1 /* 2 * copyright (c) 2001 Fabrice Bellard 3 * 4 * This file is part of FFmpeg. 5 * 6 * FFmpeg is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * FFmpeg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with FFmpeg; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21 #ifndef AVFORMAT_AVFORMAT_H 22 #define AVFORMAT_AVFORMAT_H 23 24 /** 25 * @file 26 * @ingroup libavf 27 * Main libavformat public API header 28 */ 29 30 /** 31 * @defgroup libavf libavformat 32 * I/O and Muxing/Demuxing Library 33 * 34 * Libavformat (lavf) is a library for dealing with various media container 35 * formats. Its main two purposes are demuxing - i.e. splitting a media file 36 * into component streams, and the reverse process of muxing - writing supplied 37 * data in a specified container format. It also has an @ref lavf_io 38 * "I/O module" which supports a number of protocols for accessing the data (e.g. 39 * file, tcp, http and others). 40 * Unless you are absolutely sure you won't use libavformat's network 41 * capabilities, you should also call avformat_network_init(). 42 * 43 * A supported input format is described by an AVInputFormat struct, conversely 44 * an output format is described by AVOutputFormat. You can iterate over all 45 * input/output formats using the av_demuxer_iterate / av_muxer_iterate() functions. 46 * The protocols layer is not part of the public API, so you can only get the names 47 * of supported protocols with the avio_enum_protocols() function. 48 * 49 * Main lavf structure used for both muxing and demuxing is AVFormatContext, 50 * which exports all information about the file being read or written. As with 51 * most Libavformat structures, its size is not part of public ABI, so it cannot be 52 * allocated on stack or directly with av_malloc(). To create an 53 * AVFormatContext, use avformat_alloc_context() (some functions, like 54 * avformat_open_input() might do that for you). 55 * 56 * Most importantly an AVFormatContext contains: 57 * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat 58 * "output" format. It is either autodetected or set by user for input; 59 * always set by user for output. 60 * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all 61 * elementary streams stored in the file. AVStreams are typically referred to 62 * using their index in this array. 63 * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or 64 * set by user for input, always set by user for output (unless you are dealing 65 * with an AVFMT_NOFILE format). 66 * 67 * @section lavf_options Passing options to (de)muxers 68 * It is possible to configure lavf muxers and demuxers using the @ref avoptions 69 * mechanism. Generic (format-independent) libavformat options are provided by 70 * AVFormatContext, they can be examined from a user program by calling 71 * av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass 72 * from avformat_get_class()). Private (format-specific) options are provided by 73 * AVFormatContext.priv_data if and only if AVInputFormat.priv_class / 74 * AVOutputFormat.priv_class of the corresponding format struct is non-NULL. 75 * Further options may be provided by the @ref AVFormatContext.pb "I/O context", 76 * if its AVClass is non-NULL, and the protocols layer. See the discussion on 77 * nesting in @ref avoptions documentation to learn how to access those. 78 * 79 * @section urls 80 * URL strings in libavformat are made of a scheme/protocol, a ':', and a 81 * scheme specific string. URLs without a scheme and ':' used for local files 82 * are supported but deprecated. "file:" should be used for local files. 83 * 84 * It is important that the scheme string is not taken from untrusted 85 * sources without checks. 86 * 87 * Note that some schemes/protocols are quite powerful, allowing access to 88 * both local and remote files, parts of them, concatenations of them, local 89 * audio and video devices and so on. 90 * 91 * @{ 92 * 93 * @defgroup lavf_decoding Demuxing 94 * @{ 95 * Demuxers read a media file and split it into chunks of data (@em packets). A 96 * @ref AVPacket "packet" contains one or more encoded frames which belongs to a 97 * single elementary stream. In the lavf API this process is represented by the 98 * avformat_open_input() function for opening a file, av_read_frame() for 99 * reading a single packet and finally avformat_close_input(), which does the 100 * cleanup. 101 * 102 * @section lavf_decoding_open Opening a media file 103 * The minimum information required to open a file is its URL, which 104 * is passed to avformat_open_input(), as in the following code: 105 * @code 106 * const char *url = "file:in.mp3"; 107 * AVFormatContext *s = NULL; 108 * int ret = avformat_open_input(&s, url, NULL, NULL); 109 * if (ret < 0) 110 * abort(); 111 * @endcode 112 * The above code attempts to allocate an AVFormatContext, open the 113 * specified file (autodetecting the format) and read the header, exporting the 114 * information stored there into s. Some formats do not have a header or do not 115 * store enough information there, so it is recommended that you call the 116 * avformat_find_stream_info() function which tries to read and decode a few 117 * frames to find missing information. 118 * 119 * In some cases you might want to preallocate an AVFormatContext yourself with 120 * avformat_alloc_context() and do some tweaking on it before passing it to 121 * avformat_open_input(). One such case is when you want to use custom functions 122 * for reading input data instead of lavf internal I/O layer. 123 * To do that, create your own AVIOContext with avio_alloc_context(), passing 124 * your reading callbacks to it. Then set the @em pb field of your 125 * AVFormatContext to newly created AVIOContext. 126 * 127 * Since the format of the opened file is in general not known until after 128 * avformat_open_input() has returned, it is not possible to set demuxer private 129 * options on a preallocated context. Instead, the options should be passed to 130 * avformat_open_input() wrapped in an AVDictionary: 131 * @code 132 * AVDictionary *options = NULL; 133 * av_dict_set(&options, "video_size", "640x480", 0); 134 * av_dict_set(&options, "pixel_format", "rgb24", 0); 135 * 136 * if (avformat_open_input(&s, url, NULL, &options) < 0) 137 * abort(); 138 * av_dict_free(&options); 139 * @endcode 140 * This code passes the private options 'video_size' and 'pixel_format' to the 141 * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it 142 * cannot know how to interpret raw video data otherwise. If the format turns 143 * out to be something different than raw video, those options will not be 144 * recognized by the demuxer and therefore will not be applied. Such unrecognized 145 * options are then returned in the options dictionary (recognized options are 146 * consumed). The calling program can handle such unrecognized options as it 147 * wishes, e.g. 148 * @code 149 * AVDictionaryEntry *e; 150 * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) { 151 * fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key); 152 * abort(); 153 * } 154 * @endcode 155 * 156 * After you have finished reading the file, you must close it with 157 * avformat_close_input(). It will free everything associated with the file. 158 * 159 * @section lavf_decoding_read Reading from an opened file 160 * Reading data from an opened AVFormatContext is done by repeatedly calling 161 * av_read_frame() on it. Each call, if successful, will return an AVPacket 162 * containing encoded data for one AVStream, identified by 163 * AVPacket.stream_index. This packet may be passed straight into the libavcodec 164 * decoding functions avcodec_send_packet() or avcodec_decode_subtitle2() if the 165 * caller wishes to decode the data. 166 * 167 * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be 168 * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for 169 * pts/dts, 0 for duration) if the stream does not provide them. The timing 170 * information will be in AVStream.time_base units, i.e. it has to be 171 * multiplied by the timebase to convert them to seconds. 172 * 173 * A packet returned by av_read_frame() is always reference-counted, 174 * i.e. AVPacket.buf is set and the user may keep it indefinitely. 175 * The packet must be freed with av_packet_unref() when it is no 176 * longer needed. 177 * 178 * @section lavf_decoding_seek Seeking 179 * @} 180 * 181 * @defgroup lavf_encoding Muxing 182 * @{ 183 * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write 184 * it into files or other output bytestreams in the specified container format. 185 * 186 * The main API functions for muxing are avformat_write_header() for writing the 187 * file header, av_write_frame() / av_interleaved_write_frame() for writing the 188 * packets and av_write_trailer() for finalizing the file. 189 * 190 * At the beginning of the muxing process, the caller must first call 191 * avformat_alloc_context() to create a muxing context. The caller then sets up 192 * the muxer by filling the various fields in this context: 193 * 194 * - The @ref AVFormatContext.oformat "oformat" field must be set to select the 195 * muxer that will be used. 196 * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb 197 * "pb" field must be set to an opened IO context, either returned from 198 * avio_open2() or a custom one. 199 * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must 200 * be created with the avformat_new_stream() function. The caller should fill 201 * the @ref AVStream.codecpar "stream codec parameters" information, such as the 202 * codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id 203 * "id" and other parameters (e.g. width / height, the pixel or sample format, 204 * etc.) as known. The @ref AVStream.time_base "stream timebase" should 205 * be set to the timebase that the caller desires to use for this stream (note 206 * that the timebase actually used by the muxer can be different, as will be 207 * described later). 208 * - It is advised to manually initialize only the relevant fields in 209 * AVCodecParameters, rather than using @ref avcodec_parameters_copy() during 210 * remuxing: there is no guarantee that the codec context values remain valid 211 * for both input and output format contexts. 212 * - The caller may fill in additional information, such as @ref 213 * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream" 214 * metadata, @ref AVFormatContext.chapters "chapters", @ref 215 * AVFormatContext.programs "programs", etc. as described in the 216 * AVFormatContext documentation. Whether such information will actually be 217 * stored in the output depends on what the container format and the muxer 218 * support. 219 * 220 * When the muxing context is fully set up, the caller must call 221 * avformat_write_header() to initialize the muxer internals and write the file 222 * header. Whether anything actually is written to the IO context at this step 223 * depends on the muxer, but this function must always be called. Any muxer 224 * private options must be passed in the options parameter to this function. 225 * 226 * The data is then sent to the muxer by repeatedly calling av_write_frame() or 227 * av_interleaved_write_frame() (consult those functions' documentation for 228 * discussion on the difference between them; only one of them may be used with 229 * a single muxing context, they should not be mixed). Do note that the timing 230 * information on the packets sent to the muxer must be in the corresponding 231 * AVStream's timebase. That timebase is set by the muxer (in the 232 * avformat_write_header() step) and may be different from the timebase 233 * requested by the caller. 234 * 235 * Once all the data has been written, the caller must call av_write_trailer() 236 * to flush any buffered packets and finalize the output file, then close the IO 237 * context (if any) and finally free the muxing context with 238 * avformat_free_context(). 239 * @} 240 * 241 * @defgroup lavf_io I/O Read/Write 242 * @{ 243 * @section lavf_io_dirlist Directory listing 244 * The directory listing API makes it possible to list files on remote servers. 245 * 246 * Some of possible use cases: 247 * - an "open file" dialog to choose files from a remote location, 248 * - a recursive media finder providing a player with an ability to play all 249 * files from a given directory. 250 * 251 * @subsection lavf_io_dirlist_open Opening a directory 252 * At first, a directory needs to be opened by calling avio_open_dir() 253 * supplied with a URL and, optionally, ::AVDictionary containing 254 * protocol-specific parameters. The function returns zero or positive 255 * integer and allocates AVIODirContext on success. 256 * 257 * @code 258 * AVIODirContext *ctx = NULL; 259 * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) { 260 * fprintf(stderr, "Cannot open directory.\n"); 261 * abort(); 262 * } 263 * @endcode 264 * 265 * This code tries to open a sample directory using smb protocol without 266 * any additional parameters. 267 * 268 * @subsection lavf_io_dirlist_read Reading entries 269 * Each directory's entry (i.e. file, another directory, anything else 270 * within ::AVIODirEntryType) is represented by AVIODirEntry. 271 * Reading consecutive entries from an opened AVIODirContext is done by 272 * repeatedly calling avio_read_dir() on it. Each call returns zero or 273 * positive integer if successful. Reading can be stopped right after the 274 * NULL entry has been read -- it means there are no entries left to be 275 * read. The following code reads all entries from a directory associated 276 * with ctx and prints their names to standard output. 277 * @code 278 * AVIODirEntry *entry = NULL; 279 * for (;;) { 280 * if (avio_read_dir(ctx, &entry) < 0) { 281 * fprintf(stderr, "Cannot list directory.