mm7: lib/libavformat/avformat.h comparison

comparison lib/libavformat/avformat.h @ 2134:992d2e6f907d

preparation for libavcodec

author	zipi
date	Tue, 31 Dec 2013 14:52:14 +0000
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comparison

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-:e378232bfd36
+:992d2e6f907d
+/*
+* copyright (c) 2001 Fabrice Bellard
+*
+* This file is part of FFmpeg.
+*
+* FFmpeg is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public
+* License as published by the Free Software Foundation; either
+* version 2.1 of the License, or (at your option) any later version.
+*
+* FFmpeg is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with FFmpeg; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+*/
+#ifndef AVFORMAT_AVFORMAT_H
+#define AVFORMAT_AVFORMAT_H
+/**
+* @file
+* @ingroup libavf
+* Main libavformat public API header
+*/
+/**
+* @defgroup libavf I/O and Muxing/Demuxing Library
+* @{
+*
+* Libavformat (lavf) is a library for dealing with various media container
+* formats. Its main two purposes are demuxing - i.e. splitting a media file
+* into component streams, and the reverse process of muxing - writing supplied
+* data in a specified container format. It also has an @ref lavf_io
+* "I/O module" which supports a number of protocols for accessing the data (e.g.
+* file, tcp, http and others). Before using lavf, you need to call
+* av_register_all() to register all compiled muxers, demuxers and protocols.
+* Unless you are absolutely sure you won't use libavformat's network
+* capabilities, you should also call avformat_network_init().
+*
+* A supported input format is described by an AVInputFormat struct, conversely
+* an output format is described by AVOutputFormat. You can iterate over all
+* registered input/output formats using the av_iformat_next() /
+* av_oformat_next() functions. The protocols layer is not part of the public
+* API, so you can only get the names of supported protocols with the
+* avio_enum_protocols() function.
+*
+* Main lavf structure used for both muxing and demuxing is AVFormatContext,
+* which exports all information about the file being read or written. As with
+* most Libavformat structures, its size is not part of public ABI, so it cannot be
+* allocated on stack or directly with av_malloc(). To create an
+* AVFormatContext, use avformat_alloc_context() (some functions, like
+* avformat_open_input() might do that for you).
+*
+* Most importantly an AVFormatContext contains:
+* @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat
+* "output" format. It is either autodetected or set by user for input;
+* always set by user for output.
+* @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all
+* elementary streams stored in the file. AVStreams are typically referred to
+* using their index in this array.
+* @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or
+* set by user for input, always set by user for output (unless you are dealing
+* with an AVFMT_NOFILE format).
+*
+* @section lavf_options Passing options to (de)muxers
+* Lavf allows to configure muxers and demuxers using the @ref avoptions
+* mechanism. Generic (format-independent) libavformat options are provided by
+* AVFormatContext, they can be examined from a user program by calling
+* av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass
+* from avformat_get_class()). Private (format-specific) options are provided by
+* AVFormatContext.priv_data if and only if AVInputFormat.priv_class /
+* AVOutputFormat.priv_class of the corresponding format struct is non-NULL.
+* Further options may be provided by the @ref AVFormatContext.pb "I/O context",
+* if its AVClass is non-NULL, and the protocols layer. See the discussion on
+* nesting in @ref avoptions documentation to learn how to access those.
+*
+* @defgroup lavf_decoding Demuxing
+* @{
+* Demuxers read a media file and split it into chunks of data (@em packets). A
+* @ref AVPacket "packet" contains one or more encoded frames which belongs to a
+* single elementary stream. In the lavf API this process is represented by the
+* avformat_open_input() function for opening a file, av_read_frame() for
+* reading a single packet and finally avformat_close_input(), which does the
+* cleanup.
+*
+* @section lavf_decoding_open Opening a media file
+* The minimum information required to open a file is its URL or filename, which
+* is passed to avformat_open_input(), as in the following code:
+* @code
+* const char    *url = "in.mp3";
+* AVFormatContext *s = NULL;
+* int ret = avformat_open_input(&s, url, NULL, NULL);
+* if (ret < 0)
+*     abort();
+* @endcode
+* The above code attempts to allocate an AVFormatContext, open the
+* specified file (autodetecting the format) and read the header, exporting the
+* information stored there into s. Some formats do not have a header or do not
+* store enough information there, so it is recommended that you call the
+* avformat_find_stream_info() function which tries to read and decode a few
+* frames to find missing information.
+*
+* In some cases you might want to preallocate an AVFormatContext yourself with
+* avformat_alloc_context() and do some tweaking on it before passing it to
+* avformat_open_input(). One such case is when you want to use custom functions
+* for reading input data instead of lavf internal I/O layer.
+* To do that, create your own AVIOContext with avio_alloc_context(), passing
+* your reading callbacks to it. Then set the @em pb field of your
+* AVFormatContext to newly created AVIOContext.
+*
+* Since the format of the opened file is in general not known until after
+* avformat_open_input() has returned, it is not possible to set demuxer private
+* options on a preallocated context. Instead, the options should be passed to
+* avformat_open_input() wrapped in an AVDictionary:
+* @code
+* AVDictionary *options = NULL;
+* av_dict_set(&options, "video_size", "640x480", 0);
+* av_dict_set(&options, "pixel_format", "rgb24", 0);
+*
+* if (avformat_open_input(&s, url, NULL, &options) < 0)
+*     abort();
+* av_dict_free(&options);
+* @endcode
+* This code passes the private options 'video_size' and 'pixel_format' to the
+* demuxer. They would be necessary for e.g. the rawvideo demuxer, since it
+* cannot know how to interpret raw video data otherwise. If the format turns
+* out to be something different than raw video, those options will not be
+* recognized by the demuxer and therefore will not be applied. Such unrecognized
+* options are then returned in the options dictionary (recognized options are
+* consumed). The calling program can handle such unrecognized options as it
+* wishes, e.g.
+* @code
+* AVDictionaryEntry *e;
+* if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
+*     fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key);
+*     abort();
+* }
+* @endcode
+*
+* After you have finished reading the file, you must close it with
+* avformat_close_input(). It will free everything associated with the file.
+*
+* @section lavf_decoding_read Reading from an opened file
+* Reading data from an opened AVFormatContext is done by repeatedly calling
+* av_read_frame() on it. Each call, if successful, will return an AVPacket
+* containing encoded data for one AVStream, identified by
+* AVPacket.stream_index. This packet may be passed straight into the libavcodec
+* decoding functions avcodec_decode_video2(), avcodec_decode_audio4() or
+* avcodec_decode_subtitle2() if the caller wishes to decode the data.
+*
+* AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be
+* set if known. They may also be unset (i.e. AV_NOPTS_VALUE for
+* pts/dts, 0 for duration) if the stream does not provide them. The timing
+* information will be in AVStream.time_base units, i.e. it has to be
+* multiplied by the timebase to convert them to seconds.
+*
+* If AVPacket.buf is set on the returned packet, then the packet is
+* allocated dynamically and the user may keep it indefinitely.
+* Otherwise, if AVPacket.buf is NULL, the packet data is backed by a
+* static storage somewhere inside the demuxer and the packet is only valid
+* until the next av_read_frame() call or closing the file. If the caller
+* requires a longer lifetime, av_dup_packet() will make an av_malloc()ed copy
+* of it.
+* In both cases, the packet must be freed with av_free_packet() when it is no
+* longer needed.
+*
+* @section lavf_decoding_seek Seeking
+* @}
+*
+* @defgroup lavf_encoding Muxing
+* @{
+* @}
+*
+* @defgroup lavf_io I/O Read/Write
+* @{
+* @}
+*
+* @defgroup lavf_codec Demuxers
+* @{
+* @defgroup lavf_codec_native Native Demuxers
+* @{
+* @}
+* @defgroup lavf_codec_wrappers External library wrappers
+* @{
+* @}
+* @}
+* @defgroup lavf_protos I/O Protocols
+* @{
+* @}
+* @defgroup lavf_internal Internal
+* @{
+* @}
+* @}
+*
+*/
+#include <time.h>
+#include <stdio.h>  /* FILE */
+#include "../libavcodec/avcodec.h"
+#include "../libavutil/dict.h"
+#include "../libavutil/log.h"
+#include "avio.h"
+#include "version.h"
+struct AVFormatContext;
+/**
+* @defgroup metadata_api Public Metadata API
+* @{
+* @ingroup libavf
+* The metadata API allows libavformat to export metadata tags to a client
+* application when demuxing. Conversely it allows a client application to
+* set metadata when muxing.
+*
+* Metadata is exported or set as pairs of key/value strings in the 'metadata'
+* fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs
+* using the @ref lavu_dict "AVDictionary" API. Like all strings in FFmpeg,
+* metadata is assumed to be UTF-8 encoded Unicode. Note that metadata
+* exported by demuxers isn't checked to be valid UTF-8 in most cases.
