PeerStreamer

/*

 * 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

#define LIBAVFORMAT_VERSION_MAJOR 52

#define LIBAVFORMAT_VERSION_MINOR 56

#define LIBAVFORMAT_VERSION_MICRO  0

#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \

                                               LIBAVFORMAT_VERSION_MINOR, \

                                               LIBAVFORMAT_VERSION_MICRO)

#define LIBAVFORMAT_VERSION     AV_VERSION(LIBAVFORMAT_VERSION_MAJOR,   \

                                           LIBAVFORMAT_VERSION_MINOR,   \

                                           LIBAVFORMAT_VERSION_MICRO)

#define LIBAVFORMAT_BUILD       LIBAVFORMAT_VERSION_INT

#define LIBAVFORMAT_IDENT       "Lavf" AV_STRINGIFY(LIBAVFORMAT_VERSION)

/**

 * I return the LIBAVFORMAT_VERSION_INT constant.  You got

 * a fucking problem with that, douchebag?

 */

unsigned avformat_version(void);

/**

 * Returns the libavformat build-time configuration.

 */

const char *avformat_configuration(void);

/**

 * Returns the libavformat license.

 */

const char *avformat_license(void);

#include <time.h>

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

#include "libavcodec/avcodec.h"

#include "avio.h"

struct AVFormatContext;

/*

 * 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:

 * 1. 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.

 * 2. 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.

 * 3. 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.

 *    a) 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.

 *    b) 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".

 *

 * 4. Tag names are normally exported exactly as stored in the container to

 *    allow lossless remuxing to the same format. For container-independent

 *    handling of metadata, av_metadata_conv() can convert it to ffmpeg generic

 *    format. Follows a list of generic tag names:

 *

 * 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.

 * 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.

 * 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.

 * title        -- name of the work.

 * track        -- number of this work in the set, can be in form current/total.

 */

#define AV_METADATA_MATCH_CASE      1

#define AV_METADATA_IGNORE_SUFFIX   2

#define AV_METADATA_DONT_STRDUP_KEY 4

#define AV_METADATA_DONT_STRDUP_VAL 8

typedef struct {

    char *key;

    char *value;

}AVMetadataTag;

typedef struct AVMetadata AVMetadata;

typedef struct AVMetadataConv AVMetadataConv;

/**

 * Gets a metadata element with matching key.

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

 * @param flags Allows case as well as suffix-insensitive comparisons.

 * @return Found tag or NULL, changing key or value leads to undefined behavior.

 */

AVMetadataTag *

av_metadata_get(AVMetadata *m, const char *key, const AVMetadataTag *prev, int flags);

#if LIBAVFORMAT_VERSION_MAJOR == 52

/**

 * Sets the given tag in m, overwriting an existing tag.

 * @param key tag key to add to m (will be av_strduped)

 * @param value tag value to add to m (will be av_strduped)

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

 */

int av_metadata_set(AVMetadata **pm, const char *key, const char *value);

#endif

/**

 * Sets the given tag in m, overwriting an existing tag.

 * @param key tag key to add to m (will be av_strduped depending on flags)

 * @param value tag value to add to m (will be av_strduped depending on flags)

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

 */

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

/**

 * Converts all the metadata sets from ctx according to the source and

 * destination conversion tables. If one of the tables is NULL, then

 * tags are converted to/from ffmpeg generic tag names.

 * @param d_conv destination tags format conversion table

 * @param s_conv source tags format conversion table

 */

void av_metadata_conv(struct AVFormatContext *ctx,const AVMetadataConv *d_conv,

                                                  const AVMetadataConv *s_conv);

/**

 * Frees all the memory allocated for an AVMetadata struct.

 */

void av_metadata_free(AVMetadata **m);

/* packet functions */

/**

 * Allocates and reads the payload of a packet and initializes 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(ByteIOContext *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 {

    AVRational time_base;

    int sample_rate;

    int channels;

    int width;

    int height;

    enum PixelFormat pix_fmt;

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

    const char *standard; /**< TV standard, NTSC, PAL, SECAM */

    unsigned int mpeg2ts_raw:1;  /**< Force raw MPEG-2 transport stream output, if possible. */

    unsigned int mpeg2ts_compute_pcr:1; /**< Compute exact PCR for each transport

                                            stream packet (only meaningful if

                                            mpeg2ts_raw is TRUE). */

    unsigned int initial_pause:1;       /**< Do not begin to play the stream

                                            immediately (RTSP only). */

    unsigned int prealloced_context:1;

#if LIBAVFORMAT_VERSION_INT < (53<<16)

    enum CodecID video_codec_id;

    enum CodecID audio_codec_id;

#endif

} 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

                                      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. */

#define AVFMT_VARIABLE_FPS  0x0400 /**< Format allows variable fps. */

#define AVFMT_NODIMENSIONS  0x0800 /**< Format does not need width/height */

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_GLOBALHEADER */

    int flags;

    /** 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 terminated by CODEC_ID_NONE.

