2 * copyright (c) 2001 Fabrice Bellard
4 * This file is part of Libav.
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #ifndef AVFORMAT_AVFORMAT_H
22 #define AVFORMAT_AVFORMAT_H
27 * Main libavformat public API header
31 * @defgroup libavf I/O and Muxing/Demuxing Library
34 * Libavformat (lavf) is a library for dealing with various media container
35 * formats. Its main two purposes are demuxing - i.e. splitting a media file
36 * into component streams, and the reverse process of muxing - writing supplied
37 * data in a specified container format. It also has an @ref lavf_io
38 * "I/O module" which supports a number of protocols for accessing the data (e.g.
39 * file, tcp, http and others). Before using lavf, you need to call
40 * av_register_all() to register all compiled muxers, demuxers and protocols.
41 * Unless you are absolutely sure you won't use libavformat's network
42 * capabilities, you should also call avformat_network_init().
44 * A supported input format is described by an AVInputFormat struct, conversely
45 * an output format is described by AVOutputFormat. You can iterate over all
46 * registered input/output formats using the av_iformat_next() /
47 * av_oformat_next() functions. The protocols layer is not part of the public
48 * API, so you can only get the names of supported protocols with the
49 * avio_enum_protocols() function.
51 * Main lavf structure used for both muxing and demuxing is AVFormatContext,
52 * which exports all information about the file being read or written. As with
53 * most Libav structures, its size is not part of public ABI, so it cannot be
54 * allocated on stack or directly with av_malloc(). To create an
55 * AVFormatContext, use avformat_alloc_context() (some functions, like
56 * avformat_open_input() might do that for you).
58 * Most importantly an AVFormatContext contains:
59 * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat
60 * "output" format. It is either autodetected or set by user for input;
61 * always set by user for output.
62 * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all
63 * elementary streams stored in the file. AVStreams are typically referred to
64 * using their index in this array.
65 * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or
66 * set by user for input, always set by user for output (unless you are dealing
67 * with an AVFMT_NOFILE format).
69 * @defgroup lavf_decoding Demuxing
71 * Demuxers read a media file and split it into chunks of data (@em packets). A
72 * @ref AVPacket "packet" contains one or more frames which belong a single
73 * elementary stream. In lavf API this process is represented by the
74 * avformat_open_input() function for opening a file, av_read_frame() for
75 * reading a single packet and finally avformat_close_input(), which does the
78 * @section lavf_decoding_open Opening a media file
79 * The minimum information required to open a file is its URL or filename, which
80 * is passed to avformat_open_input(), as in the following code:
82 * const char *url = "in.mp3";
83 * AVFormatContext *s = NULL;
84 * int ret = avformat_open_input(&s, url, NULL, NULL);
88 * The above code attempts to allocate an AVFormatContext, open the
89 * specified file (autodetecting the format) and read the header, exporting the
90 * information stored there into s. Some formats do not have a header or do not
91 * store enough information there, so it is recommended that you call the
92 * avformat_find_stream_info() function which tries to read and decode a few
93 * frames to find missing information.
95 * In some cases you might want to preallocate an AVFormatContext yourself with
96 * avformat_alloc_context() and do some tweaking on it before passing it to
97 * avformat_open_input(). One such case is when you want to use custom functions
98 * for reading input data instead of lavf internal I/O layer.
99 * To do that, create your own AVIOContext with avio_alloc_context(), passing
100 * your reading callbacks to it. Then set the @em pb field of your
101 * AVFormatContext to newly created AVIOContext.
103 * After you have finished reading the file, you must close it with
104 * avformat_close_input(). It will free everything associated with the file.
106 * @section lavf_decoding_read Reading from an opened file
108 * @section lavf_decoding_seek Seeking
111 * @defgroup lavf_encoding Muxing
115 * @defgroup lavf_io I/O Read/Write
119 * @defgroup lavf_codec Demuxers
121 * @defgroup lavf_codec_native Native Demuxers
124 * @defgroup lavf_codec_wrappers External library wrappers
128 * @defgroup lavf_protos I/O Protocols
131 * @defgroup lavf_internal Internal
139 #include <stdio.h> /* FILE */
140 #include "libavcodec/avcodec.h"
141 #include "libavutil/dict.h"
142 #include "libavutil/log.h"
145 #include "libavformat/version.h"
147 struct AVFormatContext;
151 * @defgroup metadata_api Public Metadata API
154 * The metadata API allows libavformat to export metadata tags to a client
155 * application when demuxing. Conversely it allows a client application to
156 * set metadata when muxing.
158 * Metadata is exported or set as pairs of key/value strings in the 'metadata'
159 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
160 * using the @ref lavu_dict "AVDictionary" API. Like all strings in Libav,
161 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
162 * exported by demuxers isn't checked to be valid UTF-8 in most cases.
164 * Important concepts to keep in mind:
165 * - Keys are unique; there can never be 2 tags with the same key. This is
166 * also meant semantically, i.e., a demuxer should not knowingly produce
167 * several keys that are literally different but semantically identical.
168 * E.g., key=Author5, key=Author6. In this example, all authors must be
169 * placed in the same tag.
170 * - Metadata is flat, not hierarchical; there are no subtags. If you
171 * want to store, e.g., the email address of the child of producer Alice
172 * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
173 * - Several modifiers can be applied to the tag name. This is done by
174 * appending a dash character ('-') and the modifier name in the order
175 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
176 * - language -- a tag whose value is localized for a particular language
177 * is appended with the ISO 639-2/B 3-letter language code.
178 * For example: Author-ger=Michael, Author-eng=Mike
179 * The original/default language is in the unqualified "Author" tag.
180 * A demuxer should set a default if it sets any translated tag.
181 * - sorting -- a modified version of a tag that should be used for
182 * sorting will have '-sort' appended. E.g. artist="The Beatles",
183 * artist-sort="Beatles, The".
