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 module ffmpeg.libavformat.avformat;
22 
23 import core.stdc.stdio;
24 
25 import ffmpeg.libavformat.avio;
26 
27 extern (C):
28 import ffmpeg; @nogc nothrow:
29 
30 /**
31  * @file
32  * @ingroup libavf
33  * Main libavformat public API header
34  */
35 
36 /**
37  * @defgroup libavf libavformat
38  * I/O and Muxing/Demuxing Library
39  *
40  * Libavformat (lavf) is a library for dealing with various media container
41  * formats. Its main two purposes are demuxing - i.e. splitting a media file
42  * into component streams, and the reverse process of muxing - writing supplied
43  * data in a specified container format. It also has an @ref lavf_io
44  * "I/O module" which supports a number of protocols for accessing the data (e.g.
45  * file, tcp, http and others). Before using lavf, you need to call
46  * av_register_all() to register all compiled muxers, demuxers and protocols.
47  * Unless you are absolutely sure you won't use libavformat's network
48  * capabilities, you should also call avformat_network_init().
49  *
50  * A supported input format is described by an AVInputFormat struct, conversely
51  * an output format is described by AVOutputFormat. You can iterate over all
52  * registered input/output formats using the av_iformat_next() /
53  * av_oformat_next() functions. The protocols layer is not part of the public
54  * API, so you can only get the names of supported protocols with the
55  * avio_enum_protocols() function.
56  *
57  * Main lavf structure used for both muxing and demuxing is AVFormatContext,
58  * which exports all information about the file being read or written. As with
59  * most Libavformat structures, its size is not part of public ABI, so it cannot be
60  * allocated on stack or directly with av_malloc(). To create an
61  * AVFormatContext, use avformat_alloc_context() (some functions, like
62  * avformat_open_input() might do that for you).
63  *
64  * Most importantly an AVFormatContext contains:
65  * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat
66  * "output" format. It is either autodetected or set by user for input;
67  * always set by user for output.
68  * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all
69  * elementary streams stored in the file. AVStreams are typically referred to
70  * using their index in this array.
71  * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or
72  * set by user for input, always set by user for output (unless you are dealing
73  * with an AVFMT_NOFILE format).
74  *
75  * @section lavf_options Passing options to (de)muxers
76  * It is possible to configure lavf muxers and demuxers using the @ref avoptions
77  * mechanism. Generic (format-independent) libavformat options are provided by
78  * AVFormatContext, they can be examined from a user program by calling
79  * av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass
80  * from avformat_get_class()). Private (format-specific) options are provided by
81  * AVFormatContext.priv_data if and only if AVInputFormat.priv_class /
82  * AVOutputFormat.priv_class of the corresponding format struct is non-NULL.
83  * Further options may be provided by the @ref AVFormatContext.pb "I/O context",
84  * if its AVClass is non-NULL, and the protocols layer. See the discussion on
85  * nesting in @ref avoptions documentation to learn how to access those.
86  *
87  * @section urls
88  * URL strings in libavformat are made of a scheme/protocol, a ':', and a
89  * scheme specific string. URLs without a scheme and ':' used for local files
90  * are supported but deprecated. "file:" should be used for local files.
91  *
92  * It is important that the scheme string is not taken from untrusted
93  * sources without checks.
94  *
95  * Note that some schemes/protocols are quite powerful, allowing access to
96  * both local and remote files, parts of them, concatenations of them, local
97  * audio and video devices and so on.
98  *
99  * @{
100  *
101  * @defgroup lavf_decoding Demuxing
102  * @{
103  * Demuxers read a media file and split it into chunks of data (@em packets). A
104  * @ref AVPacket "packet" contains one or more encoded frames which belongs to a
105  * single elementary stream. In the lavf API this process is represented by the
106  * avformat_open_input() function for opening a file, av_read_frame() for
107  * reading a single packet and finally avformat_close_input(), which does the
108  * cleanup.
109  *
110  * @section lavf_decoding_open Opening a media file
111  * The minimum information required to open a file is its URL, which
112  * is passed to avformat_open_input(), as in the following code:
113  * @code
114  * const char    *url = "file:in.mp3";
115  * AVFormatContext *s = NULL;
116  * int ret = avformat_open_input(&s, url, NULL, NULL);
117  * if (ret < 0)
118  *     abort();
119  * @endcode
120  * The above code attempts to allocate an AVFormatContext, open the
121  * specified file (autodetecting the format) and read the header, exporting the
122  * information stored there into s. Some formats do not have a header or do not
123  * store enough information there, so it is recommended that you call the
124  * avformat_find_stream_info() function which tries to read and decode a few
125  * frames to find missing information.
126  *
127  * In some cases you might want to preallocate an AVFormatContext yourself with
128  * avformat_alloc_context() and do some tweaking on it before passing it to
129  * avformat_open_input(). One such case is when you want to use custom functions
130  * for reading input data instead of lavf internal I/O layer.
131  * To do that, create your own AVIOContext with avio_alloc_context(), passing
132  * your reading callbacks to it. Then set the @em pb field of your
133  * AVFormatContext to newly created AVIOContext.
134  *
135  * Since the format of the opened file is in general not known until after
136  * avformat_open_input() has returned, it is not possible to set demuxer private
137  * options on a preallocated context. Instead, the options should be passed to
138  * avformat_open_input() wrapped in an AVDictionary:
139  * @code
140  * AVDictionary *options = NULL;
141  * av_dict_set(&options, "video_size", "640x480", 0);
142  * av_dict_set(&options, "pixel_format", "rgb24", 0);
143  *
144  * if (avformat_open_input(&s, url, NULL, &options) < 0)
145  *     abort();
146  * av_dict_free(&options);
147  * @endcode
148  * This code passes the private options 'video_size' and 'pixel_format' to the
149  * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it
150  * cannot know how to interpret raw video data otherwise. If the format turns
151  * out to be something different than raw video, those options will not be
152  * recognized by the demuxer and therefore will not be applied. Such unrecognized
153  * options are then returned in the options dictionary (recognized options are
154  * consumed). The calling program can handle such unrecognized options as it
155  * wishes, e.g.
156  * @code
157  * AVDictionaryEntry *e;
158  * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
159  *     fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key);
160  *     abort();
161  * }
162  * @endcode
163  *
164  * After you have finished reading the file, you must close it with
165  * avformat_close_input(). It will free everything associated with the file.
166  *
167  * @section lavf_decoding_read Reading from an opened file
168  * Reading data from an opened AVFormatContext is done by repeatedly calling
169  * av_read_frame() on it. Each call, if successful, will return an AVPacket
170  * containing encoded data for one AVStream, identified by
171  * AVPacket.stream_index. This packet may be passed straight into the libavcodec
172  * decoding functions avcodec_send_packet() or avcodec_decode_subtitle2() if the
173  * caller wishes to decode the data.
174  *
175  * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be
176  * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for
177  * pts/dts, 0 for duration) if the stream does not provide them. The timing
178  * information will be in AVStream.time_base units, i.e. it has to be
179  * multiplied by the timebase to convert them to seconds.
180  *
181  * If AVPacket.buf is set on the returned packet, then the packet is
182  * allocated dynamically and the user may keep it indefinitely.
183  * Otherwise, if AVPacket.buf is NULL, the packet data is backed by a
184  * static storage somewhere inside the demuxer and the packet is only valid
185  * until the next av_read_frame() call or closing the file. If the caller
186  * requires a longer lifetime, av_dup_packet() will make an av_malloc()ed copy
187  * of it.
188  * In both cases, the packet must be freed with av_packet_unref() when it is no
189  * longer needed.
190  *
191  * @section lavf_decoding_seek Seeking
192  * @}
193  *
194  * @defgroup lavf_encoding Muxing
195  * @{
196  * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write
197  * it into files or other output bytestreams in the specified container format.
198  *
199  * The main API functions for muxing are avformat_write_header() for writing the
200  * file header, av_write_frame() / av_interleaved_write_frame() for writing the
201  * packets and av_write_trailer() for finalizing the file.
202  *
203  * At the beginning of the muxing process, the caller must first call
204  * avformat_alloc_context() to create a muxing context. The caller then sets up
205  * the muxer by filling the various fields in this context:
206  *
207  * - The @ref AVFormatContext.oformat "oformat" field must be set to select the
208  *   muxer that will be used.
209  * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb
210  *   "pb" field must be set to an opened IO context, either returned from
211  *   avio_open2() or a custom one.
212  * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must
213  *   be created with the avformat_new_stream() function. The caller should fill
214  *   the @ref AVStream.codecpar "stream codec parameters" information, such as the
215  *   codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id
216  *   "id" and other parameters (e.g. width / height, the pixel or sample format,
217  *   etc.) as known. The @ref AVStream.time_base "stream timebase" should
218  *   be set to the timebase that the caller desires to use for this stream (note
219  *   that the timebase actually used by the muxer can be different, as will be
220  *   described later).
221  * - It is advised to manually initialize only the relevant fields in
222  *   AVCodecParameters, rather than using @ref avcodec_parameters_copy() during
223  *   remuxing: there is no guarantee that the codec context values remain valid
224  *   for both input and output format contexts.
225  * - The caller may fill in additional information, such as @ref
226  *   AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream"
227  *   metadata, @ref AVFormatContext.chapters "chapters", @ref
228  *   AVFormatContext.programs "programs", etc. as described in the
229  *   AVFormatContext documentation. Whether such information will actually be
230  *   stored in the output depends on what the container format and the muxer
231  *   support.
232  *
233  * When the muxing context is fully set up, the caller must call
234  * avformat_write_header() to initialize the muxer internals and write the file
235  * header. Whether anything actually is written to the IO context at this step
236  * depends on the muxer, but this function must always be called. Any muxer
237  * private options must be passed in the options parameter to this function.
238  *
239  * The data is then sent to the muxer by repeatedly calling av_write_frame() or
240  * av_interleaved_write_frame() (consult those functions' documentation for
241  * discussion on the difference between them; only one of them may be used with
242  * a single muxing context, they should not be mixed). Do note that the timing
243  * information on the packets sent to the muxer must be in the corresponding
244  * AVStream's timebase. That timebase is set by the muxer (in the
245  * avformat_write_header() step) and may be different from the timebase
246  * requested by the caller.
247  *
248  * Once all the data has been written, the caller must call av_write_trailer()
249  * to flush any buffered packets and finalize the output file, then close the IO
250  * context (if any) and finally free the muxing context with
251  * avformat_free_context().
252  * @}
253  *
254  * @defgroup lavf_io I/O Read/Write
255  * @{
256  * @section lavf_io_dirlist Directory listing
257  * The directory listing API makes it possible to list files on remote servers.
258  *
259  * Some of possible use cases:
260  * - an "open file" dialog to choose files from a remote location,
261  * - a recursive media finder providing a player with an ability to play all
262  * files from a given directory.
263  *
264  * @subsection lavf_io_dirlist_open Opening a directory
265  * At first, a directory needs to be opened by calling avio_open_dir()
266  * supplied with a URL and, optionally, ::AVDictionary containing
267  * protocol-specific parameters. The function returns zero or positive
268  * integer and allocates AVIODirContext on success.
269  *
270  * @code
271  * AVIODirContext *ctx = NULL;
272  * if (avio_open_dir(&ctx, "smb://example.com/some_dir", NULL) < 0) {
273  *     fprintf(stderr, "Cannot open directory.\n");
274  *     abort();
275  * }
276  * @endcode
277  *
278  * This code tries to open a sample directory using smb protocol without
279  * any additional parameters.
280  *
281  * @subsection lavf_io_dirlist_read Reading entries
282  * Each directory's entry (i.e. file, another directory, anything else
283  * within ::AVIODirEntryType) is represented by AVIODirEntry.
284  * Reading consecutive entries from an opened AVIODirContext is done by
285  * repeatedly calling avio_read_dir() on it. Each call returns zero or
286  * positive integer if successful. Reading can be stopped right after the
287  * NULL entry has been read -- it means there are no entries left to be
288  * read. The following code reads all entries from a directory associated
289  * with ctx and prints their names to standard output.
290  * @code
291  * AVIODirEntry *entry = NULL;
292  * for (;;) {
293  *     if (avio_read_dir(ctx, &entry) < 0) {
294  *         fprintf(stderr, "Cannot list directory.\n");
295  *         abort();
296  *     }
297  *     if (!entry)
298  *         break;
299  *     printf("%s\n", entry->name);
300  *     avio_free_directory_entry(&entry);
301  * }
302  * @endcode
303  * @}
304  *
305  * @defgroup lavf_codec Demuxers
306  * @{
307  * @defgroup lavf_codec_native Native Demuxers
308  * @{
309  * @}
310  * @defgroup lavf_codec_wrappers External library wrappers
311  * @{
312  * @}
313  * @}
314  * @defgroup lavf_protos I/O Protocols
315  * @{
316  * @}
317  * @defgroup lavf_internal Internal
318  * @{
319  * @}
320  * @}
321  */
322 
323 /* FILE */
324 
325 struct AVDeviceInfoList;
326 struct AVDeviceCapabilitiesQuery;
327 
328 /**
329  * @defgroup metadata_api Public Metadata API
330  * @{
331  * @ingroup libavf
332  * The metadata API allows libavformat to export metadata tags to a client
333  * application when demuxing. Conversely it allows a client application to
334  * set metadata when muxing.
335  *
336  * Metadata is exported or set as pairs of key/value strings in the 'metadata'
337  * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
338  * using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
339  * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
340  * exported by demuxers isn't checked to be valid UTF-8 in most cases.
341  *
342  * Important concepts to keep in mind:
343  * -  Keys are unique; there can never be 2 tags with the same key. This is
344  *    also meant semantically, i.e., a demuxer should not knowingly produce
345  *    several keys that are literally different but semantically identical.
346  *    E.g., key=Author5, key=Author6. In this example, all authors must be
347  *    placed in the same tag.
348  * -  Metadata is flat, not hierarchical; there are no subtags. If you
349  *    want to store, e.g., the email address of the child of producer Alice
350  *    and actor Bob, that could have key=alice_and_bobs_childs_email_address.
351  * -  Several modifiers can be applied to the tag name. This is done by
352  *    appending a dash character ('-') and the modifier name in the order
353  *    they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
354  *    -  language -- a tag whose value is localized for a particular language
355  *       is appended with the ISO 639-2/B 3-letter language code.
356  *       For example: Author-ger=Michael, Author-eng=Mike
357  *       The original/default language is in the unqualified "Author" tag.
