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 * @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 Libav,
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 0x20000 /**< 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,
385 * List of supported codec_id-codec_tag pairs, ordered by "better
386 * choice first". The arrays are all terminated by CODEC_ID_NONE.
388 const struct AVCodecTag * const *codec_tag;
391 const AVClass *priv_class; ///< AVClass for the private context
393 /*****************************************************************
394 * No fields below this line are part of the public API. They
395 * may not be used outside of libavformat and can be changed and
397 * New public fields should be added right above.
398 *****************************************************************
400 struct AVOutputFormat *next;
402 * size of private data so that it can be allocated in the wrapper
406 int (*write_header)(struct AVFormatContext *);
408 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
409 * pkt can be NULL in order to flush data buffered in the muxer.
410 * When flushing, return 0 if there still is more data to flush,
411 * or 1 if everything was flushed and there is no more buffered
414 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
415 int (*write_trailer)(struct AVFormatContext *);
417 * Currently only used to set pixel format if not YUV420P.
419 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
420 AVPacket *in, int flush);
422 * Test if the given codec can be stored in this container.
424 * @return 1 if the codec is supported, 0 if it is not.
425 * A negative number if unknown.
427 int (*query_codec)(enum CodecID id, int std_compliance);
434 * @addtogroup lavf_decoding
437 typedef struct AVInputFormat {
439 * A comma separated list of short names for the format. New names
440 * may be appended with a minor bump.
445 * Descriptive name for the format, meant to be more human-readable
446 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
449 const char *long_name;
452 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
453 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
454 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK.
459 * If extensions are defined, then no probe is done. You should
460 * usually not use extension format guessing because it is not
463 const char *extensions;
465 const struct AVCodecTag * const *codec_tag;
467 const AVClass *priv_class; ///< AVClass for the private context
469 /*****************************************************************
470 * No fields below this line are part of the public API. They
471 * may not be used outside of libavformat and can be changed and
473 * New public fields should be added right above.
474 *****************************************************************
476 struct AVInputFormat *next;
479 * Raw demuxers store their codec ID here.
484 * Size of private data so that it can be allocated in the wrapper.
489 * Tell if a given file has a chance of being parsed as this format.
490 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
491 * big so you do not have to check for that unless you need more.
493 int (*read_probe)(AVProbeData *);
496 * Read the format header and initialize the AVFormatContext
497 * structure. Return 0 if OK. Only used in raw format right
498 * now. 'avformat_new_stream' should be called to create new streams.
500 int (*read_header)(struct AVFormatContext *);
503 * Read one packet and put it in 'pkt'. pts and flags are also
504 * set. 'avformat_new_stream' can be called only if the flag
505 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
506 * background thread).
507 * @return 0 on success, < 0 on error.
508 * When returning an error, pkt must not have been allocated
509 * or must be freed before returning
511 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
514 * Close the stream. The AVFormatContext and AVStreams are not
515 * freed by this function
517 int (*read_close)(struct AVFormatContext *);
520 * Seek to a given timestamp relative to the frames in
521 * stream component stream_index.
522 * @param stream_index Must not be -1.
523 * @param flags Selects which direction should be preferred if no exact
524 * match is available.
525 * @return >= 0 on success (but not necessarily the new offset)
527 int (*read_seek)(struct AVFormatContext *,
528 int stream_index, int64_t timestamp, int flags);
531 * Get the next timestamp in stream[stream_index].time_base units.
532 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
534 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
535 int64_t *pos, int64_t pos_limit);
538 * Start/resume playing - only meaningful if using a network-based format
541 int (*read_play)(struct AVFormatContext *);
544 * Pause playing - only meaningful if using a network-based format
547 int (*read_pause)(struct AVFormatContext *);
550 * Seek to timestamp ts.
551 * Seeking will be done so that the point from which all active streams
552 * can be presented successfully will be closest to ts and within min/max_ts.
553 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
555 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
561 enum AVStreamParseType {
563 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
564 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
565 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
566 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
569 typedef struct AVIndexEntry {
572 #define AVINDEX_KEYFRAME 0x0001
574 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).
575 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
578 #define AV_DISPOSITION_DEFAULT 0x0001
579 #define AV_DISPOSITION_DUB 0x0002
580 #define AV_DISPOSITION_ORIGINAL 0x0004
581 #define AV_DISPOSITION_COMMENT 0x0008
582 #define AV_DISPOSITION_LYRICS 0x0010
583 #define AV_DISPOSITION_KARAOKE 0x0020
586 * Track should be used during playback by default.
