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.destruct is set on the returned packet, then the packet is
162 * allocated dynamically and the user may keep it indefinitely.
163 * Otherwise, if AVPacket.destruct 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 #if FF_API_AV_GETTIME
211 #include "libavutil/time.h"
214 struct AVFormatContext;
218 * @defgroup metadata_api Public Metadata API
221 * The metadata API allows libavformat to export metadata tags to a client
222 * application when demuxing. Conversely it allows a client application to
223 * set metadata when muxing.
225 * Metadata is exported or set as pairs of key/value strings in the 'metadata'
226 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
227 * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
228 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
229 * exported by demuxers isn't checked to be valid UTF-8 in most cases.
231 * Important concepts to keep in mind:
232 * - Keys are unique; there can never be 2 tags with the same key. This is
233 * also meant semantically, i.e., a demuxer should not knowingly produce
234 * several keys that are literally different but semantically identical.
235 * E.g., key=Author5, key=Author6. In this example, all authors must be
236 * placed in the same tag.
237 * - Metadata is flat, not hierarchical; there are no subtags. If you
238 * want to store, e.g., the email address of the child of producer Alice
239 * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
240 * - Several modifiers can be applied to the tag name. This is done by
241 * appending a dash character ('-') and the modifier name in the order
242 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
243 * - language -- a tag whose value is localized for a particular language
244 * is appended with the ISO 639-2/B 3-letter language code.
245 * For example: Author-ger=Michael, Author-eng=Mike
246 * The original/default language is in the unqualified "Author" tag.
247 * A demuxer should set a default if it sets any translated tag.
248 * - sorting -- a modified version of a tag that should be used for
249 * sorting will have '-sort' appended. E.g. artist="The Beatles",
250 * artist-sort="Beatles, The".
252 * - Demuxers attempt to export metadata in a generic format, however tags
253 * with no generic equivalents are left as they are stored in the container.
254 * Follows a list of generic tag names:
257 album -- name of the set this work belongs to
258 album_artist -- main creator of the set/album, if different from artist.
259 e.g. "Various Artists" for compilation albums.
260 artist -- main creator of the work
261 comment -- any additional description of the file.
262 composer -- who composed the work, if different from artist.
263 copyright -- name of copyright holder.
264 creation_time-- date when the file was created, preferably in ISO 8601.
265 date -- date when the work was created, preferably in ISO 8601.
266 disc -- number of a subset, e.g. disc in a multi-disc collection.
267 encoder -- name/settings of the software/hardware that produced the file.
268 encoded_by -- person/group who created the file.
269 filename -- original name of the file.
270 genre -- <self-evident>.
271 language -- main language in which the work is performed, preferably
272 in ISO 639-2 format. Multiple languages can be specified by
273 separating them with commas.
274 performer -- artist who performed the work, if different from artist.
275 E.g for "Also sprach Zarathustra", artist would be "Richard
276 Strauss" and performer "London Philharmonic Orchestra".
277 publisher -- name of the label/publisher.
278 service_name -- name of the service in broadcasting (channel name).
279 service_provider -- name of the service provider in broadcasting.
280 title -- name of the work.
281 track -- number of this work in the set, can be in form current/total.
282 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
285 * Look in the examples section for an application example how to use the Metadata API.
290 /* packet functions */
294 * Allocate and read the payload of a packet and initialize its
295 * fields with default values.
298 * @param size desired payload size
299 * @return >0 (read size) if OK, AVERROR_xxx otherwise
301 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
305 * Read data and append it to the current content of the AVPacket.
306 * If pkt->size is 0 this is identical to av_get_packet.
307 * Note that this uses av_grow_packet and thus involves a realloc
308 * which is inefficient. Thus this function should only be used
309 * when there is no reasonable way to know (an upper bound of)
313 * @param size amount of data to read
314 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
315 * will not be lost even if an error occurs.
317 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
319 /*************************************************/
320 /* fractional numbers for exact pts handling */
323 * The exact value of the fractional number is: 'val + num / den'.
324 * num is assumed to be 0 <= num < den.
326 typedef struct AVFrac {
327 int64_t val, num, den;
330 /*************************************************/
331 /* input/output formats */
336 * This structure contains the data a format has to probe a file.
338 typedef struct AVProbeData {
339 const char *filename;
340 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
341 int buf_size; /**< Size of buf except extra allocated bytes */
344 #define AVPROBE_SCORE_MAX 100 ///< maximum score, half of that is used for file-extension-based detection
345 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
346 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
348 /// Demuxer will use avio_open, no opened file should be provided by the caller.
349 #define AVFMT_NOFILE 0x0001
350 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
351 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
352 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
354 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
355 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
356 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
357 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
358 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
359 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
360 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
361 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fallback to binary search via read_timestamp */
362 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fallback to generic search */
363 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
364 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
365 #if LIBAVFORMAT_VERSION_MAJOR <= 54
366 #define AVFMT_TS_NONSTRICT 0x8020000 //we try to be compatible to the ABIs of ffmpeg and major forks
368 #define AVFMT_TS_NONSTRICT 0x20000
370 /**< Format does not require strictly
371 increasing timestamps, but they must
372 still be monotonic */
374 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
377 * @addtogroup lavf_encoding
380 typedef struct AVOutputFormat {
383 * Descriptive name for the format, meant to be more human-readable
384 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
387 const char *long_name;
388 const char *mime_type;
389 const char *extensions; /**< comma-separated filename extensions */
391 enum AVCodecID audio_codec; /**< default audio codec */
392 enum AVCodecID video_codec; /**< default video codec */
393 enum AVCodecID subtitle_codec; /**< default subtitle codec */
395 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
396 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
397 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
403 * List of supported codec_id-codec_tag pairs, ordered by "better
404 * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
406 const struct AVCodecTag * const *codec_tag;
409 const AVClass *priv_class; ///< AVClass for the private context
411 /*****************************************************************
412 * No fields below this line are part of the public API. They
413 * may not be used outside of libavformat and can be changed and
415 * New public fields should be added right above.
