2 * copyright (c) 2001 Fabrice Bellard
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #ifndef AVFORMAT_AVFORMAT_H
22 #define AVFORMAT_AVFORMAT_H
27 * Main libavformat public API header
31 * @defgroup libavf I/O and Muxing/Demuxing Library
34 * Libavformat (lavf) is a library for dealing with various media container
35 * formats. Its main two purposes are demuxing - i.e. splitting a media file
36 * into component streams, and the reverse process of muxing - writing supplied
37 * data in a specified container format. It also has an @ref lavf_io
38 * "I/O module" which supports a number of protocols for accessing the data (e.g.
39 * file, tcp, http and others). Before using lavf, you need to call
40 * av_register_all() to register all compiled muxers, demuxers and protocols.
41 * Unless you are absolutely sure you won't use libavformat's network
42 * capabilities, you should also call avformat_network_init().
44 * A supported input format is described by an AVInputFormat struct, conversely
45 * an output format is described by AVOutputFormat. You can iterate over all
46 * registered input/output formats using the av_iformat_next() /
47 * av_oformat_next() functions. The protocols layer is not part of the public
48 * API, so you can only get the names of supported protocols with the
49 * avio_enum_protocols() function.
51 * Main lavf structure used for both muxing and demuxing is AVFormatContext,
52 * which exports all information about the file being read or written. As with
53 * most Libavformat structures, its size is not part of public ABI, so it cannot be
54 * allocated on stack or directly with av_malloc(). To create an
55 * AVFormatContext, use avformat_alloc_context() (some functions, like
56 * avformat_open_input() might do that for you).
58 * Most importantly an AVFormatContext contains:
59 * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat
60 * "output" format. It is either autodetected or set by user for input;
61 * always set by user for output.
62 * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all
63 * elementary streams stored in the file. AVStreams are typically referred to
64 * using their index in this array.
65 * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or
66 * set by user for input, always set by user for output (unless you are dealing
67 * with an AVFMT_NOFILE format).
69 * @section lavf_options Passing options to (de)muxers
70 * Lavf allows to configure muxers and demuxers using the @ref avoptions
71 * mechanism. Generic (format-independent) libavformat options are provided by
72 * AVFormatContext, they can be examined from a user program by calling
73 * av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass
74 * from avformat_get_class()). Private (format-specific) options are provided by
75 * AVFormatContext.priv_data if and only if AVInputFormat.priv_class /
76 * AVOutputFormat.priv_class of the corresponding format struct is non-NULL.
77 * Further options may be provided by the @ref AVFormatContext.pb "I/O context",
78 * if its AVClass is non-NULL, and the protocols layer. See the discussion on
79 * nesting in @ref avoptions documentation to learn how to access those.
81 * @defgroup lavf_decoding Demuxing
83 * Demuxers read a media file and split it into chunks of data (@em packets). A
84 * @ref AVPacket "packet" contains one or more encoded frames which belongs to a
85 * single elementary stream. In the lavf API this process is represented by the
86 * avformat_open_input() function for opening a file, av_read_frame() for
87 * reading a single packet and finally avformat_close_input(), which does the
90 * @section lavf_decoding_open Opening a media file
91 * The minimum information required to open a file is its URL or filename, which
92 * is passed to avformat_open_input(), as in the following code:
94 * const char *url = "in.mp3";
95 * AVFormatContext *s = NULL;
96 * int ret = avformat_open_input(&s, url, NULL, NULL);
100 * The above code attempts to allocate an AVFormatContext, open the
101 * specified file (autodetecting the format) and read the header, exporting the
102 * information stored there into s. Some formats do not have a header or do not
103 * store enough information there, so it is recommended that you call the
104 * avformat_find_stream_info() function which tries to read and decode a few
105 * frames to find missing information.
107 * In some cases you might want to preallocate an AVFormatContext yourself with
108 * avformat_alloc_context() and do some tweaking on it before passing it to
109 * avformat_open_input(). One such case is when you want to use custom functions
110 * for reading input data instead of lavf internal I/O layer.
111 * To do that, create your own AVIOContext with avio_alloc_context(), passing
112 * your reading callbacks to it. Then set the @em pb field of your
113 * AVFormatContext to newly created AVIOContext.
115 * Since the format of the opened file is in general not known until after
116 * avformat_open_input() has returned, it is not possible to set demuxer private
117 * options on a preallocated context. Instead, the options should be passed to
118 * avformat_open_input() wrapped in an AVDictionary:
120 * AVDictionary *options = NULL;
121 * av_dict_set(&options, "video_size", "640x480", 0);
122 * av_dict_set(&options, "pixel_format", "rgb24", 0);
124 * if (avformat_open_input(&s, url, NULL, &options) < 0)
126 * av_dict_free(&options);
128 * This code passes the private options 'video_size' and 'pixel_format' to the
129 * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it
130 * cannot know how to interpret raw video data otherwise. If the format turns
131 * out to be something different than raw video, those options will not be
132 * recognized by the demuxer and therefore will not be applied. Such unrecognized
133 * options are then returned in the options dictionary (recognized options are
134 * consumed). The calling program can handle such unrecognized options as it
137 * AVDictionaryEntry *e;
138 * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
139 * fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key);
144 * After you have finished reading the file, you must close it with
145 * avformat_close_input(). It will free everything associated with the file.
147 * @section lavf_decoding_read Reading from an opened file
148 * Reading data from an opened AVFormatContext is done by repeatedly calling
149 * av_read_frame() on it. Each call, if successful, will return an AVPacket
150 * containing encoded data for one AVStream, identified by
151 * AVPacket.stream_index. This packet may be passed straight into the libavcodec
152 * decoding functions avcodec_decode_video2(), avcodec_decode_audio4() or
153 * avcodec_decode_subtitle2() if the caller wishes to decode the data.
155 * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be
156 * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for
157 * pts/dts, 0 for duration) if the stream does not provide them. The timing
158 * information will be in AVStream.time_base units, i.e. it has to be
159 * multiplied by the timebase to convert them to seconds.
161 * The packet data belongs to the demuxer and is invalid after the next call to
162 * av_read_frame(). The user must free the packet with av_free_packet() before
163 * calling av_read_frame() again or closing the file.
