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;
842 * Format I/O context.
843 * New fields can be added to the end with minor version bumps.
844 * Removal, reordering and changes to existing fields require a major
846 * sizeof(AVFormatContext) must not be used outside libav*, use
847 * avformat_alloc_context() to create an AVFormatContext.
849 typedef struct AVFormatContext {
851 * A class for logging and AVOptions. Set by avformat_alloc_context().
852 * Exports (de)muxer private options if they exist.
854 const AVClass *av_class;
857 * Can only be iformat or oformat, not both at the same time.
859 * decoding: set by avformat_open_input().
860 * encoding: set by the user.
862 struct AVInputFormat *iformat;
863 struct AVOutputFormat *oformat;
866 * Format private data. This is an AVOptions-enabled struct
867 * if and only if iformat/oformat.priv_class is not NULL.
874 * decoding: either set by the user before avformat_open_input() (then
875 * the user must close it manually) or set by avformat_open_input().
876 * encoding: set by the user.
878 * Do NOT set this field if AVFMT_NOFILE flag is set in
879 * iformat/oformat.flags. In such a case, the (de)muxer will handle
880 * I/O in some other way and this field will be NULL.
885 int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
888 * A list of all streams in the file. New streams are created with
889 * avformat_new_stream().
891 * decoding: streams are created by libavformat in avformat_open_input().
892 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
893 * appear in av_read_frame().
894 * encoding: streams are created by the user before avformat_write_header().
896 unsigned int nb_streams;
899 char filename[1024]; /**< input or output filename */
902 * Decoding: position of the first frame of the component, in
903 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
904 * It is deduced from the AVStream values.
909 * Decoding: duration of the stream, in AV_TIME_BASE fractional
910 * seconds. Only set this value if you know none of the individual stream
911 * durations and also do not set any of them. This is deduced from the
912 * AVStream values if not set.
917 * Decoding: total stream bitrate in bit/s, 0 if not
918 * available. Never set it directly if the file_size and the
919 * duration are known as FFmpeg can compute it automatically.
923 unsigned int packet_size;
927 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
928 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
929 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
930 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
931 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
932 #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
933 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
934 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
935 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload
936 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
937 #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)
938 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Dont merge side data but keep it separate.
941 * decoding: size of data to probe; encoding: unused.
943 unsigned int probesize;
946 * decoding: maximum time (in AV_TIME_BASE units) during which the input should
947 * be analyzed in avformat_find_stream_info().
949 int max_analyze_duration;
954 unsigned int nb_programs;
955 AVProgram **programs;
958 * Forced video codec_id.
959 * Demuxing: Set by user.
961 enum CodecID video_codec_id;
964 * Forced audio codec_id.
965 * Demuxing: Set by user.
967 enum CodecID audio_codec_id;
970 * Forced subtitle codec_id.
971 * Demuxing: Set by user.
973 enum CodecID subtitle_codec_id;
976 * Maximum amount of memory in bytes to use for the index of each stream.
977 * If the index exceeds this size, entries will be discarded as
978 * needed to maintain a smaller size. This can lead to slower or less
979 * accurate seeking (depends on demuxer).
980 * Demuxers for which a full in-memory index is mandatory will ignore
983 * demuxing: set by user
985 unsigned int max_index_size;
988 * Maximum amount of memory in bytes to use for buffering frames
989 * obtained from realtime capture devices.
991 unsigned int max_picture_buffer;
993 unsigned int nb_chapters;
994 AVChapter **chapters;
996 AVDictionary *metadata;
999 * Start time of the stream in real world time, in microseconds
1000 * since the unix epoch (00:00 1st January 1970). That is, pts=0
1001 * in the stream was captured at this real world time.
1002 * - encoding: Set by user.
1003 * - decoding: Unused.
1005 int64_t start_time_realtime;
1008 * decoding: number of frames used to probe fps
1013 * Error recognition; higher values will detect more errors but may
1014 * misdetect some more or less valid parts as errors.
1015 * - encoding: unused
1016 * - decoding: Set by user.
1018 int error_recognition;
1021 * Custom interrupt callbacks for the I/O layer.
1023 * decoding: set by the user before avformat_open_input().
1024 * encoding: set by the user before avformat_write_header()
1025 * (mainly useful for AVFMT_NOFILE formats). The callback
1026 * should also be passed to avio_open2() if it's used to
1029 AVIOInterruptCB interrupt_callback;
1032 * Flags to enable debugging.
