1 /* 2 * copyright (c) 2001 Fabrice Bellard 3 * 4 * This file is part of FFmpeg. 5 * 6 * FFmpeg is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * FFmpeg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with FFmpeg; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21 #ifndef AVFORMAT_AVFORMAT_H 22 #define AVFORMAT_AVFORMAT_H 23 24 /** 25 * @file 26 * @ingroup libavf 27 * Main libavformat public API header 28 */ 29 30 /** 31 * @defgroup libavf libavformat 32 * I/O and Muxing/Demuxing Library 33 * 34 * Libavformat (lavf) is a library for dealing with various media container 35 * formats. Its main two purposes are demuxing - i.e. splitting a media file 36 * into component streams, and the reverse process of muxing - writing supplied 37 * data in a specified container format. It also has an @ref lavf_io 38 * "I/O module" which supports a number of protocols for accessing the data (e.g. 39 * file, tcp, http and others). 40 * Unless you are absolutely sure you won't use libavformat's network 41 * capabilities, you should also call avformat_network_init(). 42 * 43 * A supported input format is described by an AVInputFormat struct, conversely 44 * an output format is described by AVOutputFormat. You can iterate over all 45 * input/output formats using the av_demuxer_iterate / av_muxer_iterate() functions. 46 * The protocols layer is not part of the public API, so you can only get the names 47 * of supported protocols with the avio_enum_protocols() function. 48 * 49 * Main lavf structure used for both muxing and demuxing is AVFormatContext, 50 * which exports all information about the file being read or written. As with 51 * most Libavformat structures, its size is not part of public ABI, so it cannot be 52 * allocated on stack or directly with av_malloc(). To create an 53 * AVFormatContext, use avformat_alloc_context() (some functions, like 54 * avformat_open_input() might do that for you). 55 * 56 * Most importantly an AVFormatContext contains: 57 * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat 58 * "output" format. It is either autodetected or set by user for input; 59 * always set by user for output. 60 * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all 61 * elementary streams stored in the file. AVStreams are typically referred to 62 * using their index in this array. 63 * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or 64 * set by user for input, always set by user for output (unless you are dealing 65 * with an AVFMT_NOFILE format). 66 * 67 * @section lavf_options Passing options to (de)muxers 68 * It is possible to configure lavf muxers and demuxers using the @ref avoptions 69 * mechanism. Generic (format-independent) libavformat options are provided by 70 * AVFormatContext, they can be examined from a user program by calling 71 * av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass 72 * from avformat_get_class()). Private (format-specific) options are provided by 73 * AVFormatContext.priv_data if and only if AVInputFormat.priv_class / 74 * AVOutputFormat.priv_class of the corresponding format struct is non-NULL. 75 * Further options may be provided by the @ref AVFormatContext.pb "I/O context", 76 * if its AVClass is non-NULL, and the protocols layer. See the discussion on 77 * nesting in @ref avoptions documentation to learn how to access those. 78 * 79 * @section urls 80 * URL strings in libavformat are made of a scheme/protocol, a ':', and a 81 * scheme specific string. URLs without a scheme and ':' used for local files 82 * are supported but deprecated. "file:" should be used for local files. 83 * 84 * It is important that the scheme string is not taken from untrusted 85 * sources without checks. 86 * 87 * Note that some schemes/protocols are quite powerful, allowing access to 88 * both local and remote files, parts of them, concatenations of them, local 89 * audio and video devices and so on. 90 * 91 * @{ 92 * 93 * @defgroup lavf_decoding Demuxing 94 * @{ 95 * Demuxers read a media file and split it into chunks of data (@em packets). A 96 * @ref AVPacket "packet" contains one or more encoded frames which belongs to a 97 * single elementary stream. In the lavf API this process is represented by the 98 * avformat_open_input() function for opening a file, av_read_frame() for 99 * reading a single packet and finally avformat_close_input(), which does the 100 * cleanup. 101 * 102 * @section lavf_decoding_open Opening a media file 103 * The minimum information required to open a file is its URL, which 104 * is passed to avformat_open_input(), as in the following code: 105 * @code 106 * const char *url = "file:in.mp3"; 107 * AVFormatContext *s = NULL; 108 * int ret = avformat_open_input(&s, url, NULL, NULL); 109 * if (ret < 0) 110 * abort(); 111 * @endcode 112 * The above code attempts to allocate an AVFormatContext, open the 113 * specified file (autodetecting the format) and read the header, exporting the 114 * information stored there into s. Some formats do not have a header or do not 115 * store enough information there, so it is recommended that you call the 116 * avformat_find_stream_info() function which tries to read and decode a few 117 * frames to find missing information. 118 * 119 * In some cases you might want to preallocate an AVFormatContext yourself with 120 * avformat_alloc_context() and do some tweaking on it before passing it to 121 * avformat_open_input(). One such case is when you want to use custom functions 122 * for reading input data instead of lavf internal I/O layer. 123 * To do that, create your own AVIOContext with avio_alloc_context(), passing 124 * your reading callbacks to it. Then set the @em pb field of your 125 * AVFormatContext to newly created AVIOContext. 126 * 127 * Since the format of the opened file is in general not known until after 128 * avformat_open_input() has returned, it is not possible to set demuxer private 129 * options on a preallocated context. Instead, the options should be passed to 130 * avformat_open_input() wrapped in an AVDictionary: 131 * @code 132 * AVDictionary *options = NULL; 133 * av_dict_set(&options, "video_size", "640x480", 0); 134 * av_dict_set(&options, "pixel_format", "rgb24", 0); 135 * 136 * if (avformat_open_input(&s, url, NULL, &options) < 0) 137 * abort(); 138 * av_dict_free(&options); 139 * @endcode 140 * This code passes the private options 'video_size' and 'pixel_format' to the 141 * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it 142 * cannot know how to interpret raw video data otherwise. If the format turns 143 * out to be something different than raw video, those options will not be 144 * recognized by the demuxer and therefore will not be applied. Such unrecognized 145 * options are then returned in the options dictionary (recognized options are 146 * consumed). The calling program can handle such unrecognized options as it 147 * wishes, e.g. 148 * @code 149 * AVDictionaryEntry *e; 150 * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) { 151 * fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key); 152 * abort(); 153 * } 154 * @endcode 155 * 156 * After you have finished reading the file, you must close it with 157 * avformat_close_input(). It will free everything associated with the file. 158 * 159 * @section lavf_decoding_read Reading from an opened file 160 * Reading data from an opened AVFormatContext is done by repeatedly calling 161 * av_read_frame() on it. Each call, if successful, will return an AVPacket 162 * containing encoded data for one AVStream, identified by 163 * AVPacket.stream_index. This packet may be passed straight into the libavcodec 164 * decoding functions avcodec_send_packet() or avcodec_decode_subtitle2() if the 165 * caller wishes to decode the data. 166 * 167 * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be 168 * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for 169 * pts/dts, 0 for duration) if the stream does not provide them. The timing 170 * information will be in AVStream.time_base units, i.e. it has to be 171 * multiplied by the timebase to convert them to seconds. 172 * 173 * A packet returned by av_read_frame() is always reference-counted, 174 * i.e. AVPacket.buf is set and the user may keep it indefinitely. 175 * The packet must be freed with av_packet_unref() when it is no 176 * longer needed. 177 * 178 * @section lavf_decoding_seek Seeking 179 * @} 180 * 181 * @defgroup lavf_encoding Muxing 182 * @{ 183 * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write 184 * it into files or other output bytestreams in the specified container format. 185 * 186 * The main API functions for muxing are avformat_write_header() for writing the 187 * file header, av_write_frame() / av_interleaved_write_frame() for writing the 188 * packets and av_write_trailer() for finalizing the file. 189 * 190 * At the beginning of the muxing process, the caller must first call 191 * avformat_alloc_context() to create a muxing context. The caller then sets up 192 * the muxer by filling the various fields in this context: 193 * 194 * - The @ref AVFormatContext.oformat "oformat" field must be set to select the 195 * muxer that will be used. 196 * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb 197 * "pb" field must be set to an opened IO context, either returned from 198 * avio_open2() or a custom one. 199 * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must 200 * be created with the avformat_new_stream() function. The caller should fill 201 * the @ref AVStream.codecpar "stream codec parameters" information, such as the 202 * codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id 203 * "id" and other parameters (e.g. width / height, the pixel or sample format, 204 * etc.) as known. The @ref AVStream.time_base "stream timebase" should 205 * be set to the timebase that the caller desires to use for this stream (note 206 * that the timebase actually used by the muxer can be different, as will be 207 * described later). 208 * - It is advised to manually initialize only the relevant fields in 209 * AVCodecParameters, rather than using @ref avcodec_parameters_copy() during 210 * remuxing: there is no guarantee that the codec context values remain valid 211 * for both input and output format contexts. 212 * - The caller may fill in additional information, such as @ref 213 * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream" 214 * metadata, @ref AVFormatContext.chapters "chapters", @ref 215 * AVFormatContext.programs "programs", etc. as described in the 216 * AVFormatContext documentation. Whether such information will actually be 217 * stored in the output depends on what the container format and the muxer 218 * support. 219 * 220 * When the muxing context is fully set up, the caller must call 221 * avformat_write_header() to initialize the muxer internals and write the file 222 * header. Whether anything actually is written to the IO context at this step 223 * depends on the muxer, but this function must always be called. Any muxer 224 * private options must be passed in the options parameter to this function. 225 * 226 * The data is then sent to the muxer by repeatedly calling av_write_frame() or 227 * av_interleaved_write_frame() (consult those functions' documentation for 228 * discussion on the difference between them; only one of them may be used with 229 * a single muxing context, they should not be mixed). Do note that the timing 230 * information on the packets sent to the muxer must be in the corresponding 231 * AVStream's timebase. That timebase is set by the muxer (in the 232 * avformat_write_header() step) and may be different from the timebase 233 * requested by the caller. 234 * 235 * Once all the data has been written, the caller must call av_write_trailer() 236 * to flush any buffered packets and finalize the output file, then close the IO 237 * context (if any) and finally free the muxing context with 238 * avformat_free_context(). 239 * @} 240 * 241 * @defgroup lavf_io I/O Read/Write 242 * @{ 243 * @section lavf_io_dirlist Directory listing 244 * The directory listing API makes it possible to list files on remote servers. 245 * 246 * Some of possible use cases: 247 * - an "open file" dialog to choose files from a remote location, 248 * - a recursive media finder providing a player with an ability to play all 249 * files from a given directory. 250 * 251 * @subsection lavf_io_dirlist_open Opening a directory 252 * At first, a directory needs to be opened by calling avio_open_dir() 253 * supplied with a URL and, optionally, ::AVDictionary containing 254 * protocol-specific parameters. The function returns zero or positive 255 * integer and allocates AVIODirContext on success. 256 * 257 * @code 258 * AVIODirContext *ctx = NULL; 259 * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) { 260 * fprintf(stderr, "Cannot open directory.\n"); 261 * abort(); 262 * } 263 * @endcode 264 * 265 * This code tries to open a sample directory using smb protocol without 266 * any additional parameters. 267 * 268 * @subsection lavf_io_dirlist_read Reading entries 269 * Each directory's entry (i.e. file, another directory, anything else 270 * within ::AVIODirEntryType) is represented by AVIODirEntry. 271 * Reading consecutive entries from an opened AVIODirContext is done by 272 * repeatedly calling avio_read_dir() on it. Each call returns zero or 273 * positive integer if successful. Reading can be stopped right after the 274 * NULL entry has been read -- it means there are no entries left to be 275 * read. The following code reads all entries from a directory associated 276 * with ctx and prints their names to standard output. 277 * @code 278 * AVIODirEntry *entry = NULL; 279 * for (;;) { 280 * if (avio_read_dir(ctx, &entry) < 0) { 281 * fprintf(stderr, "Cannot list directory.\n"); 282 * abort(); 283 * } 284 * if (!entry) 285 * break; 286 * printf("%s\n", entry->name); 287 * avio_free_directory_entry(&entry); 288 * } 289 * @endcode 290 * @} 291 * 292 * @defgroup lavf_codec Demuxers 293 * @{ 294 * @defgroup lavf_codec_native Native Demuxers 295 * @{ 296 * @} 297 * @defgroup lavf_codec_wrappers External library wrappers 298 * @{ 299 * @} 300 * @} 301 * @defgroup lavf_protos I/O Protocols 302 * @{ 303 * @} 304 * @defgroup lavf_internal Internal 305 * @{ 306 * @} 307 * @} 308 */ 309 310 #include <time.h> 311 #include <stdio.h> /* FILE */ 312 #include "libavcodec/avcodec.h" 313 #include "libavutil/dict.h" 314 #include "libavutil/log.h" 315 316 #include "avio.h" 317 #include "libavformat/version.h" 318 319 struct AVFormatContext; 320 321 struct AVDeviceInfoList; 322 struct AVDeviceCapabilitiesQuery; 323 324 /** 325 * @defgroup metadata_api Public Metadata API 326 * @{ 327 * @ingroup libavf 328 * The metadata API allows libavformat to export metadata tags to a client 329 * application when demuxing. Conversely it allows a client application to 330 * set metadata when muxing. 