587 * Useful for subtitle track that should be displayed
588 * even when user did not explicitly ask for subtitles.
590 #define AV_DISPOSITION_FORCED 0x0040
591 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
592 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
593 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
595 * The stream is stored in the file as an attached picture/"cover art" (e.g.
596 * APIC frame in ID3v2). The single packet associated with it will be returned
597 * among the first few packets read from the file unless seeking takes place.
598 * It can also be accessed at any time in AVStream.attached_pic.
600 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
604 * New fields can be added to the end with minor version bumps.
605 * Removal, reordering and changes to existing fields require a major
607 * sizeof(AVStream) must not be used outside libav*.
609 typedef struct AVStream {
610 int index; /**< stream index in AVFormatContext */
612 * Format-specific stream ID.
613 * decoding: set by libavformat
614 * encoding: set by the user
618 * Codec context associated with this stream. Allocated and freed by
621 * - decoding: The demuxer exports codec information stored in the headers
623 * - encoding: The user sets codec information, the muxer writes it to the
624 * output. Mandatory fields as specified in AVCodecContext
625 * documentation must be set even if this AVCodecContext is
626 * not actually used for encoding.
628 AVCodecContext *codec;
630 * Real base framerate of the stream.
631 * This is the lowest framerate with which all timestamps can be
632 * represented accurately (it is the least common multiple of all
633 * framerates in the stream). Note, this value is just a guess!
634 * For example, if the time base is 1/90000 and all frames have either
635 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
637 AVRational r_frame_rate;
641 * encoding: pts generation when outputting stream
646 * This is the fundamental unit of time (in seconds) in terms
647 * of which frame timestamps are represented.
649 * decoding: set by libavformat
650 * encoding: set by libavformat in av_write_header. The muxer may use the
651 * user-provided value of @ref AVCodecContext.time_base "codec->time_base"
654 AVRational time_base;
657 * Decoding: pts of the first frame of the stream, in stream time base.
658 * Only set this if you are absolutely 100% sure that the value you set
659 * it to really is the pts of the first frame.
660 * This may be undefined (AV_NOPTS_VALUE).
665 * Decoding: duration of the stream, in stream time base.
666 * If a source file does not specify a duration, but does specify
667 * a bitrate, this value will be estimated from bitrate and file size.
671 int64_t nb_frames; ///< number of frames in this stream if known or 0
673 int disposition; /**< AV_DISPOSITION_* bit field */
675 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
678 * sample aspect ratio (0 if unknown)
679 * - encoding: Set by user.
680 * - decoding: Set by libavformat.
682 AVRational sample_aspect_ratio;
684 AVDictionary *metadata;
689 AVRational avg_frame_rate;
692 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
693 * will contain the attached picture.
695 * decoding: set by libavformat, must not be modified by the caller.
698 AVPacket attached_pic;
700 /*****************************************************************
701 * All fields below this line are not part of the public API. They
702 * may not be used outside of libavformat and can be changed and
704 * New public fields should be added right above.
705 *****************************************************************
709 * Stream information used internally by av_find_stream_info()
711 #define MAX_STD_TIMEBASES (60*12+5)
714 int64_t duration_gcd;
716 double duration_error[MAX_STD_TIMEBASES];
717 int64_t codec_info_duration;
718 int nb_decoded_frames;
722 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
724 // Timestamp generation support:
726 * Timestamp corresponding to the last dts sync point.
728 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
729 * a DTS is received from the underlying container. Otherwise set to
730 * AV_NOPTS_VALUE by default.
732 int64_t reference_dts;
736 int last_IP_duration;
739 * Number of packets to buffer for codec probing
741 #define MAX_PROBE_PACKETS 2500
745 * Number of frames that have been demuxed during av_find_stream_info()
747 int codec_info_nb_frames;
749 /* av_read_frame() support */
750 enum AVStreamParseType need_parsing;
751 struct AVCodecParserContext *parser;
754 * last packet in packet_buffer for this stream when muxing.