165 * @section lavf_decoding_seek Seeking
168 * @defgroup lavf_encoding Muxing
172 * @defgroup lavf_io I/O Read/Write
176 * @defgroup lavf_codec Demuxers
178 * @defgroup lavf_codec_native Native Demuxers
181 * @defgroup lavf_codec_wrappers External library wrappers
185 * @defgroup lavf_protos I/O Protocols
188 * @defgroup lavf_internal Internal
196 #include <stdio.h> /* FILE */
197 #include "libavcodec/avcodec.h"
198 #include "libavutil/dict.h"
199 #include "libavutil/log.h"
202 #include "libavformat/version.h"
204 #if FF_API_AV_GETTIME
205 #include "libavutil/time.h"
208 struct AVFormatContext;
212 * @defgroup metadata_api Public Metadata API
215 * The metadata API allows libavformat to export metadata tags to a client
216 * application when demuxing. Conversely it allows a client application to
217 * set metadata when muxing.
219 * Metadata is exported or set as pairs of key/value strings in the 'metadata'
220 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
221 * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
222 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
223 * exported by demuxers isn't checked to be valid UTF-8 in most cases.
225 * Important concepts to keep in mind:
226 * - Keys are unique; there can never be 2 tags with the same key. This is
227 * also meant semantically, i.e., a demuxer should not knowingly produce
228 * several keys that are literally different but semantically identical.
229 * E.g., key=Author5, key=Author6. In this example, all authors must be
230 * placed in the same tag.
231 * - Metadata is flat, not hierarchical; there are no subtags. If you
232 * want to store, e.g., the email address of the child of producer Alice
233 * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
234 * - Several modifiers can be applied to the tag name. This is done by
235 * appending a dash character ('-') and the modifier name in the order
236 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
237 * - language -- a tag whose value is localized for a particular language
238 * is appended with the ISO 639-2/B 3-letter language code.
239 * For example: Author-ger=Michael, Author-eng=Mike
240 * The original/default language is in the unqualified "Author" tag.
241 * A demuxer should set a default if it sets any translated tag.
242 * - sorting -- a modified version of a tag that should be used for
243 * sorting will have '-sort' appended. E.g. artist="The Beatles",
244 * artist-sort="Beatles, The".
246 * - Demuxers attempt to export metadata in a generic format, however tags
247 * with no generic equivalents are left as they are stored in the container.
248 * Follows a list of generic tag names:
251 album -- name of the set this work belongs to
252 album_artist -- main creator of the set/album, if different from artist.
253 e.g. "Various Artists" for compilation albums.
254 artist -- main creator of the work
255 comment -- any additional description of the file.
256 composer -- who composed the work, if different from artist.
257 copyright -- name of copyright holder.
258 creation_time-- date when the file was created, preferably in ISO 8601.
259 date -- date when the work was created, preferably in ISO 8601.
260 disc -- number of a subset, e.g. disc in a multi-disc collection.
261 encoder -- name/settings of the software/hardware that produced the file.
262 encoded_by -- person/group who created the file.
263 filename -- original name of the file.
264 genre -- <self-evident>.
265 language -- main language in which the work is performed, preferably
266 in ISO 639-2 format. Multiple languages can be specified by
267 separating them with commas.
268 performer -- artist who performed the work, if different from artist.
269 E.g for "Also sprach Zarathustra", artist would be "Richard
270 Strauss" and performer "London Philharmonic Orchestra".
271 publisher -- name of the label/publisher.
272 service_name -- name of the service in broadcasting (channel name).
273 service_provider -- name of the service provider in broadcasting.
274 title -- name of the work.
275 track -- number of this work in the set, can be in form current/total.
276 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
279 * Look in the examples section for an application example how to use the Metadata API.
284 /* packet functions */
288 * Allocate and read the payload of a packet and initialize its
289 * fields with default values.
292 * @param size desired payload size
293 * @return >0 (read size) if OK, AVERROR_xxx otherwise
295 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
299 * Read data and append it to the current content of the AVPacket.
300 * If pkt->size is 0 this is identical to av_get_packet.
301 * Note that this uses av_grow_packet and thus involves a realloc
302 * which is inefficient. Thus this function should only be used
303 * when there is no reasonable way to know (an upper bound of)
307 * @param size amount of data to read
308 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
309 * will not be lost even if an error occurs.
311 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
313 /*************************************************/
314 /* fractional numbers for exact pts handling */
317 * The exact value of the fractional number is: 'val + num / den'.
318 * num is assumed to be 0 <= num < den.
320 typedef struct AVFrac {
321 int64_t val, num, den;
324 /*************************************************/
325 /* input/output formats */
330 * This structure contains the data a format has to probe a file.
332 typedef struct AVProbeData {
333 const char *filename;
334 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
335 int buf_size; /**< Size of buf except extra allocated bytes */
338 #define AVPROBE_SCORE_MAX 100 ///< maximum score, half of that is used for file-extension-based detection
339 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
341 /// Demuxer will use avio_open, no opened file should be provided by the caller.
342 #define AVFMT_NOFILE 0x0001
343 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
344 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
345 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
347 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
348 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
349 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
350 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
351 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
352 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
353 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
354 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fallback to binary search via read_timestamp */
355 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fallback to generic search */
356 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
357 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
358 #if LIBAVFORMAT_VERSION_MAJOR <= 54
359 #define AVFMT_TS_NONSTRICT 0x8020000 //we try to be compatible to the ABIs of ffmpeg and major forks
361 #define AVFMT_TS_NONSTRICT 0x20000
363 /**< Format does not require strictly
364 increasing timestamps, but they must
365 still be monotonic */
367 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
370 * @addtogroup lavf_encoding
373 typedef struct AVOutputFormat {
376 * Descriptive name for the format, meant to be more human-readable
377 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
380 const char *long_name;
381 const char *mime_type;
382 const char *extensions; /**< comma-separated filename extensions */
384 enum CodecID audio_codec; /**< default audio codec */
385 enum CodecID video_codec; /**< default video codec */
386 enum CodecID subtitle_codec; /**< default subtitle codec */
388 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
389 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
390 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
396 * List of supported codec_id-codec_tag pairs, ordered by "better
397 * choice first". The arrays are all terminated by CODEC_ID_NONE.
399 const struct AVCodecTag * const *codec_tag;
402 const AVClass *priv_class; ///< AVClass for the private context
404 /*****************************************************************
405 * No fields below this line are part of the public API. They
406 * may not be used outside of libavformat and can be changed and
408 * New public fields should be added right above.
409 *****************************************************************
411 struct AVOutputFormat *next;
413 * size of private data so that it can be allocated in the wrapper
417 int (*write_header)(struct AVFormatContext *);
419 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
420 * pkt can be NULL in order to flush data buffered in the muxer.
421 * When flushing, return 0 if there still is more data to flush,
422 * or 1 if everything was flushed and there is no more buffered
425 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
426 int (*write_trailer)(struct AVFormatContext *);
428 * Currently only used to set pixel format if not YUV420P.