416 *****************************************************************
418 struct AVOutputFormat *next;
420 * size of private data so that it can be allocated in the wrapper
424 int (*write_header)(struct AVFormatContext *);
426 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
427 * pkt can be NULL in order to flush data buffered in the muxer.
428 * When flushing, return 0 if there still is more data to flush,
429 * or 1 if everything was flushed and there is no more buffered
432 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
433 int (*write_trailer)(struct AVFormatContext *);
435 * Currently only used to set pixel format if not YUV420P.
437 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
438 AVPacket *in, int flush);
440 * Test if the given codec can be stored in this container.
442 * @return 1 if the codec is supported, 0 if it is not.
443 * A negative number if unknown.
444 * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
446 int (*query_codec)(enum AVCodecID id, int std_compliance);
448 void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
449 int64_t *dts, int64_t *wall);
456 * @addtogroup lavf_decoding
459 typedef struct AVInputFormat {
461 * A comma separated list of short names for the format. New names
462 * may be appended with a minor bump.
467 * Descriptive name for the format, meant to be more human-readable
468 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
471 const char *long_name;
474 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
475 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
476 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
481 * If extensions are defined, then no probe is done. You should
482 * usually not use extension format guessing because it is not
485 const char *extensions;
487 const struct AVCodecTag * const *codec_tag;
489 const AVClass *priv_class; ///< AVClass for the private context
491 /*****************************************************************
492 * No fields below this line are part of the public API. They
493 * may not be used outside of libavformat and can be changed and
495 * New public fields should be added right above.
496 *****************************************************************
498 struct AVInputFormat *next;
501 * Raw demuxers store their codec ID here.
506 * Size of private data so that it can be allocated in the wrapper.
511 * Tell if a given file has a chance of being parsed as this format.
512 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
513 * big so you do not have to check for that unless you need more.
515 int (*read_probe)(AVProbeData *);
518 * Read the format header and initialize the AVFormatContext
519 * structure. Return 0 if OK. Only used in raw format right
520 * now. 'avformat_new_stream' should be called to create new streams.
522 int (*read_header)(struct AVFormatContext *);
525 * Read one packet and put it in 'pkt'. pts and flags are also
526 * set. 'avformat_new_stream' can be called only if the flag
527 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
528 * background thread).
529 * @return 0 on success, < 0 on error.
530 * When returning an error, pkt must not have been allocated
531 * or must be freed before returning
533 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
536 * Close the stream. The AVFormatContext and AVStreams are not
537 * freed by this function
539 int (*read_close)(struct AVFormatContext *);
542 * Seek to a given timestamp relative to the frames in
543 * stream component stream_index.
544 * @param stream_index Must not be -1.
545 * @param flags Selects which direction should be preferred if no exact
546 * match is available.
547 * @return >= 0 on success (but not necessarily the new offset)
549 int (*read_seek)(struct AVFormatContext *,
550 int stream_index, int64_t timestamp, int flags);
553 * Get the next timestamp in stream[stream_index].time_base units.
554 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
556 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
557 int64_t *pos, int64_t pos_limit);
560 * Start/resume playing - only meaningful if using a network-based format
563 int (*read_play)(struct AVFormatContext *);
566 * Pause playing - only meaningful if using a network-based format
569 int (*read_pause)(struct AVFormatContext *);
572 * Seek to timestamp ts.
573 * Seeking will be done so that the point from which all active streams
574 * can be presented successfully will be closest to ts and within min/max_ts.
575 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
577 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
583 enum AVStreamParseType {
585 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
586 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
587 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
588 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
589 AVSTREAM_PARSE_FULL_RAW=MKTAG(0,'R','A','W'), /**< full parsing and repack with timestamp and position generation by parser for raw
590 this assumes that each packet in the file contains no demuxer level headers and
591 just codec level data, otherwise position generation would fail */
594 typedef struct AVIndexEntry {
596 int64_t timestamp; /**<
597 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
598 * when seeking to this entry. That means preferable PTS on keyframe based formats.
599 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
602 #define AVINDEX_KEYFRAME 0x0001
604 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).
605 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
608 #define AV_DISPOSITION_DEFAULT 0x0001
609 #define AV_DISPOSITION_DUB 0x0002
610 #define AV_DISPOSITION_ORIGINAL 0x0004
611 #define AV_DISPOSITION_COMMENT 0x0008
612 #define AV_DISPOSITION_LYRICS 0x0010
613 #define AV_DISPOSITION_KARAOKE 0x0020
616 * Track should be used during playback by default.
617 * Useful for subtitle track that should be displayed
618 * even when user did not explicitly ask for subtitles.
620 #define AV_DISPOSITION_FORCED 0x0040
621 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
622 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
623 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
625 * The stream is stored in the file as an attached picture/"cover art" (e.g.
626 * APIC frame in ID3v2). The single packet associated with it will be returned
627 * among the first few packets read from the file unless seeking takes place.
628 * It can also be accessed at any time in AVStream.attached_pic.
630 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
634 * New fields can be added to the end with minor version bumps.
635 * Removal, reordering and changes to existing fields require a major
637 * sizeof(AVStream) must not be used outside libav*.
639 typedef struct AVStream {
640 int index; /**< stream index in AVFormatContext */
642 * Format-specific stream ID.
643 * decoding: set by libavformat
644 * encoding: set by the user, replaced by libavformat if left unset
648 * Codec context associated with this stream. Allocated and freed by
651 * - decoding: The demuxer exports codec information stored in the headers
653 * - encoding: The user sets codec information, the muxer writes it to the
654 * output. Mandatory fields as specified in AVCodecContext
655 * documentation must be set even if this AVCodecContext is
656 * not actually used for encoding.
658 AVCodecContext *codec;
659 #if FF_API_R_FRAME_RATE
661 * Real base framerate of the stream.