\n"); 282 * abort(); 283 * } 284 * if (!entry) 285 * break; 286 * printf("%s\n", entry->name); 287 * avio_free_directory_entry(&entry); 288 * } 289 * @endcode 290 * @} 291 * 292 * @defgroup lavf_codec Demuxers 293 * @{ 294 * @defgroup lavf_codec_native Native Demuxers 295 * @{ 296 * @} 297 * @defgroup lavf_codec_wrappers External library wrappers 298 * @{ 299 * @} 300 * @} 301 * @defgroup lavf_protos I/O Protocols 302 * @{ 303 * @} 304 * @defgroup lavf_internal Internal 305 * @{ 306 * @} 307 * @} 308 */ 309 310 #include <time.h> 311 #include <stdio.h> /* FILE */ 312 #include "libavcodec/avcodec.h" 313 #include "libavutil/dict.h" 314 #include "libavutil/log.h" 315 316 #include "avio.h" 317 #include "libavformat/version.h" 318 319 struct AVFormatContext; 320 321 struct AVDeviceInfoList; 322 struct AVDeviceCapabilitiesQuery; 323 324 /** 325 * @defgroup metadata_api Public Metadata API 326 * @{ 327 * @ingroup libavf 328 * The metadata API allows libavformat to export metadata tags to a client 329 * application when demuxing. Conversely it allows a client application to 330 * set metadata when muxing. 331 * 332 * Metadata is exported or set as pairs of key/value strings in the 'metadata' 333 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs 334 * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg, 335 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata 336 * exported by demuxers isn't checked to be valid UTF-8 in most cases. 337 * 338 * Important concepts to keep in mind: 339 * - Keys are unique; there can never be 2 tags with the same key. This is 340 * also meant semantically, i.e., a demuxer should not knowingly produce 341 * several keys that are literally different but semantically identical. 342 * E.g., key=Author5, key=Author6. In this example, all authors must be 343 * placed in the same tag. 344 * - Metadata is flat, not hierarchical; there are no subtags. If you 345 * want to store, e.g., the email address of the child of producer Alice 346 * and actor Bob, that could have key=alice_and_bobs_childs_email_address. 347 * - Several modifiers can be applied to the tag name. This is done by 348 * appending a dash character ('-') and the modifier name in the order 349 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng. 350 * - language -- a tag whose value is localized for a particular language 351 * is appended with the ISO 639-2/B 3-letter language code. 352 * For example: Author-ger=Michael, Author-eng=Mike 353 * The original/default language is in the unqualified "Author" tag. 354 * A demuxer should set a default if it sets any translated tag. 355 * - sorting -- a modified version of a tag that should be used for 356 * sorting will have '-sort' appended. E.g. artist="The Beatles", 357 * artist-sort="Beatles, The". 358 * - Some protocols and demuxers support metadata updates. After a successful 359 * call to av_read_frame(), AVFormatContext.event_flags or AVStream.event_flags 360 * will be updated to indicate if metadata changed. In order to detect metadata 361 * changes on a stream, you need to loop through all streams in the AVFormatContext 362 * and check their individual event_flags. 363 * 364 * - Demuxers attempt to export metadata in a generic format, however tags 365 * with no generic equivalents are left as they are stored in the container. 366 * Follows a list of generic tag names: 367 * 368 @verbatim 369 album -- name of the set this work belongs to 370 album_artist -- main creator of the set/album, if different from artist. 371 e.g. "Various Artists" for compilation albums. 372 artist -- main creator of the work 373 comment -- any additional description of the file. 374 composer -- who composed the work, if different from artist. 375 copyright -- name of copyright holder. 376 creation_time-- date when the file was created, preferably in ISO 8601. 377 date -- date when the work was created, preferably in ISO 8601. 378 disc -- number of a subset, e.g. disc in a multi-disc collection. 379 encoder -- name/settings of the software/hardware that produced the file. 380 encoded_by -- person/group who created the file. 381 filename -- original name of the file. 382 genre -- <self-evident>. 383 language -- main language in which the work is performed, preferably 384 in ISO 639-2 format. Multiple languages can be specified by 385 separating them with commas. 386 performer -- artist who performed the work, if different from artist. 387 E.g for "Also sprach Zarathustra", artist would be "Richard 388 Strauss" and performer "London Philharmonic Orchestra". 389 publisher -- name of the label/publisher. 390 service_name -- name of the service in broadcasting (channel name). 391 service_provider -- name of the service provider in broadcasting. 392 title -- name of the work. 393 track -- number of this work in the set, can be in form current/total. 394 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of 395 @endverbatim 396 * 397 * Look in the examples section for an application example how to use the Metadata API. 398 * 399 * @} 400 */ 401 402 /* packet functions */ 403 404 405 /** 406 * Allocate and read the payload of a packet and initialize its 407 * fields with default values. 408 * 409 * @param s associated IO context 410 * @param pkt packet 411 * @param size desired payload size 412 * @return >0 (read size) if OK, AVERROR_xxx otherwise 413 */ 414 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size); 415 416 417 /** 418 * Read data and append it to the current content of the AVPacket. 419 * If pkt->size is 0 this is identical to av_get_packet. 420 * Note that this uses av_grow_packet and thus involves a realloc 421 * which is inefficient. Thus this function should only be used 422 * when there is no reasonable way to know (an upper bound of) 423 * the final size. 424 * 425 * @param s associated IO context 426 * @param pkt packet 427 * @param size amount of data to read 428 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data 429 * will not be lost even if an error occurs. 430 */ 431 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size); 432 433 /*************************************************/ 434 /* input/output formats */ 435 436 struct AVCodecTag; 437 438 /** 439 * This structure contains the data a format has to probe a file. 440 */ 441 typedef struct AVProbeData { 442 const char *filename; 443 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */ 444 int buf_size; /**< Size of buf except extra allocated bytes */ 445 const char *mime_type; /**< mime_type, when known. */ 446 } AVProbeData; 447 448 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4) 449 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1) 450 451 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension 452 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type 453 #define AVPROBE_SCORE_MAX 100 ///< maximum score 454 455 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer 456 457 /// Demuxer will use avio_open, no opened file should be provided by the caller. 458 #define AVFMT_NOFILE 0x0001 459 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */ 460 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */ 461 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */ 462 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */ 463 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */ 464 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */ 465 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */ 466 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */ 467 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */ 468 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */ 469 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */ 470 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */ 471 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */ 472 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly 473 increasing timestamps, but they must 474 still be monotonic */ 475 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative 476 timestamps. If not set the timestamp 477 will be shifted in av_write_frame and 478 av_interleaved_write_frame so they 479 start from 0. 480 The user or muxer can override this through 481 AVFormatContext.avoid_negative_ts 482 */ 483 484 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */ 485 486 /** 487 * @addtogroup lavf_encoding 488 * @{ 489 */ 490 typedef struct AVOutputFormat { 491 const char *name; 492 /** 493 * Descriptive name for the format, meant to be more human-readable 494 * than name. You should use the NULL_IF_CONFIG_SMALL() macro 495 * to define it. 496 */ 497 const char *long_name; 498 const char *mime_type; 499 const char *extensions; /**< comma-separated filename extensions */ 500 /* output support */ 501 enum AVCodecID audio_codec; /**< default audio codec */ 502 enum AVCodecID video_codec; /**< default video codec */ 503 enum AVCodecID subtitle_codec; /**< default subtitle codec */ 504 /** 505 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, 506 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS, 507 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH, 508 * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE 509 */ 510 int flags; 511 512 /** 513 * List of supported codec_id-codec_tag pairs, ordered by "better 514 * choice first". The arrays are all terminated by AV_CODEC_ID_NONE. 515 */ 516 const struct AVCodecTag * const *codec_tag; 517 518 519 const AVClass *priv_class; ///< AVClass for the private context 520 521 /***************************************************************** 522 * No fields below this line are part of the public API. They 523 * may not be used outside of libavformat and can be changed and 524 * removed at will. 525 * New public fields should be added right above. 526 ***************************************************************** 527 */ 528 /** 529 * The ff_const59 define is not part of the public API and will 530 * be removed without further warning. 531 */ 532 #if FF_API_AVIOFORMAT 533 #define ff_const59 534 #else 535 #define ff_const59 const 536 #endif 537 #if FF_API_NEXT 538 ff_const59 struct AVOutputFormat *next; 539 #endif 540 /** 541 * size of private data so that it can be allocated in the wrapper 542 */ 543 int priv_data_size; 544 545 int (*write_header)(struct AVFormatContext *); 546 /** 547 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags, 548 * pkt can be NULL in order to flush data buffered in the muxer. 549 * When flushing, return 0 if there still is more data to flush, 550 * or 1 if everything was flushed and there is no more buffered 551 * data. 552 */ 553 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt); 554 int (*write_trailer)(struct AVFormatContext *); 555 /** 556 * A format-specific function for interleavement. 557 * If unset, packets will be interleaved by dts. 558 */ 559 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out, 560 AVPacket *in, int flush); 561 /** 562 * Test if the given codec can be stored in this container. 563 * 564 * @return 1 if the codec is supported, 0 if it is not. 565 * A negative number if unknown. 566 * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC 567 */ 568 int (*query_codec)(enum AVCodecID id, int std_compliance); 569 570 void (*get_output_timestamp)(struct AVFormatContext *s, int stream, 571 int64_t *dts, int64_t *wall); 572 /** 573 * Allows sending messages from application to device. 574 */ 575 int (*control_message)(struct AVFormatContext *s, int type, 576 void *data, size_t data_size); 577 578 /** 579 * Write an uncoded AVFrame. 580 * 581 * See av_write_uncoded_frame() for details. 582 * 583 * The library will free *frame afterwards, but the muxer can prevent it 584 * by setting the pointer to NULL. 585 */ 586 int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index, 587 AVFrame **frame, unsigned flags); 588 /** 589 * Returns device list with it properties. 590 * @see avdevice_list_devices() for more details. 591 */ 592 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list); 593 #if LIBAVFORMAT_VERSION_MAJOR < 59 594 /** 595 * Initialize device capabilities submodule. 596 * @see avdevice_capabilities_create() for more details. 597 */ 598 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps); 599 /** 600 * Free device capabilities submodule. 601 * @see avdevice_capabilities_free() for more details. 602 */ 603 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps); 604 #endif 605 enum AVCodecID data_codec; /**< default data codec */ 606 /** 607 * Initialize format. May allocate data here, and set any AVFormatContext or 608 * AVStream parameters that need to be set before packets are sent. 609 * This method must not write output. 610 * 611 * Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure 612 * 613 * Any allocations made here must be freed in deinit(). 614 */ 615 int (*init)(struct AVFormatContext *); 616 /** 617 * Deinitialize format. If present, this is called whenever the muxer is being 618 * destroyed, regardless of whether or not the header has been written. 619 * 620 * If a trailer is being written, this is called after write_trailer(). 621 * 622 * This is called if init() fails as well. 623 */ 624 void (*deinit)(struct AVFormatContext *); 625 /** 626 * Set up any necessary bitstream filtering and extract any extra data needed 627 * for the global header. 628 * Return 0 if more packets from this stream must be checked; 1 if not. 629 */ 630 int (*check_bitstream)(struct AVFormatContext *, const AVPacket *pkt); 631 } AVOutputFormat; 632 /** 633 * @} 634 */ 635 636 /** 637 * @addtogroup lavf_decoding 638 * @{ 639 */ 640 typedef struct AVInputFormat { 641 /** 642 * A comma separated list of short names for the format. New names 643 * may be appended with a minor bump. 644 */ 645 const char *name; 646 647 /** 648 * Descriptive name for the format, meant to be more human-readable 649 * than name. You should use the NULL_IF_CONFIG_SMALL() macro 650 * to define it. 651 */ 652 const char *long_name; 653 654 /** 655 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS, 656 * AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH, 657 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS. 658 */ 659 int flags; 660 661 /** 662 * If extensions are defined, then no probe is done. You should 663 * usually not use extension format guessing because it is not 664 * reliable enough 665 */ 666 const char *extensions; 667 668 const struct AVCodecTag * const *codec_tag; 669 670 const AVClass *priv_class; ///< AVClass for the private context 671 672 /** 673 * Comma-separated list of mime types. 674 * It is used check for matching mime types while probing. 