lavf: include libavutil/time.h instead of redeclaring av_gettime()
[libav.git] / libavformat / avformat.h
1 /*
2 * copyright (c) 2001 Fabrice Bellard
3 *
4 * This file is part of Libav.
5 *
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 Libav structures, its size is not part of public ABI, so it cannot be
54 * allocated on stack or directly with av_malloc(). To create an
55 * AVFormatContext, use avformat_alloc_context() (some functions, like
56 * avformat_open_input() might do that for you).
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 * The packet data belongs to the demuxer and is invalid after the next call to
162 * av_read_frame(). The user must free the packet with av_free_packet() before
163 * calling av_read_frame() again or closing the file.
164 *
165 * @section lavf_decoding_seek Seeking
166 * @}
167 *
168 * @defgroup lavf_encoding Muxing
169 * @{
170 * @}
171 *
172 * @defgroup lavf_io I/O Read/Write
173 * @{
174 * @}
175 *
176 * @defgroup lavf_codec Demuxers
177 * @{
178 * @defgroup lavf_codec_native Native Demuxers
179 * @{
180 * @}
181 * @defgroup lavf_codec_wrappers External library wrappers
182 * @{
183 * @}
184 * @}
185 * @defgroup lavf_protos I/O Protocols
186 * @{
187 * @}
188 * @defgroup lavf_internal Internal
189 * @{
190 * @}
191 * @}
192 *
193 */
194
195 #include <time.h>
196 #include <stdio.h> /* FILE */
197 #include "libavcodec/avcodec.h"
198 #include "libavutil/dict.h"
199 #include "libavutil/log.h"
200
201 #include "avio.h"
202 #include "libavformat/version.h"
203
204 #if FF_API_AV_GETTIME
205 #include "libavutil/time.h"
206 #endif
207
208 struct AVFormatContext;
209
210
211 /**
212 * @defgroup metadata_api Public Metadata API
213 * @{
214 * @ingroup libavf
215 * The metadata API allows libavformat to export metadata tags to a client
216 * application when demuxing. Conversely it allows a client application to
217 * set metadata when muxing.
218 *
219 * Metadata is exported or set as pairs of key/value strings in the 'metadata'
220 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
221 * using the @ref lavu_dict "AVDictionary" API. Like all strings in Libav,
222 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
223 * exported by demuxers isn't checked to be valid UTF-8 in most cases.
224 *
225 * Important concepts to keep in mind:
226 * - Keys are unique; there can never be 2 tags with the same key. This is
227 * also meant semantically, i.e., a demuxer should not knowingly produce
228 * several keys that are literally different but semantically identical.
229 * E.g., key=Author5, key=Author6. In this example, all authors must be
230 * placed in the same tag.
231 * - Metadata is flat, not hierarchical; there are no subtags. If you
232 * want to store, e.g., the email address of the child of producer Alice
233 * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
234 * - Several modifiers can be applied to the tag name. This is done by
235 * appending a dash character ('-') and the modifier name in the order
236 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
237 * - language -- a tag whose value is localized for a particular language
238 * is appended with the ISO 639-2/B 3-letter language code.
239 * For example: Author-ger=Michael, Author-eng=Mike
240 * The original/default language is in the unqualified "Author" tag.
241 * A demuxer should set a default if it sets any translated tag.
242 * - sorting -- a modified version of a tag that should be used for
243 * sorting will have '-sort' appended. E.g. artist="The Beatles",
244 * artist-sort="Beatles, The".
245 *
246 * - Demuxers attempt to export metadata in a generic format, however tags
247 * with no generic equivalents are left as they are stored in the container.
248 * Follows a list of generic tag names:
249 *
250 @verbatim
251 album -- name of the set this work belongs to
252 album_artist -- main creator of the set/album, if different from artist.
253 e.g. "Various Artists" for compilation albums.
254 artist -- main creator of the work
255 comment -- any additional description of the file.
256 composer -- who composed the work, if different from artist.
257 copyright -- name of copyright holder.
258 creation_time-- date when the file was created, preferably in ISO 8601.
259 date -- date when the work was created, preferably in ISO 8601.
260 disc -- number of a subset, e.g. disc in a multi-disc collection.
261 encoder -- name/settings of the software/hardware that produced the file.
262 encoded_by -- person/group who created the file.
263 filename -- original name of the file.
264 genre -- <self-evident>.
265 language -- main language in which the work is performed, preferably
266 in ISO 639-2 format. Multiple languages can be specified by
267 separating them with commas.
268 performer -- artist who performed the work, if different from artist.
269 E.g for "Also sprach Zarathustra", artist would be "Richard
270 Strauss" and performer "London Philharmonic Orchestra".
271 publisher -- name of the label/publisher.
272 service_name -- name of the service in broadcasting (channel name).
273 service_provider -- name of the service provider in broadcasting.
274 title -- name of the work.
275 track -- number of this work in the set, can be in form current/total.
276 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
277 @endverbatim
278 *
279 * Look in the examples section for an application example how to use the Metadata API.
280 *
281 * @}
282 */
283
284 /* packet functions */
285
286
287 /**
288 * Allocate and read the payload of a packet and initialize its
289 * fields with default values.
290 *
291 * @param pkt packet
292 * @param size desired payload size
293 * @return >0 (read size) if OK, AVERROR_xxx otherwise
294 */
295 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
296
297
298 /**
299 * Read data and append it to the current content of the AVPacket.
300 * If pkt->size is 0 this is identical to av_get_packet.
301 * Note that this uses av_grow_packet and thus involves a realloc
302 * which is inefficient. Thus this function should only be used
303 * when there is no reasonable way to know (an upper bound of)
304 * the final size.
305 *
306 * @param pkt packet
307 * @param size amount of data to read
308 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
309 * will not be lost even if an error occurs.
310 */
311 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
312
313 /*************************************************/
314 /* fractional numbers for exact pts handling */
315
316 /**
317 * The exact value of the fractional number is: 'val + num / den'.
318 * num is assumed to be 0 <= num < den.
319 */
320 typedef struct AVFrac {
321 int64_t val, num, den;
322 } AVFrac;
323
324 /*************************************************/
325 /* input/output formats */
326
327 struct AVCodecTag;
328
329 /**
330 * This structure contains the data a format has to probe a file.
