I like to have the possibility to use the parallax effect in my custom theme. For posts or pages I have a custom shortcode where I can pass the link to the image to use and the text content for it, but I'm unable to find a way to manage this if I want to make use of the parallax for a page like the index or if I want to assign to a custom post type. Is there a good solution to let the user choice what Image to use and on what page? Thanks