2fa93af31c2c49a6943c6d632f23410686901826
[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*.
740 */
741 typedef struct AVFormatContext {
742 const AVClass *av_class; /**< Set by avformat_alloc_context. */
743 /* Can only be iformat or oformat, not both at the same time. */
744 struct AVInputFormat *iformat;
745 struct AVOutputFormat *oformat;
746 void *priv_data;
747 AVIOContext *pb;
748 unsigned int nb_streams;
749 AVStream **streams;
750 char filename[1024]; /**< input or output filename */
751 /* stream info */
752 #if FF_API_TIMESTAMP
753 /**
754 * @deprecated use 'creation_time' metadata tag instead
755 */
756 attribute_deprecated int64_t timestamp;
757 #endif
758
759 int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
760 #if FF_API_REORDER_PRIVATE
761 /* private data for pts handling (do not modify directly). */
762 /**
763 * This buffer is only needed when packets were already buffered but
764 * not decoded, for example to get the codec parameters in MPEG
765 * streams.
766 */
767 struct AVPacketList *packet_buffer;
768 #endif
769
770 /**
771 * Decoding: position of the first frame of the component, in
772 * AV_TIME_BASE fractional seconds. NEVER set this value directly:
773 * It is deduced from the AVStream values.
774 */
775 int64_t start_time;
776
777 /**
778 * Decoding: duration of the stream, in AV_TIME_BASE fractional
779 * seconds. Only set this value if you know none of the individual stream
780 * durations and also dont set any of them. This is deduced from the
781 * AVStream values if not set.
782 */
783 int64_t duration;
784
785 #if FF_API_FILESIZE
786 /**
787 * decoding: total file size, 0 if unknown
788 */
789 attribute_deprecated int64_t file_size;
790 #endif
791
792 /**
793 * Decoding: total stream bitrate in bit/s, 0 if not
794 * available. Never set it directly if the file_size and the
795 * duration are known as Libav can compute it automatically.
796 */
797 int bit_rate;
798
799 #if FF_API_REORDER_PRIVATE
800 /* av_read_frame() support */
801 AVStream *cur_st;
802
803 /* av_seek_frame() support */
804 int64_t data_offset; /**< offset of the first packet */
805 #endif
806
807 #if FF_API_MUXRATE
808 /**
809 * use mpeg muxer private options instead
810 */
811 attribute_deprecated int mux_rate;
812 #endif
813 unsigned int packet_size;
814 #if FF_API_PRELOAD
815 attribute_deprecated int preload;
816 #endif
817 int max_delay;
818
819 #if FF_API_LOOP_OUTPUT
820 #define AVFMT_NOOUTPUTLOOP -1
821 #define AVFMT_INFINITEOUTPUTLOOP 0
822 /**
823 * number of times to loop output in formats that support it
824 *
825 * @deprecated use the 'loop' private option in the gif muxer.
826 */
827 attribute_deprecated int loop_output;
828 #endif
829
830 int flags;
831 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames.
832 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index.
833 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input.
834 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
835 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container
836 #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
837 #if FF_API_FLAG_RTP_HINT
838 #define AVFMT_FLAG_RTP_HINT 0x0040 ///< Deprecated, use the -movflags rtphint muxer specific AVOption instead
839 #endif
840 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
841 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted
842
843 #if FF_API_LOOP_INPUT
844 /**
845 * @deprecated, use the 'loop' img2 demuxer private option.
846 */
847 attribute_deprecated int loop_input;
848 #endif
849
850 /**
851 * decoding: size of data to probe; encoding: unused.
852 */
853 unsigned int probesize;
854
855 /**
856 * Maximum time (in AV_TIME_BASE units) during which the input should
857 * be analyzed in av_find_stream_info().
858 */
859 int max_analyze_duration;
860
861 const uint8_t *key;
862 int keylen;
863
864 unsigned int nb_programs;
865 AVProgram **programs;
866
867 /**
868 * Forced video codec_id.
869 * Demuxing: Set by user.
870 */
871 enum CodecID video_codec_id;
872
873 /**
874 * Forced audio codec_id.
875 * Demuxing: Set by user.
876 */
877 enum CodecID audio_codec_id;
878
879 /**
880 * Forced subtitle codec_id.
881 * Demuxing: Set by user.
882 */
883 enum CodecID subtitle_codec_id;
884
885 /**
886 * Maximum amount of memory in bytes to use for the index of each stream.
