al_get_sample_length - Allegro 5 API

       Return the length of the sample in sample values.

       al_get_sample_length - Allegro 5 API

al_get_sample_channels(3alleg5),      al_get_sample_depth(3alleg5),     al_get_sample_frequency(3alleg5),
       al_get_sample_data(3alleg5)

Allegro reference manual                                                           al_get_sample_length(3alleg5)

              #include <allegro5/allegro_audio.h>

              unsigned int al_get_sample_length(const ALLEGRO_SAMPLE *spl)