756 struct AVPacketList *last_in_packet_buffer;
757 AVProbeData probe_data;
758 #define MAX_REORDER_DELAY 16
759 int64_t pts_buffer[MAX_REORDER_DELAY+1];
761 AVIndexEntry *index_entries; /**< Only used if the format does not
762 support seeking natively. */
763 int nb_index_entries;
764 unsigned int index_entries_allocated_size;
767 #define AV_PROGRAM_RUNNING 1
770 * New fields can be added to the end with minor version bumps.
771 * Removal, reordering and changes to existing fields require a major
773 * sizeof(AVProgram) must not be used outside libav*.
775 typedef struct AVProgram {
778 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
779 unsigned int *stream_index;
780 unsigned int nb_stream_indexes;
781 AVDictionary *metadata;
784 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
785 (streams are added dynamically) */
787 typedef struct AVChapter {
788 int id; ///< unique ID to identify the chapter
789 AVRational time_base; ///< time base in which the start/end timestamps are specified
790 int64_t start, end; ///< chapter start/end time in time_base units
791 AVDictionary *metadata;
795 * Format I/O context.
796 * New fields can be added to the end with minor version bumps.
797 * Removal, reordering and changes to existing fields require a major
799 * sizeof(AVFormatContext) must not be used outside libav*, use
800 * avformat_alloc_context() to create an AVFormatContext.
802 typedef struct AVFormatContext {
804 * A class for logging and AVOptions. Set by avformat_alloc_context().
805 * Exports (de)muxer private options if they exist.
807 const AVClass *av_class;
810 * Can only be iformat or oformat, not both at the same time.
812 * decoding: set by avformat_open_input().
813 * encoding: set by the user.
815 struct AVInputFormat *iformat;
816 struct AVOutputFormat *oformat;
819 * Format private data. This is an AVOptions-enabled struct
820 * if and only if iformat/oformat.priv_class is not NULL.
827 * decoding: either set by the user before avformat_open_input() (then
828 * the user must close it manually) or set by avformat_open_input().
829 * encoding: set by the user.
831 * Do NOT set this field if AVFMT_NOFILE flag is set in
832 * iformat/oformat.flags. In such a case, the (de)muxer will handle
833 * I/O in some other way and this field will be NULL.
838 int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
841 * A list of all streams in the file. New streams are created with
842 * avformat_new_stream().
844 * decoding: streams are created by libavformat in avformat_open_input().
845 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
846 * appear in av_read_frame().
847 * encoding: streams are created by the user before avformat_write_header().
849 unsigned int nb_streams;
852 char filename[1024]; /**< input or output filename */
855 * Decoding: position of the first frame of the component, in
856 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
857 * It is deduced from the AVStream values.
862 * Decoding: duration of the stream, in AV_TIME_BASE fractional
863 * seconds. Only set this value if you know none of the individual stream
864 * durations and also do not set any of them. This is deduced from the
865 * AVStream values if not set.
870 * Decoding: total stream bitrate in bit/s, 0 if not
871 * available. Never set it directly if the file_size and the
872 * duration are known as Libav can compute it automatically.
876 unsigned int packet_size;
880 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
881 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
882 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
883 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
884 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
885 #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
886 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
887 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
890 * decoding: size of data to probe; encoding: unused.
892 unsigned int probesize;
895 * decoding: maximum time (in AV_TIME_BASE units) during which the input should
896 * be analyzed in avformat_find_stream_info().
898 int max_analyze_duration;
903 unsigned int nb_programs;
904 AVProgram **programs;
907 * Forced video codec_id.
908 * Demuxing: Set by user.
910 enum CodecID video_codec_id;
913 * Forced audio codec_id.
914 * Demuxing: Set by user.
916 enum CodecID audio_codec_id;
919 * Forced subtitle codec_id.
920 * Demuxing: Set by user.
922 enum CodecID subtitle_codec_id;
925 * Maximum amount of memory in bytes to use for the index of each stream.
926 * If the index exceeds this size, entries will be discarded as
927 * needed to maintain a smaller size. This can lead to slower or less
928 * accurate seeking (depends on demuxer).
929 * Demuxers for which a full in-memory index is mandatory will ignore
932 * demuxing: set by user
934 unsigned int max_index_size;
937 * Maximum amount of memory in bytes to use for buffering frames
938 * obtained from realtime capture devices.
