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  • /*
     * 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
     */
    
    
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    #ifndef AVFORMAT_H
    #define AVFORMAT_H
    
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    #define LIBAVFORMAT_VERSION_INT ((51<<16)+(12<<8)+1)
    #define LIBAVFORMAT_VERSION     51.12.1
    
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    #define LIBAVFORMAT_BUILD       LIBAVFORMAT_VERSION_INT
    
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    #define LIBAVFORMAT_IDENT       "Lavf" AV_STRINGIFY(LIBAVFORMAT_VERSION)
    
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    #include <stdio.h>  /* FILE */
    
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    #include "avcodec.h"
    
    #include "avio.h"
    
    /* packet functions */
    
    typedef struct AVPacket {
    
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        int64_t pts;                            ///< presentation time stamp in time_base units
        int64_t dts;                            ///< decompression time stamp in time_base units
    
        uint8_t *data;
    
        int   size;
        int   stream_index;
        int   flags;
    
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        int   duration;                         ///< presentation duration in time_base units (0 if not available)
    
        void  (*destruct)(struct AVPacket *);
        void  *priv;
    
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        int64_t pos;                            ///< byte position in stream, -1 if unknown
    
    void av_destruct_packet_nofree(AVPacket *pkt);
    
    void av_destruct_packet(AVPacket *pkt);
    
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    /**
     * Initialize optional fields of a packet to default values.
     *
     * @param pkt packet
     */
    
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    void av_init_packet(AVPacket *pkt);
    
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     * Allocate the payload of a packet and initialize its fields to default values.
    
     *
     * @param pkt packet
     * @param size wanted payload size
     * @return 0 if OK. AVERROR_xxx otherwise.
     */
    
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    int av_new_packet(AVPacket *pkt, int size);
    
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     * Allocate and read the payload of a packet and initialize its fields to default values.
    
     *
     * @param pkt packet
     * @param size wanted payload size
     * @return >0 (read size) if OK. AVERROR_xxx otherwise.
     */
    
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    int av_get_packet(ByteIOContext *s, AVPacket *pkt, int size);
    
    /**
     * @warning This is a hack - the packet memory allocation stuff is broken. The
     * packet is allocated if it was not really allocated
     */
    
    int av_dup_packet(AVPacket *pkt);
    
    
    /**
     * Free a packet
     *
     * @param pkt packet to free
     */
    static inline void av_free_packet(AVPacket *pkt)
    {
    
        if (pkt && pkt->destruct) {
    
            pkt->destruct(pkt);
    
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    /*************************************************/
    /* fractional numbers for exact pts handling */
    
    
    /**
     * the exact value of the fractional number is: 'val + num / den'.
     * num is assumed to be such as 0 <= num < den
     * @deprecated Use AVRational instead
    */
    
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    typedef struct AVFrac {
    
        int64_t val, num, den;
    
    } AVFrac attribute_deprecated;
    
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    /*************************************************/
    
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    struct AVFormatContext;
    
    /** this structure contains the data a format has to probe a file */
    
        const char *filename;
    
    #define AVPROBE_SCORE_MAX 100               ///< max 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
    
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    typedef struct AVFormatParameters {
    
        AVRational time_base;
    
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        int sample_rate;
        int channels;
        int width;
        int height;
    
        enum PixelFormat pix_fmt;
    
        int channel; /**< used to select dv channel */
    
    #if LIBAVFORMAT_VERSION_INT < (52<<16)
    
        const char *device; /**< video, audio or DV device */
    
        const char *standard; /**< tv standard, NTSC, PAL, SECAM */
        int mpeg2ts_raw:1;  /**< force raw MPEG2 transport stream output, if possible */
        int mpeg2ts_compute_pcr:1; /**< compute exact PCR for each transport
    
                                      stream packet (only meaningful if
    
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                                      mpeg2ts_raw is TRUE) */
    
        int initial_pause:1;       /**< do not begin to play the stream
    
                                      immediately (RTSP only) */
    
        int prealloced_context:1;
    
        enum CodecID video_codec_id;
        enum CodecID audio_codec_id;
    