1035 #define FF_FDEBUG_TS 0x0001
1038 * Transport stream id.
1039 * This will be moved into demuxer private options. Thus no API/ABI compatibility
1044 * Audio preload in microseconds.
1045 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1046 * - encoding: Set by user via AVOptions (NO direct access)
1047 * - decoding: unused
1052 * Max chunk time in microseconds.
1053 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1054 * - encoding: Set by user via AVOptions (NO direct access)
1055 * - decoding: unused
1057 int max_chunk_duration;
1060 * Max chunk size in bytes
1061 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1062 * - encoding: Set by user via AVOptions (NO direct access)
1063 * - decoding: unused
1067 /*****************************************************************
1068 * All fields below this line are not part of the public API. They
1069 * may not be used outside of libavformat and can be changed and
1071 * New public fields should be added right above.
1072 *****************************************************************
1076 * This buffer is only needed when packets were already buffered but
1077 * not decoded, for example to get the codec parameters in MPEG
1080 struct AVPacketList *packet_buffer;
1081 struct AVPacketList *packet_buffer_end;
1083 /* av_seek_frame() support */
1084 int64_t data_offset; /**< offset of the first packet */
1087 * Raw packets from the demuxer, prior to parsing and decoding.
1088 * This buffer is used for buffering packets until the codec can
1089 * be identified, as parsing cannot be done without knowing the
1092 struct AVPacketList *raw_packet_buffer;
1093 struct AVPacketList *raw_packet_buffer_end;
1095 * Packets split by the parser get queued here.
1097 struct AVPacketList *parse_queue;
1098 struct AVPacketList *parse_queue_end;
1100 * Remaining size available for raw_packet_buffer, in bytes.
1102 #define RAW_PACKET_BUFFER_SIZE 2500000
1103 int raw_packet_buffer_remaining_size;
1108 * The duration field can be estimated through various ways, and this field can be used
1109 * to know how the duration was estimated.
1112 AVFMT_DURATION_FROM_PTS, ///< duration accurately estimated from PTSes
1113 AVFMT_DURATION_FROM_STREAM, ///< duration estimated from a stream with a known duration
1114 AVFMT_DURATION_FROM_BITRATE ///< duration estimated from bitrate (less accurate)
1115 } duration_estimation_method;
1119 * Returns the method used to set ctx->duration.
1121 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1123 int av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
1125 typedef struct AVPacketList {
1127 struct AVPacketList *next;
1132 * @defgroup lavf_core Core functions
1135 * Functions for querying libavformat capabilities, allocating core structures,
1141 * Return the LIBAVFORMAT_VERSION_INT constant.
1143 unsigned avformat_version(void);
1146 * Return the libavformat build-time configuration.
1148 const char *avformat_configuration(void);
1151 * Return the libavformat license.
1153 const char *avformat_license(void);
1156 * Initialize libavformat and register all the muxers, demuxers and
1157 * protocols. If you do not call this function, then you can select
1158 * exactly which formats you want to support.
1160 * @see av_register_input_format()
1161 * @see av_register_output_format()
1162 * @see av_register_protocol()
1164 void av_register_all(void);
1166 void av_register_input_format(AVInputFormat *format);
1167 void av_register_output_format(AVOutputFormat *format);
1170 * Do global initialization of network components. This is optional,
1171 * but recommended, since it avoids the overhead of implicitly
1172 * doing the setup for each session.
1174 * Calling this function will become mandatory if using network
1175 * protocols at some major version bump.
1177 int avformat_network_init(void);
1180 * Undo the initialization done by avformat_network_init.
1182 int avformat_network_deinit(void);
1185 * If f is NULL, returns the first registered input format,
1186 * if f is non-NULL, returns the next registered input format after f
1187 * or NULL if f is the last one.
1189 AVInputFormat *av_iformat_next(AVInputFormat *f);
1192 * If f is NULL, returns the first registered output format,
1193 * if f is non-NULL, returns the next registered output format after f
1194 * or NULL if f is the last one.
1196 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1199 * Allocate an AVFormatContext.
1200 * avformat_free_context() can be used to free the context and everything
1201 * allocated by the framework within it.
1203 AVFormatContext *avformat_alloc_context(void);
1206 * Free an AVFormatContext and all its streams.