887 * If the index exceeds this size, entries will be discarded as
888 * needed to maintain a smaller size. This can lead to slower or less
889 * accurate seeking (depends on demuxer).
890 * Demuxers for which a full in-memory index is mandatory will ignore
891 * this.
892 * muxing : unused
893 * demuxing: set by user
894 */
895 unsigned int max_index_size;
896
897 /**
898 * Maximum amount of memory in bytes to use for buffering frames
899 * obtained from realtime capture devices.
900 */
901 unsigned int max_picture_buffer;
902
903 unsigned int nb_chapters;
904 AVChapter **chapters;
905
906 /**
907 * Flags to enable debugging.
908 */
909 int debug;
910 #define FF_FDEBUG_TS 0x0001
911
912 #if FF_API_REORDER_PRIVATE
913 /**
914 * Raw packets from the demuxer, prior to parsing and decoding.
915 * This buffer is used for buffering packets until the codec can
916 * be identified, as parsing cannot be done without knowing the
917 * codec.
918 */
919 struct AVPacketList *raw_packet_buffer;
920 struct AVPacketList *raw_packet_buffer_end;
921
922 struct AVPacketList *packet_buffer_end;
923 #endif
924
925 AVDictionary *metadata;
926
927 #if FF_API_REORDER_PRIVATE
928 /**
929 * Remaining size available for raw_packet_buffer, in bytes.
930 * NOT PART OF PUBLIC API
931 */
932 #define RAW_PACKET_BUFFER_SIZE 2500000
933 int raw_packet_buffer_remaining_size;
934 #endif
935
936 /**
937 * Start time of the stream in real world time, in microseconds
938 * since the unix epoch (00:00 1st January 1970). That is, pts=0
939 * in the stream was captured at this real world time.
940 * - encoding: Set by user.
941 * - decoding: Unused.
942 */
943 int64_t start_time_realtime;
944
945 /**
946 * decoding: number of frames used to probe fps
947 */
948 int fps_probe_size;
949
950 /**
951 * Error recognition; higher values will detect more errors but may
952 * misdetect some more or less valid parts as errors.
953 * - encoding: unused
954 * - decoding: Set by user.
955 */
956 int error_recognition;
957
958 /*****************************************************************
959 * All fields below this line are not part of the public API. They
960 * may not be used outside of libavformat and can be changed and
961 * removed at will.
962 * New public fields should be added right above.
963 *****************************************************************
964 */
965 #if !FF_API_REORDER_PRIVATE
966 /**
967 * Raw packets from the demuxer, prior to parsing and decoding.
968 * This buffer is used for buffering packets until the codec can
969 * be identified, as parsing cannot be done without knowing the
970 * codec.
971 */
972 struct AVPacketList *raw_packet_buffer;
973 struct AVPacketList *raw_packet_buffer_end;
974 /**
975 * Remaining size available for raw_packet_buffer, in bytes.
976 */
977 #define RAW_PACKET_BUFFER_SIZE 2500000
978 int raw_packet_buffer_remaining_size;
979
980 /**
981 * This buffer is only needed when packets were already buffered but
982 * not decoded, for example to get the codec parameters in MPEG
983 * streams.
984 */
985 struct AVPacketList *packet_buffer;
986 struct AVPacketList *packet_buffer_end;
987
988 /* av_read_frame() support */
989 AVStream *cur_st;
990
991 /* av_seek_frame() support */
992 int64_t data_offset; /**< offset of the first packet */
993 #endif
994 } AVFormatContext;
995
996 typedef struct AVPacketList {
997 AVPacket pkt;
998 struct AVPacketList *next;
999 } AVPacketList;
1000
1001 /**
1002 * If f is NULL, returns the first registered input format,
1003 * if f is non-NULL, returns the next registered input format after f
1004 * or NULL if f is the last one.
1005 */
1006 AVInputFormat *av_iformat_next(AVInputFormat *f);
1007
1008 /**
1009 * If f is NULL, returns the first registered output format,
1010 * if f is non-NULL, returns the next registered output format after f
1011 * or NULL if f is the last one.
1012 */
1013 AVOutputFormat *av_oformat_next(AVOutputFormat *f);
1014
1015 #if FF_API_GUESS_IMG2_CODEC
1016 attribute_deprecated enum CodecID av_guess_image2_codec(const char *filename);
1017 #endif
1018
1019 /* XXX: Use automatic init with either ELF sections or C file parser */
1020 /* modules. */
1021
1022 /* utils.c */
1023 void av_register_input_format(AVInputFormat *format);
1024 void av_register_output_format(AVOutputFormat *format);
1025
1026 /**
1027 * Return the output format in the list of registered output formats
1028 * which best matches the provided parameters, or return NULL if
1029 * there is no match.