331 */
332 typedef struct AVProbeData {
333 const char *filename;
334 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
335 int buf_size; /**< Size of buf except extra allocated bytes */
336 } AVProbeData;
337
338 #define AVPROBE_SCORE_MAX 100 ///< maximum score, half of that is used for file-extension-based detection
339 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
340
341 /// Demuxer will use avio_open, no opened file should be provided by the caller.
342 #define AVFMT_NOFILE 0x0001
343 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
344 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
345 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
346 raw picture data. */
347 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
348 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
349 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
350 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
351 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
352 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
353 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
354 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fallback to binary search via read_timestamp */
355 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fallback to generic search */
356 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
357 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
358 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly
359 increasing timestamps, but they must
360 still be monotonic */
361
362 /**
363 * @addtogroup lavf_encoding
364 * @{
365 */
366 typedef struct AVOutputFormat {
367 const char *name;
368 /**
369 * Descriptive name for the format, meant to be more human-readable
370 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
371 * to define it.
372 */
373 const char *long_name;
374 const char *mime_type;
375 const char *extensions; /**< comma-separated filename extensions */
376 /* output support */
377 enum CodecID audio_codec; /**< default audio codec */
378 enum CodecID video_codec; /**< default video codec */
379 enum CodecID subtitle_codec; /**< default subtitle codec */
380 /**
381 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
382 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
383 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
384 * AVFMT_TS_NONSTRICT
385 */
386 int flags;
387
388 /**
389 * List of supported codec_id-codec_tag pairs, ordered by "better
390 * choice first". The arrays are all terminated by CODEC_ID_NONE.
391 */
392 const struct AVCodecTag * const *codec_tag;
393
394
395 const AVClass *priv_class; ///< AVClass for the private context
396
397 /*****************************************************************
398 * No fields below this line are part of the public API. They
399 * may not be used outside of libavformat and can be changed and
400 * removed at will.
401 * New public fields should be added right above.
402 *****************************************************************
403 */
404 struct AVOutputFormat *next;
405 /**
406 * size of private data so that it can be allocated in the wrapper
407 */
408 int priv_data_size;
409
410 int (*write_header)(struct AVFormatContext *);
411 /**
412 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
413 * pkt can be NULL in order to flush data buffered in the muxer.
414 * When flushing, return 0 if there still is more data to flush,
415 * or 1 if everything was flushed and there is no more buffered
416 * data.
417 */
418 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
419 int (*write_trailer)(struct AVFormatContext *);
420 /**
421 * Currently only used to set pixel format if not YUV420P.
422 */
423 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
424 AVPacket *in, int flush);
425 /**
426 * Test if the given codec can be stored in this container.
427 *
428 * @return 1 if the codec is supported, 0 if it is not.
429 * A negative number if unknown.
430 */
431 int (*query_codec)(enum CodecID id, int std_compliance);
432 } AVOutputFormat;
433 /**
434 * @}
435 */
436
437 /**
438 * @addtogroup lavf_decoding
439 * @{
440 */
441 typedef struct AVInputFormat {
442 /**
443 * A comma separated list of short names for the format. New names
444 * may be appended with a minor bump.
445 */
446 const char *name;
447
448 /**
449 * Descriptive name for the format, meant to be more human-readable
450 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
451 * to define it.
452 */
453 const char *long_name;
454
455 /**
456 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
457 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
458 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK.
459 */
460 int flags;
461
462 /**
463 * If extensions are defined, then no probe is done. You should
464 * usually not use extension format guessing because it is not
465 * reliable enough
466 */
467 const char *extensions;
468
469 const struct AVCodecTag * const *codec_tag;
470
471 const AVClass *priv_class; ///< AVClass for the private context
472
473 /*****************************************************************
474 * No fields below this line are part of the public API. They
475 * may not be used outside of libavformat and can be changed and
476 * removed at will.
477 * New public fields should be added right above.
478 *****************************************************************
479 */
480 struct AVInputFormat *next;
481
482 /**
483 * Raw demuxers store their codec ID here.
484 */
485 int raw_codec_id;
486
487 /**
488 * Size of private data so that it can be allocated in the wrapper.
489 */
490 int priv_data_size;
491
492 /**
493 * Tell if a given file has a chance of being parsed as this format.
494 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
495 * big so you do not have to check for that unless you need more.
496 */
497 int (*read_probe)(AVProbeData *);
498
499 /**
500 * Read the format header and initialize the AVFormatContext
501 * structure. Return 0 if OK. Only used in raw format right
502 * now. 'avformat_new_stream' should be called to create new streams.
503 */
504 int (*read_header)(struct AVFormatContext *);
505
506 /**
507 * Read one packet and put it in 'pkt'. pts and flags are also
508 * set. 'avformat_new_stream' can be called only if the flag
509 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
510 * background thread).
511 * @return 0 on success, < 0 on error.
512 * When returning an error, pkt must not have been allocated
513 * or must be freed before returning
514 */
515 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
516
517 /**
518 * Close the stream. The AVFormatContext and AVStreams are not
519 * freed by this function
520 */
521 int (*read_close)(struct AVFormatContext *);
522
523 /**
524 * Seek to a given timestamp relative to the frames in
525 * stream component stream_index.
526 * @param stream_index Must not be -1.
527 * @param flags Selects which direction should be preferred if no exact
528 * match is available.
529 * @return >= 0 on success (but not necessarily the new offset)
530 */
531 int (*read_seek)(struct AVFormatContext *,
532 int stream_index, int64_t timestamp, int flags);
533
534 /**
535 * Get the next timestamp in stream[stream_index].time_base units.
536 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
537 */
538 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
539 int64_t *pos, int64_t pos_limit);
540
541 /**
542 * Start/resume playing - only meaningful if using a network-based format
543 * (RTSP).
544 */
545 int (*read_play)(struct AVFormatContext *);
546
547 /**
548 * Pause playing - only meaningful if using a network-based format
549 * (RTSP).
550 */
551 int (*read_pause)(struct AVFormatContext *);
552
553 /**
554 * Seek to timestamp ts.
555 * Seeking will be done so that the point from which all active streams
556 * can be presented successfully will be closest to ts and within min/max_ts.