331 * 332 * Metadata is exported or set as pairs of key/value strings in the 'metadata' 333 * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs 334 * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg, 335 * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata 336 * exported by demuxers isn't checked to be valid UTF-8 in most cases. 337 * 338 * Important concepts to keep in mind: 339 * - Keys are unique; there can never be 2 tags with the same key. This is 340 * also meant semantically, i.e., a demuxer should not knowingly produce 341 * several keys that are literally different but semantically identical. 342 * E.g., key=Author5, key=Author6. In this example, all authors must be 343 * placed in the same tag. 344 * - Metadata is flat, not hierarchical; there are no subtags. If you 345 * want to store, e.g., the email address of the child of producer Alice 346 * and actor Bob, that could have key=alice_and_bobs_childs_email_address. 347 * - Several modifiers can be applied to the tag name. This is done by 348 * appending a dash character ('-') and the modifier name in the order 349 * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng. 350 * - language -- a tag whose value is localized for a particular language 351 * is appended with the ISO 639-2/B 3-letter language code. 352 * For example: Author-ger=Michael, Author-eng=Mike 353 * The original/default language is in the unqualified "Author" tag. 354 * A demuxer should set a default if it sets any translated tag. 355 * - sorting -- a modified version of a tag that should be used for 356 * sorting will have '-sort' appended. E.g. artist="The Beatles", 357 * artist-sort="Beatles, The". 358 * - Some protocols and demuxers support metadata updates. After a successful 359 * call to av_read_packet(), AVFormatContext.event_flags or AVStream.event_flags 360 * will be updated to indicate if metadata changed. In order to detect metadata 361 * changes on a stream, you need to loop through all streams in the AVFormatContext 362 * and check their individual event_flags. 363 * 364 * - Demuxers attempt to export metadata in a generic format, however tags 365 * with no generic equivalents are left as they are stored in the container. 366 * Follows a list of generic tag names: 367 * 368 @verbatim 369 album -- name of the set this work belongs to 370 album_artist -- main creator of the set/album, if different from artist. 371 e.g. "Various Artists" for compilation albums. 372 artist -- main creator of the work 373 comment -- any additional description of the file. 374 composer -- who composed the work, if different from artist. 375 copyright -- name of copyright holder. 376 creation_time-- date when the file was created, preferably in ISO 8601. 377 date -- date when the work was created, preferably in ISO 8601. 378 disc -- number of a subset, e.g. disc in a multi-disc collection. 379 encoder -- name/settings of the software/hardware that produced the file. 380 encoded_by -- person/group who created the file. 381 filename -- original name of the file. 382 genre -- <self-evident>. 383 language -- main language in which the work is performed, preferably 384 in ISO 639-2 format. Multiple languages can be specified by 385 separating them with commas. 386 performer -- artist who performed the work, if different from artist. 387 E.g for "Also sprach Zarathustra", artist would be "Richard 388 Strauss" and performer "London Philharmonic Orchestra". 389 publisher -- name of the label/publisher. 390 service_name -- name of the service in broadcasting (channel name). 391 service_provider -- name of the service provider in broadcasting. 392 title -- name of the work. 393 track -- number of this work in the set, can be in form current/total. 394 variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of 395 @endverbatim 396 * 397 * Look in the examples section for an application example how to use the Metadata API. 398 * 399 * @} 400 */ 401 402 /* packet functions */ 403 404 405 /** 406 * Allocate and read the payload of a packet and initialize its 407 * fields with default values. 408 * 409 * @param s associated IO context 410 * @param pkt packet 411 * @param size desired payload size 412 * @return >0 (read size) if OK, AVERROR_xxx otherwise 413 */ 414 int av_get_packet(AVIOContext *s, AVPacket *pkt, int size); 415 416 417 /** 418 * Read data and append it to the current content of the AVPacket. 419 * If pkt->size is 0 this is identical to av_get_packet. 420 * Note that this uses av_grow_packet and thus involves a realloc 421 * which is inefficient. Thus this function should only be used 422 * when there is no reasonable way to know (an upper bound of) 423 * the final size. 424 * 425 * @param s associated IO context 426 * @param pkt packet 427 * @param size amount of data to read 428 * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data 429 * will not be lost even if an error occurs. 430 */ 431 int av_append_packet(AVIOContext *s, AVPacket *pkt, int size); 432 433 /*************************************************/ 434 /* input/output formats */ 435 436 struct AVCodecTag; 437 438 /** 439 * This structure contains the data a format has to probe a file. 440 */ 441 typedef struct AVProbeData { 442 const char *filename; 443 unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */ 444 int buf_size; /**< Size of buf except extra allocated bytes */ 445 const char *mime_type; /**< mime_type, when known. */ 446 } AVProbeData; 447 448 #define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4) 449 #define AVPROBE_SCORE_STREAM_RETRY (AVPROBE_SCORE_MAX/4-1) 450 451 #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension 452 #define AVPROBE_SCORE_MIME 75 ///< score for file mime type 453 #define AVPROBE_SCORE_MAX 100 ///< maximum score 454 455 #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer 456 457 /// Demuxer will use avio_open, no opened file should be provided by the caller. 458 #define AVFMT_NOFILE 0x0001 459 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */ 460 #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */ 461 #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */ 462 #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */ 463 #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */ 464 #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */ 465 #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */ 466 #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */ 467 #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */ 468 #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */ 469 #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */ 470 #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */ 471 #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */ 472 #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly 473 increasing timestamps, but they must 474 still be monotonic */ 475 #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative 476 timestamps. If not set the timestamp 477 will be shifted in av_write_frame and 478 av_interleaved_write_frame so they 479 start from 0. 480 The user or muxer can override this through 481 AVFormatContext.avoid_negative_ts 482 */ 483 484 #define AVFMT_SEEK_TO_PTS 0x4000000 /**< Seeking is based on PTS */ 485 486 /** 487 * @addtogroup lavf_encoding 488 * @{ 489 */ 490 typedef struct AVOutputFormat { 491 const char *name; 492 /** 493 * Descriptive name for the format, meant to be more human-readable 494 * than name. You should use the NULL_IF_CONFIG_SMALL() macro 495 * to define it. 496 */ 497 const char *long_name; 498 const char *mime_type; 499 const char *extensions; /**< comma-separated filename extensions */ 500 /* output support */ 501 enum AVCodecID audio_codec; /**< default audio codec */ 502 enum AVCodecID video_codec; /**< default video codec */ 503 enum AVCodecID subtitle_codec; /**< default subtitle codec */ 504 /** 505 * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, 506 * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS, 507 * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH, 508 * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE 509 */ 510 int flags; 511 512 /** 513 * List of supported codec_id-codec_tag pairs, ordered by "better 514 * choice first". The arrays are all terminated by AV_CODEC_ID_NONE. 515 */ 516 const struct AVCodecTag * const *codec_tag; 517 518 519 const AVClass *priv_class; ///< AVClass for the private context 520 521 /***************************************************************** 522 * No fields below this line are part of the public API. They 523 * may not be used outside of libavformat and can be changed and 524 * removed at will. 525 * New public fields should be added right above. 526 ***************************************************************** 527 */ 528 /** 529 * The ff_const59 define is not part of the public API and will 530 * be removed without further warning. 531 */ 532 #if FF_API_AVIOFORMAT 533 #define ff_const59 534 #else 535 #define ff_const59 const 536 #endif 537 ff_const59 struct AVOutputFormat *next; 538 /** 539 * size of private data so that it can be allocated in the wrapper 540 */ 541 int priv_data_size; 542 543 int (*write_header)(struct AVFormatContext *); 544 /** 545 * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags, 546 * pkt can be NULL in order to flush data buffered in the muxer. 547 * When flushing, return 0 if there still is more data to flush, 548 * or 1 if everything was flushed and there is no more buffered 549 * data. 550 */ 551 int (*write_packet)(struct AVFormatContext *, AVPacket *pkt); 552 int (*write_trailer)(struct AVFormatContext *); 553 /** 554 * A format-specific function for interleavement. 555 * If unset, packets will be interleaved by dts. 556 */ 557 int (*interleave_packet)(struct AVFormatContext *, AVPacket *out, 558 AVPacket *in, int flush); 559 /** 560 * Test if the given codec can be stored in this container. 561 * 562 * @return 1 if the codec is supported, 0 if it is not. 563 * A negative number if unknown. 564 * MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC 565 */ 566 int (*query_codec)(enum AVCodecID id, int std_compliance); 567 568 void (*get_output_timestamp)(struct AVFormatContext *s, int stream, 569 int64_t *dts, int64_t *wall); 570 /** 571 * Allows sending messages from application to device. 572 */ 573 int (*control_message)(struct AVFormatContext *s, int type, 574 void *data, size_t data_size); 575 576 /** 577 * Write an uncoded AVFrame. 578 * 579 * See av_write_uncoded_frame() for details. 580 * 581 * The library will free *frame afterwards, but the muxer can prevent it 582 * by setting the pointer to NULL. 583 */ 584 int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index, 585 AVFrame **frame, unsigned flags); 586 /** 587 * Returns device list with it properties. 588 * @see avdevice_list_devices() for more details. 589 */ 590 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list); 591 /** 592 * Initialize device capabilities submodule. 593 * @see avdevice_capabilities_create() for more details. 594 */ 595 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps); 596 /** 597 * Free device capabilities submodule. 598 * @see avdevice_capabilities_free() for more details. 599 */ 600 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps); 601 enum AVCodecID data_codec; /**< default data codec */ 602 /** 603 * Initialize format. May allocate data here, and set any AVFormatContext or 604 * AVStream parameters that need to be set before packets are sent. 605 * This method must not write output. 606 * 607 * Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure 608 * 609 * Any allocations made here must be freed in deinit(). 610 */ 611 int (*init)(struct AVFormatContext *); 612 /** 613 * Deinitialize format. If present, this is called whenever the muxer is being 614 * destroyed, regardless of whether or not the header has been written. 615 * 616 * If a trailer is being written, this is called after write_trailer(). 617 * 618 * This is called if init() fails as well. 619 */ 620 void (*deinit)(struct AVFormatContext *); 621 /** 622 * Set up any necessary bitstream filtering and extract any extra data needed 623 * for the global header. 624 * Return 0 if more packets from this stream must be checked; 1 if not. 625 */ 626 int (*check_bitstream)(struct AVFormatContext *, const AVPacket *pkt); 627 } AVOutputFormat; 628 /** 629 * @} 630 */ 631 632 /** 633 * @addtogroup lavf_decoding 634 * @{ 635 */ 636 typedef struct AVInputFormat { 637 /** 638 * A comma separated list of short names for the format. New names 639 * may be appended with a minor bump. 640 */ 641 const char *name; 642 643 /** 644 * Descriptive name for the format, meant to be more human-readable 645 * than name. You should use the NULL_IF_CONFIG_SMALL() macro 646 * to define it. 647 */ 648 const char *long_name; 649 650 /** 651 * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS, 652 * AVFMT_NOTIMESTAMPS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH, 653 * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS. 654 */ 655 int flags; 656 657 /** 658 * If extensions are defined, then no probe is done. You should 659 * usually not use extension format guessing because it is not 660 * reliable enough 661 */ 662 const char *extensions; 663 664 const struct AVCodecTag * const *codec_tag; 665 666 const AVClass *priv_class; ///< AVClass for the private context 667 668 /** 669 * Comma-separated list of mime types. 670 * It is used check for matching mime types while probing. 671 * @see av_probe_input_format2 672 */ 673 const char *mime_type; 674 675 /***************************************************************** 676 * No fields below this line are part of the public API. They 677 * may not be used outside of libavformat and can be changed and 678 * removed at will. 679 * New public fields should be added right above. 680 ***************************************************************** 681 */ 682 ff_const59 struct AVInputFormat *next; 683 684 /** 685 * Raw demuxers store their codec ID here. 686 */ 687 int raw_codec_id; 688 689 /** 690 * Size of private data so that it can be allocated in the wrapper. 