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_MAX 100 ///< maximum score, half of that is used for file-extension-based detection
341 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
342 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
344 /// Demuxer will use avio_open, no opened file should be provided by the caller.
345 #define AVFMT_NOFILE 0x0001
346 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
347 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
348 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
350 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
351 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
352 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
353 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
354 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
355 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
356 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
357 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fallback to binary search via read_timestamp */
358 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fallback to generic search */
359 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
360 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
361 #if LIBAVFORMAT_VERSION_MAJOR <= 54
362 #define AVFMT_TS_NONSTRICT 0x8020000 //we try to be compatible to the ABIs of ffmpeg and major forks
364 #define AVFMT_TS_NONSTRICT 0x20000
366 /**< Format does not require strictly
367 increasing timestamps, but they must
368 still be monotonic */
369 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
370 timestamps. If not set the timestamp
371 will be shifted in av_write_frame and
372 av_interleaved_write_frame so they
374 The user or muxer can override this through
375 AVFormatContext.avoid_negative_ts
378 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
381 * @addtogroup lavf_encoding
384 typedef struct AVOutputFormat {
387 * Descriptive name for the format, meant to be more human-readable
388 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
391 const char *long_name;
392 const char *mime_type;
393 const char *extensions; /**< comma-separated filename extensions */
395 enum AVCodecID audio_codec; /**< default audio codec */
396 enum AVCodecID video_codec; /**< default video codec */
397 enum AVCodecID subtitle_codec; /**< default subtitle codec */
399 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
400 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
401 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
407 * List of supported codec_id-codec_tag pairs, ordered by "better
408 * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
410 const struct AVCodecTag * const *codec_tag;
413 const AVClass *priv_class; ///< AVClass for the private context
415 /*****************************************************************
416 * No fields below this line are part of the public API. They
417 * may not be used outside of libavformat and can be changed and
419 * New public fields should be added right above.
420 *****************************************************************
422 struct AVOutputFormat *next;
424 * size of private data so that it can be allocated in the wrapper
428 int (*write_header)(struct AVFormatContext *);
430 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
431 * pkt can be NULL in order to flush data buffered in the muxer.
432 * When flushing, return 0 if there still is more data to flush,
433 * or 1 if everything was flushed and there is no more buffered
436 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
437 int (*write_trailer)(struct AVFormatContext *);
439 * Currently only used to set pixel format if not YUV420P.
441 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
442 AVPacket *in, int flush);
444 * Test if the given codec can be stored in this container.
446 * @return 1 if the codec is supported, 0 if it is not.
447 * A negative number if unknown.
448 * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
450 int (*query_codec)(enum AVCodecID id, int std_compliance);
452 void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
453 int64_t *dts, int64_t *wall);
460 * @addtogroup lavf_decoding
463 typedef struct AVInputFormat {
465 * A comma separated list of short names for the format. New names
466 * may be appended with a minor bump.
471 * Descriptive name for the format, meant to be more human-readable
472 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
475 const char *long_name;
478 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
479 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
480 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
485 * If extensions are defined, then no probe is done. You should
486 * usually not use extension format guessing because it is not
489 const char *extensions;
491 const struct AVCodecTag * const *codec_tag;
493 const AVClass *priv_class; ///< AVClass for the private context
495 /*****************************************************************
496 * No fields below this line are part of the public API. They
497 * may not be used outside of libavformat and can be changed and
499 * New public fields should be added right above.
500 *****************************************************************
502 struct AVInputFormat *next;
505 * Raw demuxers store their codec ID here.
510 * Size of private data so that it can be allocated in the wrapper.
515 * Tell if a given file has a chance of being parsed as this format.
516 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
517 * big so you do not have to check for that unless you need more.
519 int (*read_probe)(AVProbeData *);
522 * Read the format header and initialize the AVFormatContext
523 * structure. Return 0 if OK. Only used in raw format right
524 * now. 'avformat_new_stream' should be called to create new streams.
526 int (*read_header)(struct AVFormatContext *);
529 * Read one packet and put it in 'pkt'. pts and flags are also
530 * set. 'avformat_new_stream' can be called only if the flag
531 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
532 * background thread).
533 * @return 0 on success, < 0 on error.
534 * When returning an error, pkt must not have been allocated
535 * or must be freed before returning
537 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
540 * Close the stream. The AVFormatContext and AVStreams are not
541 * freed by this function
543 int (*read_close)(struct AVFormatContext *);
546 * Seek to a given timestamp relative to the frames in
547 * stream component stream_index.
548 * @param stream_index Must not be -1.
549 * @param flags Selects which direction should be preferred if no exact
550 * match is available.
551 * @return >= 0 on success (but not necessarily the new offset)
553 int (*read_seek)(struct AVFormatContext *,
554 int stream_index, int64_t timestamp, int flags);
557 * Get the next timestamp in stream[stream_index].time_base units.
558 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
560 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
561 int64_t *pos, int64_t pos_limit);
564 * Start/resume playing - only meaningful if using a network-based format
567 int (*read_play)(struct AVFormatContext *);
570 * Pause playing - only meaningful if using a network-based format
573 int (*read_pause)(struct AVFormatContext *);
576 * Seek to timestamp ts.
577 * Seeking will be done so that the point from which all active streams
578 * can be presented successfully will be closest to ts and within min/max_ts.
579 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
581 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
587 enum AVStreamParseType {
589 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
590 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
591 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
592 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
593 AVSTREAM_PARSE_FULL_RAW=MKTAG(0,'R','A','W'), /**< full parsing and repack with timestamp and position generation by parser for raw
594 this assumes that each packet in the file contains no demuxer level headers and
595 just codec level data, otherwise position generation would fail */
598 typedef struct AVIndexEntry {
600 int64_t timestamp; /**<
601 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
602 * when seeking to this entry. That means preferable PTS on keyframe based formats.