185 * - Demuxers attempt to export metadata in a generic format, however tags
186 * with no generic equivalents are left as they are stored in the container.
187 * Follows a list of generic tag names:
190 album -- name of the set this work belongs to
191 album_artist -- main creator of the set/album, if different from artist.
192 e.g. "Various Artists" for compilation albums.
193 artist -- main creator of the work
194 comment -- any additional description of the file.
195 composer -- who composed the work, if different from artist.
196 copyright -- name of copyright holder.
197 creation_time-- date when the file was created, preferably in ISO 8601.
198 date -- date when the work was created, preferably in ISO 8601.
199 disc -- number of a subset, e.g. disc in a multi-disc collection.
200 encoder -- name/settings of the software/hardware that produced the file.
201 encoded_by -- person/group who created the file.
202 filename -- original name of the file.
203 genre -- <self-evident>.
204 language -- main language in which the work is performed, preferably
205 in ISO 639-2 format. Multiple languages can be specified by
206 separating them with commas.
207 performer -- artist who performed the work, if different from artist.
208 E.g for "Also sprach Zarathustra", artist would be "Richard
209 Strauss" and performer "London Philharmonic Orchestra".
210 publisher -- name of the label/publisher.
211 service_name -- name of the service in broadcasting (channel name).
212 service_provider -- name of the service provider in broadcasting.
213 title -- name of the work.
214 track -- number of this work in the set, can be in form current/total.
215 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
218 * Look in the examples section for an application example how to use the Metadata API.
223 /* packet functions */
227 * Allocate and read the payload of a packet and initialize its
228 * fields with default values.
231 * @param size desired payload size
232 * @return >0 (read size) if OK, AVERROR_xxx otherwise
234 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
238 * Read data and append it to the current content of the AVPacket.
239 * If pkt->size is 0 this is identical to av_get_packet.
240 * Note that this uses av_grow_packet and thus involves a realloc
241 * which is inefficient. Thus this function should only be used
242 * when there is no reasonable way to know (an upper bound of)
246 * @param size amount of data to read
247 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
248 * will not be lost even if an error occurs.
250 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
252 /*************************************************/
253 /* fractional numbers for exact pts handling */
256 * The exact value of the fractional number is: 'val + num / den'.
257 * num is assumed to be 0 <= num < den.
259 typedef struct AVFrac {
260 int64_t val, num, den;
263 /*************************************************/
264 /* input/output formats */
269 * This structure contains the data a format has to probe a file.
271 typedef struct AVProbeData {
272 const char *filename;
273 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
274 int buf_size; /**< Size of buf except extra allocated bytes */
277 #define AVPROBE_SCORE_MAX 100 ///< maximum score, half of that is used for file-extension-based detection
278 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
280 /// Demuxer will use avio_open, no opened file should be provided by the caller.
281 #define AVFMT_NOFILE 0x0001
282 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
283 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
284 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
286 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
287 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
288 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
289 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
290 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
291 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
292 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
293 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fallback to binary search via read_timestamp */
294 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fallback to generic search */
295 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
296 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
299 * @addtogroup lavf_encoding
302 typedef struct AVOutputFormat {
305 * Descriptive name for the format, meant to be more human-readable
306 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
309 const char *long_name;
310 const char *mime_type;
311 const char *extensions; /**< comma-separated filename extensions */
313 * size of private data so that it can be allocated in the wrapper
317 enum CodecID audio_codec; /**< default audio codec */
318 enum CodecID video_codec; /**< default video codec */
319 int (*write_header)(struct AVFormatContext *);
321 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
322 * pkt can be NULL in order to flush data buffered in the muxer.
323 * When flushing, return 0 if there still is more data to flush,
324 * or 1 if everything was flushed and there is no more buffered
327 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
328 int (*write_trailer)(struct AVFormatContext *);
330 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
331 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
332 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH
336 * Currently only used to set pixel format if not YUV420P.
338 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
339 AVPacket *in, int flush);
342 * List of supported codec_id-codec_tag pairs, ordered by "better
343 * choice first". The arrays are all terminated by CODEC_ID_NONE.
345 const struct AVCodecTag * const *codec_tag;
347 enum CodecID subtitle_codec; /**< default subtitle codec */
349 const AVClass *priv_class; ///< AVClass for the private context
352 * Test if the given codec can be stored in this container.
354 * @return 1 if the codec is supported, 0 if it is not.
355 * A negative number if unknown.
357 int (*query_codec)(enum CodecID id, int std_compliance);
360 struct AVOutputFormat *next;
367 * @addtogroup lavf_decoding
370 typedef struct AVInputFormat {
372 * A comma separated list of short names for the format. New names
373 * may be appended with a minor bump.
378 * Descriptive name for the format, meant to be more human-readable
379 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
382 const char *long_name;
385 * Size of private data so that it can be allocated in the wrapper.
390 * Tell if a given file has a chance of being parsed as this format.
391 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
392 * big so you do not have to check for that unless you need more.
394 int (*read_probe)(AVProbeData *);
397 * Read the format header and initialize the AVFormatContext
398 * structure. Return 0 if OK. 'ap' if non-NULL contains
399 * additional parameters. Only used in raw format right
400 * now. 'av_new_stream' should be called to create new streams.
402 int (*read_header)(struct AVFormatContext *);
405 * Read one packet and put it in 'pkt'. pts and flags are also
406 * set. 'av_new_stream' can be called only if the flag
407 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
408 * background thread).
409 * @return 0 on success, < 0 on error.
410 * When returning an error, pkt must not have been allocated
411 * or must be freed before returning
413 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
416 * Close the stream. The AVFormatContext and AVStreams are not
417 * freed by this function
419 int (*read_close)(struct AVFormatContext *);
422 * Seek to a given timestamp relative to the frames in
423 * stream component stream_index.
424 * @param stream_index Must not be -1.
425 * @param flags Selects which direction should be preferred if no exact
426 * match is available.
