I recently viewed "Voces de Mixquic," a documentary about Dia de los Muertos traditions in a small town on the outskirts of Mexico City. I HIGHLY recommend this film. It is by far the most informative film I have seen about Dia de los Muertos. You truly feel like you are welcoming home departed loved ones with the families that are filmed.
"Voces de Mixquic" is available on Amazon, and is free to view with Amazon Prime. It is well worth the rental price, too.
Find the film here: Voces de Mixquic