avformat.h

ts流的解复用

#ifndef __AVFORMAT_H__
#define __AVFORMAT_H__

#include "type.h"
#include "avcodec.h"
#include "ringbuffer.h"

struct AVFormatContext;
/**
 * 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
*/
typedef struct AVFrac {
    int64_t val, num, den;
} AVFrac;// attribute_deprecated;

enum AVDiscard{
    /* We leave some space between them for extensions (drop some
     * keyframes for intra-only or drop just some bidir frames). */
    AVDISCARD_NONE   =-16, ///< discard nothing
    AVDISCARD_DEFAULT=  0, ///< discard useless packets like 0 size packets in avi
    AVDISCARD_NONREF =  8, ///< discard all non reference
    AVDISCARD_BIDIR  = 16, ///< discard all bidirectional frames
    AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
    AVDISCARD_ALL    = 48, ///< discard all
};

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 AVPacket {
    /**
     * Presentation time stamp in time_base units.
     * This is the time at which the decompressed packet will be presented
     * to the user.
     * Can be AV_NOPTS_VALUE if it is not stored in the file.
     * pts MUST be larger or equal to dts as presentation can not happen before
     * decompression, unless one wants to view hex dumps. Some formats misuse
     * the terms dts and pts/cts to mean something different, these timestamps
     * must be converted to true pts/dts before they are stored in AVPacket.
     */
    int64_t pts;
    /**
     * Decompression time stamp in time_base units.
     * This is the time at which the packet is decompressed.
     * Can be AV_NOPTS_VALUE if it is not stored in the file.
     */
    int64_t dts;
    uint8_t *data;
    int   size;
    int   stream_index;
    int   flags;
    int   duration;                         ///< presentation duration in time_base units (0 if not available)
    void  (*destruct)(struct AVPacket *);
    void  *priv;
    int64_t pos;                            ///< byte position in stream, -1 if unknown
} AVPacket;

/**
 * Bytestream IO 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(ByteIOContext) must not be used outside libav*.
 */
typedef struct {
    unsigned char *buffer;
    int buffer_size;
    unsigned char *buf_ptr, *buf_end;
    void *opaque;
    int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
    int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
    offset_t (*seek)(void *opaque, offset_t offset, int whence);
    offset_t pos; /**< position in the file of the current buffer */
    int must_flush; /**< true if the next seek should flush */
    int eof_reached; /**< true if eof reached */
    int write_flag;  /**< true if open for writing */
    int is_streamed;
    int max_packet_size;
    unsigned long checksum;
    unsigned char *checksum_ptr;
    unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
    int error;         ///< contains the error code or 0 if no error happened
    int (*read_pause)(void *opaque, int pause);
    offset_t (*read_seek)(void *opaque,
                     int stream_index, int64_t timestamp, int flags);
} ByteIOContext;



/* frame parsing */
typedef struct AVCodecParserContext {
    void *priv_data;
    struct AVCodecParser *parser;
    int64_t frame_offset; /* offset of the current frame */
    int64_t cur_offset; /* current offset
                           (incremented by each av_parser_parse()) */
    int64_t last_frame_offset; /* offset of the last frame */
    /* video info */
    int pict_type; /* XXX: Put it back in AVCodecContext. */
    int repeat_pict; /* XXX: Put it back in AVCodecContext. */
    int64_t pts;     /* pts of the current frame */
    int64_t dts;     /* dts of the current frame */

    /* private data */
    int64_t last_pts;
    int64_t last_dts;
    int fetch_timestamp;

#define AV_PARSER_PTS_NB 4
    int cur_frame_start_index;
    int64_t cur_frame_offset[AV_PARSER_PTS_NB];
    int64_t cur_frame_pts[AV_PARSER_PTS_NB];
    int64_t cur_frame_dts[AV_PARSER_PTS_NB];

    int flags;
#define PARSER_FLAG_COMPLETE_FRAMES           0x0001

    int64_t offset;      ///< byte offset from starting packet start
    int64_t last_offset;
} AVCodecParserContext;


typedef struct AVCodecParser {
    int codec_ids[5]; /* several codec IDs are permitted */
    int priv_data_size;
    int (*parser_init)(AVCodecParserContext *s);
    int (*parser_parse)(AVCodecParserContext *s,
                        AVCodecContext *avctx,
                        const uint8_t **poutbuf, int *poutbuf_size,
                        const uint8_t *buf, int buf_size);
    void (*parser_close)(AVCodecParserContext *s);
    int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
    struct AVCodecParser *next;
} AVCodecParser;

/**
 * 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;
    char           *provider_name; ///< Network name for DVB streams
    char           *name;          ///< Service name for DVB streams
    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;
} AVProgram;


/**
 * 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 frame rate of the stream.
     * This is the lowest frame rate with which all timestamps can be
     * represented accurately (it is the least common multiple of all
     * frame rates 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;
    void *priv_data;

    /* internal data used in av_find_stream_info() */
    int64_t first_dts;
    /** encoding: PTS generation when outputing 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,
     * timebase should be 1/frame rate and timestamp increments should be
     * identically 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 estimates from bit rate and file size.
     */
    int64_t duration;

    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