358  *       A demuxer should set a default if it sets any translated tag.
359  *    -  sorting  -- a modified version of a tag that should be used for
360  *       sorting will have '-sort' appended. E.g. artist="The Beatles",
361  *       artist-sort="Beatles, The".
362  * - Some protocols and demuxers support metadata updates. After a successful
363  *   call to av_read_packet(), AVFormatContext.event_flags or AVStream.event_flags
364  *   will be updated to indicate if metadata changed. In order to detect metadata
365  *   changes on a stream, you need to loop through all streams in the AVFormatContext
366  *   and check their individual event_flags.
367  *
368  * -  Demuxers attempt to export metadata in a generic format, however tags
369  *    with no generic equivalents are left as they are stored in the container.
370  *    Follows a list of generic tag names:
371  *
372  @verbatim
373  album        -- name of the set this work belongs to
374  album_artist -- main creator of the set/album, if different from artist.
375                  e.g. "Various Artists" for compilation albums.
376  artist       -- main creator of the work
377  comment      -- any additional description of the file.
378  composer     -- who composed the work, if different from artist.
379  copyright    -- name of copyright holder.
380  creation_time-- date when the file was created, preferably in ISO 8601.
381  date         -- date when the work was created, preferably in ISO 8601.
382  disc         -- number of a subset, e.g. disc in a multi-disc collection.
383  encoder      -- name/settings of the software/hardware that produced the file.
384  encoded_by   -- person/group who created the file.
385  filename     -- original name of the file.
386  genre        -- <self-evident>.
387  language     -- main language in which the work is performed, preferably
388                  in ISO 639-2 format. Multiple languages can be specified by
389                  separating them with commas.
390  performer    -- artist who performed the work, if different from artist.
391                  E.g for "Also sprach Zarathustra", artist would be "Richard
392                  Strauss" and performer "London Philharmonic Orchestra".
393  publisher    -- name of the label/publisher.
394  service_name     -- name of the service in broadcasting (channel name).
395  service_provider -- name of the service provider in broadcasting.
396  title        -- name of the work.
397  track        -- number of this work in the set, can be in form current/total.
398  variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
399  @endverbatim
400  *
401  * Look in the examples section for an application example how to use the Metadata API.
402  *
403  * @}
404  */
405 
406 /* packet functions */
407 
408 /**
409  * Allocate and read the payload of a packet and initialize its
410  * fields with default values.
411  *
412  * @param s    associated IO context
413  * @param pkt packet
414  * @param size desired payload size
415  * @return >0 (read size) if OK, AVERROR_xxx otherwise
416  */
417 int av_get_packet (AVIOContext* s, AVPacket* pkt, int size);
418 
419 /**
420  * Read data and append it to the current content of the AVPacket.
421  * If pkt->size is 0 this is identical to av_get_packet.
422  * Note that this uses av_grow_packet and thus involves a realloc
423  * which is inefficient. Thus this function should only be used
424  * when there is no reasonable way to know (an upper bound of)
425  * the final size.
426  *
427  * @param s    associated IO context
428  * @param pkt packet
429  * @param size amount of data to read
430  * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
431  *         will not be lost even if an error occurs.
432  */
433 int av_append_packet (AVIOContext* s, AVPacket* pkt, int size);
434 
435 /*************************************************/
436 /* input/output formats */
437 
438 struct AVCodecTag;
439 
440 /**
441  * This structure contains the data a format has to probe a file.
442  */
443 struct AVProbeData
444 {
445     const(char)* filename;
446     ubyte* buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
447     int buf_size; /**< Size of buf except extra allocated bytes */
448     const(char)* mime_type; /**< mime_type, when known. */
449 }
450 
451 enum AVPROBE_SCORE_RETRY = AVPROBE_SCORE_MAX / 4;
452 enum AVPROBE_SCORE_STREAM_RETRY = AVPROBE_SCORE_MAX / 4 - 1;
453 
454 enum AVPROBE_SCORE_EXTENSION = 50; ///< score for file extension
455 enum AVPROBE_SCORE_MIME = 75; ///< score for file mime type
456 enum AVPROBE_SCORE_MAX = 100; ///< maximum score
457 
458 enum AVPROBE_PADDING_SIZE = 32; ///< extra allocated bytes at the end of the probe buffer
459 
460 /// Demuxer will use avio_open, no opened file should be provided by the caller.
461 enum AVFMT_NOFILE = 0x0001;
462 enum AVFMT_NEEDNUMBER = 0x0002; /**< Needs '%d' in filename. */
463 enum AVFMT_SHOW_IDS = 0x0008; /**< Show format stream IDs numbers. */
464 enum AVFMT_GLOBALHEADER = 0x0040; /**< Format wants global header. */
465 enum AVFMT_NOTIMESTAMPS = 0x0080; /**< Format does not need / have any timestamps. */
466 enum AVFMT_GENERIC_INDEX = 0x0100; /**< Use generic index building code. */
467 enum AVFMT_TS_DISCONT = 0x0200; /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
468 enum AVFMT_VARIABLE_FPS = 0x0400; /**< Format allows variable fps. */
469 enum AVFMT_NODIMENSIONS = 0x0800; /**< Format does not need width/height */
470 enum AVFMT_NOSTREAMS = 0x1000; /**< Format does not require any streams */
471 enum AVFMT_NOBINSEARCH = 0x2000; /**< Format does not allow to fall back on binary search via read_timestamp */
472 enum AVFMT_NOGENSEARCH = 0x4000; /**< Format does not allow to fall back on generic search */
473 enum AVFMT_NO_BYTE_SEEK = 0x8000; /**< Format does not allow seeking by bytes */
474 enum AVFMT_ALLOW_FLUSH = 0x10000; /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
475 enum AVFMT_TS_NONSTRICT = 0x20000; /**< Format does not require strictly
476      increasing timestamps, but they must
477      still be monotonic */
478 enum AVFMT_TS_NEGATIVE = 0x40000; /**< Format allows muxing negative
479      timestamps. If not set the timestamp
480      will be shifted in av_write_frame and
481      av_interleaved_write_frame so they
482      start from 0.
483      The user or muxer can override this through
484      AVFormatContext.avoid_negative_ts
485      */
486 
487 enum AVFMT_SEEK_TO_PTS = 0x4000000; /**< Seeking is based on PTS */
488 
489 /**
490  * @addtogroup lavf_encoding
491  * @{
492  */
493 struct AVOutputFormat
494 {
495     const(char)* name;
496     /**
497      * Descriptive name for the format, meant to be more human-readable
498      * than name. You should use the NULL_IF_CONFIG_SMALL() macro
499      * to define it.
500      */
501     const(char)* long_name;
502     const(char)* mime_type;
503     const(char)* extensions; /**< comma-separated filename extensions */
504     /* output support */
505     AVCodecID audio_codec; /**< default audio codec */
506     AVCodecID video_codec; /**< default video codec */
507     AVCodecID subtitle_codec; /**< default subtitle codec */
508     /**
509      * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER,
510      * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
511      * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
512      * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
513      */
514     int flags;
515 
516     /**
517      * List of supported codec_id-codec_tag pairs, ordered by "better
518      * choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
519      */
520     const(AVCodecTag*)* codec_tag;
521 
522     const(AVClass)* priv_class; ///< AVClass for the private context
523 
524     /*****************************************************************
525      * No fields below this line are part of the public API. They
526      * may not be used outside of libavformat and can be changed and
527      * removed at will.
528      * New public fields should be added right above.
529      *****************************************************************
530      */
531     AVOutputFormat* next;
532     /**
533      * size of private data so that it can be allocated in the wrapper
534      */
535     int priv_data_size;
536 
537     int function (AVFormatContext*) write_header;
538     /**
539      * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
540      * pkt can be NULL in order to flush data buffered in the muxer.
541      * When flushing, return 0 if there still is more data to flush,
542      * or 1 if everything was flushed and there is no more buffered
543      * data.
544      */
545     int function (AVFormatContext*, AVPacket* pkt) write_packet;
546     int function (AVFormatContext*) write_trailer;
547     /**
548      * Currently only used to set pixel format if not YUV420P.
549      */
550     int function (
551         AVFormatContext*,
552         AVPacket* out_,
553         AVPacket* in_,
554         int flush) interleave_packet;
555     /**
556      * Test if the given codec can be stored in this container.
557      *
558      * @return 1 if the codec is supported, 0 if it is not.
559      *         A negative number if unknown.
560      *         MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
561      */
562     int function (AVCodecID id, int std_compliance) query_codec;
563 
564     void function (
565         AVFormatContext* s,
566         int stream,
567         long* dts,
568         long* wall) get_output_timestamp;
569     /**
570      * Allows sending messages from application to device.
571      */
572     int function (
573         AVFormatContext* s,
574         int type,
575         void* data,
576         size_t data_size) control_message;
577 
578     /**
579      * Write an uncoded AVFrame.
580      *
581      * See av_write_uncoded_frame() for details.
582      *
583      * The library will free *frame afterwards, but the muxer can prevent it
584      * by setting the pointer to NULL.
585      */
586     int function (
587         AVFormatContext*,
588         int stream_index,
589         AVFrame** frame,
590         uint flags) write_uncoded_frame;
591     /**
592      * Returns device list with it properties.
593      * @see avdevice_list_devices() for more details.
594      */
595     int function (AVFormatContext* s, AVDeviceInfoList* device_list) get_device_list;
596     /**
597      * Initialize device capabilities submodule.
598      * @see avdevice_capabilities_create() for more details.
599      */
600     int function (AVFormatContext* s, AVDeviceCapabilitiesQuery* caps) create_device_capabilities;
601     /**
602      * Free device capabilities submodule.
603      * @see avdevice_capabilities_free() for more details.
604      */
605     int function (AVFormatContext* s, AVDeviceCapabilitiesQuery* caps) free_device_capabilities;
606     AVCodecID data_codec; /**< default data codec */
607     /**
608      * Initialize format. May allocate data here, and set any AVFormatContext or
609      * AVStream parameters that need to be set before packets are sent.
610      * This method must not write output.
611      *
612      * Return 0 if streams were fully configured, 1 if not, negative AVERROR on failure
613      *
614      * Any allocations made here must be freed in deinit().
615      */
616     int function (AVFormatContext*) init;
617     /**
618      * Deinitialize format. If present, this is called whenever the muxer is being
619      * destroyed, regardless of whether or not the header has been written.
620      *
621      * If a trailer is being written, this is called after write_trailer().
622      *
623      * This is called if init() fails as well.
624      */
625     void function (AVFormatContext*) deinit;
626     /**
627      * Set up any necessary bitstream filtering and extract any extra data needed
628      * for the global header.
629      * Return 0 if more packets from this stream must be checked; 1 if not.
630      */
631     int function (AVFormatContext*, const(AVPacket)* pkt) check_bitstream;
632 }
633 
634 /**
635  * @}
636  */
637 
638 /**
639  * @addtogroup lavf_decoding
640  * @{
641  */
642 struct AVInputFormat
643 {
644     /**
645      * A comma separated list of short names for the format. New names
646      * may be appended with a minor bump.
647      */
648     const(char)* name;
649 
650     /**
651      * Descriptive name for the format, meant to be more human-readable
652      * than name. You should use the NULL_IF_CONFIG_SMALL() macro
653      * to define it.
654      */
655     const(char)* long_name;
656 
657     /**
658      * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
659      * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
660      * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
661      */
662     int flags;
663 
664     /**
665      * If extensions are defined, then no probe is done. You should
666      * usually not use extension format guessing because it is not
667      * reliable enough
668      */
669     const(char)* extensions;
670 
671     const(AVCodecTag*)* codec_tag;
672 
673     const(AVClass)* priv_class; ///< AVClass for the private context
674 
675     /**
676      * Comma-separated list of mime types.
677      * It is used check for matching mime types while probing.
678      * @see av_probe_input_format2
679      */
680     const(char)* mime_type;
681 
682     /*****************************************************************
683      * No fields below this line are part of the public API. They
684      * may not be used outside of libavformat and can be changed and
685      * removed at will.
686      * New public fields should be added right above.
687      *****************************************************************
688      */
689     AVInputFormat* next;
690 
691     /**
692      * Raw demuxers store their codec ID here.
693      */
694     int raw_codec_id;
695 
696     /**
697      * Size of private data so that it can be allocated in the wrapper.
698      */
699     int priv_data_size;
700 
701     /**
702      * Tell if a given file has a chance of being parsed as this format.
703      * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
704      * big so you do not have to check for that unless you need more.
705      */
706     int function (AVProbeData*) read_probe;
707 
708     /**
709      * Read the format header and initialize the AVFormatContext
710      * structure. Return 0 if OK. 'avformat_new_stream' should be
711      * called to create new streams.
712      */
713     int function (AVFormatContext*) read_header;
714 
715     /**
716      * Read one packet and put it in 'pkt'. pts and flags are also
717      * set. 'avformat_new_stream' can be called only if the flag
718      * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
719      * background thread).
720      * @return 0 on success, < 0 on error.
721      *         When returning an error, pkt must not have been allocated
722      *         or must be freed before returning
723      */
724     int function (AVFormatContext*, AVPacket* pkt) read_packet;
725 
726     /**
727      * Close the stream. The AVFormatContext and AVStreams are not
728      * freed by this function
729      */
730     int function (AVFormatContext*) read_close;
731 
732     /**
733      * Seek to a given timestamp relative to the frames in
734      * stream component stream_index.
735      * @param stream_index Must not be -1.
736      * @param flags Selects which direction should be preferred if no exact
737      *              match is available.
738      * @return >= 0 on success (but not necessarily the new offset)
739      */
740     int function (
741         AVFormatContext*,
742         int stream_index,
743         long timestamp,
744         int flags) read_seek;
745 
746     /**
747      * Get the next timestamp in stream[stream_index].time_base units.
748      * @return the timestamp or AV_NOPTS_VALUE if an error occurred
749      */
750     long function (
751         AVFormatContext* s,
752         int stream_index,
753         long* pos,
754         long pos_limit) read_timestamp;
755 
756     /**
757      * Start/resume playing - only meaningful if using a network-based format
758      * (RTSP).
759      */
760     int function (AVFormatContext*) read_play;
761 
762     /**
763      * Pause playing - only meaningful if using a network-based format
764      * (RTSP).
765      */
766     int function (AVFormatContext*) read_pause;
767 
768     /**
769      * Seek to timestamp ts.
