The Digital Fact Book - Quantel

Video standard Active lines Active samples/lineSMPTE 274M 1080 1920SMPTE S17.392 720 1280ITU-R BT.601-4 483 720ATSC Annex A, Table 1: Standardized video input formatsTarga (.TGA)An image file format widely used in computer systems. It was developed by Truevision Inc.and there are many variations of the format.TBCTimebase Corrector.This is often included as a part of a VTR to correct the timing inaccuraciesof the pictures read from the tape. Early models were limited by their dependence on analogstorage devices, such as ultrasonic glass delay lines. This meant that VTRs, such as theoriginal quadruplex machines, had to be mechanically highly accurate and stable to keepthe replayed signal within the correction range (window) of the TBC – just a few microseconds.The introduction of digital techniques made larger stores economic so widening the correctionwindow and reducing the need for especially accurate, expensive mechanical engineering.Digital TBC has had a profound effect on VTR design – and price. Quantel’s first product wasa digital TBC for use with IVC VTRs.TCP/IPTransfer Control Protocol/Internet Protocol. A set of standards that enables the transferof data between computers. Besides its application directly to the Internet it is also widelyused throughout the computer industry. It was designed for transferring data files rather thanlarge files of television or film pictures. Thus, although TCP/IP has the advantage of beingwidely compatible it is a relatively inefficient way of moving picture files.TSee also: FTP, IPT-DMBSee DMBTimelineA graphical representation of editing, compositing, grading or other processes – usually as ahorizontal line. This works well with disk-based operations providing instant access to any partof the process and, hopefully, to all the footage, decisions, associated tools and their settings.TIFF (.TIF)Tagged Image File Format. A bit-mapped file format for scanned images – widely usedin the computer industry. There are many variations of this format.167