427 * @return >= 0 on success (but not necessarily the new offset)
429 int (*read_seek)(struct AVFormatContext *,
430 int stream_index, int64_t timestamp, int flags);
433 * Get the next timestamp in stream[stream_index].time_base units.
434 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
436 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
437 int64_t *pos, int64_t pos_limit);
440 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
441 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
442 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK.
447 * If extensions are defined, then no probe is done. You should
448 * usually not use extension format guessing because it is not
451 const char *extensions;
454 * General purpose read-only value that the format can use.
459 * Start/resume playing - only meaningful if using a network-based format
462 int (*read_play)(struct AVFormatContext *);
465 * Pause playing - only meaningful if using a network-based format
468 int (*read_pause)(struct AVFormatContext *);
470 const struct AVCodecTag * const *codec_tag;
473 * Seek to timestamp ts.
474 * Seeking will be done so that the point from which all active streams
475 * can be presented successfully will be closest to ts and within min/max_ts.
476 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
478 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
480 const AVClass *priv_class; ///< AVClass for the private context
483 struct AVInputFormat *next;
489 enum AVStreamParseType {
491 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
492 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
493 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
494 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
497 typedef struct AVIndexEntry {
500 #define AVINDEX_KEYFRAME 0x0001
502 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).
503 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
506 #define AV_DISPOSITION_DEFAULT 0x0001
507 #define AV_DISPOSITION_DUB 0x0002
508 #define AV_DISPOSITION_ORIGINAL 0x0004
509 #define AV_DISPOSITION_COMMENT 0x0008
510 #define AV_DISPOSITION_LYRICS 0x0010
511 #define AV_DISPOSITION_KARAOKE 0x0020
514 * Track should be used during playback by default.
515 * Useful for subtitle track that should be displayed
516 * even when user did not explicitly ask for subtitles.
518 #define AV_DISPOSITION_FORCED 0x0040
519 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
520 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
521 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
525 * New fields can be added to the end with minor version bumps.
526 * Removal, reordering and changes to existing fields require a major
528 * sizeof(AVStream) must not be used outside libav*.
530 typedef struct AVStream {
531 int index; /**< stream index in AVFormatContext */
532 int id; /**< format-specific stream ID */
533 AVCodecContext *codec; /**< codec context */
535 * Real base framerate of the stream.
536 * This is the lowest framerate with which all timestamps can be
537 * represented accurately (it is the least common multiple of all
538 * framerates in the stream). Note, this value is just a guess!
539 * For example, if the time base is 1/90000 and all frames have either
540 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
542 AVRational r_frame_rate;
545 #if FF_API_REORDER_PRIVATE
546 /* internal data used in av_find_stream_info() */
551 * encoding: pts generation when outputting stream
556 * This is the fundamental unit of time (in seconds) in terms
557 * of which frame timestamps are represented. For fixed-fps content,
558 * time base should be 1/framerate and timestamp increments should be 1.
559 * decoding: set by libavformat
560 * encoding: set by libavformat in av_write_header
562 AVRational time_base;
563 #if FF_API_REORDER_PRIVATE
564 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
566 #if FF_API_STREAM_COPY
567 /* ffmpeg.c private use */
568 attribute_deprecated int stream_copy; /**< If set, just copy stream. */
570 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
572 #if FF_API_AVSTREAM_QUALITY
573 //FIXME move stuff to a flags field?
575 * Quality, as it has been removed from AVCodecContext and put in AVVideoFrame.
576 * MN: dunno if that is the right place for it
578 attribute_deprecated float quality;
582 * Decoding: pts of the first frame of the stream, in stream time base.
583 * Only set this if you are absolutely 100% sure that the value you set
584 * it to really is the pts of the first frame.
585 * This may be undefined (AV_NOPTS_VALUE).
590 * Decoding: duration of the stream, in stream time base.
591 * If a source file does not specify a duration, but does specify
592 * a bitrate, this value will be estimated from bitrate and file size.
596 #if FF_API_REORDER_PRIVATE
597 /* av_read_frame() support */
598 enum AVStreamParseType need_parsing;
599 struct AVCodecParserContext *parser;
602 int last_IP_duration;
604 /* av_seek_frame() support */
605 AVIndexEntry *index_entries; /**< Only used if the format does not
606 support seeking natively. */
607 int nb_index_entries;
608 unsigned int index_entries_allocated_size;
611 int64_t nb_frames; ///< number of frames in this stream if known or 0
613 int disposition; /**< AV_DISPOSITION_* bit field */
615 #if FF_API_REORDER_PRIVATE
616 AVProbeData probe_data;
617 #define MAX_REORDER_DELAY 16
618 int64_t pts_buffer[MAX_REORDER_DELAY+1];
622 * sample aspect ratio (0 if unknown)
623 * - encoding: Set by user.
624 * - decoding: Set by libavformat.
626 AVRational sample_aspect_ratio;
628 AVDictionary *metadata;
630 #if FF_API_REORDER_PRIVATE
631 /* Intended mostly for av_read_frame() support. Not supposed to be used by */
632 /* external applications; try to use something else if at all possible. */
633 const uint8_t *cur_ptr;
637 // Timestamp generation support:
639 * Timestamp corresponding to the last dts sync point.
641 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
642 * a DTS is received from the underlying container. Otherwise set to
643 * AV_NOPTS_VALUE by default.
645 int64_t reference_dts;
648 * Number of packets to buffer for codec probing
649 * NOT PART OF PUBLIC API
651 #define MAX_PROBE_PACKETS 2500
655 * last packet in packet_buffer for this stream when muxing.
656 * Used internally, NOT PART OF PUBLIC API, do not read or
657 * write from outside of libav*
659 struct AVPacketList *last_in_packet_buffer;
665 AVRational avg_frame_rate;
667 /*****************************************************************
668 * All fields below this line are not part of the public API. They
669 * may not be used outside of libavformat and can be changed and
671 * New public fields should be added right above.