940 unsigned int max_picture_buffer;
942 unsigned int nb_chapters;
943 AVChapter **chapters;
945 AVDictionary *metadata;
948 * Start time of the stream in real world time, in microseconds
949 * since the unix epoch (00:00 1st January 1970). That is, pts=0
950 * in the stream was captured at this real world time.
951 * - encoding: Set by user.
952 * - decoding: Unused.
954 int64_t start_time_realtime;
957 * decoding: number of frames used to probe fps
962 * Error recognition; higher values will detect more errors but may
963 * misdetect some more or less valid parts as errors.
965 * - decoding: Set by user.
967 int error_recognition;
970 * Custom interrupt callbacks for the I/O layer.
972 * decoding: set by the user before avformat_open_input().
973 * encoding: set by the user before avformat_write_header()
974 * (mainly useful for AVFMT_NOFILE formats). The callback
975 * should also be passed to avio_open2() if it's used to
978 AVIOInterruptCB interrupt_callback;
981 * Flags to enable debugging.
984 #define FF_FDEBUG_TS 0x0001
985 /*****************************************************************
986 * All fields below this line are not part of the public API. They
987 * may not be used outside of libavformat and can be changed and
989 * New public fields should be added right above.
990 *****************************************************************
994 * This buffer is only needed when packets were already buffered but
995 * not decoded, for example to get the codec parameters in MPEG
998 struct AVPacketList *packet_buffer;
999 struct AVPacketList *packet_buffer_end;
1001 /* av_seek_frame() support */
1002 int64_t data_offset; /**< offset of the first packet */
1005 * Raw packets from the demuxer, prior to parsing and decoding.
1006 * This buffer is used for buffering packets until the codec can
1007 * be identified, as parsing cannot be done without knowing the
1010 struct AVPacketList *raw_packet_buffer;
1011 struct AVPacketList *raw_packet_buffer_end;
1013 * Packets split by the parser get queued here.
1015 struct AVPacketList *parse_queue;
1016 struct AVPacketList *parse_queue_end;
1018 * Remaining size available for raw_packet_buffer, in bytes.
1020 #define RAW_PACKET_BUFFER_SIZE 2500000
1021 int raw_packet_buffer_remaining_size;
1024 typedef struct AVPacketList {
1026 struct AVPacketList *next;
1031 * @defgroup lavf_core Core functions
1034 * Functions for querying libavformat capabilities, allocating core structures,
1040 * Return the LIBAVFORMAT_VERSION_INT constant.
1042 unsigned avformat_version(void);
1045 * Return the libavformat build-time configuration.
1047 const char *avformat_configuration(void);
1050 * Return the libavformat license.
1052 const char *avformat_license(void);
1055 * Initialize libavformat and register all the muxers, demuxers and
1056 * protocols. If you do not call this function, then you can select
1057 * exactly which formats you want to support.
1059 * @see av_register_input_format()
1060 * @see av_register_output_format()
1061 * @see av_register_protocol()
1063 void av_register_all(void);
1065 void av_register_input_format(AVInputFormat *format);
1066 void av_register_output_format(AVOutputFormat *format);
1069 * Do global initialization of network components. This is optional,
1070 * but recommended, since it avoids the overhead of implicitly
1071 * doing the setup for each session.
1073 * Calling this function will become mandatory if using network
1074 * protocols at some major version bump.
1076 int avformat_network_init(void);
1079 * Undo the initialization done by avformat_network_init.
1081 int avformat_network_deinit(void);
1084 * If f is NULL, returns the first registered input format,
1085 * if f is non-NULL, returns the next registered input format after f
1086 * or NULL if f is the last one.
1088 AVInputFormat *av_iformat_next(AVInputFormat *f);
1091 * If f is NULL, returns the first registered output format,
1092 * if f is non-NULL, returns the next registered output format after f
1093 * or NULL if f is the last one.
1095 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1098 * Allocate an AVFormatContext.
1099 * avformat_free_context() can be used to free the context and everything
1100 * allocated by the framework within it.
1102 AVFormatContext *avformat_alloc_context(void);
1105 * Free an AVFormatContext and all its streams.
1106 * @param s context to free
1108 void avformat_free_context(AVFormatContext *s);
1111 * Get the AVClass for AVFormatContext. It can be used in combination with
1112 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1114 * @see av_opt_find().
1116 const AVClass *avformat_get_class(void);
1119 * Add a new stream to a media file.
