taglinefilesource code
SOUND_MIXER_LINE123include/linux/soundcard.h#define SOUND_MIXER_READ_LINE    (SOUND_BASE | SOUND_MIXER | SOUND_READ  | SOUND_MIXER_LINE   )
SOUND_MIXER_LINE132include/linux/soundcard.h#define SOUND_MIXER_WRITE_LINE    (SOUND_BASE | SOUND_MIXER | SOUND_WRITE | SOUND_MIXER_LINE   )