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 * 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 FFmpeg,
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_RETRY (AVPROBE_SCORE_MAX/4)
341 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
342 #define AVPROBE_SCORE_MAX 100 ///< maximum score
344 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
346 /// Demuxer will use avio_open, no opened file should be provided by the caller.
347 #define AVFMT_NOFILE 0x0001
348 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
349 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
350 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
352 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
353 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
354 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
355 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
356 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
357 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
358 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
359 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
360 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
361 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
362 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
363 #if LIBAVFORMAT_VERSION_MAJOR <= 54
364 #define AVFMT_TS_NONSTRICT 0x8020000 //we try to be compatible to the ABIs of ffmpeg and major forks
366 #define AVFMT_TS_NONSTRICT 0x20000
368 /**< Format does not require strictly
369 increasing timestamps, but they must
370 still be monotonic */
371 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
372 timestamps. If not set the timestamp
373 will be shifted in av_write_frame and
374 av_interleaved_write_frame so they
376 The user or muxer can override this through
377 AVFormatContext.avoid_negative_ts
380 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
383 * @addtogroup lavf_encoding
386 typedef struct AVOutputFormat {
389 * Descriptive name for the format, meant to be more human-readable
390 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
393 const char *long_name;
394 const char *mime_type;
395 const char *extensions; /**< comma-separated filename extensions */
397 enum AVCodecID audio_codec; /**< default audio codec */
398 enum AVCodecID video_codec; /**< default video codec */
399 enum AVCodecID subtitle_codec; /**< default subtitle codec */
401 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
402 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
403 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
409 * List of supported codec_id-codec_tag pairs, ordered by "better
410 * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
412 const struct AVCodecTag * const *codec_tag;
415 const AVClass *priv_class; ///< AVClass for the private context
417 /*****************************************************************
418 * No fields below this line are part of the public API. They
419 * may not be used outside of libavformat and can be changed and
421 * New public fields should be added right above.
422 *****************************************************************
424 struct AVOutputFormat *next;
426 * size of private data so that it can be allocated in the wrapper
430 int (*write_header)(struct AVFormatContext *);
432 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
433 * pkt can be NULL in order to flush data buffered in the muxer.
434 * When flushing, return 0 if there still is more data to flush,
435 * or 1 if everything was flushed and there is no more buffered
438 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
439 int (*write_trailer)(struct AVFormatContext *);
441 * Currently only used to set pixel format if not YUV420P.
443 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
444 AVPacket *in, int flush);
446 * Test if the given codec can be stored in this container.
448 * @return 1 if the codec is supported, 0 if it is not.
449 * A negative number if unknown.
450 * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
452 int (*query_codec)(enum AVCodecID id, int std_compliance);
454 void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
455 int64_t *dts, int64_t *wall);
462 * @addtogroup lavf_decoding
465 typedef struct AVInputFormat {
467 * A comma separated list of short names for the format. New names
468 * may be appended with a minor bump.
473 * Descriptive name for the format, meant to be more human-readable
474 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
477 const char *long_name;
480 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
481 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
482 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
487 * If extensions are defined, then no probe is done. You should
488 * usually not use extension format guessing because it is not
491 const char *extensions;
493 const struct AVCodecTag * const *codec_tag;
495 const AVClass *priv_class; ///< AVClass for the private context
497 /*****************************************************************
498 * No fields below this line are part of the public API. They
499 * may not be used outside of libavformat and can be changed and
501 * New public fields should be added right above.
502 *****************************************************************
504 struct AVInputFormat *next;
507 * Raw demuxers store their codec ID here.
512 * Size of private data so that it can be allocated in the wrapper.
517 * Tell if a given file has a chance of being parsed as this format.
518 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
519 * big so you do not have to check for that unless you need more.
521 int (*read_probe)(AVProbeData *);
524 * Read the format header and initialize the AVFormatContext
525 * structure. Return 0 if OK. Only used in raw format right
526 * now. 'avformat_new_stream' should be called to create new streams.
528 int (*read_header)(struct AVFormatContext *);
531 * Read one packet and put it in 'pkt'. pts and flags are also
532 * set. 'avformat_new_stream' can be called only if the flag
533 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
534 * background thread).
535 * @return 0 on success, < 0 on error.
536 * When returning an error, pkt must not have been allocated
537 * or must be freed before returning
539 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
542 * Close the stream. The AVFormatContext and AVStreams are not
543 * freed by this function
545 int (*read_close)(struct AVFormatContext *);
548 * Seek to a given timestamp relative to the frames in
549 * stream component stream_index.
550 * @param stream_index Must not be -1.
551 * @param flags Selects which direction should be preferred if no exact
552 * match is available.
553 * @return >= 0 on success (but not necessarily the new offset)
555 int (*read_seek)(struct AVFormatContext *,
556 int stream_index, int64_t timestamp, int flags);
559 * Get the next timestamp in stream[stream_index].time_base units.
560 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
562 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
563 int64_t *pos, int64_t pos_limit);
566 * Start/resume playing - only meaningful if using a network-based format
569 int (*read_play)(struct AVFormatContext *);
572 * Pause playing - only meaningful if using a network-based format
575 int (*read_pause)(struct AVFormatContext *);
578 * Seek to timestamp ts.
579 * Seeking will be done so that the point from which all active streams
580 * can be presented successfully will be closest to ts and within min/max_ts.
581 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
583 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
589 enum AVStreamParseType {
591 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
592 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
593 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
594 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
595 AVSTREAM_PARSE_FULL_RAW=MKTAG(0,'R','A','W'), /**< full parsing and repack with timestamp and position generation by parser for raw
596 this assumes that each packet in the file contains no demuxer level headers and
597 just codec level data, otherwise position generation would fail */
600 typedef struct AVIndexEntry {
602 int64_t timestamp; /**<
603 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
604 * when seeking to this entry. That means preferable PTS on keyframe based formats.
605 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
608 #define AVINDEX_KEYFRAME 0x0001
610 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).
