Closed captioning (CC) and subtitling are both a means of illustrating text on a TV, video screen, or other pictorial display to give extra or interpretive information.
They are commonly employed as a transcription of the audio part of a program as it happens (either verbal or in edited form), occasionally including descriptions of writing elements.
Other uses of closed captioning and subtitling include providing a textual substitute language interpretation of a presentation’s central audio language. This is often burned-in or open to the video and is also unselectable.
Closed captions were developed for the hearing impaired as well as those that find it challenging to hear to assist them in comprehension.
They can be employed as a tool by individuals learning to read, learning to speak a foreign language, or in an atmosphere where the audio is impossible to listen.
Closed captioning can also be utilized by viewers who want to read a transcript alongside the program audio.
The uses of closed captioning in other media
DVDs and Blu-ray Discs
NTSC DVDs might transmit closed captions in data packets of the MPEG-2 video streams within the Video-TS folder. As soon as it plays out of the analogue outputs of a set-top DVD player, the caption data is transformed into the Line 21 format.
The player releases them to the composite video or any available RF connector for a corresponding TV’s in-built decoder or a set-top decoder. They can’t be released on S-Video or component video outputs because of the lack of a colour burst signal on line 21.
Supposing the DVD player is infused instead of the progressive mode, closed captioning will be shown on the TV over component video input if the TV captioning is switched on and assign to CC1.
Additionally, video DVDs could also send subtitles, which are commonly made from the EIA-608 captions as a pixmap overlay that can be initiated through a set-top DVD player or DVD player software such as the textual captions.
This kind of captioning is typically transmitted in a subtitle track labelled either “English for the hearing impaired” or, more lately, “SDH” (subtitled for the deaf and Hard of hearing).
On some DVDs, the Line 21 captions might include a similar text as the subtitles. At the same time, on other DVDs, just the Line 21 captions have the extra non-speech information (even occasional song lyrics) required for deaf and hard of hearing watchers.
European Region 2 DVDs do not hold up Line 21 captions, but rather list the available subtitle languages.
English is usually listed twice, one as an indication of the conversation alone, and a second subtitle set that carries more information for the deaf and hard of hearing audience.
Blu-ray media can’t transmit any VBI data that include Line 21 closed captioning because of the layout of DVI-based High-Definition Multimedia Interface (HDMI) specifications.
This is only useful for synchronised digital audio renewing older analogue standards like S-Video, VGA, component video, and SCART.
Both DVD and Blu-ray can make use of either PNG bitmap subtitles or advance subtitles to transmit SDH kind of subtitling.
Advance subtitling is an XML-based written format that incorporates styling, font & positioning information, and a Unicode representation of the text. It also includes more media accessibility aspects like illustrative audio.
Movies
There are various contending technologies employed to provide captioning for movies in theatres. Cinema captioning falls into the option of open and closed captioning.
The description of closed captioning, in this case, is different from TV, as it relates to any technology that enables as little as a single member of the audience to view the captions.
Sports venues
Captioning systems have been accepted by the most top league and reputable college stadiums as well as arenas. This is used generally via reliable fractions of their main scoreboards or as a component of balcony fascia LED boards.
These screens show captions of the public address commentator and other verbal content that include those incorporated within in-game sections, available service notifications, and lyrics of songs played in the stadium.
In a few facilities, these systems were included due to discrimination claims, following a lawsuit under the Americans with Disabilities Act, FedExField incorporated caption screens in 2006. Some stadiums use on-scene captioners while others deploy them to external providers who caption remotely.
Video games
The unusual appearance of closed captioning in video games became an issue in the 1990s as games started to feature voice tracks, which in some cases constitutes information that the player requires to understand how to advance in the game. Closed captioning of video games is evolving and is more common.
Among the first video game companies to use closed captioning was Bethesda Softworks in their 1990 release of The Terminator 2029 and Hockey League Simulator.
A lot of games ever since have at least provided subtitles for unwritten dialogue during cutscenes, and many involve significant in-game conversation and sound effects in the captions as well.
Video games do not offer Line 21 captioning, which is decrypted and shown by the television but instead shows an in-built subtitle display, more like that of a DVD.
The game systems have no part in the captioning either, however, each game must have its subtitle scene programmed separately.
Online video streaming
Internet video streaming service, such as YouTube, offers captioning aids in videos. The producer of the video can upload a SubRip (*.SRT), SubViewer (*.SUB), or *.SBV file.
The site also includes the means to automatically transcribe and create captioning on videos, with different levels of success depending on the content of the video.
The automatic captioning is usually inaccurate on videos with background music or excessive emotion in verbalizing.
Differences in volume can also cause ridiculous machine-generated captions. More problems are noticed with sarcasm, rigid accents, differing contexts, or homonyms.
Theatre
Real-time plays can be open captioned by a captioner who illustrates lines from the script and include non-speech elements on an enormous display screen close to the stage.
Presently, the software is available that automatically creates the captioning and streams the captioning to the audience in the theatre.
This captioning is viewed utilizing heads-up glasses, smartphones, or computer tablets.
Telephones
A captioned telephone is one that shows real-time captions of the current dialogue. The captions are commonly displayed on a screen incorporated into the telephone basis.
Conversations
Software programs are available that automatically produce a closed-captioning of speeches. Examples of such dialogues include conversations in conference halls, classroom lectures, and religious services.
Large chains of errors could be the result of treating online videos via digital processing of their audio content by several automated algorithms. When a video is accurately transcribed, then the closed-captioning publication serves a practical purpose.
This makes its content accessible for search engines to index and also makes it available to users on the internet. Some TV sets can be automatically assigned to turn on the caption when the volume is muted.
