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). Before using lavf, you need to call 40 * av_register_all() to register all compiled muxers, demuxers and protocols. 41 * Unless you are absolutely sure you won't use libavformat's network 42 * capabilities, you should also call avformat_network_init(). 43 * 44 * A supported input format is described by an AVInputFormat struct, conversely 45 * an output format is described by AVOutputFormat. You can iterate over all 46 * registered input/output formats using the av_iformat_next() / 47 * av_oformat_next() functions. The protocols layer is not part of the public 48 * API, so you can only get the names of supported protocols with the 49 * avio_enum_protocols() function. 50 * 51 * Main lavf structure used for both muxing and demuxing is AVFormatContext, 52 * which exports all information about the file being read or written. As with 53 * most Libavformat structures, its size is not part of public ABI, so it cannot be 54 * allocated on stack or directly with av_malloc(). To create an 55 * AVFormatContext, use avformat_alloc_context() (some functions, like 56 * avformat_open_input() might do that for you). 57 * 58 * Most importantly an AVFormatContext contains: 59 * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat 60 * "output" format. It is either autodetected or set by user for input; 61 * always set by user for output. 62 * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all 63 * elementary streams stored in the file. AVStreams are typically referred to 64 * using their index in this array. 65 * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or 66 * set by user for input, always set by user for output (unless you are dealing 67 * with an AVFMT_NOFILE format). 68 * 69 * @section lavf_options Passing options to (de)muxers 70 * It is possible to configure lavf muxers and demuxers using the @ref avoptions 71 * mechanism. Generic (format-independent) libavformat options are provided by 72 * AVFormatContext, they can be examined from a user program by calling 73 * av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass 74 * from avformat_get_class()). Private (format-specific) options are provided by 75 * AVFormatContext.priv_data if and only if AVInputFormat.priv_class / 76 * AVOutputFormat.priv_class of the corresponding format struct is non-NULL. 77 * Further options may be provided by the @ref AVFormatContext.pb "I/O context", 78 * if its AVClass is non-NULL, and the protocols layer. See the discussion on 79 * nesting in @ref avoptions documentation to learn how to access those. 80 * 81 * @section urls 82 * URL strings in libavformat are made of a scheme/protocol, a ':', and a 83 * scheme specific string. URLs without a scheme and ':' used for local files 84 * are supported but deprecated. "file:" should be used for local files. 85 * 86 * It is important that the scheme string is not taken from untrusted 87 * sources without checks. 88 * 89 * Note that some schemes/protocols are quite powerful, allowing access to 90 * both local and remote files, parts of them, concatenations of them, local 91 * audio and video devices and so on. 92 * 93 * @{ 94 * 95 * @defgroup lavf_decoding Demuxing 96 * @{ 97 * Demuxers read a media file and split it into chunks of data (@em packets). A 98 * @ref AVPacket "packet" contains one or more encoded frames which belongs to a 99 * single elementary stream. In the lavf API this process is represented by the 100 * avformat_open_input() function for opening a file, av_read_frame() for 101 * reading a single packet and finally avformat_close_input(), which does the 102 * cleanup. 103 * 104 * @section lavf_decoding_open Opening a media file 105 * The minimum information required to open a file is its URL, which 106 * is passed to avformat_open_input(), as in the following code: 107 * @code 108 * const char *url = "file:in.mp3"; 109 * AVFormatContext *s = NULL; 110 * int ret = avformat_open_input(&s, url, NULL, NULL); 111 * if (ret < 0) 112 * abort(); 113 * @endcode 114 * The above code attempts to allocate an AVFormatContext, open the 115 * specified file (autodetecting the format) and read the header, exporting the 116 * information stored there into s. Some formats do not have a header or do not 117 * store enough information there, so it is recommended that you call the 118 * avformat_find_stream_info() function which tries to read and decode a few 119 * frames to find missing information. 120 * 121 * In some cases you might want to preallocate an AVFormatContext yourself with 122 * avformat_alloc_context() and do some tweaking on it before passing it to 123 * avformat_open_input(). One such case is when you want to use custom functions 124 * for reading input data instead of lavf internal I/O layer. 125 * To do that, create your own AVIOContext with avio_alloc_context(), passing 126 * your reading callbacks to it. Then set the @em pb field of your 127 * AVFormatContext to newly created AVIOContext. 128 * 129 * Since the format of the opened file is in general not known until after 130 * avformat_open_input() has returned, it is not possible to set demuxer private 131 * options on a preallocated context. Instead, the options should be passed to 132 * avformat_open_input() wrapped in an AVDictionary: 133 * @code 134 * AVDictionary *options = NULL; 135 * av_dict_set(&options, "video_size", "640x480", 0); 136 * av_dict_set(&options, "pixel_format", "rgb24", 0); 137 * 138 * if (avformat_open_input(&s, url, NULL, &options) < 0) 139 * abort(); 140 * av_dict_free(&options); 141 * @endcode 142 * This code passes the private options 'video_size' and 'pixel_format' to the 143 * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it 144 * cannot know how to interpret raw video data otherwise. If the format turns 145 * out to be something different than raw video, those options will not be 146 * recognized by the demuxer and therefore will not be applied. Such unrecognized 147 * options are then returned in the options dictionary (recognized options are 148 * consumed). The calling program can handle such unrecognized options as it 149 * wishes, e.g. 150 * @code 151 * AVDictionaryEntry *e; 152 * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) { 153 * fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key); 154 * abort(); 155 * } 156 * @endcode 157 * 158 * After you have finished reading the file, you must close it with 159 * avformat_close_input(). It will free everything associated with the file. 160 * 161 * @section lavf_decoding_read Reading from an opened file 162 * Reading data from an opened AVFormatContext is done by repeatedly calling 163 * av_read_frame() on it. Each call, if successful, will return an AVPacket 164 * containing encoded data for one AVStream, identified by 165 * AVPacket.stream_index. This packet may be passed straight into the libavcodec 166 * decoding functions avcodec_send_packet() or avcodec_decode_subtitle2() if the 167 * caller wishes to decode the data. 168 * 169 * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be 170 * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for 171 * pts/dts, 0 for duration) if the stream does not provide them. The timing 172 * information will be in AVStream.time_base units, i.e. it has to be 173 * multiplied by the timebase to convert them to seconds. 174 * 175 * If AVPacket.buf is set on the returned packet, then the packet is 176 * allocated dynamically and the user may keep it indefinitely. 177 * Otherwise, if AVPacket.buf is NULL, the packet data is backed by a 178 * static storage somewhere inside the demuxer and the packet is only valid 179 * until the next av_read_frame() call or closing the file. If the caller 180 * requires a longer lifetime, av_dup_packet() will make an av_malloc()ed copy 181 * of it. 182 * In both cases, the packet must be freed with av_packet_unref() when it is no 183 * longer needed. 184 * 185 * @section lavf_decoding_seek Seeking 186 * @} 187 * 188 * @defgroup lavf_encoding Muxing 189 * @{ 190 * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write 191 * it into files or other output bytestreams in the specified container format. 192 * 193 * The main API functions for muxing are avformat_write_header() for writing the 194 * file header, av_write_frame() / av_interleaved_write_frame() for writing the 195 * packets and av_write_trailer() for finalizing the file. 196 * 197 * At the beginning of the muxing process, the caller must first call 198 * avformat_alloc_context() to create a muxing context. The caller then sets up 199 * the muxer by filling the various fields in this context: 200 * 201 * - The @ref AVFormatContext.oformat "oformat" field must be set to select the 202 * muxer that will be used. 203 * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb 204 * "pb" field must be set to an opened IO context, either returned from 205 * avio_open2() or a custom one. 206 * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must 207 * be created with the avformat_new_stream() function. The caller should fill 208 * the @ref AVStream.codecpar "stream codec parameters" information, such as the 209 * codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id 210 * "id" and other parameters (e.g. width / height, the pixel or sample format, 211 * etc.) as known. The @ref AVStream.time_base "stream timebase" should 212 * be set to the timebase that the caller desires to use for this stream (note 213 * that the timebase actually used by the muxer can be different, as will be 214 * described later). 215 * - It is advised to manually initialize only the relevant fields in 216 * AVCodecParameters, rather than using @ref avcodec_parameters_copy() during 217 * remuxing: there is no guarantee that the codec context values remain valid 218 * for both input and output format contexts. 219 * - The caller may fill in additional information, such as @ref 220 * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream" 221 * metadata, @ref AVFormatContext.chapters "chapters", @ref 222 * AVFormatContext.programs "programs", etc. as described in the 223 * AVFormatContext documentation. Whether such information will actually be 224 * stored in the output depends on what the container format and the muxer 225 * support. 226 * 227 * When the muxing context is fully set up, the caller must call 228 * avformat_write_header() to initialize the muxer internals and write the file 229 * header. Whether anything actually is written to the IO context at this step 230 * depends on the muxer, but this function must always be called. Any muxer 231 * private options must be passed in the options parameter to this function. 232 * 233 * The data is then sent to the muxer by repeatedly calling av_write_frame() or 234 * av_interleaved_write_frame() (consult those functions' documentation for 235 * discussion on the difference between them; only one of them may be used with 236 * a single muxing context, they should not be mixed). Do note that the timing 237 * information on the packets sent to the muxer must be in the corresponding 238 * AVStream's timebase. That timebase is set by the muxer (in the 239 * avformat_write_header() step) and may be different from the timebase 240 * requested by the caller. 241 * 242 * Once all the data has been written, the caller must call av_write_trailer() 243 * to flush any buffered packets and finalize the output file, then close the IO 244 * context (if any) and finally free the muxing context with 245 * avformat_free_context(). 246 * @} 247 * 248 * @defgroup lavf_io I/O Read/Write 249 * @{ 250 * @section lavf_io_dirlist Directory listing 251 * The directory listing API makes it possible to list files on remote servers. 252 * 253 * Some of possible use cases: 254 * - an "open file" dialog to choose files from a remote location, 255 * - a recursive media finder providing a player with an ability to play all 256 * files from a given directory. 257 * 258 * @subsection lavf_io_dirlist_open Opening a directory 259 * At first, a directory needs to be opened by calling avio_open_dir() 260 * supplied with a URL and, optionally, ::AVDictionary containing 261 * protocol-specific parameters. The function returns zero or positive 262 * integer and allocates AVIODirContext on success. 263 * 264 * @code 265 * AVIODirContext *ctx = NULL; 266 * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) { 267 * fprintf(stderr, "Cannot open directory.\n"); 268 * abort(); 269 * } 270 * @endcode 271 * 272 * This code tries to open a sample directory using smb protocol without 273 * any additional parameters. 274 * 275 * @subsection lavf_io_dirlist_read Reading entries 276 * Each directory's entry (i.e. file, another directory, anything else 277 * within ::AVIODirEntryType) is represented by AVIODirEntry. 278 * Reading consecutive entries from an opened AVIODirContext is done by 279 * repeatedly calling avio_read_dir() on it. Each call returns zero or 280 * positive integer if successful. Reading can be stopped right after the 281 * NULL entry has been read -- it means there are no entries left to be 282 * read. The following code reads all entries from a directory associated 283 * with ctx and prints their names to standard output. 284 * @code 285 * AVIODirEntry *entry = NULL; 286 * for (;;) { 287 * if (avio_read_dir(ctx, &entry) < 0) { 288 * fprintf(stderr, "Cannot list directory.\n"); 289 * abort(); 290 * } 291 * if (!entry) 292 * break; 293 * printf("%s\n", entry->name); 294 * avio_free_directory_entry(&entry); 295 * } 296 * @endcode 297 * @} 298 * 299 * @defgroup lavf_codec Demuxers 300 * @{ 301 * @defgroup lavf_codec_native Native Demuxers 302 * @{ 303 * @} 304 * @defgroup lavf_codec_wrappers External library wrappers 305 * @{ 306 * @} 307 * @} 308 * @defgroup lavf_protos I/O Protocols 309 * @{ 310 * @} 311 * @defgroup lavf_internal Internal 312 * @{ 313 * @} 314 * @} 315 */ 316 317 #include <time.h> 318 #include <stdio.h> /* FILE */ 319 #include "libavcodec/avcodec.h" 320 #include "libavutil/dict.h" 321 #include "libavutil/log.h" 322 323 #include "avio.h" 324 #include "libavformat/version.h" 325 326 struct AVFormatContext; 327 328 struct AVDeviceInfoList; 329 struct AVDeviceCapabilitiesQuery; 330 331 /** 332 * @defgroup metadata_api Public Metadata API 333 * @{ 334 * @ingroup libavf 335 * The metadata API allows libavformat to export metadata tags to a client 336 * application when demuxing. Conversely it allows a client application to 337 * set metadata when muxing. 