675 * @see av_probe_input_format2 676 */ 677 const char *mime_type; 678 679 /***************************************************************** 680 * No fields below this line are part of the public API. They 681 * may not be used outside of libavformat and can be changed and 682 * removed at will. 683 * New public fields should be added right above. 684 ***************************************************************** 685 */ 686 #if FF_API_NEXT 687 ff_const59 struct AVInputFormat *next; 688 #endif 689 690 /** 691 * Raw demuxers store their codec ID here. 692 */ 693 int raw_codec_id; 694 695 /** 696 * Size of private data so that it can be allocated in the wrapper. 697 */ 698 int priv_data_size; 699 700 /** 701 * Tell if a given file has a chance of being parsed as this format. 702 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes 703 * big so you do not have to check for that unless you need more. 704 */ 705 int (*read_probe)(const AVProbeData *); 706 707 /** 708 * Read the format header and initialize the AVFormatContext 709 * structure. Return 0 if OK. 'avformat_new_stream' should be 710 * called to create new streams. 711 */ 712 int (*read_header)(struct AVFormatContext *); 713 714 /** 715 * Read one packet and put it in 'pkt'. pts and flags are also 716 * set. 'avformat_new_stream' can be called only if the flag 717 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a 718 * background thread). 719 * @return 0 on success, < 0 on error. 720 * Upon returning an error, pkt must be unreferenced by the caller. 721 */ 722 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt); 723 724 /** 725 * Close the stream. The AVFormatContext and AVStreams are not 726 * freed by this function 727 */ 728 int (*read_close)(struct AVFormatContext *); 729 730 /** 731 * Seek to a given timestamp relative to the frames in 732 * stream component stream_index. 733 * @param stream_index Must not be -1. 734 * @param flags Selects which direction should be preferred if no exact 735 * match is available. 736 * @return >= 0 on success (but not necessarily the new offset) 737 */ 738 int (*read_seek)(struct AVFormatContext *, 739 int stream_index, int64_t timestamp, int flags); 740 741 /** 742 * Get the next timestamp in stream[stream_index].time_base units. 743 * @return the timestamp or AV_NOPTS_VALUE if an error occurred 744 */ 745 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index, 746 int64_t *pos, int64_t pos_limit); 747 748 /** 749 * Start/resume playing - only meaningful if using a network-based format 750 * (RTSP). 751 */ 752 int (*read_play)(struct AVFormatContext *); 753 754 /** 755 * Pause playing - only meaningful if using a network-based format 756 * (RTSP). 757 */ 758 int (*read_pause)(struct AVFormatContext *); 759 760 /** 761 * Seek to timestamp ts. 762 * Seeking will be done so that the point from which all active streams 763 * can be presented successfully will be closest to ts and within min/max_ts. 764 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL. 765 */ 766 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags); 767 768 /** 769 * Returns device list with it properties. 770 * @see avdevice_list_devices() for more details. 771 */ 772 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list); 773 774 #if LIBAVFORMAT_VERSION_MAJOR < 59 775 /** 776 * Initialize device capabilities submodule. 777 * @see avdevice_capabilities_create() for more details. 778 */ 779 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps); 780 781 /** 782 * Free device capabilities submodule. 783 * @see avdevice_capabilities_free() for more details. 784 */ 785 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps); 786 #endif 787 } AVInputFormat; 788 /** 789 * @} 790 */ 791 792 enum AVStreamParseType { 793 AVSTREAM_PARSE_NONE, 794 AVSTREAM_PARSE_FULL, /**< full parsing and repack */ 795 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */ 796 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */ 797 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */ 798 AVSTREAM_PARSE_FULL_RAW, /**< full parsing and repack with timestamp and position generation by parser for raw 799 this assumes that each packet in the file contains no demuxer level headers and 800 just codec level data, otherwise position generation would fail */ 801 }; 802 803 typedef struct AVIndexEntry { 804 int64_t pos; 805 int64_t timestamp; /**< 806 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available 807 * when seeking to this entry. That means preferable PTS on keyframe based formats. 808 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better 809 * is known 810 */ 811 #define AVINDEX_KEYFRAME 0x0001 812 #define AVINDEX_DISCARD_FRAME 0x0002 /** 813 * Flag is used to indicate which frame should be discarded after decoding. 814 */ 815 int flags:2; 816 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). 817 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */ 818 } AVIndexEntry; 819 820 #define AV_DISPOSITION_DEFAULT 0x0001 821 #define AV_DISPOSITION_DUB 0x0002 822 #define AV_DISPOSITION_ORIGINAL 0x0004 823 #define AV_DISPOSITION_COMMENT 0x0008 824 #define AV_DISPOSITION_LYRICS 0x0010 825 #define AV_DISPOSITION_KARAOKE 0x0020 826 827 /** 828 * Track should be used during playback by default. 829 * Useful for subtitle track that should be displayed 830 * even when user did not explicitly ask for subtitles. 831 */ 832 #define AV_DISPOSITION_FORCED 0x0040 833 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */ 834 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */ 835 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */ 836 /** 837 * The stream is stored in the file as an attached picture/"cover art" (e.g. 838 * APIC frame in ID3v2). The first (usually only) packet associated with it 839 * will be returned among the first few packets read from the file unless 840 * seeking takes place. It can also be accessed at any time in 841 * AVStream.attached_pic. 842 */ 843 #define AV_DISPOSITION_ATTACHED_PIC 0x0400 844 /** 845 * The stream is sparse, and contains thumbnail images, often corresponding 846 * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC. 847 */ 848 #define AV_DISPOSITION_TIMED_THUMBNAILS 0x0800 849 850 typedef struct AVStreamInternal AVStreamInternal; 851 852 /** 853 * To specify text track kind (different from subtitles default). 854 */ 855 #define AV_DISPOSITION_CAPTIONS 0x10000 856 #define AV_DISPOSITION_DESCRIPTIONS 0x20000 857 #define AV_DISPOSITION_METADATA 0x40000 858 #define AV_DISPOSITION_DEPENDENT 0x80000 ///< dependent audio stream (mix_type=0 in mpegts) 859 #define AV_DISPOSITION_STILL_IMAGE 0x100000 ///< still images in video stream (still_picture_flag=1 in mpegts) 860 861 /** 862 * Options for behavior on timestamp wrap detection. 863 */ 864 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap 865 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection 866 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection 867 868 /** 869 * Stream structure. 870 * New fields can be added to the end with minor version bumps. 871 * Removal, reordering and changes to existing fields require a major 872 * version bump. 873 * sizeof(AVStream) must not be used outside libav*. 874 */ 875 typedef struct AVStream { 876 int index; /**< stream index in AVFormatContext */ 877 /** 878 * Format-specific stream ID. 879 * decoding: set by libavformat 880 * encoding: set by the user, replaced by libavformat if left unset 881 */ 882 int id; 883 #if FF_API_LAVF_AVCTX 884 /** 885 * @deprecated use the codecpar struct instead 886 */ 887 attribute_deprecated 888 AVCodecContext *codec; 889 #endif 890 void *priv_data; 891 892 /** 893 * This is the fundamental unit of time (in seconds) in terms 894 * of which frame timestamps are represented. 895 * 896 * decoding: set by libavformat 897 * encoding: May be set by the caller before avformat_write_header() to 898 * provide a hint to the muxer about the desired timebase. In 899 * avformat_write_header(), the muxer will overwrite this field 900 * with the timebase that will actually be used for the timestamps 901 * written into the file (which may or may not be related to the 902 * user-provided one, depending on the format). 903 */ 904 AVRational time_base; 905 906 /** 907 * Decoding: pts of the first frame of the stream in presentation order, in stream time base. 908 * Only set this if you are absolutely 100% sure that the value you set 909 * it to really is the pts of the first frame. 910 * This may be undefined (AV_NOPTS_VALUE). 911 * @note The ASF header does NOT contain a correct start_time the ASF 912 * demuxer must NOT set this. 913 */ 914 int64_t start_time; 915 916 /** 917 * Decoding: duration of the stream, in stream time base. 918 * If a source file does not specify a duration, but does specify 919 * a bitrate, this value will be estimated from bitrate and file size. 920 * 921 * Encoding: May be set by the caller before avformat_write_header() to 922 * provide a hint to the muxer about the estimated duration. 923 */ 924 int64_t duration; 925 926 int64_t nb_frames; ///< number of frames in this stream if known or 0 927 928 int disposition; /**< AV_DISPOSITION_* bit field */ 929 930 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed. 931 932 /** 933 * sample aspect ratio (0 if unknown) 934 * - encoding: Set by user. 935 * - decoding: Set by libavformat. 936 */ 937 AVRational sample_aspect_ratio; 938 939 AVDictionary *metadata; 940 941 /** 942 * Average framerate 943 * 944 * - demuxing: May be set by libavformat when creating the stream or in 945 * avformat_find_stream_info(). 946 * - muxing: May be set by the caller before avformat_write_header(). 947 */ 948 AVRational avg_frame_rate; 949 950 /** 951 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet 952 * will contain the attached picture. 953 * 954 * decoding: set by libavformat, must not be modified by the caller. 955 * encoding: unused 956 */ 957 AVPacket attached_pic; 958 959 /** 960 * An array of side data that applies to the whole stream (i.e. the 961 * container does not allow it to change between packets). 962 * 963 * There may be no overlap between the side data in this array and side data 964 * in the packets. I.e. a given side data is either exported by the muxer 965 * (demuxing) / set by the caller (muxing) in this array, then it never 966 * appears in the packets, or the side data is exported / sent through 967 * the packets (always in the first packet where the value becomes known or 968 * changes), then it does not appear in this array. 969 * 970 * - demuxing: Set by libavformat when the stream is created. 971 * - muxing: May be set by the caller before avformat_write_header(). 972 * 973 * Freed by libavformat in avformat_free_context(). 974 * 975 * @see av_format_inject_global_side_data() 976 */ 977 AVPacketSideData *side_data; 978 /** 979 * The number of elements in the AVStream.side_data array. 980 */ 981 int nb_side_data; 982 983 /** 984 * Flags indicating events happening on the stream, a combination of 985 * AVSTREAM_EVENT_FLAG_*. 986 * 987 * - demuxing: may be set by the demuxer in avformat_open_input(), 988 * avformat_find_stream_info() and av_read_frame(). Flags must be cleared 989 * by the user once the event has been handled. 990 * - muxing: may be set by the user after avformat_write_header(). to 991 * indicate a user-triggered event. The muxer will clear the flags for 992 * events it has handled in av_[interleaved]_write_frame(). 993 */ 994 int event_flags; 995 /** 996 * - demuxing: the demuxer read new metadata from the file and updated 997 * AVStream.metadata accordingly 998 * - muxing: the user updated AVStream.metadata and wishes the muxer to write 999 * it into the file 1000 */ 1001 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 1002 /** 1003 * - demuxing: new packets for this stream were read from the file. This 1004 * event is informational only and does not guarantee that new packets 1005 * for this stream will necessarily be returned from av_read_frame(). 1006 */ 1007 #define AVSTREAM_EVENT_FLAG_NEW_PACKETS (1 << 1) 1008 1009 /** 1010 * Real base framerate of the stream. 1011 * This is the lowest framerate with which all timestamps can be 1012 * represented accurately (it is the least common multiple of all 1013 * framerates in the stream). Note, this value is just a guess! 1014 * For example, if the time base is 1/90000 and all frames have either 1015 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1. 1016 */ 1017 AVRational r_frame_rate; 1018 1019 #if FF_API_LAVF_FFSERVER 1020 /** 1021 * String containing pairs of key and values describing recommended encoder configuration. 1022 * Pairs are separated by ','. 1023 * Keys are separated from values by '='. 1024 * 1025 * @deprecated unused 1026 */ 1027 attribute_deprecated 1028 char *recommended_encoder_configuration; 1029 #endif 1030 1031 /** 1032 * Codec parameters associated with this stream. Allocated and freed by 1033 * libavformat in avformat_new_stream() and avformat_free_context() 1034 * respectively. 1035 * 1036 * - demuxing: filled by libavformat on stream creation or in 1037 * avformat_find_stream_info() 1038 * - muxing: filled by the caller before avformat_write_header() 1039 */ 1040 AVCodecParameters *codecpar; 1041 1042 /***************************************************************** 1043 * All fields below this line are not part of the public API. They 1044 * may not be used outside of libavformat and can be changed and 1045 * removed at will. 1046 * Internal note: be aware that physically removing these fields 1047 * will break ABI. Replace removed fields with dummy fields, and 1048 * add new fields to AVStreamInternal. 1049 ***************************************************************** 1050 */ 1051 1052 #if LIBAVFORMAT_VERSION_MAJOR < 59 1053 // kept for ABI compatibility only, do not access in any way 1054 void *unused; 1055 #endif 1056 1057 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */ 1058 1059 // Timestamp generation support: 1060 /** 1061 * Timestamp corresponding to the last dts sync point. 1062 * 1063 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and 1064 * a DTS is received from the underlying container. Otherwise set to 1065 * AV_NOPTS_VALUE by default. 