Preface to the second edition

Since the first edition of Timecode: A user's guide was published, major developments in technology and data handling systems have had a major impact in timecode formats and applications. Digital VITC is now established, timecode can be placed in the audio sectors of digital VCR recordings, there is now a standard for the extended use of the timecode word's user bits, time data are frequently carried in the RS422 digital interface and there is now a standard for timecode in High Definition Television.

Within Europe, the EBU has published the uses to which some of its members have put the binary groups within the timecode word. Uses include the control of Telecine 'panscan' for the selection of which area of a wide-screen 16:9 aspect ratio picture will be transmitted in 4:3, and the inclusion of date information. Additionally, some broadcasters are using the AES/EBU digital interface to carry time-related data, and proposals have been made for the carrying of time-related data in a form not related to the digital sampling rate.

Perhaps the most significant development in time-and-control code has been concerned with its use in the field of video assisted film postproduction. Timecode is now no longer the 'Cinderella' of post-production, confined to looking after the housekeeping while its older sisters, pictures and sound, enjoy all the glamour and adulation. Timecode has met her 'Prince Charming' in the form of KeyKode^®, and the 'glass slipper' of recognition has been the powerful data logging and management systems such as Excalibur and Keylink, coupled with intuitive nonlinear editing systems such as Avid, D/Vision and Lightworks. Timecode is now the 'business manager' to her older sisters, allowing them to be edited more flexibly and efficiently, and easing the production of film and video versions of programmes, commercials and feature films for worldwide distribution. As this edition is being written, 3-line VITC is being developed to enable non-linear editors to manage a variety of film, video and audio timecode databases more effectively.

This edition aims to explain and de-mystify these new forms of and uses for timecode, and I would like to thank all who so freely gave me both their knowledge and time in its preparation, especially David Bryant of Filmlab Systems, Tony Harcourt of Kodak Limited, Anita Sinclair and Mick Colthart of Lightworks Editing Systems Limited, Francis Rumsey of the University of Surrey, and Jon Hocking of Wren Communications.