338 * 339 * Metadata is exported or set as pairs of key/value strings in the 'metadata' 340 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs 341 * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg, 342 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata 343 * exported by demuxers isn't checked to be valid UTF-8 in most cases. 344 * 345 * Important concepts to keep in mind: 346 * - Keys are unique; there can never be 2 tags with the same key. This is 347 * also meant semantically, i.e., a demuxer should not knowingly produce 348 * several keys that are literally different but semantically identical. 349 * E.g., key=Author5, key=Author6. In this example, all authors must be 350 * placed in the same tag. 351 * - Metadata is flat, not hierarchical; there are no subtags. If you 352 * want to store, e.g., the email address of the child of producer Alice 353 * and actor Bob, that could have key=alice_and_bobs_childs_email_address. 354 * - Several modifiers can be applied to the tag name. This is done by 355 * appending a dash character ('-') and the modifier name in the order 356 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng. 357 * - language -- a tag whose value is localized for a particular language 358 * is appended with the ISO 639-2/B 3-letter language code. 359 * For example: Author-ger=Michael, Author-eng=Mike 360 * The original/default language is in the unqualified "Author" tag. 361 * A demuxer should set a default if it sets any translated tag. 362 * - sorting -- a modified version of a tag that should be used for 363 * sorting will have '-sort' appended. E.g. artist="The Beatles", 364 * artist-sort="Beatles, The". 365 * - Some protocols and demuxers support metadata updates. After a successful 366 * call to av_read_packet(), AVFormatContext.event_flags or AVStream.event_flags 367 * will be updated to indicate if metadata changed. In order to detect metadata 368 * changes on a stream, you need to loop through all streams in the AVFormatContext 369 * and check their individual event_flags. 370 * 371 * - Demuxers attempt to export metadata in a generic format, however tags 372 * with no generic equivalents are left as they are stored in the container. 373 * Follows a list of generic tag names: 374 * 375 @verbatim 376 album -- name of the set this work belongs to 377 album_artist -- main creator of the set/album, if different from artist. 378 e.g. "Various Artists" for compilation albums. 379 artist -- main creator of the work 380 comment -- any additional description of the file. 381 composer -- who composed the work, if different from artist. 382 copyright -- name of copyright holder. 383 creation_time-- date when the file was created, preferably in ISO 8601. 384 date -- date when the work was created, preferably in ISO 8601. 385 disc -- number of a subset, e.g. disc in a multi-disc collection. 386 encoder -- name/settings of the software/hardware that produced the file. 387 encoded_by -- person/group who created the file. 388 filename -- original name of the file. 389 genre -- <self-evident>. 390 language -- main language in which the work is performed, preferably 391 in ISO 639-2 format. Multiple languages can be specified by 392 separating them with commas. 393 performer -- artist who performed the work, if different from artist. 394 E.g for "Also sprach Zarathustra", artist would be "Richard 395 Strauss" and performer "London Philharmonic Orchestra". 396 publisher -- name of the label/publisher. 397 service_name -- name of the service in broadcasting (channel name). 398 service_provider -- name of the service provider in broadcasting. 399 title -- name of the work. 400 track -- number of this work in the set, can be in form current/total. 401 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of 402 @endverbatim 403 * 404 * Look in the examples section for an application example how to use the Metadata API. 405 * 406 * @} 407 */ 408 409 /* packet functions */ 410 411 412 /** 413 * Allocate and read the payload of a packet and initialize its 414 * fields with default values. 415 * 416 * @param s associated IO context 417 * @param pkt packet 418 * @param size desired payload size 419 * @return >0 (read size) if OK, AVERROR_xxx otherwise 420 */ 421 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size); 422 423 424 /** 425 * Read data and append it to the current content of the AVPacket. 426 * If pkt->size is 0 this is identical to av_get_packet. 427 * Note that this uses av_grow_packet and thus involves a realloc 428 * which is inefficient. Thus this function should only be used 429 * when there is no reasonable way to know (an upper bound of) 430 * the final size. 431 * 432 * @param s associated IO context 433 * @param pkt packet 434 * @param size amount of data to read 435 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data 436 * will not be lost even if an error occurs. 437 */ 438 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size); 439 440 /*************************************************/ 441 /* input/output formats */ 442 443 struct AVCodecTag; 444 445 /** 446 * This structure contains the data a format has to probe a file. 447 */ 448 typedef struct AVProbeData { 449 const char *filename; 450 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */ 451 int buf_size; /**< Size of buf except extra allocated bytes */ 452 const char *mime_type; /**< mime_type, when known. */ 453 } AVProbeData; 454 455 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4) 456 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1) 457 458 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension 459 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type 460 #define AVPROBE_SCORE_MAX 100 ///< maximum score 461 462 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer 463 464 /// Demuxer will use avio_open, no opened file should be provided by the caller. 465 #define AVFMT_NOFILE 0x0001 466 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */ 467 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */ 468 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */ 469 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */ 470 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */ 471 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */ 472 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */ 473 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */ 474 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */ 475 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */ 476 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */ 477 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */ 478 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */ 479 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly 480 increasing timestamps, but they must 481 still be monotonic */ 482 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative 483 timestamps. If not set the timestamp 484 will be shifted in av_write_frame and 485 av_interleaved_write_frame so they 486 start from 0. 487 The user or muxer can override this through 488 AVFormatContext.avoid_negative_ts 489 */ 490 491 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */ 492 493 /** 494 * @addtogroup lavf_encoding 495 * @{ 496 */ 497 typedef struct AVOutputFormat { 498 const char *name; 499 /** 500 * Descriptive name for the format, meant to be more human-readable 501 * than name. You should use the NULL_IF_CONFIG_SMALL() macro 502 * to define it. 503 */ 504 const char *long_name; 505 const char *mime_type; 506 const char *extensions; /**< comma-separated filename extensions */ 507 /* output support */ 508 enum AVCodecID audio_codec; /**< default audio codec */ 509 enum AVCodecID video_codec; /**< default video codec */ 510 enum AVCodecID subtitle_codec; /**< default subtitle codec */ 511 /** 512 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, 513 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS, 514 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH, 515 * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE 516 */ 517 int flags; 518 519 /** 520 * List of supported codec_id-codec_tag pairs, ordered by "better 521 * choice first". The arrays are all terminated by AV_CODEC_ID_NONE. 522 */ 523 const struct AVCodecTag * const *codec_tag; 524 525 526 const AVClass *priv_class; ///< AVClass for the private context 527 528 /***************************************************************** 529 * No fields below this line are part of the public API. They 530 * may not be used outside of libavformat and can be changed and 531 * removed at will. 532 * New public fields should be added right above. 533 ***************************************************************** 534 */ 535 struct AVOutputFormat *next; 536 /** 537 * size of private data so that it can be allocated in the wrapper 538 */ 539 int priv_data_size; 540 541 int (*write_header)(struct AVFormatContext *); 542 /** 543 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags, 544 * pkt can be NULL in order to flush data buffered in the muxer. 545 * When flushing, return 0 if there still is more data to flush, 546 * or 1 if everything was flushed and there is no more buffered 547 * data. 548 */ 549 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt); 550 int (*write_trailer)(struct AVFormatContext *); 551 /** 552 * Currently only used to set pixel format if not YUV420P. 553 */ 554 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out, 555 AVPacket *in, int flush); 556 /** 557 * Test if the given codec can be stored in this container. 558 * 559 * @return 1 if the codec is supported, 0 if it is not. 560 * A negative number if unknown. 561 * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC 562 */ 563 int (*query_codec)(enum AVCodecID id, int std_compliance); 564 565 void (*get_output_timestamp)(struct AVFormatContext *s, int stream, 566 int64_t *dts, int64_t *wall); 567 /** 568 * Allows sending messages from application to device. 569 */ 570 int (*control_message)(struct AVFormatContext *s, int type, 571 void *data, size_t data_size); 572 573 /** 574 * Write an uncoded AVFrame. 575 * 576 * See av_write_uncoded_frame() for details. 577 * 578 * The library will free *frame afterwards, but the muxer can prevent it 579 * by setting the pointer to NULL. 580 */ 581 int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index, 582 AVFrame **frame, unsigned flags); 583 /** 584 * Returns device list with it properties. 585 * @see avdevice_list_devices() for more details. 586 */ 587 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list); 588 /** 589 * Initialize device capabilities submodule. 590 * @see avdevice_capabilities_create() for more details. 591 */ 592 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps); 593 /** 594 * Free device capabilities submodule. 595 * @see avdevice_capabilities_free() for more details. 596 */ 597 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps); 598 enum AVCodecID data_codec; /**< default data codec */ 599 /** 600 * Initialize format. May allocate data here, and set any AVFormatContext or 601 * AVStream parameters that need to be set before packets are sent. 602 * This method must not write output. 603 * 604 * Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure 605 * 606 * Any allocations made here must be freed in deinit(). 607 */ 608 int (*init)(struct AVFormatContext *); 609 /** 610 * Deinitialize format. If present, this is called whenever the muxer is being 611 * destroyed, regardless of whether or not the header has been written. 612 * 613 * If a trailer is being written, this is called after write_trailer(). 614 * 615 * This is called if init() fails as well. 616 */ 617 void (*deinit)(struct AVFormatContext *); 618 /** 619 * Set up any necessary bitstream filtering and extract any extra data needed 620 * for the global header. 621 * Return 0 if more packets from this stream must be checked; 1 if not. 622 */ 623 int (*check_bitstream)(struct AVFormatContext *, const AVPacket *pkt); 624 } AVOutputFormat; 625 /** 626 * @} 627 */ 628 629 /** 630 * @addtogroup lavf_decoding 631 * @{ 632 */ 633 typedef struct AVInputFormat { 634 /** 635 * A comma separated list of short names for the format. New names 636 * may be appended with a minor bump. 637 */ 638 const char *name; 639 640 /** 641 * Descriptive name for the format, meant to be more human-readable 642 * than name. You should use the NULL_IF_CONFIG_SMALL() macro 643 * to define it. 644 */ 645 const char *long_name; 646 647 /** 648 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS, 649 * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH, 650 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS. 651 */ 652 int flags; 653 654 /** 655 * If extensions are defined, then no probe is done. You should 656 * usually not use extension format guessing because it is not 657 * reliable enough 658 */ 659 const char *extensions; 660 661 const struct AVCodecTag * const *codec_tag; 662 663 const AVClass *priv_class; ///< AVClass for the private context 664 665 /** 666 * Comma-separated list of mime types. 667 * It is used check for matching mime types while probing. 668 * @see av_probe_input_format2 669 */ 670 const char *mime_type; 671 672 /***************************************************************** 673 * No fields below this line are part of the public API. They 674 * may not be used outside of libavformat and can be changed and 675 * removed at will. 676 * New public fields should be added right above. 677 ***************************************************************** 678 */ 679 struct AVInputFormat *next; 680 681 /** 682 * Raw demuxers store their codec ID here. 683 */ 684 int raw_codec_id; 685 686 /** 687 * Size of private data so that it can be allocated in the wrapper. 688 */ 689 int priv_data_size; 690 691 /** 692 * Tell if a given file has a chance of being parsed as this format. 