611 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
614 #define AV_DISPOSITION_DEFAULT 0x0001
615 #define AV_DISPOSITION_DUB 0x0002
616 #define AV_DISPOSITION_ORIGINAL 0x0004
617 #define AV_DISPOSITION_COMMENT 0x0008
618 #define AV_DISPOSITION_LYRICS 0x0010
619 #define AV_DISPOSITION_KARAOKE 0x0020
622 * Track should be used during playback by default.
623 * Useful for subtitle track that should be displayed
624 * even when user did not explicitly ask for subtitles.
626 #define AV_DISPOSITION_FORCED 0x0040
627 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
628 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
629 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
631 * The stream is stored in the file as an attached picture/"cover art" (e.g.
632 * APIC frame in ID3v2). The single packet associated with it will be returned
633 * among the first few packets read from the file unless seeking takes place.
634 * It can also be accessed at any time in AVStream.attached_pic.
636 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
639 * To specify text track kind (different from subtitles default).
641 #define AV_DISPOSITION_CAPTIONS 0x10000
642 #define AV_DISPOSITION_DESCRIPTIONS 0x20000
643 #define AV_DISPOSITION_METADATA 0x40000
646 * Options for behavior on timestamp wrap detection.
648 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
649 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
650 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
654 * New fields can be added to the end with minor version bumps.
655 * Removal, reordering and changes to existing fields require a major
657 * sizeof(AVStream) must not be used outside libav*.
659 typedef struct AVStream {
660 int index; /**< stream index in AVFormatContext */
662 * Format-specific stream ID.
663 * decoding: set by libavformat
664 * encoding: set by the user, replaced by libavformat if left unset
668 * Codec context associated with this stream. Allocated and freed by
671 * - decoding: The demuxer exports codec information stored in the headers
673 * - encoding: The user sets codec information, the muxer writes it to the
674 * output. Mandatory fields as specified in AVCodecContext
675 * documentation must be set even if this AVCodecContext is
676 * not actually used for encoding.
678 AVCodecContext *codec;
682 * encoding: pts generation when outputting stream
687 * This is the fundamental unit of time (in seconds) in terms
688 * of which frame timestamps are represented.
690 * decoding: set by libavformat
691 * encoding: set by libavformat in avformat_write_header. The muxer may use the
692 * user-provided value of @ref AVCodecContext.time_base "codec->time_base"
695 AVRational time_base;
698 * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
699 * Only set this if you are absolutely 100% sure that the value you set
700 * it to really is the pts of the first frame.
701 * This may be undefined (AV_NOPTS_VALUE).
702 * @note The ASF header does NOT contain a correct start_time the ASF
703 * demuxer must NOT set this.
708 * Decoding: duration of the stream, in stream time base.
709 * If a source file does not specify a duration, but does specify
710 * a bitrate, this value will be estimated from bitrate and file size.
714 int64_t nb_frames; ///< number of frames in this stream if known or 0
716 int disposition; /**< AV_DISPOSITION_* bit field */
718 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
721 * sample aspect ratio (0 if unknown)
722 * - encoding: Set by user.
723 * - decoding: Set by libavformat.
725 AVRational sample_aspect_ratio;
727 AVDictionary *metadata;
732 AVRational avg_frame_rate;
735 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
736 * will contain the attached picture.
738 * decoding: set by libavformat, must not be modified by the caller.
741 AVPacket attached_pic;
743 /*****************************************************************
744 * All fields below this line are not part of the public API. They
745 * may not be used outside of libavformat and can be changed and
747 * New public fields should be added right above.
748 *****************************************************************
752 * Stream information used internally by av_find_stream_info()
754 #define MAX_STD_TIMEBASES (60*12+6)
757 int64_t duration_gcd;
759 double (*duration_error)[2][MAX_STD_TIMEBASES];
760 int64_t codec_info_duration;
761 int64_t codec_info_duration_fields;
764 int64_t last_duration;
767 * Those are used for average framerate estimation.
769 int64_t fps_first_dts;
770 int fps_first_dts_idx;
771 int64_t fps_last_dts;
772 int fps_last_dts_idx;
776 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
778 // Timestamp generation support:
780 * Timestamp corresponding to the last dts sync point.
782 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
783 * a DTS is received from the underlying container. Otherwise set to
784 * AV_NOPTS_VALUE by default.
786 int64_t reference_dts;
790 int last_IP_duration;
793 * Number of packets to buffer for codec probing
795 #define MAX_PROBE_PACKETS 2500
799 * Number of frames that have been demuxed during av_find_stream_info()
801 int codec_info_nb_frames;
803 /* av_read_frame() support */
804 enum AVStreamParseType need_parsing;
805 struct AVCodecParserContext *parser;
808 * last packet in packet_buffer for this stream when muxing.
810 struct AVPacketList *last_in_packet_buffer;
811 AVProbeData probe_data;
812 #define MAX_REORDER_DELAY 16
813 int64_t pts_buffer[MAX_REORDER_DELAY+1];
815 AVIndexEntry *index_entries; /**< Only used if the format does not
816 support seeking natively. */
817 int nb_index_entries;
818 unsigned int index_entries_allocated_size;
821 * Real base framerate of the stream.
822 * This is the lowest framerate with which all timestamps can be
823 * represented accurately (it is the least common multiple of all
824 * framerates in the stream). Note, this value is just a guess!
825 * For example, if the time base is 1/90000 and all frames have either
826 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
828 * Code outside avformat should access this field using:
829 * av_stream_get/set_r_frame_rate(stream)
831 AVRational r_frame_rate;
835 * This is the MPEG-TS stream identifier +1
838 int stream_identifier;
840 int64_t interleaver_chunk_size;
841 int64_t interleaver_chunk_duration;
844 * stream probing state
845 * -1 -> probing finished
846 * 0 -> no probing requested
847 * rest -> perform probing with request_probe being the minimum score to accept.
848 * NOT PART OF PUBLIC API
852 * Indicates that everything up to the next keyframe
853 * should be discarded.
