Feature 'Set marker' when recording / screencast is active

#1

We use jitsi / jibri for usability studies.
We ask participants to try out our prototypes, while the session is screencast and recorded.
It would be helpful if one could set markers or bookmarks in the video, e.g. when the participants performs an unexpected action. The experiment should not be interrupted, so bookmarking the moment and asking the participant after the experiment for her/his motivation would be ideal.

The manual workaround is sitting aside with a stopwatch, starting when the recording starts and noting down the time by hand.

Does such a feature already exist?
Could the mp4 ‘chapter’ feature used for this?

Imagine a button ‘add bookmark’ shown only when recording is active and for moderators of the room, that simply adds a new chapter 1, chapter 2 … everytime it is clicked.

#2

There is no such feature at the moment. Regarding signalling this will be tricky cause selenium cannot be notified from js side to the java side. You can be sending this data which is accumulated in a json and at the end jibri will extract it before hanging up and will push it to the file. How will that be marked I have no idea, not sure what is chapter and how it can be used and when it needs to be created.