770      * Seeking will be done so that the point from which all active streams
771      * can be presented successfully will be closest to ts and within min/max_ts.
772      * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
773      */
774     int function (AVFormatContext* s, int stream_index, long min_ts, long ts, long max_ts, int flags) read_seek2;
775 
776     /**
777      * Returns device list with it properties.
778      * @see avdevice_list_devices() for more details.
779      */
780     int function (AVFormatContext* s, AVDeviceInfoList* device_list) get_device_list;
781 
782     /**
783      * Initialize device capabilities submodule.
784      * @see avdevice_capabilities_create() for more details.
785      */
786     int function (AVFormatContext* s, AVDeviceCapabilitiesQuery* caps) create_device_capabilities;
787 
788     /**
789      * Free device capabilities submodule.
790      * @see avdevice_capabilities_free() for more details.
791      */
792     int function (AVFormatContext* s, AVDeviceCapabilitiesQuery* caps) free_device_capabilities;
793 }
794 
795 /**
796  * @}
797  */
798 
799 enum AVStreamParseType
800 {
801     AVSTREAM_PARSE_NONE = 0,
802     AVSTREAM_PARSE_FULL = 1, /**< full parsing and repack */
803     AVSTREAM_PARSE_HEADERS = 2, /**< Only parse headers, do not repack. */
804     AVSTREAM_PARSE_TIMESTAMPS = 3, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
805     AVSTREAM_PARSE_FULL_ONCE = 4, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
806     AVSTREAM_PARSE_FULL_RAW = 5 /**< full parsing and repack with timestamp and position generation by parser for raw
807          this assumes that each packet in the file contains no demuxer level headers and
808          just codec level data, otherwise position generation would fail */
809 }
810 
811 struct AVIndexEntry
812 {
813     import std.bitmanip : bitfields;
814 
815     long pos;
816     long timestamp;
817 
818     mixin(bitfields!(
819         int, "flags", 2,
820         int, "size", 30)); /**<
821      * Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
822      * when seeking to this entry. That means preferable PTS on keyframe based formats.
823      * But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
824      * is known
825      */
826 
827     /**
828      * Flag is used to indicate which frame should be discarded after decoding.
829      */
830 
831     //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).
832     int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
833 }
834 
835 enum AVINDEX_KEYFRAME = 0x0001;
836 enum AVINDEX_DISCARD_FRAME = 0x0002;
837 
838 enum AV_DISPOSITION_DEFAULT = 0x0001;
839 enum AV_DISPOSITION_DUB = 0x0002;
840 enum AV_DISPOSITION_ORIGINAL = 0x0004;
841 enum AV_DISPOSITION_COMMENT = 0x0008;
842 enum AV_DISPOSITION_LYRICS = 0x0010;
843 enum AV_DISPOSITION_KARAOKE = 0x0020;
844 
845 /**
846  * Track should be used during playback by default.
847  * Useful for subtitle track that should be displayed
848  * even when user did not explicitly ask for subtitles.
849  */
850 enum AV_DISPOSITION_FORCED = 0x0040;
851 enum AV_DISPOSITION_HEARING_IMPAIRED = 0x0080; /**< stream for hearing impaired audiences */
852 enum AV_DISPOSITION_VISUAL_IMPAIRED = 0x0100; /**< stream for visual impaired audiences */
853 enum AV_DISPOSITION_CLEAN_EFFECTS = 0x0200; /**< stream without voice */
854 /**
855  * The stream is stored in the file as an attached picture/"cover art" (e.g.
856  * APIC frame in ID3v2). The first (usually only) packet associated with it
857  * will be returned among the first few packets read from the file unless
858  * seeking takes place. It can also be accessed at any time in
859  * AVStream.attached_pic.
860  */
861 enum AV_DISPOSITION_ATTACHED_PIC = 0x0400;
862 /**
863  * The stream is sparse, and contains thumbnail images, often corresponding
864  * to chapter markers. Only ever used with AV_DISPOSITION_ATTACHED_PIC.
865  */
866 enum AV_DISPOSITION_TIMED_THUMBNAILS = 0x0800;
867 
868 struct AVStreamInternal;
869 
870 /**
871  * To specify text track kind (different from subtitles default).
872  */
873 enum AV_DISPOSITION_CAPTIONS = 0x10000;
874 enum AV_DISPOSITION_DESCRIPTIONS = 0x20000;
875 enum AV_DISPOSITION_METADATA = 0x40000;
876 enum AV_DISPOSITION_DEPENDENT = 0x80000; ///< dependent audio stream (mix_type=0 in mpegts)
877 enum AV_DISPOSITION_STILL_IMAGE = 0x100000; ///< still images in video stream (still_picture_flag=1 in mpegts)
878 
879 /**
880  * Options for behavior on timestamp wrap detection.
881  */
882 enum AV_PTS_WRAP_IGNORE = 0; ///< ignore the wrap
883 enum AV_PTS_WRAP_ADD_OFFSET = 1; ///< add the format specific offset on wrap detection
884 enum AV_PTS_WRAP_SUB_OFFSET = -1; ///< subtract the format specific offset on wrap detection
885 
886 /**
887  * Stream structure.
888  * New fields can be added to the end with minor version bumps.
889  * Removal, reordering and changes to existing fields require a major
890  * version bump.
891  * sizeof(AVStream) must not be used outside libav*.
892  */
893 struct AVStream
894 {
895     int index; /**< stream index in AVFormatContext */
896     /**
897      * Format-specific stream ID.
898      * decoding: set by libavformat
899      * encoding: set by the user, replaced by libavformat if left unset
900      */
901     int id;
902 
903     /**
904      * @deprecated use the codecpar struct instead
905      */
906     AVCodecContext* codec;
907 
908     void* priv_data;
909 
910     /**
911      * This is the fundamental unit of time (in seconds) in terms
912      * of which frame timestamps are represented.
913      *
914      * decoding: set by libavformat
915      * encoding: May be set by the caller before avformat_write_header() to
916      *           provide a hint to the muxer about the desired timebase. In
917      *           avformat_write_header(), the muxer will overwrite this field
918      *           with the timebase that will actually be used for the timestamps
919      *           written into the file (which may or may not be related to the
920      *           user-provided one, depending on the format).
921      */
922     AVRational time_base;
923 
924     /**
925      * Decoding: pts of the first frame of the stream in presentation order, in stream time base.
926      * Only set this if you are absolutely 100% sure that the value you set
927      * it to really is the pts of the first frame.
928      * This may be undefined (AV_NOPTS_VALUE).
929      * @note The ASF header does NOT contain a correct start_time the ASF
930      * demuxer must NOT set this.
931      */
932     long start_time;
933 
934     /**
935      * Decoding: duration of the stream, in stream time base.
936      * If a source file does not specify a duration, but does specify
937      * a bitrate, this value will be estimated from bitrate and file size.
938      *
939      * Encoding: May be set by the caller before avformat_write_header() to
940      * provide a hint to the muxer about the estimated duration.
941      */
942     long duration;
943 
944     long nb_frames; ///< number of frames in this stream if known or 0
945 
946     int disposition; /**< AV_DISPOSITION_* bit field */
947 
948     AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
949 
950     /**
951      * sample aspect ratio (0 if unknown)
952      * - encoding: Set by user.
953      * - decoding: Set by libavformat.
954      */
955     AVRational sample_aspect_ratio;
956 
957     AVDictionary* metadata;
958 
959     /**
960      * Average framerate
961      *
962      * - demuxing: May be set by libavformat when creating the stream or in
963      *             avformat_find_stream_info().
964      * - muxing: May be set by the caller before avformat_write_header().
965      */
966     AVRational avg_frame_rate;
967 
968     /**
969      * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
970      * will contain the attached picture.
971      *
972      * decoding: set by libavformat, must not be modified by the caller.
973      * encoding: unused
974      */
975     AVPacket attached_pic;
976 
977     /**
978      * An array of side data that applies to the whole stream (i.e. the
979      * container does not allow it to change between packets).
980      *
981      * There may be no overlap between the side data in this array and side data
982      * in the packets. I.e. a given side data is either exported by the muxer
983      * (demuxing) / set by the caller (muxing) in this array, then it never
984      * appears in the packets, or the side data is exported / sent through
985      * the packets (always in the first packet where the value becomes known or
986      * changes), then it does not appear in this array.
987      *
988      * - demuxing: Set by libavformat when the stream is created.
989      * - muxing: May be set by the caller before avformat_write_header().
990      *
991      * Freed by libavformat in avformat_free_context().
992      *
993      * @see av_format_inject_global_side_data()
994      */
995     AVPacketSideData* side_data;
996     /**
997      * The number of elements in the AVStream.side_data array.
998      */
999     int nb_side_data;
1000 
1001     /**
1002      * Flags for the user to detect events happening on the stream. Flags must
1003      * be cleared by the user once the event has been handled.
1004      * A combination of AVSTREAM_EVENT_FLAG_*.
1005      */
1006     int event_flags;
1007     ///< The call resulted in updated metadata.
1008 
1009     /**
1010      * Real base framerate of the stream.
1011      * This is the lowest framerate with which all timestamps can be
1012      * represented accurately (it is the least common multiple of all
1013      * framerates in the stream). Note, this value is just a guess!
1014      * For example, if the time base is 1/90000 and all frames have either
1015      * approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
1016      */
1017     AVRational r_frame_rate;
1018 
1019     /**
1020      * String containing pairs of key and values describing recommended encoder configuration.
1021      * Pairs are separated by ','.
1022      * Keys are separated from values by '='.
1023      *
1024      * @deprecated unused
1025      */
1026     char* recommended_encoder_configuration;
1027 
1028     /**
1029      * Codec parameters associated with this stream. Allocated and freed by
1030      * libavformat in avformat_new_stream() and avformat_free_context()
1031      * respectively.
1032      *
1033      * - demuxing: filled by libavformat on stream creation or in
1034      *             avformat_find_stream_info()
1035      * - muxing: filled by the caller before avformat_write_header()
1036      */
1037     AVCodecParameters* codecpar;
1038 
1039     /*****************************************************************
1040      * All fields below this line are not part of the public API. They
1041      * may not be used outside of libavformat and can be changed and
1042      * removed at will.
1043      * Internal note: be aware that physically removing these fields
1044      * will break ABI. Replace removed fields with dummy fields, and
1045      * add new fields to AVStreamInternal.
1046      *****************************************************************
1047      */
1048 
1049     /**
1050      * Stream information used internally by avformat_find_stream_info()
1051      */
1052 
1053     /**
1054      * 0  -> decoder has not been searched for yet.
1055      * >0 -> decoder found
1056      * <0 -> decoder with codec_id == -found_decoder has not been found
1057      */
1058 
1059     /**
1060      * Those are used for average framerate estimation.
1061      */
1062     struct _Anonymous_0
1063     {
1064         long last_dts;
1065         long duration_gcd;
1066         int duration_count;
1067         long rfps_duration_sum;
1068         double[MAX_STD_TIMEBASES][2]* duration_error;
1069         long codec_info_duration;
1070         long codec_info_duration_fields;
1071         int frame_delay_evidence;
1072         int found_decoder;
1073         long last_duration;
1074         long fps_first_dts;
1075         int fps_first_dts_idx;
1076         long fps_last_dts;
1077         int fps_last_dts_idx;
1078     }
1079 
1080     _Anonymous_0* info;
1081 
1082     int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
1083 
1084     // Timestamp generation support:
1085     /**
1086      * Timestamp corresponding to the last dts sync point.
1087      *
1088      * Initialized when AVCodecParserContext.dts_sync_point >= 0 and
1089      * a DTS is received from the underlying container. Otherwise set to
1090      * AV_NOPTS_VALUE by default.
1091      */
1092     long first_dts;
1093     long cur_dts;
1094     long last_IP_pts;
1095     int last_IP_duration;
1096 
1097     /**
1098      * Number of packets to buffer for codec probing
1099      */
1100     int probe_packets;
1101 
1102     /**
1103      * Number of frames that have been demuxed during avformat_find_stream_info()
1104      */
1105     int codec_info_nb_frames;
1106 
1107     /* av_read_frame() support */
1108     AVStreamParseType need_parsing;
1109     AVCodecParserContext* parser;
1110 
1111     /**
1112      * last packet in packet_buffer for this stream when muxing.
1113      */
1114     AVPacketList* last_in_packet_buffer;
1115     AVProbeData probe_data;
1116 
1117     long[17] pts_buffer;
1118 
1119     AVIndexEntry* index_entries; /**< Only used if the format does not
1120        support seeking natively. */
1121     int nb_index_entries;
1122     uint index_entries_allocated_size;
1123 
1124     /**
1125      * Stream Identifier
1126      * This is the MPEG-TS stream identifier +1
1127      * 0 means unknown
1128      */
1129     int stream_identifier;
1130 
1131     /**
1132      * Details of the MPEG-TS program which created this stream.
1133      */
1134     int program_num;
1135     int pmt_version;
1136     int pmt_stream_idx;
1137 
1138     long interleaver_chunk_size;
1139     long interleaver_chunk_duration;
1140 
1141     /**
1142      * stream probing state
1143      * -1   -> probing finished
1144      *  0   -> no probing requested
1145      * rest -> perform probing with request_probe being the minimum score to accept.
1146      * NOT PART OF PUBLIC API
1147      */
1148     int request_probe;
1149     /**
1150      * Indicates that everything up to the next keyframe
1151      * should be discarded.
1152      */
1153     int skip_to_keyframe;
1154 
1155     /**
1156      * Number of samples to skip at the start of the frame decoded from the next packet.
1157      */
1158     int skip_samples;
1159 
1160     /**
1161      * If not 0, the number of samples that should be skipped from the start of
1162      * the stream (the samples are removed from packets with pts==0, which also
1163      * assumes negative timestamps do not happen).
1164      * Intended for use with formats such as mp3 with ad-hoc gapless audio
1165      * support.
1166      */
1167     long start_skip_samples;
1168 
1169     /**
1170      * If not 0, the first audio sample that should be discarded from the stream.
1171      * This is broken by design (needs global sample count), but can't be
1172      * avoided for broken by design formats such as mp3 with ad-hoc gapless
1173      * audio support.
1174      */
1175     long first_discard_sample;
1176 
1177     /**
1178      * The sample after last sample that is intended to be discarded after
1179      * first_discard_sample. Works on frame boundaries only. Used to prevent
1180      * early EOF if the gapless info is broken (considered concatenated mp3s).
