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 * If AVPacket.buf is set on the returned packet, then the packet is
162 * allocated dynamically and the user may keep it indefinitely.
163 * Otherwise, if AVPacket.buf is NULL, the packet data is backed by a
164 * static storage somewhere inside the demuxer and the packet is only valid
165 * until the next av_read_frame() call or closing the file. If the caller
166 * requires a longer lifetime, av_dup_packet() will make an av_malloc()ed copy
168 * In both cases, the packet must be freed with av_free_packet() when it is no
171 * @section lavf_decoding_seek Seeking
174 * @defgroup lavf_encoding Muxing
176 * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write
177 * it into files or other output bytestreams in the specified container format.
179 * The main API functions for muxing are avformat_write_header() for writing the
180 * file header, av_write_frame() / av_interleaved_write_frame() for writing the
181 * packets and av_write_trailer() for finalizing the file.
183 * At the beginning of the muxing process, the caller must first call
184 * avformat_alloc_context() to create a muxing context. The caller then sets up
185 * the muxer by filling the various fields in this context:
187 * - The @ref AVFormatContext.oformat "oformat" field must be set to select the
188 * muxer that will be used.
189 * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb
190 * "pb" field must be set to an opened IO context, either returned from
191 * avio_open2() or a custom one.
192 * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must
193 * be created with the avformat_new_stream() function. The caller should fill
194 * the @ref AVStream.codec "stream codec context" information, such as the
195 * codec @ref AVCodecContext.codec_type "type", @ref AVCodecContext.codec_id
196 * "id" and other parameters (e.g. width / height, the pixel or sample format,
197 * etc.) as known. The @ref AVCodecContext.time_base "codec timebase" should
198 * be set to the timebase that the caller desires to use for this stream (note
199 * that the timebase actually used by the muxer can be different, as will be
201 * - The caller may fill in additional information, such as @ref
202 * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream"
203 * metadata, @ref AVFormatContext.chapters "chapters", @ref
204 * AVFormatContext.programs "programs", etc. as described in the
205 * AVFormatContext documentation. Whether such information will actually be
206 * stored in the output depends on what the container format and the muxer
209 * When the muxing context is fully set up, the caller must call
210 * avformat_write_header() to initialize the muxer internals and write the file
211 * header. Whether anything actually is written to the IO context at this step
212 * depends on the muxer, but this function must always be called. Any muxer
213 * private options must be passed in the options parameter to this function.
215 * The data is then sent to the muxer by repeatedly calling av_write_frame() or
216 * av_interleaved_write_frame() (consult those functions' documentation for
217 * discussion on the difference between them; only one of them may be used with
218 * a single muxing context, they should not be mixed). Do note that the timing
219 * information on the packets sent to the muxer must be in the corresponding
220 * AVStream's timebase. That timebase is set by the muxer (in the
221 * avformat_write_header() step) and may be different from the timebase the
222 * caller set on the codec context.
224 * Once all the data has been written, the caller must call av_write_trailer()
225 * to flush any buffered packets and finalize the output file, then close the IO
226 * context (if any) and finally free the muxing context with
227 * avformat_free_context().
230 * @defgroup lavf_io I/O Read/Write
234 * @defgroup lavf_codec Demuxers
236 * @defgroup lavf_codec_native Native Demuxers
239 * @defgroup lavf_codec_wrappers External library wrappers
243 * @defgroup lavf_protos I/O Protocols
246 * @defgroup lavf_internal Internal
254 #include <stdio.h> /* FILE */
255 #include "libavcodec/avcodec.h"
256 #include "libavutil/dict.h"
257 #include "libavutil/log.h"
260 #include "libavformat/version.h"
262 struct AVFormatContext;
264 struct AVDeviceInfoList;
265 struct AVDeviceCapabilitiesQuery;
268 * @defgroup metadata_api Public Metadata API
271 * The metadata API allows libavformat to export metadata tags to a client
272 * application when demuxing. Conversely it allows a client application to
273 * set metadata when muxing.
275 * Metadata is exported or set as pairs of key/value strings in the 'metadata'
276 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
277 * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
278 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
279 * exported by demuxers isn't checked to be valid UTF-8 in most cases.
281 * Important concepts to keep in mind:
282 * - Keys are unique; there can never be 2 tags with the same key. This is
283 * also meant semantically, i.e., a demuxer should not knowingly produce
284 * several keys that are literally different but semantically identical.
285 * E.g., key=Author5, key=Author6. In this example, all authors must be
286 * placed in the same tag.
287 * - Metadata is flat, not hierarchical; there are no subtags. If you
288 * want to store, e.g., the email address of the child of producer Alice
289 * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
290 * - Several modifiers can be applied to the tag name. This is done by
291 * appending a dash character ('-') and the modifier name in the order
292 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
293 * - language -- a tag whose value is localized for a particular language
294 * is appended with the ISO 639-2/B 3-letter language code.
295 * For example: Author-ger=Michael, Author-eng=Mike
296 * The original/default language is in the unqualified "Author" tag.
297 * A demuxer should set a default if it sets any translated tag.
298 * - sorting -- a modified version of a tag that should be used for
299 * sorting will have '-sort' appended. E.g. artist="The Beatles",
300 * artist-sort="Beatles, The".
302 * - Demuxers attempt to export metadata in a generic format, however tags
303 * with no generic equivalents are left as they are stored in the container.
304 * Follows a list of generic tag names:
307 album -- name of the set this work belongs to
308 album_artist -- main creator of the set/album, if different from artist.
309 e.g. "Various Artists" for compilation albums.
310 artist -- main creator of the work
311 comment -- any additional description of the file.
312 composer -- who composed the work, if different from artist.
313 copyright -- name of copyright holder.
314 creation_time-- date when the file was created, preferably in ISO 8601.
315 date -- date when the work was created, preferably in ISO 8601.
316 disc -- number of a subset, e.g. disc in a multi-disc collection.
317 encoder -- name/settings of the software/hardware that produced the file.
318 encoded_by -- person/group who created the file.
319 filename -- original name of the file.
320 genre -- <self-evident>.
321 language -- main language in which the work is performed, preferably
322 in ISO 639-2 format. Multiple languages can be specified by
323 separating them with commas.
324 performer -- artist who performed the work, if different from artist.
325 E.g for "Also sprach Zarathustra", artist would be "Richard
326 Strauss" and performer "London Philharmonic Orchestra".
327 publisher -- name of the label/publisher.
328 service_name -- name of the service in broadcasting (channel name).
329 service_provider -- name of the service provider in broadcasting.
330 title -- name of the work.
331 track -- number of this work in the set, can be in form current/total.
332 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
335 * Look in the examples section for an application example how to use the Metadata API.
340 /* packet functions */
344 * Allocate and read the payload of a packet and initialize its
345 * fields with default values.
347 * @param s associated IO context
349 * @param size desired payload size
350 * @return >0 (read size) if OK, AVERROR_xxx otherwise
352 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
356 * Read data and append it to the current content of the AVPacket.
357 * If pkt->size is 0 this is identical to av_get_packet.
358 * Note that this uses av_grow_packet and thus involves a realloc
359 * which is inefficient. Thus this function should only be used
360 * when there is no reasonable way to know (an upper bound of)
363 * @param s associated IO context
365 * @param size amount of data to read
366 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
367 * will not be lost even if an error occurs.
369 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
372 /*************************************************/
373 /* fractional numbers for exact pts handling */
376 * The exact value of the fractional number is: 'val + num / den'.
377 * num is assumed to be 0 <= num < den.
379 typedef struct AVFrac {
380 int64_t val, num, den;
384 /*************************************************/
385 /* input/output formats */
390 * This structure contains the data a format has to probe a file.
392 typedef struct AVProbeData {
393 const char *filename;
394 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
395 int buf_size; /**< Size of buf except extra allocated bytes */
398 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
399 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
401 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
402 #define AVPROBE_SCORE_MAX 100 ///< maximum score
404 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
406 /// Demuxer will use avio_open, no opened file should be provided by the caller.