1207 * @param s context to free
1209 void avformat_free_context(AVFormatContext *s);
1212 * Get the AVClass for AVFormatContext. It can be used in combination with
1213 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1215 * @see av_opt_find().
1217 const AVClass *avformat_get_class(void);
1220 * Add a new stream to a media file.
1222 * When demuxing, it is called by the demuxer in read_header(). If the
1223 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1224 * be called in read_packet().
1226 * When muxing, should be called by the user before avformat_write_header().
1228 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1229 * will be initialized to use this codec. This is needed for e.g. codec-specific
1230 * defaults to be set, so codec should be provided if it is known.
1232 * @return newly created stream or NULL on error.
1234 AVStream *avformat_new_stream(AVFormatContext *s, AVCodec *c);
1236 AVProgram *av_new_program(AVFormatContext *s, int id);
1244 attribute_deprecated void av_pkt_dump(FILE *f, AVPacket *pkt, int dump_payload);
1245 attribute_deprecated void av_pkt_dump_log(void *avcl, int level, AVPacket *pkt,
1249 #if FF_API_ALLOC_OUTPUT_CONTEXT
1251 * @deprecated deprecated in favor of avformat_alloc_output_context2()
1253 attribute_deprecated
1254 AVFormatContext *avformat_alloc_output_context(const char *format,
1255 AVOutputFormat *oformat,
1256 const char *filename);
1260 * Allocate an AVFormatContext for an output format.
1261 * avformat_free_context() can be used to free the context and
1262 * everything allocated by the framework within it.
1264 * @param *ctx is set to the created format context, or to NULL in
1266 * @param oformat format to use for allocating the context, if NULL
1267 * format_name and filename are used instead
1268 * @param format_name the name of output format to use for allocating the
1269 * context, if NULL filename is used instead
1270 * @param filename the name of the filename to use for allocating the
1271 * context, may be NULL
1272 * @return >= 0 in case of success, a negative AVERROR code in case of
1275 int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat,
1276 const char *format_name, const char *filename);
1279 * @addtogroup lavf_decoding
1284 * Find AVInputFormat based on the short name of the input format.
1286 AVInputFormat *av_find_input_format(const char *short_name);
1289 * Guess the file format.
1291 * @param is_opened Whether the file is already opened; determines whether
1292 * demuxers with or without AVFMT_NOFILE are probed.
1294 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1297 * Guess the file format.
1299 * @param is_opened Whether the file is already opened; determines whether
1300 * demuxers with or without AVFMT_NOFILE are probed.
1301 * @param score_max A probe score larger that this is required to accept a
1302 * detection, the variable is set to the actual detection
1304 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1305 * to retry with a larger probe buffer.
1307 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1310 * Guess the file format.
1312 * @param is_opened Whether the file is already opened; determines whether
1313 * demuxers with or without AVFMT_NOFILE are probed.
1314 * @param score_ret The score of the best detection.
1316 AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
1319 * Probe a bytestream to determine the input format. Each time a probe returns
1320 * with a score that is too low, the probe buffer size is increased and another
1321 * attempt is made. When the maximum probe size is reached, the input format
1322 * with the highest score is returned.
1324 * @param pb the bytestream to probe
1325 * @param fmt the input format is put here
1326 * @param filename the filename of the stream
1327 * @param logctx the log context
1328 * @param offset the offset within the bytestream to probe from
1329 * @param max_probe_size the maximum probe buffer size (zero for default)
1330 * @return 0 in case of success, a negative value corresponding to an
1331 * AVERROR code otherwise
1333 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1334 const char *filename, void *logctx,
1335 unsigned int offset, unsigned int max_probe_size);
1338 * Open an input stream and read the header. The codecs are not opened.
1339 * The stream must be closed with av_close_input_file().
1341 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1342 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1343 * function and written into ps.
1344 * Note that a user-supplied AVFormatContext will be freed on failure.
1345 * @param filename Name of the stream to open.
1346 * @param fmt If non-NULL, this parameter forces a specific input format.
1347 * Otherwise the format is autodetected.
1348 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1349 * On return this parameter will be destroyed and replaced with a dict containing
1350 * options that were not found. May be NULL.
1352 * @return 0 on success, a negative AVERROR on failure.
1354 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1356 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1358 attribute_deprecated
1359 int av_demuxer_open(AVFormatContext *ic);
1361 #if FF_API_FORMAT_PARAMETERS
1363 * Read packets of a media file to get stream information. This
1364 * is useful for file formats with no headers such as MPEG. This
1365 * function also computes the real framerate in case of MPEG-2 repeat
1367 * The logical file position is not changed by this function;
1368 * examined packets may be buffered for later processing.