662 * This is the lowest framerate with which all timestamps can be
663 * represented accurately (it is the least common multiple of all
664 * framerates in the stream). Note, this value is just a guess!
665 * For example, if the time base is 1/90000 and all frames have either
666 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
668 AVRational r_frame_rate;
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;
734 /*****************************************************************
735 * All fields below this line are not part of the public API. They
736 * may not be used outside of libavformat and can be changed and
738 * New public fields should be added right above.
739 *****************************************************************
743 * Stream information used internally by av_find_stream_info()
745 #define MAX_STD_TIMEBASES (60*12+6)
748 int64_t duration_gcd;
750 double duration_error[2][2][MAX_STD_TIMEBASES];
751 int64_t codec_info_duration;
752 int64_t codec_info_duration_fields;
756 * Those are used for average framerate estimation.
758 int64_t fps_first_dts;
759 int fps_first_dts_idx;
760 int64_t fps_last_dts;
761 int fps_last_dts_idx;
765 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
767 // Timestamp generation support:
769 * Timestamp corresponding to the last dts sync point.
771 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
772 * a DTS is received from the underlying container. Otherwise set to
773 * AV_NOPTS_VALUE by default.
775 int64_t reference_dts;
779 int last_IP_duration;
782 * Number of packets to buffer for codec probing
784 #define MAX_PROBE_PACKETS 2500
788 * Number of frames that have been demuxed during av_find_stream_info()
790 int codec_info_nb_frames;
794 * This is the MPEG-TS stream identifier +1
797 int stream_identifier;
799 int64_t interleaver_chunk_size;
800 int64_t interleaver_chunk_duration;
802 /* av_read_frame() support */
803 enum AVStreamParseType need_parsing;
804 struct AVCodecParserContext *parser;
807 * last packet in packet_buffer for this stream when muxing.
809 struct AVPacketList *last_in_packet_buffer;
810 AVProbeData probe_data;
811 #define MAX_REORDER_DELAY 16
812 int64_t pts_buffer[MAX_REORDER_DELAY+1];
814 AVIndexEntry *index_entries; /**< Only used if the format does not
815 support seeking natively. */
816 int nb_index_entries;
817 unsigned int index_entries_allocated_size;
820 * stream probing state
821 * -1 -> probing finished
822 * 0 -> no probing requested
823 * rest -> perform probing with request_probe being the minimum score to accept.
824 * NOT PART OF PUBLIC API
828 * Indicates that everything up to the next keyframe
829 * should be discarded.
831 int skip_to_keyframe;
834 * Number of samples to skip at the start of the frame decoded from the next packet.
839 * Number of internally decoded frames, used internally in libavformat, do not access
840 * its lifetime differs from info which is why its not in that structure.
842 int nb_decoded_frames;
845 * Timestamp offset added to timestamps before muxing
846 * NOT PART OF PUBLIC API
848 int64_t mux_ts_offset;
852 #define AV_PROGRAM_RUNNING 1
855 * New fields can be added to the end with minor version bumps.
856 * Removal, reordering and changes to existing fields require a major
858 * sizeof(AVProgram) must not be used outside libav*.
860 typedef struct AVProgram {
863 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
864 unsigned int *stream_index;
865 unsigned int nb_stream_indexes;
866 AVDictionary *metadata;
872 /*****************************************************************
873 * All fields below this line are not part of the public API. They
874 * may not be used outside of libavformat and can be changed and
876 * New public fields should be added right above.
877 *****************************************************************
883 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
884 (streams are added dynamically) */
886 typedef struct AVChapter {
887 int id; ///< unique ID to identify the chapter
888 AVRational time_base; ///< time base in which the start/end timestamps are specified
889 int64_t start, end; ///< chapter start/end time in time_base units
890 AVDictionary *metadata;
895 * The duration of a video can be estimated through various ways, and this enum can be used
896 * to know how the duration was estimated.
898 enum AVDurationEstimationMethod {
899 AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
900 AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
901 AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
905 * Format I/O context.
906 * New fields can be added to the end with minor version bumps.
907 * Removal, reordering and changes to existing fields require a major
909 * sizeof(AVFormatContext) must not be used outside libav*, use
910 * avformat_alloc_context() to create an AVFormatContext.
912 typedef struct AVFormatContext {
914 * A class for logging and AVOptions. Set by avformat_alloc_context().
915 * Exports (de)muxer private options if they exist.
917 const AVClass *av_class;
920 * Can only be iformat or oformat, not both at the same time.
922 * decoding: set by avformat_open_input().
923 * encoding: set by the user.
925 struct AVInputFormat *iformat;
926 struct AVOutputFormat *oformat;
929 * Format private data. This is an AVOptions-enabled struct
930 * if and only if iformat/oformat.priv_class is not NULL.
937 * decoding: either set by the user before avformat_open_input() (then
938 * the user must close it manually) or set by avformat_open_input().
939 * encoding: set by the user.
941 * Do NOT set this field if AVFMT_NOFILE flag is set in
942 * iformat/oformat.flags. In such a case, the (de)muxer will handle
943 * I/O in some other way and this field will be NULL.
948 int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
951 * A list of all streams in the file. New streams are created with
952 * avformat_new_stream().
954 * decoding: streams are created by libavformat in avformat_open_input().
955 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
956 * appear in av_read_frame().
957 * encoding: streams are created by the user before avformat_write_header().
959 unsigned int nb_streams;
962 char filename[1024]; /**< input or output filename */
965 * Decoding: position of the first frame of the component, in
966 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
967 * It is deduced from the AVStream values.
972 * Decoding: duration of the stream, in AV_TIME_BASE fractional
973 * seconds. Only set this value if you know none of the individual stream
974 * durations and also do not set any of them. This is deduced from the
975 * AVStream values if not set.
