gbs_close
gbs_configure
gbs_configure_channels
gbs_configure_output
gbs_get_metadata
gbs_get_status
gbs_init
gbs_io_peek
gbs_open
gbs_print_info
gbs_set_filter
gbs_set_nextsubsong_cb
gbs_set_io_callback
gbs_set_step_callback
gbs_set_sound_callback
gbs_step
gbs_toggle_mute
gbs_write
gbs_internal_api