snd_afm_open()

Updated: May 06, 2022

Create a handle and open a connection to a specified AMP Functional Module (AFM)

Synopsis:

#include <sys/asoundlib.h>

int snd_afm_open( snd_afm_t **handle, 
                  int card, 
                  int device );

Arguments:

handle
A pointer to a location where snd_afm_open() stores a handle for the AFM
card
The card number.
device
The audio device number.

Library:

libasound.so

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

Description:

Note: This function can only be used if you have QNX Acoustic Management Platform 3.0 installed.

The snd_afm_open() function creates a handle and opens a connection to the Acoustics Management Platform (AMP) Functional Module (AFM) for sound card number card and audio device number device. AFMs are installed in /dev/snd and their names are in the form afmCxDy, where x is the card number, and y is the device number. The card number depends on the order in which the cards are specified in the io-audio .conf file.

There are no defaults; your application must specify all the arguments to this function.

Using names for audio devices (snd_afm_open_name()) is preferred to using numbers (snd_afm_open()).

Returns:

Zero on success, or a negative error code.

This function can also return the negative of the values that open() can assign to errno (see open() in the QNX Neutrino C Library Reference).

Errors:

-EINVAL
The card number or the device number is invalid.
-ENOMEM
There wasn't enough memory to allocate control structures.
-SND_ERROR_INCOMPATIBLE_VERSION
The audio driver version is incompatible with the client library that the application is using.

Classification:

QNX Neutrino

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

Caveats:

This function is not thread safe if the handle (snd_afm_t) is used across multiple threads.