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 * The packet data belongs to the demuxer and is invalid after the next call to
162 * av_read_frame(). The user must free the packet with av_free_packet() before
163 * calling av_read_frame() again or closing the file.
165 * @section lavf_decoding_seek Seeking
168 * @defgroup lavf_encoding Muxing
172 * @defgroup lavf_io I/O Read/Write
176 * @defgroup lavf_codec Demuxers
178 * @defgroup lavf_codec_native Native Demuxers
181 * @defgroup lavf_codec_wrappers External library wrappers
185 * @defgroup lavf_protos I/O Protocols
188 * @defgroup lavf_internal Internal
196 #include <stdio.h> /* FILE */
197 #include "libavcodec/avcodec.h"
198 #include "libavutil/dict.h"
199 #include "libavutil/log.h"
202 #include "libavformat/version.h"
204 struct AVFormatContext;
208 * @defgroup metadata_api Public Metadata API
211 * The metadata API allows libavformat to export metadata tags to a client
212 * application when demuxing. Conversely it allows a client application to
213 * set metadata when muxing.
215 * Metadata is exported or set as pairs of key/value strings in the 'metadata'
216 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
217 * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
218 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
219 * exported by demuxers isn't checked to be valid UTF-8 in most cases.
221 * Important concepts to keep in mind:
222 * - Keys are unique; there can never be 2 tags with the same key. This is
223 * also meant semantically, i.e., a demuxer should not knowingly produce
224 * several keys that are literally different but semantically identical.
225 * E.g., key=Author5, key=Author6. In this example, all authors must be
226 * placed in the same tag.
227 * - Metadata is flat, not hierarchical; there are no subtags. If you
228 * want to store, e.g., the email address of the child of producer Alice
229 * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
230 * - Several modifiers can be applied to the tag name. This is done by
231 * appending a dash character ('-') and the modifier name in the order
232 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
233 * - language -- a tag whose value is localized for a particular language
234 * is appended with the ISO 639-2/B 3-letter language code.
235 * For example: Author-ger=Michael, Author-eng=Mike
236 * The original/default language is in the unqualified "Author" tag.
237 * A demuxer should set a default if it sets any translated tag.
238 * - sorting -- a modified version of a tag that should be used for
239 * sorting will have '-sort' appended. E.g. artist="The Beatles",
240 * artist-sort="Beatles, The".
242 * - Demuxers attempt to export metadata in a generic format, however tags
243 * with no generic equivalents are left as they are stored in the container.
244 * Follows a list of generic tag names:
247 album -- name of the set this work belongs to
248 album_artist -- main creator of the set/album, if different from artist.
249 e.g. "Various Artists" for compilation albums.
250 artist -- main creator of the work
251 comment -- any additional description of the file.
252 composer -- who composed the work, if different from artist.
253 copyright -- name of copyright holder.
254 creation_time-- date when the file was created, preferably in ISO 8601.
255 date -- date when the work was created, preferably in ISO 8601.
256 disc -- number of a subset, e.g. disc in a multi-disc collection.
257 encoder -- name/settings of the software/hardware that produced the file.
258 encoded_by -- person/group who created the file.
259 filename -- original name of the file.
260 genre -- <self-evident>.
261 language -- main language in which the work is performed, preferably
262 in ISO 639-2 format. Multiple languages can be specified by
263 separating them with commas.
264 performer -- artist who performed the work, if different from artist.
265 E.g for "Also sprach Zarathustra", artist would be "Richard
266 Strauss" and performer "London Philharmonic Orchestra".
267 publisher -- name of the label/publisher.
268 service_name -- name of the service in broadcasting (channel name).
269 service_provider -- name of the service provider in broadcasting.
270 title -- name of the work.
271 track -- number of this work in the set, can be in form current/total.
272 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
275 * Look in the examples section for an application example how to use the Metadata API.
280 /* packet functions */
284 * Allocate and read the payload of a packet and initialize its
285 * fields with default values.
288 * @param size desired payload size
289 * @return >0 (read size) if OK, AVERROR_xxx otherwise
291 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
295 * Read data and append it to the current content of the AVPacket.
296 * If pkt->size is 0 this is identical to av_get_packet.
297 * Note that this uses av_grow_packet and thus involves a realloc
298 * which is inefficient. Thus this function should only be used
299 * when there is no reasonable way to know (an upper bound of)
303 * @param size amount of data to read
304 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
305 * will not be lost even if an error occurs.
307 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
309 /*************************************************/
310 /* fractional numbers for exact pts handling */
313 * The exact value of the fractional number is: 'val + num / den'.
314 * num is assumed to be 0 <= num < den.
316 typedef struct AVFrac {
317 int64_t val, num, den;
320 /*************************************************/
321 /* input/output formats */
326 * This structure contains the data a format has to probe a file.
328 typedef struct AVProbeData {
329 const char *filename;
330 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
331 int buf_size; /**< Size of buf except extra allocated bytes */
334 #define AVPROBE_SCORE_MAX 100 ///< maximum score, half of that is used for file-extension-based detection
335 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
337 /// Demuxer will use avio_open, no opened file should be provided by the caller.
338 #define AVFMT_NOFILE 0x0001
339 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
340 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
341 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
343 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
344 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
345 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
346 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
347 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
348 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
349 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
350 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fallback to binary search via read_timestamp */
351 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fallback to generic search */
352 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
353 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
354 #define AVFMT_TS_NONSTRICT 0x8000000 /**< Format does not require strictly
355 increasing timestamps, but they must
356 still be monotonic */
359 * @addtogroup lavf_encoding
362 typedef struct AVOutputFormat {
365 * Descriptive name for the format, meant to be more human-readable
366 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
369 const char *long_name;
370 const char *mime_type;
371 const char *extensions; /**< comma-separated filename extensions */
373 enum CodecID audio_codec; /**< default audio codec */
374 enum CodecID video_codec; /**< default video codec */
375 enum CodecID subtitle_codec; /**< default subtitle codec */
377 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
378 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
379 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH
384 * List of supported codec_id-codec_tag pairs, ordered by "better
385 * choice first". The arrays are all terminated by CODEC_ID_NONE.
