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

Clevercast Translate@Home supports adding multilingual closed captions for a live stream through real-time transcription. This transcription can be automatically translated by Clevercast into closed captions in multiple languages.

Alternatively, you can use automatic speech-to-text conversion with manual correction. See our Closed Caption Event Management manual for more info.


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 three seconds without typing. You can go back and correct typos without viewers seeing them first.
  • When you press enter, all remaining input is immediately sent.
  • When over 80 characters are typed without a three second pause and without enter being pressed, the characters are sent the next time the spacebar is hit (so the captions can appear in a timely manner)

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


Adding automatic translations for transcribed languages

To make closed captions available in multiple languages, you can have people type the transcriptions in different languages. But you can also let Clevercast automatically translate a single transcription into different languages. In that case, you only need to set the languages to which a transcription should be translated.

Alternatively, you can use automatic speech-to-text conversion with translation into other languages. In that case, you can’t use manual transcription.


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 or 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.