Is possible to add time informations in a video recording? This image is an example of this feature
Out of the box with OpenVidu, it is not. But you can process the video after the recording and put it on top with ffmpeg or something like that.
Doing this in real time would be very inefficient. And be aware that post-processing the video files will also be CPU intensive, so make sure to do so in a separate server or when load is low in your OpenVidu nodes.