DVCPRO: A Comprehensive Format Overview

Currently, broadcast and ENG camcorders and video editors use mainly analog 1/2-in. (12.7-mm) equipment. However, as news acquisition increases in importance and digitization occurs throughout broadcasting, more compact and cost-effective digital systems with easy editing, improved features, and high picture quality are now in demand. To meet this demand, we have developed DVCPRO, a 6mm videocassette format using digital component recording to assure picture quality that surpasses that of analog component VTRs. Two cassette sizes hold 63 and 123 min, respectively, and have one-quarter the volume, one-sixth the weight, and twice the recording time of conventional analog 1/2-in. cassettes. DVCPRO records 4:1:1 component digital video signals on 6.35mm tape at a video data recording rate of 25 Mbits/sec, using 5:1 intraframe compression. The DVCPRO compression scheme, as well as the transport and cassette design, share technology and development work done to implement the consumer digital video (DV) format. While many aspects are similar and gain the benefit of partial backward compatibility (e.g., recorded consumer tapes can play on some professional models), many aspects are different. In addition, the approach to 625 signals closely follows that of 525, which is also unique. This paper will describe the compression scheme — the differences as well as the similarities — together with the technical rationale for the choices.