There are so many terms and definitions floating around in the subtitling and closed captioning industry. For clients or professionals new to the sector, the complexity can seem overwhelming but it’s not all as complicated as it sounds. This blog explores terminology about subtitles and closed captions, to help you understand just what the hell it is we’re all talking about!

About Subtitles and Closed Captions – Basic Terms

Subtitles – Onscreen text that displays on a video, which includes speech.

Open Subtitles – Open subtitles are burned onto a video. They cannot be turned on or off but rather display on a video as an image.

Closed/Teletext Subtitles – Closed subtitles for broadcast are sent as a stream of characters encoded in the broadcast feed. Closed subtitles are often provided in foreign languages. The display of closed subtitles can be turned on or off and if applicable, different languages can be selected.

Closed Captions – Closed captions are similar to subtitles but rather than being burned on, are accessible through a decoder. Television closed captions for broadcast have been typically encoded into Line-21 and actually broadcast separately to the video feed. 

Closed Captions for the Deaf and Hard of Hearing – Pretty much what it says on the tin! Closed captions of this nature include sound effects, indication of music, vocal sounds and speaker identification where required.

SDH – The American term for closed captions for the deaf. SDH stands for Subtitles for Deaf and Hard of Hearing.

Foreign subtitles – Subtitles which are in a different language to the source video.

Forced Subtitles – Forced subtitles display on portions of a video and cannot be turned off. They are typically used when the language changes in a video to which a viewer will need access. For instance, subtitles in Elvish during the Lord of the Rings movies.

Narrative Captions – Used frequently in documentaries, narrative captions are burned on and cannot be removed. They outline important information, names, dates or titles in a movie or programme.

Localisation – In-depth translation which take into account cultural or regional differences. In terms of subtitles, localisation can also relate to changing the encoding of a foreign subtitle file in order to display foreign characters correctly.

Closed Caption and Subtitle Timing Related Terms

Reading Speed – The rate at which text displays in relation to length of text divided by time. Reading speed can be calculated as words per minute or characters per second. It ensures there is sufficient time for viewers to read any given subtitle or closed caption.

Sync – The process of aligning time exactly with the appearance and disappearance of each caption.

Offset – Shifting the timing of a subtitle to be before or after its current position, (without changing the amount of time displayed) in order to achieve better sync.

Logging Rushes – Time coded transcription with notation of shot changes and other important information around filming which is then used for video editing, prior to creating subtitles or closed captions.

In/Show time – The time at which a caption appears onscreen.

Out/Hide time – The time at which a caption disappears off-screen.

Helper files – Automatic files created for a video which outline information on shot changes, audio stream and timings.

Closed Caption and Subtitle Formatting Terms

Alignment – The positioning of captions horizontally on a video, for instance, centre, left aligned or right aligned.

Placement – Caption position changes in order to aid ease of reading where there are forced subtitles, text, or a busy background. Placement can be top, bottom, central or specified exactly by the subtitle editor.

Subtitle background – A coloured box that displays behind subtitle or closed caption text in order to help ease of reading. This colour is typically black but can also display as a shadow.

Pop-on Subtitles – Traditional subtitles which appear and disappear off screen in a set position. 

Roll-up Subtitles – Subtitles that appear one line at a time, rolling down to the next. These typically display up to three lines at a time and are often used for online or live closed captioning.

Paint-on Subtitles – Paint-on subtitles appear in incremental stages from left to right as dialogue is spoken.

Aspect Ratio – The ratio size of the video display, which can differ in terms of the input as well as output video format and resolution.

Burning – A video editing process which includes converting a subtitle to an image format which is then permanently ‘burned’ to display on the video.

Encoding – The process of attaching subtitles or closed captions as text to a video file, broadcast or feed so that a viewer can turn them on or off. 

That’s our comprehensive guide to terminology about subtitles and closed captions. Do check back for more updates and useful terms and we’ll continue to ensure this information is up to date.