557 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
558 */
559 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
560 } AVInputFormat;
561 /**
562 * @}
563 */
564
565 enum AVStreamParseType {
566 AVSTREAM_PARSE_NONE,
567 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
568 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
569 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
570 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
571 };
572
573 typedef struct AVIndexEntry {
574 int64_t pos;
575 int64_t timestamp;
576 #define AVINDEX_KEYFRAME 0x0001
577 int flags:2;
578 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).
579 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
580 } AVIndexEntry;
581
582 #define AV_DISPOSITION_DEFAULT 0x0001
583 #define AV_DISPOSITION_DUB 0x0002
584 #define AV_DISPOSITION_ORIGINAL 0x0004
585 #define AV_DISPOSITION_COMMENT 0x0008
586 #define AV_DISPOSITION_LYRICS 0x0010
587 #define AV_DISPOSITION_KARAOKE 0x0020
588
589 /**
590 * Track should be used during playback by default.
591 * Useful for subtitle track that should be displayed
592 * even when user did not explicitly ask for subtitles.
593 */
594 #define AV_DISPOSITION_FORCED 0x0040
595 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
596 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
597 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
598 /**
599 * The stream is stored in the file as an attached picture/"cover art" (e.g.
600 * APIC frame in ID3v2). The single packet associated with it will be returned
601 * among the first few packets read from the file unless seeking takes place.
602 * It can also be accessed at any time in AVStream.attached_pic.
603 */
604 #define AV_DISPOSITION_ATTACHED_PIC 0x0400
605
606 /**
607 * Stream structure.
608 * New fields can be added to the end with minor version bumps.
609 * Removal, reordering and changes to existing fields require a major
610 * version bump.
611 * sizeof(AVStream) must not be used outside libav*.
612 */
613 typedef struct AVStream {
614 int index; /**< stream index in AVFormatContext */
615 /**
616 * Format-specific stream ID.
617 * decoding: set by libavformat
618 * encoding: set by the user
619 */
620 int id;
621 /**
622 * Codec context associated with this stream. Allocated and freed by
623 * libavformat.
624 *
625 * - decoding: The demuxer exports codec information stored in the headers
626 * here.
627 * - encoding: The user sets codec information, the muxer writes it to the
628 * output. Mandatory fields as specified in AVCodecContext
629 * documentation must be set even if this AVCodecContext is
630 * not actually used for encoding.
631 */
632 AVCodecContext *codec;
633 /**
634 * Real base framerate of the stream.
635 * This is the lowest framerate with which all timestamps can be
636 * represented accurately (it is the least common multiple of all
637 * framerates in the stream). Note, this value is just a guess!
638 * For example, if the time base is 1/90000 and all frames have either
639 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
640 */
641 AVRational r_frame_rate;
642 void *priv_data;
643
644 /**
645 * encoding: pts generation when outputting stream
646 */
647 struct AVFrac pts;
648
649 /**
650 * This is the fundamental unit of time (in seconds) in terms
651 * of which frame timestamps are represented.
652 *
653 * decoding: set by libavformat
654 * encoding: set by libavformat in av_write_header. The muxer may use the
655 * user-provided value of @ref AVCodecContext.time_base "codec->time_base"
656 * as a hint.
657 */
658 AVRational time_base;
659
660 /**
661 * Decoding: pts of the first frame of the stream, in stream time base.
662 * Only set this if you are absolutely 100% sure that the value you set
663 * it to really is the pts of the first frame.
664 * This may be undefined (AV_NOPTS_VALUE).
665 */
666 int64_t start_time;
667
668 /**
669 * Decoding: duration of the stream, in stream time base.
670 * If a source file does not specify a duration, but does specify
671 * a bitrate, this value will be estimated from bitrate and file size.
672 */
673 int64_t duration;
674
675 int64_t nb_frames; ///< number of frames in this stream if known or 0
676
677 int disposition; /**< AV_DISPOSITION_* bit field */
678
679 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
680
681 /**
682 * sample aspect ratio (0 if unknown)
683 * - encoding: Set by user.
684 * - decoding: Set by libavformat.
685 */
686 AVRational sample_aspect_ratio;
687
688 AVDictionary *metadata;
689
690 /**
691 * Average framerate
692 */
693 AVRational avg_frame_rate;
694
695 /**
696 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
697 * will contain the attached picture.
698 *
699 * decoding: set by libavformat, must not be modified by the caller.
700 * encoding: unused
701 */
702 AVPacket attached_pic;
703
704 /*****************************************************************
705 * All fields below this line are not part of the public API. They
706 * may not be used outside of libavformat and can be changed and
707 * removed at will.
708 * New public fields should be added right above.
709 *****************************************************************
710 */
711
712 /**
713 * Stream information used internally by av_find_stream_info()
714 */
715 #define MAX_STD_TIMEBASES (60*12+5)
716 struct {
717 int64_t last_dts;
718 int64_t duration_gcd;
719 int duration_count;
720 double duration_error[MAX_STD_TIMEBASES];
721 int64_t codec_info_duration;
722 int nb_decoded_frames;
723 int found_decoder;
724 } *info;
725
726 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
727
728 // Timestamp generation support:
729 /**
730 * Timestamp corresponding to the last dts sync point.
731 *
732 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
733 * a DTS is received from the underlying container. Otherwise set to
734 * AV_NOPTS_VALUE by default.
735 */
736 int64_t reference_dts;
737 int64_t first_dts;
738 int64_t cur_dts;
739 int64_t last_IP_pts;
740 int last_IP_duration;
741
742 /**
743 * Number of packets to buffer for codec probing
744 */
745 #define MAX_PROBE_PACKETS 2500
746 int probe_packets;
747
748 /**
749 * Number of frames that have been demuxed during av_find_stream_info()
750 */
751 int codec_info_nb_frames;
752
753 /* av_read_frame() support */
754 enum AVStreamParseType need_parsing;
755 struct AVCodecParserContext *parser;
756
757 /**
758 * last packet in packet_buffer for this stream when muxing.
