Getting Started with Translate@Home

Creating a multilingual live event

As an administrator in Clevercast, you first create a Multilingual Event for your live stream. You do this by going to the event overview page and clicking on the Create Multilingual menu on the left side of the screen. A popup dialog will be displayed, allowing you to select:

  • The name of your live stream
  • The Broadcast Protocol: select Translate at Home - RTMP (IN), Translate at Home - SRT (IN) or Translate@Home – Intercontinental RTMP (when using our ingest hub)
  • The Default Language: select the language used in the broadcast you will send to Clevercast. If the floor audio contains multiple languages, you can select Original instead of a language
  • The Video Resolutions: Clevercast does server-side transcoding to deliver your stream in multiple video resolutions. Make sure the highest resolution doesn’t exceed the resolution in which you are broadcasting.

Create a multilingual live event for Clevercast T@H

After you create the new event, go to its event management page. This allows you to configure and monitor the live stream. If you haven’t used it before, first check out how the interface works.

Start by adding the language room(s) for your interpreters. In the Language Rooms panel, press the ‘Add Language’ button and select a language for which you want to provide simultaneous translation. Do this until you’ve added all required languages.

Add language rooms for simultaneous interpretation

Test broadcast and translation

Note: this section describes how to test a live broadcast with remote interpretation. Before that, we recommend that you send each interpreter a link to our interpreter manual and ask them to perform a Translate@Home connection test. The test lets you find out whether all interpreter’s connections are suited for remote simultaneous interpretation.

After creating your event, adding your language rooms and configuring your event settings, you are ready for a live stream with simultaneous translation. Start with these preparations:

  • Copy the event’s embed code to your website.
  • Copy the broadcast URL and stream key and use them to configure your encoder or broadcast solution.
  • Copy the link to each language room and send it to your interpreters.

Make sure to configure your encoder in accordance with our broadcasting guidelines as much as possible. Clevercast will send a multilingual live stream with a video frame rate of 25 frames per second (FPS) and keyframes every 2 seconds (= 50 frames). We strongly recommend that you also configure your encoder this way. Higher frame rates may cause the floor audio to go shortly out of sync if not all frames reach Clevercast in time (eg. insufficient bandwidth at the event location).

Before beginning to broadcast, change the event status to preview or started. This is required to make the event accept your incoming stream. After a number of seconds (HLS latency), you can refresh the preview player to see the stream.

Your interpreters are now able to see and hear the live stream and start to translate. It is important to test in advance, to make sure every interpreter has a connection and equipment that meets the requirements and observes the best practices for RSI. The quality of the translated audio streams will depend on this, so make sure to test sufficiently. Also make sure that the microphone volume of each interpreter is loud enough.

Language Room Management

Clevercast allows administrators to chat with interpreters and listen in on their translation while the event status is preview, started or paused by clicking on the ‘Manage Language Rooms’ button. The interface looks like this:

The ‘Manage Language Rooms’ interface

On the management page, first press the ‘Connect’ button to connect to the rooms and enter your name. You can then chat with translators in separate rooms or send messages to all rooms at once.

By default, the real-time player on this page will display the incoming video and floor audio without latency. When you select a translation, the real-time player audio lets you listen to both the floor audio and the incoming translation. You can use the sliders (below the player) to change the volume of the translation and the floor audio.

The slider on the right of the page lets you control the floor audio volume, used as background for translated languages in the embedded Clevercast player (for your viewers). So, updating the slider affects what your viewers will hear. Keep in mind that the stream in Clevercast player comes with HLS  latency: although the volume is changed immediately, you won’t hear it in the player until about 18 seconds later. We recommend to set the background volume very low or disable it: since interpreter volume may differ, the background volume may make it more difficult to understand the translation.

The ‘Other participants’ window lets you see which interpreters are inside which language rooms and provides info about them:

  • The microphone icon shows whether an interpreter is unmuted (black mic icon) or muted (red crossed out mic icon). The ‘Unmute’ and ‘Mute’ buttons allow you to change their mute status. When you do this, the interpreter will also see his mute status changing inside the language room.
  • The connection level indicates how good an interpreter’s connection is. If it turns orange or red, it is highly recommended to use another connection or interpreter.
  • The Firefox icon shows whether the interpreter is using the Firefox browser. If not, the icon is crossed out. Please note that, even though Google Chrome fully supports WebRTC and should also work, we recommend using Firefox for a number of reasons.

For more info on using the Manage Language Rooms interface and solving interpreter issues, see the T@H testing and troubleshooting manual.

Starting your live stream

We recommend to first set the event status to preview. This gives you the opportunity to already start broadcasting and allows your interpreters to connect to the language rooms, while viewers can’t see the live stream (they see an image or message instead). As a Clevercast administrator, you can go to the Language Room Management page, check if all interpreters are present, and give some last minute instructions.

Note: if you are broadcasting a variable bitrate (VBR) don’t start by sending a still image or animated intro (while in preview mode). When the language rooms are initialized with a very low bitrate, it may cause the translated audio to be slightly ahead of the original audio. This is a known issue in T@H which we are trying to resolve. It only applies to a VBR broadcast and to the very first images that you send: if you start with a few moving images, you can safely continue with a still image. For more info, see our broadcasting guidelines.

When the event is about to start, press the ‘Start Event‘ button. At this point, make sure all interpreters are muted until they are about to start translating. We recommend to start the event at least a few minutes before the live stream begins. After all, HTTP live streaming (HLS) has a certain latency, and it gives the player an opportunity to build a buffer in advance.

For events that consist of several parts, there are two options:

    • If it is a relatively short break, the best option is probably to set the event status to paused. In that case, the stream can continue to run and interpreters can remain connected in their language rooms. Viewers won’t be able to see the live stream, they will see a message or image instead.
    • For long pauses you could also choose to set the event status to ended. This is mostly done because of server-side recording: the recording is also ended, so you can already download it or publish it as VoD. You can then reset the event status to waiting or preview, so that everything is ready for the next part.

When the live stream has finished, set the event status to ended and stop broadcasting.

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