/*
  * 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

 /**

  * 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);

 #include <time.h>

 #include <stdio.h>  /* FILE */

 #include "libavcodec/avcodec.h"

 #include "libavutil/dict.h"

 
 #include "avio.h"

 #include "libavformat/version.h"

 struct AVFormatContext;
 

 /**
  * @defgroup metadata_api Public Metadata API
  * @{

  * The metadata API allows libavformat to export metadata tags to a client

  * application using a sequence of key/value pairs. Like all strings in FFmpeg,
  * metadata must be stored as 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.
  *

  * @}

  */
 

 #if FF_API_OLD_METADATA2
 /**
  * @defgroup old_metadata Old metadata API
  * The following functions are deprecated, use
  * their equivalents from libavutil/dict.h instead.
  * @{
  */

 #define AV_METADATA_MATCH_CASE      AV_DICT_MATCH_CASE
 #define AV_METADATA_IGNORE_SUFFIX   AV_DICT_IGNORE_SUFFIX
 #define AV_METADATA_DONT_STRDUP_KEY AV_DICT_DONT_STRDUP_KEY
 #define AV_METADATA_DONT_STRDUP_VAL AV_DICT_DONT_STRDUP_VAL
 #define AV_METADATA_DONT_OVERWRITE  AV_DICT_DONT_OVERWRITE
 
 typedef attribute_deprecated AVDictionary AVMetadata;
 typedef attribute_deprecated AVDictionaryEntry  AVMetadataTag;

 typedef struct AVMetadataConv AVMetadataConv;

 
 /**

  * Get a metadata element with matching key.

  *

  * @param prev Set to the previous matching element to find the next.

  *             If set to NULL the first matching element is returned.

  * @param flags Allows case as well as suffix-insensitive comparisons.
  * @return Found tag or NULL, changing key or value leads to undefined behavior.

  */

 attribute_deprecated AVDictionaryEntry *
 av_metadata_get(AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags);

 /**

  * Set the given tag in *pm, overwriting an existing tag.

  *

  * @param pm pointer to a pointer to a metadata struct. If *pm is NULL
  * a metadata struct is allocated and put in *pm.

  * @param key tag key to add to *pm (will be av_strduped depending on flags)
  * @param value tag value to add to *pm (will be av_strduped depending on flags).

  *        Passing a NULL value will cause an existing tag to be deleted.

  * @return >= 0 on success otherwise an error code <0
  */

 attribute_deprecated int av_metadata_set2(AVDictionary **pm, const char *key, const char *value, int flags);

 /**

  * This function is provided for compatibility reason and currently does nothing.

  */

 attribute_deprecated void av_metadata_conv(struct AVFormatContext *ctx, const AVMetadataConv *d_conv,
                                                                         const AVMetadataConv *s_conv);

 
 /**

  * Copy metadata from one AVDictionary struct into another.
  * @param dst pointer to a pointer to a AVDictionary struct. If *dst is NULL,

  *            this function will allocate a struct for you and put it in *dst

  * @param src pointer to source AVDictionary struct

  * @param flags flags to use when setting metadata in *dst

  * @note metadata is read using the AV_DICT_IGNORE_SUFFIX flag

  */

 attribute_deprecated void av_metadata_copy(AVDictionary **dst, AVDictionary *src, int flags);

 
 /**

  * Free all the memory allocated for an AVDictionary struct.

  */

 attribute_deprecated void av_metadata_free(AVDictionary **m);
 /**
  * @}
  */
 #endif

 /* 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_MAX 100               ///< maximum score, half of that is used for file-extension-based detection

 #define AVPROBE_PADDING_SIZE 32             ///< extra allocated bytes at the end of the probe buffer

 
 typedef struct AVFormatParameters {

 #if FF_API_FORMAT_PARAMETERS

     attribute_deprecated AVRational time_base;

     attribute_deprecated int sample_rate;
     attribute_deprecated int channels;

     attribute_deprecated int width;
     attribute_deprecated int height;

     attribute_deprecated enum PixelFormat pix_fmt;

     attribute_deprecated int channel; /**< Used to select DV channel. */

     attribute_deprecated const char *standard; /**< deprecated, use demuxer-specific options instead. */

     attribute_deprecated unsigned int mpeg2ts_raw:1;  /**< deprecated, use mpegtsraw demuxer */