603 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
606 #define AVINDEX_KEYFRAME 0x0001
608 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).
609 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
612 #define AV_DISPOSITION_DEFAULT 0x0001
613 #define AV_DISPOSITION_DUB 0x0002
614 #define AV_DISPOSITION_ORIGINAL 0x0004
615 #define AV_DISPOSITION_COMMENT 0x0008
616 #define AV_DISPOSITION_LYRICS 0x0010
617 #define AV_DISPOSITION_KARAOKE 0x0020
620 * Track should be used during playback by default.
621 * Useful for subtitle track that should be displayed
622 * even when user did not explicitly ask for subtitles.
624 #define AV_DISPOSITION_FORCED 0x0040
625 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
626 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
627 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
629 * The stream is stored in the file as an attached picture/"cover art" (e.g.
630 * APIC frame in ID3v2). The single packet associated with it will be returned
631 * among the first few packets read from the file unless seeking takes place.
632 * It can also be accessed at any time in AVStream.attached_pic.
634 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
637 * Options for behavior on timestamp wrap detection.
639 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
640 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
641 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
645 * New fields can be added to the end with minor version bumps.
646 * Removal, reordering and changes to existing fields require a major
648 * sizeof(AVStream) must not be used outside libav*.
650 typedef struct AVStream {
651 int index; /**< stream index in AVFormatContext */
653 * Format-specific stream ID.
654 * decoding: set by libavformat
655 * encoding: set by the user, replaced by libavformat if left unset
659 * Codec context associated with this stream. Allocated and freed by
662 * - decoding: The demuxer exports codec information stored in the headers
664 * - encoding: The user sets codec information, the muxer writes it to the
665 * output. Mandatory fields as specified in AVCodecContext
666 * documentation must be set even if this AVCodecContext is
667 * not actually used for encoding.
669 AVCodecContext *codec;
673 * encoding: pts generation when outputting stream
678 * This is the fundamental unit of time (in seconds) in terms
679 * of which frame timestamps are represented.
681 * decoding: set by libavformat
682 * encoding: set by libavformat in avformat_write_header. The muxer may use the
683 * user-provided value of @ref AVCodecContext.time_base "codec->time_base"
686 AVRational time_base;
689 * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
690 * Only set this if you are absolutely 100% sure that the value you set
691 * it to really is the pts of the first frame.
692 * This may be undefined (AV_NOPTS_VALUE).
693 * @note The ASF header does NOT contain a correct start_time the ASF
694 * demuxer must NOT set this.
699 * Decoding: duration of the stream, in stream time base.
700 * If a source file does not specify a duration, but does specify
701 * a bitrate, this value will be estimated from bitrate and file size.
705 int64_t nb_frames; ///< number of frames in this stream if known or 0
707 int disposition; /**< AV_DISPOSITION_* bit field */
709 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
712 * sample aspect ratio (0 if unknown)
713 * - encoding: Set by user.
714 * - decoding: Set by libavformat.
716 AVRational sample_aspect_ratio;
718 AVDictionary *metadata;
723 AVRational avg_frame_rate;
726 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
727 * will contain the attached picture.
729 * decoding: set by libavformat, must not be modified by the caller.
732 AVPacket attached_pic;
735 * Real base framerate of the stream.
736 * This is the lowest framerate with which all timestamps can be
737 * represented accurately (it is the least common multiple of all
738 * framerates in the stream). Note, this value is just a guess!
739 * For example, if the time base is 1/90000 and all frames have either
740 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
742 * Code outside avformat should access this field using:
743 * av_stream_get/set_r_frame_rate(stream)
745 AVRational r_frame_rate;
747 /*****************************************************************
748 * All fields below this line are not part of the public API. They
749 * may not be used outside of libavformat and can be changed and
751 * New public fields should be added right above.
752 *****************************************************************
756 * Stream information used internally by av_find_stream_info()
758 #define MAX_STD_TIMEBASES (60*12+6)
761 int64_t duration_gcd;
763 double (*duration_error)[2][MAX_STD_TIMEBASES];
764 int64_t codec_info_duration;
765 int64_t codec_info_duration_fields;
768 int64_t last_duration;
771 * Those are used for average framerate estimation.
773 int64_t fps_first_dts;
774 int fps_first_dts_idx;
775 int64_t fps_last_dts;
776 int fps_last_dts_idx;
780 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
782 // Timestamp generation support:
784 * Timestamp corresponding to the last dts sync point.
786 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
787 * a DTS is received from the underlying container. Otherwise set to
788 * AV_NOPTS_VALUE by default.
790 int64_t reference_dts;
794 int last_IP_duration;
797 * Number of packets to buffer for codec probing
799 #define MAX_PROBE_PACKETS 2500
803 * Number of frames that have been demuxed during av_find_stream_info()
805 int codec_info_nb_frames;
809 * This is the MPEG-TS stream identifier +1
812 int stream_identifier;
814 int64_t interleaver_chunk_size;
815 int64_t interleaver_chunk_duration;
817 /* av_read_frame() support */
818 enum AVStreamParseType need_parsing;
819 struct AVCodecParserContext *parser;
822 * last packet in packet_buffer for this stream when muxing.
824 struct AVPacketList *last_in_packet_buffer;
825 AVProbeData probe_data;
826 #define MAX_REORDER_DELAY 16
827 int64_t pts_buffer[MAX_REORDER_DELAY+1];
829 AVIndexEntry *index_entries; /**< Only used if the format does not
830 support seeking natively. */
831 int nb_index_entries;
832 unsigned int index_entries_allocated_size;
835 * stream probing state
836 * -1 -> probing finished
837 * 0 -> no probing requested
838 * rest -> perform probing with request_probe being the minimum score to accept.
839 * NOT PART OF PUBLIC API
843 * Indicates that everything up to the next keyframe
844 * should be discarded.