1370 * @param ic media file handle
1371 * @return >=0 if OK, AVERROR_xxx on error
1372 * @todo Let the user decide somehow what information is needed so that
1373 * we do not waste time getting stuff the user does not need.
1375 * @deprecated use avformat_find_stream_info.
1377 attribute_deprecated
1378 int av_find_stream_info(AVFormatContext *ic);
1382 * Read packets of a media file to get stream information. This
1383 * is useful for file formats with no headers such as MPEG. This
1384 * function also computes the real framerate in case of MPEG-2 repeat
1386 * The logical file position is not changed by this function;
1387 * examined packets may be buffered for later processing.
1389 * @param ic media file handle
1390 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1391 * dictionaries, where i-th member contains options for
1392 * codec corresponding to i-th stream.
1393 * On return each dictionary will be filled with options that were not found.
1394 * @return >=0 if OK, AVERROR_xxx on error
1396 * @note this function isn't guaranteed to open all the codecs, so
1397 * options being non-empty at return is a perfectly normal behavior.
1399 * @todo Let the user decide somehow what information is needed so that
1400 * we do not waste time getting stuff the user does not need.
1402 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1405 * Find the programs which belong to a given stream.
1407 * @param ic media file handle
1408 * @param last the last found program, the search will start after this
1409 * program, or from the beginning if it is NULL
1410 * @param s stream index
1411 * @return the next program which belongs to s, NULL if no program is found or
1412 * the last program is not among the programs of ic.
1414 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s);
1417 * Find the "best" stream in the file.
1418 * The best stream is determined according to various heuristics as the most
1419 * likely to be what the user expects.
1420 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1421 * default decoder for the stream's codec; streams for which no decoder can
1422 * be found are ignored.
1424 * @param ic media file handle
1425 * @param type stream type: video, audio, subtitles, etc.
1426 * @param wanted_stream_nb user-requested stream number,
1427 * or -1 for automatic selection
1428 * @param related_stream try to find a stream related (eg. in the same
1429 * program) to this one, or -1 if none
1430 * @param decoder_ret if non-NULL, returns the decoder for the
1432 * @param flags flags; none are currently defined
1433 * @return the non-negative stream number in case of success,
1434 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
1436 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
1437 * @note If av_find_best_stream returns successfully and decoder_ret is not
1438 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
1440 int av_find_best_stream(AVFormatContext *ic,
1441 enum AVMediaType type,
1442 int wanted_stream_nb,
1444 AVCodec **decoder_ret,
1447 #if FF_API_READ_PACKET
1449 * @deprecated use AVFMT_FLAG_NOFILLIN | AVFMT_FLAG_NOPARSE to read raw
1450 * unprocessed packets
1452 * Read a transport packet from a media file.
1454 * This function is obsolete and should never be used.
1455 * Use av_read_frame() instead.
1457 * @param s media file handle
1458 * @param pkt is filled
1459 * @return 0 if OK, AVERROR_xxx on error
1461 attribute_deprecated
1462 int av_read_packet(AVFormatContext *s, AVPacket *pkt);
1466 * Return the next frame of a stream.
1467 * This function returns what is stored in the file, and does not validate
1468 * that what is there are valid frames for the decoder. It will split what is
1469 * stored in the file into frames and return one for each call. It will not
1470 * omit invalid data between valid frames so as to give the decoder the maximum
1471 * information possible for decoding.
1473 * The returned packet is valid
1474 * until the next av_read_frame() or until av_close_input_file() and
1475 * must be freed with av_free_packet. For video, the packet contains
1476 * exactly one frame. For audio, it contains an integer number of
1477 * frames if each frame has a known fixed size (e.g. PCM or ADPCM
1478 * data). If the audio frames have a variable size (e.g. MPEG audio),
1479 * then it contains one frame.
1481 * pkt->pts, pkt->dts and pkt->duration are always set to correct
1482 * values in AVStream.time_base units (and guessed if the format cannot
1483 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
1484 * has B-frames, so it is better to rely on pkt->dts if you do not
1485 * decompress the payload.
1487 * @return 0 if OK, < 0 on error or end of file
1489 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
1492 * Seek to the keyframe at timestamp.
1493 * 'timestamp' in 'stream_index'.
