Captioning differs from subtitling in many respects. For starters, captioning is targeted at the hearing impaired, therefore not only you need to transcribe the dialog, but it is necessary to include character names and descriptive text as well so the viewer is able to understand who's talking at a particular moment or when music is playing. Another difference involves fonts: While in subtitling we have full control over which font is used on screen and big it is, in captioning fonts are usually fixed width fonts (like Courier), setup in the TV decoder.
Captioning can be divided into the following categories:
This is the most common method of captioning. The captions are encoded into the video signal and are not visible on screen until you turn captioning ON on your TV set. This is how captioning is included in TV broadcasts, home videos and some DVDs.
As the word entails, open captions are not encoded into the video signals and are instead burned into the video (like subtitles for video), being visible all the time. Open captions are mostly used behind the scenes to review check videos, however there are some end-user applications, for example when doing a captioning project where a decoder is not available and the audience needs to read captions.
Subtitles for the Hearing Impaired (SDH)
This is the method of choice for closed captioning on DVD/Blu-Ray. This allows more control over the look of the caption text and the captions are turned on via the DVD menu, like standard subtitles. The difference between standard DVD subtitling and SDH is the addition of descriptive text to better describe the story/movie to the hearing impaired viewer.
Internet distribution of movies is a reality and we're are providing captioning services to a variety of distribution partners on all current and future standards including Flash Video, HTML 5, Window Media Video and QuickTime.