430 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
431 AVPacket *in, int flush);
433 * Test if the given codec can be stored in this container.
435 * @return 1 if the codec is supported, 0 if it is not.
436 * A negative number if unknown.
438 int (*query_codec)(enum CodecID id, int std_compliance);
440 void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
441 int64_t *dts, int64_t *wall);
448 * @addtogroup lavf_decoding
451 typedef struct AVInputFormat {
453 * A comma separated list of short names for the format. New names
454 * may be appended with a minor bump.
459 * Descriptive name for the format, meant to be more human-readable
460 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
463 const char *long_name;
466 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
467 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
468 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
473 * If extensions are defined, then no probe is done. You should
474 * usually not use extension format guessing because it is not
477 const char *extensions;
479 const struct AVCodecTag * const *codec_tag;
481 const AVClass *priv_class; ///< AVClass for the private context
483 /*****************************************************************
484 * No fields below this line are part of the public API. They
485 * may not be used outside of libavformat and can be changed and
487 * New public fields should be added right above.
488 *****************************************************************
490 struct AVInputFormat *next;
493 * Raw demuxers store their codec ID here.
498 * Size of private data so that it can be allocated in the wrapper.
503 * Tell if a given file has a chance of being parsed as this format.
504 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
505 * big so you do not have to check for that unless you need more.
507 int (*read_probe)(AVProbeData *);
510 * Read the format header and initialize the AVFormatContext
511 * structure. Return 0 if OK. Only used in raw format right
512 * now. 'avformat_new_stream' should be called to create new streams.
514 int (*read_header)(struct AVFormatContext *);
517 * Read one packet and put it in 'pkt'. pts and flags are also
518 * set. 'avformat_new_stream' can be called only if the flag
519 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
520 * background thread).
521 * @return 0 on success, < 0 on error.
522 * When returning an error, pkt must not have been allocated
523 * or must be freed before returning
525 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
528 * Close the stream. The AVFormatContext and AVStreams are not
529 * freed by this function
531 int (*read_close)(struct AVFormatContext *);
534 * Seek to a given timestamp relative to the frames in
535 * stream component stream_index.
536 * @param stream_index Must not be -1.
537 * @param flags Selects which direction should be preferred if no exact
538 * match is available.
539 * @return >= 0 on success (but not necessarily the new offset)
541 int (*read_seek)(struct AVFormatContext *,
542 int stream_index, int64_t timestamp, int flags);
545 * Get the next timestamp in stream[stream_index].time_base units.
546 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
548 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
549 int64_t *pos, int64_t pos_limit);
552 * Start/resume playing - only meaningful if using a network-based format
555 int (*read_play)(struct AVFormatContext *);
558 * Pause playing - only meaningful if using a network-based format
561 int (*read_pause)(struct AVFormatContext *);
564 * Seek to timestamp ts.
565 * Seeking will be done so that the point from which all active streams
566 * can be presented successfully will be closest to ts and within min/max_ts.
567 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
569 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
575 enum AVStreamParseType {
577 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
578 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
579 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
580 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
581 AVSTREAM_PARSE_FULL_RAW=MKTAG(0,'R','A','W'), /**< full parsing and repack with timestamp generation for raw */
584 typedef struct AVIndexEntry {
586 int64_t timestamp; /**<
587 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
588 * when seeking to this entry. That means preferable PTS on keyframe based formats.
589 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
592 #define AVINDEX_KEYFRAME 0x0001
594 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).
595 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
598 #define AV_DISPOSITION_DEFAULT 0x0001
599 #define AV_DISPOSITION_DUB 0x0002
600 #define AV_DISPOSITION_ORIGINAL 0x0004
601 #define AV_DISPOSITION_COMMENT 0x0008
602 #define AV_DISPOSITION_LYRICS 0x0010
603 #define AV_DISPOSITION_KARAOKE 0x0020
606 * Track should be used during playback by default.
607 * Useful for subtitle track that should be displayed
608 * even when user did not explicitly ask for subtitles.
610 #define AV_DISPOSITION_FORCED 0x0040
611 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
612 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
613 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
615 * The stream is stored in the file as an attached picture/"cover art" (e.g.
616 * APIC frame in ID3v2). The single packet associated with it will be returned
617 * among the first few packets read from the file unless seeking takes place.
618 * It can also be accessed at any time in AVStream.attached_pic.
620 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
624 * New fields can be added to the end with minor version bumps.
625 * Removal, reordering and changes to existing fields require a major
627 * sizeof(AVStream) must not be used outside libav*.
629 typedef struct AVStream {
630 int index; /**< stream index in AVFormatContext */
632 * Format-specific stream ID.
633 * decoding: set by libavformat
634 * encoding: set by the user
638 * Codec context associated with this stream. Allocated and freed by
641 * - decoding: The demuxer exports codec information stored in the headers
643 * - encoding: The user sets codec information, the muxer writes it to the
644 * output. Mandatory fields as specified in AVCodecContext
645 * documentation must be set even if this AVCodecContext is
646 * not actually used for encoding.
648 AVCodecContext *codec;
650 * Real base framerate of the stream.
651 * This is the lowest framerate with which all timestamps can be
652 * represented accurately (it is the least common multiple of all
653 * framerates in the stream). Note, this value is just a guess!
654 * For example, if the time base is 1/90000 and all frames have either
655 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
657 AVRational r_frame_rate;
661 * encoding: pts generation when outputting stream
666 * This is the fundamental unit of time (in seconds) in terms
667 * of which frame timestamps are represented.
669 * decoding: set by libavformat
670 * encoding: set by libavformat in av_write_header. The muxer may use the
671 * user-provided value of @ref AVCodecContext.time_base "codec->time_base"
674 AVRational time_base;
677 * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
678 * Only set this if you are absolutely 100% sure that the value you set
679 * it to really is the pts of the first frame.
680 * This may be undefined (AV_NOPTS_VALUE).
681 * @note The ASF header does NOT contain a correct start_time the ASF
682 * demuxer must NOT set this.
687 * Decoding: duration of the stream, in stream time base.
688 * If a source file does not specify a duration, but does specify
689 * a bitrate, this value will be estimated from bitrate and file size.
693 int64_t nb_frames; ///< number of frames in this stream if known or 0
695 int disposition; /**< AV_DISPOSITION_* bit field */
697 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
700 * sample aspect ratio (0 if unknown)
701 * - encoding: Set by user.
702 * - decoding: Set by libavformat.
704 AVRational sample_aspect_ratio;
706 AVDictionary *metadata;
711 AVRational avg_frame_rate;
714 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
715 * will contain the attached picture.
717 * decoding: set by libavformat, must not be modified by the caller.