980 * Decoding: total stream bitrate in bit/s, 0 if not
981 * available. Never set it directly if the file_size and the
982 * duration are known as FFmpeg can compute it automatically.
986 unsigned int packet_size;
990 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
991 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
992 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
993 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
994 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
995 #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
996 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
997 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
998 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
999 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload
1000 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1001 #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)
1002 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Don't merge side data but keep it separate.
1005 * decoding: size of data to probe; encoding: unused.
1007 unsigned int probesize;
1010 * decoding: maximum time (in AV_TIME_BASE units) during which the input should
1011 * be analyzed in avformat_find_stream_info().
1013 int max_analyze_duration;
1018 unsigned int nb_programs;
1019 AVProgram **programs;
1022 * Forced video codec_id.
1023 * Demuxing: Set by user.
1025 enum AVCodecID video_codec_id;
1028 * Forced audio codec_id.
1029 * Demuxing: Set by user.
1031 enum AVCodecID audio_codec_id;
1034 * Forced subtitle codec_id.
1035 * Demuxing: Set by user.
1037 enum AVCodecID subtitle_codec_id;
1040 * Maximum amount of memory in bytes to use for the index of each stream.
1041 * If the index exceeds this size, entries will be discarded as
1042 * needed to maintain a smaller size. This can lead to slower or less
1043 * accurate seeking (depends on demuxer).
1044 * Demuxers for which a full in-memory index is mandatory will ignore
1047 * demuxing: set by user
1049 unsigned int max_index_size;
1052 * Maximum amount of memory in bytes to use for buffering frames
1053 * obtained from realtime capture devices.
1055 unsigned int max_picture_buffer;
1057 unsigned int nb_chapters;
1058 AVChapter **chapters;
1060 AVDictionary *metadata;
1063 * Start time of the stream in real world time, in microseconds
1064 * since the unix epoch (00:00 1st January 1970). That is, pts=0
1065 * in the stream was captured at this real world time.
1066 * - encoding: Set by user.
1067 * - decoding: Unused.
1069 int64_t start_time_realtime;
1072 * decoding: number of frames used to probe fps
1077 * Error recognition; higher values will detect more errors but may
1078 * misdetect some more or less valid parts as errors.
1079 * - encoding: unused
1080 * - decoding: Set by user.
1082 int error_recognition;
1085 * Custom interrupt callbacks for the I/O layer.
1087 * decoding: set by the user before avformat_open_input().
1088 * encoding: set by the user before avformat_write_header()
1089 * (mainly useful for AVFMT_NOFILE formats). The callback
1090 * should also be passed to avio_open2() if it's used to
1093 AVIOInterruptCB interrupt_callback;
1096 * Flags to enable debugging.
1099 #define FF_FDEBUG_TS 0x0001
1102 * Transport stream id.
1103 * This will be moved into demuxer private options. Thus no API/ABI compatibility
1108 * Audio preload in microseconds.
1109 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1110 * - encoding: Set by user via AVOptions (NO direct access)
1111 * - decoding: unused
1116 * Max chunk time in microseconds.
1117 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1118 * - encoding: Set by user via AVOptions (NO direct access)
1119 * - decoding: unused
1121 int max_chunk_duration;
1124 * Max chunk size in bytes
1125 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1126 * - encoding: Set by user via AVOptions (NO direct access)
1127 * - decoding: unused
1132 * forces the use of wallclock timestamps as pts/dts of packets
1133 * This has undefined results in the presence of B frames.
1134 * - encoding: unused
1135 * - decoding: Set by user via AVOptions (NO direct access)
1137 int use_wallclock_as_timestamps;
1140 * Avoids negative timestamps during muxing
1141 * 0 -> allow negative timestamps
1142 * 1 -> avoid negative timestamps
1143 * -1 -> choose automatically (default)
1144 * Note, this is only works when interleave_packet_per_dts is in use
1145 * - encoding: Set by user via AVOptions (NO direct access)
1146 * - decoding: unused
1148 int avoid_negative_ts;
1151 * avio flags, used to force AVIO_FLAG_DIRECT.
1152 * - encoding: unused
1153 * - decoding: Set by user via AVOptions (NO direct access)
1158 * The duration field can be estimated through various ways, and this field can be used
1159 * to know how the duration was estimated.
1160 * - encoding: unused
1161 * - decoding: Read by user via AVOptions (NO direct access)
1163 enum AVDurationEstimationMethod duration_estimation_method;
1165 /*****************************************************************
1166 * All fields below this line are not part of the public API. They
1167 * may not be used outside of libavformat and can be changed and
1169 * New public fields should be added right above.
1170 *****************************************************************
1174 * This buffer is only needed when packets were already buffered but
1175 * not decoded, for example to get the codec parameters in MPEG
1178 struct AVPacketList *packet_buffer;
1179 struct AVPacketList *packet_buffer_end;
1181 /* av_seek_frame() support */
1182 int64_t data_offset; /**< offset of the first packet */
1185 * Raw packets from the demuxer, prior to parsing and decoding.
1186 * This buffer is used for buffering packets until the codec can
1187 * be identified, as parsing cannot be done without knowing the
1190 struct AVPacketList *raw_packet_buffer;
1191 struct AVPacketList *raw_packet_buffer_end;
1193 * Packets split by the parser get queued here.
1195 struct AVPacketList *parse_queue;
1196 struct AVPacketList *parse_queue_end;
1198 * Remaining size available for raw_packet_buffer, in bytes.
1200 #define RAW_PACKET_BUFFER_SIZE 2500000
1201 int raw_packet_buffer_remaining_size;
1205 * Returns the method used to set ctx->duration.
1207 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1209 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
1211 typedef struct AVPacketList {
1213 struct AVPacketList *next;
1218 * @defgroup lavf_core Core functions
1221 * Functions for querying libavformat capabilities, allocating core structures,
1227 * Return the LIBAVFORMAT_VERSION_INT constant.
