82d245e6884a17acbc60342c387cc1e863aa7687
[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 /**
26 * Return the LIBAVFORMAT_VERSION_INT constant.
27 */
28 unsigned avformat_version(void);
29
30 /**
31 * Return the libavformat build-time configuration.
32 */
33 const char *avformat_configuration(void);
34
35 /**
36 * Return the libavformat license.
37 */
38 const char *avformat_license(void);
39
40 #include <time.h>
41 #include <stdio.h> /* FILE */
42 #include "libavcodec/avcodec.h"
43 #include "libavutil/dict.h"
44 #include "libavutil/log.h"
45
46 #include "avio.h"
47 #include "libavformat/version.h"
48
49 struct AVFormatContext;
50
51
52 /**
53 * @defgroup metadata_api Public Metadata API
54 * @{
55 * The metadata API allows libavformat to export metadata tags to a client
56 * application using a sequence of key/value pairs. Like all strings in Libav,
57 * metadata must be stored as UTF-8 encoded Unicode. Note that metadata
58 * exported by demuxers isn't checked to be valid UTF-8 in most cases.
59 * Important concepts to keep in mind:
60 * - Keys are unique; there can never be 2 tags with the same key. This is
61 * also meant semantically, i.e., a demuxer should not knowingly produce
62 * several keys that are literally different but semantically identical.
63 * E.g., key=Author5, key=Author6. In this example, all authors must be
64 * placed in the same tag.
65 * - Metadata is flat, not hierarchical; there are no subtags. If you
66 * want to store, e.g., the email address of the child of producer Alice
67 * and actor Bob, that could have key=alice_and_bobs_childs_email_address.
68 * - Several modifiers can be applied to the tag name. This is done by
69 * appending a dash character ('-') and the modifier name in the order
70 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
71 * - language -- a tag whose value is localized for a particular language
72 * is appended with the ISO 639-2/B 3-letter language code.
73 * For example: Author-ger=Michael, Author-eng=Mike
74 * The original/default language is in the unqualified "Author" tag.
75 * A demuxer should set a default if it sets any translated tag.
76 * - sorting -- a modified version of a tag that should be used for
77 * sorting will have '-sort' appended. E.g. artist="The Beatles",
78 * artist-sort="Beatles, The".
79 *
80 * - Demuxers attempt to export metadata in a generic format, however tags
81 * with no generic equivalents are left as they are stored in the container.
82 * Follows a list of generic tag names:
83 *
84 @verbatim
85 album -- name of the set this work belongs to
86 album_artist -- main creator of the set/album, if different from artist.
87 e.g. "Various Artists" for compilation albums.
88 artist -- main creator of the work
89 comment -- any additional description of the file.
90 composer -- who composed the work, if different from artist.
91 copyright -- name of copyright holder.
92 creation_time-- date when the file was created, preferably in ISO 8601.
93 date -- date when the work was created, preferably in ISO 8601.
94 disc -- number of a subset, e.g. disc in a multi-disc collection.
95 encoder -- name/settings of the software/hardware that produced the file.
96 encoded_by -- person/group who created the file.
97 filename -- original name of the file.
98 genre -- <self-evident>.
99 language -- main language in which the work is performed, preferably
100 in ISO 639-2 format. Multiple languages can be specified by
101 separating them with commas.
102 performer -- artist who performed the work, if different from artist.
103 E.g for "Also sprach Zarathustra", artist would be "Richard
104 Strauss" and performer "London Philharmonic Orchestra".
105 publisher -- name of the label/publisher.
106 service_name -- name of the service in broadcasting (channel name).
107 service_provider -- name of the service provider in broadcasting.
108 title -- name of the work.
109 track -- number of this work in the set, can be in form current/total.
110 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
111 @endverbatim
112 *
113 * Look in the examples section for an application example how to use the Metadata API.
114 *
115 * @}
116 */
117
118 #if FF_API_OLD_METADATA2
119 /**
120 * @defgroup old_metadata Old metadata API
121 * The following functions are deprecated, use
122 * their equivalents from libavutil/dict.h instead.
123 * @{
124 */
125
126 #define AV_METADATA_MATCH_CASE AV_DICT_MATCH_CASE
127 #define AV_METADATA_IGNORE_SUFFIX AV_DICT_IGNORE_SUFFIX
128 #define AV_METADATA_DONT_STRDUP_KEY AV_DICT_DONT_STRDUP_KEY
129 #define AV_METADATA_DONT_STRDUP_VAL AV_DICT_DONT_STRDUP_VAL
130 #define AV_METADATA_DONT_OVERWRITE AV_DICT_DONT_OVERWRITE
131
132 typedef attribute_deprecated AVDictionary AVMetadata;
133 typedef attribute_deprecated AVDictionaryEntry AVMetadataTag;
134
135 typedef struct AVMetadataConv AVMetadataConv;
136
137 /**
138 * Get a metadata element with matching key.
139 *
140 * @param prev Set to the previous matching element to find the next.
141 * If set to NULL the first matching element is returned.
142 * @param flags Allows case as well as suffix-insensitive comparisons.
143 * @return Found tag or NULL, changing key or value leads to undefined behavior.
144 */
145 attribute_deprecated AVDictionaryEntry *
146 av_metadata_get(AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags);
147
148 /**
149 * Set the given tag in *pm, overwriting an existing tag.
150 *
151 * @param pm pointer to a pointer to a metadata struct. If *pm is NULL
152 * a metadata struct is allocated and put in *pm.
153 * @param key tag key to add to *pm (will be av_strduped depending on flags)
154 * @param value tag value to add to *pm (will be av_strduped depending on flags).
155 * Passing a NULL value will cause an existing tag to be deleted.
156 * @return >= 0 on success otherwise an error code <0
157 */
158 attribute_deprecated int av_metadata_set2(AVDictionary **pm, const char *key, const char *value, int flags);
159
160 /**
161 * This function is provided for compatibility reason and currently does nothing.
162 */
163 attribute_deprecated void av_metadata_conv(struct AVFormatContext *ctx, const AVMetadataConv *d_conv,
164 const AVMetadataConv *s_conv);
165
166 /**
167 * Copy metadata from one AVDictionary struct into another.
168 * @param dst pointer to a pointer to a AVDictionary struct. If *dst is NULL,
169 * this function will allocate a struct for you and put it in *dst
170 * @param src pointer to source AVDictionary struct
171 * @param flags flags to use when setting metadata in *dst
172 * @note metadata is read using the AV_DICT_IGNORE_SUFFIX flag
173 */
174 attribute_deprecated void av_metadata_copy(AVDictionary **dst, AVDictionary *src, int flags);
175
176 /**
177 * Free all the memory allocated for an AVDictionary struct.
178 */
179 attribute_deprecated void av_metadata_free(AVDictionary **m);
180 /**
181 * @}
182 */
183 #endif
184
185
186 /* packet functions */
187
188
189 /**
190 * Allocate and read the payload of a packet and initialize its
191 * fields with default values.
192 *
193 * @param pkt packet
194 * @param size desired payload size
195 * @return >0 (read size) if OK, AVERROR_xxx otherwise
196 */
197 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
198
199
200 /**
201 * Read data and append it to the current content of the AVPacket.
202 * If pkt->size is 0 this is identical to av_get_packet.
203 * Note that this uses av_grow_packet and thus involves a realloc
204 * which is inefficient. Thus this function should only be used
205 * when there is no reasonable way to know (an upper bound of)
206 * the final size.