846 int skip_to_keyframe;
849 * Number of samples to skip at the start of the frame decoded from the next packet.
854 * Number of internally decoded frames, used internally in libavformat, do not access
855 * its lifetime differs from info which is why it is not in that structure.
857 int nb_decoded_frames;
860 * Timestamp offset added to timestamps before muxing
861 * NOT PART OF PUBLIC API
863 int64_t mux_ts_offset;
866 * Internal data to check for wrapping of the time stamp
868 int64_t pts_wrap_reference;
871 * Options for behavior, when a wrap is detected.
873 * Defined by AV_PTS_WRAP_ values.
875 * If correction is enabled, there are two possibilities:
876 * If the first time stamp is near the wrap point, the wrap offset
877 * will be subtracted, which will create negative time stamps.
878 * Otherwise the offset will be added.
880 int pts_wrap_behavior;
884 AVRational av_stream_get_r_frame_rate(const AVStream *s);
885 void av_stream_set_r_frame_rate(AVStream *s, AVRational r);
887 #define AV_PROGRAM_RUNNING 1
890 * New fields can be added to the end with minor version bumps.
891 * Removal, reordering and changes to existing fields require a major
893 * sizeof(AVProgram) must not be used outside libav*.
895 typedef struct AVProgram {
898 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
899 unsigned int *stream_index;
900 unsigned int nb_stream_indexes;
901 AVDictionary *metadata;
907 /*****************************************************************
908 * All fields below this line are not part of the public API. They
909 * may not be used outside of libavformat and can be changed and
911 * New public fields should be added right above.
912 *****************************************************************
917 int64_t pts_wrap_reference; ///< reference dts for wrap detection
918 int pts_wrap_behavior; ///< behavior on wrap detection
921 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
922 (streams are added dynamically) */
924 typedef struct AVChapter {
925 int id; ///< unique ID to identify the chapter
926 AVRational time_base; ///< time base in which the start/end timestamps are specified
927 int64_t start, end; ///< chapter start/end time in time_base units
928 AVDictionary *metadata;
933 * The duration of a video can be estimated through various ways, and this enum can be used
934 * to know how the duration was estimated.
936 enum AVDurationEstimationMethod {
937 AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
938 AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
939 AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
943 * Format I/O context.
944 * New fields can be added to the end with minor version bumps.
945 * Removal, reordering and changes to existing fields require a major
947 * sizeof(AVFormatContext) must not be used outside libav*, use
948 * avformat_alloc_context() to create an AVFormatContext.
950 typedef struct AVFormatContext {
952 * A class for logging and AVOptions. Set by avformat_alloc_context().
953 * Exports (de)muxer private options if they exist.
955 const AVClass *av_class;
958 * Can only be iformat or oformat, not both at the same time.
960 * decoding: set by avformat_open_input().
961 * encoding: set by the user.
963 struct AVInputFormat *iformat;
964 struct AVOutputFormat *oformat;
967 * Format private data. This is an AVOptions-enabled struct
968 * if and only if iformat/oformat.priv_class is not NULL.
975 * decoding: either set by the user before avformat_open_input() (then
976 * the user must close it manually) or set by avformat_open_input().
977 * encoding: set by the user.
979 * Do NOT set this field if AVFMT_NOFILE flag is set in
980 * iformat/oformat.flags. In such a case, the (de)muxer will handle
981 * I/O in some other way and this field will be NULL.
986 int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
989 * A list of all streams in the file. New streams are created with
990 * avformat_new_stream().
992 * decoding: streams are created by libavformat in avformat_open_input().
993 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
994 * appear in av_read_frame().
995 * encoding: streams are created by the user before avformat_write_header().
997 unsigned int nb_streams;
1000 char filename[1024]; /**< input or output filename */
1003 * Decoding: position of the first frame of the component, in
1004 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1005 * It is deduced from the AVStream values.
1010 * Decoding: duration of the stream, in AV_TIME_BASE fractional
1011 * seconds. Only set this value if you know none of the individual stream
1012 * durations and also do not set any of them. This is deduced from the
1013 * AVStream values if not set.
1018 * Decoding: total stream bitrate in bit/s, 0 if not
1019 * available. Never set it directly if the file_size and the
1020 * duration are known as FFmpeg can compute it automatically.
1024 unsigned int packet_size;
1028 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1029 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1030 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1031 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1032 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1033 #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
1034 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1035 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1036 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1037 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload
1038 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1039 #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)
1040 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Don't merge side data but keep it separate.
1043 * decoding: size of data to probe; encoding: unused.
1045 unsigned int probesize;
1048 * decoding: maximum time (in AV_TIME_BASE units) during which the input should
1049 * be analyzed in avformat_find_stream_info().
1051 int max_analyze_duration;
1056 unsigned int nb_programs;
1057 AVProgram **programs;
1060 * Forced video codec_id.
1061 * Demuxing: Set by user.
1063 enum AVCodecID video_codec_id;
1066 * Forced audio codec_id.
1067 * Demuxing: Set by user.
1069 enum AVCodecID audio_codec_id;
1072 * Forced subtitle codec_id.
1073 * Demuxing: Set by user.
1075 enum AVCodecID subtitle_codec_id;
1078 * Maximum amount of memory in bytes to use for the index of each stream.
1079 * If the index exceeds this size, entries will be discarded as
1080 * needed to maintain a smaller size. This can lead to slower or less
1081 * accurate seeking (depends on demuxer).
1082 * Demuxers for which a full in-memory index is mandatory will ignore
1085 * demuxing: set by user
1087 unsigned int max_index_size;
1090 * Maximum amount of memory in bytes to use for buffering frames
1091 * obtained from realtime capture devices.
1093 unsigned int max_picture_buffer;
1095 unsigned int nb_chapters;
1096 AVChapter **chapters;
1098 AVDictionary *metadata;
1101 * Start time of the stream in real world time, in microseconds
1102 * since the unix epoch (00:00 1st January 1970). That is, pts=0
1103 * in the stream was captured at this real world time.