     /**< deprecated, use mpegtsraw demuxer-specific options instead */
     attribute_deprecated unsigned int mpeg2ts_compute_pcr:1;

     attribute_deprecated unsigned int initial_pause:1;       /**< Do not begin to play the stream
                                                                   immediately (RTSP only). */

     attribute_deprecated unsigned int prealloced_context:1;

 #endif

 } AVFormatParameters;
 

 //! 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 fallback to binary search via read_timestamp */
 #define AVFMT_NOGENSEARCH   0x4000 /**< Format does not allow to fallback to generic search */

 #define AVFMT_TS_NONSTRICT  0x8000 /**< Format does not require strictly
                                           increasing timestamps, but they must
                                           still be monotonic */

 
 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 */

     /**
      * size of private data so that it can be allocated in the wrapper
      */

     int priv_data_size;

     /* output support */

     enum CodecID audio_codec; /**< default audio codec */
     enum CodecID video_codec; /**< default video codec */

     int (*write_header)(struct AVFormatContext *);

     int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);

     int (*write_trailer)(struct AVFormatContext *);

     /**

      * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
      * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
      * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS

      */

     int flags;

 
     void *dummy;
 

     int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
                              AVPacket *in, int flush);

 
     /**

      * List of supported codec_id-codec_tag pairs, ordered by "better

      * choice first". The arrays are all terminated by CODEC_ID_NONE.

      */

     const struct AVCodecTag * const *codec_tag;

     enum CodecID subtitle_codec; /**< default subtitle codec */
 

 #if FF_API_OLD_METADATA2

     const AVMetadataConv *metadata_conv;

 #endif

     const AVClass *priv_class; ///< AVClass for the private context
 

     /* private fields */
     struct AVOutputFormat *next;
 } AVOutputFormat;

 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;

 
     /**
      * 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. 'ap' if non-NULL contains
      * additional parameters. Only used in raw format right
      * now. 'av_new_stream' should be called to create new streams.
      */

     int (*read_header)(struct AVFormatContext *,
                        AVFormatParameters *ap);

 
     /**
      * Read one packet and put it in 'pkt'. pts and flags are also
      * set. 'av_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 *);

 #if FF_API_READ_SEEK

     /**

      * 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)

      */

     attribute_deprecated int (*read_seek)(struct AVFormatContext *,
                                           int stream_index, int64_t timestamp, int flags);

 #endif

     /**

      * Gets 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);

 
     /**
      * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER.
      */

     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;

 
     /**
      * General purpose read-only value that the format can use.
      */

     int value;

     /**
      * 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 *);
 

     const struct AVCodecTag * const *codec_tag;

     /**

      * 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);

 #if FF_API_OLD_METADATA2

     const AVMetadataConv *metadata_conv;

 #endif

     const AVClass *priv_class; ///< AVClass for the private context
 

     /* private fields */
     struct AVInputFormat *next;
 } 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 */

 };
 

 typedef struct AVIndexEntry {
     int64_t pos;
     int64_t timestamp;
 #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 */

 /**
  * 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 */

     int id;       /**< format-specific stream ID */

     AVCodecContext *codec; /**< codec context */

     /**

      * 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.

      */
     AVRational r_frame_rate;

     void *priv_data;

     /* internal data used in av_find_stream_info() */

     int64_t first_dts;

 
     /**
      * 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. For fixed-fps content,

      * time base should be 1/framerate and timestamp increments should be 1.

      * decoding: set by libavformat
      * encoding: set by libavformat in av_write_header

      */

     AVRational time_base;

     int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */

     /* ffmpeg.c private use */

     int stream_copy; /**< If set, just copy stream. */
     enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed.

     //FIXME move stuff to a flags field?

     /**
      * Quality, as it has been removed from AVCodecContext and put in AVVideoFrame.
      * MN: dunno if that is the right place for it
      */

     float quality;

     /**

      * Decoding: pts of the first frame of the stream, 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;

 
     /* av_read_frame() support */

     enum AVStreamParseType need_parsing;

     struct AVCodecParserContext *parser;

     int64_t cur_dts;

     int last_IP_duration;
     int64_t last_IP_pts;

     /* av_seek_frame() support */

     AVIndexEntry *index_entries; /**< Only used if the format does not
                                     support seeking natively. */

     int nb_index_entries;

     unsigned int index_entries_allocated_size;

     int64_t nb_frames;                 ///< number of frames in this stream if known or 0

     int disposition; /**< AV_DISPOSITION_* bit field */

 
     AVProbeData probe_data;