759 */
760 struct AVPacketList *last_in_packet_buffer;
761 AVProbeData probe_data;
762 #define MAX_REORDER_DELAY 16
763 int64_t pts_buffer[MAX_REORDER_DELAY+1];
764
765 AVIndexEntry *index_entries; /**< Only used if the format does not
766 support seeking natively. */
767 int nb_index_entries;
768 unsigned int index_entries_allocated_size;
769 } AVStream;
770
771 #define AV_PROGRAM_RUNNING 1
772
773 /**
774 * New fields can be added to the end with minor version bumps.
775 * Removal, reordering and changes to existing fields require a major
776 * version bump.
777 * sizeof(AVProgram) must not be used outside libav*.
778 */
779 typedef struct AVProgram {
780 int id;
781 int flags;
782 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
783 unsigned int *stream_index;
784 unsigned int nb_stream_indexes;
785 AVDictionary *metadata;
786 } AVProgram;
787
788 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
789 (streams are added dynamically) */
790
791 typedef struct AVChapter {
792 int id; ///< unique ID to identify the chapter
793 AVRational time_base; ///< time base in which the start/end timestamps are specified
794 int64_t start, end; ///< chapter start/end time in time_base units
795 AVDictionary *metadata;
796 } AVChapter;
797
798 /**
799 * Format I/O context.
800 * New fields can be added to the end with minor version bumps.
801 * Removal, reordering and changes to existing fields require a major
802 * version bump.
803 * sizeof(AVFormatContext) must not be used outside libav*, use
804 * avformat_alloc_context() to create an AVFormatContext.
805 */
806 typedef struct AVFormatContext {
807 /**
808 * A class for logging and AVOptions. Set by avformat_alloc_context().
809 * Exports (de)muxer private options if they exist.
810 */
811 const AVClass *av_class;
812
813 /**
814 * Can only be iformat or oformat, not both at the same time.
815 *
816 * decoding: set by avformat_open_input().
817 * encoding: set by the user.
818 */
819 struct AVInputFormat *iformat;
820 struct AVOutputFormat *oformat;
821
822 /**
823 * Format private data. This is an AVOptions-enabled struct
824 * if and only if iformat/oformat.priv_class is not NULL.
825 */
826 void *priv_data;
827
828 /**
829 * I/O context.
830 *
831 * decoding: either set by the user before avformat_open_input() (then
832 * the user must close it manually) or set by avformat_open_input().
833 * encoding: set by the user.
834 *
835 * Do NOT set this field if AVFMT_NOFILE flag is set in
836 * iformat/oformat.flags. In such a case, the (de)muxer will handle
837 * I/O in some other way and this field will be NULL.
838 */
839 AVIOContext *pb;
840
841 /* stream info */
842 int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
843
844 /**
845 * A list of all streams in the file. New streams are created with
846 * avformat_new_stream().
847 *
848 * decoding: streams are created by libavformat in avformat_open_input().
849 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
850 * appear in av_read_frame().
851 * encoding: streams are created by the user before avformat_write_header().
852 */
853 unsigned int nb_streams;
854 AVStream **streams;
855
856 char filename[1024]; /**< input or output filename */
857
858 /**
859 * Decoding: position of the first frame of the component, in
860 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
861 * It is deduced from the AVStream values.
862 */
863 int64_t start_time;
864
865 /**
866 * Decoding: duration of the stream, in AV_TIME_BASE fractional
867 * seconds. Only set this value if you know none of the individual stream
868 * durations and also do not set any of them. This is deduced from the
869 * AVStream values if not set.
870 */
871 int64_t duration;
872
873 /**
874 * Decoding: total stream bitrate in bit/s, 0 if not
875 * available. Never set it directly if the file_size and the
876 * duration are known as Libav can compute it automatically.
877 */
878 int bit_rate;
879
880 unsigned int packet_size;
881 int max_delay;
882
883 int flags;
884 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
885 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
886 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
887 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
888 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
889 #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
890 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
891 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
892
893 /**
894 * decoding: size of data to probe; encoding: unused.
895 */
896 unsigned int probesize;
897
898 /**
899 * decoding: maximum time (in AV_TIME_BASE units) during which the input should
900 * be analyzed in avformat_find_stream_info().
901 */
902 int max_analyze_duration;
903
904 const uint8_t *key;
905 int keylen;
906
907 unsigned int nb_programs;
908 AVProgram **programs;
909
910 /**
911 * Forced video codec_id.
912 * Demuxing: Set by user.
913 */
914 enum CodecID video_codec_id;
915
916 /**
917 * Forced audio codec_id.
918 * Demuxing: Set by user.
919 */
920 enum CodecID audio_codec_id;
921
922 /**
923 * Forced subtitle codec_id.
924 * Demuxing: Set by user.
925 */
926 enum CodecID subtitle_codec_id;
927
928 /**
929 * Maximum amount of memory in bytes to use for the index of each stream.
930 * If the index exceeds this size, entries will be discarded as
931 * needed to maintain a smaller size. This can lead to slower or less
932 * accurate seeking (depends on demuxer).
933 * Demuxers for which a full in-memory index is mandatory will ignore
934 * this.
935 * muxing : unused
936 * demuxing: set by user
937 */
938 unsigned int max_index_size;
939
940 /**
941 * Maximum amount of memory in bytes to use for buffering frames
942 * obtained from realtime capture devices.
943 */
944 unsigned int max_picture_buffer;
945
946 unsigned int nb_chapters;
947 AVChapter **chapters;
948
949 AVDictionary *metadata;
950
951 /**
952 * Start time of the stream in real world time, in microseconds
953 * since the unix epoch (00:00 1st January 1970). That is, pts=0
954 * in the stream was captured at this real world time.
955 * - encoding: Set by user.
956 * - decoding: Unused.
957 */
958 int64_t start_time_realtime;
959
960 /**
961 * decoding: number of frames used to probe fps
962 */
963 int fps_probe_size;
964
965 /**
966 * Error recognition; higher values will detect more errors but may
967 * misdetect some more or less valid parts as errors.
968 * - encoding: unused
969 * - decoding: Set by user.
970 */
971 int error_recognition;
972
973 /**
974 * Custom interrupt callbacks for the I/O layer.
975 *
976 * decoding: set by the user before avformat_open_input().
977 * encoding: set by the user before avformat_write_header()
978 * (mainly useful for AVFMT_NOFILE formats). The callback
979 * should also be passed to avio_open2() if it's used to
980 * open the file.