207 *
208 * @param pkt packet
209 * @param size amount of data to read
210 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
211 * will not be lost even if an error occurs.
212 */
213 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
214
215 /*************************************************/
216 /* fractional numbers for exact pts handling */
217
218 /**
219 * The exact value of the fractional number is: 'val + num / den'.
220 * num is assumed to be 0 <= num < den.
221 */
222 typedef struct AVFrac {
223 int64_t val, num, den;
224 } AVFrac;
225
226 /*************************************************/
227 /* input/output formats */
228
229 struct AVCodecTag;
230
231 /**
232 * This structure contains the data a format has to probe a file.
233 */
234 typedef struct AVProbeData {
235 const char *filename;
236 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
237 int buf_size; /**< Size of buf except extra allocated bytes */
238 } AVProbeData;
239
240 #define AVPROBE_SCORE_MAX 100 ///< maximum score, half of that is used for file-extension-based detection
241 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer
242
243 typedef struct AVFormatParameters {
244 #if FF_API_FORMAT_PARAMETERS
245 attribute_deprecated AVRational time_base;
246 attribute_deprecated int sample_rate;
247 attribute_deprecated int channels;
248 attribute_deprecated int width;
249 attribute_deprecated int height;
250 attribute_deprecated enum PixelFormat pix_fmt;
251 attribute_deprecated int channel; /**< Used to select DV channel. */
252 attribute_deprecated const char *standard; /**< deprecated, use demuxer-specific options instead. */
253 attribute_deprecated unsigned int mpeg2ts_raw:1; /**< deprecated, use mpegtsraw demuxer */
254 /**< deprecated, use mpegtsraw demuxer-specific options instead */
255 attribute_deprecated unsigned int mpeg2ts_compute_pcr:1;
256 attribute_deprecated unsigned int initial_pause:1; /**< Do not begin to play the stream
257 immediately (RTSP only). */
258 attribute_deprecated unsigned int prealloced_context:1;
259 #endif
260 } AVFormatParameters;
261
262 //! Demuxer will use avio_open, no opened file should be provided by the caller.
263 #define AVFMT_NOFILE 0x0001
264 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */
265 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */
266 #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for
267 raw picture data. */
268 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */
269 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */
270 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
271 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
272 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */
273 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */
274 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */
275 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fallback to binary search via read_timestamp */
276 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fallback to generic search */
277 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */
278
279 typedef struct AVOutputFormat {
280 const char *name;
281 /**
282 * Descriptive name for the format, meant to be more human-readable
283 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
284 * to define it.
285 */
286 const char *long_name;
287 const char *mime_type;
288 const char *extensions; /**< comma-separated filename extensions */
289 /**
290 * size of private data so that it can be allocated in the wrapper
291 */
292 int priv_data_size;
293 /* output support */
294 enum CodecID audio_codec; /**< default audio codec */
295 enum CodecID video_codec; /**< default video codec */
296 int (*write_header)(struct AVFormatContext *);
297 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
298 int (*write_trailer)(struct AVFormatContext *);
299 /**
300 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
301 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
302 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS
303 */
304 int flags;
305 /**
306 * Currently only used to set pixel format if not YUV420P.
307 */
308 int (*set_parameters)(struct AVFormatContext *, AVFormatParameters *);
309 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
310 AVPacket *in, int flush);
311
312 /**
313 * List of supported codec_id-codec_tag pairs, ordered by "better
314 * choice first". The arrays are all terminated by CODEC_ID_NONE.
315 */
316 const struct AVCodecTag * const *codec_tag;
317
318 enum CodecID subtitle_codec; /**< default subtitle codec */
319
320 #if FF_API_OLD_METADATA2
321 const AVMetadataConv *metadata_conv;
322 #endif
323
324 const AVClass *priv_class; ///< AVClass for the private context
325
326 /**
327 * Test if the given codec can be stored in this container.
328 *
329 * @return 1 if the codec is supported, 0 if it is not.
330 * A negative number if unknown.
331 */
332 int (*query_codec)(enum CodecID id, int std_compliance);
333
334 /* private fields */
335 struct AVOutputFormat *next;
336 } AVOutputFormat;
337
338 typedef struct AVInputFormat {
339 /**
340 * A comma separated list of short names for the format. New names
341 * may be appended with a minor bump.
342 */
343 const char *name;
344
345 /**
346 * Descriptive name for the format, meant to be more human-readable
347 * than name. You should use the NULL_IF_CONFIG_SMALL() macro
348 * to define it.
349 */
350 const char *long_name;
351
352 /**
353 * Size of private data so that it can be allocated in the wrapper.
354 */
355 int priv_data_size;
356
357 /**
358 * Tell if a given file has a chance of being parsed as this format.
359 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
360 * big so you do not have to check for that unless you need more.
361 */
362 int (*read_probe)(AVProbeData *);
363
364 /**
365 * Read the format header and initialize the AVFormatContext
366 * structure. Return 0 if OK. 'ap' if non-NULL contains
367 * additional parameters. Only used in raw format right
368 * now. 'av_new_stream' should be called to create new streams.
369 */
370 int (*read_header)(struct AVFormatContext *,
371 AVFormatParameters *ap);
372
373 /**
374 * Read one packet and put it in 'pkt'. pts and flags are also
375 * set. 'av_new_stream' can be called only if the flag
376 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
377 * background thread).
378 * @return 0 on success, < 0 on error.
379 * When returning an error, pkt must not have been allocated
380 * or must be freed before returning
381 */
382 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
383
384 /**
385 * Close the stream. The AVFormatContext and AVStreams are not
386 * freed by this function
387 */
388 int (*read_close)(struct AVFormatContext *);
389
390 #if FF_API_READ_SEEK
391 /**
392 * Seek to a given timestamp relative to the frames in
393 * stream component stream_index.
394 * @param stream_index Must not be -1.
395 * @param flags Selects which direction should be preferred if no exact
396 * match is available.
397 * @return >= 0 on success (but not necessarily the new offset)
398 */
399 attribute_deprecated int (*read_seek)(struct AVFormatContext *,
400 int stream_index, int64_t timestamp, int flags);
401 #endif
402 /**
403 * Gets the next timestamp in stream[stream_index].time_base units.
404 * @return the timestamp or AV_NOPTS_VALUE if an error occurred
405 */
406 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
407 int64_t *pos, int64_t pos_limit);
408
409 /**
410 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
411 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
412 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK.
413 */
414 int flags;
415
416 /**
417 * If extensions are defined, then no probe is done. You should
418 * usually not use extension format guessing because it is not
419 * reliable enough
420 */
421 const char *extensions;
422
423 /**
424 * General purpose read-only value that the format can use.
425 */
426 int value;
427
428 /**
429 * Start/resume playing - only meaningful if using a network-based format
430 * (RTSP).
431 */
432 int (*read_play)(struct AVFormatContext *);
433
434 /**
435 * Pause playing - only meaningful if using a network-based format
436 * (RTSP).
437 */
438 int (*read_pause)(struct AVFormatContext *);
439
440 const struct AVCodecTag * const *codec_tag;
441
442 /**
443 * Seek to timestamp ts.
444 * Seeking will be done so that the point from which all active streams
445 * can be presented successfully will be closest to ts and within min/max_ts.