1104 * - encoding: Set by user.
1105 * - decoding: Unused.
1107 int64_t start_time_realtime;
1110 * decoding: number of frames used to probe fps
1115 * Error recognition; higher values will detect more errors but may
1116 * misdetect some more or less valid parts as errors.
1117 * - encoding: unused
1118 * - decoding: Set by user.
1120 int error_recognition;
1123 * Custom interrupt callbacks for the I/O layer.
1125 * decoding: set by the user before avformat_open_input().
1126 * encoding: set by the user before avformat_write_header()
1127 * (mainly useful for AVFMT_NOFILE formats). The callback
1128 * should also be passed to avio_open2() if it's used to
1131 AVIOInterruptCB interrupt_callback;
1134 * Flags to enable debugging.
1137 #define FF_FDEBUG_TS 0x0001
1140 * Transport stream id.
1141 * This will be moved into demuxer private options. Thus no API/ABI compatibility
1146 * Audio preload in microseconds.
1147 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1148 * - encoding: Set by user via AVOptions (NO direct access)
1149 * - decoding: unused
1154 * Max chunk time in microseconds.
1155 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1156 * - encoding: Set by user via AVOptions (NO direct access)
1157 * - decoding: unused
1159 int max_chunk_duration;
1162 * Max chunk size in bytes
1163 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1164 * - encoding: Set by user via AVOptions (NO direct access)
1165 * - decoding: unused
1170 * forces the use of wallclock timestamps as pts/dts of packets
1171 * This has undefined results in the presence of B frames.
1172 * - encoding: unused
1173 * - decoding: Set by user via AVOptions (NO direct access)
1175 int use_wallclock_as_timestamps;
1178 * Avoid negative timestamps during muxing.
1179 * 0 -> allow negative timestamps
1180 * 1 -> avoid negative timestamps
1181 * -1 -> choose automatically (default)
1182 * Note, this only works when interleave_packet_per_dts is in use.
1183 * - encoding: Set by user via AVOptions (NO direct access)
1184 * - decoding: unused
1186 int avoid_negative_ts;
1189 * avio flags, used to force AVIO_FLAG_DIRECT.
1190 * - encoding: unused
1191 * - decoding: Set by user via AVOptions (NO direct access)
1196 * The duration field can be estimated through various ways, and this field can be used
1197 * to know how the duration was estimated.
1198 * - encoding: unused
1199 * - decoding: Read by user via AVOptions (NO direct access)
1201 enum AVDurationEstimationMethod duration_estimation_method;
1204 * Skip initial bytes when opening stream
1205 * - encoding: unused
1206 * - decoding: Set by user via AVOptions (NO direct access)
1208 unsigned int skip_initial_bytes;
1211 * Correct single timestamp overflows
1212 * - encoding: unused
1213 * - decoding: Set by user via AVOPtions (NO direct access)
1215 unsigned int correct_ts_overflow;
1218 * Force seeking to any (also non key) frames.
1219 * - encoding: unused
1220 * - decoding: Set by user via AVOPtions (NO direct access)
1225 * Flush the I/O context after each packet.
1226 * - encoding: Set by user via AVOptions (NO direct access)
1227 * - decoding: unused
1231 /*****************************************************************
1232 * All fields below this line are not part of the public API. They
1233 * may not be used outside of libavformat and can be changed and
1235 * New public fields should be added right above.
1236 *****************************************************************
1240 * This buffer is only needed when packets were already buffered but
1241 * not decoded, for example to get the codec parameters in MPEG
1244 struct AVPacketList *packet_buffer;
1245 struct AVPacketList *packet_buffer_end;
1247 /* av_seek_frame() support */
1248 int64_t data_offset; /**< offset of the first packet */
1251 * Raw packets from the demuxer, prior to parsing and decoding.
1252 * This buffer is used for buffering packets until the codec can
1253 * be identified, as parsing cannot be done without knowing the
1256 struct AVPacketList *raw_packet_buffer;
1257 struct AVPacketList *raw_packet_buffer_end;
1259 * Packets split by the parser get queued here.
1261 struct AVPacketList *parse_queue;
1262 struct AVPacketList *parse_queue_end;
1264 * Remaining size available for raw_packet_buffer, in bytes.
1266 #define RAW_PACKET_BUFFER_SIZE 2500000
1267 int raw_packet_buffer_remaining_size;
1270 * Offset to remap timestamps to be non-negative.
1271 * Expressed in timebase units.
1272 * @see AVStream.mux_ts_offset
1277 * Timebase for the timestamp offset.
1279 AVRational offset_timebase;
1282 * IO repositioned flag.
1283 * This is set by avformat when the underlaying IO context read pointer
1284 * is repositioned, for example when doing byte based seeking.
1285 * Demuxers can use the flag to detect such changes.
1287 int io_repositioned;
1291 * Returns the method used to set ctx->duration.
1293 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1295 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
1297 typedef struct AVPacketList {
1299 struct AVPacketList *next;
1304 * @defgroup lavf_core Core functions
1307 * Functions for querying libavformat capabilities, allocating core structures,
1313 * Return the LIBAVFORMAT_VERSION_INT constant.
1315 unsigned avformat_version(void);
1318 * Return the libavformat build-time configuration.
1320 const char *avformat_configuration(void);
1323 * Return the libavformat license.
1325 const char *avformat_license(void);
1328 * Initialize libavformat and register all the muxers, demuxers and
1329 * protocols. If you do not call this function, then you can select
1330 * exactly which formats you want to support.
1332 * @see av_register_input_format()
1333 * @see av_register_output_format()
1335 void av_register_all(void);
1337 void av_register_input_format(AVInputFormat *format);
1338 void av_register_output_format(AVOutputFormat *format);
1341 * Do global initialization of network components. This is optional,
1342 * but recommended, since it avoids the overhead of implicitly
1343 * doing the setup for each session.