387 const struct AVCodecTag * const *codec_tag;
390 const AVClass *priv_class; ///< AVClass for the private context
392 /*****************************************************************
393 * No fields below this line are part of the public API. They
394 * may not be used outside of libavformat and can be changed and
396 * New public fields should be added right above.
397 *****************************************************************
399 struct AVOutputFormat *next;
401 * size of private data so that it can be allocated in the wrapper
405 int (*write_header)(struct AVFormatContext *);
407 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
408 * pkt can be NULL in order to flush data buffered in the muxer.
409 * When flushing, return 0 if there still is more data to flush,
410 * or 1 if everything was flushed and there is no more buffered
413 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
414 int (*write_trailer)(struct AVFormatContext *);
416 * Currently only used to set pixel format if not YUV420P.
418 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
419 AVPacket *in, int flush);
421 * Test if the given codec can be stored in this container.
423 * @return 1 if the codec is supported, 0 if it is not.
424 * A negative number if unknown.
426 int (*query_codec)(enum CodecID id, int std_compliance);
428 void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
429 int64_t *dts, int64_t *wall);
436 * @addtogroup lavf_decoding
439 typedef struct AVInputFormat {
441 * A comma separated list of short names for the format. New names
442 * may be appended with a minor bump.
447 * Descriptive name for the format, meant to be more human-readable
448 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
451 const char *long_name;
454 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
455 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
456 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK.
461 * If extensions are defined, then no probe is done. You should
462 * usually not use extension format guessing because it is not
465 const char *extensions;
467 const struct AVCodecTag * const *codec_tag;
469 const AVClass *priv_class; ///< AVClass for the private context
471 /*****************************************************************
472 * No fields below this line are part of the public API. They
473 * may not be used outside of libavformat and can be changed and
475 * New public fields should be added right above.
476 *****************************************************************
478 struct AVInputFormat *next;
481 * Raw demuxers store their codec ID here.
486 * Size of private data so that it can be allocated in the wrapper.
491 * Tell if a given file has a chance of being parsed as this format.
492 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
493 * big so you do not have to check for that unless you need more.
495 int (*read_probe)(AVProbeData *);
498 * Read the format header and initialize the AVFormatContext
499 * structure. Return 0 if OK. Only used in raw format right
500 * now. 'avformat_new_stream' should be called to create new streams.
502 int (*read_header)(struct AVFormatContext *);
505 * Read one packet and put it in 'pkt'. pts and flags are also
506 * set. 'avformat_new_stream' can be called only if the flag
507 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
508 * background thread).
509 * @return 0 on success, < 0 on error.
510 * When returning an error, pkt must not have been allocated
511 * or must be freed before returning
513 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
516 * Close the stream. The AVFormatContext and AVStreams are not
517 * freed by this function
519 int (*read_close)(struct AVFormatContext *);
522 * Seek to a given timestamp relative to the frames in
523 * stream component stream_index.
524 * @param stream_index Must not be -1.
525 * @param flags Selects which direction should be preferred if no exact
526 * match is available.
527 * @return >= 0 on success (but not necessarily the new offset)
529 int (*read_seek)(struct AVFormatContext *,
530 int stream_index, int64_t timestamp, int flags);
533 * Get the next timestamp in stream[stream_index].time_base units.
534 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
536 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
537 int64_t *pos, int64_t pos_limit);
540 * Start/resume playing - only meaningful if using a network-based format
543 int (*read_play)(struct AVFormatContext *);
546 * Pause playing - only meaningful if using a network-based format
549 int (*read_pause)(struct AVFormatContext *);
552 * Seek to timestamp ts.
553 * Seeking will be done so that the point from which all active streams
554 * can be presented successfully will be closest to ts and within min/max_ts.
555 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
557 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
563 enum AVStreamParseType {
565 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
566 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
567 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
568 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
571 typedef struct AVIndexEntry {
573 int64_t timestamp; /**<
574 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
575 * when seeking to this entry. That means preferable PTS on keyframe based formats.
576 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
579 #define AVINDEX_KEYFRAME 0x0001
581 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).
582 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
585 #define AV_DISPOSITION_DEFAULT 0x0001
586 #define AV_DISPOSITION_DUB 0x0002
587 #define AV_DISPOSITION_ORIGINAL 0x0004
588 #define AV_DISPOSITION_COMMENT 0x0008
589 #define AV_DISPOSITION_LYRICS 0x0010
590 #define AV_DISPOSITION_KARAOKE 0x0020
593 * Track should be used during playback by default.
594 * Useful for subtitle track that should be displayed
595 * even when user did not explicitly ask for subtitles.
597 #define AV_DISPOSITION_FORCED 0x0040
598 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
599 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
600 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
602 * The stream is stored in the file as an attached picture/"cover art" (e.g.
603 * APIC frame in ID3v2). The single packet associated with it will be returned
604 * among the first few packets read from the file unless seeking takes place.
605 * It can also be accessed at any time in AVStream.attached_pic.
607 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
611 * New fields can be added to the end with minor version bumps.
612 * Removal, reordering and changes to existing fields require a major
614 * sizeof(AVStream) must not be used outside libav*.
616 typedef struct AVStream {
617 int index; /**< stream index in AVFormatContext */
619 * Format-specific stream ID.