693 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes 694 * big so you do not have to check for that unless you need more. 695 */ 696 int (*read_probe)(AVProbeData *); 697 698 /** 699 * Read the format header and initialize the AVFormatContext 700 * structure. Return 0 if OK. 'avformat_new_stream' should be 701 * called to create new streams. 702 */ 703 int (*read_header)(struct AVFormatContext *); 704 705 /** 706 * Read one packet and put it in 'pkt'. pts and flags are also 707 * set. 'avformat_new_stream' can be called only if the flag 708 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a 709 * background thread). 710 * @return 0 on success, < 0 on error. 711 * When returning an error, pkt must not have been allocated 712 * or must be freed before returning 713 */ 714 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt); 715 716 /** 717 * Close the stream. The AVFormatContext and AVStreams are not 718 * freed by this function 719 */ 720 int (*read_close)(struct AVFormatContext *); 721 722 /** 723 * Seek to a given timestamp relative to the frames in 724 * stream component stream_index. 725 * @param stream_index Must not be -1. 726 * @param flags Selects which direction should be preferred if no exact 727 * match is available. 728 * @return >= 0 on success (but not necessarily the new offset) 729 */ 730 int (*read_seek)(struct AVFormatContext *, 731 int stream_index, int64_t timestamp, int flags); 732 733 /** 734 * Get the next timestamp in stream[stream_index].time_base units. 735 * @return the timestamp or AV_NOPTS_VALUE if an error occurred 736 */ 737 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index, 738 int64_t *pos, int64_t pos_limit); 739 740 /** 741 * Start/resume playing - only meaningful if using a network-based format 742 * (RTSP). 743 */ 744 int (*read_play)(struct AVFormatContext *); 745 746 /** 747 * Pause playing - only meaningful if using a network-based format 748 * (RTSP). 749 */ 750 int (*read_pause)(struct AVFormatContext *); 751 752 /** 753 * Seek to timestamp ts. 754 * Seeking will be done so that the point from which all active streams 755 * can be presented successfully will be closest to ts and within min/max_ts. 756 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL. 757 */ 758 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags); 759 760 /** 761 * Returns device list with it properties. 762 * @see avdevice_list_devices() for more details. 763 */ 764 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list); 765 766 /** 767 * Initialize device capabilities submodule. 768 * @see avdevice_capabilities_create() for more details. 769 */ 770 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps); 771 772 /** 773 * Free device capabilities submodule. 774 * @see avdevice_capabilities_free() for more details. 775 */ 776 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps); 777 } AVInputFormat; 778 /** 779 * @} 780 */ 781 782 enum AVStreamParseType { 783 AVSTREAM_PARSE_NONE, 784 AVSTREAM_PARSE_FULL, /**< full parsing and repack */ 785 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */ 786 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */ 787 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */ 788 AVSTREAM_PARSE_FULL_RAW, /**< full parsing and repack with timestamp and position generation by parser for raw 789 this assumes that each packet in the file contains no demuxer level headers and 790 just codec level data, otherwise position generation would fail */ 791 }; 792 793 typedef struct AVIndexEntry { 794 int64_t pos; 795 int64_t timestamp; /**< 796 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available 797 * when seeking to this entry. That means preferable PTS on keyframe based formats. 798 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better 799 * is known 800 */ 801 #define AVINDEX_KEYFRAME 0x0001 802 #define AVINDEX_DISCARD_FRAME 0x0002 /** 803 * Flag is used to indicate which frame should be discarded after decoding. 804 */ 805 int flags:2; 806 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). 807 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */ 808 } AVIndexEntry; 809 810 #define AV_DISPOSITION_DEFAULT 0x0001 811 #define AV_DISPOSITION_DUB 0x0002 812 #define AV_DISPOSITION_ORIGINAL 0x0004 813 #define AV_DISPOSITION_COMMENT 0x0008 814 #define AV_DISPOSITION_LYRICS 0x0010 815 #define AV_DISPOSITION_KARAOKE 0x0020 816 817 /** 818 * Track should be used during playback by default. 819 * Useful for subtitle track that should be displayed 820 * even when user did not explicitly ask for subtitles. 821 */ 822 #define AV_DISPOSITION_FORCED 0x0040 823 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */ 824 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */ 825 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */ 826 /** 827 * The stream is stored in the file as an attached picture/"cover art" (e.g. 828 * APIC frame in ID3v2). The first (usually only) packet associated with it 829 * will be returned among the first few packets read from the file unless 830 * seeking takes place. It can also be accessed at any time in 831 * AVStream.attached_pic. 832 */ 833 #define AV_DISPOSITION_ATTACHED_PIC 0x0400 834 /** 835 * The stream is sparse, and contains thumbnail images, often corresponding 836 * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC. 837 */ 838 #define AV_DISPOSITION_TIMED_THUMBNAILS 0x0800 839 840 typedef struct AVStreamInternal AVStreamInternal; 841 842 /** 843 * To specify text track kind (different from subtitles default). 844 */ 845 #define AV_DISPOSITION_CAPTIONS 0x10000 846 #define AV_DISPOSITION_DESCRIPTIONS 0x20000 847 #define AV_DISPOSITION_METADATA 0x40000 848 #define AV_DISPOSITION_DEPENDENT 0x80000 ///< dependent audio stream (mix_type=0 in mpegts) 849 850 /** 851 * Options for behavior on timestamp wrap detection. 852 */ 853 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap 854 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection 855 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection 856 857 /** 858 * Stream structure. 859 * New fields can be added to the end with minor version bumps. 860 * Removal, reordering and changes to existing fields require a major 861 * version bump. 862 * sizeof(AVStream) must not be used outside libav*. 863 */ 864 typedef struct AVStream { 865 int index; /**< stream index in AVFormatContext */ 866 /** 867 * Format-specific stream ID. 868 * decoding: set by libavformat 869 * encoding: set by the user, replaced by libavformat if left unset 870 */ 871 int id; 872 #if FF_API_LAVF_AVCTX 873 /** 874 * @deprecated use the codecpar struct instead 875 */ 876 attribute_deprecated 877 AVCodecContext *codec; 878 #endif 879 void *priv_data; 880 881 /** 882 * This is the fundamental unit of time (in seconds) in terms 883 * of which frame timestamps are represented. 884 * 885 * decoding: set by libavformat 886 * encoding: May be set by the caller before avformat_write_header() to 887 * provide a hint to the muxer about the desired timebase. In 888 * avformat_write_header(), the muxer will overwrite this field 889 * with the timebase that will actually be used for the timestamps 890 * written into the file (which may or may not be related to the 891 * user-provided one, depending on the format). 892 */ 893 AVRational time_base; 894 895 /** 896 * Decoding: pts of the first frame of the stream in presentation order, in stream time base. 897 * Only set this if you are absolutely 100% sure that the value you set 898 * it to really is the pts of the first frame. 899 * This may be undefined (AV_NOPTS_VALUE). 900 * @note The ASF header does NOT contain a correct start_time the ASF 901 * demuxer must NOT set this. 902 */ 903 int64_t start_time; 904 905 /** 906 * Decoding: duration of the stream, in stream time base. 907 * If a source file does not specify a duration, but does specify 908 * a bitrate, this value will be estimated from bitrate and file size. 909 * 910 * Encoding: May be set by the caller before avformat_write_header() to 911 * provide a hint to the muxer about the estimated duration. 912 */ 913 int64_t duration; 914 915 int64_t nb_frames; ///< number of frames in this stream if known or 0 916 917 int disposition; /**< AV_DISPOSITION_* bit field */ 918 919 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed. 920 921 /** 922 * sample aspect ratio (0 if unknown) 923 * - encoding: Set by user. 924 * - decoding: Set by libavformat. 925 */ 926 AVRational sample_aspect_ratio; 927 928 AVDictionary *metadata; 929 930 /** 931 * Average framerate 932 * 933 * - demuxing: May be set by libavformat when creating the stream or in 934 * avformat_find_stream_info(). 935 * - muxing: May be set by the caller before avformat_write_header(). 936 */ 937 AVRational avg_frame_rate; 938 939 /** 940 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet 941 * will contain the attached picture. 942 * 943 * decoding: set by libavformat, must not be modified by the caller. 944 * encoding: unused 945 */ 946 AVPacket attached_pic; 947 948 /** 949 * An array of side data that applies to the whole stream (i.e. the 950 * container does not allow it to change between packets). 951 * 952 * There may be no overlap between the side data in this array and side data 953 * in the packets. I.e. a given side data is either exported by the muxer 954 * (demuxing) / set by the caller (muxing) in this array, then it never 955 * appears in the packets, or the side data is exported / sent through 956 * the packets (always in the first packet where the value becomes known or 957 * changes), then it does not appear in this array. 958 * 959 * - demuxing: Set by libavformat when the stream is created. 960 * - muxing: May be set by the caller before avformat_write_header(). 961 * 962 * Freed by libavformat in avformat_free_context(). 963 * 964 * @see av_format_inject_global_side_data() 965 */ 966 AVPacketSideData *side_data; 967 /** 968 * The number of elements in the AVStream.side_data array. 969 */ 970 int nb_side_data; 971 972 /** 973 * Flags for the user to detect events happening on the stream. Flags must 974 * be cleared by the user once the event has been handled. 975 * A combination of AVSTREAM_EVENT_FLAG_*. 976 */ 977 int event_flags; 978 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata. 979 980 /** 981 * Real base framerate of the stream. 982 * This is the lowest framerate with which all timestamps can be 983 * represented accurately (it is the least common multiple of all 984 * framerates in the stream). Note, this value is just a guess! 985 * For example, if the time base is 1/90000 and all frames have either 986 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1. 987 */ 988 AVRational r_frame_rate; 989 990 #if FF_API_LAVF_FFSERVER 991 /** 992 * String containing pairs of key and values describing recommended encoder configuration. 993 * Pairs are separated by ','. 994 * Keys are separated from values by '='. 995 * 996 * @deprecated unused 997 */ 998 attribute_deprecated 999 char *recommended_encoder_configuration; 1000 #endif 1001 1002 /** 1003 * Codec parameters associated with this stream. Allocated and freed by 1004 * libavformat in avformat_new_stream() and avformat_free_context() 1005 * respectively. 1006 * 1007 * - demuxing: filled by libavformat on stream creation or in 1008 * avformat_find_stream_info() 1009 * - muxing: filled by the caller before avformat_write_header() 1010 */ 1011 AVCodecParameters *codecpar; 1012 1013 /***************************************************************** 1014 * All fields below this line are not part of the public API. They 1015 * may not be used outside of libavformat and can be changed and 1016 * removed at will. 1017 * Internal note: be aware that physically removing these fields 1018 * will break ABI. Replace removed fields with dummy fields, and 1019 * add new fields to AVStreamInternal. 1020 ***************************************************************** 1021 */ 1022 1023 #define MAX_STD_TIMEBASES (30*12+30+3+6) 1024 /** 1025 * Stream information used internally by avformat_find_stream_info() 1026 */ 1027 struct { 1028 int64_t last_dts; 1029 int64_t duration_gcd; 1030 int duration_count; 1031 int64_t rfps_duration_sum; 1032 double (*duration_error)[2][MAX_STD_TIMEBASES]; 1033 int64_t codec_info_duration; 1034 int64_t codec_info_duration_fields; 1035 int frame_delay_evidence; 1036 1037 /** 1038 * 0 -> decoder has not been searched for yet. 1039 * >0 -> decoder found 1040 * <0 -> decoder with codec_id == -found_decoder has not been found 1041 */ 1042 int found_decoder; 1043 1044 int64_t last_duration; 1045 1046 /** 1047 * Those are used for average framerate estimation. 1048 */ 1049 int64_t fps_first_dts; 1050 int fps_first_dts_idx; 1051 int64_t fps_last_dts; 1052 int fps_last_dts_idx; 1053 1054 } *info; 1055 1056 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */ 1057 1058 // Timestamp generation support: 1059 /** 1060 * Timestamp corresponding to the last dts sync point. 1061 * 1062 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and 1063 * a DTS is received from the underlying container. Otherwise set to 1064 * AV_NOPTS_VALUE by default. 1065 */ 1066 int64_t first_dts; 1067 int64_t cur_dts; 1068 int64_t last_IP_pts; 1069 int last_IP_duration; 1070 1071 /** 1072 * Number of packets to buffer for codec probing 1073 */ 1074 int probe_packets; 1075 1076 /** 1077 * Number of frames that have been demuxed during avformat_find_stream_info() 1078 */ 1079 int codec_info_nb_frames; 1080 1081 /* av_read_frame() support */ 1082 enum AVStreamParseType need_parsing; 1083 struct AVCodecParserContext *parser; 1084 1085 /** 1086 * last packet in packet_buffer for this stream when muxing. 1087 */ 1088 struct AVPacketList *last_in_packet_buffer; 1089 AVProbeData probe_data; 1090 #define MAX_REORDER_DELAY 16 1091 int64_t pts_buffer[MAX_REORDER_DELAY+1]; 1092 1093 AVIndexEntry *index_entries; /**< Only used if the format does not 1094 support seeking natively. */ 1095 int nb_index_entries; 1096 unsigned int index_entries_allocated_size; 1097 1098 /** 1099 * Stream Identifier 1100 * This is the MPEG-TS stream identifier +1 1101 * 0 means unknown 1102 */ 1103 int stream_identifier; 1104 1105 int64_t interleaver_chunk_size; 1106 int64_t interleaver_chunk_duration; 1107 1108 /** 1109 * stream probing state 1110 * -1 -> probing finished 1111 * 0 -> no probing requested 1112 * rest -> perform probing with request_probe being the minimum score to accept. 