snd_mixer_file_descriptor()
Return the file descriptor of the connection to the sound mixer interface
Synopsis:
#include <sys/asoundlib.h>
int snd_mixer_file_descriptor(
snd_mixer_t *handle );
Arguments:
- handle
- The handle for the mixer device. This must have been created by snd_mixer_open() .
Library:
libasound.so
Use the -l asound option to qcc to link against this library.
Description:
The snd_mixer_file_descriptor() function returns the file descriptor of the connection to the sound mixer interface.
You should use this file descriptor with the select() synchronous multiplexer function (see the QNX Library Reference) to receive notification of mixer events. If data is waiting to be read, you can read in the events with snd_mixer_read() .
Returns:
The file descriptor of the connection to the mixer interface on success, or a negative error code.
Errors:
- -EINVAL
- Invalid handle argument.
Classification:
QNX Neutrino
| Safety: | |
|---|---|
| Cancellation point | No |
| Interrupt handler | No |
| Signal handler | Yes |
| Thread | Yes |