1030 *
1031 * @param short_name if non-NULL checks if short_name matches with the
1032 * names of the registered formats
1033 * @param filename if non-NULL checks if filename terminates with the
1034 * extensions of the registered formats
1035 * @param mime_type if non-NULL checks if mime_type matches with the
1036 * MIME type of the registered formats
1037 */
1038 AVOutputFormat *av_guess_format(const char *short_name,
1039 const char *filename,
1040 const char *mime_type);
1041
1042 /**
1043 * Guess the codec ID based upon muxer and filename.
1044 */
1045 enum CodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
1046 const char *filename, const char *mime_type,
1047 enum AVMediaType type);
1048
1049 /**
1050 * Send a nice hexadecimal dump of a buffer to the specified file stream.
1051 *
1052 * @param f The file stream pointer where the dump should be sent to.
1053 * @param buf buffer
1054 * @param size buffer size
1055 *
1056 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
1057 */
1058 void av_hex_dump(FILE *f, uint8_t *buf, int size);
1059
1060 /**
1061 * Send a nice hexadecimal dump of a buffer to the log.
1062 *
1063 * @param avcl A pointer to an arbitrary struct of which the first field is a
1064 * pointer to an AVClass struct.
1065 * @param level The importance level of the message, lower values signifying
1066 * higher importance.
1067 * @param buf buffer
1068 * @param size buffer size
1069 *
1070 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
1071 */
1072 void av_hex_dump_log(void *avcl, int level, uint8_t *buf, int size);
1073
1074 /**
1075 * Send a nice dump of a packet to the specified file stream.
1076 *
1077 * @param f The file stream pointer where the dump should be sent to.
1078 * @param pkt packet to dump
1079 * @param dump_payload True if the payload must be displayed, too.
1080 * @param st AVStream that the packet belongs to
1081 */
1082 void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
1083
1084
1085 /**
1086 * Send a nice dump of a packet to the log.
1087 *
1088 * @param avcl A pointer to an arbitrary struct of which the first field is a
1089 * pointer to an AVClass struct.
1090 * @param level The importance level of the message, lower values signifying
1091 * higher importance.
1092 * @param pkt packet to dump
1093 * @param dump_payload True if the payload must be displayed, too.
1094 * @param st AVStream that the packet belongs to
1095 */
1096 void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
1097 AVStream *st);
1098
1099 #if FF_API_PKT_DUMP
1100 attribute_deprecated void av_pkt_dump(FILE *f, AVPacket *pkt, int dump_payload);
1101 attribute_deprecated void av_pkt_dump_log(void *avcl, int level, AVPacket *pkt,
1102 int dump_payload);
1103 #endif
1104
1105 /**
1106 * Initialize libavformat and register all the muxers, demuxers and
1107 * protocols. If you do not call this function, then you can select
1108 * exactly which formats you want to support.
1109 *
1110 * @see av_register_input_format()
1111 * @see av_register_output_format()
1112 * @see av_register_protocol()
1113 */
1114 void av_register_all(void);
1115
1116 /**
1117 * Get the CodecID for the given codec tag tag.
1118 * If no codec id is found returns CODEC_ID_NONE.
1119 *
1120 * @param tags list of supported codec_id-codec_tag pairs, as stored
1121 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1122 */
1123 enum CodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
1124
1125 /**
1126 * Get the codec tag for the given codec id id.
1127 * If no codec tag is found returns 0.
1128 *
1129 * @param tags list of supported codec_id-codec_tag pairs, as stored
1130 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
1131 */
1132 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum CodecID id);
1133
1134 /* media file input */
1135
1136 /**
1137 * Find AVInputFormat based on the short name of the input format.
1138 */
1139 AVInputFormat *av_find_input_format(const char *short_name);
1140
1141 /**
1142 * Guess the file format.
1143 *
1144 * @param is_opened Whether the file is already opened; determines whether
1145 * demuxers with or without AVFMT_NOFILE are probed.
1146 */
1147 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
1148
1149 /**
1150 * Guess the file format.
1151 *
1152 * @param is_opened Whether the file is already opened; determines whether
1153 * demuxers with or without AVFMT_NOFILE are probed.
1154 * @param score_max A probe score larger that this is required to accept a
1155 * detection, the variable is set to the actual detection
1156 * score afterwards.