620 * decoding: set by libavformat
621 * encoding: set by the user
625 * Codec context associated with this stream. Allocated and freed by
628 * - decoding: The demuxer exports codec information stored in the headers
630 * - encoding: The user sets codec information, the muxer writes it to the
631 * output. Mandatory fields as specified in AVCodecContext
632 * documentation must be set even if this AVCodecContext is
633 * not actually used for encoding.
635 AVCodecContext *codec;
637 * Real base framerate of the stream.
638 * This is the lowest framerate with which all timestamps can be
639 * represented accurately (it is the least common multiple of all
640 * framerates in the stream). Note, this value is just a guess!
641 * For example, if the time base is 1/90000 and all frames have either
642 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
644 AVRational r_frame_rate;
648 * encoding: pts generation when outputting stream
653 * This is the fundamental unit of time (in seconds) in terms
654 * of which frame timestamps are represented.
656 * decoding: set by libavformat
657 * encoding: set by libavformat in av_write_header. The muxer may use the
658 * user-provided value of @ref AVCodecContext.time_base "codec->time_base"
661 AVRational time_base;
664 * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
665 * Only set this if you are absolutely 100% sure that the value you set
666 * it to really is the pts of the first frame.
667 * This may be undefined (AV_NOPTS_VALUE).
668 * @note The ASF header does NOT contain a correct start_time the ASF
669 * demuxer must NOT set this.
674 * Decoding: duration of the stream, in stream time base.
675 * If a source file does not specify a duration, but does specify
676 * a bitrate, this value will be estimated from bitrate and file size.
680 int64_t nb_frames; ///< number of frames in this stream if known or 0
682 int disposition; /**< AV_DISPOSITION_* bit field */
684 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
687 * sample aspect ratio (0 if unknown)
688 * - encoding: Set by user.
689 * - decoding: Set by libavformat.
691 AVRational sample_aspect_ratio;
693 AVDictionary *metadata;
698 AVRational avg_frame_rate;
701 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
702 * will contain the attached picture.
704 * decoding: set by libavformat, must not be modified by the caller.
707 AVPacket attached_pic;
709 /*****************************************************************
710 * All fields below this line are not part of the public API. They
711 * may not be used outside of libavformat and can be changed and
713 * New public fields should be added right above.
714 *****************************************************************
718 * Stream information used internally by av_find_stream_info()
720 #define MAX_STD_TIMEBASES (60*12+5)
723 int64_t duration_gcd;
725 double duration_error[2][2][MAX_STD_TIMEBASES];
726 int64_t codec_info_duration;
727 int nb_decoded_frames;
731 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
733 // Timestamp generation support:
735 * Timestamp corresponding to the last dts sync point.
737 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
738 * a DTS is received from the underlying container. Otherwise set to
739 * AV_NOPTS_VALUE by default.
741 int64_t reference_dts;
745 int last_IP_duration;
748 * Number of packets to buffer for codec probing
750 #define MAX_PROBE_PACKETS 2500
754 * Number of frames that have been demuxed during av_find_stream_info()
756 int codec_info_nb_frames;
760 * This is the MPEG-TS stream identifier +1
763 int stream_identifier;
765 int64_t interleaver_chunk_size;
766 int64_t interleaver_chunk_duration;
768 /* av_read_frame() support */
769 enum AVStreamParseType need_parsing;
770 struct AVCodecParserContext *parser;
773 * last packet in packet_buffer for this stream when muxing.
775 struct AVPacketList *last_in_packet_buffer;
776 AVProbeData probe_data;
777 #define MAX_REORDER_DELAY 16
778 int64_t pts_buffer[MAX_REORDER_DELAY+1];
780 AVIndexEntry *index_entries; /**< Only used if the format does not
781 support seeking natively. */
782 int nb_index_entries;
783 unsigned int index_entries_allocated_size;
786 * flag to indicate that probing is requested
787 * NOT PART OF PUBLIC API
792 #define AV_PROGRAM_RUNNING 1
795 * New fields can be added to the end with minor version bumps.
796 * Removal, reordering and changes to existing fields require a major
798 * sizeof(AVProgram) must not be used outside libav*.
800 typedef struct AVProgram {
803 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
804 unsigned int *stream_index;
805 unsigned int nb_stream_indexes;
806 AVDictionary *metadata;
813 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
814 (streams are added dynamically) */
816 typedef struct AVChapter {
817 int id; ///< unique ID to identify the chapter
818 AVRational time_base; ///< time base in which the start/end timestamps are specified
819 int64_t start, end; ///< chapter start/end time in time_base units
820 AVDictionary *metadata;
824 * Format I/O context.
825 * New fields can be added to the end with minor version bumps.
826 * Removal, reordering and changes to existing fields require a major
828 * sizeof(AVFormatContext) must not be used outside libav*, use
829 * avformat_alloc_context() to create an AVFormatContext.
831 typedef struct AVFormatContext {
833 * A class for logging and AVOptions. Set by avformat_alloc_context().
834 * Exports (de)muxer private options if they exist.
836 const AVClass *av_class;
839 * Can only be iformat or oformat, not both at the same time.
841 * decoding: set by avformat_open_input().
842 * encoding: set by the user.
844 struct AVInputFormat *iformat;
845 struct AVOutputFormat *oformat;
848 * Format private data. This is an AVOptions-enabled struct
849 * if and only if iformat/oformat.priv_class is not NULL.
856 * decoding: either set by the user before avformat_open_input() (then
857 * the user must close it manually) or set by avformat_open_input().
858 * encoding: set by the user.