691 */ 692 int priv_data_size; 693 694 /** 695 * Tell if a given file has a chance of being parsed as this format. 696 * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes 697 * big so you do not have to check for that unless you need more. 698 */ 699 int (*read_probe)(const AVProbeData *); 700 701 /** 702 * Read the format header and initialize the AVFormatContext 703 * structure. Return 0 if OK. 'avformat_new_stream' should be 704 * called to create new streams. 705 */ 706 int (*read_header)(struct AVFormatContext *); 707 708 /** 709 * Read one packet and put it in 'pkt'. pts and flags are also 710 * set. 'avformat_new_stream' can be called only if the flag 711 * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a 712 * background thread). 713 * @return 0 on success, < 0 on error. 714 * Upon returning an error, pkt must be unreferenced by the caller. 715 */ 716 int (*read_packet)(struct AVFormatContext *, AVPacket *pkt); 717 718 /** 719 * Close the stream. The AVFormatContext and AVStreams are not 720 * freed by this function 721 */ 722 int (*read_close)(struct AVFormatContext *); 723 724 /** 725 * Seek to a given timestamp relative to the frames in 726 * stream component stream_index. 727 * @param stream_index Must not be -1. 728 * @param flags Selects which direction should be preferred if no exact 729 * match is available. 730 * @return >= 0 on success (but not necessarily the new offset) 731 */ 732 int (*read_seek)(struct AVFormatContext *, 733 int stream_index, int64_t timestamp, int flags); 734 735 /** 736 * Get the next timestamp in stream[stream_index].time_base units. 737 * @return the timestamp or AV_NOPTS_VALUE if an error occurred 738 */ 739 int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index, 740 int64_t *pos, int64_t pos_limit); 741 742 /** 743 * Start/resume playing - only meaningful if using a network-based format 744 * (RTSP). 745 */ 746 int (*read_play)(struct AVFormatContext *); 747 748 /** 749 * Pause playing - only meaningful if using a network-based format 750 * (RTSP). 751 */ 752 int (*read_pause)(struct AVFormatContext *); 753 754 /** 755 * Seek to timestamp ts. 756 * Seeking will be done so that the point from which all active streams 757 * can be presented successfully will be closest to ts and within min/max_ts. 758 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL. 759 */ 760 int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags); 761 762 /** 763 * Returns device list with it properties. 764 * @see avdevice_list_devices() for more details. 765 */ 766 int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list); 767 768 /** 769 * Initialize device capabilities submodule. 770 * @see avdevice_capabilities_create() for more details. 771 */ 772 int (*create_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps); 773 774 /** 775 * Free device capabilities submodule. 776 * @see avdevice_capabilities_free() for more details. 777 */ 778 int (*free_device_capabilities)(struct AVFormatContext *s, struct AVDeviceCapabilitiesQuery *caps); 779 } AVInputFormat; 780 /** 781 * @} 782 */ 783 784 enum AVStreamParseType { 785 AVSTREAM_PARSE_NONE, 786 AVSTREAM_PARSE_FULL, /**< full parsing and repack */ 787 AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */ 788 AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */ 789 AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */ 790 AVSTREAM_PARSE_FULL_RAW, /**< full parsing and repack with timestamp and position generation by parser for raw 791 this assumes that each packet in the file contains no demuxer level headers and 792 just codec level data, otherwise position generation would fail */ 793 }; 794 795 typedef struct AVIndexEntry { 796 int64_t pos; 797 int64_t timestamp; /**< 798 * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available 799 * when seeking to this entry. That means preferable PTS on keyframe based formats. 800 * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better 801 * is known 802 */ 803 #define AVINDEX_KEYFRAME 0x0001 804 #define AVINDEX_DISCARD_FRAME 0x0002 /** 805 * Flag is used to indicate which frame should be discarded after decoding. 806 */ 807 int flags:2; 808 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). 809 int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */ 810 } AVIndexEntry; 811 812 #define AV_DISPOSITION_DEFAULT 0x0001 813 #define AV_DISPOSITION_DUB 0x0002 814 #define AV_DISPOSITION_ORIGINAL 0x0004 815 #define AV_DISPOSITION_COMMENT 0x0008 816 #define AV_DISPOSITION_LYRICS 0x0010 817 #define AV_DISPOSITION_KARAOKE 0x0020 818 819 /** 820 * Track should be used during playback by default. 821 * Useful for subtitle track that should be displayed 822 * even when user did not explicitly ask for subtitles. 823 */ 824 #define AV_DISPOSITION_FORCED 0x0040 825 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */ 826 #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */ 827 #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */ 828 /** 829 * The stream is stored in the file as an attached picture/"cover art" (e.g. 830 * APIC frame in ID3v2). The first (usually only) packet associated with it 831 * will be returned among the first few packets read from the file unless 832 * seeking takes place. It can also be accessed at any time in 833 * AVStream.attached_pic. 834 */ 835 #define AV_DISPOSITION_ATTACHED_PIC 0x0400 836 /** 837 * The stream is sparse, and contains thumbnail images, often corresponding 838 * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC. 839 */ 840 #define AV_DISPOSITION_TIMED_THUMBNAILS 0x0800 841 842 typedef struct AVStreamInternal AVStreamInternal; 843 844 /** 845 * To specify text track kind (different from subtitles default). 846 */ 847 #define AV_DISPOSITION_CAPTIONS 0x10000 848 #define AV_DISPOSITION_DESCRIPTIONS 0x20000 849 #define AV_DISPOSITION_METADATA 0x40000 850 #define AV_DISPOSITION_DEPENDENT 0x80000 ///< dependent audio stream (mix_type=0 in mpegts) 851 #define AV_DISPOSITION_STILL_IMAGE 0x100000 ///< still images in video stream (still_picture_flag=1 in mpegts) 852 853 /** 854 * Options for behavior on timestamp wrap detection. 855 */ 856 #define AV_PTS_WRAP_IGNORE 0 ///< ignore the wrap 857 #define AV_PTS_WRAP_ADD_OFFSET 1 ///< add the format specific offset on wrap detection 858 #define AV_PTS_WRAP_SUB_OFFSET -1 ///< subtract the format specific offset on wrap detection 859 860 /** 861 * Stream structure. 862 * New fields can be added to the end with minor version bumps. 863 * Removal, reordering and changes to existing fields require a major 864 * version bump. 865 * sizeof(AVStream) must not be used outside libav*. 866 */ 867 typedef struct AVStream { 868 int index; /**< stream index in AVFormatContext */ 869 /** 870 * Format-specific stream ID. 871 * decoding: set by libavformat 872 * encoding: set by the user, replaced by libavformat if left unset 873 */ 874 int id; 875 #if FF_API_LAVF_AVCTX 876 /** 877 * @deprecated use the codecpar struct instead 878 */ 879 attribute_deprecated 880 AVCodecContext *codec; 881 #endif 882 void *priv_data; 883 884 /** 885 * This is the fundamental unit of time (in seconds) in terms 886 * of which frame timestamps are represented. 887 * 888 * decoding: set by libavformat 889 * encoding: May be set by the caller before avformat_write_header() to 890 * provide a hint to the muxer about the desired timebase. In 891 * avformat_write_header(), the muxer will overwrite this field 892 * with the timebase that will actually be used for the timestamps 893 * written into the file (which may or may not be related to the 894 * user-provided one, depending on the format). 895 */ 896 AVRational time_base; 897 898 /** 899 * Decoding: pts of the first frame of the stream in presentation order, in stream time base. 900 * Only set this if you are absolutely 100% sure that the value you set 901 * it to really is the pts of the first frame. 902 * This may be undefined (AV_NOPTS_VALUE). 903 * @note The ASF header does NOT contain a correct start_time the ASF 904 * demuxer must NOT set this. 905 */ 906 int64_t start_time; 907 908 /** 909 * Decoding: duration of the stream, in stream time base. 910 * If a source file does not specify a duration, but does specify 911 * a bitrate, this value will be estimated from bitrate and file size. 912 * 913 * Encoding: May be set by the caller before avformat_write_header() to 914 * provide a hint to the muxer about the estimated duration. 915 */ 916 int64_t duration; 917 918 int64_t nb_frames; ///< number of frames in this stream if known or 0 919 920 int disposition; /**< AV_DISPOSITION_* bit field */ 921 922 enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed. 923 924 /** 925 * sample aspect ratio (0 if unknown) 926 * - encoding: Set by user. 927 * - decoding: Set by libavformat. 928 */ 929 AVRational sample_aspect_ratio; 930 931 AVDictionary *metadata; 932 933 /** 934 * Average framerate 935 * 936 * - demuxing: May be set by libavformat when creating the stream or in 937 * avformat_find_stream_info(). 938 * - muxing: May be set by the caller before avformat_write_header(). 939 */ 940 AVRational avg_frame_rate; 941 942 /** 943 * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet 944 * will contain the attached picture. 945 * 946 * decoding: set by libavformat, must not be modified by the caller. 947 * encoding: unused 948 */ 949 AVPacket attached_pic; 950 951 /** 952 * An array of side data that applies to the whole stream (i.e. the 953 * container does not allow it to change between packets). 954 * 955 * There may be no overlap between the side data in this array and side data 956 * in the packets. I.e. a given side data is either exported by the muxer 957 * (demuxing) / set by the caller (muxing) in this array, then it never 958 * appears in the packets, or the side data is exported / sent through 959 * the packets (always in the first packet where the value becomes known or 960 * changes), then it does not appear in this array. 961 * 962 * - demuxing: Set by libavformat when the stream is created. 963 * - muxing: May be set by the caller before avformat_write_header(). 964 * 965 * Freed by libavformat in avformat_free_context(). 966 * 967 * @see av_format_inject_global_side_data() 968 */ 969 AVPacketSideData *side_data; 970 /** 971 * The number of elements in the AVStream.side_data array. 972 */ 973 int nb_side_data; 974 975 /** 976 * Flags for the user to detect events happening on the stream. Flags must 977 * be cleared by the user once the event has been handled. 978 * A combination of AVSTREAM_EVENT_FLAG_*. 979 */ 980 int event_flags; 981 #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata. 982 983 /** 984 * Real base framerate of the stream. 985 * This is the lowest framerate with which all timestamps can be 986 * represented accurately (it is the least common multiple of all 987 * framerates in the stream). Note, this value is just a guess! 988 * For example, if the time base is 1/90000 and all frames have either 989 * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1. 990 */ 991 AVRational r_frame_rate; 992 993 #if FF_API_LAVF_FFSERVER 994 /** 995 * String containing pairs of key and values describing recommended encoder configuration. 996 * Pairs are separated by ','. 997 * Keys are separated from values by '='. 998 * 999 * @deprecated unused 1000 */ 1001 attribute_deprecated 1002 char *recommended_encoder_configuration; 1003 #endif 1004 1005 /** 1006 * Codec parameters associated with this stream. Allocated and freed by 1007 * libavformat in avformat_new_stream() and avformat_free_context() 1008 * respectively. 1009 * 1010 * - demuxing: filled by libavformat on stream creation or in 1011 * avformat_find_stream_info() 1012 * - muxing: filled by the caller before avformat_write_header() 1013 */ 1014 AVCodecParameters *codecpar; 1015 1016 /***************************************************************** 1017 * All fields below this line are not part of the public API. They 1018 * may not be used outside of libavformat and can be changed and 1019 * removed at will. 1020 * Internal note: be aware that physically removing these fields 1021 * will break ABI. Replace removed fields with dummy fields, and 1022 * add new fields to AVStreamInternal. 1023 ***************************************************************** 1024 */ 1025 1026 #define MAX_STD_TIMEBASES (30*12+30+3+6) 1027 /** 1028 * Stream information used internally by avformat_find_stream_info() 1029 */ 1030 struct { 1031 int64_t last_dts; 1032 int64_t duration_gcd; 1033 int duration_count; 1034 int64_t rfps_duration_sum; 1035 double (*duration_error)[2][MAX_STD_TIMEBASES]; 1036 int64_t codec_info_duration; 1037 int64_t codec_info_duration_fields; 1038 int frame_delay_evidence; 1039 1040 /** 1041 * 0 -> decoder has not been searched for yet. 1042 * >0 -> decoder found 1043 * <0 -> decoder with codec_id == -found_decoder has not been found 1044 */ 1045 int found_decoder; 1046 1047 int64_t last_duration; 1048 1049 /** 1050 * Those are used for average framerate estimation. 1051 */ 1052 int64_t fps_first_dts; 1053 int fps_first_dts_idx; 1054 int64_t fps_last_dts; 1055 int fps_last_dts_idx; 1056 1057 } *info; 1058 1059 int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */ 1060 1061 // Timestamp generation support: 1062 /** 1063 * Timestamp corresponding to the last dts sync point. 1064 * 1065 * Initialized when AVCodecParserContext.dts_sync_point >= 0 and 1066 * a DTS is received from the underlying container. Otherwise set to 1067 * AV_NOPTS_VALUE by default. 1068 */ 1069 int64_t first_dts; 1070 int64_t cur_dts; 1071 int64_t last_IP_pts; 1072 int last_IP_duration; 1073 1074 /** 1075 * Number of packets to buffer for codec probing 1076 */ 1077 int probe_packets; 1078 1079 /** 1080 * Number of frames that have been demuxed during avformat_find_stream_info() 1081 */ 1082 int codec_info_nb_frames; 1083 1084 /* av_read_frame() support */ 1085 enum AVStreamParseType need_parsing; 1086 struct AVCodecParserContext *parser; 1087 1088 /** 1089 * last packet in packet_buffer for this stream when muxing. 1090 */ 1091 struct AVPacketList *last_in_packet_buffer; 1092 AVProbeData probe_data; 1093 #define MAX_REORDER_DELAY 16 1094 int64_t pts_buffer[MAX_REORDER_DELAY+1]; 1095 1096 AVIndexEntry *index_entries; /**< Only used if the format does not 1097 support seeking natively. */ 1098 int nb_index_entries; 1099 unsigned int index_entries_allocated_size; 1100 1101 /** 1102 * Stream Identifier 1103 * This is the MPEG-TS stream identifier +1 1104 * 0 means unknown 1105 */ 1106 int stream_identifier; 1107 1108 /** 1109 * Details of the MPEG-TS program which created this stream. 