/** get_audio_buffer() handler for filters which simply pass audio along */
AVFilterBufferRef *avfilter_null_get_audio_buffer(AVFilterLink *link, int perms,
enum AVSampleFormat sample_fmt, int size,
/** get_audio_buffer() handler for filters which simply pass audio along */
AVFilterBufferRef *avfilter_null_get_audio_buffer(AVFilterLink *link, int perms,
enum AVSampleFormat sample_fmt, int size,