1494 * @param stream_index If stream_index is (-1), a default
1495 * stream is selected, and timestamp is automatically converted
1496 * from AV_TIME_BASE units to the stream specific time_base.
1497 * @param timestamp Timestamp in AVStream.time_base units
1498 * or, if no stream is specified, in AV_TIME_BASE units.
1499 * @param flags flags which select direction and seeking mode
1500 * @return >= 0 on success
1502 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
1506 * Seek to timestamp ts.
1507 * Seeking will be done so that the point from which all active streams
1508 * can be presented successfully will be closest to ts and within min/max_ts.
1509 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
1511 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
1512 * are the file position (this may not be supported by all demuxers).
1513 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
1514 * in the stream with stream_index (this may not be supported by all demuxers).
1515 * Otherwise all timestamps are in units of the stream selected by stream_index
1516 * or if stream_index is -1, in AV_TIME_BASE units.
1517 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
1518 * keyframes (this may not be supported by all demuxers).
1520 * @param stream_index index of the stream which is used as time base reference
1521 * @param min_ts smallest acceptable timestamp
1522 * @param ts target timestamp
1523 * @param max_ts largest acceptable timestamp
1524 * @param flags flags
1525 * @return >=0 on success, error code otherwise
1527 * @note This is part of the new seek API which is still under construction.
1528 * Thus do not use this yet. It may change at any time, do not expect
1529 * ABI compatibility yet!
1531 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
1534 * Start playing a network-based stream (e.g. RTSP stream) at the
1537 int av_read_play(AVFormatContext *s);
1540 * Pause a network-based stream (e.g. RTSP stream).
1542 * Use av_read_play() to resume it.
1544 int av_read_pause(AVFormatContext *s);
1546 #if FF_API_CLOSE_INPUT_FILE
1548 * @deprecated use avformat_close_input()
1549 * Close a media file (but not its codecs).
1551 * @param s media file handle
1553 attribute_deprecated
1554 void av_close_input_file(AVFormatContext *s);
1558 * Close an opened input AVFormatContext. Free it and all its contents
1559 * and set *s to NULL.
1561 void avformat_close_input(AVFormatContext **s);
1566 #if FF_API_NEW_STREAM
1568 * Add a new stream to a media file.
1570 * Can only be called in the read_header() function. If the flag
1571 * AVFMTCTX_NOHEADER is in the format context, then new streams
1572 * can be added in read_packet too.
1574 * @param s media file handle
1575 * @param id file-format-dependent stream ID
1577 attribute_deprecated
1578 AVStream *av_new_stream(AVFormatContext *s, int id);
1581 #if FF_API_SET_PTS_INFO
1583 * @deprecated this function is not supposed to be called outside of lavf
1585 attribute_deprecated
1586 void av_set_pts_info(AVStream *s, int pts_wrap_bits,
1587 unsigned int pts_num, unsigned int pts_den);
1590 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
1591 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
1592 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
1593 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
1596 * @addtogroup lavf_encoding
1600 * Allocate the stream private data and write the stream header to
1601 * an output media file.
1603 * @param s Media file handle, must be allocated with avformat_alloc_context().
1604 * Its oformat field must be set to the desired output format;
1605 * Its pb field must be set to an already openened AVIOContext.
1606 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
1607 * On return this parameter will be destroyed and replaced with a dict containing
1608 * options that were not found. May be NULL.
1610 * @return 0 on success, negative AVERROR on failure.
1612 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
1614 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
1617 * Write a packet to an output media file.
1619 * The packet shall contain one audio or video frame.
1620 * The packet must be correctly interleaved according to the container
1621 * specification, if not then av_interleaved_write_frame must be used.
1623 * @param s media file handle
1624 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1626 * This can be NULL (at any time, not just at the end), in
1627 * order to immediately flush data buffered within the muxer,
1628 * for muxers that buffer up data internally before writing it
1630 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
1632 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
1635 * Write a packet to an output media file ensuring correct interleaving.
1637 * The packet must contain one audio or video frame.
1638 * If the packets are already correctly interleaved, the application should
1639 * call av_write_frame() instead as it is slightly faster. It is also important
1640 * to keep in mind that completely non-interleaved input will need huge amounts
1641 * of memory to interleave with this, so it is preferable to interleave at the
1644 * @param s media file handle
1645 * @param pkt The packet containing the data to be written. Libavformat takes
1646 * ownership of the data and will free it when it sees fit using the packet's
1647 * This can be NULL (at any time, not just at the end), to flush the
1648 * interleaving queues.