1181      */
1182     long last_discard_sample;
1183 
1184     /**
1185      * Number of internally decoded frames, used internally in libavformat, do not access
1186      * its lifetime differs from info which is why it is not in that structure.
1187      */
1188     int nb_decoded_frames;
1189 
1190     /**
1191      * Timestamp offset added to timestamps before muxing
1192      * NOT PART OF PUBLIC API
1193      */
1194     long mux_ts_offset;
1195 
1196     /**
1197      * Internal data to check for wrapping of the time stamp
1198      */
1199     long pts_wrap_reference;
1200 
1201     /**
1202      * Options for behavior, when a wrap is detected.
1203      *
1204      * Defined by AV_PTS_WRAP_ values.
1205      *
1206      * If correction is enabled, there are two possibilities:
1207      * If the first time stamp is near the wrap point, the wrap offset
1208      * will be subtracted, which will create negative time stamps.
1209      * Otherwise the offset will be added.
1210      */
1211     int pts_wrap_behavior;
1212 
1213     /**
1214      * Internal data to prevent doing update_initial_durations() twice
1215      */
1216     int update_initial_durations_done;
1217 
1218     /**
1219      * Internal data to generate dts from pts
1220      */
1221     long[17] pts_reorder_error;
1222     ubyte[17] pts_reorder_error_count;
1223 
1224     /**
1225      * Internal data to analyze DTS and detect faulty mpeg streams
1226      */
1227     long last_dts_for_order_check;
1228     ubyte dts_ordered;
1229     ubyte dts_misordered;
1230 
1231     /**
1232      * Internal data to inject global side data
1233      */
1234     int inject_global_side_data;
1235 
1236     /**
1237      * display aspect ratio (0 if unknown)
1238      * - encoding: unused
1239      * - decoding: Set by libavformat to calculate sample_aspect_ratio internally
1240      */
1241     AVRational display_aspect_ratio;
1242 
1243     /**
1244      * An opaque field for libavformat internal usage.
1245      * Must not be accessed in any way by callers.
1246      */
1247     AVStreamInternal* internal;
1248 }
1249 
1250 enum AVSTREAM_EVENT_FLAG_METADATA_UPDATED = 0x0001;
1251 enum MAX_STD_TIMEBASES = 30 * 12 + 30 + 3 + 6;
1252 enum MAX_REORDER_DELAY = 16;
1253 
1254 /**
1255  * Accessors for some AVStream fields. These used to be provided for ABI
1256  * compatibility, and do not need to be used anymore.
1257  */
1258 AVRational av_stream_get_r_frame_rate (const(AVStream)* s);
1259 void av_stream_set_r_frame_rate (AVStream* s, AVRational r);
1260 char* av_stream_get_recommended_encoder_configuration (const(AVStream)* s);
1261 void av_stream_set_recommended_encoder_configuration (
1262     AVStream* s,
1263     char* configuration);
1264 
1265 AVCodecParserContext* av_stream_get_parser (const(AVStream)* s);
1266 
1267 /**
1268  * Returns the pts of the last muxed packet + its duration
1269  *
1270  * the retuned value is undefined when used with a demuxer.
1271  */
1272 long av_stream_get_end_pts (const(AVStream)* st);
1273 
1274 enum AV_PROGRAM_RUNNING = 1;
1275 
1276 /**
1277  * New fields can be added to the end with minor version bumps.
1278  * Removal, reordering and changes to existing fields require a major
1279  * version bump.
1280  * sizeof(AVProgram) must not be used outside libav*.
1281  */
1282 struct AVProgram
1283 {
1284     int id;
1285     int flags;
1286     AVDiscard discard; ///< selects which program to discard and which to feed to the caller
1287     uint* stream_index;
1288     uint nb_stream_indexes;
1289     AVDictionary* metadata;
1290 
1291     int program_num;
1292     int pmt_pid;
1293     int pcr_pid;
1294     int pmt_version;
1295 
1296     /*****************************************************************
1297      * All fields below this line are not part of the public API. They
1298      * may not be used outside of libavformat and can be changed and
1299      * removed at will.
1300      * New public fields should be added right above.
1301      *****************************************************************
1302      */
1303     long start_time;
1304     long end_time;
1305 
1306     long pts_wrap_reference; ///< reference dts for wrap detection
1307     int pts_wrap_behavior; ///< behavior on wrap detection
1308 }
1309 
1310 enum AVFMTCTX_NOHEADER = 0x0001; /**< signal that no header is present
1311    (streams are added dynamically) */
1312 enum AVFMTCTX_UNSEEKABLE = 0x0002; /**< signal that the stream is definitely
1313    not seekable, and attempts to call the
1314    seek function will fail. For some
1315    network protocols (e.g. HLS), this can
1316    change dynamically at runtime. */
1317 
1318 struct AVChapter
1319 {
1320     int id; ///< unique ID to identify the chapter
1321     AVRational time_base; ///< time base in which the start/end timestamps are specified
1322     long start;
1323     long end; ///< chapter start/end time in time_base units
1324     AVDictionary* metadata;
1325 }
1326 
1327 /**
1328  * Callback used by devices to communicate with application.
1329  */
1330 alias av_format_control_message = int function (
1331     AVFormatContext* s,
1332     int type,
1333     void* data,
1334     size_t data_size);
1335 
1336 alias AVOpenCallback = int function (
1337     AVFormatContext* s,
1338     AVIOContext** pb,
1339     const(char)* url,
1340     int flags,
1341     const(AVIOInterruptCB)* int_cb,
1342     AVDictionary** options);
1343 
1344 /**
1345  * The duration of a video can be estimated through various ways, and this enum can be used
1346  * to know how the duration was estimated.
1347  */
1348 enum AVDurationEstimationMethod
1349 {
1350     AVFMT_DURATION_FROM_PTS = 0, ///< Duration accurately estimated from PTSes
1351     AVFMT_DURATION_FROM_STREAM = 1, ///< Duration estimated from a stream with a known duration
1352     AVFMT_DURATION_FROM_BITRATE = 2 ///< Duration estimated from bitrate (less accurate)
1353 }
1354 
1355 struct AVFormatInternal;
1356 
1357 /**
1358  * Format I/O context.
1359  * New fields can be added to the end with minor version bumps.
1360  * Removal, reordering and changes to existing fields require a major
1361  * version bump.
1362  * sizeof(AVFormatContext) must not be used outside libav*, use
1363  * avformat_alloc_context() to create an AVFormatContext.
1364  *
1365  * Fields can be accessed through AVOptions (av_opt*),
1366  * the name string used matches the associated command line parameter name and
1367  * can be found in libavformat/options_table.h.
1368  * The AVOption/command line parameter names differ in some cases from the C
1369  * structure field names for historic reasons or brevity.
1370  */
1371 struct AVFormatContext
1372 {
1373     /**
1374      * A class for logging and @ref avoptions. Set by avformat_alloc_context().
1375      * Exports (de)muxer private options if they exist.
1376      */
1377     const(AVClass)* av_class;
1378 
1379     /**
1380      * The input container format.
1381      *
1382      * Demuxing only, set by avformat_open_input().
1383      */
1384     AVInputFormat* iformat;
1385 
1386     /**
1387      * The output container format.
1388      *
1389      * Muxing only, must be set by the caller before avformat_write_header().
1390      */
1391     AVOutputFormat* oformat;
1392 
1393     /**
1394      * Format private data. This is an AVOptions-enabled struct
1395      * if and only if iformat/oformat.priv_class is not NULL.
1396      *
1397      * - muxing: set by avformat_write_header()
1398      * - demuxing: set by avformat_open_input()
1399      */
1400     void* priv_data;
1401 
1402     /**
1403      * I/O context.
1404      *
1405      * - demuxing: either set by the user before avformat_open_input() (then
1406      *             the user must close it manually) or set by avformat_open_input().
1407      * - muxing: set by the user before avformat_write_header(). The caller must
1408      *           take care of closing / freeing the IO context.
1409      *
1410      * Do NOT set this field if AVFMT_NOFILE flag is set in
1411      * iformat/oformat.flags. In such a case, the (de)muxer will handle
1412      * I/O in some other way and this field will be NULL.
1413      */
1414     AVIOContext* pb;
1415 
1416     /* stream info */
1417     /**
1418      * Flags signalling stream properties. A combination of AVFMTCTX_*.
1419      * Set by libavformat.
1420      */
1421     int ctx_flags;
1422 
1423     /**
1424      * Number of elements in AVFormatContext.streams.
1425      *
1426      * Set by avformat_new_stream(), must not be modified by any other code.
1427      */
1428     uint nb_streams;
1429     /**
1430      * A list of all streams in the file. New streams are created with
1431      * avformat_new_stream().
1432      *
1433      * - demuxing: streams are created by libavformat in avformat_open_input().
1434      *             If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
1435      *             appear in av_read_frame().
1436      * - muxing: streams are created by the user before avformat_write_header().
1437      *
1438      * Freed by libavformat in avformat_free_context().
1439      */
1440     AVStream** streams;
1441 
1442     /**
1443      * input or output filename
1444      *
1445      * - demuxing: set by avformat_open_input()
1446      * - muxing: may be set by the caller before avformat_write_header()
1447      *
1448      * @deprecated Use url instead.
1449      */
1450     char[1024] filename;
1451 
1452     /**
1453      * input or output URL. Unlike the old filename field, this field has no
1454      * length restriction.
1455      *
1456      * - demuxing: set by avformat_open_input(), initialized to an empty
1457      *             string if url parameter was NULL in avformat_open_input().
1458      * - muxing: may be set by the caller before calling avformat_write_header()
1459      *           (or avformat_init_output() if that is called first) to a string
1460      *           which is freeable by av_free(). Set to an empty string if it
1461      *           was NULL in avformat_init_output().
1462      *
1463      * Freed by libavformat in avformat_free_context().
1464      */
1465     char* url;
1466 
1467     /**
1468      * Position of the first frame of the component, in
1469      * AV_TIME_BASE fractional seconds. NEVER set this value directly:
1470      * It is deduced from the AVStream values.
1471      *
1472      * Demuxing only, set by libavformat.
1473      */
1474     long start_time;
1475 
1476     /**
1477      * Duration of the stream, in AV_TIME_BASE fractional
1478      * seconds. Only set this value if you know none of the individual stream
1479      * durations and also do not set any of them. This is deduced from the
1480      * AVStream values if not set.
1481      *
1482      * Demuxing only, set by libavformat.
1483      */
1484     long duration;
1485 
1486     /**
1487      * Total stream bitrate in bit/s, 0 if not
1488      * available. Never set it directly if the file_size and the
1489      * duration are known as FFmpeg can compute it automatically.
1490      */
1491     long bit_rate;
1492 
1493     uint packet_size;
1494     int max_delay;
1495 
1496     /**
1497      * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*.
1498      * Set by the user before avformat_open_input() / avformat_write_header().
1499      */
1500     int flags;
1501     ///< Generate missing pts even if it requires parsing future frames.
1502     ///< Ignore index.
1503     ///< Do not block when reading packets from input.
1504     ///< Ignore DTS on frames that contain both DTS & PTS
1505     ///< Do not infer any values from other values, just return what is stored in the container
1506     ///< 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
1507     ///< Do not buffer frames when possible
1508     ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
1509     ///< Discard frames marked corrupted
1510     ///< Flush the AVIOContext every packet.
1511     /**
1512      * When muxing, try to avoid writing any random/volatile data to the output.
1513      * This includes any random IDs, real-time timestamps/dates, muxer version, etc.
1514      *
1515      * This flag is mainly intended for testing.
1516      */
1517 
1518     ///< Deprecated, does nothing.
1519 
1520     ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
1521     ///< Enable use of private options by delaying codec open (this could be made default once all code is converted)
1522 
1523     ///< Deprecated, does nothing.
1524 
1525     ///< Enable fast, but inaccurate seeks for some formats
1526     ///< Stop muxing when the shortest stream stops.
1527     ///< Add bitstream filters as requested by the muxer
1528 
1529     /**
1530      * Maximum size of the data read from input for determining
1531      * the input container format.
1532      * Demuxing only, set by the caller before avformat_open_input().
1533      */
1534     long probesize;
1535 
1536     /**
1537      * Maximum duration (in AV_TIME_BASE units) of the data read
1538      * from input in avformat_find_stream_info().
1539      * Demuxing only, set by the caller before avformat_find_stream_info().
1540      * Can be set to 0 to let avformat choose using a heuristic.
1541      */
1542     long max_analyze_duration;
1543 
1544     const(ubyte)* key;
1545     int keylen;
1546 
1547     uint nb_programs;
1548     AVProgram** programs;
1549 
1550     /**
1551      * Forced video codec_id.
1552      * Demuxing: Set by user.
1553      */
1554     AVCodecID video_codec_id;
1555 
1556     /**
1557      * Forced audio codec_id.
1558      * Demuxing: Set by user.
1559      */
1560     AVCodecID audio_codec_id;
1561 
1562     /**
1563      * Forced subtitle codec_id.
1564      * Demuxing: Set by user.
1565      */
1566     AVCodecID subtitle_codec_id;
1567 
1568     /**
1569      * Maximum amount of memory in bytes to use for the index of each stream.
1570      * If the index exceeds this size, entries will be discarded as
1571      * needed to maintain a smaller size. This can lead to slower or less
1572      * accurate seeking (depends on demuxer).
1573      * Demuxers for which a full in-memory index is mandatory will ignore
1574      * this.
1575      * - muxing: unused
1576      * - demuxing: set by user
1577      */
1578     uint max_index_size;
1579 
1580     /**
1581      * Maximum amount of memory in bytes to use for buffering frames
1582      * obtained from realtime capture devices.
1583      */
1584     uint max_picture_buffer;
1585 
1586     /**
1587      * Number of chapters in AVChapter array.
1588      * When muxing, chapters are normally written in the file header,
1589      * so nb_chapters should normally be initialized before write_header
1590      * is called. Some muxers (e.g. mov and mkv) can also write chapters
1591      * in the trailer.  To write chapters in the trailer, nb_chapters
1592      * must be zero when write_header is called and non-zero when
1593      * write_trailer is called.
1594      * - muxing: set by user
1595      * - demuxing: set by libavformat
1596      */
1597     uint nb_chapters;
1598     AVChapter** chapters;
1599 
1600     /**
1601      * Metadata that applies to the whole file.