407 #define AVFMT_NOFILE 0x0001
408 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
409 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
410 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
412 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
413 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
414 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
415 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
416 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
417 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
418 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
419 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
420 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
421 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
422 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
423 #if LIBAVFORMAT_VERSION_MAJOR <= 54
424 #define AVFMT_TS_NONSTRICT 0x8020000 //we try to be compatible to the ABIs of ffmpeg and major forks
426 #define AVFMT_TS_NONSTRICT 0x20000
428 /**< Format does not require strictly
429 increasing timestamps, but they must
430 still be monotonic */
431 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
432 timestamps. If not set the timestamp
433 will be shifted in av_write_frame and
434 av_interleaved_write_frame so they
436 The user or muxer can override this through
437 AVFormatContext.avoid_negative_ts
440 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
443 * @addtogroup lavf_encoding
446 typedef struct AVOutputFormat {
449 * Descriptive name for the format, meant to be more human-readable
450 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
453 const char *long_name;
454 const char *mime_type;
455 const char *extensions; /**< comma-separated filename extensions */
457 enum AVCodecID audio_codec; /**< default audio codec */
458 enum AVCodecID video_codec; /**< default video codec */
459 enum AVCodecID subtitle_codec; /**< default subtitle codec */
461 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
462 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
463 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
469 * List of supported codec_id-codec_tag pairs, ordered by "better
470 * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
472 const struct AVCodecTag * const *codec_tag;
475 const AVClass *priv_class; ///< AVClass for the private context
477 /*****************************************************************
478 * No fields below this line are part of the public API. They
479 * may not be used outside of libavformat and can be changed and
481 * New public fields should be added right above.
482 *****************************************************************
484 struct AVOutputFormat *next;
486 * size of private data so that it can be allocated in the wrapper
490 int (*write_header)(struct AVFormatContext *);
492 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
493 * pkt can be NULL in order to flush data buffered in the muxer.
494 * When flushing, return 0 if there still is more data to flush,
495 * or 1 if everything was flushed and there is no more buffered
498 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
499 int (*write_trailer)(struct AVFormatContext *);
501 * Currently only used to set pixel format if not YUV420P.
503 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
504 AVPacket *in, int flush);
506 * Test if the given codec can be stored in this container.
508 * @return 1 if the codec is supported, 0 if it is not.
509 * A negative number if unknown.
510 * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
512 int (*query_codec)(enum AVCodecID id, int std_compliance);
514 void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
515 int64_t *dts, int64_t *wall);
517 * Allows sending messages from application to device.
519 int (*control_message)(struct AVFormatContext *s, int type,
520 void *data, size_t data_size);
523 * Write an uncoded AVFrame.
525 * See av_write_uncoded_frame() for details.
527 * The library will free *frame afterwards, but the muxer can prevent it
528 * by setting the pointer to NULL.
530 int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
531 AVFrame **frame, unsigned flags);
533 * Returns device list with it properties.
534 * @see avdevice_list_devices() for more details.
536 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
538 * Initialize device capabilities submodule.
539 * @see avdevice_capabilities_create() for more details.
541 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
543 * Free device capabilities submodule.
544 * @see avdevice_capabilities_free() for more details.
546 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
553 * @addtogroup lavf_decoding
556 typedef struct AVInputFormat {
558 * A comma separated list of short names for the format. New names
559 * may be appended with a minor bump.
564 * Descriptive name for the format, meant to be more human-readable
565 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
568 const char *long_name;
571 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
572 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
573 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
578 * If extensions are defined, then no probe is done. You should
579 * usually not use extension format guessing because it is not
582 const char *extensions;
584 const struct AVCodecTag * const *codec_tag;
586 const AVClass *priv_class; ///< AVClass for the private context
588 /*****************************************************************
589 * No fields below this line are part of the public API. They
590 * may not be used outside of libavformat and can be changed and
592 * New public fields should be added right above.
593 *****************************************************************
595 struct AVInputFormat *next;
598 * Raw demuxers store their codec ID here.
603 * Size of private data so that it can be allocated in the wrapper.
608 * Tell if a given file has a chance of being parsed as this format.
609 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
610 * big so you do not have to check for that unless you need more.
612 int (*read_probe)(AVProbeData *);
615 * Read the format header and initialize the AVFormatContext
616 * structure. Return 0 if OK. Only used in raw format right
617 * now. 'avformat_new_stream' should be called to create new streams.
619 int (*read_header)(struct AVFormatContext *);
622 * Read one packet and put it in 'pkt'. pts and flags are also
623 * set. 'avformat_new_stream' can be called only if the flag
624 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
625 * background thread).
626 * @return 0 on success, < 0 on error.
627 * When returning an error, pkt must not have been allocated
628 * or must be freed before returning
630 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
633 * Close the stream. The AVFormatContext and AVStreams are not
634 * freed by this function
636 int (*read_close)(struct AVFormatContext *);
639 * Seek to a given timestamp relative to the frames in
640 * stream component stream_index.
641 * @param stream_index Must not be -1.
642 * @param flags Selects which direction should be preferred if no exact
643 * match is available.
644 * @return >= 0 on success (but not necessarily the new offset)
646 int (*read_seek)(struct AVFormatContext *,
647 int stream_index, int64_t timestamp, int flags);
650 * Get the next timestamp in stream[stream_index].time_base units.
651 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
653 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
654 int64_t *pos, int64_t pos_limit);
657 * Start/resume playing - only meaningful if using a network-based format
660 int (*read_play)(struct AVFormatContext *);
663 * Pause playing - only meaningful if using a network-based format
666 int (*read_pause)(struct AVFormatContext *);
669 * Seek to timestamp ts.
670 * Seeking will be done so that the point from which all active streams
671 * can be presented successfully will be closest to ts and within min/max_ts.
672 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
674 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
677 * Returns device list with it properties.
678 * @see avdevice_list_devices() for more details.
680 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
683 * Initialize device capabilities submodule.
684 * @see avdevice_capabilities_create() for more details.
686 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
689 * Free device capabilities submodule.
690 * @see avdevice_capabilities_free() for more details.
692 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
698 enum AVStreamParseType {
700 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
701 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
702 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
703 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
704 AVSTREAM_PARSE_FULL_RAW=MKTAG(0,'R','A','W'), /**< full parsing and repack with timestamp and position generation by parser for raw
705 this assumes that each packet in the file contains no demuxer level headers and
706 just codec level data, otherwise position generation would fail */
709 typedef struct AVIndexEntry {
711 int64_t timestamp; /**<
712 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
713 * when seeking to this entry. That means preferable PTS on keyframe based formats.
714 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
717 #define AVINDEX_KEYFRAME 0x0001
719 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).
720 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
723 #define AV_DISPOSITION_DEFAULT 0x0001
724 #define AV_DISPOSITION_DUB 0x0002
725 #define AV_DISPOSITION_ORIGINAL 0x0004
726 #define AV_DISPOSITION_COMMENT 0x0008
727 #define AV_DISPOSITION_LYRICS 0x0010
728 #define AV_DISPOSITION_KARAOKE 0x0020
731 * Track should be used during playback by default.
732 * Useful for subtitle track that should be displayed
733 * even when user did not explicitly ask for subtitles.
735 #define AV_DISPOSITION_FORCED 0x0040
736 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
737 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
738 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
740 * The stream is stored in the file as an attached picture/"cover art" (e.g.
741 * APIC frame in ID3v2). The single packet associated with it will be returned
742 * among the first few packets read from the file unless seeking takes place.
743 * It can also be accessed at any time in AVStream.attached_pic.
745 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
748 * To specify text track kind (different from subtitles default).
750 #define AV_DISPOSITION_CAPTIONS 0x10000
751 #define AV_DISPOSITION_DESCRIPTIONS 0x20000
752 #define AV_DISPOSITION_METADATA 0x40000
755 * Options for behavior on timestamp wrap detection.
757 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
758 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
759 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
763 * New fields can be added to the end with minor version bumps.
764 * Removal, reordering and changes to existing fields require a major
766 * sizeof(AVStream) must not be used outside libav*.
768 typedef struct AVStream {
769 int index; /**< stream index in AVFormatContext */
771 * Format-specific stream ID.
772 * decoding: set by libavformat
773 * encoding: set by the user, replaced by libavformat if left unset
777 * Codec context associated with this stream. Allocated and freed by
780 * - decoding: The demuxer exports codec information stored in the headers
782 * - encoding: The user sets codec information, the muxer writes it to the
783 * output. Mandatory fields as specified in AVCodecContext
784 * documentation must be set even if this AVCodecContext is
785 * not actually used for encoding.
