public static extern int avformat_open_input(AVFormatContext** ps, String filename, AVInputFormat* fmt, AVDictionary** options);
 public static extern AVInputFormat* av_iformat_next(AVInputFormat* f);
 public static extern int av_probe_input_buffer(AVIOContext* pb, AVInputFormat** fmt, String filename, void* logctx, int offset, int max_probe_size);
 public static extern void av_register_input_format(AVInputFormat* format);