720 AVPacket attached_pic;
722 /*****************************************************************
723 * All fields below this line are not part of the public API. They
724 * may not be used outside of libavformat and can be changed and
726 * New public fields should be added right above.
727 *****************************************************************
731 * Stream information used internally by av_find_stream_info()
733 #define MAX_STD_TIMEBASES (60*12+6)
736 int64_t duration_gcd;
738 double duration_error[2][2][MAX_STD_TIMEBASES];
739 int64_t codec_info_duration;
740 int nb_decoded_frames;
744 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
746 // Timestamp generation support:
748 * Timestamp corresponding to the last dts sync point.
750 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
751 * a DTS is received from the underlying container. Otherwise set to
752 * AV_NOPTS_VALUE by default.
754 int64_t reference_dts;
758 int last_IP_duration;
761 * Number of packets to buffer for codec probing
763 #define MAX_PROBE_PACKETS 2500
767 * Number of frames that have been demuxed during av_find_stream_info()
769 int codec_info_nb_frames;
773 * This is the MPEG-TS stream identifier +1
776 int stream_identifier;
778 int64_t interleaver_chunk_size;
779 int64_t interleaver_chunk_duration;
781 /* av_read_frame() support */
782 enum AVStreamParseType need_parsing;
783 struct AVCodecParserContext *parser;
786 * last packet in packet_buffer for this stream when muxing.
788 struct AVPacketList *last_in_packet_buffer;
789 AVProbeData probe_data;
790 #define MAX_REORDER_DELAY 16
791 int64_t pts_buffer[MAX_REORDER_DELAY+1];
793 AVIndexEntry *index_entries; /**< Only used if the format does not
794 support seeking natively. */
795 int nb_index_entries;
796 unsigned int index_entries_allocated_size;
799 * flag to indicate that probing is requested
800 * NOT PART OF PUBLIC API
804 * Indicates that everything up to the next keyframe
805 * should be discarded.
807 int skip_to_keyframe;
810 #define AV_PROGRAM_RUNNING 1
813 * New fields can be added to the end with minor version bumps.
814 * Removal, reordering and changes to existing fields require a major
816 * sizeof(AVProgram) must not be used outside libav*.
818 typedef struct AVProgram {
821 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
822 unsigned int *stream_index;
823 unsigned int nb_stream_indexes;
824 AVDictionary *metadata;
831 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
832 (streams are added dynamically) */
834 typedef struct AVChapter {
835 int id; ///< unique ID to identify the chapter
836 AVRational time_base; ///< time base in which the start/end timestamps are specified
837 int64_t start, end; ///< chapter start/end time in time_base units
838 AVDictionary *metadata;
843 * The duration of a video can be estimated through various ways, and this enum can be used
844 * to know how the duration was estimated.
846 enum AVDurationEstimationMethod {
847 AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
848 AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
849 AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
853 * Format I/O context.
854 * New fields can be added to the end with minor version bumps.
855 * Removal, reordering and changes to existing fields require a major
857 * sizeof(AVFormatContext) must not be used outside libav*, use
858 * avformat_alloc_context() to create an AVFormatContext.
860 typedef struct AVFormatContext {
862 * A class for logging and AVOptions. Set by avformat_alloc_context().
863 * Exports (de)muxer private options if they exist.
865 const AVClass *av_class;
868 * Can only be iformat or oformat, not both at the same time.
870 * decoding: set by avformat_open_input().
871 * encoding: set by the user.
873 struct AVInputFormat *iformat;
874 struct AVOutputFormat *oformat;
877 * Format private data. This is an AVOptions-enabled struct
878 * if and only if iformat/oformat.priv_class is not NULL.
885 * decoding: either set by the user before avformat_open_input() (then
886 * the user must close it manually) or set by avformat_open_input().
887 * encoding: set by the user.
889 * Do NOT set this field if AVFMT_NOFILE flag is set in
890 * iformat/oformat.flags. In such a case, the (de)muxer will handle
891 * I/O in some other way and this field will be NULL.
896 int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
899 * A list of all streams in the file. New streams are created with
900 * avformat_new_stream().
902 * decoding: streams are created by libavformat in avformat_open_input().
903 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
904 * appear in av_read_frame().
905 * encoding: streams are created by the user before avformat_write_header().
907 unsigned int nb_streams;
910 char filename[1024]; /**< input or output filename */
913 * Decoding: position of the first frame of the component, in
914 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
915 * It is deduced from the AVStream values.
920 * Decoding: duration of the stream, in AV_TIME_BASE fractional
921 * seconds. Only set this value if you know none of the individual stream
922 * durations and also do not set any of them. This is deduced from the
923 * AVStream values if not set.
928 * Decoding: total stream bitrate in bit/s, 0 if not
929 * available. Never set it directly if the file_size and the
930 * duration are known as FFmpeg can compute it automatically.
934 unsigned int packet_size;
938 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
939 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
940 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
941 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
942 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
943 #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
944 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
945 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
946 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload
947 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
948 #define AVFMT_FLAG_PRIV_OPT 0x20000 ///< Enable use of private options by delaying codec open (this could be made default once all code is converted)
949 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Dont merge side data but keep it separate.
952 * decoding: size of data to probe; encoding: unused.
954 unsigned int probesize;
957 * decoding: maximum time (in AV_TIME_BASE units) during which the input should
958 * be analyzed in avformat_find_stream_info().
960 int max_analyze_duration;
965 unsigned int nb_programs;
966 AVProgram **programs;
969 * Forced video codec_id.
970 * Demuxing: Set by user.
972 enum CodecID video_codec_id;
975 * Forced audio codec_id.
976 * Demuxing: Set by user.
978 enum CodecID audio_codec_id;
981 * Forced subtitle codec_id.
982 * Demuxing: Set by user.
984 enum CodecID subtitle_codec_id;
987 * Maximum amount of memory in bytes to use for the index of each stream.
988 * If the index exceeds this size, entries will be discarded as
989 * needed to maintain a smaller size. This can lead to slower or less
990 * accurate seeking (depends on demuxer).
991 * Demuxers for which a full in-memory index is mandatory will ignore
994 * demuxing: set by user
996 unsigned int max_index_size;
999 * Maximum amount of memory in bytes to use for buffering frames
1000 * obtained from realtime capture devices.
1002 unsigned int max_picture_buffer;
1004 unsigned int nb_chapters;
1005 AVChapter **chapters;
1007 AVDictionary *metadata;
1010 * Start time of the stream in real world time, in microseconds
1011 * since the unix epoch (00:00 1st January 1970). That is, pts=0
1012 * in the stream was captured at this real world time.
1013 * - encoding: Set by user.
