Adding multilingual closed captions to a live stream by transcription in real-time

Clevercast Translate@Home now supports adding multilingual closed captions for a live stream through transcription in real-time.


Generating the closed captions in real-time

You can add closed captions for any number of languages, simply by letting your interpreters type the transcription. They only need a browser with WebRTC capabilities to watch and transcribe the incoming broadcast, through the language room interface provided by Clevercast.

T@H Language Room for transcription (adding closed captions to a live stream)

To begin transcribing, an interpreter just starts typing in the Transcription edit box (next to the keyboard icon). Text is automatically added to the closed captions while she is typing, in the following ways: 

  • Characters are sent automatically after a three second delay, so typos can be corrected without viewers seeing them.
  • A completed word is sent when you hit the spacebar.
  • A full sentence is sent when you press enter. 

For more info about how to transcribe, see our real time transcription manual for interpreters.

For more info about setting up and managing the live event in Clevercast, see §6b of our multilingual manual.


Watching the live stream with closed captions

Clevercast player lets your viewers select the closed captions for their preferred language and change the selection at any time. You can embed Clevercast player on your site on a third-party platform.

Selecting the preferred closed caption language in the public player

The live stream is streamed globally (using the Akamai CDN) using the standard HTTP Live Streaming (HLS) protocol, which means it will have a latency of about 18 seconds. It’s a regular live stream, so all other Clevercast and Clevercast Player features apply (see our FAQ for more info).


Server-side recording

Clevercast automatically records the closed captions, which are the result of transcription, as WebVTT files. The .vtt files for each transcribed language can be downloaded along with the MP4 file.

If your plan includes support for Video on-Demand hosting, you can convert a recording to a VoD video with closed captions. The player for this VoD item can be embedded on your site or a 3rd party platform. Viewers are able to select the closed captions in the embedded player, in the same way as for the live stream.

Please note that real-time transcription is currently a beta feature in Clevercast. During a first phase we will only offer it to a limited number of customers. So let us know as soon as possible if you want to try it.