855 int skip_to_keyframe;
858 * Number of samples to skip at the start of the frame decoded from the next packet.
863 * Number of internally decoded frames, used internally in libavformat, do not access
864 * its lifetime differs from info which is why it is not in that structure.
866 int nb_decoded_frames;
869 * Timestamp offset added to timestamps before muxing
870 * NOT PART OF PUBLIC API
872 int64_t mux_ts_offset;
875 * Internal data to check for wrapping of the time stamp
877 int64_t pts_wrap_reference;
880 * Options for behavior, when a wrap is detected.
882 * Defined by AV_PTS_WRAP_ values.
884 * If correction is enabled, there are two possibilities:
885 * If the first time stamp is near the wrap point, the wrap offset
886 * will be subtracted, which will create negative time stamps.
887 * Otherwise the offset will be added.
889 int pts_wrap_behavior;
893 AVRational av_stream_get_r_frame_rate(const AVStream *s);
894 void av_stream_set_r_frame_rate(AVStream *s, AVRational r);
896 #define AV_PROGRAM_RUNNING 1
899 * New fields can be added to the end with minor version bumps.
900 * Removal, reordering and changes to existing fields require a major
902 * sizeof(AVProgram) must not be used outside libav*.
904 typedef struct AVProgram {
907 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
908 unsigned int *stream_index;
909 unsigned int nb_stream_indexes;
910 AVDictionary *metadata;
916 /*****************************************************************
917 * All fields below this line are not part of the public API. They
918 * may not be used outside of libavformat and can be changed and
920 * New public fields should be added right above.
921 *****************************************************************
926 int64_t pts_wrap_reference; ///< reference dts for wrap detection
927 int pts_wrap_behavior; ///< behavior on wrap detection
930 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
931 (streams are added dynamically) */
933 typedef struct AVChapter {
934 int id; ///< unique ID to identify the chapter
935 AVRational time_base; ///< time base in which the start/end timestamps are specified
936 int64_t start, end; ///< chapter start/end time in time_base units
937 AVDictionary *metadata;
942 * The duration of a video can be estimated through various ways, and this enum can be used
943 * to know how the duration was estimated.
945 enum AVDurationEstimationMethod {
946 AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
947 AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
948 AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
952 * Format I/O context.
953 * New fields can be added to the end with minor version bumps.
954 * Removal, reordering and changes to existing fields require a major
956 * sizeof(AVFormatContext) must not be used outside libav*, use
957 * avformat_alloc_context() to create an AVFormatContext.
959 typedef struct AVFormatContext {
961 * A class for logging and AVOptions. Set by avformat_alloc_context().
962 * Exports (de)muxer private options if they exist.
964 const AVClass *av_class;
967 * Can only be iformat or oformat, not both at the same time.
969 * decoding: set by avformat_open_input().
970 * encoding: set by the user.
972 struct AVInputFormat *iformat;
973 struct AVOutputFormat *oformat;
976 * Format private data. This is an AVOptions-enabled struct
977 * if and only if iformat/oformat.priv_class is not NULL.
984 * decoding: either set by the user before avformat_open_input() (then
985 * the user must close it manually) or set by avformat_open_input().
986 * encoding: set by the user.
988 * Do NOT set this field if AVFMT_NOFILE flag is set in
989 * iformat/oformat.flags. In such a case, the (de)muxer will handle
990 * I/O in some other way and this field will be NULL.
995 int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
998 * A list of all streams in the file. New streams are created with
999 * avformat_new_stream().
1001 * decoding: streams are created by libavformat in avformat_open_input().
1002 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1003 * appear in av_read_frame().
1004 * encoding: streams are created by the user before avformat_write_header().
1006 unsigned int nb_streams;
1009 char filename[1024]; /**< input or output filename */
1012 * Decoding: position of the first frame of the component, in
1013 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1014 * It is deduced from the AVStream values.
1019 * Decoding: duration of the stream, in AV_TIME_BASE fractional
1020 * seconds. Only set this value if you know none of the individual stream
1021 * durations and also do not set any of them. This is deduced from the
1022 * AVStream values if not set.
1027 * Decoding: total stream bitrate in bit/s, 0 if not
1028 * available. Never set it directly if the file_size and the
1029 * duration are known as FFmpeg can compute it automatically.
1033 unsigned int packet_size;
1037 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1038 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1039 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1040 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1041 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1042 #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
1043 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1044 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1045 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1046 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1047 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload
1048 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1049 #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)
1050 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Don't merge side data but keep it separate.
1053 * decoding: size of data to probe; encoding: unused.
1055 unsigned int probesize;
1058 * decoding: maximum time (in AV_TIME_BASE units) during which the input should
1059 * be analyzed in avformat_find_stream_info().
1061 int max_analyze_duration;
1066 unsigned int nb_programs;
1067 AVProgram **programs;
1070 * Forced video codec_id.
1071 * Demuxing: Set by user.
1073 enum AVCodecID video_codec_id;
1076 * Forced audio codec_id.
1077 * Demuxing: Set by user.
1079 enum AVCodecID audio_codec_id;
1082 * Forced subtitle codec_id.
1083 * Demuxing: Set by user.
1085 enum AVCodecID subtitle_codec_id;
1088 * Maximum amount of memory in bytes to use for the index of each stream.
1089 * If the index exceeds this size, entries will be discarded as
1090 * needed to maintain a smaller size. This can lead to slower or less
1091 * accurate seeking (depends on demuxer).
1092 * Demuxers for which a full in-memory index is mandatory will ignore
1095 * demuxing: set by user
1097 unsigned int max_index_size;
1100 * Maximum amount of memory in bytes to use for buffering frames
1101 * obtained from realtime capture devices.
1103 unsigned int max_picture_buffer;
1106 * Number of chapters in AVChapter array.
1107 * When muxing, chapters are normally written in the file header,
1108 * so nb_chapters should normally be initialized before write_header
1109 * is called. Some muxers (e.g. mov and mkv) can also write chapters
1110 * in the trailer. To write chapters in the trailer, nb_chapters
1111 * must be zero when write_header is called and non-zero when
1112 * write_trailer is called.