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    } AVFormatParameters;
    
    
    //! demuxer will use url_fopen, 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
    
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                                          raw picture data */
    
    #define AVFMT_GLOBALHEADER  0x0040 /**< format wants global header */
    #define AVFMT_NOTIMESTAMPS  0x0080 /**< format doesnt need / has any timestamps */
    #define AVFMT_GENERIC_INDEX 0x0100 /**< use generic index building code */
    
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        const char *name;
        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 */
    
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        /* output support */
    
        enum CodecID audio_codec; /**< default audio codec */
        enum CodecID video_codec; /**< default video codec */
    
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        int (*write_header)(struct AVFormatContext *);
    
        int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
    
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        int (*write_trailer)(struct AVFormatContext *);
    
        /** can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER */
    
        /** currently only used to set pixel format if not YUV420P */
    
        int (*set_parameters)(struct AVFormatContext *, AVFormatParameters *);
    
        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 CODEC_ID_NONE terminated
         */
    
        const struct AVCodecTag **codec_tag;
    
        /* private fields */
        struct AVOutputFormat *next;
    } AVOutputFormat;
    
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    typedef struct AVInputFormat {
        const char *name;
        const char *long_name;
    
        /** size of private data so that it can be allocated in the wrapper */
    
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        /** tell if a given file has a chance of being parsed by this format */
    
        /** read the format header and initialize the AVFormatContext
    
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           structure. Return 0 if OK. 'ap' if non NULL contains
    
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           additional paramters. Only used in raw format right
    
           now. 'av_new_stream' should be called to create new streams.  */
    
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        int (*read_header)(struct AVFormatContext *,
                           AVFormatParameters *ap);
    
        /** read one packet and put it in 'pkt'. pts and flags are also
    
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        int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
    
        /** close the stream. The AVFormatContext and AVStreams are not
    
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           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
         */
    
        int (*read_seek)(struct AVFormatContext *,
    
                         int stream_index, int64_t timestamp, int flags);
    
        /**
         * gets the next timestamp in AV_TIME_BASE units.
         */
        int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
                                  int64_t *pos, int64_t pos_limit);
    
        /** can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER */
    
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        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 */
    
        /** 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 **codec_tag;
    
        /* private fields */
        struct AVInputFormat *next;
    } AVInputFormat;
    
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    enum AVStreamParseType {
        AVSTREAM_PARSE_NONE,
        AVSTREAM_PARSE_FULL,       /**< full parsing and repack */
        AVSTREAM_PARSE_HEADERS,    /**< only parse headers, don't repack */
        AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on packet boundary */
    };
    
    
    typedef struct AVIndexEntry {
        int64_t pos;
        int64_t timestamp;
    #define AVINDEX_KEYFRAME 0x0001
    
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        int flags:2;
        int size:30; //yeah trying to keep the size of this small to reduce memory requirements (its 24 vs 32 byte due to possible 8byte align)
    
        int min_distance;         /**< min distance between this and the previous keyframe, used to avoid unneeded searching */
    
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    typedef struct AVStream {
    
        int index;    /**< stream index in AVFormatContext */
        int id;       /**< format specific stream id */
        AVCodecContext *codec; /**< codec context */
    
        /**
         * real base frame rate of the stream.
    
         * this is the lowest framerate with which all timestamps can be
    
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         * 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 timebase 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;
    
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        void *priv_data;
    
    #if LIBAVFORMAT_VERSION_INT < (52<<16)
    
        int64_t codec_info_duration;
    
        int codec_info_nb_frames;
    
        /** encoding: PTS generation when outputing stream */
    
    
        /**
         * this is the fundamental unit of time (in seconds) in terms
         * of which frame timestamps are represented. for fixed-fps content,
         * timebase should be 1/framerate and timestamp increments should be
         * identically 1.
         */
    
        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 dont need to be demuxed
    
        //FIXME move stuff to a flags field?
    