 #define MAX_REORDER_DELAY 16
     int64_t pts_buffer[MAX_REORDER_DELAY+1];

 
     /**
      * sample aspect ratio (0 if unknown)
      * - encoding: Set by user.
      * - decoding: Set by libavformat.
      */
     AVRational sample_aspect_ratio;

     AVDictionary *metadata;

     /* Intended mostly for av_read_frame() support. Not supposed to be used by */
     /* external applications; try to use something else if at all possible.    */

     const uint8_t *cur_ptr;
     int cur_len;
     AVPacket cur_pkt;

 
     // 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;

 
     /**
      * Number of packets to buffer for codec probing
      * NOT PART OF PUBLIC API
      */

 #define MAX_PROBE_PACKETS 2500

     int probe_packets;

 
     /**

      * last packet in packet_buffer for this stream when muxing.

      * used internally, NOT PART OF PUBLIC API, dont read or write from outside of libav*
      */

     struct AVPacketList *last_in_packet_buffer;

 
     /**
      * Average framerate
      */
     AVRational avg_frame_rate;

 
     /**
      * 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;
 
     /**

      * Stream informations used internally by av_find_stream_info()
      */
 #define MAX_STD_TIMEBASES (60*12+5)
     struct {
         int64_t last_dts;
         int64_t duration_gcd;
         int duration_count;
         double duration_error[MAX_STD_TIMEBASES];
         int64_t codec_info_duration;
     } *info;

 
     /**
      * flag to indicate that probing is requested
      * NOT PART OF PUBLIC API
      */
     int request_probe;

 } AVStream;
 

 #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;

 } 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;
 

 /**

  * 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*.

  */

 typedef struct AVFormatContext {

     const AVClass *av_class; /**< Set by avformat_alloc_context. */

     /* Can only be iformat or oformat, not both at the same time. */

     struct AVInputFormat *iformat;
     struct AVOutputFormat *oformat;

     void *priv_data;

     AVIOContext *pb;

     unsigned int nb_streams;

     AVStream **streams;

     char filename[1024]; /**< input or output filename */

     /* stream info */

     int64_t timestamp;

     int ctx_flags; /**< Format-specific flags, see AVFMTCTX_xx */
     /* private data for pts handling (do not modify directly). */

     /**
      * 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;
 

     /**
      * 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 dont set any of them. This is deduced from the
      * AVStream values if not set.
      */

     int64_t duration;

 
     /**
      * decoding: total file size, 0 if unknown
      */

     int64_t file_size;

 
     /**
      * 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;

 
     /* av_read_frame() support */
     AVStream *cur_st;
 
     /* av_seek_frame() support */

     int64_t data_offset; /**< offset of the first packet */

     int mux_rate;

     unsigned int packet_size;

     int preload;
     int max_delay;

 #define AVFMT_NOOUTPUTLOOP -1
 #define AVFMT_INFINITEOUTPUTLOOP 0

     /**
      * number of times to loop output in formats that support it
      */

     int loop_output;

     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

 #if FF_API_FLAG_RTP_HINT
 #define AVFMT_FLAG_RTP_HINT     0x0040 ///< Deprecated, use the -movflags rtphint muxer specific AVOption instead
 #endif

 #define AVFMT_FLAG_CUSTOM_IO    0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it.

 #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 ///< Dont merge side data but keep it seperate.

 
     int loop_input;

 
     /**
      * decoding: size of data to probe; encoding: unused.
      */

     unsigned int probesize;

 
     /**

      * Maximum time (in AV_TIME_BASE units) during which the input should
      * be analyzed in av_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 CodecID video_codec_id;

     /**
      * Forced audio codec_id.

      * Demuxing: Set by user.

      */
     enum CodecID audio_codec_id;

     /**
      * Forced subtitle codec_id.

      * Demuxing: Set by user.

      */
     enum CodecID 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;

 
     /**

      * Flags to enable debugging.

