Imported Debian version 2.5.2~trusty
[deb_ffmpeg.git] / ffmpeg / libavformat / avformat.h
... / ...
CommitLineData
1/*
2 * copyright (c) 2001 Fabrice Bellard
3 *
4 * This file is part of FFmpeg.
5 *
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.
10 *
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.
15 *
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
19 */
20
21#ifndef AVFORMAT_AVFORMAT_H
22#define AVFORMAT_AVFORMAT_H
23
24/**
25 * @file
26 * @ingroup libavf
27 * Main libavformat public API header
28 */
29
30/**
31 * @defgroup libavf I/O and Muxing/Demuxing Library
32 * @{
33 *
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().
43 *
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.
50 *
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).
57 *
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).
68 *
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.
80 *
81 * @defgroup lavf_decoding Demuxing
82 * @{
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
88 * cleanup.
89 *
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:
93 * @code
94 * const char *url = "in.mp3";
95 * AVFormatContext *s = NULL;
96 * int ret = avformat_open_input(&s, url, NULL, NULL);
97 * if (ret < 0)
98 * abort();
99 * @endcode
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.
106 *
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.
114 *
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:
119 * @code
120 * AVDictionary *options = NULL;
121 * av_dict_set(&options, "video_size", "640x480", 0);
122 * av_dict_set(&options, "pixel_format", "rgb24", 0);
123 *
124 * if (avformat_open_input(&s, url, NULL, &options) < 0)
125 * abort();
126 * av_dict_free(&options);
127 * @endcode
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
135 * wishes, e.g.
136 * @code
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);
140 * abort();
141 * }
142 * @endcode
143 *
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.
146 *
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.
154 *
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.
160 *
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
167 * of it.
168 * In both cases, the packet must be freed with av_free_packet() when it is no
169 * longer needed.
170 *
171 * @section lavf_decoding_seek Seeking
172 * @}
173 *
174 * @defgroup lavf_encoding Muxing
175 * @{
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.
178 *
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.
182 *
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:
186 *
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 AVStream.time_base "stream 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
200 * described later).
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
207 * support.
208 *
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.
214 *
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
222 * requested by the caller.
223 *
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().
228 * @}
229 *
230 * @defgroup lavf_io I/O Read/Write
231 * @{
232 * @}
233 *
234 * @defgroup lavf_codec Demuxers
235 * @{
236 * @defgroup lavf_codec_native Native Demuxers
237 * @{
238 * @}
239 * @defgroup lavf_codec_wrappers External library wrappers
240 * @{
241 * @}
242 * @}
243 * @defgroup lavf_protos I/O Protocols
244 * @{
245 * @}
246 * @defgroup lavf_internal Internal
247 * @{
248 * @}
249 * @}
250 *
251 */
252
253#include <time.h>
254#include <stdio.h> /* FILE */
255#include "libavcodec/avcodec.h"
256#include "libavutil/dict.h"
257#include "libavutil/log.h"
258
259#include "avio.h"
260#include "libavformat/version.h"
261
262struct AVFormatContext;
263
264struct AVDeviceInfoList;
265struct AVDeviceCapabilitiesQuery;
266
267/**
268 * @defgroup metadata_api Public Metadata API
269 * @{
270 * @ingroup libavf
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.
274 *
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.
280 *
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".
301 * - Some protocols and demuxers support metadata updates. After a successful
302 * call to av_read_packet(), AVFormatContext.event_flags or AVStream.event_flags
303 * will be updated to indicate if metadata changed. In order to detect metadata
304 * changes on a stream, you need to loop through all streams in the AVFormatContext
305 * and check their individual event_flags.
306 *
307 * - Demuxers attempt to export metadata in a generic format, however tags
308 * with no generic equivalents are left as they are stored in the container.
309 * Follows a list of generic tag names:
310 *
311 @verbatim
312 album -- name of the set this work belongs to
313 album_artist -- main creator of the set/album, if different from artist.
314 e.g. "Various Artists" for compilation albums.
315 artist -- main creator of the work
316 comment -- any additional description of the file.
317 composer -- who composed the work, if different from artist.
318 copyright -- name of copyright holder.
319 creation_time-- date when the file was created, preferably in ISO 8601.
320 date -- date when the work was created, preferably in ISO 8601.
321 disc -- number of a subset, e.g. disc in a multi-disc collection.
322 encoder -- name/settings of the software/hardware that produced the file.
323 encoded_by -- person/group who created the file.
324 filename -- original name of the file.
325 genre -- <self-evident>.
326 language -- main language in which the work is performed, preferably
327 in ISO 639-2 format. Multiple languages can be specified by
328 separating them with commas.
329 performer -- artist who performed the work, if different from artist.
330 E.g for "Also sprach Zarathustra", artist would be "Richard
331 Strauss" and performer "London Philharmonic Orchestra".
332 publisher -- name of the label/publisher.
333 service_name -- name of the service in broadcasting (channel name).
334 service_provider -- name of the service provider in broadcasting.
335 title -- name of the work.
336 track -- number of this work in the set, can be in form current/total.
337 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
338 @endverbatim
339 *
340 * Look in the examples section for an application example how to use the Metadata API.
341 *
342 * @}
343 */
344
345/* packet functions */
346
347
348/**
349 * Allocate and read the payload of a packet and initialize its
350 * fields with default values.
351 *
352 * @param s associated IO context
353 * @param pkt packet
354 * @param size desired payload size
355 * @return >0 (read size) if OK, AVERROR_xxx otherwise
356 */
357int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
358
359
360/**
361 * Read data and append it to the current content of the AVPacket.
362 * If pkt->size is 0 this is identical to av_get_packet.
363 * Note that this uses av_grow_packet and thus involves a realloc
364 * which is inefficient. Thus this function should only be used
365 * when there is no reasonable way to know (an upper bound of)
366 * the final size.
367 *
368 * @param s associated IO context
369 * @param pkt packet
370 * @param size amount of data to read
371 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
372 * will not be lost even if an error occurs.
373 */
374int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
375
376#if FF_API_LAVF_FRAC
377/*************************************************/
378/* fractional numbers for exact pts handling */
379
380/**
381 * The exact value of the fractional number is: 'val + num / den'.
382 * num is assumed to be 0 <= num < den.
383 */
384typedef struct AVFrac {
385 int64_t val, num, den;
386} AVFrac;
387#endif
388
389/*************************************************/
390/* input/output formats */
391
392struct AVCodecTag;
393
394/**
395 * This structure contains the data a format has to probe a file.
396 */
397typedef struct AVProbeData {
398 const char *filename;
399 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
400 int buf_size; /**< Size of buf except extra allocated bytes */
401 const char *mime_type; /**< mime_type, when known. */
402} AVProbeData;
403
404#define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
405#define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1)
406
407#define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension
408#define AVPROBE_SCORE_MIME 75 ///< score for file mime type
409#define AVPROBE_SCORE_MAX 100 ///< maximum score
410
411#define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
412
413/// Demuxer will use avio_open, no opened file should be provided by the caller.
414#define AVFMT_NOFILE 0x0001
415#define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
416#define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
417#define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
418 raw picture data. */
419#define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
420#define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
421#define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
422#define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
423#define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
424#define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
425#define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
426#define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
427#define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */
428#define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
429#define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
430#if LIBAVFORMAT_VERSION_MAJOR <= 54
431#define AVFMT_TS_NONSTRICT 0x8020000 //we try to be compatible to the ABIs of ffmpeg and major forks
432#else
433#define AVFMT_TS_NONSTRICT 0x20000
434#endif
435 /**< Format does not require strictly
436 increasing timestamps, but they must
437 still be monotonic */
438#define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative
439 timestamps. If not set the timestamp
440 will be shifted in av_write_frame and
441 av_interleaved_write_frame so they
442 start from 0.
443 The user or muxer can override this through
444 AVFormatContext.avoid_negative_ts
445 */
446
447#define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */
448
449/**
450 * @addtogroup lavf_encoding
451 * @{
452 */
453typedef struct AVOutputFormat {
454 const char *name;
455 /**
456 * Descriptive name for the format, meant to be more human-readable
457 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
458 * to define it.
459 */
460 const char *long_name;
461 const char *mime_type;
462 const char *extensions; /**< comma-separated filename extensions */
463 /* output support */
464 enum AVCodecID audio_codec; /**< default audio codec */
465 enum AVCodecID video_codec; /**< default video codec */
466 enum AVCodecID subtitle_codec; /**< default subtitle codec */
467 /**
468 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
469 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
470 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
471 * AVFMT_TS_NONSTRICT
472 */
473 int flags;
474
475 /**
476 * List of supported codec_id-codec_tag pairs, ordered by "better
477 * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
478 */
479 const struct AVCodecTag * const *codec_tag;
480
481
482 const AVClass *priv_class; ///< AVClass for the private context
483
484 /*****************************************************************
485 * No fields below this line are part of the public API. They
486 * may not be used outside of libavformat and can be changed and
487 * removed at will.
488 * New public fields should be added right above.
489 *****************************************************************
490 */
491 struct AVOutputFormat *next;
492 /**
493 * size of private data so that it can be allocated in the wrapper
494 */
495 int priv_data_size;
496
497 int (*write_header)(struct AVFormatContext *);
498 /**
499 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
500 * pkt can be NULL in order to flush data buffered in the muxer.
501 * When flushing, return 0 if there still is more data to flush,
502 * or 1 if everything was flushed and there is no more buffered
503 * data.
504 */
505 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
506 int (*write_trailer)(struct AVFormatContext *);
507 /**
508 * Currently only used to set pixel format if not YUV420P.
509 */
510 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
511 AVPacket *in, int flush);
512 /**
513 * Test if the given codec can be stored in this container.
514 *
515 * @return 1 if the codec is supported, 0 if it is not.
516 * A negative number if unknown.