1066 */ 1067 int64_t first_dts; 1068 int64_t cur_dts; 1069 int64_t last_IP_pts; 1070 int last_IP_duration; 1071 1072 /** 1073 * Number of packets to buffer for codec probing 1074 */ 1075 int probe_packets; 1076 1077 /** 1078 * Number of frames that have been demuxed during avformat_find_stream_info() 1079 */ 1080 int codec_info_nb_frames; 1081 1082 /* av_read_frame() support */ 1083 enum AVStreamParseType need_parsing; 1084 struct AVCodecParserContext *parser; 1085 1086 #if LIBAVFORMAT_VERSION_MAJOR < 59 1087 // kept for ABI compatibility only, do not access in any way 1088 void *unused7; 1089 AVProbeData unused6; 1090 int64_t unused5[16+1]; 1091 #endif 1092 AVIndexEntry *index_entries; /**< Only used if the format does not 1093 support seeking natively. */ 1094 int nb_index_entries; 1095 unsigned int index_entries_allocated_size; 1096 1097 /** 1098 * Stream Identifier 1099 * This is the MPEG-TS stream identifier +1 1100 * 0 means unknown 1101 */ 1102 int stream_identifier; 1103 1104 #if LIBAVFORMAT_VERSION_MAJOR < 59 1105 // kept for ABI compatibility only, do not access in any way 1106 int unused8; 1107 int unused9; 1108 int unused10; 1109 #endif 1110 1111 /** 1112 * An opaque field for libavformat internal usage. 1113 * Must not be accessed in any way by callers. 1114 */ 1115 AVStreamInternal *internal; 1116 } AVStream; 1117 1118 #if FF_API_FORMAT_GET_SET 1119 /** 1120 * Accessors for some AVStream fields. These used to be provided for ABI 1121 * compatibility, and do not need to be used anymore. 1122 */ 1123 attribute_deprecated 1124 AVRational av_stream_get_r_frame_rate(const AVStream *s); 1125 attribute_deprecated 1126 void av_stream_set_r_frame_rate(AVStream *s, AVRational r); 1127 #if FF_API_LAVF_FFSERVER 1128 attribute_deprecated 1129 char* av_stream_get_recommended_encoder_configuration(const AVStream *s); 1130 attribute_deprecated 1131 void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration); 1132 #endif 1133 #endif 1134 1135 struct AVCodecParserContext *av_stream_get_parser(const AVStream *s); 1136 1137 /** 1138 * Returns the pts of the last muxed packet + its duration 1139 * 1140 * the retuned value is undefined when used with a demuxer. 1141 */ 1142 int64_t av_stream_get_end_pts(const AVStream *st); 1143 1144 #define AV_PROGRAM_RUNNING 1 1145 1146 /** 1147 * New fields can be added to the end with minor version bumps. 1148 * Removal, reordering and changes to existing fields require a major 1149 * version bump. 1150 * sizeof(AVProgram) must not be used outside libav*. 1151 */ 1152 typedef struct AVProgram { 1153 int id; 1154 int flags; 1155 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller 1156 unsigned int *stream_index; 1157 unsigned int nb_stream_indexes; 1158 AVDictionary *metadata; 1159 1160 int program_num; 1161 int pmt_pid; 1162 int pcr_pid; 1163 int pmt_version; 1164 1165 /***************************************************************** 1166 * All fields below this line are not part of the public API. They 1167 * may not be used outside of libavformat and can be changed and 1168 * removed at will. 1169 * New public fields should be added right above. 1170 ***************************************************************** 1171 */ 1172 int64_t start_time; 1173 int64_t end_time; 1174 1175 int64_t pts_wrap_reference; ///< reference dts for wrap detection 1176 int pts_wrap_behavior; ///< behavior on wrap detection 1177 } AVProgram; 1178 1179 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present 1180 (streams are added dynamically) */ 1181 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely 1182 not seekable, and attempts to call the 1183 seek function will fail. For some 1184 network protocols (e.g. HLS), this can 1185 change dynamically at runtime. */ 1186 1187 typedef struct AVChapter { 1188 #if FF_API_CHAPTER_ID_INT 1189 int id; ///< unique ID to identify the chapter 1190 #else 1191 int64_t id; ///< unique ID to identify the chapter 1192 #endif 1193 AVRational time_base; ///< time base in which the start/end timestamps are specified 1194 int64_t start, end; ///< chapter start/end time in time_base units 1195 AVDictionary *metadata; 1196 } AVChapter; 1197 1198 1199 /** 1200 * Callback used by devices to communicate with application. 1201 */ 1202 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type, 1203 void *data, size_t data_size); 1204 1205 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, 1206 const AVIOInterruptCB *int_cb, AVDictionary **options); 1207 1208 /** 1209 * The duration of a video can be estimated through various ways, and this enum can be used 1210 * to know how the duration was estimated. 1211 */ 1212 enum AVDurationEstimationMethod { 1213 AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes 1214 AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration 1215 AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate) 1216 }; 1217 1218 typedef struct AVFormatInternal AVFormatInternal; 1219 1220 /** 1221 * Format I/O context. 1222 * New fields can be added to the end with minor version bumps. 1223 * Removal, reordering and changes to existing fields require a major 1224 * version bump. 1225 * sizeof(AVFormatContext) must not be used outside libav*, use 1226 * avformat_alloc_context() to create an AVFormatContext. 1227 * 1228 * Fields can be accessed through AVOptions (av_opt*), 1229 * the name string used matches the associated command line parameter name and 1230 * can be found in libavformat/options_table.h. 1231 * The AVOption/command line parameter names differ in some cases from the C 1232 * structure field names for historic reasons or brevity. 1233 */ 1234 typedef struct AVFormatContext { 1235 /** 1236 * A class for logging and @ref avoptions. Set by avformat_alloc_context(). 1237 * Exports (de)muxer private options if they exist. 1238 */ 1239 const AVClass *av_class; 1240 1241 /** 1242 * The input container format. 1243 * 1244 * Demuxing only, set by avformat_open_input(). 1245 */ 1246 ff_const59 struct AVInputFormat *iformat; 1247 1248 /** 1249 * The output container format. 1250 * 1251 * Muxing only, must be set by the caller before avformat_write_header(). 1252 */ 1253 ff_const59 struct AVOutputFormat *oformat; 1254 1255 /** 1256 * Format private data. This is an AVOptions-enabled struct 1257 * if and only if iformat/oformat.priv_class is not NULL. 1258 * 1259 * - muxing: set by avformat_write_header() 1260 * - demuxing: set by avformat_open_input() 1261 */ 1262 void *priv_data; 1263 1264 /** 1265 * I/O context. 1266 * 1267 * - demuxing: either set by the user before avformat_open_input() (then 1268 * the user must close it manually) or set by avformat_open_input(). 1269 * - muxing: set by the user before avformat_write_header(). The caller must 1270 * take care of closing / freeing the IO context. 1271 * 1272 * Do NOT set this field if AVFMT_NOFILE flag is set in 1273 * iformat/oformat.flags. In such a case, the (de)muxer will handle 1274 * I/O in some other way and this field will be NULL. 1275 */ 1276 AVIOContext *pb; 1277 1278 /* stream info */ 1279 /** 1280 * Flags signalling stream properties. A combination of AVFMTCTX_*. 1281 * Set by libavformat. 1282 */ 1283 int ctx_flags; 1284 1285 /** 1286 * Number of elements in AVFormatContext.streams. 1287 * 1288 * Set by avformat_new_stream(), must not be modified by any other code. 1289 */ 1290 unsigned int nb_streams; 1291 /** 1292 * A list of all streams in the file. New streams are created with 1293 * avformat_new_stream(). 1294 * 1295 * - demuxing: streams are created by libavformat in avformat_open_input(). 1296 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also 1297 * appear in av_read_frame(). 1298 * - muxing: streams are created by the user before avformat_write_header(). 1299 * 1300 * Freed by libavformat in avformat_free_context(). 1301 */ 1302 AVStream **streams; 1303 1304 #if FF_API_FORMAT_FILENAME 1305 /** 1306 * input or output filename 1307 * 1308 * - demuxing: set by avformat_open_input() 1309 * - muxing: may be set by the caller before avformat_write_header() 1310 * 1311 * @deprecated Use url instead. 1312 */ 1313 attribute_deprecated 1314 char filename[1024]; 1315 #endif 1316 1317 /** 1318 * input or output URL. Unlike the old filename field, this field has no 1319 * length restriction. 1320 * 1321 * - demuxing: set by avformat_open_input(), initialized to an empty 1322 * string if url parameter was NULL in avformat_open_input(). 1323 * - muxing: may be set by the caller before calling avformat_write_header() 1324 * (or avformat_init_output() if that is called first) to a string 1325 * which is freeable by av_free(). Set to an empty string if it 1326 * was NULL in avformat_init_output(). 1327 * 1328 * Freed by libavformat in avformat_free_context(). 1329 */ 1330 char *url; 1331 1332 /** 1333 * Position of the first frame of the component, in 1334 * AV_TIME_BASE fractional seconds. NEVER set this value directly: 1335 * It is deduced from the AVStream values. 1336 * 1337 * Demuxing only, set by libavformat. 1338 */ 1339 int64_t start_time; 1340 1341 /** 1342 * Duration of the stream, in AV_TIME_BASE fractional 1343 * seconds. Only set this value if you know none of the individual stream 1344 * durations and also do not set any of them. This is deduced from the 1345 * AVStream values if not set. 1346 * 1347 * Demuxing only, set by libavformat. 1348 */ 1349 int64_t duration; 1350 1351 /** 1352 * Total stream bitrate in bit/s, 0 if not 1353 * available. Never set it directly if the file_size and the 1354 * duration are known as FFmpeg can compute it automatically. 1355 */ 1356 int64_t bit_rate; 1357 1358 unsigned int packet_size; 1359 int max_delay; 1360 1361 /** 1362 * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*. 1363 * Set by the user before avformat_open_input() / avformat_write_header(). 1364 */ 1365 int flags; 1366 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames. 1367 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index. 1368 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input. 1369 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS 1370 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container 1371 #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 1372 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible 1373 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it. 1374 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted 1375 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet. 1376 /** 1377 * When muxing, try to avoid writing any random/volatile data to the output. 1378 * This includes any random IDs, real-time timestamps/dates, muxer version, etc. 1379 * 1380 * This flag is mainly intended for testing. 1381 */ 1382 #define AVFMT_FLAG_BITEXACT 0x0400 1383 #if FF_API_LAVF_MP4A_LATM 1384 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Deprecated, does nothing. 1385 #endif 1386 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down) 1387 #if FF_API_LAVF_PRIV_OPT 1388 #define AVFMT_FLAG_PRIV_OPT 0x20000 ///< Enable use of private options by delaying codec open (deprecated, will do nothing once av_demuxer_open() is removed) 1389 #endif 1390 #if FF_API_LAVF_KEEPSIDE_FLAG 1391 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Deprecated, does nothing. 1392 #endif 1393 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats 1394 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops. 1395 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer 1396 1397 /** 1398 * Maximum size of the data read from input for determining 1399 * the input container format. 1400 * Demuxing only, set by the caller before avformat_open_input(). 1401 */ 1402 int64_t probesize; 1403 1404 /** 1405 * Maximum duration (in AV_TIME_BASE units) of the data read 1406 * from input in avformat_find_stream_info(). 1407 * Demuxing only, set by the caller before avformat_find_stream_info(). 1408 * Can be set to 0 to let avformat choose using a heuristic. 1409 */ 1410 int64_t max_analyze_duration; 1411 1412 const uint8_t *key; 1413 int keylen; 1414 1415 unsigned int nb_programs; 1416 AVProgram **programs; 1417 1418 /** 1419 * Forced video codec_id. 1420 * Demuxing: Set by user. 1421 */ 1422 enum AVCodecID video_codec_id; 1423 1424 /** 1425 * Forced audio codec_id. 1426 * Demuxing: Set by user. 1427 */ 1428 enum AVCodecID audio_codec_id; 1429 1430 /** 1431 * Forced subtitle codec_id. 1432 * Demuxing: Set by user. 1433 */ 1434 enum AVCodecID subtitle_codec_id; 1435 1436 /** 1437 * Maximum amount of memory in bytes to use for the index of each stream. 1438 * If the index exceeds this size, entries will be discarded as 1439 * needed to maintain a smaller size. This can lead to slower or less 1440 * accurate seeking (depends on demuxer). 1441 * Demuxers for which a full in-memory index is mandatory will ignore 1442 * this. 1443 * - muxing: unused 1444 * - demuxing: set by user 1445 */ 1446 unsigned int max_index_size; 1447 1448 /** 1449 * Maximum amount of memory in bytes to use for buffering frames 1450 * obtained from realtime capture devices. 1451 */ 1452 unsigned int max_picture_buffer; 1453 1454 /** 1455 * Number of chapters in AVChapter array. 1456 * When muxing, chapters are normally written in the file header, 1457 * so nb_chapters should normally be initialized before write_header 1458 * is called. Some muxers (e.g. mov and mkv) can also write chapters 1459 * in the trailer. To write chapters in the trailer, nb_chapters 1460 * must be zero when write_header is called and non-zero when 1461 * write_trailer is called. 1462 * - muxing: set by user 1463 * - demuxing: set by libavformat 1464 */ 1465 unsigned int nb_chapters; 1466 AVChapter **chapters; 1467 1468 /** 1469 * Metadata that applies to the whole file. 1470 * 1471 * - demuxing: set by libavformat in avformat_open_input() 1472 * - muxing: may be set by the caller before avformat_write_header() 1473 * 1474 * Freed by libavformat in avformat_free_context(). 