Hi @harry.down, welcome to the IF community.
Are you pulling in videos/images through a data feed? Or is it a predetermined number of records in Excel?
To help get around some of these different media challenges, I use binding converters within the collection item. This will allow you to show the right media depending on the scenario.
For example, the most common one I use is a custom converter to determine if a cell ‘is blank’ (see this post for custom converters: Custom Script Converter: What can you do with it?). I would set the visibility property of the image asset that is bound to the image cell in excel or data feed. If the cell is blank, the image asset automatically hides. You can then use other converters to make content items, such as video to ‘show’ when this happens. In this way, you can have a full set of images and video, but only the content that’s available will show across your collection.
You can also solve other similar scenarios by setting a trigger…with maybe a button, or when an item is ‘in-focus’, and use the IF-THEN conditions within the trigger. For example, when an item comes into focus AND the cell value = X, then do Y.
Though I don’t know your exact application, I hope this sparks some ideas for you.