517 * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
518 */
519 int (*query_codec)(enum AVCodecID id, int std_compliance);
520
521 void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
522 int64_t *dts, int64_t *wall);
523 /**
524 * Allows sending messages from application to device.
525 */
526 int (*control_message)(struct AVFormatContext *s, int type,
527 void *data, size_t data_size);
528
529 /**
530 * Write an uncoded AVFrame.
531 *
532 * See av_write_uncoded_frame() for details.
533 *
534 * The library will free *frame afterwards, but the muxer can prevent it
535 * by setting the pointer to NULL.
536 */
537 int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
538 AVFrame **frame, unsigned flags);
539 /**
540 * Returns device list with it properties.
541 * @see avdevice_list_devices() for more details.
542 */
543 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
544 /**
545 * Initialize device capabilities submodule.
546 * @see avdevice_capabilities_create() for more details.
547 */
548 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
549 /**
550 * Free device capabilities submodule.
551 * @see avdevice_capabilities_free() for more details.
552 */
553 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
554} AVOutputFormat;
555/**
556 * @}
557 */
558
559/**
560 * @addtogroup lavf_decoding
561 * @{
562 */
563typedef struct AVInputFormat {
564 /**
565 * A comma separated list of short names for the format. New names
566 * may be appended with a minor bump.
567 */
568 const char *name;
569
570 /**
571 * Descriptive name for the format, meant to be more human-readable
572 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
573 * to define it.
574 */
575 const char *long_name;
576
577 /**
578 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
579 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
580 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
581 */
582 int flags;
583
584 /**
585 * If extensions are defined, then no probe is done. You should
586 * usually not use extension format guessing because it is not
587 * reliable enough
588 */
589 const char *extensions;
590
591 const struct AVCodecTag * const *codec_tag;
592
593 const AVClass *priv_class; ///< AVClass for the private context
594
595 /**
596 * Comma-separated list of mime types.
597 * It is used check for matching mime types while probing.
598 * @see av_probe_input_format2
599 */
600 const char *mime_type;
601
602 /*****************************************************************
603 * No fields below this line are part of the public API. They
604 * may not be used outside of libavformat and can be changed and
605 * removed at will.
606 * New public fields should be added right above.
607 *****************************************************************
608 */
609 struct AVInputFormat *next;
610
611 /**
612 * Raw demuxers store their codec ID here.
613 */
614 int raw_codec_id;
615
616 /**
617 * Size of private data so that it can be allocated in the wrapper.
618 */
619 int priv_data_size;
620
621 /**
622 * Tell if a given file has a chance of being parsed as this format.
623 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
624 * big so you do not have to check for that unless you need more.
625 */
626 int (*read_probe)(AVProbeData *);
627
628 /**
629 * Read the format header and initialize the AVFormatContext
630 * structure. Return 0 if OK. Only used in raw format right
631 * now. 'avformat_new_stream' should be called to create new streams.
632 */
633 int (*read_header)(struct AVFormatContext *);
634
635 /**
636 * Read one packet and put it in 'pkt'. pts and flags are also
637 * set. 'avformat_new_stream' can be called only if the flag
638 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
639 * background thread).
640 * @return 0 on success, < 0 on error.
641 * When returning an error, pkt must not have been allocated
642 * or must be freed before returning
643 */
644 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
645
646 /**
647 * Close the stream. The AVFormatContext and AVStreams are not
648 * freed by this function
649 */
650 int (*read_close)(struct AVFormatContext *);
651
652 /**
653 * Seek to a given timestamp relative to the frames in
654 * stream component stream_index.
655 * @param stream_index Must not be -1.
656 * @param flags Selects which direction should be preferred if no exact
657 * match is available.
658 * @return >= 0 on success (but not necessarily the new offset)
659 */
660 int (*read_seek)(struct AVFormatContext *,
661 int stream_index, int64_t timestamp, int flags);
662
663 /**
664 * Get the next timestamp in stream[stream_index].time_base units.
665 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
666 */
667 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
668 int64_t *pos, int64_t pos_limit);
669
670 /**
671 * Start/resume playing - only meaningful if using a network-based format
672 * (RTSP).
673 */
674 int (*read_play)(struct AVFormatContext *);
675
676 /**
677 * Pause playing - only meaningful if using a network-based format
678 * (RTSP).
679 */
680 int (*read_pause)(struct AVFormatContext *);
681
682 /**
683 * Seek to timestamp ts.
684 * Seeking will be done so that the point from which all active streams
685 * can be presented successfully will be closest to ts and within min/max_ts.
686 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
687 */
688 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
689
690 /**
691 * Returns device list with it properties.
692 * @see avdevice_list_devices() for more details.
693 */
694 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
695
696 /**
697 * Initialize device capabilities submodule.
698 * @see avdevice_capabilities_create() for more details.
699 */
700 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
701
702 /**
703 * Free device capabilities submodule.
704 * @see avdevice_capabilities_free() for more details.
705 */
706 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps);
707} AVInputFormat;
708/**
709 * @}
710 */
711
712enum AVStreamParseType {
713 AVSTREAM_PARSE_NONE,
714 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
715 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
716 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
717 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
718 AVSTREAM_PARSE_FULL_RAW=MKTAG(0,'R','A','W'), /**< full parsing and repack with timestamp and position generation by parser for raw
719 this assumes that each packet in the file contains no demuxer level headers and
720 just codec level data, otherwise position generation would fail */
721};
722
723typedef struct AVIndexEntry {
724 int64_t pos;
725 int64_t timestamp; /**<
726 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
727 * when seeking to this entry. That means preferable PTS on keyframe based formats.
728 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
729 * is known
730 */
731#define AVINDEX_KEYFRAME 0x0001
732 int flags:2;
733 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).
734 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
735} AVIndexEntry;
736
737#define AV_DISPOSITION_DEFAULT 0x0001
738#define AV_DISPOSITION_DUB 0x0002
739#define AV_DISPOSITION_ORIGINAL 0x0004
740#define AV_DISPOSITION_COMMENT 0x0008
741#define AV_DISPOSITION_LYRICS 0x0010
742#define AV_DISPOSITION_KARAOKE 0x0020
743
744/**
745 * Track should be used during playback by default.
746 * Useful for subtitle track that should be displayed
747 * even when user did not explicitly ask for subtitles.
748 */
749#define AV_DISPOSITION_FORCED 0x0040
750#define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
751#define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
752#define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
753/**
754 * The stream is stored in the file as an attached picture/"cover art" (e.g.
755 * APIC frame in ID3v2). The single packet associated with it will be returned
756 * among the first few packets read from the file unless seeking takes place.
757 * It can also be accessed at any time in AVStream.attached_pic.
758 */
759#define AV_DISPOSITION_ATTACHED_PIC 0x0400
760
761/**
762 * To specify text track kind (different from subtitles default).
763 */
764#define AV_DISPOSITION_CAPTIONS 0x10000
765#define AV_DISPOSITION_DESCRIPTIONS 0x20000
766#define AV_DISPOSITION_METADATA 0x40000
767
768/**
769 * Options for behavior on timestamp wrap detection.
770 */
771#define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap
772#define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection
773#define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection
774
775/**
776 * Stream structure.
777 * New fields can be added to the end with minor version bumps.
778 * Removal, reordering and changes to existing fields require a major
779 * version bump.
780 * sizeof(AVStream) must not be used outside libav*.
781 */
782typedef struct AVStream {
783 int index; /**< stream index in AVFormatContext */
784 /**
785 * Format-specific stream ID.
786 * decoding: set by libavformat
787 * encoding: set by the user, replaced by libavformat if left unset
788 */
789 int id;
790 /**
791 * Codec context associated with this stream. Allocated and freed by
792 * libavformat.
793 *
794 * - decoding: The demuxer exports codec information stored in the headers
795 * here.
796 * - encoding: The user sets codec information, the muxer writes it to the
797 * output. Mandatory fields as specified in AVCodecContext
798 * documentation must be set even if this AVCodecContext is
799 * not actually used for encoding.
800 */
801 AVCodecContext *codec;
802 void *priv_data;
803
804#if FF_API_LAVF_FRAC
805 /**
806 * @deprecated this field is unused
807 */
808 attribute_deprecated
809 struct AVFrac pts;
810#endif
811
812 /**
813 * This is the fundamental unit of time (in seconds) in terms
814 * of which frame timestamps are represented.
815 *
816 * decoding: set by libavformat
817 * encoding: May be set by the caller before avformat_write_header() to
818 * provide a hint to the muxer about the desired timebase. In
819 * avformat_write_header(), the muxer will overwrite this field
820 * with the timebase that will actually be used for the timestamps
821 * written into the file (which may or may not be related to the
822 * user-provided one, depending on the format).
823 */
824 AVRational time_base;
825
826 /**
827 * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
828 * Only set this if you are absolutely 100% sure that the value you set
829 * it to really is the pts of the first frame.
830 * This may be undefined (AV_NOPTS_VALUE).
831 * @note The ASF header does NOT contain a correct start_time the ASF
832 * demuxer must NOT set this.
833 */
834 int64_t start_time;
835
836 /**
837 * Decoding: duration of the stream, in stream time base.
838 * If a source file does not specify a duration, but does specify
839 * a bitrate, this value will be estimated from bitrate and file size.
840 */
841 int64_t duration;
842
843 int64_t nb_frames; ///< number of frames in this stream if known or 0
844
845 int disposition; /**< AV_DISPOSITION_* bit field */
846
847 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
848
849 /**
850 * sample aspect ratio (0 if unknown)
851 * - encoding: Set by user.
852 * - decoding: Set by libavformat.
853 */
854 AVRational sample_aspect_ratio;
855
856 AVDictionary *metadata;
857
858 /**
859 * Average framerate
860 *
861 * - demuxing: May be set by libavformat when creating the stream or in
862 * avformat_find_stream_info().
863 * - muxing: May be set by the caller before avformat_write_header().
