“Wait… What did he just say?”
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.
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.
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” |
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: The viewer can easily turn captions and subtitles on and off or change the language while watching. To know more visit our demo zone page or simply contact us.