1157 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
1158 * to retry with a larger probe buffer.
1159 */
1160 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
1161
1162 /**
1163 * Probe a bytestream to determine the input format. Each time a probe returns
1164 * with a score that is too low, the probe buffer size is increased and another
1165 * attempt is made. When the maximum probe size is reached, the input format
1166 * with the highest score is returned.
1167 *
1168 * @param pb the bytestream to probe
1169 * @param fmt the input format is put here
1170 * @param filename the filename of the stream
1171 * @param logctx the log context
1172 * @param offset the offset within the bytestream to probe from
1173 * @param max_probe_size the maximum probe buffer size (zero for default)
1174 * @return 0 in case of success, a negative value corresponding to an
1175 * AVERROR code otherwise
1176 */
1177 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
1178 const char *filename, void *logctx,
1179 unsigned int offset, unsigned int max_probe_size);
1180
1181 #if FF_API_FORMAT_PARAMETERS
1182 /**
1183 * Allocate all the structures needed to read an input stream.
1184 * This does not open the needed codecs for decoding the stream[s].
1185 * @deprecated use avformat_open_input instead.
1186 */
1187 attribute_deprecated int av_open_input_stream(AVFormatContext **ic_ptr,
1188 AVIOContext *pb, const char *filename,
1189 AVInputFormat *fmt, AVFormatParameters *ap);
1190
1191 /**
1192 * Open a media file as input. The codecs are not opened. Only the file
1193 * header (if present) is read.
1194 *
1195 * @param ic_ptr The opened media file handle is put here.
1196 * @param filename filename to open
1197 * @param fmt If non-NULL, force the file format to use.
1198 * @param buf_size optional buffer size (zero if default is OK)
1199 * @param ap Additional parameters needed when opening the file
1200 * (NULL if default).
1201 * @return 0 if OK, AVERROR_xxx otherwise
1202 *
1203 * @deprecated use avformat_open_input instead.
1204 */
1205 attribute_deprecated int av_open_input_file(AVFormatContext **ic_ptr, const char *filename,
1206 AVInputFormat *fmt,
1207 int buf_size,
1208 AVFormatParameters *ap);
1209 #endif
1210
1211 /**
1212 * Open an input stream and read the header. The codecs are not opened.
1213 * The stream must be closed with av_close_input_file().
1214 *
1215 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
1216 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this
1217 * function and written into ps.
1218 * Note that a user-supplied AVFormatContext will be freed on failure.
1219 * @param filename Name of the stream to open.
1220 * @param fmt If non-NULL, this parameter forces a specific input format.
1221 * Otherwise the format is autodetected.
1222 * @param options A dictionary filled with AVFormatContext and demuxer-private options.
1223 * On return this parameter will be destroyed and replaced with a dict containing
1224 * options that were not found. May be NULL.
1225 *
1226 * @return 0 on success, a negative AVERROR on failure.
1227 *
1228 * @note If you want to use custom IO, preallocate the format context and set its pb field.
1229 */
1230 int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
1231
1232 /**
1233 * Allocate an AVFormatContext.
1234 * avformat_free_context() can be used to free the context and everything
1235 * allocated by the framework within it.
1236 */
1237 AVFormatContext *avformat_alloc_context(void);
1238
1239 #if FF_API_FORMAT_PARAMETERS
1240 /**
1241 * Read packets of a media file to get stream information. This
1242 * is useful for file formats with no headers such as MPEG. This
1243 * function also computes the real framerate in case of MPEG-2 repeat
1244 * frame mode.
1245 * The logical file position is not changed by this function;
1246 * examined packets may be buffered for later processing.
1247 *
1248 * @param ic media file handle
1249 * @return >=0 if OK, AVERROR_xxx on error
1250 * @todo Let the user decide somehow what information is needed so that
1251 * we do not waste time getting stuff the user does not need.
1252 *
1253 * @deprecated use avformat_find_stream_info.
1254 */
1255 attribute_deprecated
1256 int av_find_stream_info(AVFormatContext *ic);
1257 #endif
1258
1259 /**
1260 * Read packets of a media file to get stream information. This
1261 * is useful for file formats with no headers such as MPEG. This
1262 * function also computes the real framerate in case of MPEG-2 repeat
1263 * frame mode.
1264 * The logical file position is not changed by this function;
1265 * examined packets may be buffered for later processing.
1266 *
1267 * @param ic media file handle
1268 * @param options If non-NULL, an ic.nb_streams long array of pointers to
1269 * dictionaries, where i-th member contains options for
1270 * codec corresponding to i-th stream.