446 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
447 */
448 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
449
450 #if FF_API_OLD_METADATA2
451 const AVMetadataConv *metadata_conv;
452 #endif
453
454 const AVClass *priv_class; ///< AVClass for the private context
455
456 /* private fields */
457 struct AVInputFormat *next;
458 } AVInputFormat;
459
460 enum AVStreamParseType {
461 AVSTREAM_PARSE_NONE,
462 AVSTREAM_PARSE_FULL, /**< full parsing and repack */
463 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */
464 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
465 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
466 };
467
468 typedef struct AVIndexEntry {
469 int64_t pos;
470 int64_t timestamp;
471 #define AVINDEX_KEYFRAME 0x0001
472 int flags:2;
473 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).
474 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
475 } AVIndexEntry;
476
477 #define AV_DISPOSITION_DEFAULT 0x0001
478 #define AV_DISPOSITION_DUB 0x0002
479 #define AV_DISPOSITION_ORIGINAL 0x0004
480 #define AV_DISPOSITION_COMMENT 0x0008
481 #define AV_DISPOSITION_LYRICS 0x0010
482 #define AV_DISPOSITION_KARAOKE 0x0020
483
484 /**
485 * Track should be used during playback by default.
486 * Useful for subtitle track that should be displayed
487 * even when user did not explicitly ask for subtitles.
488 */
489 #define AV_DISPOSITION_FORCED 0x0040
490 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */
491 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */
492 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */
493
494 /**
495 * Stream structure.
496 * New fields can be added to the end with minor version bumps.
497 * Removal, reordering and changes to existing fields require a major
498 * version bump.
499 * sizeof(AVStream) must not be used outside libav*.
500 */
501 typedef struct AVStream {
502 int index; /**< stream index in AVFormatContext */
503 int id; /**< format-specific stream ID */
504 AVCodecContext *codec; /**< codec context */
505 /**
506 * Real base framerate of the stream.
507 * This is the lowest framerate with which all timestamps can be
508 * represented accurately (it is the least common multiple of all
509 * framerates in the stream). Note, this value is just a guess!
510 * For example, if the time base is 1/90000 and all frames have either
511 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
512 */
513 AVRational r_frame_rate;
514 void *priv_data;
515
516 #if FF_API_REORDER_PRIVATE
517 /* internal data used in av_find_stream_info() */
518 int64_t first_dts;
519 #endif
520
521 /**
522 * encoding: pts generation when outputting stream
523 */
524 struct AVFrac pts;
525
526 /**
527 * This is the fundamental unit of time (in seconds) in terms
528 * of which frame timestamps are represented. For fixed-fps content,
529 * time base should be 1/framerate and timestamp increments should be 1.
530 * decoding: set by libavformat
531 * encoding: set by libavformat in av_write_header
532 */
533 AVRational time_base;
534 #if FF_API_REORDER_PRIVATE
535 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
536 #endif
537 #if FF_API_STREAM_COPY
538 /* ffmpeg.c private use */
539 attribute_deprecated int stream_copy; /**< If set, just copy stream. */
540 #endif
541 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
542
543 #if FF_API_AVSTREAM_QUALITY
544 //FIXME move stuff to a flags field?
545 /**
546 * Quality, as it has been removed from AVCodecContext and put in AVVideoFrame.
547 * MN: dunno if that is the right place for it
548 */
549 attribute_deprecated float quality;
550 #endif
551
552 /**
553 * Decoding: pts of the first frame of the stream, in stream time base.
554 * Only set this if you are absolutely 100% sure that the value you set
555 * it to really is the pts of the first frame.
556 * This may be undefined (AV_NOPTS_VALUE).
557 */
558 int64_t start_time;
559
560 /**
561 * Decoding: duration of the stream, in stream time base.
562 * If a source file does not specify a duration, but does specify
563 * a bitrate, this value will be estimated from bitrate and file size.
564 */
565 int64_t duration;
566
567 #if FF_API_REORDER_PRIVATE
568 /* av_read_frame() support */
569 enum AVStreamParseType need_parsing;
570 struct AVCodecParserContext *parser;
571
572 int64_t cur_dts;
573 int last_IP_duration;
574 int64_t last_IP_pts;
575 /* av_seek_frame() support */
576 AVIndexEntry *index_entries; /**< Only used if the format does not
577 support seeking natively. */
578 int nb_index_entries;
579 unsigned int index_entries_allocated_size;
580 #endif
581
582 int64_t nb_frames; ///< number of frames in this stream if known or 0
583
584 int disposition; /**< AV_DISPOSITION_* bit field */
585
586 #if FF_API_REORDER_PRIVATE
587 AVProbeData probe_data;
588 #define MAX_REORDER_DELAY 16
589 int64_t pts_buffer[MAX_REORDER_DELAY+1];
590 #endif
591
592 /**
593 * sample aspect ratio (0 if unknown)
594 * - encoding: Set by user.
595 * - decoding: Set by libavformat.
596 */
597 AVRational sample_aspect_ratio;
598
599 AVDictionary *metadata;
600
601 #if FF_API_REORDER_PRIVATE
602 /* Intended mostly for av_read_frame() support. Not supposed to be used by */
603 /* external applications; try to use something else if at all possible. */
604 const uint8_t *cur_ptr;
605 int cur_len;
606 AVPacket cur_pkt;
607
608 // Timestamp generation support:
609 /**
610 * Timestamp corresponding to the last dts sync point.
611 *
612 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
613 * a DTS is received from the underlying container. Otherwise set to
614 * AV_NOPTS_VALUE by default.
615 */
616 int64_t reference_dts;
617
618 /**
619 * Number of packets to buffer for codec probing
620 * NOT PART OF PUBLIC API
621 */
622 #define MAX_PROBE_PACKETS 2500
623 int probe_packets;
624
625 /**
626 * last packet in packet_buffer for this stream when muxing.
627 * used internally, NOT PART OF PUBLIC API, dont read or write from outside of libav*
628 */
629 struct AVPacketList *last_in_packet_buffer;
630 #endif
631
632 /**
633 * Average framerate
634 */
635 AVRational avg_frame_rate;
636
637 /*****************************************************************
638 * All fields below this line are not part of the public API. They
639 * may not be used outside of libavformat and can be changed and
640 * removed at will.
641 * New public fields should be added right above.
642 *****************************************************************
643 */
644
645 /**
646 * Number of frames that have been demuxed during av_find_stream_info()
647 */
648 int codec_info_nb_frames;
649
650 /**
651 * Stream informations used internally by av_find_stream_info()
652 */
653 #define MAX_STD_TIMEBASES (60*12+5)
654 struct {
655 int64_t last_dts;
656 int64_t duration_gcd;
657 int duration_count;
658 double duration_error[MAX_STD_TIMEBASES];
659 int64_t codec_info_duration;
660 int nb_decoded_frames;
661 } *info;
662 #if !FF_API_REORDER_PRIVATE
663 const uint8_t *cur_ptr;
664 int cur_len;
665 AVPacket cur_pkt;
666
667 // Timestamp generation support:
668 /**
669 * Timestamp corresponding to the last dts sync point.
670 *
671 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
672 * a DTS is received from the underlying container. Otherwise set to
673 * AV_NOPTS_VALUE by default.
674 */
675 int64_t reference_dts;
676 int64_t first_dts;
677 int64_t cur_dts;
678 int last_IP_duration;
679 int64_t last_IP_pts;
680
681 /**
682 * Number of packets to buffer for codec probing
683 */
684 #define MAX_PROBE_PACKETS 2500
685 int probe_packets;
686
687 /**
688 * last packet in packet_buffer for this stream when muxing.
