public static extern int av_get_audio_frame_duration2(AVCodecParameters* @par, int @frame_bytes);
 public static extern int avcodec_parameters_to_context(AVCodecContext* @codec, AVCodecParameters* @par);
 public static extern int avcodec_parameters_copy(AVCodecParameters* @dst, AVCodecParameters* @src);
 public static extern int avcodec_parameters_from_context(AVCodecParameters* @par, AVCodecContext* @codec);
 public static extern void avcodec_parameters_free(AVCodecParameters** @par);