672 *****************************************************************
676 * Number of frames that have been demuxed during av_find_stream_info()
678 int codec_info_nb_frames;
681 * Stream information used internally by av_find_stream_info()
683 #define MAX_STD_TIMEBASES (60*12+5)
686 int64_t duration_gcd;
688 double duration_error[MAX_STD_TIMEBASES];
689 int64_t codec_info_duration;
690 int nb_decoded_frames;
692 #if !FF_API_REORDER_PRIVATE
693 const uint8_t *cur_ptr;
697 // Timestamp generation support:
699 * Timestamp corresponding to the last dts sync point.
701 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
702 * a DTS is received from the underlying container. Otherwise set to
703 * AV_NOPTS_VALUE by default.
705 int64_t reference_dts;
708 int last_IP_duration;
712 * Number of packets to buffer for codec probing
714 #define MAX_PROBE_PACKETS 2500
718 * last packet in packet_buffer for this stream when muxing.
720 struct AVPacketList *last_in_packet_buffer;
721 AVProbeData probe_data;
722 #define MAX_REORDER_DELAY 16
723 int64_t pts_buffer[MAX_REORDER_DELAY+1];
724 /* av_read_frame() support */
725 enum AVStreamParseType need_parsing;
726 struct AVCodecParserContext *parser;
728 AVIndexEntry *index_entries; /**< Only used if the format does not
729 support seeking natively. */
730 int nb_index_entries;
731 unsigned int index_entries_allocated_size;
733 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
737 #define AV_PROGRAM_RUNNING 1
740 * New fields can be added to the end with minor version bumps.
741 * Removal, reordering and changes to existing fields require a major
743 * sizeof(AVProgram) must not be used outside libav*.
745 typedef struct AVProgram {
748 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
749 unsigned int *stream_index;
750 unsigned int nb_stream_indexes;
751 AVDictionary *metadata;
754 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
755 (streams are added dynamically) */
757 typedef struct AVChapter {
758 int id; ///< unique ID to identify the chapter
759 AVRational time_base; ///< time base in which the start/end timestamps are specified
760 int64_t start, end; ///< chapter start/end time in time_base units
761 AVDictionary *metadata;
765 * Format I/O context.
766 * New fields can be added to the end with minor version bumps.
767 * Removal, reordering and changes to existing fields require a major
769 * sizeof(AVFormatContext) must not be used outside libav*, use
770 * avformat_alloc_context() to create an AVFormatContext.
772 typedef struct AVFormatContext {
774 * A class for logging and AVOptions. Set by avformat_alloc_context().
775 * Exports (de)muxer private options if they exist.
777 const AVClass *av_class;
780 * Can only be iformat or oformat, not both at the same time.
782 * decoding: set by avformat_open_input().
783 * encoding: set by the user.
785 struct AVInputFormat *iformat;
786 struct AVOutputFormat *oformat;
789 * Format private data. This is an AVOptions-enabled struct
790 * if and only if iformat/oformat.priv_class is not NULL.
797 * decoding: either set by the user before avformat_open_input() (then
798 * the user must close it manually) or set by avformat_open_input().
799 * encoding: set by the user.
801 * Do NOT set this field if AVFMT_NOFILE flag is set in
802 * iformat/oformat.flags. In such a case, the (de)muxer will handle
803 * I/O in some other way and this field will be NULL.
808 * A list of all streams in the file. New streams are created with
809 * avformat_new_stream().
811 * decoding: streams are created by libavformat in avformat_open_input().
812 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
813 * appear in av_read_frame().
814 * encoding: streams are created by the user before avformat_write_header().
816 unsigned int nb_streams;
819 char filename[1024]; /**< input or output filename */
823 * @deprecated use 'creation_time' metadata tag instead
825 attribute_deprecated int64_t timestamp;
828 int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
829 #if FF_API_REORDER_PRIVATE
830 /* private data for pts handling (do not modify directly). */
832 * This buffer is only needed when packets were already buffered but
833 * not decoded, for example to get the codec parameters in MPEG
836 struct AVPacketList *packet_buffer;
840 * Decoding: position of the first frame of the component, in
841 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
842 * It is deduced from the AVStream values.
847 * Decoding: duration of the stream, in AV_TIME_BASE fractional
848 * seconds. Only set this value if you know none of the individual stream
849 * durations and also do not set any of them. This is deduced from the
850 * AVStream values if not set.
856 * decoding: total file size, 0 if unknown
858 attribute_deprecated int64_t file_size;
862 * Decoding: total stream bitrate in bit/s, 0 if not
863 * available. Never set it directly if the file_size and the
864 * duration are known as Libav can compute it automatically.
868 #if FF_API_REORDER_PRIVATE
869 /* av_read_frame() support */
872 /* av_seek_frame() support */
873 int64_t data_offset; /**< offset of the first packet */
878 * use mpeg muxer private options instead
880 attribute_deprecated int mux_rate;
882 unsigned int packet_size;
884 attribute_deprecated int preload;
888 #if FF_API_LOOP_OUTPUT
889 #define AVFMT_NOOUTPUTLOOP -1
890 #define AVFMT_INFINITEOUTPUTLOOP 0
892 * number of times to loop output in formats that support it
894 * @deprecated use the 'loop' private option in the gif muxer.
896 attribute_deprecated int loop_output;
900 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
901 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
902 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
903 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
904 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
905 #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
906 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
907 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
909 #if FF_API_LOOP_INPUT
911 * @deprecated, use the 'loop' img2 demuxer private option.
913 attribute_deprecated int loop_input;
917 * decoding: size of data to probe; encoding: unused.
919 unsigned int probesize;
922 * decoding: maximum time (in AV_TIME_BASE units) during which the input should
923 * be analyzed in avformat_find_stream_info().
925 int max_analyze_duration;
930 unsigned int nb_programs;
931 AVProgram **programs;
934 * Forced video codec_id.
935 * Demuxing: Set by user.