1121 * When demuxing, it is called by the demuxer in read_header(). If the
1122 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1123 * be called in read_packet().
1125 * When muxing, should be called by the user before avformat_write_header().
1127 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1128 * will be initialized to use this codec. This is needed for e.g. codec-specific
1129 * defaults to be set, so codec should be provided if it is known.
1131 * @return newly created stream or NULL on error.
1133 AVStream *avformat_new_stream(AVFormatContext *s, AVCodec *c);
1135 AVProgram *av_new_program(AVFormatContext *s, int id);
1143 * @addtogroup lavf_decoding
1148 * Find AVInputFormat based on the short name of the input format.
1150 AVInputFormat *av_find_input_format(const char *short_name);
1153 * Guess the file format.
1155 * @param is_opened Whether the file is already opened; determines whether
1156 * demuxers with or without AVFMT_NOFILE are probed.
1158 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1161 * Guess the file format.
1163 * @param is_opened Whether the file is already opened; determines whether
1164 * demuxers with or without AVFMT_NOFILE are probed.
1165 * @param score_max A probe score larger that this is required to accept a
1166 * detection, the variable is set to the actual detection
1168 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1169 * to retry with a larger probe buffer.
1171 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1174 * Probe a bytestream to determine the input format. Each time a probe returns
1175 * with a score that is too low, the probe buffer size is increased and another
1176 * attempt is made. When the maximum probe size is reached, the input format
1177 * with the highest score is returned.
1179 * @param pb the bytestream to probe
1180 * @param fmt the input format is put here
1181 * @param filename the filename of the stream
1182 * @param logctx the log context
1183 * @param offset the offset within the bytestream to probe from
1184 * @param max_probe_size the maximum probe buffer size (zero for default)
1185 * @return 0 in case of success, a negative value corresponding to an
1186 * AVERROR code otherwise
1188 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1189 const char *filename, void *logctx,
1190 unsigned int offset, unsigned int max_probe_size);
1193 * Open an input stream and read the header. The codecs are not opened.
1194 * The stream must be closed with av_close_input_file().
1196 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1197 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1198 * function and written into ps.
1199 * Note that a user-supplied AVFormatContext will be freed on failure.
1200 * @param filename Name of the stream to open.
1201 * @param fmt If non-NULL, this parameter forces a specific input format.
1202 * Otherwise the format is autodetected.
1203 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1204 * On return this parameter will be destroyed and replaced with a dict containing
1205 * options that were not found. May be NULL.
1207 * @return 0 on success, a negative AVERROR on failure.
1209 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1211 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1214 * Read packets of a media file to get stream information. This
1215 * is useful for file formats with no headers such as MPEG. This
1216 * function also computes the real framerate in case of MPEG-2 repeat
1218 * The logical file position is not changed by this function;
1219 * examined packets may be buffered for later processing.
1221 * @param ic media file handle
1222 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1223 * dictionaries, where i-th member contains options for
1224 * codec corresponding to i-th stream.
1225 * On return each dictionary will be filled with options that were not found.
1226 * @return >=0 if OK, AVERROR_xxx on error
1228 * @note this function isn't guaranteed to open all the codecs, so
1229 * options being non-empty at return is a perfectly normal behavior.
1231 * @todo Let the user decide somehow what information is needed so that
1232 * we do not waste time getting stuff the user does not need.
1234 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1237 * Find the "best" stream in the file.
1238 * The best stream is determined according to various heuristics as the most
1239 * likely to be what the user expects.
1240 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1241 * default decoder for the stream's codec; streams for which no decoder can
1242 * be found are ignored.
1244 * @param ic media file handle
1245 * @param type stream type: video, audio, subtitles, etc.
1246 * @param wanted_stream_nb user-requested stream number,
1247 * or -1 for automatic selection
1248 * @param related_stream try to find a stream related (eg. in the same
1249 * program) to this one, or -1 if none
1250 * @param decoder_ret if non-NULL, returns the decoder for the
1252 * @param flags flags; none are currently defined
1253 * @return the non-negative stream number in case of success,
1254 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
1256 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
1257 * @note If av_find_best_stream returns successfully and decoder_ret is not
1258 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
1260 int av_find_best_stream(AVFormatContext *ic,
1261 enum AVMediaType type,
1262 int wanted_stream_nb,
1264 AVCodec **decoder_ret,
1267 #if FF_API_READ_PACKET
1269 * @deprecated use AVFMT_FLAG_NOFILLIN | AVFMT_FLAG_NOPARSE to read raw
1270 * unprocessed packets
1272 * Read a transport packet from a media file.