787 AVCodecContext *codec;
792 * @deprecated this field is unused
799 * This is the fundamental unit of time (in seconds) in terms
800 * of which frame timestamps are represented.
802 * decoding: set by libavformat
803 * encoding: set by libavformat in avformat_write_header. The muxer may use the
804 * user-provided value of @ref AVCodecContext.time_base "codec->time_base"
807 AVRational time_base;
810 * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
811 * Only set this if you are absolutely 100% sure that the value you set
812 * it to really is the pts of the first frame.
813 * This may be undefined (AV_NOPTS_VALUE).
814 * @note The ASF header does NOT contain a correct start_time the ASF
815 * demuxer must NOT set this.
820 * Decoding: duration of the stream, in stream time base.
821 * If a source file does not specify a duration, but does specify
822 * a bitrate, this value will be estimated from bitrate and file size.
826 int64_t nb_frames; ///< number of frames in this stream if known or 0
828 int disposition; /**< AV_DISPOSITION_* bit field */
830 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
833 * sample aspect ratio (0 if unknown)
834 * - encoding: Set by user.
835 * - decoding: Set by libavformat.
837 AVRational sample_aspect_ratio;
839 AVDictionary *metadata;
844 * - demuxing: May be set by libavformat when creating the stream or in
845 * avformat_find_stream_info().
846 * - muxing: May be set by the caller before avformat_write_header().
848 AVRational avg_frame_rate;
851 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
852 * will contain the attached picture.
854 * decoding: set by libavformat, must not be modified by the caller.
857 AVPacket attached_pic;
860 * An array of side data that applies to the whole stream (i.e. the
861 * container does not allow it to change between packets).
863 * There may be no overlap between the side data in this array and side data
864 * in the packets. I.e. a given side data is either exported by the muxer
865 * (demuxing) / set by the caller (muxing) in this array, then it never
866 * appears in the packets, or the side data is exported / sent through
867 * the packets (always in the first packet where the value becomes known or
868 * changes), then it does not appear in this array.
870 * - demuxing: Set by libavformat when the stream is created.
871 * - muxing: May be set by the caller before avformat_write_header().
873 * Freed by libavformat in avformat_free_context().
875 * @see av_format_inject_global_side_data()
877 AVPacketSideData *side_data;
879 * The number of elements in the AVStream.side_data array.
883 /*****************************************************************
884 * All fields below this line are not part of the public API. They
885 * may not be used outside of libavformat and can be changed and
887 * New public fields should be added right above.
888 *****************************************************************
892 * Stream information used internally by av_find_stream_info()
894 #define MAX_STD_TIMEBASES (60*12+6)
897 int64_t duration_gcd;
899 int64_t rfps_duration_sum;
900 double (*duration_error)[2][MAX_STD_TIMEBASES];
901 int64_t codec_info_duration;
902 int64_t codec_info_duration_fields;
905 * 0 -> decoder has not been searched for yet.
906 * >0 -> decoder found
907 * <0 -> decoder with codec_id == -found_decoder has not been found
911 int64_t last_duration;
914 * Those are used for average framerate estimation.
916 int64_t fps_first_dts;
917 int fps_first_dts_idx;
918 int64_t fps_last_dts;
919 int fps_last_dts_idx;
923 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
925 #if FF_API_REFERENCE_DTS
926 /* a hack to keep ABI compatibility for ffmpeg and other applications, which accesses parser even
927 * though it should not */
930 // Timestamp generation support:
932 * Timestamp corresponding to the last dts sync point.
934 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
935 * a DTS is received from the underlying container. Otherwise set to
936 * AV_NOPTS_VALUE by default.
941 int last_IP_duration;
944 * Number of packets to buffer for codec probing
946 #define MAX_PROBE_PACKETS 2500
950 * Number of frames that have been demuxed during av_find_stream_info()
952 int codec_info_nb_frames;
954 /* av_read_frame() support */
955 enum AVStreamParseType need_parsing;
956 struct AVCodecParserContext *parser;
959 * last packet in packet_buffer for this stream when muxing.
961 struct AVPacketList *last_in_packet_buffer;
962 AVProbeData probe_data;
963 #define MAX_REORDER_DELAY 16
964 int64_t pts_buffer[MAX_REORDER_DELAY+1];
966 AVIndexEntry *index_entries; /**< Only used if the format does not
967 support seeking natively. */
968 int nb_index_entries;
969 unsigned int index_entries_allocated_size;
972 * Real base framerate of the stream.
973 * This is the lowest framerate with which all timestamps can be
974 * represented accurately (it is the least common multiple of all
975 * framerates in the stream). Note, this value is just a guess!
976 * For example, if the time base is 1/90000 and all frames have either
977 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
979 * Code outside avformat should access this field using:
980 * av_stream_get/set_r_frame_rate(stream)
982 AVRational r_frame_rate;
986 * This is the MPEG-TS stream identifier +1
989 int stream_identifier;
991 int64_t interleaver_chunk_size;
992 int64_t interleaver_chunk_duration;
995 * stream probing state
996 * -1 -> probing finished
997 * 0 -> no probing requested
998 * rest -> perform probing with request_probe being the minimum score to accept.
999 * NOT PART OF PUBLIC API
1003 * Indicates that everything up to the next keyframe
1004 * should be discarded.
1006 int skip_to_keyframe;
1009 * Number of samples to skip at the start of the frame decoded from the next packet.
1014 * Number of internally decoded frames, used internally in libavformat, do not access
1015 * its lifetime differs from info which is why it is not in that structure.
1017 int nb_decoded_frames;
1020 * Timestamp offset added to timestamps before muxing
1021 * NOT PART OF PUBLIC API
1023 int64_t mux_ts_offset;
1026 * Internal data to check for wrapping of the time stamp
1028 int64_t pts_wrap_reference;
1031 * Options for behavior, when a wrap is detected.
1033 * Defined by AV_PTS_WRAP_ values.
1035 * If correction is enabled, there are two possibilities:
1036 * If the first time stamp is near the wrap point, the wrap offset
1037 * will be subtracted, which will create negative time stamps.
1038 * Otherwise the offset will be added.
1040 int pts_wrap_behavior;
1043 * Internal data to prevent doing update_initial_durations() twice
1045 int update_initial_durations_done;
1048 * Internal data to generate dts from pts
1050 int64_t pts_reorder_error[MAX_REORDER_DELAY+1];
1051 uint8_t pts_reorder_error_count[MAX_REORDER_DELAY+1];
1054 * Internal data to analyze DTS and detect faulty mpeg streams
1056 int64_t last_dts_for_order_check;
1057 uint8_t dts_ordered;
1058 uint8_t dts_misordered;
1061 * Internal data to inject global side data
1063 int inject_global_side_data;
1067 AVRational av_stream_get_r_frame_rate(const AVStream *s);
1068 void av_stream_set_r_frame_rate(AVStream *s, AVRational r);
1071 * Returns the pts of the last muxed packet + its duration
1073 * the retuned value is undefined when used with a demuxer.
1075 int64_t av_stream_get_end_pts(const AVStream *st);
1077 #define AV_PROGRAM_RUNNING 1
1080 * New fields can be added to the end with minor version bumps.
1081 * Removal, reordering and changes to existing fields require a major
1083 * sizeof(AVProgram) must not be used outside libav*.
1085 typedef struct AVProgram {
1088 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1089 unsigned int *stream_index;
1090 unsigned int nb_stream_indexes;
1091 AVDictionary *metadata;
1097 /*****************************************************************
1098 * All fields below this line are not part of the public API. They
1099 * may not be used outside of libavformat and can be changed and
1101 * New public fields should be added right above.
1102 *****************************************************************
1107 int64_t pts_wrap_reference; ///< reference dts for wrap detection
1108 int pts_wrap_behavior; ///< behavior on wrap detection
1111 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1112 (streams are added dynamically) */
1114 typedef struct AVChapter {
1115 int id; ///< unique ID to identify the chapter
1116 AVRational time_base; ///< time base in which the start/end timestamps are specified
1117 int64_t start, end; ///< chapter start/end time in time_base units
1118 AVDictionary *metadata;
1123 * Callback used by devices to communicate with application.