1602      *
1603      * - demuxing: set by libavformat in avformat_open_input()
1604      * - muxing: may be set by the caller before avformat_write_header()
1605      *
1606      * Freed by libavformat in avformat_free_context().
1607      */
1608     AVDictionary* metadata;
1609 
1610     /**
1611      * Start time of the stream in real world time, in microseconds
1612      * since the Unix epoch (00:00 1st January 1970). That is, pts=0 in the
1613      * stream was captured at this real world time.
1614      * - muxing: Set by the caller before avformat_write_header(). If set to
1615      *           either 0 or AV_NOPTS_VALUE, then the current wall-time will
1616      *           be used.
1617      * - demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that
1618      *             the value may become known after some number of frames
1619      *             have been received.
1620      */
1621     long start_time_realtime;
1622 
1623     /**
1624      * The number of frames used for determining the framerate in
1625      * avformat_find_stream_info().
1626      * Demuxing only, set by the caller before avformat_find_stream_info().
1627      */
1628     int fps_probe_size;
1629 
1630     /**
1631      * Error recognition; higher values will detect more errors but may
1632      * misdetect some more or less valid parts as errors.
1633      * Demuxing only, set by the caller before avformat_open_input().
1634      */
1635     int error_recognition;
1636 
1637     /**
1638      * Custom interrupt callbacks for the I/O layer.
1639      *
1640      * demuxing: set by the user before avformat_open_input().
1641      * muxing: set by the user before avformat_write_header()
1642      * (mainly useful for AVFMT_NOFILE formats). The callback
1643      * should also be passed to avio_open2() if it's used to
1644      * open the file.
1645      */
1646     AVIOInterruptCB interrupt_callback;
1647 
1648     /**
1649      * Flags to enable debugging.
1650      */
1651     int debug_;
1652 
1653     /**
1654      * Maximum buffering duration for interleaving.
1655      *
1656      * To ensure all the streams are interleaved correctly,
1657      * av_interleaved_write_frame() will wait until it has at least one packet
1658      * for each stream before actually writing any packets to the output file.
1659      * When some streams are "sparse" (i.e. there are large gaps between
1660      * successive packets), this can result in excessive buffering.
1661      *
1662      * This field specifies the maximum difference between the timestamps of the
1663      * first and the last packet in the muxing queue, above which libavformat
1664      * will output a packet regardless of whether it has queued a packet for all
1665      * the streams.
1666      *
1667      * Muxing only, set by the caller before avformat_write_header().
1668      */
1669     long max_interleave_delta;
1670 
1671     /**
1672      * Allow non-standard and experimental extension
1673      * @see AVCodecContext.strict_std_compliance
1674      */
1675     int strict_std_compliance;
1676 
1677     /**
1678      * Flags for the user to detect events happening on the file. Flags must
1679      * be cleared by the user once the event has been handled.
1680      * A combination of AVFMT_EVENT_FLAG_*.
1681      */
1682     int event_flags;
1683     ///< The call resulted in updated metadata.
1684 
1685     /**
1686      * Maximum number of packets to read while waiting for the first timestamp.
1687      * Decoding only.
1688      */
1689     int max_ts_probe;
1690 
1691     /**
1692      * Avoid negative timestamps during muxing.
1693      * Any value of the AVFMT_AVOID_NEG_TS_* constants.
1694      * Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use)
1695      * - muxing: Set by user
1696      * - demuxing: unused
1697      */
1698     int avoid_negative_ts;
1699     ///< Enabled when required by target format
1700     ///< Shift timestamps so they are non negative
1701     ///< Shift timestamps so that they start at 0
1702 
1703     /**
1704      * Transport stream id.
1705      * This will be moved into demuxer private options. Thus no API/ABI compatibility
1706      */
1707     int ts_id;
1708 
1709     /**
1710      * Audio preload in microseconds.
1711      * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1712      * - encoding: Set by user
1713      * - decoding: unused
1714      */
1715     int audio_preload;
1716 
1717     /**
1718      * Max chunk time in microseconds.
1719      * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1720      * - encoding: Set by user
1721      * - decoding: unused
1722      */
1723     int max_chunk_duration;
1724 
1725     /**
1726      * Max chunk size in bytes
1727      * Note, not all formats support this and unpredictable things may happen if it is used when not supported.
1728      * - encoding: Set by user
1729      * - decoding: unused
1730      */
1731     int max_chunk_size;
1732 
1733     /**
1734      * forces the use of wallclock timestamps as pts/dts of packets
1735      * This has undefined results in the presence of B frames.
1736      * - encoding: unused
1737      * - decoding: Set by user
1738      */
1739     int use_wallclock_as_timestamps;
1740 
1741     /**
1742      * avio flags, used to force AVIO_FLAG_DIRECT.
1743      * - encoding: unused
1744      * - decoding: Set by user
1745      */
1746     int avio_flags;
1747 
1748     /**
1749      * The duration field can be estimated through various ways, and this field can be used
1750      * to know how the duration was estimated.
1751      * - encoding: unused
1752      * - decoding: Read by user
1753      */
1754     AVDurationEstimationMethod duration_estimation_method;
1755 
1756     /**
1757      * Skip initial bytes when opening stream
1758      * - encoding: unused
1759      * - decoding: Set by user
1760      */
1761     long skip_initial_bytes;
1762 
1763     /**
1764      * Correct single timestamp overflows
1765      * - encoding: unused
1766      * - decoding: Set by user
1767      */
1768     uint correct_ts_overflow;
1769 
1770     /**
1771      * Force seeking to any (also non key) frames.
1772      * - encoding: unused
1773      * - decoding: Set by user
1774      */
1775     int seek2any;
1776 
1777     /**
1778      * Flush the I/O context after each packet.
1779      * - encoding: Set by user
1780      * - decoding: unused
1781      */
1782     int flush_packets;
1783 
1784     /**
1785      * format probing score.
1786      * The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes
1787      * the format.
1788      * - encoding: unused
1789      * - decoding: set by avformat, read by user
1790      */
1791     int probe_score;
1792 
1793     /**
1794      * number of bytes to read maximally to identify format.
1795      * - encoding: unused
1796      * - decoding: set by user
1797      */
1798     int format_probesize;
1799 
1800     /**
1801      * ',' separated list of allowed decoders.
1802      * If NULL then all are allowed
1803      * - encoding: unused
1804      * - decoding: set by user
1805      */
1806     char* codec_whitelist;
1807 
1808     /**
1809      * ',' separated list of allowed demuxers.
1810      * If NULL then all are allowed
1811      * - encoding: unused
1812      * - decoding: set by user
1813      */
1814     char* format_whitelist;
1815 
1816     /**
1817      * An opaque field for libavformat internal usage.
1818      * Must not be accessed in any way by callers.
1819      */
1820     AVFormatInternal* internal;
1821 
1822     /**
1823      * IO repositioned flag.
1824      * This is set by avformat when the underlaying IO context read pointer
1825      * is repositioned, for example when doing byte based seeking.
1826      * Demuxers can use the flag to detect such changes.
1827      */
1828     int io_repositioned;
1829 
1830     /**
1831      * Forced video codec.
1832      * This allows forcing a specific decoder, even when there are multiple with
1833      * the same codec_id.
1834      * Demuxing: Set by user
1835      */
1836     AVCodec* video_codec;
1837 
1838     /**
1839      * Forced audio codec.
1840      * This allows forcing a specific decoder, even when there are multiple with
1841      * the same codec_id.
1842      * Demuxing: Set by user
1843      */
1844     AVCodec* audio_codec;
1845 
1846     /**
1847      * Forced subtitle codec.
1848      * This allows forcing a specific decoder, even when there are multiple with
1849      * the same codec_id.
1850      * Demuxing: Set by user
1851      */
1852     AVCodec* subtitle_codec;
1853 
1854     /**
1855      * Forced data codec.
1856      * This allows forcing a specific decoder, even when there are multiple with
1857      * the same codec_id.
1858      * Demuxing: Set by user
1859      */
1860     AVCodec* data_codec;
1861 
1862     /**
1863      * Number of bytes to be written as padding in a metadata header.
1864      * Demuxing: Unused.
1865      * Muxing: Set by user via av_format_set_metadata_header_padding.
1866      */
1867     int metadata_header_padding;
1868 
1869     /**
1870      * User data.
1871      * This is a place for some private data of the user.
1872      */
1873     void* opaque;
1874 
1875     /**
1876      * Callback used by devices to communicate with application.
1877      */
1878     av_format_control_message control_message_cb;
1879 
1880     /**
1881      * Output timestamp offset, in microseconds.
1882      * Muxing: set by user
1883      */
1884     long output_ts_offset;
1885 
1886     /**
1887      * dump format separator.
1888      * can be ", " or "\n      " or anything else
1889      * - muxing: Set by user.
1890      * - demuxing: Set by user.
1891      */
1892     ubyte* dump_separator;
1893 
1894     /**
1895      * Forced Data codec_id.
1896      * Demuxing: Set by user.
1897      */
1898     AVCodecID data_codec_id;
1899 
1900     /**
1901      * Called to open further IO contexts when needed for demuxing.
1902      *
1903      * This can be set by the user application to perform security checks on
1904      * the URLs before opening them.
1905      * The function should behave like avio_open2(), AVFormatContext is provided
1906      * as contextual information and to reach AVFormatContext.opaque.
1907      *
1908      * If NULL then some simple checks are used together with avio_open2().
1909      *
1910      * Must not be accessed directly from outside avformat.
1911      * @See av_format_set_open_cb()
1912      *
1913      * Demuxing: Set by user.
1914      *
1915      * @deprecated Use io_open and io_close.
1916      */
1917     int function (
1918         AVFormatContext* s,
1919         AVIOContext** p,
1920         const(char)* url,
1921         int flags,
1922         const(AVIOInterruptCB)* int_cb,
1923         AVDictionary** options) open_cb;
1924 
1925     /**
1926      * ',' separated list of allowed protocols.
1927      * - encoding: unused
1928      * - decoding: set by user
1929      */
1930     char* protocol_whitelist;
1931 
1932     /**
1933      * A callback for opening new IO streams.
1934      *
1935      * Whenever a muxer or a demuxer needs to open an IO stream (typically from
1936      * avformat_open_input() for demuxers, but for certain formats can happen at
1937      * other times as well), it will call this callback to obtain an IO context.
1938      *
1939      * @param s the format context
1940      * @param pb on success, the newly opened IO context should be returned here
1941      * @param url the url to open
1942      * @param flags a combination of AVIO_FLAG_*
1943      * @param options a dictionary of additional options, with the same
1944      *                semantics as in avio_open2()
1945      * @return 0 on success, a negative AVERROR code on failure
1946      *
1947      * @note Certain muxers and demuxers do nesting, i.e. they open one or more
1948      * additional internal format contexts. Thus the AVFormatContext pointer
1949      * passed to this callback may be different from the one facing the caller.
1950      * It will, however, have the same 'opaque' field.
1951      */
1952     int function (
1953         AVFormatContext* s,
1954         AVIOContext** pb,
1955         const(char)* url,
1956         int flags,
1957         AVDictionary** options) io_open;
1958 
1959     /**
1960      * A callback for closing the streams opened with AVFormatContext.io_open().
1961      */
1962     void function (AVFormatContext* s, AVIOContext* pb) io_close;
1963 
1964     /**
1965      * ',' separated list of disallowed protocols.
1966      * - encoding: unused
1967      * - decoding: set by user
1968      */
1969     char* protocol_blacklist;
1970 
1971     /**
1972      * The maximum number of streams.
1973      * - encoding: unused
1974      * - decoding: set by user
1975      */
1976     int max_streams;
1977 
1978     /**
1979      * Skip duration calcuation in estimate_timings_from_pts.
1980      * - encoding: unused
1981      * - decoding: set by user
1982      */
1983     int skip_estimate_duration_from_pts;
1984 }
1985 
1986 enum AVFMT_FLAG_GENPTS = 0x0001;
1987 enum AVFMT_FLAG_IGNIDX = 0x0002;
1988 enum AVFMT_FLAG_NONBLOCK = 0x0004;
1989 enum AVFMT_FLAG_IGNDTS = 0x0008;
1990 enum AVFMT_FLAG_NOFILLIN = 0x0010;
1991 enum AVFMT_FLAG_NOPARSE = 0x0020;
1992 enum AVFMT_FLAG_NOBUFFER = 0x0040;
1993 enum AVFMT_FLAG_CUSTOM_IO = 0x0080;
1994 enum AVFMT_FLAG_DISCARD_CORRUPT = 0x0100;
1995 enum AVFMT_FLAG_FLUSH_PACKETS = 0x0200;
1996 enum AVFMT_FLAG_BITEXACT = 0x0400;
1997 enum AVFMT_FLAG_MP4A_LATM = 0x8000;
1998 enum AVFMT_FLAG_SORT_DTS = 0x10000;
1999 enum AVFMT_FLAG_PRIV_OPT = 0x20000;
2000 enum AVFMT_FLAG_KEEP_SIDE_DATA = 0x40000;
2001 enum AVFMT_FLAG_FAST_SEEK = 0x80000;
2002 enum AVFMT_FLAG_SHORTEST = 0x100000;
2003 enum AVFMT_FLAG_AUTO_BSF = 0x200000;
2004 enum FF_FDEBUG_TS = 0x0001;
2005 enum AVFMT_EVENT_FLAG_METADATA_UPDATED = 0x0001;
2006 enum AVFMT_AVOID_NEG_TS_AUTO = -1;
2007 enum AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE = 1;
2008 enum AVFMT_AVOID_NEG_TS_MAKE_ZERO = 2;
2009 
2010 /**
2011  * Accessors for some AVFormatContext fields. These used to be provided for ABI
2012  * compatibility, and do not need to be used anymore.