1014 * - decoding: Unused.
1016 int64_t start_time_realtime;
1019 * decoding: number of frames used to probe fps
1024 * Error recognition; higher values will detect more errors but may
1025 * misdetect some more or less valid parts as errors.
1026 * - encoding: unused
1027 * - decoding: Set by user.
1029 int error_recognition;
1032 * Custom interrupt callbacks for the I/O layer.
1034 * decoding: set by the user before avformat_open_input().
1035 * encoding: set by the user before avformat_write_header()
1036 * (mainly useful for AVFMT_NOFILE formats). The callback
1037 * should also be passed to avio_open2() if it's used to
1040 AVIOInterruptCB interrupt_callback;
1043 * Flags to enable debugging.
1046 #define FF_FDEBUG_TS 0x0001
1049 * Transport stream id.
1050 * This will be moved into demuxer private options. Thus no API/ABI compatibility
1055 * Audio preload in microseconds.
1056 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1057 * - encoding: Set by user via AVOptions (NO direct access)
1058 * - decoding: unused
1063 * Max chunk time in microseconds.
1064 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1065 * - encoding: Set by user via AVOptions (NO direct access)
1066 * - decoding: unused
1068 int max_chunk_duration;
1071 * Max chunk size in bytes
1072 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1073 * - encoding: Set by user via AVOptions (NO direct access)
1074 * - decoding: unused
1078 /*****************************************************************
1079 * All fields below this line are not part of the public API. They
1080 * may not be used outside of libavformat and can be changed and
1082 * New public fields should be added right above.
1083 *****************************************************************
1087 * This buffer is only needed when packets were already buffered but
1088 * not decoded, for example to get the codec parameters in MPEG
1091 struct AVPacketList *packet_buffer;
1092 struct AVPacketList *packet_buffer_end;
1094 /* av_seek_frame() support */
1095 int64_t data_offset; /**< offset of the first packet */
1098 * Raw packets from the demuxer, prior to parsing and decoding.
1099 * This buffer is used for buffering packets until the codec can
1100 * be identified, as parsing cannot be done without knowing the
1103 struct AVPacketList *raw_packet_buffer;
1104 struct AVPacketList *raw_packet_buffer_end;
1106 * Packets split by the parser get queued here.
1108 struct AVPacketList *parse_queue;
1109 struct AVPacketList *parse_queue_end;
1111 * Remaining size available for raw_packet_buffer, in bytes.
1113 #define RAW_PACKET_BUFFER_SIZE 2500000
1114 int raw_packet_buffer_remaining_size;
1119 * The duration field can be estimated through various ways, and this field can be used
1120 * to know how the duration was estimated.
1122 enum AVDurationEstimationMethod duration_estimation_method;
1126 * Returns the method used to set ctx->duration.
1128 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1130 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
1132 typedef struct AVPacketList {
1134 struct AVPacketList *next;
1139 * @defgroup lavf_core Core functions
1142 * Functions for querying libavformat capabilities, allocating core structures,
1148 * Return the LIBAVFORMAT_VERSION_INT constant.
1150 unsigned avformat_version(void);
1153 * Return the libavformat build-time configuration.
1155 const char *avformat_configuration(void);
1158 * Return the libavformat license.
1160 const char *avformat_license(void);
1163 * Initialize libavformat and register all the muxers, demuxers and
1164 * protocols. If you do not call this function, then you can select
1165 * exactly which formats you want to support.
1167 * @see av_register_input_format()
1168 * @see av_register_output_format()
1169 * @see av_register_protocol()
1171 void av_register_all(void);
1173 void av_register_input_format(AVInputFormat *format);
1174 void av_register_output_format(AVOutputFormat *format);
1177 * Do global initialization of network components. This is optional,
1178 * but recommended, since it avoids the overhead of implicitly
1179 * doing the setup for each session.
1181 * Calling this function will become mandatory if using network
1182 * protocols at some major version bump.
1184 int avformat_network_init(void);
1187 * Undo the initialization done by avformat_network_init.
1189 int avformat_network_deinit(void);
1192 * If f is NULL, returns the first registered input format,
1193 * if f is non-NULL, returns the next registered input format after f
1194 * or NULL if f is the last one.
1196 AVInputFormat *av_iformat_next(AVInputFormat *f);
1199 * If f is NULL, returns the first registered output format,
1200 * if f is non-NULL, returns the next registered output format after f
1201 * or NULL if f is the last one.
1203 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1206 * Allocate an AVFormatContext.
1207 * avformat_free_context() can be used to free the context and everything
1208 * allocated by the framework within it.
1210 AVFormatContext *avformat_alloc_context(void);
1213 * Free an AVFormatContext and all its streams.
1214 * @param s context to free
1216 void avformat_free_context(AVFormatContext *s);
1219 * Get the AVClass for AVFormatContext. It can be used in combination with
1220 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1222 * @see av_opt_find().
1224 const AVClass *avformat_get_class(void);
1227 * Add a new stream to a media file.
1229 * When demuxing, it is called by the demuxer in read_header(). If the
1230 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1231 * be called in read_packet().
1233 * When muxing, should be called by the user before avformat_write_header().
1235 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1236 * will be initialized to use this codec. This is needed for e.g. codec-specific
1237 * defaults to be set, so codec should be provided if it is known.
1239 * @return newly created stream or NULL on error.
1241 AVStream *avformat_new_stream(AVFormatContext *s, AVCodec *c);
1243 AVProgram *av_new_program(AVFormatContext *s, int id);
1251 attribute_deprecated void av_pkt_dump(FILE *f, AVPacket *pkt, int dump_payload);
1252 attribute_deprecated void av_pkt_dump_log(void *avcl, int level, AVPacket *pkt,
1256 #if FF_API_ALLOC_OUTPUT_CONTEXT
1258 * @deprecated deprecated in favor of avformat_alloc_output_context2()
1260 attribute_deprecated
1261 AVFormatContext *avformat_alloc_output_context(const char *format,
1262 AVOutputFormat *oformat,
1263 const char *filename);
1267 * Allocate an AVFormatContext for an output format.
1268 * avformat_free_context() can be used to free the context and
1269 * everything allocated by the framework within it.
1271 * @param *ctx is set to the created format context, or to NULL in
1273 * @param oformat format to use for allocating the context, if NULL
1274 * format_name and filename are used instead
1275 * @param format_name the name of output format to use for allocating the
1276 * context, if NULL filename is used instead
1277 * @param filename the name of the filename to use for allocating the
1278 * context, may be NULL
1279 * @return >= 0 in case of success, a negative AVERROR code in case of
1282 int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat,
1283 const char *format_name, const char *filename);
1286 * @addtogroup lavf_decoding
1291 * Find AVInputFormat based on the short name of the input format.