+*
+* Important concepts to keep in mind:
+* -  Keys are unique; there can never be 2 tags with the same key. This is
+*    also meant semantically, i.e., a demuxer should not knowingly produce
+*    several keys that are literally different but semantically identical.
+*    E.g., key=Author5, key=Author6. In this example, all authors must be
+*    placed in the same tag.
+* -  Metadata is flat, not hierarchical; there are no subtags. If you
+*    want to store, e.g., the email address of the child of producer Alice
+*    and actor Bob, that could have key=alice_and_bobs_childs_email_address.
+* -  Several modifiers can be applied to the tag name. This is done by
+*    appending a dash character ('-') and the modifier name in the order
+*    they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng.
+*    -  language -- a tag whose value is localized for a particular language
+*       is appended with the ISO 639-2/B 3-letter language code.
+*       For example: Author-ger=Michael, Author-eng=Mike
+*       The original/default language is in the unqualified "Author" tag.
+*       A demuxer should set a default if it sets any translated tag.
+*    -  sorting  -- a modified version of a tag that should be used for
+*       sorting will have '-sort' appended. E.g. artist="The Beatles",
+*       artist-sort="Beatles, The".
+*
+* -  Demuxers attempt to export metadata in a generic format, however tags
+*    with no generic equivalents are left as they are stored in the container.
+*    Follows a list of generic tag names:
+*
+@verbatim
+album        -- name of the set this work belongs to
+album_artist -- main creator of the set/album, if different from artist.
+e.g. "Various Artists" for compilation albums.
+artist       -- main creator of the work
+comment      -- any additional description of the file.
+composer     -- who composed the work, if different from artist.
+copyright    -- name of copyright holder.
+creation_time-- date when the file was created, preferably in ISO 8601.
+date         -- date when the work was created, preferably in ISO 8601.
+disc         -- number of a subset, e.g. disc in a multi-disc collection.
+encoder      -- name/settings of the software/hardware that produced the file.
+encoded_by   -- person/group who created the file.
+filename     -- original name of the file.
+genre        -- <self-evident>.
+language     -- main language in which the work is performed, preferably
+in ISO 639-2 format. Multiple languages can be specified by
+separating them with commas.
+performer    -- artist who performed the work, if different from artist.
+E.g for "Also sprach Zarathustra", artist would be "Richard
+Strauss" and performer "London Philharmonic Orchestra".
+publisher    -- name of the label/publisher.
+service_name     -- name of the service in broadcasting (channel name).
+service_provider -- name of the service provider in broadcasting.
+title        -- name of the work.
+track        -- number of this work in the set, can be in form current/total.
+variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of
+@endverbatim
+*
+* Look in the examples section for an application example how to use the Metadata API.
+*
+* @}
+*/
+/* packet functions */
+/**
+* Allocate and read the payload of a packet and initialize its
+* fields with default values.
+*
+* @param pkt packet
+* @param size desired payload size
+* @return >0 (read size) if OK, AVERROR_xxx otherwise
+*/
+int av_get_packet(AVIOContext *s, AVPacket *pkt, int size);
+/**
+* Read data and append it to the current content of the AVPacket.
+* If pkt->size is 0 this is identical to av_get_packet.
+* Note that this uses av_grow_packet and thus involves a realloc
+* which is inefficient. Thus this function should only be used
+* when there is no reasonable way to know (an upper bound of)
+* the final size.
+*
+* @param pkt packet
+* @param size amount of data to read
+* @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data
+*         will not be lost even if an error occurs.
+*/
+int av_append_packet(AVIOContext *s, AVPacket *pkt, int size);
+/*************************************************/
+/* fractional numbers for exact pts handling */
+/**
+* The exact value of the fractional number is: 'val + num / den'.
+* num is assumed to be 0 <= num < den.
+*/
+typedef struct AVFrac {
+int64_t val, num, den;
+} AVFrac;
+/*************************************************/
+/* input/output formats */
+struct AVCodecTag;
+/**
+* This structure contains the data a format has to probe a file.
+*/
+typedef struct AVProbeData {
+const char *filename;
+unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */
+int buf_size;       /**< Size of buf except extra allocated bytes */
+} AVProbeData;
+#define AVPROBE_SCORE_RETRY (AVPROBE_SCORE_MAX/4)
+#define AVPROBE_SCORE_EXTENSION  50 ///< score for file extension
+#define AVPROBE_SCORE_MAX       100 ///< maximum score
+#define AVPROBE_PADDING_SIZE 32             ///< extra allocated bytes at the end of the probe buffer
+/// Demuxer will use avio_open, no opened file should be provided by the caller.
+#define AVFMT_NOFILE        0x0001
+#define AVFMT_NEEDNUMBER    0x0002 /**< Needs '%d' in filename. */
+#define AVFMT_SHOW_IDS      0x0008 /**< Show format stream IDs numbers. */
+#define AVFMT_RAWPICTURE    0x0020 /**< Format wants AVPicture structure for
+raw picture data. */
+#define AVFMT_GLOBALHEADER  0x0040 /**< Format wants global header. */
+#define AVFMT_NOTIMESTAMPS  0x0080 /**< Format does not need / have any timestamps. */
+#define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */
+#define AVFMT_TS_DISCONT    0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */
+#define AVFMT_VARIABLE_FPS  0x0400 /**< Format allows variable fps. */
+#define AVFMT_NODIMENSIONS  0x0800 /**< Format does not need width/height */
+#define AVFMT_NOSTREAMS     0x1000 /**< Format does not require any streams */
+#define AVFMT_NOBINSEARCH   0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */
+#define AVFMT_NOGENSEARCH   0x4000 /**< Format does not allow to fall back on generic search */
+#define AVFMT_NO_BYTE_SEEK  0x8000 /**< Format does not allow seeking by bytes */
+#define AVFMT_ALLOW_FLUSH  0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */
+#if LIBAVFORMAT_VERSION_MAJOR <= 54
+#define AVFMT_TS_NONSTRICT 0x8020000 //we try to be compatible to the ABIs of ffmpeg and major forks
+#else
+#define AVFMT_TS_NONSTRICT 0x20000
+#endif
+/**< Format does not require strictly
+increasing timestamps, but they must
+still be monotonic */
+#define AVFMT_TS_NEGATIVE  0x40000 /**< Format allows muxing negative
+timestamps. If not set the timestamp
+will be shifted in av_write_frame and
+av_interleaved_write_frame so they
+start from 0.
+The user or muxer can override this through
+AVFormatContext.avoid_negative_ts
+*/
+#define AVFMT_SEEK_TO_PTS   0x4000000 /**< Seeking is based on PTS */
+/**
+* @addtogroup lavf_encoding
+* @{
+*/
+typedef struct AVOutputFormat {
+const char *name;
+/**
+* Descriptive name for the format, meant to be more human-readable
+* than name. You should use the NULL_IF_CONFIG_SMALL() macro
+* to define it.
+*/
+const char *long_name;
+const char *mime_type;
+const char *extensions; /**< comma-separated filename extensions */
+/* output support */
+enum AVCodecID audio_codec;    /**< default audio codec */
+enum AVCodecID video_codec;    /**< default video codec */
+enum AVCodecID subtitle_codec; /**< default subtitle codec */
+/**
+* can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
+* AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
+* AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH,
+* AVFMT_TS_NONSTRICT
+*/
+int flags;
+/**
+* List of supported codec_id-codec_tag pairs, ordered by "better
+* choice first". The arrays are all terminated by AV_CODEC_ID_NONE.
+*/
+const struct AVCodecTag * const *codec_tag;
+const AVClass *priv_class; ///< AVClass for the private context
+/*****************************************************************
+* No fields below this line are part of the public API. They
+* may not be used outside of libavformat and can be changed and
+* removed at will.
+* New public fields should be added right above.
+*****************************************************************
+*/
+struct AVOutputFormat *next;
+/**
+* size of private data so that it can be allocated in the wrapper
+*/
+int priv_data_size;
+int (*write_header)(struct AVFormatContext *);
+/**
+* Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
+* pkt can be NULL in order to flush data buffered in the muxer.
+* When flushing, return 0 if there still is more data to flush,
+* or 1 if everything was flushed and there is no more buffered
+* data.
+*/
+int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
+int (*write_trailer)(struct AVFormatContext *);
+/**
+* Currently only used to set pixel format if not YUV420P.
+*/
+int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
+AVPacket *in, int flush);
+/**
+* Test if the given codec can be stored in this container.
+*
+* @return 1 if the codec is supported, 0 if it is not.
+*         A negative number if unknown.
+*         MKTAG('A', 'P', 'I', 'C') if the codec is only supported as AV_DISPOSITION_ATTACHED_PIC
+*/
+int (*query_codec)(enum AVCodecID id, int std_compliance);
+void (*get_output_timestamp)(struct AVFormatContext *s, int stream,
+int64_t *dts, int64_t *wall);
+} AVOutputFormat;
+/**
+* @}
+*/
+/**
+* @addtogroup lavf_decoding
+* @{
+*/
+typedef struct AVInputFormat {
+/**
+* A comma separated list of short names for the format. New names
+* may be appended with a minor bump.