1475 */ 1476 AVDictionary *metadata; 1477 1478 /** 1479 * Start time of the stream in real world time, in microseconds 1480 * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the 1481 * stream was captured at this real world time. 1482 * - muxing: Set by the caller before avformat_write_header(). If set to 1483 * either 0 or AV_NOPTS_VALUE, then the current wall-time will 1484 * be used. 1485 * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that 1486 * the value may become known after some number of frames 1487 * have been received. 1488 */ 1489 int64_t start_time_realtime; 1490 1491 /** 1492 * The number of frames used for determining the framerate in 1493 * avformat_find_stream_info(). 1494 * Demuxing only, set by the caller before avformat_find_stream_info(). 1495 */ 1496 int fps_probe_size; 1497 1498 /** 1499 * Error recognition; higher values will detect more errors but may 1500 * misdetect some more or less valid parts as errors. 1501 * Demuxing only, set by the caller before avformat_open_input(). 1502 */ 1503 int error_recognition; 1504 1505 /** 1506 * Custom interrupt callbacks for the I/O layer. 1507 * 1508 * demuxing: set by the user before avformat_open_input(). 1509 * muxing: set by the user before avformat_write_header() 1510 * (mainly useful for AVFMT_NOFILE formats). The callback 1511 * should also be passed to avio_open2() if it's used to 1512 * open the file. 1513 */ 1514 AVIOInterruptCB interrupt_callback; 1515 1516 /** 1517 * Flags to enable debugging. 1518 */ 1519 int debug; 1520 #define FF_FDEBUG_TS 0x0001 1521 1522 /** 1523 * Maximum buffering duration for interleaving. 1524 * 1525 * To ensure all the streams are interleaved correctly, 1526 * av_interleaved_write_frame() will wait until it has at least one packet 1527 * for each stream before actually writing any packets to the output file. 1528 * When some streams are "sparse" (i.e. there are large gaps between 1529 * successive packets), this can result in excessive buffering. 1530 * 1531 * This field specifies the maximum difference between the timestamps of the 1532 * first and the last packet in the muxing queue, above which libavformat 1533 * will output a packet regardless of whether it has queued a packet for all 1534 * the streams. 1535 * 1536 * Muxing only, set by the caller before avformat_write_header(). 1537 */ 1538 int64_t max_interleave_delta; 1539 1540 /** 1541 * Allow non-standard and experimental extension 1542 * @see AVCodecContext.strict_std_compliance 1543 */ 1544 int strict_std_compliance; 1545 1546 /** 1547 * Flags indicating events happening on the file, a combination of 1548 * AVFMT_EVENT_FLAG_*. 1549 * 1550 * - demuxing: may be set by the demuxer in avformat_open_input(), 1551 * avformat_find_stream_info() and av_read_frame(). Flags must be cleared 1552 * by the user once the event has been handled. 1553 * - muxing: may be set by the user after avformat_write_header() to 1554 * indicate a user-triggered event. The muxer will clear the flags for 1555 * events it has handled in av_[interleaved]_write_frame(). 1556 */ 1557 int event_flags; 1558 /** 1559 * - demuxing: the demuxer read new metadata from the file and updated 1560 * AVFormatContext.metadata accordingly 1561 * - muxing: the user updated AVFormatContext.metadata and wishes the muxer to 1562 * write it into the file 1563 */ 1564 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 1565 1566 /** 1567 * Maximum number of packets to read while waiting for the first timestamp. 1568 * Decoding only. 1569 */ 1570 int max_ts_probe; 1571 1572 /** 1573 * Avoid negative timestamps during muxing. 1574 * Any value of the AVFMT_AVOID_NEG_TS_* constants. 1575 * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use) 1576 * - muxing: Set by user 1577 * - demuxing: unused 1578 */ 1579 int avoid_negative_ts; 1580 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format 1581 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative 1582 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0 1583 1584 /** 1585 * Transport stream id. 1586 * This will be moved into demuxer private options. Thus no API/ABI compatibility 1587 */ 1588 int ts_id; 1589 1590 /** 1591 * Audio preload in microseconds. 1592 * Note, not all formats support this and unpredictable things may happen if it is used when not supported. 1593 * - encoding: Set by user 1594 * - decoding: unused 1595 */ 1596 int audio_preload; 1597 1598 /** 1599 * Max chunk time in microseconds. 1600 * Note, not all formats support this and unpredictable things may happen if it is used when not supported. 1601 * - encoding: Set by user 1602 * - decoding: unused 1603 */ 1604 int max_chunk_duration; 1605 1606 /** 1607 * Max chunk size in bytes 1608 * Note, not all formats support this and unpredictable things may happen if it is used when not supported. 1609 * - encoding: Set by user 1610 * - decoding: unused 1611 */ 1612 int max_chunk_size; 1613 1614 /** 1615 * forces the use of wallclock timestamps as pts/dts of packets 1616 * This has undefined results in the presence of B frames. 1617 * - encoding: unused 1618 * - decoding: Set by user 1619 */ 1620 int use_wallclock_as_timestamps; 1621 1622 /** 1623 * avio flags, used to force AVIO_FLAG_DIRECT. 1624 * - encoding: unused 1625 * - decoding: Set by user 1626 */ 1627 int avio_flags; 1628 1629 /** 1630 * The duration field can be estimated through various ways, and this field can be used 1631 * to know how the duration was estimated. 1632 * - encoding: unused 1633 * - decoding: Read by user 1634 */ 1635 enum AVDurationEstimationMethod duration_estimation_method; 1636 1637 /** 1638 * Skip initial bytes when opening stream 1639 * - encoding: unused 1640 * - decoding: Set by user 1641 */ 1642 int64_t skip_initial_bytes; 1643 1644 /** 1645 * Correct single timestamp overflows 1646 * - encoding: unused 1647 * - decoding: Set by user 1648 */ 1649 unsigned int correct_ts_overflow; 1650 1651 /** 1652 * Force seeking to any (also non key) frames. 1653 * - encoding: unused 1654 * - decoding: Set by user 1655 */ 1656 int seek2any; 1657 1658 /** 1659 * Flush the I/O context after each packet. 1660 * - encoding: Set by user 1661 * - decoding: unused 1662 */ 1663 int flush_packets; 1664 1665 /** 1666 * format probing score. 1667 * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes 1668 * the format. 1669 * - encoding: unused 1670 * - decoding: set by avformat, read by user 1671 */ 1672 int probe_score; 1673 1674 /** 1675 * number of bytes to read maximally to identify format. 1676 * - encoding: unused 1677 * - decoding: set by user 1678 */ 1679 int format_probesize; 1680 1681 /** 1682 * ',' separated list of allowed decoders. 1683 * If NULL then all are allowed 1684 * - encoding: unused 1685 * - decoding: set by user 1686 */ 1687 char *codec_whitelist; 1688 1689 /** 1690 * ',' separated list of allowed demuxers. 1691 * If NULL then all are allowed 1692 * - encoding: unused 1693 * - decoding: set by user 1694 */ 1695 char *format_whitelist; 1696 1697 /** 1698 * An opaque field for libavformat internal usage. 1699 * Must not be accessed in any way by callers. 1700 */ 1701 AVFormatInternal *internal; 1702 1703 /** 1704 * IO repositioned flag. 1705 * This is set by avformat when the underlaying IO context read pointer 1706 * is repositioned, for example when doing byte based seeking. 1707 * Demuxers can use the flag to detect such changes. 1708 */ 1709 int io_repositioned; 1710 1711 /** 1712 * Forced video codec. 1713 * This allows forcing a specific decoder, even when there are multiple with 1714 * the same codec_id. 1715 * Demuxing: Set by user 1716 */ 1717 AVCodec *video_codec; 1718 1719 /** 1720 * Forced audio codec. 1721 * This allows forcing a specific decoder, even when there are multiple with 1722 * the same codec_id. 1723 * Demuxing: Set by user 1724 */ 1725 AVCodec *audio_codec; 1726 1727 /** 1728 * Forced subtitle codec. 1729 * This allows forcing a specific decoder, even when there are multiple with 1730 * the same codec_id. 1731 * Demuxing: Set by user 1732 */ 1733 AVCodec *subtitle_codec; 1734 1735 /** 1736 * Forced data codec. 1737 * This allows forcing a specific decoder, even when there are multiple with 1738 * the same codec_id. 1739 * Demuxing: Set by user 1740 */ 1741 AVCodec *data_codec; 1742 1743 /** 1744 * Number of bytes to be written as padding in a metadata header. 1745 * Demuxing: Unused. 1746 * Muxing: Set by user via av_format_set_metadata_header_padding. 1747 */ 1748 int metadata_header_padding; 1749 1750 /** 1751 * User data. 1752 * This is a place for some private data of the user. 1753 */ 1754 void *opaque; 1755 1756 /** 1757 * Callback used by devices to communicate with application. 1758 */ 1759 av_format_control_message control_message_cb; 1760 1761 /** 1762 * Output timestamp offset, in microseconds. 1763 * Muxing: set by user 1764 */ 1765 int64_t output_ts_offset; 1766 1767 /** 1768 * dump format separator. 1769 * can be ", " or "\n " or anything else 1770 * - muxing: Set by user. 1771 * - demuxing: Set by user. 1772 */ 1773 uint8_t *dump_separator; 1774 1775 /** 1776 * Forced Data codec_id. 1777 * Demuxing: Set by user. 1778 */ 1779 enum AVCodecID data_codec_id; 1780 1781 #if FF_API_OLD_OPEN_CALLBACKS 1782 /** 1783 * Called to open further IO contexts when needed for demuxing. 1784 * 1785 * This can be set by the user application to perform security checks on 1786 * the URLs before opening them. 1787 * The function should behave like avio_open2(), AVFormatContext is provided 1788 * as contextual information and to reach AVFormatContext.opaque. 1789 * 1790 * If NULL then some simple checks are used together with avio_open2(). 1791 * 1792 * Must not be accessed directly from outside avformat. 1793 * @See av_format_set_open_cb() 1794 * 1795 * Demuxing: Set by user. 1796 * 1797 * @deprecated Use io_open and io_close. 1798 */ 1799 attribute_deprecated 1800 int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options); 1801 #endif 1802 1803 /** 1804 * ',' separated list of allowed protocols. 1805 * - encoding: unused 1806 * - decoding: set by user 1807 */ 1808 char *protocol_whitelist; 1809 1810 /** 1811 * A callback for opening new IO streams. 1812 * 1813 * Whenever a muxer or a demuxer needs to open an IO stream (typically from 1814 * avformat_open_input() for demuxers, but for certain formats can happen at 1815 * other times as well), it will call this callback to obtain an IO context. 1816 * 1817 * @param s the format context 1818 * @param pb on success, the newly opened IO context should be returned here 1819 * @param url the url to open 1820 * @param flags a combination of AVIO_FLAG_* 1821 * @param options a dictionary of additional options, with the same 1822 * semantics as in avio_open2() 1823 * @return 0 on success, a negative AVERROR code on failure 1824 * 1825 * @note Certain muxers and demuxers do nesting, i.e. they open one or more 1826 * additional internal format contexts. Thus the AVFormatContext pointer 1827 * passed to this callback may be different from the one facing the caller. 1828 * It will, however, have the same 'opaque' field. 1829 */ 1830 int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url, 1831 int flags, AVDictionary **options); 1832 1833 /** 1834 * A callback for closing the streams opened with AVFormatContext.io_open(). 1835 */ 1836 void (*io_close)(struct AVFormatContext *s, AVIOContext *pb); 1837 1838 /** 1839 * ',' separated list of disallowed protocols. 1840 * - encoding: unused 1841 * - decoding: set by user 1842 */ 1843 char *protocol_blacklist; 1844 1845 /** 1846 * The maximum number of streams. 1847 * - encoding: unused 1848 * - decoding: set by user 1849 */ 1850 int max_streams; 1851 1852 /** 1853 * Skip duration calcuation in estimate_timings_from_pts. 1854 * - encoding: unused 1855 * - decoding: set by user 1856 */ 1857 int skip_estimate_duration_from_pts; 1858 1859 /** 1860 * Maximum number of packets that can be probed 1861 * - encoding: unused 1862 * - decoding: set by user 1863 */ 1864 int max_probe_packets; 1865 } AVFormatContext; 1866 1867 #if FF_API_FORMAT_GET_SET 1868 /** 1869 * Accessors for some AVFormatContext fields. These used to be provided for ABI 1870 * compatibility, and do not need to be used anymore. 1871 */ 1872 attribute_deprecated 1873 int av_format_get_probe_score(const AVFormatContext *s); 1874 attribute_deprecated 1875 AVCodec * av_format_get_video_codec(const AVFormatContext *s); 1876 attribute_deprecated 1877 void av_format_set_video_codec(AVFormatContext *s, AVCodec *c); 1878 attribute_deprecated 1879 AVCodec * av_format_get_audio_codec(const AVFormatContext *s); 1880 attribute_deprecated 1881 void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c); 1882 attribute_deprecated 1883 AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s); 1884 attribute_deprecated 1885 void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c); 1886 attribute_deprecated 1887 AVCodec * av_format_get_data_codec(const AVFormatContext *s); 1888 attribute_deprecated 1889 void av_format_set_data_codec(AVFormatContext *s, AVCodec *c); 1890 attribute_deprecated 1891 int av_format_get_metadata_header_padding(const AVFormatContext *s); 1892 attribute_deprecated 1893 void av_format_set_metadata_header_padding(AVFormatContext *s, int c); 1894 attribute_deprecated 1895 void * av_format_get_opaque(const AVFormatContext *s); 1896 attribute_deprecated 1897 void av_format_set_opaque(AVFormatContext *s, void *opaque); 1898 attribute_deprecated 1899 av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s); 1900 attribute_deprecated 1901 void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback); 1902 #if FF_API_OLD_OPEN_CALLBACKS 1903 attribute_deprecated AVOpenCallback av_format_get_open_cb(const AVFormatContext *s); 1904 attribute_deprecated void av_format_set_open_cb(AVFormatContext *s, AVOpenCallback callback); 1905 #endif 1906 #endif 1907 1908 /** 1909 * This function will cause global side data to be injected in the next packet 1910 * of each stream as well as after any subsequent seek. 1911 */ 1912 void av_format_inject_global_side_data(AVFormatContext *s); 1913 1914 /** 1915 * Returns the method used to set ctx->duration. 1916 * 1917 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE. 1918 */ 1919 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx); 1920 1921 /** 1922 * @defgroup lavf_core Core functions 1923 * @ingroup libavf 1924 * 1925 * Functions for querying libavformat capabilities, allocating core structures, 1926 * etc. 1927 * @{ 1928 */ 1929 1930 /** 1931 * Return the LIBAVFORMAT_VERSION_INT constant. 