https://itzaber.ch/wp-content/plugins/onepress-plus/assets/js/slider.js?ver=7.1

1jQuery( document ).ready( function( $ ){
2    $('.section-op-slider').each( function(){
3
4        var $slider = $( this );
5        var  $wrapper =  $( this ).parent();
6        var h = $slider.height();
7		var settings = $slider.data( 'settings' ) || {};
8		
9		if ('objectFit' in document.documentElement.style !== true) {
10			$slider.find('.item > img').css({
11				'top': '50%',
12				'left': '50%',
13				'transform': 'translate(-50%, -50%)',
14			});
15		}
16
17        settings.items = 1;
18
19        var owl = $slider.owlCarousel( settings );
20
21        owl.on('changed.owl.carousel', function(event) {
22            $slider.height( '' );
23            h = $slider.height();
24            parallax();
25        });
26
27        owl.on('initialize.owl.carousel', function(event) {
28            $slider.height( '' );
29            h = $slider.height( );
30            parallax();
31        });
32
33        function parallax(){
34
35            if ( ! settings.parallax ) {
36                return false;
37            }
38
39            var scrolled = $(window).scrollTop();
40            var o = $wrapper.offset();
41            var h = $slider.height();
42            // $wrapper.height( h );
43            if ( scrolled >= o.top ) {
44
45                var diff = scrolled - o.top  ;
46
47                var sliderHeight = h - diff;
48                if ( sliderHeight < 0 ) {
49                    sliderHeight = 0;
50                }
51
52                var _tt = diff  / 3.5;
53                $slider.css( 'transform', 'translateY('+( _tt  )+'px)' );
54
55                var $active = $( '.owl-item.active', owl ).eq( 0 );
56                var active_content_height = $active.find( '.item--content' ).height();
57
58                var op = 1 - ( diff * 1.8 / h);
59
60                if (  active_content_height > sliderHeight  ) {
61                    op = 0;
62                }
63
64                $( '.owl-dots', $slider ).css( 'transform', 'translateY('+( - _tt  )+'px)' );
65
66                $( '.item--content, .owl-nav, .owl-dots', $slider ).css(  {
67                    'opacity': op,
68                } );
69
70            } else {
71
72                $slider.css( 'transform', 'translateY('+( 0 )+'px)' );
73                $( '.owl-dots', $slider )
74                $wrapper.height( 'auto' );
75                $( '.item--content, .owl-nav, .owl-dots', $slider ).css(  {
76                    'opacity' :   1 ,
77                }  );
78            }
79
80        }
81
82        $(window).scroll(function(){
83            parallax();
84        });
85
86        $(window).resize(function(){
87            parallax();
88        });
89
90    } );
91
92
93});