Closed Captioning
and Subtitling


What is Closed Captioning?

Closed captions are a text version of the spoken words and the written descriptions of music, sound effects, and other audio cues of a television, movie, or digital presentation (SDH). Captions should assume that the viewer cannot hear the audio at all. Closed captions are typically located at the lower-third of the video or moved to make room for graphics. When you see white text on black bars, it is closed captioning.

Closed captioning was developed to aid hearing-impaired people, but it’s useful for a variety of situations. For example, captions can be read when audio can’t be heard, either because of a noisy environment, such as an airport, or because of an environment that must be kept quiet, such as a hospital.

The process of closed captioning involves transcribing the audio to text, dividing the text into chunks known as “caption frames,” and then synchronizing the caption frames with the video. Final step is the caption file output.

Under the regulations of the CRTC, 100% of broadcasted programs during the day, including advertising, and promotional content, must be captioned.

Onextra provides captioning services in English, French and Spanish.

What are Subtitles?

Subtitling is the translation of an original script into another language. This is done in order to provide greater accessibility to other language groups, and wider exposure for the media feature.

Unlike in closed captioning, sound effects and music are not included in this text, because it is assumed the viewer can hear but does not understand the original language spoken in the media. Same-language subtitling may often be provided to bring clarity to hard-to-hear situations.

Onextra provides subtitling services in English, French and Spanish.