981 */
982 AVIOInterruptCB interrupt_callback;
983
984 /**
985 * Flags to enable debugging.
986 */
987 int debug;
988 #define FF_FDEBUG_TS 0x0001
989 /*****************************************************************
990 * All fields below this line are not part of the public API. They
991 * may not be used outside of libavformat and can be changed and
992 * removed at will.
993 * New public fields should be added right above.
994 *****************************************************************
995 */
996
997 /**
998 * This buffer is only needed when packets were already buffered but
999 * not decoded, for example to get the codec parameters in MPEG
1000 * streams.
1001 */
1002 struct AVPacketList *packet_buffer;
1003 struct AVPacketList *packet_buffer_end;
1004
1005 /* av_seek_frame() support */
1006 int64_t data_offset; /**< offset of the first packet */
1007
1008 /**
1009 * Raw packets from the demuxer, prior to parsing and decoding.
1010 * This buffer is used for buffering packets until the codec can
1011 * be identified, as parsing cannot be done without knowing the
1012 * codec.
1013 */
1014 struct AVPacketList *raw_packet_buffer;
1015 struct AVPacketList *raw_packet_buffer_end;
1016 /**
1017 * Packets split by the parser get queued here.
1018 */
1019 struct AVPacketList *parse_queue;
1020 struct AVPacketList *parse_queue_end;
1021 /**
1022 * Remaining size available for raw_packet_buffer, in bytes.
1023 */
1024 #define RAW_PACKET_BUFFER_SIZE 2500000
1025 int raw_packet_buffer_remaining_size;
1026 } AVFormatContext;
1027
1028 typedef struct AVPacketList {
1029 AVPacket pkt;
1030 struct AVPacketList *next;
1031 } AVPacketList;
1032
1033
1034 /**
1035 * @defgroup lavf_core Core functions
1036 * @ingroup libavf
1037 *
1038 * Functions for querying libavformat capabilities, allocating core structures,
1039 * etc.
1040 * @{
1041 */
1042
1043 /**
1044 * Return the LIBAVFORMAT_VERSION_INT constant.
1045 */
1046 unsigned avformat_version(void);
1047
1048 /**
1049 * Return the libavformat build-time configuration.
1050 */
1051 const char *avformat_configuration(void);
1052
1053 /**
1054 * Return the libavformat license.
1055 */
1056 const char *avformat_license(void);
1057
1058 /**
1059 * Initialize libavformat and register all the muxers, demuxers and
1060 * protocols. If you do not call this function, then you can select
1061 * exactly which formats you want to support.
1062 *
1063 * @see av_register_input_format()
1064 * @see av_register_output_format()
1065 * @see av_register_protocol()
1066 */
1067 void av_register_all(void);
1068
1069 void av_register_input_format(AVInputFormat *format);
1070 void av_register_output_format(AVOutputFormat *format);
1071
1072 /**
1073 * Do global initialization of network components. This is optional,
1074 * but recommended, since it avoids the overhead of implicitly
1075 * doing the setup for each session.
1076 *
1077 * Calling this function will become mandatory if using network
1078 * protocols at some major version bump.
1079 */
1080 int avformat_network_init(void);
1081
1082 /**
1083 * Undo the initialization done by avformat_network_init.
1084 */
1085 int avformat_network_deinit(void);
1086
1087 /**
1088 * If f is NULL, returns the first registered input format,
1089 * if f is non-NULL, returns the next registered input format after f
1090 * or NULL if f is the last one.
1091 */
1092 AVInputFormat *av_iformat_next(AVInputFormat *f);
1093
1094 /**
1095 * If f is NULL, returns the first registered output format,
1096 * if f is non-NULL, returns the next registered output format after f
1097 * or NULL if f is the last one.
1098 */
1099 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1100
1101 /**
1102 * Allocate an AVFormatContext.
1103 * avformat_free_context() can be used to free the context and everything
1104 * allocated by the framework within it.
1105 */
1106 AVFormatContext *avformat_alloc_context(void);
1107
1108 /**
1109 * Free an AVFormatContext and all its streams.
1110 * @param s context to free
1111 */
1112 void avformat_free_context(AVFormatContext *s);
1113
1114 /**
1115 * Get the AVClass for AVFormatContext. It can be used in combination with
1116 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1117 *
1118 * @see av_opt_find().
1119 */
1120 const AVClass *avformat_get_class(void);
1121
1122 /**
1123 * Add a new stream to a media file.
1124 *
1125 * When demuxing, it is called by the demuxer in read_header(). If the
1126 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1127 * be called in read_packet().
1128 *
1129 * When muxing, should be called by the user before avformat_write_header().
1130 *
1131 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1132 * will be initialized to use this codec. This is needed for e.g. codec-specific
1133 * defaults to be set, so codec should be provided if it is known.
1134 *
1135 * @return newly created stream or NULL on error.
1136 */
1137 AVStream *avformat_new_stream(AVFormatContext *s, AVCodec *c);
1138
1139 AVProgram *av_new_program(AVFormatContext *s, int id);
1140
1141 /**
1142 * @}
1143 */
1144
1145
1146 /**
1147 * @addtogroup lavf_decoding
1148 * @{
1149 */
1150
1151 /**
1152 * Find AVInputFormat based on the short name of the input format.
1153 */
1154 AVInputFormat *av_find_input_format(const char *short_name);
1155
1156 /**
1157 * Guess the file format.
1158 *
1159 * @param is_opened Whether the file is already opened; determines whether
1160 * demuxers with or without AVFMT_NOFILE are probed.
1161 */
1162 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1163
1164 /**
1165 * Guess the file format.
1166 *
1167 * @param is_opened Whether the file is already opened; determines whether
1168 * demuxers with or without AVFMT_NOFILE are probed.
1169 * @param score_max A probe score larger that this is required to accept a
1170 * detection, the variable is set to the actual detection
1171 * score afterwards.
1172 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1173 * to retry with a larger probe buffer.
1174 */
1175 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1176
1177 /**
1178 * Probe a bytestream to determine the input format. Each time a probe returns
1179 * with a score that is too low, the probe buffer size is increased and another
1180 * attempt is made. When the maximum probe size is reached, the input format
1181 * with the highest score is returned.