1110 */ 1111 int program_num; 1112 int pmt_version; 1113 int pmt_stream_idx; 1114 1115 int64_t interleaver_chunk_size; 1116 int64_t interleaver_chunk_duration; 1117 1118 /** 1119 * stream probing state 1120 * -1 -> probing finished 1121 * 0 -> no probing requested 1122 * rest -> perform probing with request_probe being the minimum score to accept. 1123 */ 1124 int request_probe; 1125 /** 1126 * Indicates that everything up to the next keyframe 1127 * should be discarded. 1128 */ 1129 int skip_to_keyframe; 1130 1131 /** 1132 * Number of samples to skip at the start of the frame decoded from the next packet. 1133 */ 1134 int skip_samples; 1135 1136 /** 1137 * If not 0, the number of samples that should be skipped from the start of 1138 * the stream (the samples are removed from packets with pts==0, which also 1139 * assumes negative timestamps do not happen). 1140 * Intended for use with formats such as mp3 with ad-hoc gapless audio 1141 * support. 1142 */ 1143 int64_t start_skip_samples; 1144 1145 /** 1146 * If not 0, the first audio sample that should be discarded from the stream. 1147 * This is broken by design (needs global sample count), but can't be 1148 * avoided for broken by design formats such as mp3 with ad-hoc gapless 1149 * audio support. 1150 */ 1151 int64_t first_discard_sample; 1152 1153 /** 1154 * The sample after last sample that is intended to be discarded after 1155 * first_discard_sample. Works on frame boundaries only. Used to prevent 1156 * early EOF if the gapless info is broken (considered concatenated mp3s). 1157 */ 1158 int64_t last_discard_sample; 1159 1160 /** 1161 * Number of internally decoded frames, used internally in libavformat, do not access 1162 * its lifetime differs from info which is why it is not in that structure. 1163 */ 1164 int nb_decoded_frames; 1165 1166 /** 1167 * Timestamp offset added to timestamps before muxing 1168 */ 1169 int64_t mux_ts_offset; 1170 1171 /** 1172 * Internal data to check for wrapping of the time stamp 1173 */ 1174 int64_t pts_wrap_reference; 1175 1176 /** 1177 * Options for behavior, when a wrap is detected. 1178 * 1179 * Defined by AV_PTS_WRAP_ values. 1180 * 1181 * If correction is enabled, there are two possibilities: 1182 * If the first time stamp is near the wrap point, the wrap offset 1183 * will be subtracted, which will create negative time stamps. 1184 * Otherwise the offset will be added. 1185 */ 1186 int pts_wrap_behavior; 1187 1188 /** 1189 * Internal data to prevent doing update_initial_durations() twice 1190 */ 1191 int update_initial_durations_done; 1192 1193 /** 1194 * Internal data to generate dts from pts 1195 */ 1196 int64_t pts_reorder_error[MAX_REORDER_DELAY+1]; 1197 uint8_t pts_reorder_error_count[MAX_REORDER_DELAY+1]; 1198 1199 /** 1200 * Internal data to analyze DTS and detect faulty mpeg streams 1201 */ 1202 int64_t last_dts_for_order_check; 1203 uint8_t dts_ordered; 1204 uint8_t dts_misordered; 1205 1206 /** 1207 * Internal data to inject global side data 1208 */ 1209 int inject_global_side_data; 1210 1211 /** 1212 * display aspect ratio (0 if unknown) 1213 * - encoding: unused 1214 * - decoding: Set by libavformat to calculate sample_aspect_ratio internally 1215 */ 1216 AVRational display_aspect_ratio; 1217 1218 /** 1219 * An opaque field for libavformat internal usage. 1220 * Must not be accessed in any way by callers. 1221 */ 1222 AVStreamInternal *internal; 1223 } AVStream; 1224 1225 #if FF_API_FORMAT_GET_SET 1226 /** 1227 * Accessors for some AVStream fields. These used to be provided for ABI 1228 * compatibility, and do not need to be used anymore. 1229 */ 1230 attribute_deprecated 1231 AVRational av_stream_get_r_frame_rate(const AVStream *s); 1232 attribute_deprecated 1233 void av_stream_set_r_frame_rate(AVStream *s, AVRational r); 1234 #if FF_API_LAVF_FFSERVER 1235 attribute_deprecated 1236 char* av_stream_get_recommended_encoder_configuration(const AVStream *s); 1237 attribute_deprecated 1238 void av_stream_set_recommended_encoder_configuration(AVStream *s, char *configuration); 1239 #endif 1240 #endif 1241 1242 struct AVCodecParserContext *av_stream_get_parser(const AVStream *s); 1243 1244 /** 1245 * Returns the pts of the last muxed packet + its duration 1246 * 1247 * the retuned value is undefined when used with a demuxer. 1248 */ 1249 int64_t av_stream_get_end_pts(const AVStream *st); 1250 1251 #define AV_PROGRAM_RUNNING 1 1252 1253 /** 1254 * New fields can be added to the end with minor version bumps. 1255 * Removal, reordering and changes to existing fields require a major 1256 * version bump. 1257 * sizeof(AVProgram) must not be used outside libav*. 1258 */ 1259 typedef struct AVProgram { 1260 int id; 1261 int flags; 1262 enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller 1263 unsigned int *stream_index; 1264 unsigned int nb_stream_indexes; 1265 AVDictionary *metadata; 1266 1267 int program_num; 1268 int pmt_pid; 1269 int pcr_pid; 1270 int pmt_version; 1271 1272 /***************************************************************** 1273 * All fields below this line are not part of the public API. They 1274 * may not be used outside of libavformat and can be changed and 1275 * removed at will. 1276 * New public fields should be added right above. 1277 ***************************************************************** 1278 */ 1279 int64_t start_time; 1280 int64_t end_time; 1281 1282 int64_t pts_wrap_reference; ///< reference dts for wrap detection 1283 int pts_wrap_behavior; ///< behavior on wrap detection 1284 } AVProgram; 1285 1286 #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present 1287 (streams are added dynamically) */ 1288 #define AVFMTCTX_UNSEEKABLE 0x0002 /**< signal that the stream is definitely 1289 not seekable, and attempts to call the 1290 seek function will fail. For some 1291 network protocols (e.g. HLS), this can 1292 change dynamically at runtime. */ 1293 1294 typedef struct AVChapter { 1295 int id; ///< unique ID to identify the chapter 1296 AVRational time_base; ///< time base in which the start/end timestamps are specified 1297 int64_t start, end; ///< chapter start/end time in time_base units 1298 AVDictionary *metadata; 1299 } AVChapter; 1300 1301 1302 /** 1303 * Callback used by devices to communicate with application. 1304 */ 1305 typedef int (*av_format_control_message)(struct AVFormatContext *s, int type, 1306 void *data, size_t data_size); 1307 1308 typedef int (*AVOpenCallback)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, 1309 const AVIOInterruptCB *int_cb, AVDictionary **options); 1310 1311 /** 1312 * The duration of a video can be estimated through various ways, and this enum can be used 1313 * to know how the duration was estimated. 1314 */ 1315 enum AVDurationEstimationMethod { 1316 AVFMT_DURATION_FROM_PTS, ///< Duration accurately estimated from PTSes 1317 AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration 1318 AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate) 1319 }; 1320 1321 typedef struct AVFormatInternal AVFormatInternal; 1322 1323 /** 1324 * Format I/O context. 1325 * New fields can be added to the end with minor version bumps. 1326 * Removal, reordering and changes to existing fields require a major 1327 * version bump. 1328 * sizeof(AVFormatContext) must not be used outside libav*, use 1329 * avformat_alloc_context() to create an AVFormatContext. 1330 * 1331 * Fields can be accessed through AVOptions (av_opt*), 1332 * the name string used matches the associated command line parameter name and 1333 * can be found in libavformat/options_table.h. 1334 * The AVOption/command line parameter names differ in some cases from the C 1335 * structure field names for historic reasons or brevity. 1336 */ 1337 typedef struct AVFormatContext { 1338 /** 1339 * A class for logging and @ref avoptions. Set by avformat_alloc_context(). 1340 * Exports (de)muxer private options if they exist. 1341 */ 1342 const AVClass *av_class; 1343 1344 /** 1345 * The input container format. 1346 * 1347 * Demuxing only, set by avformat_open_input(). 1348 */ 1349 ff_const59 struct AVInputFormat *iformat; 1350 1351 /** 1352 * The output container format. 1353 * 1354 * Muxing only, must be set by the caller before avformat_write_header(). 1355 */ 1356 ff_const59 struct AVOutputFormat *oformat; 1357 1358 /** 1359 * Format private data. This is an AVOptions-enabled struct 1360 * if and only if iformat/oformat.priv_class is not NULL. 1361 * 1362 * - muxing: set by avformat_write_header() 1363 * - demuxing: set by avformat_open_input() 1364 */ 1365 void *priv_data; 1366 1367 /** 1368 * I/O context. 1369 * 1370 * - demuxing: either set by the user before avformat_open_input() (then 1371 * the user must close it manually) or set by avformat_open_input(). 1372 * - muxing: set by the user before avformat_write_header(). The caller must 1373 * take care of closing / freeing the IO context. 1374 * 1375 * Do NOT set this field if AVFMT_NOFILE flag is set in 1376 * iformat/oformat.flags. In such a case, the (de)muxer will handle 1377 * I/O in some other way and this field will be NULL. 1378 */ 1379 AVIOContext *pb; 1380 1381 /* stream info */ 1382 /** 1383 * Flags signalling stream properties. A combination of AVFMTCTX_*. 1384 * Set by libavformat. 1385 */ 1386 int ctx_flags; 1387 1388 /** 1389 * Number of elements in AVFormatContext.streams. 1390 * 1391 * Set by avformat_new_stream(), must not be modified by any other code. 1392 */ 1393 unsigned int nb_streams; 1394 /** 1395 * A list of all streams in the file. New streams are created with 1396 * avformat_new_stream(). 1397 * 1398 * - demuxing: streams are created by libavformat in avformat_open_input(). 1399 * If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also 1400 * appear in av_read_frame(). 1401 * - muxing: streams are created by the user before avformat_write_header(). 1402 * 1403 * Freed by libavformat in avformat_free_context(). 1404 */ 1405 AVStream **streams; 1406 1407 #if FF_API_FORMAT_FILENAME 1408 /** 1409 * input or output filename 1410 * 1411 * - demuxing: set by avformat_open_input() 1412 * - muxing: may be set by the caller before avformat_write_header() 1413 * 1414 * @deprecated Use url instead. 1415 */ 1416 attribute_deprecated 1417 char filename[1024]; 1418 #endif 1419 1420 /** 1421 * input or output URL. Unlike the old filename field, this field has no 1422 * length restriction. 1423 * 1424 * - demuxing: set by avformat_open_input(), initialized to an empty 1425 * string if url parameter was NULL in avformat_open_input(). 1426 * - muxing: may be set by the caller before calling avformat_write_header() 1427 * (or avformat_init_output() if that is called first) to a string 1428 * which is freeable by av_free(). Set to an empty string if it 1429 * was NULL in avformat_init_output(). 1430 * 1431 * Freed by libavformat in avformat_free_context(). 1432 */ 1433 char *url; 1434 1435 /** 1436 * Position of the first frame of the component, in 1437 * AV_TIME_BASE fractional seconds. NEVER set this value directly: 1438 * It is deduced from the AVStream values. 1439 * 1440 * Demuxing only, set by libavformat. 1441 */ 1442 int64_t start_time; 1443 1444 /** 1445 * Duration of the stream, in AV_TIME_BASE fractional 1446 * seconds. Only set this value if you know none of the individual stream 1447 * durations and also do not set any of them. This is deduced from the 1448 * AVStream values if not set. 1449 * 1450 * Demuxing only, set by libavformat. 1451 */ 1452 int64_t duration; 1453 1454 /** 1455 * Total stream bitrate in bit/s, 0 if not 1456 * available. Never set it directly if the file_size and the 1457 * duration are known as FFmpeg can compute it automatically. 1458 */ 1459 int64_t bit_rate; 1460 1461 unsigned int packet_size; 1462 int max_delay; 1463 1464 /** 1465 * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*. 1466 * Set by the user before avformat_open_input() / avformat_write_header(). 1467 */ 1468 int flags; 1469 #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames. 1470 #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index. 1471 #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input. 1472 #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS 1473 #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container 1474 #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 1475 #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible 1476 #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it. 1477 #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted 1478 #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet. 1479 /** 1480 * When muxing, try to avoid writing any random/volatile data to the output. 1481 * This includes any random IDs, real-time timestamps/dates, muxer version, etc. 1482 * 1483 * This flag is mainly intended for testing. 1484 */ 1485 #define AVFMT_FLAG_BITEXACT 0x0400 1486 #if FF_API_LAVF_MP4A_LATM 1487 #define AVFMT_FLAG_MP4A_LATM 0x8000 ///< Deprecated, does nothing. 1488 #endif 1489 #define AVFMT_FLAG_SORT_DTS 0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down) 1490 #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) 1491 #if FF_API_LAVF_KEEPSIDE_FLAG 1492 #define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Deprecated, does nothing. 1493 #endif 1494 #define AVFMT_FLAG_FAST_SEEK 0x80000 ///< Enable fast, but inaccurate seeks for some formats 1495 #define AVFMT_FLAG_SHORTEST 0x100000 ///< Stop muxing when the shortest stream stops. 1496 #define AVFMT_FLAG_AUTO_BSF 0x200000 ///< Add bitstream filters as requested by the muxer 1497 1498 /** 1499 * Maximum size of the data read from input for determining 1500 * the input container format. 1501 * Demuxing only, set by the caller before avformat_open_input(). 1502 */ 1503 int64_t probesize; 1504 1505 /** 1506 * Maximum duration (in AV_TIME_BASE units) of the data read 1507 * from input in avformat_find_stream_info(). 1508 * Demuxing only, set by the caller before avformat_find_stream_info(). 1509 * Can be set to 0 to let avformat choose using a heuristic. 1510 */ 1511 int64_t max_analyze_duration; 1512 1513 const uint8_t *key; 1514 int keylen; 1515 1516 unsigned int nb_programs; 1517 AVProgram **programs; 1518 1519 /** 1520 * Forced video codec_id. 1521 * Demuxing: Set by user. 1522 */ 1523 enum AVCodecID video_codec_id; 1524 1525 /** 1526 * Forced audio codec_id. 1527 * Demuxing: Set by user. 1528 */ 1529 enum AVCodecID audio_codec_id; 1530 1531 /** 1532 * Forced subtitle codec_id. 1533 * Demuxing: Set by user. 1534 */ 1535 enum AVCodecID subtitle_codec_id; 1536 1537 /** 1538 * Maximum amount of memory in bytes to use for the index of each stream. 