1113 * muxing : set by user
1114 * demuxing: set by libavformat
1116 unsigned int nb_chapters;
1117 AVChapter **chapters;
1119 AVDictionary *metadata;
1122 * Start time of the stream in real world time, in microseconds
1123 * since the unix epoch (00:00 1st January 1970). That is, pts=0
1124 * in the stream was captured at this real world time.
1125 * - encoding: Set by user.
1126 * - decoding: Unused.
1128 int64_t start_time_realtime;
1131 * decoding: number of frames used to probe fps
1136 * Error recognition; higher values will detect more errors but may
1137 * misdetect some more or less valid parts as errors.
1138 * - encoding: unused
1139 * - decoding: Set by user.
1141 int error_recognition;
1144 * Custom interrupt callbacks for the I/O layer.
1146 * decoding: set by the user before avformat_open_input().
1147 * encoding: set by the user before avformat_write_header()
1148 * (mainly useful for AVFMT_NOFILE formats). The callback
1149 * should also be passed to avio_open2() if it's used to
1152 AVIOInterruptCB interrupt_callback;
1155 * Flags to enable debugging.
1158 #define FF_FDEBUG_TS 0x0001
1161 * Transport stream id.
1162 * This will be moved into demuxer private options. Thus no API/ABI compatibility
1167 * Audio preload in microseconds.
1168 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1169 * - encoding: Set by user via AVOptions (NO direct access)
1170 * - decoding: unused
1175 * Max chunk time in microseconds.
1176 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1177 * - encoding: Set by user via AVOptions (NO direct access)
1178 * - decoding: unused
1180 int max_chunk_duration;
1183 * Max chunk size in bytes
1184 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1185 * - encoding: Set by user via AVOptions (NO direct access)
1186 * - decoding: unused
1191 * forces the use of wallclock timestamps as pts/dts of packets
1192 * This has undefined results in the presence of B frames.
1193 * - encoding: unused
1194 * - decoding: Set by user via AVOptions (NO direct access)
1196 int use_wallclock_as_timestamps;
1199 * Avoid negative timestamps during muxing.
1200 * 0 -> allow negative timestamps
1201 * 1 -> avoid negative timestamps
1202 * -1 -> choose automatically (default)
1203 * Note, this only works when interleave_packet_per_dts is in use.
1204 * - encoding: Set by user via AVOptions (NO direct access)
1205 * - decoding: unused
1207 int avoid_negative_ts;
1210 * avio flags, used to force AVIO_FLAG_DIRECT.
1211 * - encoding: unused
1212 * - decoding: Set by user via AVOptions (NO direct access)
1217 * The duration field can be estimated through various ways, and this field can be used
1218 * to know how the duration was estimated.
1219 * - encoding: unused
1220 * - decoding: Read by user via AVOptions (NO direct access)
1222 enum AVDurationEstimationMethod duration_estimation_method;
1225 * Skip initial bytes when opening stream
1226 * - encoding: unused
1227 * - decoding: Set by user via AVOptions (NO direct access)
1229 unsigned int skip_initial_bytes;
1232 * Correct single timestamp overflows
1233 * - encoding: unused
1234 * - decoding: Set by user via AVOPtions (NO direct access)
1236 unsigned int correct_ts_overflow;
1239 * Force seeking to any (also non key) frames.
1240 * - encoding: unused
1241 * - decoding: Set by user via AVOPtions (NO direct access)
1246 * Flush the I/O context after each packet.
1247 * - encoding: Set by user via AVOptions (NO direct access)
1248 * - decoding: unused
1253 * format probing score.
1254 * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1256 * - encoding: unused
1257 * - decoding: set by avformat, read by user via av_format_get_probe_score() (NO direct access)
1261 /*****************************************************************
1262 * All fields below this line are not part of the public API. They
1263 * may not be used outside of libavformat and can be changed and
1265 * New public fields should be added right above.
1266 *****************************************************************
1270 * This buffer is only needed when packets were already buffered but
1271 * not decoded, for example to get the codec parameters in MPEG
1274 struct AVPacketList *packet_buffer;
1275 struct AVPacketList *packet_buffer_end;
1277 /* av_seek_frame() support */
1278 int64_t data_offset; /**< offset of the first packet */
1281 * Raw packets from the demuxer, prior to parsing and decoding.
1282 * This buffer is used for buffering packets until the codec can
1283 * be identified, as parsing cannot be done without knowing the
1286 struct AVPacketList *raw_packet_buffer;
1287 struct AVPacketList *raw_packet_buffer_end;
1289 * Packets split by the parser get queued here.
1291 struct AVPacketList *parse_queue;
1292 struct AVPacketList *parse_queue_end;
1294 * Remaining size available for raw_packet_buffer, in bytes.
1296 #define RAW_PACKET_BUFFER_SIZE 2500000
1297 int raw_packet_buffer_remaining_size;
1300 * Offset to remap timestamps to be non-negative.
1301 * Expressed in timebase units.
1302 * @see AVStream.mux_ts_offset
1307 * Timebase for the timestamp offset.
1309 AVRational offset_timebase;
1312 * IO repositioned flag.
1313 * This is set by avformat when the underlaying IO context read pointer
1314 * is repositioned, for example when doing byte based seeking.
1315 * Demuxers can use the flag to detect such changes.
1317 int io_repositioned;
1320 int av_format_get_probe_score(const AVFormatContext *s);
1323 * Returns the method used to set ctx->duration.
1325 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1327 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
1329 typedef struct AVPacketList {
1331 struct AVPacketList *next;
1336 * @defgroup lavf_core Core functions
1339 * Functions for querying libavformat capabilities, allocating core structures,
1345 * Return the LIBAVFORMAT_VERSION_INT constant.
1347 unsigned avformat_version(void);
1350 * Return the libavformat build-time configuration.
1352 const char *avformat_configuration(void);
1355 * Return the libavformat license.