1649 * @ref AVPacket.destruct "destruct" field. The caller must not access the data
1650 * after this function returns, as it may already be freed.
1651 * Packet's @ref AVPacket.stream_index "stream_index" field must be set to the
1652 * index of the corresponding stream in @ref AVFormatContext.streams
1654 * It is very strongly recommended that timing information (@ref AVPacket.pts
1655 * "pts", @ref AVPacket.dts "dts" @ref AVPacket.duration "duration") is set to
1658 * @return 0 on success, a negative AVERROR on error.
1660 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
1662 #if FF_API_INTERLEAVE_PACKET
1664 * @deprecated this function was never meant to be called by the user
1667 attribute_deprecated
1668 int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
1669 AVPacket *pkt, int flush);
1673 * Write the stream trailer to an output media file and free the
1674 * file private data.
1676 * May only be called after a successful call to av_write_header.
1678 * @param s media file handle
1679 * @return 0 if OK, AVERROR_xxx on error
1681 int av_write_trailer(AVFormatContext *s);
1684 * Return the output format in the list of registered output formats
1685 * which best matches the provided parameters, or return NULL if
1686 * there is no match.
1688 * @param short_name if non-NULL checks if short_name matches with the
1689 * names of the registered formats
1690 * @param filename if non-NULL checks if filename terminates with the
1691 * extensions of the registered formats
1692 * @param mime_type if non-NULL checks if mime_type matches with the
1693 * MIME type of the registered formats
1695 AVOutputFormat *av_guess_format(const char *short_name,
1696 const char *filename,
1697 const char *mime_type);
1700 * Guess the codec ID based upon muxer and filename.
1702 enum CodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
1703 const char *filename, const char *mime_type,
1704 enum AVMediaType type);
1707 * Get timing information for the data currently output.
1708 * The exact meaning of "currently output" depends on the format.
1709 * It is mostly relevant for devices that have an internal buffer and/or
1710 * work in real time.
1711 * @param s media file handle
1712 * @param stream stream in the media file
1713 * @param dts[out] DTS of the last packet output for the stream, in stream
1715 * @param wall[out] absolute time when that packet whas output,
1717 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
1718 * Note: some formats or devices may not allow to measure dts and wall
1721 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
1722 int64_t *dts, int64_t *wall);
1731 * @defgroup lavf_misc Utility functions
1735 * Miscelaneous utility functions related to both muxing and demuxing
1740 * Send a nice hexadecimal dump of a buffer to the specified file stream.
1742 * @param f The file stream pointer where the dump should be sent to.
1744 * @param size buffer size
1746 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
1748 void av_hex_dump(FILE *f, uint8_t *buf, int size);
1751 * Send a nice hexadecimal dump of a buffer to the log.
1753 * @param avcl A pointer to an arbitrary struct of which the first field is a
1754 * pointer to an AVClass struct.
1755 * @param level The importance level of the message, lower values signifying
1756 * higher importance.
1758 * @param size buffer size
1760 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
1762 void av_hex_dump_log(void *avcl, int level, uint8_t *buf, int size);
1765 * Send a nice dump of a packet to the specified file stream.
1767 * @param f The file stream pointer where the dump should be sent to.
1768 * @param pkt packet to dump
1769 * @param dump_payload True if the payload must be displayed, too.
1770 * @param st AVStream that the packet belongs to
1772 void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
1776 * Send a nice dump of a packet to the log.
1778 * @param avcl A pointer to an arbitrary struct of which the first field is a
1779 * pointer to an AVClass struct.
1780 * @param level The importance level of the message, lower values signifying
1781 * higher importance.
1782 * @param pkt packet to dump
1783 * @param dump_payload True if the payload must be displayed, too.
1784 * @param st AVStream that the packet belongs to
1786 void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
1790 * Get the CodecID for the given codec tag tag.
1791 * If no codec id is found returns CODEC_ID_NONE.
1793 * @param tags list of supported codec_id-codec_tag pairs, as stored
1794 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1796 enum CodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
1799 * Get the codec tag for the given codec id id.
1800 * If no codec tag is found returns 0.
1802 * @param tags list of supported codec_id-codec_tag pairs, as stored
1803 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1805 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum CodecID id);
1807 int av_find_default_stream_index(AVFormatContext *s);
1810 * Get the index for a specific timestamp.
