Real-Time Video and Audio in the World Wide Web

The architecture of World Wide Web (WWW) browsers and servers support full le transfer for document retrieval. TCP is used for data transfers by Web browsers and their associated Hypertext Transfer Protocol (HTTP) servers. Full le transfer and TCP are unsuitable for continuous media, such as real time audio and video. In order for the WWW to support continuous media, we require the transmission of video and audio on-demand and in real time, as well as new protocols for real time data. We extend the architecture of the WWW to encompass the dynamic, real time information space of video and audio. Our WWW browser Vosaic, short for Video Mosaic, incorporates real time video and audio into standard hypertext pages and which are displayed in place. Video and audio transfers occur in real time; there is no le retrieval latency. The video and audio result in compelling Web pages. Real time video and audio data can be eeectively served over the present day Internet with the proper transmission protocol. We have developed a real time protocol called VDP that we specialize for handling real time video over the WWW. VDP minimizes inter-frame jitter and dynamically adapts to the client CPU load and network congestion. Our WWW server dynamically changes transfer protocols, adapting to the request stream and the meta-information in requested documents. Experiments show a forty-four-fold increase in received video frame rate (0.2 frames per second (fps) to 9 fps) with the use of VDP in lieu of TCP, with a commensurate improvement in observed video quality. Our work enables a video-enhanced Web.