Watching movies that contradict the teachings of Islam and contain pornographic pictures is impermissible, because the Prophet (peace and blessings be upon him) said, “The eyes commit adultery, the tongue commits adultery, the hands commit adultery, the feet commit adultery and then the private parts confirm it or deny it.” (Musnad Ahmad Ibn Hanbal)
Moreover, assisting in promoting and spreading it is also haram. Almighty Allah says in the Qur’an: [Those who love (to see) scandal published broadcast among the Believers, will have a grievous Penalty in this life and in the Hereafter: Allah knows, and ye know not.](An-Nur 24:19)
Through subtitling the person is both watching and assisting in its promotion, so we advise you to avoid such work. You should be aware that if a person leaves something for the sake of Almighty Allah, He recompenses him with something that is even better than what he left. Almighty Allah says […and whosoever keeps his duty to Allah, Allah will appoint a way out for him, And give him sustenance from whence he thinks not; and whoever trusts in Allah, He is sufficient for him; surely Allah attains His purpose; Allah indeed has appointed a measure for everything.] (At-Talaq 65:2-3)
In his explanation on this issue, Sheikh Ahmad Kutty, an Islamic scholar stated:
You are best advised to stay away from such jobs because by doing them you are inadvertently contributing to spreading corruption in the land, especially if these movies are obscene or have themes that spread vice in society.
Moreover, you should ask Almighty Allah to give you halal sources of income; surely, if you turn to Him sincerely and strive to find one, He will certainly help you.