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Getting started with real-time human subtitling in live streams

Besides generating live closed captions through AI, Clevercast also supports (multilingual) real-time human subtitling by humans. This can be combined with automatic AI translations to additional closed caption and/or speech translation languages.

Clevercast supports different input methods for humans to create closed captions in real-time (contact us for more info). Like AI generated closed captions, human subtitles can also be corrected (in real-time) before they are used.

You can source real-time subtitlers and/or correctors through us or hire them yourself. In the latter case, make sure to provide them with our subtitling manual and/or correction manual. Please note that real-time subtitling adds 30-40 seconds of delay to the live stream delivery, and correction an additional 20 seconds.

This tutorial applies to enterprise and webinar plans. Skip step 1 for webinars, since an event is automatically created when you create a webinar.

1 Creating an event

Select the Live > Events menu. On the events page, press the Create Multilingual Event button in the sidebar. In the popup dialog, enter the following info and press Create:

  • an event name (for your own information only)
  • select one of the broadcast protocols that support closed captions.
  • select the origin of your broadcast
  • select the Default Language. This is the language being spoken in the live stream, which will in most cases also be the first closed caption language. If the floor audio contains multiple languages, you can select 'Original' instead of a real language.
  • Optionally, select the Streaming Resolutions. Clevercast does cloud transcoding for adaptive bitrate streaming. Make sure the highest resolution doesn’t exceed the resolution in which you are broadcasting.

2 Configuring the event

When you press the Create button, Clevercast creates the event and redirects you to its detail page. Among other things, the event page allows you to do the following:

  • Copy the event’s embed code from the Management tab to your website or 3rd party platform.
  • On the Appearance tab, you can upload a poster image and show a countdown timer in the embedded player (among others)

To add closed captions to the event, go to the Caption Languages tab. Press the Add subtitling language button to create the languages for human captioning. If included in your plan, you can also add AI translations or spoken versions of the caption language(s) (on the Audio Languages tab).

3 Test broadcast

Configure your encoder by using the settings on the Broadcast tab and our broadcast guidelines.

When you are ready to test, go to the Management tab and set the event status to Preview by pressing the Set to preview button. This is required for your broadcast to be processed, and for human captioners and correctors to connect to their rooms.

Start your broadcast. After a number of seconds, the captioners are able to start subtitling in their rooms.

You can use the Real-time Management page to communicate with them through text chat. Unfortunately, it is not yet possible to see the captions in the real-time player on this page. You can use the Preview player on the Management tab to see the captions (with a delay of 18-60 seconds, depending on your event settings).

4 Starting the live stream

When the event is about to start, go the Management tab and press the Start event button. We recommend to start the event at least three minutes before the live action begins. This allows the player to start buffering and ensures that nobody misses the start.

When you start the event, Clevercast also starts recording the live stream. So, starting the event in time also ensures that the cloud recording is complete.

The embedded player automatically detects the status change and makes the live stream visible to your participants. You can also see the live stream in the Public Player on the Management tab. If you want to display a message in the embedded player, use the Service Message on the Management tab.

5 Stopping the live stream

After the live action has ended, wait at least 3 minutes before setting the event status to Ended, by pressing the Change Event Status button and selecting End event. The embedded player automatically detects this and shows a poster image or message to your viewers (see the Appearance tab) instead of the live stream.

Clevercast automatically completes the cloud recording and converts it to an MP4 file. You can download it via the Events > Recording menu. If your plan includes VoD, you can publish the recording to Video on-Demand.