        /** quality, as it has been removed from AVCodecContext and put in AVVideoFrame
    
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         * MN:dunno if thats the right place, for it */
    
        /** decoding: pts of the first frame of the stream, in stream time base. */
    
        int64_t start_time;
    
        /** decoding: duration of the stream, in stream time base. */
    
        char language[4]; /** ISO 639 3-letter language code (empty string if undefined) */
    
        /* 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
    
    
    #define MAX_REORDER_DELAY 4
        int64_t pts_buffer[MAX_REORDER_DELAY+1];
    
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    } AVStream;
    
    
    #define AVFMTCTX_NOHEADER      0x0001 /**< signal that no header is present
    
                                             (streams are added dynamically) */
    
    
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    #define MAX_STREAMS 20
    
    /* format I/O context */
    typedef struct AVFormatContext {
    
        const AVClass *av_class; /**< set by av_alloc_format_context */
    
        /* can only be iformat or oformat, not both at the same time */
        struct AVInputFormat *iformat;
        struct AVOutputFormat *oformat;
    
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        void *priv_data;
        ByteIOContext pb;
    
        unsigned int nb_streams;
    
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        AVStream *streams[MAX_STREAMS];
    
        char filename[1024]; /**< input or output filename */
    
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        /* stream info */
    
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        char title[512];
        char author[512];
        char copyright[512];
        char comment[512];
    
        char album[512];
    
        int year;  /**< ID3 year, 0 if none */
        int track; /**< track number, 0 if none */
        char genre[32]; /**< ID3 genre */
    
        int ctx_flags; /**< format specific flags, see AVFMTCTX_xx */
    
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        /* private data for pts handling (do not modify directly) */
    
        /** This buffer is only needed when packets were already buffered but
    
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           not decoded, for example to get the codec parameters in mpeg
           streams */
    
        /** 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. NEVER set this value directly: it is deduced from the
           AVStream values.  */
        int64_t duration;
    
        /** decoding: total file size. 0 if unknown */
    
        /** 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;
        const uint8_t *cur_ptr;
        int cur_len;
        AVPacket cur_pkt;
    
        /* av_seek_frame() support */
    
        int64_t data_offset; /** offset of the first packet */
    
        int mux_rate;
        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 flags;
    #define AVFMT_FLAG_GENPTS       0x0001 ///< generate pts if missing even if it requires parsing future frames
    
    #define AVFMT_FLAG_IGNIDX       0x0002 ///< ignore index
    
        /** decoding: size of data to probe; encoding unused */
    
    
        /**
         * maximum duration in AV_TIME_BASE units over which the input should be analyzed in av_find_stream_info()
         */
        int max_analyze_duration;
    
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    } AVFormatContext;
    
    typedef struct AVPacketList {
        AVPacket pkt;
        struct AVPacketList *next;
    } AVPacketList;
    
    
    extern AVInputFormat *first_iformat;
    extern AVOutputFormat *first_oformat;
    
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    enum CodecID av_guess_image2_codec(const char *filename);
    
    /* XXX: use automatic init with either ELF sections or C file parser */
    /* modules */
    
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    #include "rtp.h"
    
    #include "rtsp.h"
    
    
    /* utils.c */
    void av_register_input_format(AVInputFormat *format);
    void av_register_output_format(AVOutputFormat *format);
    
    AVOutputFormat *guess_stream_format(const char *short_name,
    
                                        const char *filename, const char *mime_type);
    
    AVOutputFormat *guess_format(const char *short_name,
    
    
    /**
     * Guesses 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 CodecType type);
    
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     * 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_dump, av_pkt_dump_log
    
    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_dump, av_pkt_dump_log
     */
    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
     */
    
    void av_pkt_dump(FILE *f, AVPacket *pkt, int dump_payload);
    
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    /**
     * 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
     */
    void av_pkt_dump_log(void *avcl, int level, AVPacket *pkt, int dump_payload);
    
