Include closed captions in a live stream or transcoder in Wowza Video

The Wowza Video™ service can receive closed caption data from a video source so that captions appear when the stream is played. Closed captions make your streams accessible to hearing-impaired viewers and allow your streams to comply with the United States FCC 21st Century Communication and Video Accessibility Act (CVAA) of 2010.

To learn about other live stream or transcoder settings you might see in the user interface, see Live Stream Setup page in Wowza Video or Transcoder Setup page in Wowza Video.

You'll need to choose which workflow you'll use, live stream or transcoder, before you begin this task. See Decide between a live stream or transcoder workflow for more information about these workflows.

About closed captions


Just as there are a number of protocols and formats for receiving and playing live adaptive bitrate streams, there are multiple types of closed-caption formats that can be used when streaming live events. Wowza Video can receive two closed-caption formats from a video source: CEA-608 (digital) and onTextData.

  • CEA-608 supports playback over HLS on Apple iOS devices, VideoLAN VLC player, and many set-top boxes.
     
  • onTextData supports playback over HDS and RTMP, including JW Player and Flowplayer.

Some video sources can send either CEA-608 or onTextData captions to a transcoder. Other sources can send both. Whatever format or formats Wowza Video receives, it decodes and translates incoming caption events so that captions appear when the stream is viewed over all three playback protocols—HDS, HLS, and RTMP.

Notes:
  • Wowza Video supports only the digital CEA-608 portion of the CEA-708 standard.
     
  • The Original HTML5 player and Wowza Video Player support CEA-608 captions for playback in HLS streams.
     
  • The Wowza Player doesn't support closed captions.
  • onTextData and CEA-608 captions are included in Wowza Video recordings, if you create them.

Live stream workflow

In the live stream workflow, we'll automatically configure the transcoder, output renditions, and stream targets to get you started quickly. This is the preferred workflow for most of our customers. 

To display closed captions on a live stream, choose the type of closed caption that the video source is sending to Wowza Video.

  1. Click Add Live Stream.
     
  2. On the Live Stream Setup page, enter a Live Stream Name, choose a Broadcast Location, and then click Next.
     
  3. On the Video Source and Transcoder Settings page, specify your Camera/Encoder and the Aspect Ratio of your source video. If your subscription allows, choose a Live Stream Type and Billing Mode.
     
  4. For the closed caption option, choose one of the following:

  • CEA-608-digital - Captions that can be played on devices and browsers that support HLS, including the Original HTML5 player in Wowza Video.
  • onTextData - Captions that can be played on devices and browsers that support Adobe HDS or RTMP.
  • CEA-608-digital and onTextData  - Captions that can be played on devices and browsers that support HDS, HLS, and RTMP.
  1. Specify all of the other settings for your live stream, review your choices, and click Finish to create the live stream.
     

Transcoder workflow

In the transcoder workflow, you'll manually configure the transcoder, output renditions, and stream targets to fit your specific streaming solution.

To display closed captions on a custom transcoder, choose the type of closed caption that the video source is sending to Wowza Video.

  1. Under Advanced on the left navigation bar, click Transcoders, and then click Add Transcoder.
  2. On the Transcoder Setup page, enter a Transcoder Name and Broadcast Location. If your subscription allows, choose a Transcoder Type and Billing Mode.
     
  3. For Closed Captions, choose one of the following:

  • CEA-608-digital - Captions that can be played on devices and browsers that support HLS, including the Original HTML5 player in Wowza Video.
  • onTextData - Captions that can be played on devices and browsers that support HDS or RTMP.
  • CEA-608-digital and onTextData  - Captions that can be placed on devices and browsers that support HDS, HLS, and RTMP.
  1. Specify the other settings for your transcoder setup, review your choices, and click Add to create the transcoder.

Wowza Video creates the transcoder and displays the Outputs & Targets tab of the transcoder detail page.

The transcoder isn't finished until you create outputs and targets for it. For more information how to finish creating the transcoder, see Create a custom transcoder with many outputs and targets in Wowza Video.