What is most efficient way to filter a users's inventory?

Lets say I want to get a list of all the "Vinyl" a user has in their inventory. I can loop through user.inventory and check if Format == "Vinyl" but this uses the API for each one, and for most sellers they can have 1000's so that would take a long time. Is there an faster way to get this data? Like first being able filter for the format and/or genre? 

Thanks.