864 */
865 AVRational avg_frame_rate;
866
867 /**
868 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
869 * will contain the attached picture.
870 *
871 * decoding: set by libavformat, must not be modified by the caller.
872 * encoding: unused
873 */
874 AVPacket attached_pic;
875
876 /**
877 * An array of side data that applies to the whole stream (i.e. the
878 * container does not allow it to change between packets).
879 *
880 * There may be no overlap between the side data in this array and side data
881 * in the packets. I.e. a given side data is either exported by the muxer
882 * (demuxing) / set by the caller (muxing) in this array, then it never
883 * appears in the packets, or the side data is exported / sent through
884 * the packets (always in the first packet where the value becomes known or
885 * changes), then it does not appear in this array.
886 *
887 * - demuxing: Set by libavformat when the stream is created.
888 * - muxing: May be set by the caller before avformat_write_header().
889 *
890 * Freed by libavformat in avformat_free_context().
891 *
892 * @see av_format_inject_global_side_data()
893 */
894 AVPacketSideData *side_data;
895 /**
896 * The number of elements in the AVStream.side_data array.
897 */
898 int nb_side_data;
899
900 /**
901 * Flags for the user to detect events happening on the stream. Flags must
902 * be cleared by the user once the event has been handled.
903 * A combination of AVSTREAM_EVENT_FLAG_*.
904 */
905 int event_flags;
906#define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
907
908 /*****************************************************************
909 * All fields below this line are not part of the public API. They
910 * may not be used outside of libavformat and can be changed and
911 * removed at will.
912 * New public fields should be added right above.
913 *****************************************************************
914 */
915
916 /**
917 * Stream information used internally by av_find_stream_info()
918 */
919#define MAX_STD_TIMEBASES (30*12+7+6)
920 struct {
921 int64_t last_dts;
922 int64_t duration_gcd;
923 int duration_count;
924 int64_t rfps_duration_sum;
925 double (*duration_error)[2][MAX_STD_TIMEBASES];
926 int64_t codec_info_duration;
927 int64_t codec_info_duration_fields;
928
929 /**
930 * 0 -> decoder has not been searched for yet.
931 * >0 -> decoder found
932 * <0 -> decoder with codec_id == -found_decoder has not been found
933 */
934 int found_decoder;
935
936 int64_t last_duration;
937
938 /**
939 * Those are used for average framerate estimation.
940 */
941 int64_t fps_first_dts;
942 int fps_first_dts_idx;
943 int64_t fps_last_dts;
944 int fps_last_dts_idx;
945
946 } *info;
947
948 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
949
950 // Timestamp generation support:
951 /**
952 * Timestamp corresponding to the last dts sync point.
953 *
954 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
955 * a DTS is received from the underlying container. Otherwise set to
956 * AV_NOPTS_VALUE by default.
957 */
958 int64_t first_dts;
959 int64_t cur_dts;
960 int64_t last_IP_pts;
961 int last_IP_duration;
962
963 /**
964 * Number of packets to buffer for codec probing
965 */
966#define MAX_PROBE_PACKETS 2500
967 int probe_packets;
968
969 /**
970 * Number of frames that have been demuxed during av_find_stream_info()
971 */
972 int codec_info_nb_frames;
973
974 /* av_read_frame() support */
975 enum AVStreamParseType need_parsing;
976 struct AVCodecParserContext *parser;
977
978 /**
979 * last packet in packet_buffer for this stream when muxing.
980 */
981 struct AVPacketList *last_in_packet_buffer;
982 AVProbeData probe_data;
983#define MAX_REORDER_DELAY 16
984 int64_t pts_buffer[MAX_REORDER_DELAY+1];
985
986 AVIndexEntry *index_entries; /**< Only used if the format does not
987 support seeking natively. */
988 int nb_index_entries;
989 unsigned int index_entries_allocated_size;
990
991 /**
992 * Real base framerate of the stream.
993 * This is the lowest framerate with which all timestamps can be
994 * represented accurately (it is the least common multiple of all
995 * framerates in the stream). Note, this value is just a guess!
996 * For example, if the time base is 1/90000 and all frames have either
997 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
998 *
999 * Code outside avformat should access this field using:
1000 * av_stream_get/set_r_frame_rate(stream)
1001 */
1002 AVRational r_frame_rate;
1003
1004 /**
1005 * Stream Identifier
1006 * This is the MPEG-TS stream identifier +1
1007 * 0 means unknown
1008 */
1009 int stream_identifier;
1010
1011 int64_t interleaver_chunk_size;
1012 int64_t interleaver_chunk_duration;
1013
1014 /**
1015 * stream probing state
1016 * -1 -> probing finished
1017 * 0 -> no probing requested
1018 * rest -> perform probing with request_probe being the minimum score to accept.
1019 * NOT PART OF PUBLIC API
1020 */
1021 int request_probe;
1022 /**
1023 * Indicates that everything up to the next keyframe
1024 * should be discarded.
1025 */
1026 int skip_to_keyframe;
1027
1028 /**
1029 * Number of samples to skip at the start of the frame decoded from the next packet.
1030 */
1031 int skip_samples;
1032
1033 /**
1034 * If not 0, the first audio sample that should be discarded from the stream.
1035 * This is broken by design (needs global sample count), but can't be
1036 * avoided for broken by design formats such as mp3 with ad-hoc gapless
1037 * audio support.
1038 */
1039 int64_t first_discard_sample;
1040
1041 /**
1042 * The sample after last sample that is intended to be discarded after
1043 * first_discard_sample. Works on frame boundaries only. Used to prevent
1044 * early EOF if the gapless info is broken (considered concatenated mp3s).
1045 */
1046 int64_t last_discard_sample;
1047
1048 /**
1049 * Number of internally decoded frames, used internally in libavformat, do not access
1050 * its lifetime differs from info which is why it is not in that structure.
1051 */
1052 int nb_decoded_frames;
1053
1054 /**
1055 * Timestamp offset added to timestamps before muxing
1056 * NOT PART OF PUBLIC API
1057 */
1058 int64_t mux_ts_offset;
1059
1060 /**
1061 * Internal data to check for wrapping of the time stamp
1062 */
1063 int64_t pts_wrap_reference;
1064
1065 /**
1066 * Options for behavior, when a wrap is detected.
1067 *
1068 * Defined by AV_PTS_WRAP_ values.
1069 *
1070 * If correction is enabled, there are two possibilities:
1071 * If the first time stamp is near the wrap point, the wrap offset
1072 * will be subtracted, which will create negative time stamps.
1073 * Otherwise the offset will be added.
1074 */
1075 int pts_wrap_behavior;
1076
1077 /**
1078 * Internal data to prevent doing update_initial_durations() twice
1079 */
1080 int update_initial_durations_done;
1081
1082 /**
1083 * Internal data to generate dts from pts
1084 */
1085 int64_t pts_reorder_error[MAX_REORDER_DELAY+1];
1086 uint8_t pts_reorder_error_count[MAX_REORDER_DELAY+1];
1087
1088 /**
1089 * Internal data to analyze DTS and detect faulty mpeg streams
1090 */
1091 int64_t last_dts_for_order_check;
1092 uint8_t dts_ordered;
1093 uint8_t dts_misordered;
1094
1095 /**
1096 * Internal data to inject global side data
1097 */
1098 int inject_global_side_data;
1099
1100 /**
1101 * String containing paris of key and values describing recommended encoder configuration.
1102 * Paris are separated by ','.
1103 * Keys are separated from values by '='.
1104 */
1105 char *recommended_encoder_configuration;
1106
1107 /**
1108 * display aspect ratio (0 if unknown)
1109 * - encoding: unused
1110 * - decoding: Set by libavformat to calculate sample_aspect_ratio internally
1111 */
1112 AVRational display_aspect_ratio;
1113} AVStream;
1114
1115AVRational av_stream_get_r_frame_rate(const AVStream *s);
1116void av_stream_set_r_frame_rate(AVStream *s, AVRational r);
1117struct AVCodecParserContext *av_stream_get_parser(const AVStream *s);
1118char* av_stream_get_recommended_encoder_configuration(const AVStream *s);
1119void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration);
1120
1121/**
1122 * Returns the pts of the last muxed packet + its duration
1123 *
1124 * the retuned value is undefined when used with a demuxer.
1125 */
1126int64_t av_stream_get_end_pts(const AVStream *st);
1127
1128#define AV_PROGRAM_RUNNING 1
1129
1130/**
1131 * New fields can be added to the end with minor version bumps.
1132 * Removal, reordering and changes to existing fields require a major
1133 * version bump.
1134 * sizeof(AVProgram) must not be used outside libav*.
1135 */
1136typedef struct AVProgram {
1137 int id;
1138 int flags;
1139 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1140 unsigned int *stream_index;
1141 unsigned int nb_stream_indexes;
1142 AVDictionary *metadata;
1143
1144 int program_num;
1145 int pmt_pid;
1146 int pcr_pid;
1147
1148 /*****************************************************************
1149 * All fields below this line are not part of the public API. They
1150 * may not be used outside of libavformat and can be changed and
1151 * removed at will.
1152 * New public fields should be added right above.
1153 *****************************************************************
1154 */
1155 int64_t start_time;
1156 int64_t end_time;
1157
1158 int64_t pts_wrap_reference; ///< reference dts for wrap detection
1159 int pts_wrap_behavior; ///< behavior on wrap detection
1160} AVProgram;
1161
1162#define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
1163 (streams are added dynamically) */
1164
1165typedef struct AVChapter {
1166 int id; ///< unique ID to identify the chapter
1167 AVRational time_base; ///< time base in which the start/end timestamps are specified
1168 int64_t start, end; ///< chapter start/end time in time_base units
1169 AVDictionary *metadata;
1170} AVChapter;
1171
1172
1173/**
1174 * Callback used by devices to communicate with application.
