Sampling Movies/Spoken Word/news casts

What are the laws on this? I found tons of stuff on music but what about movies/spoken word/news stories? I know about Public Domain and all the movies/tv shows in there. If I wanted modern movies what would i have to do to Legally sample them?

New broadcasts require written permission to reproduce their works....

i remember reading from a music buisness book that with movies the studio that produced the movie owns the audio to the film, they need permission to use songs not created for the film, so your supposed to get/buy permission to sample them, i also remember reading off a website that somewere in actors contracts for films it says they own a part of what they say
basicly

its just like sampling music, u need permission off the person or band (that made the sound/speech) and then permission off the person who recorded it.
ive heard it costs way too much to legaly sample movies/actors lines thats why you dont hear it that much these days

hope this makes sense im very tired