1182 *
1183 * @param pb the bytestream to probe
1184 * @param fmt the input format is put here
1185 * @param filename the filename of the stream
1186 * @param logctx the log context
1187 * @param offset the offset within the bytestream to probe from
1188 * @param max_probe_size the maximum probe buffer size (zero for default)
1189 * @return 0 in case of success, a negative value corresponding to an
1190 * AVERROR code otherwise
1191 */
1192 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1193 const char *filename, void *logctx,
1194 unsigned int offset, unsigned int max_probe_size);
1195
1196 /**
1197 * Open an input stream and read the header. The codecs are not opened.
1198 * The stream must be closed with av_close_input_file().
1199 *
1200 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1201 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1202 * function and written into ps.
1203 * Note that a user-supplied AVFormatContext will be freed on failure.
1204 * @param filename Name of the stream to open.
1205 * @param fmt If non-NULL, this parameter forces a specific input format.
1206 * Otherwise the format is autodetected.
1207 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1208 * On return this parameter will be destroyed and replaced with a dict containing
1209 * options that were not found. May be NULL.
1210 *
1211 * @return 0 on success, a negative AVERROR on failure.
1212 *
1213 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1214 */
1215 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1216
1217 /**
1218 * Read packets of a media file to get stream information. This
1219 * is useful for file formats with no headers such as MPEG. This
1220 * function also computes the real framerate in case of MPEG-2 repeat
1221 * frame mode.
1222 * The logical file position is not changed by this function;
1223 * examined packets may be buffered for later processing.
1224 *
1225 * @param ic media file handle
1226 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1227 * dictionaries, where i-th member contains options for
1228 * codec corresponding to i-th stream.
1229 * On return each dictionary will be filled with options that were not found.
1230 * @return >=0 if OK, AVERROR_xxx on error
1231 *
1232 * @note this function isn't guaranteed to open all the codecs, so
1233 * options being non-empty at return is a perfectly normal behavior.
1234 *
1235 * @todo Let the user decide somehow what information is needed so that
1236 * we do not waste time getting stuff the user does not need.
1237 */
1238 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1239
1240 /**
1241 * Find the "best" stream in the file.
1242 * The best stream is determined according to various heuristics as the most
1243 * likely to be what the user expects.
1244 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1245 * default decoder for the stream's codec; streams for which no decoder can
1246 * be found are ignored.
1247 *
1248 * @param ic media file handle
1249 * @param type stream type: video, audio, subtitles, etc.
1250 * @param wanted_stream_nb user-requested stream number,
1251 * or -1 for automatic selection
1252 * @param related_stream try to find a stream related (eg. in the same
1253 * program) to this one, or -1 if none
1254 * @param decoder_ret if non-NULL, returns the decoder for the
1255 * selected stream
1256 * @param flags flags; none are currently defined
1257 * @return the non-negative stream number in case of success,
1258 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
1259 * could be found,
1260 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
1261 * @note If av_find_best_stream returns successfully and decoder_ret is not
1262 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
1263 */
1264 int av_find_best_stream(AVFormatContext *ic,
1265 enum AVMediaType type,
1266 int wanted_stream_nb,
1267 int related_stream,
1268 AVCodec **decoder_ret,
1269 int flags);
1270
1271 #if FF_API_READ_PACKET
1272 /**
1273 * @deprecated use AVFMT_FLAG_NOFILLIN | AVFMT_FLAG_NOPARSE to read raw
1274 * unprocessed packets
1275 *
1276 * Read a transport packet from a media file.
1277 *
1278 * This function is obsolete and should never be used.
1279 * Use av_read_frame() instead.
1280 *
1281 * @param s media file handle
1282 * @param pkt is filled
1283 * @return 0 if OK, AVERROR_xxx on error
1284 */
1285 attribute_deprecated
1286 int av_read_packet(AVFormatContext *s, AVPacket *pkt);
1287 #endif
1288
1289 /**
1290 * Return the next frame of a stream.
1291 * This function returns what is stored in the file, and does not validate
1292 * that what is there are valid frames for the decoder. It will split what is
1293 * stored in the file into frames and return one for each call. It will not
1294 * omit invalid data between valid frames so as to give the decoder the maximum
1295 * information possible for decoding.
1296 *
1297 * The returned packet is valid
1298 * until the next av_read_frame() or until av_close_input_file() and
1299 * must be freed with av_free_packet. For video, the packet contains
1300 * exactly one frame. For audio, it contains an integer number of
1301 * frames if each frame has a known fixed size (e.g. PCM or ADPCM
1302 * data). If the audio frames have a variable size (e.g. MPEG audio),
1303 * then it contains one frame.
1304 *
1305 * pkt->pts, pkt->dts and pkt->duration are always set to correct
1306 * values in AVStream.time_base units (and guessed if the format cannot
1307 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
1308 * has B-frames, so it is better to rely on pkt->dts if you do not
1309 * decompress the payload.
1310 *
1311 * @return 0 if OK, < 0 on error or end of file
1312 */
1313 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
1314
1315 /**
1316 * Seek to the keyframe at timestamp.
1317 * 'timestamp' in 'stream_index'.
1318 * @param stream_index If stream_index is (-1), a default
1319 * stream is selected, and timestamp is automatically converted
1320 * from AV_TIME_BASE units to the stream specific time_base.
1321 * @param timestamp Timestamp in AVStream.time_base units
1322 * or, if no stream is specified, in AV_TIME_BASE units.
1323 * @param flags flags which select direction and seeking mode
1324 * @return >= 0 on success
1325 */
1326 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
1327 int flags);
1328
1329 /**
1330 * Seek to timestamp ts.
1331 * Seeking will be done so that the point from which all active streams
1332 * can be presented successfully will be closest to ts and within min/max_ts.
1333 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
1334 *
1335 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
1336 * are the file position (this may not be supported by all demuxers).
1337 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
1338 * in the stream with stream_index (this may not be supported by all demuxers).
1339 * Otherwise all timestamps are in units of the stream selected by stream_index
1340 * or if stream_index is -1, in AV_TIME_BASE units.
1341 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
1342 * keyframes (this may not be supported by all demuxers).