689 */
690 struct AVPacketList *last_in_packet_buffer;
691 AVProbeData probe_data;
692 #define MAX_REORDER_DELAY 16
693 int64_t pts_buffer[MAX_REORDER_DELAY+1];
694 /* av_read_frame() support */
695 enum AVStreamParseType need_parsing;
696 struct AVCodecParserContext *parser;
697
698 AVIndexEntry *index_entries; /**< Only used if the format does not
699 support seeking natively. */
700 int nb_index_entries;
701 unsigned int index_entries_allocated_size;
702
703 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
704 #endif
705 } AVStream;
706
707 #define AV_PROGRAM_RUNNING 1
708
709 /**
710 * New fields can be added to the end with minor version bumps.
711 * Removal, reordering and changes to existing fields require a major
712 * version bump.
713 * sizeof(AVProgram) must not be used outside libav*.
714 */
715 typedef struct AVProgram {
716 int id;
717 int flags;
718 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller
719 unsigned int *stream_index;
720 unsigned int nb_stream_indexes;
721 AVDictionary *metadata;
722 } AVProgram;
723
724 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present
725 (streams are added dynamically) */
726
727 typedef struct AVChapter {
728 int id; ///< unique ID to identify the chapter
729 AVRational time_base; ///< time base in which the start/end timestamps are specified
730 int64_t start, end; ///< chapter start/end time in time_base units
731 AVDictionary *metadata;
732 } AVChapter;
733
734 /**
735 * Format I/O context.
736 * New fields can be added to the end with minor version bumps.
737 * Removal, reordering and changes to existing fields require a major
738 * version bump.
739 * sizeof(AVFormatContext) must not be used outside libav*, use
740 * avformat_alloc_context() to create an AVFormatContext.
741 */
742 typedef struct AVFormatContext {
743 /**
744 * A class for logging and AVOptions. Set by avformat_alloc_context().
745 * Exports (de)muxer private options if they exist.
746 */
747 const AVClass *av_class;
748
749 /**
750 * Can only be iformat or oformat, not both at the same time.
751 *
752 * decoding: set by avformat_open_input().
753 * encoding: set by the user.
754 */
755 struct AVInputFormat *iformat;
756 struct AVOutputFormat *oformat;
757
758 /**
759 * Format private data. This is an AVOptions-enabled struct
760 * if and only if iformat/oformat.priv_class is not NULL.
761 */
762 void *priv_data;
763
764 /*
765 * I/O context.
766 *
767 * decoding: either set by the user before avformat_open_input() (then
768 * the user must close it manually) or set by avformat_open_input().
769 * encoding: set by the user.
770 *
771 * Do NOT set this field if AVFMT_NOFILE flag is set in
772 * iformat/oformat.flags. In such a case, the (de)muxer will handle
773 * I/O in some other way and this field will be NULL.
774 */
775 AVIOContext *pb;
776
777 /**
778 * A list of all streams in the file. New streams are created with
779 * avformat_new_stream().
780 *
781 * decoding: streams are created by libavformat in avformat_open_input().
782 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
783 * appear in av_read_frame().
784 * encoding: streams are created by the user before avformat_write_header().
785 */
786 unsigned int nb_streams;
787 AVStream **streams;
788
789 char filename[1024]; /**< input or output filename */
790 /* stream info */
791 #if FF_API_TIMESTAMP
792 /**
793 * @deprecated use 'creation_time' metadata tag instead
794 */
795 attribute_deprecated int64_t timestamp;
796 #endif
797
798 int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
799 #if FF_API_REORDER_PRIVATE
800 /* private data for pts handling (do not modify directly). */
801 /**
802 * This buffer is only needed when packets were already buffered but
803 * not decoded, for example to get the codec parameters in MPEG
804 * streams.
805 */
806 struct AVPacketList *packet_buffer;
807 #endif
808
809 /**
810 * Decoding: position of the first frame of the component, in
811 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
812 * It is deduced from the AVStream values.
813 */
814 int64_t start_time;
815
816 /**
817 * Decoding: duration of the stream, in AV_TIME_BASE fractional
818 * seconds. Only set this value if you know none of the individual stream
819 * durations and also dont set any of them. This is deduced from the
820 * AVStream values if not set.
821 */
822 int64_t duration;
823
824 #if FF_API_FILESIZE
825 /**
826 * decoding: total file size, 0 if unknown
827 */
828 attribute_deprecated int64_t file_size;
829 #endif
830
831 /**
832 * Decoding: total stream bitrate in bit/s, 0 if not
833 * available. Never set it directly if the file_size and the
834 * duration are known as Libav can compute it automatically.
835 */
836 int bit_rate;
837
838 #if FF_API_REORDER_PRIVATE
839 /* av_read_frame() support */
840 AVStream *cur_st;
841
842 /* av_seek_frame() support */
843 int64_t data_offset; /**< offset of the first packet */
844 #endif
845
846 #if FF_API_MUXRATE
847 /**
848 * use mpeg muxer private options instead
849 */
850 attribute_deprecated int mux_rate;
851 #endif
852 unsigned int packet_size;
853 #if FF_API_PRELOAD
854 attribute_deprecated int preload;
855 #endif
856 int max_delay;
857
858 #if FF_API_LOOP_OUTPUT
859 #define AVFMT_NOOUTPUTLOOP -1
860 #define AVFMT_INFINITEOUTPUTLOOP 0
861 /**
862 * number of times to loop output in formats that support it
863 *
864 * @deprecated use the 'loop' private option in the gif muxer.
865 */
866 attribute_deprecated int loop_output;
867 #endif
868
869 int flags;
870 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
871 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
872 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
873 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
874 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
875 #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
876 #if FF_API_FLAG_RTP_HINT
877 #define AVFMT_FLAG_RTP_HINT 0x0040 ///< Deprecated, use the -movflags rtphint muxer specific AVOption instead
878 #endif
879 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
880 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
881
882 #if FF_API_LOOP_INPUT
883 /**
884 * @deprecated, use the 'loop' img2 demuxer private option.
885 */
886 attribute_deprecated int loop_input;
887 #endif
888
889 /**
890 * decoding: size of data to probe; encoding: unused.
891 */
892 unsigned int probesize;
893
894 /**
895 * decoding: maximum time (in AV_TIME_BASE units) during which the input should
896 * be analyzed in avformat_find_stream_info().
897 */
898 int max_analyze_duration;
899
900 const uint8_t *key;
901 int keylen;
902
903 unsigned int nb_programs;
904 AVProgram **programs;
905
906 /**
907 * Forced video codec_id.
908 * Demuxing: Set by user.
909 */
910 enum CodecID video_codec_id;
911
912 /**
913 * Forced audio codec_id.
914 * Demuxing: Set by user.
915 */
916 enum CodecID audio_codec_id;
917
918 /**
919 * Forced subtitle codec_id.
920 * Demuxing: Set by user.
921 */
922 enum CodecID subtitle_codec_id;
923
924 /**
925 * Maximum amount of memory in bytes to use for the index of each stream.
926 * If the index exceeds this size, entries will be discarded as
927 * needed to maintain a smaller size. This can lead to slower or less
928 * accurate seeking (depends on demuxer).
929 * Demuxers for which a full in-memory index is mandatory will ignore
930 * this.
931 * muxing : unused
932 * demuxing: set by user
933 */
934 unsigned int max_index_size;
935
936 /**
937 * Maximum amount of memory in bytes to use for buffering frames
938 * obtained from realtime capture devices.
