I liked the movie" means he had liked it since the time he felt it deserved the time,if an american says I like the movie instead, suggesting that he might not understand the movie, or slept in the cinema, or whatever the reason.
2) "liked" emphasized the Action of "like", which toook place in the past, not necessarily suggesting the State "I am not liking it now", it does suggest that if used together with some other reminders like stress, facial look, etc. If spoken in a way of normal delivery, it just means 我喜歡那個電影。