1932 */ 1933 unsigned avformat_version(void); 1934 1935 /** 1936 * Return the libavformat build-time configuration. 1937 */ 1938 const char *avformat_configuration(void); 1939 1940 /** 1941 * Return the libavformat license. 1942 */ 1943 const char *avformat_license(void); 1944 1945 #if FF_API_NEXT 1946 /** 1947 * Initialize libavformat and register all the muxers, demuxers and 1948 * protocols. If you do not call this function, then you can select 1949 * exactly which formats you want to support. 1950 * 1951 * @see av_register_input_format() 1952 * @see av_register_output_format() 1953 */ 1954 attribute_deprecated 1955 void av_register_all(void); 1956 1957 attribute_deprecated 1958 void av_register_input_format(AVInputFormat *format); 1959 attribute_deprecated 1960 void av_register_output_format(AVOutputFormat *format); 1961 #endif 1962 1963 /** 1964 * Do global initialization of network libraries. This is optional, 1965 * and not recommended anymore. 1966 * 1967 * This functions only exists to work around thread-safety issues 1968 * with older GnuTLS or OpenSSL libraries. If libavformat is linked 1969 * to newer versions of those libraries, or if you do not use them, 1970 * calling this function is unnecessary. Otherwise, you need to call 1971 * this function before any other threads using them are started. 1972 * 1973 * This function will be deprecated once support for older GnuTLS and 1974 * OpenSSL libraries is removed, and this function has no purpose 1975 * anymore. 1976 */ 1977 int avformat_network_init(void); 1978 1979 /** 1980 * Undo the initialization done by avformat_network_init. Call it only 1981 * once for each time you called avformat_network_init. 1982 */ 1983 int avformat_network_deinit(void); 1984 1985 #if FF_API_NEXT 1986 /** 1987 * If f is NULL, returns the first registered input format, 1988 * if f is non-NULL, returns the next registered input format after f 1989 * or NULL if f is the last one. 1990 */ 1991 attribute_deprecated 1992 AVInputFormat *av_iformat_next(const AVInputFormat *f); 1993 1994 /** 1995 * If f is NULL, returns the first registered output format, 1996 * if f is non-NULL, returns the next registered output format after f 1997 * or NULL if f is the last one. 1998 */ 1999 attribute_deprecated 2000 AVOutputFormat *av_oformat_next(const AVOutputFormat *f); 2001 #endif 2002 2003 /** 2004 * Iterate over all registered muxers. 2005 * 2006 * @param opaque a pointer where libavformat will store the iteration state. Must 2007 * point to NULL to start the iteration. 2008 * 2009 * @return the next registered muxer or NULL when the iteration is 2010 * finished 2011 */ 2012 const AVOutputFormat *av_muxer_iterate(void **opaque); 2013 2014 /** 2015 * Iterate over all registered demuxers. 2016 * 2017 * @param opaque a pointer where libavformat will store the iteration state. Must 2018 * point to NULL to start the iteration. 2019 * 2020 * @return the next registered demuxer or NULL when the iteration is 2021 * finished 2022 */ 2023 const AVInputFormat *av_demuxer_iterate(void **opaque); 2024 2025 /** 2026 * Allocate an AVFormatContext. 2027 * avformat_free_context() can be used to free the context and everything 2028 * allocated by the framework within it. 2029 */ 2030 AVFormatContext *avformat_alloc_context(void); 2031 2032 /** 2033 * Free an AVFormatContext and all its streams. 2034 * @param s context to free 2035 */ 2036 void avformat_free_context(AVFormatContext *s); 2037 2038 /** 2039 * Get the AVClass for AVFormatContext. It can be used in combination with 2040 * AV_OPT_SEARCH_FAKE_OBJ for examining options. 2041 * 2042 * @see av_opt_find(). 2043 */ 2044 const AVClass *avformat_get_class(void); 2045 2046 /** 2047 * Add a new stream to a media file. 2048 * 2049 * When demuxing, it is called by the demuxer in read_header(). If the 2050 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also 2051 * be called in read_packet(). 2052 * 2053 * When muxing, should be called by the user before avformat_write_header(). 2054 * 2055 * User is required to call avcodec_close() and avformat_free_context() to 2056 * clean up the allocation by avformat_new_stream(). 2057 * 2058 * @param s media file handle 2059 * @param c If non-NULL, the AVCodecContext corresponding to the new stream 2060 * will be initialized to use this codec. This is needed for e.g. codec-specific 2061 * defaults to be set, so codec should be provided if it is known. 2062 * 2063 * @return newly created stream or NULL on error. 2064 */ 2065 AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c); 2066 2067 /** 2068 * Wrap an existing array as stream side data. 2069 * 2070 * @param st stream 2071 * @param type side information type 2072 * @param data the side data array. It must be allocated with the av_malloc() 2073 * family of functions. The ownership of the data is transferred to 2074 * st. 2075 * @param size side information size 2076 * @return zero on success, a negative AVERROR code on failure. On failure, 2077 * the stream is unchanged and the data remains owned by the caller. 2078 */ 2079 int av_stream_add_side_data(AVStream *st, enum AVPacketSideDataType type, 2080 uint8_t *data, size_t size); 2081 2082 /** 2083 * Allocate new information from stream. 2084 * 2085 * @param stream stream 2086 * @param type desired side information type 2087 * @param size side information size 2088 * @return pointer to fresh allocated data or NULL otherwise 2089 */ 2090 uint8_t *av_stream_new_side_data(AVStream *stream, 2091 #if FF_API_BUFFER_SIZE_T 2092 enum AVPacketSideDataType type, int size); 2093 #else 2094 enum AVPacketSideDataType type, size_t size); 2095 #endif 2096 /** 2097 * Get side information from stream. 2098 * 2099 * @param stream stream 2100 * @param type desired side information type 2101 * @param size If supplied, *size will be set to the size of the side data 2102 * or to zero if the desired side data is not present. 2103 * @return pointer to data if present or NULL otherwise 2104 */ 2105 uint8_t *av_stream_get_side_data(const AVStream *stream, 2106 #if FF_API_BUFFER_SIZE_T 2107 enum AVPacketSideDataType type, int *size); 2108 #else 2109 enum AVPacketSideDataType type, size_t *size); 2110 #endif 2111 2112 AVProgram *av_new_program(AVFormatContext *s, int id); 2113 2114 /** 2115 * @} 2116 */ 2117 2118 2119 /** 2120 * Allocate an AVFormatContext for an output format. 2121 * avformat_free_context() can be used to free the context and 2122 * everything allocated by the framework within it. 2123 * 2124 * @param *ctx is set to the created format context, or to NULL in 2125 * case of failure 2126 * @param oformat format to use for allocating the context, if NULL 2127 * format_name and filename are used instead 2128 * @param format_name the name of output format to use for allocating the 2129 * context, if NULL filename is used instead 2130 * @param filename the name of the filename to use for allocating the 2131 * context, may be NULL 2132 * @return >= 0 in case of success, a negative AVERROR code in case of 2133 * failure 2134 */ 2135 int avformat_alloc_output_context2(AVFormatContext **ctx, ff_const59 AVOutputFormat *oformat, 2136 const char *format_name, const char *filename); 2137 2138 /** 2139 * @addtogroup lavf_decoding 2140 * @{ 2141 */ 2142 2143 /** 2144 * Find AVInputFormat based on the short name of the input format. 2145 */ 2146 ff_const59 AVInputFormat *av_find_input_format(const char *short_name); 2147 2148 /** 2149 * Guess the file format. 2150 * 2151 * @param pd data to be probed 2152 * @param is_opened Whether the file is already opened; determines whether 2153 * demuxers with or without AVFMT_NOFILE are probed. 2154 */ 2155 ff_const59 AVInputFormat *av_probe_input_format(ff_const59 AVProbeData *pd, int is_opened); 2156 2157 /** 2158 * Guess the file format. 2159 * 2160 * @param pd data to be probed 2161 * @param is_opened Whether the file is already opened; determines whether 2162 * demuxers with or without AVFMT_NOFILE are probed. 2163 * @param score_max A probe score larger that this is required to accept a 2164 * detection, the variable is set to the actual detection 2165 * score afterwards. 2166 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended 2167 * to retry with a larger probe buffer. 2168 */ 2169 ff_const59 AVInputFormat *av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max); 2170 2171 /** 2172 * Guess the file format. 2173 * 2174 * @param is_opened Whether the file is already opened; determines whether 2175 * demuxers with or without AVFMT_NOFILE are probed. 2176 * @param score_ret The score of the best detection. 2177 */ 2178 ff_const59 AVInputFormat *av_probe_input_format3(ff_const59 AVProbeData *pd, int is_opened, int *score_ret); 2179 2180 /** 2181 * Probe a bytestream to determine the input format. Each time a probe returns 2182 * with a score that is too low, the probe buffer size is increased and another 2183 * attempt is made. When the maximum probe size is reached, the input format 2184 * with the highest score is returned. 2185 * 2186 * @param pb the bytestream to probe 2187 * @param fmt the input format is put here 2188 * @param url the url of the stream 2189 * @param logctx the log context 2190 * @param offset the offset within the bytestream to probe from 2191 * @param max_probe_size the maximum probe buffer size (zero for default) 2192 * @return the score in case of success, a negative value corresponding to an 2193 * the maximal score is AVPROBE_SCORE_MAX 2194 * AVERROR code otherwise 2195 */ 2196 int av_probe_input_buffer2(AVIOContext *pb, ff_const59 AVInputFormat **fmt, 2197 const char *url, void *logctx, 2198 unsigned int offset, unsigned int max_probe_size); 2199 2200 /** 2201 * Like av_probe_input_buffer2() but returns 0 on success 2202 */ 2203 int av_probe_input_buffer(AVIOContext *pb, ff_const59 AVInputFormat **fmt, 2204 const char *url, void *logctx, 2205 unsigned int offset, unsigned int max_probe_size); 2206 2207 /** 2208 * Open an input stream and read the header. The codecs are not opened. 2209 * The stream must be closed with avformat_close_input(). 2210 * 2211 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context). 2212 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this 2213 * function and written into ps. 2214 * Note that a user-supplied AVFormatContext will be freed on failure. 2215 * @param url URL of the stream to open. 2216 * @param fmt If non-NULL, this parameter forces a specific input format. 2217 * Otherwise the format is autodetected. 2218 * @param options A dictionary filled with AVFormatContext and demuxer-private options. 2219 * On return this parameter will be destroyed and replaced with a dict containing 2220 * options that were not found. May be NULL. 2221 * 2222 * @return 0 on success, a negative AVERROR on failure. 2223 * 2224 * @note If you want to use custom IO, preallocate the format context and set its pb field. 2225 */ 2226 int avformat_open_input(AVFormatContext **ps, const char *url, ff_const59 AVInputFormat *fmt, AVDictionary **options); 2227 2228 #if FF_API_DEMUXER_OPEN 2229 /** 2230 * @deprecated Use an AVDictionary to pass options to a demuxer. 2231 */ 2232 attribute_deprecated 2233 int av_demuxer_open(AVFormatContext *ic); 2234 #endif 2235 2236 /** 2237 * Read packets of a media file to get stream information. This 2238 * is useful for file formats with no headers such as MPEG. This 2239 * function also computes the real framerate in case of MPEG-2 repeat 2240 * frame mode. 2241 * The logical file position is not changed by this function; 2242 * examined packets may be buffered for later processing. 2243 * 2244 * @param ic media file handle 2245 * @param options If non-NULL, an ic.nb_streams long array of pointers to 2246 * dictionaries, where i-th member contains options for 2247 * codec corresponding to i-th stream. 2248 * On return each dictionary will be filled with options that were not found. 2249 * @return >=0 if OK, AVERROR_xxx on error 2250 * 2251 * @note this function isn't guaranteed to open all the codecs, so 2252 * options being non-empty at return is a perfectly normal behavior. 2253 * 2254 * @todo Let the user decide somehow what information is needed so that 2255 * we do not waste time getting stuff the user does not need. 2256 */ 2257 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options); 2258 2259 /** 2260 * Find the programs which belong to a given stream. 2261 * 2262 * @param ic media file handle 2263 * @param last the last found program, the search will start after this 2264 * program, or from the beginning if it is NULL 2265 * @param s stream index 2266 * @return the next program which belongs to s, NULL if no program is found or 2267 * the last program is not among the programs of ic. 2268 */ 2269 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s); 2270 2271 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx); 2272 2273 /** 2274 * Find the "best" stream in the file. 2275 * The best stream is determined according to various heuristics as the most 2276 * likely to be what the user expects. 2277 * If the decoder parameter is non-NULL, av_find_best_stream will find the 2278 * default decoder for the stream's codec; streams for which no decoder can 2279 * be found are ignored. 2280 * 2281 * @param ic media file handle 2282 * @param type stream type: video, audio, subtitles, etc. 2283 * @param wanted_stream_nb user-requested stream number, 2284 * or -1 for automatic selection 2285 * @param related_stream try to find a stream related (eg. in the same 2286 * program) to this one, or -1 if none 2287 * @param decoder_ret if non-NULL, returns the decoder for the 2288 * selected stream 2289 * @param flags flags; none are currently defined 2290 * @return the non-negative stream number in case of success, 2291 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type 2292 * could be found, 2293 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder 2294 * @note If av_find_best_stream returns successfully and decoder_ret is not 2295 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec. 2296 */ 2297 int av_find_best_stream(AVFormatContext *ic, 2298 enum AVMediaType type, 2299 int wanted_stream_nb, 2300 int related_stream, 2301 AVCodec **decoder_ret, 2302 int flags); 2303 2304 /** 2305 * Return the next frame of a stream. 