AUX_INPUT_MUTE
l = ce4231_read(sc, SP_LEFT_AUX1_CONTROL) & ~AUX_INPUT_MUTE;
r = ce4231_read(sc, SP_RIGHT_AUX1_CONTROL) & ~AUX_INPUT_MUTE;
l |= AUX_INPUT_MUTE;
r |= AUX_INPUT_MUTE;
AUX_INPUT_MUTE) ? 1 : 0;