There are four methods to adapt a video into foreign languages:
1. U.N. Style Interpretation
U.N. Style Interpretation is similar to what you see on the news with world leaders. On-camera the interpreter’s voice is heard “over” the original dialog. This method is less costly than dialog replacement, and is often better than lip-synched audio when the person on-camera is well known to the target audience.
Subtitles are by far the least expensive option, and are the same as what you might expect when watching a foreign movie with subtitles.
With Semi-Sync the entire audio track is replaced with the foreign language. After the script is translated, the language is then “timed” against the original video and edited to fit the time of the English speakers (usually a much shorter period of time than most languages). The effect is a “semi-sync,” where people begin and end speaking in sync, but the lip movements may not match exactly. This method is usually the best mix of quality vs. cost across a broad spectrum of corporate and industrial needs.
4. Complete Lip Sync
A Complete Lip Sync is just like in the best foreign movies, and just about as expensive. A great deal of work has to be done both with translation and the editing to pull this effect off as well as we did in this clip.