Possible Uses for Video Applications

• In video conferencing and in the majority of video applications, at both end-user sides, such a tool can be used to monitor the received video quality in real time for control purposes. For example, changing the bit rate, using another codec, changing the frame rate, using some kind of FEC, changing the playback buffer size, etc. are possible decisions that can be taken to improve the quality or to maintain it at a certain level.
• Based on the ability to measure video quality in real time, operators could use quality as a criterion for billing.
• The applications that transmit video on packet networks can use this tool to negotiate the best configuration in order to achieve the best possible quality.
• It can also help in the encoding process, as quality in encoders is also a way to ``fit'' the stream into the available global channel bandwidth. In video codecs using temporal compression (ex: MPEG, H.261, H.263...), a quality factor parameter is usually used to reduce the output stream bandwidth and to improve, at the same time, the assessed quality (yet before any transmission). It would be even more interesting to have the history of all the important parameters (network and video) to compress the video signal rather than only the PSNR (Peak Signal to Noise Ratio) objective measure (which is poorer in quality and time consuming than our approach).