snd_mixer_filter_t

Updated: April 19, 2023

Information about a mixer's filters

Synopsis:

typedef struct snd_mixer_filter
{
    uint32_t    enable;          /* bitfield of 1 << SND_MIXER_READ_* */
    uint8_t     reserved[124];   /* must be filled with zeroes */
} snd_mixer_filter_t;

Description:

The snd_mixer_filter_t structure describes the filters for a mixer. You can call snd_mixer_set_filter() to specify the events you want to track, and snd_mixer_get_filter() to determine which you're tracking.

Currently, the only member of this structure is enable, which is a mask of the mixer events. The bits in the mask include:

SND_MIXER_READ_REBUILD
The mixer has been rebuilt.
SND_MIXER_READ_ELEMENT_VALUE
An element's value has changed.
SND_MIXER_READ_ELEMENT_CHANGE
An element has changed in some way other than its value.
SND_MIXER_READ_ELEMENT_ADD
An element was added to the mixer.
SND_MIXER_READ_ELEMENT_REMOVE
An element was removed from the mixer.
SND_MIXER_READ_ELEMENT_ROUTE
A route was added or changed.
SND_MIXER_READ_GROUP_VALUE
A group's value has changed.
SND_MIXER_READ_GROUP_CHANGE
A group has changed in some way other than its value.
SND_MIXER_READ_GROUP_ADD
A group was added to the mixer.
SND_MIXER_READ_GROUP_REMOVE
A group was removed from the mixer.

Classification:

QNX Neutrino