1345 * Calling this function will become mandatory if using network
1346 * protocols at some major version bump.
1348 int avformat_network_init(void);
1351 * Undo the initialization done by avformat_network_init.
1353 int avformat_network_deinit(void);
1356 * If f is NULL, returns the first registered input format,
1357 * if f is non-NULL, returns the next registered input format after f
1358 * or NULL if f is the last one.
1360 AVInputFormat *av_iformat_next(AVInputFormat *f);
1363 * If f is NULL, returns the first registered output format,
1364 * if f is non-NULL, returns the next registered output format after f
1365 * or NULL if f is the last one.
1367 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1370 * Allocate an AVFormatContext.
1371 * avformat_free_context() can be used to free the context and everything
1372 * allocated by the framework within it.
1374 AVFormatContext *avformat_alloc_context(void);
1377 * Free an AVFormatContext and all its streams.
1378 * @param s context to free
1380 void avformat_free_context(AVFormatContext *s);
1383 * Get the AVClass for AVFormatContext. It can be used in combination with
1384 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1386 * @see av_opt_find().
1388 const AVClass *avformat_get_class(void);
1391 * Add a new stream to a media file.
1393 * When demuxing, it is called by the demuxer in read_header(). If the
1394 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1395 * be called in read_packet().
1397 * When muxing, should be called by the user before avformat_write_header().
1399 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1400 * will be initialized to use this codec. This is needed for e.g. codec-specific
1401 * defaults to be set, so codec should be provided if it is known.
1403 * @return newly created stream or NULL on error.
1405 AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c);
1407 AVProgram *av_new_program(AVFormatContext *s, int id);
1415 attribute_deprecated void av_pkt_dump(FILE *f, AVPacket *pkt, int dump_payload);
1416 attribute_deprecated void av_pkt_dump_log(void *avcl, int level, AVPacket *pkt,
1420 #if FF_API_ALLOC_OUTPUT_CONTEXT
1422 * @deprecated deprecated in favor of avformat_alloc_output_context2()
1424 attribute_deprecated
1425 AVFormatContext *avformat_alloc_output_context(const char *format,
1426 AVOutputFormat *oformat,
1427 const char *filename);
1431 * Allocate an AVFormatContext for an output format.
1432 * avformat_free_context() can be used to free the context and
1433 * everything allocated by the framework within it.
1435 * @param *ctx is set to the created format context, or to NULL in
1437 * @param oformat format to use for allocating the context, if NULL
1438 * format_name and filename are used instead
1439 * @param format_name the name of output format to use for allocating the
1440 * context, if NULL filename is used instead
1441 * @param filename the name of the filename to use for allocating the
1442 * context, may be NULL
1443 * @return >= 0 in case of success, a negative AVERROR code in case of
1446 int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat,
1447 const char *format_name, const char *filename);
1450 * @addtogroup lavf_decoding
1455 * Find AVInputFormat based on the short name of the input format.
1457 AVInputFormat *av_find_input_format(const char *short_name);
1460 * Guess the file format.
1462 * @param is_opened Whether the file is already opened; determines whether
1463 * demuxers with or without AVFMT_NOFILE are probed.
1465 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1468 * Guess the file format.
1470 * @param is_opened Whether the file is already opened; determines whether
1471 * demuxers with or without AVFMT_NOFILE are probed.
1472 * @param score_max A probe score larger that this is required to accept a
1473 * detection, the variable is set to the actual detection
1475 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1476 * to retry with a larger probe buffer.
1478 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1481 * Guess the file format.
1483 * @param is_opened Whether the file is already opened; determines whether
1484 * demuxers with or without AVFMT_NOFILE are probed.
1485 * @param score_ret The score of the best detection.
1487 AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
1490 * Probe a bytestream to determine the input format. Each time a probe returns
1491 * with a score that is too low, the probe buffer size is increased and another
1492 * attempt is made. When the maximum probe size is reached, the input format
1493 * with the highest score is returned.
1495 * @param pb the bytestream to probe
1496 * @param fmt the input format is put here
1497 * @param filename the filename of the stream
1498 * @param logctx the log context
1499 * @param offset the offset within the bytestream to probe from
1500 * @param max_probe_size the maximum probe buffer size (zero for default)
1501 * @return 0 in case of success, a negative value corresponding to an
1502 * AVERROR code otherwise
1504 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1505 const char *filename, void *logctx,
1506 unsigned int offset, unsigned int max_probe_size);
1509 * Open an input stream and read the header. The codecs are not opened.
1510 * The stream must be closed with av_close_input_file().
1512 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1513 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1514 * function and written into ps.
1515 * Note that a user-supplied AVFormatContext will be freed on failure.
1516 * @param filename Name of the stream to open.
1517 * @param fmt If non-NULL, this parameter forces a specific input format.
1518 * Otherwise the format is autodetected.
1519 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1520 * On return this parameter will be destroyed and replaced with a dict containing
1521 * options that were not found. May be NULL.
1523 * @return 0 on success, a negative AVERROR on failure.
1525 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1527 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1529 attribute_deprecated
1530 int av_demuxer_open(AVFormatContext *ic);
1532 #if FF_API_FORMAT_PARAMETERS
1534 * Read packets of a media file to get stream information. This
1535 * is useful for file formats with no headers such as MPEG. This
1536 * function also computes the real framerate in case of MPEG-2 repeat
1538 * The logical file position is not changed by this function;
1539 * examined packets may be buffered for later processing.
1541 * @param ic media file handle
1542 * @return >=0 if OK, AVERROR_xxx on error
1543 * @todo Let the user decide somehow what information is needed so that
1544 * we do not waste time getting stuff the user does not need.
1546 * @deprecated use avformat_find_stream_info.
