Holy cannoli, did John Noble play Denethor as a complete and utter fool in The Lord of the Rings movies. Indulge me a brief recap. Denethor was openly abusive to Faramir and favored Boromir. His military strategies were, to say the least, delusional (retaking Osgiliath?). He called for his troops to abandon their posts and "Flee! Flee for your lives!" until Gandalf whacks him a good one upside the conk and takes over as commanding general for Gondor. There's of course the part where Denethor enjoys a nice meal as Faramir and Gondor's troops ride to their certain deaths, and when Faramir returns to Minas Tirith, gravely injured, Denethor decides that the most appropriate course of action at that time is, naturally, to burn himself and Faramir alive.
But. . . I honestly don't remember Denethor being so brutal and uncaring in the books. Was Denethor villified for the films and, if so, why? Was he really so cold and uncaring to Faramir while favoring Boromir so openly in the books?
How drastically did Lord Denethor's characterization change between LOTR canon and the movies?