1539 * If the index exceeds this size, entries will be discarded as 1540 * needed to maintain a smaller size. This can lead to slower or less 1541 * accurate seeking (depends on demuxer). 1542 * Demuxers for which a full in-memory index is mandatory will ignore 1543 * this. 1544 * - muxing: unused 1545 * - demuxing: set by user 1546 */ 1547 unsigned int max_index_size; 1548 1549 /** 1550 * Maximum amount of memory in bytes to use for buffering frames 1551 * obtained from realtime capture devices. 1552 */ 1553 unsigned int max_picture_buffer; 1554 1555 /** 1556 * Number of chapters in AVChapter array. 1557 * When muxing, chapters are normally written in the file header, 1558 * so nb_chapters should normally be initialized before write_header 1559 * is called. Some muxers (e.g. mov and mkv) can also write chapters 1560 * in the trailer. To write chapters in the trailer, nb_chapters 1561 * must be zero when write_header is called and non-zero when 1562 * write_trailer is called. 1563 * - muxing: set by user 1564 * - demuxing: set by libavformat 1565 */ 1566 unsigned int nb_chapters; 1567 AVChapter **chapters; 1568 1569 /** 1570 * Metadata that applies to the whole file. 1571 * 1572 * - demuxing: set by libavformat in avformat_open_input() 1573 * - muxing: may be set by the caller before avformat_write_header() 1574 * 1575 * Freed by libavformat in avformat_free_context(). 1576 */ 1577 AVDictionary *metadata; 1578 1579 /** 1580 * Start time of the stream in real world time, in microseconds 1581 * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the 1582 * stream was captured at this real world time. 1583 * - muxing: Set by the caller before avformat_write_header(). If set to 1584 * either 0 or AV_NOPTS_VALUE, then the current wall-time will 1585 * be used. 1586 * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that 1587 * the value may become known after some number of frames 1588 * have been received. 1589 */ 1590 int64_t start_time_realtime; 1591 1592 /** 1593 * The number of frames used for determining the framerate in 1594 * avformat_find_stream_info(). 1595 * Demuxing only, set by the caller before avformat_find_stream_info(). 1596 */ 1597 int fps_probe_size; 1598 1599 /** 1600 * Error recognition; higher values will detect more errors but may 1601 * misdetect some more or less valid parts as errors. 1602 * Demuxing only, set by the caller before avformat_open_input(). 1603 */ 1604 int error_recognition; 1605 1606 /** 1607 * Custom interrupt callbacks for the I/O layer. 1608 * 1609 * demuxing: set by the user before avformat_open_input(). 1610 * muxing: set by the user before avformat_write_header() 1611 * (mainly useful for AVFMT_NOFILE formats). The callback 1612 * should also be passed to avio_open2() if it's used to 1613 * open the file. 1614 */ 1615 AVIOInterruptCB interrupt_callback; 1616 1617 /** 1618 * Flags to enable debugging. 1619 */ 1620 int debug; 1621 #define FF_FDEBUG_TS 0x0001 1622 1623 /** 1624 * Maximum buffering duration for interleaving. 1625 * 1626 * To ensure all the streams are interleaved correctly, 1627 * av_interleaved_write_frame() will wait until it has at least one packet 1628 * for each stream before actually writing any packets to the output file. 1629 * When some streams are "sparse" (i.e. there are large gaps between 1630 * successive packets), this can result in excessive buffering. 1631 * 1632 * This field specifies the maximum difference between the timestamps of the 1633 * first and the last packet in the muxing queue, above which libavformat 1634 * will output a packet regardless of whether it has queued a packet for all 1635 * the streams. 1636 * 1637 * Muxing only, set by the caller before avformat_write_header(). 1638 */ 1639 int64_t max_interleave_delta; 1640 1641 /** 1642 * Allow non-standard and experimental extension 1643 * @see AVCodecContext.strict_std_compliance 1644 */ 1645 int strict_std_compliance; 1646 1647 /** 1648 * Flags for the user to detect events happening on the file. Flags must 1649 * be cleared by the user once the event has been handled. 1650 * A combination of AVFMT_EVENT_FLAG_*. 1651 */ 1652 int event_flags; 1653 #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata. 1654 1655 /** 1656 * Maximum number of packets to read while waiting for the first timestamp. 1657 * Decoding only. 1658 */ 1659 int max_ts_probe; 1660 1661 /** 1662 * Avoid negative timestamps during muxing. 1663 * Any value of the AVFMT_AVOID_NEG_TS_* constants. 1664 * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use) 1665 * - muxing: Set by user 1666 * - demuxing: unused 1667 */ 1668 int avoid_negative_ts; 1669 #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format 1670 #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative 1671 #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0 1672 1673 /** 1674 * Transport stream id. 1675 * This will be moved into demuxer private options. Thus no API/ABI compatibility 1676 */ 1677 int ts_id; 1678 1679 /** 1680 * Audio preload in microseconds. 1681 * Note, not all formats support this and unpredictable things may happen if it is used when not supported. 1682 * - encoding: Set by user 1683 * - decoding: unused 1684 */ 1685 int audio_preload; 1686 1687 /** 1688 * Max chunk time in microseconds. 1689 * Note, not all formats support this and unpredictable things may happen if it is used when not supported. 1690 * - encoding: Set by user 1691 * - decoding: unused 1692 */ 1693 int max_chunk_duration; 1694 1695 /** 1696 * Max chunk size in bytes 1697 * Note, not all formats support this and unpredictable things may happen if it is used when not supported. 1698 * - encoding: Set by user 1699 * - decoding: unused 1700 */ 1701 int max_chunk_size; 1702 1703 /** 1704 * forces the use of wallclock timestamps as pts/dts of packets 1705 * This has undefined results in the presence of B frames. 1706 * - encoding: unused 1707 * - decoding: Set by user 1708 */ 1709 int use_wallclock_as_timestamps; 1710 1711 /** 1712 * avio flags, used to force AVIO_FLAG_DIRECT. 1713 * - encoding: unused 1714 * - decoding: Set by user 1715 */ 1716 int avio_flags; 1717 1718 /** 1719 * The duration field can be estimated through various ways, and this field can be used 1720 * to know how the duration was estimated. 1721 * - encoding: unused 1722 * - decoding: Read by user 1723 */ 1724 enum AVDurationEstimationMethod duration_estimation_method; 1725 1726 /** 1727 * Skip initial bytes when opening stream 1728 * - encoding: unused 1729 * - decoding: Set by user 1730 */ 1731 int64_t skip_initial_bytes; 1732 1733 /** 1734 * Correct single timestamp overflows 1735 * - encoding: unused 1736 * - decoding: Set by user 1737 */ 1738 unsigned int correct_ts_overflow; 1739 1740 /** 1741 * Force seeking to any (also non key) frames. 1742 * - encoding: unused 1743 * - decoding: Set by user 1744 */ 1745 int seek2any; 1746 1747 /** 1748 * Flush the I/O context after each packet. 1749 * - encoding: Set by user 1750 * - decoding: unused 1751 */ 1752 int flush_packets; 1753 1754 /** 1755 * format probing score. 1756 * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes 1757 * the format. 1758 * - encoding: unused 1759 * - decoding: set by avformat, read by user 1760 */ 1761 int probe_score; 1762 1763 /** 1764 * number of bytes to read maximally to identify format. 1765 * - encoding: unused 1766 * - decoding: set by user 1767 */ 1768 int format_probesize; 1769 1770 /** 1771 * ',' separated list of allowed decoders. 1772 * If NULL then all are allowed 1773 * - encoding: unused 1774 * - decoding: set by user 1775 */ 1776 char *codec_whitelist; 1777 1778 /** 1779 * ',' separated list of allowed demuxers. 1780 * If NULL then all are allowed 1781 * - encoding: unused 1782 * - decoding: set by user 1783 */ 1784 char *format_whitelist; 1785 1786 /** 1787 * An opaque field for libavformat internal usage. 1788 * Must not be accessed in any way by callers. 1789 */ 1790 AVFormatInternal *internal; 1791 1792 /** 1793 * IO repositioned flag. 1794 * This is set by avformat when the underlaying IO context read pointer 1795 * is repositioned, for example when doing byte based seeking. 1796 * Demuxers can use the flag to detect such changes. 1797 */ 1798 int io_repositioned; 1799 1800 /** 1801 * Forced video codec. 1802 * This allows forcing a specific decoder, even when there are multiple with 1803 * the same codec_id. 1804 * Demuxing: Set by user 1805 */ 1806 AVCodec *video_codec; 1807 1808 /** 1809 * Forced audio codec. 1810 * This allows forcing a specific decoder, even when there are multiple with 1811 * the same codec_id. 1812 * Demuxing: Set by user 1813 */ 1814 AVCodec *audio_codec; 1815 1816 /** 1817 * Forced subtitle codec. 1818 * This allows forcing a specific decoder, even when there are multiple with 1819 * the same codec_id. 1820 * Demuxing: Set by user 1821 */ 1822 AVCodec *subtitle_codec; 1823 1824 /** 1825 * Forced data codec. 1826 * This allows forcing a specific decoder, even when there are multiple with 1827 * the same codec_id. 1828 * Demuxing: Set by user 1829 */ 1830 AVCodec *data_codec; 1831 1832 /** 1833 * Number of bytes to be written as padding in a metadata header. 1834 * Demuxing: Unused. 1835 * Muxing: Set by user via av_format_set_metadata_header_padding. 1836 */ 1837 int metadata_header_padding; 1838 1839 /** 1840 * User data. 1841 * This is a place for some private data of the user. 1842 */ 1843 void *opaque; 1844 1845 /** 1846 * Callback used by devices to communicate with application. 1847 */ 1848 av_format_control_message control_message_cb; 1849 1850 /** 1851 * Output timestamp offset, in microseconds. 1852 * Muxing: set by user 1853 */ 1854 int64_t output_ts_offset; 1855 1856 /** 1857 * dump format separator. 1858 * can be ", " or "\n " or anything else 1859 * - muxing: Set by user. 1860 * - demuxing: Set by user. 1861 */ 1862 uint8_t *dump_separator; 1863 1864 /** 1865 * Forced Data codec_id. 1866 * Demuxing: Set by user. 1867 */ 1868 enum AVCodecID data_codec_id; 1869 1870 #if FF_API_OLD_OPEN_CALLBACKS 1871 /** 1872 * Called to open further IO contexts when needed for demuxing. 1873 * 1874 * This can be set by the user application to perform security checks on 1875 * the URLs before opening them. 1876 * The function should behave like avio_open2(), AVFormatContext is provided 1877 * as contextual information and to reach AVFormatContext.opaque. 1878 * 1879 * If NULL then some simple checks are used together with avio_open2(). 1880 * 1881 * Must not be accessed directly from outside avformat. 1882 * @See av_format_set_open_cb() 1883 * 1884 * Demuxing: Set by user. 1885 * 1886 * @deprecated Use io_open and io_close. 1887 */ 1888 attribute_deprecated 1889 int (*open_cb)(struct AVFormatContext *s, AVIOContext **p, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options); 1890 #endif 1891 1892 /** 1893 * ',' separated list of allowed protocols. 1894 * - encoding: unused 1895 * - decoding: set by user 1896 */ 1897 char *protocol_whitelist; 1898 1899 /** 1900 * A callback for opening new IO streams. 1901 * 1902 * Whenever a muxer or a demuxer needs to open an IO stream (typically from 1903 * avformat_open_input() for demuxers, but for certain formats can happen at 1904 * other times as well), it will call this callback to obtain an IO context. 1905 * 1906 * @param s the format context 1907 * @param pb on success, the newly opened IO context should be returned here 1908 * @param url the url to open 1909 * @param flags a combination of AVIO_FLAG_* 1910 * @param options a dictionary of additional options, with the same 1911 * semantics as in avio_open2() 1912 * @return 0 on success, a negative AVERROR code on failure 1913 * 1914 * @note Certain muxers and demuxers do nesting, i.e. they open one or more 1915 * additional internal format contexts. Thus the AVFormatContext pointer 1916 * passed to this callback may be different from the one facing the caller. 1917 * It will, however, have the same 'opaque' field. 1918 */ 1919 int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url, 1920 int flags, AVDictionary **options); 1921 1922 /** 1923 * A callback for closing the streams opened with AVFormatContext.io_open(). 1924 */ 1925 void (*io_close)(struct AVFormatContext *s, AVIOContext *pb); 1926 1927 /** 1928 * ',' separated list of disallowed protocols. 1929 * - encoding: unused 1930 * - decoding: set by user 1931 */ 1932 char *protocol_blacklist; 1933 1934 /** 1935 * The maximum number of streams. 1936 * - encoding: unused 1937 * - decoding: set by user 1938 */ 1939 int max_streams; 1940 1941 /** 1942 * Skip duration calcuation in estimate_timings_from_pts. 1943 * - encoding: unused 1944 * - decoding: set by user 1945 */ 1946 int skip_estimate_duration_from_pts; 1947 1948 /** 1949 * Maximum number of packets that can be probed 1950 * - encoding: unused 1951 * - decoding: set by user 1952 */ 1953 int max_probe_packets; 1954 } AVFormatContext; 1955 1956 #if FF_API_FORMAT_GET_SET 1957 /** 1958 * Accessors for some AVFormatContext fields. These used to be provided for ABI 1959 * compatibility, and do not need to be used anymore. 1960 */ 1961 attribute_deprecated 1962 int av_format_get_probe_score(const AVFormatContext *s); 1963 attribute_deprecated 1964 AVCodec * av_format_get_video_codec(const AVFormatContext *s); 1965 attribute_deprecated 1966 void av_format_set_video_codec(AVFormatContext *s, AVCodec *c); 1967 attribute_deprecated 1968 AVCodec * av_format_get_audio_codec(const AVFormatContext *s); 1969 attribute_deprecated 1970 void av_format_set_audio_codec(AVFormatContext *s, AVCodec *c); 1971 attribute_deprecated 1972 AVCodec * av_format_get_subtitle_codec(const AVFormatContext *s); 1973 attribute_deprecated 1974 void av_format_set_subtitle_codec(AVFormatContext *s, AVCodec *c); 1975 attribute_deprecated 1976 AVCodec * av_format_get_data_codec(const AVFormatContext *s); 1977 attribute_deprecated 1978 void av_format_set_data_codec(AVFormatContext *s, AVCodec *c); 1979 attribute_deprecated 1980 int av_format_get_metadata_header_padding(const AVFormatContext *s); 1981 attribute_deprecated 1982 void av_format_set_metadata_header_padding(AVFormatContext *s, int c); 1983 attribute_deprecated 1984 void * av_format_get_opaque(const AVFormatContext *s); 1985 attribute_deprecated 1986 void av_format_set_opaque(AVFormatContext *s, void *opaque); 1987 attribute_deprecated 1988 av_format_control_message av_format_get_control_message_cb(const AVFormatContext *s); 1989 attribute_deprecated 1990 void av_format_set_control_message_cb(AVFormatContext *s, av_format_control_message callback); 1991 #if FF_API_OLD_OPEN_CALLBACKS 1992 attribute_deprecated AVOpenCallback av_format_get_open_cb(const AVFormatContext *s); 1993 attribute_deprecated void av_format_set_open_cb(AVFormatContext *s, AVOpenCallback callback); 1994 #endif 1995 #endif 1996 1997 /** 1998 * This function will cause global side data to be injected in the next packet 1999 * of each stream as well as after any subsequent seek. 2000 */ 2001 void av_format_inject_global_side_data(AVFormatContext *s); 2002 2003 /** 2004 * Returns the method used to set ctx->duration. 