1125 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1126 void *data, size_t data_size);
1130 * The duration of a video can be estimated through various ways, and this enum can be used
1131 * to know how the duration was estimated.
1133 enum AVDurationEstimationMethod {
1134 AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1135 AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1136 AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1139 typedef struct AVFormatInternal AVFormatInternal;
1142 * Format I/O context.
1143 * New fields can be added to the end with minor version bumps.
1144 * Removal, reordering and changes to existing fields require a major
1146 * sizeof(AVFormatContext) must not be used outside libav*, use
1147 * avformat_alloc_context() to create an AVFormatContext.
1149 typedef struct AVFormatContext {
1151 * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1152 * Exports (de)muxer private options if they exist.
1154 const AVClass *av_class;
1157 * The input container format.
1159 * Demuxing only, set by avformat_open_input().
1161 struct AVInputFormat *iformat;
1164 * The output container format.
1166 * Muxing only, must be set by the caller before avformat_write_header().
1168 struct AVOutputFormat *oformat;
1171 * Format private data. This is an AVOptions-enabled struct
1172 * if and only if iformat/oformat.priv_class is not NULL.
1174 * - muxing: set by avformat_write_header()
1175 * - demuxing: set by avformat_open_input()
1182 * - demuxing: either set by the user before avformat_open_input() (then
1183 * the user must close it manually) or set by avformat_open_input().
1184 * - muxing: set by the user before avformat_write_header(). The caller must
1185 * take care of closing / freeing the IO context.
1187 * Do NOT set this field if AVFMT_NOFILE flag is set in
1188 * iformat/oformat.flags. In such a case, the (de)muxer will handle
1189 * I/O in some other way and this field will be NULL.
1195 * Flags signalling stream properties. A combination of AVFMTCTX_*.
1196 * Set by libavformat.
1201 * Number of elements in AVFormatContext.streams.
1203 * Set by avformat_new_stream(), must not be modified by any other code.
1205 unsigned int nb_streams;
1207 * A list of all streams in the file. New streams are created with
1208 * avformat_new_stream().
1210 * - demuxing: streams are created by libavformat in avformat_open_input().
1211 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1212 * appear in av_read_frame().
1213 * - muxing: streams are created by the user before avformat_write_header().
1215 * Freed by libavformat in avformat_free_context().
1220 * input or output filename
1222 * - demuxing: set by avformat_open_input()
1223 * - muxing: may be set by the caller before avformat_write_header()
1225 char filename[1024];
1228 * Position of the first frame of the component, in
1229 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1230 * It is deduced from the AVStream values.
1232 * Demuxing only, set by libavformat.
1237 * Duration of the stream, in AV_TIME_BASE fractional
1238 * seconds. Only set this value if you know none of the individual stream
1239 * durations and also do not set any of them. This is deduced from the
1240 * AVStream values if not set.
1242 * Demuxing only, set by libavformat.
1247 * Total stream bitrate in bit/s, 0 if not
1248 * available. Never set it directly if the file_size and the
1249 * duration are known as FFmpeg can compute it automatically.
1253 unsigned int packet_size;
1257 * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1258 * Set by the user before avformat_open_input() / avformat_write_header().
1261 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1262 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1263 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1264 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1265 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1266 #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
1267 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1268 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1269 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1270 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1272 * When muxing, try to avoid writing any random/volatile data to the output.
1273 * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1275 * This flag is mainly intended for testing.
1277 #define AVFMT_FLAG_BITEXACT 0x0400
1278 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload
1279 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1280 #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)
1281 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Don't merge side data but keep it separate.
1284 * Maximum size of the data read from input for determining
1285 * the input container format.
1286 * Demuxing only, set by the caller before avformat_open_input().
1288 unsigned int probesize;
1291 * Maximum duration (in AV_TIME_BASE units) of the data read
1292 * from input in avformat_find_stream_info().
1293 * Demuxing only, set by the caller before avformat_find_stream_info().
1295 int max_analyze_duration;
1300 unsigned int nb_programs;
1301 AVProgram **programs;
1304 * Forced video codec_id.
1305 * Demuxing: Set by user.
1307 enum AVCodecID video_codec_id;
1310 * Forced audio codec_id.
1311 * Demuxing: Set by user.
1313 enum AVCodecID audio_codec_id;
1316 * Forced subtitle codec_id.
1317 * Demuxing: Set by user.
1319 enum AVCodecID subtitle_codec_id;
1322 * Maximum amount of memory in bytes to use for the index of each stream.
1323 * If the index exceeds this size, entries will be discarded as
1324 * needed to maintain a smaller size. This can lead to slower or less
1325 * accurate seeking (depends on demuxer).
1326 * Demuxers for which a full in-memory index is mandatory will ignore
1329 * - demuxing: set by user
1331 unsigned int max_index_size;
1334 * Maximum amount of memory in bytes to use for buffering frames
1335 * obtained from realtime capture devices.
1337 unsigned int max_picture_buffer;
1340 * Number of chapters in AVChapter array.
1341 * When muxing, chapters are normally written in the file header,
1342 * so nb_chapters should normally be initialized before write_header
1343 * is called. Some muxers (e.g. mov and mkv) can also write chapters
1344 * in the trailer. To write chapters in the trailer, nb_chapters
1345 * must be zero when write_header is called and non-zero when
1346 * write_trailer is called.
1347 * - muxing: set by user
1348 * - demuxing: set by libavformat
1350 unsigned int nb_chapters;
1351 AVChapter **chapters;
1354 * Metadata that applies to the whole file.
1356 * - demuxing: set by libavformat in avformat_open_input()
1357 * - muxing: may be set by the caller before avformat_write_header()
1359 * Freed by libavformat in avformat_free_context().
1361 AVDictionary *metadata;
1364 * Start time of the stream in real world time, in microseconds
1365 * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1366 * stream was captured at this real world time.
1367 * - muxing: Set by the caller before avformat_write_header(). If set to
1368 * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1370 * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1371 * the value may become known after some number of frames
1372 * have been received.
1374 int64_t start_time_realtime;
1377 * The number of frames used for determining the framerate in
1378 * avformat_find_stream_info().
1379 * Demuxing only, set by the caller before avformat_find_stream_info().
1384 * Error recognition; higher values will detect more errors but may
1385 * misdetect some more or less valid parts as errors.
1386 * Demuxing only, set by the caller before avformat_open_input().
1388 int error_recognition;
1391 * Custom interrupt callbacks for the I/O layer.
1393 * demuxing: set by the user before avformat_open_input().
1394 * muxing: set by the user before avformat_write_header()
1395 * (mainly useful for AVFMT_NOFILE formats). The callback
1396 * should also be passed to avio_open2() if it's used to
1399 AVIOInterruptCB interrupt_callback;
1402 * Flags to enable debugging.
1405 #define FF_FDEBUG_TS 0x0001
1408 * Maximum buffering duration for interleaving.
1410 * To ensure all the streams are interleaved correctly,
1411 * av_interleaved_write_frame() will wait until it has at least one packet
1412 * for each stream before actually writing any packets to the output file.
1413 * When some streams are "sparse" (i.e. there are large gaps between
1414 * successive packets), this can result in excessive buffering.
1416 * This field specifies the maximum difference between the timestamps of the
1417 * first and the last packet in the muxing queue, above which libavformat
1418 * will output a packet regardless of whether it has queued a packet for all
1421 * Muxing only, set by the caller before avformat_write_header().
1423 int64_t max_interleave_delta;
1426 * Transport stream id.
1427 * This will be moved into demuxer private options. Thus no API/ABI compatibility
1432 * Audio preload in microseconds.
1433 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1434 * - encoding: Set by user via AVOptions (NO direct access)
1435 * - decoding: unused
1440 * Max chunk time in microseconds.
1441 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1442 * - encoding: Set by user via AVOptions (NO direct access)
1443 * - decoding: unused
1445 int max_chunk_duration;
1448 * Max chunk size in bytes
1449 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1450 * - encoding: Set by user via AVOptions (NO direct access)
1451 * - decoding: unused
1456 * forces the use of wallclock timestamps as pts/dts of packets
1457 * This has undefined results in the presence of B frames.
1458 * - encoding: unused
1459 * - decoding: Set by user via AVOptions (NO direct access)
1461 int use_wallclock_as_timestamps;
1464 * Avoid negative timestamps during muxing.
