Comment 29 for bug 1246929

 use -audio-help to list the available backend

   if (!found) {
            dolog ("Unknown audio driver `%s'\n", drvname);
            dolog ("Run with -audio-help to list available drivers\n");
        }
    }

    if (!done) {
        for (i = 0; !done && i < ARRAY_SIZE (drvtab); i++) {
            if (drvtab[i]->can_be_default) {
                done = !audio_driver_init (s, drvtab[i]);
            }
        }
    }

    if (!done) {
        done = !audio_driver_init (s, &no_audio_driver);
        if (!done) {
            hw_error("Could not initialize audio subsystem\n");
        }
        else {
            dolog ("warning: Using timer based audio emulation\n");
        }
    }