2013  */
2014 int av_format_get_probe_score (const(AVFormatContext)* s);
2015 AVCodec* av_format_get_video_codec (const(AVFormatContext)* s);
2016 void av_format_set_video_codec (AVFormatContext* s, AVCodec* c);
2017 AVCodec* av_format_get_audio_codec (const(AVFormatContext)* s);
2018 void av_format_set_audio_codec (AVFormatContext* s, AVCodec* c);
2019 AVCodec* av_format_get_subtitle_codec (const(AVFormatContext)* s);
2020 void av_format_set_subtitle_codec (AVFormatContext* s, AVCodec* c);
2021 AVCodec* av_format_get_data_codec (const(AVFormatContext)* s);
2022 void av_format_set_data_codec (AVFormatContext* s, AVCodec* c);
2023 int av_format_get_metadata_header_padding (const(AVFormatContext)* s);
2024 void av_format_set_metadata_header_padding (AVFormatContext* s, int c);
2025 void* av_format_get_opaque (const(AVFormatContext)* s);
2026 void av_format_set_opaque (AVFormatContext* s, void* opaque);
2027 av_format_control_message av_format_get_control_message_cb (
2028     const(AVFormatContext)* s);
2029 void av_format_set_control_message_cb (
2030     AVFormatContext* s,
2031     av_format_control_message callback);
2032 AVOpenCallback av_format_get_open_cb (const(AVFormatContext)* s);
2033 void av_format_set_open_cb (AVFormatContext* s, AVOpenCallback callback);
2034 
2035 /**
2036  * This function will cause global side data to be injected in the next packet
2037  * of each stream as well as after any subsequent seek.
2038  */
2039 void av_format_inject_global_side_data (AVFormatContext* s);
2040 
2041 /**
2042  * Returns the method used to set ctx->duration.
2043  *
2044  * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
2045  */
2046 AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method (const(AVFormatContext)* ctx);
2047 
2048 struct AVPacketList
2049 {
2050     AVPacket pkt;
2051     AVPacketList* next;
2052 }
2053 
2054 /**
2055  * @defgroup lavf_core Core functions
2056  * @ingroup libavf
2057  *
2058  * Functions for querying libavformat capabilities, allocating core structures,
2059  * etc.
2060  * @{
2061  */
2062 
2063 /**
2064  * Return the LIBAVFORMAT_VERSION_INT constant.
2065  */
2066 uint avformat_version ();
2067 
2068 /**
2069  * Return the libavformat build-time configuration.
2070  */
2071 const(char)* avformat_configuration ();
2072 
2073 /**
2074  * Return the libavformat license.
2075  */
2076 const(char)* avformat_license ();
2077 
2078 /**
2079  * Initialize libavformat and register all the muxers, demuxers and
2080  * protocols. If you do not call this function, then you can select
2081  * exactly which formats you want to support.
2082  *
2083  * @see av_register_input_format()
2084  * @see av_register_output_format()
2085  */
2086 void av_register_all ();
2087 
2088 void av_register_input_format (AVInputFormat* format);
2089 void av_register_output_format (AVOutputFormat* format);
2090 
2091 /**
2092  * Do global initialization of network libraries. This is optional,
2093  * and not recommended anymore.
2094  *
2095  * This functions only exists to work around thread-safety issues
2096  * with older GnuTLS or OpenSSL libraries. If libavformat is linked
2097  * to newer versions of those libraries, or if you do not use them,
2098  * calling this function is unnecessary. Otherwise, you need to call
2099  * this function before any other threads using them are started.
2100  *
2101  * This function will be deprecated once support for older GnuTLS and
2102  * OpenSSL libraries is removed, and this function has no purpose
2103  * anymore.
2104  */
2105 int avformat_network_init ();
2106 
2107 /**
2108  * Undo the initialization done by avformat_network_init. Call it only
2109  * once for each time you called avformat_network_init.
2110  */
2111 int avformat_network_deinit ();
2112 
2113 /**
2114  * If f is NULL, returns the first registered input format,
2115  * if f is non-NULL, returns the next registered input format after f
2116  * or NULL if f is the last one.
2117  */
2118 AVInputFormat* av_iformat_next (const(AVInputFormat)* f);
2119 
2120 /**
2121  * If f is NULL, returns the first registered output format,
2122  * if f is non-NULL, returns the next registered output format after f
2123  * or NULL if f is the last one.
2124  */
2125 AVOutputFormat* av_oformat_next (const(AVOutputFormat)* f);
2126 
2127 /**
2128  * Iterate over all registered muxers.
2129  *
2130  * @param opaque a pointer where libavformat will store the iteration state. Must
2131  *               point to NULL to start the iteration.
2132  *
2133  * @return the next registered muxer or NULL when the iteration is
2134  *         finished
2135  */
2136 const(AVOutputFormat)* av_muxer_iterate (void** opaque);
2137 
2138 /**
2139  * Iterate over all registered demuxers.
2140  *
2141  * @param opaque a pointer where libavformat will store the iteration state. Must
2142  *               point to NULL to start the iteration.
2143  *
2144  * @return the next registered demuxer or NULL when the iteration is
2145  *         finished
2146  */
2147 const(AVInputFormat)* av_demuxer_iterate (void** opaque);
2148 
2149 /**
2150  * Allocate an AVFormatContext.
2151  * avformat_free_context() can be used to free the context and everything
2152  * allocated by the framework within it.
2153  */
2154 AVFormatContext* avformat_alloc_context ();
2155 
2156 /**
2157  * Free an AVFormatContext and all its streams.
2158  * @param s context to free
2159  */
2160 void avformat_free_context (AVFormatContext* s);
2161 
2162 /**
2163  * Get the AVClass for AVFormatContext. It can be used in combination with
2164  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
2165  *
2166  * @see av_opt_find().
2167  */
2168 const(AVClass)* avformat_get_class ();
2169 
2170 /**
2171  * Add a new stream to a media file.
2172  *
2173  * When demuxing, it is called by the demuxer in read_header(). If the
2174  * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
2175  * be called in read_packet().
2176  *
2177  * When muxing, should be called by the user before avformat_write_header().
2178  *
2179  * User is required to call avcodec_close() and avformat_free_context() to
2180  * clean up the allocation by avformat_new_stream().
2181  *
2182  * @param s media file handle
2183  * @param c If non-NULL, the AVCodecContext corresponding to the new stream
2184  * will be initialized to use this codec. This is needed for e.g. codec-specific
2185  * defaults to be set, so codec should be provided if it is known.
2186  *
2187  * @return newly created stream or NULL on error.
2188  */
2189 AVStream* avformat_new_stream (AVFormatContext* s, const(AVCodec)* c);
2190 
2191 /**
2192  * Wrap an existing array as stream side data.
2193  *
2194  * @param st stream
2195  * @param type side information type
2196  * @param data the side data array. It must be allocated with the av_malloc()
2197  *             family of functions. The ownership of the data is transferred to
2198  *             st.
2199  * @param size side information size
2200  * @return zero on success, a negative AVERROR code on failure. On failure,
2201  *         the stream is unchanged and the data remains owned by the caller.
2202  */
2203 int av_stream_add_side_data (
2204     AVStream* st,
2205     AVPacketSideDataType type,
2206     ubyte* data,
2207     size_t size);
2208 
2209 /**
2210  * Allocate new information from stream.
2211  *
2212  * @param stream stream
2213  * @param type desired side information type
2214  * @param size side information size
2215  * @return pointer to fresh allocated data or NULL otherwise
2216  */
2217 ubyte* av_stream_new_side_data (
2218     AVStream* stream,
2219     AVPacketSideDataType type,
2220     int size);
2221 /**
2222  * Get side information from stream.
2223  *
2224  * @param stream stream
2225  * @param type desired side information type
2226  * @param size pointer for side information size to store (optional)
2227  * @return pointer to data if present or NULL otherwise
2228  */
2229 ubyte* av_stream_get_side_data (
2230     const(AVStream)* stream,
2231     AVPacketSideDataType type,
2232     int* size);
2233 
2234 AVProgram* av_new_program (AVFormatContext* s, int id);
2235 
2236 /**
2237  * @}
2238  */
2239 
2240 /**
2241  * Allocate an AVFormatContext for an output format.
2242  * avformat_free_context() can be used to free the context and
2243  * everything allocated by the framework within it.
2244  *
2245  * @param *ctx is set to the created format context, or to NULL in
2246  * case of failure
2247  * @param oformat format to use for allocating the context, if NULL
2248  * format_name and filename are used instead
2249  * @param format_name the name of output format to use for allocating the
2250  * context, if NULL filename is used instead
2251  * @param filename the name of the filename to use for allocating the
2252  * context, may be NULL
2253  * @return >= 0 in case of success, a negative AVERROR code in case of
2254  * failure
2255  */
2256 int avformat_alloc_output_context2 (
2257     AVFormatContext** ctx,
2258     AVOutputFormat* oformat,
2259     const(char)* format_name,
2260     const(char)* filename);
2261 
2262 /**
2263  * @addtogroup lavf_decoding
2264  * @{
2265  */
2266 
2267 /**
2268  * Find AVInputFormat based on the short name of the input format.
2269  */
2270 AVInputFormat* av_find_input_format (const(char)* short_name);
2271 
2272 /**
2273  * Guess the file format.
2274  *
2275  * @param pd        data to be probed
2276  * @param is_opened Whether the file is already opened; determines whether
2277  *                  demuxers with or without AVFMT_NOFILE are probed.
2278  */
2279 AVInputFormat* av_probe_input_format (AVProbeData* pd, int is_opened);
2280 
2281 /**
2282  * Guess the file format.
2283  *
2284  * @param pd        data to be probed
2285  * @param is_opened Whether the file is already opened; determines whether
2286  *                  demuxers with or without AVFMT_NOFILE are probed.
2287  * @param score_max A probe score larger that this is required to accept a
2288  *                  detection, the variable is set to the actual detection
2289  *                  score afterwards.
2290  *                  If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
2291  *                  to retry with a larger probe buffer.
2292  */
2293 AVInputFormat* av_probe_input_format2 (AVProbeData* pd, int is_opened, int* score_max);
2294 
2295 /**
2296  * Guess the file format.
2297  *
2298  * @param is_opened Whether the file is already opened; determines whether
2299  *                  demuxers with or without AVFMT_NOFILE are probed.
2300  * @param score_ret The score of the best detection.
2301  */
2302 AVInputFormat* av_probe_input_format3 (AVProbeData* pd, int is_opened, int* score_ret);
2303 
2304 /**
2305  * Probe a bytestream to determine the input format. Each time a probe returns
2306  * with a score that is too low, the probe buffer size is increased and another
2307  * attempt is made. When the maximum probe size is reached, the input format
2308  * with the highest score is returned.
2309  *
2310  * @param pb the bytestream to probe
2311  * @param fmt the input format is put here
2312  * @param url the url of the stream
2313  * @param logctx the log context
2314  * @param offset the offset within the bytestream to probe from
2315  * @param max_probe_size the maximum probe buffer size (zero for default)
2316  * @return the score in case of success, a negative value corresponding to an
2317  *         the maximal score is AVPROBE_SCORE_MAX
2318  * AVERROR code otherwise
2319  */
2320 int av_probe_input_buffer2 (
2321     AVIOContext* pb,
2322     AVInputFormat** fmt,
2323     const(char)* url,
2324     void* logctx,
2325     uint offset,
2326     uint max_probe_size);
2327 
2328 /**
2329  * Like av_probe_input_buffer2() but returns 0 on success
2330  */
2331 int av_probe_input_buffer (
2332     AVIOContext* pb,
2333     AVInputFormat** fmt,
2334     const(char)* url,
2335     void* logctx,
2336     uint offset,
2337     uint max_probe_size);
2338 
2339 /**
2340  * Open an input stream and read the header. The codecs are not opened.
2341  * The stream must be closed with avformat_close_input().
2342  *
2343  * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
2344  *           May be a pointer to NULL, in which case an AVFormatContext is allocated by this
2345  *           function and written into ps.
2346  *           Note that a user-supplied AVFormatContext will be freed on failure.
2347  * @param url URL of the stream to open.
2348  * @param fmt If non-NULL, this parameter forces a specific input format.
2349  *            Otherwise the format is autodetected.
2350  * @param options  A dictionary filled with AVFormatContext and demuxer-private options.
2351  *                 On return this parameter will be destroyed and replaced with a dict containing
2352  *                 options that were not found. May be NULL.
2353  *
2354  * @return 0 on success, a negative AVERROR on failure.
2355  *
2356  * @note If you want to use custom IO, preallocate the format context and set its pb field.
2357  */
2358 int avformat_open_input (AVFormatContext** ps, const(char)* url, AVInputFormat* fmt, AVDictionary** options);
2359 
2360 int av_demuxer_open (AVFormatContext* ic);
2361 
2362 /**
2363  * Read packets of a media file to get stream information. This
2364  * is useful for file formats with no headers such as MPEG. This
2365  * function also computes the real framerate in case of MPEG-2 repeat
2366  * frame mode.
2367  * The logical file position is not changed by this function;
2368  * examined packets may be buffered for later processing.
2369  *
2370  * @param ic media file handle
2371  * @param options  If non-NULL, an ic.nb_streams long array of pointers to
2372  *                 dictionaries, where i-th member contains options for
2373  *                 codec corresponding to i-th stream.
2374  *                 On return each dictionary will be filled with options that were not found.
2375  * @return >=0 if OK, AVERROR_xxx on error
2376  *
2377  * @note this function isn't guaranteed to open all the codecs, so
2378  *       options being non-empty at return is a perfectly normal behavior.
2379  *
2380  * @todo Let the user decide somehow what information is needed so that
2381  *       we do not waste time getting stuff the user does not need.
2382  */
2383 int avformat_find_stream_info (AVFormatContext* ic, AVDictionary** options);
2384 
2385 /**
2386  * Find the programs which belong to a given stream.
2387  *
2388  * @param ic    media file handle
2389  * @param last  the last found program, the search will start after this
2390  *              program, or from the beginning if it is NULL
2391  * @param s     stream index
2392  * @return the next program which belongs to s, NULL if no program is found or
2393  *         the last program is not among the programs of ic.
2394  */
2395 AVProgram* av_find_program_from_stream (AVFormatContext* ic, AVProgram* last, int s);
2396 
2397 void av_program_add_stream_index (AVFormatContext* ac, int progid, uint idx);
2398 
2399 /**
2400  * Find the "best" stream in the file.
2401  * The best stream is determined according to various heuristics as the most
2402  * likely to be what the user expects.
2403  * If the decoder parameter is non-NULL, av_find_best_stream will find the
2404  * default decoder for the stream's codec; streams for which no decoder can
2405  * be found are ignored.
2406  *
2407  * @param ic                media file handle
2408  * @param type              stream type: video, audio, subtitles, etc.
