This standard includes support for many different caption implementations, including caption text as images, and the Teletext standard used in Europe. This text is encoded into line 21 using an oscillating frequency, which either the television itself or a decoder translates into on-screen text.įor modern HDTV signals, the ATSC standard for closed captioning is CEA-708. Without going into too much detail on how CRT televisions work, line 21 is part of these special lines, which contains the closed captioning text. There are segments outside of the visible picture called blanking lines, which control such things as vertical and horizontal refresh. Specifically, they are part of line 21 in a standard NTSC broadcast signal as defined by the FCC in 1976.Ī standard NTSC CRT television signal is separated into 525 lines by the television set. For over-the-air television broadcasts, closed captions are part of the broadcast transmission. In fact, the first use of captioning in the United States was "The French Chef" broadcast on PBS in 1972, which was open captioned.ĭepending on the type of media, the exact method of implementing closed captioning differs.
There are also open captions, which are embedded directly into the video itself, and are permanently displayed at all times.Ĭlosed captioning is typically used for over-the-air, digital, and online broadcasts, whereas open captioning is used for offline video and legacy media such as analog tape. The word "closed" in closed captioning indicates that captions are transmitted separately from the video, and can be toggled on or off by the viewer.
These indicators (known as descriptive text) help the deaf or hard-of-hearing person to understand the full context of the scene. This is the main difference between captioning and subtitles. Captioning conveys sound information, while subtitles assist with clarity of the language being spoken.įor example, in addition to the spoken dialog, captions will also include other sounds, such as birds singing, dog barking, and other ambient sounds, as well as sound events like a door being shut, glass breaking, etc. In the United States and Canada, closed captioning is a method of presenting sound information to a viewer who is deaf or hard-of-hearing. In this article, we will explore the details of what closed captioning actually is, how it works, and how it differs from subtitles. But what exactly is closed captioning? You might think of it as simply subtitles, but it's actually more than that.
New York, NY 10019 THIRTEEN.You've probably heard of closed captioning at some point, or seen the familiar "CC" icon on TV and web broadcasts. WNET Television Closed Captioning Contact Information:įor immediate response to your closed captioning concerns:įor written closed captioning complaints: § 79.1(d), including programming for which the audio is in a language other than English or Spanish and that is not scripted programming that can be captioned using the “electronic news room” technique interstitial material, promotional announcements, and public service announcements that are 10 minutes or less in duration and/or programming that consists primarily of non-vocal music. § 79.1(k)(1) or (iii) being subject to one or more of the captioning exemptions set forth in 47 C.F.R. § 79.1(j)(2) (ii) adopting and following the “Video Programmer Best Practices” set forth in 47 C.F.R.
Programming broadcast on WNET’s channels (WNET, WLIW and NJTV) complies with these regulations by either: (i) satisfying the caption quality standards set forth in 47 C.F.R. § 79.1, including regulations concerning closed captioning quality. All programming produced by WNET’s production subsidiaries and broadcast on our channels complies with the closed captioning requirements established by the Federal Communications Commission in 47 C.F.R.