+*/
+const char *name;
+/**
+* Descriptive name for the format, meant to be more human-readable
+* than name. You should use the NULL_IF_CONFIG_SMALL() macro
+* to define it.
+*/
+const char *long_name;
+/**
+* Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
+* AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
+* AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
+*/
+int flags;
+/**
+* If extensions are defined, then no probe is done. You should
+* usually not use extension format guessing because it is not
+* reliable enough
+*/
+const char *extensions;
+const struct AVCodecTag * const *codec_tag;
+const AVClass *priv_class; ///< AVClass for the private context
+/*****************************************************************
+* No fields below this line are part of the public API. They
+* may not be used outside of libavformat and can be changed and
+* removed at will.
+* New public fields should be added right above.
+*****************************************************************
+*/
+struct AVInputFormat *next;
+/**
+* Raw demuxers store their codec ID here.
+*/
+int raw_codec_id;
+/**
+* Size of private data so that it can be allocated in the wrapper.
+*/
+int priv_data_size;
+/**
+* Tell if a given file has a chance of being parsed as this format.
+* The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
+* big so you do not have to check for that unless you need more.
+*/
+int (*read_probe)(AVProbeData *);
+/**
+* Read the format header and initialize the AVFormatContext
+* structure. Return 0 if OK. Only used in raw format right
+* now. 'avformat_new_stream' should be called to create new streams.
+*/
+int (*read_header)(struct AVFormatContext *);
+/**
+* Read one packet and put it in 'pkt'. pts and flags are also
+* set. 'avformat_new_stream' can be called only if the flag
+* AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
+* background thread).
+* @return 0 on success, < 0 on error.
+*         When returning an error, pkt must not have been allocated
+*         or must be freed before returning
+*/
+int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
+/**
+* Close the stream. The AVFormatContext and AVStreams are not
+* freed by this function
+*/
+int (*read_close)(struct AVFormatContext *);
+/**
+* Seek to a given timestamp relative to the frames in
+* stream component stream_index.
+* @param stream_index Must not be -1.
+* @param flags Selects which direction should be preferred if no exact
+*              match is available.
+* @return >= 0 on success (but not necessarily the new offset)
+*/
+int (*read_seek)(struct AVFormatContext *,
+int stream_index, int64_t timestamp, int flags);
+/**
+* Get the next timestamp in stream[stream_index].time_base units.
+* @return the timestamp or AV_NOPTS_VALUE if an error occurred
+*/
+int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
+int64_t *pos, int64_t pos_limit);
+/**
+* Start/resume playing - only meaningful if using a network-based format
+* (RTSP).
+*/
+int (*read_play)(struct AVFormatContext *);
+/**
+* Pause playing - only meaningful if using a network-based format
+* (RTSP).
+*/
+int (*read_pause)(struct AVFormatContext *);
+/**
+* Seek to timestamp ts.
+* Seeking will be done so that the point from which all active streams
+* can be presented successfully will be closest to ts and within min/max_ts.
+* Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
+*/
+int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
+} AVInputFormat;
+/**
+* @}
+*/
+enum AVStreamParseType {
+AVSTREAM_PARSE_NONE,
+AVSTREAM_PARSE_FULL,       /**< full parsing and repack */
+AVSTREAM_PARSE_HEADERS,    /**< Only parse headers, do not repack. */
+AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */
+AVSTREAM_PARSE_FULL_ONCE,  /**< full parsing and repack of the first frame only, only implemented for H.264 currently */
+AVSTREAM_PARSE_FULL_RAW=MKTAG(0,'R','A','W'),       /**< full parsing and repack with timestamp and position generation by parser for raw
+this assumes that each packet in the file contains no demuxer level headers and
+just codec level data, otherwise position generation would fail */
+};
+typedef struct AVIndexEntry {
+int64_t pos;
+int64_t timestamp;        /**<
+* Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are available
+* when seeking to this entry. That means preferable PTS on keyframe based formats.
+* But demuxers can choose to store a different timestamp, if it is more convenient for the implementation or nothing better
+* is known
+*/
+#define AVINDEX_KEYFRAME 0x0001
+int flags:2;
+int size:30; //Yeah, trying to keep the size of this small to reduce memory requirements (it is 24 vs. 32 bytes due to possible 8-byte alignment).
+int min_distance;         /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */
+} AVIndexEntry;
+#define AV_DISPOSITION_DEFAULT   0x0001
+#define AV_DISPOSITION_DUB       0x0002
+#define AV_DISPOSITION_ORIGINAL  0x0004
+#define AV_DISPOSITION_COMMENT   0x0008
+#define AV_DISPOSITION_LYRICS    0x0010
+#define AV_DISPOSITION_KARAOKE   0x0020
+/**
+* Track should be used during playback by default.
+* Useful for subtitle track that should be displayed
+* even when user did not explicitly ask for subtitles.
+*/
+#define AV_DISPOSITION_FORCED    0x0040
+#define AV_DISPOSITION_HEARING_IMPAIRED  0x0080  /**< stream for hearing impaired audiences */
+#define AV_DISPOSITION_VISUAL_IMPAIRED   0x0100  /**< stream for visual impaired audiences */
+#define AV_DISPOSITION_CLEAN_EFFECTS     0x0200  /**< stream without voice */
+/**
+* The stream is stored in the file as an attached picture/"cover art" (e.g.
+* APIC frame in ID3v2). The single packet associated with it will be returned
+* among the first few packets read from the file unless seeking takes place.
+* It can also be accessed at any time in AVStream.attached_pic.
+*/
+#define AV_DISPOSITION_ATTACHED_PIC      0x0400
+/**
+* Options for behavior on timestamp wrap detection.
+*/
+#define AV_PTS_WRAP_IGNORE      0   ///< ignore the wrap
+#define AV_PTS_WRAP_ADD_OFFSET  1   ///< add the format specific offset on wrap detection
+#define AV_PTS_WRAP_SUB_OFFSET  -1  ///< subtract the format specific offset on wrap detection
+/**
+* Stream structure.
+* New fields can be added to the end with minor version bumps.
+* Removal, reordering and changes to existing fields require a major
+* version bump.
+* sizeof(AVStream) must not be used outside libav*.
+*/
+typedef struct AVStream {
+int index;    /**< stream index in AVFormatContext */
+/**
+* Format-specific stream ID.
+* decoding: set by libavformat
+* encoding: set by the user, replaced by libavformat if left unset
+*/
+int id;
+/**
+* Codec context associated with this stream. Allocated and freed by
+* libavformat.
+*
+* - decoding: The demuxer exports codec information stored in the headers
+*             here.
+* - encoding: The user sets codec information, the muxer writes it to the
+*             output. Mandatory fields as specified in AVCodecContext
+*             documentation must be set even if this AVCodecContext is
+*             not actually used for encoding.
+*/
+AVCodecContext *codec;
+void *priv_data;
+/**
+* encoding: pts generation when outputting stream
+*/
+struct AVFrac pts;
+/**
+* This is the fundamental unit of time (in seconds) in terms
+* of which frame timestamps are represented.
+*
+* decoding: set by libavformat
+* encoding: set by libavformat in avformat_write_header. The muxer may use the
+* user-provided value of @ref AVCodecContext.time_base "codec->time_base"
+* as a hint.
+*/
+AVRational time_base;
+/**
+* Decoding: pts of the first frame of the stream in presentation order, in stream time base.
+* Only set this if you are absolutely 100% sure that the value you set
+* it to really is the pts of the first frame.
+* This may be undefined (AV_NOPTS_VALUE).
+* @note The ASF header does NOT contain a correct start_time the ASF
+* demuxer must NOT set this.
+*/
+int64_t start_time;
+/**
+* Decoding: duration of the stream, in stream time base.
+* If a source file does not specify a duration, but does specify
+* a bitrate, this value will be estimated from bitrate and file size.
+*/
+int64_t duration;
+int64_t nb_frames;                 ///< number of frames in this stream if known or 0
+int disposition; /**< AV_DISPOSITION_* bit field */
+enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.
+/**
+* sample aspect ratio (0 if unknown)
+* - encoding: Set by user.
+* - decoding: Set by libavformat.
+*/
+AVRational sample_aspect_ratio;
+AVDictionary *metadata;
+/**
+* Average framerate
+*/
+AVRational avg_frame_rate;
+/**
+* For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet
+* will contain the attached picture.
+*
+* decoding: set by libavformat, must not be modified by the caller.
+* encoding: unused
+*/
+AVPacket attached_pic;
+/**
+* Real base framerate of the stream.
+* This is the lowest framerate with which all timestamps can be
+* represented accurately (it is the least common multiple of all
+* framerates in the stream). Note, this value is just a guess!