1274 * This function is obsolete and should never be used.
1275 * Use av_read_frame() instead.
1277 * @param s media file handle
1278 * @param pkt is filled
1279 * @return 0 if OK, AVERROR_xxx on error
1281 attribute_deprecated
1282 int av_read_packet(AVFormatContext *s, AVPacket *pkt);
1286 * Return the next frame of a stream.
1287 * This function returns what is stored in the file, and does not validate
1288 * that what is there are valid frames for the decoder. It will split what is
1289 * stored in the file into frames and return one for each call. It will not
1290 * omit invalid data between valid frames so as to give the decoder the maximum
1291 * information possible for decoding.
1293 * The returned packet is valid
1294 * until the next av_read_frame() or until av_close_input_file() and
1295 * must be freed with av_free_packet. For video, the packet contains
1296 * exactly one frame. For audio, it contains an integer number of
1297 * frames if each frame has a known fixed size (e.g. PCM or ADPCM
1298 * data). If the audio frames have a variable size (e.g. MPEG audio),
1299 * then it contains one frame.
1301 * pkt->pts, pkt->dts and pkt->duration are always set to correct
1302 * values in AVStream.time_base units (and guessed if the format cannot
1303 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
1304 * has B-frames, so it is better to rely on pkt->dts if you do not
1305 * decompress the payload.
1307 * @return 0 if OK, < 0 on error or end of file
1309 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
1312 * Seek to the keyframe at timestamp.
1313 * 'timestamp' in 'stream_index'.
1314 * @param stream_index If stream_index is (-1), a default
1315 * stream is selected, and timestamp is automatically converted
1316 * from AV_TIME_BASE units to the stream specific time_base.
1317 * @param timestamp Timestamp in AVStream.time_base units
1318 * or, if no stream is specified, in AV_TIME_BASE units.
1319 * @param flags flags which select direction and seeking mode
1320 * @return >= 0 on success
1322 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
1326 * Seek to timestamp ts.
1327 * Seeking will be done so that the point from which all active streams
1328 * can be presented successfully will be closest to ts and within min/max_ts.
1329 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
1331 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
1332 * are the file position (this may not be supported by all demuxers).
1333 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
1334 * in the stream with stream_index (this may not be supported by all demuxers).
1335 * Otherwise all timestamps are in units of the stream selected by stream_index
1336 * or if stream_index is -1, in AV_TIME_BASE units.
1337 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
1338 * keyframes (this may not be supported by all demuxers).
1340 * @param stream_index index of the stream which is used as time base reference
1341 * @param min_ts smallest acceptable timestamp
1342 * @param ts target timestamp
1343 * @param max_ts largest acceptable timestamp
1344 * @param flags flags
1345 * @return >=0 on success, error code otherwise
1347 * @note This is part of the new seek API which is still under construction.
1348 * Thus do not use this yet. It may change at any time, do not expect
1349 * ABI compatibility yet!
1351 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
1354 * Start playing a network-based stream (e.g. RTSP stream) at the
1357 int av_read_play(AVFormatContext *s);
1360 * Pause a network-based stream (e.g. RTSP stream).
1362 * Use av_read_play() to resume it.
1364 int av_read_pause(AVFormatContext *s);
1366 #if FF_API_CLOSE_INPUT_FILE
1368 * @deprecated use avformat_close_input()
1369 * Close a media file (but not its codecs).
1371 * @param s media file handle
1373 attribute_deprecated
1374 void av_close_input_file(AVFormatContext *s);
1378 * Close an opened input AVFormatContext. Free it and all its contents
1379 * and set *s to NULL.
1381 void avformat_close_input(AVFormatContext **s);
1386 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
1387 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
1388 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
1389 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
1392 * @addtogroup lavf_encoding
1396 * Allocate the stream private data and write the stream header to
1397 * an output media file.
1399 * @param s Media file handle, must be allocated with avformat_alloc_context().
1400 * Its oformat field must be set to the desired output format;
1401 * Its pb field must be set to an already openened AVIOContext.
1402 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
1403 * On return this parameter will be destroyed and replaced with a dict containing
1404 * options that were not found. May be NULL.