      */
     int debug;
 #define FF_FDEBUG_TS        0x0001

 
     /**

      * 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;
 
     struct AVPacketList *packet_buffer_end;

     AVDictionary *metadata;

 
     /**
      * Remaining size available for raw_packet_buffer, in bytes.
      * NOT PART OF PUBLIC API
      */

 #define RAW_PACKET_BUFFER_SIZE 2500000

     int raw_packet_buffer_remaining_size;

 
     /**
      * 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;

 
     /**
      * Transport stream id.
      * This will be moved into demuxer private options. Thus no API/ABI compatibility
      */
     int ts_id;

 } AVFormatContext;
 
 typedef struct AVPacketList {
     AVPacket pkt;
     struct AVPacketList *next;
 } AVPacketList;
 

 /**
  * 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);

 #if FF_API_GUESS_IMG2_CODEC
 attribute_deprecated enum CodecID av_guess_image2_codec(const char *filename);
 #endif

 /* XXX: Use automatic init with either ELF sections or C file parser */
 /* modules. */

 /* utils.c */
 void av_register_input_format(AVInputFormat *format);
 void av_register_output_format(AVOutputFormat *format);

 
 /**

  * 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 CodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,

                             const char *filename, const char *mime_type,

                             enum AVMediaType type);

 /**

  * 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, 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, 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);
 

 #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

 /**

  * 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()

  * @see av_register_protocol()

  */

 void av_register_all(void);

 /**

  * Get the CodecID for the given codec tag tag.

  * If no codec id is found returns CODEC_ID_NONE.
  *
  * @param tags list of supported codec_id-codec_tag pairs, as stored
  * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag
  */

 enum CodecID 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 CodecID id);

 /* media file input */

 
 /**

  * 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);
 

 #if FF_API_FORMAT_PARAMETERS

 /**

  * Allocate all the structures needed to read an input stream.

  *        This does not open the needed codecs for decoding the stream[s].

  * @deprecated use avformat_open_input instead.

  */

 attribute_deprecated int av_open_input_stream(AVFormatContext **ic_ptr,

                          AVIOContext *pb, const char *filename,

                          AVInputFormat *fmt, AVFormatParameters *ap);

 
 /**

  * Open a media file as input. The codecs are not opened. Only the file

  * header (if present) is read.
  *

  * @param ic_ptr The opened media file handle is put here.
  * @param filename filename to open
  * @param fmt If non-NULL, force the file format to use.

  * @param buf_size optional buffer size (zero if default is OK)

  * @param ap Additional parameters needed when opening the file
  *           (NULL if default).

  * @return 0 if OK, AVERROR_xxx otherwise

  *
  * @deprecated use avformat_open_input instead.

  */

 attribute_deprecated int av_open_input_file(AVFormatContext **ic_ptr, const char *filename,

                        AVInputFormat *fmt,
                        int buf_size,
                        AVFormatParameters *ap);

 #endif

 /**

  * 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);

 int av_demuxer_open(AVFormatContext *ic, AVFormatParameters *ap);
 

 /**

  * 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);

 #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);

 
 /**

  * 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.

  */

 int av_find_stream_info(AVFormatContext *ic);

 
 /**

  * 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);
 
 /**

  * 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

  */

 int av_read_packet(AVFormatContext *s, AVPacket *pkt);

 
 /**

  * 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.

  *
  * The returned packet is valid
  * until the next av_read_frame() or until av_close_input_file() and
  * must be freed with av_free_packet. 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).
  *

  * @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);

 
 /**

  * Free a AVFormatContext allocated by av_open_input_stream.

  * @param s context to free
  */
 void av_close_input_stream(AVFormatContext *s);
 
 /**

  * Close a media file (but not its codecs).

  *
  * @param s media file handle
  */

 void av_close_input_file(AVFormatContext *s);

 
 /**

  * Free an AVFormatContext and all its streams.
  * @param s context to free
  */
 void avformat_free_context(AVFormatContext *s);
 
 /**

  * 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

  */

 AVStream *av_new_stream(AVFormatContext *s, int id);

 AVProgram *av_new_program(AVFormatContext *s, int id);

 
 /**

  * Set the pts for a given stream. If the new values would be invalid
  * (<= 0), it leaves the AVStream unchanged.

  *
  * @param s stream
  * @param pts_wrap_bits number of bits effectively used by the pts
  *        (used for wrap control, 33 is the value for MPEG)
  * @param pts_num numerator to convert to seconds (MPEG: 1)
  * @param pts_den denominator to convert to seconds (MPEG: 90000)
  */

 void av_set_pts_info(AVStream *s, int pts_wrap_bits,

                      unsigned int pts_num, unsigned int pts_den);

 #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

 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);

 
 /**

  * Perform a binary search using av_index_search_timestamp() and

  * AVInputFormat.read_timestamp().

  * This is not supposed to be called directly by a user application,
  * but by demuxers.