2306 * This function returns what is stored in the file, and does not validate 2307 * that what is there are valid frames for the decoder. It will split what is 2308 * stored in the file into frames and return one for each call. It will not 2309 * omit invalid data between valid frames so as to give the decoder the maximum 2310 * information possible for decoding. 2311 * 2312 * On success, the returned packet is reference-counted (pkt->buf is set) and 2313 * valid indefinitely. The packet must be freed with av_packet_unref() when 2314 * it is no longer needed. For video, the packet contains exactly one frame. 2315 * For audio, it contains an integer number of frames if each frame has 2316 * a known fixed size (e.g. PCM or ADPCM data). If the audio frames have 2317 * a variable size (e.g. MPEG audio), then it contains one frame. 2318 * 2319 * pkt->pts, pkt->dts and pkt->duration are always set to correct 2320 * values in AVStream.time_base units (and guessed if the format cannot 2321 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format 2322 * has B-frames, so it is better to rely on pkt->dts if you do not 2323 * decompress the payload. 2324 * 2325 * @return 0 if OK, < 0 on error or end of file. On error, pkt will be blank 2326 * (as if it came from av_packet_alloc()). 2327 * 2328 * @note pkt will be initialized, so it may be uninitialized, but it must not 2329 * contain data that needs to be freed. 2330 */ 2331 int av_read_frame(AVFormatContext *s, AVPacket *pkt); 2332 2333 /** 2334 * Seek to the keyframe at timestamp. 2335 * 'timestamp' in 'stream_index'. 2336 * 2337 * @param s media file handle 2338 * @param stream_index If stream_index is (-1), a default 2339 * stream is selected, and timestamp is automatically converted 2340 * from AV_TIME_BASE units to the stream specific time_base. 2341 * @param timestamp Timestamp in AVStream.time_base units 2342 * or, if no stream is specified, in AV_TIME_BASE units. 2343 * @param flags flags which select direction and seeking mode 2344 * @return >= 0 on success 2345 */ 2346 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp, 2347 int flags); 2348 2349 /** 2350 * Seek to timestamp ts. 2351 * Seeking will be done so that the point from which all active streams 2352 * can be presented successfully will be closest to ts and within min/max_ts. 2353 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL. 2354 * 2355 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and 2356 * are the file position (this may not be supported by all demuxers). 2357 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames 2358 * in the stream with stream_index (this may not be supported by all demuxers). 2359 * Otherwise all timestamps are in units of the stream selected by stream_index 2360 * or if stream_index is -1, in AV_TIME_BASE units. 2361 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as 2362 * keyframes (this may not be supported by all demuxers). 2363 * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored. 2364 * 2365 * @param s media file handle 2366 * @param stream_index index of the stream which is used as time base reference 2367 * @param min_ts smallest acceptable timestamp 2368 * @param ts target timestamp 2369 * @param max_ts largest acceptable timestamp 2370 * @param flags flags 2371 * @return >=0 on success, error code otherwise 2372 * 2373 * @note This is part of the new seek API which is still under construction. 2374 */ 2375 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags); 2376 2377 /** 2378 * Discard all internally buffered data. This can be useful when dealing with 2379 * discontinuities in the byte stream. Generally works only with formats that 2380 * can resync. This includes headerless formats like MPEG-TS/TS but should also 2381 * work with NUT, Ogg and in a limited way AVI for example. 2382 * 2383 * The set of streams, the detected duration, stream parameters and codecs do 2384 * not change when calling this function. If you want a complete reset, it's 2385 * better to open a new AVFormatContext. 2386 * 2387 * This does not flush the AVIOContext (s->pb). If necessary, call 2388 * avio_flush(s->pb) before calling this function. 2389 * 2390 * @param s media file handle 2391 * @return >=0 on success, error code otherwise 2392 */ 2393 int avformat_flush(AVFormatContext *s); 2394 2395 /** 2396 * Start playing a network-based stream (e.g. RTSP stream) at the 2397 * current position. 2398 */ 2399 int av_read_play(AVFormatContext *s); 2400 2401 /** 2402 * Pause a network-based stream (e.g. RTSP stream). 2403 * 2404 * Use av_read_play() to resume it. 2405 */ 2406 int av_read_pause(AVFormatContext *s); 2407 2408 /** 2409 * Close an opened input AVFormatContext. Free it and all its contents 2410 * and set *s to NULL. 2411 */ 2412 void avformat_close_input(AVFormatContext **s); 2413 /** 2414 * @} 2415 */ 2416 2417 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward 2418 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes 2419 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes 2420 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number 2421 2422 /** 2423 * @addtogroup lavf_encoding 2424 * @{ 2425 */ 2426 2427 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header 2428 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output 2429 2430 /** 2431 * Allocate the stream private data and write the stream header to 2432 * an output media file. 2433 * 2434 * @param s Media file handle, must be allocated with avformat_alloc_context(). 2435 * Its oformat field must be set to the desired output format; 2436 * Its pb field must be set to an already opened AVIOContext. 2437 * @param options An AVDictionary filled with AVFormatContext and muxer-private options. 2438 * On return this parameter will be destroyed and replaced with a dict containing 2439 * options that were not found. May be NULL. 2440 * 2441 * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init, 2442 * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init, 2443 * negative AVERROR on failure. 2444 * 2445 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output. 2446 */ 2447 av_warn_unused_result 2448 int avformat_write_header(AVFormatContext *s, AVDictionary **options); 2449 2450 /** 2451 * Allocate the stream private data and initialize the codec, but do not write the header. 2452 * May optionally be used before avformat_write_header to initialize stream parameters 2453 * before actually writing the header. 2454 * If using this function, do not pass the same options to avformat_write_header. 2455 * 2456 * @param s Media file handle, must be allocated with avformat_alloc_context(). 2457 * Its oformat field must be set to the desired output format; 2458 * Its pb field must be set to an already opened AVIOContext. 2459 * @param options An AVDictionary filled with AVFormatContext and muxer-private options. 2460 * On return this parameter will be destroyed and replaced with a dict containing 2461 * options that were not found. May be NULL. 2462 * 2463 * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec requires avformat_write_header to fully initialize, 2464 * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec has been fully initialized, 2465 * negative AVERROR on failure. 2466 * 2467 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header. 2468 */ 2469 av_warn_unused_result 2470 int avformat_init_output(AVFormatContext *s, AVDictionary **options); 2471 2472 /** 2473 * Write a packet to an output media file. 2474 * 2475 * This function passes the packet directly to the muxer, without any buffering 2476 * or reordering. The caller is responsible for correctly interleaving the 2477 * packets if the format requires it. Callers that want libavformat to handle 2478 * the interleaving should call av_interleaved_write_frame() instead of this 2479 * function. 2480 * 2481 * @param s media file handle 2482 * @param pkt The packet containing the data to be written. Note that unlike 2483 * av_interleaved_write_frame(), this function does not take 2484 * ownership of the packet passed to it (though some muxers may make 2485 * an internal reference to the input packet). 2486 * <br> 2487 * This parameter can be NULL (at any time, not just at the end), in 2488 * order to immediately flush data buffered within the muxer, for 2489 * muxers that buffer up data internally before writing it to the 2490 * output. 2491 * <br> 2492 * Packet's @ref AVPacket.stream_index "stream_index" field must be 2493 * set to the index of the corresponding stream in @ref 2494 * AVFormatContext.streams "s->streams". 2495 * <br> 2496 * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts") 2497 * must be set to correct values in the stream's timebase (unless the 2498 * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then 2499 * they can be set to AV_NOPTS_VALUE). 2500 * The dts for subsequent packets passed to this function must be strictly 2501 * increasing when compared in their respective timebases (unless the 2502 * output format is flagged with the AVFMT_TS_NONSTRICT, then they 2503 * merely have to be nondecreasing). @ref AVPacket.duration 2504 * "duration") should also be set if known. 2505 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush 2506 * 2507 * @see av_interleaved_write_frame() 2508 */ 2509 int av_write_frame(AVFormatContext *s, AVPacket *pkt); 2510 2511 /** 2512 * Write a packet to an output media file ensuring correct interleaving. 2513 * 2514 * This function will buffer the packets internally as needed to make sure the 2515 * packets in the output file are properly interleaved in the order of 2516 * increasing dts. Callers doing their own interleaving should call 2517 * av_write_frame() instead of this function. 2518 * 2519 * Using this function instead of av_write_frame() can give muxers advance 2520 * knowledge of future packets, improving e.g. the behaviour of the mp4 2521 * muxer for VFR content in fragmenting mode. 2522 * 2523 * @param s media file handle 2524 * @param pkt The packet containing the data to be written. 2525 * <br> 2526 * If the packet is reference-counted, this function will take 2527 * ownership of this reference and unreference it later when it sees 2528 * fit. 2529 * The caller must not access the data through this reference after 2530 * this function returns. If the packet is not reference-counted, 2531 * libavformat will make a copy. 2532 * <br> 2533 * This parameter can be NULL (at any time, not just at the end), to 2534 * flush the interleaving queues. 2535 * <br> 2536 * Packet's @ref AVPacket.stream_index "stream_index" field must be 2537 * set to the index of the corresponding stream in @ref 2538 * AVFormatContext.streams "s->streams". 2539 * <br> 2540 * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts") 2541 * must be set to correct values in the stream's timebase (unless the 2542 * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then 2543 * they can be set to AV_NOPTS_VALUE). 2544 * The dts for subsequent packets in one stream must be strictly 2545 * increasing (unless the output format is flagged with the 2546 * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing). 2547 * @ref AVPacket.duration "duration") should also be set if known. 2548 * 2549 * @return 0 on success, a negative AVERROR on error. Libavformat will always 2550 * take care of freeing the packet, even if this function fails. 2551 * 2552 * @see av_write_frame(), AVFormatContext.max_interleave_delta 2553 */ 2554 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt); 2555 2556 /** 2557 * Write an uncoded frame to an output media file. 2558 * 2559 * The frame must be correctly interleaved according to the container 2560 * specification; if not, av_interleaved_write_uncoded_frame() must be used. 2561 * 2562 * See av_interleaved_write_uncoded_frame() for details. 2563 */ 2564 int av_write_uncoded_frame(AVFormatContext *s, int stream_index, 2565 AVFrame *frame); 2566 2567 /** 2568 * Write an uncoded frame to an output media file. 2569 * 2570 * If the muxer supports it, this function makes it possible to write an AVFrame 2571 * structure directly, without encoding it into a packet. 2572 * It is mostly useful for devices and similar special muxers that use raw 2573 * video or PCM data and will not serialize it into a byte stream. 2574 * 2575 * To test whether it is possible to use it with a given muxer and stream, 2576 * use av_write_uncoded_frame_query(). 2577 * 2578 * The caller gives up ownership of the frame and must not access it 2579 * afterwards. 2580 * 2581 * @return >=0 for success, a negative code on error 2582 */ 2583 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index, 2584 AVFrame *frame); 2585 2586 /** 2587 * Test whether a muxer supports uncoded frame. 2588 * 2589 * @return >=0 if an uncoded frame can be written to that muxer and stream, 2590 * <0 if not 2591 */ 2592 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index); 2593 2594 /** 2595 * Write the stream trailer to an output media file and free the 2596 * file private data. 2597 * 2598 * May only be called after a successful call to avformat_write_header. 2599 * 2600 * @param s media file handle 2601 * @return 0 if OK, AVERROR_xxx on error 2602 */ 2603 int av_write_trailer(AVFormatContext *s); 2604 2605 /** 2606 * Return the output format in the list of registered output formats 2607 * which best matches the provided parameters, or return NULL if 2608 * there is no match. 2609 * 2610 * @param short_name if non-NULL checks if short_name matches with the 2611 * names of the registered formats 2612 * @param filename if non-NULL checks if filename terminates with the 2613 * extensions of the registered formats 2614 * @param mime_type if non-NULL checks if mime_type matches with the 2615 * MIME type of the registered formats 2616 */ 2617 ff_const59 AVOutputFormat *av_guess_format(const char *short_name, 2618 const char *filename, 2619 const char *mime_type); 2620 2621 /** 2622 * Guess the codec ID based upon muxer and filename. 