1229 unsigned avformat_version(void);
1232 * Return the libavformat build-time configuration.
1234 const char *avformat_configuration(void);
1237 * Return the libavformat license.
1239 const char *avformat_license(void);
1242 * Initialize libavformat and register all the muxers, demuxers and
1243 * protocols. If you do not call this function, then you can select
1244 * exactly which formats you want to support.
1246 * @see av_register_input_format()
1247 * @see av_register_output_format()
1248 * @see av_register_protocol()
1250 void av_register_all(void);
1252 void av_register_input_format(AVInputFormat *format);
1253 void av_register_output_format(AVOutputFormat *format);
1256 * Do global initialization of network components. This is optional,
1257 * but recommended, since it avoids the overhead of implicitly
1258 * doing the setup for each session.
1260 * Calling this function will become mandatory if using network
1261 * protocols at some major version bump.
1263 int avformat_network_init(void);
1266 * Undo the initialization done by avformat_network_init.
1268 int avformat_network_deinit(void);
1271 * If f is NULL, returns the first registered input format,
1272 * if f is non-NULL, returns the next registered input format after f
1273 * or NULL if f is the last one.
1275 AVInputFormat *av_iformat_next(AVInputFormat *f);
1278 * If f is NULL, returns the first registered output format,
1279 * if f is non-NULL, returns the next registered output format after f
1280 * or NULL if f is the last one.
1282 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1285 * Allocate an AVFormatContext.
1286 * avformat_free_context() can be used to free the context and everything
1287 * allocated by the framework within it.
1289 AVFormatContext *avformat_alloc_context(void);
1292 * Free an AVFormatContext and all its streams.
1293 * @param s context to free
1295 void avformat_free_context(AVFormatContext *s);
1298 * Get the AVClass for AVFormatContext. It can be used in combination with
1299 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1301 * @see av_opt_find().
1303 const AVClass *avformat_get_class(void);
1306 * Add a new stream to a media file.
1308 * When demuxing, it is called by the demuxer in read_header(). If the
1309 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1310 * be called in read_packet().
1312 * When muxing, should be called by the user before avformat_write_header().
1314 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1315 * will be initialized to use this codec. This is needed for e.g. codec-specific
1316 * defaults to be set, so codec should be provided if it is known.
1318 * @return newly created stream or NULL on error.
1320 AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c);
1322 AVProgram *av_new_program(AVFormatContext *s, int id);
1330 attribute_deprecated void av_pkt_dump(FILE *f, AVPacket *pkt, int dump_payload);
1331 attribute_deprecated void av_pkt_dump_log(void *avcl, int level, AVPacket *pkt,
1335 #if FF_API_ALLOC_OUTPUT_CONTEXT
1337 * @deprecated deprecated in favor of avformat_alloc_output_context2()
1339 attribute_deprecated
1340 AVFormatContext *avformat_alloc_output_context(const char *format,
1341 AVOutputFormat *oformat,
1342 const char *filename);
1346 * Allocate an AVFormatContext for an output format.
1347 * avformat_free_context() can be used to free the context and
1348 * everything allocated by the framework within it.
1350 * @param *ctx is set to the created format context, or to NULL in
1352 * @param oformat format to use for allocating the context, if NULL
1353 * format_name and filename are used instead
1354 * @param format_name the name of output format to use for allocating the
1355 * context, if NULL filename is used instead
1356 * @param filename the name of the filename to use for allocating the
1357 * context, may be NULL
1358 * @return >= 0 in case of success, a negative AVERROR code in case of
1361 int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat,
1362 const char *format_name, const char *filename);
1365 * @addtogroup lavf_decoding
1370 * Find AVInputFormat based on the short name of the input format.
1372 AVInputFormat *av_find_input_format(const char *short_name);
1375 * Guess the file format.
1377 * @param is_opened Whether the file is already opened; determines whether
1378 * demuxers with or without AVFMT_NOFILE are probed.
1380 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1383 * Guess the file format.
1385 * @param is_opened Whether the file is already opened; determines whether
1386 * demuxers with or without AVFMT_NOFILE are probed.
1387 * @param score_max A probe score larger that this is required to accept a
1388 * detection, the variable is set to the actual detection
1390 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1391 * to retry with a larger probe buffer.
1393 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1396 * Guess the file format.
1398 * @param is_opened Whether the file is already opened; determines whether
1399 * demuxers with or without AVFMT_NOFILE are probed.
1400 * @param score_ret The score of the best detection.
1402 AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
1405 * Probe a bytestream to determine the input format. Each time a probe returns
1406 * with a score that is too low, the probe buffer size is increased and another
1407 * attempt is made. When the maximum probe size is reached, the input format
1408 * with the highest score is returned.
1410 * @param pb the bytestream to probe
1411 * @param fmt the input format is put here
1412 * @param filename the filename of the stream
1413 * @param logctx the log context
1414 * @param offset the offset within the bytestream to probe from
1415 * @param max_probe_size the maximum probe buffer size (zero for default)
1416 * @return 0 in case of success, a negative value corresponding to an
1417 * AVERROR code otherwise
1419 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1420 const char *filename, void *logctx,
1421 unsigned int offset, unsigned int max_probe_size);
1424 * Open an input stream and read the header. The codecs are not opened.
1425 * The stream must be closed with av_close_input_file().
1427 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1428 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1429 * function and written into ps.
1430 * Note that a user-supplied AVFormatContext will be freed on failure.
1431 * @param filename Name of the stream to open.
1432 * @param fmt If non-NULL, this parameter forces a specific input format.
1433 * Otherwise the format is autodetected.
1434 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1435 * On return this parameter will be destroyed and replaced with a dict containing
1436 * options that were not found. May be NULL.
1438 * @return 0 on success, a negative AVERROR on failure.