939 */
940 unsigned int max_picture_buffer;
941
942 unsigned int nb_chapters;
943 AVChapter **chapters;
944
945 /**
946 * Flags to enable debugging.
947 */
948 int debug;
949 #define FF_FDEBUG_TS 0x0001
950
951 #if FF_API_REORDER_PRIVATE
952 /**
953 * Raw packets from the demuxer, prior to parsing and decoding.
954 * This buffer is used for buffering packets until the codec can
955 * be identified, as parsing cannot be done without knowing the
956 * codec.
957 */
958 struct AVPacketList *raw_packet_buffer;
959 struct AVPacketList *raw_packet_buffer_end;
960
961 struct AVPacketList *packet_buffer_end;
962 #endif
963
964 AVDictionary *metadata;
965
966 #if FF_API_REORDER_PRIVATE
967 /**
968 * Remaining size available for raw_packet_buffer, in bytes.
969 * NOT PART OF PUBLIC API
970 */
971 #define RAW_PACKET_BUFFER_SIZE 2500000
972 int raw_packet_buffer_remaining_size;
973 #endif
974
975 /**
976 * Start time of the stream in real world time, in microseconds
977 * since the unix epoch (00:00 1st January 1970). That is, pts=0
978 * in the stream was captured at this real world time.
979 * - encoding: Set by user.
980 * - decoding: Unused.
981 */
982 int64_t start_time_realtime;
983
984 /**
985 * decoding: number of frames used to probe fps
986 */
987 int fps_probe_size;
988
989 /**
990 * Error recognition; higher values will detect more errors but may
991 * misdetect some more or less valid parts as errors.
992 * - encoding: unused
993 * - decoding: Set by user.
994 */
995 int error_recognition;
996
997 /*****************************************************************
998 * All fields below this line are not part of the public API. They
999 * may not be used outside of libavformat and can be changed and
1000 * removed at will.
1001 * New public fields should be added right above.
1002 *****************************************************************
1003 */
1004 #if !FF_API_REORDER_PRIVATE
1005 /**
1006 * Raw packets from the demuxer, prior to parsing and decoding.
1007 * This buffer is used for buffering packets until the codec can
1008 * be identified, as parsing cannot be done without knowing the
1009 * codec.
1010 */
1011 struct AVPacketList *raw_packet_buffer;
1012 struct AVPacketList *raw_packet_buffer_end;
1013 /**
1014 * Remaining size available for raw_packet_buffer, in bytes.
1015 */
1016 #define RAW_PACKET_BUFFER_SIZE 2500000
1017 int raw_packet_buffer_remaining_size;
1018
1019 /**
1020 * This buffer is only needed when packets were already buffered but
1021 * not decoded, for example to get the codec parameters in MPEG
1022 * streams.
1023 */
1024 struct AVPacketList *packet_buffer;
1025 struct AVPacketList *packet_buffer_end;
1026
1027 /* av_read_frame() support */
1028 AVStream *cur_st;
1029
1030 /* av_seek_frame() support */
1031 int64_t data_offset; /**< offset of the first packet */
1032 #endif
1033 } AVFormatContext;
1034
1035 typedef struct AVPacketList {
1036 AVPacket pkt;
1037 struct AVPacketList *next;
1038 } AVPacketList;
1039
1040 /**
1041 * If f is NULL, returns the first registered input format,
1042 * if f is non-NULL, returns the next registered input format after f
1043 * or NULL if f is the last one.
1044 */
1045 AVInputFormat *av_iformat_next(AVInputFormat *f);
1046
1047 /**
1048 * If f is NULL, returns the first registered output format,
1049 * if f is non-NULL, returns the next registered output format after f
1050 * or NULL if f is the last one.
1051 */
1052 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1053
1054 #if FF_API_GUESS_IMG2_CODEC
1055 attribute_deprecated enum CodecID av_guess_image2_codec(const char *filename);
1056 #endif
1057
1058 /* XXX: Use automatic init with either ELF sections or C file parser */
1059 /* modules. */
1060
1061 /* utils.c */
1062 void av_register_input_format(AVInputFormat *format);
1063 void av_register_output_format(AVOutputFormat *format);
1064
1065 /**
1066 * Return the output format in the list of registered output formats
1067 * which best matches the provided parameters, or return NULL if
1068 * there is no match.
1069 *
1070 * @param short_name if non-NULL checks if short_name matches with the
1071 * names of the registered formats
1072 * @param filename if non-NULL checks if filename terminates with the
1073 * extensions of the registered formats
1074 * @param mime_type if non-NULL checks if mime_type matches with the
1075 * MIME type of the registered formats
1076 */
1077 AVOutputFormat *av_guess_format(const char *short_name,
1078 const char *filename,
1079 const char *mime_type);
1080
1081 /**
1082 * Guess the codec ID based upon muxer and filename.
1083 */
1084 enum CodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
1085 const char *filename, const char *mime_type,
1086 enum AVMediaType type);
1087
1088 /**
1089 * Send a nice hexadecimal dump of a buffer to the specified file stream.
1090 *
1091 * @param f The file stream pointer where the dump should be sent to.
1092 * @param buf buffer
1093 * @param size buffer size
1094 *
1095 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
1096 */
1097 void av_hex_dump(FILE *f, uint8_t *buf, int size);
1098
1099 /**
1100 * Send a nice hexadecimal dump of a buffer to the log.
1101 *
1102 * @param avcl A pointer to an arbitrary struct of which the first field is a
1103 * pointer to an AVClass struct.
1104 * @param level The importance level of the message, lower values signifying
1105 * higher importance.
1106 * @param buf buffer
1107 * @param size buffer size
1108 *
1109 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
1110 */
1111 void av_hex_dump_log(void *avcl, int level, uint8_t *buf, int size);
1112
1113 /**
1114 * Send a nice dump of a packet to the specified file stream.
1115 *
1116 * @param f The file stream pointer where the dump should be sent to.
1117 * @param pkt packet to dump
1118 * @param dump_payload True if the payload must be displayed, too.
1119 * @param st AVStream that the packet belongs to
1120 */
1121 void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
1122
1123
1124 /**
1125 * Send a nice dump of a packet to the log.
1126 *
1127 * @param avcl A pointer to an arbitrary struct of which the first field is a
1128 * pointer to an AVClass struct.
1129 * @param level The importance level of the message, lower values signifying
1130 * higher importance.
1131 * @param pkt packet to dump
1132 * @param dump_payload True if the payload must be displayed, too.
1133 * @param st AVStream that the packet belongs to
1134 */
1135 void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
1136 AVStream *st);
1137
1138 #if FF_API_PKT_DUMP
1139 attribute_deprecated void av_pkt_dump(FILE *f, AVPacket *pkt, int dump_payload);
1140 attribute_deprecated void av_pkt_dump_log(void *avcl, int level, AVPacket *pkt,
1141 int dump_payload);
1142 #endif
1143
1144 /**
1145 * Initialize libavformat and register all the muxers, demuxers and
1146 * protocols. If you do not call this function, then you can select
1147 * exactly which formats you want to support.
1148 *
1149 * @see av_register_input_format()
1150 * @see av_register_output_format()
1151 * @see av_register_protocol()
1152 */
1153 void av_register_all(void);
1154
1155 /**
1156 * Get the CodecID for the given codec tag tag.
1157 * If no codec id is found returns CODEC_ID_NONE.
