How to Close Caption Your Event

Incorporating captioning in your livestream and video on demand

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Adding closed captioning will make your stream accessible to a larger audience, including hearing-impaired viewers and those who are still learning the language.

If you are broadcasting your stream on Stellar through an encoder, we support CEA-708 and EIA-608 captions.

If you are offering a video on demand or using our scheduling tool to run pre-recorded content, we do not support CEA-708/EIA-608 captioning, nor do we currently support transmitting an alternate RMTP feed.

How to Use Live CEA-708/EIA-608 Captions

If you want to offer captions to your customers, caption files will need to be transmitted to Stellar through your encoder in either CEA-708 or EIA-608 format. You are responsible for all content in your broadcast, including closed captioning any part of your broadcast.

Captions are transmitted through RTMP, which is the standard format for internet broadcast encoders, including OBS.

Here are three ways you can add closed captioning with OBS:

  1. Cloud Closed Captioning: This is an open-source add-on that you can install on your computer. It will integrate with OBS and send captions to your stream when it's enabled. You can find the plug-in and learn more about it in the OBS Resources forum.
  2. Open Captions: You can also add captions using a secondary website called This website transcribes the audio it captures from your microphone in OBS and converts it to text. To add the captions to your stream, share the webcaptioner page to your screen, and use the blending options in OBS and Webcaptioner to show the text on OBS. The con to this method is that the text will always show on top of the video if you have screen share enabled and the viewer won't be able to turn off captions.
  3. Use a Live Captioner: You can have someone write captions as the event is happening. To add their captions to your stream, integrate the captioner’s video as an overlay to the video you're broadcasting in OBS.

Using Captions for a Scheduled Livestream

If you are using our scheduling tool, captions will need to be embedded into the video file and they will need to be always on. We do not currently allow separate video files to be transmitted simultaneously when scheduled through the Stream Studio. Another option would be to link to a third party live captioning website that can run the text in a separate window or app. This external captioning source can be linked to from a widget on your stream page.

Captioning a VOD

If you are doing a video on demand, again, captions would need to embedded in the file so they are always on. There's not currently an option to toggle captions off if you are not interested in captioning. This generally means you need to provide two different versions of the content for your video on demand. You could then sell separate tickets to the captioned and uncaptioned video feeds, or offer multiple versions from which the viewers can choose.

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