1357 const char *avformat_license(void);
1360 * Initialize libavformat and register all the muxers, demuxers and
1361 * protocols. If you do not call this function, then you can select
1362 * exactly which formats you want to support.
1364 * @see av_register_input_format()
1365 * @see av_register_output_format()
1367 void av_register_all(void);
1369 void av_register_input_format(AVInputFormat *format);
1370 void av_register_output_format(AVOutputFormat *format);
1373 * Do global initialization of network components. This is optional,
1374 * but recommended, since it avoids the overhead of implicitly
1375 * doing the setup for each session.
1377 * Calling this function will become mandatory if using network
1378 * protocols at some major version bump.
1380 int avformat_network_init(void);
1383 * Undo the initialization done by avformat_network_init.
1385 int avformat_network_deinit(void);
1388 * If f is NULL, returns the first registered input format,
1389 * if f is non-NULL, returns the next registered input format after f
1390 * or NULL if f is the last one.
1392 AVInputFormat *av_iformat_next(AVInputFormat *f);
1395 * If f is NULL, returns the first registered output format,
1396 * if f is non-NULL, returns the next registered output format after f
1397 * or NULL if f is the last one.
1399 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1402 * Allocate an AVFormatContext.
1403 * avformat_free_context() can be used to free the context and everything
1404 * allocated by the framework within it.
1406 AVFormatContext *avformat_alloc_context(void);
1409 * Free an AVFormatContext and all its streams.
1410 * @param s context to free
1412 void avformat_free_context(AVFormatContext *s);
1415 * Get the AVClass for AVFormatContext. It can be used in combination with
1416 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1418 * @see av_opt_find().
1420 const AVClass *avformat_get_class(void);
1423 * Add a new stream to a media file.
1425 * When demuxing, it is called by the demuxer in read_header(). If the
1426 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1427 * be called in read_packet().
1429 * When muxing, should be called by the user before avformat_write_header().
1431 * User is required to call avcodec_close() and avformat_free_context() to
1432 * clean up the allocation by avformat_new_stream().
1434 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1435 * will be initialized to use this codec. This is needed for e.g. codec-specific
1436 * defaults to be set, so codec should be provided if it is known.
1438 * @return newly created stream or NULL on error.
1440 AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c);
1442 AVProgram *av_new_program(AVFormatContext *s, int id);
1449 #if FF_API_ALLOC_OUTPUT_CONTEXT
1451 * @deprecated deprecated in favor of avformat_alloc_output_context2()
1453 attribute_deprecated
1454 AVFormatContext *avformat_alloc_output_context(const char *format,
1455 AVOutputFormat *oformat,
1456 const char *filename);
1460 * Allocate an AVFormatContext for an output format.
1461 * avformat_free_context() can be used to free the context and
1462 * everything allocated by the framework within it.
1464 * @param *ctx is set to the created format context, or to NULL in
1466 * @param oformat format to use for allocating the context, if NULL
1467 * format_name and filename are used instead
1468 * @param format_name the name of output format to use for allocating the
1469 * context, if NULL filename is used instead
1470 * @param filename the name of the filename to use for allocating the
1471 * context, may be NULL
1472 * @return >= 0 in case of success, a negative AVERROR code in case of
1475 int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat,
1476 const char *format_name, const char *filename);
1479 * @addtogroup lavf_decoding
1484 * Find AVInputFormat based on the short name of the input format.
1486 AVInputFormat *av_find_input_format(const char *short_name);
1489 * Guess the file format.
1491 * @param is_opened Whether the file is already opened; determines whether
1492 * demuxers with or without AVFMT_NOFILE are probed.
1494 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1497 * Guess the file format.
1499 * @param is_opened Whether the file is already opened; determines whether
1500 * demuxers with or without AVFMT_NOFILE are probed.
1501 * @param score_max A probe score larger that this is required to accept a
1502 * detection, the variable is set to the actual detection
1504 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1505 * to retry with a larger probe buffer.
1507 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1510 * Guess the file format.
1512 * @param is_opened Whether the file is already opened; determines whether
1513 * demuxers with or without AVFMT_NOFILE are probed.
1514 * @param score_ret The score of the best detection.
1516 AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
1519 * Probe a bytestream to determine the input format. Each time a probe returns
1520 * with a score that is too low, the probe buffer size is increased and another
1521 * attempt is made. When the maximum probe size is reached, the input format
1522 * with the highest score is returned.
1524 * @param pb the bytestream to probe
1525 * @param fmt the input format is put here
1526 * @param filename the filename of the stream
1527 * @param logctx the log context
1528 * @param offset the offset within the bytestream to probe from
1529 * @param max_probe_size the maximum probe buffer size (zero for default)
1530 * @return the score in case of success, a negative value corresponding to an
1531 * the maximal score is AVPROBE_SCORE_MAX
1532 * AVERROR code otherwise
1534 int av_probe_input_buffer2(AVIOContext *pb, AVInputFormat **fmt,
1535 const char *filename, void *logctx,
1536 unsigned int offset, unsigned int max_probe_size);
1539 * Like av_probe_input_buffer2() but returns 0 on success
1541 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1542 const char *filename, void *logctx,
1543 unsigned int offset, unsigned int max_probe_size);
1546 * Open an input stream and read the header. The codecs are not opened.
1547 * The stream must be closed with avformat_close_input().
1549 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1550 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1551 * function and written into ps.
1552 * Note that a user-supplied AVFormatContext will be freed on failure.
1553 * @param filename Name of the stream to open.
1554 * @param fmt If non-NULL, this parameter forces a specific input format.
1555 * Otherwise the format is autodetected.
1556 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1557 * On return this parameter will be destroyed and replaced with a dict containing
1558 * options that were not found. May be NULL.
1560 * @return 0 on success, a negative AVERROR on failure.
1562 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1564 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1566 attribute_deprecated
1567 int av_demuxer_open(AVFormatContext *ic);
1569 #if FF_API_FORMAT_PARAMETERS
1571 * Read packets of a media file to get stream information. This
1572 * is useful for file formats with no headers such as MPEG. This
1573 * function also computes the real framerate in case of MPEG-2 repeat
1575 * The logical file position is not changed by this function;
1576 * examined packets may be buffered for later processing.