937 enum CodecID video_codec_id;
940 * Forced audio codec_id.
941 * Demuxing: Set by user.
943 enum CodecID audio_codec_id;
946 * Forced subtitle codec_id.
947 * Demuxing: Set by user.
949 enum CodecID subtitle_codec_id;
952 * Maximum amount of memory in bytes to use for the index of each stream.
953 * If the index exceeds this size, entries will be discarded as
954 * needed to maintain a smaller size. This can lead to slower or less
955 * accurate seeking (depends on demuxer).
956 * Demuxers for which a full in-memory index is mandatory will ignore
959 * demuxing: set by user
961 unsigned int max_index_size;
964 * Maximum amount of memory in bytes to use for buffering frames
965 * obtained from realtime capture devices.
967 unsigned int max_picture_buffer;
969 unsigned int nb_chapters;
970 AVChapter **chapters;
973 * Flags to enable debugging.
976 #define FF_FDEBUG_TS 0x0001
978 #if FF_API_REORDER_PRIVATE
980 * Raw packets from the demuxer, prior to parsing and decoding.
981 * This buffer is used for buffering packets until the codec can
982 * be identified, as parsing cannot be done without knowing the
985 struct AVPacketList *raw_packet_buffer;
986 struct AVPacketList *raw_packet_buffer_end;
988 struct AVPacketList *packet_buffer_end;
991 AVDictionary *metadata;
993 #if FF_API_REORDER_PRIVATE
995 * Remaining size available for raw_packet_buffer, in bytes.
996 * NOT PART OF PUBLIC API
998 #define RAW_PACKET_BUFFER_SIZE 2500000
999 int raw_packet_buffer_remaining_size;
1003 * Start time of the stream in real world time, in microseconds
1004 * since the unix epoch (00:00 1st January 1970). That is, pts=0
1005 * in the stream was captured at this real world time.
1006 * - encoding: Set by user.
1007 * - decoding: Unused.
1009 int64_t start_time_realtime;
1012 * decoding: number of frames used to probe fps
1017 * Error recognition; higher values will detect more errors but may
1018 * misdetect some more or less valid parts as errors.
1019 * - encoding: unused
1020 * - decoding: Set by user.
1022 int error_recognition;
1025 * Custom interrupt callbacks for the I/O layer.
1027 * decoding: set by the user before avformat_open_input().
1028 * encoding: set by the user before avformat_write_header()
1029 * (mainly useful for AVFMT_NOFILE formats). The callback
1030 * should also be passed to avio_open2() if it's used to
1033 AVIOInterruptCB interrupt_callback;
1035 /*****************************************************************
1036 * All fields below this line are not part of the public API. They
1037 * may not be used outside of libavformat and can be changed and
1039 * New public fields should be added right above.
1040 *****************************************************************
1042 #if !FF_API_REORDER_PRIVATE
1044 * Raw packets from the demuxer, prior to parsing and decoding.
1045 * This buffer is used for buffering packets until the codec can
1046 * be identified, as parsing cannot be done without knowing the
1049 struct AVPacketList *raw_packet_buffer;
1050 struct AVPacketList *raw_packet_buffer_end;
1052 * Remaining size available for raw_packet_buffer, in bytes.
1054 #define RAW_PACKET_BUFFER_SIZE 2500000
1055 int raw_packet_buffer_remaining_size;
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_read_frame() support */
1068 /* av_seek_frame() support */
1069 int64_t data_offset; /**< offset of the first packet */
1073 typedef struct AVPacketList {
1075 struct AVPacketList *next;
1080 * @defgroup lavf_core Core functions
1083 * Functions for querying libavformat capabilities, allocating core structures,
1089 * Return the LIBAVFORMAT_VERSION_INT constant.
1091 unsigned avformat_version(void);
1094 * Return the libavformat build-time configuration.
1096 const char *avformat_configuration(void);
1099 * Return the libavformat license.
1101 const char *avformat_license(void);
1104 * Initialize libavformat and register all the muxers, demuxers and
1105 * protocols. If you do not call this function, then you can select
1106 * exactly which formats you want to support.
1108 * @see av_register_input_format()
1109 * @see av_register_output_format()
1110 * @see av_register_protocol()
1112 void av_register_all(void);
1114 void av_register_input_format(AVInputFormat *format);
1115 void av_register_output_format(AVOutputFormat *format);
1118 * Do global initialization of network components. This is optional,
1119 * but recommended, since it avoids the overhead of implicitly
1120 * doing the setup for each session.
1122 * Calling this function will become mandatory if using network
1123 * protocols at some major version bump.
1125 int avformat_network_init(void);
1128 * Undo the initialization done by avformat_network_init.
1130 int avformat_network_deinit(void);
1133 * If f is NULL, returns the first registered input format,
1134 * if f is non-NULL, returns the next registered input format after f
1135 * or NULL if f is the last one.
1137 AVInputFormat *av_iformat_next(AVInputFormat *f);
1140 * If f is NULL, returns the first registered output format,
1141 * if f is non-NULL, returns the next registered output format after f
1142 * or NULL if f is the last one.
1144 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1147 * Allocate an AVFormatContext.
1148 * avformat_free_context() can be used to free the context and everything
1149 * allocated by the framework within it.
1151 AVFormatContext *avformat_alloc_context(void);
1154 * Free an AVFormatContext and all its streams.
1155 * @param s context to free
1157 void avformat_free_context(AVFormatContext *s);
1160 * Get the AVClass for AVFormatContext. It can be used in combination with
1161 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1163 * @see av_opt_find().
1165 const AVClass *avformat_get_class(void);
1168 * Add a new stream to a media file.
1170 * When demuxing, it is called by the demuxer in read_header(). If the
1171 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1172 * be called in read_packet().
1174 * When muxing, should be called by the user before avformat_write_header().
1176 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1177 * will be initialized to use this codec. This is needed for e.g. codec-specific
1178 * defaults to be set, so codec should be provided if it is known.