+* For example, if the time base is 1/90000 and all frames have either
+* approximately 3600 or 1800 timer ticks, then r_frame_rate will be 50/1.
+*
+* Code outside avformat should access this field using:
+* av_stream_get/set_r_frame_rate(stream)
+*/
+AVRational r_frame_rate;
+/*****************************************************************
+* All fields below this line are not part of the public API. They
+* may not be used outside of libavformat and can be changed and
+* removed at will.
+* New public fields should be added right above.
+*****************************************************************
+*/
+/**
+* Stream information used internally by av_find_stream_info()
+*/
+#define MAX_STD_TIMEBASES (60*12+6)
+struct {
+int64_t last_dts;
+int64_t duration_gcd;
+int duration_count;
+double (*duration_error)[2][MAX_STD_TIMEBASES];
+int64_t codec_info_duration;
+int64_t codec_info_duration_fields;
+int found_decoder;
+int64_t last_duration;
+/**
+* Those are used for average framerate estimation.
+*/
+int64_t fps_first_dts;
+int     fps_first_dts_idx;
+int64_t fps_last_dts;
+int     fps_last_dts_idx;
+} *info;
+int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
+// Timestamp generation support:
+/**
+* Timestamp corresponding to the last dts sync point.
+*
+* Initialized when AVCodecParserContext.dts_sync_point >= 0 and
+* a DTS is received from the underlying container. Otherwise set to
+* AV_NOPTS_VALUE by default.
+*/
+int64_t reference_dts;
+int64_t first_dts;
+int64_t cur_dts;
+int64_t last_IP_pts;
+int last_IP_duration;
+/**
+* Number of packets to buffer for codec probing
+*/
+#define MAX_PROBE_PACKETS 2500
+int probe_packets;
+/**
+* Number of frames that have been demuxed during av_find_stream_info()
+*/
+int codec_info_nb_frames;
+/**
+* Stream Identifier
+* This is the MPEG-TS stream identifier +1
+* 0 means unknown
+*/
+int stream_identifier;
+int64_t interleaver_chunk_size;
+int64_t interleaver_chunk_duration;
+/* av_read_frame() support */
+enum AVStreamParseType need_parsing;
+struct AVCodecParserContext *parser;
+/**
+* last packet in packet_buffer for this stream when muxing.
+*/
+struct AVPacketList *last_in_packet_buffer;
+AVProbeData probe_data;
+#define MAX_REORDER_DELAY 16
+int64_t pts_buffer[MAX_REORDER_DELAY+1];
+AVIndexEntry *index_entries; /**< Only used if the format does not
+support seeking natively. */
+int nb_index_entries;
+unsigned int index_entries_allocated_size;
+/**
+* stream probing state
+* -1   -> probing finished
+*  0   -> no probing requested
+* rest -> perform probing with request_probe being the minimum score to accept.
+* NOT PART OF PUBLIC API
+*/
+int request_probe;
+/**
+* Indicates that everything up to the next keyframe
+* should be discarded.
+*/
+int skip_to_keyframe;
+/**
+* Number of samples to skip at the start of the frame decoded from the next packet.
+*/
+int skip_samples;
+/**
+* Number of internally decoded frames, used internally in libavformat, do not access
+* its lifetime differs from info which is why it is not in that structure.
+*/
+int nb_decoded_frames;
+/**
+* Timestamp offset added to timestamps before muxing
+* NOT PART OF PUBLIC API
+*/
+int64_t mux_ts_offset;
+/**
+* Internal data to check for wrapping of the time stamp
+*/
+int64_t pts_wrap_reference;
+/**
+* Options for behavior, when a wrap is detected.
+*
+* Defined by AV_PTS_WRAP_ values.
+*
+* If correction is enabled, there are two possibilities:
+* If the first time stamp is near the wrap point, the wrap offset
+* will be subtracted, which will create negative time stamps.
+* Otherwise the offset will be added.
+*/
+int pts_wrap_behavior;
+} AVStream;
+AVRational av_stream_get_r_frame_rate(const AVStream *s);
+void       av_stream_set_r_frame_rate(AVStream *s, AVRational r);
+#define AV_PROGRAM_RUNNING 1
+/**
+* New fields can be added to the end with minor version bumps.
+* Removal, reordering and changes to existing fields require a major
+* version bump.
+* sizeof(AVProgram) must not be used outside libav*.
+*/
+typedef struct AVProgram {
+int            id;
+int            flags;
+enum AVDiscard discard;        ///< selects which program to discard and which to feed to the caller
+unsigned int   *stream_index;
+unsigned int   nb_stream_indexes;
+AVDictionary *metadata;
+int program_num;
+int pmt_pid;
+int pcr_pid;
+/*****************************************************************
+* All fields below this line are not part of the public API. They
+* may not be used outside of libavformat and can be changed and
+* removed at will.
+* New public fields should be added right above.
+*****************************************************************
+*/
+int64_t start_time;
+int64_t end_time;
+int64_t pts_wrap_reference;    ///< reference dts for wrap detection
+int pts_wrap_behavior;         ///< behavior on wrap detection
+} AVProgram;
+#define AVFMTCTX_NOHEADER      0x0001 /**< signal that no header is present
+(streams are added dynamically) */
+typedef struct AVChapter {
+int id;                 ///< unique ID to identify the chapter
+AVRational time_base;   ///< time base in which the start/end timestamps are specified
+int64_t start, end;     ///< chapter start/end time in time_base units
+AVDictionary *metadata;
+} AVChapter;
+/**
+* The duration of a video can be estimated through various ways, and this enum can be used
+* to know how the duration was estimated.
+*/
+enum AVDurationEstimationMethod {
+AVFMT_DURATION_FROM_PTS,    ///< Duration accurately estimated from PTSes
+AVFMT_DURATION_FROM_STREAM, ///< Duration estimated from a stream with a known duration
+AVFMT_DURATION_FROM_BITRATE ///< Duration estimated from bitrate (less accurate)
+};
+/**
+* Format I/O context.
+* New fields can be added to the end with minor version bumps.
+* Removal, reordering and changes to existing fields require a major
+* version bump.
+* sizeof(AVFormatContext) must not be used outside libav*, use
+* avformat_alloc_context() to create an AVFormatContext.
+*/
+typedef struct AVFormatContext {
+/**
+* A class for logging and AVOptions. Set by avformat_alloc_context().
+* Exports (de)muxer private options if they exist.
+*/
+const AVClass *av_class;
+/**
+* Can only be iformat or oformat, not both at the same time.
+*
+* decoding: set by avformat_open_input().
+* encoding: set by the user.
+*/
+struct AVInputFormat *iformat;
+struct AVOutputFormat *oformat;
+/**
+* Format private data. This is an AVOptions-enabled struct
+* if and only if iformat/oformat.priv_class is not NULL.
+*/
+void *priv_data;
+/**
+* I/O context.
+*
+* decoding: either set by the user before avformat_open_input() (then
+* the user must close it manually) or set by avformat_open_input().
+* encoding: set by the user.
+*
+* Do NOT set this field if AVFMT_NOFILE flag is set in
+* iformat/oformat.flags. In such a case, the (de)muxer will handle
+* I/O in some other way and this field will be NULL.
+*/
+AVIOContext *pb;
+/* stream info */
+int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
+/**
+* A list of all streams in the file. New streams are created with
+* avformat_new_stream().
+*
+* decoding: streams are created by libavformat in avformat_open_input().
+* If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also
+* appear in av_read_frame().
+* encoding: streams are created by the user before avformat_write_header().
+*/
+unsigned int nb_streams;
+AVStream **streams;
+char filename[1024]; /**< input or output filename */
+/**
+* Decoding: position of the first frame of the component, in
+* AV_TIME_BASE fractional seconds. NEVER set this value directly:
+* It is deduced from the AVStream values.
+*/
+int64_t start_time;
+/**
+* Decoding: duration of the stream, in AV_TIME_BASE fractional
+* seconds. Only set this value if you know none of the individual stream
+* durations and also do not set any of them. This is deduced from the
+* AVStream values if not set.
+*/
+int64_t duration;
+/**
+* Decoding: total stream bitrate in bit/s, 0 if not
+* available. Never set it directly if the file_size and the
+* duration are known as FFmpeg can compute it automatically.
+*/
+int bit_rate;
+unsigned int packet_size;
+int max_delay;
+int flags;
+#define AVFMT_FLAG_GENPTS       0x0001 ///< Generate missing pts even if it requires parsing future frames.
+#define AVFMT_FLAG_IGNIDX       0x0002 ///< Ignore index.
+#define AVFMT_FLAG_NONBLOCK     0x0004 ///< Do not block when reading packets from input.
