DELPHI and VRVS

The VRVS (Virtual Room Videoconferencing System) is a set of programs for videoconferencing via internet. Delphi experiment starts to use this system to broadcast meetings from CERN to other institutes. We have obtained first experience during broadcasting Plenary Physics Meeting on 8th July 1999. Here are some remarks:
Sound quality
The sound transmitted from the room 40/S2-A01 was good only when the speakers used small microphone pinned on their jacket (T-shirt, blouse, ...), the bigger microphones on the table were not sufficient. The switch on the microphone should be in the position to give higher output (there are only two positions). The questions from the audience were transmitted well, the portable microphone should be for every comment and this microphone should again be switched to get higher output.
The sound from Council chamber was generally good, the reason is that it is much bigger room and the speakers have to use microphone even for the audience present in the room. We did not try to transmit questions from outside.

Video quality
The main reason for video transmission is to show transparencies. The hand-written transparencies or transparencies printed with small fonts was difficult (or impossible?) to read, the shape of histograms was clear (but captions and axis descriptions were lost). The result would be better if we would use document camera to scan transparencies, but this would deteriorate the quality of the picture in the room. Given that the majority of the audience was present in the room, we have chosen the first solution. The system enables to transmit so called attached documents. The transparencies available as a PS file could be sent by this way. So we encourage all speakers to use computer written transparencies and to give them to us just before the meeting.

Participants in the VC
The number of participants outside the room was not too big - just one for the morning session (thanks to Pierre for all comments regarding the sound and video quality) and three for the afternoon session. But it was sufficient to gain some experience and to demonstrate the possibilities of the VRVS. Just to remind other interested users that you need only PC or workstation with sound card and speakers or headphones to participate. All details about installation can be found on the VRVS pages.

Suggested improvements
The VRVS system enables either public sessions or private sessions protected by password. For the Delphi meetings, we use the protection. The system enables to store the session on the hard disk, then it can be transferred via ftp and watched from user machine. This enables good access for users with slower connection. But, the current setup does not permit to use protection and storage on the disk simultaneously :-( We have asked for changes.




Comments and questions send to delphi.webmaster@cern.ch

Created by Jiri Chudoba.
Last modification: 9 July 1999