1440 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1442 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1444 attribute_deprecated
1445 int av_demuxer_open(AVFormatContext *ic);
1447 #if FF_API_FORMAT_PARAMETERS
1449 * Read packets of a media file to get stream information. This
1450 * is useful for file formats with no headers such as MPEG. This
1451 * function also computes the real framerate in case of MPEG-2 repeat
1453 * The logical file position is not changed by this function;
1454 * examined packets may be buffered for later processing.
1456 * @param ic media file handle
1457 * @return >=0 if OK, AVERROR_xxx on error
1458 * @todo Let the user decide somehow what information is needed so that
1459 * we do not waste time getting stuff the user does not need.
1461 * @deprecated use avformat_find_stream_info.
1463 attribute_deprecated
1464 int av_find_stream_info(AVFormatContext *ic);
1468 * Read packets of a media file to get stream information. This
1469 * is useful for file formats with no headers such as MPEG. This
1470 * function also computes the real framerate in case of MPEG-2 repeat
1472 * The logical file position is not changed by this function;
1473 * examined packets may be buffered for later processing.
1475 * @param ic media file handle
1476 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1477 * dictionaries, where i-th member contains options for
1478 * codec corresponding to i-th stream.
1479 * On return each dictionary will be filled with options that were not found.
1480 * @return >=0 if OK, AVERROR_xxx on error
1482 * @note this function isn't guaranteed to open all the codecs, so
1483 * options being non-empty at return is a perfectly normal behavior.
1485 * @todo Let the user decide somehow what information is needed so that
1486 * we do not waste time getting stuff the user does not need.
1488 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1491 * Find the programs which belong to a given stream.
1493 * @param ic media file handle
1494 * @param last the last found program, the search will start after this
1495 * program, or from the beginning if it is NULL
1496 * @param s stream index
1497 * @return the next program which belongs to s, NULL if no program is found or
1498 * the last program is not among the programs of ic.
1500 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s);
1503 * Find the "best" stream in the file.
1504 * The best stream is determined according to various heuristics as the most
1505 * likely to be what the user expects.
1506 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1507 * default decoder for the stream's codec; streams for which no decoder can
1508 * be found are ignored.
1510 * @param ic media file handle
1511 * @param type stream type: video, audio, subtitles, etc.
1512 * @param wanted_stream_nb user-requested stream number,
1513 * or -1 for automatic selection
1514 * @param related_stream try to find a stream related (eg. in the same
1515 * program) to this one, or -1 if none
1516 * @param decoder_ret if non-NULL, returns the decoder for the
1518 * @param flags flags; none are currently defined
1519 * @return the non-negative stream number in case of success,
1520 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
1522 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
1523 * @note If av_find_best_stream returns successfully and decoder_ret is not
1524 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
1526 int av_find_best_stream(AVFormatContext *ic,
1527 enum AVMediaType type,
1528 int wanted_stream_nb,
1530 AVCodec **decoder_ret,
1533 #if FF_API_READ_PACKET
1535 * @deprecated use AVFMT_FLAG_NOFILLIN | AVFMT_FLAG_NOPARSE to read raw
1536 * unprocessed packets
1538 * Read a transport packet from a media file.
1540 * This function is obsolete and should never be used.
1541 * Use av_read_frame() instead.
1543 * @param s media file handle
1544 * @param pkt is filled
1545 * @return 0 if OK, AVERROR_xxx on error
1547 attribute_deprecated
1548 int av_read_packet(AVFormatContext *s, AVPacket *pkt);
1552 * Return the next frame of a stream.
1553 * This function returns what is stored in the file, and does not validate
1554 * that what is there are valid frames for the decoder. It will split what is
1555 * stored in the file into frames and return one for each call. It will not
1556 * omit invalid data between valid frames so as to give the decoder the maximum
1557 * information possible for decoding.
1559 * If pkt->destruct is NULL, then the packet is valid until the next
1560 * av_read_frame() or until av_close_input_file(). Otherwise the packet is valid
1561 * indefinitely. In both cases the packet must be freed with
1562 * av_free_packet when it is no longer needed. For video, the packet contains
1563 * exactly one frame. For audio, it contains an integer number of frames if each
1564 * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
1565 * have a variable size (e.g. MPEG audio), then it contains one frame.
1567 * pkt->pts, pkt->dts and pkt->duration are always set to correct
1568 * values in AVStream.time_base units (and guessed if the format cannot
1569 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
1570 * has B-frames, so it is better to rely on pkt->dts if you do not
1571 * decompress the payload.
1573 * @return 0 if OK, < 0 on error or end of file
1575 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
1578 * Seek to the keyframe at timestamp.
1579 * 'timestamp' in 'stream_index'.
1580 * @param stream_index If stream_index is (-1), a default
1581 * stream is selected, and timestamp is automatically converted
1582 * from AV_TIME_BASE units to the stream specific time_base.
1583 * @param timestamp Timestamp in AVStream.time_base units
1584 * or, if no stream is specified, in AV_TIME_BASE units.
1585 * @param flags flags which select direction and seeking mode
1586 * @return >= 0 on success
1588 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
1592 * Seek to timestamp ts.
1593 * Seeking will be done so that the point from which all active streams
1594 * can be presented successfully will be closest to ts and within min/max_ts.
1595 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
1597 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
1598 * are the file position (this may not be supported by all demuxers).
1599 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
1600 * in the stream with stream_index (this may not be supported by all demuxers).
1601 * Otherwise all timestamps are in units of the stream selected by stream_index
1602 * or if stream_index is -1, in AV_TIME_BASE units.
1603 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
1604 * keyframes (this may not be supported by all demuxers).
1606 * @param stream_index index of the stream which is used as time base reference
1607 * @param min_ts smallest acceptable timestamp
1608 * @param ts target timestamp
1609 * @param max_ts largest acceptable timestamp
1610 * @param flags flags
1611 * @return >=0 on success, error code otherwise
1613 * @note This is part of the new seek API which is still under construction.
1614 * Thus do not use this yet. It may change at any time, do not expect
1615 * ABI compatibility yet!
