Editing Closed captioning (section)

=== Incompatibility issues with digital TV ===
Many viewers find that when they acquire a [[digital television]] or [[set-top box]] they are unable to view closed caption (CC) information, even though the broadcaster is sending it and the [[Television|TV]] is able to display it.

Originally, CC information was included in the picture ("line 21") via a [[Composite video|composite video input]], but there is no equivalent capability in digital video interconnects (such as [[Digital Visual Interface|DVI]] and [[HDMI]]) between the display and a "source". A "source", in this case, can be a [[DVD player]] or a [[Terrestrial television|terrestrial]] or cable digital television receiver. When CC information is encoded in the [[MPEG-2]] data stream, only the device that decodes the [[MPEG-2|MPEG-2 data]] (a source) has access to the ''closed caption'' information; there is no standard for transmitting the CC information to a display monitor separately. Thus, if there is CC information, the source device needs to overlay the CC information on the picture prior to transmitting to the display over the interconnect's video output.

The responsibility of decoding the CC information and overlaying onto the visible video image has been taken away from the TV display and put into the "source" of DVI and HDMI digital video interconnects. Because the TV handles "mute" and, when using [[Digital Visual Interface|DVI]] and [[HDMI]], a different device handles turning on and off CC, this means the "captions come on automatically when the [[Television|TV]] is muted" feature no longer works. That source device—such as a [[DVD player]] or [[set-top box]]—must "burn" the image of the CC text into the picture data carried by the [[HDMI]] or [[Digital Visual Interface|DVI]] cable; there's no other way for the CC text to be carried over the [[HDMI]] or [[Digital Visual Interface|DVI]] cable.<ref>
{{cite web |url=https://denon.custhelp.com/app/answers/detail/a_id/299/~/hdmi-support-for-closed-captioning |title=HDMI Support for 'Closed Captioning' |archive-url=https://web.archive.org/web/20210213061121/https://denon.custhelp.com/app/answers/detail/a_id/299/~/hdmi-support-for-closed-captioning |archive-date=2021-02-13 |url-status=dead}}
</ref><ref>
{{cite web |url=https://video.stackexchange.com/questions/14977/what-types-of-cables-support-closed-captioning |title=What types of cables support closed captioning?}}
</ref><ref>
{{cite web |author=Steve Barber
|url=https://www.nchearingloss.org/article_digcap.htm |title=Understanding Digital Captions |archive-url=https://web.archive.org/web/20240226160247/https://www.nchearingloss.org/article_digcap.htm |archive-date=2024-02-26 |url-status=dead}}
</ref><ref>
{{cite web |author=Neil Bauman
|url=https://hearinglosshelp.com/blog/getting-captions-on-your-new-tv-the-good-the-bad-and-the-downright-frustrating/ |title=Getting Captions On Your New TV—The Good, the Bad and the Downright Frustrating}}
</ref><ref>
{{cite web |author=Stuart Sweet
|url=https://blog.solidsignal.com/tutorials/can-get-closed-captioning-hdmi-directv/ |title=Can you get closed captioning over HDMI with DIRECTV?|date=31 May 2022 }}
</ref><ref>
{{cite web |url=https://creativecow.net/forums/thread/closed-captions-support-in-hdlink/ |title=closed captions support in HDLink}}
</ref>

Many source devices do not have the ability to overlay CC information, for controlling the CC overlay can be complicated. For example, the [[Motorola]] DCT-5xxx and -6xxx cable set-top receivers have the ability to decode CC information located on the [[MPEG-2]] stream and overlay it on the picture, but turning CC on and off requires turning off the unit and going into a special setup menu (it is not on the standard configuration menu and it cannot be controlled using the remote). Historically, [[DVD player]]s, [[Videocassette recorder|VCRs]] and set-top tuners did not need to do this overlaying, since they simply passed this information on to the TV, and they are not mandated to perform this overlaying.

Many modern digital television receivers can be directly connected to cables, but often cannot receive scrambled channels that the user is paying for. Thus, the lack of a standard way of sending CC information between components, along with the lack of a mandate to add this information to a picture, results in CC being unavailable to many hard-of-hearing and deaf users.

The [[EBU]] [[Ceefax]]-based teletext systems are the source for closed captioning signals, thus when teletext is embedded into [[DVB-T]] or [[DVB-S]] the closed captioning signal is included.<ref>{{Cite web|url=https://www.etsi.org/deliver/etsi_en/300700_300799/300743/01.03.01_60/en_300743v010301p.pdf|title=ETSI EN 300 743: Digital Video Broadcasting (DVB); Subtitling systems}}</ref> However, for DVB-T and DVB-S, it is not necessary for a teletext page signal to also be present ([[ITV1]], for example, does not carry analogue teletext signals on [[Sky UK|Sky Digital]], but does carry the embedded version, accessible from the "Services" menu of the receiver, or more recently by turning them off/on from a mini menu accessible from the "help" button).

The [[BBC|BBC's]] Subtitle (Captioning) Editorial Guidelines were born out of the capabilities of [[Teletext]] but are now used by multiple European broadcasters as the editorial and design best practice guide <ref>{{Cite web|url=https://bbc.github.io/subtitle-guidelines/|title=BBC Subtitle Guidelines|website=bbc.github.io|access-date=2019-07-19|archive-date=2019-10-20|archive-url=https://web.archive.org/web/20191020222240/http://bbc.github.io/subtitle-guidelines/|url-status=dead}}</ref>