1113 * NOT PART OF PUBLIC API 1114 */ 1115 int request_probe; 1116 /** 1117 * Indicates that everything up to the next keyframe 1118 * should be discarded. 1119 */ 1120 int skip_to_keyframe; 1121 1122 /** 1123 * Number of samples to skip at the start of the frame decoded from the next packet. 1124 */ 1125 int skip_samples; 1126 1127 /** 1128 * If not 0, the number of samples that should be skipped from the start of 1129 * the stream (the samples are removed from packets with pts==0, which also 1130 * assumes negative timestamps do not happen). 1131 * Intended for use with formats such as mp3 with ad-hoc gapless audio 1132 * support. 1133 */ 1134 int64_t start_skip_samples; 1135 1136 /** 1137 * If not 0, the first audio sample that should be discarded from the stream. 1138 * This is broken by design (needs global sample count), but can't be 1139 * avoided for broken by design formats such as mp3 with ad-hoc gapless 1140 * audio support. 1141 */ 1142 int64_t first_discard_sample; 1143 1144 /** 1145 * The sample after last sample that is intended to be discarded after 1146 * first_discard_sample. Works on frame boundaries only. Used to prevent 1147 * early EOF if the gapless info is broken (considered concatenated mp3s). 1148 */ 1149 int64_t last_discard_sample; 1150 1151 /** 1152 * Number of internally decoded frames, used internally in libavformat, do not access 1153 * its lifetime differs from info which is why it is not in that structure. 1154 */ 1155 int nb_decoded_frames; 1156 1157 /** 1158 * Timestamp offset added to timestamps before muxing 1159 * NOT PART OF PUBLIC API 1160 */ 1161 int64_t mux_ts_offset; 1162 1163 /** 1164 * Internal data to check for wrapping of the time stamp 1165 */ 1166 int64_t pts_wrap_reference; 1167 1168 /** 1169 * Options for behavior, when a wrap is detected. 1170 * 1171 * Defined by AV_PTS_WRAP_ values. 1172 * 1173 * If correction is enabled, there are two possibilities: 1174 * If the first time stamp is near the wrap point, the wrap offset 1175 * will be subtracted, which will create negative time stamps. 1176 * Otherwise the offset will be added. 1177 */ 1178 int pts_wrap_behavior; 1179 1180 /** 1181 * Internal data to prevent doing update_initial_durations() twice 1182 */ 1183 int update_initial_durations_done; 1184 1185 /** 1186 * Internal data to generate dts from pts 1187 */ 1188 int64_t pts_reorder_error[MAX_REORDER_DELAY+1]; 1189 uint8_t pts_reorder_error_count[MAX_REORDER_DELAY+1]; 1190 1191 /** 1192 * Internal data to analyze DTS and detect faulty mpeg streams 1193 */ 1194 int64_t last_dts_for_order_check; 1195 uint8_t dts_ordered; 1196 uint8_t dts_misordered; 1197 1198 /** 1199 * Internal data to inject global side data 1200 */ 1201 int inject_global_side_data; 1202 1203 /** 1204 * display aspect ratio (0 if unknown) 1205 * - encoding: unused 1206 * - decoding: Set by libavformat to calculate sample_aspect_ratio internally 1207 */ 1208 AVRational display_aspect_ratio; 1209 1210 /** 1211 * An opaque field for libavformat internal usage. 1212 * Must not be accessed in any way by callers. 1213 */ 1214 AVStreamInternal *internal; 1215 } AVStream; 1216 1217 #if FF_API_FORMAT_GET_SET 1218 /** 1219 * Accessors for some AVStream fields. These used to be provided for ABI 1220 * compatibility, and do not need to be used anymore. 1221 */ 1222 attribute_deprecated 1223 AVRational av_stream_get_r_frame_rate(const AVStream *s); 1224 attribute_deprecated 1225 void av_stream_set_r_frame_rate(AVStream *s, AVRational r); 1226 #if FF_API_LAVF_FFSERVER 1227 attribute_deprecated 1228 char* av_stream_get_recommended_encoder_configuration(const AVStream *s); 1229 attribute_deprecated 1230 void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration); 1231 #endif 1232 #endif 1233 1234 struct AVCodecParserContext *av_stream_get_parser(const AVStream *s); 1235 1236 /** 1237 * Returns the pts of the last muxed packet + its duration 1238 * 1239 * the retuned value is undefined when used with a demuxer. 1240 */ 1241 int64_t av_stream_get_end_pts(const AVStream *st); 1242 1243 #define AV_PROGRAM_RUNNING 1 1244 1245 /** 1246 * New fields can be added to the end with minor version bumps. 1247 * Removal, reordering and changes to existing fields require a major 1248 * version bump. 1249 * sizeof(AVProgram) must not be used outside libav*. 1250 */ 1251 typedef struct AVProgram { 1252 int id; 1253 int flags; 1254 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller 1255 unsigned int *stream_index; 1256 unsigned int nb_stream_indexes; 1257 AVDictionary *metadata; 1258 1259 int program_num; 1260 int pmt_pid; 1261 int pcr_pid; 1262 1263 /***************************************************************** 1264 * All fields below this line are not part of the public API. They 1265 * may not be used outside of libavformat and can be changed and 1266 * removed at will. 1267 * New public fields should be added right above. 1268 ***************************************************************** 1269 */ 1270 int64_t start_time; 1271 int64_t end_time; 1272 1273 int64_t pts_wrap_reference; ///< reference dts for wrap detection 1274 int pts_wrap_behavior; ///< behavior on wrap detection 1275 } AVProgram; 1276 1277 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present 1278 (streams are added dynamically) */ 1279 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely 1280 not seekable, and attempts to call the 1281 seek function will fail. For some 1282 network protocols (e.g. HLS), this can 1283 change dynamically at runtime. */ 1284 1285 typedef struct AVChapter { 1286 int id; ///< unique ID to identify the chapter 1287 AVRational time_base; ///< time base in which the start/end timestamps are specified 1288 int64_t start, end; ///< chapter start/end time in time_base units 1289 AVDictionary *metadata; 1290 } AVChapter; 1291 1292 1293 /** 1294 * Callback used by devices to communicate with application. 1295 */ 1296 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type, 1297 void *data, size_t data_size); 1298 1299 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, 1300 const AVIOInterruptCB *int_cb, AVDictionary **options); 1301 1302 /** 1303 * The duration of a video can be estimated through various ways, and this enum can be used 1304 * to know how the duration was estimated. 1305 */ 1306 enum AVDurationEstimationMethod { 1307 AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes 1308 AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration 1309 AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate) 1310 }; 1311 1312 typedef struct AVFormatInternal AVFormatInternal; 1313 1314 /** 1315 * Format I/O context. 1316 * New fields can be added to the end with minor version bumps. 1317 * Removal, reordering and changes to existing fields require a major 1318 * version bump. 1319 * sizeof(AVFormatContext) must not be used outside libav*, use 1320 * avformat_alloc_context() to create an AVFormatContext. 1321 * 1322 * Fields can be accessed through AVOptions (av_opt*), 1323 * the name string used matches the associated command line parameter name and 1324 * can be found in libavformat/options_table.h. 1325 * The AVOption/command line parameter names differ in some cases from the C 1326 * structure field names for historic reasons or brevity. 1327 */ 1328 typedef struct AVFormatContext { 1329 /** 1330 * A class for logging and @ref avoptions. Set by avformat_alloc_context(). 1331 * Exports (de)muxer private options if they exist. 1332 */ 1333 const AVClass *av_class; 1334 1335 /** 1336 * The input container format. 1337 * 1338 * Demuxing only, set by avformat_open_input(). 1339 */ 1340 struct AVInputFormat *iformat; 1341 1342 /** 1343 * The output container format. 1344 * 1345 * Muxing only, must be set by the caller before avformat_write_header(). 1346 */ 1347 struct AVOutputFormat *oformat; 1348 1349 /** 1350 * Format private data. This is an AVOptions-enabled struct 1351 * if and only if iformat/oformat.priv_class is not NULL. 1352 * 1353 * - muxing: set by avformat_write_header() 1354 * - demuxing: set by avformat_open_input() 1355 */ 1356 void *priv_data; 1357 1358 /** 1359 * I/O context. 1360 * 1361 * - demuxing: either set by the user before avformat_open_input() (then 1362 * the user must close it manually) or set by avformat_open_input(). 1363 * - muxing: set by the user before avformat_write_header(). The caller must 1364 * take care of closing / freeing the IO context. 1365 * 1366 * Do NOT set this field if AVFMT_NOFILE flag is set in 1367 * iformat/oformat.flags. In such a case, the (de)muxer will handle 1368 * I/O in some other way and this field will be NULL. 1369 */ 1370 AVIOContext *pb; 1371 1372 /* stream info */ 1373 /** 1374 * Flags signalling stream properties. A combination of AVFMTCTX_*. 1375 * Set by libavformat. 1376 */ 1377 int ctx_flags; 1378 1379 /** 1380 * Number of elements in AVFormatContext.streams. 1381 * 1382 * Set by avformat_new_stream(), must not be modified by any other code. 1383 */ 1384 unsigned int nb_streams; 1385 /** 1386 * A list of all streams in the file. New streams are created with 1387 * avformat_new_stream(). 1388 * 1389 * - demuxing: streams are created by libavformat in avformat_open_input(). 1390 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also 1391 * appear in av_read_frame(). 1392 * - muxing: streams are created by the user before avformat_write_header(). 1393 * 1394 * Freed by libavformat in avformat_free_context(). 1395 */ 1396 AVStream **streams; 1397 1398 #if FF_API_FORMAT_FILENAME 1399 /** 1400 * input or output filename 1401 * 1402 * - demuxing: set by avformat_open_input() 1403 * - muxing: may be set by the caller before avformat_write_header() 1404 * 1405 * @deprecated Use url instead. 1406 */ 1407 attribute_deprecated 1408 char filename[1024]; 1409 #endif 1410 1411 /** 1412 * input or output URL. Unlike the old filename field, this field has no 1413 * length restriction. 1414 * 1415 * - demuxing: set by avformat_open_input(), initialized to an empty 1416 * string if url parameter was NULL in avformat_open_input(). 1417 * - muxing: may be set by the caller before calling avformat_write_header() 1418 * (or avformat_init_output() if that is called first) to a string 1419 * which is freeable by av_free(). Set to an empty string if it 1420 * was NULL in avformat_init_output(). 1421 * 1422 * Freed by libavformat in avformat_free_context(). 1423 */ 1424 char *url; 1425 1426 /** 1427 * Position of the first frame of the component, in 1428 * AV_TIME_BASE fractional seconds. NEVER set this value directly: 1429 * It is deduced from the AVStream values. 1430 * 1431 * Demuxing only, set by libavformat. 1432 */ 1433 int64_t start_time; 1434 1435 /** 1436 * Duration of the stream, in AV_TIME_BASE fractional 1437 * seconds. Only set this value if you know none of the individual stream 1438 * durations and also do not set any of them. This is deduced from the 1439 * AVStream values if not set. 1440 * 1441 * Demuxing only, set by libavformat. 1442 */ 1443 int64_t duration; 1444 1445 /** 1446 * Total stream bitrate in bit/s, 0 if not 1447 * available. Never set it directly if the file_size and the 1448 * duration are known as FFmpeg can compute it automatically. 1449 */ 1450 int64_t bit_rate; 1451 1452 unsigned int packet_size; 1453 int max_delay; 1454 1455 /** 1456 * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*. 1457 * Set by the user before avformat_open_input() / avformat_write_header(). 1458 */ 1459 int flags; 1460 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames. 1461 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index. 1462 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input. 1463 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS 1464 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container 1465 #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 1466 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible 1467 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it. 1468 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted 1469 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet. 1470 /** 1471 * When muxing, try to avoid writing any random/volatile data to the output. 1472 * This includes any random IDs, real-time timestamps/dates, muxer version, etc. 1473 * 1474 * This flag is mainly intended for testing. 1475 */ 1476 #define AVFMT_FLAG_BITEXACT 0x0400 1477 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Enable RTP MP4A-LATM payload 1478 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down) 1479 #define AVFMT_FLAG_PRIV_OPT 0x20000 ///< Enable use of private options by delaying codec open (this could be made default once all code is converted) 1480 #if FF_API_LAVF_KEEPSIDE_FLAG 1481 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Deprecated, does nothing. 1482 #endif 1483 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats 1484 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops. 1485 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer 1486 1487 /** 1488 * Maximum size of the data read from input for determining 1489 * the input container format. 1490 * Demuxing only, set by the caller before avformat_open_input(). 1491 */ 1492 int64_t probesize; 1493 1494 /** 1495 * Maximum duration (in AV_TIME_BASE units) of the data read 1496 * from input in avformat_find_stream_info(). 1497 * Demuxing only, set by the caller before avformat_find_stream_info(). 1498 * Can be set to 0 to let avformat choose using a heuristic. 1499 */ 1500 int64_t max_analyze_duration; 1501 1502 const uint8_t *key; 1503 int keylen; 1504 1505 unsigned int nb_programs; 1506 AVProgram **programs; 1507 1508 /** 1509 * Forced video codec_id. 1510 * Demuxing: Set by user. 1511 */ 1512 enum AVCodecID video_codec_id; 1513 1514 /** 1515 * Forced audio codec_id. 1516 * Demuxing: Set by user. 1517 */ 1518 enum AVCodecID audio_codec_id; 1519 1520 /** 1521 * Forced subtitle codec_id. 1522 * Demuxing: Set by user. 1523 */ 1524 enum AVCodecID subtitle_codec_id; 1525 1526 /** 1527 * Maximum amount of memory in bytes to use for the index of each stream. 