1811 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
1812 * to the timestamp which is <= the requested one, if backward
1813 * is 0, then it will be >=
1814 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
1815 * @return < 0 if no such timestamp could be found
1817 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
1820 * Add an index entry into a sorted list. Update the entry if the list
1821 * already contains it.
1823 * @param timestamp timestamp in the time base of the given stream
1825 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
1826 int size, int distance, int flags);
1830 * Split a URL string into components.
1832 * The pointers to buffers for storing individual components may be null,
1833 * in order to ignore that component. Buffers for components not found are
1834 * set to empty strings. If the port is not found, it is set to a negative
1837 * @param proto the buffer for the protocol
1838 * @param proto_size the size of the proto buffer
1839 * @param authorization the buffer for the authorization
1840 * @param authorization_size the size of the authorization buffer
1841 * @param hostname the buffer for the host name
1842 * @param hostname_size the size of the hostname buffer
1843 * @param port_ptr a pointer to store the port number in
1844 * @param path the buffer for the path
1845 * @param path_size the size of the path buffer
1846 * @param url the URL to split
1848 void av_url_split(char *proto, int proto_size,
1849 char *authorization, int authorization_size,
1850 char *hostname, int hostname_size,
1852 char *path, int path_size,
1856 void av_dump_format(AVFormatContext *ic,
1862 * Return in 'buf' the path with '%d' replaced by a number.
1864 * Also handles the '%0nd' format where 'n' is the total number
1865 * of digits and '%%'.
1867 * @param buf destination buffer
1868 * @param buf_size destination buffer size
1869 * @param path numbered sequence string
1870 * @param number frame number
1871 * @return 0 if OK, -1 on format error
1873 int av_get_frame_filename(char *buf, int buf_size,
1874 const char *path, int number);
1877 * Check whether filename actually is a numbered sequence generator.
1879 * @param filename possible numbered sequence string
1880 * @return 1 if a valid numbered sequence string, 0 otherwise
1882 int av_filename_number_test(const char *filename);
1885 * Generate an SDP for an RTP session.
1887 * @param ac array of AVFormatContexts describing the RTP streams. If the
1888 * array is composed by only one context, such context can contain
1889 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
1890 * all the contexts in the array (an AVCodecContext per RTP stream)
1891 * must contain only one AVStream.
1892 * @param n_files number of AVCodecContexts contained in ac
1893 * @param buf buffer where the SDP will be stored (must be allocated by
1895 * @param size the size of the buffer
1896 * @return 0 if OK, AVERROR_xxx on error
1898 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
1901 * Return a positive value if the given filename has one of the given
1902 * extensions, 0 otherwise.
1904 * @param extensions a comma-separated list of filename extensions
1906 int av_match_ext(const char *filename, const char *extensions);
1909 * Test if the given container can store a codec.
1911 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
1913 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
1914 * A negative number if this information is not available.
1916 int avformat_query_codec(AVOutputFormat *ofmt, enum CodecID codec_id, int std_compliance);
1919 * @defgroup riff_fourcc RIFF FourCCs
1921 * Get the tables mapping RIFF FourCCs to libavcodec CodecIDs. The tables are
1922 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
1925 * uint32_t tag = MKTAG('H', '2', '6', '4');
1926 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
1927 * enum CodecID id = av_codec_get_id(table, tag);
1931 * @return the table mapping RIFF FourCCs for video to libavcodec CodecID.
1933 const struct AVCodecTag *avformat_get_riff_video_tags(void);
1935 * @return the table mapping RIFF FourCCs for audio to CodecID.
1937 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
1940 * Guesses the sample aspect ratio of a frame, based on both the stream and the
1941 * frame aspect ratio.
1943 * Since the frame aspect ratio is set by the codec but the stream aspect ratio
1944 * is set by the demuxer, these two may not be equal. This function tries to
1945 * return the value that you should use if you would like to display the frame.
1947 * Basic logic is to use the stream aspect ratio if it is set to something sane
1948 * otherwise use the frame aspect ratio. This way a container setting, which is
1949 * usually easy to modify can override the coded value in the frames.
1951 * @param format the format context which the stream is part of
1952 * @param stream the stream which the frame is part of
1953 * @param frame the frame with the aspect ratio to be determined
1954 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
1956 AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame);
1966 #endif /* AVFORMAT_AVFORMAT_H */