+#define AVFMT_FLAG_IGNDTS       0x0008 ///< Ignore DTS on frames that contain both DTS & PTS
+#define AVFMT_FLAG_NOFILLIN     0x0010 ///< Do not infer any values from other values, just return what is stored in the container
+#define AVFMT_FLAG_NOPARSE      0x0020 ///< Do not use AVParsers, you also must set AVFMT_FLAG_NOFILLIN as the fillin code works on frames and no parsing -> no frames. Also seeking to frames can not work if parsing to find frame boundaries has been disabled
+#define AVFMT_FLAG_NOBUFFER     0x0040 ///< Do not buffer frames when possible
+#define AVFMT_FLAG_CUSTOM_IO    0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.
+#define AVFMT_FLAG_DISCARD_CORRUPT  0x0100 ///< Discard frames marked corrupted
+#define AVFMT_FLAG_MP4A_LATM    0x8000 ///< Enable RTP MP4A-LATM payload
+#define AVFMT_FLAG_SORT_DTS    0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
+#define AVFMT_FLAG_PRIV_OPT    0x20000 ///< Enable use of private options by delaying codec open (this could be made default once all code is converted)
+#define AVFMT_FLAG_KEEP_SIDE_DATA 0x40000 ///< Don't merge side data but keep it separate.
+/**
+* decoding: size of data to probe; encoding: unused.
+*/
+unsigned int probesize;
+/**
+* decoding: maximum time (in AV_TIME_BASE units) during which the input should
+* be analyzed in avformat_find_stream_info().
+*/
+int max_analyze_duration;
+const uint8_t *key;
+int keylen;
+unsigned int nb_programs;
+AVProgram **programs;
+/**
+* Forced video codec_id.
+* Demuxing: Set by user.
+*/
+enum AVCodecID video_codec_id;
+/**
+* Forced audio codec_id.
+* Demuxing: Set by user.
+*/
+enum AVCodecID audio_codec_id;
+/**
+* Forced subtitle codec_id.
+* Demuxing: Set by user.
+*/
+enum AVCodecID subtitle_codec_id;
+/**
+* Maximum amount of memory in bytes to use for the index of each stream.
+* If the index exceeds this size, entries will be discarded as
+* needed to maintain a smaller size. This can lead to slower or less
+* accurate seeking (depends on demuxer).
+* Demuxers for which a full in-memory index is mandatory will ignore
+* this.
+* muxing  : unused
+* demuxing: set by user
+*/
+unsigned int max_index_size;
+/**
+* Maximum amount of memory in bytes to use for buffering frames
+* obtained from realtime capture devices.
+*/
+unsigned int max_picture_buffer;
+unsigned int nb_chapters;
+AVChapter **chapters;
+AVDictionary *metadata;
+/**
+* Start time of the stream in real world time, in microseconds
+* since the unix epoch (00:00 1st January 1970). That is, pts=0
+* in the stream was captured at this real world time.
+* - encoding: Set by user.
+* - decoding: Unused.
+*/
+int64_t start_time_realtime;
+/**
+* decoding: number of frames used to probe fps
+*/
+int fps_probe_size;
+/**
+* Error recognition; higher values will detect more errors but may
+* misdetect some more or less valid parts as errors.
+* - encoding: unused
+* - decoding: Set by user.
+*/
+int error_recognition;
+/**
+* Custom interrupt callbacks for the I/O layer.
+*
+* decoding: set by the user before avformat_open_input().
+* encoding: set by the user before avformat_write_header()
+* (mainly useful for AVFMT_NOFILE formats). The callback
+* should also be passed to avio_open2() if it's used to
+* open the file.
+*/
+AVIOInterruptCB interrupt_callback;
+/**
+* Flags to enable debugging.
+*/
+int debug;
+#define FF_FDEBUG_TS        0x0001
+/**
+* Transport stream id.
+* This will be moved into demuxer private options. Thus no API/ABI compatibility
+*/
+int ts_id;
+/**
+* Audio preload in microseconds.
+* Note, not all formats support this and unpredictable things may happen if it is used when not supported.
+* - encoding: Set by user via AVOptions (NO direct access)
+* - decoding: unused
+*/
+int audio_preload;
+/**
+* Max chunk time in microseconds.
+* Note, not all formats support this and unpredictable things may happen if it is used when not supported.
+* - encoding: Set by user via AVOptions (NO direct access)
+* - decoding: unused
+*/
+int max_chunk_duration;
+/**
+* Max chunk size in bytes
+* Note, not all formats support this and unpredictable things may happen if it is used when not supported.
+* - encoding: Set by user via AVOptions (NO direct access)
+* - decoding: unused
+*/
+int max_chunk_size;
+/**
+* forces the use of wallclock timestamps as pts/dts of packets
+* This has undefined results in the presence of B frames.
+* - encoding: unused
+* - decoding: Set by user via AVOptions (NO direct access)
+*/
+int use_wallclock_as_timestamps;
+/**
+* Avoid negative timestamps during muxing.
+*  0 -> allow negative timestamps
+*  1 -> avoid negative timestamps
+* -1 -> choose automatically (default)
+* Note, this only works when interleave_packet_per_dts is in use.
+* - encoding: Set by user via AVOptions (NO direct access)
+* - decoding: unused
+*/
+int avoid_negative_ts;
+/**
+* avio flags, used to force AVIO_FLAG_DIRECT.
+* - encoding: unused
+* - decoding: Set by user via AVOptions (NO direct access)
+*/
+int avio_flags;
+/**
+* The duration field can be estimated through various ways, and this field can be used
+* to know how the duration was estimated.
+* - encoding: unused
+* - decoding: Read by user via AVOptions (NO direct access)
+*/
+enum AVDurationEstimationMethod duration_estimation_method;
+/**
+* Skip initial bytes when opening stream
+* - encoding: unused
+* - decoding: Set by user via AVOptions (NO direct access)
+*/
+unsigned int skip_initial_bytes;
+/**
+* Correct single timestamp overflows
+* - encoding: unused
+* - decoding: Set by user via AVOPtions (NO direct access)
+*/
+unsigned int correct_ts_overflow;
+/**
+* Force seeking to any (also non key) frames.
+* - encoding: unused
+* - decoding: Set by user via AVOPtions (NO direct access)
+*/
+int seek2any;
+/**
+* Flush the I/O context after each packet.
+* - encoding: Set by user via AVOptions (NO direct access)
+* - decoding: unused
+*/
+int flush_packets;
+/*****************************************************************
+* All fields below this line are not part of the public API. They
+* may not be used outside of libavformat and can be changed and
+* removed at will.
+* New public fields should be added right above.
+*****************************************************************
+*/
+/**
+* This buffer is only needed when packets were already buffered but
+* not decoded, for example to get the codec parameters in MPEG
+* streams.
+*/
+struct AVPacketList *packet_buffer;
+struct AVPacketList *packet_buffer_end;
+/* av_seek_frame() support */
+int64_t data_offset; /**< offset of the first packet */
+/**
+* Raw packets from the demuxer, prior to parsing and decoding.
+* This buffer is used for buffering packets until the codec can
+* be identified, as parsing cannot be done without knowing the
+* codec.
+*/
+struct AVPacketList *raw_packet_buffer;
+struct AVPacketList *raw_packet_buffer_end;
+/**
+* Packets split by the parser get queued here.
+*/
+struct AVPacketList *parse_queue;
+struct AVPacketList *parse_queue_end;
+/**
+* Remaining size available for raw_packet_buffer, in bytes.
+*/
+#define RAW_PACKET_BUFFER_SIZE 2500000
+int raw_packet_buffer_remaining_size;
+/**
+* Offset to remap timestamps to be non-negative.
+* Expressed in timebase units.
+* @see AVStream.mux_ts_offset
+*/
+int64_t offset;
+/**
+* Timebase for the timestamp offset.
+*/
+AVRational offset_timebase;
+/**
+* IO repositioned flag.
+* This is set by avformat when the underlaying IO context read pointer
+* is repositioned, for example when doing byte based seeking.
+* Demuxers can use the flag to detect such changes.
+*/
+int io_repositioned;
+} AVFormatContext;
+/**
+* Returns the method used to set ctx->duration.
+*
+* @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
+*/
+enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
+typedef struct AVPacketList {
+AVPacket pkt;
+struct AVPacketList *next;
+} AVPacketList;
+/**
+* @defgroup lavf_core Core functions
+* @ingroup libavf
+*
+* Functions for querying libavformat capabilities, allocating core structures,
+* etc.
+* @{
+*/
+/**
+* Return the LIBAVFORMAT_VERSION_INT constant.
+*/
+unsigned avformat_version(void);
+/**
+* Return the libavformat build-time configuration.
+*/
+const char *avformat_configuration(void);
+/**
+* Return the libavformat license.
+*/
+const char *avformat_license(void);
+/**
+* Initialize libavformat and register all the muxers, demuxers and
+* protocols. If you do not call this function, then you can select
+* exactly which formats you want to support.