1528 * If the index exceeds this size, entries will be discarded as 1529 * needed to maintain a smaller size. This can lead to slower or less 1530 * accurate seeking (depends on demuxer). 1531 * Demuxers for which a full in-memory index is mandatory will ignore 1532 * this. 1533 * - muxing: unused 1534 * - demuxing: set by user 1535 */ 1536 unsigned int max_index_size; 1537 1538 /** 1539 * Maximum amount of memory in bytes to use for buffering frames 1540 * obtained from realtime capture devices. 1541 */ 1542 unsigned int max_picture_buffer; 1543 1544 /** 1545 * Number of chapters in AVChapter array. 1546 * When muxing, chapters are normally written in the file header, 1547 * so nb_chapters should normally be initialized before write_header 1548 * is called. Some muxers (e.g. mov and mkv) can also write chapters 1549 * in the trailer. To write chapters in the trailer, nb_chapters 1550 * must be zero when write_header is called and non-zero when 1551 * write_trailer is called. 1552 * - muxing: set by user 1553 * - demuxing: set by libavformat 1554 */ 1555 unsigned int nb_chapters; 1556 AVChapter **chapters; 1557 1558 /** 1559 * Metadata that applies to the whole file. 1560 * 1561 * - demuxing: set by libavformat in avformat_open_input() 1562 * - muxing: may be set by the caller before avformat_write_header() 1563 * 1564 * Freed by libavformat in avformat_free_context(). 1565 */ 1566 AVDictionary *metadata; 1567 1568 /** 1569 * Start time of the stream in real world time, in microseconds 1570 * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the 1571 * stream was captured at this real world time. 1572 * - muxing: Set by the caller before avformat_write_header(). If set to 1573 * either 0 or AV_NOPTS_VALUE, then the current wall-time will 1574 * be used. 1575 * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that 1576 * the value may become known after some number of frames 1577 * have been received. 1578 */ 1579 int64_t start_time_realtime; 1580 1581 /** 1582 * The number of frames used for determining the framerate in 1583 * avformat_find_stream_info(). 1584 * Demuxing only, set by the caller before avformat_find_stream_info(). 1585 */ 1586 int fps_probe_size; 1587 1588 /** 1589 * Error recognition; higher values will detect more errors but may 1590 * misdetect some more or less valid parts as errors. 1591 * Demuxing only, set by the caller before avformat_open_input(). 1592 */ 1593 int error_recognition; 1594 1595 /** 1596 * Custom interrupt callbacks for the I/O layer. 1597 * 1598 * demuxing: set by the user before avformat_open_input(). 1599 * muxing: set by the user before avformat_write_header() 1600 * (mainly useful for AVFMT_NOFILE formats). The callback 1601 * should also be passed to avio_open2() if it's used to 1602 * open the file. 1603 */ 1604 AVIOInterruptCB interrupt_callback; 1605 1606 /** 1607 * Flags to enable debugging. 1608 */ 1609 int debug; 1610 #define FF_FDEBUG_TS 0x0001 1611 1612 /** 1613 * Maximum buffering duration for interleaving. 1614 * 1615 * To ensure all the streams are interleaved correctly, 1616 * av_interleaved_write_frame() will wait until it has at least one packet 1617 * for each stream before actually writing any packets to the output file. 1618 * When some streams are "sparse" (i.e. there are large gaps between 1619 * successive packets), this can result in excessive buffering. 1620 * 1621 * This field specifies the maximum difference between the timestamps of the 1622 * first and the last packet in the muxing queue, above which libavformat 1623 * will output a packet regardless of whether it has queued a packet for all 1624 * the streams. 1625 * 1626 * Muxing only, set by the caller before avformat_write_header(). 1627 */ 1628 int64_t max_interleave_delta; 1629 1630 /** 1631 * Allow non-standard and experimental extension 1632 * @see AVCodecContext.strict_std_compliance 1633 */ 1634 int strict_std_compliance; 1635 1636 /** 1637 * Flags for the user to detect events happening on the file. Flags must 1638 * be cleared by the user once the event has been handled. 1639 * A combination of AVFMT_EVENT_FLAG_*. 1640 */ 1641 int event_flags; 1642 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata. 1643 1644 /** 1645 * Maximum number of packets to read while waiting for the first timestamp. 1646 * Decoding only. 1647 */ 1648 int max_ts_probe; 1649 1650 /** 1651 * Avoid negative timestamps during muxing. 1652 * Any value of the AVFMT_AVOID_NEG_TS_* constants. 1653 * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use) 1654 * - muxing: Set by user 1655 * - demuxing: unused 1656 */ 1657 int avoid_negative_ts; 1658 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format 1659 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative 1660 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0 1661 1662 /** 1663 * Transport stream id. 1664 * This will be moved into demuxer private options. Thus no API/ABI compatibility 1665 */ 1666 int ts_id; 1667 1668 /** 1669 * Audio preload in microseconds. 1670 * Note, not all formats support this and unpredictable things may happen if it is used when not supported. 1671 * - encoding: Set by user 1672 * - decoding: unused 1673 */ 1674 int audio_preload; 1675 1676 /** 1677 * Max chunk time in microseconds. 1678 * Note, not all formats support this and unpredictable things may happen if it is used when not supported. 1679 * - encoding: Set by user 1680 * - decoding: unused 1681 */ 1682 int max_chunk_duration; 1683 1684 /** 1685 * Max chunk size in bytes 1686 * Note, not all formats support this and unpredictable things may happen if it is used when not supported. 1687 * - encoding: Set by user 1688 * - decoding: unused 1689 */ 1690 int max_chunk_size; 1691 1692 /** 1693 * forces the use of wallclock timestamps as pts/dts of packets 1694 * This has undefined results in the presence of B frames. 1695 * - encoding: unused 1696 * - decoding: Set by user 1697 */ 1698 int use_wallclock_as_timestamps; 1699 1700 /** 1701 * avio flags, used to force AVIO_FLAG_DIRECT. 1702 * - encoding: unused 1703 * - decoding: Set by user 1704 */ 1705 int avio_flags; 1706 1707 /** 1708 * The duration field can be estimated through various ways, and this field can be used 1709 * to know how the duration was estimated. 1710 * - encoding: unused 1711 * - decoding: Read by user 1712 */ 1713 enum AVDurationEstimationMethod duration_estimation_method; 1714 1715 /** 1716 * Skip initial bytes when opening stream 1717 * - encoding: unused 1718 * - decoding: Set by user 1719 */ 1720 int64_t skip_initial_bytes; 1721 1722 /** 1723 * Correct single timestamp overflows 1724 * - encoding: unused 1725 * - decoding: Set by user 1726 */ 1727 unsigned int correct_ts_overflow; 1728 1729 /** 1730 * Force seeking to any (also non key) frames. 1731 * - encoding: unused 1732 * - decoding: Set by user 1733 */ 1734 int seek2any; 1735 1736 /** 1737 * Flush the I/O context after each packet. 1738 * - encoding: Set by user 1739 * - decoding: unused 1740 */ 1741 int flush_packets; 1742 1743 /** 1744 * format probing score. 1745 * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes 1746 * the format. 1747 * - encoding: unused 1748 * - decoding: set by avformat, read by user 1749 */ 1750 int probe_score; 1751 1752 /** 1753 * number of bytes to read maximally to identify format. 1754 * - encoding: unused 1755 * - decoding: set by user 1756 */ 1757 int format_probesize; 1758 1759 /** 1760 * ',' separated list of allowed decoders. 1761 * If NULL then all are allowed 1762 * - encoding: unused 1763 * - decoding: set by user 1764 */ 1765 char *codec_whitelist; 1766 1767 /** 1768 * ',' separated list of allowed demuxers. 1769 * If NULL then all are allowed 1770 * - encoding: unused 1771 * - decoding: set by user 1772 */ 1773 char *format_whitelist; 1774 1775 /** 1776 * An opaque field for libavformat internal usage. 1777 * Must not be accessed in any way by callers. 1778 */ 1779 AVFormatInternal *internal; 1780 1781 /** 1782 * IO repositioned flag. 1783 * This is set by avformat when the underlaying IO context read pointer 1784 * is repositioned, for example when doing byte based seeking. 1785 * Demuxers can use the flag to detect such changes. 1786 */ 1787 int io_repositioned; 1788 1789 /** 1790 * Forced video codec. 1791 * This allows forcing a specific decoder, even when there are multiple with 1792 * the same codec_id. 1793 * Demuxing: Set by user 1794 */ 1795 AVCodec *video_codec; 1796 1797 /** 1798 * Forced audio codec. 1799 * This allows forcing a specific decoder, even when there are multiple with 1800 * the same codec_id. 1801 * Demuxing: Set by user 1802 */ 1803 AVCodec *audio_codec; 1804 1805 /** 1806 * Forced subtitle codec. 1807 * This allows forcing a specific decoder, even when there are multiple with 1808 * the same codec_id. 1809 * Demuxing: Set by user 1810 */ 1811 AVCodec *subtitle_codec; 1812 1813 /** 1814 * Forced data codec. 1815 * This allows forcing a specific decoder, even when there are multiple with 1816 * the same codec_id. 1817 * Demuxing: Set by user 1818 */ 1819 AVCodec *data_codec; 1820 1821 /** 1822 * Number of bytes to be written as padding in a metadata header. 1823 * Demuxing: Unused. 1824 * Muxing: Set by user via av_format_set_metadata_header_padding. 1825 */ 1826 int metadata_header_padding; 1827 1828 /** 1829 * User data. 1830 * This is a place for some private data of the user. 1831 */ 1832 void *opaque; 1833 1834 /** 1835 * Callback used by devices to communicate with application. 1836 */ 1837 av_format_control_message control_message_cb; 1838 1839 /** 1840 * Output timestamp offset, in microseconds. 1841 * Muxing: set by user 1842 */ 1843 int64_t output_ts_offset; 1844 1845 /** 1846 * dump format separator. 1847 * can be ", " or "\n " or anything else 1848 * - muxing: Set by user. 1849 * - demuxing: Set by user. 1850 */ 1851 uint8_t *dump_separator; 1852 1853 /** 1854 * Forced Data codec_id. 1855 * Demuxing: Set by user. 1856 */ 1857 enum AVCodecID data_codec_id; 1858 1859 #if FF_API_OLD_OPEN_CALLBACKS 1860 /** 1861 * Called to open further IO contexts when needed for demuxing. 1862 * 1863 * This can be set by the user application to perform security checks on 1864 * the URLs before opening them. 1865 * The function should behave like avio_open2(), AVFormatContext is provided 1866 * as contextual information and to reach AVFormatContext.opaque. 1867 * 1868 * If NULL then some simple checks are used together with avio_open2(). 1869 * 1870 * Must not be accessed directly from outside avformat. 1871 * @See av_format_set_open_cb() 1872 * 1873 * Demuxing: Set by user. 1874 * 1875 * @deprecated Use io_open and io_close. 1876 */ 1877 attribute_deprecated 1878 int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options); 1879 #endif 1880 1881 /** 1882 * ',' separated list of allowed protocols. 1883 * - encoding: unused 1884 * - decoding: set by user 1885 */ 1886 char *protocol_whitelist; 1887 1888 /** 1889 * A callback for opening new IO streams. 1890 * 1891 * Whenever a muxer or a demuxer needs to open an IO stream (typically from 1892 * avformat_open_input() for demuxers, but for certain formats can happen at 1893 * other times as well), it will call this callback to obtain an IO context. 1894 * 1895 * @param s the format context 1896 * @param pb on success, the newly opened IO context should be returned here 1897 * @param url the url to open 1898 * @param flags a combination of AVIO_FLAG_* 1899 * @param options a dictionary of additional options, with the same 1900 * semantics as in avio_open2() 1901 * @return 0 on success, a negative AVERROR code on failure 1902 * 1903 * @note Certain muxers and demuxers do nesting, i.e. they open one or more 1904 * additional internal format contexts. Thus the AVFormatContext pointer 1905 * passed to this callback may be different from the one facing the caller. 1906 * It will, however, have the same 'opaque' field. 1907 */ 1908 int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url, 1909 int flags, AVDictionary **options); 1910 1911 /** 1912 * A callback for closing the streams opened with AVFormatContext.io_open(). 1913 */ 1914 void (*io_close)(struct AVFormatContext *s, AVIOContext *pb); 1915 1916 /** 1917 * ',' separated list of disallowed protocols. 1918 * - encoding: unused 1919 * - decoding: set by user 1920 */ 1921 char *protocol_blacklist; 1922 1923 /** 1924 * The maximum number of streams. 1925 * - encoding: unused 1926 * - decoding: set by user 1927 */ 1928 int max_streams; 1929 } AVFormatContext; 1930 1931 #if FF_API_FORMAT_GET_SET 1932 /** 1933 * Accessors for some AVFormatContext fields. These used to be provided for ABI 1934 * compatibility, and do not need to be used anymore. 1935 */ 1936 attribute_deprecated 1937 int av_format_get_probe_score(const AVFormatContext *s); 1938 attribute_deprecated 1939 AVCodec * av_format_get_video_codec(const AVFormatContext *s); 1940 attribute_deprecated 1941 void av_format_set_video_codec(AVFormatContext *s, AVCodec *c); 1942 attribute_deprecated 1943 AVCodec * av_format_get_audio_codec(const AVFormatContext *s); 1944 attribute_deprecated 1945 void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c); 1946 attribute_deprecated 1947 AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s); 1948 attribute_deprecated 1949 void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c); 1950 attribute_deprecated 1951 AVCodec * av_format_get_data_codec(const AVFormatContext *s); 1952 attribute_deprecated 1953 void av_format_set_data_codec(AVFormatContext *s, AVCodec *c); 1954 attribute_deprecated 1955 int av_format_get_metadata_header_padding(const AVFormatContext *s); 1956 attribute_deprecated 1957 void av_format_set_metadata_header_padding(AVFormatContext *s, int c); 1958 attribute_deprecated 1959 void * av_format_get_opaque(const AVFormatContext *s); 1960 attribute_deprecated 1961 void av_format_set_opaque(AVFormatContext *s, void *opaque); 1962 attribute_deprecated 1963 av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s); 1964 attribute_deprecated 1965 void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback); 1966 #if FF_API_OLD_OPEN_CALLBACKS 1967 attribute_deprecated AVOpenCallback av_format_get_open_cb(const AVFormatContext *s); 1968 attribute_deprecated void av_format_set_open_cb(AVFormatContext *s, AVOpenCallback callback); 1969 #endif 1970 #endif 1971 1972 /** 1973 * This function will cause global side data to be injected in the next packet 1974 * of each stream as well as after any subsequent seek. 1975 */ 1976 void av_format_inject_global_side_data(AVFormatContext *s); 1977 1978 /** 1979 * Returns the method used to set ctx->duration. 