2005 * 2006 * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE. 2007 */ 2008 enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx); 2009 2010 typedef struct AVPacketList { 2011 AVPacket pkt; 2012 struct AVPacketList *next; 2013 } AVPacketList; 2014 2015 2016 /** 2017 * @defgroup lavf_core Core functions 2018 * @ingroup libavf 2019 * 2020 * Functions for querying libavformat capabilities, allocating core structures, 2021 * etc. 2022 * @{ 2023 */ 2024 2025 /** 2026 * Return the LIBAVFORMAT_VERSION_INT constant. 2027 */ 2028 unsigned avformat_version(void); 2029 2030 /** 2031 * Return the libavformat build-time configuration. 2032 */ 2033 const char *avformat_configuration(void); 2034 2035 /** 2036 * Return the libavformat license. 2037 */ 2038 const char *avformat_license(void); 2039 2040 #if FF_API_NEXT 2041 /** 2042 * Initialize libavformat and register all the muxers, demuxers and 2043 * protocols. If you do not call this function, then you can select 2044 * exactly which formats you want to support. 2045 * 2046 * @see av_register_input_format() 2047 * @see av_register_output_format() 2048 */ 2049 attribute_deprecated 2050 void av_register_all(void); 2051 2052 attribute_deprecated 2053 void av_register_input_format(AVInputFormat *format); 2054 attribute_deprecated 2055 void av_register_output_format(AVOutputFormat *format); 2056 #endif 2057 2058 /** 2059 * Do global initialization of network libraries. This is optional, 2060 * and not recommended anymore. 2061 * 2062 * This functions only exists to work around thread-safety issues 2063 * with older GnuTLS or OpenSSL libraries. If libavformat is linked 2064 * to newer versions of those libraries, or if you do not use them, 2065 * calling this function is unnecessary. Otherwise, you need to call 2066 * this function before any other threads using them are started. 2067 * 2068 * This function will be deprecated once support for older GnuTLS and 2069 * OpenSSL libraries is removed, and this function has no purpose 2070 * anymore. 2071 */ 2072 int avformat_network_init(void); 2073 2074 /** 2075 * Undo the initialization done by avformat_network_init. Call it only 2076 * once for each time you called avformat_network_init. 2077 */ 2078 int avformat_network_deinit(void); 2079 2080 #if FF_API_NEXT 2081 /** 2082 * If f is NULL, returns the first registered input format, 2083 * if f is non-NULL, returns the next registered input format after f 2084 * or NULL if f is the last one. 2085 */ 2086 attribute_deprecated 2087 AVInputFormat *av_iformat_next(const AVInputFormat *f); 2088 2089 /** 2090 * If f is NULL, returns the first registered output format, 2091 * if f is non-NULL, returns the next registered output format after f 2092 * or NULL if f is the last one. 2093 */ 2094 attribute_deprecated 2095 AVOutputFormat *av_oformat_next(const AVOutputFormat *f); 2096 #endif 2097 2098 /** 2099 * Iterate over all registered muxers. 2100 * 2101 * @param opaque a pointer where libavformat will store the iteration state. Must 2102 * point to NULL to start the iteration. 2103 * 2104 * @return the next registered muxer or NULL when the iteration is 2105 * finished 2106 */ 2107 const AVOutputFormat *av_muxer_iterate(void **opaque); 2108 2109 /** 2110 * Iterate over all registered demuxers. 2111 * 2112 * @param opaque a pointer where libavformat will store the iteration state. Must 2113 * point to NULL to start the iteration. 2114 * 2115 * @return the next registered demuxer or NULL when the iteration is 2116 * finished 2117 */ 2118 const AVInputFormat *av_demuxer_iterate(void **opaque); 2119 2120 /** 2121 * Allocate an AVFormatContext. 2122 * avformat_free_context() can be used to free the context and everything 2123 * allocated by the framework within it. 2124 */ 2125 AVFormatContext *avformat_alloc_context(void); 2126 2127 /** 2128 * Free an AVFormatContext and all its streams. 2129 * @param s context to free 2130 */ 2131 void avformat_free_context(AVFormatContext *s); 2132 2133 /** 2134 * Get the AVClass for AVFormatContext. It can be used in combination with 2135 * AV_OPT_SEARCH_FAKE_OBJ for examining options. 2136 * 2137 * @see av_opt_find(). 2138 */ 2139 const AVClass *avformat_get_class(void); 2140 2141 /** 2142 * Add a new stream to a media file. 2143 * 2144 * When demuxing, it is called by the demuxer in read_header(). If the 2145 * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also 2146 * be called in read_packet(). 2147 * 2148 * When muxing, should be called by the user before avformat_write_header(). 2149 * 2150 * User is required to call avcodec_close() and avformat_free_context() to 2151 * clean up the allocation by avformat_new_stream(). 2152 * 2153 * @param s media file handle 2154 * @param c If non-NULL, the AVCodecContext corresponding to the new stream 2155 * will be initialized to use this codec. This is needed for e.g. codec-specific 2156 * defaults to be set, so codec should be provided if it is known. 2157 * 2158 * @return newly created stream or NULL on error. 2159 */ 2160 AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c); 2161 2162 /** 2163 * Wrap an existing array as stream side data. 2164 * 2165 * @param st stream 2166 * @param type side information type 2167 * @param data the side data array. It must be allocated with the av_malloc() 2168 * family of functions. The ownership of the data is transferred to 2169 * st. 2170 * @param size side information size 2171 * @return zero on success, a negative AVERROR code on failure. On failure, 2172 * the stream is unchanged and the data remains owned by the caller. 2173 */ 2174 int av_stream_add_side_data(AVStream *st, enum AVPacketSideDataType type, 2175 uint8_t *data, size_t size); 2176 2177 /** 2178 * Allocate new information from stream. 2179 * 2180 * @param stream stream 2181 * @param type desired side information type 2182 * @param size side information size 2183 * @return pointer to fresh allocated data or NULL otherwise 2184 */ 2185 uint8_t *av_stream_new_side_data(AVStream *stream, 2186 enum AVPacketSideDataType type, int size); 2187 /** 2188 * Get side information from stream. 2189 * 2190 * @param stream stream 2191 * @param type desired side information type 2192 * @param size pointer for side information size to store (optional) 2193 * @return pointer to data if present or NULL otherwise 2194 */ 2195 uint8_t *av_stream_get_side_data(const AVStream *stream, 2196 enum AVPacketSideDataType type, int *size); 2197 2198 AVProgram *av_new_program(AVFormatContext *s, int id); 2199 2200 /** 2201 * @} 2202 */ 2203 2204 2205 /** 2206 * Allocate an AVFormatContext for an output format. 2207 * avformat_free_context() can be used to free the context and 2208 * everything allocated by the framework within it. 2209 * 2210 * @param *ctx is set to the created format context, or to NULL in 2211 * case of failure 2212 * @param oformat format to use for allocating the context, if NULL 2213 * format_name and filename are used instead 2214 * @param format_name the name of output format to use for allocating the 2215 * context, if NULL filename is used instead 2216 * @param filename the name of the filename to use for allocating the 2217 * context, may be NULL 2218 * @return >= 0 in case of success, a negative AVERROR code in case of 2219 * failure 2220 */ 2221 int avformat_alloc_output_context2(AVFormatContext **ctx, ff_const59 AVOutputFormat *oformat, 2222 const char *format_name, const char *filename); 2223 2224 /** 2225 * @addtogroup lavf_decoding 2226 * @{ 2227 */ 2228 2229 /** 2230 * Find AVInputFormat based on the short name of the input format. 2231 */ 2232 ff_const59 AVInputFormat *av_find_input_format(const char *short_name); 2233 2234 /** 2235 * Guess the file format. 2236 * 2237 * @param pd data to be probed 2238 * @param is_opened Whether the file is already opened; determines whether 2239 * demuxers with or without AVFMT_NOFILE are probed. 2240 */ 2241 ff_const59 AVInputFormat *av_probe_input_format(ff_const59 AVProbeData *pd, int is_opened); 2242 2243 /** 2244 * Guess the file format. 2245 * 2246 * @param pd data to be probed 2247 * @param is_opened Whether the file is already opened; determines whether 2248 * demuxers with or without AVFMT_NOFILE are probed. 2249 * @param score_max A probe score larger that this is required to accept a 2250 * detection, the variable is set to the actual detection 2251 * score afterwards. 2252 * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended 2253 * to retry with a larger probe buffer. 2254 */ 2255 ff_const59 AVInputFormat *av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max); 2256 2257 /** 2258 * Guess the file format. 2259 * 2260 * @param is_opened Whether the file is already opened; determines whether 2261 * demuxers with or without AVFMT_NOFILE are probed. 2262 * @param score_ret The score of the best detection. 2263 */ 2264 ff_const59 AVInputFormat *av_probe_input_format3(ff_const59 AVProbeData *pd, int is_opened, int *score_ret); 2265 2266 /** 2267 * Probe a bytestream to determine the input format. Each time a probe returns 2268 * with a score that is too low, the probe buffer size is increased and another 2269 * attempt is made. When the maximum probe size is reached, the input format 2270 * with the highest score is returned. 2271 * 2272 * @param pb the bytestream to probe 2273 * @param fmt the input format is put here 2274 * @param url the url of the stream 2275 * @param logctx the log context 2276 * @param offset the offset within the bytestream to probe from 2277 * @param max_probe_size the maximum probe buffer size (zero for default) 2278 * @return the score in case of success, a negative value corresponding to an 2279 * the maximal score is AVPROBE_SCORE_MAX 2280 * AVERROR code otherwise 2281 */ 2282 int av_probe_input_buffer2(AVIOContext *pb, ff_const59 AVInputFormat **fmt, 2283 const char *url, void *logctx, 2284 unsigned int offset, unsigned int max_probe_size); 2285 2286 /** 2287 * Like av_probe_input_buffer2() but returns 0 on success 2288 */ 2289 int av_probe_input_buffer(AVIOContext *pb, ff_const59 AVInputFormat **fmt, 2290 const char *url, void *logctx, 2291 unsigned int offset, unsigned int max_probe_size); 2292 2293 /** 2294 * Open an input stream and read the header. The codecs are not opened. 2295 * The stream must be closed with avformat_close_input(). 2296 * 2297 * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context). 2298 * May be a pointer to NULL, in which case an AVFormatContext is allocated by this 2299 * function and written into ps. 2300 * Note that a user-supplied AVFormatContext will be freed on failure. 2301 * @param url URL of the stream to open. 2302 * @param fmt If non-NULL, this parameter forces a specific input format. 2303 * Otherwise the format is autodetected. 2304 * @param options A dictionary filled with AVFormatContext and demuxer-private options. 2305 * On return this parameter will be destroyed and replaced with a dict containing 2306 * options that were not found. May be NULL. 2307 * 2308 * @return 0 on success, a negative AVERROR on failure. 2309 * 2310 * @note If you want to use custom IO, preallocate the format context and set its pb field. 2311 */ 2312 int avformat_open_input(AVFormatContext **ps, const char *url, ff_const59 AVInputFormat *fmt, AVDictionary **options); 2313 2314 attribute_deprecated 2315 int av_demuxer_open(AVFormatContext *ic); 2316 2317 /** 2318 * Read packets of a media file to get stream information. This 2319 * is useful for file formats with no headers such as MPEG. This 2320 * function also computes the real framerate in case of MPEG-2 repeat 2321 * frame mode. 2322 * The logical file position is not changed by this function; 2323 * examined packets may be buffered for later processing. 2324 * 2325 * @param ic media file handle 2326 * @param options If non-NULL, an ic.nb_streams long array of pointers to 2327 * dictionaries, where i-th member contains options for 2328 * codec corresponding to i-th stream. 2329 * On return each dictionary will be filled with options that were not found. 2330 * @return >=0 if OK, AVERROR_xxx on error 2331 * 2332 * @note this function isn't guaranteed to open all the codecs, so 2333 * options being non-empty at return is a perfectly normal behavior. 2334 * 2335 * @todo Let the user decide somehow what information is needed so that 2336 * we do not waste time getting stuff the user does not need. 2337 */ 2338 int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options); 2339 2340 /** 2341 * Find the programs which belong to a given stream. 2342 * 2343 * @param ic media file handle 2344 * @param last the last found program, the search will start after this 2345 * program, or from the beginning if it is NULL 2346 * @param s stream index 2347 * @return the next program which belongs to s, NULL if no program is found or 2348 * the last program is not among the programs of ic. 2349 */ 2350 AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s); 2351 2352 void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx); 2353 2354 /** 2355 * Find the "best" stream in the file. 2356 * The best stream is determined according to various heuristics as the most 2357 * likely to be what the user expects. 2358 * If the decoder parameter is non-NULL, av_find_best_stream will find the 2359 * default decoder for the stream's codec; streams for which no decoder can 2360 * be found are ignored. 