1271 * On return each dictionary will be filled with options that were not found.
1272 * @return >=0 if OK, AVERROR_xxx on error
1273 *
1274 * @note this function isn't guaranteed to open all the codecs, so
1275 * options being non-empty at return is a perfectly normal behavior.
1276 *
1277 * @todo Let the user decide somehow what information is needed so that
1278 * we do not waste time getting stuff the user does not need.
1279 */
1280 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
1281
1282 /**
1283 * Find the "best" stream in the file.
1284 * The best stream is determined according to various heuristics as the most
1285 * likely to be what the user expects.
1286 * If the decoder parameter is non-NULL, av_find_best_stream will find the
1287 * default decoder for the stream's codec; streams for which no decoder can
1288 * be found are ignored.
1289 *
1290 * @param ic media file handle
1291 * @param type stream type: video, audio, subtitles, etc.
1292 * @param wanted_stream_nb user-requested stream number,
1293 * or -1 for automatic selection
1294 * @param related_stream try to find a stream related (eg. in the same
1295 * program) to this one, or -1 if none
1296 * @param decoder_ret if non-NULL, returns the decoder for the
1297 * selected stream
1298 * @param flags flags; none are currently defined
1299 * @return the non-negative stream number in case of success,
1300 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
1301 * could be found,
1302 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
1303 * @note If av_find_best_stream returns successfully and decoder_ret is not
1304 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
1305 */
1306 int av_find_best_stream(AVFormatContext *ic,
1307 enum AVMediaType type,
1308 int wanted_stream_nb,
1309 int related_stream,
1310 AVCodec **decoder_ret,
1311 int flags);
1312
1313 /**
1314 * Read a transport packet from a media file.
1315 *
1316 * This function is obsolete and should never be used.
1317 * Use av_read_frame() instead.
1318 *
1319 * @param s media file handle
1320 * @param pkt is filled
1321 * @return 0 if OK, AVERROR_xxx on error
1322 */
1323 int av_read_packet(AVFormatContext *s, AVPacket *pkt);
1324
1325 /**
1326 * Return the next frame of a stream.
1327 * This function returns what is stored in the file, and does not validate
1328 * that what is there are valid frames for the decoder. It will split what is
1329 * stored in the file into frames and return one for each call. It will not
1330 * omit invalid data between valid frames so as to give the decoder the maximum
1331 * information possible for decoding.
1332 *
1333 * The returned packet is valid
1334 * until the next av_read_frame() or until av_close_input_file() and
1335 * must be freed with av_free_packet. For video, the packet contains
1336 * exactly one frame. For audio, it contains an integer number of
1337 * frames if each frame has a known fixed size (e.g. PCM or ADPCM
1338 * data). If the audio frames have a variable size (e.g. MPEG audio),
1339 * then it contains one frame.
1340 *
1341 * pkt->pts, pkt->dts and pkt->duration are always set to correct
1342 * values in AVStream.time_base units (and guessed if the format cannot
1343 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
1344 * has B-frames, so it is better to rely on pkt->dts if you do not
1345 * decompress the payload.
1346 *
1347 * @return 0 if OK, < 0 on error or end of file
1348 */
1349 int av_read_frame(AVFormatContext *s, AVPacket *pkt);
1350
1351 /**
1352 * Seek to the keyframe at timestamp.
1353 * 'timestamp' in 'stream_index'.
1354 * @param stream_index If stream_index is (-1), a default
1355 * stream is selected, and timestamp is automatically converted
1356 * from AV_TIME_BASE units to the stream specific time_base.
1357 * @param timestamp Timestamp in AVStream.time_base units
1358 * or, if no stream is specified, in AV_TIME_BASE units.
1359 * @param flags flags which select direction and seeking mode
1360 * @return >= 0 on success
1361 */
1362 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
1363 int flags);
1364
1365 /**
1366 * Seek to timestamp ts.
1367 * Seeking will be done so that the point from which all active streams
1368 * can be presented successfully will be closest to ts and within min/max_ts.
1369 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
1370 *
1371 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
1372 * are the file position (this may not be supported by all demuxers).
1373 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
1374 * in the stream with stream_index (this may not be supported by all demuxers).
1375 * Otherwise all timestamps are in units of the stream selected by stream_index
1376 * or if stream_index is -1, in AV_TIME_BASE units.
1377 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
1378 * keyframes (this may not be supported by all demuxers).