1980 * 1981 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE. 1982 */ 1983 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx); 1984 1985 typedef struct AVPacketList { 1986 AVPacket pkt; 1987 struct AVPacketList *next; 1988 } AVPacketList; 1989 1990 1991 /** 1992 * @defgroup lavf_core Core functions 1993 * @ingroup libavf 1994 * 1995 * Functions for querying libavformat capabilities, allocating core structures, 1996 * etc. 1997 * @{ 1998 */ 1999 2000 /** 2001 * Return the LIBAVFORMAT_VERSION_INT constant. 2002 */ 2003 unsigned avformat_version(void); 2004 2005 /** 2006 * Return the libavformat build-time configuration. 2007 */ 2008 const char *avformat_configuration(void); 2009 2010 /** 2011 * Return the libavformat license. 2012 */ 2013 const char *avformat_license(void); 2014 2015 #if FF_API_NEXT 2016 /** 2017 * Initialize libavformat and register all the muxers, demuxers and 2018 * protocols. If you do not call this function, then you can select 2019 * exactly which formats you want to support. 2020 * 2021 * @see av_register_input_format() 2022 * @see av_register_output_format() 2023 */ 2024 attribute_deprecated 2025 void av_register_all(void); 2026 2027 attribute_deprecated 2028 void av_register_input_format(AVInputFormat *format); 2029 attribute_deprecated 2030 void av_register_output_format(AVOutputFormat *format); 2031 #endif 2032 2033 /** 2034 * Do global initialization of network libraries. This is optional, 2035 * and not recommended anymore. 2036 * 2037 * This functions only exists to work around thread-safety issues 2038 * with older GnuTLS or OpenSSL libraries. If libavformat is linked 2039 * to newer versions of those libraries, or if you do not use them, 2040 * calling this function is unnecessary. Otherwise, you need to call 2041 * this function before any other threads using them are started. 2042 * 2043 * This function will be deprecated once support for older GnuTLS and 2044 * OpenSSL libraries is removed, and this function has no purpose 2045 * anymore. 2046 */ 2047 int avformat_network_init(void); 2048 2049 /** 2050 * Undo the initialization done by avformat_network_init. Call it only 2051 * once for each time you called avformat_network_init. 2052 */ 2053 int avformat_network_deinit(void); 2054 2055 #if FF_API_NEXT 2056 /** 2057 * If f is NULL, returns the first registered input format, 2058 * if f is non-NULL, returns the next registered input format after f 2059 * or NULL if f is the last one. 2060 */ 2061 attribute_deprecated 2062 AVInputFormat *av_iformat_next(const AVInputFormat *f); 2063 2064 /** 2065 * If f is NULL, returns the first registered output format, 2066 * if f is non-NULL, returns the next registered output format after f 2067 * or NULL if f is the last one. 2068 */ 2069 attribute_deprecated 2070 AVOutputFormat *av_oformat_next(const AVOutputFormat *f); 2071 #endif 2072 2073 /** 2074 * Iterate over all registered muxers. 2075 * 2076 * @param opaque a pointer where libavformat will store the iteration state. Must 2077 * point to NULL to start the iteration. 2078 * 2079 * @return the next registered muxer or NULL when the iteration is 2080 * finished 2081 */ 2082 const AVOutputFormat *av_muxer_iterate(void **opaque); 2083 2084 /** 2085 * Iterate over all registered demuxers. 2086 * 2087 * @param opaque a pointer where libavformat will store the iteration state. Must 2088 * point to NULL to start the iteration. 2089 * 2090 * @return the next registered demuxer or NULL when the iteration is 2091 * finished 2092 */ 2093 const AVInputFormat *av_demuxer_iterate(void **opaque); 2094 2095 /** 2096 * Allocate an AVFormatContext. 2097 * avformat_free_context() can be used to free the context and everything 2098 * allocated by the framework within it. 2099 */ 2100 AVFormatContext *avformat_alloc_context(void); 2101 2102 /** 2103 * Free an AVFormatContext and all its streams. 2104 * @param s context to free 2105 */ 2106 void avformat_free_context(AVFormatContext *s); 2107 2108 /** 2109 * Get the AVClass for AVFormatContext. It can be used in combination with 2110 * AV_OPT_SEARCH_FAKE_OBJ for examining options. 2111 * 2112 * @see av_opt_find(). 2113 */ 2114 const AVClass *avformat_get_class(void); 2115 2116 /** 2117 * Add a new stream to a media file. 2118 * 2119 * When demuxing, it is called by the demuxer in read_header(). If the 2120 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also 2121 * be called in read_packet(). 2122 * 2123 * When muxing, should be called by the user before avformat_write_header(). 2124 * 2125 * User is required to call avcodec_close() and avformat_free_context() to 2126 * clean up the allocation by avformat_new_stream(). 2127 * 2128 * @param s media file handle 2129 * @param c If non-NULL, the AVCodecContext corresponding to the new stream 2130 * will be initialized to use this codec. This is needed for e.g. codec-specific 2131 * defaults to be set, so codec should be provided if it is known. 2132 * 2133 * @return newly created stream or NULL on error. 2134 */ 2135 AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c); 2136 2137 /** 2138 * Wrap an existing array as stream side data. 2139 * 2140 * @param st stream 2141 * @param type side information type 2142 * @param data the side data array. It must be allocated with the av_malloc() 2143 * family of functions. The ownership of the data is transferred to 2144 * st. 2145 * @param size side information size 2146 * @return zero on success, a negative AVERROR code on failure. On failure, 2147 * the stream is unchanged and the data remains owned by the caller. 2148 */ 2149 int av_stream_add_side_data(AVStream *st, enum AVPacketSideDataType type, 2150 uint8_t *data, size_t size); 2151 2152 /** 2153 * Allocate new information from stream. 2154 * 2155 * @param stream stream 2156 * @param type desired side information type 2157 * @param size side information size 2158 * @return pointer to fresh allocated data or NULL otherwise 2159 */ 2160 uint8_t *av_stream_new_side_data(AVStream *stream, 2161 enum AVPacketSideDataType type, int size); 2162 /** 2163 * Get side information from stream. 2164 * 2165 * @param stream stream 2166 * @param type desired side information type 2167 * @param size pointer for side information size to store (optional) 2168 * @return pointer to data if present or NULL otherwise 2169 */ 2170 uint8_t *av_stream_get_side_data(const AVStream *stream, 2171 enum AVPacketSideDataType type, int *size); 2172 2173 AVProgram *av_new_program(AVFormatContext *s, int id); 2174 2175 /** 2176 * @} 2177 */ 2178 2179 2180 /** 2181 * Allocate an AVFormatContext for an output format. 2182 * avformat_free_context() can be used to free the context and 2183 * everything allocated by the framework within it. 2184 * 2185 * @param *ctx is set to the created format context, or to NULL in 2186 * case of failure 2187 * @param oformat format to use for allocating the context, if NULL 2188 * format_name and filename are used instead 2189 * @param format_name the name of output format to use for allocating the 2190 * context, if NULL filename is used instead 2191 * @param filename the name of the filename to use for allocating the 2192 * context, may be NULL 2193 * @return >= 0 in case of success, a negative AVERROR code in case of 2194 * failure 2195 */ 2196 int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat, 2197 const char *format_name, const char *filename); 2198 2199 /** 2200 * @addtogroup lavf_decoding 2201 * @{ 2202 */ 2203 2204 /** 2205 * Find AVInputFormat based on the short name of the input format. 2206 */ 2207 AVInputFormat *av_find_input_format(const char *short_name); 2208 2209 /** 2210 * Guess the file format. 2211 * 2212 * @param pd data to be probed 2213 * @param is_opened Whether the file is already opened; determines whether 2214 * demuxers with or without AVFMT_NOFILE are probed. 2215 */ 2216 AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened); 2217 2218 /** 2219 * Guess the file format. 2220 * 2221 * @param pd data to be probed 2222 * @param is_opened Whether the file is already opened; determines whether 2223 * demuxers with or without AVFMT_NOFILE are probed. 2224 * @param score_max A probe score larger that this is required to accept a 2225 * detection, the variable is set to the actual detection 2226 * score afterwards. 2227 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended 2228 * to retry with a larger probe buffer. 2229 */ 2230 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max); 2231 2232 /** 2233 * Guess the file format. 2234 * 2235 * @param is_opened Whether the file is already opened; determines whether 2236 * demuxers with or without AVFMT_NOFILE are probed. 2237 * @param score_ret The score of the best detection. 2238 */ 2239 AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret); 2240 2241 /** 2242 * Probe a bytestream to determine the input format. Each time a probe returns 2243 * with a score that is too low, the probe buffer size is increased and another 2244 * attempt is made. When the maximum probe size is reached, the input format 2245 * with the highest score is returned. 2246 * 2247 * @param pb the bytestream to probe 2248 * @param fmt the input format is put here 2249 * @param url the url of the stream 2250 * @param logctx the log context 2251 * @param offset the offset within the bytestream to probe from 2252 * @param max_probe_size the maximum probe buffer size (zero for default) 2253 * @return the score in case of success, a negative value corresponding to an 2254 * the maximal score is AVPROBE_SCORE_MAX 2255 * AVERROR code otherwise 2256 */ 2257 int av_probe_input_buffer2(AVIOContext *pb, AVInputFormat **fmt, 2258 const char *url, void *logctx, 2259 unsigned int offset, unsigned int max_probe_size); 2260 2261 /** 2262 * Like av_probe_input_buffer2() but returns 0 on success 2263 */ 2264 int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt, 2265 const char *url, void *logctx, 2266 unsigned int offset, unsigned int max_probe_size); 2267 2268 /** 2269 * Open an input stream and read the header. The codecs are not opened. 2270 * The stream must be closed with avformat_close_input(). 2271 * 2272 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context). 2273 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this 2274 * function and written into ps. 2275 * Note that a user-supplied AVFormatContext will be freed on failure. 2276 * @param url URL of the stream to open. 2277 * @param fmt If non-NULL, this parameter forces a specific input format. 2278 * Otherwise the format is autodetected. 2279 * @param options A dictionary filled with AVFormatContext and demuxer-private options. 2280 * On return this parameter will be destroyed and replaced with a dict containing 2281 * options that were not found. May be NULL. 2282 * 2283 * @return 0 on success, a negative AVERROR on failure. 2284 * 2285 * @note If you want to use custom IO, preallocate the format context and set its pb field. 2286 */ 2287 int avformat_open_input(AVFormatContext **ps, const char *url, AVInputFormat *fmt, AVDictionary **options); 2288 2289 attribute_deprecated 2290 int av_demuxer_open(AVFormatContext *ic); 2291 2292 /** 2293 * Read packets of a media file to get stream information. This 2294 * is useful for file formats with no headers such as MPEG. This 2295 * function also computes the real framerate in case of MPEG-2 repeat 2296 * frame mode. 2297 * The logical file position is not changed by this function; 2298 * examined packets may be buffered for later processing. 2299 * 2300 * @param ic media file handle 2301 * @param options If non-NULL, an ic.nb_streams long array of pointers to 2302 * dictionaries, where i-th member contains options for 2303 * codec corresponding to i-th stream. 2304 * On return each dictionary will be filled with options that were not found. 2305 * @return >=0 if OK, AVERROR_xxx on error 2306 * 2307 * @note this function isn't guaranteed to open all the codecs, so 2308 * options being non-empty at return is a perfectly normal behavior. 2309 * 2310 * @todo Let the user decide somehow what information is needed so that 2311 * we do not waste time getting stuff the user does not need. 2312 */ 2313 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options); 2314 2315 /** 2316 * Find the programs which belong to a given stream. 2317 * 2318 * @param ic media file handle 2319 * @param last the last found program, the search will start after this 2320 * program, or from the beginning if it is NULL 2321 * @param s stream index 2322 * @return the next program which belongs to s, NULL if no program is found or 2323 * the last program is not among the programs of ic. 2324 */ 2325 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s); 2326 2327 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx); 2328 2329 /** 2330 * Find the "best" stream in the file. 2331 * The best stream is determined according to various heuristics as the most 2332 * likely to be what the user expects. 2333 * If the decoder parameter is non-NULL, av_find_best_stream will find the 2334 * default decoder for the stream's codec; streams for which no decoder can 2335 * be found are ignored. 2336 * 2337 * @param ic media file handle 2338 * @param type stream type: video, audio, subtitles, etc. 2339 * @param wanted_stream_nb user-requested stream number, 2340 * or -1 for automatic selection 2341 * @param related_stream try to find a stream related (eg. in the same 2342 * program) to this one, or -1 if none 2343 * @param decoder_ret if non-NULL, returns the decoder for the 2344 * selected stream 2345 * @param flags flags; none are currently defined 2346 * @return the non-negative stream number in case of success, 2347 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type 2348 * could be found, 2349 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder 2350 * @note If av_find_best_stream returns successfully and decoder_ret is not 2351 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec. 2352 */ 2353 int av_find_best_stream(AVFormatContext *ic, 2354 enum AVMediaType type, 2355 int wanted_stream_nb, 2356 int related_stream, 2357 AVCodec **decoder_ret, 2358 int flags); 2359 2360 /** 2361 * Return the next frame of a stream. 