IVS allows to use standard Internet technology to transmit video/audio-data. This is achieved by implementing PCM and ADPCM audio codecs and a software version of a H.261 codec (video codec for audiovisual services at p*64 kb/s).
Furthermore, where conventional H.261 hardware codecs require leased lines or switched circuits for data-transmission, the H.261 software codec of IVS uses standard UDP datagrams. Minimal changes are required to use this coding on packet switched networks such as the Internet. A packetization scheme of H.261 video stream has been designed and is described in an Internet Draft submitted to the Audio Video Transport Working Group at the IETF. Both IVS and hardware codecs such as GPT and Bitfield use this packetization scheme, so interoperability is now possible.
IVS also includes an error control scheme to handle packet losses in the Internet. Version 3.3 of IVS includes a feedback rate control scheme which adapts the image coding process, and hence the output rate of the coder, depending on network conditions. The feedback information is periodic loss-rate measurements sent back from decoders to the coder.
IVS runs on several UNIX platforms such as SPARC, Silicon Graphic, HP and DEC stations. Sources and binaries are freely available in the public domain by anonymous ftp from zenon.inria.fr at the URL
This figure shows a fairly typical workstation configuration.