1406 * @return 0 on success, negative AVERROR on failure.
1408 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
1410 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
1413 * Write a packet to an output media file.
1415 * The packet shall contain one audio or video frame.
1416 * The packet must be correctly interleaved according to the container
1417 * specification, if not then av_interleaved_write_frame must be used.
1419 * @param s media file handle
1420 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1422 * This can be NULL (at any time, not just at the end), in
1423 * order to immediately flush data buffered within the muxer,
1424 * for muxers that buffer up data internally before writing it
1426 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
1428 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
1431 * Write a packet to an output media file ensuring correct interleaving.
1433 * The packet must contain one audio or video frame.
1434 * If the packets are already correctly interleaved, the application should
1435 * call av_write_frame() instead as it is slightly faster. It is also important
1436 * to keep in mind that completely non-interleaved input will need huge amounts
1437 * of memory to interleave with this, so it is preferable to interleave at the
1440 * @param s media file handle
1441 * @param pkt The packet containing the data to be written. Libavformat takes
1442 * ownership of the data and will free it when it sees fit using the packet's
1443 * This can be NULL (at any time, not just at the end), to flush the
1444 * interleaving queues.
1445 * @ref AVPacket.destruct "destruct" field. The caller must not access the data
1446 * after this function returns, as it may already be freed.
1447 * Packet's @ref AVPacket.stream_index "stream_index" field must be set to the
1448 * index of the corresponding stream in @ref AVFormatContext.streams
1450 * It is very strongly recommended that timing information (@ref AVPacket.pts
1451 * "pts", @ref AVPacket.dts "dts" @ref AVPacket.duration "duration") is set to
1454 * @return 0 on success, a negative AVERROR on error.
1456 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
1458 #if FF_API_INTERLEAVE_PACKET
1460 * @deprecated this function was never meant to be called by the user
1463 attribute_deprecated
1464 int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
1465 AVPacket *pkt, int flush);
1469 * Write the stream trailer to an output media file and free the
1470 * file private data.
1472 * May only be called after a successful call to av_write_header.
1474 * @param s media file handle
1475 * @return 0 if OK, AVERROR_xxx on error
1477 int av_write_trailer(AVFormatContext *s);
1480 * Return the output format in the list of registered output formats
1481 * which best matches the provided parameters, or return NULL if
1482 * there is no match.
1484 * @param short_name if non-NULL checks if short_name matches with the
1485 * names of the registered formats
1486 * @param filename if non-NULL checks if filename terminates with the
1487 * extensions of the registered formats
1488 * @param mime_type if non-NULL checks if mime_type matches with the
1489 * MIME type of the registered formats
1491 AVOutputFormat *av_guess_format(const char *short_name,
1492 const char *filename,
1493 const char *mime_type);
1496 * Guess the codec ID based upon muxer and filename.
1498 enum CodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
1499 const char *filename, const char *mime_type,
1500 enum AVMediaType type);
1508 * @defgroup lavf_misc Utility functions
1512 * Miscelaneous utility functions related to both muxing and demuxing
1517 * Send a nice hexadecimal dump of a buffer to the specified file stream.
1519 * @param f The file stream pointer where the dump should be sent to.
1521 * @param size buffer size
1523 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
1525 void av_hex_dump(FILE *f, uint8_t *buf, int size);
1528 * Send a nice hexadecimal dump of a buffer to the log.
1530 * @param avcl A pointer to an arbitrary struct of which the first field is a
1531 * pointer to an AVClass struct.
1532 * @param level The importance level of the message, lower values signifying
1533 * higher importance.
1535 * @param size buffer size
1537 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
1539 void av_hex_dump_log(void *avcl, int level, uint8_t *buf, int size);
1542 * Send a nice dump of a packet to the specified file stream.
1544 * @param f The file stream pointer where the dump should be sent to.
1545 * @param pkt packet to dump
1546 * @param dump_payload True if the payload must be displayed, too.
1547 * @param st AVStream that the packet belongs to
1549 void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
1553 * Send a nice dump of a packet to the log.
1555 * @param avcl A pointer to an arbitrary struct of which the first field is a
1556 * pointer to an AVClass struct.
1557 * @param level The importance level of the message, lower values signifying
1558 * higher importance.
1559 * @param pkt packet to dump
1560 * @param dump_payload True if the payload must be displayed, too.