1617 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
1620 * Start playing a network-based stream (e.g. RTSP stream) at the
1623 int av_read_play(AVFormatContext *s);
1626 * Pause a network-based stream (e.g. RTSP stream).
1628 * Use av_read_play() to resume it.
1630 int av_read_pause(AVFormatContext *s);
1632 #if FF_API_CLOSE_INPUT_FILE
1634 * @deprecated use avformat_close_input()
1635 * Close a media file (but not its codecs).
1637 * @param s media file handle
1639 attribute_deprecated
1640 void av_close_input_file(AVFormatContext *s);
1644 * Close an opened input AVFormatContext. Free it and all its contents
1645 * and set *s to NULL.
1647 void avformat_close_input(AVFormatContext **s);
1652 #if FF_API_NEW_STREAM
1654 * Add a new stream to a media file.
1656 * Can only be called in the read_header() function. If the flag
1657 * AVFMTCTX_NOHEADER is in the format context, then new streams
1658 * can be added in read_packet too.
1660 * @param s media file handle
1661 * @param id file-format-dependent stream ID
1663 attribute_deprecated
1664 AVStream *av_new_stream(AVFormatContext *s, int id);
1667 #if FF_API_SET_PTS_INFO
1669 * @deprecated this function is not supposed to be called outside of lavf
1671 attribute_deprecated
1672 void av_set_pts_info(AVStream *s, int pts_wrap_bits,
1673 unsigned int pts_num, unsigned int pts_den);
1676 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
1677 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
1678 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
1679 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
1682 * @addtogroup lavf_encoding
1686 * Allocate the stream private data and write the stream header to
1687 * an output media file.
1689 * @param s Media file handle, must be allocated with avformat_alloc_context().
1690 * Its oformat field must be set to the desired output format;
1691 * Its pb field must be set to an already openened AVIOContext.
1692 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
1693 * On return this parameter will be destroyed and replaced with a dict containing
1694 * options that were not found. May be NULL.
1696 * @return 0 on success, negative AVERROR on failure.
1698 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
1700 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
1703 * Write a packet to an output media file.
1705 * The packet shall contain one audio or video frame.
1706 * The packet must be correctly interleaved according to the container
1707 * specification, if not then av_interleaved_write_frame must be used.
1709 * @param s media file handle
1710 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1712 * This can be NULL (at any time, not just at the end), in
1713 * order to immediately flush data buffered within the muxer,
1714 * for muxers that buffer up data internally before writing it
1716 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
1718 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
1721 * Write a packet to an output media file ensuring correct interleaving.
1723 * The packet must contain one audio or video frame.
1724 * If the packets are already correctly interleaved, the application should
1725 * call av_write_frame() instead as it is slightly faster. It is also important
1726 * to keep in mind that completely non-interleaved input will need huge amounts
1727 * of memory to interleave with this, so it is preferable to interleave at the
1730 * @param s media file handle
1731 * @param pkt The packet containing the data to be written. Libavformat takes
1732 * ownership of the data and will free it when it sees fit using the packet's
1733 * @ref AVPacket.destruct "destruct" field. The caller must not access the data
1734 * after this function returns, as it may already be freed.
1735 * This can be NULL (at any time, not just at the end), to flush the
1736 * interleaving queues.
1737 * Packet's @ref AVPacket.stream_index "stream_index" field must be set to the
1738 * index of the corresponding stream in @ref AVFormatContext.streams
1740 * It is very strongly recommended that timing information (@ref AVPacket.pts
1741 * "pts", @ref AVPacket.dts "dts" @ref AVPacket.duration "duration") is set to
1744 * @return 0 on success, a negative AVERROR on error.
1746 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
1748 #if FF_API_INTERLEAVE_PACKET
1750 * @deprecated this function was never meant to be called by the user
1753 attribute_deprecated
1754 int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
1755 AVPacket *pkt, int flush);
1759 * Write the stream trailer to an output media file and free the
1760 * file private data.
1762 * May only be called after a successful call to avformat_write_header.
1764 * @param s media file handle
1765 * @return 0 if OK, AVERROR_xxx on error
1767 int av_write_trailer(AVFormatContext *s);
1770 * Return the output format in the list of registered output formats
1771 * which best matches the provided parameters, or return NULL if
1772 * there is no match.
1774 * @param short_name if non-NULL checks if short_name matches with the
1775 * names of the registered formats
1776 * @param filename if non-NULL checks if filename terminates with the
1777 * extensions of the registered formats
1778 * @param mime_type if non-NULL checks if mime_type matches with the
1779 * MIME type of the registered formats
1781 AVOutputFormat *av_guess_format(const char *short_name,
1782 const char *filename,
1783 const char *mime_type);
1786 * Guess the codec ID based upon muxer and filename.
1788 enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
1789 const char *filename, const char *mime_type,
1790 enum AVMediaType type);
1793 * Get timing information for the data currently output.
1794 * The exact meaning of "currently output" depends on the format.
1795 * It is mostly relevant for devices that have an internal buffer and/or
1796 * work in real time.
1797 * @param s media file handle
1798 * @param stream stream in the media file
1799 * @param dts[out] DTS of the last packet output for the stream, in stream
1801 * @param wall[out] absolute time when that packet whas output,
1803 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
1804 * Note: some formats or devices may not allow to measure dts and wall
1807 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
1808 int64_t *dts, int64_t *wall);
1817 * @defgroup lavf_misc Utility functions
1821 * Miscellaneous utility functions related to both muxing and demuxing
1826 * Send a nice hexadecimal dump of a buffer to the specified file stream.
1828 * @param f The file stream pointer where the dump should be sent to.
1830 * @param size buffer size
1832 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
1834 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
1837 * Send a nice hexadecimal dump of a buffer to the log.
1839 * @param avcl A pointer to an arbitrary struct of which the first field is a
1840 * pointer to an AVClass struct.