2623 */ 2624 enum AVCodecID av_guess_codec(ff_const59 AVOutputFormat *fmt, const char *short_name, 2625 const char *filename, const char *mime_type, 2626 enum AVMediaType type); 2627 2628 /** 2629 * Get timing information for the data currently output. 2630 * The exact meaning of "currently output" depends on the format. 2631 * It is mostly relevant for devices that have an internal buffer and/or 2632 * work in real time. 2633 * @param s media file handle 2634 * @param stream stream in the media file 2635 * @param[out] dts DTS of the last packet output for the stream, in stream 2636 * time_base units 2637 * @param[out] wall absolute time when that packet whas output, 2638 * in microsecond 2639 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it 2640 * Note: some formats or devices may not allow to measure dts and wall 2641 * atomically. 2642 */ 2643 int av_get_output_timestamp(struct AVFormatContext *s, int stream, 2644 int64_t *dts, int64_t *wall); 2645 2646 2647 /** 2648 * @} 2649 */ 2650 2651 2652 /** 2653 * @defgroup lavf_misc Utility functions 2654 * @ingroup libavf 2655 * @{ 2656 * 2657 * Miscellaneous utility functions related to both muxing and demuxing 2658 * (or neither). 2659 */ 2660 2661 /** 2662 * Send a nice hexadecimal dump of a buffer to the specified file stream. 2663 * 2664 * @param f The file stream pointer where the dump should be sent to. 2665 * @param buf buffer 2666 * @param size buffer size 2667 * 2668 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2 2669 */ 2670 void av_hex_dump(FILE *f, const uint8_t *buf, int size); 2671 2672 /** 2673 * Send a nice hexadecimal dump of a buffer to the log. 2674 * 2675 * @param avcl A pointer to an arbitrary struct of which the first field is a 2676 * pointer to an AVClass struct. 2677 * @param level The importance level of the message, lower values signifying 2678 * higher importance. 2679 * @param buf buffer 2680 * @param size buffer size 2681 * 2682 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2 2683 */ 2684 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size); 2685 2686 /** 2687 * Send a nice dump of a packet to the specified file stream. 2688 * 2689 * @param f The file stream pointer where the dump should be sent to. 2690 * @param pkt packet to dump 2691 * @param dump_payload True if the payload must be displayed, too. 2692 * @param st AVStream that the packet belongs to 2693 */ 2694 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st); 2695 2696 2697 /** 2698 * Send a nice dump of a packet to the log. 2699 * 2700 * @param avcl A pointer to an arbitrary struct of which the first field is a 2701 * pointer to an AVClass struct. 2702 * @param level The importance level of the message, lower values signifying 2703 * higher importance. 2704 * @param pkt packet to dump 2705 * @param dump_payload True if the payload must be displayed, too. 2706 * @param st AVStream that the packet belongs to 2707 */ 2708 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload, 2709 const AVStream *st); 2710 2711 /** 2712 * Get the AVCodecID for the given codec tag tag. 2713 * If no codec id is found returns AV_CODEC_ID_NONE. 2714 * 2715 * @param tags list of supported codec_id-codec_tag pairs, as stored 2716 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag 2717 * @param tag codec tag to match to a codec ID 2718 */ 2719 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag); 2720 2721 /** 2722 * Get the codec tag for the given codec id id. 2723 * If no codec tag is found returns 0. 2724 * 2725 * @param tags list of supported codec_id-codec_tag pairs, as stored 2726 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag 2727 * @param id codec ID to match to a codec tag 2728 */ 2729 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id); 2730 2731 /** 2732 * Get the codec tag for the given codec id. 2733 * 2734 * @param tags list of supported codec_id - codec_tag pairs, as stored 2735 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag 2736 * @param id codec id that should be searched for in the list 2737 * @param tag A pointer to the found tag 2738 * @return 0 if id was not found in tags, > 0 if it was found 2739 */ 2740 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id, 2741 unsigned int *tag); 2742 2743 int av_find_default_stream_index(AVFormatContext *s); 2744 2745 /** 2746 * Get the index for a specific timestamp. 2747 * 2748 * @param st stream that the timestamp belongs to 2749 * @param timestamp timestamp to retrieve the index for 2750 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond 2751 * to the timestamp which is <= the requested one, if backward 2752 * is 0, then it will be >= 2753 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise 2754 * @return < 0 if no such timestamp could be found 2755 */ 2756 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags); 2757 2758 /** 2759 * Add an index entry into a sorted list. Update the entry if the list 2760 * already contains it. 2761 * 2762 * @param timestamp timestamp in the time base of the given stream 2763 */ 2764 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, 2765 int size, int distance, int flags); 2766 2767 2768 /** 2769 * Split a URL string into components. 2770 * 2771 * The pointers to buffers for storing individual components may be null, 2772 * in order to ignore that component. Buffers for components not found are 2773 * set to empty strings. If the port is not found, it is set to a negative 2774 * value. 2775 * 2776 * @param proto the buffer for the protocol 2777 * @param proto_size the size of the proto buffer 2778 * @param authorization the buffer for the authorization 2779 * @param authorization_size the size of the authorization buffer 2780 * @param hostname the buffer for the host name 2781 * @param hostname_size the size of the hostname buffer 2782 * @param port_ptr a pointer to store the port number in 2783 * @param path the buffer for the path 2784 * @param path_size the size of the path buffer 2785 * @param url the URL to split 2786 */ 2787 void av_url_split(char *proto, int proto_size, 2788 char *authorization, int authorization_size, 2789 char *hostname, int hostname_size, 2790 int *port_ptr, 2791 char *path, int path_size, 2792 const char *url); 2793 2794 2795 /** 2796 * Print detailed information about the input or output format, such as 2797 * duration, bitrate, streams, container, programs, metadata, side data, 2798 * codec and time base. 2799 * 2800 * @param ic the context to analyze 2801 * @param index index of the stream to dump information about 2802 * @param url the URL to print, such as source or destination file 2803 * @param is_output Select whether the specified context is an input(0) or output(1) 2804 */ 2805 void av_dump_format(AVFormatContext *ic, 2806 int index, 2807 const char *url, 2808 int is_output); 2809 2810 2811 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d 2812 2813 /** 2814 * Return in 'buf' the path with '%d' replaced by a number. 2815 * 2816 * Also handles the '%0nd' format where 'n' is the total number 2817 * of digits and '%%'. 2818 * 2819 * @param buf destination buffer 2820 * @param buf_size destination buffer size 2821 * @param path numbered sequence string 2822 * @param number frame number 2823 * @param flags AV_FRAME_FILENAME_FLAGS_* 2824 * @return 0 if OK, -1 on format error 2825 */ 2826 int av_get_frame_filename2(char *buf, int buf_size, 2827 const char *path, int number, int flags); 2828 2829 int av_get_frame_filename(char *buf, int buf_size, 2830 const char *path, int number); 2831 2832 /** 2833 * Check whether filename actually is a numbered sequence generator. 2834 * 2835 * @param filename possible numbered sequence string 2836 * @return 1 if a valid numbered sequence string, 0 otherwise 2837 */ 2838 int av_filename_number_test(const char *filename); 2839 2840 /** 2841 * Generate an SDP for an RTP session. 2842 * 2843 * Note, this overwrites the id values of AVStreams in the muxer contexts 2844 * for getting unique dynamic payload types. 2845 * 2846 * @param ac array of AVFormatContexts describing the RTP streams. If the 2847 * array is composed by only one context, such context can contain 2848 * multiple AVStreams (one AVStream per RTP stream). Otherwise, 2849 * all the contexts in the array (an AVCodecContext per RTP stream) 2850 * must contain only one AVStream. 2851 * @param n_files number of AVCodecContexts contained in ac 2852 * @param buf buffer where the SDP will be stored (must be allocated by 2853 * the caller) 2854 * @param size the size of the buffer 2855 * @return 0 if OK, AVERROR_xxx on error 2856 */ 2857 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size); 2858 2859 /** 2860 * Return a positive value if the given filename has one of the given 2861 * extensions, 0 otherwise. 2862 * 2863 * @param filename file name to check against the given extensions 2864 * @param extensions a comma-separated list of filename extensions 2865 */ 2866 int av_match_ext(const char *filename, const char *extensions); 2867 2868 /** 2869 * Test if the given container can store a codec. 2870 * 2871 * @param ofmt container to check for compatibility 2872 * @param codec_id codec to potentially store in container 2873 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_* 2874 * 2875 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot. 2876 * A negative number if this information is not available. 2877 */ 2878 int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id, 2879 int std_compliance); 2880 2881 /** 2882 * @defgroup riff_fourcc RIFF FourCCs 2883 * @{ 2884 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are 2885 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the 2886 * following code: 2887 * @code 2888 * uint32_t tag = MKTAG('H', '2', '6', '4'); 2889 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 }; 2890 * enum AVCodecID id = av_codec_get_id(table, tag); 2891 * @endcode 2892 */ 2893 /** 2894 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID. 2895 */ 2896 const struct AVCodecTag *avformat_get_riff_video_tags(void); 2897 /** 2898 * @return the table mapping RIFF FourCCs for audio to AVCodecID. 2899 */ 2900 const struct AVCodecTag *avformat_get_riff_audio_tags(void); 2901 /** 2902 * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID. 2903 */ 2904 const struct AVCodecTag *avformat_get_mov_video_tags(void); 2905 /** 2906 * @return the table mapping MOV FourCCs for audio to AVCodecID. 2907 */ 2908 const struct AVCodecTag *avformat_get_mov_audio_tags(void); 2909 2910 /** 2911 * @} 2912 */ 2913 2914 /** 2915 * Guess the sample aspect ratio of a frame, based on both the stream and the 2916 * frame aspect ratio. 2917 * 2918 * Since the frame aspect ratio is set by the codec but the stream aspect ratio 2919 * is set by the demuxer, these two may not be equal. This function tries to 2920 * return the value that you should use if you would like to display the frame. 2921 * 2922 * Basic logic is to use the stream aspect ratio if it is set to something sane 2923 * otherwise use the frame aspect ratio. This way a container setting, which is 2924 * usually easy to modify can override the coded value in the frames. 2925 * 2926 * @param format the format context which the stream is part of 2927 * @param stream the stream which the frame is part of 2928 * @param frame the frame with the aspect ratio to be determined 2929 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea 2930 */ 2931 AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame); 2932 2933 /** 2934 * Guess the frame rate, based on both the container and codec information. 2935 * 2936 * @param ctx the format context which the stream is part of 2937 * @param stream the stream which the frame is part of 2938 * @param frame the frame for which the frame rate should be determined, may be NULL 2939 * @return the guessed (valid) frame rate, 0/1 if no idea 2940 */ 2941 AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame); 2942 2943 /** 2944 * Check if the stream st contained in s is matched by the stream specifier 2945 * spec. 2946 * 2947 * See the "stream specifiers" chapter in the documentation for the syntax 2948 * of spec. 2949 * 2950 * @return >0 if st is matched by spec; 2951 * 0 if st is not matched by spec; 2952 * AVERROR code if spec is invalid 2953 * 2954 * @note A stream specifier can match several streams in the format. 2955 */ 2956 int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st, 2957 const char *spec); 2958 2959 int avformat_queue_attached_pictures(AVFormatContext *s); 2960 2961 #if FF_API_OLD_BSF 2962 /** 2963 * Apply a list of bitstream filters to a packet. 2964 * 2965 * @param codec AVCodecContext, usually from an AVStream 2966 * @param pkt the packet to apply filters to. If, on success, the returned 2967 * packet has size == 0 and side_data_elems == 0, it indicates that 2968 * the packet should be dropped 2969 * @param bsfc a NULL-terminated list of filters to apply 2970 * @return >=0 on success; 2971 * AVERROR code on failure 2972 */ 2973 attribute_deprecated 2974 int av_apply_bitstream_filters(AVCodecContext *codec, AVPacket *pkt, 2975 AVBitStreamFilterContext *bsfc); 2976 #endif 2977 2978 enum AVTimebaseSource { 2979 AVFMT_TBCF_AUTO = -1, 2980 AVFMT_TBCF_DECODER, 2981 AVFMT_TBCF_DEMUXER, 2982 #if FF_API_R_FRAME_RATE 2983 AVFMT_TBCF_R_FRAMERATE, 2984 #endif 2985 }; 2986 2987 /** 2988 * Transfer internal timing information from one stream to another. 2989 * 2990 * This function is useful when doing stream copy. 2991 * 2992 * @param ofmt target output format for ost 2993 * @param ost output stream which needs timings copy and adjustments 2994 * @param ist reference input stream to copy timings from 2995 * @param copy_tb define from where the stream codec timebase needs to be imported 2996 */ 2997 int avformat_transfer_internal_stream_timing_info(const AVOutputFormat *ofmt, 2998 AVStream *ost, const AVStream *ist, 2999 enum AVTimebaseSource copy_tb); 3000 3001 /** 3002 * Get the internal codec timebase from a stream. 3003 * 3004 * @param st input stream to extract the timebase from 3005 */ 3006 AVRational av_stream_get_codec_timebase(const AVStream *st); 3007 3008 /** 3009 * @} 3010 */ 3011 3012 #endif /* AVFORMAT_AVFORMAT_H */ 3013