1158 *
1159 * @param tags list of supported codec_id-codec_tag pairs, as stored
1160 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1161 */
1162 enum CodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
1163
1164 /**
1165 * Get the codec tag for the given codec id id.
1166 * If no codec tag is found returns 0.
1167 *
1168 * @param tags list of supported codec_id-codec_tag pairs, as stored
1169 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1170 */
1171 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum CodecID id);
1172
1173 /* media file input */
1174
1175 /**
1176 * Find AVInputFormat based on the short name of the input format.
1177 */
1178 AVInputFormat *av_find_input_format(const char *short_name);
1179
1180 /**
1181 * Guess the file format.
1182 *
1183 * @param is_opened Whether the file is already opened; determines whether
1184 * demuxers with or without AVFMT_NOFILE are probed.
1185 */
1186 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1187
1188 /**
1189 * Guess the file format.
1190 *
1191 * @param is_opened Whether the file is already opened; determines whether
1192 * demuxers with or without AVFMT_NOFILE are probed.
1193 * @param score_max A probe score larger that this is required to accept a
1194 * detection, the variable is set to the actual detection
1195 * score afterwards.
1196 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1197 * to retry with a larger probe buffer.
1198 */
1199 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1200
1201 /**
1202 * Probe a bytestream to determine the input format. Each time a probe returns
1203 * with a score that is too low, the probe buffer size is increased and another
1204 * attempt is made. When the maximum probe size is reached, the input format
1205 * with the highest score is returned.
1206 *
1207 * @param pb the bytestream to probe
1208 * @param fmt the input format is put here
1209 * @param filename the filename of the stream
1210 * @param logctx the log context
1211 * @param offset the offset within the bytestream to probe from
1212 * @param max_probe_size the maximum probe buffer size (zero for default)
1213 * @return 0 in case of success, a negative value corresponding to an
1214 * AVERROR code otherwise
1215 */
1216 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1217 const char *filename, void *logctx,
1218 unsigned int offset, unsigned int max_probe_size);
1219
1220 #if FF_API_FORMAT_PARAMETERS
1221 /**
1222 * Allocate all the structures needed to read an input stream.
1223 * This does not open the needed codecs for decoding the stream[s].
1224 * @deprecated use avformat_open_input instead.
1225 */
1226 attribute_deprecated int av_open_input_stream(AVFormatContext **ic_ptr,
1227 AVIOContext *pb, const char *filename,
1228 AVInputFormat *fmt, AVFormatParameters *ap);
1229
1230 /**
1231 * Open a media file as input. The codecs are not opened. Only the file
1232 * header (if present) is read.
1233 *
1234 * @param ic_ptr The opened media file handle is put here.
1235 * @param filename filename to open
1236 * @param fmt If non-NULL, force the file format to use.
1237 * @param buf_size optional buffer size (zero if default is OK)
1238 * @param ap Additional parameters needed when opening the file
1239 * (NULL if default).
1240 * @return 0 if OK, AVERROR_xxx otherwise
1241 *
1242 * @deprecated use avformat_open_input instead.
1243 */
1244 attribute_deprecated int av_open_input_file(AVFormatContext **ic_ptr, const char *filename,
1245 AVInputFormat *fmt,
1246 int buf_size,
1247 AVFormatParameters *ap);
1248 #endif
1249
1250 /**
1251 * Open an input stream and read the header. The codecs are not opened.
1252 * The stream must be closed with av_close_input_file().
1253 *
1254 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1255 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1256 * function and written into ps.
1257 * Note that a user-supplied AVFormatContext will be freed on failure.
1258 * @param filename Name of the stream to open.
1259 * @param fmt If non-NULL, this parameter forces a specific input format.
1260 * Otherwise the format is autodetected.
1261 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1262 * On return this parameter will be destroyed and replaced with a dict containing
1263 * options that were not found. May be NULL.
1264 *
1265 * @return 0 on success, a negative AVERROR on failure.
1266 *
1267 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1268 */
1269 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1270
1271 /**
1272 * Allocate an AVFormatContext.
1273 * avformat_free_context() can be used to free the context and everything
1274 * allocated by the framework within it.
1275 */
1276 AVFormatContext *avformat_alloc_context(void);
1277
1278 #if FF_API_FORMAT_PARAMETERS
1279 /**
1280 * Read packets of a media file to get stream information. This
1281 * is useful for file formats with no headers such as MPEG. This
1282 * function also computes the real framerate in case of MPEG-2 repeat
1283 * frame mode.
1284 * The logical file position is not changed by this function;
1285 * examined packets may be buffered for later processing.
1286 *
1287 * @param ic media file handle
1288 * @return >=0 if OK, AVERROR_xxx on error
1289 * @todo Let the user decide somehow what information is needed so that
1290 * we do not waste time getting stuff the user does not need.
1291 *
1292 * @deprecated use avformat_find_stream_info.
1293 */
1294 attribute_deprecated
1295 int av_find_stream_info(AVFormatContext *ic);
1296 #endif
1297
1298 /**
1299 * Read packets of a media file to get stream information. This
1300 * is useful for file formats with no headers such as MPEG. This
1301 * function also computes the real framerate in case of MPEG-2 repeat
1302 * frame mode.
1303 * The logical file position is not changed by this function;
1304 * examined packets may be buffered for later processing.
1305 *
1306 * @param ic media file handle
1307 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1308 * dictionaries, where i-th member contains options for
1309 * codec corresponding to i-th stream.
1310 * On return each dictionary will be filled with options that were not found.
1311 * @return >=0 if OK, AVERROR_xxx on error
1312 *
1313 * @note this function isn't guaranteed to open all the codecs, so
1314 * options being non-empty at return is a perfectly normal behavior.
1315 *
1316 * @todo Let the user decide somehow what information is needed so that
1317 * we do not waste time getting stuff the user does not need.
1318 */
1319 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1320
1321 /**
1322 * Find the "best" stream in the file.
1323 * The best stream is determined according to various heuristics as the most
1324 * likely to be what the user expects.
1325 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1326 * default decoder for the stream's codec; streams for which no decoder can
1327 * be found are ignored.
1328 *
1329 * @param ic media file handle
1330 * @param type stream type: video, audio, subtitles, etc.
1331 * @param wanted_stream_nb user-requested stream number,
1332 * or -1 for automatic selection
1333 * @param related_stream try to find a stream related (eg. in the same
1334 * program) to this one, or -1 if none
1335 * @param decoder_ret if non-NULL, returns the decoder for the
1336 * selected stream
1337 * @param flags flags; none are currently defined
1338 * @return the non-negative stream number in case of success,
1339 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
1340 * could be found,
1341 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
1342 * @note If av_find_best_stream returns successfully and decoder_ret is not
1343 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
1344 */
1345 int av_find_best_stream(AVFormatContext *ic,
1346 enum AVMediaType type,
1347 int wanted_stream_nb,
1348 int related_stream,
1349 AVCodec **decoder_ret,
1350 int flags);
1351
1352 /**
1353 * Read a transport packet from a media file.
1354 *
1355 * This function is obsolete and should never be used.
1356 * Use av_read_frame() instead.
1357 *
1358 * @param s media file handle
1359 * @param pkt is filled
1360 * @return 0 if OK, AVERROR_xxx on error
1361 */
1362 int av_read_packet(AVFormatContext *s, AVPacket *pkt);
1363
1364 /**
1365 * Return the next frame of a stream.
1366 * This function returns what is stored in the file, and does not validate
1367 * that what is there are valid frames for the decoder. It will split what is
1368 * stored in the file into frames and return one for each call. It will not
1369 * omit invalid data between valid frames so as to give the decoder the maximum
1370 * information possible for decoding.
