 * If no codec tag is found returns 0.
1573 * @param tags list of supported codec_id-codec_tag pairs, as stored
1574 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1576 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
1578 int av_find_default_stream_index(AVFormatContext *s);
1581 * Get the index for a specific timestamp.
1582 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
1583 * to the timestamp which is <= the requested one, if backward
1584 * is 0, then it will be >=
1585 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
1586 * @return < 0 if no such timestamp could be found
1588 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
1591 * Add an index entry into a sorted list. Update the entry if the list
1592 * already contains it.
1594 * @param timestamp timestamp in the time base of the given stream
1596 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
1597 int size, int distance, int flags);
1601 * Split a URL string into components.
1603 * The pointers to buffers for storing individual components may be null,
1604 * in order to ignore that component. Buffers for components not found are
1605 * set to empty strings. If the port is not found, it is set to a negative
1608 * @param proto the buffer for the protocol
1609 * @param proto_size the size of the proto buffer
1610 * @param authorization the buffer for the authorization
1611 * @param authorization_size the size of the authorization buffer
1612 * @param hostname the buffer for the host name
1613 * @param hostname_size the size of the hostname buffer
1614 * @param port_ptr a pointer to store the port number in
1615 * @param path the buffer for the path
1616 * @param path_size the size of the path buffer
1617 * @param url the URL to split
1619 void av_url_split(char *proto, int proto_size,
1620 char *authorization, int authorization_size,
1621 char *hostname, int hostname_size,
1623 char *path, int path_size,
1627 void av_dump_format(AVFormatContext *ic,
1633 * Return in 'buf' the path with '%d' replaced by a number.
1635 * Also handles the '%0nd' format where 'n' is the total number
1636 * of digits and '%%'.
1638 * @param buf destination buffer
1639 * @param buf_size destination buffer size
1640 * @param path numbered sequence string
1641 * @param number frame number
1642 * @return 0 if OK, -1 on format error
1644 int av_get_frame_filename(char *buf, int buf_size,
1645 const char *path, int number);
1648 * Check whether filename actually is a numbered sequence generator.
1650 * @param filename possible numbered sequence string
1651 * @return 1 if a valid numbered sequence string, 0 otherwise
1653 int av_filename_number_test(const char *filename);
1656 * Generate an SDP for an RTP session.
1658 * Note, this overwrites the id values of AVStreams in the muxer contexts
1659 * for getting unique dynamic payload types.
1661 * @param ac array of AVFormatContexts describing the RTP streams. If the
1662 * array is composed by only one context, such context can contain
1663 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
1664 * all the contexts in the array (an AVCodecContext per RTP stream)
1665 * must contain only one AVStream.
1666 * @param n_files number of AVCodecContexts contained in ac
1667 * @param buf buffer where the SDP will be stored (must be allocated by
1669 * @param size the size of the buffer
1670 * @return 0 if OK, AVERROR_xxx on error
1672 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
1675 * Return a positive value if the given filename has one of the given
1676 * extensions, 0 otherwise.
1678 * @param extensions a comma-separated list of filename extensions
1680 int av_match_ext(const char *filename, const char *extensions);
1683 * Test if the given container can store a codec.
1685 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
1687 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
1688 * A negative number if this information is not available.
1690 int avformat_query_codec(AVOutputFormat *ofmt, enum AVCodecID codec_id, int std_compliance);
1693 * @defgroup riff_fourcc RIFF FourCCs
1695 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
1696 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
1699 * uint32_t tag = MKTAG('H', '2', '6', '4');
1700 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
1701 * enum AVCodecID id = av_codec_get_id(table, tag);
1705 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
1707 const struct AVCodecTag *avformat_get_riff_video_tags(void);
1709 * @return the table mapping RIFF FourCCs for audio to AVCodecID.
1711 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
1720 #endif /* AVFORMAT_AVFORMAT_H */