1343 *
1344 * @param stream_index index of the stream which is used as time base reference
1345 * @param min_ts smallest acceptable timestamp
1346 * @param ts target timestamp
1347 * @param max_ts largest acceptable timestamp
1348 * @param flags flags
1349 * @return >=0 on success, error code otherwise
1350 *
1351 * @note This is part of the new seek API which is still under construction.
1352 * Thus do not use this yet. It may change at any time, do not expect
1353 * ABI compatibility yet!
1354 */
1355 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
1356
1357 /**
1358 * Start playing a network-based stream (e.g. RTSP stream) at the
1359 * current position.
1360 */
1361 int av_read_play(AVFormatContext *s);
1362
1363 /**
1364 * Pause a network-based stream (e.g. RTSP stream).
1365 *
1366 * Use av_read_play() to resume it.
1367 */
1368 int av_read_pause(AVFormatContext *s);
1369
1370 #if FF_API_CLOSE_INPUT_FILE
1371 /**
1372 * @deprecated use avformat_close_input()
1373 * Close a media file (but not its codecs).
1374 *
1375 * @param s media file handle
1376 */
1377 attribute_deprecated
1378 void av_close_input_file(AVFormatContext *s);
1379 #endif
1380
1381 /**
1382 * Close an opened input AVFormatContext. Free it and all its contents
1383 * and set *s to NULL.
1384 */
1385 void avformat_close_input(AVFormatContext **s);
1386 /**
1387 * @}
1388 */
1389
1390 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
1391 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
1392 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
1393 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
1394
1395 /**
1396 * @addtogroup lavf_encoding
1397 * @{
1398 */
1399 /**
1400 * Allocate the stream private data and write the stream header to
1401 * an output media file.
1402 *
1403 * @param s Media file handle, must be allocated with avformat_alloc_context().
1404 * Its oformat field must be set to the desired output format;
1405 * Its pb field must be set to an already openened AVIOContext.
1406 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
1407 * On return this parameter will be destroyed and replaced with a dict containing
1408 * options that were not found. May be NULL.
1409 *
1410 * @return 0 on success, negative AVERROR on failure.
1411 *
1412 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
1413 */
1414 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
1415
1416 /**
1417 * Write a packet to an output media file.
1418 *
1419 * The packet shall contain one audio or video frame.
1420 * The packet must be correctly interleaved according to the container
1421 * specification, if not then av_interleaved_write_frame must be used.
1422 *
1423 * @param s media file handle
1424 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1425 * dts/pts, ...
1426 * This can be NULL (at any time, not just at the end), in
1427 * order to immediately flush data buffered within the muxer,
1428 * for muxers that buffer up data internally before writing it
1429 * to the output.
1430 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
1431 */
1432 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
1433
1434 /**
1435 * Write a packet to an output media file ensuring correct interleaving.
1436 *
1437 * The packet must contain one audio or video frame.
1438 * If the packets are already correctly interleaved, the application should
1439 * call av_write_frame() instead as it is slightly faster. It is also important
1440 * to keep in mind that completely non-interleaved input will need huge amounts
1441 * of memory to interleave with this, so it is preferable to interleave at the
1442 * demuxer level.
1443 *
1444 * @param s media file handle
1445 * @param pkt The packet containing the data to be written. Libavformat takes
1446 * ownership of the data and will free it when it sees fit using the packet's
1447 * This can be NULL (at any time, not just at the end), to flush the
1448 * interleaving queues.
1449 * @ref AVPacket.destruct "destruct" field. The caller must not access the data
1450 * after this function returns, as it may already be freed.
1451 * Packet's @ref AVPacket.stream_index "stream_index" field must be set to the
1452 * index of the corresponding stream in @ref AVFormatContext.streams
1453 * "s.streams".
1454 * It is very strongly recommended that timing information (@ref AVPacket.pts
1455 * "pts", @ref AVPacket.dts "dts" @ref AVPacket.duration "duration") is set to
1456 * correct values.
1457 *
1458 * @return 0 on success, a negative AVERROR on error.
1459 */
1460 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
1461
1462 #if FF_API_INTERLEAVE_PACKET
1463 /**
1464 * @deprecated this function was never meant to be called by the user
1465 * programs.
1466 */
1467 attribute_deprecated
1468 int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
1469 AVPacket *pkt, int flush);
1470 #endif
1471
1472 /**
1473 * Write the stream trailer to an output media file and free the
1474 * file private data.
1475 *
1476 * May only be called after a successful call to av_write_header.
1477 *
1478 * @param s media file handle
1479 * @return 0 if OK, AVERROR_xxx on error
1480 */
1481 int av_write_trailer(AVFormatContext *s);
1482
1483 /**
1484 * Return the output format in the list of registered output formats
1485 * which best matches the provided parameters, or return NULL if
1486 * there is no match.
1487 *
1488 * @param short_name if non-NULL checks if short_name matches with the
1489 * names of the registered formats
1490 * @param filename if non-NULL checks if filename terminates with the
1491 * extensions of the registered formats
1492 * @param mime_type if non-NULL checks if mime_type matches with the
1493 * MIME type of the registered formats
1494 */
1495 AVOutputFormat *av_guess_format(const char *short_name,
1496 const char *filename,
1497 const char *mime_type);
1498
1499 /**
1500 * Guess the codec ID based upon muxer and filename.
1501 */
1502 enum CodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
1503 const char *filename, const char *mime_type,
1504 enum AVMediaType type);
1505
1506 /**
1507 * @}
1508 */
1509
1510
1511 /**
1512 * @defgroup lavf_misc Utility functions
1513 * @ingroup libavf
1514 * @{
1515 *
1516 * Miscelaneous utility functions related to both muxing and demuxing
1517 * (or neither).
1518 */
1519
1520 /**
1521 * Send a nice hexadecimal dump of a buffer to the specified file stream.
1522 *
1523 * @param f The file stream pointer where the dump should be sent to.
1524 * @param buf buffer
1525 * @param size buffer size
1526 *
1527 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
1528 */
1529 void av_hex_dump(FILE *f, uint8_t *buf, int size);
1530
1531 /**
1532 * Send a nice hexadecimal dump of a buffer to the log.
1533 *
1534 * @param avcl A pointer to an arbitrary struct of which the first field is a
1535 * pointer to an AVClass struct.