1561 * @param st AVStream that the packet belongs to
1563 void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
1567 * Get the CodecID for the given codec tag tag.
1568 * If no codec id is found returns CODEC_ID_NONE.
1570 * @param tags list of supported codec_id-codec_tag pairs, as stored
1571 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1573 enum CodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
1576 * Get the codec tag for the given codec id id.
1577 * If no codec tag is found returns 0.
1579 * @param tags list of supported codec_id-codec_tag pairs, as stored
1580 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1582 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum CodecID id);
1584 int av_find_default_stream_index(AVFormatContext *s);
1587 * Get the index for a specific timestamp.
1588 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
1589 * to the timestamp which is <= the requested one, if backward
1590 * is 0, then it will be >=
1591 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
1592 * @return < 0 if no such timestamp could be found
1594 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
1597 * Add an index entry into a sorted list. Update the entry if the list
1598 * already contains it.
1600 * @param timestamp timestamp in the time base of the given stream
1602 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
1603 int size, int distance, int flags);
1607 * Split a URL string into components.
1609 * The pointers to buffers for storing individual components may be null,
1610 * in order to ignore that component. Buffers for components not found are
1611 * set to empty strings. If the port is not found, it is set to a negative
1614 * @param proto the buffer for the protocol
1615 * @param proto_size the size of the proto buffer
1616 * @param authorization the buffer for the authorization
1617 * @param authorization_size the size of the authorization buffer
1618 * @param hostname the buffer for the host name
1619 * @param hostname_size the size of the hostname buffer
1620 * @param port_ptr a pointer to store the port number in
1621 * @param path the buffer for the path
1622 * @param path_size the size of the path buffer
1623 * @param url the URL to split
1625 void av_url_split(char *proto, int proto_size,
1626 char *authorization, int authorization_size,
1627 char *hostname, int hostname_size,
1629 char *path, int path_size,
1633 void av_dump_format(AVFormatContext *ic,
1639 * Get the current time in microseconds.
1641 int64_t av_gettime(void);
1644 * Return in 'buf' the path with '%d' replaced by a number.
1646 * Also handles the '%0nd' format where 'n' is the total number
1647 * of digits and '%%'.
1649 * @param buf destination buffer
1650 * @param buf_size destination buffer size
1651 * @param path numbered sequence string
1652 * @param number frame number
1653 * @return 0 if OK, -1 on format error
1655 int av_get_frame_filename(char *buf, int buf_size,
1656 const char *path, int number);
1659 * Check whether filename actually is a numbered sequence generator.
1661 * @param filename possible numbered sequence string
1662 * @return 1 if a valid numbered sequence string, 0 otherwise
1664 int av_filename_number_test(const char *filename);
1667 * Generate an SDP for an RTP session.
1669 * @param ac array of AVFormatContexts describing the RTP streams. If the
1670 * array is composed by only one context, such context can contain
1671 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
1672 * all the contexts in the array (an AVCodecContext per RTP stream)
1673 * must contain only one AVStream.
1674 * @param n_files number of AVCodecContexts contained in ac
1675 * @param buf buffer where the SDP will be stored (must be allocated by
1677 * @param size the size of the buffer
1678 * @return 0 if OK, AVERROR_xxx on error
1680 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
1683 * Return a positive value if the given filename has one of the given
1684 * extensions, 0 otherwise.
1686 * @param extensions a comma-separated list of filename extensions
1688 int av_match_ext(const char *filename, const char *extensions);
1691 * Test if the given container can store a codec.
1693 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
1695 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
1696 * A negative number if this information is not available.
1698 int avformat_query_codec(AVOutputFormat *ofmt, enum CodecID codec_id, int std_compliance);
1701 * @defgroup riff_fourcc RIFF FourCCs
1703 * Get the tables mapping RIFF FourCCs to libavcodec CodecIDs. The tables are
1704 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
1707 * uint32_t tag = MKTAG('H', '2', '6', '4');
1708 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
1709 * enum CodecID id = av_codec_get_id(table, tag);
1713 * @return the table mapping RIFF FourCCs for video to libavcodec CodecID.
1715 const struct AVCodecTag *avformat_get_riff_video_tags(void);
1717 * @return the table mapping RIFF FourCCs for audio to CodecID.
1719 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
1728 #endif /* AVFORMAT_AVFORMAT_H */