1293 AVInputFormat *av_find_input_format(const char *short_name);
1296 * Guess the file format.
1298 * @param is_opened Whether the file is already opened; determines whether
1299 * demuxers with or without AVFMT_NOFILE are probed.
1301 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1304 * Guess the file format.
1306 * @param is_opened Whether the file is already opened; determines whether
1307 * demuxers with or without AVFMT_NOFILE are probed.
1308 * @param score_max A probe score larger that this is required to accept a
1309 * detection, the variable is set to the actual detection
1311 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1312 * to retry with a larger probe buffer.
1314 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1317 * Guess the file format.
1319 * @param is_opened Whether the file is already opened; determines whether
1320 * demuxers with or without AVFMT_NOFILE are probed.
1321 * @param score_ret The score of the best detection.
1323 AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
1326 * Probe a bytestream to determine the input format. Each time a probe returns
1327 * with a score that is too low, the probe buffer size is increased and another
1328 * attempt is made. When the maximum probe size is reached, the input format
1329 * with the highest score is returned.
1331 * @param pb the bytestream to probe
1332 * @param fmt the input format is put here
1333 * @param filename the filename of the stream
1334 * @param logctx the log context
1335 * @param offset the offset within the bytestream to probe from
1336 * @param max_probe_size the maximum probe buffer size (zero for default)
1337 * @return 0 in case of success, a negative value corresponding to an
1338 * AVERROR code otherwise
1340 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1341 const char *filename, void *logctx,
1342 unsigned int offset, unsigned int max_probe_size);
1345 * Open an input stream and read the header. The codecs are not opened.
1346 * The stream must be closed with av_close_input_file().
1348 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1349 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1350 * function and written into ps.
1351 * Note that a user-supplied AVFormatContext will be freed on failure.
1352 * @param filename Name of the stream to open.
1353 * @param fmt If non-NULL, this parameter forces a specific input format.
1354 * Otherwise the format is autodetected.
1355 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1356 * On return this parameter will be destroyed and replaced with a dict containing
1357 * options that were not found. May be NULL.
1359 * @return 0 on success, a negative AVERROR on failure.
1361 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1363 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1365 attribute_deprecated
1366 int av_demuxer_open(AVFormatContext *ic);
1368 #if FF_API_FORMAT_PARAMETERS
1370 * Read packets of a media file to get stream information. This
1371 * is useful for file formats with no headers such as MPEG. This
1372 * function also computes the real framerate in case of MPEG-2 repeat
1374 * The logical file position is not changed by this function;
1375 * examined packets may be buffered for later processing.
1377 * @param ic media file handle
1378 * @return >=0 if OK, AVERROR_xxx on error
1379 * @todo Let the user decide somehow what information is needed so that
1380 * we do not waste time getting stuff the user does not need.
1382 * @deprecated use avformat_find_stream_info.
1384 attribute_deprecated
1385 int av_find_stream_info(AVFormatContext *ic);
1389 * Read packets of a media file to get stream information. This
1390 * is useful for file formats with no headers such as MPEG. This
1391 * function also computes the real framerate in case of MPEG-2 repeat
1393 * The logical file position is not changed by this function;
1394 * examined packets may be buffered for later processing.
1396 * @param ic media file handle
1397 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1398 * dictionaries, where i-th member contains options for
1399 * codec corresponding to i-th stream.
1400 * On return each dictionary will be filled with options that were not found.
1401 * @return >=0 if OK, AVERROR_xxx on error
1403 * @note this function isn't guaranteed to open all the codecs, so
1404 * options being non-empty at return is a perfectly normal behavior.
1406 * @todo Let the user decide somehow what information is needed so that
1407 * we do not waste time getting stuff the user does not need.
1409 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1412 * Find the programs which belong to a given stream.
1414 * @param ic media file handle
1415 * @param last the last found program, the search will start after this
1416 * program, or from the beginning if it is NULL
1417 * @param s stream index
1418 * @return the next program which belongs to s, NULL if no program is found or
1419 * the last program is not among the programs of ic.
1421 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s);
1424 * Find the "best" stream in the file.
1425 * The best stream is determined according to various heuristics as the most
1426 * likely to be what the user expects.
1427 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1428 * default decoder for the stream's codec; streams for which no decoder can
1429 * be found are ignored.
1431 * @param ic media file handle
1432 * @param type stream type: video, audio, subtitles, etc.
1433 * @param wanted_stream_nb user-requested stream number,
1434 * or -1 for automatic selection
1435 * @param related_stream try to find a stream related (eg. in the same
1436 * program) to this one, or -1 if none
1437 * @param decoder_ret if non-NULL, returns the decoder for the
1439 * @param flags flags; none are currently defined
1440 * @return the non-negative stream number in case of success,
1441 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
1443 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
1444 * @note If av_find_best_stream returns successfully and decoder_ret is not
1445 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
1447 int av_find_best_stream(AVFormatContext *ic,
1448 enum AVMediaType type,
1449 int wanted_stream_nb,
1451 AVCodec **decoder_ret,
1454 #if FF_API_READ_PACKET
1456 * @deprecated use AVFMT_FLAG_NOFILLIN | AVFMT_FLAG_NOPARSE to read raw
1457 * unprocessed packets
1459 * Read a transport packet from a media file.
1461 * This function is obsolete and should never be used.
1462 * Use av_read_frame() instead.
1464 * @param s media file handle
1465 * @param pkt is filled
1466 * @return 0 if OK, AVERROR_xxx on error
1468 attribute_deprecated
1469 int av_read_packet(AVFormatContext *s, AVPacket *pkt);
1473 * Return the next frame of a stream.
1474 * This function returns what is stored in the file, and does not validate
1475 * that what is there are valid frames for the decoder. It will split what is
1476 * stored in the file into frames and return one for each call. It will not
1477 * omit invalid data between valid frames so as to give the decoder the maximum
1478 * information possible for decoding.
1480 * The returned packet is valid
1481 * until the next av_read_frame() or until av_close_input_file() and
1482 * must be freed with av_free_packet. For video, the packet contains
1483 * exactly one frame. For audio, it contains an integer number of
1484 * frames if each frame has a known fixed size (e.g. PCM or ADPCM
1485 * data). If the audio frames have a variable size (e.g. MPEG audio),
1486 * then it contains one frame.
1488 * pkt->pts, pkt->dts and pkt->duration are always set to correct
1489 * values in AVStream.time_base units (and guessed if the format cannot
1490 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
1491 * has B-frames, so it is better to rely on pkt->dts if you do not
1492 * decompress the payload.