  * @param target_ts target timestamp in the time base of the given stream
  * @param stream_index stream number
  */

 int av_seek_frame_binary(AVFormatContext *s, int stream_index,
                          int64_t target_ts, int flags);

 
 /**

  * Update cur_dts of all streams based on the given timestamp and AVStream.

  *

  * Stream ref_st unchanged, others set cur_dts in their native time base.
  * Only needed for timestamp wrapping or if (dts not set and pts!=dts).

  * @param timestamp new dts expressed in time_base of param ref_st
  * @param ref_st reference stream giving time_base of param timestamp
  */

 void av_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp);

 
 /**

  * Perform a binary search using read_timestamp().

  * This is not supposed to be called directly by a user application,
  * but by demuxers.

  * @param target_ts target timestamp in the time base of the given stream
  * @param stream_index stream number
  */

 int64_t av_gen_search(AVFormatContext *s, int stream_index,
                       int64_t target_ts, int64_t pos_min,
                       int64_t pos_max, int64_t pos_limit,
                       int64_t ts_min, int64_t ts_max,
                       int flags, int64_t *ts_ret,
                       int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));

 /**
  * media file output
  */

 #if FF_API_FORMAT_PARAMETERS
 /**
  * @deprecated pass the options to avformat_write_header directly.
  */

 attribute_deprecated int av_set_parameters(AVFormatContext *s, AVFormatParameters *ap);

 #endif

 
 /**

  * 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);
 
 /**

  * 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 openened 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);
 
 #if FF_API_FORMAT_PARAMETERS
 /**

  * Allocate the stream private data and write the stream header to an

  * output media file.

  * @note: this sets stream time-bases, if possible to stream->codec->time_base

  * but for some formats it might also be some other time base

  *
  * @param s media file handle

  * @return 0 if OK, AVERROR_xxx on error

  *
  * @deprecated use avformat_write_header.

  */

 attribute_deprecated int av_write_header(AVFormatContext *s);
 #endif

 
 /**

  * 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, ...

  * @return < 0 on error, = 0 if OK, 1 if end of stream wanted

  */

 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, which contains the stream_index, buf/buf_size,
               dts/pts, ...

  * @return < 0 on error, = 0 if OK, 1 if end of stream wanted

  */

 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);

 
 /**

  * Interleave a packet per dts in an output media file.

  *

  * Packets with pkt->destruct == av_destruct_packet will be freed inside this

  * function, so they cannot be used after it. Note that calling av_free_packet()

  * on them is still safe.

  *
  * @param s media file handle
  * @param out the interleaved packet will be output here

  * @param pkt the input packet

  * @param flush 1 if no further packets are available as input and all
  *              remaining packets should be output
  * @return 1 if a packet was output, 0 if no packet could be output,

  *         < 0 if an error occurred

  */

 int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
                                  AVPacket *pkt, int flush);

 /**

  * Write the stream trailer to an output media file and free the

  * file private data.

  *

  * May only be called after a successful call to av_write_header.
  *

  * @param s media file handle

  * @return 0 if OK, AVERROR_xxx on error

  */

 int av_write_trailer(AVFormatContext *s);

 #if FF_API_DUMP_FORMAT

 /**
  * @deprecated Deprecated in favor of av_dump_format().
  */

 attribute_deprecated void dump_format(AVFormatContext *ic,
                                       int index,
                                       const char *url,
                                       int is_output);
 #endif
 
 void av_dump_format(AVFormatContext *ic,
                     int index,
                     const char *url,
                     int is_output);

 #if FF_API_PARSE_DATE

 /**

  * Parse datestr and return a corresponding number of microseconds.

  *

  * @param datestr String representing a date or a duration.

  * See av_parse_time() for the syntax of the provided string.
  * @deprecated in favor of av_parse_time()

  */

 attribute_deprecated

 int64_t parse_date(const char *datestr, int duration);

 #endif

 /**
  * Get the current time in microseconds.
  */

 int64_t av_gettime(void);

 #if FF_API_FIND_INFO_TAG

 /**

  * @deprecated use av_find_info_tag in libavutil instead.

  */

 attribute_deprecated int find_info_tag(char *arg, int arg_size, const char *tag1, const char *info);
 #endif

 /**

  * 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.

  *
  * @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);

 
 #if FF_API_SDP_CREATE
 attribute_deprecated int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size);
 #endif

 /**

  * 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);
 

 #endif /* AVFORMAT_AVFORMAT_H */