1841 * @param level The importance level of the message, lower values signifying
1842 * higher importance.
1844 * @param size buffer size
1846 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
1848 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
1851 * Send a nice dump of a packet to the specified file stream.
1853 * @param f The file stream pointer where the dump should be sent to.
1854 * @param pkt packet to dump
1855 * @param dump_payload True if the payload must be displayed, too.
1856 * @param st AVStream that the packet belongs to
1858 void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
1862 * Send a nice dump of a packet to the log.
1864 * @param avcl A pointer to an arbitrary struct of which the first field is a
1865 * pointer to an AVClass struct.
1866 * @param level The importance level of the message, lower values signifying
1867 * higher importance.
1868 * @param pkt packet to dump
1869 * @param dump_payload True if the payload must be displayed, too.
1870 * @param st AVStream that the packet belongs to
1872 void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
1876 * Get the AVCodecID for the given codec tag tag.
1877 * If no codec id is found returns AV_CODEC_ID_NONE.
1879 * @param tags list of supported codec_id-codec_tag pairs, as stored
1880 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1882 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
1885 * Get the codec tag for the given codec id id.
1886 * If no codec tag is found returns 0.
1888 * @param tags list of supported codec_id-codec_tag pairs, as stored
1889 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1891 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
1893 int av_find_default_stream_index(AVFormatContext *s);
1896 * Get the index for a specific timestamp.
1897 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
1898 * to the timestamp which is <= the requested one, if backward
1899 * is 0, then it will be >=
1900 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
1901 * @return < 0 if no such timestamp could be found
1903 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
1906 * Add an index entry into a sorted list. Update the entry if the list
1907 * already contains it.
1909 * @param timestamp timestamp in the time base of the given stream
1911 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
1912 int size, int distance, int flags);
1916 * Split a URL string into components.
1918 * The pointers to buffers for storing individual components may be null,
1919 * in order to ignore that component. Buffers for components not found are
1920 * set to empty strings. If the port is not found, it is set to a negative
1923 * @param proto the buffer for the protocol
1924 * @param proto_size the size of the proto buffer
1925 * @param authorization the buffer for the authorization
1926 * @param authorization_size the size of the authorization buffer
1927 * @param hostname the buffer for the host name
1928 * @param hostname_size the size of the hostname buffer
1929 * @param port_ptr a pointer to store the port number in
1930 * @param path the buffer for the path
1931 * @param path_size the size of the path buffer
1932 * @param url the URL to split
1934 void av_url_split(char *proto, int proto_size,
1935 char *authorization, int authorization_size,
1936 char *hostname, int hostname_size,
1938 char *path, int path_size,
1942 void av_dump_format(AVFormatContext *ic,
1948 * Return in 'buf' the path with '%d' replaced by a number.
1950 * Also handles the '%0nd' format where 'n' is the total number
1951 * of digits and '%%'.
1953 * @param buf destination buffer
1954 * @param buf_size destination buffer size
1955 * @param path numbered sequence string
1956 * @param number frame number
1957 * @return 0 if OK, -1 on format error
1959 int av_get_frame_filename(char *buf, int buf_size,
1960 const char *path, int number);
1963 * Check whether filename actually is a numbered sequence generator.
1965 * @param filename possible numbered sequence string
1966 * @return 1 if a valid numbered sequence string, 0 otherwise
1968 int av_filename_number_test(const char *filename);
1971 * Generate an SDP for an RTP session.
1973 * Note, this overwrites the id values of AVStreams in the muxer contexts
1974 * for getting unique dynamic payload types.
1976 * @param ac array of AVFormatContexts describing the RTP streams. If the
1977 * array is composed by only one context, such context can contain
1978 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
1979 * all the contexts in the array (an AVCodecContext per RTP stream)
1980 * must contain only one AVStream.
1981 * @param n_files number of AVCodecContexts contained in ac
1982 * @param buf buffer where the SDP will be stored (must be allocated by
1984 * @param size the size of the buffer
1985 * @return 0 if OK, AVERROR_xxx on error
1987 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
1990 * Return a positive value if the given filename has one of the given
1991 * extensions, 0 otherwise.
1993 * @param extensions a comma-separated list of filename extensions
1995 int av_match_ext(const char *filename, const char *extensions);
1998 * Test if the given container can store a codec.
2000 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2002 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2003 * A negative number if this information is not available.
2005 int avformat_query_codec(AVOutputFormat *ofmt, enum AVCodecID codec_id, int std_compliance);
2008 * @defgroup riff_fourcc RIFF FourCCs
2010 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2011 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2014 * uint32_t tag = MKTAG('H', '2', '6', '4');
2015 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2016 * enum AVCodecID id = av_codec_get_id(table, tag);
2020 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2022 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2024 * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2026 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2033 * Guess the sample aspect ratio of a frame, based on both the stream and the
2034 * frame aspect ratio.
2036 * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2037 * is set by the demuxer, these two may not be equal. This function tries to
2038 * return the value that you should use if you would like to display the frame.
2040 * Basic logic is to use the stream aspect ratio if it is set to something sane
2041 * otherwise use the frame aspect ratio. This way a container setting, which is
2042 * usually easy to modify can override the coded value in the frames.
2044 * @param format the format context which the stream is part of
2045 * @param stream the stream which the frame is part of
2046 * @param frame the frame with the aspect ratio to be determined
2047 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2049 AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame);
2052 * Check if the stream st contained in s is matched by the stream specifier
2055 * See the "stream specifiers" chapter in the documentation for the syntax
2058 * @return >0 if st is matched by spec;
2059 * 0 if st is not matched by spec;
2060 * AVERROR code if spec is invalid
2062 * @note A stream specifier can match several streams in the format.
2064 int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st,
2067 void avformat_queue_attached_pictures(AVFormatContext *s);
2074 #endif /* AVFORMAT_AVFORMAT_H */