+*
+* @see av_register_input_format()
+* @see av_register_output_format()
+*/
+void av_register_all(void);
+void av_register_input_format(AVInputFormat *format);
+void av_register_output_format(AVOutputFormat *format);
+/**
+* Do global initialization of network components. This is optional,
+* but recommended, since it avoids the overhead of implicitly
+* doing the setup for each session.
+*
+* Calling this function will become mandatory if using network
+* protocols at some major version bump.
+*/
+int avformat_network_init(void);
+/**
+* Undo the initialization done by avformat_network_init.
+*/
+int avformat_network_deinit(void);
+/**
+* If f is NULL, returns the first registered input format,
+* if f is non-NULL, returns the next registered input format after f
+* or NULL if f is the last one.
+*/
+AVInputFormat  *av_iformat_next(AVInputFormat  *f);
+/**
+* If f is NULL, returns the first registered output format,
+* if f is non-NULL, returns the next registered output format after f
+* or NULL if f is the last one.
+*/
+AVOutputFormat *av_oformat_next(AVOutputFormat *f);
+/**
+* Allocate an AVFormatContext.
+* avformat_free_context() can be used to free the context and everything
+* allocated by the framework within it.
+*/
+AVFormatContext *avformat_alloc_context(void);
+/**
+* Free an AVFormatContext and all its streams.
+* @param s context to free
+*/
+void avformat_free_context(AVFormatContext *s);
+/**
+* Get the AVClass for AVFormatContext. It can be used in combination with
+* AV_OPT_SEARCH_FAKE_OBJ for examining options.
+*
+* @see av_opt_find().
+*/
+const AVClass *avformat_get_class(void);
+/**
+* Add a new stream to a media file.
+*
+* When demuxing, it is called by the demuxer in read_header(). If the
+* flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also
+* be called in read_packet().
+*
+* When muxing, should be called by the user before avformat_write_header().
+*
+* @param c If non-NULL, the AVCodecContext corresponding to the new stream
+* will be initialized to use this codec. This is needed for e.g. codec-specific
+* defaults to be set, so codec should be provided if it is known.
+*
+* @return newly created stream or NULL on error.
+*/
+AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c);
+AVProgram *av_new_program(AVFormatContext *s, int id);
+/**
+* @}
+*/
+#if FF_API_PKT_DUMP
+attribute_deprecated void av_pkt_dump(FILE *f, AVPacket *pkt, int dump_payload);
+attribute_deprecated void av_pkt_dump_log(void *avcl, int level, AVPacket *pkt,
+int dump_payload);
+#endif
+#if FF_API_ALLOC_OUTPUT_CONTEXT
+/**
+* @deprecated deprecated in favor of avformat_alloc_output_context2()
+*/
+attribute_deprecated
+AVFormatContext *avformat_alloc_output_context(const char *format,
+AVOutputFormat *oformat,
+const char *filename);
+#endif
+/**
+* Allocate an AVFormatContext for an output format.
+* avformat_free_context() can be used to free the context and
+* everything allocated by the framework within it.
+*
+* @param *ctx is set to the created format context, or to NULL in
+* case of failure
+* @param oformat format to use for allocating the context, if NULL
+* format_name and filename are used instead
+* @param format_name the name of output format to use for allocating the
+* context, if NULL filename is used instead
+* @param filename the name of the filename to use for allocating the
+* context, may be NULL
+* @return >= 0 in case of success, a negative AVERROR code in case of
+* failure
+*/
+int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat,
+const char *format_name, const char *filename);
+/**
+* @addtogroup lavf_decoding
+* @{
+*/
+/**
+* Find AVInputFormat based on the short name of the input format.
+*/
+AVInputFormat *av_find_input_format(const char *short_name);
+/**
+* Guess the file format.
+*
+* @param is_opened Whether the file is already opened; determines whether
+*                  demuxers with or without AVFMT_NOFILE are probed.
+*/
+AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
+/**
+* Guess the file format.
+*
+* @param is_opened Whether the file is already opened; determines whether
+*                  demuxers with or without AVFMT_NOFILE are probed.
+* @param score_max A probe score larger that this is required to accept a
+*                  detection, the variable is set to the actual detection
+*                  score afterwards.
+*                  If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended
+*                  to retry with a larger probe buffer.
+*/
+AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max);
+/**
+* Guess the file format.
+*
+* @param is_opened Whether the file is already opened; determines whether
+*                  demuxers with or without AVFMT_NOFILE are probed.
+* @param score_ret The score of the best detection.
+*/
+AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened, int *score_ret);
+/**
+* Probe a bytestream to determine the input format. Each time a probe returns
+* with a score that is too low, the probe buffer size is increased and another
+* attempt is made. When the maximum probe size is reached, the input format
+* with the highest score is returned.
+*
+* @param pb the bytestream to probe
+* @param fmt the input format is put here
+* @param filename the filename of the stream
+* @param logctx the log context
+* @param offset the offset within the bytestream to probe from
+* @param max_probe_size the maximum probe buffer size (zero for default)
+* @return 0 in case of success, a negative value corresponding to an
+* AVERROR code otherwise
+*/
+int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
+const char *filename, void *logctx,
+unsigned int offset, unsigned int max_probe_size);
+/**
+* Open an input stream and read the header. The codecs are not opened.
+* The stream must be closed with av_close_input_file().
+*
+* @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context).
+*           May be a pointer to NULL, in which case an AVFormatContext is allocated by this
+*           function and written into ps.
+*           Note that a user-supplied AVFormatContext will be freed on failure.
+* @param filename Name of the stream to open.
+* @param fmt If non-NULL, this parameter forces a specific input format.
+*            Otherwise the format is autodetected.
+* @param options  A dictionary filled with AVFormatContext and demuxer-private options.
+*                 On return this parameter will be destroyed and replaced with a dict containing
+*                 options that were not found. May be NULL.
+*
+* @return 0 on success, a negative AVERROR on failure.
+*
+* @note If you want to use custom IO, preallocate the format context and set its pb field.
+*/
+int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options);
+attribute_deprecated
+int av_demuxer_open(AVFormatContext *ic);
+#if FF_API_FORMAT_PARAMETERS
+/**
+* Read packets of a media file to get stream information. This
+* is useful for file formats with no headers such as MPEG. This
+* function also computes the real framerate in case of MPEG-2 repeat
+* frame mode.
+* The logical file position is not changed by this function;
+* examined packets may be buffered for later processing.
+*
+* @param ic media file handle
+* @return >=0 if OK, AVERROR_xxx on error
+* @todo Let the user decide somehow what information is needed so that
+*       we do not waste time getting stuff the user does not need.
+*
+* @deprecated use avformat_find_stream_info.
+*/
+attribute_deprecated
+int av_find_stream_info(AVFormatContext *ic);
+#endif
+/**
+* Read packets of a media file to get stream information. This
+* is useful for file formats with no headers such as MPEG. This
+* function also computes the real framerate in case of MPEG-2 repeat
+* frame mode.
+* The logical file position is not changed by this function;
+* examined packets may be buffered for later processing.
+*
+* @param ic media file handle
+* @param options  If non-NULL, an ic.nb_streams long array of pointers to
+*                 dictionaries, where i-th member contains options for
+*                 codec corresponding to i-th stream.
+*                 On return each dictionary will be filled with options that were not found.
+* @return >=0 if OK, AVERROR_xxx on error
+*
+* @note this function isn't guaranteed to open all the codecs, so
+*       options being non-empty at return is a perfectly normal behavior.
+*
+* @todo Let the user decide somehow what information is needed so that
+*       we do not waste time getting stuff the user does not need.
+*/
+int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options);
+/**
+* Find the programs which belong to a given stream.
+*
+* @param ic    media file handle
+* @param last  the last found program, the search will start after this
+*              program, or from the beginning if it is NULL
+* @param s     stream index
+* @return the next program which belongs to s, NULL if no program is found or
+*         the last program is not among the programs of ic.
+*/
+AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s);
+/**
+* Find the "best" stream in the file.
+* The best stream is determined according to various heuristics as the most
+* likely to be what the user expects.
+* If the decoder parameter is non-NULL, av_find_best_stream will find the
+* default decoder for the stream's codec; streams for which no decoder can
+* be found are ignored.
+*
+* @param ic                media file handle
+* @param type              stream type: video, audio, subtitles, etc.
+* @param wanted_stream_nb  user-requested stream number,
+*                          or -1 for automatic selection
+* @param related_stream    try to find a stream related (eg. in the same
+*                          program) to this one, or -1 if none
+* @param decoder_ret       if non-NULL, returns the decoder for the
+*                          selected stream
+* @param flags             flags; none are currently defined
+* @return  the non-negative stream number in case of success,
+*          AVERROR_STREAM_NOT_FOUND if no stream with the requested type
+*          could be found,
+*          AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
+* @note  If av_find_best_stream returns successfully and decoder_ret is not
+*        NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
+*/
+int av_find_best_stream(AVFormatContext *ic,
+enum AVMediaType type,
+int wanted_stream_nb,
+int related_stream,
+AVCodec **decoder_ret,
+int flags);
+#if FF_API_READ_PACKET
+/**
+* @deprecated use AVFMT_FLAG_NOFILLIN | AVFMT_FLAG_NOPARSE to read raw
+* unprocessed packets
+*
+* Read a transport packet from a media file.