860 * Do NOT set this field if AVFMT_NOFILE flag is set in
861 * iformat/oformat.flags. In such a case, the (de)muxer will handle
862 * I/O in some other way and this field will be NULL.
867 int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
870 * A list of all streams in the file. New streams are created with
871 * avformat_new_stream().
873 * decoding: streams are created by libavformat in avformat_open_input().
874 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
875 * appear in av_read_frame().
876 * encoding: streams are created by the user before avformat_write_header().
878 unsigned int nb_streams;
881 char filename[1024]; /**< input or output filename */
884 * Decoding: position of the first frame of the component, in
885 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
886 * It is deduced from the AVStream values.
891 * Decoding: duration of the stream, in AV_TIME_BASE fractional
892 * seconds. Only set this value if you know none of the individual stream
893 * durations and also do not set any of them. This is deduced from the
894 * AVStream values if not set.
899 * Decoding: total stream bitrate in bit/s, 0 if not
900 * available. Never set it directly if the file_size and the
901 * duration are known as FFmpeg can compute it automatically.
905 unsigned int packet_size;
909 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
910 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
911 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
912 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
913 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
914 #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
915 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
916 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
917 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload
918 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
919 #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)
920 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Dont merge side data but keep it separate.
923 * decoding: size of data to probe; encoding: unused.
925 unsigned int probesize;
928 * decoding: maximum time (in AV_TIME_BASE units) during which the input should
929 * be analyzed in avformat_find_stream_info().
931 int max_analyze_duration;
936 unsigned int nb_programs;
937 AVProgram **programs;
940 * Forced video codec_id.
941 * Demuxing: Set by user.
943 enum CodecID video_codec_id;
946 * Forced audio codec_id.
947 * Demuxing: Set by user.
949 enum CodecID audio_codec_id;
952 * Forced subtitle codec_id.
953 * Demuxing: Set by user.
955 enum CodecID subtitle_codec_id;
958 * Maximum amount of memory in bytes to use for the index of each stream.
959 * If the index exceeds this size, entries will be discarded as
960 * needed to maintain a smaller size. This can lead to slower or less
961 * accurate seeking (depends on demuxer).
962 * Demuxers for which a full in-memory index is mandatory will ignore
965 * demuxing: set by user
967 unsigned int max_index_size;
970 * Maximum amount of memory in bytes to use for buffering frames
971 * obtained from realtime capture devices.
973 unsigned int max_picture_buffer;
975 unsigned int nb_chapters;
976 AVChapter **chapters;
978 AVDictionary *metadata;
981 * Start time of the stream in real world time, in microseconds
982 * since the unix epoch (00:00 1st January 1970). That is, pts=0
983 * in the stream was captured at this real world time.
984 * - encoding: Set by user.
985 * - decoding: Unused.
987 int64_t start_time_realtime;
990 * decoding: number of frames used to probe fps
995 * Error recognition; higher values will detect more errors but may
996 * misdetect some more or less valid parts as errors.
998 * - decoding: Set by user.
1000 int error_recognition;
1003 * Custom interrupt callbacks for the I/O layer.
1005 * decoding: set by the user before avformat_open_input().
1006 * encoding: set by the user before avformat_write_header()
1007 * (mainly useful for AVFMT_NOFILE formats). The callback
1008 * should also be passed to avio_open2() if it's used to
1011 AVIOInterruptCB interrupt_callback;
1014 * Flags to enable debugging.
1017 #define FF_FDEBUG_TS 0x0001
1020 * Transport stream id.
1021 * This will be moved into demuxer private options. Thus no API/ABI compatibility
1026 * Audio preload in microseconds.
1027 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1028 * - encoding: Set by user via AVOptions (NO direct access)
1029 * - decoding: unused
1034 * Max chunk time in microseconds.
1035 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1036 * - encoding: Set by user via AVOptions (NO direct access)
1037 * - decoding: unused
1039 int max_chunk_duration;
1042 * Max chunk size in bytes
1043 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1044 * - encoding: Set by user via AVOptions (NO direct access)
1045 * - decoding: unused
1049 /*****************************************************************
1050 * All fields below this line are not part of the public API. They
1051 * may not be used outside of libavformat and can be changed and
1053 * New public fields should be added right above.
1054 *****************************************************************
1058 * This buffer is only needed when packets were already buffered but
1059 * not decoded, for example to get the codec parameters in MPEG
1062 struct AVPacketList *packet_buffer;
1063 struct AVPacketList *packet_buffer_end;
1065 /* av_seek_frame() support */
1066 int64_t data_offset; /**< offset of the first packet */
1069 * Raw packets from the demuxer, prior to parsing and decoding.
1070 * This buffer is used for buffering packets until the codec can
1071 * be identified, as parsing cannot be done without knowing the
1074 struct AVPacketList *raw_packet_buffer;
1075 struct AVPacketList *raw_packet_buffer_end;
1077 * Packets split by the parser get queued here.
1079 struct AVPacketList *parse_queue;
1080 struct AVPacketList *parse_queue_end;
1082 * Remaining size available for raw_packet_buffer, in bytes.
1084 #define RAW_PACKET_BUFFER_SIZE 2500000
1085 int raw_packet_buffer_remaining_size;
1088 typedef struct AVPacketList {
1090 struct AVPacketList *next;
1095 * @defgroup lavf_core Core functions
1098 * Functions for querying libavformat capabilities, allocating core structures,
1104 * Return the LIBAVFORMAT_VERSION_INT constant.
1106 unsigned avformat_version(void);
1109 * Return the libavformat build-time configuration.
1111 const char *avformat_configuration(void);
1114 * Return the libavformat license.
1116 const char *avformat_license(void);
1119 * Initialize libavformat and register all the muxers, demuxers and
1120 * protocols. If you do not call this function, then you can select
1121 * exactly which formats you want to support.