     */

    const struct AVCodecTag * const *codec_tag;

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

    const AVMetadataConv *metadata_conv;

    /* private fields */

    struct AVOutputFormat *next;

} AVOutputFormat;

typedef struct AVInputFormat {

    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.

       @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 LIBAVFORMAT_VERSION_MAJOR < 53

    /**

     * Seek to a given timestamp relative to the frames in

     * stream component stream_index.

     * @param stream_index Must not be -1.

     * @param flags Selects which direction should be preferred if no exact

     *              match is available.

     * @return >= 0 on success (but not necessarily the new offset)

     */

    int (*read_seek)(struct AVFormatContext *,

                     int stream_index, int64_t timestamp, int flags);

#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;

    /** Starts/resumes playing - only meaningful if using a network-based format

       (RTSP). */

    int (*read_play)(struct AVFormatContext *);

    /** Pauses playing - only meaningful if using a network-based format

       (RTSP). */

    int (*read_pause)(struct AVFormatContext *);

    const struct AVCodecTag * const *codec_tag;

    /**

     * Seeks 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);

    const AVMetadataConv *metadata_conv;

    /* 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 */

};

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

/**

 * 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.

     */

    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;

#if LIBAVFORMAT_VERSION_INT < (53<<16)

    char language[4]; /** ISO 639-2/B 3-letter language code (empty string if undefined) */

#endif

    /* 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

#if LIBAVFORMAT_VERSION_INT < (53<<16)

    int64_t unused[4+1];

    char *filename; /**< source filename of the stream */

#endif

    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;

    AVMetadata *metadata;

    /* av_read_frame() support */

    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;

} 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;

#if LIBAVFORMAT_VERSION_INT < (53<<16)

    char           *provider_name; ///< network name for DVB streams

    char           *name;          ///< service name for DVB streams

#endif

    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;

    AVMetadata *metadata;

} 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

#if LIBAVFORMAT_VERSION_INT < (53<<16)

    char *title;            ///< chapter title

#endif

    AVMetadata *metadata;

} AVChapter;

#if LIBAVFORMAT_VERSION_MAJOR < 53

#define MAX_STREAMS 20

#else

#define MAX_STREAMS 100

#endif

/**

 * 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;

    ByteIOContext *pb;

    unsigned int nb_streams;

    AVStream *streams[MAX_STREAMS];

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

    /* stream info */

    int64_t timestamp;

#if LIBAVFORMAT_VERSION_INT < (53<<16)

    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 */

#endif

    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. NEVER set this value directly: it is deduced from the

       AVStream values.  */

    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;

#if LIBAVFORMAT_VERSION_INT < (53<<16)

    const uint8_t *cur_ptr_deprecated;

    int cur_len_deprecated;

    AVPacket cur_pkt_deprecated;

#endif

    /* av_seek_frame() support */

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

    int index_built;

    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

    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;

    AVMetadata *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;

} AVFormatContext;

typedef struct AVPacketList {

    AVPacket pkt;

    struct AVPacketList *next;

} AVPacketList;

#if LIBAVFORMAT_VERSION_INT < (53<<16)

extern AVInputFormat *first_iformat;

extern AVOutputFormat *first_oformat;

#endif

/**

 * 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);

enum CodecID av_guess_image2_codec(const char *filename);

/* 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);

#if LIBAVFORMAT_VERSION_MAJOR < 53

attribute_deprecated AVOutputFormat *guess_stream_format(const char *short_name,

                                    const char *filename,

                                    const char *mime_type);

/**

 * @deprecated Use av_guess_format() instead.

 */

attribute_deprecated AVOutputFormat *guess_format(const char *short_name,

                                                  const char *filename,

                                                  const char *mime_type);

#endif

/**

 * Returns the output format in the list of registered output formats

 * which best matches the provided parameters, or returns 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);

/**

 * 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);

/**

 * Sends 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);

/**

 * Sends 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);

/**

 * Sends 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);

/**

 * Sends 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);

/**

 * Initializes libavformat and registers 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);

/** codec tag <-> codec id */

enum CodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag);

unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum CodecID id);

/* media file input */

/**

 * Finds AVInputFormat based on the short name of the input format.