1578 * @param ic media file handle
1579 * @return >=0 if OK, AVERROR_xxx on error
1580 * @todo Let the user decide somehow what information is needed so that
1581 * we do not waste time getting stuff the user does not need.
1583 * @deprecated use avformat_find_stream_info.
1585 attribute_deprecated
1586 int av_find_stream_info(AVFormatContext *ic);
1590 * Read packets of a media file to get stream information. This
1591 * is useful for file formats with no headers such as MPEG. This
1592 * function also computes the real framerate in case of MPEG-2 repeat
1594 * The logical file position is not changed by this function;
1595 * examined packets may be buffered for later processing.
1597 * @param ic media file handle
1598 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1599 * dictionaries, where i-th member contains options for
1600 * codec corresponding to i-th stream.
1601 * On return each dictionary will be filled with options that were not found.
1602 * @return >=0 if OK, AVERROR_xxx on error
1604 * @note this function isn't guaranteed to open all the codecs, so
1605 * options being non-empty at return is a perfectly normal behavior.
1607 * @todo Let the user decide somehow what information is needed so that
1608 * we do not waste time getting stuff the user does not need.
1610 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1613 * Find the programs which belong to a given stream.
1615 * @param ic media file handle
1616 * @param last the last found program, the search will start after this
1617 * program, or from the beginning if it is NULL
1618 * @param s stream index
1619 * @return the next program which belongs to s, NULL if no program is found or
1620 * the last program is not among the programs of ic.
1622 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s);
1625 * Find the "best" stream in the file.
1626 * The best stream is determined according to various heuristics as the most
1627 * likely to be what the user expects.
1628 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1629 * default decoder for the stream's codec; streams for which no decoder can
1630 * be found are ignored.
1632 * @param ic media file handle
1633 * @param type stream type: video, audio, subtitles, etc.
1634 * @param wanted_stream_nb user-requested stream number,
1635 * or -1 for automatic selection
1636 * @param related_stream try to find a stream related (eg. in the same
1637 * program) to this one, or -1 if none
1638 * @param decoder_ret if non-NULL, returns the decoder for the
1640 * @param flags flags; none are currently defined
1641 * @return the non-negative stream number in case of success,
1642 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
1644 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
1645 * @note If av_find_best_stream returns successfully and decoder_ret is not
1646 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
1648 int av_find_best_stream(AVFormatContext *ic,
1649 enum AVMediaType type,
1650 int wanted_stream_nb,
1652 AVCodec **decoder_ret,
1655 #if FF_API_READ_PACKET
1657 * @deprecated use AVFMT_FLAG_NOFILLIN | AVFMT_FLAG_NOPARSE to read raw
1658 * unprocessed packets
1660 * Read a transport packet from a media file.
1662 * This function is obsolete and should never be used.
1663 * Use av_read_frame() instead.
1665 * @param s media file handle
1666 * @param pkt is filled
1667 * @return 0 if OK, AVERROR_xxx on error
1669 attribute_deprecated
1670 int av_read_packet(AVFormatContext *s, AVPacket *pkt);
1674 * Return the next frame of a stream.
1675 * This function returns what is stored in the file, and does not validate
1676 * that what is there are valid frames for the decoder. It will split what is
1677 * stored in the file into frames and return one for each call. It will not
1678 * omit invalid data between valid frames so as to give the decoder the maximum
1679 * information possible for decoding.
1681 * If pkt->buf is NULL, then the packet is valid until the next
1682 * av_read_frame() or until avformat_close_input(). Otherwise the packet
1683 * is valid indefinitely. In both cases the packet must be freed with
1684 * av_free_packet when it is no longer needed. For video, the packet contains
1685 * exactly one frame. For audio, it contains an integer number of frames if each
1686 * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
1687 * have a variable size (e.g. MPEG audio), then it contains one frame.
1689 * pkt->pts, pkt->dts and pkt->duration are always set to correct
1690 * values in AVStream.time_base units (and guessed if the format cannot
1691 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
1692 * has B-frames, so it is better to rely on pkt->dts if you do not
1693 * decompress the payload.
1695 * @return 0 if OK, < 0 on error or end of file
1697 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
1700 * Seek to the keyframe at timestamp.
1701 * 'timestamp' in 'stream_index'.
1702 * @param stream_index If stream_index is (-1), a default
1703 * stream is selected, and timestamp is automatically converted
1704 * from AV_TIME_BASE units to the stream specific time_base.
1705 * @param timestamp Timestamp in AVStream.time_base units
1706 * or, if no stream is specified, in AV_TIME_BASE units.
1707 * @param flags flags which select direction and seeking mode
1708 * @return >= 0 on success
1710 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
1714 * Seek to timestamp ts.
1715 * Seeking will be done so that the point from which all active streams
1716 * can be presented successfully will be closest to ts and within min/max_ts.
1717 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
1719 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
1720 * are the file position (this may not be supported by all demuxers).
1721 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
1722 * in the stream with stream_index (this may not be supported by all demuxers).
1723 * Otherwise all timestamps are in units of the stream selected by stream_index
1724 * or if stream_index is -1, in AV_TIME_BASE units.
1725 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
1726 * keyframes (this may not be supported by all demuxers).
1727 * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
1729 * @param stream_index index of the stream which is used as time base reference
1730 * @param min_ts smallest acceptable timestamp
1731 * @param ts target timestamp
1732 * @param max_ts largest acceptable timestamp
1733 * @param flags flags
1734 * @return >=0 on success, error code otherwise
1736 * @note This is part of the new seek API which is still under construction.
1737 * Thus do not use this yet. It may change at any time, do not expect
1738 * ABI compatibility yet!
1740 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
1743 * Start playing a network-based stream (e.g. RTSP stream) at the
1746 int av_read_play(AVFormatContext *s);
1749 * Pause a network-based stream (e.g. RTSP stream).
