Film subtitle translation is different from common literal translation, this chapter will introduce the traditional theories of translation and summarize the special features of film language.
2.1 Traditional theories on translation criteria
Throughout the history of Chinese traditional translation, like the principle of xin, da, ya by Yanfu or the common saying that it is better to be faithful than to be elegant by Luxun, they both follow the rules of faith. The fidelity rule demands translator use direct translation as far as possible. The merit of this rule is the reservation of original edition. So, the direct translation is a preferred manner for traditional translation.
2.2 Special features of film subtitle translation
To explore the principle of new buzzword applied in foreign films, it is the first thing to comprehend the characteristics of film language. Film language is different from the written language. It has the features of colloquiality, instantaneity and spatiality, so the movie translation is different from the translation of other literary works.
(1) Colloquiality
Film is aimed at various audiences who rank from different layers. Besides any special films, it would be better to use the common language, which means the spoken language in films. Based on this special feature, translator must consider the style of language and choose the most familiar words in audience’s native language in  the film translation. 影视作品翻译中流行语的应用兼谈大众对“神翻译”的接受(3):http://www.youerw.com/yingyu/lunwen_12701.html