 */

AVInputFormat *av_find_input_format(const char *short_name);

/**

 * Guesses 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);

/**

 * 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);

/**

 * Opens 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

 */

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

                       AVInputFormat *fmt,

                       int buf_size,

                       AVFormatParameters *ap);

#if LIBAVFORMAT_VERSION_MAJOR < 53

/**

 * @deprecated Use avformat_alloc_context() instead.

 */

attribute_deprecated AVFormatContext *av_alloc_format_context(void);

#endif

/**

 * Allocates an AVFormatContext.

 * Can be freed with av_free() but do not forget to free everything you

 * explicitly allocated as well!

 */

AVFormatContext *avformat_alloc_context(void);

/**

 * Reads 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);

/**

 * Reads 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);

/**

 * Returns 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.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);

/**

 * Seeks 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);

/**

 * Seeks 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

 * @returns >=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);

/**

 * Starts playing a network-based stream (e.g. RTSP stream) at the

 * current position.

 */

int av_read_play(AVFormatContext *s);

/**

 * Pauses a network-based stream (e.g. RTSP stream).

 *

 * Use av_read_play() to resume it.

 */

int av_read_pause(AVFormatContext *s);

/**

 * Frees a AVFormatContext allocated by av_open_input_stream.

 * @param s context to free

 */

void av_close_input_stream(AVFormatContext *s);

/**

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

 *

 * @param s media file handle

 */

void av_close_input_file(AVFormatContext *s);

/**

 * Adds 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);

/**

 * Adds a new chapter.

 * This function is NOT part of the public API

 * and should ONLY be used by demuxers.

 *

 * @param s media file handle

 * @param id unique ID for this chapter

 * @param start chapter start time in time_base units

 * @param end chapter end time in time_base units

 * @param title chapter title

 *

 * @return AVChapter or NULL on error

 */

AVChapter *ff_new_chapter(AVFormatContext *s, int id, AVRational time_base,

                          int64_t start, int64_t end, const char *title);

/**

 * Sets 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,

                     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);

/**

 * 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);

/**

 * Ensures the index uses less memory than the maximum specified in

 * AVFormatContext.max_index_size by discarding entries if it grows

 * too large.

 * This function is not part of the public API and should only be called

 * by demuxers.

 */

void ff_reduce_index(AVFormatContext *s, int stream_index);

/**

 * Adds an index entry into a sorted list. Updates 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);

/**

 * Does a binary search using av_index_search_timestamp() and

 * AVCodec.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);

/**

 * Updates 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);

/**

 * Does 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 */

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

/**

 * Allocates the stream private data and writes the stream header to an

 * output media file.

 *

 * @param s media file handle

 * @return 0 if OK, AVERROR_xxx on error

 */

int av_write_header(AVFormatContext *s);

/**

 * Writes 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);

/**

 * 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

 * 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);

/**

 * Interleaves 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 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 occurred

 */

int av_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,

                                 AVPacket *pkt, int flush);

/**

 * Writes the stream trailer to an output media file and frees 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);

void dump_format(AVFormatContext *ic,

                 int index,

                 const char *url,

                 int is_output);

#if LIBAVFORMAT_VERSION_MAJOR < 53

/**

 * 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 framerate from a 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);

#endif

/**

 * Parses datestr and returns a corresponding number of microseconds.

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

 * - If a date the syntax is:

 * @code

 *  [{YYYY-MM-DD|YYYYMMDD}]{T| }{HH[:MM[:SS[.m...]]][Z]|HH[MM[SS[.m...]]][Z]}

 * @endcode

 * Time is local time unless Z is appended, in which case it is

 * interpreted as UTC.

 * If the year-month-day part is not specified it takes the current

 * year-month-day.

 * Returns the number of microseconds since 1st of January, 1970 up to

 * the time of the parsed date or INT64_MIN if datestr cannot be

 * successfully parsed.

 * - If a duration the syntax is:

 * @code

 *  [-]HH[:MM[:SS[.m...]]]

 *  [-]S+[.m...]

 * @endcode

 * Returns the number of microseconds contained in a time interval

 * with the specified duration or INT64_MIN if datestr cannot be

 * successfully parsed.

 * @param duration Flag which tells how to interpret datestr, if

 * not zero datestr is interpreted as a duration, otherwise as a

 * date.

 */

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

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

int64_t av_gettime(void);

/* ffm-specific for ffserver */

#define FFM_PACKET_SIZE 4096

int64_t ffm_read_write_index(int fd);

int ffm_write_write_index(int fd, int64_t pos);

void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_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.

 */

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

/**

 * Returns 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);

/**

 * Checks whether filename actually is a numbered sequence generator.

 *

 * @param filename possible numbered sequence string

 * @return 1 if a valid numbered sequence string, 0 otherwise

 */