1238 typedef struct AVFormatContext {  struct
1243     const AVClass *av_class;
1250     const struct AVInputFormat *iformat;
1257     const struct AVOutputFormat *oformat;
1266     void *priv_data;
1290      * Number of elements in AVFormatContext.streams.  argument
1294     unsigned int nb_streams;
1306     AVStream **streams;
1321     char *url;
1330     int64_t start_time;
1340     int64_t duration;
1347     int64_t bit_rate;
1349     unsigned int packet_size;
1350     int max_delay;
1356     int flags;
1393     int64_t probesize;
1401     int64_t max_analyze_duration;
1403     const uint8_t *key;
1404     int keylen;
1406     unsigned int nb_programs;
1407     AVProgram **programs;
1413     enum AVCodecID video_codec_id;
1419     enum AVCodecID audio_codec_id;
1425     enum AVCodecID subtitle_codec_id;
1437     unsigned int max_index_size;
1443     unsigned int max_picture_buffer;
1456     unsigned int nb_chapters;
1457     AVChapter **chapters;
1467     AVDictionary *metadata;
1480     int64_t start_time_realtime;
1487     int fps_probe_size;
1494     int error_recognition;
1505     AVIOInterruptCB interrupt_callback;
1510     int debug;
1551  *   AVFormatContext.metadata accordingly  argument
1561     int max_ts_probe;
1570     int avoid_negative_ts;
1580     int ts_id;
1588     int audio_preload;
1596     int max_chunk_duration;
1604     int max_chunk_size;
1612     int use_wallclock_as_timestamps;
1619     int avio_flags;
1627     enum AVDurationEstimationMethod duration_estimation_method;
1634     int64_t skip_initial_bytes;
1641     unsigned int correct_ts_overflow;
1648     int seek2any;
1655     int flush_packets;
1664     int probe_score;
1675     int format_probesize;
1683     char *codec_whitelist;
1691     char *format_whitelist;
1699     int io_repositioned;
1707     const AVCodec *video_codec;
1715     const AVCodec *audio_codec;
1723     const AVCodec *subtitle_codec;
1731     const AVCodec *data_codec;
1738     int metadata_header_padding;
1744     void *opaque;
1749     av_format_control_message control_message_cb;
1755     int64_t output_ts_offset;
1763     uint8_t *dump_separator;
1769     enum AVCodecID data_codec_id;
1794      * additional internal format contexts. Thus the AVFormatContext pointer  argument
1798     int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url,  argument
1804     void (*io_close)(struct AVFormatContext *s, AVIOContext *pb);  argument
1811     char *protocol_blacklist;
1835      * A callback for closing the streams opened with AVFormatContext.io_open().  argument
1845     int (*io_close2)(struct AVFormatContext *s, AVIOContext *pb);  argument
1846 } AVFormatContext;  typedef