1371 *
1372 * The returned packet is valid
1373 * until the next av_read_frame() or until av_close_input_file() and
1374 * must be freed with av_free_packet. For video, the packet contains
1375 * exactly one frame. For audio, it contains an integer number of
1376 * frames if each frame has a known fixed size (e.g. PCM or ADPCM
1377 * data). If the audio frames have a variable size (e.g. MPEG audio),
1378 * then it contains one frame.
1379 *
1380 * pkt->pts, pkt->dts and pkt->duration are always set to correct
1381 * values in AVStream.time_base units (and guessed if the format cannot
1382 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
1383 * has B-frames, so it is better to rely on pkt->dts if you do not
1384 * decompress the payload.
1385 *
1386 * @return 0 if OK, < 0 on error or end of file
1387 */
1388 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
1389
1390 /**
1391 * Seek to the keyframe at timestamp.
1392 * 'timestamp' in 'stream_index'.
1393 * @param stream_index If stream_index is (-1), a default
1394 * stream is selected, and timestamp is automatically converted
1395 * from AV_TIME_BASE units to the stream specific time_base.
1396 * @param timestamp Timestamp in AVStream.time_base units
1397 * or, if no stream is specified, in AV_TIME_BASE units.
1398 * @param flags flags which select direction and seeking mode
1399 * @return >= 0 on success
1400 */
1401 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
1402 int flags);
1403
1404 /**
1405 * Seek to timestamp ts.
1406 * Seeking will be done so that the point from which all active streams
1407 * can be presented successfully will be closest to ts and within min/max_ts.
1408 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
1409 *
1410 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
1411 * are the file position (this may not be supported by all demuxers).
1412 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
1413 * in the stream with stream_index (this may not be supported by all demuxers).
1414 * Otherwise all timestamps are in units of the stream selected by stream_index
1415 * or if stream_index is -1, in AV_TIME_BASE units.
1416 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
1417 * keyframes (this may not be supported by all demuxers).
1418 *
1419 * @param stream_index index of the stream which is used as time base reference
1420 * @param min_ts smallest acceptable timestamp
1421 * @param ts target timestamp
1422 * @param max_ts largest acceptable timestamp
1423 * @param flags flags
1424 * @return >=0 on success, error code otherwise
1425 *
1426 * @note This is part of the new seek API which is still under construction.
1427 * Thus do not use this yet. It may change at any time, do not expect
1428 * ABI compatibility yet!
1429 */
1430 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
1431
1432 /**
1433 * Start playing a network-based stream (e.g. RTSP stream) at the
1434 * current position.
1435 */
1436 int av_read_play(AVFormatContext *s);
1437
1438 /**
1439 * Pause a network-based stream (e.g. RTSP stream).
1440 *
1441 * Use av_read_play() to resume it.
1442 */
1443 int av_read_pause(AVFormatContext *s);
1444
1445 /**
1446 * Free a AVFormatContext allocated by av_open_input_stream.
1447 * @param s context to free
1448 */
1449 void av_close_input_stream(AVFormatContext *s);
1450
1451 /**
1452 * Close a media file (but not its codecs).
1453 *
1454 * @param s media file handle
1455 */
1456 void av_close_input_file(AVFormatContext *s);
1457
1458 /**
1459 * Free an AVFormatContext and all its streams.
1460 * @param s context to free
1461 */
1462 void avformat_free_context(AVFormatContext *s);
1463
1464 #if FF_API_NEW_STREAM
1465 /**
1466 * Add a new stream to a media file.
1467 *
1468 * Can only be called in the read_header() function. If the flag
1469 * AVFMTCTX_NOHEADER is in the format context, then new streams
1470 * can be added in read_packet too.
1471 *
1472 * @param s media file handle
1473 * @param id file-format-dependent stream ID
1474 */
1475 attribute_deprecated
1476 AVStream *av_new_stream(AVFormatContext *s, int id);
1477 #endif
1478
1479 /**
1480 * Add a new stream to a media file.
1481 *
1482 * When demuxing, it is called by the demuxer in read_header(). If the
1483 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1484 * be called in read_packet().
1485 *
1486 * When muxing, should be called by the user before avformat_write_header().
1487 *
1488 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1489 * will be initialized to use this codec. This is needed for e.g. codec-specific
1490 * defaults to be set, so codec should be provided if it is known.
1491 *
1492 * @return newly created stream or NULL on error.
1493 */
1494 AVStream *avformat_new_stream(AVFormatContext *s, AVCodec *c);
1495
1496 AVProgram *av_new_program(AVFormatContext *s, int id);
1497
1498 /**
1499 * Set the pts for a given stream. If the new values would be invalid
1500 * (<= 0), it leaves the AVStream unchanged.
1501 *
1502 * @param s stream
1503 * @param pts_wrap_bits number of bits effectively used by the pts
1504 * (used for wrap control, 33 is the value for MPEG)
1505 * @param pts_num numerator to convert to seconds (MPEG: 1)
1506 * @param pts_den denominator to convert to seconds (MPEG: 90000)
1507 */
1508 void av_set_pts_info(AVStream *s, int pts_wrap_bits,
1509 unsigned int pts_num, unsigned int pts_den);
1510
1511 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
1512 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
1513 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
1514 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
1515
1516 int av_find_default_stream_index(AVFormatContext *s);
1517
1518 /**
1519 * Get the index for a specific timestamp.
1520 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
1521 * to the timestamp which is <= the requested one, if backward
1522 * is 0, then it will be >=
1523 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
1524 * @return < 0 if no such timestamp could be found
1525 */
1526 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
1527
1528 /**
1529 * Add an index entry into a sorted list. Update the entry if the list
1530 * already contains it.
1531 *
1532 * @param timestamp timestamp in the time base of the given stream
1533 */
1534 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
1535 int size, int distance, int flags);
1536
1537 #if FF_API_SEEK_PUBLIC
1538 attribute_deprecated
1539 int av_seek_frame_binary(AVFormatContext *s, int stream_index,
1540 int64_t target_ts, int flags);
1541 attribute_deprecated
1542 void av_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp);
1543 attribute_deprecated
1544 int64_t av_gen_search(AVFormatContext *s, int stream_index,
1545 int64_t target_ts, int64_t pos_min,
1546 int64_t pos_max, int64_t pos_limit,
1547 int64_t ts_min, int64_t ts_max,
1548 int flags, int64_t *ts_ret,
1549 int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
1550 #endif
1551
1552 /**
1553 * media file output
1554 */
1555 #if FF_API_FORMAT_PARAMETERS
1556 /**
1557 * @deprecated pass the options to avformat_write_header directly.
1558 */
1559 attribute_deprecated int av_set_parameters(AVFormatContext *s, AVFormatParameters *ap);
1560 #endif
1561
1562 /**
1563 * Split a URL string into components.
1564 *
1565 * The pointers to buffers for storing individual components may be null,
1566 * in order to ignore that component. Buffers for components not found are
1567 * set to empty strings. If the port is not found, it is set to a negative
1568 * value.