1175 */
1176typedef int (*av_format_control_message)(struct AVFormatContext *s, int type,
1177 void *data, size_t data_size);
1178
1179
1180/**
1181 * The duration of a video can be estimated through various ways, and this enum can be used
1182 * to know how the duration was estimated.
1183 */
1184enum AVDurationEstimationMethod {
1185 AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes
1186 AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
1187 AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
1188};
1189
1190typedef struct AVFormatInternal AVFormatInternal;
1191
1192/**
1193 * Format I/O context.
1194 * New fields can be added to the end with minor version bumps.
1195 * Removal, reordering and changes to existing fields require a major
1196 * version bump.
1197 * sizeof(AVFormatContext) must not be used outside libav*, use
1198 * avformat_alloc_context() to create an AVFormatContext.
1199 */
1200typedef struct AVFormatContext {
1201 /**
1202 * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1203 * Exports (de)muxer private options if they exist.
1204 */
1205 const AVClass *av_class;
1206
1207 /**
1208 * The input container format.
1209 *
1210 * Demuxing only, set by avformat_open_input().
1211 */
1212 struct AVInputFormat *iformat;
1213
1214 /**
1215 * The output container format.
1216 *
1217 * Muxing only, must be set by the caller before avformat_write_header().
1218 */
1219 struct AVOutputFormat *oformat;
1220
1221 /**
1222 * Format private data. This is an AVOptions-enabled struct
1223 * if and only if iformat/oformat.priv_class is not NULL.
1224 *
1225 * - muxing: set by avformat_write_header()
1226 * - demuxing: set by avformat_open_input()
1227 */
1228 void *priv_data;
1229
1230 /**
1231 * I/O context.
1232 *
1233 * - demuxing: either set by the user before avformat_open_input() (then
1234 * the user must close it manually) or set by avformat_open_input().
1235 * - muxing: set by the user before avformat_write_header(). The caller must
1236 * take care of closing / freeing the IO context.
1237 *
1238 * Do NOT set this field if AVFMT_NOFILE flag is set in
1239 * iformat/oformat.flags. In such a case, the (de)muxer will handle
1240 * I/O in some other way and this field will be NULL.
1241 */
1242 AVIOContext *pb;
1243
1244 /* stream info */
1245 /**
1246 * Flags signalling stream properties. A combination of AVFMTCTX_*.
1247 * Set by libavformat.
1248 */
1249 int ctx_flags;
1250
1251 /**
1252 * Number of elements in AVFormatContext.streams.
1253 *
1254 * Set by avformat_new_stream(), must not be modified by any other code.
1255 */
1256 unsigned int nb_streams;
1257 /**
1258 * A list of all streams in the file. New streams are created with
1259 * avformat_new_stream().
1260 *
1261 * - demuxing: streams are created by libavformat in avformat_open_input().
1262 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1263 * appear in av_read_frame().
1264 * - muxing: streams are created by the user before avformat_write_header().
1265 *
1266 * Freed by libavformat in avformat_free_context().
1267 */
1268 AVStream **streams;
1269
1270 /**
1271 * input or output filename
1272 *
1273 * - demuxing: set by avformat_open_input()
1274 * - muxing: may be set by the caller before avformat_write_header()
1275 */
1276 char filename[1024];
1277
1278 /**
1279 * Position of the first frame of the component, in
1280 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1281 * It is deduced from the AVStream values.
1282 *
1283 * Demuxing only, set by libavformat.
1284 */
1285 int64_t start_time;
1286
1287 /**
1288 * Duration of the stream, in AV_TIME_BASE fractional
1289 * seconds. Only set this value if you know none of the individual stream
1290 * durations and also do not set any of them. This is deduced from the
1291 * AVStream values if not set.
1292 *
1293 * Demuxing only, set by libavformat.
1294 */
1295 int64_t duration;
1296
1297 /**
1298 * Total stream bitrate in bit/s, 0 if not
1299 * available. Never set it directly if the file_size and the
1300 * duration are known as FFmpeg can compute it automatically.
1301 */
1302 int bit_rate;
1303
1304 unsigned int packet_size;
1305 int max_delay;
1306
1307 /**
1308 * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1309 * Set by the user before avformat_open_input() / avformat_write_header().
1310 */
1311 int flags;
1312#define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
1313#define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
1314#define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
1315#define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
1316#define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
1317#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
1318#define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible
1319#define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1320#define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
1321#define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet.
1322/**
1323 * When muxing, try to avoid writing any random/volatile data to the output.
1324 * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1325 *
1326 * This flag is mainly intended for testing.
1327 */
1328#define AVFMT_FLAG_BITEXACT 0x0400
1329#define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload
1330#define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1331#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)
1332#define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Don't merge side data but keep it separate.
1333
1334 /**
1335 * @deprecated deprecated in favor of probesize2
1336 */
1337 unsigned int probesize;
1338
1339 /**
1340 * @deprecated deprecated in favor of max_analyze_duration2
1341 */
1342 attribute_deprecated
1343 int max_analyze_duration;
1344
1345 const uint8_t *key;
1346 int keylen;
1347
1348 unsigned int nb_programs;
1349 AVProgram **programs;
1350
1351 /**
1352 * Forced video codec_id.
1353 * Demuxing: Set by user.
1354 */
1355 enum AVCodecID video_codec_id;
1356
1357 /**
1358 * Forced audio codec_id.
1359 * Demuxing: Set by user.
1360 */
1361 enum AVCodecID audio_codec_id;
1362
1363 /**
1364 * Forced subtitle codec_id.
1365 * Demuxing: Set by user.
1366 */
1367 enum AVCodecID subtitle_codec_id;
1368
1369 /**
1370 * Maximum amount of memory in bytes to use for the index of each stream.
1371 * If the index exceeds this size, entries will be discarded as
1372 * needed to maintain a smaller size. This can lead to slower or less
1373 * accurate seeking (depends on demuxer).
1374 * Demuxers for which a full in-memory index is mandatory will ignore
1375 * this.
1376 * - muxing: unused
1377 * - demuxing: set by user
1378 */
1379 unsigned int max_index_size;
1380
1381 /**
1382 * Maximum amount of memory in bytes to use for buffering frames
1383 * obtained from realtime capture devices.
1384 */
1385 unsigned int max_picture_buffer;
1386
1387 /**
1388 * Number of chapters in AVChapter array.
1389 * When muxing, chapters are normally written in the file header,
1390 * so nb_chapters should normally be initialized before write_header
1391 * is called. Some muxers (e.g. mov and mkv) can also write chapters
1392 * in the trailer. To write chapters in the trailer, nb_chapters
1393 * must be zero when write_header is called and non-zero when
1394 * write_trailer is called.
1395 * - muxing: set by user
1396 * - demuxing: set by libavformat
1397 */
1398 unsigned int nb_chapters;
1399 AVChapter **chapters;
1400
1401 /**
1402 * Metadata that applies to the whole file.
1403 *
1404 * - demuxing: set by libavformat in avformat_open_input()
1405 * - muxing: may be set by the caller before avformat_write_header()
1406 *
1407 * Freed by libavformat in avformat_free_context().
1408 */
1409 AVDictionary *metadata;
1410
1411 /**
1412 * Start time of the stream in real world time, in microseconds
1413 * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1414 * stream was captured at this real world time.
1415 * - muxing: Set by the caller before avformat_write_header(). If set to
1416 * either 0 or AV_NOPTS_VALUE, then the current wall-time will
1417 * be used.
1418 * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1419 * the value may become known after some number of frames
1420 * have been received.
1421 */
1422 int64_t start_time_realtime;
1423
1424 /**
1425 * The number of frames used for determining the framerate in
1426 * avformat_find_stream_info().
1427 * Demuxing only, set by the caller before avformat_find_stream_info().
1428 */
1429 int fps_probe_size;
1430
1431 /**
1432 * Error recognition; higher values will detect more errors but may
1433 * misdetect some more or less valid parts as errors.
1434 * Demuxing only, set by the caller before avformat_open_input().
1435 */
1436 int error_recognition;
1437
1438 /**
1439 * Custom interrupt callbacks for the I/O layer.
1440 *
1441 * demuxing: set by the user before avformat_open_input().
1442 * muxing: set by the user before avformat_write_header()
1443 * (mainly useful for AVFMT_NOFILE formats). The callback
1444 * should also be passed to avio_open2() if it's used to
1445 * open the file.
1446 */
1447 AVIOInterruptCB interrupt_callback;
1448
1449 /**
1450 * Flags to enable debugging.
1451 */
1452 int debug;
1453#define FF_FDEBUG_TS 0x0001
1454
1455 /**
1456 * Maximum buffering duration for interleaving.
1457 *
1458 * To ensure all the streams are interleaved correctly,
1459 * av_interleaved_write_frame() will wait until it has at least one packet
1460 * for each stream before actually writing any packets to the output file.
1461 * When some streams are "sparse" (i.e. there are large gaps between
1462 * successive packets), this can result in excessive buffering.
1463 *
1464 * This field specifies the maximum difference between the timestamps of the
1465 * first and the last packet in the muxing queue, above which libavformat
1466 * will output a packet regardless of whether it has queued a packet for all
1467 * the streams.
1468 *
1469 * Muxing only, set by the caller before avformat_write_header().
1470 */
1471 int64_t max_interleave_delta;
1472
1473 /**
1474 * Allow non-standard and experimental extension
1475 * @see AVCodecContext.strict_std_compliance
1476 */
1477 int strict_std_compliance;
1478
1479 /**
1480 * Flags for the user to detect events happening on the file. Flags must
1481 * be cleared by the user once the event has been handled.
1482 * A combination of AVFMT_EVENT_FLAG_*.
1483 */
1484 int event_flags;
1485#define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
1486
1487 /**
1488 * Maximum number of packets to read while waiting for the first timestamp.
1489 * Decoding only.
1490 */
1491 int max_ts_probe;
1492
1493 /**
1494 * Avoid negative timestamps during muxing.
