public static extern long swr_get_delay(libswresample.SwrContext *s, long _base);
 public static extern int swr_drop_output(libswresample.SwrContext *s, int count);
 public static extern int swr_inject_silence(libswresample.SwrContext *s, int count);
 public static extern int swr_set_channel_mapping(libswresample.SwrContext *s, int *channel_map);
 public static extern int swr_set_matrix(libswresample.SwrContext *s, double *matrix, int stride);
 public static extern long swr_next_pts(libswresample.SwrContext *s, long pts);
 public static extern int swr_set_compensation(libswresample.SwrContext *s, int sample_delta, int compensation_distance);
 public static extern void swr_close(libswresample.SwrContext *s);
 public static extern int swr_convert(libswresample.SwrContext *s, ref byte *_out, int out_count, ref byte *_in, int in_count);
 public static extern libswresample.SwrContext *swr_alloc_set_opts(libswresample.SwrContext * s, long out_ch_layout, libavutil.AVSampleFormat out_sample_fmt, int out_sample_rate, long in_ch_layout, libavutil.AVSampleFormat in_sample_fmt, int in_sample_rate, int log_offset, void *log_ctx);
 public static extern void swr_free(ref libswresample.SwrContext *s);
 public static extern int swr_is_initialized(libswresample.SwrContext *s);
 public static extern int swr_init(libswresample.SwrContext *s);
 public static extern int swr_config_frame(libswresample.SwrContext *swr, libavutil.AVFrame *_out, libavutil.AVFrame *_in);
 public static extern int swr_convert_frame(libswresample.SwrContext *swr, libavutil.AVFrame *output, libavutil.AVFrame *input);
 public static extern int swr_get_out_samples(libswresample.SwrContext *s, int in_samples);