2362 * This function returns what is stored in the file, and does not validate 2363 * that what is there are valid frames for the decoder. It will split what is 2364 * stored in the file into frames and return one for each call. It will not 2365 * omit invalid data between valid frames so as to give the decoder the maximum 2366 * information possible for decoding. 2367 * 2368 * If pkt->buf is NULL, then the packet is valid until the next 2369 * av_read_frame() or until avformat_close_input(). Otherwise the packet 2370 * is valid indefinitely. In both cases the packet must be freed with 2371 * av_packet_unref when it is no longer needed. For video, the packet contains 2372 * exactly one frame. For audio, it contains an integer number of frames if each 2373 * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames 2374 * have a variable size (e.g. MPEG audio), then it contains one frame. 2375 * 2376 * pkt->pts, pkt->dts and pkt->duration are always set to correct 2377 * values in AVStream.time_base units (and guessed if the format cannot 2378 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format 2379 * has B-frames, so it is better to rely on pkt->dts if you do not 2380 * decompress the payload. 2381 * 2382 * @return 0 if OK, < 0 on error or end of file 2383 */ 2384 int av_read_frame(AVFormatContext *s, AVPacket *pkt); 2385 2386 /** 2387 * Seek to the keyframe at timestamp. 2388 * 'timestamp' in 'stream_index'. 2389 * 2390 * @param s media file handle 2391 * @param stream_index If stream_index is (-1), a default 2392 * stream is selected, and timestamp is automatically converted 2393 * from AV_TIME_BASE units to the stream specific time_base. 2394 * @param timestamp Timestamp in AVStream.time_base units 2395 * or, if no stream is specified, in AV_TIME_BASE units. 2396 * @param flags flags which select direction and seeking mode 2397 * @return >= 0 on success 2398 */ 2399 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp, 2400 int flags); 2401 2402 /** 2403 * Seek to timestamp ts. 2404 * Seeking will be done so that the point from which all active streams 2405 * can be presented successfully will be closest to ts and within min/max_ts. 2406 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL. 2407 * 2408 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and 2409 * are the file position (this may not be supported by all demuxers). 2410 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames 2411 * in the stream with stream_index (this may not be supported by all demuxers). 2412 * Otherwise all timestamps are in units of the stream selected by stream_index 2413 * or if stream_index is -1, in AV_TIME_BASE units. 2414 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as 2415 * keyframes (this may not be supported by all demuxers). 2416 * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored. 2417 * 2418 * @param s media file handle 2419 * @param stream_index index of the stream which is used as time base reference 2420 * @param min_ts smallest acceptable timestamp 2421 * @param ts target timestamp 2422 * @param max_ts largest acceptable timestamp 2423 * @param flags flags 2424 * @return >=0 on success, error code otherwise 2425 * 2426 * @note This is part of the new seek API which is still under construction. 2427 * Thus do not use this yet. It may change at any time, do not expect 2428 * ABI compatibility yet! 2429 */ 2430 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags); 2431 2432 /** 2433 * Discard all internally buffered data. This can be useful when dealing with 2434 * discontinuities in the byte stream. Generally works only with formats that 2435 * can resync. This includes headerless formats like MPEG-TS/TS but should also 2436 * work with NUT, Ogg and in a limited way AVI for example. 2437 * 2438 * The set of streams, the detected duration, stream parameters and codecs do 2439 * not change when calling this function. If you want a complete reset, it's 2440 * better to open a new AVFormatContext. 2441 * 2442 * This does not flush the AVIOContext (s->pb). If necessary, call 2443 * avio_flush(s->pb) before calling this function. 2444 * 2445 * @param s media file handle 2446 * @return >=0 on success, error code otherwise 2447 */ 2448 int avformat_flush(AVFormatContext *s); 2449 2450 /** 2451 * Start playing a network-based stream (e.g. RTSP stream) at the 2452 * current position. 2453 */ 2454 int av_read_play(AVFormatContext *s); 2455 2456 /** 2457 * Pause a network-based stream (e.g. RTSP stream). 2458 * 2459 * Use av_read_play() to resume it. 2460 */ 2461 int av_read_pause(AVFormatContext *s); 2462 2463 /** 2464 * Close an opened input AVFormatContext. Free it and all its contents 2465 * and set *s to NULL. 2466 */ 2467 void avformat_close_input(AVFormatContext **s); 2468 /** 2469 * @} 2470 */ 2471 2472 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward 2473 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes 2474 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes 2475 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number 2476 2477 /** 2478 * @addtogroup lavf_encoding 2479 * @{ 2480 */ 2481 2482 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header 2483 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output 2484 2485 /** 2486 * Allocate the stream private data and write the stream header to 2487 * an output media file. 2488 * 2489 * @param s Media file handle, must be allocated with avformat_alloc_context(). 2490 * Its oformat field must be set to the desired output format; 2491 * Its pb field must be set to an already opened AVIOContext. 2492 * @param options An AVDictionary filled with AVFormatContext and muxer-private options. 2493 * On return this parameter will be destroyed and replaced with a dict containing 2494 * options that were not found. May be NULL. 2495 * 2496 * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init, 2497 * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init, 2498 * negative AVERROR on failure. 2499 * 2500 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output. 2501 */ 2502 av_warn_unused_result 2503 int avformat_write_header(AVFormatContext *s, AVDictionary **options); 2504 2505 /** 2506 * Allocate the stream private data and initialize the codec, but do not write the header. 2507 * May optionally be used before avformat_write_header to initialize stream parameters 2508 * before actually writing the header. 2509 * If using this function, do not pass the same options to avformat_write_header. 2510 * 2511 * @param s Media file handle, must be allocated with avformat_alloc_context(). 2512 * Its oformat field must be set to the desired output format; 2513 * Its pb field must be set to an already opened AVIOContext. 2514 * @param options An AVDictionary filled with AVFormatContext and muxer-private options. 2515 * On return this parameter will be destroyed and replaced with a dict containing 2516 * options that were not found. May be NULL. 2517 * 2518 * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec requires avformat_write_header to fully initialize, 2519 * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec has been fully initialized, 2520 * negative AVERROR on failure. 2521 * 2522 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header. 2523 */ 2524 av_warn_unused_result 2525 int avformat_init_output(AVFormatContext *s, AVDictionary **options); 2526 2527 /** 2528 * Write a packet to an output media file. 2529 * 2530 * This function passes the packet directly to the muxer, without any buffering 2531 * or reordering. The caller is responsible for correctly interleaving the 2532 * packets if the format requires it. Callers that want libavformat to handle 2533 * the interleaving should call av_interleaved_write_frame() instead of this 2534 * function. 2535 * 2536 * @param s media file handle 2537 * @param pkt The packet containing the data to be written. Note that unlike 2538 * av_interleaved_write_frame(), this function does not take 2539 * ownership of the packet passed to it (though some muxers may make 2540 * an internal reference to the input packet). 2541 * <br> 2542 * This parameter can be NULL (at any time, not just at the end), in 2543 * order to immediately flush data buffered within the muxer, for 2544 * muxers that buffer up data internally before writing it to the 2545 * output. 2546 * <br> 2547 * Packet's @ref AVPacket.stream_index "stream_index" field must be 2548 * set to the index of the corresponding stream in @ref 2549 * AVFormatContext.streams "s->streams". 2550 * <br> 2551 * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts") 2552 * must be set to correct values in the stream's timebase (unless the 2553 * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then 2554 * they can be set to AV_NOPTS_VALUE). 2555 * The dts for subsequent packets passed to this function must be strictly 2556 * increasing when compared in their respective timebases (unless the 2557 * output format is flagged with the AVFMT_TS_NONSTRICT, then they 2558 * merely have to be nondecreasing). @ref AVPacket.duration 2559 * "duration") should also be set if known. 2560 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush 2561 * 2562 * @see av_interleaved_write_frame() 2563 */ 2564 int av_write_frame(AVFormatContext *s, AVPacket *pkt); 2565 2566 /** 2567 * Write a packet to an output media file ensuring correct interleaving. 2568 * 2569 * This function will buffer the packets internally as needed to make sure the 2570 * packets in the output file are properly interleaved in the order of 2571 * increasing dts. Callers doing their own interleaving should call 2572 * av_write_frame() instead of this function. 2573 * 2574 * Using this function instead of av_write_frame() can give muxers advance 2575 * knowledge of future packets, improving e.g. the behaviour of the mp4 2576 * muxer for VFR content in fragmenting mode. 2577 * 2578 * @param s media file handle 2579 * @param pkt The packet containing the data to be written. 2580 * <br> 2581 * If the packet is reference-counted, this function will take 2582 * ownership of this reference and unreference it later when it sees 2583 * fit. 2584 * The caller must not access the data through this reference after 2585 * this function returns. If the packet is not reference-counted, 2586 * libavformat will make a copy. 2587 * <br> 2588 * This parameter can be NULL (at any time, not just at the end), to 2589 * flush the interleaving queues. 2590 * <br> 2591 * Packet's @ref AVPacket.stream_index "stream_index" field must be 2592 * set to the index of the corresponding stream in @ref 2593 * AVFormatContext.streams "s->streams". 2594 * <br> 2595 * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts") 2596 * must be set to correct values in the stream's timebase (unless the 2597 * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then 2598 * they can be set to AV_NOPTS_VALUE). 2599 * The dts for subsequent packets in one stream must be strictly 2600 * increasing (unless the output format is flagged with the 2601 * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing). 2602 * @ref AVPacket.duration "duration") should also be set if known. 2603 * 2604 * @return 0 on success, a negative AVERROR on error. Libavformat will always 2605 * take care of freeing the packet, even if this function fails. 2606 * 2607 * @see av_write_frame(), AVFormatContext.max_interleave_delta 2608 */ 2609 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt); 2610 2611 /** 2612 * Write an uncoded frame to an output media file. 2613 * 2614 * The frame must be correctly interleaved according to the container 2615 * specification; if not, then av_interleaved_write_frame() must be used. 2616 * 2617 * See av_interleaved_write_frame() for details. 2618 */ 2619 int av_write_uncoded_frame(AVFormatContext *s, int stream_index, 2620 AVFrame *frame); 2621 2622 /** 2623 * Write an uncoded frame to an output media file. 2624 * 2625 * If the muxer supports it, this function makes it possible to write an AVFrame 2626 * structure directly, without encoding it into a packet. 2627 * It is mostly useful for devices and similar special muxers that use raw 2628 * video or PCM data and will not serialize it into a byte stream. 2629 * 2630 * To test whether it is possible to use it with a given muxer and stream, 2631 * use av_write_uncoded_frame_query(). 2632 * 2633 * The caller gives up ownership of the frame and must not access it 2634 * afterwards. 2635 * 2636 * @return >=0 for success, a negative code on error 2637 */ 2638 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index, 2639 AVFrame *frame); 2640 2641 /** 2642 * Test whether a muxer supports uncoded frame. 2643 * 2644 * @return >=0 if an uncoded frame can be written to that muxer and stream, 2645 * <0 if not 2646 */ 2647 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index); 2648 2649 /** 2650 * Write the stream trailer to an output media file and free the 2651 * file private data. 2652 * 2653 * May only be called after a successful call to avformat_write_header. 2654 * 2655 * @param s media file handle 2656 * @return 0 if OK, AVERROR_xxx on error 2657 */ 2658 int av_write_trailer(AVFormatContext *s); 2659 2660 /** 2661 * Return the output format in the list of registered output formats 2662 * which best matches the provided parameters, or return NULL if 2663 * there is no match. 2664 * 2665 * @param short_name if non-NULL checks if short_name matches with the 2666 * names of the registered formats 2667 * @param filename if non-NULL checks if filename terminates with the 2668 * extensions of the registered formats 2669 * @param mime_type if non-NULL checks if mime_type matches with the 2670 * MIME type of the registered formats 2671 */ 2672 AVOutputFormat *av_guess_format(const char *short_name, 2673 const char *filename, 2674 const char *mime_type); 2675 2676 /** 2677 * Guess the codec ID based upon muxer and filename. 