2361 * 2362 * @param ic media file handle 2363 * @param type stream type: video, audio, subtitles, etc. 2364 * @param wanted_stream_nb user-requested stream number, 2365 * or -1 for automatic selection 2366 * @param related_stream try to find a stream related (eg. in the same 2367 * program) to this one, or -1 if none 2368 * @param decoder_ret if non-NULL, returns the decoder for the 2369 * selected stream 2370 * @param flags flags; none are currently defined 2371 * @return the non-negative stream number in case of success, 2372 * AVERROR_STREAM_NOT_FOUND if no stream with the requested type 2373 * could be found, 2374 * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder 2375 * @note If av_find_best_stream returns successfully and decoder_ret is not 2376 * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec. 2377 */ 2378 int av_find_best_stream(AVFormatContext *ic, 2379 enum AVMediaType type, 2380 int wanted_stream_nb, 2381 int related_stream, 2382 AVCodec **decoder_ret, 2383 int flags); 2384 2385 /** 2386 * Return the next frame of a stream. 2387 * This function returns what is stored in the file, and does not validate 2388 * that what is there are valid frames for the decoder. It will split what is 2389 * stored in the file into frames and return one for each call. It will not 2390 * omit invalid data between valid frames so as to give the decoder the maximum 2391 * information possible for decoding. 2392 * 2393 * On success, the returned packet is reference-counted (pkt->buf is set) and 2394 * valid indefinitely. The packet must be freed with av_packet_unref() when 2395 * it is no longer needed. For video, the packet contains exactly one frame. 2396 * For audio, it contains an integer number of frames if each frame has 2397 * a known fixed size (e.g. PCM or ADPCM data). If the audio frames have 2398 * a variable size (e.g. MPEG audio), then it contains one frame. 2399 * 2400 * pkt->pts, pkt->dts and pkt->duration are always set to correct 2401 * values in AVStream.time_base units (and guessed if the format cannot 2402 * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format 2403 * has B-frames, so it is better to rely on pkt->dts if you do not 2404 * decompress the payload. 2405 * 2406 * @return 0 if OK, < 0 on error or end of file. On error, pkt will be blank 2407 * (as if it came from av_packet_alloc()). 2408 * 2409 * @note pkt will be initialized, so it may be uninitialized, but it must not 2410 * contain data that needs to be freed. 2411 */ 2412 int av_read_frame(AVFormatContext *s, AVPacket *pkt); 2413 2414 /** 2415 * Seek to the keyframe at timestamp. 2416 * 'timestamp' in 'stream_index'. 2417 * 2418 * @param s media file handle 2419 * @param stream_index If stream_index is (-1), a default 2420 * stream is selected, and timestamp is automatically converted 2421 * from AV_TIME_BASE units to the stream specific time_base. 2422 * @param timestamp Timestamp in AVStream.time_base units 2423 * or, if no stream is specified, in AV_TIME_BASE units. 2424 * @param flags flags which select direction and seeking mode 2425 * @return >= 0 on success 2426 */ 2427 int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp, 2428 int flags); 2429 2430 /** 2431 * Seek to timestamp ts. 2432 * Seeking will be done so that the point from which all active streams 2433 * can be presented successfully will be closest to ts and within min/max_ts. 2434 * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL. 2435 * 2436 * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and 2437 * are the file position (this may not be supported by all demuxers). 2438 * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames 2439 * in the stream with stream_index (this may not be supported by all demuxers). 2440 * Otherwise all timestamps are in units of the stream selected by stream_index 2441 * or if stream_index is -1, in AV_TIME_BASE units. 2442 * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as 2443 * keyframes (this may not be supported by all demuxers). 2444 * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored. 2445 * 2446 * @param s media file handle 2447 * @param stream_index index of the stream which is used as time base reference 2448 * @param min_ts smallest acceptable timestamp 2449 * @param ts target timestamp 2450 * @param max_ts largest acceptable timestamp 2451 * @param flags flags 2452 * @return >=0 on success, error code otherwise 2453 * 2454 * @note This is part of the new seek API which is still under construction. 2455 */ 2456 int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags); 2457 2458 /** 2459 * Discard all internally buffered data. This can be useful when dealing with 2460 * discontinuities in the byte stream. Generally works only with formats that 2461 * can resync. This includes headerless formats like MPEG-TS/TS but should also 2462 * work with NUT, Ogg and in a limited way AVI for example. 2463 * 2464 * The set of streams, the detected duration, stream parameters and codecs do 2465 * not change when calling this function. If you want a complete reset, it's 2466 * better to open a new AVFormatContext. 2467 * 2468 * This does not flush the AVIOContext (s->pb). If necessary, call 2469 * avio_flush(s->pb) before calling this function. 2470 * 2471 * @param s media file handle 2472 * @return >=0 on success, error code otherwise 2473 */ 2474 int avformat_flush(AVFormatContext *s); 2475 2476 /** 2477 * Start playing a network-based stream (e.g. RTSP stream) at the 2478 * current position. 2479 */ 2480 int av_read_play(AVFormatContext *s); 2481 2482 /** 2483 * Pause a network-based stream (e.g. RTSP stream). 2484 * 2485 * Use av_read_play() to resume it. 2486 */ 2487 int av_read_pause(AVFormatContext *s); 2488 2489 /** 2490 * Close an opened input AVFormatContext. Free it and all its contents 2491 * and set *s to NULL. 2492 */ 2493 void avformat_close_input(AVFormatContext **s); 2494 /** 2495 * @} 2496 */ 2497 2498 #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward 2499 #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes 2500 #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes 2501 #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number 2502 2503 /** 2504 * @addtogroup lavf_encoding 2505 * @{ 2506 */ 2507 2508 #define AVSTREAM_INIT_IN_WRITE_HEADER 0 ///< stream parameters initialized in avformat_write_header 2509 #define AVSTREAM_INIT_IN_INIT_OUTPUT 1 ///< stream parameters initialized in avformat_init_output 2510 2511 /** 2512 * Allocate the stream private data and write the stream header to 2513 * an output media file. 2514 * 2515 * @param s Media file handle, must be allocated with avformat_alloc_context(). 2516 * Its oformat field must be set to the desired output format; 2517 * Its pb field must be set to an already opened AVIOContext. 2518 * @param options An AVDictionary filled with AVFormatContext and muxer-private options. 2519 * On return this parameter will be destroyed and replaced with a dict containing 2520 * options that were not found. May be NULL. 2521 * 2522 * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init, 2523 * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec had already been fully initialized in avformat_init, 2524 * negative AVERROR on failure. 2525 * 2526 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output. 2527 */ 2528 av_warn_unused_result 2529 int avformat_write_header(AVFormatContext *s, AVDictionary **options); 2530 2531 /** 2532 * Allocate the stream private data and initialize the codec, but do not write the header. 2533 * May optionally be used before avformat_write_header to initialize stream parameters 2534 * before actually writing the header. 2535 * If using this function, do not pass the same options to avformat_write_header. 2536 * 2537 * @param s Media file handle, must be allocated with avformat_alloc_context(). 2538 * Its oformat field must be set to the desired output format; 2539 * Its pb field must be set to an already opened AVIOContext. 2540 * @param options An AVDictionary filled with AVFormatContext and muxer-private options. 2541 * On return this parameter will be destroyed and replaced with a dict containing 2542 * options that were not found. May be NULL. 2543 * 2544 * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec requires avformat_write_header to fully initialize, 2545 * AVSTREAM_INIT_IN_INIT_OUTPUT on success if the codec has been fully initialized, 2546 * negative AVERROR on failure. 2547 * 2548 * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header. 2549 */ 2550 av_warn_unused_result 2551 int avformat_init_output(AVFormatContext *s, AVDictionary **options); 2552 2553 /** 2554 * Write a packet to an output media file. 2555 * 2556 * This function passes the packet directly to the muxer, without any buffering 2557 * or reordering. The caller is responsible for correctly interleaving the 2558 * packets if the format requires it. Callers that want libavformat to handle 2559 * the interleaving should call av_interleaved_write_frame() instead of this 2560 * function. 2561 * 2562 * @param s media file handle 2563 * @param pkt The packet containing the data to be written. Note that unlike 2564 * av_interleaved_write_frame(), this function does not take 2565 * ownership of the packet passed to it (though some muxers may make 2566 * an internal reference to the input packet). 2567 * <br> 2568 * This parameter can be NULL (at any time, not just at the end), in 2569 * order to immediately flush data buffered within the muxer, for 2570 * muxers that buffer up data internally before writing it to the 2571 * output. 2572 * <br> 2573 * Packet's @ref AVPacket.stream_index "stream_index" field must be 2574 * set to the index of the corresponding stream in @ref 2575 * AVFormatContext.streams "s->streams". 2576 * <br> 2577 * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts") 2578 * must be set to correct values in the stream's timebase (unless the 2579 * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then 2580 * they can be set to AV_NOPTS_VALUE). 2581 * The dts for subsequent packets passed to this function must be strictly 2582 * increasing when compared in their respective timebases (unless the 2583 * output format is flagged with the AVFMT_TS_NONSTRICT, then they 2584 * merely have to be nondecreasing). @ref AVPacket.duration 2585 * "duration") should also be set if known. 2586 * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush 2587 * 2588 * @see av_interleaved_write_frame() 2589 */ 2590 int av_write_frame(AVFormatContext *s, AVPacket *pkt); 2591 2592 /** 2593 * Write a packet to an output media file ensuring correct interleaving. 2594 * 2595 * This function will buffer the packets internally as needed to make sure the 2596 * packets in the output file are properly interleaved in the order of 2597 * increasing dts. Callers doing their own interleaving should call 2598 * av_write_frame() instead of this function. 2599 * 2600 * Using this function instead of av_write_frame() can give muxers advance 2601 * knowledge of future packets, improving e.g. the behaviour of the mp4 2602 * muxer for VFR content in fragmenting mode. 2603 * 2604 * @param s media file handle 2605 * @param pkt The packet containing the data to be written. 2606 * <br> 2607 * If the packet is reference-counted, this function will take 2608 * ownership of this reference and unreference it later when it sees 2609 * fit. 2610 * The caller must not access the data through this reference after 2611 * this function returns. If the packet is not reference-counted, 2612 * libavformat will make a copy. 2613 * <br> 2614 * This parameter can be NULL (at any time, not just at the end), to 2615 * flush the interleaving queues. 2616 * <br> 2617 * Packet's @ref AVPacket.stream_index "stream_index" field must be 2618 * set to the index of the corresponding stream in @ref 2619 * AVFormatContext.streams "s->streams". 2620 * <br> 2621 * The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts") 2622 * must be set to correct values in the stream's timebase (unless the 2623 * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then 2624 * they can be set to AV_NOPTS_VALUE). 2625 * The dts for subsequent packets in one stream must be strictly 2626 * increasing (unless the output format is flagged with the 2627 * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing). 2628 * @ref AVPacket.duration "duration") should also be set if known. 2629 * 2630 * @return 0 on success, a negative AVERROR on error. Libavformat will always 2631 * take care of freeing the packet, even if this function fails. 2632 * 2633 * @see av_write_frame(), AVFormatContext.max_interleave_delta 2634 */ 2635 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt); 2636 2637 /** 2638 * Write an uncoded frame to an output media file. 2639 * 2640 * The frame must be correctly interleaved according to the container 2641 * specification; if not, av_interleaved_write_uncoded_frame() must be used. 2642 * 2643 * See av_interleaved_write_uncoded_frame() for details. 2644 */ 2645 int av_write_uncoded_frame(AVFormatContext *s, int stream_index, 2646 AVFrame *frame); 2647 2648 /** 2649 * Write an uncoded frame to an output media file. 2650 * 2651 * If the muxer supports it, this function makes it possible to write an AVFrame 2652 * structure directly, without encoding it into a packet. 2653 * It is mostly useful for devices and similar special muxers that use raw 2654 * video or PCM data and will not serialize it into a byte stream. 2655 * 2656 * To test whether it is possible to use it with a given muxer and stream, 2657 * use av_write_uncoded_frame_query(). 2658 * 2659 * The caller gives up ownership of the frame and must not access it 2660 * afterwards. 2661 * 2662 * @return >=0 for success, a negative code on error 2663 */ 2664 int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index, 2665 AVFrame *frame); 2666 2667 /** 2668 * Test whether a muxer supports uncoded frame. 2669 * 2670 * @return >=0 if an uncoded frame can be written to that muxer and stream, 2671 * <0 if not 2672 */ 2673 int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index); 2674 2675 /** 2676 * Write the stream trailer to an output media file and free the 2677 * file private data. 2678 * 2679 * May only be called after a successful call to avformat_write_header. 2680 * 2681 * @param s media file handle 2682 * @return 0 if OK, AVERROR_xxx on error 2683 */ 2684 int av_write_trailer(AVFormatContext *s); 2685 2686 /** 2687 * Return the output format in the list of registered output formats 2688 * which best matches the provided parameters, or return NULL if 2689 * there is no match. 2690 * 2691 * @param short_name if non-NULL checks if short_name matches with the 2692 * names of the registered formats 2693 * @param filename if non-NULL checks if filename terminates with the 2694 * extensions of the registered formats 2695 * @param mime_type if non-NULL checks if mime_type matches with the 2696 * MIME type of the registered formats 2697 */ 2698 ff_const59 AVOutputFormat *av_guess_format(const char *short_name, 2699 const char *filename, 2700 const char *mime_type); 2701 2702 /** 2703 * Guess the codec ID based upon muxer and filename. 