1180 * @return newly created stream or NULL on error.
1182 AVStream *avformat_new_stream(AVFormatContext *s, AVCodec *c);
1184 AVProgram *av_new_program(AVFormatContext *s, int id);
1192 * @addtogroup lavf_decoding
1197 * Find AVInputFormat based on the short name of the input format.
1199 AVInputFormat *av_find_input_format(const char *short_name);
1202 * Guess the file format.
1204 * @param is_opened Whether the file is already opened; determines whether
1205 * demuxers with or without AVFMT_NOFILE are probed.
1207 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1210 * Guess the file format.
1212 * @param is_opened Whether the file is already opened; determines whether
1213 * demuxers with or without AVFMT_NOFILE are probed.
1214 * @param score_max A probe score larger that this is required to accept a
1215 * detection, the variable is set to the actual detection
1217 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1218 * to retry with a larger probe buffer.
1220 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1223 * Probe a bytestream to determine the input format. Each time a probe returns
1224 * with a score that is too low, the probe buffer size is increased and another
1225 * attempt is made. When the maximum probe size is reached, the input format
1226 * with the highest score is returned.
1228 * @param pb the bytestream to probe
1229 * @param fmt the input format is put here
1230 * @param filename the filename of the stream
1231 * @param logctx the log context
1232 * @param offset the offset within the bytestream to probe from
1233 * @param max_probe_size the maximum probe buffer size (zero for default)
1234 * @return 0 in case of success, a negative value corresponding to an
1235 * AVERROR code otherwise
1237 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1238 const char *filename, void *logctx,
1239 unsigned int offset, unsigned int max_probe_size);
1242 * Open an input stream and read the header. The codecs are not opened.
1243 * The stream must be closed with av_close_input_file().
1245 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1246 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1247 * function and written into ps.
1248 * Note that a user-supplied AVFormatContext will be freed on failure.
1249 * @param filename Name of the stream to open.
1250 * @param fmt If non-NULL, this parameter forces a specific input format.
1251 * Otherwise the format is autodetected.
1252 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1253 * On return this parameter will be destroyed and replaced with a dict containing
1254 * options that were not found. May be NULL.
1256 * @return 0 on success, a negative AVERROR on failure.
1258 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1260 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1263 * Read packets of a media file to get stream information. This
1264 * is useful for file formats with no headers such as MPEG. This
1265 * function also computes the real framerate in case of MPEG-2 repeat
1267 * The logical file position is not changed by this function;
1268 * examined packets may be buffered for later processing.
1270 * @param ic media file handle
1271 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1272 * dictionaries, where i-th member contains options for
1273 * codec corresponding to i-th stream.
1274 * On return each dictionary will be filled with options that were not found.
1275 * @return >=0 if OK, AVERROR_xxx on error
1277 * @note this function isn't guaranteed to open all the codecs, so
1278 * options being non-empty at return is a perfectly normal behavior.
1280 * @todo Let the user decide somehow what information is needed so that
1281 * we do not waste time getting stuff the user does not need.
1283 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1286 * Find the "best" stream in the file.
1287 * The best stream is determined according to various heuristics as the most
1288 * likely to be what the user expects.
1289 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1290 * default decoder for the stream's codec; streams for which no decoder can
1291 * be found are ignored.
1293 * @param ic media file handle
1294 * @param type stream type: video, audio, subtitles, etc.
1295 * @param wanted_stream_nb user-requested stream number,
1296 * or -1 for automatic selection
1297 * @param related_stream try to find a stream related (eg. in the same
1298 * program) to this one, or -1 if none
1299 * @param decoder_ret if non-NULL, returns the decoder for the
1301 * @param flags flags; none are currently defined
1302 * @return the non-negative stream number in case of success,
1303 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
1305 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
1306 * @note If av_find_best_stream returns successfully and decoder_ret is not
1307 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
1309 int av_find_best_stream(AVFormatContext *ic,
1310 enum AVMediaType type,
1311 int wanted_stream_nb,
1313 AVCodec **decoder_ret,
1317 * Read a transport packet from a media file.
1319 * This function is obsolete and should never be used.
1320 * Use av_read_frame() instead.
1322 * @param s media file handle
1323 * @param pkt is filled
1324 * @return 0 if OK, AVERROR_xxx on error
1326 int av_read_packet(AVFormatContext *s, AVPacket *pkt);
1329 * Return the next frame of a stream.
1330 * This function returns what is stored in the file, and does not validate
1331 * that what is there are valid frames for the decoder. It will split what is
1332 * stored in the file into frames and return one for each call. It will not
1333 * omit invalid data between valid frames so as to give the decoder the maximum
1334 * information possible for decoding.
1336 * The returned packet is valid
1337 * until the next av_read_frame() or until av_close_input_file() and
1338 * must be freed with av_free_packet. For video, the packet contains
1339 * exactly one frame. For audio, it contains an integer number of
1340 * frames if each frame has a known fixed size (e.g. PCM or ADPCM
1341 * data). If the audio frames have a variable size (e.g. MPEG audio),
1342 * then it contains one frame.
1344 * pkt->pts, pkt->dts and pkt->duration are always set to correct
1345 * values in AVStream.time_base units (and guessed if the format cannot
1346 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
1347 * has B-frames, so it is better to rely on pkt->dts if you do not
1348 * decompress the payload.
1350 * @return 0 if OK, < 0 on error or end of file
1352 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
1355 * Seek to the keyframe at timestamp.
1356 * 'timestamp' in 'stream_index'.
1357 * @param stream_index If stream_index is (-1), a default
1358 * stream is selected, and timestamp is automatically converted
1359 * from AV_TIME_BASE units to the stream specific time_base.
1360 * @param timestamp Timestamp in AVStream.time_base units
1361 * or, if no stream is specified, in AV_TIME_BASE units.
1362 * @param flags flags which select direction and seeking mode
1363 * @return >= 0 on success
1365 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
1369 * Seek to timestamp ts.