+*
+* This function is obsolete and should never be used.
+* Use av_read_frame() instead.
+*
+* @param s media file handle
+* @param pkt is filled
+* @return 0 if OK, AVERROR_xxx on error
+*/
+attribute_deprecated
+int av_read_packet(AVFormatContext *s, AVPacket *pkt);
+#endif
+/**
+* Return the next frame of a stream.
+* This function returns what is stored in the file, and does not validate
+* that what is there are valid frames for the decoder. It will split what is
+* stored in the file into frames and return one for each call. It will not
+* omit invalid data between valid frames so as to give the decoder the maximum
+* information possible for decoding.
+*
+* If pkt->buf is NULL, then the packet is valid until the next
+* av_read_frame() or until av_close_input_file(). Otherwise the packet is valid
+* indefinitely. In both cases the packet must be freed with
+* av_free_packet when it is no longer needed. For video, the packet contains
+* exactly one frame. For audio, it contains an integer number of frames if each
+* frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames
+* have a variable size (e.g. MPEG audio), then it contains one frame.
+*
+* pkt->pts, pkt->dts and pkt->duration are always set to correct
+* values in AVStream.time_base units (and guessed if the format cannot
+* provide them). pkt->pts can be AV_NOPTS_VALUE if the video format
+* has B-frames, so it is better to rely on pkt->dts if you do not
+* decompress the payload.
+*
+* @return 0 if OK, < 0 on error or end of file
+*/
+int av_read_frame(AVFormatContext *s, AVPacket *pkt);
+/**
+* Seek to the keyframe at timestamp.
+* 'timestamp' in 'stream_index'.
+* @param stream_index If stream_index is (-1), a default
+* stream is selected, and timestamp is automatically converted
+* from AV_TIME_BASE units to the stream specific time_base.
+* @param timestamp Timestamp in AVStream.time_base units
+*        or, if no stream is specified, in AV_TIME_BASE units.
+* @param flags flags which select direction and seeking mode
+* @return >= 0 on success
+*/
+int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp,
+int flags);
+/**
+* Seek to timestamp ts.
+* Seeking will be done so that the point from which all active streams
+* can be presented successfully will be closest to ts and within min/max_ts.
+* Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
+*
+* If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and
+* are the file position (this may not be supported by all demuxers).
+* If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames
+* in the stream with stream_index (this may not be supported by all demuxers).
+* Otherwise all timestamps are in units of the stream selected by stream_index
+* or if stream_index is -1, in AV_TIME_BASE units.
+* If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as
+* keyframes (this may not be supported by all demuxers).
+* If flags contain AVSEEK_FLAG_BACKWARD, it is ignored.
+*
+* @param stream_index index of the stream which is used as time base reference
+* @param min_ts smallest acceptable timestamp
+* @param ts target timestamp
+* @param max_ts largest acceptable timestamp
+* @param flags flags
+* @return >=0 on success, error code otherwise
+*
+* @note This is part of the new seek API which is still under construction.
+*       Thus do not use this yet. It may change at any time, do not expect
+*       ABI compatibility yet!
+*/
+int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
+/**
+* Start playing a network-based stream (e.g. RTSP stream) at the
+* current position.
+*/
+int av_read_play(AVFormatContext *s);
+/**
+* Pause a network-based stream (e.g. RTSP stream).
+*
+* Use av_read_play() to resume it.
+*/
+int av_read_pause(AVFormatContext *s);
+#if FF_API_CLOSE_INPUT_FILE
+/**
+* @deprecated use avformat_close_input()
+* Close a media file (but not its codecs).
+*
+* @param s media file handle
+*/
+attribute_deprecated
+void av_close_input_file(AVFormatContext *s);
+#endif
+/**
+* Close an opened input AVFormatContext. Free it and all its contents
+* and set *s to NULL.
+*/
+void avformat_close_input(AVFormatContext **s);
+/**
+* @}
+*/
+#if FF_API_NEW_STREAM
+/**
+* Add a new stream to a media file.
+*
+* Can only be called in the read_header() function. If the flag
+* AVFMTCTX_NOHEADER is in the format context, then new streams
+* can be added in read_packet too.
+*
+* @param s media file handle
+* @param id file-format-dependent stream ID
+*/
+attribute_deprecated
+AVStream *av_new_stream(AVFormatContext *s, int id);
+#endif
+#if FF_API_SET_PTS_INFO
+/**
+* @deprecated this function is not supposed to be called outside of lavf
+*/
+attribute_deprecated
+void av_set_pts_info(AVStream *s, int pts_wrap_bits,
+unsigned int pts_num, unsigned int pts_den);
+#endif
+#define AVSEEK_FLAG_BACKWARD 1 ///< seek backward
+#define AVSEEK_FLAG_BYTE     2 ///< seeking based on position in bytes
+#define AVSEEK_FLAG_ANY      4 ///< seek to any frame, even non-keyframes
+#define AVSEEK_FLAG_FRAME    8 ///< seeking based on frame number
+/**
+* @addtogroup lavf_encoding
+* @{
+*/
+/**
+* Allocate the stream private data and write the stream header to
+* an output media file.
+*
+* @param s Media file handle, must be allocated with avformat_alloc_context().
+*          Its oformat field must be set to the desired output format;
+*          Its pb field must be set to an already opened AVIOContext.
+* @param options  An AVDictionary filled with AVFormatContext and muxer-private options.
+*                 On return this parameter will be destroyed and replaced with a dict containing
+*                 options that were not found. May be NULL.
+*
+* @return 0 on success, negative AVERROR on failure.
+*
+* @see av_opt_find, av_dict_set, avio_open, av_oformat_next.
+*/
+int avformat_write_header(AVFormatContext *s, AVDictionary **options);
+/**
+* Write a packet to an output media file.
+*
+* The packet shall contain one audio or video frame.
+* The packet must be correctly interleaved according to the container
+* specification, if not then av_interleaved_write_frame must be used.
+*
+* @param s media file handle
+* @param pkt The packet, which contains the stream_index, buf/buf_size,
+*            dts/pts, ...
+*            This can be NULL (at any time, not just at the end), in
+*            order to immediately flush data buffered within the muxer,
+*            for muxers that buffer up data internally before writing it
+*            to the output.
+* @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush
+*/
+int av_write_frame(AVFormatContext *s, AVPacket *pkt);
+/**
+* Write a packet to an output media file ensuring correct interleaving.
+*
+* The packet must contain one audio or video frame.
+* If the packets are already correctly interleaved, the application should
+* call av_write_frame() instead as it is slightly faster. It is also important
+* to keep in mind that completely non-interleaved input will need huge amounts
+* of memory to interleave with this, so it is preferable to interleave at the
+* demuxer level.
+*
+* @param s media file handle
+* @param pkt The packet containing the data to be written. pkt->buf must be set
+* to a valid AVBufferRef describing the packet data. Libavformat takes
+* ownership of this reference and will unref it when it sees fit. The caller
+* must not access the data through this reference after this function returns.
+* This can be NULL (at any time, not just at the end), to flush the
+* interleaving queues.
+* Packet's @ref AVPacket.stream_index "stream_index" field must be set to the
+* index of the corresponding stream in @ref AVFormatContext.streams
+* "s.streams".
+* It is very strongly recommended that timing information (@ref AVPacket.pts
+* "pts", @ref AVPacket.dts "dts" @ref AVPacket.duration "duration") is set to
+* correct values.
+*
+* @return 0 on success, a negative AVERROR on error.
+*/
+int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
+/**
+* Write the stream trailer to an output media file and free the
+* file private data.
+*
+* May only be called after a successful call to avformat_write_header.
+*
+* @param s media file handle
+* @return 0 if OK, AVERROR_xxx on error
+*/
+int av_write_trailer(AVFormatContext *s);
+/**
+* Return the output format in the list of registered output formats
+* which best matches the provided parameters, or return NULL if
+* there is no match.
+*
+* @param short_name if non-NULL checks if short_name matches with the
+* names of the registered formats
+* @param filename if non-NULL checks if filename terminates with the
+* extensions of the registered formats
+* @param mime_type if non-NULL checks if mime_type matches with the
+* MIME type of the registered formats
+*/
+AVOutputFormat *av_guess_format(const char *short_name,
+const char *filename,
+const char *mime_type);
+/**
+* Guess the codec ID based upon muxer and filename.
+*/
+enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
+const char *filename, const char *mime_type,
+enum AVMediaType type);
+/**
+* Get timing information for the data currently output.
