Function: Displays header video URL.

Function: Retrieves header video settings.

Function: Checks whether a custom header is set or not.

Function: Checks whether the custom header video is eligible to show on the current page.

Function: Retrieves the markup for a custom header.

Function: Prints the markup for a custom header.

Function: Retrieves background image for custom background.

Function: Gets random header image URL from registered images in theme.

Function: Checks if random header image is in use.

Function: Displays header image URL.