ALSA Library Reference Manual
DECLARATION
typedef struct snd_mixer_filter { unsigned int read_cmds[8]; } snd_mixer_filter_t;
REFERENCE
int
snd_mixer_get_filter
(snd_mixer_t * handle, snd_mixer_filter_t * filter);
int
snd_mixer_put_filter
(snd_mixer_t * handle, snd_mixer_filter_t * filter);