Assessing subjective perception of the video and audio quality during the PIPVIC sessions has been a priority during the project. Up until now, subjective assessment of the quality has been done after the end of a session.

QUASS is a new tool which has been developed by Anna Bouch at UCL. The tool consists of a sliderbar which allows users to rate the quality of either audio or video during the session. This allows us to see users' peception of quality at any one point in time during the session, which means that we can see the effect of fluctuations of quality during a session.

Download QUASS

QUASS can be downloaded from here. It is available for the following platforms: Solaris, Irix6.2, Linux and Windows95. (Please note that the Solaris, Irix and Linux versions are .gz files)

How to use QUASS

To start up QUASS, type quass at the command line - or double click on quass.exe Windows95.

QUASS starts up with two windows, a Participant Information Window  and a QUASS Main Window. You must fill out the details in the Participant Information Window before you begin rating.

To begin rating, press the Start button in the QUASS Main Window.
To stop rating, press the Quit button in the QUASS Main Window.

To rate, move the slider bar up or down depending on the how you perceive the quality of the session. The top, marked with a +, indicates quality which is adequate for the session; the bottom, marked with a -, indicates quality which is not adequate for the session. REMEMBER TO PRESS START BEFORE YOU BEGIN RATING.

QUASS produces a file named QUASS followed by a number, e.g. QUASS896695705. Please send the file to Louise (l.clark@cs.ucl.ac.uk) after the session.

Thanks Louise

PIPVIC Multicast Addresses

Sdr session "PIPVIC (Private)" or


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