1123 * @see av_register_input_format()
1124 * @see av_register_output_format()
1125 * @see av_register_protocol()
1127 void av_register_all(void);
1129 void av_register_input_format(AVInputFormat *format);
1130 void av_register_output_format(AVOutputFormat *format);
1133 * Do global initialization of network components. This is optional,
1134 * but recommended, since it avoids the overhead of implicitly
1135 * doing the setup for each session.
1137 * Calling this function will become mandatory if using network
1138 * protocols at some major version bump.
1140 int avformat_network_init(void);
1143 * Undo the initialization done by avformat_network_init.
1145 int avformat_network_deinit(void);
1148 * If f is NULL, returns the first registered input format,
1149 * if f is non-NULL, returns the next registered input format after f
1150 * or NULL if f is the last one.
1152 AVInputFormat *av_iformat_next(AVInputFormat *f);
1155 * If f is NULL, returns the first registered output format,
1156 * if f is non-NULL, returns the next registered output format after f
1157 * or NULL if f is the last one.
1159 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1162 * Allocate an AVFormatContext.
1163 * avformat_free_context() can be used to free the context and everything
1164 * allocated by the framework within it.
1166 AVFormatContext *avformat_alloc_context(void);
1169 * Free an AVFormatContext and all its streams.
1170 * @param s context to free
1172 void avformat_free_context(AVFormatContext *s);
1175 * Get the AVClass for AVFormatContext. It can be used in combination with
1176 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1178 * @see av_opt_find().
1180 const AVClass *avformat_get_class(void);
1183 * Add a new stream to a media file.
1185 * When demuxing, it is called by the demuxer in read_header(). If the
1186 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1187 * be called in read_packet().
1189 * When muxing, should be called by the user before avformat_write_header().
1191 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1192 * will be initialized to use this codec. This is needed for e.g. codec-specific
1193 * defaults to be set, so codec should be provided if it is known.
1195 * @return newly created stream or NULL on error.
1197 AVStream *avformat_new_stream(AVFormatContext *s, AVCodec *c);
1199 AVProgram *av_new_program(AVFormatContext *s, int id);
1207 attribute_deprecated void av_pkt_dump(FILE *f, AVPacket *pkt, int dump_payload);
1208 attribute_deprecated void av_pkt_dump_log(void *avcl, int level, AVPacket *pkt,
1212 #if FF_API_ALLOC_OUTPUT_CONTEXT
1214 * @deprecated deprecated in favor of avformat_alloc_output_context2()
1216 attribute_deprecated
1217 AVFormatContext *avformat_alloc_output_context(const char *format,
1218 AVOutputFormat *oformat,
1219 const char *filename);
1223 * Allocate an AVFormatContext for an output format.
1224 * avformat_free_context() can be used to free the context and
1225 * everything allocated by the framework within it.
1227 * @param *ctx is set to the created format context, or to NULL in
1229 * @param oformat format to use for allocating the context, if NULL
1230 * format_name and filename are used instead
1231 * @param format_name the name of output format to use for allocating the
1232 * context, if NULL filename is used instead
1233 * @param filename the name of the filename to use for allocating the
1234 * context, may be NULL
1235 * @return >= 0 in case of success, a negative AVERROR code in case of
1238 int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat,
1239 const char *format_name, const char *filename);
1242 * @addtogroup lavf_decoding
1247 * Find AVInputFormat based on the short name of the input format.
1249 AVInputFormat *av_find_input_format(const char *short_name);
1252 * Guess the file format.
1254 * @param is_opened Whether the file is already opened; determines whether
1255 * demuxers with or without AVFMT_NOFILE are probed.
1257 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1260 * Guess the file format.
1262 * @param is_opened Whether the file is already opened; determines whether
1263 * demuxers with or without AVFMT_NOFILE are probed.
1264 * @param score_max A probe score larger that this is required to accept a
1265 * detection, the variable is set to the actual detection
1267 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1268 * to retry with a larger probe buffer.
1270 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1273 * Guess the file format.
1275 * @param is_opened Whether the file is already opened; determines whether
1276 * demuxers with or without AVFMT_NOFILE are probed.
1277 * @param score_ret The score of the best detection.
1279 AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
1282 * Probe a bytestream to determine the input format. Each time a probe returns
1283 * with a score that is too low, the probe buffer size is increased and another
1284 * attempt is made. When the maximum probe size is reached, the input format
1285 * with the highest score is returned.
1287 * @param pb the bytestream to probe
1288 * @param fmt the input format is put here
1289 * @param filename the filename of the stream
1290 * @param logctx the log context
1291 * @param offset the offset within the bytestream to probe from
1292 * @param max_probe_size the maximum probe buffer size (zero for default)
1293 * @return 0 in case of success, a negative value corresponding to an
1294 * AVERROR code otherwise
1296 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1297 const char *filename, void *logctx,
1298 unsigned int offset, unsigned int max_probe_size);
1301 * Open an input stream and read the header. The codecs are not opened.
1302 * The stream must be closed with av_close_input_file().
1304 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1305 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1306 * function and written into ps.
1307 * Note that a user-supplied AVFormatContext will be freed on failure.
1308 * @param filename Name of the stream to open.
1309 * @param fmt If non-NULL, this parameter forces a specific input format.
1310 * Otherwise the format is autodetected.
1311 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1312 * On return this parameter will be destroyed and replaced with a dict containing
1313 * options that were not found. May be NULL.
1315 * @return 0 on success, a negative AVERROR on failure.
