Provided by: allegro5-doc_5.2.9.1+dfsg-1.1build4_all 
NAME
al_get_num_audio_output_devices - Allegro 5 API
SYNOPSIS
#include <allegro5/allegro_audio.h>
int al_get_num_audio_output_devices()
DESCRIPTION
Get the number of available audio output devices on the system.
SINCE
5.2.8
return -1 for unsupported drivers.