High Speed Data Recording: Digital VTRs Find New Applications

Abstract

Entertainment production, be it cinema, television, or even “game” software, is turning increasingly to computer-generated or manipulated information. Computer processing and digital manipulation has permitted the creation of images otherwise impossible, the production of effects not otherwise practical, and correction of innumerable image defects large and small. Given this combination of voluminous data and expensive hardware, the industry faced a dilemma: how to “move” jobs in and out of a facility quickly so the equipment could be made available to other clients and projects. Existing small format data recorders generally have proven unsatisfactory for these purposes due to the limited data rates and media size. Current digital videotape recorders are now capable of data rates well in excess of 200 Mbits/sec (25 Mbytes/sec). Unfortunately, some recorders incorporate data compression, rendering them suitable only for traditional video. Other video formats have been customized and repurposed for data recording, hut these machines are no longer applicable for video recording. As the boundaries between the computer and video worlds blur, users need multipurpose solutions for both fast data storage of nonrasterized image information and high-quality conventional video storage. Full bit-rate uncompressed digital video recorders can provide the desired performance capabilities for both video and high-performance data recording, allowing dual-purpose use of the same transport and cassettes. Panasonic developed the D-5 (uncompressed 10-bit ITU-R 601) videotape recorder (VTR) format for high-end video post-production, and it has met with wide acceptance. The Viewgraphics (Mountain View, Calif.) “Dataview” is an industry-standard computer bus (VME) interface device developed to allow large data files to be recorded on unmodified D-5 VTRs and to allow video to be input as data into platforms like the Silicon Graphics Onyx and Challenge. This paper describes the D-5 format, the Viewgraphics Dataview adaptor, and data recording on videotape.