1751 * Use av_read_play() to resume it.
1753 int av_read_pause(AVFormatContext *s);
1755 #if FF_API_CLOSE_INPUT_FILE
1757 * @deprecated use avformat_close_input()
1758 * Close a media file (but not its codecs).
1760 * @param s media file handle
1762 attribute_deprecated
1763 void av_close_input_file(AVFormatContext *s);
1767 * Close an opened input AVFormatContext. Free it and all its contents
1768 * and set *s to NULL.
1770 void avformat_close_input(AVFormatContext **s);
1775 #if FF_API_NEW_STREAM
1777 * Add a new stream to a media file.
1779 * Can only be called in the read_header() function. If the flag
1780 * AVFMTCTX_NOHEADER is in the format context, then new streams
1781 * can be added in read_packet too.
1783 * @param s media file handle
1784 * @param id file-format-dependent stream ID
1786 attribute_deprecated
1787 AVStream *av_new_stream(AVFormatContext *s, int id);
1790 #if FF_API_SET_PTS_INFO
1792 * @deprecated this function is not supposed to be called outside of lavf
1794 attribute_deprecated
1795 void av_set_pts_info(AVStream *s, int pts_wrap_bits,
1796 unsigned int pts_num, unsigned int pts_den);
1799 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
1800 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
1801 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
1802 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
1805 * @addtogroup lavf_encoding
1809 * Allocate the stream private data and write the stream header to
1810 * an output media file.
1812 * @param s Media file handle, must be allocated with avformat_alloc_context().
1813 * Its oformat field must be set to the desired output format;
1814 * Its pb field must be set to an already opened AVIOContext.
1815 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
1816 * On return this parameter will be destroyed and replaced with a dict containing
1817 * options that were not found. May be NULL.
1819 * @return 0 on success, negative AVERROR on failure.
1821 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
1823 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
1826 * Write a packet to an output media file.
1828 * The packet shall contain one audio or video frame.
1829 * The packet must be correctly interleaved according to the container
1830 * specification, if not then av_interleaved_write_frame must be used.
1832 * @param s media file handle
1833 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1835 * This can be NULL (at any time, not just at the end), in
1836 * order to immediately flush data buffered within the muxer,
1837 * for muxers that buffer up data internally before writing it
1839 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
1841 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
1844 * Write a packet to an output media file ensuring correct interleaving.
1846 * The packet must contain one audio or video frame.
1847 * If the packets are already correctly interleaved, the application should
1848 * call av_write_frame() instead as it is slightly faster. It is also important
1849 * to keep in mind that completely non-interleaved input will need huge amounts
1850 * of memory to interleave with this, so it is preferable to interleave at the
1853 * @param s media file handle
1854 * @param pkt The packet containing the data to be written. pkt->buf must be set
1855 * to a valid AVBufferRef describing the packet data. Libavformat takes
1856 * ownership of this reference and will unref it when it sees fit. The caller
1857 * must not access the data through this reference after this function returns.
1858 * This can be NULL (at any time, not just at the end), to flush the
1859 * interleaving queues.
1860 * Packet's @ref AVPacket.stream_index "stream_index" field must be set to the
1861 * index of the corresponding stream in @ref AVFormatContext.streams
1863 * It is very strongly recommended that timing information (@ref AVPacket.pts
1864 * "pts", @ref AVPacket.dts "dts" @ref AVPacket.duration "duration") is set to
1867 * @return 0 on success, a negative AVERROR on error.
1869 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
1872 * Write the stream trailer to an output media file and free the
1873 * file private data.
1875 * May only be called after a successful call to avformat_write_header.
1877 * @param s media file handle
1878 * @return 0 if OK, AVERROR_xxx on error
1880 int av_write_trailer(AVFormatContext *s);
1883 * Return the output format in the list of registered output formats
1884 * which best matches the provided parameters, or return NULL if
1885 * there is no match.
1887 * @param short_name if non-NULL checks if short_name matches with the
1888 * names of the registered formats
1889 * @param filename if non-NULL checks if filename terminates with the
1890 * extensions of the registered formats
1891 * @param mime_type if non-NULL checks if mime_type matches with the
1892 * MIME type of the registered formats
1894 AVOutputFormat *av_guess_format(const char *short_name,
1895 const char *filename,
1896 const char *mime_type);
1899 * Guess the codec ID based upon muxer and filename.
1901 enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
1902 const char *filename, const char *mime_type,
1903 enum AVMediaType type);
1906 * Get timing information for the data currently output.
1907 * The exact meaning of "currently output" depends on the format.
1908 * It is mostly relevant for devices that have an internal buffer and/or
1909 * work in real time.
1910 * @param s media file handle
1911 * @param stream stream in the media file
1912 * @param[out] dts DTS of the last packet output for the stream, in stream
1914 * @param[out] wall absolute time when that packet whas output,
1916 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
1917 * Note: some formats or devices may not allow to measure dts and wall
1920 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
1921 int64_t *dts, int64_t *wall);
1930 * @defgroup lavf_misc Utility functions
1934 * Miscellaneous utility functions related to both muxing and demuxing
1939 * Send a nice hexadecimal dump of a buffer to the specified file stream.
1941 * @param f The file stream pointer where the dump should be sent to.
1943 * @param size buffer size
1945 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
1947 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
1950 * Send a nice hexadecimal dump of a buffer to the log.
1952 * @param avcl A pointer to an arbitrary struct of which the first field is a
1953 * pointer to an AVClass struct.
1954 * @param level The importance level of the message, lower values signifying
1955 * higher importance.
1957 * @param size buffer size
1959 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
1961 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
1964 * Send a nice dump of a packet to the specified file stream.
1966 * @param f The file stream pointer where the dump should be sent to.
1967 * @param pkt packet to dump
1968 * @param dump_payload True if the payload must be displayed, too.
1969 * @param st AVStream that the packet belongs to
1971 void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
1975 * Send a nice dump of a packet to the log.