1370 * Seeking will be done so that the point from which all active streams
1371 * can be presented successfully will be closest to ts and within min/max_ts.
1372 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
1374 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
1375 * are the file position (this may not be supported by all demuxers).
1376 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
1377 * in the stream with stream_index (this may not be supported by all demuxers).
1378 * Otherwise all timestamps are in units of the stream selected by stream_index
1379 * or if stream_index is -1, in AV_TIME_BASE units.
1380 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
1381 * keyframes (this may not be supported by all demuxers).
1383 * @param stream_index index of the stream which is used as time base reference
1384 * @param min_ts smallest acceptable timestamp
1385 * @param ts target timestamp
1386 * @param max_ts largest acceptable timestamp
1387 * @param flags flags
1388 * @return >=0 on success, error code otherwise
1390 * @note This is part of the new seek API which is still under construction.
1391 * Thus do not use this yet. It may change at any time, do not expect
1392 * ABI compatibility yet!
1394 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
1397 * Start playing a network-based stream (e.g. RTSP stream) at the
1400 int av_read_play(AVFormatContext *s);
1403 * Pause a network-based stream (e.g. RTSP stream).
1405 * Use av_read_play() to resume it.
1407 int av_read_pause(AVFormatContext *s);
1409 #if FF_API_CLOSE_INPUT_FILE
1411 * @deprecated use avformat_close_input()
1412 * Close a media file (but not its codecs).
1414 * @param s media file handle
1416 attribute_deprecated
1417 void av_close_input_file(AVFormatContext *s);
1421 * Close an opened input AVFormatContext. Free it and all its contents
1422 * and set *s to NULL.
1424 void avformat_close_input(AVFormatContext **s);
1429 #if FF_API_NEW_STREAM
1431 * Add a new stream to a media file.
1433 * Can only be called in the read_header() function. If the flag
1434 * AVFMTCTX_NOHEADER is in the format context, then new streams
1435 * can be added in read_packet too.
1437 * @param s media file handle
1438 * @param id file-format-dependent stream ID
1440 attribute_deprecated
1441 AVStream *av_new_stream(AVFormatContext *s, int id);
1444 #if FF_API_SET_PTS_INFO
1446 * @deprecated this function is not supposed to be called outside of lavf
1448 attribute_deprecated
1449 void av_set_pts_info(AVStream *s, int pts_wrap_bits,
1450 unsigned int pts_num, unsigned int pts_den);
1453 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
1454 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
1455 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
1456 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
1458 #if FF_API_SEEK_PUBLIC
1459 attribute_deprecated
1460 int av_seek_frame_binary(AVFormatContext *s, int stream_index,
1461 int64_t target_ts, int flags);
1462 attribute_deprecated
1463 void av_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp);
1464 attribute_deprecated
1465 int64_t av_gen_search(AVFormatContext *s, int stream_index,
1466 int64_t target_ts, int64_t pos_min,
1467 int64_t pos_max, int64_t pos_limit,
1468 int64_t ts_min, int64_t ts_max,
1469 int flags, int64_t *ts_ret,
1470 int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
1474 * @addtogroup lavf_encoding
1478 * Allocate the stream private data and write the stream header to
1479 * an output media file.
1481 * @param s Media file handle, must be allocated with avformat_alloc_context().
1482 * Its oformat field must be set to the desired output format;
1483 * Its pb field must be set to an already openened AVIOContext.
1484 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
1485 * On return this parameter will be destroyed and replaced with a dict containing
1486 * options that were not found. May be NULL.
1488 * @return 0 on success, negative AVERROR on failure.
1490 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
1492 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
1495 * Write a packet to an output media file.
1497 * The packet shall contain one audio or video frame.
1498 * The packet must be correctly interleaved according to the container
1499 * specification, if not then av_interleaved_write_frame must be used.
1501 * @param s media file handle
1502 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1504 * This can be NULL (at any time, not just at the end), in
1505 * order to immediately flush data buffered within the muxer,
1506 * for muxers that buffer up data internally before writing it
1508 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
1510 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
1513 * Write a packet to an output media file ensuring correct interleaving.
1515 * The packet must contain one audio or video frame.
1516 * If the packets are already correctly interleaved, the application should
1517 * call av_write_frame() instead as it is slightly faster. It is also important
1518 * to keep in mind that completely non-interleaved input will need huge amounts
1519 * of memory to interleave with this, so it is preferable to interleave at the
1522 * @param s media file handle
1523 * @param pkt The packet containing the data to be written. Libavformat takes
1524 * ownership of the data and will free it when it sees fit using the packet's
1525 * @ref AVPacket.destruct "destruct" field. The caller must not access the data
1526 * after this function returns, as it may already be freed.
1527 * Packet's @ref AVPacket.stream_index "stream_index" field must be set to the
1528 * index of the corresponding stream in @ref AVFormatContext.streams
1530 * It is very strongly recommended that timing information (@ref AVPacket.pts
1531 * "pts", @ref AVPacket.dts "dts" @ref AVPacket.duration "duration") is set to
1534 * @return 0 on success, a negative AVERROR on error.
1536 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
1539 * Interleave a packet per dts in an output media file.
1541 * Packets with pkt->destruct == av_destruct_packet will be freed inside this
1542 * function, so they cannot be used after it. Note that calling av_free_packet()
1543 * on them is still safe.
1545 * @param s media file handle
1546 * @param out the interleaved packet will be output here
1547 * @param pkt the input packet
1548 * @param flush 1 if no further packets are available as input and all
1549 * remaining packets should be output
1550 * @return 1 if a packet was output, 0 if no packet could be output,
1551 * < 0 if an error occurred
1553 int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
1554 AVPacket *pkt, int flush);
1557 * Write the stream trailer to an output media file and free the
1558 * file private data.
1560 * May only be called after a successful call to av_write_header.
