BigBlueButton 2.4: New features

On Tuesday, November 30th, 2021, our BigBlueButton cluster has been updated to the latest version 2.4. In the following article, we will introduce new features and improvements to you.

The most important improvements:

• Virtual backgrounds are now selectable.
• A larger number of cameras can be activated simultaneously.
• Durations of ongoing breakout rooms can be extended.
• Breakout room can be named when created.
• The picture-in-picture effect when sharing screens has been improved.
• Various layouts are available.
• In Polls, the voter’s name can be hidden from moderators.
• A complete list of all new features and improvements can be found at the version description of BBB.

 Detailed description of the new features

BigBlueButton version 2.4 is the consistent enhancement of version 2.3. It focuses on improving the usability for teaching as well as for bigger group usage. As with the previous version, URZ employees were involved in the development and testing of this new version.

Virtual backgrounds

The most eager expected feature is probably the possibility of applying virtual backgrounds for video conferencing. It is possible to blur your background or replace it entirely with university related pictures. We would like to thank the press office for providing those marvelous pictures to us.

Because of its mode of operation, the feature “virtual background” requires a relatively large amount of computing power. For each pixel, a neural network has to calculate the probability of whether that pixel is part of a person or part of the background. This process has to be recalculated for each picture. Anyway, the majority of modern computers are capable of handling this feature well. Our test machine was an old laptop from 2015 which had no problems running this process.

Please be aware that most browsers will stop calculation the neural network when another browser tab is brought to the foreground, thus resulting in a frozen image of you seen by the other participants. This is not a malfunction of BigBlueButton but rather a protective feature of your browser. It is supposed to stop malicious websites from using all your computer’s processing power for calculations such as mining of cryptocurrencies. Virtual backgrounds are supported by Chrome and Firefox on desktop PCs as well as on Android devices. Unfortunately, Safari and Browser on iOS devices are unable to use this feature due to lack of necessary application programming interfaces.

Larger number of cameras used simultaneously

Before the release of BigBlueButton version 2.4 the numbers of cameras used at the same time was limited due to technical restrictions. This was caused by the used software components responsible for video distribution, which was limited to around 1200 simultaneous videos connections. Every video from the server has to be distributed to all other people, therefore the number of video connections with n participants is n*(n-1), i.e. it grows as the square of the number of participants. With the latest version 2.4 the server component responsible for video distribution can be replaced with another software, which lacks this limitation. A test session of the BigBlueButton community with 150 participants all using their cameras concurrently worked perfectly.

Improvement of breakout rooms

With version 2.4, the duration of ongoing breakout rooms can be extended retrospectively in BigBlueButton. In former versions, the time originally set at the creation could not be changed afterward, thus the breakout rooms closed automatically when the defined time had expired. In addition, it is now possible to name the breakout rooms. The latter was designed to make it possible for participants to choose a breakout room rather than being assigned to by the moderators. A possible usage scenario of the above features might be thematically named rooms for conferences.

The breakout rooms can be created and named meaningfully by replacing the text “Room 1”, “Room 2” etc. inside the input field.

In order to extend the duration of breakout rooms, open the breakout room section by clicking on it on the sidebar (1) . You will then see the time, which can now easily be changed (2).

Screen sharing

Sharing your screen as a presenter can lead to a picture-in-picture effect. This effect can be eased by reducing your own screen view. The participants will still see the full size of the split window or screen, just as they have before.

Conference layouts

With version 2.4 BigBlueButton finally supports various conference layout for the first time. This allows the user to place videos beneath the chat area, thereby showing more details of the presentation. Of course, the layout can also be arranged vice versa. Placing the presentation beneath the chat area will give the camera more space. Moderators have the option of specifying the layout for all other participants.

You can change the layout in the conference setting via the 3-point menu at the top right, then go to open settings.

Polls without names

In surveys, the presenter can choose to whether or not see which person vote and how. In the survey dialogue, the participants can see whether their individual voting behavior can be seen by the presenter. This procedure may allow for more honest results in one situation or another. Nevertheless, these polls are not completely anonymous, because the individual voting behavior is known to the BigBlueButton server. Accordingly, this tool is not suitable for elections.

Further minor changes

• During recordings: The URL of external videos is recorded as well.
• A summary of the survey results is saved.
• Chat messages from moderators are highlighted in bold, thus making them easier to distinguish.
• The menu for changing the microphone is accessible via the option arrow on the audio icon.
• Video settings for the background can be changed via the option arrow on the camera icon. The virtual background can be adjusted via this.
• The volume of external videos can be adjusted individually by all participants.
• The list of participants shows which person has shared their camera.

As of late, besides the recordings in BigBlueButton format, there is also the possibility to download the recordings as a video file in mp4 format.