1495 * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1496 * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use)
1497 * - muxing: Set by user
1498 * - demuxing: unused
1499 */
1500 int avoid_negative_ts;
1501#define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format
1502#define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative
1503#define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0
1504
1505
1506 /**
1507 * Transport stream id.
1508 * This will be moved into demuxer private options. Thus no API/ABI compatibility
1509 */
1510 int ts_id;
1511
1512 /**
1513 * Audio preload in microseconds.
1514 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1515 * - encoding: Set by user via AVOptions (NO direct access)
1516 * - decoding: unused
1517 */
1518 int audio_preload;
1519
1520 /**
1521 * Max chunk time in microseconds.
1522 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1523 * - encoding: Set by user via AVOptions (NO direct access)
1524 * - decoding: unused
1525 */
1526 int max_chunk_duration;
1527
1528 /**
1529 * Max chunk size in bytes
1530 * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1531 * - encoding: Set by user via AVOptions (NO direct access)
1532 * - decoding: unused
1533 */
1534 int max_chunk_size;
1535
1536 /**
1537 * forces the use of wallclock timestamps as pts/dts of packets
1538 * This has undefined results in the presence of B frames.
1539 * - encoding: unused
1540 * - decoding: Set by user via AVOptions (NO direct access)
1541 */
1542 int use_wallclock_as_timestamps;
1543
1544 /**
1545 * avio flags, used to force AVIO_FLAG_DIRECT.
1546 * - encoding: unused
1547 * - decoding: Set by user via AVOptions (NO direct access)
1548 */
1549 int avio_flags;
1550
1551 /**
1552 * The duration field can be estimated through various ways, and this field can be used
1553 * to know how the duration was estimated.
1554 * - encoding: unused
1555 * - decoding: Read by user via AVOptions (NO direct access)
1556 */
1557 enum AVDurationEstimationMethod duration_estimation_method;
1558
1559 /**
1560 * Skip initial bytes when opening stream
1561 * - encoding: unused
1562 * - decoding: Set by user via AVOptions (NO direct access)
1563 */
1564 int64_t skip_initial_bytes;
1565
1566 /**
1567 * Correct single timestamp overflows
1568 * - encoding: unused
1569 * - decoding: Set by user via AVOptions (NO direct access)
1570 */
1571 unsigned int correct_ts_overflow;
1572
1573 /**
1574 * Force seeking to any (also non key) frames.
1575 * - encoding: unused
1576 * - decoding: Set by user via AVOptions (NO direct access)
1577 */
1578 int seek2any;
1579
1580 /**
1581 * Flush the I/O context after each packet.
1582 * - encoding: Set by user via AVOptions (NO direct access)
1583 * - decoding: unused
1584 */
1585 int flush_packets;
1586
1587 /**
1588 * format probing score.
1589 * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1590 * the format.
1591 * - encoding: unused
1592 * - decoding: set by avformat, read by user via av_format_get_probe_score() (NO direct access)
1593 */
1594 int probe_score;
1595
1596 /**
1597 * number of bytes to read maximally to identify format.
1598 * - encoding: unused
1599 * - decoding: set by user through AVOPtions (NO direct access)
1600 */
1601 int format_probesize;
1602
1603 /**
1604 * ',' separated list of allowed decoders.
1605 * If NULL then all are allowed
1606 * - encoding: unused
1607 * - decoding: set by user through AVOptions (NO direct access)
1608 */
1609 char *codec_whitelist;
1610
1611 /**
1612 * ',' separated list of allowed demuxers.
1613 * If NULL then all are allowed
1614 * - encoding: unused
1615 * - decoding: set by user through AVOptions (NO direct access)
1616 */
1617 char *format_whitelist;
1618
1619 /*****************************************************************
1620 * All fields below this line are not part of the public API. They
1621 * may not be used outside of libavformat and can be changed and
1622 * removed at will.
1623 * New public fields should be added right above.
1624 *****************************************************************
1625 */
1626
1627 /**
1628 * This buffer is only needed when packets were already buffered but
1629 * not decoded, for example to get the codec parameters in MPEG
1630 * streams.
1631 */
1632 struct AVPacketList *packet_buffer;
1633 struct AVPacketList *packet_buffer_end;
1634
1635 /* av_seek_frame() support */
1636 int64_t data_offset; /**< offset of the first packet */
1637
1638 /**
1639 * Raw packets from the demuxer, prior to parsing and decoding.
1640 * This buffer is used for buffering packets until the codec can
1641 * be identified, as parsing cannot be done without knowing the
1642 * codec.
1643 */
1644 struct AVPacketList *raw_packet_buffer;
1645 struct AVPacketList *raw_packet_buffer_end;
1646 /**
1647 * Packets split by the parser get queued here.
1648 */
1649 struct AVPacketList *parse_queue;
1650 struct AVPacketList *parse_queue_end;
1651 /**
1652 * Remaining size available for raw_packet_buffer, in bytes.
1653 */
1654#define RAW_PACKET_BUFFER_SIZE 2500000
1655 int raw_packet_buffer_remaining_size;
1656
1657 /**
1658 * Offset to remap timestamps to be non-negative.
1659 * Expressed in timebase units.
1660 * @see AVStream.mux_ts_offset
1661 */
1662 int64_t offset;
1663
1664 /**
1665 * Timebase for the timestamp offset.
1666 */
1667 AVRational offset_timebase;
1668
1669 /**
1670 * An opaque field for libavformat internal usage.
1671 * Must not be accessed in any way by callers.
1672 */
1673 AVFormatInternal *internal;
1674
1675 /**
1676 * IO repositioned flag.
1677 * This is set by avformat when the underlaying IO context read pointer
1678 * is repositioned, for example when doing byte based seeking.
1679 * Demuxers can use the flag to detect such changes.
1680 */
1681 int io_repositioned;
1682
1683 /**
1684 * Forced video codec.
1685 * This allows forcing a specific decoder, even when there are multiple with
1686 * the same codec_id.
1687 * Demuxing: Set by user via av_format_set_video_codec (NO direct access).
1688 */
1689 AVCodec *video_codec;
1690
1691 /**
1692 * Forced audio codec.
1693 * This allows forcing a specific decoder, even when there are multiple with
1694 * the same codec_id.
1695 * Demuxing: Set by user via av_format_set_audio_codec (NO direct access).
1696 */
1697 AVCodec *audio_codec;
1698
1699 /**
1700 * Forced subtitle codec.
1701 * This allows forcing a specific decoder, even when there are multiple with
1702 * the same codec_id.
1703 * Demuxing: Set by user via av_format_set_subtitle_codec (NO direct access).
1704 */
1705 AVCodec *subtitle_codec;
1706
1707 /**
1708 * Number of bytes to be written as padding in a metadata header.
1709 * Demuxing: Unused.
1710 * Muxing: Set by user via av_format_set_metadata_header_padding.
1711 */
1712 int metadata_header_padding;
1713
1714 /**
1715 * User data.
1716 * This is a place for some private data of the user.
1717 * Mostly usable with control_message_cb or any future callbacks in device's context.
1718 */
1719 void *opaque;
1720
1721 /**
1722 * Callback used by devices to communicate with application.
1723 */
1724 av_format_control_message control_message_cb;
1725
1726 /**
1727 * Output timestamp offset, in microseconds.
1728 * Muxing: set by user via AVOptions (NO direct access)
1729 */
1730 int64_t output_ts_offset;
1731
1732 /**
1733 * Maximum duration (in AV_TIME_BASE units) of the data read
1734 * from input in avformat_find_stream_info().
1735 * Demuxing only, set by the caller before avformat_find_stream_info()
1736 * via AVOptions (NO direct access).
1737 * Can be set to 0 to let avformat choose using a heuristic.
1738 */
1739 int64_t max_analyze_duration2;
1740
1741 /**
1742 * Maximum size of the data read from input for determining
1743 * the input container format.
1744 * Demuxing only, set by the caller before avformat_open_input()
1745 * via AVOptions (NO direct access).
1746 */
1747 int64_t probesize2;
1748
1749 /**
1750 * dump format separator.
1751 * can be ", " or "\n " or anything else
1752 * Code outside libavformat should access this field using AVOptions
1753 * (NO direct access).
1754 * - muxing: Set by user.
1755 * - demuxing: Set by user.
1756 */
1757 uint8_t *dump_separator;
1758} AVFormatContext;
1759
1760int av_format_get_probe_score(const AVFormatContext *s);
1761AVCodec * av_format_get_video_codec(const AVFormatContext *s);
1762void av_format_set_video_codec(AVFormatContext *s, AVCodec *c);
1763AVCodec * av_format_get_audio_codec(const AVFormatContext *s);
1764void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c);
1765AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s);
1766void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c);
1767int av_format_get_metadata_header_padding(const AVFormatContext *s);
1768void av_format_set_metadata_header_padding(AVFormatContext *s, int c);
1769void * av_format_get_opaque(const AVFormatContext *s);
1770void av_format_set_opaque(AVFormatContext *s, void *opaque);
1771av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s);
1772void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback);
1773
1774/**
1775 * This function will cause global side data to be injected in the next packet
1776 * of each stream as well as after any subsequent seek.
1777 */
1778void av_format_inject_global_side_data(AVFormatContext *s);
1779
1780/**
1781 * Returns the method used to set ctx->duration.
1782 *
1783 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
1784 */
1785enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
1786
1787typedef struct AVPacketList {
1788 AVPacket pkt;
1789 struct AVPacketList *next;
1790} AVPacketList;
1791
1792
1793/**
1794 * @defgroup lavf_core Core functions
1795 * @ingroup libavf
1796 *
1797 * Functions for querying libavformat capabilities, allocating core structures,
1798 * etc.
1799 * @{
1800 */
1801
1802/**
1803 * Return the LIBAVFORMAT_VERSION_INT constant.
1804 */
1805unsigned avformat_version(void);
1806
1807/**
1808 * Return the libavformat build-time configuration.