1562 * @param s media file handle
1563 * @return 0 if OK, AVERROR_xxx on error
1565 int av_write_trailer(AVFormatContext *s);
1568 * Return the output format in the list of registered output formats
1569 * which best matches the provided parameters, or return NULL if
1570 * there is no match.
1572 * @param short_name if non-NULL checks if short_name matches with the
1573 * names of the registered formats
1574 * @param filename if non-NULL checks if filename terminates with the
1575 * extensions of the registered formats
1576 * @param mime_type if non-NULL checks if mime_type matches with the
1577 * MIME type of the registered formats
1579 AVOutputFormat *av_guess_format(const char *short_name,
1580 const char *filename,
1581 const char *mime_type);
1584 * Guess the codec ID based upon muxer and filename.
1586 enum CodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
1587 const char *filename, const char *mime_type,
1588 enum AVMediaType type);
1596 * @defgroup lavf_misc Utility functions
1600 * Miscelaneous utility functions related to both muxing and demuxing
1605 * Send a nice hexadecimal dump of a buffer to the specified file stream.
1607 * @param f The file stream pointer where the dump should be sent to.
1609 * @param size buffer size
1611 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
1613 void av_hex_dump(FILE *f, uint8_t *buf, int size);
1616 * Send a nice hexadecimal dump of a buffer to the log.
1618 * @param avcl A pointer to an arbitrary struct of which the first field is a
1619 * pointer to an AVClass struct.
1620 * @param level The importance level of the message, lower values signifying
1621 * higher importance.
1623 * @param size buffer size
1625 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
1627 void av_hex_dump_log(void *avcl, int level, uint8_t *buf, int size);
1630 * Send a nice dump of a packet to the specified file stream.
1632 * @param f The file stream pointer where the dump should be sent to.
1633 * @param pkt packet to dump
1634 * @param dump_payload True if the payload must be displayed, too.
1635 * @param st AVStream that the packet belongs to
1637 void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
1641 * Send a nice dump of a packet to the log.
1643 * @param avcl A pointer to an arbitrary struct of which the first field is a
1644 * pointer to an AVClass struct.
1645 * @param level The importance level of the message, lower values signifying
1646 * higher importance.
1647 * @param pkt packet to dump
1648 * @param dump_payload True if the payload must be displayed, too.
1649 * @param st AVStream that the packet belongs to
1651 void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
1655 * Get the CodecID for the given codec tag tag.
1656 * If no codec id is found returns CODEC_ID_NONE.
1658 * @param tags list of supported codec_id-codec_tag pairs, as stored
1659 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1661 enum CodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
1664 * Get the codec tag for the given codec id id.
1665 * If no codec tag is found returns 0.
1667 * @param tags list of supported codec_id-codec_tag pairs, as stored
1668 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1670 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum CodecID id);
1672 int av_find_default_stream_index(AVFormatContext *s);
1675 * Get the index for a specific timestamp.
1676 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
1677 * to the timestamp which is <= the requested one, if backward
1678 * is 0, then it will be >=
1679 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
1680 * @return < 0 if no such timestamp could be found
1682 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
1685 * Add an index entry into a sorted list. Update the entry if the list
1686 * already contains it.
1688 * @param timestamp timestamp in the time base of the given stream
1690 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
1691 int size, int distance, int flags);
1695 * Split a URL string into components.
1697 * The pointers to buffers for storing individual components may be null,
1698 * in order to ignore that component. Buffers for components not found are
1699 * set to empty strings. If the port is not found, it is set to a negative
1702 * @param proto the buffer for the protocol
1703 * @param proto_size the size of the proto buffer
1704 * @param authorization the buffer for the authorization
1705 * @param authorization_size the size of the authorization buffer
1706 * @param hostname the buffer for the host name
1707 * @param hostname_size the size of the hostname buffer
1708 * @param port_ptr a pointer to store the port number in
1709 * @param path the buffer for the path
1710 * @param path_size the size of the path buffer
1711 * @param url the URL to split
1713 void av_url_split(char *proto, int proto_size,
1714 char *authorization, int authorization_size,
1715 char *hostname, int hostname_size,
1717 char *path, int path_size,
1721 void av_dump_format(AVFormatContext *ic,
1727 * Get the current time in microseconds.
1729 int64_t av_gettime(void);
1732 * Return in 'buf' the path with '%d' replaced by a number.
1734 * Also handles the '%0nd' format where 'n' is the total number
1735 * of digits and '%%'.
1737 * @param buf destination buffer
1738 * @param buf_size destination buffer size
1739 * @param path numbered sequence string
1740 * @param number frame number
1741 * @return 0 if OK, -1 on format error
1743 int av_get_frame_filename(char *buf, int buf_size,
1744 const char *path, int number);
1747 * Check whether filename actually is a numbered sequence generator.
1749 * @param filename possible numbered sequence string
1750 * @return 1 if a valid numbered sequence string, 0 otherwise
1752 int av_filename_number_test(const char *filename);
1755 * Generate an SDP for an RTP session.
1757 * @param ac array of AVFormatContexts describing the RTP streams. If the
1758 * array is composed by only one context, such context can contain
1759 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
1760 * all the contexts in the array (an AVCodecContext per RTP stream)
1761 * must contain only one AVStream.
1762 * @param n_files number of AVCodecContexts contained in ac
1763 * @param buf buffer where the SDP will be stored (must be allocated by
1765 * @param size the size of the buffer
1766 * @return 0 if OK, AVERROR_xxx on error
1768 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
1771 * Return a positive value if the given filename has one of the given
1772 * extensions, 0 otherwise.
1774 * @param extensions a comma-separated list of filename extensions
1776 int av_match_ext(const char *filename, const char *extensions);
1779 * Test if the given container can store a codec.
1781 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
1783 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
1784 * A negative number if this information is not available.
1786 int avformat_query_codec(AVOutputFormat *ofmt, enum CodecID codec_id, int std_compliance);
1792 #endif /* AVFORMAT_AVFORMAT_H */