1379 *
1380 * @param stream_index index of the stream which is used as time base reference
1381 * @param min_ts smallest acceptable timestamp
1382 * @param ts target timestamp
1383 * @param max_ts largest acceptable timestamp
1384 * @param flags flags
1385 * @return >=0 on success, error code otherwise
1386 *
1387 * @note This is part of the new seek API which is still under construction.
1388 * Thus do not use this yet. It may change at any time, do not expect
1389 * ABI compatibility yet!
1390 */
1391 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
1392
1393 /**
1394 * Start playing a network-based stream (e.g. RTSP stream) at the
1395 * current position.
1396 */
1397 int av_read_play(AVFormatContext *s);
1398
1399 /**
1400 * Pause a network-based stream (e.g. RTSP stream).
1401 *
1402 * Use av_read_play() to resume it.
1403 */
1404 int av_read_pause(AVFormatContext *s);
1405
1406 /**
1407 * Free a AVFormatContext allocated by av_open_input_stream.
1408 * @param s context to free
1409 */
1410 void av_close_input_stream(AVFormatContext *s);
1411
1412 /**
1413 * Close a media file (but not its codecs).
1414 *
1415 * @param s media file handle
1416 */
1417 void av_close_input_file(AVFormatContext *s);
1418
1419 /**
1420 * Free an AVFormatContext and all its streams.
1421 * @param s context to free
1422 */
1423 void avformat_free_context(AVFormatContext *s);
1424
1425 #if FF_API_NEW_STREAM
1426 /**
1427 * Add a new stream to a media file.
1428 *
1429 * Can only be called in the read_header() function. If the flag
1430 * AVFMTCTX_NOHEADER is in the format context, then new streams
1431 * can be added in read_packet too.
1432 *
1433 * @param s media file handle
1434 * @param id file-format-dependent stream ID
1435 */
1436 attribute_deprecated
1437 AVStream *av_new_stream(AVFormatContext *s, int id);
1438 #endif
1439
1440 /**
1441 * Add a new stream to a media file.
1442 *
1443 * When demuxing, it is called by the demuxer in read_header(). If the
1444 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
1445 * be called in read_packet().
1446 *
1447 * When muxing, should be called by the user before avformat_write_header().
1448 *
1449 * @param c If non-NULL, the AVCodecContext corresponding to the new stream
1450 * will be initialized to use this codec. This is needed for e.g. codec-specific
1451 * defaults to be set, so codec should be provided if it is known.
1452 *
1453 * @return newly created stream or NULL on error.
1454 */
1455 AVStream *avformat_new_stream(AVFormatContext *s, AVCodec *c);
1456
1457 AVProgram *av_new_program(AVFormatContext *s, int id);
1458
1459 /**
1460 * Set the pts for a given stream. If the new values would be invalid
1461 * (<= 0), it leaves the AVStream unchanged.
1462 *
1463 * @param s stream
1464 * @param pts_wrap_bits number of bits effectively used by the pts
1465 * (used for wrap control, 33 is the value for MPEG)
1466 * @param pts_num numerator to convert to seconds (MPEG: 1)
1467 * @param pts_den denominator to convert to seconds (MPEG: 90000)
1468 */
1469 void av_set_pts_info(AVStream *s, int pts_wrap_bits,
1470 unsigned int pts_num, unsigned int pts_den);
1471
1472 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
1473 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes
1474 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes
1475 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number
1476
1477 int av_find_default_stream_index(AVFormatContext *s);
1478
1479 /**
1480 * Get the index for a specific timestamp.
1481 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
1482 * to the timestamp which is <= the requested one, if backward
1483 * is 0, then it will be >=
1484 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
1485 * @return < 0 if no such timestamp could be found
1486 */
1487 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
1488
1489 /**
1490 * Add an index entry into a sorted list. Update the entry if the list
1491 * already contains it.
1492 *
1493 * @param timestamp timestamp in the time base of the given stream
1494 */
1495 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
1496 int size, int distance, int flags);
1497
1498 #if FF_API_SEEK_PUBLIC
1499 attribute_deprecated
1500 int av_seek_frame_binary(AVFormatContext *s, int stream_index,
1501 int64_t target_ts, int flags);
1502 attribute_deprecated
1503 void av_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp);
1504 attribute_deprecated
1505 int64_t av_gen_search(AVFormatContext *s, int stream_index,
1506 int64_t target_ts, int64_t pos_min,
1507 int64_t pos_max, int64_t pos_limit,
1508 int64_t ts_min, int64_t ts_max,
1509 int flags, int64_t *ts_ret,
1510 int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
1511 #endif
1512
1513 /**
1514 * media file output
1515 */
1516 #if FF_API_FORMAT_PARAMETERS
1517 /**
1518 * @deprecated pass the options to avformat_write_header directly.