1809 */
1810const char *avformat_configuration(void);
1811
1812/**
1813 * Return the libavformat license.
1814 */
1815const char *avformat_license(void);
1816
1817/**
1818 * Initialize libavformat and register all the muxers, demuxers and
1819 * protocols. If you do not call this function, then you can select
1820 * exactly which formats you want to support.
1821 *
1822 * @see av_register_input_format()
1823 * @see av_register_output_format()
1824 */
1825void av_register_all(void);
1826
1827void av_register_input_format(AVInputFormat *format);
1828void av_register_output_format(AVOutputFormat *format);
1829
1830/**
1831 * Do global initialization of network components. This is optional,
1832 * but recommended, since it avoids the overhead of implicitly
1833 * doing the setup for each session.
1834 *
1835 * Calling this function will become mandatory if using network
1836 * protocols at some major version bump.
1837 */
1838int avformat_network_init(void);
1839
1840/**
1841 * Undo the initialization done by avformat_network_init.
1842 */
1843int avformat_network_deinit(void);
1844
1845/**
1846 * If f is NULL, returns the first registered input format,
1847 * if f is non-NULL, returns the next registered input format after f
1848 * or NULL if f is the last one.
1849 */
1850AVInputFormat *av_iformat_next(const AVInputFormat *f);
1851
1852/**
1853 * If f is NULL, returns the first registered output format,
1854 * if f is non-NULL, returns the next registered output format after f
1855 * or NULL if f is the last one.
1856 */
1857AVOutputFormat *av_oformat_next(const AVOutputFormat *f);
1858
1859/**
1860 * Allocate an AVFormatContext.
1861 * avformat_free_context() can be used to free the context and everything
1862 * allocated by the framework within it.
1863 */
1864AVFormatContext *avformat_alloc_context(void);
1865
1866/**
1867 * Free an AVFormatContext and all its streams.
1868 * @param s context to free
1869 */
1870void avformat_free_context(AVFormatContext *s);
1871
1872/**
1873 * Get the AVClass for AVFormatContext. It can be used in combination with
1874 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1875 *
1876 * @see av_opt_find().
1877 */
1878const AVClass *avformat_get_class(void);
1879
1880/**
1881 * Add a new stream to a media file.
1882 *
1883 * When demuxing, it is called by the demuxer in read_header(). If the
1884 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1885 * be called in read_packet().
1886 *
1887 * When muxing, should be called by the user before avformat_write_header().
1888 *
1889 * User is required to call avcodec_close() and avformat_free_context() to
1890 * clean up the allocation by avformat_new_stream().
1891 *
1892 * @param s media file handle
1893 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1894 * will be initialized to use this codec. This is needed for e.g. codec-specific
1895 * defaults to be set, so codec should be provided if it is known.
1896 *
1897 * @return newly created stream or NULL on error.
1898 */
1899AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c);
1900
1901/**
1902 * Get side information from stream.
1903 *
1904 * @param stream stream
1905 * @param type desired side information type
1906 * @param size pointer for side information size to store (optional)
1907 * @return pointer to data if present or NULL otherwise
1908 */
1909uint8_t *av_stream_get_side_data(AVStream *stream,
1910 enum AVPacketSideDataType type, int *size);
1911
1912AVProgram *av_new_program(AVFormatContext *s, int id);
1913
1914/**
1915 * @}
1916 */
1917
1918
1919/**
1920 * Allocate an AVFormatContext for an output format.
1921 * avformat_free_context() can be used to free the context and
1922 * everything allocated by the framework within it.
1923 *
1924 * @param *ctx is set to the created format context, or to NULL in
1925 * case of failure
1926 * @param oformat format to use for allocating the context, if NULL
1927 * format_name and filename are used instead
1928 * @param format_name the name of output format to use for allocating the
1929 * context, if NULL filename is used instead
1930 * @param filename the name of the filename to use for allocating the
1931 * context, may be NULL
1932 * @return >= 0 in case of success, a negative AVERROR code in case of
1933 * failure
1934 */
1935int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat,
1936 const char *format_name, const char *filename);
1937
1938/**
1939 * @addtogroup lavf_decoding
1940 * @{
1941 */
1942
1943/**
1944 * Find AVInputFormat based on the short name of the input format.
1945 */
1946AVInputFormat *av_find_input_format(const char *short_name);
1947
1948/**
1949 * Guess the file format.
1950 *
1951 * @param pd data to be probed
1952 * @param is_opened Whether the file is already opened; determines whether
1953 * demuxers with or without AVFMT_NOFILE are probed.
1954 */
1955AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1956
1957/**
1958 * Guess the file format.
1959 *
1960 * @param pd data to be probed
1961 * @param is_opened Whether the file is already opened; determines whether
1962 * demuxers with or without AVFMT_NOFILE are probed.
1963 * @param score_max A probe score larger that this is required to accept a
1964 * detection, the variable is set to the actual detection
1965 * score afterwards.
1966 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1967 * to retry with a larger probe buffer.
1968 */
1969AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1970
1971/**
1972 * Guess the file format.
1973 *
1974 * @param is_opened Whether the file is already opened; determines whether
1975 * demuxers with or without AVFMT_NOFILE are probed.
1976 * @param score_ret The score of the best detection.
1977 */
1978AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
1979
1980/**
1981 * Probe a bytestream to determine the input format. Each time a probe returns
1982 * with a score that is too low, the probe buffer size is increased and another
1983 * attempt is made. When the maximum probe size is reached, the input format
1984 * with the highest score is returned.
1985 *
1986 * @param pb the bytestream to probe
1987 * @param fmt the input format is put here
1988 * @param filename the filename of the stream
1989 * @param logctx the log context
1990 * @param offset the offset within the bytestream to probe from
1991 * @param max_probe_size the maximum probe buffer size (zero for default)
1992 * @return the score in case of success, a negative value corresponding to an
1993 * the maximal score is AVPROBE_SCORE_MAX
1994 * AVERROR code otherwise
1995 */
1996int av_probe_input_buffer2(AVIOContext *pb, AVInputFormat **fmt,
1997 const char *filename, void *logctx,
1998 unsigned int offset, unsigned int max_probe_size);
1999
2000/**
2001 * Like av_probe_input_buffer2() but returns 0 on success
2002 */
2003int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
2004 const char *filename, void *logctx,
2005 unsigned int offset, unsigned int max_probe_size);
2006
2007/**
2008 * Open an input stream and read the header. The codecs are not opened.
2009 * The stream must be closed with avformat_close_input().
2010 *
2011 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
2012 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
2013 * function and written into ps.
2014 * Note that a user-supplied AVFormatContext will be freed on failure.
2015 * @param filename Name of the stream to open.
2016 * @param fmt If non-NULL, this parameter forces a specific input format.
2017 * Otherwise the format is autodetected.
2018 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
2019 * On return this parameter will be destroyed and replaced with a dict containing
2020 * options that were not found. May be NULL.
2021 *
2022 * @return 0 on success, a negative AVERROR on failure.
2023 *
2024 * @note If you want to use custom IO, preallocate the format context and set its pb field.
2025 */
2026int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
2027
2028attribute_deprecated
2029int av_demuxer_open(AVFormatContext *ic);
2030
2031/**
2032 * Read packets of a media file to get stream information. This
2033 * is useful for file formats with no headers such as MPEG. This
2034 * function also computes the real framerate in case of MPEG-2 repeat
2035 * frame mode.
2036 * The logical file position is not changed by this function;
2037 * examined packets may be buffered for later processing.
2038 *
2039 * @param ic media file handle
2040 * @param options If non-NULL, an ic.nb_streams long array of pointers to
2041 * dictionaries, where i-th member contains options for
2042 * codec corresponding to i-th stream.
2043 * On return each dictionary will be filled with options that were not found.
2044 * @return >=0 if OK, AVERROR_xxx on error
2045 *
2046 * @note this function isn't guaranteed to open all the codecs, so
2047 * options being non-empty at return is a perfectly normal behavior.
2048 *
2049 * @todo Let the user decide somehow what information is needed so that
2050 * we do not waste time getting stuff the user does not need.
2051 */
2052int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
2053
2054/**
2055 * Find the programs which belong to a given stream.
2056 *
2057 * @param ic media file handle
2058 * @param last the last found program, the search will start after this
2059 * program, or from the beginning if it is NULL
2060 * @param s stream index
2061 * @return the next program which belongs to s, NULL if no program is found or
2062 * the last program is not among the programs of ic.
2063 */
2064AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s);
2065
2066/**
2067 * Find the "best" stream in the file.
2068 * The best stream is determined according to various heuristics as the most
2069 * likely to be what the user expects.
2070 * If the decoder parameter is non-NULL, av_find_best_stream will find the
2071 * default decoder for the stream's codec; streams for which no decoder can
2072 * be found are ignored.
2073 *
2074 * @param ic media file handle
2075 * @param type stream type: video, audio, subtitles, etc.
2076 * @param wanted_stream_nb user-requested stream number,
2077 * or -1 for automatic selection
2078 * @param related_stream try to find a stream related (eg. in the same
2079 * program) to this one, or -1 if none
2080 * @param decoder_ret if non-NULL, returns the decoder for the
2081 * selected stream
2082 * @param flags flags; none are currently defined
2083 * @return the non-negative stream number in case of success,
2084 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2085 * could be found,
2086 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2087 * @note If av_find_best_stream returns successfully and decoder_ret is not
2088 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2089 */
2090int av_find_best_stream(AVFormatContext *ic,
2091 enum AVMediaType type,
2092 int wanted_stream_nb,
2093 int related_stream,
2094 AVCodec **decoder_ret,
2095 int flags);
2096
2097/**
2098 * Return the next frame of a stream.
2099 * This function returns what is stored in the file, and does not validate
2100 * that what is there are valid frames for the decoder. It will split what is
2101 * stored in the file into frames and return one for each call. It will not
2102 * omit invalid data between valid frames so as to give the decoder the maximum
2103 * information possible for decoding.