1465 * 0 -> allow negative timestamps
1466 * 1 -> avoid negative timestamps
1467 * -1 -> choose automatically (default)
1468 * Note, this only works when interleave_packet_per_dts is in use.
1469 * - encoding: Set by user via AVOptions (NO direct access)
1470 * - decoding: unused
1472 int avoid_negative_ts;
1475 * avio flags, used to force AVIO_FLAG_DIRECT.
1476 * - encoding: unused
1477 * - decoding: Set by user via AVOptions (NO direct access)
1482 * The duration field can be estimated through various ways, and this field can be used
1483 * to know how the duration was estimated.
1484 * - encoding: unused
1485 * - decoding: Read by user via AVOptions (NO direct access)
1487 enum AVDurationEstimationMethod duration_estimation_method;
1490 * Skip initial bytes when opening stream
1491 * - encoding: unused
1492 * - decoding: Set by user via AVOptions (NO direct access)
1494 unsigned int skip_initial_bytes;
1497 * Correct single timestamp overflows
1498 * - encoding: unused
1499 * - decoding: Set by user via AVOptions (NO direct access)
1501 unsigned int correct_ts_overflow;
1504 * Force seeking to any (also non key) frames.
1505 * - encoding: unused
1506 * - decoding: Set by user via AVOptions (NO direct access)
1511 * Flush the I/O context after each packet.
1512 * - encoding: Set by user via AVOptions (NO direct access)
1513 * - decoding: unused
1518 * format probing score.
1519 * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1521 * - encoding: unused
1522 * - decoding: set by avformat, read by user via av_format_get_probe_score() (NO direct access)
1527 * number of bytes to read maximally to identify format.
1528 * - encoding: unused
1529 * - decoding: set by user through AVOPtions (NO direct access)
1531 int format_probesize;
1533 /*****************************************************************
1534 * All fields below this line are not part of the public API. They
1535 * may not be used outside of libavformat and can be changed and
1537 * New public fields should be added right above.
1538 *****************************************************************
1542 * This buffer is only needed when packets were already buffered but
1543 * not decoded, for example to get the codec parameters in MPEG
1546 struct AVPacketList *packet_buffer;
1547 struct AVPacketList *packet_buffer_end;
1549 /* av_seek_frame() support */
1550 int64_t data_offset; /**< offset of the first packet */
1553 * Raw packets from the demuxer, prior to parsing and decoding.
1554 * This buffer is used for buffering packets until the codec can
1555 * be identified, as parsing cannot be done without knowing the
1558 struct AVPacketList *raw_packet_buffer;
1559 struct AVPacketList *raw_packet_buffer_end;
1561 * Packets split by the parser get queued here.
1563 struct AVPacketList *parse_queue;
1564 struct AVPacketList *parse_queue_end;
1566 * Remaining size available for raw_packet_buffer, in bytes.
1568 #define RAW_PACKET_BUFFER_SIZE 2500000
1569 int raw_packet_buffer_remaining_size;
1572 * Offset to remap timestamps to be non-negative.
1573 * Expressed in timebase units.
1574 * @see AVStream.mux_ts_offset
1579 * Timebase for the timestamp offset.
1581 AVRational offset_timebase;
1584 * An opaque field for libavformat internal usage.
1585 * Must not be accessed in any way by callers.
1587 AVFormatInternal *internal;
1590 * IO repositioned flag.
1591 * This is set by avformat when the underlaying IO context read pointer
1592 * is repositioned, for example when doing byte based seeking.
1593 * Demuxers can use the flag to detect such changes.
1595 int io_repositioned;
1598 * Forced video codec.
1599 * This allows forcing a specific decoder, even when there are multiple with
1600 * the same codec_id.
1601 * Demuxing: Set by user via av_format_set_video_codec (NO direct access).
1603 AVCodec *video_codec;
1606 * Forced audio codec.
1607 * This allows forcing a specific decoder, even when there are multiple with
1608 * the same codec_id.
1609 * Demuxing: Set by user via av_format_set_audio_codec (NO direct access).
1611 AVCodec *audio_codec;
1614 * Forced subtitle codec.
1615 * This allows forcing a specific decoder, even when there are multiple with
1616 * the same codec_id.
1617 * Demuxing: Set by user via av_format_set_subtitle_codec (NO direct access).
1619 AVCodec *subtitle_codec;
1622 * Number of bytes to be written as padding in a metadata header.
1624 * Muxing: Set by user via av_format_set_metadata_header_padding.
1626 int metadata_header_padding;
1630 * This is a place for some private data of the user.
1631 * Mostly usable with control_message_cb or any future callbacks in device's context.
1636 * Callback used by devices to communicate with application.
1638 av_format_control_message control_message_cb;
1641 * Output timestamp offset, in microseconds.
1642 * Muxing: set by user via AVOptions (NO direct access)
1644 int64_t output_ts_offset;
1647 int av_format_get_probe_score(const AVFormatContext *s);
1648 AVCodec * av_format_get_video_codec(const AVFormatContext *s);
1649 void av_format_set_video_codec(AVFormatContext *s, AVCodec *c);
1650 AVCodec * av_format_get_audio_codec(const AVFormatContext *s);
1651 void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c);
1652 AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s);
1653 void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c);
1654 int av_format_get_metadata_header_padding(const AVFormatContext *s);
1655 void av_format_set_metadata_header_padding(AVFormatContext *s, int c);
1656 void * av_format_get_opaque(const AVFormatContext *s);
1657 void av_format_set_opaque(AVFormatContext *s, void *opaque);
1658 av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s);
1659 void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback);
1662 * This function will cause global side data to be injected in the next packet
1663 * of each stream as well as after any subsequent seek.
1665 void av_format_inject_global_side_data(AVFormatContext *s);
1668 * Returns the method used to set ctx->duration.
1670 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1672 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
1674 typedef struct AVPacketList {
1676 struct AVPacketList *next;
1681 * @defgroup lavf_core Core functions
1684 * Functions for querying libavformat capabilities, allocating core structures,
1690 * Return the LIBAVFORMAT_VERSION_INT constant.
1692 unsigned avformat_version(void);
1695 * Return the libavformat build-time configuration.
1697 const char *avformat_configuration(void);
1700 * Return the libavformat license.
1702 const char *avformat_license(void);
1705 * Initialize libavformat and register all the muxers, demuxers and
1706 * protocols. If you do not call this function, then you can select
1707 * exactly which formats you want to support.
1709 * @see av_register_input_format()
1710 * @see av_register_output_format()
1712 void av_register_all(void);
1714 void av_register_input_format(AVInputFormat *format);
1715 void av_register_output_format(AVOutputFormat *format);
1718 * Do global initialization of network components. This is optional,
1719 * but recommended, since it avoids the overhead of implicitly
1720 * doing the setup for each session.
1722 * Calling this function will become mandatory if using network
1723 * protocols at some major version bump.
1725 int avformat_network_init(void);
1728 * Undo the initialization done by avformat_network_init.
1730 int avformat_network_deinit(void);
1733 * If f is NULL, returns the first registered input format,
1734 * if f is non-NULL, returns the next registered input format after f
1735 * or NULL if f is the last one.
1737 AVInputFormat *av_iformat_next(AVInputFormat *f);
1740 * If f is NULL, returns the first registered output format,
1741 * if f is non-NULL, returns the next registered output format after f
1742 * or NULL if f is the last one.
1744 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1747 * Allocate an AVFormatContext.
1748 * avformat_free_context() can be used to free the context and everything
1749 * allocated by the framework within it.
1751 AVFormatContext *avformat_alloc_context(void);
1754 * Free an AVFormatContext and all its streams.
1755 * @param s context to free
1757 void avformat_free_context(AVFormatContext *s);
1760 * Get the AVClass for AVFormatContext. It can be used in combination with
1761 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1763 * @see av_opt_find().
1765 const AVClass *avformat_get_class(void);
1768 * Add a new stream to a media file.
1770 * When demuxing, it is called by the demuxer in read_header(). If the
1771 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1772 * be called in read_packet().
1774 * When muxing, should be called by the user before avformat_write_header().
1776 * User is required to call avcodec_close() and avformat_free_context() to
1777 * clean up the allocation by avformat_new_stream().