1519 */
1520 attribute_deprecated int av_set_parameters(AVFormatContext *s, AVFormatParameters *ap);
1521 #endif
1522
1523 /**
1524 * Split a URL string into components.
1525 *
1526 * The pointers to buffers for storing individual components may be null,
1527 * in order to ignore that component. Buffers for components not found are
1528 * set to empty strings. If the port is not found, it is set to a negative
1529 * value.
1530 *
1531 * @param proto the buffer for the protocol
1532 * @param proto_size the size of the proto buffer
1533 * @param authorization the buffer for the authorization
1534 * @param authorization_size the size of the authorization buffer
1535 * @param hostname the buffer for the host name
1536 * @param hostname_size the size of the hostname buffer
1537 * @param port_ptr a pointer to store the port number in
1538 * @param path the buffer for the path
1539 * @param path_size the size of the path buffer
1540 * @param url the URL to split
1541 */
1542 void av_url_split(char *proto, int proto_size,
1543 char *authorization, int authorization_size,
1544 char *hostname, int hostname_size,
1545 int *port_ptr,
1546 char *path, int path_size,
1547 const char *url);
1548
1549 /**
1550 * Allocate the stream private data and write the stream header to
1551 * an output media file.
1552 *
1553 * @param s Media file handle, must be allocated with avformat_alloc_context().
1554 * Its oformat field must be set to the desired output format;
1555 * Its pb field must be set to an already openened AVIOContext.
1556 * @param options An AVDictionary filled with AVFormatContext and muxer-private options.
1557 * On return this parameter will be destroyed and replaced with a dict containing
1558 * options that were not found. May be NULL.
1559 *
1560 * @return 0 on success, negative AVERROR on failure.
1561 *
1562 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
1563 */
1564 int avformat_write_header(AVFormatContext *s, AVDictionary **options);
1565
1566 #if FF_API_FORMAT_PARAMETERS
1567 /**
1568 * Allocate the stream private data and write the stream header to an
1569 * output media file.
1570 * @note: this sets stream time-bases, if possible to stream->codec->time_base
1571 * but for some formats it might also be some other time base
1572 *
1573 * @param s media file handle
1574 * @return 0 if OK, AVERROR_xxx on error
1575 *
1576 * @deprecated use avformat_write_header.
1577 */
1578 attribute_deprecated int av_write_header(AVFormatContext *s);
1579 #endif
1580
1581 /**
1582 * Write a packet to an output media file.
1583 *
1584 * The packet shall contain one audio or video frame.
1585 * The packet must be correctly interleaved according to the container
1586 * specification, if not then av_interleaved_write_frame must be used.
1587 *
1588 * @param s media file handle
1589 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1590 dts/pts, ...
1591 * @return < 0 on error, = 0 if OK, 1 if end of stream wanted
1592 */
1593 int av_write_frame(AVFormatContext *s, AVPacket *pkt);
1594
1595 /**
1596 * Write a packet to an output media file ensuring correct interleaving.
1597 *
1598 * The packet must contain one audio or video frame.
1599 * If the packets are already correctly interleaved, the application should
1600 * call av_write_frame() instead as it is slightly faster. It is also important
1601 * to keep in mind that completely non-interleaved input will need huge amounts
1602 * of memory to interleave with this, so it is preferable to interleave at the
1603 * demuxer level.
1604 *
1605 * @param s media file handle
1606 * @param pkt The packet, which contains the stream_index, buf/buf_size,
1607 dts/pts, ...
1608 * @return < 0 on error, = 0 if OK, 1 if end of stream wanted
1609 */
1610 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
1611
1612 /**
1613 * Interleave a packet per dts in an output media file.
1614 *
1615 * Packets with pkt->destruct == av_destruct_packet will be freed inside this
1616 * function, so they cannot be used after it. Note that calling av_free_packet()
1617 * on them is still safe.
1618 *
1619 * @param s media file handle
1620 * @param out the interleaved packet will be output here
1621 * @param pkt the input packet
1622 * @param flush 1 if no further packets are available as input and all
1623 * remaining packets should be output
1624 * @return 1 if a packet was output, 0 if no packet could be output,
1625 * < 0 if an error occurred
1626 */
1627 int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
1628 AVPacket *pkt, int flush);
1629
1630 /**
1631 * Write the stream trailer to an output media file and free the
1632 * file private data.