1977 * @param avcl A pointer to an arbitrary struct of which the first field is a
1978 * pointer to an AVClass struct.
1979 * @param level The importance level of the message, lower values signifying
1980 * higher importance.
1981 * @param pkt packet to dump
1982 * @param dump_payload True if the payload must be displayed, too.
1983 * @param st AVStream that the packet belongs to
1985 void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
1989 * Get the AVCodecID for the given codec tag tag.
1990 * If no codec id is found returns AV_CODEC_ID_NONE.
1992 * @param tags list of supported codec_id-codec_tag pairs, as stored
1993 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1995 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
1998 * Get the codec tag for the given codec id id.
1999 * If no codec tag is found returns 0.
2001 * @param tags list of supported codec_id-codec_tag pairs, as stored
2002 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2004 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2007 * Get the codec tag for the given codec id.
2009 * @param tags list of supported codec_id - codec_tag pairs, as stored
2010 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2011 * @param id codec id that should be searched for in the list
2012 * @param tag A pointer to the found tag
2013 * @return 0 if id was not found in tags, > 0 if it was found
2015 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2018 int av_find_default_stream_index(AVFormatContext *s);
2021 * Get the index for a specific timestamp.
2022 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2023 * to the timestamp which is <= the requested one, if backward
2024 * is 0, then it will be >=
2025 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2026 * @return < 0 if no such timestamp could be found
2028 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2031 * Add an index entry into a sorted list. Update the entry if the list
2032 * already contains it.
2034 * @param timestamp timestamp in the time base of the given stream
2036 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2037 int size, int distance, int flags);
2041 * Split a URL string into components.
2043 * The pointers to buffers for storing individual components may be null,
2044 * in order to ignore that component. Buffers for components not found are
2045 * set to empty strings. If the port is not found, it is set to a negative
2048 * @param proto the buffer for the protocol
2049 * @param proto_size the size of the proto buffer
2050 * @param authorization the buffer for the authorization
2051 * @param authorization_size the size of the authorization buffer
2052 * @param hostname the buffer for the host name
2053 * @param hostname_size the size of the hostname buffer
2054 * @param port_ptr a pointer to store the port number in
2055 * @param path the buffer for the path
2056 * @param path_size the size of the path buffer
2057 * @param url the URL to split
2059 void av_url_split(char *proto, int proto_size,
2060 char *authorization, int authorization_size,
2061 char *hostname, int hostname_size,
2063 char *path, int path_size,
2067 void av_dump_format(AVFormatContext *ic,
2073 * Return in 'buf' the path with '%d' replaced by a number.
2075 * Also handles the '%0nd' format where 'n' is the total number
2076 * of digits and '%%'.
2078 * @param buf destination buffer
2079 * @param buf_size destination buffer size
2080 * @param path numbered sequence string
2081 * @param number frame number
2082 * @return 0 if OK, -1 on format error
2084 int av_get_frame_filename(char *buf, int buf_size,
2085 const char *path, int number);
2088 * Check whether filename actually is a numbered sequence generator.
2090 * @param filename possible numbered sequence string
2091 * @return 1 if a valid numbered sequence string, 0 otherwise
2093 int av_filename_number_test(const char *filename);
2096 * Generate an SDP for an RTP session.
2098 * Note, this overwrites the id values of AVStreams in the muxer contexts
2099 * for getting unique dynamic payload types.
2101 * @param ac array of AVFormatContexts describing the RTP streams. If the
2102 * array is composed by only one context, such context can contain
2103 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2104 * all the contexts in the array (an AVCodecContext per RTP stream)
2105 * must contain only one AVStream.
2106 * @param n_files number of AVCodecContexts contained in ac
2107 * @param buf buffer where the SDP will be stored (must be allocated by
2109 * @param size the size of the buffer
2110 * @return 0 if OK, AVERROR_xxx on error
2112 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2115 * Return a positive value if the given filename has one of the given
2116 * extensions, 0 otherwise.
2118 * @param extensions a comma-separated list of filename extensions
2120 int av_match_ext(const char *filename, const char *extensions);
2123 * Test if the given container can store a codec.
2125 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2127 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2128 * A negative number if this information is not available.
2130 int avformat_query_codec(AVOutputFormat *ofmt, enum AVCodecID codec_id, int std_compliance);
2133 * @defgroup riff_fourcc RIFF FourCCs
2135 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2136 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2139 * uint32_t tag = MKTAG('H', '2', '6', '4');
2140 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2141 * enum AVCodecID id = av_codec_get_id(table, tag);
2145 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2147 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2149 * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2151 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2158 * Guess the sample aspect ratio of a frame, based on both the stream and the
2159 * frame aspect ratio.
2161 * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2162 * is set by the demuxer, these two may not be equal. This function tries to
2163 * return the value that you should use if you would like to display the frame.
2165 * Basic logic is to use the stream aspect ratio if it is set to something sane
2166 * otherwise use the frame aspect ratio. This way a container setting, which is
2167 * usually easy to modify can override the coded value in the frames.
2169 * @param format the format context which the stream is part of
2170 * @param stream the stream which the frame is part of
2171 * @param frame the frame with the aspect ratio to be determined
2172 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2174 AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame);
2177 * Guess the frame rate, based on both the container and codec information.
2179 * @param ctx the format context which the stream is part of
2180 * @param stream the stream which the frame is part of
2181 * @param frame the frame for which the frame rate should be determined, may be NULL
2182 * @return the guessed (valid) frame rate, 0/1 if no idea
2184 AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame);
2187 * Check if the stream st contained in s is matched by the stream specifier
2190 * See the "stream specifiers" chapter in the documentation for the syntax
2193 * @return >0 if st is matched by spec;
2194 * 0 if st is not matched by spec;
2195 * AVERROR code if spec is invalid
2197 * @note A stream specifier can match several streams in the format.
2199 int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st,
2202 int avformat_queue_attached_pictures(AVFormatContext *s);
2209 #endif /* AVFORMAT_AVFORMAT_H */