2409  * @param wanted_stream_nb  user-requested stream number,
2410  *                          or -1 for automatic selection
2411  * @param related_stream    try to find a stream related (eg. in the same
2412  *                          program) to this one, or -1 if none
2413  * @param decoder_ret       if non-NULL, returns the decoder for the
2414  *                          selected stream
2415  * @param flags             flags; none are currently defined
2416  * @return  the non-negative stream number in case of success,
2417  *          AVERROR_STREAM_NOT_FOUND if no stream with the requested type
2418  *          could be found,
2419  *          AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
2420  * @note  If av_find_best_stream returns successfully and decoder_ret is not
2421  *        NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
2422  */
2423 int av_find_best_stream (
2424     AVFormatContext* ic,
2425     AVMediaType type,
2426     int wanted_stream_nb,
2427     int related_stream,
2428     AVCodec** decoder_ret,
2429     int flags);
2430 
2431 /**
2432  * Return the next frame of a stream.
2433  * This function returns what is stored in the file, and does not validate
2434  * that what is there are valid frames for the decoder. It will split what is
2435  * stored in the file into frames and return one for each call. It will not
2436  * omit invalid data between valid frames so as to give the decoder the maximum
2437  * information possible for decoding.
2438  *
2439  * If pkt->buf is NULL, then the packet is valid until the next
2440  * av_read_frame() or until avformat_close_input(). Otherwise the packet
2441  * is valid indefinitely. In both cases the packet must be freed with
2442  * av_packet_unref when it is no longer needed. For video, the packet contains
2443  * exactly one frame. For audio, it contains an integer number of frames if each
2444  * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
2445  * have a variable size (e.g. MPEG audio), then it contains one frame.
2446  *
2447  * pkt->pts, pkt->dts and pkt->duration are always set to correct
2448  * values in AVStream.time_base units (and guessed if the format cannot
2449  * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
2450  * has B-frames, so it is better to rely on pkt->dts if you do not
2451  * decompress the payload.
2452  *
2453  * @return 0 if OK, < 0 on error or end of file
2454  */
2455 int av_read_frame (AVFormatContext* s, AVPacket* pkt);
2456 
2457 /**
2458  * Seek to the keyframe at timestamp.
2459  * 'timestamp' in 'stream_index'.
2460  *
2461  * @param s media file handle
2462  * @param stream_index If stream_index is (-1), a default
2463  * stream is selected, and timestamp is automatically converted
2464  * from AV_TIME_BASE units to the stream specific time_base.
2465  * @param timestamp Timestamp in AVStream.time_base units
2466  *        or, if no stream is specified, in AV_TIME_BASE units.
2467  * @param flags flags which select direction and seeking mode
2468  * @return >= 0 on success
2469  */
2470 int av_seek_frame (
2471     AVFormatContext* s,
2472     int stream_index,
2473     long timestamp,
2474     int flags);
2475 
2476 /**
2477  * Seek to timestamp ts.
2478  * Seeking will be done so that the point from which all active streams
2479  * can be presented successfully will be closest to ts and within min/max_ts.
2480  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
2481  *
2482  * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
2483  * are the file position (this may not be supported by all demuxers).
2484  * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
2485  * in the stream with stream_index (this may not be supported by all demuxers).
2486  * Otherwise all timestamps are in units of the stream selected by stream_index
2487  * or if stream_index is -1, in AV_TIME_BASE units.
2488  * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
2489  * keyframes (this may not be supported by all demuxers).
2490  * If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
2491  *
2492  * @param s media file handle
2493  * @param stream_index index of the stream which is used as time base reference
2494  * @param min_ts smallest acceptable timestamp
2495  * @param ts target timestamp
2496  * @param max_ts largest acceptable timestamp
2497  * @param flags flags
2498  * @return >=0 on success, error code otherwise
2499  *
2500  * @note This is part of the new seek API which is still under construction.
2501  *       Thus do not use this yet. It may change at any time, do not expect
2502  *       ABI compatibility yet!
2503  */
2504 int avformat_seek_file (AVFormatContext* s, int stream_index, long min_ts, long ts, long max_ts, int flags);
2505 
2506 /**
2507  * Discard all internally buffered data. This can be useful when dealing with
2508  * discontinuities in the byte stream. Generally works only with formats that
2509  * can resync. This includes headerless formats like MPEG-TS/TS but should also
2510  * work with NUT, Ogg and in a limited way AVI for example.
2511  *
2512  * The set of streams, the detected duration, stream parameters and codecs do
2513  * not change when calling this function. If you want a complete reset, it's
2514  * better to open a new AVFormatContext.
2515  *
2516  * This does not flush the AVIOContext (s->pb). If necessary, call
2517  * avio_flush(s->pb) before calling this function.
2518  *
2519  * @param s media file handle
2520  * @return >=0 on success, error code otherwise
2521  */
2522 int avformat_flush (AVFormatContext* s);
2523 
2524 /**
2525  * Start playing a network-based stream (e.g. RTSP stream) at the
2526  * current position.
2527  */
2528 int av_read_play (AVFormatContext* s);
2529 
2530 /**
2531  * Pause a network-based stream (e.g. RTSP stream).
2532  *
2533  * Use av_read_play() to resume it.
2534  */
2535 int av_read_pause (AVFormatContext* s);
2536 
2537 /**
2538  * Close an opened input AVFormatContext. Free it and all its contents
2539  * and set *s to NULL.
2540  */
2541 void avformat_close_input (AVFormatContext** s);
2542 /**
2543  * @}
2544  */
2545 
2546 enum AVSEEK_FLAG_BACKWARD = 1; ///< seek backward
2547 enum AVSEEK_FLAG_BYTE = 2; ///< seeking based on position in bytes
2548 enum AVSEEK_FLAG_ANY = 4; ///< seek to any frame, even non-keyframes
2549 enum AVSEEK_FLAG_FRAME = 8; ///< seeking based on frame number
2550 
2551 /**
2552  * @addtogroup lavf_encoding
2553  * @{
2554  */
2555 
2556 enum AVSTREAM_INIT_IN_WRITE_HEADER = 0; ///< stream parameters initialized in avformat_write_header
2557 enum AVSTREAM_INIT_IN_INIT_OUTPUT = 1; ///< stream parameters initialized in avformat_init_output
2558 
2559 /**
2560  * Allocate the stream private data and write the stream header to
2561  * an output media file.
2562  *
2563  * @param s Media file handle, must be allocated with avformat_alloc_context().
2564  *          Its oformat field must be set to the desired output format;
2565  *          Its pb field must be set to an already opened AVIOContext.
2566  * @param options  An AVDictionary filled with AVFormatContext and muxer-private options.
2567  *                 On return this parameter will be destroyed and replaced with a dict containing
2568  *                 options that were not found. May be NULL.
2569  *
2570  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec had not already been fully initialized in avformat_init,
2571  *         AVSTREAM_INIT_IN_INIT_OUTPUT  on success if the codec had already been fully initialized in avformat_init,
2572  *         negative AVERROR on failure.
2573  *
2574  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_init_output.
2575  */
2576 int avformat_write_header (AVFormatContext* s, AVDictionary** options);
2577 
2578 /**
2579  * Allocate the stream private data and initialize the codec, but do not write the header.
2580  * May optionally be used before avformat_write_header to initialize stream parameters
2581  * before actually writing the header.
2582  * If using this function, do not pass the same options to avformat_write_header.
2583  *
2584  * @param s Media file handle, must be allocated with avformat_alloc_context().
2585  *          Its oformat field must be set to the desired output format;
2586  *          Its pb field must be set to an already opened AVIOContext.
2587  * @param options  An AVDictionary filled with AVFormatContext and muxer-private options.
2588  *                 On return this parameter will be destroyed and replaced with a dict containing
2589  *                 options that were not found. May be NULL.
2590  *
2591  * @return AVSTREAM_INIT_IN_WRITE_HEADER on success if the codec requires avformat_write_header to fully initialize,
2592  *         AVSTREAM_INIT_IN_INIT_OUTPUT  on success if the codec has been fully initialized,
2593  *         negative AVERROR on failure.
2594  *
2595  * @see av_opt_find, av_dict_set, avio_open, av_oformat_next, avformat_write_header.
2596  */
2597 int avformat_init_output (AVFormatContext* s, AVDictionary** options);
2598 
2599 /**
2600  * Write a packet to an output media file.
2601  *
2602  * This function passes the packet directly to the muxer, without any buffering
2603  * or reordering. The caller is responsible for correctly interleaving the
2604  * packets if the format requires it. Callers that want libavformat to handle
2605  * the interleaving should call av_interleaved_write_frame() instead of this
2606  * function.
2607  *
2608  * @param s media file handle
2609  * @param pkt The packet containing the data to be written. Note that unlike
2610  *            av_interleaved_write_frame(), this function does not take
2611  *            ownership of the packet passed to it (though some muxers may make
2612  *            an internal reference to the input packet).
2613  *            <br>
2614  *            This parameter can be NULL (at any time, not just at the end), in
2615  *            order to immediately flush data buffered within the muxer, for
2616  *            muxers that buffer up data internally before writing it to the
2617  *            output.
2618  *            <br>
2619  *            Packet's @ref AVPacket.stream_index "stream_index" field must be
2620  *            set to the index of the corresponding stream in @ref
2621  *            AVFormatContext.streams "s->streams".
2622  *            <br>
2623  *            The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2624  *            must be set to correct values in the stream's timebase (unless the
2625  *            output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2626  *            they can be set to AV_NOPTS_VALUE).
2627  *            The dts for subsequent packets passed to this function must be strictly
2628  *            increasing when compared in their respective timebases (unless the
2629  *            output format is flagged with the AVFMT_TS_NONSTRICT, then they
2630  *            merely have to be nondecreasing).  @ref AVPacket.duration
2631  *            "duration") should also be set if known.
2632  * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
2633  *
2634  * @see av_interleaved_write_frame()
2635  */
2636 int av_write_frame (AVFormatContext* s, AVPacket* pkt);
2637 
2638 /**
2639  * Write a packet to an output media file ensuring correct interleaving.
2640  *
2641  * This function will buffer the packets internally as needed to make sure the
2642  * packets in the output file are properly interleaved in the order of
2643  * increasing dts. Callers doing their own interleaving should call
2644  * av_write_frame() instead of this function.
2645  *
2646  * Using this function instead of av_write_frame() can give muxers advance
2647  * knowledge of future packets, improving e.g. the behaviour of the mp4
2648  * muxer for VFR content in fragmenting mode.
2649  *
2650  * @param s media file handle
2651  * @param pkt The packet containing the data to be written.
2652  *            <br>
2653  *            If the packet is reference-counted, this function will take
2654  *            ownership of this reference and unreference it later when it sees
2655  *            fit.
2656  *            The caller must not access the data through this reference after
2657  *            this function returns. If the packet is not reference-counted,
2658  *            libavformat will make a copy.
2659  *            <br>
2660  *            This parameter can be NULL (at any time, not just at the end), to
2661  *            flush the interleaving queues.
2662  *            <br>
2663  *            Packet's @ref AVPacket.stream_index "stream_index" field must be
2664  *            set to the index of the corresponding stream in @ref
2665  *            AVFormatContext.streams "s->streams".
2666  *            <br>
2667  *            The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts")
2668  *            must be set to correct values in the stream's timebase (unless the
2669  *            output format is flagged with the AVFMT_NOTIMESTAMPS flag, then
2670  *            they can be set to AV_NOPTS_VALUE).
2671  *            The dts for subsequent packets in one stream must be strictly
2672  *            increasing (unless the output format is flagged with the
2673  *            AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing).
2674  *            @ref AVPacket.duration "duration") should also be set if known.
2675  *
2676  * @return 0 on success, a negative AVERROR on error. Libavformat will always
2677  *         take care of freeing the packet, even if this function fails.
2678  *
2679  * @see av_write_frame(), AVFormatContext.max_interleave_delta
2680  */
2681 int av_interleaved_write_frame (AVFormatContext* s, AVPacket* pkt);
2682 
2683 /**
2684  * Write an uncoded frame to an output media file.
2685  *
2686  * The frame must be correctly interleaved according to the container
2687  * specification; if not, then av_interleaved_write_frame() must be used.
2688  *
2689  * See av_interleaved_write_frame() for details.
2690  */
2691 int av_write_uncoded_frame (
2692     AVFormatContext* s,
2693     int stream_index,
2694     AVFrame* frame);
2695 
2696 /**
2697  * Write an uncoded frame to an output media file.
2698  *
2699  * If the muxer supports it, this function makes it possible to write an AVFrame
2700  * structure directly, without encoding it into a packet.
2701  * It is mostly useful for devices and similar special muxers that use raw
2702  * video or PCM data and will not serialize it into a byte stream.
2703  *
2704  * To test whether it is possible to use it with a given muxer and stream,
2705  * use av_write_uncoded_frame_query().
2706  *
2707  * The caller gives up ownership of the frame and must not access it
2708  * afterwards.
2709  *
2710  * @return  >=0 for success, a negative code on error
2711  */
2712 int av_interleaved_write_uncoded_frame (
2713     AVFormatContext* s,
2714     int stream_index,
2715     AVFrame* frame);
2716 
2717 /**
2718  * Test whether a muxer supports uncoded frame.
2719  *
2720  * @return  >=0 if an uncoded frame can be written to that muxer and stream,
2721  *          <0 if not
2722  */
2723 int av_write_uncoded_frame_query (AVFormatContext* s, int stream_index);
2724 
2725 /**
2726  * Write the stream trailer to an output media file and free the
2727  * file private data.
2728  *
2729  * May only be called after a successful call to avformat_write_header.
2730  *
2731  * @param s media file handle
2732  * @return 0 if OK, AVERROR_xxx on error
2733  */
2734 int av_write_trailer (AVFormatContext* s);
2735 
2736 /**
2737  * Return the output format in the list of registered output formats
2738  * which best matches the provided parameters, or return NULL if
2739  * there is no match.
2740  *
2741  * @param short_name if non-NULL checks if short_name matches with the
2742  * names of the registered formats
2743  * @param filename if non-NULL checks if filename terminates with the
2744  * extensions of the registered formats
2745  * @param mime_type if non-NULL checks if mime_type matches with the
2746  * MIME type of the registered formats
2747  */
2748 AVOutputFormat* av_guess_format (
2749     const(char)* short_name,
2750     const(char)* filename,
2751     const(char)* mime_type);
2752 
2753 /**
2754  * Guess the codec ID based upon muxer and filename.
2755  */
2756 AVCodecID av_guess_codec (
2757     AVOutputFormat* fmt,
2758     const(char)* short_name,
2759     const(char)* filename,
2760     const(char)* mime_type,
2761     AVMediaType type);
2762 
2763 /**
2764  * Get timing information for the data currently output.
2765  * The exact meaning of "currently output" depends on the format.