2704 */ 2705 enum AVCodecID av_guess_codec(ff_const59 AVOutputFormat *fmt, const char *short_name, 2706 const char *filename, const char *mime_type, 2707 enum AVMediaType type); 2708 2709 /** 2710 * Get timing information for the data currently output. 2711 * The exact meaning of "currently output" depends on the format. 2712 * It is mostly relevant for devices that have an internal buffer and/or 2713 * work in real time. 2714 * @param s media file handle 2715 * @param stream stream in the media file 2716 * @param[out] dts DTS of the last packet output for the stream, in stream 2717 * time_base units 2718 * @param[out] wall absolute time when that packet whas output, 2719 * in microsecond 2720 * @return 0 if OK, AVERROR(ENOSYS) if the format does not support it 2721 * Note: some formats or devices may not allow to measure dts and wall 2722 * atomically. 2723 */ 2724 int av_get_output_timestamp(struct AVFormatContext *s, int stream, 2725 int64_t *dts, int64_t *wall); 2726 2727 2728 /** 2729 * @} 2730 */ 2731 2732 2733 /** 2734 * @defgroup lavf_misc Utility functions 2735 * @ingroup libavf 2736 * @{ 2737 * 2738 * Miscellaneous utility functions related to both muxing and demuxing 2739 * (or neither). 2740 */ 2741 2742 /** 2743 * Send a nice hexadecimal dump of a buffer to the specified file stream. 2744 * 2745 * @param f The file stream pointer where the dump should be sent to. 2746 * @param buf buffer 2747 * @param size buffer size 2748 * 2749 * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2 2750 */ 2751 void av_hex_dump(FILE *f, const uint8_t *buf, int size); 2752 2753 /** 2754 * Send a nice hexadecimal dump of a buffer to the log. 2755 * 2756 * @param avcl A pointer to an arbitrary struct of which the first field is a 2757 * pointer to an AVClass struct. 2758 * @param level The importance level of the message, lower values signifying 2759 * higher importance. 2760 * @param buf buffer 2761 * @param size buffer size 2762 * 2763 * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2 2764 */ 2765 void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size); 2766 2767 /** 2768 * Send a nice dump of a packet to the specified file stream. 2769 * 2770 * @param f The file stream pointer where the dump should be sent to. 2771 * @param pkt packet to dump 2772 * @param dump_payload True if the payload must be displayed, too. 2773 * @param st AVStream that the packet belongs to 2774 */ 2775 void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st); 2776 2777 2778 /** 2779 * Send a nice dump of a packet to the log. 2780 * 2781 * @param avcl A pointer to an arbitrary struct of which the first field is a 2782 * pointer to an AVClass struct. 2783 * @param level The importance level of the message, lower values signifying 2784 * higher importance. 2785 * @param pkt packet to dump 2786 * @param dump_payload True if the payload must be displayed, too. 2787 * @param st AVStream that the packet belongs to 2788 */ 2789 void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload, 2790 const AVStream *st); 2791 2792 /** 2793 * Get the AVCodecID for the given codec tag tag. 2794 * If no codec id is found returns AV_CODEC_ID_NONE. 2795 * 2796 * @param tags list of supported codec_id-codec_tag pairs, as stored 2797 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag 2798 * @param tag codec tag to match to a codec ID 2799 */ 2800 enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag); 2801 2802 /** 2803 * Get the codec tag for the given codec id id. 2804 * If no codec tag is found returns 0. 2805 * 2806 * @param tags list of supported codec_id-codec_tag pairs, as stored 2807 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag 2808 * @param id codec ID to match to a codec tag 2809 */ 2810 unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id); 2811 2812 /** 2813 * Get the codec tag for the given codec id. 2814 * 2815 * @param tags list of supported codec_id - codec_tag pairs, as stored 2816 * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag 2817 * @param id codec id that should be searched for in the list 2818 * @param tag A pointer to the found tag 2819 * @return 0 if id was not found in tags, > 0 if it was found 2820 */ 2821 int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id, 2822 unsigned int *tag); 2823 2824 int av_find_default_stream_index(AVFormatContext *s); 2825 2826 /** 2827 * Get the index for a specific timestamp. 2828 * 2829 * @param st stream that the timestamp belongs to 2830 * @param timestamp timestamp to retrieve the index for 2831 * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond 2832 * to the timestamp which is <= the requested one, if backward 2833 * is 0, then it will be >= 2834 * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise 2835 * @return < 0 if no such timestamp could be found 2836 */ 2837 int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags); 2838 2839 /** 2840 * Add an index entry into a sorted list. Update the entry if the list 2841 * already contains it. 2842 * 2843 * @param timestamp timestamp in the time base of the given stream 2844 */ 2845 int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, 2846 int size, int distance, int flags); 2847 2848 2849 /** 2850 * Split a URL string into components. 2851 * 2852 * The pointers to buffers for storing individual components may be null, 2853 * in order to ignore that component. Buffers for components not found are 2854 * set to empty strings. If the port is not found, it is set to a negative 2855 * value. 2856 * 2857 * @param proto the buffer for the protocol 2858 * @param proto_size the size of the proto buffer 2859 * @param authorization the buffer for the authorization 2860 * @param authorization_size the size of the authorization buffer 2861 * @param hostname the buffer for the host name 2862 * @param hostname_size the size of the hostname buffer 2863 * @param port_ptr a pointer to store the port number in 2864 * @param path the buffer for the path 2865 * @param path_size the size of the path buffer 2866 * @param url the URL to split 2867 */ 2868 void av_url_split(char *proto, int proto_size, 2869 char *authorization, int authorization_size, 2870 char *hostname, int hostname_size, 2871 int *port_ptr, 2872 char *path, int path_size, 2873 const char *url); 2874 2875 2876 /** 2877 * Print detailed information about the input or output format, such as 2878 * duration, bitrate, streams, container, programs, metadata, side data, 2879 * codec and time base. 2880 * 2881 * @param ic the context to analyze 2882 * @param index index of the stream to dump information about 2883 * @param url the URL to print, such as source or destination file 2884 * @param is_output Select whether the specified context is an input(0) or output(1) 2885 */ 2886 void av_dump_format(AVFormatContext *ic, 2887 int index, 2888 const char *url, 2889 int is_output); 2890 2891 2892 #define AV_FRAME_FILENAME_FLAGS_MULTIPLE 1 ///< Allow multiple %d 2893 2894 /** 2895 * Return in 'buf' the path with '%d' replaced by a number. 2896 * 2897 * Also handles the '%0nd' format where 'n' is the total number 2898 * of digits and '%%'. 2899 * 2900 * @param buf destination buffer 2901 * @param buf_size destination buffer size 2902 * @param path numbered sequence string 2903 * @param number frame number 2904 * @param flags AV_FRAME_FILENAME_FLAGS_* 2905 * @return 0 if OK, -1 on format error 2906 */ 2907 int av_get_frame_filename2(char *buf, int buf_size, 2908 const char *path, int number, int flags); 2909 2910 int av_get_frame_filename(char *buf, int buf_size, 2911 const char *path, int number); 2912 2913 /** 2914 * Check whether filename actually is a numbered sequence generator. 2915 * 2916 * @param filename possible numbered sequence string 2917 * @return 1 if a valid numbered sequence string, 0 otherwise 2918 */ 2919 int av_filename_number_test(const char *filename); 2920 2921 /** 2922 * Generate an SDP for an RTP session. 2923 * 2924 * Note, this overwrites the id values of AVStreams in the muxer contexts 2925 * for getting unique dynamic payload types. 2926 * 2927 * @param ac array of AVFormatContexts describing the RTP streams. If the 2928 * array is composed by only one context, such context can contain 2929 * multiple AVStreams (one AVStream per RTP stream). Otherwise, 2930 * all the contexts in the array (an AVCodecContext per RTP stream) 2931 * must contain only one AVStream. 2932 * @param n_files number of AVCodecContexts contained in ac 2933 * @param buf buffer where the SDP will be stored (must be allocated by 2934 * the caller) 2935 * @param size the size of the buffer 2936 * @return 0 if OK, AVERROR_xxx on error 2937 */ 2938 int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size); 2939 2940 /** 2941 * Return a positive value if the given filename has one of the given 2942 * extensions, 0 otherwise. 2943 * 2944 * @param filename file name to check against the given extensions 2945 * @param extensions a comma-separated list of filename extensions 2946 */ 2947 int av_match_ext(const char *filename, const char *extensions); 2948 2949 /** 2950 * Test if the given container can store a codec. 2951 * 2952 * @param ofmt container to check for compatibility 2953 * @param codec_id codec to potentially store in container 2954 * @param std_compliance standards compliance level, one of FF_COMPLIANCE_* 2955 * 2956 * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot. 2957 * A negative number if this information is not available. 2958 */ 2959 int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id, 2960 int std_compliance); 2961 2962 /** 2963 * @defgroup riff_fourcc RIFF FourCCs 2964 * @{ 2965 * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are 2966 * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the 2967 * following code: 2968 * @code 2969 * uint32_t tag = MKTAG('H', '2', '6', '4'); 2970 * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 }; 2971 * enum AVCodecID id = av_codec_get_id(table, tag); 2972 * @endcode 2973 */ 2974 /** 2975 * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID. 2976 */ 2977 const struct AVCodecTag *avformat_get_riff_video_tags(void); 2978 /** 2979 * @return the table mapping RIFF FourCCs for audio to AVCodecID. 2980 */ 2981 const struct AVCodecTag *avformat_get_riff_audio_tags(void); 2982 /** 2983 * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID. 2984 */ 2985 const struct AVCodecTag *avformat_get_mov_video_tags(void); 2986 /** 2987 * @return the table mapping MOV FourCCs for audio to AVCodecID. 2988 */ 2989 const struct AVCodecTag *avformat_get_mov_audio_tags(void); 2990 2991 /** 2992 * @} 2993 */ 2994 2995 /** 2996 * Guess the sample aspect ratio of a frame, based on both the stream and the 2997 * frame aspect ratio. 2998 * 2999 * Since the frame aspect ratio is set by the codec but the stream aspect ratio 3000 * is set by the demuxer, these two may not be equal. This function tries to 3001 * return the value that you should use if you would like to display the frame. 3002 * 3003 * Basic logic is to use the stream aspect ratio if it is set to something sane 3004 * otherwise use the frame aspect ratio. This way a container setting, which is 3005 * usually easy to modify can override the coded value in the frames. 3006 * 3007 * @param format the format context which the stream is part of 3008 * @param stream the stream which the frame is part of 3009 * @param frame the frame with the aspect ratio to be determined 3010 * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea 3011 */ 3012 AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame); 3013 3014 /** 3015 * Guess the frame rate, based on both the container and codec information. 3016 * 3017 * @param ctx the format context which the stream is part of 3018 * @param stream the stream which the frame is part of 3019 * @param frame the frame for which the frame rate should be determined, may be NULL 3020 * @return the guessed (valid) frame rate, 0/1 if no idea 3021 */ 3022 AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame); 3023 3024 /** 3025 * Check if the stream st contained in s is matched by the stream specifier 3026 * spec. 3027 * 3028 * See the "stream specifiers" chapter in the documentation for the syntax 3029 * of spec. 3030 * 3031 * @return >0 if st is matched by spec; 3032 * 0 if st is not matched by spec; 3033 * AVERROR code if spec is invalid 3034 * 3035 * @note A stream specifier can match several streams in the format. 3036 */ 3037 int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st, 3038 const char *spec); 3039 3040 int avformat_queue_attached_pictures(AVFormatContext *s); 3041 3042 #if FF_API_OLD_BSF 3043 /** 3044 * Apply a list of bitstream filters to a packet. 3045 * 3046 * @param codec AVCodecContext, usually from an AVStream 3047 * @param pkt the packet to apply filters to. If, on success, the returned 3048 * packet has size == 0 and side_data_elems == 0, it indicates that 3049 * the packet should be dropped 3050 * @param bsfc a NULL-terminated list of filters to apply 3051 * @return >=0 on success; 3052 * AVERROR code on failure 3053 */ 3054 attribute_deprecated 3055 int av_apply_bitstream_filters(AVCodecContext *codec, AVPacket *pkt, 3056 AVBitStreamFilterContext *bsfc); 3057 #endif 3058 3059 enum AVTimebaseSource { 3060 AVFMT_TBCF_AUTO = -1, 3061 AVFMT_TBCF_DECODER, 3062 AVFMT_TBCF_DEMUXER, 3063 #if FF_API_R_FRAME_RATE 3064 AVFMT_TBCF_R_FRAMERATE, 3065 #endif 3066 }; 3067 3068 /** 3069 * Transfer internal timing information from one stream to another. 3070 * 3071 * This function is useful when doing stream copy. 3072 * 3073 * @param ofmt target output format for ost 3074 * @param ost output stream which needs timings copy and adjustments 3075 * @param ist reference input stream to copy timings from 3076 * @param copy_tb define from where the stream codec timebase needs to be imported 3077 */ 3078 int avformat_transfer_internal_stream_timing_info(const AVOutputFormat *ofmt, 3079 AVStream *ost, const AVStream *ist, 3080 enum AVTimebaseSource copy_tb); 3081 3082 /** 3083 * Get the internal codec timebase from a stream. 3084 * 3085 * @param st input stream to extract the timebase from 3086 */ 3087 AVRational av_stream_get_codec_timebase(const AVStream *st); 3088 3089 /** 3090 * @} 3091 */ 3092 3093 #endif /* AVFORMAT_AVFORMAT_H */ 3094