2104 *
2105 * If pkt->buf is NULL, then the packet is valid until the next
2106 * av_read_frame() or until avformat_close_input(). Otherwise the packet
2107 * is valid indefinitely. In both cases the packet must be freed with
2108 * av_free_packet when it is no longer needed. For video, the packet contains
2109 * exactly one frame. For audio, it contains an integer number of frames if each
2110 * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
2111 * have a variable size (e.g. MPEG audio), then it contains one frame.
2112 *
2113 * pkt->pts, pkt->dts and pkt->duration are always set to correct
2114 * values in AVStream.time_base units (and guessed if the format cannot
2115 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2116 * has B-frames, so it is better to rely on pkt->dts if you do not
2117 * decompress the payload.
2118 *
2119 * @return 0 if OK, < 0 on error or end of file
2120 */
2121int av_read_frame(AVFormatContext *s, AVPacket *pkt);
2122
2123/**
2124 * Seek to the keyframe at timestamp.
2125 * 'timestamp' in 'stream_index'.
2126 *
2127 * @param s media file handle
2128 * @param stream_index If stream_index is (-1), a default
2129 * stream is selected, and timestamp is automatically converted
2130 * from AV_TIME_BASE units to the stream specific time_base.
2131 * @param timestamp Timestamp in AVStream.time_base units
2132 * or, if no stream is specified, in AV_TIME_BASE units.
2133 * @param flags flags which select direction and seeking mode
2134 * @return >= 0 on success
2135 */
2136int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
2137 int flags);
2138
2139/**
2140 * Seek to timestamp ts.
2141 * Seeking will be done so that the point from which all active streams
2142 * can be presented successfully will be closest to ts and within min/max_ts.
2143 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2144 *
2145 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2146 * are the file position (this may not be supported by all demuxers).
2147 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2148 * in the stream with stream_index (this may not be supported by all demuxers).
2149 * Otherwise all timestamps are in units of the stream selected by stream_index
2150 * or if stream_index is -1, in AV_TIME_BASE units.
2151 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2152 * keyframes (this may not be supported by all demuxers).
2153 * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2154 *
2155 * @param s media file handle
2156 * @param stream_index index of the stream which is used as time base reference
2157 * @param min_ts smallest acceptable timestamp
2158 * @param ts target timestamp
2159 * @param max_ts largest acceptable timestamp
2160 * @param flags flags
2161 * @return >=0 on success, error code otherwise
2162 *
2163 * @note This is part of the new seek API which is still under construction.
2164 * Thus do not use this yet. It may change at any time, do not expect
2165 * ABI compatibility yet!
2166 */
2167int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
2168
2169/**
2170 * Start playing a network-based stream (e.g. RTSP stream) at the
2171 * current position.
2172 */
2173int av_read_play(AVFormatContext *s);
2174
2175/**
2176 * Pause a network-based stream (e.g. RTSP stream).
2177 *
2178 * Use av_read_play() to resume it.
2179 */
2180int av_read_pause(AVFormatContext *s);
2181
2182/**
2183 * Close an opened input AVFormatContext. Free it and all its contents
2184 * and set *s to NULL.
2185 */
2186void avformat_close_input(AVFormatContext **s);
2187/**
2188 * @}
2189 */
2190
2191#define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
2192#define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
2193#define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
2194#define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
2195
2196/**
2197 * @addtogroup lavf_encoding
2198 * @{
2199 */
2200/**
2201 * Allocate the stream private data and write the stream header to
2202 * an output media file.
2203 *
2204 * @param s Media file handle, must be allocated with avformat_alloc_context().
2205 * Its oformat field must be set to the desired output format;
2206 * Its pb field must be set to an already opened AVIOContext.
2207 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
2208 * On return this parameter will be destroyed and replaced with a dict containing
2209 * options that were not found. May be NULL.
2210 *
2211 * @return 0 on success, negative AVERROR on failure.
2212 *
2213 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
2214 */
2215int avformat_write_header(AVFormatContext *s, AVDictionary **options);
2216
2217/**
2218 * Write a packet to an output media file.
2219 *
2220 * This function passes the packet directly to the muxer, without any buffering
2221 * or reordering. The caller is responsible for correctly interleaving the
2222 * packets if the format requires it. Callers that want libavformat to handle
2223 * the interleaving should call av_interleaved_write_frame() instead of this
2224 * function.
2225 *
2226 * @param s media file handle
2227 * @param pkt The packet containing the data to be written. Note that unlike
2228 * av_interleaved_write_frame(), this function does not take
2229 * ownership of the packet passed to it (though some muxers may make
2230 * an internal reference to the input packet).
2231 * <br>
2232 * This parameter can be NULL (at any time, not just at the end), in
2233 * order to immediately flush data buffered within the muxer, for
2234 * muxers that buffer up data internally before writing it to the
2235 * output.
2236 * <br>
2237 * Packet's @ref AVPacket.stream_index "stream_index" field must be
2238 * set to the index of the corresponding stream in @ref
2239 * AVFormatContext.streams "s->streams". It is very strongly
2240 * recommended that timing information (@ref AVPacket.pts "pts", @ref
2241 * AVPacket.dts "dts", @ref AVPacket.duration "duration") is set to
2242 * correct values.
2243 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2244 *
2245 * @see av_interleaved_write_frame()
2246 */
2247int av_write_frame(AVFormatContext *s, AVPacket *pkt);
2248
2249/**
2250 * Write a packet to an output media file ensuring correct interleaving.
2251 *
2252 * This function will buffer the packets internally as needed to make sure the
2253 * packets in the output file are properly interleaved in the order of
2254 * increasing dts. Callers doing their own interleaving should call
2255 * av_write_frame() instead of this function.
2256 *
2257 * @param s media file handle
2258 * @param pkt The packet containing the data to be written.
2259 * <br>
2260 * If the packet is reference-counted, this function will take
2261 * ownership of this reference and unreference it later when it sees
2262 * fit.
2263 * The caller must not access the data through this reference after
2264 * this function returns. If the packet is not reference-counted,
2265 * libavformat will make a copy.
2266 * <br>
2267 * This parameter can be NULL (at any time, not just at the end), to
2268 * flush the interleaving queues.
2269 * <br>
2270 * Packet's @ref AVPacket.stream_index "stream_index" field must be
2271 * set to the index of the corresponding stream in @ref
2272 * AVFormatContext.streams "s->streams". It is very strongly
2273 * recommended that timing information (@ref AVPacket.pts "pts", @ref
2274 * AVPacket.dts "dts", @ref AVPacket.duration "duration") is set to
2275 * correct values.
2276 *
2277 * @return 0 on success, a negative AVERROR on error. Libavformat will always
2278 * take care of freeing the packet, even if this function fails.
2279 *
2280 * @see av_write_frame(), AVFormatContext.max_interleave_delta
2281 */
2282int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
2283
2284/**
2285 * Write a uncoded frame to an output media file.
2286 *
2287 * The frame must be correctly interleaved according to the container
2288 * specification; if not, then av_interleaved_write_frame() must be used.
2289 *
2290 * See av_interleaved_write_frame() for details.
2291 */
2292int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
2293 AVFrame *frame);
2294
2295/**
2296 * Write a uncoded frame to an output media file.
2297 *
2298 * If the muxer supports it, this function allows to write an AVFrame
2299 * structure directly, without encoding it into a packet.
2300 * It is mostly useful for devices and similar special muxers that use raw
2301 * video or PCM data and will not serialize it into a byte stream.
2302 *
2303 * To test whether it is possible to use it with a given muxer and stream,
2304 * use av_write_uncoded_frame_query().
2305 *
2306 * The caller gives up ownership of the frame and must not access it
2307 * afterwards.
2308 *
2309 * @return >=0 for success, a negative code on error
2310 */
2311int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
2312 AVFrame *frame);
2313
2314/**
2315 * Test whether a muxer supports uncoded frame.
2316 *
2317 * @return >=0 if an uncoded frame can be written to that muxer and stream,
2318 * <0 if not
2319 */
2320int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
2321
2322/**
2323 * Write the stream trailer to an output media file and free the
2324 * file private data.
2325 *
2326 * May only be called after a successful call to avformat_write_header.
2327 *
2328 * @param s media file handle
2329 * @return 0 if OK, AVERROR_xxx on error
2330 */
2331int av_write_trailer(AVFormatContext *s);
2332
2333/**
2334 * Return the output format in the list of registered output formats
2335 * which best matches the provided parameters, or return NULL if
2336 * there is no match.
2337 *
2338 * @param short_name if non-NULL checks if short_name matches with the
2339 * names of the registered formats
2340 * @param filename if non-NULL checks if filename terminates with the
2341 * extensions of the registered formats
2342 * @param mime_type if non-NULL checks if mime_type matches with the
2343 * MIME type of the registered formats
2344 */
2345AVOutputFormat *av_guess_format(const char *short_name,
2346 const char *filename,
2347 const char *mime_type);
2348
2349/**
2350 * Guess the codec ID based upon muxer and filename.
2351 */
2352enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
2353 const char *filename, const char *mime_type,
2354 enum AVMediaType type);
2355
2356/**
2357 * Get timing information for the data currently output.
2358 * The exact meaning of "currently output" depends on the format.
2359 * It is mostly relevant for devices that have an internal buffer and/or
2360 * work in real time.
2361 * @param s media file handle
2362 * @param stream stream in the media file
2363 * @param[out] dts DTS of the last packet output for the stream, in stream
2364 * time_base units
2365 * @param[out] wall absolute time when that packet whas output,
2366 * in microsecond
2367 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it
2368 * Note: some formats or devices may not allow to measure dts and wall
2369 * atomically.
