public static extern int av_buffersink_read_samples(AVFilterContext* ctx, AVFilterBufferRef** buf, int nb_samples);
 public static extern int av_buffersink_get_buffer_ref(AVFilterContext* buffer_sink, AVFilterBufferRef** bufref, int flags);
 public static extern int av_buffersink_read(AVFilterContext* ctx, AVFilterBufferRef** buf);
 public static extern int avfilter_ref_get_channels(AVFilterBufferRef* @ref);
 public static extern int avfilter_copy_buf_props(AVFrame* dst, AVFilterBufferRef* src);
 public static extern void avfilter_unref_bufferp(AVFilterBufferRef** @ref);
 public static extern AVFilterBufferRef* avfilter_ref_buffer(AVFilterBufferRef* @ref, int pmask);
 public static extern void avfilter_copy_buffer_ref_props(AVFilterBufferRef* dst, AVFilterBufferRef* src);
 public static extern int av_buffersrc_buffer(AVFilterContext* ctx, AVFilterBufferRef* buf);
 public static extern int av_buffersrc_add_ref(AVFilterContext* buffer_src, AVFilterBufferRef* picref, int flags);