1779 * @param s media file handle
1780 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1781 * will be initialized to use this codec. This is needed for e.g. codec-specific
1782 * defaults to be set, so codec should be provided if it is known.
1784 * @return newly created stream or NULL on error.
1786 AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c);
1789 * Get side information from stream.
1791 * @param stream stream
1792 * @param type desired side information type
1793 * @param size pointer for side information size to store (optional)
1794 * @return pointer to data if present or NULL otherwise
1796 uint8_t *av_stream_get_side_data(AVStream *stream,
1797 enum AVPacketSideDataType type, int *size);
1799 AVProgram *av_new_program(AVFormatContext *s, int id);
1806 #if FF_API_ALLOC_OUTPUT_CONTEXT
1808 * @deprecated deprecated in favor of avformat_alloc_output_context2()
1810 attribute_deprecated
1811 AVFormatContext *avformat_alloc_output_context(const char *format,
1812 AVOutputFormat *oformat,
1813 const char *filename);
1817 * Allocate an AVFormatContext for an output format.
1818 * avformat_free_context() can be used to free the context and
1819 * everything allocated by the framework within it.
1821 * @param *ctx is set to the created format context, or to NULL in
1823 * @param oformat format to use for allocating the context, if NULL
1824 * format_name and filename are used instead
1825 * @param format_name the name of output format to use for allocating the
1826 * context, if NULL filename is used instead
1827 * @param filename the name of the filename to use for allocating the
1828 * context, may be NULL
1829 * @return >= 0 in case of success, a negative AVERROR code in case of
1832 int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat,
1833 const char *format_name, const char *filename);
1836 * @addtogroup lavf_decoding
1841 * Find AVInputFormat based on the short name of the input format.
1843 AVInputFormat *av_find_input_format(const char *short_name);
1846 * Guess the file format.
1848 * @param pd data to be probed
1849 * @param is_opened Whether the file is already opened; determines whether
1850 * demuxers with or without AVFMT_NOFILE are probed.
1852 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1855 * Guess the file format.
1857 * @param pd data to be probed
1858 * @param is_opened Whether the file is already opened; determines whether
1859 * demuxers with or without AVFMT_NOFILE are probed.
1860 * @param score_max A probe score larger that this is required to accept a
1861 * detection, the variable is set to the actual detection
1863 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1864 * to retry with a larger probe buffer.
1866 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1869 * Guess the file format.
1871 * @param is_opened Whether the file is already opened; determines whether
1872 * demuxers with or without AVFMT_NOFILE are probed.
1873 * @param score_ret The score of the best detection.
1875 AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
1878 * Probe a bytestream to determine the input format. Each time a probe returns
1879 * with a score that is too low, the probe buffer size is increased and another
1880 * attempt is made. When the maximum probe size is reached, the input format
1881 * with the highest score is returned.
1883 * @param pb the bytestream to probe
1884 * @param fmt the input format is put here
1885 * @param filename the filename of the stream
1886 * @param logctx the log context
1887 * @param offset the offset within the bytestream to probe from
1888 * @param max_probe_size the maximum probe buffer size (zero for default)
1889 * @return the score in case of success, a negative value corresponding to an
1890 * the maximal score is AVPROBE_SCORE_MAX
1891 * AVERROR code otherwise
1893 int av_probe_input_buffer2(AVIOContext *pb, AVInputFormat **fmt,
1894 const char *filename, void *logctx,
1895 unsigned int offset, unsigned int max_probe_size);
1898 * Like av_probe_input_buffer2() but returns 0 on success
1900 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1901 const char *filename, void *logctx,
1902 unsigned int offset, unsigned int max_probe_size);
1905 * Open an input stream and read the header. The codecs are not opened.
1906 * The stream must be closed with avformat_close_input().
1908 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1909 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1910 * function and written into ps.
1911 * Note that a user-supplied AVFormatContext will be freed on failure.
1912 * @param filename Name of the stream to open.
1913 * @param fmt If non-NULL, this parameter forces a specific input format.
1914 * Otherwise the format is autodetected.
1915 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1916 * On return this parameter will be destroyed and replaced with a dict containing
1917 * options that were not found. May be NULL.
1919 * @return 0 on success, a negative AVERROR on failure.
1921 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1923 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1925 attribute_deprecated
1926 int av_demuxer_open(AVFormatContext *ic);
1928 #if FF_API_FORMAT_PARAMETERS
1930 * Read packets of a media file to get stream information. This
1931 * is useful for file formats with no headers such as MPEG. This
1932 * function also computes the real framerate in case of MPEG-2 repeat
1934 * The logical file position is not changed by this function;
1935 * examined packets may be buffered for later processing.
1937 * @param ic media file handle
1938 * @return >=0 if OK, AVERROR_xxx on error
1939 * @todo Let the user decide somehow what information is needed so that
1940 * we do not waste time getting stuff the user does not need.
1942 * @deprecated use avformat_find_stream_info.
1944 attribute_deprecated
1945 int av_find_stream_info(AVFormatContext *ic);
1949 * Read packets of a media file to get stream information. This
1950 * is useful for file formats with no headers such as MPEG. This
1951 * function also computes the real framerate in case of MPEG-2 repeat
1953 * The logical file position is not changed by this function;
1954 * examined packets may be buffered for later processing.
1956 * @param ic media file handle
1957 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1958 * dictionaries, where i-th member contains options for
1959 * codec corresponding to i-th stream.
1960 * On return each dictionary will be filled with options that were not found.
1961 * @return >=0 if OK, AVERROR_xxx on error
1963 * @note this function isn't guaranteed to open all the codecs, so
1964 * options being non-empty at return is a perfectly normal behavior.
1966 * @todo Let the user decide somehow what information is needed so that
1967 * we do not waste time getting stuff the user does not need.
1969 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1972 * Find the programs which belong to a given stream.
1974 * @param ic media file handle
1975 * @param last the last found program, the search will start after this
1976 * program, or from the beginning if it is NULL
1977 * @param s stream index
1978 * @return the next program which belongs to s, NULL if no program is found or
1979 * the last program is not among the programs of ic.
1981 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s);
1984 * Find the "best" stream in the file.
1985 * The best stream is determined according to various heuristics as the most
1986 * likely to be what the user expects.
1987 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1988 * default decoder for the stream's codec; streams for which no decoder can
1989 * be found are ignored.
1991 * @param ic media file handle
1992 * @param type stream type: video, audio, subtitles, etc.
1993 * @param wanted_stream_nb user-requested stream number,
1994 * or -1 for automatic selection
1995 * @param related_stream try to find a stream related (eg. in the same
1996 * program) to this one, or -1 if none
1997 * @param decoder_ret if non-NULL, returns the decoder for the
1999 * @param flags flags; none are currently defined
2000 * @return the non-negative stream number in case of success,
2001 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2003 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2004 * @note If av_find_best_stream returns successfully and decoder_ret is not
2005 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2007 int av_find_best_stream(AVFormatContext *ic,
2008 enum AVMediaType type,
2009 int wanted_stream_nb,
2011 AVCodec **decoder_ret,
2014 #if FF_API_READ_PACKET
2016 * @deprecated use AVFMT_FLAG_NOFILLIN | AVFMT_FLAG_NOPARSE to read raw
2017 * unprocessed packets
2019 * Read a transport packet from a media file.
2021 * This function is obsolete and should never be used.
2022 * Use av_read_frame() instead.
2024 * @param s media file handle
2025 * @param pkt is filled
2026 * @return 0 if OK, AVERROR_xxx on error
2028 attribute_deprecated
2029 int av_read_packet(AVFormatContext *s, AVPacket *pkt);
2033 * Return the next frame of a stream.
2034 * This function returns what is stored in the file, and does not validate
2035 * that what is there are valid frames for the decoder. It will split what is
2036 * stored in the file into frames and return one for each call. It will not
2037 * omit invalid data between valid frames so as to give the decoder the maximum
2038 * information possible for decoding.
2040 * If pkt->buf is NULL, then the packet is valid until the next
2041 * av_read_frame() or until avformat_close_input(). Otherwise the packet
2042 * is valid indefinitely. In both cases the packet must be freed with
2043 * av_free_packet when it is no longer needed. For video, the packet contains
2044 * exactly one frame. For audio, it contains an integer number of frames if each
2045 * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
2046 * have a variable size (e.g. MPEG audio), then it contains one frame.