1548 attribute_deprecated
1549 int av_find_stream_info(AVFormatContext *ic);
1553 * Read packets of a media file to get stream information. This
1554 * is useful for file formats with no headers such as MPEG. This
1555 * function also computes the real framerate in case of MPEG-2 repeat
1557 * The logical file position is not changed by this function;
1558 * examined packets may be buffered for later processing.
1560 * @param ic media file handle
1561 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1562 * dictionaries, where i-th member contains options for
1563 * codec corresponding to i-th stream.
1564 * On return each dictionary will be filled with options that were not found.
1565 * @return >=0 if OK, AVERROR_xxx on error
1567 * @note this function isn't guaranteed to open all the codecs, so
1568 * options being non-empty at return is a perfectly normal behavior.
1570 * @todo Let the user decide somehow what information is needed so that
1571 * we do not waste time getting stuff the user does not need.
1573 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1576 * Find the programs which belong to a given stream.
1578 * @param ic media file handle
1579 * @param last the last found program, the search will start after this
1580 * program, or from the beginning if it is NULL
1581 * @param s stream index
1582 * @return the next program which belongs to s, NULL if no program is found or
1583 * the last program is not among the programs of ic.
1585 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s);
1588 * Find the "best" stream in the file.
1589 * The best stream is determined according to various heuristics as the most
1590 * likely to be what the user expects.
1591 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1592 * default decoder for the stream's codec; streams for which no decoder can
1593 * be found are ignored.
1595 * @param ic media file handle
1596 * @param type stream type: video, audio, subtitles, etc.
1597 * @param wanted_stream_nb user-requested stream number,
1598 * or -1 for automatic selection
1599 * @param related_stream try to find a stream related (eg. in the same
1600 * program) to this one, or -1 if none
1601 * @param decoder_ret if non-NULL, returns the decoder for the
1603 * @param flags flags; none are currently defined
1604 * @return the non-negative stream number in case of success,
1605 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
1607 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
1608 * @note If av_find_best_stream returns successfully and decoder_ret is not
1609 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
1611 int av_find_best_stream(AVFormatContext *ic,
1612 enum AVMediaType type,
1613 int wanted_stream_nb,
1615 AVCodec **decoder_ret,
1618 #if FF_API_READ_PACKET
1620 * @deprecated use AVFMT_FLAG_NOFILLIN | AVFMT_FLAG_NOPARSE to read raw
1621 * unprocessed packets
1623 * Read a transport packet from a media file.
1625 * This function is obsolete and should never be used.
1626 * Use av_read_frame() instead.
1628 * @param s media file handle
1629 * @param pkt is filled
1630 * @return 0 if OK, AVERROR_xxx on error
1632 attribute_deprecated
1633 int av_read_packet(AVFormatContext *s, AVPacket *pkt);
1637 * Return the next frame of a stream.
1638 * This function returns what is stored in the file, and does not validate
1639 * that what is there are valid frames for the decoder. It will split what is
1640 * stored in the file into frames and return one for each call. It will not
1641 * omit invalid data between valid frames so as to give the decoder the maximum
1642 * information possible for decoding.
1644 * If pkt->buf is NULL, then the packet is valid until the next
1645 * av_read_frame() or until av_close_input_file(). Otherwise the packet is valid
1646 * indefinitely. In both cases the packet must be freed with
1647 * av_free_packet when it is no longer needed. For video, the packet contains
1648 * exactly one frame. For audio, it contains an integer number of frames if each
1649 * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
1650 * have a variable size (e.g. MPEG audio), then it contains one frame.
1652 * pkt->pts, pkt->dts and pkt->duration are always set to correct
1653 * values in AVStream.time_base units (and guessed if the format cannot
1654 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
1655 * has B-frames, so it is better to rely on pkt->dts if you do not
1656 * decompress the payload.
1658 * @return 0 if OK, < 0 on error or end of file
1660 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
1663 * Seek to the keyframe at timestamp.
1664 * 'timestamp' in 'stream_index'.
1665 * @param stream_index If stream_index is (-1), a default
1666 * stream is selected, and timestamp is automatically converted
1667 * from AV_TIME_BASE units to the stream specific time_base.
1668 * @param timestamp Timestamp in AVStream.time_base units
1669 * or, if no stream is specified, in AV_TIME_BASE units.
1670 * @param flags flags which select direction and seeking mode
1671 * @return >= 0 on success
1673 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
1677 * Seek to timestamp ts.
1678 * Seeking will be done so that the point from which all active streams
1679 * can be presented successfully will be closest to ts and within min/max_ts.
1680 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
1682 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
1683 * are the file position (this may not be supported by all demuxers).
1684 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
1685 * in the stream with stream_index (this may not be supported by all demuxers).
1686 * Otherwise all timestamps are in units of the stream selected by stream_index
1687 * or if stream_index is -1, in AV_TIME_BASE units.
1688 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
1689 * keyframes (this may not be supported by all demuxers).
1691 * @param stream_index index of the stream which is used as time base reference
1692 * @param min_ts smallest acceptable timestamp
1693 * @param ts target timestamp
1694 * @param max_ts largest acceptable timestamp
1695 * @param flags flags
1696 * @return >=0 on success, error code otherwise
1698 * @note This is part of the new seek API which is still under construction.
1699 * Thus do not use this yet. It may change at any time, do not expect
1700 * ABI compatibility yet!
1702 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
1705 * Start playing a network-based stream (e.g. RTSP stream) at the
1708 int av_read_play(AVFormatContext *s);
1711 * Pause a network-based stream (e.g. RTSP stream).
1713 * Use av_read_play() to resume it.
1715 int av_read_pause(AVFormatContext *s);
1717 #if FF_API_CLOSE_INPUT_FILE
1719 * @deprecated use avformat_close_input()
1720 * Close a media file (but not its codecs).