    
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    void av_register_all(void);
    
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    enum CodecID av_codec_get_id(const struct AVCodecTag **tags, unsigned int tag);
    unsigned int av_codec_get_tag(const struct AVCodecTag **tags, enum CodecID id);
    
    
    /**
     * finds AVInputFormat based on input format's short name.
     */
    
    AVInputFormat *av_find_input_format(const char *short_name);
    
    
    /**
     * Guess file format.
     *
     * @param is_opened whether the file is already opened, determines whether
     *                  demuxers with or without AVFMT_NOFILE are probed
     */
    
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    AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened);
    
    
    /**
     * Allocates all the structures needed to read an input stream.
     *        This does not open the needed codecs for decoding the stream[s].
     */
    
    int av_open_input_stream(AVFormatContext **ic_ptr,
                             ByteIOContext *pb, const char *filename,
    
                             AVInputFormat *fmt, AVFormatParameters *ap);
    
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     * 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)
    
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     * @param ap additional parameters needed when opening the file (NULL if default)
    
     * @return 0 if OK. AVERROR_xxx otherwise.
     */
    
    int av_open_input_file(AVFormatContext **ic_ptr, const char *filename,
    
    /** no av_open for output, so applications will need this: */
    
    AVFormatContext *av_alloc_format_context(void);
    
    /**
     * 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 frame rate in case of mpeg2 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 if error.
     * @todo let user decide somehow what information is needed so we dont waste time geting stuff the user doesnt need
     */
    
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     * 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 if error.
     */
    
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    int av_read_packet(AVFormatContext *s, AVPacket *pkt);
    
    
    /**
     * Return the next frame of a stream.
     *
     * 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.timebase units (and guessed if the format cannot
    
     * provided 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 if error or end of file.
     */
    
    int av_read_frame(AVFormatContext *s, AVPacket *pkt);
    
    
    /**
     * Seek to the key frame 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 there is no stream specified then 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);
    
    
    /**
     * 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);
    
    
    /**
     * Close a media file (but not its codecs).
     *
     * @param s media file handle
     */
    
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    void av_close_input_file(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);
    
    
    /**
     * Set the pts for a given stream.
     *
     * @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,
    
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                         int pts_num, int pts_den);
    
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    #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
    
    int av_find_default_stream_index(AVFormatContext *s);
    
    
    /**
     * Gets 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 a index entry into a sorted list updateing if it is already there.
     *
     * @param timestamp timestamp in the timebase of the given stream
     */
    
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                           int64_t pos, int64_t timestamp, int size, int distance, int flags);
    
    
    /**
     * Does a binary search using av_index_search_timestamp() and AVCodec.read_timestamp().
     * this isnt 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);
    
    
    /**
     * Updates cur_dts of all streams based on given timestamp and AVStream.
     *
     * Stream ref_st unchanged, others set cur_dts in their native timebase
     * 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);
    
    
    /**
     * Does a binary search using read_timestamp().
     * this isnt 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 ));
    
    int av_set_parameters(AVFormatContext *s, AVFormatParameters *ap);
    
    
    /**
     * allocate the stream private data and write the stream header to an
     * output media file
     *
     * @param s media file handle
     * @return 0 if OK. AVERROR_xxx if error.
     */
    
    
    /**
     * 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 if error, = 0 if OK, 1 if end of stream wanted.
     */
    
    int av_write_frame(AVFormatContext *s, AVPacket *pkt);
    
    
    /**
     * Writes 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
    
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     * call av_write_frame() instead as it is slightly faster, it is also important
    
     * to keep in mind that completly non interleaved input will need huge amounts
     * of memory to interleave with this, so its prefereable 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 if 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 calling av_free_packet() on them is still safe.
     *
     * @param s media file handle
     * @param out the interleaved packet will be output here
     * @param in 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 occured
     */
    
    int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out, AVPacket *pkt, int flush);
    
    /**
     * @brief Write the stream trailer to an output media file and
     *        free the file private data.
     *
     * @param s media file handle
     * @return 0 if OK. AVERROR_xxx if error.
     */
    
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    void dump_format(AVFormatContext *ic,
    
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                     const char *url,
                     int is_output);
    
    
    /**
     * parses width and height out of string str.
    