1633 *
1634 * May only be called after a successful call to av_write_header.
1635 *
1636 * @param s media file handle
1637 * @return 0 if OK, AVERROR_xxx on error
1638 */
1639 int av_write_trailer(AVFormatContext *s);
1640
1641 #if FF_API_DUMP_FORMAT
1642 attribute_deprecated void dump_format(AVFormatContext *ic,
1643 int index,
1644 const char *url,
1645 int is_output);
1646 #endif
1647
1648 void av_dump_format(AVFormatContext *ic,
1649 int index,
1650 const char *url,
1651 int is_output);
1652
1653 #if FF_API_PARSE_DATE
1654 /**
1655 * Parse datestr and return a corresponding number of microseconds.
1656 *
1657 * @param datestr String representing a date or a duration.
1658 * See av_parse_time() for the syntax of the provided string.
1659 * @deprecated in favor of av_parse_time()
1660 */
1661 attribute_deprecated
1662 int64_t parse_date(const char *datestr, int duration);
1663 #endif
1664
1665 /**
1666 * Get the current time in microseconds.
1667 */
1668 int64_t av_gettime(void);
1669
1670 #if FF_API_FIND_INFO_TAG
1671 /**
1672 * @deprecated use av_find_info_tag in libavutil instead.
1673 */
1674 attribute_deprecated int find_info_tag(char *arg, int arg_size, const char *tag1, const char *info);
1675 #endif
1676
1677 /**
1678 * Return in 'buf' the path with '%d' replaced by a number.
1679 *
1680 * Also handles the '%0nd' format where 'n' is the total number
1681 * of digits and '%%'.
1682 *
1683 * @param buf destination buffer
1684 * @param buf_size destination buffer size
1685 * @param path numbered sequence string
1686 * @param number frame number
1687 * @return 0 if OK, -1 on format error
1688 */
1689 int av_get_frame_filename(char *buf, int buf_size,
1690 const char *path, int number);
1691
1692 /**
1693 * Check whether filename actually is a numbered sequence generator.
1694 *
1695 * @param filename possible numbered sequence string
1696 * @return 1 if a valid numbered sequence string, 0 otherwise
1697 */
1698 int av_filename_number_test(const char *filename);
1699
1700 /**
1701 * Generate an SDP for an RTP session.
1702 *
1703 * @param ac array of AVFormatContexts describing the RTP streams. If the
1704 * array is composed by only one context, such context can contain
1705 * multiple AVStreams (one AVStream per RTP stream). Otherwise,
1706 * all the contexts in the array (an AVCodecContext per RTP stream)
1707 * must contain only one AVStream.
1708 * @param n_files number of AVCodecContexts contained in ac
1709 * @param buf buffer where the SDP will be stored (must be allocated by
1710 * the caller)
1711 * @param size the size of the buffer
1712 * @return 0 if OK, AVERROR_xxx on error
1713 */
1714 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
1715
1716 #if FF_API_SDP_CREATE
1717 attribute_deprecated int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size);
1718 #endif
1719
1720 /**
1721 * Return a positive value if the given filename has one of the given
1722 * extensions, 0 otherwise.
1723 *
1724 * @param extensions a comma-separated list of filename extensions
1725 */
1726 int av_match_ext(const char *filename, const char *extensions);
1727
1728 /**
1729 * Test if the given container can store a codec.
1730 *
1731 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
1732 *
1733 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
1734 * A negative number if this information is not available.
1735 */
1736 int avformat_query_codec(AVOutputFormat *ofmt, enum CodecID codec_id, int std_compliance);
1737
1738 /**
1739 * Get the AVClass for AVFormatContext. It can be used in combination with
1740 * AV_OPT_SEARCH_FAKE_OBJ for examining options.
1741 *
1742 * @see av_opt_find().
1743 */
1744 const AVClass *avformat_get_class(void);
1745
1746 /**
1747 * Do global initialization of network components. This is optional,
1748 * but recommended, since it avoids the overhead of implicitly
1749 * doing the setup for each session.
1750 *
1751 * Calling this function will become mandatory if using network
1752 * protocols at some major version bump.
1753 */
1754 int avformat_network_init(void);
1755
1756 /**
1757 * Undo the initialization done by avformat_network_init.
1758 */
1759 int avformat_network_deinit(void);
1760
1761 #endif /* AVFORMAT_AVFORMAT_H */