Need help with a table relationships and over-all design
The question to ask yourself is simple: Can a single Transcode record be associated with more than one Movie or Episode?

If Yes, you need a linking table that links Movies and Transcodes and one that links Episodes and Transcodes to create a Many-To-Many relationship. 

If No, you simply add transcode_id and a foreign key to the Movies and Episodes tables.

You need to apply that same logic to some of your other tables/relationships. For example, can a Movie really only be associated with a single user as per the current design? What is that relationship - the user who uploaded it, a user who watched it, a user who recommended it?

A few others:


Shouldn't poster_id on Episodes actually be on Seasons? A season may have a different poster, but surely not an individual episode?
Can users have multiple roles? If so, you need a linking table.
Can Movies or Shows have multiple Genres (Action &amp; Thriller, Drama &amp; Comedy for example)? Again, if so, linking table.


Check out this Wikipedia page which covers off some basics on database/ERD design. You need to identify the various entities within your data model (a Movie, for example, is an entity, as is a user) then define the relationship between each entity (Entity A can have only one Entity B associated, and Entity C can have many associated Entity D records etc) and that will help you determine and design your ERD.