avformat.h

ts流的解复用

#define MAX_REORDER_DELAY 4
    int64_t pts_buffer[MAX_REORDER_DELAY+1];

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

    int disposition; /**< AV_DISPOSITION_* bitfield */
} AVStream;

typedef struct AVChapter {
    int id;                 ///< Unique id to identify the chapter
    AVRational time_base;   ///< Timebase in which the start/end timestamps are specified
    int64_t start, end;     ///< chapter start/end time in time_base units
    char *title;            ///< chapter title
} AVChapter;

#define MAX_STREAMS		20


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 */
    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
                                  mpeg2ts_raw is TRUE) */
    int initial_pause:1;       /**< do not begin to play the stream
                                  immediately (RTSP only) */
    int prealloced_context:1;
#if LIBAVFORMAT_VERSION_INT < (53<<16)
    enum CodecID video_codec_id;
    enum CodecID audio_codec_id;
#endif
} AVFormatParameters;

typedef struct AVInputFormat {
    const char *name;
    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 by 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 paramters. 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. */
    int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
    /** close the stream. The AVFormatContext and AVStreams are not
       freed by this function */
    int (*read_close)(struct AVFormatContext *);
    /**
     * seek to a given timestamp relative to the frames in
     * stream component stream_index
     * @param stream_index must not be -1
     * @param flags selects which direction should be preferred if no exact
     *              match is available
     * @return >= 0 on success (but not necessarily the new offset)
     */
    int (*read_seek)(struct AVFormatContext *,
                     int stream_index, int64_t timestamp, int flags);
    /**
     * gets the next timestamp in stream[stream_index].time_base units.
     * @return the timestamp or AV_NOPTS_VALUE if an error occurred
     */
    int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
                              int64_t *pos, int64_t pos_limit);
    /** can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER */
    int flags;
    /** if extensions are defined, then no probe is done. You should
       usually not use extension format guessing because it is not
       reliable enough */
    const char *extensions;
    /** general purpose read only value that the format can use */
    int value;

    /** start/resume playing - only meaningful if using a network based format
       (RTSP) */
    int (*read_play)(struct AVFormatContext *);

    /** pause playing - only meaningful if using a network based format
       (RTSP) */
    int (*read_pause)(struct AVFormatContext *);

//    const struct AVCodecTag **codec_tag;

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


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;
    void *priv_data;
    ByteIOContext *pb;
    RingBuffer_s  *rb;  //代替上面的ByteIOContext
    unsigned int nb_streams;
    AVStream *streams[MAX_STREAMS];
    char filename[1024]; /**< input or output filename */
    /* stream info */
    int64_t timestamp;
    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 */
    /* 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;
    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 index_built;

    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 loop_output;

    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
#define AVFMT_FLAG_NONBLOCK     0x0004 ///< do not block when reading packets from input

    int loop_input;
    /** decoding: size of data to probe; encoding unused */
    unsigned int probesize;

    /**
     * maximum duration in AV_TIME_BASE units over 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 per stream for the index.
     * If the needed 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 real-time capture devices.
     */
    unsigned int max_picture_buffer;

    unsigned int nb_chapters;
    AVChapter **chapters;
} AVFormatContext;


#endif //__AVFORMAT_H__