Automate the capture a full BigBlueButton conference replay, with bbb-downloader

BigBlueButton, aka BBB, is a webrtc conferencing solution, that among many features, allows to record a conference, for later replay.

We have been working together with my colleague François Trahay, on a set of scripts (bbb-downloader) that will allow to easily (on Linux) download recordings of BBB conferences, for local backup, video editing, upload on video sharing platforms, etc. This is particularly useful in our distance learning contexts where students may have to catch up on a live session that was recorded.

We have integrated a hackish solution to capture, as a single video, presentations that contained slide deck presentations. Let me explain why this was necessary.

A nice feature of BBB is the fact that, to present a slides deck, you don’t need to share your screen (as a video stream), but just have to upload your file, which is then auto-converted to images, that are sent to participants, in sync with your next/previous browsing of the slides.

This is great for participants with low bandwidth, which can see the slides (“static” images) instead of receiving a full screen video stream.

But a side effect is that the recording of a  class/conference that is done by BBB replays the slides just as it was done live : displaying images one after the other.

While it is easy to retrieve the audio, webcams of participants, or screen sharings as video streams, directly available from the recordings replay app, it is thus not the same for the slides, which don’t come as a video.

Our script will perform a replay, using a Docker container which drives Selenium under the hood, to capture the full replay, as a single video, which then includes the slides and everything. You can see my demo of this process in the following video:

bbb-downloader full capture demo.

It takes long to replay, in real-time, the recordings, to perform this capture… but it works. Kudos to elgalu/docker-selenium for the Docker env.

Feel free to test it and profit, or to report issues in the Guthub issues of the repo:

Experimenting on distant labs and labs on the Cloud

I have delivered a speech last week about some ideas and experiments I have about the use of remote access and Cloud technologies for labs. I have collected the speech recording and stuff, in french, in another post.

The presentation was in french originaly, so I’ve quickly translated my slides and recorded an english version.

I mention tools like Guacamole, MeshCentral, NRELab’s Antidote, Eclipse Che and Labtainers, as well as k8s and Docker, as interesting tools that may allow us to continue teaching in labs while allowing more flexibility, distant learning, and hopefully improved quality.

You can find the slides here:, and the recording is here:

Experimenting on distant labs and labs on the Cloud.

Expérimentations autour de TPs en distanciel, TPs sur le Cloud

J’ai participé au colloque IMT4ET de l’IMT, pour faire une courte présentation sur le thème des Travaux Pratiques à distance et des expérimentations sur les TP “virtuels” sur le Cloud sur lesquelles je travaille en ce moment.

Update: a version in english is also available.

J’y parle de Guacamole et MeshCentral, d’Antidote, de Eclipse Che et de Labtainers, les différents trucs excitants du moment, mais aussi de kubernetes, docker et de trucs louches comme du DevOps académique 😉

Les slides sont disponibles en ligne, et voici une vidéo ou j’expose mes idées sur la question :

Update : une version rédigée de mon propos est parue sur le site “Innovation pédagogique”, si vous préférez une version textuelle.

N’hésitez pas à me contacter si vous voulez creuser les sujets présentés, pour collaborer sur tous ces outils en logiciel libre.

Labtainers in a Web desktop through noVNC X11 proxy, full docker containers

Here’s another recording of a demo I’ve made of our efforts on running Labtainers with a Web desktop.

This time, we’re using a modified version of DoroWu’s noVNC X11 wrapper container (“docker-ubuntu-vnc-desktop“), to provide an X11 Display to labtainers.

I initially adapted DoroWu’s container image by using Debian instead of Ubuntu, but it appeared that noVNC 1.0.0 was a bit too old in the Debian package. So I switched back to the same version as the one DoroWu chose, and this time no more disconnections.

Also, we’re now rebuilding the Labtainer master container from upstream’s Git repo. Fresh Labs every day 😉

Continue reading “Labtainers in a Web desktop through noVNC X11 proxy, full docker containers”

Two demos of programming inside the Web browser with Theia for Java and PHP, using Docker

Theia is a Web IDE that can be used to offer a development environment displayed in a Web browser.

I’ve recorded 2 screencasts of running Theia inside Docker containers, to develop Java and PHP applications, respectively using Maven and Composer (the latter is a Symfony application).
Continue reading “Two demos of programming inside the Web browser with Theia for Java and PHP, using Docker”