1536 * @param level The importance level of the message, lower values signifying
1537 * higher importance.
1538 * @param buf buffer
1539 * @param size buffer size
1540 *
1541 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
1542 */
1543 void av_hex_dump_log(void *avcl, int level, uint8_t *buf, int size);
1544
1545 /**
1546 * Send a nice dump of a packet to the specified file stream.
1547 *
1548 * @param f The file stream pointer where the dump should be sent to.
1549 * @param pkt packet to dump
1550 * @param dump_payload True if the payload must be displayed, too.
1551 * @param st AVStream that the packet belongs to
1552 */
1553 void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
1554
1555
1556 /**
1557 * Send a nice dump of a packet to the log.
1558 *
1559 * @param avcl A pointer to an arbitrary struct of which the first field is a
1560 * pointer to an AVClass struct.
1561 * @param level The importance level of the message, lower values signifying
1562 * higher importance.
1563 * @param pkt packet to dump
1564 * @param dump_payload True if the payload must be displayed, too.
1565 * @param st AVStream that the packet belongs to
1566 */
1567 void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
1568 AVStream *st);
1569
1570 /**
1571 * Get the CodecID for the given codec tag tag.
1572 * If no codec id is found returns CODEC_ID_NONE.
1573 *
1574 * @param tags list of supported codec_id-codec_tag pairs, as stored
1575 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1576 */
1577 enum CodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
1578
1579 /**
1580 * Get the codec tag for the given codec id id.
1581 * If no codec tag is found returns 0.
1582 *
1583 * @param tags list of supported codec_id-codec_tag pairs, as stored
1584 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1585 */
1586 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum CodecID id);
1587
1588 int av_find_default_stream_index(AVFormatContext *s);
1589
1590 /**
1591 * Get the index for a specific timestamp.
1592 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
1593 * to the timestamp which is <= the requested one, if backward
1594 * is 0, then it will be >=
1595 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
1596 * @return < 0 if no such timestamp could be found
1597 */
1598 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
1599
1600 /**
1601 * Add an index entry into a sorted list. Update the entry if the list
1602 * already contains it.
1603 *
1604 * @param timestamp timestamp in the time base of the given stream
1605 */
1606 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
1607 int size, int distance, int flags);
1608
1609
1610 /**
1611 * Split a URL string into components.
1612 *
1613 * The pointers to buffers for storing individual components may be null,
1614 * in order to ignore that component. Buffers for components not found are
1615 * set to empty strings. If the port is not found, it is set to a negative
1616 * value.
1617 *
1618 * @param proto the buffer for the protocol
1619 * @param proto_size the size of the proto buffer
1620 * @param authorization the buffer for the authorization
1621 * @param authorization_size the size of the authorization buffer
1622 * @param hostname the buffer for the host name
1623 * @param hostname_size the size of the hostname buffer
1624 * @param port_ptr a pointer to store the port number in
1625 * @param path the buffer for the path
1626 * @param path_size the size of the path buffer
1627 * @param url the URL to split
1628 */
1629 void av_url_split(char *proto, int proto_size,
1630 char *authorization, int authorization_size,
1631 char *hostname, int hostname_size,
1632 int *port_ptr,
1633 char *path, int path_size,
1634 const char *url);
1635
1636
1637 void av_dump_format(AVFormatContext *ic,
1638 int index,
1639 const char *url,
1640 int is_output);
1641
1642 /**
1643 * Return in 'buf' the path with '%d' replaced by a number.
1644 *
1645 * Also handles the '%0nd' format where 'n' is the total number
1646 * of digits and '%%'.
1647 *
1648 * @param buf destination buffer
1649 * @param buf_size destination buffer size
1650 * @param path numbered sequence string
1651 * @param number frame number
1652 * @return 0 if OK, -1 on format error
1653 */
1654 int av_get_frame_filename(char *buf, int buf_size,
1655 const char *path, int number);
1656
1657 /**
1658 * Check whether filename actually is a numbered sequence generator.
1659 *
1660 * @param filename possible numbered sequence string
1661 * @return 1 if a valid numbered sequence string, 0 otherwise
1662 */
1663 int av_filename_number_test(const char *filename);
1664
1665 /**
1666 * Generate an SDP for an RTP session.
1667 *
1668 * @param ac array of AVFormatContexts describing the RTP streams. If the
1669 * array is composed by only one context, such context can contain
1670 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
1671 * all the contexts in the array (an AVCodecContext per RTP stream)
1672 * must contain only one AVStream.
1673 * @param n_files number of AVCodecContexts contained in ac
1674 * @param buf buffer where the SDP will be stored (must be allocated by
1675 * the caller)
1676 * @param size the size of the buffer
1677 * @return 0 if OK, AVERROR_xxx on error
1678 */
1679 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
1680
1681 /**
1682 * Return a positive value if the given filename has one of the given
1683 * extensions, 0 otherwise.
1684 *
1685 * @param extensions a comma-separated list of filename extensions
1686 */
1687 int av_match_ext(const char *filename, const char *extensions);
1688
1689 /**
1690 * Test if the given container can store a codec.
1691 *
1692 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
1693 *
1694 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
1695 * A negative number if this information is not available.
1696 */
1697 int avformat_query_codec(AVOutputFormat *ofmt, enum CodecID codec_id, int std_compliance);
1698
1699 /**
1700 * @defgroup riff_fourcc RIFF FourCCs
1701 * @{
1702 * Get the tables mapping RIFF FourCCs to libavcodec CodecIDs. The tables are
1703 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
1704 * following code:
1705 * @code
1706 * uint32_t tag = MKTAG('H', '2', '6', '4');
1707 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
1708 * enum CodecID id = av_codec_get_id(table, tag);
1709 * @endcode
1710 */
1711 /**
1712 * @return the table mapping RIFF FourCCs for video to libavcodec CodecID.
1713 */
1714 const struct AVCodecTag *avformat_get_riff_video_tags(void);
1715 /**
1716 * @return the table mapping RIFF FourCCs for audio to CodecID.
1717 */
1718 const struct AVCodecTag *avformat_get_riff_audio_tags(void);
1719 /**
1720 * @}
1721 */
1722
1723 /**
1724 * @}
1725 */
1726
1727 #endif /* AVFORMAT_AVFORMAT_H */