1494 * @return 0 if OK, < 0 on error or end of file
1496 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
1499 * Seek to the keyframe at timestamp.
1500 * 'timestamp' in 'stream_index'.
1501 * @param stream_index If stream_index is (-1), a default
1502 * stream is selected, and timestamp is automatically converted
1503 * from AV_TIME_BASE units to the stream specific time_base.
1504 * @param timestamp Timestamp in AVStream.time_base units
1505 * or, if no stream is specified, in AV_TIME_BASE units.
1506 * @param flags flags which select direction and seeking mode
1507 * @return >= 0 on success
1509 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
1513 * Seek to timestamp ts.
1514 * Seeking will be done so that the point from which all active streams
1515 * can be presented successfully will be closest to ts and within min/max_ts.
1516 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
1518 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
1519 * are the file position (this may not be supported by all demuxers).
1520 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
1521 * in the stream with stream_index (this may not be supported by all demuxers).
1522 * Otherwise all timestamps are in units of the stream selected by stream_index
1523 * or if stream_index is -1, in AV_TIME_BASE units.
1524 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
1525 * keyframes (this may not be supported by all demuxers).
1527 * @param stream_index index of the stream which is used as time base reference
1528 * @param min_ts smallest acceptable timestamp
1529 * @param ts target timestamp
1530 * @param max_ts largest acceptable timestamp
1531 * @param flags flags
1532 * @return >=0 on success, error code otherwise
1534 * @note This is part of the new seek API which is still under construction.
1535 * Thus do not use this yet. It may change at any time, do not expect
1536 * ABI compatibility yet!
1538 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
1541 * Start playing a network-based stream (e.g. RTSP stream) at the
1544 int av_read_play(AVFormatContext *s);
1547 * Pause a network-based stream (e.g. RTSP stream).
1549 * Use av_read_play() to resume it.
1551 int av_read_pause(AVFormatContext *s);
1553 #if FF_API_CLOSE_INPUT_FILE
1555 * @deprecated use avformat_close_input()
1556 * Close a media file (but not its codecs).
1558 * @param s media file handle
1560 attribute_deprecated
1561 void av_close_input_file(AVFormatContext *s);
1565 * Close an opened input AVFormatContext. Free it and all its contents
1566 * and set *s to NULL.
1568 void avformat_close_input(AVFormatContext **s);
1573 #if FF_API_NEW_STREAM
1575 * Add a new stream to a media file.
1577 * Can only be called in the read_header() function. If the flag
1578 * AVFMTCTX_NOHEADER is in the format context, then new streams
1579 * can be added in read_packet too.
1581 * @param s media file handle
1582 * @param id file-format-dependent stream ID
1584 attribute_deprecated
1585 AVStream *av_new_stream(AVFormatContext *s, int id);
1588 #if FF_API_SET_PTS_INFO
1590 * @deprecated this function is not supposed to be called outside of lavf
1592 attribute_deprecated
1593 void av_set_pts_info(AVStream *s, int pts_wrap_bits,
1594 unsigned int pts_num, unsigned int pts_den);
1597 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
1598 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
1599 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
1600 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
1603 * @addtogroup lavf_encoding
1607 * Allocate the stream private data and write the stream header to
1608 * an output media file.
1610 * @param s Media file handle, must be allocated with avformat_alloc_context().
1611 * Its oformat field must be set to the desired output format;
1612 * Its pb field must be set to an already openened AVIOContext.
1613 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
1614 * On return this parameter will be destroyed and replaced with a dict containing
1615 * options that were not found. May be NULL.
1617 * @return 0 on success, negative AVERROR on failure.
1619 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
1621 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
1624 * Write a packet to an output media file.
1626 * The packet shall contain one audio or video frame.
1627 * The packet must be correctly interleaved according to the container
1628 * specification, if not then av_interleaved_write_frame must be used.
1630 * @param s media file handle
1631 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1633 * This can be NULL (at any time, not just at the end), in
1634 * order to immediately flush data buffered within the muxer,
1635 * for muxers that buffer up data internally before writing it
1637 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
1639 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
1642 * Write a packet to an output media file ensuring correct interleaving.
1644 * The packet must contain one audio or video frame.
1645 * If the packets are already correctly interleaved, the application should
1646 * call av_write_frame() instead as it is slightly faster. It is also important
1647 * to keep in mind that completely non-interleaved input will need huge amounts
1648 * of memory to interleave with this, so it is preferable to interleave at the
1651 * @param s media file handle
1652 * @param pkt The packet containing the data to be written. Libavformat takes
1653 * ownership of the data and will free it when it sees fit using the packet's
1654 * This can be NULL (at any time, not just at the end), to flush the
1655 * interleaving queues.
1656 * @ref AVPacket.destruct "destruct" field. The caller must not access the data
1657 * after this function returns, as it may already be freed.
1658 * Packet's @ref AVPacket.stream_index "stream_index" field must be set to the
1659 * index of the corresponding stream in @ref AVFormatContext.streams
1661 * It is very strongly recommended that timing information (@ref AVPacket.pts
1662 * "pts", @ref AVPacket.dts "dts" @ref AVPacket.duration "duration") is set to
1665 * @return 0 on success, a negative AVERROR on error.
1667 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
1669 #if FF_API_INTERLEAVE_PACKET
1671 * @deprecated this function was never meant to be called by the user
1674 attribute_deprecated
1675 int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
1676 AVPacket *pkt, int flush);
1680 * Write the stream trailer to an output media file and free the
1681 * file private data.
1683 * May only be called after a successful call to av_write_header.
1685 * @param s media file handle
1686 * @return 0 if OK, AVERROR_xxx on error
1688 int av_write_trailer(AVFormatContext *s);
1691 * Return the output format in the list of registered output formats
1692 * which best matches the provided parameters, or return NULL if
1693 * there is no match.
1695 * @param short_name if non-NULL checks if short_name matches with the
1696 * names of the registered formats
1697 * @param filename if non-NULL checks if filename terminates with the
1698 * extensions of the registered formats
1699 * @param mime_type if non-NULL checks if mime_type matches with the
1700 * MIME type of the registered formats
1702 AVOutputFormat *av_guess_format(const char *short_name,
1703 const char *filename,
1704 const char *mime_type);
1707 * Guess the codec ID based upon muxer and filename.
1709 enum CodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
1710 const char *filename, const char *mime_type,
1711 enum AVMediaType type);
1714 * Get timing information for the data currently output.
1715 * The exact meaning of "currently output" depends on the format.
1716 * It is mostly relevant for devices that have an internal buffer and/or
1717 * work in real time.