1722 * @param s media file handle
1724 attribute_deprecated
1725 void av_close_input_file(AVFormatContext *s);
1729 * Close an opened input AVFormatContext. Free it and all its contents
1730 * and set *s to NULL.
1732 void avformat_close_input(AVFormatContext **s);
1737 #if FF_API_NEW_STREAM
1739 * Add a new stream to a media file.
1741 * Can only be called in the read_header() function. If the flag
1742 * AVFMTCTX_NOHEADER is in the format context, then new streams
1743 * can be added in read_packet too.
1745 * @param s media file handle
1746 * @param id file-format-dependent stream ID
1748 attribute_deprecated
1749 AVStream *av_new_stream(AVFormatContext *s, int id);
1752 #if FF_API_SET_PTS_INFO
1754 * @deprecated this function is not supposed to be called outside of lavf
1756 attribute_deprecated
1757 void av_set_pts_info(AVStream *s, int pts_wrap_bits,
1758 unsigned int pts_num, unsigned int pts_den);
1761 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
1762 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
1763 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
1764 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
1767 * @addtogroup lavf_encoding
1771 * Allocate the stream private data and write the stream header to
1772 * an output media file.
1774 * @param s Media file handle, must be allocated with avformat_alloc_context().
1775 * Its oformat field must be set to the desired output format;
1776 * Its pb field must be set to an already openened AVIOContext.
1777 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
1778 * On return this parameter will be destroyed and replaced with a dict containing
1779 * options that were not found. May be NULL.
1781 * @return 0 on success, negative AVERROR on failure.
1783 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
1785 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
1788 * Write a packet to an output media file.
1790 * The packet shall contain one audio or video frame.
1791 * The packet must be correctly interleaved according to the container
1792 * specification, if not then av_interleaved_write_frame must be used.
1794 * @param s media file handle
1795 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1797 * This can be NULL (at any time, not just at the end), in
1798 * order to immediately flush data buffered within the muxer,
1799 * for muxers that buffer up data internally before writing it
1801 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
1803 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
1806 * Write a packet to an output media file ensuring correct interleaving.
1808 * The packet must contain one audio or video frame.
1809 * If the packets are already correctly interleaved, the application should
1810 * call av_write_frame() instead as it is slightly faster. It is also important
1811 * to keep in mind that completely non-interleaved input will need huge amounts
1812 * of memory to interleave with this, so it is preferable to interleave at the
1815 * @param s media file handle
1816 * @param pkt The packet containing the data to be written. pkt->buf must be set
1817 * to a valid AVBufferRef describing the packet data. Libavformat takes
1818 * ownership of this reference and will unref it when it sees fit. The caller
1819 * must not access the data through this reference after this function returns.
1820 * This can be NULL (at any time, not just at the end), to flush the
1821 * interleaving queues.
1822 * Packet's @ref AVPacket.stream_index "stream_index" field must be set to the
1823 * index of the corresponding stream in @ref AVFormatContext.streams
1825 * It is very strongly recommended that timing information (@ref AVPacket.pts
1826 * "pts", @ref AVPacket.dts "dts" @ref AVPacket.duration "duration") is set to
1829 * @return 0 on success, a negative AVERROR on error.
1831 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
1834 * Write the stream trailer to an output media file and free the
1835 * file private data.
1837 * May only be called after a successful call to avformat_write_header.
1839 * @param s media file handle
1840 * @return 0 if OK, AVERROR_xxx on error
1842 int av_write_trailer(AVFormatContext *s);
1845 * Return the output format in the list of registered output formats
1846 * which best matches the provided parameters, or return NULL if
1847 * there is no match.
1849 * @param short_name if non-NULL checks if short_name matches with the
1850 * names of the registered formats
1851 * @param filename if non-NULL checks if filename terminates with the
1852 * extensions of the registered formats
1853 * @param mime_type if non-NULL checks if mime_type matches with the
1854 * MIME type of the registered formats
1856 AVOutputFormat *av_guess_format(const char *short_name,
1857 const char *filename,
1858 const char *mime_type);
1861 * Guess the codec ID based upon muxer and filename.
1863 enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
1864 const char *filename, const char *mime_type,
1865 enum AVMediaType type);
1868 * Get timing information for the data currently output.
1869 * The exact meaning of "currently output" depends on the format.
1870 * It is mostly relevant for devices that have an internal buffer and/or
1871 * work in real time.
1872 * @param s media file handle
1873 * @param stream stream in the media file
1874 * @param[out] dts DTS of the last packet output for the stream, in stream
1876 * @param[out] wall absolute time when that packet whas output,
1878 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
1879 * Note: some formats or devices may not allow to measure dts and wall
1882 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
1883 int64_t *dts, int64_t *wall);
1892 * @defgroup lavf_misc Utility functions
1896 * Miscellaneous utility functions related to both muxing and demuxing
1901 * Send a nice hexadecimal dump of a buffer to the specified file stream.
1903 * @param f The file stream pointer where the dump should be sent to.
1905 * @param size buffer size
1907 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
1909 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
1912 * Send a nice hexadecimal dump of a buffer to the log.
1914 * @param avcl A pointer to an arbitrary struct of which the first field is a
1915 * pointer to an AVClass struct.
1916 * @param level The importance level of the message, lower values signifying
1917 * higher importance.
1919 * @param size buffer size
1921 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
1923 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
1926 * Send a nice dump of a packet to the specified file stream.
1928 * @param f The file stream pointer where the dump should be sent to.
1929 * @param pkt packet to dump
1930 * @param dump_payload True if the payload must be displayed, too.
1931 * @param st AVStream that the packet belongs to
1933 void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
1937 * Send a nice dump of a packet to the log.
1939 * @param avcl A pointer to an arbitrary struct of which the first field is a
1940 * pointer to an AVClass struct.
1941 * @param level The importance level of the message, lower values signifying
1942 * higher importance.