2766  * It is mostly relevant for devices that have an internal buffer and/or
2767  * work in real time.
2768  * @param s          media file handle
2769  * @param stream     stream in the media file
2770  * @param[out] dts   DTS of the last packet output for the stream, in stream
2771  *                   time_base units
2772  * @param[out] wall  absolute time when that packet whas output,
2773  *                   in microsecond
2774  * @return  0 if OK, AVERROR(ENOSYS) if the format does not support it
2775  * Note: some formats or devices may not allow to measure dts and wall
2776  * atomically.
2777  */
2778 int av_get_output_timestamp (
2779     AVFormatContext* s,
2780     int stream,
2781     long* dts,
2782     long* wall);
2783 
2784 /**
2785  * @}
2786  */
2787 
2788 /**
2789  * @defgroup lavf_misc Utility functions
2790  * @ingroup libavf
2791  * @{
2792  *
2793  * Miscellaneous utility functions related to both muxing and demuxing
2794  * (or neither).
2795  */
2796 
2797 /**
2798  * Send a nice hexadecimal dump of a buffer to the specified file stream.
2799  *
2800  * @param f The file stream pointer where the dump should be sent to.
2801  * @param buf buffer
2802  * @param size buffer size
2803  *
2804  * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
2805  */
2806 void av_hex_dump (FILE* f, const(ubyte)* buf, int size);
2807 
2808 /**
2809  * Send a nice hexadecimal dump of a buffer to the log.
2810  *
2811  * @param avcl A pointer to an arbitrary struct of which the first field is a
2812  * pointer to an AVClass struct.
2813  * @param level The importance level of the message, lower values signifying
2814  * higher importance.
2815  * @param buf buffer
2816  * @param size buffer size
2817  *
2818  * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
2819  */
2820 void av_hex_dump_log (void* avcl, int level, const(ubyte)* buf, int size);
2821 
2822 /**
2823  * Send a nice dump of a packet to the specified file stream.
2824  *
2825  * @param f The file stream pointer where the dump should be sent to.
2826  * @param pkt packet to dump
2827  * @param dump_payload True if the payload must be displayed, too.
2828  * @param st AVStream that the packet belongs to
2829  */
2830 void av_pkt_dump2 (FILE* f, const(AVPacket)* pkt, int dump_payload, const(AVStream)* st);
2831 
2832 /**
2833  * Send a nice dump of a packet to the log.
2834  *
2835  * @param avcl A pointer to an arbitrary struct of which the first field is a
2836  * pointer to an AVClass struct.
2837  * @param level The importance level of the message, lower values signifying
2838  * higher importance.
2839  * @param pkt packet to dump
2840  * @param dump_payload True if the payload must be displayed, too.
2841  * @param st AVStream that the packet belongs to
2842  */
2843 void av_pkt_dump_log2 (
2844     void* avcl,
2845     int level,
2846     const(AVPacket)* pkt,
2847     int dump_payload,
2848     const(AVStream)* st);
2849 
2850 /**
2851  * Get the AVCodecID for the given codec tag tag.
2852  * If no codec id is found returns AV_CODEC_ID_NONE.
2853  *
2854  * @param tags list of supported codec_id-codec_tag pairs, as stored
2855  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2856  * @param tag  codec tag to match to a codec ID
2857  */
2858 AVCodecID av_codec_get_id (const(AVCodecTag*)* tags, uint tag);
2859 
2860 /**
2861  * Get the codec tag for the given codec id id.
2862  * If no codec tag is found returns 0.
2863  *
2864  * @param tags list of supported codec_id-codec_tag pairs, as stored
2865  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2866  * @param id   codec ID to match to a codec tag
2867  */
2868 uint av_codec_get_tag (const(AVCodecTag*)* tags, AVCodecID id);
2869 
2870 /**
2871  * Get the codec tag for the given codec id.
2872  *
2873  * @param tags list of supported codec_id - codec_tag pairs, as stored
2874  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
2875  * @param id codec id that should be searched for in the list
2876  * @param tag A pointer to the found tag
2877  * @return 0 if id was not found in tags, > 0 if it was found
2878  */
2879 int av_codec_get_tag2 (const(AVCodecTag*)* tags, AVCodecID id, uint* tag);
2880 
2881 int av_find_default_stream_index (AVFormatContext* s);
2882 
2883 /**
2884  * Get the index for a specific timestamp.
2885  *
2886  * @param st        stream that the timestamp belongs to
2887  * @param timestamp timestamp to retrieve the index for
2888  * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
2889  *                 to the timestamp which is <= the requested one, if backward
2890  *                 is 0, then it will be >=
2891  *              if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
2892  * @return < 0 if no such timestamp could be found
2893  */
2894 int av_index_search_timestamp (AVStream* st, long timestamp, int flags);
2895 
2896 /**
2897  * Add an index entry into a sorted list. Update the entry if the list
2898  * already contains it.
2899  *
2900  * @param timestamp timestamp in the time base of the given stream
2901  */
2902 int av_add_index_entry (
2903     AVStream* st,
2904     long pos,
2905     long timestamp,
2906     int size,
2907     int distance,
2908     int flags);
2909 
2910 /**
2911  * Split a URL string into components.
2912  *
2913  * The pointers to buffers for storing individual components may be null,
2914  * in order to ignore that component. Buffers for components not found are
2915  * set to empty strings. If the port is not found, it is set to a negative
2916  * value.
2917  *
2918  * @param proto the buffer for the protocol
2919  * @param proto_size the size of the proto buffer
2920  * @param authorization the buffer for the authorization
2921  * @param authorization_size the size of the authorization buffer
2922  * @param hostname the buffer for the host name
2923  * @param hostname_size the size of the hostname buffer
2924  * @param port_ptr a pointer to store the port number in
2925  * @param path the buffer for the path
2926  * @param path_size the size of the path buffer
2927  * @param url the URL to split
2928  */
2929 void av_url_split (
2930     char* proto,
2931     int proto_size,
2932     char* authorization,
2933     int authorization_size,
2934     char* hostname,
2935     int hostname_size,
2936     int* port_ptr,
2937     char* path,
2938     int path_size,
2939     const(char)* url);
2940 
2941 /**
2942  * Print detailed information about the input or output format, such as
2943  * duration, bitrate, streams, container, programs, metadata, side data,
2944  * codec and time base.
2945  *
2946  * @param ic        the context to analyze
2947  * @param index     index of the stream to dump information about
2948  * @param url       the URL to print, such as source or destination file
2949  * @param is_output Select whether the specified context is an input(0) or output(1)
2950  */
2951 void av_dump_format (
2952     AVFormatContext* ic,
2953     int index,
2954     const(char)* url,
2955     int is_output);
2956 
2957 enum AV_FRAME_FILENAME_FLAGS_MULTIPLE = 1; ///< Allow multiple %d
2958 
2959 /**
2960  * Return in 'buf' the path with '%d' replaced by a number.
2961  *
2962  * Also handles the '%0nd' format where 'n' is the total number
2963  * of digits and '%%'.
2964  *
2965  * @param buf destination buffer
2966  * @param buf_size destination buffer size
2967  * @param path numbered sequence string
2968  * @param number frame number
2969  * @param flags AV_FRAME_FILENAME_FLAGS_*
2970  * @return 0 if OK, -1 on format error
2971  */
2972 int av_get_frame_filename2 (
2973     char* buf,
2974     int buf_size,
2975     const(char)* path,
2976     int number,
2977     int flags);
2978 
2979 int av_get_frame_filename (
2980     char* buf,
2981     int buf_size,
2982     const(char)* path,
2983     int number);
2984 
2985 /**
2986  * Check whether filename actually is a numbered sequence generator.
2987  *
2988  * @param filename possible numbered sequence string
2989  * @return 1 if a valid numbered sequence string, 0 otherwise
2990  */
2991 int av_filename_number_test (const(char)* filename);
2992 
2993 /**
2994  * Generate an SDP for an RTP session.
2995  *
2996  * Note, this overwrites the id values of AVStreams in the muxer contexts
2997  * for getting unique dynamic payload types.
2998  *
2999  * @param ac array of AVFormatContexts describing the RTP streams. If the
3000  *           array is composed by only one context, such context can contain
3001  *           multiple AVStreams (one AVStream per RTP stream). Otherwise,
3002  *           all the contexts in the array (an AVCodecContext per RTP stream)
3003  *           must contain only one AVStream.
3004  * @param n_files number of AVCodecContexts contained in ac
3005  * @param buf buffer where the SDP will be stored (must be allocated by
3006  *            the caller)
3007  * @param size the size of the buffer
3008  * @return 0 if OK, AVERROR_xxx on error
3009  */
3010 int av_sdp_create (AVFormatContext** ac, int n_files, char* buf, int size);
3011 
3012 /**
3013  * Return a positive value if the given filename has one of the given
3014  * extensions, 0 otherwise.
3015  *
3016  * @param filename   file name to check against the given extensions
3017  * @param extensions a comma-separated list of filename extensions
3018  */
3019 int av_match_ext (const(char)* filename, const(char)* extensions);
3020 
3021 /**
3022  * Test if the given container can store a codec.
3023  *
3024  * @param ofmt           container to check for compatibility
3025  * @param codec_id       codec to potentially store in container
3026  * @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
3027  *
3028  * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
3029  *         A negative number if this information is not available.
3030  */
3031 int avformat_query_codec (
3032     const(AVOutputFormat)* ofmt,
3033     AVCodecID codec_id,
3034     int std_compliance);
3035 
3036 /**
3037  * @defgroup riff_fourcc RIFF FourCCs
3038  * @{
3039  * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
3040  * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
3041  * following code:
3042  * @code
3043  * uint32_t tag = MKTAG('H', '2', '6', '4');
3044  * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
3045  * enum AVCodecID id = av_codec_get_id(table, tag);
3046  * @endcode
3047  */
3048 /**
3049  * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
3050  */
3051 const(AVCodecTag)* avformat_get_riff_video_tags ();
3052 /**
3053  * @return the table mapping RIFF FourCCs for audio to AVCodecID.
3054  */
3055 const(AVCodecTag)* avformat_get_riff_audio_tags ();
3056 /**
3057  * @return the table mapping MOV FourCCs for video to libavcodec AVCodecID.
3058  */
3059 const(AVCodecTag)* avformat_get_mov_video_tags ();
3060 /**
3061  * @return the table mapping MOV FourCCs for audio to AVCodecID.
3062  */
3063 const(AVCodecTag)* avformat_get_mov_audio_tags ();
3064 
3065 /**
3066  * @}
3067  */
3068 
3069 /**
3070  * Guess the sample aspect ratio of a frame, based on both the stream and the
3071  * frame aspect ratio.
3072  *
3073  * Since the frame aspect ratio is set by the codec but the stream aspect ratio
3074  * is set by the demuxer, these two may not be equal. This function tries to
3075  * return the value that you should use if you would like to display the frame.
3076  *
3077  * Basic logic is to use the stream aspect ratio if it is set to something sane
3078  * otherwise use the frame aspect ratio. This way a container setting, which is
3079  * usually easy to modify can override the coded value in the frames.
3080  *
3081  * @param format the format context which the stream is part of
3082  * @param stream the stream which the frame is part of
3083  * @param frame the frame with the aspect ratio to be determined
3084  * @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
3085  */
3086 AVRational av_guess_sample_aspect_ratio (AVFormatContext* format, AVStream* stream, AVFrame* frame);
3087 
3088 /**
3089  * Guess the frame rate, based on both the container and codec information.
3090  *
3091  * @param ctx the format context which the stream is part of
3092  * @param stream the stream which the frame is part of
3093  * @param frame the frame for which the frame rate should be determined, may be NULL
3094  * @return the guessed (valid) frame rate, 0/1 if no idea
3095  */
3096 AVRational av_guess_frame_rate (AVFormatContext* ctx, AVStream* stream, AVFrame* frame);
3097 
3098 /**
3099  * Check if the stream st contained in s is matched by the stream specifier
3100  * spec.
3101  *
3102  * See the "stream specifiers" chapter in the documentation for the syntax
3103  * of spec.
3104  *
3105  * @return  >0 if st is matched by spec;
3106  *          0  if st is not matched by spec;
3107  *          AVERROR code if spec is invalid
3108  *
3109  * @note  A stream specifier can match several streams in the format.
3110  */
3111 int avformat_match_stream_specifier (
3112     AVFormatContext* s,
3113     AVStream* st,
3114     const(char)* spec);
3115 
3116 int avformat_queue_attached_pictures (AVFormatContext* s);
3117 
3118 /**
3119  * Apply a list of bitstream filters to a packet.
3120  *
3121  * @param codec AVCodecContext, usually from an AVStream
3122  * @param pkt the packet to apply filters to. If, on success, the returned
3123  *        packet has size == 0 and side_data_elems == 0, it indicates that
3124  *        the packet should be dropped
3125  * @param bsfc a NULL-terminated list of filters to apply
3126  * @return  >=0 on success;
3127  *          AVERROR code on failure
3128  */
3129 int av_apply_bitstream_filters (
3130     AVCodecContext* codec,
3131     AVPacket* pkt,
3132     AVBitStreamFilterContext* bsfc);
3133 
3134 enum AVTimebaseSource
3135 {
3136     AVFMT_TBCF_AUTO = -1,
3137     AVFMT_TBCF_DECODER = 0,
3138     AVFMT_TBCF_DEMUXER = 1,
3139 
3140     AVFMT_TBCF_R_FRAMERATE = 2
3141 }
3142 
3143 /**
3144  * Transfer internal timing information from one stream to another.
3145  *
3146  * This function is useful when doing stream copy.
3147  *
3148  * @param ofmt     target output format for ost
3149  * @param ost      output stream which needs timings copy and adjustments
3150  * @param ist      reference input stream to copy timings from
3151  * @param copy_tb  define from where the stream codec timebase needs to be imported
3152  */
3153 int avformat_transfer_internal_stream_timing_info (
3154     const(AVOutputFormat)* ofmt,
3155     AVStream* ost,
3156     const(AVStream)* ist,
3157     AVTimebaseSource copy_tb);
3158 
3159 /**
3160  * Get the internal codec timebase from a stream.
3161  *
3162  * @param st  input stream to extract the timebase from
3163  */
3164 AVRational av_stream_get_codec_timebase (const(AVStream)* st);
3165 
3166 /**
3167  * @}
3168  */
3169 
3170 /* AVFORMAT_AVFORMAT_H */