1317 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1319 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1321 attribute_deprecated
1322 int av_demuxer_open(AVFormatContext *ic);
1324 #if FF_API_FORMAT_PARAMETERS
1326 * Read packets of a media file to get stream information. This
1327 * is useful for file formats with no headers such as MPEG. This
1328 * function also computes the real framerate in case of MPEG-2 repeat
1330 * The logical file position is not changed by this function;
1331 * examined packets may be buffered for later processing.
1333 * @param ic media file handle
1334 * @return >=0 if OK, AVERROR_xxx on error
1335 * @todo Let the user decide somehow what information is needed so that
1336 * we do not waste time getting stuff the user does not need.
1338 * @deprecated use avformat_find_stream_info.
1340 attribute_deprecated
1341 int av_find_stream_info(AVFormatContext *ic);
1345 * Read packets of a media file to get stream information. This
1346 * is useful for file formats with no headers such as MPEG. This
1347 * function also computes the real framerate in case of MPEG-2 repeat
1349 * The logical file position is not changed by this function;
1350 * examined packets may be buffered for later processing.
1352 * @param ic media file handle
1353 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1354 * dictionaries, where i-th member contains options for
1355 * codec corresponding to i-th stream.
1356 * On return each dictionary will be filled with options that were not found.
1357 * @return >=0 if OK, AVERROR_xxx on error
1359 * @note this function isn't guaranteed to open all the codecs, so
1360 * options being non-empty at return is a perfectly normal behavior.
1362 * @todo Let the user decide somehow what information is needed so that
1363 * we do not waste time getting stuff the user does not need.
1365 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1368 * Find the programs which belong to a given stream.
1370 * @param ic media file handle
1371 * @param last the last found program, the search will start after this
1372 * program, or from the beginning if it is NULL
1373 * @param s stream index
1374 * @return the next program which belongs to s, NULL if no program is found or
1375 * the last program is not among the programs of ic.
1377 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s);
1380 * Find the "best" stream in the file.
1381 * The best stream is determined according to various heuristics as the most
1382 * likely to be what the user expects.
1383 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1384 * default decoder for the stream's codec; streams for which no decoder can
1385 * be found are ignored.
1387 * @param ic media file handle
1388 * @param type stream type: video, audio, subtitles, etc.
1389 * @param wanted_stream_nb user-requested stream number,
1390 * or -1 for automatic selection
1391 * @param related_stream try to find a stream related (eg. in the same
1392 * program) to this one, or -1 if none
1393 * @param decoder_ret if non-NULL, returns the decoder for the
1395 * @param flags flags; none are currently defined
1396 * @return the non-negative stream number in case of success,
1397 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
1399 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
1400 * @note If av_find_best_stream returns successfully and decoder_ret is not
1401 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
1403 int av_find_best_stream(AVFormatContext *ic,
1404 enum AVMediaType type,
1405 int wanted_stream_nb,
1407 AVCodec **decoder_ret,
1410 #if FF_API_READ_PACKET
1412 * @deprecated use AVFMT_FLAG_NOFILLIN | AVFMT_FLAG_NOPARSE to read raw
1413 * unprocessed packets
1415 * Read a transport packet from a media file.
1417 * This function is obsolete and should never be used.
1418 * Use av_read_frame() instead.
1420 * @param s media file handle
1421 * @param pkt is filled
1422 * @return 0 if OK, AVERROR_xxx on error
1424 attribute_deprecated
1425 int av_read_packet(AVFormatContext *s, AVPacket *pkt);
1429 * Return the next frame of a stream.
1430 * This function returns what is stored in the file, and does not validate
1431 * that what is there are valid frames for the decoder. It will split what is
1432 * stored in the file into frames and return one for each call. It will not
1433 * omit invalid data between valid frames so as to give the decoder the maximum
1434 * information possible for decoding.
1436 * The returned packet is valid
1437 * until the next av_read_frame() or until av_close_input_file() and
1438 * must be freed with av_free_packet. For video, the packet contains
1439 * exactly one frame. For audio, it contains an integer number of
1440 * frames if each frame has a known fixed size (e.g. PCM or ADPCM
1441 * data). If the audio frames have a variable size (e.g. MPEG audio),
1442 * then it contains one frame.
1444 * pkt->pts, pkt->dts and pkt->duration are always set to correct
1445 * values in AVStream.time_base units (and guessed if the format cannot
1446 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
1447 * has B-frames, so it is better to rely on pkt->dts if you do not
1448 * decompress the payload.
1450 * @return 0 if OK, < 0 on error or end of file
1452 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
1455 * Seek to the keyframe at timestamp.
1456 * 'timestamp' in 'stream_index'.
1457 * @param stream_index If stream_index is (-1), a default
1458 * stream is selected, and timestamp is automatically converted
1459 * from AV_TIME_BASE units to the stream specific time_base.
1460 * @param timestamp Timestamp in AVStream.time_base units
1461 * or, if no stream is specified, in AV_TIME_BASE units.
1462 * @param flags flags which select direction and seeking mode
1463 * @return >= 0 on success
1465 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
1469 * Seek to timestamp ts.
1470 * Seeking will be done so that the point from which all active streams
1471 * can be presented successfully will be closest to ts and within min/max_ts.
1472 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
1474 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
1475 * are the file position (this may not be supported by all demuxers).
1476 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
1477 * in the stream with stream_index (this may not be supported by all demuxers).
1478 * Otherwise all timestamps are in units of the stream selected by stream_index
1479 * or if stream_index is -1, in AV_TIME_BASE units.
1480 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
1481 * keyframes (this may not be supported by all demuxers).
1483 * @param stream_index index of the stream which is used as time base reference
1484 * @param min_ts smallest acceptable timestamp
1485 * @param ts target timestamp
1486 * @param max_ts largest acceptable timestamp
1487 * @param flags flags
1488 * @return >=0 on success, error code otherwise
1490 * @note This is part of the new seek API which is still under construction.