2048 * pkt->pts, pkt->dts and pkt->duration are always set to correct
2049 * values in AVStream.time_base units (and guessed if the format cannot
2050 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2051 * has B-frames, so it is better to rely on pkt->dts if you do not
2052 * decompress the payload.
2054 * @return 0 if OK, < 0 on error or end of file
2056 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
2059 * Seek to the keyframe at timestamp.
2060 * 'timestamp' in 'stream_index'.
2062 * @param s media file handle
2063 * @param stream_index If stream_index is (-1), a default
2064 * stream is selected, and timestamp is automatically converted
2065 * from AV_TIME_BASE units to the stream specific time_base.
2066 * @param timestamp Timestamp in AVStream.time_base units
2067 * or, if no stream is specified, in AV_TIME_BASE units.
2068 * @param flags flags which select direction and seeking mode
2069 * @return >= 0 on success
2071 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2075 * Seek to timestamp ts.
2076 * Seeking will be done so that the point from which all active streams
2077 * can be presented successfully will be closest to ts and within min/max_ts.
2078 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2080 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2081 * are the file position (this may not be supported by all demuxers).
2082 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2083 * in the stream with stream_index (this may not be supported by all demuxers).
2084 * Otherwise all timestamps are in units of the stream selected by stream_index
2085 * or if stream_index is -1, in AV_TIME_BASE units.
2086 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2087 * keyframes (this may not be supported by all demuxers).
2088 * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2090 * @param s media file handle
2091 * @param stream_index index of the stream which is used as time base reference
2092 * @param min_ts smallest acceptable timestamp
2093 * @param ts target timestamp
2094 * @param max_ts largest acceptable timestamp
2095 * @param flags flags
2096 * @return >=0 on success, error code otherwise
2098 * @note This is part of the new seek API which is still under construction.
2099 * Thus do not use this yet. It may change at any time, do not expect
2100 * ABI compatibility yet!
2102 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2105 * Start playing a network-based stream (e.g. RTSP stream) at the
2108 int av_read_play(AVFormatContext *s);
2111 * Pause a network-based stream (e.g. RTSP stream).
2113 * Use av_read_play() to resume it.
2115 int av_read_pause(AVFormatContext *s);
2117 #if FF_API_CLOSE_INPUT_FILE
2119 * @deprecated use avformat_close_input()
2120 * Close a media file (but not its codecs).
2122 * @param s media file handle
2124 attribute_deprecated
2125 void av_close_input_file(AVFormatContext *s);
2129 * Close an opened input AVFormatContext. Free it and all its contents
2130 * and set *s to NULL.
2132 void avformat_close_input(AVFormatContext **s);
2137 #if FF_API_NEW_STREAM
2139 * Add a new stream to a media file.
2141 * Can only be called in the read_header() function. If the flag
2142 * AVFMTCTX_NOHEADER is in the format context, then new streams
2143 * can be added in read_packet too.
2145 * @param s media file handle
2146 * @param id file-format-dependent stream ID
2148 attribute_deprecated
2149 AVStream *av_new_stream(AVFormatContext *s, int id);
2152 #if FF_API_SET_PTS_INFO
2154 * @deprecated this function is not supposed to be called outside of lavf
2156 attribute_deprecated
2157 void av_set_pts_info(AVStream *s, int pts_wrap_bits,
2158 unsigned int pts_num, unsigned int pts_den);
2161 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2162 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2163 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2164 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2167 * @addtogroup lavf_encoding
2171 * Allocate the stream private data and write the stream header to
2172 * an output media file.
2174 * @param s Media file handle, must be allocated with avformat_alloc_context().
2175 * Its oformat field must be set to the desired output format;
2176 * Its pb field must be set to an already opened AVIOContext.
2177 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2178 * On return this parameter will be destroyed and replaced with a dict containing
2179 * options that were not found. May be NULL.
2181 * @return 0 on success, negative AVERROR on failure.
2183 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
2185 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
2188 * Write a packet to an output media file.
2190 * This function passes the packet directly to the muxer, without any buffering
2191 * or reordering. The caller is responsible for correctly interleaving the
2192 * packets if the format requires it. Callers that want libavformat to handle
2193 * the interleaving should call av_interleaved_write_frame() instead of this
2196 * @param s media file handle
2197 * @param pkt The packet containing the data to be written. Note that unlike
2198 * av_interleaved_write_frame(), this function does not take
2199 * ownership of the packet passed to it (though some muxers may make
2200 * an internal reference to the input packet).
2202 * This parameter can be NULL (at any time, not just at the end), in
2203 * order to immediately flush data buffered within the muxer, for
2204 * muxers that buffer up data internally before writing it to the
2207 * Packet's @ref AVPacket.stream_index "stream_index" field must be
2208 * set to the index of the corresponding stream in @ref
2209 * AVFormatContext.streams "s->streams". It is very strongly
2210 * recommended that timing information (@ref AVPacket.pts "pts", @ref
2211 * AVPacket.dts "dts", @ref AVPacket.duration "duration") is set to
2213 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2215 * @see av_interleaved_write_frame()
2217 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
2220 * Write a packet to an output media file ensuring correct interleaving.
2222 * This function will buffer the packets internally as needed to make sure the
2223 * packets in the output file are properly interleaved in the order of
2224 * increasing dts. Callers doing their own interleaving should call
2225 * av_write_frame() instead of this function.
2227 * @param s media file handle
2228 * @param pkt The packet containing the data to be written.
2230 * If the packet is reference-counted, this function will take
2231 * ownership of this reference and unreference it later when it sees
2233 * The caller must not access the data through this reference after
2234 * this function returns. If the packet is not reference-counted,
2235 * libavformat will make a copy.
2237 * This parameter can be NULL (at any time, not just at the end), to
2238 * flush the interleaving queues.
2240 * Packet's @ref AVPacket.stream_index "stream_index" field must be
2241 * set to the index of the corresponding stream in @ref
2242 * AVFormatContext.streams "s->streams". It is very strongly
2243 * recommended that timing information (@ref AVPacket.pts "pts", @ref
2244 * AVPacket.dts "dts", @ref AVPacket.duration "duration") is set to
2247 * @return 0 on success, a negative AVERROR on error. Libavformat will always
2248 * take care of freeing the packet, even if this function fails.
2250 * @see av_write_frame(), AVFormatContext.max_interleave_delta
2252 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
2255 * Write a uncoded frame to an output media file.
2257 * The frame must be correctly interleaved according to the container
2258 * specification; if not, then av_interleaved_write_frame() must be used.
2260 * See av_interleaved_write_frame() for details.
2262 int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2266 * Write a uncoded frame to an output media file.
2268 * If the muxer supports it, this function allows to write an AVFrame
2269 * structure directly, without encoding it into a packet.
2270 * It is mostly useful for devices and similar special muxers that use raw
2271 * video or PCM data and will not serialize it into a byte stream.
2273 * To test whether it is possible to use it with a given muxer and stream,
2274 * use av_write_uncoded_frame_query().
2276 * The caller gives up ownership of the frame and must not access it
2279 * @return >=0 for success, a negative code on error
2281 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
2285 * Test whether a muxer supports uncoded frame.
2287 * @return >=0 if an uncoded frame can be written to that muxer and stream,
2290 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2293 * Write the stream trailer to an output media file and free the
2294 * file private data.
2296 * May only be called after a successful call to avformat_write_header.
2298 * @param s media file handle
2299 * @return 0 if OK, AVERROR_xxx on error
2301 int av_write_trailer(AVFormatContext *s);
2304 * Return the output format in the list of registered output formats
2305 * which best matches the provided parameters, or return NULL if
2306 * there is no match.
2308 * @param short_name if non-NULL checks if short_name matches with the
2309 * names of the registered formats
2310 * @param filename if non-NULL checks if filename terminates with the
2311 * extensions of the registered formats
2312 * @param mime_type if non-NULL checks if mime_type matches with the
2313 * MIME type of the registered formats
2315 AVOutputFormat *av_guess_format(const char *short_name,
2316 const char *filename,
2317 const char *mime_type);
2320 * Guess the codec ID based upon muxer and filename.
2322 enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
2323 const char *filename, const char *mime_type,
2324 enum AVMediaType type);
2327 * Get timing information for the data currently output.
