CEA-608/708 Closed Captions - Your content accessible for everyone

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CEA-608/708 closed caption“Wait… What did he just say?” This is a well-known problem for many of the 100 million people who watch online video every day or for alone the 1.5 billion English learners worldwide. More than that, 5% of the world population is hearing-impaired and does not even get the chance to enjoy online video to its full extent. In this article, we will show you how we can help make your content more accessible for everyone using subtitles and CEA-608/708 captions so that your audience can get the most of their online video experience.

What are closed captions (CC)?

Closed captions are the text version of a TV, movie or video game. Not only do they include the spoken text parts (that is what subtitles do), but also sound cues that tell the user what is happening. This is of course beneficial for hearing-impaired people or also in a noisy environment. Closed captions can be turned on and off easily by users everywhere, whereas open captions cannot be disabled.

Why should you use Closed Captions?

  • Increased usability and accessibility and hence greater audience
  • Improved viewer experience by providing clarity of the content
  • Education and literacy benefits, especially for government and education institutions
  • Better user engagement (captions increase the video completion rate up to 80%)
  • Increased brand awareness and recognition since your brand name will be displayed in written
  • Compliance with legal standards to ensure accessibility of videos to people with disabilities (e. g. the US The 21st Century Communications and Video Accessibility Act of 2010)


CEA-608/708 closed captions

CEA-608 and CEA-708 are both standards used for closed captions in broadcasting television, but are widely used for online video and video games as well. CEA-608 is also known as Line 21 caption and is the standard for analog TV. CEA-708 captions are the new standard for digital television.

In 2009, the US DTV Delay Act introduced the transition from analog to digital television, which caused most captions to switch from CEA-608 to CEA-708. Nonetheless, TVs do still support 608 to organize the cutoff somewhat smoother.

Comparing CEA-608 and CEA-708

  CEA-608 (Line 21) CEA-708
Standard Analog TV Digital TV (DTV)
Appearance Black-box background, white text Customization:

8 font sizes, 3 text sizes, 64 text colors, 64 background colors and opacity

Positioning Very limited positioning options Variety of options for positioning and anchoring
Languages English, Spanish, French, Portuguese, Italian, German, Dutch

2 languages at a time

Supports every language using special characters and symbols

Multilingual captions

Transmission Information is encoded in Line 21 of the analog TV signal Placed into MPEG-2 streams within the picture user data of DTV (DTVCC transport stream)
Decoder Needed (separate or built-in)  Needed (separate or built-in)
Compatibility Can be processed by CEA-708 Carry 2 data types: “608 over 708” and “native 708”


Closed captions and subtitles with THEOplayer

Most of the available video players support closed captions and subtitles in WebVTT which is the format for subtitles which was developed for video on the web. THEOplayer offers you another alternative for closed captions by extracting CEA-608/708 CC from h.264 packages. When CEA captions are present in in the stream, THEOplayer will automatically detect them without any additional configuration and will show them to your audience.

As CEA-708 is the current standard for DTV content, publishing your content on the web can be made a lot easier. You can simply transfer your content and use the same closed captions on the web that you are using for TV.


 Closed captions with THEOplayer

 Closed captions with THEOplayer: The viewer can easily turn captions and subtitles on and off or change the language while watching.


closed captions / CEA-608 / CEA-708 / subtitles