snd_mixer_set_filter()

Set the mask of mixer events that the driver will track

Synopsis:

#include <sys/asoundlib.h>

int snd_mixer_set_filter(
       snd_mixer_t *handle, 
       snd_mixer_filter_t *filter );

Arguments:

handle
The handle for the mixer device. This must have been created by snd_mixer_open() .
filter
A pointer to a snd_mixer_filter_t structure that defines a mask of events to track.

Library:

libasound.so

Use the -l asound option to qcc to link against this library.

Description:

The snd_mixer_set_filter() function uses the snd_mixer_filter_t structure to set the mask of all mixer events for the mixer that the handle was opened on that the driver will track. Only those events that are specified in the mask are tracked; all others are discarded as they occur.

You can arrange to have your application receive notification when an event occurs by calling select() on the mixer's file descriptor, which you can get by calling snd_mixer_file_descriptor() . You can use snd_mixer_read() to read the event's data.

Returns:

Zero on success, or a negative value on error.

Errors:

-EINVAL
Invalid handle or filter is NULL.

Classification:

QNX Neutrino

Safety:
Cancellation point No
Interrupt handler No
Signal handler Yes
Thread Yes