1943 * @param pkt packet to dump
1944 * @param dump_payload True if the payload must be displayed, too.
1945 * @param st AVStream that the packet belongs to
1947 void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
1951 * Get the AVCodecID for the given codec tag tag.
1952 * If no codec id is found returns AV_CODEC_ID_NONE.
1954 * @param tags list of supported codec_id-codec_tag pairs, as stored
1955 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1957 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
1960 * Get the codec tag for the given codec id id.
1961 * If no codec tag is found returns 0.
1963 * @param tags list of supported codec_id-codec_tag pairs, as stored
1964 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1966 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
1969 * Get the codec tag for the given codec id.
1971 * @param tags list of supported codec_id - codec_tag pairs, as stored
1972 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1973 * @param id codec id that should be searched for in the list
1974 * @param tag A pointer to the found tag
1975 * @return 0 if id was not found in tags, > 0 if it was found
1977 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
1980 int av_find_default_stream_index(AVFormatContext *s);
1983 * Get the index for a specific timestamp.
1984 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
1985 * to the timestamp which is <= the requested one, if backward
1986 * is 0, then it will be >=
1987 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
1988 * @return < 0 if no such timestamp could be found
1990 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
1993 * Add an index entry into a sorted list. Update the entry if the list
1994 * already contains it.
1996 * @param timestamp timestamp in the time base of the given stream
1998 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
1999 int size, int distance, int flags);
2003 * Split a URL string into components.
2005 * The pointers to buffers for storing individual components may be null,
2006 * in order to ignore that component. Buffers for components not found are
2007 * set to empty strings. If the port is not found, it is set to a negative
2010 * @param proto the buffer for the protocol
2011 * @param proto_size the size of the proto buffer
2012 * @param authorization the buffer for the authorization
2013 * @param authorization_size the size of the authorization buffer
2014 * @param hostname the buffer for the host name
2015 * @param hostname_size the size of the hostname buffer
2016 * @param port_ptr a pointer to store the port number in
2017 * @param path the buffer for the path
2018 * @param path_size the size of the path buffer
2019 * @param url the URL to split
2021 void av_url_split(char *proto, int proto_size,
2022 char *authorization, int authorization_size,
2023 char *hostname, int hostname_size,
2025 char *path, int path_size,
2029 void av_dump_format(AVFormatContext *ic,
2035 * Return in 'buf' the path with '%d' replaced by a number.
2037 * Also handles the '%0nd' format where 'n' is the total number
2038 * of digits and '%%'.
2040 * @param buf destination buffer
2041 * @param buf_size destination buffer size
2042 * @param path numbered sequence string
2043 * @param number frame number
2044 * @return 0 if OK, -1 on format error
2046 int av_get_frame_filename(char *buf, int buf_size,
2047 const char *path, int number);
2050 * Check whether filename actually is a numbered sequence generator.
2052 * @param filename possible numbered sequence string
2053 * @return 1 if a valid numbered sequence string, 0 otherwise
2055 int av_filename_number_test(const char *filename);
2058 * Generate an SDP for an RTP session.
2060 * Note, this overwrites the id values of AVStreams in the muxer contexts
2061 * for getting unique dynamic payload types.
2063 * @param ac array of AVFormatContexts describing the RTP streams. If the
2064 * array is composed by only one context, such context can contain
2065 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2066 * all the contexts in the array (an AVCodecContext per RTP stream)
2067 * must contain only one AVStream.
2068 * @param n_files number of AVCodecContexts contained in ac
2069 * @param buf buffer where the SDP will be stored (must be allocated by
2071 * @param size the size of the buffer
2072 * @return 0 if OK, AVERROR_xxx on error
2074 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2077 * Return a positive value if the given filename has one of the given
2078 * extensions, 0 otherwise.
2080 * @param extensions a comma-separated list of filename extensions
2082 int av_match_ext(const char *filename, const char *extensions);
2085 * Test if the given container can store a codec.
2087 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2089 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2090 * A negative number if this information is not available.
2092 int avformat_query_codec(AVOutputFormat *ofmt, enum AVCodecID codec_id, int std_compliance);
2095 * @defgroup riff_fourcc RIFF FourCCs
2097 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2098 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2101 * uint32_t tag = MKTAG('H', '2', '6', '4');
2102 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2103 * enum AVCodecID id = av_codec_get_id(table, tag);
2107 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2109 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2111 * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2113 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2120 * Guess the sample aspect ratio of a frame, based on both the stream and the
2121 * frame aspect ratio.
2123 * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2124 * is set by the demuxer, these two may not be equal. This function tries to
2125 * return the value that you should use if you would like to display the frame.
2127 * Basic logic is to use the stream aspect ratio if it is set to something sane
2128 * otherwise use the frame aspect ratio. This way a container setting, which is
2129 * usually easy to modify can override the coded value in the frames.
2131 * @param format the format context which the stream is part of
2132 * @param stream the stream which the frame is part of
2133 * @param frame the frame with the aspect ratio to be determined
2134 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2136 AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame);
2139 * Guess the frame rate, based on both the container and codec information.
2141 * @param ctx the format context which the stream is part of
2142 * @param stream the stream which the frame is part of
2143 * @param frame the frame for which the frame rate should be determined, may be NULL
2144 * @return the guessed (valid) frame rate, 0/1 if no idea
2146 AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame);
2149 * Check if the stream st contained in s is matched by the stream specifier
2152 * See the "stream specifiers" chapter in the documentation for the syntax
2155 * @return >0 if st is matched by spec;
2156 * 0 if st is not matched by spec;
2157 * AVERROR code if spec is invalid
2159 * @note A stream specifier can match several streams in the format.
2161 int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st,
2164 int avformat_queue_attached_pictures(AVFormatContext *s);
2171 #endif /* AVFORMAT_AVFORMAT_H */