2678 */ 2679 enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name, 2680 const char *filename, const char *mime_type, 2681 enum AVMediaType type); 2682 2683 /** 2684 * Get timing information for the data currently output. 2685 * The exact meaning of "currently output" depends on the format. 2686 * It is mostly relevant for devices that have an internal buffer and/or 2687 * work in real time. 2688 * @param s media file handle 2689 * @param stream stream in the media file 2690 * @param[out] dts DTS of the last packet output for the stream, in stream 2691 * time_base units 2692 * @param[out] wall absolute time when that packet whas output, 2693 * in microsecond 2694 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it 2695 * Note: some formats or devices may not allow to measure dts and wall 2696 * atomically. 2697 */ 2698 int av_get_output_timestamp(struct AVFormatContext *s, int stream, 2699 int64_t *dts, int64_t *wall); 2700 2701 2702 /** 2703 * @} 2704 */ 2705 2706 2707 /** 2708 * @defgroup lavf_misc Utility functions 2709 * @ingroup libavf 2710 * @{ 2711 * 2712 * Miscellaneous utility functions related to both muxing and demuxing 2713 * (or neither). 2714 */ 2715 2716 /** 2717 * Send a nice hexadecimal dump of a buffer to the specified file stream. 2718 * 2719 * @param f The file stream pointer where the dump should be sent to. 2720 * @param buf buffer 2721 * @param size buffer size 2722 * 2723 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2 2724 */ 2725 void av_hex_dump(FILE *f, const uint8_t *buf, int size); 2726 2727 /** 2728 * Send a nice hexadecimal dump of a buffer to the log. 2729 * 2730 * @param avcl A pointer to an arbitrary struct of which the first field is a 2731 * pointer to an AVClass struct. 2732 * @param level The importance level of the message, lower values signifying 2733 * higher importance. 2734 * @param buf buffer 2735 * @param size buffer size 2736 * 2737 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2 2738 */ 2739 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size); 2740 2741 /** 2742 * Send a nice dump of a packet to the specified file stream. 2743 * 2744 * @param f The file stream pointer where the dump should be sent to. 2745 * @param pkt packet to dump 2746 * @param dump_payload True if the payload must be displayed, too. 2747 * @param st AVStream that the packet belongs to 2748 */ 2749 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st); 2750 2751 2752 /** 2753 * Send a nice dump of a packet to the log. 2754 * 2755 * @param avcl A pointer to an arbitrary struct of which the first field is a 2756 * pointer to an AVClass struct. 2757 * @param level The importance level of the message, lower values signifying 2758 * higher importance. 2759 * @param pkt packet to dump 2760 * @param dump_payload True if the payload must be displayed, too. 2761 * @param st AVStream that the packet belongs to 2762 */ 2763 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload, 2764 const AVStream *st); 2765 2766 /** 2767 * Get the AVCodecID for the given codec tag tag. 2768 * If no codec id is found returns AV_CODEC_ID_NONE. 2769 * 2770 * @param tags list of supported codec_id-codec_tag pairs, as stored 2771 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag 2772 * @param tag codec tag to match to a codec ID 2773 */ 2774 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag); 2775 2776 /** 2777 * Get the codec tag for the given codec id id. 2778 * If no codec tag is found returns 0. 2779 * 2780 * @param tags list of supported codec_id-codec_tag pairs, as stored 2781 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag 2782 * @param id codec ID to match to a codec tag 2783 */ 2784 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id); 2785 2786 /** 2787 * Get the codec tag for the given codec id. 2788 * 2789 * @param tags list of supported codec_id - codec_tag pairs, as stored 2790 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag 2791 * @param id codec id that should be searched for in the list 2792 * @param tag A pointer to the found tag 2793 * @return 0 if id was not found in tags, > 0 if it was found 2794 */ 2795 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id, 2796 unsigned int *tag); 2797 2798 int av_find_default_stream_index(AVFormatContext *s); 2799 2800 /** 2801 * Get the index for a specific timestamp. 2802 * 2803 * @param st stream that the timestamp belongs to 2804 * @param timestamp timestamp to retrieve the index for 2805 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond 2806 * to the timestamp which is <= the requested one, if backward 2807 * is 0, then it will be >= 2808 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise 2809 * @return < 0 if no such timestamp could be found 2810 */ 2811 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags); 2812 2813 /** 2814 * Add an index entry into a sorted list. Update the entry if the list 2815 * already contains it. 2816 * 2817 * @param timestamp timestamp in the time base of the given stream 2818 */ 2819 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, 2820 int size, int distance, int flags); 2821 2822 2823 /** 2824 * Split a URL string into components. 2825 * 2826 * The pointers to buffers for storing individual components may be null, 2827 * in order to ignore that component. Buffers for components not found are 2828 * set to empty strings. If the port is not found, it is set to a negative 2829 * value. 2830 * 2831 * @param proto the buffer for the protocol 2832 * @param proto_size the size of the proto buffer 2833 * @param authorization the buffer for the authorization 2834 * @param authorization_size the size of the authorization buffer 2835 * @param hostname the buffer for the host name 2836 * @param hostname_size the size of the hostname buffer 2837 * @param port_ptr a pointer to store the port number in 2838 * @param path the buffer for the path 2839 * @param path_size the size of the path buffer 2840 * @param url the URL to split 2841 */ 2842 void av_url_split(char *proto, int proto_size, 2843 char *authorization, int authorization_size, 2844 char *hostname, int hostname_size, 2845 int *port_ptr, 2846 char *path, int path_size, 2847 const char *url); 2848 2849 2850 /** 2851 * Print detailed information about the input or output format, such as 2852 * duration, bitrate, streams, container, programs, metadata, side data, 2853 * codec and time base. 2854 * 2855 * @param ic the context to analyze 2856 * @param index index of the stream to dump information about 2857 * @param url the URL to print, such as source or destination file 2858 * @param is_output Select whether the specified context is an input(0) or output(1) 2859 */ 2860 void av_dump_format(AVFormatContext *ic, 2861 int index, 2862 const char *url, 2863 int is_output); 2864 2865 2866 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d 2867 2868 /** 2869 * Return in 'buf' the path with '%d' replaced by a number. 2870 * 2871 * Also handles the '%0nd' format where 'n' is the total number 2872 * of digits and '%%'. 2873 * 2874 * @param buf destination buffer 2875 * @param buf_size destination buffer size 2876 * @param path numbered sequence string 2877 * @param number frame number 2878 * @param flags AV_FRAME_FILENAME_FLAGS_* 2879 * @return 0 if OK, -1 on format error 2880 */ 2881 int av_get_frame_filename2(char *buf, int buf_size, 2882 const char *path, int number, int flags); 2883 2884 int av_get_frame_filename(char *buf, int buf_size, 2885 const char *path, int number); 2886 2887 /** 2888 * Check whether filename actually is a numbered sequence generator. 2889 * 2890 * @param filename possible numbered sequence string 2891 * @return 1 if a valid numbered sequence string, 0 otherwise 2892 */ 2893 int av_filename_number_test(const char *filename); 2894 2895 /** 2896 * Generate an SDP for an RTP session. 2897 * 2898 * Note, this overwrites the id values of AVStreams in the muxer contexts 2899 * for getting unique dynamic payload types. 2900 * 2901 * @param ac array of AVFormatContexts describing the RTP streams. If the 2902 * array is composed by only one context, such context can contain 2903 * multiple AVStreams (one AVStream per RTP stream). Otherwise, 2904 * all the contexts in the array (an AVCodecContext per RTP stream) 2905 * must contain only one AVStream. 2906 * @param n_files number of AVCodecContexts contained in ac 2907 * @param buf buffer where the SDP will be stored (must be allocated by 2908 * the caller) 2909 * @param size the size of the buffer 2910 * @return 0 if OK, AVERROR_xxx on error 2911 */ 2912 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size); 2913 2914 /** 2915 * Return a positive value if the given filename has one of the given 2916 * extensions, 0 otherwise. 2917 * 2918 * @param filename file name to check against the given extensions 2919 * @param extensions a comma-separated list of filename extensions 2920 */ 2921 int av_match_ext(const char *filename, const char *extensions); 2922 2923 /** 2924 * Test if the given container can store a codec. 2925 * 2926 * @param ofmt container to check for compatibility 2927 * @param codec_id codec to potentially store in container 2928 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_* 2929 * 2930 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot. 2931 * A negative number if this information is not available. 2932 */ 2933 int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id, 2934 int std_compliance); 2935 2936 /** 2937 * @defgroup riff_fourcc RIFF FourCCs 2938 * @{ 2939 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are 2940 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the 2941 * following code: 2942 * @code 2943 * uint32_t tag = MKTAG('H', '2', '6', '4'); 2944 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 }; 2945 * enum AVCodecID id = av_codec_get_id(table, tag); 2946 * @endcode 2947 */ 2948 /** 2949 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID. 2950 */ 2951 const struct AVCodecTag *avformat_get_riff_video_tags(void); 2952 /** 2953 * @return the table mapping RIFF FourCCs for audio to AVCodecID. 2954 */ 2955 const struct AVCodecTag *avformat_get_riff_audio_tags(void); 2956 /** 2957 * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID. 2958 */ 2959 const struct AVCodecTag *avformat_get_mov_video_tags(void); 2960 /** 2961 * @return the table mapping MOV FourCCs for audio to AVCodecID. 2962 */ 2963 const struct AVCodecTag *avformat_get_mov_audio_tags(void); 2964 2965 /** 2966 * @} 2967 */ 2968 2969 /** 2970 * Guess the sample aspect ratio of a frame, based on both the stream and the 2971 * frame aspect ratio. 2972 * 2973 * Since the frame aspect ratio is set by the codec but the stream aspect ratio 2974 * is set by the demuxer, these two may not be equal. This function tries to 2975 * return the value that you should use if you would like to display the frame. 2976 * 2977 * Basic logic is to use the stream aspect ratio if it is set to something sane 2978 * otherwise use the frame aspect ratio. This way a container setting, which is 2979 * usually easy to modify can override the coded value in the frames. 2980 * 2981 * @param format the format context which the stream is part of 2982 * @param stream the stream which the frame is part of 2983 * @param frame the frame with the aspect ratio to be determined 2984 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea 2985 */ 2986 AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame); 2987 2988 /** 2989 * Guess the frame rate, based on both the container and codec information. 2990 * 2991 * @param ctx the format context which the stream is part of 2992 * @param stream the stream which the frame is part of 2993 * @param frame the frame for which the frame rate should be determined, may be NULL 2994 * @return the guessed (valid) frame rate, 0/1 if no idea 2995 */ 2996 AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame); 2997 2998 /** 2999 * Check if the stream st contained in s is matched by the stream specifier 3000 * spec. 3001 * 3002 * See the "stream specifiers" chapter in the documentation for the syntax 3003 * of spec. 3004 * 3005 * @return >0 if st is matched by spec; 3006 * 0 if st is not matched by spec; 3007 * AVERROR code if spec is invalid 3008 * 3009 * @note A stream specifier can match several streams in the format. 3010 */ 3011 int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st, 3012 const char *spec); 3013 3014 int avformat_queue_attached_pictures(AVFormatContext *s); 3015 3016 #if FF_API_OLD_BSF 3017 /** 3018 * Apply a list of bitstream filters to a packet. 3019 * 3020 * @param codec AVCodecContext, usually from an AVStream 3021 * @param pkt the packet to apply filters to. If, on success, the returned 3022 * packet has size == 0 and side_data_elems == 0, it indicates that 3023 * the packet should be dropped 3024 * @param bsfc a NULL-terminated list of filters to apply 3025 * @return >=0 on success; 3026 * AVERROR code on failure 3027 */ 3028 attribute_deprecated 3029 int av_apply_bitstream_filters(AVCodecContext *codec, AVPacket *pkt, 3030 AVBitStreamFilterContext *bsfc); 3031 #endif 3032 3033 enum AVTimebaseSource { 3034 AVFMT_TBCF_AUTO = -1, 3035 AVFMT_TBCF_DECODER, 3036 AVFMT_TBCF_DEMUXER, 3037 #if FF_API_R_FRAME_RATE 3038 AVFMT_TBCF_R_FRAMERATE, 3039 #endif 3040 }; 3041 3042 /** 3043 * Transfer internal timing information from one stream to another. 3044 * 3045 * This function is useful when doing stream copy. 3046 * 3047 * @param ofmt target output format for ost 3048 * @param ost output stream which needs timings copy and adjustments 3049 * @param ist reference input stream to copy timings from 3050 * @param copy_tb define from where the stream codec timebase needs to be imported 3051 */ 3052 int avformat_transfer_internal_stream_timing_info(const AVOutputFormat *ofmt, 3053 AVStream *ost, const AVStream *ist, 3054 enum AVTimebaseSource copy_tb); 3055 3056 /** 3057 * Get the internal codec timebase from a stream. 3058 * 3059 * @param st input stream to extract the timebase from 3060 */ 3061 AVRational av_stream_get_codec_timebase(const AVStream *st); 3062 3063 /** 3064 * @} 3065 */ 3066 3067 #endif /* AVFORMAT_AVFORMAT_H */ 3068