No right to The Silmarillion.

Film Some thought The Hobbit's opening chunk too long, whereas I could have watched many more hours of that sort of thing. The problem is, as The Smithsonian points out, Peter Jackson only has the rights to The Hobbit and The Lord of the Rings so can't draw on the extratextual material in The Silmarillion or any of the other supplementary texts.

"At one point, Jackson edges dangerously close to the fine line of intellectual rights. “The Quest of Erebor,” a story contained in Unfinished Tales, retells the opening chapter of The Hobbit from Gandalf’s point of view. In it, Gandalf justifies his uncanny attraction to Bilbo, a hobbit with “a love of tales” and “eagerness in his bright eyes.” In the film, Gandalf chidingly asks when Bilbo became more interested in china and doilies than in adventure, mirroring those lines from Unfinished Tales. “I wonder if the Tolkien estate will sue over it,” Drout said. “They are litigious.”

The piece then goes on to flesh out some of Jackson's fudging. Given the uplift in sales, you would think the Tolkien estate would just have made all of the material available to Jackson to play about in. Perhaps this is why the original, orginal plan for two Hobbit films then another throwing together piece of Tolkein lore to bridge the gap between the two book adaptations didn't ever come to fruition.