1491 * Thus do not use this yet. It may change at any time, do not expect
1492 * ABI compatibility yet!
1494 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
1497 * Start playing a network-based stream (e.g. RTSP stream) at the
1500 int av_read_play(AVFormatContext *s);
1503 * Pause a network-based stream (e.g. RTSP stream).
1505 * Use av_read_play() to resume it.
1507 int av_read_pause(AVFormatContext *s);
1509 #if FF_API_CLOSE_INPUT_FILE
1511 * @deprecated use avformat_close_input()
1512 * Close a media file (but not its codecs).
1514 * @param s media file handle
1516 attribute_deprecated
1517 void av_close_input_file(AVFormatContext *s);
1521 * Close an opened input AVFormatContext. Free it and all its contents
1522 * and set *s to NULL.
1524 void avformat_close_input(AVFormatContext **s);
1529 #if FF_API_NEW_STREAM
1531 * Add a new stream to a media file.
1533 * Can only be called in the read_header() function. If the flag
1534 * AVFMTCTX_NOHEADER is in the format context, then new streams
1535 * can be added in read_packet too.
1537 * @param s media file handle
1538 * @param id file-format-dependent stream ID
1540 attribute_deprecated
1541 AVStream *av_new_stream(AVFormatContext *s, int id);
1544 #if FF_API_SET_PTS_INFO
1546 * @deprecated this function is not supposed to be called outside of lavf
1548 attribute_deprecated
1549 void av_set_pts_info(AVStream *s, int pts_wrap_bits,
1550 unsigned int pts_num, unsigned int pts_den);
1553 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
1554 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
1555 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
1556 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
1559 * @addtogroup lavf_encoding
1563 * Allocate the stream private data and write the stream header to
1564 * an output media file.
1566 * @param s Media file handle, must be allocated with avformat_alloc_context().
1567 * Its oformat field must be set to the desired output format;
1568 * Its pb field must be set to an already openened AVIOContext.
1569 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
1570 * On return this parameter will be destroyed and replaced with a dict containing
1571 * options that were not found. May be NULL.
1573 * @return 0 on success, negative AVERROR on failure.
1575 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
1577 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
1580 * Write a packet to an output media file.
1582 * The packet shall contain one audio or video frame.
1583 * The packet must be correctly interleaved according to the container
1584 * specification, if not then av_interleaved_write_frame must be used.
1586 * @param s media file handle
1587 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1589 * This can be NULL (at any time, not just at the end), in
1590 * order to immediately flush data buffered within the muxer,
1591 * for muxers that buffer up data internally before writing it
1593 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
1595 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
1598 * Write a packet to an output media file ensuring correct interleaving.
1600 * The packet must contain one audio or video frame.
1601 * If the packets are already correctly interleaved, the application should
1602 * call av_write_frame() instead as it is slightly faster. It is also important
1603 * to keep in mind that completely non-interleaved input will need huge amounts
1604 * of memory to interleave with this, so it is preferable to interleave at the
1607 * @param s media file handle
1608 * @param pkt The packet containing the data to be written. Libavformat takes
1609 * ownership of the data and will free it when it sees fit using the packet's
1610 * This can be NULL (at any time, not just at the end), to flush the
1611 * interleaving queues.
1612 * @ref AVPacket.destruct "destruct" field. The caller must not access the data
1613 * after this function returns, as it may already be freed.
1614 * Packet's @ref AVPacket.stream_index "stream_index" field must be set to the
1615 * index of the corresponding stream in @ref AVFormatContext.streams
1617 * It is very strongly recommended that timing information (@ref AVPacket.pts
1618 * "pts", @ref AVPacket.dts "dts" @ref AVPacket.duration "duration") is set to
1621 * @return 0 on success, a negative AVERROR on error.
1623 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
1625 #if FF_API_INTERLEAVE_PACKET
1627 * @deprecated this function was never meant to be called by the user
1630 attribute_deprecated
1631 int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
1632 AVPacket *pkt, int flush);
1636 * Write the stream trailer to an output media file and free the
1637 * file private data.
1639 * May only be called after a successful call to av_write_header.
1641 * @param s media file handle
1642 * @return 0 if OK, AVERROR_xxx on error
1644 int av_write_trailer(AVFormatContext *s);
1647 * Return the output format in the list of registered output formats
1648 * which best matches the provided parameters, or return NULL if
1649 * there is no match.
1651 * @param short_name if non-NULL checks if short_name matches with the
1652 * names of the registered formats
1653 * @param filename if non-NULL checks if filename terminates with the
1654 * extensions of the registered formats
1655 * @param mime_type if non-NULL checks if mime_type matches with the
1656 * MIME type of the registered formats
1658 AVOutputFormat *av_guess_format(const char *short_name,
1659 const char *filename,
1660 const char *mime_type);
1663 * Guess the codec ID based upon muxer and filename.
1665 enum CodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
1666 const char *filename, const char *mime_type,
1667 enum AVMediaType type);
1670 * Get timing information for the data currently output.
1671 * The exact meaning of "currently output" depends on the format.
1672 * It is mostly relevant for devices that have an internal buffer and/or
1673 * work in real time.
1674 * @param s media file handle
1675 * @param stream stream in the media file
1676 * @param dts[out] DTS of the last packet output for the stream, in stream
1678 * @param wall[out] absolute time when that packet whas output,
1680 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
1681 * Note: some formats or devices may not allow to measure dts and wall
1684 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
1685 int64_t *dts, int64_t *wall);
1694 * @defgroup lavf_misc Utility functions
1698 * Miscelaneous utility functions related to both muxing and demuxing
1703 * Send a nice hexadecimal dump of a buffer to the specified file stream.