1569 *
1570 * @param proto the buffer for the protocol
1571 * @param proto_size the size of the proto buffer
1572 * @param authorization the buffer for the authorization
1573 * @param authorization_size the size of the authorization buffer
1574 * @param hostname the buffer for the host name
1575 * @param hostname_size the size of the hostname buffer
1576 * @param port_ptr a pointer to store the port number in
1577 * @param path the buffer for the path
1578 * @param path_size the size of the path buffer
1579 * @param url the URL to split
1580 */
1581 void av_url_split(char *proto, int proto_size,
1582 char *authorization, int authorization_size,
1583 char *hostname, int hostname_size,
1584 int *port_ptr,
1585 char *path, int path_size,
1586 const char *url);
1587
1588 /**
1589 * Allocate the stream private data and write the stream header to
1590 * an output media file.
1591 *
1592 * @param s Media file handle, must be allocated with avformat_alloc_context().
1593 * Its oformat field must be set to the desired output format;
1594 * Its pb field must be set to an already openened AVIOContext.
1595 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
1596 * On return this parameter will be destroyed and replaced with a dict containing
1597 * options that were not found. May be NULL.
1598 *
1599 * @return 0 on success, negative AVERROR on failure.
1600 *
1601 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
1602 */
1603 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
1604
1605 #if FF_API_FORMAT_PARAMETERS
1606 /**
1607 * Allocate the stream private data and write the stream header to an
1608 * output media file.
1609 * @note: this sets stream time-bases, if possible to stream->codec->time_base
1610 * but for some formats it might also be some other time base
1611 *
1612 * @param s media file handle
1613 * @return 0 if OK, AVERROR_xxx on error
1614 *
1615 * @deprecated use avformat_write_header.
1616 */
1617 attribute_deprecated int av_write_header(AVFormatContext *s);
1618 #endif
1619
1620 /**
1621 * Write a packet to an output media file.
1622 *
1623 * The packet shall contain one audio or video frame.
1624 * The packet must be correctly interleaved according to the container
1625 * specification, if not then av_interleaved_write_frame must be used.
1626 *
1627 * @param s media file handle
1628 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1629 dts/pts, ...
1630 * @return < 0 on error, = 0 if OK, 1 if end of stream wanted
1631 */
1632 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
1633
1634 /**
1635 * Write a packet to an output media file ensuring correct interleaving.
1636 *
1637 * The packet must contain one audio or video frame.
1638 * If the packets are already correctly interleaved, the application should
1639 * call av_write_frame() instead as it is slightly faster. It is also important
1640 * to keep in mind that completely non-interleaved input will need huge amounts
1641 * of memory to interleave with this, so it is preferable to interleave at the
1642 * demuxer level.
1643 *
1644 * @param s media file handle
1645 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1646 dts/pts, ...
1647 * @return < 0 on error, = 0 if OK, 1 if end of stream wanted
1648 */
1649 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
1650
1651 /**
1652 * Interleave a packet per dts in an output media file.
1653 *
1654 * Packets with pkt->destruct == av_destruct_packet will be freed inside this
1655 * function, so they cannot be used after it. Note that calling av_free_packet()
1656 * on them is still safe.
1657 *
1658 * @param s media file handle
1659 * @param out the interleaved packet will be output here
1660 * @param pkt the input packet
1661 * @param flush 1 if no further packets are available as input and all
1662 * remaining packets should be output
1663 * @return 1 if a packet was output, 0 if no packet could be output,
1664 * < 0 if an error occurred
1665 */
1666 int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
1667 AVPacket *pkt, int flush);
1668
1669 /**
1670 * Write the stream trailer to an output media file and free the
1671 * file private data.
1672 *
1673 * May only be called after a successful call to av_write_header.
1674 *
1675 * @param s media file handle
1676 * @return 0 if OK, AVERROR_xxx on error
1677 */
1678 int av_write_trailer(AVFormatContext *s);
1679
1680 #if FF_API_DUMP_FORMAT
1681 attribute_deprecated void dump_format(AVFormatContext *ic,
1682 int index,
1683 const char *url,
1684 int is_output);
1685 #endif
1686
1687 void av_dump_format(AVFormatContext *ic,
1688 int index,
1689 const char *url,
1690 int is_output);
1691
1692 #if FF_API_PARSE_DATE
1693 /**
1694 * Parse datestr and return a corresponding number of microseconds.
1695 *
1696 * @param datestr String representing a date or a duration.
1697 * See av_parse_time() for the syntax of the provided string.
1698 * @deprecated in favor of av_parse_time()
1699 */
1700 attribute_deprecated
1701 int64_t parse_date(const char *datestr, int duration);
1702 #endif
1703
1704 /**
1705 * Get the current time in microseconds.
1706 */
1707 int64_t av_gettime(void);
1708
1709 #if FF_API_FIND_INFO_TAG
1710 /**
1711 * @deprecated use av_find_info_tag in libavutil instead.
1712 */
1713 attribute_deprecated int find_info_tag(char *arg, int arg_size, const char *tag1, const char *info);
1714 #endif
1715
1716 /**
1717 * Return in 'buf' the path with '%d' replaced by a number.
1718 *
1719 * Also handles the '%0nd' format where 'n' is the total number
1720 * of digits and '%%'.
1721 *
1722 * @param buf destination buffer
1723 * @param buf_size destination buffer size
1724 * @param path numbered sequence string
1725 * @param number frame number
1726 * @return 0 if OK, -1 on format error
1727 */
1728 int av_get_frame_filename(char *buf, int buf_size,
1729 const char *path, int number);
1730
1731 /**
1732 * Check whether filename actually is a numbered sequence generator.
1733 *
1734 * @param filename possible numbered sequence string
1735 * @return 1 if a valid numbered sequence string, 0 otherwise
1736 */
1737 int av_filename_number_test(const char *filename);
1738
1739 /**
1740 * Generate an SDP for an RTP session.
1741 *
1742 * @param ac array of AVFormatContexts describing the RTP streams. If the
1743 * array is composed by only one context, such context can contain
1744 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
1745 * all the contexts in the array (an AVCodecContext per RTP stream)
1746 * must contain only one AVStream.
1747 * @param n_files number of AVCodecContexts contained in ac
1748 * @param buf buffer where the SDP will be stored (must be allocated by
1749 * the caller)
1750 * @param size the size of the buffer
1751 * @return 0 if OK, AVERROR_xxx on error
1752 */
1753 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
1754
1755 #if FF_API_SDP_CREATE
1756 attribute_deprecated int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size);
1757 #endif
1758
1759 /**
1760 * Return a positive value if the given filename has one of the given
1761 * extensions, 0 otherwise.
1762 *
1763 * @param extensions a comma-separated list of filename extensions
1764 */
1765 int av_match_ext(const char *filename, const char *extensions);
1766
1767 /**
1768 * Test if the given container can store a codec.
1769 *
1770 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
1771 *
1772 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
1773 * A negative number if this information is not available.
1774 */
1775 int avformat_query_codec(AVOutputFormat *ofmt, enum CodecID codec_id, int std_compliance);
1776
1777 /**
1778 * Get the AVClass for AVFormatContext. It can be used in combination with
1779 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1780 *
1781 * @see av_opt_find().
1782 */
1783 const AVClass *avformat_get_class(void);
1784
1785 /**
1786 * Do global initialization of network components. This is optional,
1787 * but recommended, since it avoids the overhead of implicitly
1788 * doing the setup for each session.
1789 *
1790 * Calling this function will become mandatory if using network
1791 * protocols at some major version bump.
1792 */
1793 int avformat_network_init(void);
1794
1795 /**
1796 * Undo the initialization done by avformat_network_init.
1797 */
1798 int avformat_network_deinit(void);
1799
1800 #endif /* AVFORMAT_AVFORMAT_H */