The most simple subtitle playout system consists of one video channel using a single language with the subtitles burned in. This can be achieved by adding the subtitles to the video prior to transmission. The resulting subtitled copy is then used for transmission, i.e sending out the video program.
The above solution is one very simple method of putting subtitles to air. However, it's simplicity may produce several problems.
What if a subtitle needs to be corrected? Editing a subtitle becomes a major problem and an error in a subtitle becomes difficult to correct. This method also increases the number of copies that a broadcaster needs to keep of one program. Another inherent problem in producing subtitles this way is that it uses expensive resources and manpower and that the subtitles must be ready before recording the program to the server.
Continue and read about subtitle archive and management