2328 * The exact meaning of "currently output" depends on the format.
2329 * It is mostly relevant for devices that have an internal buffer and/or
2330 * work in real time.
2331 * @param s media file handle
2332 * @param stream stream in the media file
2333 * @param[out] dts DTS of the last packet output for the stream, in stream
2335 * @param[out] wall absolute time when that packet whas output,
2337 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
2338 * Note: some formats or devices may not allow to measure dts and wall
2341 int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2342 int64_t *dts, int64_t *wall);
2351 * @defgroup lavf_misc Utility functions
2355 * Miscellaneous utility functions related to both muxing and demuxing
2360 * Send a nice hexadecimal dump of a buffer to the specified file stream.
2362 * @param f The file stream pointer where the dump should be sent to.
2364 * @param size buffer size
2366 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2368 void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2371 * Send a nice hexadecimal dump of a buffer to the log.
2373 * @param avcl A pointer to an arbitrary struct of which the first field is a
2374 * pointer to an AVClass struct.
2375 * @param level The importance level of the message, lower values signifying
2376 * higher importance.
2378 * @param size buffer size
2380 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2382 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2385 * Send a nice dump of a packet to the specified file stream.
2387 * @param f The file stream pointer where the dump should be sent to.
2388 * @param pkt packet to dump
2389 * @param dump_payload True if the payload must be displayed, too.
2390 * @param st AVStream that the packet belongs to
2392 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2396 * Send a nice dump of a packet to the log.
2398 * @param avcl A pointer to an arbitrary struct of which the first field is a
2399 * pointer to an AVClass struct.
2400 * @param level The importance level of the message, lower values signifying
2401 * higher importance.
2402 * @param pkt packet to dump
2403 * @param dump_payload True if the payload must be displayed, too.
2404 * @param st AVStream that the packet belongs to
2406 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2407 const AVStream *st);
2410 * Get the AVCodecID for the given codec tag tag.
2411 * If no codec id is found returns AV_CODEC_ID_NONE.
2413 * @param tags list of supported codec_id-codec_tag pairs, as stored
2414 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2415 * @param tag codec tag to match to a codec ID
2417 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2420 * Get the codec tag for the given codec id id.
2421 * If no codec tag is found returns 0.
2423 * @param tags list of supported codec_id-codec_tag pairs, as stored
2424 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2425 * @param id codec ID to match to a codec tag
2427 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2430 * Get the codec tag for the given codec id.
2432 * @param tags list of supported codec_id - codec_tag pairs, as stored
2433 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2434 * @param id codec id that should be searched for in the list
2435 * @param tag A pointer to the found tag
2436 * @return 0 if id was not found in tags, > 0 if it was found
2438 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2441 int av_find_default_stream_index(AVFormatContext *s);
2444 * Get the index for a specific timestamp.
2446 * @param st stream that the timestamp belongs to
2447 * @param timestamp timestamp to retrieve the index for
2448 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2449 * to the timestamp which is <= the requested one, if backward
2450 * is 0, then it will be >=
2451 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2452 * @return < 0 if no such timestamp could be found
2454 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2457 * Add an index entry into a sorted list. Update the entry if the list
2458 * already contains it.
2460 * @param timestamp timestamp in the time base of the given stream
2462 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2463 int size, int distance, int flags);
2467 * Split a URL string into components.
2469 * The pointers to buffers for storing individual components may be null,
2470 * in order to ignore that component. Buffers for components not found are
2471 * set to empty strings. If the port is not found, it is set to a negative
2474 * @param proto the buffer for the protocol
2475 * @param proto_size the size of the proto buffer
2476 * @param authorization the buffer for the authorization
2477 * @param authorization_size the size of the authorization buffer
2478 * @param hostname the buffer for the host name
2479 * @param hostname_size the size of the hostname buffer
2480 * @param port_ptr a pointer to store the port number in
2481 * @param path the buffer for the path
2482 * @param path_size the size of the path buffer
2483 * @param url the URL to split
2485 void av_url_split(char *proto, int proto_size,
2486 char *authorization, int authorization_size,
2487 char *hostname, int hostname_size,
2489 char *path, int path_size,
2493 * log a nice Dump of input format context or output format context
2494 * @param ic already initialized Format Context, must not be NULL.
2495 * @param index index of the stream to dump information about
2496 * @param url name of file or URL of stream to print information about
2497 * @param is_output Select whether specified context is of input(0) or output(1)
2499 void av_dump_format(AVFormatContext *ic,
2505 * Return in 'buf' the path with '%d' replaced by a number.
2507 * Also handles the '%0nd' format where 'n' is the total number
2508 * of digits and '%%'.
2510 * @param buf destination buffer
2511 * @param buf_size destination buffer size
2512 * @param path numbered sequence string
2513 * @param number frame number
2514 * @return 0 if OK, -1 on format error
2516 int av_get_frame_filename(char *buf, int buf_size,
2517 const char *path, int number);
2520 * Check whether filename actually is a numbered sequence generator.
2522 * @param filename possible numbered sequence string
2523 * @return 1 if a valid numbered sequence string, 0 otherwise
2525 int av_filename_number_test(const char *filename);
2528 * Generate an SDP for an RTP session.
2530 * Note, this overwrites the id values of AVStreams in the muxer contexts
2531 * for getting unique dynamic payload types.
2533 * @param ac array of AVFormatContexts describing the RTP streams. If the
2534 * array is composed by only one context, such context can contain
2535 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2536 * all the contexts in the array (an AVCodecContext per RTP stream)
2537 * must contain only one AVStream.
2538 * @param n_files number of AVCodecContexts contained in ac
2539 * @param buf buffer where the SDP will be stored (must be allocated by
2541 * @param size the size of the buffer
2542 * @return 0 if OK, AVERROR_xxx on error
2544 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2547 * Return a positive value if the given filename has one of the given
2548 * extensions, 0 otherwise.
2550 * @param filename file name to check against the given extensions
2551 * @param extensions a comma-separated list of filename extensions
2553 int av_match_ext(const char *filename, const char *extensions);
2556 * Test if the given container can store a codec.
2558 * @param ofmt container to check for compatibility
2559 * @param codec_id codec to potentially store in container
2560 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2562 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2563 * A negative number if this information is not available.
2565 int avformat_query_codec(AVOutputFormat *ofmt, enum AVCodecID codec_id, int std_compliance);
2568 * @defgroup riff_fourcc RIFF FourCCs
2570 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2571 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2574 * uint32_t tag = MKTAG('H', '2', '6', '4');
2575 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2576 * enum AVCodecID id = av_codec_get_id(table, tag);
2580 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2582 const struct AVCodecTag *avformat_get_riff_video_tags(void);
2584 * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2586 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2588 * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2590 const struct AVCodecTag *avformat_get_mov_video_tags(void);
2592 * @return the table mapping MOV FourCCs for audio to AVCodecID.
2594 const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2601 * Guess the sample aspect ratio of a frame, based on both the stream and the
2602 * frame aspect ratio.
2604 * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2605 * is set by the demuxer, these two may not be equal. This function tries to
2606 * return the value that you should use if you would like to display the frame.
2608 * Basic logic is to use the stream aspect ratio if it is set to something sane
2609 * otherwise use the frame aspect ratio. This way a container setting, which is
2610 * usually easy to modify can override the coded value in the frames.
2612 * @param format the format context which the stream is part of
2613 * @param stream the stream which the frame is part of
2614 * @param frame the frame with the aspect ratio to be determined
2615 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2617 AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame);
2620 * Guess the frame rate, based on both the container and codec information.
2622 * @param ctx the format context which the stream is part of
2623 * @param stream the stream which the frame is part of
2624 * @param frame the frame for which the frame rate should be determined, may be NULL
2625 * @return the guessed (valid) frame rate, 0/1 if no idea
2627 AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame);
2630 * Check if the stream st contained in s is matched by the stream specifier
2633 * See the "stream specifiers" chapter in the documentation for the syntax
2636 * @return >0 if st is matched by spec;
2637 * 0 if st is not matched by spec;
2638 * AVERROR code if spec is invalid
2640 * @note A stream specifier can match several streams in the format.
2642 int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st,
2645 int avformat_queue_attached_pictures(AVFormatContext *s);
2652 #endif /* AVFORMAT_AVFORMAT_H */