The networked video jukebox

The availability of low-cost compression/decompression (codec) hardware for video and audio has given us the opportunity to provide multi-media applications over data networks. The paper describes a particular system that the authors have built to demonstrate this capability. A video jukebox has been built using off-the-shelf computers connected over Ethernet. For wide area connectivity, SMDS attachment has been used. Combined video and audio clips can be selectively played on a PC equipped with low cost video and audio codec cards, using JPEG and ADPCM compression hardware. The data for these clips is retrieved in real time from a Unix workstation via the network. Following a description of the system design, the performance obtainable from a number of network configurations is shown from the results of the experiments conducted. These results show that the addition of real-time transport software on top of the standard Internet protocols allows one to provide video and audio clips with a system comprising standard off-the-shelf equipment. The quality of these clips is considered acceptable for many applications. The authors have quantified the capacity of the system in terms of the data rates and the number of users, and have identified which parts of the total system become bottlenecks as each of these parameters is increased. Solutions to overcoming these bottlenecks are described