2370 */
2371int av_get_output_timestamp(struct AVFormatContext *s, int stream,
2372 int64_t *dts, int64_t *wall);
2373
2374
2375/**
2376 * @}
2377 */
2378
2379
2380/**
2381 * @defgroup lavf_misc Utility functions
2382 * @ingroup libavf
2383 * @{
2384 *
2385 * Miscellaneous utility functions related to both muxing and demuxing
2386 * (or neither).
2387 */
2388
2389/**
2390 * Send a nice hexadecimal dump of a buffer to the specified file stream.
2391 *
2392 * @param f The file stream pointer where the dump should be sent to.
2393 * @param buf buffer
2394 * @param size buffer size
2395 *
2396 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2397 */
2398void av_hex_dump(FILE *f, const uint8_t *buf, int size);
2399
2400/**
2401 * Send a nice hexadecimal dump of a buffer to the log.
2402 *
2403 * @param avcl A pointer to an arbitrary struct of which the first field is a
2404 * pointer to an AVClass struct.
2405 * @param level The importance level of the message, lower values signifying
2406 * higher importance.
2407 * @param buf buffer
2408 * @param size buffer size
2409 *
2410 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2411 */
2412void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
2413
2414/**
2415 * Send a nice dump of a packet to the specified file stream.
2416 *
2417 * @param f The file stream pointer where the dump should be sent to.
2418 * @param pkt packet to dump
2419 * @param dump_payload True if the payload must be displayed, too.
2420 * @param st AVStream that the packet belongs to
2421 */
2422void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);
2423
2424
2425/**
2426 * Send a nice dump of a packet to the log.
2427 *
2428 * @param avcl A pointer to an arbitrary struct of which the first field is a
2429 * pointer to an AVClass struct.
2430 * @param level The importance level of the message, lower values signifying
2431 * higher importance.
2432 * @param pkt packet to dump
2433 * @param dump_payload True if the payload must be displayed, too.
2434 * @param st AVStream that the packet belongs to
2435 */
2436void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,
2437 const AVStream *st);
2438
2439/**
2440 * Get the AVCodecID for the given codec tag tag.
2441 * If no codec id is found returns AV_CODEC_ID_NONE.
2442 *
2443 * @param tags list of supported codec_id-codec_tag pairs, as stored
2444 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2445 * @param tag codec tag to match to a codec ID
2446 */
2447enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
2448
2449/**
2450 * Get the codec tag for the given codec id id.
2451 * If no codec tag is found returns 0.
2452 *
2453 * @param tags list of supported codec_id-codec_tag pairs, as stored
2454 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2455 * @param id codec ID to match to a codec tag
2456 */
2457unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
2458
2459/**
2460 * Get the codec tag for the given codec id.
2461 *
2462 * @param tags list of supported codec_id - codec_tag pairs, as stored
2463 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2464 * @param id codec id that should be searched for in the list
2465 * @param tag A pointer to the found tag
2466 * @return 0 if id was not found in tags, > 0 if it was found
2467 */
2468int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
2469 unsigned int *tag);
2470
2471int av_find_default_stream_index(AVFormatContext *s);
2472
2473/**
2474 * Get the index for a specific timestamp.
2475 *
2476 * @param st stream that the timestamp belongs to
2477 * @param timestamp timestamp to retrieve the index for
2478 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2479 * to the timestamp which is <= the requested one, if backward
2480 * is 0, then it will be >=
2481 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2482 * @return < 0 if no such timestamp could be found
2483 */
2484int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
2485
2486/**
2487 * Add an index entry into a sorted list. Update the entry if the list
2488 * already contains it.
2489 *
2490 * @param timestamp timestamp in the time base of the given stream
2491 */
2492int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
2493 int size, int distance, int flags);
2494
2495
2496/**
2497 * Split a URL string into components.
2498 *
2499 * The pointers to buffers for storing individual components may be null,
2500 * in order to ignore that component. Buffers for components not found are
2501 * set to empty strings. If the port is not found, it is set to a negative
2502 * value.
2503 *
2504 * @param proto the buffer for the protocol
2505 * @param proto_size the size of the proto buffer
2506 * @param authorization the buffer for the authorization
2507 * @param authorization_size the size of the authorization buffer
2508 * @param hostname the buffer for the host name
2509 * @param hostname_size the size of the hostname buffer
2510 * @param port_ptr a pointer to store the port number in
2511 * @param path the buffer for the path
2512 * @param path_size the size of the path buffer
2513 * @param url the URL to split
2514 */
2515void av_url_split(char *proto, int proto_size,
2516 char *authorization, int authorization_size,
2517 char *hostname, int hostname_size,
2518 int *port_ptr,
2519 char *path, int path_size,
2520 const char *url);
2521
2522
2523/**
2524 * Print detailed information about the input or output format, such as
2525 * duration, bitrate, streams, container, programs, metadata, side data,
2526 * codec and time base.
2527 *
2528 * @param ic the context to analyze
2529 * @param index index of the stream to dump information about
2530 * @param url the URL to print, such as source or destination file
2531 * @param is_output Select whether the specified context is an input(0) or output(1)
2532 */
2533void av_dump_format(AVFormatContext *ic,
2534 int index,
2535 const char *url,
2536 int is_output);
2537
2538/**
2539 * Return in 'buf' the path with '%d' replaced by a number.
2540 *
2541 * Also handles the '%0nd' format where 'n' is the total number
2542 * of digits and '%%'.
2543 *
2544 * @param buf destination buffer
2545 * @param buf_size destination buffer size
2546 * @param path numbered sequence string
2547 * @param number frame number
2548 * @return 0 if OK, -1 on format error
2549 */
2550int av_get_frame_filename(char *buf, int buf_size,
2551 const char *path, int number);
2552
2553/**
2554 * Check whether filename actually is a numbered sequence generator.
2555 *
2556 * @param filename possible numbered sequence string
2557 * @return 1 if a valid numbered sequence string, 0 otherwise
2558 */
2559int av_filename_number_test(const char *filename);
2560
2561/**
2562 * Generate an SDP for an RTP session.
2563 *
2564 * Note, this overwrites the id values of AVStreams in the muxer contexts
2565 * for getting unique dynamic payload types.
2566 *
2567 * @param ac array of AVFormatContexts describing the RTP streams. If the
2568 * array is composed by only one context, such context can contain
2569 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
2570 * all the contexts in the array (an AVCodecContext per RTP stream)
2571 * must contain only one AVStream.
2572 * @param n_files number of AVCodecContexts contained in ac
2573 * @param buf buffer where the SDP will be stored (must be allocated by
2574 * the caller)
2575 * @param size the size of the buffer
2576 * @return 0 if OK, AVERROR_xxx on error
2577 */
2578int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
2579
2580/**
2581 * Return a positive value if the given filename has one of the given
2582 * extensions, 0 otherwise.
2583 *
2584 * @param filename file name to check against the given extensions
2585 * @param extensions a comma-separated list of filename extensions
2586 */
2587int av_match_ext(const char *filename, const char *extensions);
2588
2589/**
2590 * Test if the given container can store a codec.
2591 *
2592 * @param ofmt container to check for compatibility
2593 * @param codec_id codec to potentially store in container
2594 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
2595 *
2596 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
2597 * A negative number if this information is not available.
2598 */
2599int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id,
2600 int std_compliance);
2601
2602/**
2603 * @defgroup riff_fourcc RIFF FourCCs
2604 * @{
2605 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
2606 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
2607 * following code:
2608 * @code
2609 * uint32_t tag = MKTAG('H', '2', '6', '4');
2610 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
2611 * enum AVCodecID id = av_codec_get_id(table, tag);
2612 * @endcode
2613 */
2614/**
2615 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
2616 */
2617const struct AVCodecTag *avformat_get_riff_video_tags(void);
2618/**
2619 * @return the table mapping RIFF FourCCs for audio to AVCodecID.
2620 */
2621const struct AVCodecTag *avformat_get_riff_audio_tags(void);
2622/**
2623 * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
2624 */
2625const struct AVCodecTag *avformat_get_mov_video_tags(void);
2626/**
2627 * @return the table mapping MOV FourCCs for audio to AVCodecID.
2628 */
2629const struct AVCodecTag *avformat_get_mov_audio_tags(void);
2630
2631/**
2632 * @}
2633 */
2634
2635/**
2636 * Guess the sample aspect ratio of a frame, based on both the stream and the
2637 * frame aspect ratio.
2638 *
2639 * Since the frame aspect ratio is set by the codec but the stream aspect ratio
2640 * is set by the demuxer, these two may not be equal. This function tries to
2641 * return the value that you should use if you would like to display the frame.
2642 *
2643 * Basic logic is to use the stream aspect ratio if it is set to something sane
2644 * otherwise use the frame aspect ratio. This way a container setting, which is
2645 * usually easy to modify can override the coded value in the frames.
2646 *
2647 * @param format the format context which the stream is part of
2648 * @param stream the stream which the frame is part of
2649 * @param frame the frame with the aspect ratio to be determined
2650 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
2651 */
2652AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame);
2653
2654/**
2655 * Guess the frame rate, based on both the container and codec information.
2656 *
2657 * @param ctx the format context which the stream is part of
2658 * @param stream the stream which the frame is part of
2659 * @param frame the frame for which the frame rate should be determined, may be NULL
2660 * @return the guessed (valid) frame rate, 0/1 if no idea
2661 */
2662AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame);
2663
2664/**
2665 * Check if the stream st contained in s is matched by the stream specifier
2666 * spec.
2667 *
2668 * See the "stream specifiers" chapter in the documentation for the syntax
2669 * of spec.
2670 *
2671 * @return >0 if st is matched by spec;
2672 * 0 if st is not matched by spec;
2673 * AVERROR code if spec is invalid
2674 *
2675 * @note A stream specifier can match several streams in the format.
2676 */
2677int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st,
2678 const char *spec);
2679
2680int avformat_queue_attached_pictures(AVFormatContext *s);
2681
2682
2683/**
2684 * @}
2685 */
2686
2687#endif /* AVFORMAT_AVFORMAT_H */