+* The exact meaning of "currently output" depends on the format.
+* It is mostly relevant for devices that have an internal buffer and/or
+* work in real time.
+* @param s          media file handle
+* @param stream     stream in the media file
+* @param[out] dts   DTS of the last packet output for the stream, in stream
+*                   time_base units
+* @param[out] wall  absolute time when that packet whas output,
+*                   in microsecond
+* @return  0 if OK, AVERROR(ENOSYS) if the format does not support it
+* Note: some formats or devices may not allow to measure dts and wall
+* atomically.
+*/
+int av_get_output_timestamp(struct AVFormatContext *s, int stream,
+int64_t *dts, int64_t *wall);
+/**
+* @}
+*/
+/**
+* @defgroup lavf_misc Utility functions
+* @ingroup libavf
+* @{
+*
+* Miscellaneous utility functions related to both muxing and demuxing
+* (or neither).
+*/
+/**
+* Send a nice hexadecimal dump of a buffer to the specified file stream.
+*
+* @param f The file stream pointer where the dump should be sent to.
+* @param buf buffer
+* @param size buffer size
+*
+* @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2
+*/
+void av_hex_dump(FILE *f, const uint8_t *buf, int size);
+/**
+* Send a nice hexadecimal dump of a buffer to the log.
+*
+* @param avcl A pointer to an arbitrary struct of which the first field is a
+* pointer to an AVClass struct.
+* @param level The importance level of the message, lower values signifying
+* higher importance.
+* @param buf buffer
+* @param size buffer size
+*
+* @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2
+*/
+void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);
+/**
+* Send a nice dump of a packet to the specified file stream.
+*
+* @param f The file stream pointer where the dump should be sent to.
+* @param pkt packet to dump
+* @param dump_payload True if the payload must be displayed, too.
+* @param st AVStream that the packet belongs to
+*/
+void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st);
+/**
+* Send a nice dump of a packet to the log.
+*
+* @param avcl A pointer to an arbitrary struct of which the first field is a
+* pointer to an AVClass struct.
+* @param level The importance level of the message, lower values signifying
+* higher importance.
+* @param pkt packet to dump
+* @param dump_payload True if the payload must be displayed, too.
+* @param st AVStream that the packet belongs to
+*/
+void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
+AVStream *st);
+/**
+* Get the AVCodecID for the given codec tag tag.
+* If no codec id is found returns AV_CODEC_ID_NONE.
+*
+* @param tags list of supported codec_id-codec_tag pairs, as stored
+* in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
+*/
+enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);
+/**
+* Get the codec tag for the given codec id id.
+* If no codec tag is found returns 0.
+*
+* @param tags list of supported codec_id-codec_tag pairs, as stored
+* in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
+*/
+unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id);
+/**
+* Get the codec tag for the given codec id.
+*
+* @param tags list of supported codec_id - codec_tag pairs, as stored
+* in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
+* @param id codec id that should be searched for in the list
+* @param tag A pointer to the found tag
+* @return 0 if id was not found in tags, > 0 if it was found
+*/
+int av_codec_get_tag2(const struct AVCodecTag * const *tags, enum AVCodecID id,
+unsigned int *tag);
+int av_find_default_stream_index(AVFormatContext *s);
+/**
+* Get the index for a specific timestamp.
+* @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond
+*                 to the timestamp which is <= the requested one, if backward
+*                 is 0, then it will be >=
+*              if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise
+* @return < 0 if no such timestamp could be found
+*/
+int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
+/**
+* Add an index entry into a sorted list. Update the entry if the list
+* already contains it.
+*
+* @param timestamp timestamp in the time base of the given stream
+*/
+int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
+int size, int distance, int flags);
+/**
+* Split a URL string into components.
+*
+* The pointers to buffers for storing individual components may be null,
+* in order to ignore that component. Buffers for components not found are
+* set to empty strings. If the port is not found, it is set to a negative
+* value.
+*
+* @param proto the buffer for the protocol
+* @param proto_size the size of the proto buffer
+* @param authorization the buffer for the authorization
+* @param authorization_size the size of the authorization buffer
+* @param hostname the buffer for the host name
+* @param hostname_size the size of the hostname buffer
+* @param port_ptr a pointer to store the port number in
+* @param path the buffer for the path
+* @param path_size the size of the path buffer
+* @param url the URL to split
+*/
+void av_url_split(char *proto,         int proto_size,
+char *authorization, int authorization_size,
+char *hostname,      int hostname_size,
+int *port_ptr,
+char *path,          int path_size,
+const char *url);
+void av_dump_format(AVFormatContext *ic,
+int index,
+const char *url,
+int is_output);
+/**
+* Return in 'buf' the path with '%d' replaced by a number.
+*
+* Also handles the '%0nd' format where 'n' is the total number
+* of digits and '%%'.
+*
+* @param buf destination buffer
+* @param buf_size destination buffer size
+* @param path numbered sequence string
+* @param number frame number
+* @return 0 if OK, -1 on format error
+*/
+int av_get_frame_filename(char *buf, int buf_size,
+const char *path, int number);
+/**
+* Check whether filename actually is a numbered sequence generator.
+*
+* @param filename possible numbered sequence string
+* @return 1 if a valid numbered sequence string, 0 otherwise
+*/
+int av_filename_number_test(const char *filename);
+/**
+* Generate an SDP for an RTP session.
+*
+* Note, this overwrites the id values of AVStreams in the muxer contexts
+* for getting unique dynamic payload types.
+*
+* @param ac array of AVFormatContexts describing the RTP streams. If the
+*           array is composed by only one context, such context can contain
+*           multiple AVStreams (one AVStream per RTP stream). Otherwise,
+*           all the contexts in the array (an AVCodecContext per RTP stream)
+*           must contain only one AVStream.
+* @param n_files number of AVCodecContexts contained in ac
+* @param buf buffer where the SDP will be stored (must be allocated by
+*            the caller)
+* @param size the size of the buffer
+* @return 0 if OK, AVERROR_xxx on error
+*/
+int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size);
+/**
+* Return a positive value if the given filename has one of the given
+* extensions, 0 otherwise.
+*
+* @param extensions a comma-separated list of filename extensions
+*/
+int av_match_ext(const char *filename, const char *extensions);
+/**
+* Test if the given container can store a codec.
+*
+* @param std_compliance standards compliance level, one of FF_COMPLIANCE_*
+*
+* @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot.
+*         A negative number if this information is not available.
+*/
+int avformat_query_codec(AVOutputFormat *ofmt, enum AVCodecID codec_id, int std_compliance);
+/**
+* @defgroup riff_fourcc RIFF FourCCs
+* @{
+* Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are
+* meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the
+* following code:
+* @code
+* uint32_t tag = MKTAG('H', '2', '6', '4');
+* const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 };
+* enum AVCodecID id = av_codec_get_id(table, tag);
+* @endcode
+*/
+/**
+* @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID.
+*/
+const struct AVCodecTag *avformat_get_riff_video_tags(void);
+/**
+* @return the table mapping RIFF FourCCs for audio to AVCodecID.
+*/
+const struct AVCodecTag *avformat_get_riff_audio_tags(void);
+/**
+* @}
+*/
+/**
+* Guess the sample aspect ratio of a frame, based on both the stream and the
+* frame aspect ratio.
+*
+* Since the frame aspect ratio is set by the codec but the stream aspect ratio
+* is set by the demuxer, these two may not be equal. This function tries to
+* return the value that you should use if you would like to display the frame.
+*
+* Basic logic is to use the stream aspect ratio if it is set to something sane
+* otherwise use the frame aspect ratio. This way a container setting, which is
+* usually easy to modify can override the coded value in the frames.
+*
+* @param format the format context which the stream is part of
+* @param stream the stream which the frame is part of
+* @param frame the frame with the aspect ratio to be determined
+* @return the guessed (valid) sample_aspect_ratio, 0/1 if no idea
+*/
+AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame);
+/**
+* Guess the frame rate, based on both the container and codec information.
+*
+* @param ctx the format context which the stream is part of
+* @param stream the stream which the frame is part of
+* @param frame the frame for which the frame rate should be determined, may be NULL
+* @return the guessed (valid) frame rate, 0/1 if no idea
+*/
+AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame);
+/**
+* Check if the stream st contained in s is matched by the stream specifier
+* spec.
+*
+* See the "stream specifiers" chapter in the documentation for the syntax
+* of spec.
+*
+* @return  >0 if st is matched by spec;
+*          0  if st is not matched by spec;
+*          AVERROR code if spec is invalid
+*
+* @note  A stream specifier can match several streams in the format.
+*/
+int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st,
+const char *spec);
+int avformat_queue_attached_pictures(AVFormatContext *s);
+/**
+* @}
+*/
+#endif /* AVFORMAT_AVFORMAT_H */

Mercurial > mm7

comparison lib/libavformat/avformat.h @ 2134:992d2e6f907d