1705 * @param f The file stream pointer where the dump should be sent to.
1707 * @param size buffer size
1709 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
1711 void av_hex_dump(FILE *f, uint8_t *buf, int size);
1714 * Send a nice hexadecimal dump of a buffer to the log.
1716 * @param avcl A pointer to an arbitrary struct of which the first field is a
1717 * pointer to an AVClass struct.
1718 * @param level The importance level of the message, lower values signifying
1719 * higher importance.
1721 * @param size buffer size
1723 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
1725 void av_hex_dump_log(void *avcl, int level, uint8_t *buf, int size);
1728 * Send a nice dump of a packet to the specified file stream.
1730 * @param f The file stream pointer where the dump should be sent to.
1731 * @param pkt packet to dump
1732 * @param dump_payload True if the payload must be displayed, too.
1733 * @param st AVStream that the packet belongs to
1735 void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
1739 * Send a nice dump of a packet to the log.
1741 * @param avcl A pointer to an arbitrary struct of which the first field is a
1742 * pointer to an AVClass struct.
1743 * @param level The importance level of the message, lower values signifying
1744 * higher importance.
1745 * @param pkt packet to dump
1746 * @param dump_payload True if the payload must be displayed, too.
1747 * @param st AVStream that the packet belongs to
1749 void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
1753 * Get the CodecID for the given codec tag tag.
1754 * If no codec id is found returns CODEC_ID_NONE.
1756 * @param tags list of supported codec_id-codec_tag pairs, as stored
1757 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1759 enum CodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
1762 * Get the codec tag for the given codec id id.
1763 * If no codec tag is found returns 0.
1765 * @param tags list of supported codec_id-codec_tag pairs, as stored
1766 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1768 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum CodecID id);
1770 int av_find_default_stream_index(AVFormatContext *s);
1773 * Get the index for a specific timestamp.
1774 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
1775 * to the timestamp which is <= the requested one, if backward
1776 * is 0, then it will be >=
1777 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
1778 * @return < 0 if no such timestamp could be found
1780 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
1783 * Add an index entry into a sorted list. Update the entry if the list
1784 * already contains it.
1786 * @param timestamp timestamp in the time base of the given stream
1788 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
1789 int size, int distance, int flags);
1793 * Split a URL string into components.
1795 * The pointers to buffers for storing individual components may be null,
1796 * in order to ignore that component. Buffers for components not found are
1797 * set to empty strings. If the port is not found, it is set to a negative
1800 * @param proto the buffer for the protocol
1801 * @param proto_size the size of the proto buffer
1802 * @param authorization the buffer for the authorization
1803 * @param authorization_size the size of the authorization buffer
1804 * @param hostname the buffer for the host name
1805 * @param hostname_size the size of the hostname buffer
1806 * @param port_ptr a pointer to store the port number in
1807 * @param path the buffer for the path
1808 * @param path_size the size of the path buffer
1809 * @param url the URL to split
1811 void av_url_split(char *proto, int proto_size,
1812 char *authorization, int authorization_size,
1813 char *hostname, int hostname_size,
1815 char *path, int path_size,
1819 void av_dump_format(AVFormatContext *ic,
1825 * Get the current time in microseconds.
1827 int64_t av_gettime(void);
1830 * Return in 'buf' the path with '%d' replaced by a number.
1832 * Also handles the '%0nd' format where 'n' is the total number
1833 * of digits and '%%'.
1835 * @param buf destination buffer
1836 * @param buf_size destination buffer size
1837 * @param path numbered sequence string
1838 * @param number frame number
1839 * @return 0 if OK, -1 on format error
1841 int av_get_frame_filename(char *buf, int buf_size,
1842 const char *path, int number);
1845 * Check whether filename actually is a numbered sequence generator.
1847 * @param filename possible numbered sequence string
1848 * @return 1 if a valid numbered sequence string, 0 otherwise
1850 int av_filename_number_test(const char *filename);
1853 * Generate an SDP for an RTP session.
1855 * @param ac array of AVFormatContexts describing the RTP streams. If the
1856 * array is composed by only one context, such context can contain
1857 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
1858 * all the contexts in the array (an AVCodecContext per RTP stream)
1859 * must contain only one AVStream.
1860 * @param n_files number of AVCodecContexts contained in ac
1861 * @param buf buffer where the SDP will be stored (must be allocated by
1863 * @param size the size of the buffer
1864 * @return 0 if OK, AVERROR_xxx on error
1866 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
1869 * Return a positive value if the given filename has one of the given
1870 * extensions, 0 otherwise.
1872 * @param extensions a comma-separated list of filename extensions
1874 int av_match_ext(const char *filename, const char *extensions);
1877 * Test if the given container can store a codec.
1879 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
1881 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
1882 * A negative number if this information is not available.
1884 int avformat_query_codec(AVOutputFormat *ofmt, enum CodecID codec_id, int std_compliance);
1887 * @defgroup riff_fourcc RIFF FourCCs
1889 * Get the tables mapping RIFF FourCCs to libavcodec CodecIDs. The tables are
1890 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
1893 * uint32_t tag = MKTAG('H', '2', '6', '4');
1894 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
1895 * enum CodecID id = av_codec_get_id(table, tag);
1899 * @return the table mapping RIFF FourCCs for video to libavcodec CodecID.
1901 const struct AVCodecTag *avformat_get_riff_video_tags(void);
1903 * @return the table mapping RIFF FourCCs for audio to CodecID.
1905 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
1914 #endif /* AVFORMAT_AVFORMAT_H */