1718 * @param s media file handle
1719 * @param stream stream in the media file
1720 * @param dts[out] DTS of the last packet output for the stream, in stream
1722 * @param wall[out] absolute time when that packet whas output,
1724 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
1725 * Note: some formats or devices may not allow to measure dts and wall
1728 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
1729 int64_t *dts, int64_t *wall);
1738 * @defgroup lavf_misc Utility functions
1742 * Miscelaneous utility functions related to both muxing and demuxing
1747 * Send a nice hexadecimal dump of a buffer to the specified file stream.
1749 * @param f The file stream pointer where the dump should be sent to.
1751 * @param size buffer size
1753 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
1755 void av_hex_dump(FILE *f, uint8_t *buf, int size);
1758 * Send a nice hexadecimal dump of a buffer to the log.
1760 * @param avcl A pointer to an arbitrary struct of which the first field is a
1761 * pointer to an AVClass struct.
1762 * @param level The importance level of the message, lower values signifying
1763 * higher importance.
1765 * @param size buffer size
1767 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
1769 void av_hex_dump_log(void *avcl, int level, uint8_t *buf, int size);
1772 * Send a nice dump of a packet to the specified file stream.
1774 * @param f The file stream pointer where the dump should be sent to.
1775 * @param pkt packet to dump
1776 * @param dump_payload True if the payload must be displayed, too.
1777 * @param st AVStream that the packet belongs to
1779 void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
1783 * Send a nice dump of a packet to the log.
1785 * @param avcl A pointer to an arbitrary struct of which the first field is a
1786 * pointer to an AVClass struct.
1787 * @param level The importance level of the message, lower values signifying
1788 * higher importance.
1789 * @param pkt packet to dump
1790 * @param dump_payload True if the payload must be displayed, too.
1791 * @param st AVStream that the packet belongs to
1793 void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
1797 * Get the CodecID for the given codec tag tag.
1798 * If no codec id is found returns CODEC_ID_NONE.
1800 * @param tags list of supported codec_id-codec_tag pairs, as stored
1801 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1803 enum CodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
1806 * Get the codec tag for the given codec id id.
1807 * If no codec tag is found returns 0.
1809 * @param tags list of supported codec_id-codec_tag pairs, as stored
1810 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1812 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum CodecID id);
1814 int av_find_default_stream_index(AVFormatContext *s);
1817 * Get the index for a specific timestamp.
1818 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
1819 * to the timestamp which is <= the requested one, if backward
1820 * is 0, then it will be >=
1821 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
1822 * @return < 0 if no such timestamp could be found
1824 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
1827 * Add an index entry into a sorted list. Update the entry if the list
1828 * already contains it.
1830 * @param timestamp timestamp in the time base of the given stream
1832 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
1833 int size, int distance, int flags);
1837 * Split a URL string into components.
1839 * The pointers to buffers for storing individual components may be null,
1840 * in order to ignore that component. Buffers for components not found are
1841 * set to empty strings. If the port is not found, it is set to a negative
1844 * @param proto the buffer for the protocol
1845 * @param proto_size the size of the proto buffer
1846 * @param authorization the buffer for the authorization
1847 * @param authorization_size the size of the authorization buffer
1848 * @param hostname the buffer for the host name
1849 * @param hostname_size the size of the hostname buffer
1850 * @param port_ptr a pointer to store the port number in
1851 * @param path the buffer for the path
1852 * @param path_size the size of the path buffer
1853 * @param url the URL to split
1855 void av_url_split(char *proto, int proto_size,
1856 char *authorization, int authorization_size,
1857 char *hostname, int hostname_size,
1859 char *path, int path_size,
1863 void av_dump_format(AVFormatContext *ic,
1869 * Return in 'buf' the path with '%d' replaced by a number.
1871 * Also handles the '%0nd' format where 'n' is the total number
1872 * of digits and '%%'.
1874 * @param buf destination buffer
1875 * @param buf_size destination buffer size
1876 * @param path numbered sequence string
1877 * @param number frame number
1878 * @return 0 if OK, -1 on format error
1880 int av_get_frame_filename(char *buf, int buf_size,
1881 const char *path, int number);
1884 * Check whether filename actually is a numbered sequence generator.
1886 * @param filename possible numbered sequence string
1887 * @return 1 if a valid numbered sequence string, 0 otherwise
1889 int av_filename_number_test(const char *filename);
1892 * Generate an SDP for an RTP session.
1894 * @param ac array of AVFormatContexts describing the RTP streams. If the
1895 * array is composed by only one context, such context can contain
1896 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
1897 * all the contexts in the array (an AVCodecContext per RTP stream)
1898 * must contain only one AVStream.
1899 * @param n_files number of AVCodecContexts contained in ac
1900 * @param buf buffer where the SDP will be stored (must be allocated by
1902 * @param size the size of the buffer
1903 * @return 0 if OK, AVERROR_xxx on error
1905 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
1908 * Return a positive value if the given filename has one of the given
1909 * extensions, 0 otherwise.
1911 * @param extensions a comma-separated list of filename extensions
1913 int av_match_ext(const char *filename, const char *extensions);
1916 * Test if the given container can store a codec.
1918 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
1920 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
1921 * A negative number if this information is not available.
1923 int avformat_query_codec(AVOutputFormat *ofmt, enum CodecID codec_id, int std_compliance);
1926 * @defgroup riff_fourcc RIFF FourCCs
1928 * Get the tables mapping RIFF FourCCs to libavcodec CodecIDs. The tables are
1929 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
1932 * uint32_t tag = MKTAG('H', '2', '6', '4');
1933 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
1934 * enum CodecID id = av_codec_get_id(table, tag);
1938 * @return the table mapping RIFF FourCCs for video to libavcodec CodecID.
1940 const struct AVCodecTag *avformat_get_riff_video_tags(void);
1942 * @return the table mapping RIFF FourCCs for audio to CodecID.
1944 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
1947 * Guesses the sample aspect ratio of a frame, based on both the stream and the
1948 * frame aspect ratio.
1950 * Since the frame aspect ratio is set by the codec but the stream aspect ratio
1951 * is set by the demuxer, these two may not be equal. This function tries to
1952 * return the value that you should use if you would like to display the frame.
1954 * Basic logic is to use the stream aspect ratio if it is set to something sane
1955 * otherwise use the frame aspect ratio. This way a container setting, which is
1956 * usually easy to modify can override the coded value in the frames.
1958 * @param format the format context which the stream is part of
1959 * @param stream the stream which the frame is part of
1960 * @param frame the frame with the aspect ratio to be determined
1961 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
1963 AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame);
1973 #endif /* AVFORMAT_AVFORMAT_H */