     * @deprecated Use av_parse_video_frame_size instead.
    
    attribute_deprecated int parse_image_size(int *width_ptr, int *height_ptr, const char *str);
    
    
    /**
     * Converts frame rate from string to a fraction.
    
     * @deprecated Use av_parse_video_frame_rate instead.
    
    attribute_deprecated int parse_frame_rate(int *frame_rate, int *frame_rate_base, const char *arg);
    
    
    /**
     * Converts date string to number of seconds since Jan 1st, 1970.
     *
     * @code
     * Syntax:
     * - If not a duration:
     *  [{YYYY-MM-DD|YYYYMMDD}]{T| }{HH[:MM[:SS[.m...]]][Z]|HH[MM[SS[.m...]]][Z]}
     * Time is localtime unless Z is suffixed to the end. In this case GMT
     * Return the date in micro seconds since 1970
     *
     * - If a duration:
     *  HH[:MM[:SS[.m...]]]
     *  S+[.m...]
     * @endcode
     */
    
    int64_t parse_date(const char *datestr, int duration);
    
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    int64_t av_gettime(void);
    
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    /* ffm specific for ffserver */
    #define FFM_PACKET_SIZE 4096
    offset_t ffm_read_write_index(int fd);
    void ffm_write_write_index(int fd, offset_t pos);
    void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size);
    
    
    /**
     * Attempts to find a specific tag in a URL.
     *
     * syntax: '?tag1=val1&tag2=val2...'. Little URL decoding is done.
     * Return 1 if found.
     */
    
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    int find_info_tag(char *arg, int arg_size, const char *tag1, const char *info);
    
    
    /**
     * Returns in 'buf' the path with '%d' replaced by 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
     * @number frame number
     * @return 0 if OK, -1 if 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);
    
    /* grab specific */
    int video_grab_init(void);
    int audio_init(void);
    
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    /* DV1394 */
    int dv1394_init(void);
    
    int dc1394_init(void);
    
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    #ifdef HAVE_AV_CONFIG_H
    
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    int strstart(const char *str, const char *val, const char **ptr);
    int stristart(const char *str, const char *val, const char **ptr);
    void pstrcpy(char *buf, int buf_size, const char *str);
    char *pstrcat(char *buf, int buf_size, const char *s);
    
    
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    void __dynarray_add(unsigned long **tab_ptr, int *nb_ptr, unsigned long elem);
    
    
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    #ifdef __GNUC__
    
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    #define dynarray_add(tab, nb_ptr, elem)\
    do {\
        typeof(tab) _tab = (tab);\
        typeof(elem) _elem = (elem);\
        (void)sizeof(**_tab == _elem); /* check that types are compatible */\
        __dynarray_add((unsigned long **)_tab, nb_ptr, (unsigned long)_elem);\
    } while(0)
    
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    #else
    #define dynarray_add(tab, nb_ptr, elem)\
    do {\
        __dynarray_add((unsigned long **)(tab), nb_ptr, (unsigned long)(elem));\
    } while(0)
    #endif
    
    struct tm *brktimegm(time_t secs, struct tm *tm);
    
    const char *small_strptime(const char *p, const char *fmt,
    
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    struct in_addr;
    int resolve_host(struct in_addr *sin_addr, const char *hostname);
    
    void url_split(char *proto, int proto_size,
    
                   char *authorization, int authorization_size,
    
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                   char *hostname, int hostname_size,
                   int *port_ptr,
                   char *path, int path_size,
                   const char *url);
    
    
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    int match_ext(const char *filename, const char *extensions);
    
    
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    #endif /* HAVE_AV_CONFIG_H */
    
    #endif /* AVFORMAT_H */